CN201284681Y

CN201284681Y - Engine crankcase ventilation system

Info

Publication number: CN201284681Y
Application number: CNU200820212705XU
Authority: CN
Inventors: 胡涛平; 朱小平
Original assignee: SAIC Chery Automobile Co Ltd
Current assignee: Chery Automobile Co Ltd
Priority date: 2008-10-21
Filing date: 2008-10-21
Publication date: 2009-08-05
Anticipated expiration: 2018-10-21

Abstract

The utility model discloses an engine crankcase ventilation system. A second waste gas passage is added on the basis of a waste gas passage from the prior crankcase to a intake manifold; the second waste gas passage is provided with two one-way valves with opposite flowing directions are arranged in parallel; and a PCV valve in the original passage is connected in parallel with a one-way valve. The utility model has the advantages that one reversing one-way valve is respectively connected in parallel to two waste gas passages of the crankcase ventilation system, one of the one-way valves is used for regulating the overlarge negative pressure of the crankcase when the engine is in idle-speed and high-speed small load, and the other one-way valve is used for regulating the overlarge negative pressure of the crankcase when the engine is in high speed large load; so that the crankcase ventilation system can complete the ventilation and exhaust tasks of the crankcase under the condition that the engine is in all operating states.

Description

A kind of engine crankshaft ventilation system

Technical field

The utility model relates to engine crankshaft ventilation system, particularly a kind of crankcase is carried out force ventilated crankcase ventilation system.

Background technique

The effect of crankcase ventilation system is that inflammable mixture, waste gas and the lubricant oil mist of oil etc. that make the crankcase that bleeds are in time discharged, prevent the generation of oil dilution and seeping phenomenon, to keep quality of lubrication oil, lubricating oil temperature can not raise, reduce crank shaft oil seal and bottom-end gasket leakage of oil.And can reclaim fuel vapour, both fuel saving had alleviated pollution of atmosphere again.At present, the crankcase ventilation mode has two kinds, and a kind of is natural ventilation, is used on the agricultural miniature diesel engine more.Another kind is a forced ventilation, utilizes the degree of vacuum effect in the engine intake manifold road exactly, makes the interior gas of crankcase be inhaled into the method for cylinder.Wherein, the positive drive type crankcase ventilation system is planted the system into PCV again, and in the prior art, the PCV system mainly comprises the PCV valve of crankcase, valve cage housing, vent hose, air induction hose, intake manifold and special use etc.Here Zhuan Yong PCV valve is the pressure control modulating valve, abbreviates the PCV valve later on as.The PCV valve is a control valve of waste gas one-way flow in the control crankcase, and it can be according to the different adjustment of the inlet and outlet pressure difference exhaust gas flow by it.The working procedure of existing system is as follows:

When engine operation, intake manifold vacuum affacts the PCV valve, this degree of vacuum also attracts fresh air to enter crankcase through air-strainer, air induction hose, fresh air mixes after valve chamber cover, PCV valve and steam hose enter intake manifold with gas in the crankcase in crankcase, enters into combustion chambers burn through valve.In the gas of combustion chambers burn has partly by the crankcase that bleeds through the gap of piston ring inevitably again, enter circulation next time again.This is very desirable forced ventilation system, but, in fact, for supercharged engine, because the pressure (relatively) of intake manifold fluctuates in-60KP ∽ 60KP scope under the total external characteristic operating mode, and the motor reliability of operation requires crankcase pressure to maintain-3.5KP ∽ 0KP scope, both differ greatly, rely on air-distributor pressure to come crankcase pressure is regulated, sometimes the very difficulty that becomes, and can not realize that under some operating mode both communicate, be under the barotropic condition such as the pressure in intake manifold, just can not carry out pressure release to crankcase and also just can not reach the positive crankcase ventilation (PCV) purpose.

Summary of the invention

The purpose of this utility model is to provide a kind of supercharged engine crankcase ventilation system, overcoming in the prior art, is can not carry out the deficiency that pressure release also just can not reach the positive crankcase ventilation (PCV) purpose to crankcase under the situation of malleation when the pressure of intake manifold.

For solving the problems of the technologies described above, solution of the present utility model is: a kind of engine crankshaft ventilation system, comprise first exhaust steam passage from the crankcase to the intake manifold, described first exhaust steam passage comprises crankcase valve chamber, pressure control modulating valve, intake manifold and first flexible pipe, described valve cage is communicated with described intake manifold by described first flexible pipe, and described pressure control modulating valve is installed on described first flexible pipe; Also comprise second exhaust steam passage, second one-way valve and the 3rd one-way valve from the crankcase to the air induction hose, described second exhaust steam passage comprises described valve chamber cover, first one-way valve, air induction hose, described valve cage is communicated with described air induction hose by described second flexible pipe, air induction hose is communicated with described intake manifold, described first one-way valve is installed on described second flexible pipe, its conducting direction be from described valve cage to described air induction hose, described pressure charging valve is installed between air induction hose and the intake manifold; Described second one-way valve and described first are installed in parallel to valve, and its conducting direction is to valve cage from described air induction hose; Described the 3rd one-way valve and described pressure control modulating valve are installed in parallel, and its conducting direction is to described valve cage from described intake manifold.

