CN204457936U - The crankcase closed system of ventilation - Google Patents

Abstract

The utility model discloses a crankcase closed ventilation system, which comprises a pre-separator and a main separator. The air inlet of the pre-separator is arranged opposite to the outlet of the pre-separator. The outer end of the section is provided with a pre-separator inlet, and the outer end of the pressurized section is provided with a pre-separator outlet and a pre-separator outlet pipe is connected to the pre-separator outlet, and the pre-separator is at the bottom There is a pre-separator oil return port, the first oil return pipe is connected to the pre-separator oil return port, the other end of the pre-separator air outlet pipe is connected to the main separator air inlet; the main separator is equipped with a filter element, the main separator There is a main separator air inlet and a main separator air outlet, the main separator air outlet is connected with the main separator air outlet, the main separator is equipped with a first pressure regulating valve corresponding to the filter front cavity, and the main separator is corresponding to the filter The rear chamber is provided with a second pressure regulating valve, the bottom of the main separator is provided with a main separator oil return port, and the main separator oil return port is connected with a second oil return pipe.

Description

Closed crankcase ventilation system

technical field

The utility model relates to a crankcase closed ventilation system.

Background technique

For commercial diesel engines, since China is currently implementing the National IV emission regulations, the regulations do not clearly stipulate the discharge of the oil-gas separator. Therefore, the crankcase ventilation of diesel engines is mostly open at this stage, that is, the exhaust gas in the crankcase is in the air. After simple separation of oil and gas separation, it is directly discharged into the atmosphere. This technical solution does not have excessive requirements on the separation efficiency of the oil-gas separator, as long as the oil consumption is within the user's acceptable range.

With the gradual improvement of the country's emission requirements, the crankcase open ventilation will be upgraded to closed ventilation sooner or later. It is only a matter of time before higher emission standards are implemented, and this technical solution will eventually become a thing of the past. Researching new technologies has become the general trend and the inevitable direction of historical development.

At present, some manufacturers are studying the closed ventilation of the crankcase, but the solution is simply to connect the outlet pipe of the oil-gas separator back to the intake pipe of the diesel engine, as shown in Figure 1. In this case, since the closed ventilation of the crankcase will affect the power, economy, reliability and many other aspects of the whole machine, the simple pipeline connection cannot meet the requirements of use, and its effect is self-evident. The specific analysis is as follows:

1. Since there is only one level of separation, there is no reasonable separation and distribution according to the size of the oil droplets, and it is simply handed over to an oil-gas separator to complete, so the burden on the oil-gas separator is heavy, and a lot of oil and gas are taken out before separation (similar to a tower Anti-game), the separation efficiency of the oil-gas separator will be significantly reduced, and this process is irreversible, resulting in high oil content in the separated exhaust gas, which will cause two problems: On the one hand, it will reduce the boost pressure The efficiency of the supercharger affects the power and economy of the whole machine, and the supercharger is easily damaged; on the other hand, the oil consumption is too high.

2. The burden of the oil-gas separator is heavy, which leads to another problem that the service life of the oil-gas separator is reduced, and too many impurities are deposited in the oil-gas separator, causing blockage, increasing maintenance costs, and poor stability.

3. The layout of the gas outlet pipe is unreasonable. During the process of oil and gas flowing in the pipeline, oil will continue to condense and adsorb on the wall. For this part of the oil, the best way to deal with it is to make it flow back to the oil and gas along the pipeline Separator, and then flow back to the oil pan through the oil return pipe of the oil-gas separator. Otherwise, the two problems described in "1" will arise. Therefore, a reasonable pipeline layout will directly affect the direction of this part of the oil. Because this part is too common, it is easy to be ignored.

All in all, although this scheme achieves a closed connection in appearance, due to the heavy burden of the oil-gas separator, the low separation efficiency, and the unreasonable layout of the pipelines, the performance of the whole diesel engine and other components are affected during the actual operation of the diesel engine. extremely dangerous. Therefore, this program can only be tested briefly in the laboratory, and it cannot be called a mature technology.

Contents of the invention

The technical problem to be solved by the utility model is to provide a crankcase closed ventilation system.

