WO2018133876A1

WO2018133876A1 - High-pressure pump

Info

Publication number: WO2018133876A1
Application number: PCT/CN2018/073787
Authority: WO
Inventors: 李卿; 伍中宇; 朱银; 董浩训
Original assignee: 联合汽车电子有限公司
Priority date: 2017-01-23
Filing date: 2018-01-23
Publication date: 2018-07-26
Also published as: EP3572664A1; CN106762299A; EP3572664B1; CN106762299B; EP3572664A4

Abstract

A high-pressure pump comprises: a pressure chamber; a piston sleeve (3) arranged inside the pressure chamber; and a protruding component (8) arranged at an outer side of the piston sleeve (3) and attached, in a manner of interference fit, to a wall of the pressure chamber. The piston sleeve (3) comprises a first section (31) and a second section (32) connected thereto. The protruding component (8) is arranged at an outer side of the second section (32) close to the first section (31), and divides the pressure chamber into a first pressure chamber (1) and a second pressure chamber (2). The first section (31) is located inside the first pressure chamber (1). By moving down the location of the protruding component (8), provided that the volumetric efficiency is unchanged, the high-pressure pump can achieve a larger piston gap and less piston pair wear during an oil suction process, and can achieve a longer service life.

Description

High-pressure pump

Technical field

The invention relates to the technical field of fuel injection pumps, and in particular to a high pressure pump.

Background technique

The high pressure pump is a key component of the direct fuel injection engine. As shown in FIG. 1 , the high pressure pump includes an oil inlet valve 5 ′, an oil outlet valve 6 ′, and an oil inlet valve 5 ′ and an oil outlet valve 6 . a pressure chamber 1' between the pressure chamber 1' disposed in the pressure chamber 1', a protruding member 8' disposed outside the one end of the plunger sleeve and connected to the pressure chamber 1', and The plunger 4' disposed inside the plunger sleeve 3' establishes pressure by the movement of the plunger 4' in the pressure chamber 1' to convert low pressure fuel into high pressure fuel (150 bar or more).

With the continuous improvement of energy saving and emission reduction requirements, the design and manufacture of high pressure pumps are also facing new challenges: under the premise of not losing weight, it is required to further increase the pump oil pressure (350 bar or more). However, with the increase of pressure, in the pumping stage, the problem that the high-pressure oil returns to the low-pressure area through the plunger gap (the sealing gap of the plunger-plunger sleeve) causes the volumetric efficiency to drop, and the problem is at a low speed. Especially in the working conditions, the low-speed oil supply capacity has become the bottleneck capacity of the higher pressure oil pump.

In order to solve the above problems, the current adopted scheme is as follows:

1. Use a larger pump oil volume to compensate for the loss caused by the decrease in volumetric efficiency;

2. Increase the length of the plunger gap to reduce the loss of backlash;

3. Reduce the machining gap of the plunger pair (plunger and plunger sleeve) (ie, the object referred to by 7' in Figure 1) to reduce the loss of backlash backflow.

Among them, the

schemes

1 and 2 are accompanied by the increase in weight and the cost increase; the scheme 3 is accompanied by the risk of accelerated wear of the plunger pair and a significant decrease in the life span, and it is required to use a material or surface treatment with better wear resistance but higher price. Process.

Summary of the invention

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high pressure pump to improve the use of prior art high pressure pumps in the presence of a plunger gap in the pumping stage where there is a problem in that high pressure oil returns to the low pressure zone, resulting in a decrease in volumetric efficiency.

In order to solve the above technical problem, the present invention provides a high pressure pump including: a pressure chamber, a plunger sleeve disposed in the pressure chamber, disposed outside the plunger sleeve and the pressure chamber a protruding member of the wall interference connection, a plunger disposed in the plunger sleeve, an oil inlet valve, and an oil outlet valve; wherein the plunger sleeve includes a first segment and a second portion connected to the first segment a protruding member disposed on an outer side of the second segment adjacent to the first segment, the protruding member dividing the pressure chamber into a first pressure chamber and a second pressure chamber, the first segment being located In the first pressure chamber, the oil inlet valve and the oil discharge valve are both disposed on the first pressure chamber.

