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

Abstract

The invention 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 invention relates to a pressure accumulator fuel injection high-pressure oil pump for an engine, in particular to a high-pressure oil pump using a flow metering valve with a power-off closing type of an oil inlet valve. Background Art

[0002] The accumulator fuel injection high-pressure oil pump for the engine is a device that pressurizes the fuel in the compression chamber at the top of the plunger through the movement of the plunger and outputs the high-pressure fuel to the outside.

[0003] The compression chamber is connected to the inlet valve and the outlet valve, both of which are one-way valves. The plunger is driven by a cam. When the plunger moves downward, low-pressure fuel enters the compression chamber through the inlet valve. When the plunger moves upward, the fuel is pressurized and the high-pressure fuel is output through the outlet valve.

[0004] In addition to pressurization, the high-pressure fuel pump also needs to control the output flow and pressure of the high-pressure fuel according to the real-time needs of the system. This is achieved through an electronically controlled flow metering device. There are three types of flow metering devices on the high-pressure fuel pump that control the flow and pressure of the high-pressure fuel.

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

[0006] 2. Inlet throttling type. This flow metering device is installed before the inlet valve and uses a proportional solenoid valve to adjust the throttling area of ​​the fuel channel to control the fuel flow into the high-pressure oil pump plunger, thereby controlling the output pressure. This form is the current mainstream, but its pressure control response speed is slow, the inlet throttling has efficiency loss and cavitation risks, and the proportional valve cost is relatively high.

[0007] 3. The oil inlet valve is powered on and closed. This flow metering device is installed on the oil inlet valve, and the armature core is arranged between the solenoid valve coil and the one-way sealing line of the oil inlet valve. Under normal conditions, the armature core pushes the oil inlet valve open under the force of the spring, so that it remains normally open. When the oil pump plunger moves upward, the fuel flows back from the oil inlet valve to the low-pressure oil circuit, and no high-pressure fuel is generated outward. When the solenoid valve is powered on, the armature core is separated from the oil inlet valve, so that the oil inlet valve is closed under the dual action of the internal and external pressure difference and the oil inlet valve spring, and the fuel is pressurized and output to the high-pressure oil circuit through the oil outlet valve. By adjusting the closing time of the oil inlet valve, the output flow rate and pressure of the high-pressure fuel can be controlled. This form has high pumping efficiency, but the solenoid valve needs a large driving force to close, the solenoid valve is large in size, and the electronic controller needs to provide a large driving current, and the overall system cost is high.

[0008] In summary, the high-pressure oil pump using the existing flow metering device cannot take into account both the pressure control response speed and the pumping efficiency, and the overall cost is relatively high. Summary of the Invention

[0009] The object of the present invention is to provide a high-pressure oil pump using an inlet valve that closes when power is cut off for a flow metering valve, taking into account both the pressure control response speed and the pumping efficiency, and reducing the comprehensive cost by reducing the driving current.

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

[0011] The present invention provides a high-pressure oil pump using an inlet valve that closes when power is cut off for a flow metering valve. The high-pressure oil pump includes 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 inlet valve and an outlet valve are arranged adjacent to the top of the compression chamber: under the action of the inlet spring, the inlet valve keeps the fuel flowing unidirectionally from the external inlet of the inlet valve to the compression chamber; under the action of the outlet spring, the outlet valve keeps the fuel flowing unidirectionally from the compression chamber to the external high-pressure outlet.

[0012] Adjacent to the top of the inlet valve of the high-pressure oil pump, a flow metering solenoid valve and an armature are installed. There is a small magnetic gap between the flow metering solenoid valve and the armature, and the coil of the flow metering solenoid valve is arranged between the one-way sealing line of the inlet valve and the armature. When the flow metering solenoid valve is energized, the electromagnetic force generated attracts the armature, and the armature presses on the rod part of the inlet valve, keeping the inlet valve always in an open tendency. When the plunger moves upward, the fuel in the compression chamber flows back reversely to the external inlet through the inlet valve, and no high-pressure fuel is generated; when the flow metering solenoid valve is powered off, the electromagnetic force disappears, and the inlet valve resumes the tendency of one-way flow.

[0013] By controlling the power-off moment of the flow metering solenoid valve, the control of the output flow rate and pressure of the high-pressure fuel is achieved. When the flow metering solenoid valve is energized, the inlet valve is in an open state, and the armature is already in the position closest to the flow metering solenoid valve, that is, the magnetic gap is the smallest. When the inlet valve closes, the movement of the armature does not need to be driven by the flow metering solenoid valve. Therefore, the flow metering solenoid valve only requires a very small electromagnetic suction force, and its size can be made smaller. The electronic controller only needs to provide a very small driving current, which is beneficial to reducing the system comprehensive cost. This type of flow metering device with an inlet valve that closes when power is cut off has high pumping efficiency and low system comprehensive cost.

