Structure for increasing negative pressure
Technical Field
The utility model relates to an engine, more specifically say, it relates to a structure that increases the negative pressure.
Background
GB17691 and 2018 national emission Standard for heavy-duty vehicles requires the crankcase ventilation system to be as follows: "c.5.11 measures the crankcase emissions of the ignition engine, the crankcase pressure should be measured at a proper position during the whole test and training process, the pressure measurement accuracy should be within ± 1kPa, and the crankcase pressure is not greater than the atmospheric pressure", that is, the gas engine crankcase pressure needs to be maintained at a negative pressure. Conventional crankcase ventilation systems exist: an open circulation system, a centrifugal oil-gas separator and a closed circulation system are adopted. The open circulation system is directly communicated with the atmosphere and can not form negative pressure. The conventional centrifugal oil-gas separator has low centrifugal force, insufficient generated suction force and small negative pressure, and can not ensure that the pressure of a crankcase is not more than atmospheric pressure under any working condition. A supercharger anti-surge valve pipe A and a crankcase ventilation pipe B of the existing closed circulation system are converged in advance (shown in figure 1) or have too close gaps (shown in figure 2), and when the supercharger anti-surge valve works, air flow in the crankcase ventilation pipe B can be interfered, so that the crankcase pressure is greater than the atmospheric pressure and cannot meet the requirement. Therefore, increasing the ventilation negative pressure of the crankcase of the gas engine becomes an important issue.
SUMMERY OF THE UTILITY MODEL
The to-be-solved technical problem of the utility model is not enough to the above-mentioned of prior art, the utility model aims at providing a structure that can guarantee that crankcase pressure stability is less than atmospheric pressure's increase negative pressure.
The technical scheme of the utility model is that: the utility model provides an increase structure of negative pressure, includes closed circulation crankcase, booster, still includes oil-gas separation mechanism, the ventilation pipe of closed circulation crankcase passes through oil-gas separation mechanism connects the intake duct of the compressor front end of booster, the ventilation pipe is located between the anti-surge valve pipe of booster and the compressor, interval between ventilation pipe and the compressor is less than interval between ventilation pipe and the anti-surge valve pipe, the ventilation pipe is connected the one end of intake duct to the slope of compressor direction is extended or is equipped with towards the first scarf of compressor.
As a further improvement, one end of the anti-surge valve pipe, which is connected with the air inlet channel, is obliquely extended or provided with a second inclined notch which is opposite to the air compressor in a mode of being opposite to the direction of the air compressor.
Furthermore, the included angle between the anti-surge valve pipe and the air inlet channel is 30-90 degrees.
Further, the distance between the ventilation pipe and the anti-surge valve pipe is larger than 200 mm.
Further, the oil-gas separation mechanism is an oil-gas separator with the model number of H100-140.
Further, the oil-gas separation mechanism is a gas-oil displacement gas separator, and a compressed air inlet end of the gas-oil displacement gas separator is connected with an automobile air tank or an air inlet channel at the rear end of the air compressor through an air pipe.
Further, the oil-gas separation mechanism is an oil-gas displacement separator, and the oil inlet end of the oil-gas displacement separator is connected with a high-pressure engine oil main oil gallery of the engine.
Advantageous effects
Compared with the prior art, the utility model, the advantage that has does: the utility model discloses a set up the interval between ventilation pipe and the compressor and be less than the interval between ventilation pipe and the anti-surge valve pipe to set up ventilation pipe one end and extend or be equipped with towards the first scarf joint of compressor to the slope of compressor direction, can slow down the influence of anti-surge pipe air current to the ventilation pipe, increase the suction of compressor to the interior air of crankcase, can effectively guarantee that crankcase internal pressure is stable and is less than atmospheric pressure, ensure to satisfy "GB 17691 plus 2018 heavy-duty vehicle state six emission standard" crankcase pressure and be not more than atmospheric pressure's requirement.
