CN111237108A - High pressure common rail injector with direct control of injector switch - Google Patents

Abstract

The invention is a high-pressure common rail fuel injector that directly controls the switch of the fuel injection nozzle; it is mainly composed of a terminal assembly, a fuel injector body, an electromagnet component, an intermediate body and a pressure balance fuel injection nozzle. The sleeve is connected to the top of the injector body, and the intermediate body and the pressure balance injector are connected to the bottom of the injector body through the injector screw sleeve; the electromagnet component is installed in the injector body and connected to the control pressure balance injector , in order to directly control the opening and closing of the pressure balance injector. The beneficial effects of the invention are as follows: 1. The pressure-balanced fuel injector is directly controlled by the electromagnet, which can improve the fuel injection response time and greatly simplify the structure of the fuel injector. The injector body is difficult to process, which reduces the cost of the common rail injector. 2. The present invention is also used in the fuel injection nozzle of gasoline injection, which can increase the fuel pressure of direct injection gasoline injection to improve the performance of gasoline engine.

Description

High pressure common rail injector with direct control of injector switch

technical field

The invention relates to a common rail fuel injector for a diesel engine, in particular to a common rail fuel injector that directly controls the switch of fuel injection nozzles, and belongs to the field of internal combustion engine fuel systems.

Background technique

The existing diesel engine common rail injector has two ways of controlling the fuel injector switch by electromagnet and piezoelectric crystal. They mainly control the fuel injector switch indirectly through the hydraulic servo valve. The structure is complex, the machining precision is high, and the response The speed is slow. At present, the common rail injector that uses piezoelectric crystals to directly control the nozzle switch without hydraulic servo valve has become a product. For example, Delphi Corporation of the United States and Continental Corporation of Germany have made common rail injectors that directly control the nozzle switch. Oilers are used on diesel engines.

For the common rail injector controlled by the electromagnet, due to the small size of the high-speed electromagnet of the common rail injector, the force is only more than 100 Newtons, which is much smaller than the control force of the piezoelectric crystal of several thousand Newtons. The fuel injector is shown in Figure 7. The diameter of the needle valve guide seal is d1=4mm, and the diameter of the cone seal is d2=2mm. When the electromagnet is in the low pressure area, the high-pressure fuel acting on the nozzle needle valve will generate upward unbalanced hydraulic pressure. When the fuel injection pressure is 200Mpa, it acts on the nozzle needle valve, and the upward unbalanced hydraulic pressure is as high as 1800 Newtons. The electromagnetic force of the electromagnet is far less than the unbalanced hydraulic pressure. It is impossible for the electromagnet to directly pull the needle valve to control the injection The switch of the nozzle must pass the hydraulic servo valve to convert the electromagnetic force into a strong hydraulic pressure, so that the needle valve can be pulled to control the switch of the nozzle. Therefore, at present, there is no high-pressure common rail injector directly controlled by the electromagnet at home and abroad.

FIG. 7 is a typical structure of a common rail injector for a diesel engine produced by BOSCH in Germany. Its upper end is equipped with electromagnet 21, armature 22, and spherical two-position two-way servo valve 23 is installed in the middle, so that the high pressure hydraulic pressure on the hydraulic piston 24 can be quickly transferred to low pressure, or from low pressure to high pressure, so as to control the fuel injection The switch of nozzle 25, this common rail injector, on the one hand, the electromagnet needs to switch the injector through the servo valve, the sound speed is slower than the direct control of the injector, and the effect on the hydraulic piston is as high as 180-200Mpa. Hydraulic impact force quickly wears out the precise sealing cone surface of the needle valve and valve seat, reducing the life of the nozzle and its working reliability.