Optionally, in the high pressure pump, the high pressure pump pumps the oil phase, and the plunger moves from the second pressure chamber to the first pressure chamber.

Optionally, in the high pressure pump, the high pressure pump oil pumping stage, the pressure in the first pressure chamber is higher than the pressure in the second pressure chamber.

Optionally, in the high-pressure pump, the high-pressure pump pumping stage, the first section of the plunger sleeve is deformed and contracted inward, between the first section of the plunger sleeve and the plunger The gap is smaller than the machining gap of the plunger pair.

Optionally, in the high pressure pump, in the high pressure pump oil phase, the pressure in the first pressure chamber decreases toward the second pressure chamber.

Optionally, in the high pressure pump, the high pressure pump sucks the phase, and the plunger moves from the first pressure chamber to the second pressure chamber.

Optionally, in the high pressure pump, the high pressure pump suction phase, the pressure in the first pressure chamber is equal to the pressure in the second pressure chamber.

Optionally, in the high pressure pump, the high pressure pump suction stage, the gap between the first section of the plunger sleeve and the plunger is equal to the second section of the plunger sleeve and the A gap between the plungers, a gap between the second section of the plunger sleeve and the plunger is a machining gap of the plunger pair.

Optionally, in the high pressure pump, the inner diameter of the first section of the plunger sleeve is the same as the inner diameter of the second section of the plunger sleeve, and the outer diameter of the first section of the plunger sleeve is The second section of the plunger sleeve has the same outer diameter.

Optionally, in the high pressure pump, the inner diameter of the first section of the plunger sleeve is the same as the inner diameter of the second section of the plunger sleeve, and the outer diameter of the first section of the plunger sleeve is The outer diameter of the second section of the plunger sleeve is different.

Optionally, in the high pressure pump, the length of the first section of the plunger sleeve and the total length of the plunger sleeve satisfy the following relationship:

Where L2 is the total length of the plunger sleeve and L1 is the length of the first section of the plunger sleeve.

Optionally, in the high pressure pump, an inner diameter of the first section of the plunger sleeve, an outer diameter of the first section of the plunger sleeve, and an outer diameter of the second section of the plunger sleeve are satisfied. The following relationship:

Wherein D1 is the inner diameter of the first section of the plunger sleeve, D2 is the outer diameter of the second section of the plunger sleeve, and D3 is the outer diameter of the first section of the plunger sleeve.

Optionally, in the high-pressure pump, the first segment and the second segment are connected by a transition section, and the section of the transition section is rounded, right-angled, oblique, multi-segmented, and multi-segmented. One, or a combination of a multi-segment curve and a multi-segment line.

In the high pressure pump provided by the present invention, the plunger sleeve of the high pressure pump includes a first segment and a second segment connected to the first segment, and the protruding member is disposed on the outer side of the second segment adjacent to the first segment, first The segment is located within the first pressure chamber and is moved downward relative to the prior art interference point position of the present invention. In the pumping stage, the first section is deformed and contracted inward under the pressure difference between the inside and the outside, and the gap between the first section and the plunger is reduced, which effectively reduces the loss of the backflow; in the oil suction stage, there is no inside or outside of the first section. The pressure difference causes the first segment to return from the contracted state to the state before the deformation. Therefore, under the premise of having the same volumetric efficiency, the high pressure pump of the present invention has a larger plunger clearance in the oil suction stroke, less plunger wear, and more life margin than the existing high pressure pump. Thereby, the machining gap of the plunger pair can be further reduced to increase the volumetric efficiency without increasing the weight or using a higher cost material. It shows that the greater the pump oil pressure, the greater the deformation of the first section, and the more significant the gain effect on volumetric efficiency.

