A kind of hot junction electric EGR valve water channel vacuum leak hunting methodTechnical field
The present invention relates to engine exhaust emission and control device field, particularly relate to a kind of carry the electronic of cooling structureEGR valve water channel vacuum leak hunting method.
Background technology
In engine exhaust-gas recirculating system (egr system), EGR valve is mainly used in regulation and controls the stream of EGR gasAmount.Electric EGR valve is that a kind of dependence motor drives, and carries out Real-time Feedback and the EGR of monitor aperture by institute's belt sensorValve, it has the advantages such as control is accurate, response time is fast.Carry the electric EGR valve phase direct with engine air inlet tube of cooling structureConnect, it is not necessary to increase connecting tube, reduce between engine air, simplify structure, but will also result in seepy question.Traditional detectionSeepy question uses hydrolysis to observe bubble method, and this detection method takes the most subjective judgement, and precision sensitivity is low, to operationPersonnel have dependency, limit result of leaking hunting.
Summary of the invention
It is an object of the invention to for the deficiencies in the prior art, it is provided that a kind of convenient mounting and clamping, accuracy in detection are reliable, detectionThe vacuum leak hunting method of a kind of electric EGR valve water channel that precision is high.
For solving above-mentioned technical problem, the technical solution used in the present invention is as follows:
The vacuum leak hunting method of a kind of hot junction electric EGR valve water channel, comprises the following steps:
(1) being connected to one that needs the cooling water channel measured on three way cock by connecting tube, other end plug is by itSeal；
(2) vacuum degree measuring instrument and vacuum pump are connected to two other joint of three way cock；
(3) start vacuum pump, when vacuum reaches-90kPa when, close valve, pressurize 10s, observe vacuum degree measuring instrumentChange numerical value, as pressure drop ＜ 300Pa, confirm cooling water channel qualified, as pressure drop >=300Pa, confirm cooling water channelDefective.
Owing to have employed above technical scheme, the invention technological progress is as follows:
The advantage of the leak hunting method of the present invention be convenient mounting and clamping, quick, low manually, suitable amount produce line production, with tradition sideBubble phase ratio is observed in method hydrolysis, and this leak hunting method is without the most subjective judgement, but the change of objective data more accurately,Compare with large-scale precision detection equipment simultaneously, in the case of precision reduces to a certain degree, greatly reduce equipment cost withThe detection time, the various water channels leak detection in being more suitable for, under low-pressure.
Accompanying drawing explanation
Fig. 1 is the electric EGR valve structure chart carrying cooling structure of the present invention；
Fig. 2 is the schematic diagram of the water channel vacuum leak hunting method of the electric EGR valve of the present invention.
Wherein: 1-power section, 2-gasket seal, 3-lock nut, 4-cooling water pipe, 5-cooling water channel, 6-Three way cock, 7-connecting tube, 8-plug, 9-electric EGR valve, 10-vacuum degree measuring instrument, 11-valve, 12-vacuum pump.
Detailed description of the invention
The present invention is further described below in conjunction with the accompanying drawings.
It is illustrated in figure 1 the electric EGR valve structure chart carrying cooling structure of the present invention, including power section 1, sealsPad 2, lock nut 3, cooling water pipe 4 and cooling water channel 5.
Fig. 2 is the schematic diagram of the water channel vacuum leak hunting method of the electric EGR valve of the present invention, including three way cock 6, connecting tube7, plug 8, electric EGR valve 9, vacuum degree measuring instrument 10, valve 11, vacuum pump 12, it would be desirable to of the cooling water channel 5 of measurementBeing connected on three way cock 6 by connecting tube 7, other end plug 8 is sealed against；Then vacuum degree measuring instrument 10 and vacuumPump 12 is connected to two other joint of three way cock 6；Operation principle is to utilize cooling water channel is pumped into certain vacuum degreeVacuum, observes whether its vacuum changes to judge whether cooling water channel leaks subsequently.Vacuum pump 12 is started during work,
When vacuum reaches-90kPa when, close valve 11, pressurize 10s, observe the change numerical value of vacuum degree measuring instrument 10,As pressure drop ＜ 300Pa, confirm that cooling water channel 5 is qualified, as pressure drop >=300Pa, confirm that cooling water channel 5 is defective.LiftUnder such as:
Example 1, when vacuum reaches-90kPa, close valve 11, pressurize 10s, pressure reduces to 100Pa, then cooling water channel 5 closesLattice；
Example 2, when vacuum reaches-90kPa, close valve 11, pressurize 10s, pressure reduces to 150Pa, then cooling water channel 5 is stillQualified；
Example 3, when vacuum reaches-90kpa, close valve 11, pressurize 10s, when pressure reduces to 300Pa, then cooling water channel 5 is notQualified.