A common rail injector with replaceable control valves

Abstract

This utility model relates to a common rail injector with replaceable control valves, including a solenoid valve assembly, a metering block assembly, a needle valve assembly, and a locking cap. The solenoid valve assembly includes an injector body, an electromagnet, an armature, a control valve core, a first spring, and a valve ball, with the valve ball detachably mounted on the lower end of the control valve core. The metering block assembly includes a metering block and a ball valve seat, with the ball valve seat detachably fixed in a mounting groove. The needle valve assembly includes a needle valve body, a needle valve core, a control chamber sleeve, and a second spring. The injector body, metering block, and needle valve body are arranged sequentially from top to bottom and detachably fixed together by the locking cap. This utility model is easy to maintain and adjust, and can better meet the usage requirements of marine electronically controlled common rail fuel systems.

Description

Technical Field

[0001] This utility model relates to the field of fuel injector technology, and specifically to a common rail fuel injector with replaceable control valves. Background Technology

[0002] As shipping costs continue to rise, engines using heavy oil and other low-quality combustible fuels offer unique advantages in cost reduction. However, heavy oil and other low-quality combustible fuels contain many impurities, which can corrode parts, cause sticking, and also corrode electronic components. Furthermore, heavy oil's high viscosity requires high-temperature heating during use, and excessively high oil temperatures can shorten the lifespan of electronic components.

[0003] The electronically controlled common rail fuel injection system is a type of fuel injection system based on mechanical, hydraulic, and electrical technologies. This system uses a common rail with a certain volume, located between the fuel pump and the injectors, to store fuel and smooth pressure fluctuations. Fuel is then delivered to each injector through fuel lines, and the opening and closing of the injectors is controlled by the action of the injector solenoid valves. This system has advantages such as stable injection pressure and controllable injection pressure and process.

[0004] This type of electronically controlled common rail fuel system faces the following problems during use: Existing electronically controlled common rail fuel systems use small electro-hydraulic control components to adjust the pressure difference across a needle valve to complete the injection operation. These control valves are often small and precise, making them difficult to manufacture. When using heavy oil or other low-quality combustible fuels, the damage to the injector control valves is significant, leading to a shorter lifespan. Furthermore, as companies demand increasingly higher operating pressures for high-pressure systems, the hydraulic shocks experienced by the injector control valves during operation are also increasing, further shortening their lifespan. On the one hand, the shortened lifespan of the injector control valves negatively impacts product competitiveness. On the other hand, when the injector control valves malfunction during shipping, the difficulty of customer repairs also negatively affects product competitiveness. Utility Model Content

[0005] The purpose of this invention is to provide a common rail injector with replaceable control valves to alleviate or eliminate at least one of the aforementioned technical problems.

[0006] This utility model discloses a common rail injector with replaceable control valves, comprising a solenoid valve assembly, a metering block assembly, a needle valve assembly, and a locking cap. The solenoid valve assembly includes an injector body, an electromagnet, an armature, a control valve core, a first spring, and a valve ball. The injector body has a first inner cavity, an inlet, an outlet, a first input oil passage, and a first output oil passage. The electromagnet is fixedly installed in the first inner cavity. The control valve core is installed in the first inner cavity in a way that allows it to slide up and down. The armature is connected to the upper end of the control valve core. The first spring directly or indirectly... The control valve core applies a downward spring force, and the valve ball is detachably mounted on the lower end of the control valve core; the orifice block assembly includes an orifice block and a ball valve seat, the orifice block has an upward-facing mounting groove, the ball valve seat is detachably fixed in the mounting groove, the orifice block has a second input oil passage, a third input oil passage, and a second output oil passage, the ball valve seat has a third output oil passage, the upper end of the third output oil passage has a valve port, a section of the third input oil passage is configured as an oil inlet orifice, and a section of the second output oil passage is configured as an oil outlet orifice; the needle The valve assembly includes a needle valve body, a needle valve core, a control chamber sleeve, and a second spring. The needle valve body has a second inner cavity with an open upper end, and an injection port is located at the lower end of the needle valve body. The needle valve core slides within the second inner cavity and is used to open and close the injection port. The second spring directly or indirectly applies a downward spring force to the needle valve core. A pressure accumulator is formed between the needle valve core and the needle valve body. The control chamber sleeve engages with the upper end of the needle valve core. The injector body, the metering block, and the needle valve body are arranged sequentially from top to bottom and are detachable via a locking cap. The control chamber is fixedly connected together, with the upper end of the control chamber sleeve, the needle valve core, and the measuring orifice block forming a control chamber. The oil inlet, the first input oil passage, the second input oil passage, and the accumulator are connected in sequence. The oil inlet, the first input oil passage, the second input oil passage, the third input oil passage, the control chamber, the second output oil passage, and the third output oil passage are connected in sequence. When the ball valve is open, the first output oil passage connects to the oil outlet and the third output oil passage. When the ball valve is closed, the first output oil passage and the third output oil passage are disconnected.