Our company's patent 20081004087 proposes a high-pressure common rail injector that directly controls the switch of the fuel injector. It is not a high-pressure common rail injector that directly controls the injector switch by an electromagnet.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a high-pressure common rail fuel injector that directly controls the switch of the fuel injector; it adopts the principle of equal sealing line, so that the resultant force of the high-pressure fuel pressure acting on the nozzle needle valve is zero, that is, the pressure is balanced closed fuel injector, and a high-pressure common rail fuel injector for diesel engines that uses an electromagnet to directly switch the fuel injector. It maintains that the angle of the nozzle orifice and the direction of the injection line are basically unchanged from the crude oil nozzle, and the hydraulic pressure acting on the needle valve is balanced with each other, so that the solenoid valve has enough electromagnetic force to directly control the switch of the nozzle.

The present invention is realized by the following technical solutions: a common rail fuel injector that directly controls the switch of the fuel injection nozzle, which mainly consists of a terminal assembly 1, a fuel injector body 2, an electromagnet component, an intermediate body 7 and a pressure balance fuel injection nozzle 6, the terminal assembly 1 is connected to the top of the injector body 2 through the threaded sleeve 19, the intermediate body 7 and the pressure-balanced fuel injection nozzle 6 are connected to the lower part of the fuel injector body 2 through the fuel injection nozzle threaded sleeve 9; the electromagnet components are installed It is installed in the injector body 2 and connected with the control pressure balance fuel injection nozzle 6 to realize the direct control of the opening and closing of the pressure balance fuel injection nozzle 6 .

Compared with the prior art, the beneficial effects of the present invention are:

1. The present invention uses electromagnets to directly control the pressure-balanced fuel injector, which can improve the fuel injection response time and greatly simplify the structure of the injector. 2. The processing difficulty reduces the cost of the common rail injector.

2. The present invention is also used in the fuel injection nozzle of gasoline injection, which can increase the fuel pressure of direct injection gasoline injection to improve the performance of gasoline engine.

Description of drawings

Fig. 1 is the first embodiment of the direct control fuel injector switch of the present invention;

Figure 2 is a structural diagram of a pressure-balanced closed fuel injector;

Figure 3 is a structural diagram for eliminating the dead volume of the oil nozzle;

Fig. 4 is the second embodiment of the present invention;

Fig. 5 is the F-F section view in Fig. 4;

Figure 6 is a structural diagram of the tail of the needle valve, wherein a is the overall structure, and b is the split structure;

Fig. 7 is the existing common rail fuel injector with servo ball valve;

Numeral description 1 terminal assembly, 10 guide sleeve, 11 valve seat, 12 needle valve, 13 seal sleeve, 14 clearance, 15 spring seat, 16 lever, 17 pin shaft, 18 return spring, 19 screw sleeve, 20 low pressure oil return Hole, 101 terminal, 1101 high pressure oil inlet, 1102 oil tank, 1103 sealing cone A, 1104 fuel injection hole, 1105 cylindrical hole, 1106 valve seat outer circle, 1107 inner channel, 1201 central oil return hole, 1202 sealing cone Face B, 1203 needle valve cylinder, 1204 small lubrication groove, 1205 cylindrical ring groove, 1206 inclined hole A, 1207 upper groove edge, 1208 lower groove edge, 1209 lower ring groove, 1210 inclined hole B, 1211 low pressure oil return Hole, 1212 hinge seat, 1213 outer side wall, 1214 cap, 1215 limit hole, 1216 slot, 2 injector body, 26 ring channel, 201 high pressure oil inlet hole A, 202 low pressure oil return hole A, 203 adjusting gasket , 204 electromagnet coil wire hole A, 205 internal oil return hole A, 206 high voltage oil inlet hole A, 3 return spring, 4 electromagnet parts, 401 coil, 5 armature, 501 armature rod, 502 armature head, 701 horizontal slot , 6 pressure balanced fuel injector, 7 intermediate body, 701 horizontal groove, 702 straight groove, 8 return spring, 9 fuel injector screw sleeve.