In order to solve the above-mentioned technical problems, the utility model includes a pre-separator and a main separator all provided with an air inlet and an air outlet, and is characterized in that the air inlet of the pre-separator is set opposite to the air outlet of the pre-separator, and the The pre-separator includes a separation section whose inner diameter gradually increases to be bell-shaped and a booster section connected to the largest inner diameter end of the separation section. The outer end of the separation section is provided with a pre-separator air inlet, and the booster section The outer end of the section is provided with a pre-separator gas outlet and is connected with a pre-separator gas outlet pipe at the pre-separator gas outlet. The pre-separator is provided with a pre-separator oil return port at its bottom. The pre-separator The first oil return pipe is connected to the oil return port, and the other end of the air outlet pipe of the pre-separator is connected to the air inlet of the main separator; The filter element, the main separator is provided with a main separator air inlet connected with the filter front chamber and a main separator air outlet connected with the filter rear chamber, and the main separator air outlet is connected with a main separator air outlet pipe, The main separator is provided with a first pressure regulating valve corresponding to the filter front cavity, the main separator is provided with a second pressure regulating valve corresponding to the filter rear cavity, and the bottom of the main separator is provided with a main separator oil return port. A second oil return pipe is connected to the oil return port of the main separator.

The main separator includes a cylindrical main body arranged vertically, the filter element is coaxially arranged with the main body, the upper part of the main body is connected with an air inlet pressure regulating section, and the side of the air inlet pressure regulating section is provided with There is an air inlet of the main separator, and the top of the air inlet pressure regulating section is fixed with an end plate that closes it, and an air outlet hole is opened on the end plate, and the air outlet hole is equipped with a pressure filter for the pressure in the front filter chamber. The first pressure regulating valve that can open the air outlet when the value is greater than the specified value, the top of the inlet pressure regulating section is equipped with an end cover, and an air outlet gap is provided between the end cover and the air inlet section pressure regulating section; The side of the main body is connected with a gas outlet and pressure regulating section, the side of the gas outlet and pressure regulating section is provided with a main separator gas outlet, and the end of the gas outlet and pressure regulating section is provided with a closed cover, and the closed cover is provided with a through Air hole, the air outlet pressure regulating section is provided with a second pressure regulating valve that closes the air hole when the pressure in the filter cavity is normal, and closes the air outlet of the main separator when the pressure is too low.

The first pressure regulating valve includes a connecting rod inserted into the air outlet. Both ends of the connecting rod extend out from the two ends of the air outlet. The upper plate and the lower plate, the connecting rod is set with a return spring on the rod section between the end plate and the lower plate.

The second pressure regulating valve includes a valve body whose outer surface can be attached to the air outlet so as to close the air outlet, and the outer end of the valve body is provided with an annular limiting plate that can be attached to the inner surface of the closing cover , the valve body is sleeved with a spring that can be compressed on the closing cover.

The pressurized section is cylindrical, the oil return port is arranged at the bottom of the pressurized section, a sieve plate is installed in the pressurized section, and there is an oil passage gap between the bottom of the sieve plate and the inner surface of the pressurized section, so A plurality of sieve holes are evenly distributed on the sieve plate, and the sieve holes are distributed outside the projection of the air outlet on the sieve plate.

The pre-separator is provided with a flange at its inlet.

A mounting bracket is fixedly installed on the main separator.

The air outlet pipe of the main separator is bent upwards successively to form an inverted U shape, and is arranged obliquely.

A protective cover is installed on the closing cover of the air outlet and pressure regulating section, and an air hole is opened on the protective cover.

After adopting the above structure, the utility model adopts the two-stage separation method of "pre-separation + main separation". The concentration of the oil-air mixture in the crankcase is relatively high, and the size of the oil droplets varies. Since most of the oil droplets are relatively large and easy to separate, this part of the oil droplets can be easily separated in the pre-separator. The remaining small particles of oil droplets that are difficult to separate continue to be separated by the main separator. The division of labor between the two is clear, which not only reduces the workload of the main separator, but also improves the efficiency and the service life of the main separator. The scheme of pre-separation and main separation is adopted to separate the oil return to prevent the "short circuit" of the oil-gas main separator, resulting in a decrease in separation efficiency, an increase in oil consumption, and damage to other components. The air inlet of the pre-separator is changed to a flange structure, which can be fixed on the air inlet very conveniently and reliably. This structure well solves the potential failure risk caused by collision damage. There are first pressure regulating valve and second pressure regulating valve in the main separator, which can maintain the pressure in the crankcase in the normal range. Avoid extreme cases where the pressure inside the crankcase is too high or too low, causing indirect damage to other components. The direction of the outlet pipe of the main separator is a parabolic structure, that is, the middle is high and the two sides are low. This can effectively prevent oil from entering the intake pipe of the diesel engine through the outlet pipe of the main separator. At the same time, because it is inclined, the inner wall of the outlet pipe of the main separator will not store oil, and it will always remain relatively clean and will not affect the mixture. circulation.

