High-pressure oil pump adopting oil inlet valve outage closing type flow metering valve

Abstract

The utility model discloses a high-pressure oil pump adopting an oil inlet valve power-off closing type flow metering valve. A flow metering electromagnetic valve and an armature sheet are arranged close to the top of an oil inlet valve of the high-pressure oil pump. When the flow metering electromagnetic valve is powered on, the oil inlet valve is in an open state, and the armature sheet is close to the flow metering electromagnetic valve, namely the position with the minimum magnetic gap. When the oil inlet valve is closed, the action of the armature sheet does not need to be driven by the flow metering electromagnetic valve, so that the flow metering electromagnetic valve only needs extremely small electromagnetic attraction force, the size can be smaller, the electronic controller only needs to provide extremely small driving current, and the comprehensive cost of the system is reduced. The oil inlet valve outage closing type flow metering device is high in pumping efficiency and low in system comprehensive cost.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of high-pressure fuel pumps for engine with pressure accumulation type fuel injection, especially a kind of high-pressure fuel pump with inlet valve power-off closing type flow metering valve. BACKGROUND

[0002] High-pressure fuel pump for engine with pressure accumulation type fuel injection is a device that pressurizes the fuel in the compression chamber on the top of plunger and outputs high-pressure fuel outward by plunger movement.

[0003] The compression chamber is connected with inlet valve and outlet valve, and both of them are one-way valves. The plunger is driven by cam, and when the plunger goes down, low-pressure fuel enters the compression chamber through the inlet valve, and when the plunger goes up, the fuel is pressurized, and high-pressure fuel is outputted outward through the outlet valve.

[0004] In addition to pressurization, high-pressure fuel pump also needs to control the size of high-pressure fuel output flow and pressure according to the real-time needs of the system, which is realized by electric control flow metering device. There are three types of flow metering devices on high-pressure fuel pump to control the flow and pressure of high-pressure fuel.

[0005] 1. High-pressure relief type. This flow metering device is installed after the outlet valve to relieve excess high pressure. This control method has extremely low pumping efficiency, high cost and poor reliability, and has been eliminated.

[0006] 2. Inlet throttling type. This flow metering device is installed before the inlet valve, which uses proportional solenoid valve to adjust the throttling area of fuel passage, to control the size of fuel flow entering the plunger of high-pressure fuel pump, and then control the output pressure. This form is the current mainstream, but its pressure control response speed is slow, and there is efficiency loss and cavitation risk in inlet throttling, and the cost of proportional valve is relatively high.

[0007] 3. Inlet valve power-on closing type. This flow metering device is installed on the inlet valve, and the armature core is arranged between the electromagnetic valve coil and the inlet valve one-way sealing line. Under normal circumstances, the armature core is lifted to open the inlet valve under the spring force, so that it remains open. When the plunger of the fuel pump goes up, the fuel flows back to the low-pressure oil circuit from the inlet valve, and no high-pressure fuel is generated outward. When the electromagnetic valve is powered on, the armature core is separated from the inlet valve, so that the inlet valve is closed under the double action of the pressure difference between inside and outside and the spring of the inlet valve. The fuel is pressurized and outputted to the high-pressure oil circuit through the outlet valve. By adjusting the closing time of the inlet valve, the size of high-pressure fuel output flow and pressure is realized. This form has high pumping efficiency, but the electromagnetic valve needs a lot of driving force to close, the size of the electromagnetic valve is large, and the electronic controller needs to provide a lot of driving current, so the comprehensive cost of the system is high.

[0008] In summary, the high-pressure fuel pump with existing flow metering device cannot balance the pressure control response speed and pumping efficiency, and the comprehensive cost is relatively high. SUMMARY

[0009] The present application aims to provide a high-pressure fuel pump with an oil inlet valve power-off closing type flow metering valve, which takes into account the pressure control response speed and pumping efficiency, and reduces the overall cost by reducing the driving current.

[0010] To achieve this purpose, the present application adopts the following technical solutions.

