A high pressure injector

Abstract

The application provides a high-pressure injector, which comprises an oil inlet joint, an electromagnetic valve component, a valve rod component and a nozzle component, a damping valve with a throttle hole is arranged on the upper part of the oil inlet joint, the throttle hole, an oil filter, an inner cavity of the oil inlet joint, an inner cavity of an iron core, a shunt hole, an inner cavity of a nozzle body, a cavity of the nozzle and a jet hole are communicated to form a liquid flow channel; the valve rod is accommodated in the nozzle component, the armature is accommodated in the upper inner cavity of the nozzle body and can move up and down in the upper inner cavity of the nozzle body; when the coil is not electrified, the outer conical surface of the head of the valve rod is tightly attached to the inner conical surface of the nozzle, so that the injector is in a closed state; after the coil is electrified, the electromagnetic attraction of the iron core attracts the armature, the armature drives the valve rod to move upwards, the outer conical surface of the head of the valve rod is separated from the inner conical surface of the nozzle, and liquid is sprayed from the jet hole. Compared with the prior art, the high-pressure injector provided by the application has more stable oil pressure and more reliable injection control, so that the high-pressure injector with stable oil pressure and reliable control is formed.

Description

Technical Field

[0001] This invention relates to the field of new energy fuel injection systems for automobile engines, and in particular to a high-pressure injector. Background Technology

[0002] Methanol fuel presents several challenges as an automotive energy source. For example, compared to other fuels, methanol is more corrosive, placing higher demands on the materials used in engine components; methanol has lower viscosity and poorer lubrication, requiring higher wear resistance in moving parts; and methanol has a high latent heat of vaporization, affecting the engine's low-temperature starting performance.

[0003] Currently, most methanol engines on the market use intake manifold injection with an operating pressure of 4-5 bar. The methanol injector injects methanol fuel into the intake manifold, where it is fully mixed with air before being introduced into the cylinder for combustion. This traditional design cannot precisely control the air-methanol fuel mixing ratio in each cycle. Furthermore, during cold starts, the cylinder temperature is low, resulting in incomplete fuel vaporization and incomplete combustion, which in turn affects the engine's economy, power, and emission requirements.

[0004] With increasingly stringent regulations on vehicle emissions, coupled with user demand for a balance between vehicle performance and methanol fuel economy, and driven by the dual requirements of improving urban air quality and reducing greenhouse gas emissions, more and more automakers are researching in-cylinder methanol direct injection system technology. This system operates at pressures of 150-350 bar, using high-pressure injectors to deliver methanol fuel as a fine mist into the cylinder. The injection quantity is precisely controlled proportionally and mixed with the intake air. Compared to engines with port injection, this results in better thermal efficiency and cold-start performance, significantly improving vehicle engine emissions and fuel economy.

[0005] However, existing high-pressure injectors have problems such as unstable oil pressure, unreliable control, poor liquid flow, and poor resistance to methanol fuel corrosion, which can easily cause abnormal operation of methanol engines. As a result, the technology of in-cylinder methanol direct injection system has not been widely promoted and applied. Summary of the Invention

[0006] To address the technical problems in the prior art, the present invention provides a high-pressure injector with stable oil pressure and reliable control.

[0007] A high-pressure injector for direct mounting in a combustion chamber, comprising: An oil inlet connector is equipped with a damping valve and an oil filter on its upper part. The damping valve is provided with a throttling orifice, and the oil filter is located below the damping valve. The solenoid valve component includes a coil and an iron core. The iron core is fixedly connected to the lower end of the oil inlet connector. When the coil is energized, the iron core generates an electromagnetic attraction force. A valve stem assembly includes a valve stem and an armature. The valve stem head is provided with an outer conical surface. The armature is sleeved on the valve stem and can drive the valve stem to move up and down together. The armature is provided with a flow divider hole that runs through the upper and lower parts. The nozzle assembly includes a nozzle body and a nozzle. The nozzle body is fixed to the lower end of the solenoid valve, and the nozzle is located at the lower end of the nozzle body. It has an upward-opening cavity and a spray hole communicating with the cavity. The bottom of the cavity has an inner conical surface that matches the outer conical surface of the valve stem head. The throttling orifice, oil filter, inner cavity of oil inlet connector, inner cavity of iron core, diversion orifice, inner cavity of nozzle body, cavity of nozzle, and spray hole are interconnected, so that liquid can enter from oil inlet connector through throttling orifice, be filtered by oil filter, and then pass through inner cavity of oil inlet connector, inner cavity of iron core, and diversion orifice in sequence, and then flow into the gap between nozzle cavity and outer conical surface of valve stem head; The valve stem is housed in the nozzle assembly, and the armature is housed in the upper inner cavity of the nozzle body, allowing it to move up and down within the upper inner cavity of the nozzle body. When the coil is not energized, the outer conical surface of the valve stem head is in close contact with the inner conical surface of the nozzle, keeping the injector in a closed state. When the coil is energized, the iron core generates electromagnetic attraction to attract the armature, causing the armature to move the valve stem upward. The outer conical surface of the valve stem head then disengages from the inner conical surface of the nozzle, and liquid is ejected from the nozzle orifice.