[0014] Preferably, the high-pressure oil pump includes a pair of juxtaposed plungers. Each plunger is equipped with its own inlet valve, and the pair of inlet valves are also arranged in parallel. The flow metering solenoid valve is arranged between the two inlet valves. The middle part of the armature faces the flow metering solenoid valve, and presses on the rod parts of the two inlet valves, one on the left and the other on the right. The working strokes of the pair of juxtaposed plungers are staggered by 180 degrees, that is, when one plunger is in the upward stroke, the other plunger is in the downward stroke.

[0015] When a plunger moves upward and the flow metering solenoid valve is energized, the inlet valve is in the open state at this time, and the plunger will not deliver high-pressure fuel externally. Another plunger is in the downward stroke, and its inlet valve is also in the open state. Energizing the flow metering solenoid valve will not affect this inlet valve.

[0016] When a plunger moves upward and the flow metering solenoid valve is de-energized, the inlet valve closes under the action of the internal and external pressure difference and the spring force at this time. The plunger delivers high-pressure fuel externally, and the armature plate is pushed away from the flow metering solenoid valve by the inlet valve rod. At this time, another plunger is still in the downward stroke, and its inlet valve is in the open state under the action of the internal and external pressure difference. De-energizing the flow metering solenoid valve will not affect this inlet valve either.

[0017] It can be seen that a pair of plungers can share a flow metering solenoid valve without interfering with each other, resulting in lower costs.

[0018] Advantages of the present invention: By adopting a flow metering device with a power-off closed inlet valve, the pressure control response speed and pumping efficiency are taken into account. By reducing the drive current, the drive circuit of the electronic controller is simplified, and a lower overall system cost is achieved. Description of the drawings

[0019] Figure 1 is a schematic diagram of the structure of a high-pressure oil pump with a single plunger in Embodiment 1 of the present invention.

[0020] Figure 2 is a schematic diagram of the structure of a high-pressure oil pump with a pair of plungers in Embodiment 2 of the present invention.

[0021] In the figure: 1 - pump body; 2 - camshaft; 3 / 3' - plunger; 4 / 4' - inlet valve; 5 / 5' - outlet valve; 6 / 6' - high-pressure oil outlet; 7 - flow metering solenoid valve; 8 / 8' - inlet spring; 9 - armature plate; 10 / 10' - inlet port; 11 / 11' - compression chamber; 12 - high-pressure module. Detailed implementation manners

[0022] The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the sake of description, only parts related to the present invention are shown in the drawings rather than all the structures.

[0023] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over", and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath", and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0025] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "left", and "right" are based on the orientation or positional relationships shown in the drawings. It is only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning. Embodiment

[0026] As Figure 1 Shown in Embodiment 1, a high-pressure oil pump adopting an oil inlet valve that closes when powered off. The high-pressure oil pump includes 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 axially along the plunger 3. An oil inlet valve 4 and an oil outlet valve 5 are arranged adjacent to the top of the compression chamber 11: under the action of the oil inlet spring 8, the oil inlet valve 4 makes the fuel maintain a tendency of unidirectional flow from the external oil inlet 10 of the oil inlet valve 4 to the compression chamber 11; under the action of the oil outlet spring, the oil outlet valve 5 makes the fuel maintain a tendency of unidirectional flow from the compression chamber 11 to the external high-pressure oil outlet 6.

[0027] At the top of the inlet valve 4 of the high-pressure oil pump, there is a flow measurement solenoid valve 7 and an armature plate 9. There is a tiny magnetic gap between the flow measurement solenoid valve 7 and the armature plate 9. The coil of the flow measurement solenoid valve 7 is arranged between the one-way seal line of the inlet valve 4 and the armature plate 9. When the flow measurement solenoid valve 7 is energized, the electromagnetic force generated attracts the armature plate 9, and the armature plate 9 presses against the rod part of the inlet valve 4, making the inlet valve 4 always tend to be open. When the plunger 3 moves upward, the fuel in the compression chamber 11 flows back from the inlet valve 4 to the external inlet port 10 in reverse, and no high-pressure fuel will be generated; when the flow measurement solenoid valve 7 is de-energized, the electromagnetic force disappears, and the inlet valve 4 resumes the trend of one-way flow.

[0028] By controlling the de-energization moment of the flow measurement solenoid valve 7, the control of the output flow rate of the high-pressure fuel is achieved. When the flow measurement solenoid valve 7 is energized, the inlet valve 4 is in the open state, and the armature plate 9 is already in the position closest to the flow measurement solenoid valve 7, that is, the magnetic gap is the smallest. When the inlet valve 4 closes, the movement of the armature plate 9 does not need to be driven by the flow measurement solenoid valve 7. Therefore, the flow measurement solenoid valve 7 only requires a very small electromagnetic force and can be made smaller in size. The electronic controller only needs to provide a very small driving current, which is beneficial to reducing the overall system cost. This flow measurement device with the inlet valve 4 closing when de-energized has high pumping efficiency and relatively low overall system cost.