Drawings
FIG. 1 is a schematic diagram of an anti-surge valve pipe and a vent pipe in advance converging in the prior art;
FIG. 2 is a schematic diagram of a conventional anti-surge valve pipe being too close to a vent pipe;
FIG. 3 is a schematic structural view of the connection between the ventilation pipe and the compressor of the present invention;
fig. 4 is a schematic structural diagram of embodiment 1 of the present invention;
fig. 5 is a schematic structural diagram of embodiment 2 of the present invention;
fig. 6 is a schematic structural view of embodiment 3 of the present invention.
Wherein: the device comprises a closed circulation crankcase 1, a supercharger 2, an oil-gas separation mechanism 3, a ventilation pipe 4, a gas compressor 5, an air inlet 6, an anti-surge valve pipe 7, a first inclined notch 8, a gas pipe 9 and an oil return pipe 10.
Detailed Description
The invention will be further described with reference to specific embodiments shown in the drawings.
Referring to fig. 3-6, a structure for increasing negative pressure comprises a closed circulation crankcase 1, a supercharger 2 and an oil-gas separation mechanism 3, wherein a ventilation pipe 4 of the closed circulation crankcase 1 is connected with an air inlet 6 at the front end of a compressor 5 of the supercharger 2 through the oil-gas separation mechanism 3, the ventilation pipe 4 is located between an anti-surge valve pipe 7 of the supercharger 2 and the compressor 5, a distance L1 between the ventilation pipe 4 and the compressor 5 is smaller than a distance L between the ventilation pipe 4 and the anti-surge valve pipe 7, one end of the ventilation pipe 4, which is connected with the air inlet 6, extends obliquely towards the compressor 5 or is provided with a first oblique notch 8 facing the compressor 5, so that the suction force of the compressor 5 on air in the closed circulation crankcase 1 can be increased, namely, the negative pressure is increased, the L1 can be reduced as much as possible to improve the suction force, and the.
Furthermore, one end of the anti-surge valve pipe 7, which is connected with the air inlet 6, is obliquely extended in a direction back to the air compressor 5 or is provided with a second inclined notch back to the air compressor 5, so that the influence of the air flow of the anti-surge valve pipe 7 on the ventilation pipe 4 can be effectively relieved, and the stability of the negative pressure in the closed circulation crankcase 1 is improved. Preferably, the included angle alpha between the anti-surge valve pipe 7 and the air inlet 6 is 30-90 degrees, and the distance between the vent pipe 4 and the anti-surge valve pipe 7 is more than 200 mm.
Example 1
The oil-gas separation mechanism 3 is an oil-gas separator with the model number of H100-140, and has simple structure and convenient installation.
Example 2
The oil-gas separation mechanism 3 is a gas-oil displacement gas separator, the compressed air inlet end of the gas-oil displacement gas separator is connected with an automobile gas tank or an air inlet channel 6 at the rear end of the compressor 5 through an air pipe 9, the oil outlet end of the gas-oil displacement gas separator is connected with an engine through an oil return pipe 10, and compressed air drives an oil-gas separation filter element to rotate at a high speed, so that the increase of negative pressure in the closed circulation crankcase 1 is facilitated.
Example 3
The oil-gas separation mechanism 3 is an oil-gas displacement separator, the oil inlet end of the oil-gas displacement separator is connected with a main oil gallery of high-pressure engine oil of the engine, the oil-gas displacement separator is installed on an engine body, filtered oil of the oil-gas displacement separator directly flows back to the engine, and the high-pressure engine oil drives an oil-gas separation filter element to rotate at a high speed, so that the increase of negative pressure in the closed circulation crankcase 1 is facilitated.
The utility model discloses a set up the interval between ventilation pipe and the compressor and be less than the interval between ventilation pipe and the anti-surge valve pipe to set up ventilation pipe one end and extend or be equipped with towards the first scarf of compressor to the slope of compressor direction, can slow down the influence of anti-surge pipe air current to the ventilation pipe, increase the suction of compressor to the interior air of crankcase, can effectively guarantee that crankcase internal pressure is stable and is less than atmospheric pressure, ensure to satisfy the requirement that "GB 17691-2018 heavy-duty vehicle state six emission standards" crankcase pressure is not more than atmospheric pressure.
The above is only a preferred embodiment of the present invention, and it should be noted that for those skilled in the art, without departing from the structure of the present invention, several modifications and improvements can be made, which will not affect the utility of the invention and the utility of the patent.