CN102766746A - Method for improving carrying capacity of high-pressure oil tube for diesel engine - Google Patents
Method for improving carrying capacity of high-pressure oil tube for diesel engine Download PDFInfo
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- CN102766746A CN102766746A CN2012102480235A CN201210248023A CN102766746A CN 102766746 A CN102766746 A CN 102766746A CN 2012102480235 A CN2012102480235 A CN 2012102480235A CN 201210248023 A CN201210248023 A CN 201210248023A CN 102766746 A CN102766746 A CN 102766746A
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Abstract
The invention provides a method for improving the carrying capacity of a high-pressure oil tube for a diesel engine. The method comprises the following steps of: calculating the pressure required for strengthening the oil tube according to the yield strength and the bearing pressure of an oil tube material and the depth of a strengthening layer; after the oil tube is formed by bending, sealing one end of the oil tube; and inputting high-pressure pump correction oil from the other end of the oil pump according to the previously calculated pressure value required for strengthening the oil tube, and maintaining the pressure for 3 to 4 seconds to finish the strengthening of the oil tube, wherein the numerical value of the strengthening pressure P is between the yield strength and the burst pressure of the material, and the working pressure is not more than 0.3P. After using the method, the pipe fitting strengthening effect of the oil tube is checked through fatigue tests, the test pressure is a pulse pressure, the work load of a peak value reference component is 1,000 to 2,000bar, and the frequency is 15 Hz. Results show that the service lives of unstrengthened components are generally hundreds of thousands of times to two million times, and the service lives of strengthened components are more than 10 million times. According to the method, the service life of the oil tube is greatly prolonged, and the driving safety of vehicles is ensured.
Description
Technical field
The present invention relates to a kind of method that improves use for diesel engine high-pressure line supporting capacity,, improve fatigue lifetime in order to promote high-pressure line carrying capacity pulse ability.
Background technology
Since nearly ten years, environmental protection becomes problem of paying close attention to very much of automobile industry, and the engine emission rules are gradually improved, and more and more stricter, and what use at present is state's III standard, is equivalent to European III standard, and rises to state's IV in a short time probably.
It is limited that the conventional diesel engine fuel oil supply system improves the space; It is very difficult wanting to reach this standard; Want to make diesel emission to meet relevant regulations; And cannot sacrifice dynamic property and economic index as cost, and oil supply system must have bigger improvement, and the improvement of charge oil pressure is imperative.
In order to make mover reach energy-conservation better and the environmental protection purpose, improving engine fuel injection pressure is an efficient ways, improves spraying pressure and can improve the fuel-injected atomizing effect better, makes fuel oil to burn more fully more fast; This just has higher requirement to the pressure of engine fuel plenum system; Conventional diesel engine prime the fuel system pressure is generally 180-200bar, and modern high performance diesel engine fuel jetting pressure is 800-1800bar, and this has just proposed stricter requirement to the withstand voltage life-span of high-pressure line material.
In the high-pressure line work, bear the pulse pressure that comes from high pressure fuel.Form if regard high-pressure line as one group of (axially) tubular lamellar body, fuel oil outwards transmits the pressure of tube wall from level to level, and innermost layer (pipe fitting inner wall) directly contacts with fuel oil, and stressed area is little than other aspect, and its suffered pressure (stress) is maximum.And middle layer and outer area are bigger than inwall, and the stress ratio inwall that bears is little.If material is that when the inwall pressurized reached yield strength, skin also had remaining supporting capacity uniformly.If utilize the remainder of outer voltage endurance capability, can improve the whole voltage endurance capability of pipe fitting.In other words, if through in the preset unrelieved stress of skin, make full use of the intensity of material outer layer, and be used to remedy the deficiency of internal layer intensity, make them reach yield strength simultaneously, such state is optimal.
In improving high-pressure line tubing voltage endurance capability process, the unrelieved stress of receiving in how on inside pipe wall, forming is crucial.Because the high-pressure line material is soft steel or structural low, belongs to plastic material, it is worth noting the maximum shear stress that body is suffered most.
Summary of the invention
The objective of the invention is to improve the ability to bear of diesel engine high-pressure oil pipe body paired pulses load, enable to adapt to the requirement of modern diesel engine prime the fuel system, a kind of method that improves use for diesel engine high-pressure line supporting capacity of special proposition.
Technical scheme of the present invention for this reason is that a kind of method that improves use for diesel engine high-pressure line supporting capacity is characterized in that: according to tubing material ys and the bearing pressure and the strengthening layer degree of depth; Calculate oil pipe and strengthen required pressure, tubing bending after being shaped seals oil pipe one end; Strengthen force value according to calculating before; The pump oil from the other end input highly compressed school, 3 seconds dwell times, oil pipe can be accomplished intensified process; Strengthen pressure P numerical value between material yield intensity and burstpressures, WP is not more than 0.3P.
Beneficial effect:
Present method adopts fatigue test check pipe fitting strengthening effect, and TP is a pulsating pressure, and peak value is with reference to the load (1000-2000bar) of part time job, frequency 15Hz.The part life that the result shows intensified process generally at hundreds of thousands of time to several 200 ten thousand times, through the part life of intensified process greater than 1,000 ten thousand times.Prolong the work-ing life of oil pipe greatly, guaranteed the driving safety of vehicle.
Description of drawings
Fig. 1 is the force analysis synoptic diagram of material in the body intensified process process.
1 is the elastic region of body among the figure, the 2nd, and the plastic zone of body.
Fig. 2 is that body is strengthened back pipe residual stress distribution plan.
Fig. 3 is during body is strengthened, internal surface stress and strain situation analysis figure.