[0011] The present application provides a high-pressure fuel pump with an oil inlet valve power-off closing type flow metering valve. The high-pressure fuel pump comprises a pump body, a camshaft, a plunger and a high-pressure module. The plunger is arranged in the compression chamber of the high-pressure module and can reciprocate along the axial direction of the plunger. An oil inlet valve and an oil outlet valve are arranged adjacent to the top of the compression chamber. The oil inlet valve, under the action of an oil inlet spring, keeps the fuel flowing from the oil inlet port outside the oil inlet valve to the compression chamber in a one-way manner. The oil outlet valve, under the action of an oil outlet spring, keeps the fuel flowing from the compression chamber to the high-pressure oil outlet port outside in a one-way manner.

[0012] A flow metering solenoid valve and an armature plate are arranged adjacent to the top of the oil inlet valve of the high-pressure fuel pump. There is a small magnetic gap between the flow metering solenoid valve and the armature plate. The coil of the flow metering solenoid valve is arranged between the one-way sealing line of the oil inlet valve and the armature plate. When the flow metering solenoid valve is powered on, the electromagnetic force generated by the flow metering solenoid valve attracts the armature plate, which presses the stem of the oil inlet valve, keeping the oil inlet valve always open. When the plunger goes up, the fuel in the compression chamber flows back to the oil inlet port outside from the oil inlet valve, without generating high-pressure fuel. When the flow metering solenoid valve is powered off, the electromagnetic force disappears, and the oil inlet valve restores the one-way flow tendency.

[0013] By controlling the power-off time of the flow metering solenoid valve, the output flow size and pressure of the high-pressure fuel can be controlled. When the flow metering solenoid valve is powered on, the oil inlet valve is in an open state, and the armature plate is already in the position closest to the flow metering solenoid valve, i.e., the smallest magnetic gap. When the oil inlet valve is closed, the action of the armature plate does not need to be driven by the flow metering solenoid valve. Therefore, the flow metering solenoid valve only needs a very small electromagnetic force, and the size can be made smaller. The electronic controller only needs to provide a very small driving current, which is conducive to reducing the overall cost of the system. This oil inlet valve power-off closing type flow metering device has high pumping efficiency and low overall system cost.

[0014] Preferably, the high-pressure fuel pump comprises a pair of plunger arranged in parallel, each plunger is equipped with a respective oil inlet valve, and the pair of oil inlet valves are arranged in parallel. The flow metering solenoid valve is arranged between the two oil inlet valves, and the middle part of the armature plate faces the flow metering solenoid valve, pressing the stems of the two oil inlet valves respectively.

[0015] When one plunger is ascending and the flow metering solenoid is energized, the oil inlet valve is in the open state at this time, the plunger will not deliver high pressure fuel to the outside, and the other plunger is in the descending stroke, and the oil inlet valve is also in the open state, and the energization of the flow metering solenoid will not affect the oil inlet valve.

[0016] When one plunger is ascending and the flow metering solenoid is de-energized, the oil inlet valve is closed under the action of the internal and external pressure difference and the spring force, the plunger delivers high pressure fuel to the outside, and the armature plate is pushed away from the flow metering solenoid by the oil inlet valve rod. At this time, the other plunger is still in the descending stroke, and the oil inlet valve is in the open state under the action of the internal and external pressure difference, and the de-energization of the flow metering solenoid will not affect the oil inlet valve.

[0017] It can be seen that a pair of plungers can share a flow metering solenoid, and will not interfere with each other, and the cost is lower.

[0018] The beneficial effects of the present application are:

[0019] By adopting the flow metering device of the oil inlet valve de-energization closing type, the pressure control response speed and the pumping efficiency are considered, the driving current is reduced, the electronic controller driving circuit is simplified, and the system comprehensive cost is realized. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a schematic diagram of a high pressure oil pump with a single plunger according to an embodiment of the present application.

[0021] Figure 2 is a schematic diagram of a high pressure oil pump with a pair of plungers according to an embodiment of the present application.

