Background
The common rail oil injector generally comprises an electromagnetic control valve, a metering valve sealing mechanism, a metering valve, a control valve sleeve and a needle valve, wherein the electromagnetic control valve, the metering valve sealing mechanism, the metering valve, the control valve sleeve and the needle valve are distributed from top to bottom; when oil is injected in a pressure relief mode, the electromagnetic control valve is electrified, the metering valve sealing mechanism enables the oil outlet metering hole in the metering valve to be opened under the action of the electromagnetic control valve, at the moment, the amount of fuel entering the control valve sleeve through the oil inlet metering hole is smaller than the amount of fuel flowing out of the oil outlet metering hole, the pressure of the fuel in the control valve sleeve is rapidly reduced, the needle valve is jacked up by high-pressure fuel at the lower part, and the nozzle is opened; when the electromagnetic control valve is closed to store pressure, the electromagnetic control valve is powered off, the metering valve sealing mechanism closes an oil outlet metering hole in the metering valve, fuel oil flowing into the control valve sleeve through the oil inlet metering hole enables the pressure of the fuel oil in the control valve sleeve to be rapidly increased, the pressure of the fuel oil at the upper part and the lower part of the needle valve is gradually balanced, the needle valve falls under the action of the reset spring, and the nozzle is closed;
there are problems in that: based on the prior art, in order to achieve a better combustion effect, in the oil injection process, the needle valve can be preferably enabled to move upwards at a higher speed, so that a large amount of fuel oil can be rapidly sprayed out to participate in combustion within a very short time, and in the closing process, the needle valve can also be preferably enabled to move downwards at a higher speed, so that a nozzle can be rapidly closed, and the situation that the fuel oil still enters a combustion chamber to be insufficiently combusted when the combustion process is finished is avoided;
because only one normally open oil inlet metering hole is arranged on the control valve sleeve, the amount of fuel oil entering the control valve sleeve cannot be dynamically adjusted, the movement speed of the needle valve is limited, and the opening and closing speeds of the nozzle are not ideal.
SUMMERY OF THE UTILITY MODEL
Aiming at the problems in the background art, the utility model provides a common rail oil sprayer with a quick switching function, which comprises an oil sprayer body, wherein an electromagnetic control valve, a transition gasket, a metering valve and a control valve sleeve are sequentially arranged in an inner cavity of the oil sprayer body from top to bottom; an installation cavity axially penetrating through the transition gasket is arranged in the transition gasket, and an armature mechanism is arranged in the installation cavity; the armature mechanism comprises an armature shaft, an armature and a first reset spring, the armature is arranged in the installation cavity, the middle part of the installation cavity is provided with a limiting surface, the first reset spring is arranged between the lower end surface and the limiting surface of the armature, the armature shaft is sleeved in an inner hole of the armature, and the upper end of the armature shaft is in transmission connection with a control spring in the electromagnetic control valve; an oil outlet metering hole is arranged in the metering valve, and a steel ball is tightly propped against the conical surface of the upper port of the oil outlet metering hole by the lower end of the armature shaft; a needle valve is sleeved in an inner hole of the control valve sleeve, a limiting ring is arranged in the middle of the needle valve, a second return spring is arranged between the control valve sleeve and the limiting ring, and the second return spring enables the control valve sleeve to be tightly abutted against the lower end face of the metering valve;
the innovation lies in that: the inner hole of the control valve sleeve sequentially forms a control section, a guide section and a spring mounting section from top to bottom; the inner diameter of the control section is larger than that of the guide section, and the inner diameter of the guide section is smaller than that of the spring mounting section; a supporting surface is formed at the junction of the guide section and the spring mounting section, and the upper end of the second return spring is contacted with the supporting surface;
an oil inlet metering hole and an oil inlet adjusting hole are formed in the inner wall of the through hole; the axial direction of the oil inlet metering hole is coincided with the radial direction of the through hole, the inner port of the oil inlet metering hole is positioned on the side wall of the control section, the outer port of the oil inlet metering hole is communicated with the outer wall of the control valve sleeve, and the position of the oil inlet metering hole is close to the guide section; the axial direction of the oil inlet adjusting hole is coincided with the radial direction of the through hole, the inner port of the oil inlet adjusting hole is positioned on the side wall of the guide section, the outer port of the oil inlet adjusting hole is communicated with the outer wall of the control valve sleeve, and the position of the oil inlet adjusting hole is close to the control section;
the upper part of the needle valve forms a guide area, the outer diameter of the upper section of the guide area is smaller than that of the lower section of the guide area, an annular step is formed at the junction of the upper section of the guide area and the lower section of the guide area, and the outer diameter of the lower section of the guide area is matched with the inner diameter of the guide section;
when the upper end surface of the needle valve is contacted with the lower end surface of the metering valve, the inner port of the oil inlet metering hole is opposite to the upper section of the guide area, and the lower section of the guide area seals the inner port of the oil inlet adjusting hole;
when the needle valve is located at the downward maximum stroke position, the inner port of the oil inlet adjusting hole is opposite to the upper section of the guide area.