DRAWINGS

1 is a schematic structural view of a high pressure pump in the prior art;

2 is a schematic structural view of a high pressure pump in a pumping stage according to an embodiment of the present invention;

3 is a schematic structural view of a high pressure pump in an oil absorption stage according to an embodiment of the present invention;

4 is a cross-sectional view showing a plunger sleeve according to an embodiment of the present invention;

5a-5f are cross-sectional views showing a transition between a first section and a second section of a plunger sleeve in accordance with an embodiment of the present invention.

In Fig. 1, a pressure chamber 1'; a plunger sleeve 3'; a plunger 4'; an oil inlet valve 5'; an oil outlet valve 6'; a machining gap 7' of the plunger pair; a protruding member 8';

2 to 4: first pressure chamber 1; second pressure chamber 2; plunger sleeve 3; first stage 31; second stage 32; plunger 4; oil inlet valve 5; oil outlet valve 6; Sub-machining gap 7; protruding member 8.

detailed description

The high pressure pump of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Advantages and features of the present invention will be apparent from the description and appended claims. It should be noted that the drawings are in a very simplified form and all use non-precise proportions, and are only for convenience and clarity to assist the purpose of the embodiments of the present invention.

Please refer to FIG. 2 and FIG. 4 , which are schematic structural diagrams of the high pressure pump of the present invention. As shown in FIG. 2 , the high pressure pump includes: a pressure chamber, a plunger sleeve 3 disposed in the pressure chamber, and is disposed at the same. a protruding member 8 on the outer side of the plunger sleeve 3 and connected to the pressure chamber wall, and a plunger 4 disposed in the plunger sleeve 3, an oil inlet valve 5 and an oil discharge valve 6; wherein The plunger sleeve 3 includes a first segment 31 and a second segment 32 connected to the first segment 31, and the protruding member 8 is disposed on the outer side of the second segment 32 adjacent to the first segment 31, The protruding member 8 divides the pressure chamber into a first pressure chamber 1 and a second pressure chamber 2, the first portion 31 is located in the first pressure chamber 1, and the oil inlet valve 5 and the oil discharge valve 6 are both The first pressure chamber 1 is disposed on the first pressure chamber 1 .

The protruding member serves as a dividing pressure chamber as a boundary point between the first pressure chamber 1 and the second pressure chamber 2, and comparatively analyzes FIG. 1 and FIG. 2, in which the protruding member 8 is moved downward from the protruding member 8' in FIG. So that the predetermined length of the plunger sleeve 3 (ie, the first section) is accommodated in the first pressure chamber, that is, the structure shown in FIG. 1 is increased compared with the structure shown in FIG. The length of the sleeve is used to improve the presence of the plunger gap in the pump oil phase of the high pressure pump. There is a problem that the high pressure oil returns to the low pressure region, resulting in a decrease in volumetric efficiency.

When the high-pressure pump is actually applied, it is divided into the pump oil phase and the oil suction phase. The specific working processes of the two phases are as follows:

As shown in FIG. 2, in the pumping phase, the plunger 4 moves from the second pressure chamber 2 to the first pressure chamber 1, so that the pressure in the first pressure chamber 1 is higher than the second The pressure in the pressure chamber 2, at this time, there is a pressure difference between the inside and the outside of the first section 31, which is expressed as a decrease in the pressure in the first pressure chamber 1 toward the second pressure chamber 2. The main reason is that the outer side of the first section 31 of the plunger sleeve 3 is affected by the high pressure and constant pressure in the first pressure chamber 1, and the inner side of the first section 31 of the plunger sleeve 3 is in communication with the second pressure chamber 2, so The pressure of the inner side of the first section 31 of the plunger sleeve 3 decreases in the direction of the first pressure chamber 1 toward the second pressure chamber 2 and is smaller than the pressure applied to the outside of the first section 31, under the action of the pressure difference The first segment 31 is deformed and contracted inwardly such that the gap between the first segment 31 of the plunger sleeve 3 and the plunger 4 is smaller than the machining gap 7 of the plunger pair (ie, the plunger 4 and the plunger sleeve) 3 original machining gap).