[0007] Optionally, the lower end of the control valve core is provided with a valve ball mounting part, and the valve ball mounting part is provided with a hemispherical groove, in which the valve ball is embedded.

[0008] Optionally, the inner peripheral wall of the mounting groove is provided with an internal thread, and a screw plug that is threadedly connected to the internal thread is installed in the mounting groove, the screw plug pressing down on the ball valve seat.

[0009] Optionally, the bottom of the mounting groove is provided with a downwardly recessed fitting groove, the lower end of the ball valve seat is fitted into the fitting groove, and a convex ring is provided on the bottom wall of the fitting groove that contacts the lower end face of the ball valve seat. The convex ring is arranged around the upper end of the second output oil passage.

[0010] Optionally, it also includes a control guide sleeve installed in the first inner cavity, wherein the control valve core mates with the inner circumferential surface of the control guide sleeve, and a plurality of annular grooves are provided on the outer circumferential surface of the control valve core that mates with the control guide sleeve, and a fourth output oil passage for discharging oil from the annular grooves is provided on the side wall of the control guide sleeve.

[0011] Optionally, two sealing rings are provided between the outer peripheral surface of the control guide sleeve and the inner peripheral surface of the first inner cavity, with the two sealing rings respectively positioned above and below the fourth output oil passage.

[0012] Optionally, it may also include a third spring that directly or indirectly applies a downward spring force to the electromagnet, a first support sleeve supported between the lower end of the electromagnet and the upper end of the control guide sleeve, and a second support sleeve supported between the lower end of the control guide sleeve and the measuring hole block.

[0013] This utility model has the following features:

[0014] Both the ball valve seat and the ball are detachable, independent components, allowing for replacement without affecting other parts. This facilitates easy maintenance and adjustment / modification. The compact and lightweight design allows for the storage of a larger number of ball valve seats and balls as spare parts within a limited space, saving maintenance costs in industries with high maintenance demands, such as shipping. This also better meets the requirements of marine electronically controlled common rail fuel systems.

[0015] For applications using inferior fuel, ball valve seats and balls operating in harsh environments can be made of corrosion-resistant and impact-resistant materials to extend injector life. While corrosion-resistant and impact-resistant materials are often expensive, the small size of the ball valve seat and ball means that even using these materials results in relatively small increases in processing costs, thus saving on manufacturing expenses.

[0016] For engine modifications, such as switching from light diesel to heavy diesel or other inferior fuels, injector modifications only require replacing the ball valve seat, valve ball, and some seals. The materials of the ball valve seat and valve ball can be adjusted according to the performance of the specific fuel used by the injector, offering significant modification potential.

[0017] The guide section of the control valve core is provided with multiple annular grooves, which form a dynamic sealing structure to prevent highly corrosive and inferior fuels from reaching the electromagnet, thus improving the electromagnet's lifespan. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of a common rail injector with replaceable control valves as described in some embodiments;

[0019] Figure 2 for Figure 1 A magnified view of a portion of the document;

[0020] Figure 3 This is a schematic diagram of the structure of some components of a common rail injector with replaceable control valves as described in some embodiments.

