CN119393269A - Electric control unit pump - Google Patents
Electric control unit pump Download PDFInfo
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- CN119393269A CN119393269A CN202411548041.4A CN202411548041A CN119393269A CN 119393269 A CN119393269 A CN 119393269A CN 202411548041 A CN202411548041 A CN 202411548041A CN 119393269 A CN119393269 A CN 119393269A
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- 239000000446 fuel Substances 0.000 claims abstract description 82
- 239000003921 oil Substances 0.000 claims description 126
- 238000007789 sealing Methods 0.000 claims description 57
- 238000002955 isolation Methods 0.000 claims description 8
- 239000000295 fuel oil Substances 0.000 claims description 4
- 230000002093 peripheral effect Effects 0.000 claims description 4
- 230000009916 joint effect Effects 0.000 claims 3
- 238000002347 injection Methods 0.000 abstract description 52
- 239000007924 injection Substances 0.000 abstract description 52
- 238000000520 microinjection Methods 0.000 abstract description 10
- 230000009471 action Effects 0.000 description 8
- 239000007789 gas Substances 0.000 description 6
- 238000005086 pumping Methods 0.000 description 6
- 238000000034 method Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 239000002283 diesel fuel Substances 0.000 description 3
- 239000002737 fuel gas Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 239000010720 hydraulic oil Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 230000004044 response Effects 0.000 description 1
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Abstract
本发明公开了一种电控单体泵，其阀体开设有与主油道连通的第一泄流道和第二泄流道，阀体上安装有用于控制第一泄流道通断的第一电磁阀以及用于控制第二泄流道通断的第二电磁阀，当燃油压力低于设定值时，第二电磁阀在断电状态下关闭，所述第二泄流道断开；当燃油压力高于所述设定值时，第二电磁阀在断电状态下开启，第二泄流道接通泄流，第二电磁阀在通电状态下关闭，所述第二泄流道断开。本发明通过对第一电磁阀和第二电磁阀开启和关闭时刻的控制，可实现发动机在柴油机状态的“预喷、主喷、后喷”三段式喷油要求，也能满足微喷气体发动机的燃油供给需求，并可在气体燃料用完后让发动机恢复到全功率柴油机状态运行。
The present invention discloses an electronically controlled single pump, the valve body of which is provided with a first leakage channel and a second leakage channel connected to a main oil channel, the valve body is provided with a first solenoid valve for controlling the on and off of the first leakage channel and a second solenoid valve for controlling the on and off of the second leakage channel, when the fuel pressure is lower than a set value, the second solenoid valve is closed in a power-off state, and the second leakage channel is disconnected; when the fuel pressure is higher than the set value, the second solenoid valve is opened in a power-off state, the second leakage channel is connected to the leakage flow, the second solenoid valve is closed in a power-on state, and the second leakage channel is disconnected. The present invention can realize the three-stage fuel injection requirements of "pre-injection, main injection, and post-injection" of the engine in the diesel engine state by controlling the opening and closing time of the first solenoid valve and the second solenoid valve, and can also meet the fuel supply requirements of the micro-injection gas engine, and can restore the engine to the full-power diesel engine state after the gas fuel is used up.
Description
Technical Field
The invention relates to the technical field of engine fuel supply systems, in particular to an electric control unit pump.
Background
When fuel injection is performed, the diesel fuel supply system is expected to realize three stages of pre-injection (or boot injection), main injection and post injection so as to improve the engine performance and reduce the emission. The high-pressure common rail type fuel supply system has stable fuel pressure in the rail pipe, controls the fuel injection quantity through the opening time of the electromagnetic valve, has high control precision, and can meet the requirements of three stages of pre-injection, main injection and post injection of the engine.
The micro-injection ignition dual-fuel engine taking a diesel engine as a main body takes a trace amount of diesel oil (1% -5% of full-load oil quantity) as a pilot fuel, and pilot gas main fuel does work after being injected into compression ignition in a cylinder. The fuel is the ignition energy of the gas fuel, and the quantity of the fuel injection quantity per cycle directly determines the combustion characteristic of the gas fuel, so that the performance of an engine is influenced, therefore, the requirement on the supply control precision of a small quantity of injected fuel is very high, the fuel pressure in a rail pipe is stable, the fuel injection quantity is controlled through the opening time of an electromagnetic valve, the control precision is high, and the supply requirement of micro-injection pilot fuel can be met.