Description of drawings

Below in conjunction with accompanying drawing and specific embodiment the utility model is described in further detail:

Fig. 1 is the structural representation of prior art;

Fig. 2 is the structural representation of the utility model;

Fig. 3 is the structural representation of pre-separator;

Fig. 4 is the schematic cross-sectional structure diagram of Fig. 3;

Figure 5 is a schematic diagram of the structure of the sieve plate

Fig. 6 is a schematic structural diagram of the main separator.

Detailed ways

As shown in Figures 2 to 6, the crankcase closed ventilation system includes a pre-separator 1 and a main separator 5 connected by pipelines. The pre-separator air inlet 13 is arranged opposite to the pre-separator air outlet 14, and the pre-separator 1 includes a separation section 12 whose internal diameter gradually increases to be bell-shaped and a booster section 19 connected to the maximum internal diameter end of the separation section 12, The outer end of the separation section 12, namely the left end in Fig. 3, is provided with a pre-separator air inlet 13 and this air inlet is provided with a flange 11 for fixing, and the outer end of the booster section 19 is the right end in Fig. 3 A pre-separator air outlet 14 is provided and a pre-separator air outlet pipe 2 is connected to the pre-separator air outlet 14. The pressurized section 19 is cylindrical, and the oil return port is arranged at the bottom of the pressurized section 19. The pre-separator The first oil return pipe 3 is connected to the oil return port, and the other end of the air outlet pipe 2 of the pre-separator is connected with the air inlet of the main separator 5 . A circular sieve plate 15 is installed in the pressurized section 19, and the sieve plate 15 is arranged near the air outlet 14 of the pre-separator. There is an oil passage gap between them, and a plurality of sieve holes 17 are evenly distributed on the sieve plate 15, and the sieve holes 17 are distributed on the outside of the projection of the air outlet 14 of the pre-separator on the sieve plate 15, that is, the sieve plate 15 is not provided with a sieve at the air outlet. Hole 17.

The outer surface of the main separator 5 is fixedly equipped with a mounting bracket 4, and the main separator 5 includes a cylindrical vertically arranged main body, and the main body is provided with a filter element 56 that divides its inner chamber into a pre-filter cavity and a filter rear cavity. 56 is arranged coaxially with the main body, and the main separator 5 is provided with a main separator air inlet 61 and a main separator air outlet 59 communicated with the rear cavity of the filter, and the main separator air outlet 59 is connected with a main separator air outlet pipe 7. The main separator 5 is equipped with a first pressure regulating valve corresponding to the filter front cavity, and the main separator 5 is equipped with a second pressure regulating valve corresponding to the filter rear cavity. The bottom of the main separator 5 is provided with a main separator oil return port. A second oil return pipe 6 is connected to the oil return port of the separator. The air outlet pipe 7 of the main separator is bent upward and successively to form an inverted U shape, that is, the middle is higher and the two sides are lower, which can effectively prevent oil from entering the intake pipe of the diesel engine through the air outlet pipe 7 of the main separator. At the same time, due to the inclined setting, the main separator The inner wall of the air outlet pipe 7 does not store oil, and keeps relatively clean all the time, without affecting the circulation of the mixed gas. The main separator air outlet pipe 7 can also only be directly arranged obliquely upwards, as long as it is ensured that no oil is stored in it.

The upper part of the main body is connected with an intake pressure regulating section 51, which is communicated with the inner chamber of the filter element 56 and is communicated with the front chamber of the filter. The intake pressure regulating section 51 is also cylindrical, and the intake pressure regulating section 51 The side part of the main separator is provided with the main separator air inlet 61 that communicates with the pre-filter chamber, and the top of the air inlet pressure regulating section 51 is fixed with an end plate 52 that closes the lower cavity, and the center of the end plate 52 is provided with an air outlet 57 The air outlet 57 is equipped with a first pressure regulating valve that can open the air outlet 57 when the pressure in the front chamber of the filter is greater than a specified value. The first pressure regulating valve includes a connecting rod 83 inserted into the air outlet 57, and two connecting rods 83 Both ends stretch out from the two ends of the air outlet 57, and the upper and lower ends of the connecting rod 83 are respectively connected with an upper plate 81 and a lower plate 82 whose minimum size is greater than the inner diameter of the air outlet 57, and the connecting rod 83 is connected between the end plate 52 and the lower plate 82. A back-moving spring 84 is sleeved on the bar section between. An end cover 53 is installed on the top of the intake pressure regulating section 51 , and an air outlet gap is provided between the end cover 53 and the intake pressure regulating section 51 .