Detailed ways

The present invention is described in detail below in conjunction with the accompanying drawings:

As shown in Figures 1-6: The present invention is a common rail injector that directly controls the switch of the injector, which is mainly composed of a terminal assembly 1, an injector body 2, an electromagnet component, an intermediate body 7 and a pressure balance The fuel injector 6 is formed, the terminal assembly 1 is connected to the top of the fuel injector body 2 through the screw sleeve 19, the intermediate body 7 and the pressure balance fuel injection nozzle 6 are connected to the lower part of the fuel injector body 2 through the fuel injection nozzle screw sleeve 9; The iron component is installed in the fuel injector body 2 and connected with the control pressure balance fuel injection nozzle 6 to directly control the opening and closing of the pressure balance fuel injection nozzle 6 .

Here, the basic mechanism of the terminal assembly 1 and the injector body 2 is not much different from the existing terminal assembly 1 and the injector body 2. The terminal assembly 1 is provided with a terminal 101; There are high pressure oil inlet holes A201, 206, low pressure oil return holes A202, electromagnet coil wire holes A204, internal oil return holes A205, etc.

According to the connection mode between the electromagnet component and the pressure-balanced fuel injection nozzle 6, the present invention can be divided into the following two embodiments:

Example 1

As shown in Figure 1-2: the pressure-balanced fuel injector includes a valve seat 11, a needle valve 12, a guide sleeve 10, a sealing sleeve 13, and a reset structure;

The middle of the valve seat 11 is provided with a valve seat inner channel 1107 coaxially arranged with the valve seat 11, the upper ring of the valve seat inner channel 1107 is provided with an oil holding groove 1102, and the side wall of the valve seat 11 is provided with a high pressure inlet that communicates with the oil holding groove 1102. The oil hole 1101, the lower part of the inner channel 1107 is provided with a sealing cone surface A1103, so that the inner channel 1107 is located below the sealing cone surface A1103 to form a cylindrical hole 1105, and the lower side wall of the valve seat 11 is provided with a plurality of spray nozzles communicating with the cylindrical hole 1105. oil hole 1104;

The needle valve 12 extends into the inner channel 1107 of the valve seat 11 and can move up and down in the inner channel 1107. The needle valve 12 is provided with a central oil return hole 1201 extending axially along the needle valve 12; the upper part of the needle valve 12 The side wall is provided with a low pressure oil return hole 1211 that communicates with the central oil return hole 1201. The lower side wall of the needle valve 12 is provided with a sealing cone surface B1202, so that the needle valve 12 is located below the sealing cone surface B1202. The position of the needle valve cylinder 1203 is formed ; There is a cylindrical ring groove 1205 on the outer circumference of the needle valve cylinder 1203 and the joint with the sealing cone surface B1202; the outer circumference of the needle valve cylinder 1203 is located below the cylindrical ring groove 1205. There are multiple small lubrication grooves 1204;

The sealing sleeve 13 is blocked at the bottom of the inner channel 1107; the sealing sleeve 13 is mainly after the needle valve 12 is raised, and the high-pressure fuel in the cylindrical ring groove 1205 will pass through the needle valve cylinder 1203 of the needle valve 12 and the cylinder of the valve seat 11. The gap of the hole 1105 seeps out and becomes low pressure fuel, which passes through the central oil return hole 1201, the low pressure oil return hole 1211 and the internal oil return hole A205 of the needle valve 12 through the gap 14 between the needle valve cylinder 1203 and the sealing sleeve 13, Return to the tank from the low pressure oil return hole A 202.

The inner hole of the sealing sleeve 13 is tightly matched with the outer circle 1106 of the valve seat, and is welded on the outer circle 1106 of the valve seat by laser, which can seal low-pressure fuel during use, and will not fall from the nozzle valve seat 11 into the diesel engine combustion chamber.

The guide sleeve 10 is sleeved on the upper part of the needle valve 12, and the outer periphery is in interference fit with the inner hole 1108 of the valve seat;

The reset structure is arranged on the top of the needle valve 12 and cooperates with the electromagnet component.

The cone angle of the sealing cone surface B1202 is B, the cone angle of the sealing cone surface A1103 is A, and the cone angle A is 0.5-3 degrees larger than the cone angle B.