[0008] Preferably, the nozzle cavity sidewall is provided with a plurality of oil troughs for storing liquid.

[0009] Preferably, the outer conical surface of the valve stem head and the inner conical surface of the nozzle have the same angle, which is 30°~120°.

[0010] Preferably, the nozzle is a conical nozzle with an angle of 2° to 8°.

[0011] Preferably, the nozzle is made of martensitic stainless steel with a hardness of 50 HRC or higher after heat treatment. A magnetic shielding ring is fixed on the top of the nozzle body. The magnetic shielding ring is made of austenitic stainless steel. The valve stem is made of martensitic stainless steel and has a DLC or CrN coating on its outer conical surface.

[0012] Preferably, the valve stem component further includes a stop block, a buffer spring, and a guide sleeve. The stop block is fitted onto the valve stem and fixed to the stem portion. The stop block is located below the armature so that the armature is supported by the stop block. The guide sleeve is fixed to the valve stem portion and located above the armature. The buffer spring is installed between the armature and the bottom surface of the guide sleeve. The gap between the top surface of the armature and the bottom surface of the guide sleeve can be adjusted by adjusting the position of the guide sleeve. The outer side of the guide sleeve is provided with multiple evenly distributed flow channels for liquid to flow through.

[0013] Preferably, the outer circular surface of the guide sleeve, the armature surface, and the lower end surface of the iron core are all coated with DLC or CrN.

[0014] Preferably, a C-ring and a pressure regulating spring are installed in the inner hole of the iron core. The lower end of the pressure regulating spring contacts the upper end of the guide sleeve to generate spring force so that when the coil is not energized, the outer conical surface of the valve stem head is in close contact with the inner conical surface of the nozzle. The upper end of the pressure regulating spring contacts the lower end of the C-ring so that the spring pressure of the pressure regulating spring can be adjusted by adjusting the position of the C-ring.

[0015] Preferably, the solenoid valve component further includes a coil frame, a yoke, and a cover plate. The coil is installed inside the coil frame, one end of the yoke is fixedly connected to the upper end of the nozzle body, and the other end of the yoke is fixedly connected to the cover plate, forming a closed electromagnetic circuit.

[0016] Preferably, the outer wall of the oil inlet connector head is provided with a groove, and an O-ring and a support ring are installed in the groove. The O-ring is made of methanol-resistant fluorosilicone material, and the support ring has an open structure and is located below the O-ring.

[0017] Compared with existing technologies, the high-pressure injector provided by this invention, by installing a damping valve with a throttling orifice on the upper part of the oil inlet connector, forms a liquid flow channel through which the throttling orifice, oil filter, inner cavity of the oil inlet connector, inner cavity of the iron core, diverting orifice, inner cavity of the nozzle body, nozzle cavity, and spray hole are interconnected, making the oil pressure more stable. Furthermore, by setting up a solenoid valve component and matching the outer and inner conical surfaces of the valve stem head and the nozzle, the contact and separation between the valve stem head and the nozzle can be precisely controlled, making the injection control more reliable. Thus, a high-pressure injector with stable oil pressure and reliable control can be formed, which is conducive to the large-scale promotion and application of in-cylinder methanol direct injection system technology. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the structure of a high-pressure injector provided in one embodiment; Figure 2 for Figure 1 A schematic diagram of the nozzle component in the high-pressure injector shown. Figure 3 for Figure 1 The main sectional view of the valve stem assembly in the high-pressure injector shown. Figure 4 for Figure 3 The top view of the valve stem assembly shown.