[0021] In the diagram, 1—injector body, 2—electromagnet, 3—third spring, 4—first support sleeve, 5—armature, 6—first spring, 7—control valve core, 8—control guide sleeve, 9—metering orifice block, 10—ball valve seat, 11—valve ball, 12—second support sleeve, 13—plug, 14—tightening cap, 15—needle valve body, 16—needle valve core, 17—control chamber sleeve, 18—second spring, 19—accumulator chamber, 20—control chamber, 21—nut.

[0022] 101—Oil inlet, 102—First input oil passage, 103—First inner cavity, 104—First output oil passage

[0023] 701—Valve ball mounting part, 702—Annular groove,

[0024] 801—Fourth output oil passage,

[0025] 901—Second oil input passage, 902—Third oil input passage, 903—Oil inlet orifice, 904—Second oil output passage, 905—Oil outlet orifice, 906—Mounting slot.

[0026] 1001—Third output oil passage,

[0027] 1501—Second inner cavity, 1502—Fuel injection hole. Detailed Implementation

[0028] The embodiments of this utility model will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be understood that the preferred embodiments are only for illustrating this utility model and not for limiting the scope of protection of this utility model.

[0029] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0030] like Figures 1 to 3The diagram shows a common rail injector with replaceable control valves, including a solenoid valve assembly, a metering block assembly, a needle valve assembly, and a locking cap 14. The solenoid valve assembly includes an injector body 1, an electromagnet 2, an armature 5, a control valve core 7, a first spring 6, and a valve ball 11. The injector body 1 has a first inner cavity 103, an oil inlet 101, an oil outlet, a first input oil passage 102, and a first output oil passage 104. The electromagnet 2 is fixedly installed in the first inner cavity 103. The control valve core 7 is installed in the first inner cavity 103 in a way that allows it to slide up and down. The armature 5 is fastened to the upper end of the control valve core 7 by a nut 21. The first spring 6 directly or indirectly applies pressure to the control valve core 7. With a downward spring force, the valve ball 11 is detachably mounted on the lower end of the control valve core 7; the orifice block assembly includes an orifice block 9 and a ball valve seat 10. The orifice block 9 is provided with an upward-facing mounting groove 906, and the ball valve seat 10 is detachably fixedly mounted in the mounting groove 906. The orifice block 9 is provided with a second input oil passage 901, a third input oil passage 902, and a second output oil passage 904. The ball valve seat 10 is provided with a third output oil passage 1001, and a valve port is provided at the upper end of the third output oil passage 1001. A section of the third input oil passage 902 is configured as an oil inlet orifice 903, and a section of the second output oil passage 904 is configured as an oil outlet orifice 905; the needle valve assembly includes a needle valve body. 15. Needle valve core 16, control chamber sleeve 17, and second spring 18. The needle valve body 15 has a second inner cavity 1501 with an open upper end. The lower end of the needle valve body 15 has an oil injection hole 1502. The needle valve core 16 is slidably engaged with the second inner cavity 1501. The needle valve core 16 is used to open and close the oil injection hole 1502. The second spring 18 directly or indirectly applies a downward spring force to the needle valve core 16. The needle valve core 16 and the needle valve body 15 form a pressure accumulator 19. The control chamber sleeve 17 is engaged with the upper end of the needle valve core 16. The control chamber sleeve 17 can be fixedly installed at the upper end of the first inner cavity 103. The injector body 1, the metering block 9, and the needle valve body 15 are arranged from top to bottom in the following order: The components are detachably and fixedly connected together via a tight cap 14. The upper end of the control chamber sleeve 17, the needle valve core 16, and the measuring orifice block 9 form a control chamber 20. The oil inlet 101, the first input oil passage 102, the second input oil passage 901, and the accumulator 19 are connected in sequence. The oil inlet 101, the first input oil passage 102, the second input oil passage 901, the third input oil passage 902, the control chamber 20, the second output oil passage 904, and the third output oil passage 1001 are connected in sequence. When the ball valve is open, the first output oil passage 104 connects to the oil outlet and the third output oil passage 1001. When the ball valve is closed, the first output oil passage 104 and the third output oil passage 1001 are disconnected.