The needle valve 12 is a cylinder with a gradient in diameter, the diameter of the area where the upper part of the needle valve 12 is matched with the guide sleeve 10 is d1, the diameter of the needle valve cylinder 1203 is d2, and the diameter of the middle area of the needle valve 12 is d3, where d1= d2, d3 is 0.5-1mm larger than d2.

Because the diameter of the sealing ring formed by the contact between the sealing cone surface A1103 and the sealing cone surface A1205 and B1202 is d2, which is smaller than d3, and because d1=d2, in order to be easy to assemble and disassemble, the needle valve 12 must be covered with a guide sleeve 10 , the diameter of the inner hole of the guide sleeve 10 is d1, so the hydraulic pressure statically acting on the needle valve 12 is zero; after the needle valve 12 is raised, because of the precise cooperation between the sealing cone surface A1103 and the sealing cone surface B1202, the sealing fuel acts on the The resultant hydraulic force on the needle valve 11 is also zero, so as long as the electromagnet uses a small force, the sealing cone surface B1202 of the needle valve 11 can be raised or the sealing cone surface A1103 of the valve seat 11 can be pressed tightly, so that the fuel injector can be opened and closed. For high pressure fuel, the gap between the inner channel 1107 in the valve seat 11 and the outer side wall 1213 of the needle valve 12 forms the annular channel 26 .

The reset structure includes a cap 1214 and a return spring 8;

The cap 1214 is fixedly connected to the top of the needle valve 12 , and the return spring 8 is located between the cap 1214 and the top of the valve seat 11 .

Because the cylindrical ring groove 1205 cuts off the high pressure fuel after the sealing cone surface B1202 and the sealing cone surface A1103 are connected, but the nozzle hole 1104 and the cylindrical ring groove 1205 are still connected, the dead volume of the cylindrical ring groove 1205 is large, which is harmful to the diesel engine Emissions increase, so dead volume must be minimized. So make the following changes.

As shown in FIG. 3: below the cylindrical ring groove 1205, the needle valve cylinder 1203 is also provided with a lower ring groove 1209, the cylindrical ring groove 1205 is provided with an inwardly extending oblique hole A1206, and the lower ring groove 1209 is provided with an inwardly extending oblique hole A1206. The inclined hole B1210 is extended inside, the inclined hole A1206 and the inclined hole B1210 are connected to each other; the relationship between the lower ring groove 1209 and the cylindrical ring groove 1205 satisfies the following conditions: the lower groove edge 1208 of the cylindrical ring groove 1205 is not connected to the fuel injection hole 1104 After the needle valve 12 descends, there is a distance H between the upper groove edge 1207 of the lower ring groove 1209 and the fuel injection hole 1104; when the needle valve 12 is lifted, the lower ring groove 1209 communicates with the fuel injection hole 1104. Sharp edge burrs should be removed at the intersection of the inclined hole A1206 and the inclined hole B1210 to prevent stress concentration. After the high pressure fuel is cut off, the nozzle hole 1104 and the cylindrical ring groove 1205 are no longer connected, and the dead volume is zero.

When the needle valve 12 rises and its conical surface 1202 leaves the conical surface 1103 of the valve seat, the high-pressure fuel in the ring groove 26 reaches the ring groove under the groove through the cylindrical ring groove 1205, the inclined hole A 1206 and the inclined hole B1210, and the needle valve After the 12 lift exceeds H, the upper groove edge 1207 is connected to the fuel injection hole 1104, and the high-pressure fuel is injected into the combustion chamber of the diesel engine. The size of H and the lift of the needle valve 12 affect the cross-sectional area of the injection hole 1104. At full load, the needle valve 12 has a large lift, which can fully open the cross-sectional area of the injection hole. The cross-sectional area of the oil hole 1104 is only partially open. Therefore, controlling the size of H can change the injection rate of the nozzle hole, thereby improving the combustion of the diesel engine.

The electromagnet component includes the adjusting washer 203 arranged in the injector body 2 from top to bottom, the return spring 3, the spring seat 15, the armature rod 501, and the armature 5. The upper part of the armature 5 and the outer periphery of the armature rod 501 are provided with a control armature The electromagnet part 41 is raised and lowered, and the electromagnet part 4 is provided with a coil 401;

The armature head 502 of the armature rod 501 is pressed against the upper surface of the cap 1214 .