[0020] In the diagram, 1-nozzle assembly, 101-nozzle, 102-nozzle body, 103-magnetic shielding ring, 104-oil groove, 105-inner conical surface, 106-spray hole; 2-valve stem assembly, 201-valve stem, 202-stop block, 203-buffer spring, 204-armature, 205-guide sleeve, 206-outer circle, 207-diverter hole, 208-outer conical surface, 209-diverter groove; 3-solenoid valve assembly, 301-coil frame, 302-coil, 303-yoke, 304-cover plate; 4-iron core, 5-pressure regulating spring, 6-C-ring, 7-oil inlet connector, 701-ring groove, 8-oil filter, 9-damping valve, 10-O-ring seal, 11-support ring. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly set on the other component; when a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to the other component.

[0023] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0024] like Figure 1 As shown, this embodiment of the invention provides a high-pressure injector for direct installation in the combustion chamber, particularly suitable for methanol engines (though it can also be used in engines using other fuels). The high-pressure injector mainly includes an inlet connector 7, a solenoid valve assembly 3, a valve stem assembly 2, and a nozzle assembly 1.

[0025] See also Figure 2In this embodiment, the nozzle component includes a nozzle 101, a nozzle body 102, and a magnetic shielding ring 103. The nozzle 101 is fixedly installed at the bottom of the nozzle body 102 by laser welding. The nozzle 101 has an upward-opening cavity and multiple spray holes 106 communicating with the cavity. Multiple oil grooves 104 are provided on the side wall of the cavity, and an inner conical surface 105 is provided at the bottom. The oil grooves 104 facilitate the smooth flow of liquid. The angle of the inner conical surface 105 is set to 30~120° to ensure that the liquid has a sealing effect when not spraying. The spray holes 106 are conical holes with a taper set to 2°~8°, which helps to improve the spraying effect. The magnetic shielding ring 103 is fixed to the top of the nozzle body 102 by laser welding. The magnetic shielding ring is made of austenitic stainless steel, which is beneficial to improving the magnetic circuit efficiency of the electromagnetic actuator, thereby improving the electromagnetic force and overcoming the hydraulic pressure of 350 bar. The nozzle 101 is made of martensitic stainless steel, and its hardness can reach more than 50 HRC after heat treatment. It can resist the corrosion of M100 methanol fuel, and is also wear-resistant and impact-resistant.

[0026] See also Figure 3 , Figure 4 In this embodiment, the valve stem component 2 includes a valve stem 201, a stop block 202, a buffer spring 203, an armature 204, and a guide sleeve 205. The valve stem 201 has an outer conical surface 208 at its head, with a cone angle ranging from 30° to 120°, which matches the inner conical surface 105 of the nozzle to form a sealing ring. The valve stem 201 is made of martensitic stainless steel, and the outer conical surface 208 has a DLC or CrN coating, which is resistant to M100 methanol fuel corrosion and improves wear and impact resistance. The stop block 202 is fitted onto the valve stem 201 and fixed to the stem portion. The armature 204 is fitted onto the stem portion of the valve stem 201 and can move up and down repeatedly, supported by the stop block 202. The guide sleeve 205 is fixed to the top of the valve stem 201, and the gap between the top surface of the armature 204 and the bottom surface of the guide sleeve 205 can be adjusted by adjusting the position of the guide sleeve 205. A buffer spring 203 is installed between the armature 204 and the inner bottom surface of the guide sleeve 205. During the high-speed movement of the valve stem assembly 2 under high hydraulic pressure, the buffer spring 203 effectively reduces the impact force between the outer conical surface 208 of the valve stem and the inner conical surface 105 of the nozzle, and prevents valve stem rebound, thereby improving the product's service life and operational stability. The armature 204 has multiple evenly distributed flow-diverting holes 207 inside, and the guide sleeve 205 has multiple evenly distributed flow-diverting grooves 209 on the outer side, facilitating liquid flow. The outer circle 206 of the guide sleeve and the surface of the armature 204 are coated with DLC or CrN, which reduces friction and wear during movement, extending service life.