However, the conventional fuel supply system based on the electric control unit pump cannot meet the three-stage injection requirement of a diesel engine and the small oil injection requirement of a micro-injection ignition dual-fuel engine.
The traditional fuel supply system of the electric control unit pump generally comprises a cam, a fuel pumping system, an electromagnetic valve, a high-pressure oil pipe and a fuel injector, wherein a cam driving roller drives a plunger to reciprocate to boost diesel to a high-pressure cavity, when the electromagnetic valve is not electrified, a sealing conical surface is not attached, diesel in the high-pressure cavity is discharged through a gap of the sealing conical surface, the diesel in the high-pressure oil pipe is not established to be high pressure, the fuel injector can not be driven to open, the fuel injector is not injected, when the electromagnetic valve is electrified, the pressure of the diesel in the high-pressure cavity is increased, the diesel enters the fuel injector through the high-pressure oil pipe, after the pressure of the diesel reaches the opening pressure of the fuel injector, the fuel injector is opened to inject the diesel into a cylinder, and when the electromagnetic valve is powered off again, the sealing conical surface is opened under the action of spring force to release pressure, and the fuel injector stops injecting the fuel.
In the cam oil pumping process, the duration from closing to opening of the electromagnetic valve is controlled, and the oil supply amount of each cycle of the single pump can be controlled. Under a certain rotation speed condition, the time period t from closing to opening of the electromagnetic valve corresponds to the cam angle alpha. If the system meets the requirement of the micro-injection engine, and the oil injection quantity is 1% -5% of the full-load oil quantity, the corresponding cam angle beta must be quite small during the micro-injection state operation. For example, when the duration from closing to opening of the corresponding electromagnetic valve is 2 milliseconds at a certain rotation speed of the engine, the corresponding time requirement for micro-injection is less than 0.2 milliseconds, which is far beyond the response time requirement of the electromagnetic valve.
The high-pressure common rail fuel supply system is widely applied to diesel engines with power below 500KW, and for large-sized engines with power more than 1000KW, the cost of the matched high-pressure common rail fuel supply system is greatly increased by ten times due to the change of the process and the structure, so that the application of the high-pressure common rail fuel supply system is limited, and therefore, the large-sized diesel engines still mostly adopt the fuel supply system of the electric control unit pump.
The proposal adopted by some manufacturers is that a small high-pressure common rail fuel system, such as a 1000KW engine, is matched, the matched high-pressure common rail system can only meet the diesel oil supply requirement of 300KW, the proposal solves the problems of the cost of the fuel oil supply system (the cost of the small high-pressure common rail system is low) and the control precision in a micro-injection state, but when the gas fuel is used up, the operation of the full-power diesel engine state (the diesel engine state of only 300 Kw) can not be restored, and the application is limited.
Disclosure of Invention
In view of this, the invention provides an electronically controlled unit pump, which can realize the three-stage fuel injection requirements of the engine in the state of pre-injection, main injection and post injection of the diesel engine, can also meet the fuel supply requirement of the microjet engine, and can recover the engine to the state of a full-power diesel engine to operate after the gas fuel is used up.
In order to solve the first technical problem, the invention adopts the following technical scheme:
An electric control monoblock pump comprises a pump body, wherein the pump body is fixedly provided with a valve body and is provided with a push rod in a sliding manner, a main spring is clamped between the valve body and the push rod, the push rod is provided with a roller extending out of the pump body, and the roller is controlled by an oil pumping cam of a cam shaft; the pump body is provided with an oil inlet hole, the valve body is provided with an oil inlet passage, a main oil passage, a high-pressure cavity and an oil outlet hole, the oil inlet hole is communicated with the oil inlet passage, one end of the main oil passage is communicated with the oil outlet hole, the other end of the main oil passage is communicated with the high-pressure cavity, a plunger which is abutted against the push rod is slidably mounted in the valve body, the roller is driven by the pump oil cam to drive the plunger to reciprocate, fuel oil from the oil inlet hole is pressurized to the high-pressure cavity, the valve body is provided with a first drain passage and a second drain passage which are respectively communicated with the main oil passage, the valve body is provided with a first electromagnetic valve for controlling the on-off of the first drain passage and a second electromagnetic valve for controlling the on-off of the second drain passage, the first electromagnetic valve is a normally-open electromagnetic switch valve, the second electromagnetic valve is a normally-closed electromagnetic switch valve, when the first electromagnetic valve is opened in a power-off state, the first electromagnetic valve is closed in a power-on state, the first drain passage is closed in the power-on state, the first drain passage is opened in the power-on state, and the second electromagnetic valve is closed in the power-off state of the second drain passage under the power-on state of the high pressure set value, the second electromagnetic valve is closed in the power-off state in the power-on state of the second drain passage is opened in the power state, the second leakage flow path is open.