[0031] Using the aforementioned common rail injector with replaceable control valves, in the initial state, high-pressure fuel flows through inlet 101 into the first input passage 102 and the second input passage 901, then splits into two paths. The first path flows into the accumulator chamber 19. At this time, the conical surface at the lower end of the needle valve core 16 forms a seal with the seat surface on the needle valve body 15, closing the injection hole 1502 at the seat surface, causing the first path of fuel to accumulate in the accumulator chamber 19. The second path of fuel enters the control chamber 20 from the third input passage 902. At this time, the valve ball 11 is pressed against the ball valve seat 10 by the spring force applied to the control valve core 7 by the first spring 6, causing the second path of fuel to accumulate in the control chamber 20. The needle valve core 16 is subjected to a resultant force at both ends downwards, maintaining a stationary state.

[0032] During operation, the electromagnet 2 is energized and magnetized, attracting the armature 5. This causes the armature 5 to lift the control valve core 7 against the spring force of the first spring 6, connecting the first output oil passage 104 with the third output oil passage 1001. High-pressure fuel in the control chamber 20 flows out through the second output oil passage 904, the third output oil passage 1001, and the first output oil passage 104. Because the flow cross-sectional area of ​​the fuel outlet orifice 905 is larger than that of the fuel inlet orifice 903, the fuel depressurization rate in the control chamber 20 is higher than the repressurization rate, resulting in a rapid decrease in hydraulic pressure within the control chamber 20. The high-pressure fuel accumulated in the accumulator chamber 19 lifts the needle valve core 16, opening the fuel injection port 1502. High-pressure fuel is then injected into the cylinder from the fuel injection port 1502 to participate in combustion.

[0033] When the injection is stopped, the electromagnet 2 is de-energized, the first spring 6 causes the valve ball 11 to sit, the ball valve is closed, the fuel is re-accumulated in the control chamber 20, the needle valve core 16 is reset by the spring force or hydraulic force and falls down, pressing it back onto the seat surface, the high-pressure fuel is sealed on the sealing seat surface, the injection hole 1502 is closed, and the injection stops.

[0034] The common rail injector with replaceable control valves described above uses a ball valve as the control valve. The spherical valve ball 11 has good self-alignment properties, further improving operational stability. Moreover, the ball valve seat 10 and valve ball 11 can be directly removed from the metering block 9 as individual pieces without affecting the ratio of the outlet metering orifice 905 to the inlet metering orifice 903, thus not affecting the injector's performance. This facilitates replacement due to injector maintenance and adjustment needs, or after damage. The ball valve is a replaceable control valve. For engine modifications, such as changing fuel from light diesel to heavy diesel or other inferior fuels, injector modification only requires replacing the ball valve seat 10, valve ball 11, and some sealing rings. The materials of the ball valve seat 10 and valve ball 11 can be adjusted according to the performance of the specific fuel used by the injector, offering significant modification potential. In practical implementation, the valve port on the ball valve seat 10 has a tapered structure with a diameter gradually decreasing from top to bottom.

[0035] In practical implementation, for situations involving the use of inferior fuel, the ball valve seat 10 and ball valve 11, operating in harsh environments, can be made of corrosion-resistant and impact-resistant materials to improve the lifespan of common rail injectors with replaceable control valves. For example, stainless steel can be used to manufacture the ball valve seat 10 and ball valve 11. Alternatively, for high-sulfur fuels such as heavy diesel oil, the ball valve 11 can be made of hard alloy (such as WC-Co), and the ball valve seat 10 can be made of silicon nitride ceramic to improve wear and corrosion resistance.

[0036] In some embodiments, a valve ball mounting portion 701 is provided at the lower end of the control valve core 7, and a hemispherical groove is provided on the valve ball mounting portion 701, in which the valve ball 11 is fitted. Using the above-described technical solution, the valve ball 11 is mounted using a hemispherical groove, which is easy to implement.