The working process of embodiment 1 is as follows:

The high-pressure fuel flows from the high-pressure oil inlet holes A201, 206 on the injector body 2, through the high-pressure oil inlet hole 1101 of the valve seat 11, to the oil holding tank 1102, and then passes through the ring 26 to the sealing cone surface B1202, when the electromagnet 4. After the coil 401 is energized, an electromagnetic suction force is generated, which attracts the armature assembly 5 and the armature rod 501, overcomes the pre-tightening force of the return spring 3 and rises, the needle valve 12 rises under the action of the return spring 8, and the sealing cone surface B1202 is separated from the sealing cone surface A1103, the high-pressure fuel flows from the gap between the two cone surfaces into the cylindrical annular groove 1205, and is then injected into the combustion chamber of the diesel engine from the plurality of injection holes 1104 for combustion.

The high-pressure fuel in the cylinder ring groove 1205 is sealed above the needle valve cylinder 1203, and a small amount of fuel leaking from the gap between the cylinder hole 1105 and the needle valve cylinder 1203 passes through the central oil return hole 1201, the low pressure oil return hole 1211, and the internal return. The oil hole A205 flows to the low pressure oil return hole A202 and then flows back to the oil tank.

When the line diagram 401 of the electromagnet 4 is powered off, the electromagnetic force is lost. Since the pressure of the return spring 8 is much lower than the stiffness of the return spring 3, the return spring 3 can press the sealing cone surface B1202 of the needle valve 12 against the sealing cone. On the surface A1103, the high pressure fuel is cut off, and the fuel injection hole 1104 stops fuel injection.

Example 2

As shown in Figures 4-6: the pressure-balanced fuel injector includes a valve seat 11, a needle valve 12, a guide sleeve 10, and a reset structure;

The valve seat 11 is provided with an inner channel 1107 coaxial with the valve seat 11 in the middle of the valve seat 11 , the upper ring of the inner channel 1107 of the valve seat 11 is provided with an oil holding groove 1102 , and the side wall of the valve seat 11 is provided with an oil holding groove 1102 . The high-pressure oil inlet hole 1101, the lower ring of the inner channel 1107 is provided with a sealing cone surface A1103, so that the inner channel 1107 is located below the sealing cone surface A1103 to form a cylindrical hole 1105, and the lower side wall of the valve seat 11 is provided with a plurality of rings connected to the cylindrical hole 1105. The fuel injection hole 1104;

The needle valve 12 extends into the inner channel 1107 of the valve seat 11 and can move up and down in the inner channel 1107. The needle valve 12 is provided with a central oil return hole 1201 extending axially along the needle valve 12; the upper part of the needle valve 12 The side wall is provided with a low pressure oil return hole 1211 that communicates with the central oil return hole 1201. The lower side wall of the needle valve 12 is provided with a sealing cone surface B1202, so that the needle valve 12 is located below the sealing cone surface B1202. The position of the needle valve cylinder 1203 is formed ; There is a cylindrical ring groove 1205 on the outer circumference of the needle valve cylinder 1203 and the joint with the sealing cone surface B1202; the outer circumference of the needle valve cylinder 1203 is located below the cylindrical ring groove 1205. There are multiple small lubrication grooves 1204;

The guide sleeve 10 is sleeved on the outer periphery of the upper part of the needle valve 12 and has an interference fit with the inner hole 1108 of the valve seat;

The reset structure is arranged on the top of the needle valve 12 and cooperates with the electromagnet components.

The cone angle of the sealing cone surface B1202 is B, the cone angle of the sealing cone surface A1103 is A, and the cone angle A is 0.5-3 degrees larger than the cone angle B.