As shown in FIG. 3, during the oil suction phase, the plunger 4 moves from the first pressure chamber 1 to the second pressure chamber 2, so that the pressure in the first pressure chamber 1 is equal to the second pressure chamber. The pressure in 2, therefore, there is no pressure difference between the inside and the outside of the first section 31, the first section 31 is restored from the inwardly contracted state of the pumping stage to the state before the deformation, and the first section 31 of the plunger sleeve 3 The gap with the plunger 4 is equal to the gap between the second section 32 of the plunger sleeve 3 and the plunger 4 (also the initial state of the plunger sleeve 3), which is equal to the plunger pair Machining gap 7. Preferably, the processing gap 7 of the plunger pair has a width ranging from 1 μm to 15 μm.

Therefore, the high pressure pump of the present invention has a larger plunger clearance in the oil suction stroke than the existing high pressure pump, with the same pump oil stroke plunger 4 clearance (i.e., equivalent volumetric efficiency), and less. The plunger 4 is worn and has a larger life margin, so that the machining gap 7 of the plunger pair can be further reduced to further increase the volumetric efficiency. In other words, at the expense of the loss of life margin, the machining gap 7 of the plunger pair is further reduced to reduce the gap loss. No need to add weight or use higher cost materials. Moreover, the greater the pump oil pressure, the larger the adaptive deformation, the more significant the gain effect on the volumetric efficiency, effectively improving the fuel combustion utilization rate and saving fuel consumption.

Further, the inner diameter of the first section 31 of the plunger sleeve 3 is the same as the inner diameter of the second section 32 of the plunger sleeve 3, and the outer diameter of the first section 31 of the plunger sleeve 3 is opposite to the column. The outer diameters of the second sections 32 of the plug sleeves 3 are the same or different. In this embodiment, it is preferable that the outer diameter of the first segment 31 of the plunger sleeve 3 is different from the outer diameter of the second segment 32 of the plunger sleeve 3, so that the first segment 31 is more easily deformed in the pumping phase. Contraction state.

Referring to FIG. 4, regardless of whether the outer diameter of the first section 31 of the plunger sleeve 3 and the outer diameter of the second section 32 of the plunger sleeve 3 are the same, it is necessary to satisfy the relationship as follows:

Where L2 is the total length of the plunger sleeve 3, and L1 is the length of the first section 31 of the plunger sleeve 3.

With continued reference to FIG. 4, when the outer diameter of the first section 31 of the plunger sleeve 3 is different from the outer diameter of the second section 32 of the plunger sleeve 3, it is necessary to satisfy the relationship as follows:

Wherein D1 is the inner diameter of the first section 31 of the plunger sleeve 3, D2 is the outer diameter of the second section 32 of the plunger sleeve 3, and D3 is outside the first section 31 of the plunger sleeve 3. path.

Preferably, referring to Figures 5a - 5f, the first section and the second section are connected by a transition section, and the existence of the transition section facilitates mounting the plunger sleeve in the pressure chamber, the section of the transition section It is presented as a combination of one or more of a rounded corner, a right angle, a bevel, a multi-segment curve, a multi-segment line, and a multi-segment line.

In summary, in the high pressure pump provided by the present invention, the plunger sleeve of the high pressure pump includes a first segment and a second segment connected to the first segment, and the protruding member is disposed on the outer side of the second segment adjacent to the first segment, The first segment is located within the first pressure chamber and is moved downward relative to the prior art interference point position of the present invention. In the pumping stage, the first section is deformed and contracted inward under the pressure difference between the inside and the outside, and the gap between the first section and the plunger is reduced, which effectively reduces the loss of the backflow; in the oil suction stage, there is no inside or outside of the first section. The pressure difference causes the first segment to return from the contracted state to the state before the deformation. Therefore, under the premise of having the same volumetric efficiency, the high pressure pump of the present invention has a larger plunger clearance in the oil suction stroke, less plunger wear, and more life margin than the existing high pressure pump. Thereby, the machining gap of the plunger pair can be further reduced to increase the volumetric efficiency without increasing the weight or using a higher cost material.