The first electromagnetic valve comprises a first electromagnet, a first valve core and a first positioning seat, the first drainage channel comprises a first valve core hole, a first oil return cavity and a first oil return channel which are formed in the valve body and are sequentially communicated, the first valve core hole is communicated with the main oil channel, the first oil return channel is communicated with the oil tank, the first valve core is slidably arranged in the first valve core hole and sleeved with a first control spring and a spring seat, the spring seat is propped against a shaft shoulder of the first valve core, a magnetic isolation pad is arranged between the first electromagnet and the valve body, a first spring baffle disc is restrained between the magnetic isolation pad and the valve body, the first control spring is clamped between the spring seat and the first spring baffle disc, a first valve core sealing surface is arranged on the head of the first valve core, a first valve body lift is arranged on the first valve core hole, a distance for determining opening of the first valve core is arranged between the end surface of the head of the first valve core and the first positioning seat, and the first electromagnet and the first valve core are in contact with the first valve core sealing surface or the first valve core is separated from the first valve core under the action of the first control spring, and the first valve core is in contact with the first sealing surface or the first valve body.
The second electromagnetic valve comprises a second electromagnet, a second valve core and a second positioning seat, the second leakage flow channel comprises a second valve core hole, a second oil return cavity and a second oil return channel which are sequentially communicated with each other on the valve body, the second valve core hole is communicated with the main oil channel, the second oil return channel is communicated with the oil tank, or the second oil return channel is not arranged, the second oil return cavity is communicated with the first oil return cavity through a connecting channel, the second valve core hole is a stepped hole, the stepped hole comprises a large hole and a small hole, the second valve core is slidably arranged in the small hole and sleeved with a second control spring, a second spring baffle disc is fixed on the second valve core, the second control spring is clamped between the second spring baffle disc and the valve body, a second valve core sealing surface is arranged on the head of the second valve core, the end face of the head part of the second valve core is not arranged with the second oil return channel, the second valve core hole is communicated with the first oil return cavity through a connecting channel, the stepped hole comprises a large hole, the second electromagnetic valve core is in the joint force of the second electromagnetic valve core and the second valve core is separated from the second electromagnetic valve core, the second electromagnetic valve core is in the joint force of the second electromagnetic valve core and the valve core is in the joint force of the valve core, and the high pressure of the second electromagnetic valve core is different from the valve body. Or alternatively
The second electromagnetic valve comprises a second electromagnet, a second valve core and a second positioning seat, the second drainage channel comprises a second valve core hole, a second oil return cavity and a second oil return channel which are arranged on the valve body and are communicated with each other in sequence, the second valve core hole is communicated with the main oil channel, the second oil return channel is communicated with the oil tank or is not provided with the second oil return channel, the second oil return cavity is communicated with the first oil return cavity through a connecting channel, the second valve core hole is a stepped hole, the stepped hole comprises a large hole and a small hole, the second valve core is arranged in the small hole in a sliding mode, the second positioning seat is provided with a counter bore, a third control spring is arranged in the counter bore and axially propped against the head of the second valve core, the head of the second valve core is provided with a second valve core sealing surface, the large hole is provided with a second valve body sealing surface, a distance for determining the opening lift of the second valve core is arranged between the end surface of the head of the second valve core and the end surface of the second positioning seat, under the combined action of the second electromagnet, the third control spring and the high-pressure cavity fuel pressure, the second valve core sealing surface is attached to or detached from the second valve body sealing surface to control the on-off of the second flow leakage channel, and the resultant force of the electromagnetic force set by the second electromagnetic valve and the spring force set by the third control spring is larger than the pressure difference generated on the second valve core by the highest fuel pressure.