The needle valve 12 is a cylinder with a gradient in diameter, the diameter of the area where the upper part of the needle valve 12 is matched with the guide sleeve 10 is d1, the diameter of the needle valve cylinder 1203 is d2, and the diameter of the middle area of the needle valve 12 is d3, where d1= d2, d3 is 0.5-1mm larger than d2.

The reset structure includes a hinged seat 1212, a lever 16, and a reset spring 18 on the upper end of the needle valve 12; the hinged seat 1212 is provided with a slot 1216, the two side walls of the slot 1216 are provided with limit holes 1215, and one end of the lever 16 is embedded in the The slot 1216 is hinged to the hinge seat 1212 through the pin shaft 17 passing through the limiting hole 1215 and the lever 16 . As can be seen in FIG. 5 , a horizontal groove 701 and a straight groove 702 of the return spring 18 are opened in the intermediate body 7, so that the lever 16 rotates in the horizontal groove 701, and 20 is a low pressure oil return hole.

The electromagnet component includes the adjusting washer 203 arranged in the injector body 2 from top to bottom, the return spring 3, the spring seat 15, the armature rod 501, and the armature 5. The upper part of the armature 5 and the outer periphery of the armature rod 501 are provided with a control armature The electromagnet part 41 is raised and lowered, and the electromagnet part 4 is provided with a coil 401;

As shown in FIG. 4 : the armature head 502 of the armature rod 501 presses against the upper surface of the lever 16 to form a fulcrum a, and the lower surface of the lever 16 contacts the upper surface of the valve seat 11 to form a contact b. J is the distance from the center of the pin to the contact point b, K is the distance from the fulcrum a to the contact point b, and the needle valve lift amplification ratio is J/K

The working process of embodiment 2 is as follows:

Because of the existence of the high-pressure fuel oil inlet hole A206 in the injector body 2, when the electromagnet is installed in the middle of the injector, the diameter of the electromagnet that can be selected is small, and the maximum electromagnetic force of the electromagnet is small. In order to increase the electromagnetic force, To speed up the opening and closing speed of the needle valve, it is the best choice to increase the diameter of the electromagnet. For this reason, the electromagnet is offset from the center by a distance, thereby increasing the diameter of the electromagnet.

Because the stroke of the flat electromagnet is small (generally about 0.1), the electromagnetic force is large, and the stroke of the needle valve 12 is 0.2-0.3 mm, so a lever 16 is designed between the needle valve and the electromagnet, and the lever 16 is used to increase the needle valve 12. lift. A larger needle valve 12 lift can be obtained when the solenoid armature lift is smaller. This structure can increase the needle valve lift by 1-2 times.

In specific use, when the coil 401 of the electromagnet 4 is energized, the spring 3 is restored, and the head 502 of the armature rod 501 is pressed against the point a of the lever 16, and the lever 16 takes the point b as the fulcrum to overcome the elastic force of the return spring 18. The shaft 17 presses the sealing cone surface B1202 on the sealing cone surface A1103, cutting off the passage of high-pressure fuel leading to the injection hole 1104, and the fuel injection nozzle does not have a nozzle.

After the coil 401 of the electromagnet 4 is energized, the electromagnetic suction force through the armature 5 makes the armature rod 501 rise, and the lever 16 takes b as the fulcrum under the action of the return spring 18, and the pin shaft 17 rises, thereby lifting the needle valve 12, and the sealing cone surface B1202 is disengaged. The cone surface A1103 is sealed, and the high-pressure fuel is injected into the combustion chamber through the cylindrical ring groove 1205 and the fuel injection hole 1104 from the cone surface gap.

Due to the use of the offset electromagnet and the lever 16, the lift of the electromagnet is reduced, the suction force is greatly increased, and the lift of the needle valve is also increased, and the switching speed of the needle valve 12 is increased by 1-2 times.

The present invention proposes an equal sealing line method to make the resultant force of the high pressure fuel pressure acting on the nozzle needle valve to be zero, that is, a closed fuel injector with balanced pressure, and a diesel engine high pressure total pressure that uses an electromagnet to directly switch the fuel injector. rail injector. It maintains that the angle of the nozzle orifice and the direction of the injection line are basically unchanged from the crude oil nozzle, and the hydraulic pressure acting on the needle valve is balanced with each other, so that the solenoid valve has enough electromagnetic force to directly control the switch of the nozzle.