Good effect of the present utility model is, respectively and connect a reverse one-way valve, second one-way valve is used for regulating motor excessive situation of crankcase negative pressure when idling, the little load of high speed on two exhaust steam passages of crankcase ventilation system; The 3rd one-way valve is used for regulating motor excessive situation of crankcase negative pressure when loading greatly at a high speed.Make crankcase ventilation system can under motor is in the situation of full operating mode, finish the vented exhaust task of crankcase.

Below with reference to accompanying drawing, comparatively detailed explanation is carried out in each preferred embodiment of the present utility model.

Description of drawings

Fig. 1, the utility model theory diagram.

Fig. 2, PCV valve arrangement schematic representation.

Among the figure: 1. return tube; 2. engine sump; 3. deaerator; 4. intake manifold; 5.PCV valve; 6. the 3rd one-way valve; 7. first exhaust steam passage; 8. second exhaust steam passage, 9. first one-way valves; 10. second one-way valve; 11. air-strainer; 12. air induction hose; 13. pressure charging valve; 14. threeway; 15. valve cage; 16. first flexible pipe; 17. second flexible pipe; 51. exhaust gas entrance; 52. valve body; 53. spool; 54. Regulation spring; 55. valve seat; 56. protection spring; 57; waste gas outlet.

Embodiment

As shown in Figure 1, the waste gas in the engine crankcase can be by two passages: first exhaust steam passage 7 and second exhaust steam passage 8 enter in the intake manifold 4, thereby enter into the firing chamber of motor.The starting point of two exhaust steam passages all is the valve cage 15 on the crankcase, and waste gas comes out the back crossing deaerator 3 from valve cage 15, after wherein lubricating oil separation is gone out, gets back in the crankcase from return tube 1.The waste gas of removing behind the lubricant oil can enter first exhaust steam passage 7 and second exhaust steam passage 8 respectively by a threeway 14.Wherein, first exhaust steam passage 7 comprises crankcase valve chamber 15, PCV valve 5, intake manifold 4 and first flexible pipe 16, after waste gas comes out from valve cage 15, second port by deaerator 3 and threeway 14 enters into first flexible pipe 16, enter into intake manifold 4 by first flexible pipe 16, PCV valve 5 is installed on first flexible pipe 16; The control exhaust-gas flow.One the 3rd one-way valve, 6, the three one-way valves 6 in parallel with PCV valve 5 are installed in parallel with PCV valve 5 on first exhaust steam passage 7, and its conducting direction is from intake manifold 4 to valve cage 15.Second exhaust steam passage 8 comprises described valve cage 15, first one-way valve 9, air induction hose 12, pressure charging valve 13, intake manifold 4 and second flexible pipe 17.After waste gas came out from valve cage 15, the 3rd port by deaerator 3 and threeway 14 entered second flexible pipe 17, flow in the air induction hose 12 by second flexible pipe 17, enters in the intake manifold 4 from air induction hose 12.Finish waste gas returns the firing chamber from crankcase process.Have first one-way valve 9 to be installed on second flexible pipe 17 in second exhaust steam passage 8, its conducting direction is from valve cage 15 to air induction hose 12.Also have one second one-way valve 10 and first one-way valve 9 to be installed in parallel, its conducting direction is from air induction hose 12 to valve cage 15.Pressure charging valve 13 is installed between air induction hose 12 and the intake manifold 4.The piping material that top exhaust steam passage uses is oil resistant, heat-resisting rubber material, and bypass or branch road all are to add clip connected by metal or three-way plastic tube with being connected of main passage, guarantees the exhaust steam passage sealing.Top PCV valve, one-way valve can be selected the plunger-type structure form of different flow characteristic according to the piston air leakage size.

As shown in Figure 2: the PCV valve 5 of plunger-type structure mainly is made up of valve body 52, spool 53, Regulation spring 54, valve seat 55, protection spring 56 etc., and two ends are respectively exhaust gas entrance 51 and waste gas outlet 57.PCV valve detailed operation situation is described among the utility model embodiment: A: under the engine idling condition, intake manifold vacuum is higher, at this moment piston air leakage is few, PCV valve inlet and outlet pressure difference is bigger, spool 53 moves right, the gap is very little between spool 53 and the valve seat 55, and is at this moment less via the exhaust gas flow that PCV waste gas outlet 57 flows out by the waste gas that is flowed into by PCV valve exhaust gas entrance 51; B: along with engine load increases, piston air leakage is also along with increase, intake manifold vacuum descends, it is less that pressure difference between PCV valve exhaust gas entrance 51 and the waste gas outlet 57 becomes, spool 53 moves right and is subjected to the effect of Regulation spring 54 controlled, the gap becomes greatly gradually between spool 53 and the valve seat 55, by PCV valve exhaust gas flow also along with raising.The PCV valve is exactly to change the flow that passes through of regulating waste gas by inlet outlet pressure differential, and reaches the adjusting crankcase pressure.Here protect the effect of spring 54 to be: the one, prevent that backfiring in intake manifold from entering exhaust pipe; Can also protect Regulation spring in addition.

