KR100748419B1 - Oil separation structure and internal combustion engine - Google Patents

Abstract

In the oil separation structure that separates the oil mist from the blow-by gas from the crankcase, the oil is separated from the filter well to prevent clogging and to reduce the maintenance frequency.

A filter 4 is provided for separating oil, and the filter 4 is configured to allow blow-by gas to pass from top to bottom. In other words, the blow-by gas introduced into the filter 4 is configured to escape from the lower surface of the filter 4, and is configured such that the direction exiting from the lower surface substantially coincides with the direction of gravity. The blow-by gas escaped from the lower surface of the filter 4 is configured to return to the intake side, and the oil collected by the filter 4 falls in the form of oil droplets from the lower surface of the filter 4, and then into the crankcase. Go back.

Description

OIL SEPARATION STRUCTURE AND INTERNAL COMBUSTION ENGINE}

BRIEF DESCRIPTION OF THE DRAWINGS The schematic cross section which shows the oil separation structure which concerns on one Embodiment of this invention.

* Explanation of symbols for the main parts of the drawings *

1: oil separation structure

2: case

3: gas inlet

4 filter (filter, or filter element)

5: oil outlet

6: gas outlet

Japanese Laid-Open Patent Publication No. 2002-242645 (paragraph 0011, 0012, Fig. 1).

The present invention relates to an oil separation structure for separating oil mist from blow-by gas generated in an engine. And an internal combustion engine having such an oil separation structure.

When the engine is operated, a small amount of unburned gas (blow by gas; BBG) is usually leaked into the crankcase at the clearance between the cylinder block and the piston and the piston ring. If the blow-by gas is discharged as it is, the load on the environment increases, and if it stays inside the engine, corrosion of the engine or deterioration of the oil may occur, so that the blow-by gas is returned to the intake manifold for combustion. Positive Crankcase Ventilation (PCV) has been proposed conventionally.

In this configuration, blow-by gas is usually supplied from the crankcase to the intake manifold through the PCV passage or the like. However, since a large amount of oil is scattered inside the crankcase (crankcase), the blow-by gas supplied from the crankcase contains a large amount of oil particles (oil mist). If the blow-by gas in this state is sent to the intake manifold as it is, the consumption of oil is deteriorated, and the HC of the exhaust gas is increased in that the oil is recycled during intake. In addition, when the oil mist (or particles of combustion products of oil) in the blow-by gas adheres to a valve operation system or the like, deposits are deposited.

Therefore, Patent Literature 1 proposes a separation device for separating oil mist contained in blow-by gas before sending it to the intake side. In this patent document 1, a cylindrical fibrous adsorbent is provided so as to partition a space in a cylindrical case with a bottom in a radial direction, and blow-by gas introduced into the adsorbent from the gas inlet on the upper surface of the casing causes the adsorbent to move from the inside in the radial direction. It exits to the outside and is discharged from the gas outlet on the side of the case. At this time, the oil mist is adsorbed by the adsorbent, and the oil seeping out of the adsorbent returns to the crankcase at the oil outlet at the bottom of the case.

However, in the structure of the said patent document 1, the oil mist collected by the fibrous adsorption material falls by the weight of itself, and is easy to stick to the lower side. That is, since oil is unevenly distributed on the lower side of the adsorbent, the blow-by gas passes only through the upper side of the adsorbent, which is a portion of low resistance. As a result, the entire area of the adsorbent cannot be effectively used in the collection of the oil mist, so that the collecting performance of the oil mist is lowered and the pressure loss is increased.

In addition, the localization of oil in such a fibrous adsorbent tends to cause clogging, especially in the lower part of the adsorbent. In view of this, Patent Literature 1 discloses a configuration in which a filter device including an adsorbent can be replaced. However, as described above, clogging is likely to occur, and thus the number of maintenance steps is increased due to frequent replacement of filters.

Moreover, since the shape of the filter is cylindrical, the structure of the said patent document 1 swells easily, and compactness was difficult.

The problem to be solved by the present invention is as described above. Next, the means for solving this problem and its effects will be described.

According to the first aspect of the present invention, there is provided an oil separation structure of blow-by gas, comprising a filter element for separating oil, and configured to allow the blow-by gas to pass through the filter element from top to bottom.

According to this configuration, since the inside of the filter element passes through the blow-by gas from the top to the bottom, the oil in the filter element collected from the blow-by gas drops due to its weight, and at the same time, the oil is used by the flow of the blow-by gas. It can be pushed down. Therefore, the oil separability of the filter element becomes very good, and the number of maintenance steps can be reduced or zero (maintenance free). In addition, since the blow-by gas is configured so that the filter element passes from the top to the bottom, the shape of the filter element can be configured, for example, in a simple cuboid shape, so that the oil separation structure can be easily compacted.

In the oil separation structure of the blow-by gas, it is preferable that the vertical thickness of the filter element is configured to be substantially the same.

This makes it possible to equalize the resistance when the blow-by gas passes through the filter element and allow the blow-by gas to pass through the entire area of the filter element. Therefore, the pressure loss is not excessive and the blockage is small, so that the oil mist can be stably collected.

According to the second aspect of the present invention, the blow-by gas introduced into the filter element for separating oil is configured to exit from the lower surface of the filter element, and the direction exiting from the lower surface is almost the same as the direction of gravity. A matching blow bar gas oil separation structure is provided.

For this reason, the oil in the filter element collected from the blow-by gas and pushed to the lower surface side can be pushed downward from the lower surface and discharged by the flow of blow-by gas. Therefore, the oil separability of the filter element becomes very good, and the number of maintenance steps can be reduced or zero (maintenance free).

In the oil separation structure of the blow-by gas, the following configuration is preferable. The blow-by gas is configured to escape from the lower surface of the filter element and return to the intake side. The oil collected by the filter element falls in the form of oil droplets from the lower surface of the filter element, and then returns to the engine crankcase.