After the technical scheme is adopted, the invention has the following technical effects:
The valve body is provided with a first leakage flow channel and a second leakage flow channel which are respectively communicated with the main oil duct, the valve body is provided with a first electromagnetic valve used for controlling the on-off of the first leakage flow channel and a second electromagnetic valve used for controlling the on-off of the second leakage flow channel, the first electromagnetic valve is a normally open electromagnetic switch valve, the second electromagnetic valve is a normally closed electromagnetic switch valve, when the first electromagnetic valve is opened in a power-off state, the first leakage flow channel is connected with the leakage flow channel, when the first electromagnetic valve is closed in an electrified state, the first leakage flow channel is disconnected, when the fuel pressure of the high-pressure cavity is lower than a set value, the sealing surface of the second valve is attached to the sealing surface of the second valve under the action of a spring force, the second electromagnetic valve is closed, so that the second leakage flow channel is disconnected, when the fuel pressure of the high-pressure cavity is higher than the set value, the second electromagnetic valve is in a power-off state, the pressure difference is generated on the second electromagnetic valve, when the second electromagnetic valve is in a power-off state, the second control spring is closed, the second electromagnetic valve is separated from the sealing surface of the second electromagnetic valve, and the second electromagnetic valve is completely closed, and the requirements of the fuel injection flow can be met when the second electromagnetic valve is completely opened, and the second electromagnetic valve is completely closed, and the requirements of the fuel injection flow is completely are met.
In the invention, the second valve core hole is arranged as the stepped hole, so that the pressure difference of the fuel pressure on the second valve core is generated, the second electromagnetic valve has an overflow function, thereby controlling the injection pressure of the fuel, adjusting the opening lift of the second valve core, and the second electromagnetic valve has a throttling function, thereby controlling the injection flow of the fuel, and improving the control precision by combining the two.
In the invention, the resultant force of the electromagnetic force set by the second electromagnetic valve and the spring force set by the second control spring or the third control spring is larger than the pressure difference generated by the highest fuel pressure on the second valve core, so that the second valve core can be ensured to be closed after the second electromagnetic valve is electrified.
Drawings
FIG. 1 is a longitudinal cross-sectional view of embodiment 1 of the electronically controlled unit pump of the present invention;
FIG. 2 is an enlarged view of a portion of FIG. 1 at I;
FIG. 3 is an enlarged view of a portion of FIG. 1 at II;
FIG. 4 is an enlarged view of a portion of III in FIG. 3;
FIG. 5 is a waveform diagram of injection pressure for realizing three stages of boot injection, main injection, and post injection in the embodiment 1 shown in FIG. 1;
FIG. 6 is a graph comparing the injection pressure waveforms of the unit injection pump of conventional structure of example 1 shown in FIG. 1 when it is implemented on a micro-injection dual fuel gas engine;
FIG. 7 is an enlarged view of a portion of the electronically controlled unit pump of example 2 of the present invention corresponding to example 1 at II;
In the figure, 10 parts of oil pumping cams, 21 parts of pump bodies, 211 parts of oil inlet holes, 22 parts of push rods, 23 parts of rollers, 24 parts of main springs, 25 parts of plungers, 26 parts of valve bodies, 261 parts of oil inlet channels, 262 parts of high-pressure cavities, 263 parts of main oil ducts, 264 parts of first oil return cavities, 265 parts of second oil return cavities, 266 parts of first oil return channels, 267 parts of connecting channels, 268 parts of first valve body sealing surfaces, 269 parts of second valve body sealing surfaces, 31 parts of first electromagnets, 32 parts of first valve cores, 321 parts of first valve core sealing surfaces, 33 parts of first control springs, 34 parts of first positioning seats, 35 parts of spring seats, 36 parts of first spring retaining plates, 37 parts of magnetic isolation pads, 41 parts of second electromagnets, 42 parts of second valve cores, 421 parts of second valve core sealing surfaces, 43 parts of second control springs, 44 parts of second positioning seats, 45 parts of second spring retaining plates, 46 parts of magnetic isolation pads, 47 parts of third control springs, 50 parts of high-pressure oil pipes, 60 parts of fuel injectors;
S1, a first valve core opening lift, S2, a second valve core opening lift, D, a large hole diameter, D, a small hole diameter;
And t1, the time length from closing to opening of the solenoid valve of the monomer pump with the traditional structure, and tx, the time length from closing to opening of the first solenoid valve of the embodiment of the invention.
Detailed Description
The invention will be further described with reference to the drawings and examples.
Example 1
As shown in fig. 1, in an electrically controlled monoblock pump, a pump body 21 is fixedly provided with a valve body 26 and is slidably provided with a push rod 22, a main spring 24 is clamped between the valve body 26 and the push rod 22, the push rod 22 is provided with a roller 23 extending out of the pump body 21, and the roller 23 is controlled by an oil pumping cam 10 of a cam shaft. For large bore engines, the camshaft is separate and mounted separately from the pump body 21, and for small bore engines, the camshaft is integrated into the pump body 21 and rotatably mounted with the pump body 21.