The above-mentioned equal sealing line method balances the high-pressure hydraulic pressure acting on the needle valve with each other. The basic idea is as follows: the intersection of the conical surface of the valve seat and the inner hole with a diameter of d2 is the sealing line, which is in contact with the conical surface of the needle valve to seal the high-pressure oil, and the diameter of the sealing line d2 is increased. The matching inner diameter d1 of the guide sleeve in the seat is the same, so that the resultant static hydraulic force acting on the needle valve is zero. The pressure balance control valve of the common rail injector and unit pump is to discharge high pressure fuel to low pressure. The pressure-balanced fuel injection nozzle controls the high-pressure fuel in the common rail to be sent to the front of the injection hole. Due to the small injection hole, the original high pressure is maintained in front of the injection hole, and the two-position two-way control valve is generally uncontrollable. In order to balance the hydraulic pressure acting on the needle valve during the lifting and closing of the needle valve, a cylinder with a diameter of d2 and the lower end of the valve seat must be added to the top of the needle valve. The inner hole of d2 is kept sealed, so that the high-pressure fuel before the injection hole will not flow to the bottom of the needle valve and destroy the balance of hydraulic pressure.

Although the present invention has been illustrated and described in terms of specific embodiments and its alternatives, it should be understood that various changes and modifications may be implemented without departing from the spirit and scope of the invention. Therefore, it should be understood that the present invention is not to be limited in any way, except by the appended claims and their equivalents.

Claims (8)

1. A common rail oil sprayer for directly controlling an oil nozzle switch mainly comprises a terminal post assembly (1), an oil sprayer body (2), an electromagnet assembly, an intermediate body (7) and a pressure balance oil nozzle (6), wherein the terminal post assembly (1) is connected above the oil sprayer body (2) through a threaded sleeve (19), and the intermediate body (7) and the pressure balance oil nozzle (6) are connected below the oil sprayer body (2) through an oil nozzle threaded sleeve (9); the method is characterized in that: the electromagnet part is arranged in the oil injector body (2) and is connected with the pressure balance control oil nozzle (6) to realize the direct control of the opening and closing of the pressure balance oil nozzle (6).

2. The common rail injector that directly controls the opening and closing of the injection nozzle according to claim 1, characterized in that:

the pressure balance type oil nozzle comprises a valve seat (11), a needle valve (12), a guide sleeve (10), a sealing sleeve (13) and a reset structure;

the middle of the valve seat (11) is provided with an inner channel (1107) which is coaxial with the valve seat (11), the upper part of the inner channel (1107) of the valve seat (11) is annularly provided with an oil containing groove (1102), the side wall of the valve seat (11) is provided with a high-pressure oil inlet hole (1101) which is communicated with the oil containing groove (1102), the lower part of the inner channel (1107) is annularly provided with a sealing conical surface A (1103) to enable the inner channel (1107) to be positioned below the sealing conical surface A (1103) to form a cylindrical hole (1105), and the side wall of the lower part of the valve seat (11) is annularly provided with a plurality of oil injection holes (1104);

the needle valve (12) extends into an inner channel (1107) of the valve seat (11) and can move up and down in the inner channel (1107), and the needle valve (12) is provided with a central oil return hole (1201) extending along the axial direction of the needle valve (12); a low-pressure oil return hole (1211) communicated with the central oil return hole (1201) is formed in the side wall of the upper portion of the needle valve (12), a sealing conical surface B (1202) is annularly formed in the side wall of the lower portion of the needle valve (12), and a needle valve cylinder (1203) is formed in the position, below the sealing conical surface B (1202), of the needle valve (12); a cylinder ring groove (1205) is arranged at the joint of the periphery of the needle valve cylinder (1203) and the sealing conical surface B (1202); a plurality of small lubricating grooves (1204) are annularly arranged on the periphery of the needle valve cylinder (1203) below the cylinder ring groove (1205);

the sealing sleeve (13) is plugged at the bottom of the inner channel (1107);

the guide sleeve (10) is sleeved on the periphery of the upper part of the needle valve (12) and is in interference fit with the inner hole (1108) of the valve seat;

the reset structure is arranged on the top of the needle valve (12) and is matched with the electromagnet component.