Present embodiment designs the crankcase ventilation system of form as shown in Figure 1 at the crankcase ventilation system performance requirement of supercharged engine:

1, crankcase waste gas circulates by both direction: first exhaust steam passage: valve cage → deaerator → threeway → PCV valve → intake manifold → firing chamber; Second exhaust steam passage: valve cage → deaerator → threeway → one-way valve → air induction hose → pressure charging valve → intake manifold → firing chamber.

2, oppositely be attempted by second one-way valve on second exhaust steam passage, under the big situation of intake manifold negative pressure, realization is used to regulate the excessive situation of negative pressure of engine idle, the little load condition lower crankcase of high speed from air induction hose → second one-way valve → PCV valve → intake manifold.

3, oppositely be attempted by the 3rd one-way valve in first exhaust steam passage, under the big situation of air induction hose negative pressure, realize being used to regulate the excessive situation of negative pressure of high speed high load working condition lower crankcase from intake manifold → one-way valve III → one-way valve I → air induction hose.

Generally, the crankcase pressure that the crankcase ventilation system of boosting type motor need satisfy requires, the air-distributor pressure of supercharged engine changes greatly, have between excessive zone of positive pressure, only arrive the single passage of intake manifold by crankcase, being first exhaust steam passage 7 shown in Fig. 1, is the normal air-conditioning requirement that can not realize crankcase waste gas fully.Increase crankcase i.e. second exhaust steam passage 8 among the figure of air inlet hose passages behind the empty filter, simultaneously on these two passages and connect two reverse one-way valves, be second one-way valve and the 3rd one-way valve among Fig. 1, the pressure of Under Different Work Condition of Engine lower crankcase is regulated.As long as at this moment one-way valve, PCV valve satisfy certain Flow characteristics requirement, just can realize the crankcase ventilation system needs of boosting type motor.Certain Flow characteristics here requires mainly to be meant different motors, and its piston air leakage is different under different operating modes, and the Flow characteristics of one-way valve, PCV valve is determined after according to theoretical calculation and match test.

Claims

1, a kind of engine crankshaft ventilation system, comprise first exhaust steam passage from the crankcase to the intake manifold, described first exhaust steam passage comprises crankcase valve chamber, pressure control modulating valve, intake manifold and first flexible pipe, described valve cage is communicated with described intake manifold by described first flexible pipe, and described pressure control modulating valve is installed on described first flexible pipe; It is characterized in that: also comprise second exhaust steam passage, second one-way valve and the 3rd one-way valve from the crankcase to the air induction hose, described second exhaust steam passage comprises described valve chamber cover, first one-way valve, air induction hose, described valve cage is communicated with described air induction hose by described second flexible pipe, air induction hose is communicated with described intake manifold, described first one-way valve is installed on described second flexible pipe, its conducting direction be from described valve cage to described air induction hose, described pressure charging valve is installed between air induction hose and the intake manifold; Described second one-way valve and described first are installed in parallel to valve, and its conducting direction is to valve cage from described air induction hose; Described the 3rd one-way valve and described pressure control modulating valve are installed in parallel, and its conducting direction is to described valve cage from described intake manifold.

2, a kind of engine crankshaft ventilation system according to claim 1, it is characterized in that: also comprise a threeway, its first port is communicated with described valve cage, second port connects first flexible pipe in described first exhaust steam passage, and the 3rd port connects second flexible pipe in described second exhaust steam passage.

3, a kind of engine crankshaft ventilation system according to claim 2, it is characterized in that: also comprise deaerator, its inlet opening connects described valve cage, and its gas delivery port connects first port of described threeway, and its oil return outlet connects described crankcase bottom by return tube.

4, a kind of engine crankshaft ventilation system according to claim 2 is characterized in that: described threeway is metal or three-way plastic tube.

5, a kind of engine crankshaft ventilation system according to claim 4 is characterized in that: each port of described threeway all is provided with clip.

6, a kind of engine crankshaft ventilation system according to claim 1 is characterized in that: described first flexible pipe and second flexible pipe are oil resistant and heat resistant rubber flexible pipe.

7, according to the described any engine crankshaft ventilation system of claim 1 to 6, it is characterized in that: the structure of described first one-way valve, second one-way valve, the 3rd one-way valve and pressure control modulating valve all is a plunger type.