The pump body 21 is provided with an oil inlet hole 211, the valve body 26 is provided with an oil inlet passage 261, a main oil passage 263, a high-pressure cavity 262 and an oil outlet hole, the oil inlet hole 211 is communicated with the oil inlet passage 261, one end of the main oil passage 263 is communicated with the oil outlet hole, the other end of the main oil passage 263 is communicated with the high-pressure cavity 262, the oil outlet hole is connected with a high-pressure oil pipe, and the high-pressure oil pipe 50 is connected with the oil sprayer 60. A plunger 25 abutting against the push rod 22 is slidably mounted in the valve body 26, the oil pumping cam 10 drives the roller to drive the plunger to reciprocate, fuel oil from the oil inlet hole is pressurized to the high-pressure cavity 262, and is sprayed out of the main oil duct 263 through the high-pressure oil pipe 50 by the oil sprayer 60.
The valve body 26 is provided with a first leakage flow channel and a second leakage flow channel which are respectively communicated with the main oil channel 263, and the valve body 26 is also respectively provided with a first electromagnetic valve for controlling the on-off of the first leakage flow channel and a second electromagnetic valve for controlling the on-off of the second leakage flow channel. The opening lift of the first solenoid valve core is S1, the opening lift of the second solenoid valve core is S2, and S1> S2 is set, for example, s1=0.15 mm and s2=0.015 mm are designed, and the values can be adjusted according to the needs, and do not limit the protection scope of the present invention.
As shown in fig. 1 and fig. 2 together, the first electromagnetic valve is a normally open electromagnetic switch valve, when the first electromagnetic valve is opened in a power-off state, the first drainage channel is connected with drainage, and when the first electromagnetic valve is closed in a power-on state, the first drainage channel is disconnected. The first solenoid valve comprises a first electromagnet 31, a first valve core 32 and a first positioning seat 34, the first draining passage comprises a first valve core hole, a first oil return cavity 264 and a first oil return channel 266 which are arranged on the valve body 26 and are sequentially communicated, the first valve core hole is communicated with a main oil channel 263, the first oil return channel 266 is communicated with an oil tank (not shown in the figure), the first valve core 32 is slidably arranged in the first valve core hole and sleeved with a first control spring 33 and a spring seat 35, the spring seat 35 is propped against the shaft shoulder of the first valve core 32, a magnetic isolation pad 37 is arranged between the first electromagnet 31 and the valve body 26, a first spring baffle disc 36 is restrained between the magnetic isolation pad 37 and the valve body 26, the first control spring 33 is clamped between the spring seat 35 and the first spring baffle disc 36, the head of the first valve core 32 is provided with a first valve core sealing surface 321, the first valve core hole is provided with a first valve body lift 268, the distance for determining the first valve core S1 is arranged between the end surface of the head of the first valve core 32 and the end surface of the first positioning seat 34, and the first electromagnet 31 is contacted with the first valve core sealing surface under the action of the first electromagnet 31 or the first valve core 33 or the first valve body is separated from the first valve body sealing surface.
As shown in fig. 1,3 and 4, the second electromagnetic valve is a normally closed electromagnetic switch valve, the second electromagnetic valve is closed in a power-off state and the second drainage channel is disconnected under the condition that the fuel pressure of the high-pressure cavity is lower than a set value, the second electromagnetic valve is opened in the power-off state and the second drainage channel is connected with drainage under the condition that the fuel pressure of the high-pressure cavity is higher than the set value, the second electromagnetic valve is closed in an energized state and the second drainage channel is disconnected. The second solenoid valve comprises a second electromagnet 41, a second valve core 42 and a second positioning seat 44, the second leakage flow path comprises a second valve core hole and a second oil return cavity 265 which are arranged on the valve body 26 and communicated with each other, the second valve core hole is communicated with the main oil duct 263, the second oil return cavity 265 is communicated with the first oil return cavity 264 through a connecting channel 267, the second valve core hole is a stepped hole, the stepped hole comprises a large hole (the diameter of the large hole is marked as D) and a small hole (the diameter of the small hole is marked as D), the second valve core 42 is slidably arranged in the small hole and sleeved with a second control spring 43, the second valve core 42 is fixed with a second spring baffle 45, the second control spring 43 is clamped between the second spring baffle 45 and the valve body 26, the head of the second valve core 42 is provided with a second valve core sealing surface 269, the distance for determining the second valve core S2 is reserved between the end face of the head lift of the second valve core 42 and the end face of the second positioning seat 44, and the second valve core is opened under the action of the second electromagnet 41, the second control spring 43 and the high pressure fuel pressure is separated from the second valve core sealing surface or the second valve core sealing surface.