[0027] See Figure 1In this embodiment, the solenoid valve component 3 includes an iron core 4, a coil frame 301, a coil 302, a yoke 303, and a cover plate 304. The coil 302 is installed inside the coil frame 301. One end of the yoke 303 is laser-welded to the upper end of the nozzle body 102, and the other end of the yoke 303 is laser-welded to the cover plate 304. The coil 302 has a temperature resistance rating of 220℃ or higher, which helps improve the reliability of the solenoid valve. This closed electromagnetic circuit structure effectively reduces magnetic resistance, decreases magnetic leakage, and further enhances electromagnetic force, thereby overcoming hydraulic pressures of 350 bar and above.

[0028] See Figure 1 In this embodiment, a C-ring 6 and a pressure regulating spring 5 are installed in the inner hole of the iron core 4. The lower end of the pressure regulating spring 5 contacts the upper end of the guide sleeve 205, and the upper end of the pressure regulating spring 5 contacts the lower end of the C-ring 6. The lower end face 401 of the iron core 4 has a DLC or CrN coating, which can reduce wear. By adjusting the position of the C-ring 6, the spring pressure of the pressure regulating spring 5 can be effectively adjusted, thereby more accurately controlling the flow consistency of the high-pressure injector.

[0029] In this embodiment, an oil filter 8 and a damping valve 9 are installed on the upper part of the oil inlet connector 7, and the lower end of the oil inlet connector 7 is laser-welded to the iron core 4. The damping valve 9 has a throttling orifice 901 inside, which can effectively reduce pressure fluctuations and play a stabilizing role. Moreover, the oil filter 8 and the damping valve 9 are installed on the upper part of the oil inlet connector 7, which makes assembly simpler and more convenient. The structure between the oil inlet connector 7 and the iron core 4 is also easier to design and manufacture, and can better control the liquid pressure and reduce pressure fluctuations. It can also make the length of the injector shorter.

[0030] In this embodiment, the outer wall of the oil inlet connector 7 is provided with a groove 701, and an O-ring 10 and a support ring 11 are installed in the groove 701. The O-ring 10 is made of fluorosilicone material and can withstand M100 methanol fuel. The support ring 11 has an open structure for easy installation. The support ring 11 is located below the O-ring 10, which helps to improve the high-pressure sealing performance of the O-ring 10.

[0031] The working principle of the high-pressure injector in this embodiment is as follows: Liquid enters through the throttle orifice 901 of the damping valve 9, is filtered by the oil filter 8, and then passes sequentially through the diversion groove 209 of the guide sleeve 205 and the diversion orifice 207 inside the armature 204, before flowing into the gap between the oil groove 104 of the nozzle 101 and the outer conical surface 208 of the valve stem head. When no power is applied, the force exerted by the pressure regulating spring 5 on the valve stem component 2 is vertically downward, and the force exerted by the hydraulic pressure on the valve stem component 2 is also vertically downward. Under the action of the pressure regulating spring force and the hydraulic pressure, the outer conical surface 208 of the valve stem head is tightly attached to the inner conical surface 105 of the nozzle 101 and in sealed contact. At this time, the injector is in the closed state. When the electronic control unit energizes the solenoid valve component 3 (coil 302) at the appropriate time, the iron core 4 quickly generates a sufficiently large electromagnetic attraction force, attracting the armature 204 and causing the valve stem 208 to quickly move upward against the spring force of the pressure regulating spring 5 and the hydraulic pressure. After the outer conical surface 208 of the valve stem head disengages from the inner conical surface 105 of the nozzle 101, the liquid is ejected from the spray hole 106 of the nozzle 101. Once the injection pulse width meets the requirements, the solenoid valve component 3 is de-energized, and the electromagnetic force dissipates. At this time, the valve stem component 2 is still subjected to the combined action of upward hydraulic pressure and downward spring force. When the hydraulic pressure is less than the spring force, the valve component 2 begins to move downward. During the downward movement of the valve stem component 2, the hydraulic pressures are balanced, and the resultant force is only the downward spring force. The spring force of the pressure regulating spring 5 causes the outer conical surface 208 of the valve stem head to quickly fall back onto the inner conical surface 105 of the nozzle 101. At this time, the injector is in the closed state again, and the injection ends.

[0032] The above description is merely an embodiment of the present invention. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements all fall within the protection scope of the present invention.