[0037] In some embodiments, an internal thread is provided on the inner peripheral wall of the mounting groove 906, and a screw plug 13 that is threadedly connected to the internal thread is installed in the mounting groove 906. The screw plug 13 presses down on the ball valve seat 10. Using the screw plug 13 to achieve the detachable and fixed installation of the ball valve seat 10 is easy to implement and can also ensure the installation accuracy of the ball valve seat 10.

[0038] In some embodiments, the bottom of the mounting groove 906 is provided with a downwardly recessed fitting groove, the lower end of the ball valve seat 10 is fitted into the fitting groove, and a convex ring is provided on the bottom wall of the fitting groove, which contacts the lower end face of the ball valve seat 10. The convex ring surrounds the upper end of the second output oil passage 904. The fitting groove ensures the installation accuracy of the ball valve seat 10, and the convex ring ensures the sealing performance at the connection between the second output oil passage 904 and the third output oil passage 1001.

[0039] In some embodiments, the common rail injector with replaceable control valves further includes a control guide sleeve 8 installed in the first inner cavity 103. A control valve core 7 mates with the inner circumferential surface of the control guide sleeve 8. Multiple annular grooves 702 are provided on the outer circumferential surface of the control valve core 7 that mates with the control guide sleeve 8. A fourth output oil passage 801 for discharging oil from the annular grooves 702 is provided on the side wall of the control guide sleeve 8. Using the above technical solution, the guide section of the control valve core 7 is provided with multiple annular grooves 702, forming a dynamic sealing structure. When fuel flows from the narrow slit of the guide section of the control valve core 7 to the annular grooves 702, it rapidly depressurizes due to the increased flow area. The depressurized fuel can then pass through the fourth output oil passage 801 to the outside of the common rail injector with replaceable control valves, preventing fuel from accumulating in the annular grooves 702 and thus preventing the formation of pressure that would allow the fuel to continue rising. This solution can prevent highly corrosive, low-quality fuel from reaching the electromagnet 2, which is beneficial for improving the lifespan of the electromagnet 2.

[0040] In some embodiments, two sealing rings are provided between the outer peripheral surface of the control guide sleeve 8 and the inner peripheral surface of the first inner cavity 103, with the two sealing rings respectively positioned above and below the fourth output oil passage 801. The sealing rings prevent oil leakage.

[0041] In some embodiments, the common rail injector with replaceable control valves further includes a third spring 3 that directly or indirectly applies a downward spring force to the electromagnet 2, a first support sleeve 4 supported between the lower end of the electromagnet 2 and the upper end of the control guide sleeve 8, and a second support sleeve 12 supported between the lower end of the control guide sleeve 8 and the metering block 9. By employing the above technical solution, the stability of the components within the common rail injector with replaceable control valves can be ensured.

[0042] As a specific example, the upper part of the tightening cap 14 surrounds the lower part of the injector body 1, and the upper part of the tightening cap 14 is threadedly connected to the lower part of the injector body 1. The lower part of the tightening cap 14 surrounds the upper part of the pressure needle valve body 15, and the lower part of the tightening cap 14 presses the pressure needle valve body 15 upward.

[0043] As a specific example, the second spring 18 is fitted on the upper part of the needle valve core 16, the needle valve core 16 has an outer flange in the middle, and the second spring 18 is supported between the outer flange and the lower end of the control guide sleeve 8.

[0044] As a specific example, the lower part of the needle valve core 16 is provided with a first thrust surface, which contacts the fuel in the accumulator chamber 19. The fuel in the accumulator chamber 19 acts on the first thrust surface to generate an upward force. The upper end surface of the needle valve core 16 is a second thrust surface, which contacts the fuel in the control chamber 20. The fuel in the control chamber 20 acts on the second thrust surface to generate a downward force. The first thrust surface is usually positioned upwards, and the second thrust surface is usually positioned downwards.