[0022] In the figure: 1-pump body; 2-camshaft; 3 / 3'-plunger; 4 / 4'-oil inlet valve; 5 / 5'-oil outlet valve; 6 / 6'-high pressure oil outlet; 7-flow metering solenoid; 8 / 8'-oil inlet spring; 9-armature plate; 10 / 10'-oil inlet; 11 / 11'-compression chamber; 12-high pressure module. DETAILED DESCRIPTION

[0023] The present application will be further described in detail below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, and not to limit the present application. In addition, it should be noted that, in order to facilitate description, only the parts related to the present application are shown in the drawings, but not all structures.

[0024] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0025] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0026] In the description of the present embodiment, the terms "up", "down", "left", "right" and other orientation or position relationships are based on the orientation or position relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only used to distinguish in description and have no special meaning. Embodiment

[0027] As Figure 1 shown in the first embodiment, a high-pressure oil pump using an oil inlet valve power-off closing type flow metering valve. The high-pressure oil pump comprises a pump body 1, a camshaft 2, a plunger 3 and a high-pressure module 12. The plunger 3 is arranged in the compression chamber 11 of the high-pressure module 12 and can reciprocate along the axial direction of the plunger 3, and the oil inlet valve 4 and the oil outlet valve 5 are arranged adjacent to the top of the compression chamber 11: the oil inlet valve 4 is under the action of the oil inlet spring 8, so that the fuel maintains the tendency of one-way flow from the oil inlet valve 4 external oil inlet 10 to the compression chamber 11; the oil outlet valve 5 is under the action of the oil outlet spring, so that the fuel maintains the tendency of one-way flow from the compression chamber 11 to the external high-pressure oil outlet 6.

[0028] The high-pressure oil pump inlet valve 4 top is equipped with a flow metering solenoid valve 7 and an armature plate 9, the flow metering solenoid valve 7 and the armature plate 9 have a small magnetic gap therebetween, the flow metering solenoid valve 7 coil is arranged between the inlet valve 4 one-way sealing line and the armature plate 9. When the flow metering solenoid valve 7 is energized, the generated electromagnetic force attracts the armature plate 9, the armature plate 9 presses the inlet valve 4 rod, so that the inlet valve 4 always maintains the tendency to open, when the plunger 3 goes up, the fuel in the compression chamber 11 flows back to the external inlet 10 from the inlet valve 4, and high-pressure fuel is not generated; when the flow metering solenoid valve 7 is de-energized, the electromagnetic force disappears, and the inlet valve 4 restores the tendency to one-way flow.

[0029] By controlling the de-energization time of the flow metering solenoid valve 7, the control of the size of the high-pressure fuel output flow is realized. When the flow metering solenoid valve 7 is energized, the inlet valve 4 is in an open state, and the armature plate 9 is already in the position closest to the flow metering solenoid valve 7, i.e. the smallest magnetic gap. When the inlet valve 4 is closed, the action of the armature plate 9 does not need to be driven by the flow metering solenoid valve 7, so the flow metering solenoid valve 7 only needs a very small electromagnetic force, and the size can be made smaller, and the electronic controller only needs to provide a very small driving current, which is conducive to reducing the overall cost of the system. This flow metering device with the de-energized closed type inlet valve 4 has high pumping efficiency and low overall system cost.

[0030] Figure 2 In another embodiment shown, the high-pressure oil pump includes a pair of plungers 3, 3' arranged in parallel, each plunger 3, 3' is equipped with a respective inlet valve 4, 4', and the pair of inlet valves 4, 4' are also arranged in parallel, the flow metering solenoid valve 7 is arranged between the two inlet valves 4, 4', and the middle of the armature plate 9 is towards the flow metering solenoid valve 7, and the left and right armature plates 9 press the rod portions of the two inlet valves 4, 4' respectively.

[0031] The working strokes of the pair of plungers 3, 3' arranged in parallel are staggered by 180 degrees, i.e. one plunger 3, 3' is in the upstroke while the other is in the downstroke.

[0032] When the plunger 3 goes up and the flow metering solenoid valve 7 is energized, the inlet valve 4 is in an open state at this time, the plunger 3 will not deliver high-pressure fuel to the outside, and the other plunger 3' is in the downstroke, and its inlet valve 4' is also in an open state, and the energization of the flow metering solenoid valve 7 will not affect the inlet valve 4'.