The above description is only for the description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes and modifications made by those skilled in the art in light of the above disclosure are all within the scope of the appended claims.

Claims

A high pressure pump, comprising: a pressure chamber, a plunger sleeve disposed in the pressure chamber, and a protruding member disposed on an outer side of the plunger sleeve and connected to the pressure chamber wall a plunger, an oil inlet valve and an oil outlet valve in the plunger sleeve; wherein the plunger sleeve includes a first segment and a second segment connected to the first segment, and the protruding member is disposed at the The second segment is adjacent to the outer side of the first segment, the protruding member divides the pressure chamber into a first pressure chamber and a second pressure chamber, and the first portion is located in the first pressure chamber, the An oil valve and the oil discharge valve are both disposed on the first pressure chamber.
A high pressure pump according to claim 1 wherein said plunger moves from said second pressure chamber to said first pressure chamber during a pumping phase of said high pressure pump.
The high pressure pump according to claim 2, wherein in the pumping phase of the high pressure pump, the pressure in the first pressure chamber is higher than the pressure in the second pressure chamber.
A high pressure pump according to claim 3, wherein in the pumping phase of said high pressure pump, said first section of said plunger sleeve is deformed and contracted inwardly, said first section of said plunger sleeve being said The gap between the plungers is smaller than the machining gap of the plunger pair.
The high pressure pump according to claim 3, wherein in the pumping phase of the high pressure pump, the pressure in the first pressure chamber decreases toward the second pressure chamber.
A high pressure pump according to claim 1, wherein said plunger moves from said first pressure chamber to said second pressure chamber during an oil suction phase of said high pressure pump.
A high pressure pump according to claim 6, wherein in the oil suction phase of said high pressure pump, the pressure in said first pressure chamber is equal to the pressure in said second pressure chamber.
A high pressure pump according to claim 7, wherein a gap between the first section of the plunger sleeve and the plunger is equal to a second of the plunger sleeve during an oil suction phase of the high pressure pump A gap between the segment and the plunger, a gap between the second section of the plunger sleeve and the plunger being a machining gap of the plunger pair.
A high pressure pump according to claim 1 wherein the inner diameter of the first section of the plunger sleeve is the same as the inner diameter of the second section of the plunger sleeve, the outer portion of the first section of the plunger sleeve The diameter is the same as the outer diameter of the second section of the plunger sleeve.
A high pressure pump according to claim 1 wherein the inner diameter of the first section of the plunger sleeve is the same as the inner diameter of the second section of the plunger sleeve, the outer portion of the first section of the plunger sleeve The diameter is different from the outer diameter of the second section of the plunger sleeve.
A high pressure pump according to claim 9 or 10, wherein the length of the first section of the plunger sleeve and the total length of the plunger sleeve satisfy the following relationship:

Where L2 is the total length of the plunger sleeve and L1 is the length of the first section of the plunger sleeve.
A high pressure pump according to claim 10, wherein an inner diameter of the first section of the plunger sleeve, an outer diameter of the first section of the plunger sleeve, and an outer section of the second section of the plunger sleeve The path satisfies the following relationship:

Wherein D1 is the inner diameter of the first section of the plunger sleeve, D2 is the outer diameter of the second section of the plunger sleeve, and D3 is the outer diameter of the first section of the plunger sleeve.
The high pressure pump according to claim 12, wherein the first section and the second section are connected by a transition section, and the section of the transition section is rounded, right angled, obliquely angled, multi-segmented, and multi-segmented. One of the straight lines, or a combination of a multi-segment curve and a multi-segment line.