The side of the main body is connected with an outlet pressure regulating section 54, which is also cylindrical, and its axis is in the same plane as the main body axis and perpendicular to each other. The side of the air outlet pressure regulating section 54 is provided with a main separator outlet. Air port 59, the right end of the air outlet pressure regulating section 54 is provided with a closed cover 60, the central part of the closed cover 60 is provided with a vent hole 62, and the air outlet pressure regulating section 54 is provided with a main separator that can be used when the pressure in the filter chamber is too low. The second pressure regulating valve with air outlet 59 closed. The second pressure regulating valve includes a valve body 64 whose outer surface can be fitted to the air outlet so as to close the air outlet. Plate 65, valve body 64 is provided with the ring groove of its right end opening, and the spring 63 that can be compressed on the closure cover 60 is sleeved in the ring groove, and the right end of valve body 64 can be inserted in the air hole 62. A protective cover 55 is installed on the right side of the air outlet pressure regulating section 54, and an air passage hole is opened on the protective cover 55. The protective cover 55 protects the closure cover 60 .

The first oil return pipe 3 or the second oil return pipe 6 can be directly connected to the oil return joint added to the oil dipstick tube, which does not affect the function of the oil dipstick itself, but also increases the function of oil return, avoiding the search for oil return on the body The problem of difficult layout that may be caused by the interface, the structure is simple and easy, and the cost is low. The first oil return pipe 3 or the second oil return pipe 6 can also extend into the oil pan respectively; a check valve can also be installed on the second oil return pipe 6, and then the first oil return pipe 3 and the second oil return pipe 6 are connected to the main oil return pipe, and then connect the main oil return pipe to the oil level of the oil pan; the second oil return pipe 6 can also be connected to the U-shaped pipe, and the U-shaped pipe and the first oil return pipe 3 are connected to the main oil return pipe. Then connect the main oil return pipe to the oil level of the oil pan. Aforesaid several structures mainly make machine oil only one-way flow to oil sump, the mixed gas in the crankcase can not reversely flow back in relevant parts through this channel, other similar structures all can accomplish the object of the present invention.

The oil-air mixture enters the pre-separator 1 from the air inlet 13 of the pre-separator. Since the separation section 12 of the pre-separator 1 is bell-shaped, the pressure of the oil-air mixture will gradually increase during the flow, and some particles are relatively Under the action of this pressure and gravity, the large oil droplets will be separated first, and flow out along the wall through the oil return port of the pre-separator. Then the mixed gas accelerates through the sieve hole 17 on the sieve plate 15 and hits the outer wall on the right side of the pre-separator 1, part of the oil droplets are separated again and flow down the wall, and finally flow back to the oil return port through the gap below the sieve plate 15 . The separated oil-gas mixture flows out through the gas outlet. Since the sieve holes 17 are distributed around the sieve plate 15, there is no sieve hole 17 in the middle part of the sieve plate 15, which is facing the gas outlet 14 of the pre-separator, so the mixed gas must pass through The surrounding sieve holes 17 can enter the gas outlet 14 of the pre-separator to improve the separation efficiency. The oil-air mixture enters the main separator 5 through the air outlet pipe 2 of the pre-separator, and after being filtered by the filter element 56, the separated oil flows back to the oil pan through the oil return port of the main separator, and the separated air flows to the air outlet pipe 7 of the main separator . The main separator 5 has a pressure regulating function. When the filter element 56 is blocked by too much impurities, the pressure in the main separator 5 will continue to rise. When it reaches the specified upper limit, the lower end surface of the lower plate 82 of the first pressure regulating valve will When the gas pressure is greater than the spring pressure, the compression spring opens the air outlet 57, and the oil-air mixture is directly discharged into the atmosphere through the air outlet 57, and the crankcase pressure also decreases thereupon. Since the ventilation system is closed, the crankcase and the intake pipe are connected. When the engine is working, there is negative pressure in the intake pipe. When the negative pressure value is large, the crankcase pressure will be too low. Now because the atmospheric pressure is greater than the crankcase pressure, when the crankcase pressure is lower than the limit value, the second pressure regulating valve moves to the left under the effect of the pressure difference to block the air outlet 59 of the main separator. The first pressure regulating valve and the second pressure regulating valve jointly ensure that the crankcase pressure is maintained within a stable range.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. The foregoing embodiments have described the utility model in detail, and those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the scope of the inventive concept of the present utility model are included in the protection scope of the present utility model.