[0033] When the plunger 3 goes up and the flow metering solenoid valve 7 is de-energized, the inlet valve 4 is closed under the action of the internal and external pressure difference and the spring force, the plunger 3 delivers high-pressure fuel to the outside, and the side of the armature plate 9 close to the inlet valve 4 is pushed away from the flow metering solenoid valve 7 by the inlet valve 4. At this time, the other plunger 3' is still in the downstroke, and its inlet valve 4' is in an open state under the action of the internal and external pressure difference, and the de-energization of the flow metering solenoid valve 7 will not affect the inlet valve 4'.

[0034] It can be seen that the pair of plungers 3, 3' can share one flow metering electromagnetic valve 7, and do not interfere with each other, and the cost is lower.

[0035] By using the flow metering device of the oil inlet valve power-off closing type, the pressure control response speed and the pumping efficiency are considered, the driving current is reduced, the electronic controller driving circuit is simplified, and the lower system comprehensive cost is realized.

[0036] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the implementation modes of the present application. For those skilled in the art, various obvious changes, re-adjustments and replacements can be made without departing from the protection scope of the present application. It is unnecessary and impossible to enumerate all the implementation modes. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A high pressure fuel pump with fuel inlet valve power off closing type flow metering valve, comprising a pump body (1), a cam shaft (2), a plunger (3, 3') and a high pressure module (12), characterized in that: the plunger (3, 3') is arranged in the compression chamber (11, 11') of the high pressure module (12) and can reciprocate along the axial direction of the plunger (3, 3'), and the fuel inlet valve (4, 4') and the fuel outlet valve (5, 5') are arranged adjacent to the top of the compression chamber (11, 11'); the fuel inlet valve (4, 4') is under the action of the fuel inlet spring (8, 8'), so that the fuel maintains a one-way flow trend from the fuel inlet valve (4, 4') external inlet (10, 10') to the compression chamber (11, 11'); the fuel outlet valve (5, 5') is under the action of the fuel outlet spring, so that the fuel maintains a one-way flow trend from the compression chamber (11, 11') to the external high pressure outlet (6, 6'); A flow metering solenoid valve (7) and a armature plate (9) are arranged adjacent to the top of the high pressure fuel pump fuel inlet valve (4, 4'), there is a small magnetic gap between the flow metering solenoid valve (7) and the armature plate (9), and the coil of the flow metering solenoid valve (7) is arranged between the one-way sealing line of the fuel inlet valve (4, 4') and the armature plate (9); when the flow metering solenoid valve (7) is powered on, the electromagnetic force generated by the flow metering solenoid valve (7) attracts the armature plate (9), the armature plate (9) presses the rod part of the fuel inlet valve (4, 4'), so that the fuel inlet valve (4, 4') always maintains an open trend, when the plunger (3, 3') goes up, the fuel in the compression chamber (11, 11') flows back to the external inlet (10, 10') from the fuel inlet valve (4, 4') against the flow, and high pressure fuel is not generated; when the flow metering solenoid valve (7) is powered off, the electromagnetic force disappears, and the fuel inlet valve (4, 4') restores the one-way flow trend. The high pressure fuel pump comprises a pair of said plungers (3, 3') arranged side by side, each plunger (3, 3') is equipped with a respective said fuel inlet valve (4, 4'), and a pair of fuel inlet valves (4, 4') are also arranged side by side, the flow metering solenoid valve (7) is arranged between the two fuel inlet valves (4, 4'), the middle part of the armature plate (9) faces the flow metering solenoid valve (7), and the left and right armature plates (9) respectively press the rod parts of the two fuel inlet valves (4, 4'); the working stroke of the pair of plungers (3, 3') arranged side by side is staggered by 180 degrees, that is, when one plunger (3) goes up, the other plunger (3') is in the down stroke.

2. A high pressure fuel pump employing an on-off type flow metering valve with an oil feeding valve according to claim 1, characterized in that: ​

Images