The AB section is a resilient deformation section among the figure, and the BC section is for strengthening the surrender section, and C point stress is near the breakdown point of material; The CD section is a unloading phase after reinforcement is accomplished.
Embodiment
The present invention is like Fig. 1,2, shown in 3.
A kind of method that improves use for diesel engine high-pressure line supporting capacity according to tubing material ys and the bearing pressure and the strengthening layer degree of depth, calculates oil pipe and strengthens required pressure; After tubing bending is shaped,, strengthen force value according to calculating before with the sealing of oil pipe one end; The pump oil from the other end input highly compressed school, 3 seconds dwell times, oil pipe can be accomplished intensified process; Strengthen pressure P numerical value between material yield intensity and burstpressures, WP is not more than 0.3P.
According to the faupel formula, burstpressures p
b:
In the formula: the yield strength of δ s---material, Mpa;
The breakdown point of δ b---material, MPa;
K---pipe is the ratio of external diameter and internal diameter
Strengthen pressure P numerical value between material yield intensity and burstpressures.When P=0.85*pb, strengthening effect is best, and it is maximum that fatigue of materials intensity can reach, and recommends dynamic duty pressure to be not more than 0.3P.
The A-B-C-D process is inner-wall reinforced processing loading and uninstall process.The AB section is a resilient deformation section, can only be operated in this stage without the pipe fitting of strengthening; The BC section is for strengthening the surrender section, and C point stress is near the breakdown point of material; The CD section is a unloading phase after reinforcement is accomplished.Reload after the unloading, curve is then walked along the DE section, occurs surrender after the E point once more.DE is the available work section after the intensified process.Obviously, the DE section is greater than the AB section.
The method of inspection
1, unrelieved stress detects.
Through the pipe fitting of intensified process, can come the detection enhancement effect through the variation of check pipe residual stress numerical value.Recommend to use the X ray tension gauge detect tube wall axially with the tangential unrelieved stress, use the way of galvanic corrosion, remove the body material layer by layer, at pipe diameter direction unrelieved stress numerical value of (like 0.1MM) detection at a certain distance.
Because passed through technologies such as cold-drawn and thermal treatment in making, there is original unrelieved stress in body, after the intensified process, strengthening the unrelieved stress and the original unrelieved stress that produce can superpose.Test needs to detect the part that same mother metal made, and detects the stress difference before and after strengthening.Detected result can show: 1. stress distribution ordering more; 2. the unrelieved stress variation is that trend helps the direction that work is carried.
In addition, this detection method is destructive, remove part metals and can cause the part unrelieved stress to discharge, and the overall unrelieved stress algebraic sum of part is 0.So the detection initial stage, the result of (in the 1MM) was more credible.Detected result is the display material changing conditions quantitatively, has only meaning qualitatively.
2, fatigue test.
Fatigue test is the direct method of check pipe fitting strengthening effect.TP is a pulsating pressure, and peak value is with reference to the load (1000-2000bar) of part time job, frequency 15Hz.The part life of intensified process does not generally arrive several 200 ten thousand times at hundreds of thousands of, can be greater than 1,000 ten thousand times through the part life of intensified process.
Claims (1)
1. a method that improves use for diesel engine high-pressure line supporting capacity is characterized in that: according to tubing material ys and the bearing pressure and the strengthening layer degree of depth, calculate oil pipe and strengthen required pressure; After tubing bending is shaped; With the sealing of oil pipe one end, strengthen force value according to calculating before, pump oil from the other end input highly compressed school; 3 ~ 4 seconds dwell times; Oil pipe can be accomplished intensified process, strengthens pressure P numerical value between material yield intensity and burstpressures, and WP is not more than 0.3P.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012102480235A CN102766746A (en) | 2012-07-18 | 2012-07-18 | Method for improving carrying capacity of high-pressure oil tube for diesel engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012102480235A CN102766746A (en) | 2012-07-18 | 2012-07-18 | Method for improving carrying capacity of high-pressure oil tube for diesel engine |
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| CN102766746A true CN102766746A (en) | 2012-11-07 |
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| CN2012102480235A Pending CN102766746A (en) | 2012-07-18 | 2012-07-18 | Method for improving carrying capacity of high-pressure oil tube for diesel engine |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103018107A (en) * | 2012-12-07 | 2013-04-03 | 潍柴动力股份有限公司 | Method and equipment for testing fatigue of high pressure oil pipe |
| CN109826739A (en) * | 2019-03-07 | 2019-05-31 | 广西玉柴机器股份有限公司 | Engine high pressure oil pipe |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5809818A (en) * | 1995-11-15 | 1998-09-22 | Usui Kokusai Sangyo Kaisha Limited | High-pressure piping metal tube and process for manufacturing the same |
| CN101845542A (en) * | 2010-03-02 | 2010-09-29 | 麦格思维特(上海)流体工程有限公司 | High-pressure oil pipe strengthening device |
-
2012
- 2012-07-18 CN CN2012102480235A patent/CN102766746A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5809818A (en) * | 1995-11-15 | 1998-09-22 | Usui Kokusai Sangyo Kaisha Limited | High-pressure piping metal tube and process for manufacturing the same |
| CN101845542A (en) * | 2010-03-02 | 2010-09-29 | 麦格思维特(上海)流体工程有限公司 | High-pressure oil pipe strengthening device |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103018107A (en) * | 2012-12-07 | 2013-04-03 | 潍柴动力股份有限公司 | Method and equipment for testing fatigue of high pressure oil pipe |
| CN109826739A (en) * | 2019-03-07 | 2019-05-31 | 广西玉柴机器股份有限公司 | Engine high pressure oil pipe |
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Application publication date: 20121107 |