Claims

1. A high-pressure injector for direct installation in a combustion chamber, characterized in that, include: An oil inlet connector is equipped with a damping valve and an oil filter on its upper part. The damping valve is provided with a throttling orifice, and the oil filter is located below the damping valve. The solenoid valve component includes a coil and an iron core. The iron core is fixedly connected to the lower end of the oil inlet connector. When the coil is energized, the iron core generates an electromagnetic attraction force. A valve stem assembly includes a valve stem and an armature. The valve stem head is provided with an outer conical surface. The armature is sleeved on the valve stem and can drive the valve stem to move up and down together. The armature is provided with a flow divider hole that runs through the upper and lower parts. The nozzle assembly includes a nozzle body and a nozzle. The nozzle body is fixed to the lower end of the solenoid valve, and the nozzle is located at the lower end of the nozzle body. It has an upward-opening cavity and a spray hole communicating with the cavity. The bottom of the cavity has an inner conical surface that matches the outer conical surface of the valve stem head. The throttling orifice, oil filter, inner cavity of oil inlet connector, inner cavity of iron core, diversion orifice, inner cavity of nozzle body, cavity of nozzle, and spray hole are interconnected, so that liquid can enter from oil inlet connector through throttling orifice, be filtered by oil filter, and then pass through inner cavity of oil inlet connector, inner cavity of iron core, and diversion orifice in sequence, and then flow into the gap between nozzle cavity and outer conical surface of valve stem head; The valve stem is housed in the nozzle assembly, and the armature is housed in the upper inner cavity of the nozzle body, allowing it to move up and down within the upper inner cavity of the nozzle body. When the coil is not energized, the outer conical surface of the valve stem head is in close contact with the inner conical surface of the nozzle, keeping the injector in a closed state. When the coil is energized, the iron core generates electromagnetic attraction to attract the armature, causing the armature to move the valve stem upward. The outer conical surface of the valve stem head then disengages from the inner conical surface of the nozzle, and liquid is ejected from the nozzle orifice.

2. The high-pressure injector according to claim 1, characterized in that, The nozzle cavity sidewall is provided with multiple oil troughs for storing liquid.

3. The high-pressure injector according to claim 1, characterized in that, The outer conical surface of the valve stem head and the inner conical surface of the nozzle have the same angle, which is 30°~120°.

4. The high-pressure injector according to claim 1, characterized in that, The nozzle is a conical nozzle with an angle of 2° to 8°.

5. The high-pressure injector according to claim 1, characterized in that, The nozzle is made of martensitic stainless steel with a hardness of 50 HRC or higher after heat treatment. A magnetic shielding ring is fixed on the top of the nozzle body. The magnetic shielding ring is made of austenitic stainless steel. The valve stem is made of martensitic stainless steel and has a DLC or CrN coating on its outer conical surface.

6. The high-pressure injector according to claim 1, characterized in that, The valve stem assembly also includes a stop block, a buffer spring, and a guide sleeve. The stop block is fitted onto the valve stem and fixed to the stem portion. The stop block is located below the armature so that the armature is supported by the stop block. The guide sleeve is fixed to the valve stem portion and located above the armature. The buffer spring is installed between the armature and the bottom surface of the guide sleeve. By adjusting the position of the guide sleeve, the gap between the top surface of the armature and the bottom surface of the guide sleeve can be adjusted. The outer side of the guide sleeve is provided with multiple evenly distributed flow channels for liquid to flow through.

7. The high-pressure injector according to claim 6, characterized in that, The outer circular surface of the guide sleeve, the armature surface, and the lower end face of the iron core are all coated with DLC or CrN.

8. The high-pressure injector according to claim 6, characterized in that, A C-ring and a pressure regulating spring are installed in the inner hole of the iron core. The lower end of the pressure regulating spring contacts the upper end of the guide sleeve to generate spring force so that when the coil is not energized, the outer conical surface of the valve stem head is in close contact with the inner conical surface of the nozzle. The upper end of the pressure regulating spring contacts the lower end of the C-ring so that the spring pressure of the pressure regulating spring can be adjusted by adjusting the position of the C-ring.

9. The high-pressure injector according to claim 1, characterized in that, The solenoid valve component also includes a coil frame, a yoke, and a cover plate. The coil is installed inside the coil frame, one end of the yoke is fixedly connected to the upper end of the nozzle body, and the other end of the yoke is fixedly connected to the cover plate, forming a closed electromagnetic circuit.

10. The high-pressure injector according to claim 1, characterized in that, The outer wall of the oil inlet connector head is provided with a groove, in which an O-ring and a support ring are installed. The O-ring is made of methanol-resistant fluorosilicone material, and the support ring is an open structure located below the O-ring.

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