[0045] The above embodiments are merely preferred embodiments provided to fully illustrate the present utility model, and the protection scope of the present utility model is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present utility model are all within the protection scope of the present utility model. In the description of this specification, the reference to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., means that a specific feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of the present utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

Claims

1. A common rail injector with replaceable control valves, characterized in that, Includes solenoid valve assembly, orifice block assembly, needle valve assembly, and tightening cap; The solenoid valve assembly includes an injector body, an electromagnet, an armature, a control valve core, a first spring, and a valve ball. The injector body has a first inner cavity, an oil inlet, an oil outlet, a first input oil passage, and a first output oil passage. The electromagnet is fixedly installed in the first inner cavity. The control valve core is installed in the first inner cavity in a way that allows it to slide up and down. The armature is connected to the upper end of the control valve core. The first spring directly or indirectly applies a downward spring force to the control valve core. The valve ball is detachably installed at the lower end of the control valve core. The orifice block assembly includes an orifice block and a ball valve seat. The orifice block has an upward-facing mounting groove, and the ball valve seat is detachably and fixedly installed in the mounting groove. The orifice block has a second input oil passage, a third input oil passage, and a second output oil passage. The ball valve seat has a third output oil passage, and the upper end of the third output oil passage has a valve port. One section of the third input oil passage is configured as an oil inlet orifice, and one section of the second output oil passage is configured as an oil outlet orifice. The needle valve assembly includes a needle valve body, a needle valve core, a control chamber sleeve, and a second spring. The needle valve body has a second inner cavity with an open upper end, and an oil injection hole is provided at the lower end of the needle valve body. The needle valve core is slidably engaged with the second inner cavity. The needle valve core is used to open and close the oil injection hole. The second spring directly or indirectly applies a downward spring force to the needle valve core. The needle valve core and the needle valve body form a pressure accumulator. The control chamber sleeve is engaged with the upper end of the needle valve core. The injector body, the metering orifice block, and the needle valve body are arranged sequentially from top to bottom and are detachably and fixedly connected together by the tightening cap. The control chamber sleeve, the upper end of the needle valve core, and the metering orifice block form a control chamber. The oil inlet, the first input oil passage, the second input oil passage, and the accumulator are connected in sequence. The oil inlet, the first input oil passage, the second input oil passage, the third input oil passage, the control chamber, the second output oil passage, and the third output oil passage are connected in sequence. When the ball valve is opened, the first output oil passage connects the oil outlet and the third output oil passage. When the ball valve is closed, the first output oil passage and the third output oil passage are disconnected.

2. The common rail injector with replaceable control valve as described in claim 1, characterized in that, The lower end of the control valve core is provided with a valve ball mounting part, and the valve ball mounting part is provided with a hemispherical groove, in which the valve ball is embedded.

3. The common rail injector with replaceable control valve according to claim 1, characterized in that, The inner circumferential wall of the mounting groove is provided with an internal thread, and a screw plug that is threadedly connected to the internal thread is installed in the mounting groove, and the screw plug presses down to tighten the ball valve seat.

4. The common rail injector with replaceable control valve according to claim 1, characterized in that, The bottom of the mounting groove is provided with a downwardly recessed fitting groove, the lower end of the ball valve seat is fitted into the fitting groove, and a convex ring is provided on the bottom wall of the fitting groove that contacts the lower end face of the ball valve seat. The convex ring is arranged around the upper end of the second output oil passage.

5. The common rail injector with replaceable control valve according to claim 1, characterized in that, It also includes a control guide sleeve installed in the first inner cavity. The control valve core mates with the inner circumferential surface of the control guide sleeve. Multiple annular grooves are provided on the outer circumferential surface of the control valve core that mates with the control guide sleeve. A fourth output oil passage for discharging oil from the annular grooves is provided on the side wall of the control guide sleeve.

6. The common rail injector with replaceable control valve according to claim 5, characterized in that, Two sealing rings are provided between the outer peripheral surface of the control guide sleeve and the inner peripheral surface of the first inner cavity, and the two sealing rings are respectively located above and below the fourth output oil passage.

7. The common rail injector with replaceable control valve according to claim 5, characterized in that, It also includes a third spring that directly or indirectly applies a downward spring force to the electromagnet, a first support sleeve that supports the lower end of the electromagnet and the upper end of the control guide sleeve, and a second support sleeve that supports the lower end of the control guide sleeve and the measuring hole block.

Images