3. The common rail injector that directly controls the opening and closing of the injection nozzle according to claim 2, characterized in that:

the cone angle of the sealing conical surface B (1202) is B, the cone angle of the sealing conical surface A (1103) is A, and the cone angle A is 0.5-3 degrees larger than the cone angle B.

The needle valve (12) is a cylinder with gradually changed diameter, the diameter of an area where the upper part of the needle valve (12) is matched with the guide sleeve (10) is d1, the diameter of the needle valve cylinder (1203) is d2, and the diameter of the middle area of the needle valve (12) is d3, wherein d1 is d2, and d3 is 0.5-1 mm larger than d 2.

4. The common rail injector that directly controls the opening and closing of the injection nozzle according to claim 3, characterized in that:

the reset structure comprises a cover cap (1214) and a return spring (8);

the cap (1214) is fixedly connected to the top of the needle valve (12), and the return spring (8) is positioned between the cap (1214) and the top of the valve seat (11).

5. The common rail injector that directly controls the opening and closing of the injection nozzle according to claim 4, characterized in that: a lower ring groove (1209) is further formed below the cylindrical ring groove (1205) and on the needle valve cylinder (1203), an inward extending inclined hole A (1206) is formed in the cylindrical ring groove (1205), an inward extending inclined hole B (1210) is formed in the lower ring groove (1209), and the inclined hole A (1206) and the inclined hole B (1210) are communicated with each other; the relationship of the lower ring groove (1209) and the cylinder ring groove (1205) satisfies the following condition: the lower groove edge (1208) of the cylinder ring groove (1205) is not communicated with the oil spray hole (1104); after the needle valve (12) descends, an upper groove edge (1207) of the lower ring groove (1209) has a certain distance H with the oil spray hole (1104); when the needle valve (12) is lifted, the lower ring groove (1209) is communicated with the oil spray hole (1104).

6. The common rail injector that directly controls opening and closing of the injection nozzle according to claim 4 or 5, characterized in that: the electromagnet component comprises an adjusting gasket (203), a return spring (3), a spring seat (15), an armature rod (501) and an armature (5) which are arranged in the oil injector body (2) from top to bottom in sequence, an electromagnet component (41) for controlling the armature to lift is arranged above the armature (5) and on the periphery of the armature rod (501), and a coil (401) is arranged in the electromagnet component (4);

the armature head (502) of the armature rod (501) abuts the upper surface of the cap (1214).

7. The common rail injector that directly controls the opening and closing of the injection nozzle according to claim 3, characterized in that:

the resetting structure comprises a hinge seat (1212) positioned at the upper end of the needle valve (12), a lever (16) and a resetting spring (18); an open groove (1216) is formed in the hinge seat (1212), two side walls of the open groove (1216) are provided with limit holes (1215), and one end of the lever (16) is embedded in the open groove (1216) and is hinged to the hinge seat (1212) through a pin shaft (17) penetrating through the limit holes (1215) and the lever (16).

8. The common rail injector directly controlling opening and closing of the injection nozzle according to any one of claims 7, characterized in that: the electromagnet component comprises an adjusting gasket (203), a return spring (3), a spring seat (15), an armature rod (501) and an armature (5) which are arranged in the oil injector body (2) from top to bottom in sequence, an electromagnet component (41) for controlling the armature to lift is arranged above the armature (5) and on the periphery of the armature rod (501), and a coil (401) is arranged in the electromagnet component (4);

an armature head (502) of the armature rod (501) is pressed against the upper surface of the lever (16) to form a fulcrum a, and the lower surface of the lever (16) is contacted with the upper surface of the valve seat (11) to form a contact point b.

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