As another embodiment, the second drain flow passage is independently provided, that is, a connecting passage is not provided between the first oil return chamber 264 and the second oil return chamber 265, but a second oil return passage (not shown in the drawing) communicating with the second oil return chamber 265 is provided, and the second oil return chamber 265 is directly communicated with the oil tank through the second oil return passage.
The second solenoid valve operates as follows:
1) The direction of the spring force and the electromagnetic force are the closing direction of the valve core, and the direction of the spring force and the electromagnetic force is upward in the figure.
2) As shown in fig. 3, the direction of the acting force of the high-pressure chamber fuel on the second valve core 42 is the opening direction (downward direction in the drawing) of the second valve core 42, the acting force area is pi/4 (D 2-d2), and if the pressure of the high-pressure chamber hydraulic oil is P, the acting force is pi/4 (D 2-d2) P.
3) The second valve element opening lift S2 is set to a value that can perform a throttle function.
4) Setting the elastic force of the second control spring 43, the opening pressure of the second electromagnetic valve can be controlled, for example, the opening pressure of the second electromagnetic valve is required to be 20MPa, d=10 mm, d=10.05 mm, the elastic force of the second control spring 43 is designed to be pi/4 (10.052-102) ×20=15.7n, and when the second electromagnet 41 is not electrified to generate electromagnetic force, the second valve core 42 can be opened to release the fuel when the fuel pressure reaches 20 MPa.
5) In order to ensure that the second valve core is closed after the second electromagnetic valve is electrified, the resultant force of the electromagnetic force set by the second electromagnetic valve and the spring force set by the second control spring 43 is larger than the pressure difference generated by the highest fuel pressure on the second valve core 42, for example, the highest pressure of the fuel pressure is 180MPa, the acting force on the second valve core 42 is pi/4 (10.052-102) 180= 141.7N, and if the electromagnetic force of the second electromagnetic valve is designed to be larger than 141.7-15.7=24n, the valve core can be ensured to be closed after the electromagnetic valve is electrified.
6) When the fuel pressure in the high-pressure chamber is lower than 20MPa, the second valve core 42 is closed under the spring force of the second control spring 43.
7) When the fuel pressure of the high-pressure cavity is 20MPa, the second valve core 42 is opened in the power-off state of the second electromagnet 41, and the second valve core 42 is closed in the power-on state of the second electromagnet 41.
In the invention, the second valve core hole is arranged as the stepped hole, so that the pressure difference of the fuel pressure on the second valve core 42 is generated, the second electromagnetic valve has an overflow function, thereby controlling the injection pressure of the fuel, adjusting the opening lift of the second valve core 42, and the second electromagnetic valve has a throttling function, thereby controlling the injection flow of the fuel, and improving the control precision by combining the two.
In this embodiment, the first oil return cavity 264 surrounds the outer peripheral surface of the first positioning seat 34, and the second oil return cavity 265 surrounds the outer peripheral surface of the second positioning seat 44.
In this embodiment, the first valve core sealing surface 321 and the first valve body sealing surface 268 are respectively matched sealing conical surfaces, and the second valve core sealing surface 421 and the second valve body sealing surface 269 are respectively matched sealing conical surfaces. As shown in fig. 4, the second valve element sealing surface 421 and the second valve element sealing surface 269 have different taper angles, the included angle θ is larger than zero, and when the two surfaces are abutted, a sealing band is formed, so that the sealing effect is improved relative to the surface sealing. First spool sealing surface 321 and first valve body sealing surface 268 also have similar structure and effect.
By controlling the opening and closing timings of the first solenoid valve and the second solenoid valve, a variety of injection pressure waveforms may be formed.