The utility model discloses a common rail injector's structure and basic operating principle are different from prior art by a bit, the utility model discloses an innovation point lies in the structure that has changed the control valve barrel, and the operating principle of the control valve barrel of new construction is:
when oil is not injected, the needle valve (under the action of the second return spring) is positioned at the downward maximum stroke position, the armature and the armature shaft (under the action of the control spring) are also positioned at the downward maximum stroke position, at the moment, the armature shaft (a ball seat is also arranged between the armature shaft and the steel ball during specific implementation) tightly supports the steel ball on the conical surface of the upper port of the oil outlet metering hole, the oil outlet metering hole is in a closed state, and the oil inlet metering hole and the oil inlet adjusting hole can communicate the through hole with the outer wall of the control valve sleeve;
when oil is injected, the electromagnetic control valve is electrified, the armature is upwards sucked by the electromagnetic control valve, so that the armature shaft is upwards lifted, the upper part of the steel ball loses support, high-pressure fuel in the oil outlet metering hole jacks up the steel ball, the oil outlet metering hole is opened, the fuel is outwards discharged through the oil outlet metering hole, the pressure of the fuel in the control valve sleeve is rapidly reduced as the quantity of the fuel discharged from the oil outlet metering hole is larger than that of the fuel entering from the oil inlet metering hole and the oil inlet adjusting hole, the needle valve is jacked up by the high-pressure fuel at the lower part, and the nozzle is opened; in the process, along with the upward movement of the needle valve, the lower section of the guide area gradually shields the oil inlet adjusting hole until the oil inlet adjusting hole is completely closed, so that the amount of fuel entering the control valve sleeve is gradually reduced, the difference value between the amount of fuel flowing out of the oil outlet metering hole and the amount of fuel entering the control valve sleeve is further increased, correspondingly, the fuel pressure difference between the upper end and the lower end of the needle valve is further increased, the needle valve can quickly move upward, the nozzle quickly reaches the maximum opening state, and a large amount of fuel is quickly sprayed out and participates in combustion;
when the oil injection state is converted into the closed state, the electromagnetic control valve is powered off, the armature and the armature shaft (under the action of the control spring) reset downwards, the armature shaft tightly supports the steel ball on the conical surface of the upper port of the oil outlet metering hole again, the oil outlet metering hole is closed, high-pressure fuel oil entering the control valve sleeve through the oil inlet metering hole enables the pressure in the control valve sleeve to rise rapidly, and the needle valve moves downwards along with the high-pressure fuel oil; in the process, along with descending of the needle valve, the lower section of the guide area can gradually open the oil inlet adjusting hole until the oil inlet adjusting hole is completely opened, and along with the opening of the oil inlet adjusting hole, the fuel oil quantity entering the control valve sleeve can be gradually increased, so that the rising speed of the oil pressure in the control valve sleeve is increased, the needle valve can descend at a high speed, and the nozzle is quickly closed.