Claims (9)

1. a crankcase closed system of ventilation, comprise the preseparator (1) and main separator (5) that are equipped with suction port and air outlet, it is characterized in that described preseparator suction port (13) and preseparator air outlet (14) are oppositely arranged, described preseparator (1) comprises the supercharging section (19) that its internal diameter increases the segregation section (12) in bell mouth shape gradually and is connected with segregation section (12) maximum inner diameter end, the outer end of described segregation section (12) is provided with preseparator suction port (13), the outer end of described supercharging section (19) is provided with preseparator air outlet (14) and is connected with preseparator steam outlet pipe (2) at preseparator air outlet (14) place, described preseparator (1) is provided with preseparator return opening bottom it, described preseparator return opening is connected with the first return tube (3), the other end of described preseparator steam outlet pipe (2) is connected with main separator suction port, the filter core (56) its inner chamber being divided into filter ante-chamber and filter back cavity is provided with in described main separator (5), described main separator (5) is provided with and filters the main separator suction port (61) that ante-chamber is communicated with and the main separator air outlet (59) be communicated with filter back cavity, main separator air outlet (59) place is connected with main separator steam outlet pipe, described main separator (5) correspondence filter ante-chamber is provided with the first pressure regulator valve, described main separator (5) correspondence filter back cavity is provided with the second pressure regulator valve, the bottom of described main separator (5) is provided with main separator return opening, described main separator return opening is connected with the second return tube (58).

2. the crankcase closed system of ventilation according to claim 1, it is characterized in that described main separator (5) comprises the main body of tubular vertical setting, described filter core (56) and main body are coaxially set, the top of described main body is connected with air inlet pressure regulation section (51), the sidepiece of described air inlet pressure regulation section (51) is provided with main separator suction port (61), the top of described air inlet pressure regulation section (51) is fixed with the end plate (52) closed, described end plate (52) offers air outlet hole (57), described air outlet hole (57) is provided with the first pressure regulator valve air outlet hole (57) can opened when cavity pressure is greater than specified value before filtering, the top of described air inlet pressure regulation section (51) is provided with end cap (53), gap of giving vent to anger is provided with between described end cap (53) and air inlet pressure regulation section (51), the sidepiece of described main body is connected with pressure regulation section (54) of giving vent to anger, described sidepiece of giving vent to anger pressure regulation section (54) is provided with main separator air outlet (59), described end of giving vent to anger pressure regulation section (54) is provided with closing cap (60), described closing cap (60) offers vent (62), described in give vent to anger to be provided with in pressure regulation section (54) when after filtering, cavity pressure is normal, vent (62) is closed, hypotony time the second pressure regulator valve that main separator air outlet (59) can be closed.

3. the crankcase closed system of ventilation according to claim 2, it is characterized in that described first pressure regulator valve comprises the connecting rod (83) inserting air outlet hole (57), the two ends of air outlet hole (57) are all stretched out at the two ends of described connecting rod (83), the two ends up and down of described connecting rod (83) are connected to upper plate (81) and the lower plate (82) that its minimum dimension is all greater than air outlet hole (57) internal diameter, and the bar section of described connecting rod (83) between end plate (52) and lower plate (82) is set with Returnning spring (84).

4. the crankcase closed system of ventilation according to claim 2, it is characterized in that described second pressure regulator valve comprises its outer surface and can fit with main separator air outlet (59) thus the valve body main separator air outlet (59) closed, the outer end of described valve body is provided with the ring-type limiting board (65) can fitted with closing cap (60) internal surface, is set with the spring (63) that can be pressed on closing cap (60) in described valve body.

5. the crankcase closed system of ventilation according to claim 1, it is characterized in that described supercharging section (19) cylindrically, described preseparator return opening is arranged on the bottom of supercharging section (19), in described supercharging section (19), sieve plate (15) is installed, bottom and supercharging section (19) internal surface of described sieve plate (15) had oil-gap, described sieve plate (15) is evenly equipped with multiple sieve aperture (17), described sieve aperture (17) is distributed in the outside that air outlet projects at sieve plate (15).

6. the crankcase closed system of ventilation according to any one of claim 1 to 5, is characterized in that described preseparator is provided with flange (11) at its suction port place.

7. the crankcase closed system of ventilation according to claim 6, is characterized in that described main separator (5) is fixed with mounting bracket (4).

8. the crankcase closed system of ventilation according to claim 6, is characterized in that described main separator steam outlet pipe (7) is upwards bent to form inverted U-shaped successively successively, and is obliquely installed.

9. the crankcase closed system of ventilation according to claim 2, the closing cap (60) of pressure regulation section (54) of giving vent to anger described in it is characterized in that is provided with safety cover (55), and (55) offer air passing hole with safety cover.