As shown in FIG. 5, an Electronic Control Unit (ECU) controls the first electromagnetic valve 32 to be electrified and closed, the second electromagnetic valve 42 is opened after the fuel pressure of the high-pressure cavity is increased to 20MPa, after a certain time, the second electromagnetic valve 42 is electrified and closed, the pressure begins to be rapidly increased to form boot-shaped injection, after a certain time, the first electromagnetic valve 32 and the second electromagnetic valve 42 are simultaneously powered off and opened to generate a main injection waveform, the first electromagnetic valve is subsequently controlled to be electrified/disconnected and opened/closed by the first electromagnet 31, the second electromagnetic valve 41 is not electrified, and the second electromagnetic valve is kept opened under the action of the fuel pressure, so that a post injection waveform is generated.
Regarding the control of the post injection, it is necessary to keep the second solenoid valve open after reaching a certain pressure, and the two-dot chain line part in fig. 5 is a post injection waveform diagram when the second solenoid valve is not provided, the solid line is a waveform diagram when the second solenoid valve is kept open, and as can be seen from fig. 5, the same fuel post injection amount, the corresponding duration of the solid line waveform is longer, and as can be seen from the fact that the requirement on the solenoid valve is reduced by providing the second solenoid valve, the fuel supply control method can realize three-stage fuel injection of "boot injection, main injection and post injection", and the same effect of three-stage fuel injection of "pre injection, main injection and post injection" can be expected.
As shown in fig. 6, in the micro-injection dual-fuel gas engine, the second electromagnetic valve is kept in a non-energized state, and the duration tx, tx > > t1 from closing to opening of the first electromagnetic valve is controlled, so that the fuel injection quantity with high precision and small injection quantity can be obtained. Therefore, the fuel supply control method can meet the fuel supply requirement of the microjet engine, and can restore the engine to the full-power diesel engine state after the gas fuel is used up.
Example 2
The structure of embodiment 2 is basically the same as that of embodiment 1, except that the control springs are arranged differently, as shown in fig. 7, the second positioning seat 44 is provided with a counter bore, and a third control spring 47 is disposed in the counter bore, and the third control spring 47 axially abuts against the head of the second valve core 42. Under the action of the second electromagnet 41, the third control spring 47 and the high-pressure cavity fuel pressure, the second valve core sealing surface 421 is attached to or detached from the second valve body sealing surface 269 so as to control the on-off of the second flow leakage channel.
The present invention is not limited to the above embodiments, and for example, a combination of three or more solenoid valves may be used, and by setting different valve spool lifts, more fuel injection waveforms may be generated. All modifications of the concepts, principles, structures and methods of the invention are intended to be within the scope of the invention.
Claims (10)
1. An electronically controlled unit pump, comprising:
The oil pump is characterized in that one end of the main oil duct is communicated with the oil outlet, the other end of the main oil duct is communicated with the high-pressure cavity, a plunger which is abutted against the push rod is slidably mounted in the valve body, the pump oil cam drives the roller to drive the plunger to reciprocate, and fuel oil from the oil inlet is pressurized to the high-pressure cavity,
The valve body is provided with a first leakage flow channel and a second leakage flow channel which are respectively communicated with the main oil channel, the valve body is provided with a first electromagnetic valve used for controlling the on-off of the first leakage flow channel and a second electromagnetic valve used for controlling the on-off of the second leakage flow channel, the first electromagnetic valve is a normally open electromagnetic switch valve, the second electromagnetic valve is a normally closed electromagnetic switch valve, when the first electromagnetic valve is opened in a power-off state, the first leakage flow channel is connected with a leakage flow, when the first electromagnetic valve is closed in a power-on state, the first leakage flow channel is disconnected, when the fuel pressure of the high-pressure cavity is lower than a set value, the second electromagnetic valve is closed in a power-off state, when the fuel pressure of the high-pressure cavity is higher than the set value, the second electromagnetic valve is opened in a power-off state, the second leakage flow channel is connected with the leakage flow channel, and the second electromagnetic valve is disconnected in the power-on state.
2. The electric control unit pump according to claim 1, wherein the first solenoid valve comprises a first electromagnet, a first valve core and a first positioning seat, the first leakage flow channel comprises a first valve core hole, a first oil return cavity and a first oil return channel which are arranged on the valve body and are sequentially communicated, the first valve core hole is communicated with the main oil channel, the first oil return channel is communicated with an oil tank, the first valve core is slidably arranged in the first valve core hole and sleeved with a first control spring and a spring seat, the spring seat is propped against a shaft shoulder of the first valve core, a magnetic isolation pad is arranged between the first electromagnet and the valve body, a first spring baffle is restrained between the magnetic isolation pad and the valve body, the first control spring is clamped between the spring seat and the first spring baffle, the head of the first valve core is provided with a first valve core sealing surface, the first valve core hole is provided with a first sealing surface, the first valve core end surface and the first positioning seat end surface are provided with a first control spring for determining the opening and closing and opening of the first electromagnet or opening and closing of the first valve core under the first control valve core or the first valve core.