After the scheme is adopted, when the common rail oil sprayer works, along with the movement of the needle valve, the device can automatically and dynamically adjust the fuel quantity entering the control valve sleeve, so that the ascending speed and the descending speed of the needle valve are greatly improved, the combustion effect of the fuel can be finally improved, and the operation of an engine is more economic and environment-friendly.
Preferably, the oil inlet metering hole and the oil inlet adjusting hole are symmetrically arranged along the axis of the through hole. The optimal scheme can avoid the excessive concentration of the pore channel structure and is favorable for stress balance.
The utility model has the beneficial technical effects that: the proposal provides the common rail oil sprayer with the rapid switching function, can effectively improve the spraying effect of the common rail oil sprayer, improves the economical efficiency of the operation of an engine, and is beneficial to environmental protection.
Detailed Description
A common rail oil injector with a quick switching function comprises an oil injector body A, wherein an electromagnetic control valve B, a transition gasket C, a metering valve D and a control valve sleeve 1 are sequentially arranged in an inner cavity of the oil injector body A from top to bottom; an installation cavity axially penetrating through the transition gasket C is arranged in the transition gasket C, and an armature mechanism is arranged in the installation cavity; the armature mechanism comprises an armature shaft, an armature and a first reset spring, the armature is arranged in the installation cavity, the middle part of the installation cavity is provided with a limiting surface, the first reset spring is arranged between the lower end surface and the limiting surface of the armature, the armature shaft is sleeved in an inner hole of the armature, and the upper end of the armature shaft is in transmission connection with a control spring in the electromagnetic control valve B; an oil outlet metering hole is formed in the metering valve D, and a steel ball is tightly propped against the conical surface of the upper port of the oil outlet metering hole by the lower end of the armature shaft; a needle valve is sleeved in an inner hole of the control valve sleeve 1, a limiting ring is arranged in the middle of the needle valve, a second return spring is arranged between the control valve sleeve 1 and the limiting ring, and the second return spring enables the control valve sleeve 1 to be tightly abutted against the lower end face of the metering valve D;
the innovation lies in that: an inner hole of the control valve sleeve 1 sequentially forms a control section 2, a guide section 3 and a spring mounting section 4 from top to bottom; the inner diameter of the control section 2 is larger than that of the guide section 3, and the inner diameter of the guide section 3 is smaller than that of the spring mounting section 4; a supporting surface is formed at the junction of the guide section 3 and the spring mounting section 4, and the upper end of the second return spring is contacted with the supporting surface;
an oil inlet metering hole 5 and an oil inlet adjusting hole 6 are formed in the inner wall of the through hole; the axial direction of the oil inlet metering hole 5 is coincided with the radial direction of the through hole, the inner port of the oil inlet metering hole 5 is positioned on the side wall of the control section 2, the outer port of the oil inlet metering hole 5 is communicated with the outer wall of the control valve sleeve 1, and the position of the oil inlet metering hole 5 is close to the guide section 3; the axial direction of the oil inlet adjusting hole 6 is coincided with the radial direction of the through hole, the inner port of the oil inlet adjusting hole 6 is positioned on the side wall of the guide section 3, the outer port of the oil inlet adjusting hole 6 is communicated with the outer wall of the control valve sleeve 1, and the position of the oil inlet adjusting hole 6 is close to the control section 2;
the upper part of the needle valve forms a guide area, the outer diameter of the upper section of the guide area is smaller than that of the lower section of the guide area, an annular step is formed at the junction of the upper section of the guide area and the lower section of the guide area, and the outer diameter of the lower section of the guide area is matched with the inner diameter of the guide section 3;
when the upper end surface of the needle valve is contacted with the lower end surface of the metering valve D, the inner port of the oil inlet metering hole 5 is opposite to the upper section of the guide area, and the lower section of the guide area seals the inner port of the oil inlet adjusting hole 6;
when the needle valve is located at the downward maximum stroke position, the inner port of the oil feed adjusting hole 6 is opposed to the guide area upper section.
Further, the oil inlet metering hole 5 and the oil inlet adjusting hole 6 are symmetrically arranged along the axis of the through hole.