[0029] Figure 2 In another embodiment shown, the high-pressure oil pump includes a pair of juxtaposed plungers 3, 3'. Each plunger 3, 3' is equipped with its own inlet valve 4, 4', and the pair of inlet valves 4, 4' are also arranged side by side. The flow measurement solenoid valve 7 is arranged between the two inlet valves 4, 4'. The middle of the armature plate 9 faces the flow measurement solenoid valve 7, and presses against the rod parts of the two inlet valves 4, 4' from left to right respectively.

[0030] The working strokes of the pair of juxtaposed plungers 3, 3' are staggered by 180 degrees, that is, when one plunger 3, 3' is in the upward stroke, the other is in the downward stroke.

[0031] When the plunger 3 moves upward and the flow measurement solenoid valve 7 is energized, at this time the inlet valve 4 is in the open state, and the plunger 3 will not deliver high-pressure fuel to the outside. And the other plunger 3' is in the downward stroke, and its inlet valve 4' is also in the open state. The energization of the flow measurement solenoid valve 7 will not affect this inlet valve 4'.

[0032] When the plunger 3 moves upward and the flow measurement solenoid valve 7 is de-energized, at this time the inlet valve 4 closes under the action of the internal and external pressure difference and the spring force, and the plunger 3 delivers high-pressure fuel to the outside. The side of the armature plate 9 close to the inlet valve 4 is pushed away from the flow measurement solenoid valve 7 by the inlet valve 4. At this time, the other plunger 3' is still in the downward stroke, and its inlet valve 4' is in the open state under the action of the internal and external pressure difference. The de-energization of the flow measurement solenoid valve 7 will not affect this inlet valve 4' either.

[0033] It can be seen that a pair of plungers 3 and 3' can share a flow metering solenoid valve 7 without interfering with each other, resulting in lower costs.

[0034] By adopting a flow metering device with a power-off closed inlet valve, the pressure control response speed and pumping efficiency are taken into account. By reducing the drive current, the drive circuit of the electronic controller is simplified, achieving a lower overall system cost.

[0035] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A high-pressure oil pump using an oil inlet valve power-off closing type flow metering valve, comprising a pump body (1), a camshaft (2), a plunger (3, 3') and a high-pressure module (12), wherein: The plunger (3, 3') is arranged in the compression chamber (11, 11') of the high-pressure module (12) and can slide back and forth along the axis of the plunger (3, 3'). An oil inlet valve (4, 4') and an oil outlet valve (5, 5') are arranged adjacent to the top of the compression chamber (11, 11'): the oil inlet valve (4, 4') maintains a tendency of one-way flow of fuel from an external oil inlet (10, 10') of the oil inlet valve (4, 4') to the compression chamber (11, 11') under the action of an oil inlet spring (8, 8'); the oil outlet valve (5, 5') maintains a tendency of one-way flow of fuel from the compression chamber (11, 11') to an external high-pressure oil outlet (6, 6') under the action of an oil outlet spring; A flow metering solenoid valve (7) and an armature piece (9) are installed adjacent to the top of the high-pressure oil pump inlet valve (4, 4'). A small magnetic gap is provided between the flow metering solenoid valve (7) and the armature piece (9). The coil of the flow metering solenoid valve (7) is arranged between the one-way sealing line of the oil inlet valve (4, 4') and the armature piece (9). When the flow metering solenoid valve (7) is energized, the electromagnetic force generated attracts the armature piece (9), and the armature piece (9) presses the rod of the oil inlet valve (4, 4'), so that the oil inlet valve (4, 4') always maintains an opening tendency. When the plunger (3, 3') moves upward, the fuel in the compression chamber (11, 11') flows back from the oil inlet valve (4, 4') to the external oil inlet port (10, 10'), and no high-pressure fuel is generated. When the flow metering solenoid valve (7) is de-energized, the electromagnetic force disappears, and the oil inlet valve (4, 4') resumes a one-way flow tendency.

2. A high-pressure oil pump using an oil inlet valve power-off closing type flow metering valve according to claim 1, characterized in that: The high-pressure oil pump comprises a pair of parallel plungers (3, 3'), each plunger (3, 3') is equipped with its own oil inlet valve (4, 4'), and the pair of oil inlet valves (4, 4') are also arranged in parallel, the flow metering solenoid valve (7) is arranged between the two oil inlet valves (4, 4'), the middle part of the armature plate (9) faces the flow metering solenoid valve (7), and presses the two oil inlet valve (4, 4') rods on the left and right respectively; the working strokes of the parallel pair of plungers (3, 3') are staggered by 180 degrees, that is, when one plunger (3) is in an upward stroke, the other plunger (3') is in a downward stroke.

Images