3. The electric control monoblock pump of claim 2, wherein the second solenoid valve comprises a second electromagnet, a second valve core and a second positioning seat, the second leakage flow channel comprises a second valve core hole, a second oil return cavity and a second oil return channel which are sequentially communicated with each other and arranged on the valve body, the second valve core hole is communicated with the main oil channel, the second oil return channel is communicated with the oil tank or is not provided with the second oil return channel, the second oil return cavity is communicated with the first oil return cavity through a connecting channel, the second valve core hole is a stepped hole, the stepped hole comprises a large hole and a small hole, the second valve core is slidably arranged on the small hole and sleeved with a second control spring, the second valve core is fixedly provided with a second spring baffle disc, the second control spring is clamped between the second spring baffle disc and the valve body, the head part of the second valve core is provided with a second valve core sealing surface, the large hole is provided with a second sealing surface, the end surface of the second valve core and the end surface of the second valve core is provided with a connecting channel, the stepped hole is matched with the second valve core sealing surface or the second valve body under the joint action of the second valve core, and the sealing surface is separated from the second valve body under the joint action of the second positioning seat.
4. The electric unit pump of claim 3, wherein a resultant force of the electromagnetic force set by the second electromagnetic valve and the spring force set by the second control spring is greater than a pressure difference generated by the highest fuel pressure on the second spool.
5. The electric control monoblock pump of claim 2, wherein the second solenoid valve comprises a second electromagnet, a second valve core and a second positioning seat, the second leakage flow channel comprises a second valve core hole, a second oil return cavity and a second oil return channel which are arranged on the valve body and are communicated with each other in sequence, the second valve core hole is communicated with the main oil channel, the second oil return channel is communicated with the oil tank or is not provided with the second oil return channel, the second oil return cavity is communicated with the first oil return cavity through a connecting channel, the second valve core hole is a stepped hole, the stepped hole comprises a large hole and a small hole, the second valve core is arranged in the small hole in a sliding mode, the second positioning seat is provided with a counter bore, a third control spring is arranged in the counter bore, the third control spring axially abuts against the head of the second valve core, the head of the second valve core is provided with a second valve core sealing surface, the end face of the second valve core is provided with a second valve core end face, the second valve core end face and the second positioning seat end face are provided with a large hole, the second valve core end face and the second positioning seat are provided with a second valve core opening and a second pressure release spring or a second valve core sealing surface under the joint action of the second valve body.
6. The electric unit pump according to claim 5, wherein a resultant force of the electromagnetic force set by the second electromagnetic valve and the spring force set by the third control spring is greater than a pressure difference generated by the highest fuel pressure on the second spool.
7. The electric unit pump according to claim 3 or 5, wherein the first oil return chamber surrounds the outer peripheral surface of the first positioning seat, and the second oil return chamber surrounds the outer peripheral surface of the second positioning seat.
8. The electric control unit pump according to claim 3 or 5, wherein the first valve core sealing surface and the first valve body sealing surface are respectively matched sealing conical surfaces, the cone angles of the first valve core sealing surface and the first valve body sealing surface are different, the second valve core sealing surface and the second valve body sealing surface are respectively matched sealing conical surfaces, and the cone angles of the second valve core sealing surface and the second valve body sealing surface are different.
9. The electrically controlled unit pump of claim 1, wherein the camshaft is rotatably mounted to the pump body or the camshaft is mounted separately from the pump body.
10. The electronically controlled unit pump of claim 1, wherein the oil outlet is connected to a high pressure oil line, the high pressure oil line being connected to an oil injector.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411548041.4A CN119393269A (en) | 2024-11-01 | 2024-11-01 | Electric control unit pump |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411548041.4A CN119393269A (en) | 2024-11-01 | 2024-11-01 | Electric control unit pump |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN119393269A true CN119393269A (en) | 2025-02-07 |
Family
ID=94430722
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202411548041.4A Pending CN119393269A (en) | 2024-11-01 | 2024-11-01 | Electric control unit pump |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN119393269A (en) |
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2024
- 2024-11-01 CN CN202411548041.4A patent/CN119393269A/en active Pending
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