According to this structure, since the oil which escaped from the filter element falls as large oil droplets, the oil does not enter the blow-by gas through which the oil mist was removed through the filter element. Therefore, it is possible to avoid the incorporation of oil again by blow-by gas. In addition, the space below the filter element can be used as a passage of oil and a passage of blow-by gas, and a special structure for distinguishing both passages is not necessary, so that a simple and compact oil separation structure can be realized.

In the oil separation structure of blow-by-gas, it is preferable to be used for the engine for gas heat pumps.

In other words, the oil separation structure has a good oil separation, so that the filter element is less clogged and the maintenance frequency can be reduced to zero (maintenance free), so that the engine for a gas heat pump is expected to have a long continuous operation. It is especially preferable to use.

According to a third aspect of the present invention, there is provided an internal combustion engine having the oil separation structure and having the filter element embedded in the engine main body.

This makes it possible to realize a compact engine with a low load on the environment and a low sediment problem.

(The best mode for carrying out the invention)

Next, an embodiment of the invention will be described with reference to FIG. 1. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic cross section which shows the oil separation structure which concerns on one Embodiment of this invention.

This oil separation structure 1 is provided with the case 2, The gas inlet 3 is formed in the upper surface. From the gas inlet 3, blow-by gas from the crank chamber of the engine driven heat pump apparatus engine is introduced into the case 2 through piping not shown.

The filter 4 as a filter element is supported by the case 2 so as to partition the space in this case 2 up and down. This filter 4 laminates the filter material of predetermined thickness (several millimeters-several tens of millimeters) comprised from a nonwoven fabric in the up-down direction, and is comprised in substantially rectangular parallelepiped form. The horizontal size of the filter 4 is slightly larger than the inner space of the case 2, and the filter 4 is fitted into the case 2 so that the side edge of the filter 4 and the inner wall of the case 2 are positioned. Is tight and sealed so that blow-by gas does not pass between the filter and the inner wall.

An oil outlet 5 is formed on the lower surface of the case 2, and the oil separated by the filter 4 is returned to the crankcase of the engine at the oil outlet 5.

In addition, a gas outlet 6 is formed on the side of the case 2 below the filter 4. Blow-by gas from this gas outlet 6 is supplied to the intake side of the engine.

With the above configuration, the blow-by gas mixed with the oil mist is introduced into the case 2 from the gas inlet 3 through the pipe (not shown) from the crankcase, as shown by the hatching arrow of FIG. Go inside from the top. And as the blow-by gas flows in the filter 4 from top to bottom, the oil mist contained in it is collected by the filter 4. The blow-by gas from which the oil mist has been removed escapes downward from the lower surface of the filter 4 and returns to the intake side of the engine via the gas outlet 6 as indicated by the white arrow.

On the other hand, the oil mist collected by the filter 4 descends the inside of the filter 4 due to its own weight, which helps the flow of blow-by gas inside the filter 4. Therefore, the oil smoothly drops down the inside of the filter 4 (so-called forcibly) and easily escapes from the lower surface of the filter 4. The oil drops from the lower surface of the filter 4, forms oil droplets, falls to the bottom of the case 2, and then returns to the crankcase from the oil outlet 5 via a pipe (not shown).

As shown above, in the oil separation structure of the present embodiment, a filter 4 for separating oil is provided, and the filter 4 is configured such that blow-by gas passes from the top to the bottom.

Thus, the oil collected by the blow-by gas is introduced into the filter 4 moves downward due to its weight, but the movement is supported by the phenomenon that the blow-by gas in the filter 4 flows from the top to the bottom. Therefore, the oil can be pushed downward by the blow-by gas and actively discharged from the filter 4, so that the oil can be separated from the filter 4 satisfactorily.

In addition, in the oil separation structure of the present embodiment, the blow-by gas introduced into the filter 4 exits from the lower surface of the filter 4, and the blow-by gas exits from the lower surface of the filter 4. Almost coincides with this direction of gravity.

Thus, the oil collected by the blow-by gas is introduced into the filter 4 is easily pushed by the flow (flow from top to bottom) that the blow-by gas is about to escape from the bottom of the filter 4 and easily matches the own weight of the oil itself. Discharged from the lower surface of the filter 4. As a result, the oil can be actively discharged from the filter 4, so that the oil can be satisfactorily separated from the filter 4.

In addition, in the oil separation structure of the present embodiment, the blow-by gas escaped from the lower surface of the filter 4 is returned to the intake side from the gas outlet 6, while the oil collected by the filter 4 is separated from the filter 4. It is comprised so that it may fall in the form of oil droplets from a lower surface, and return to a crankcase from the oil discharge port 5 after that.

By this structure, the oil which escaped from the filter 4 becomes oil droplets much larger than the particle | grains of an oil mist, and falls from the lower surface of the filter 4. Therefore, as long as the flow rate of the blow-by gas is not very large, the oil is not mixed in the blow-by gas through which the oil mist is removed through the filter 4. As a result, oil can be prevented from being mixed in the blow-by gas discharged from the gas outlet 6 (in other words, oil can be avoided from being mixed again by the blow-by gas). In addition, since the space under the filter element can be used both as part of the oil passage and part of the blow-by gas passage, the oil separation structure 1 can be simplified and compact.

And in the oil separation structure of this embodiment, the filter 4 is comprised by the shape of the substantially same thickness of the up-down direction. Therefore, since the resistance when the blow-by gas passes through the filter 4 becomes uniform, it is possible to flow the blow-by gas evenly over the entire area of the filter 4. Therefore, even if the pressure loss does not become excessive and the engine operation period becomes long, clogging can be reduced, and oil mist can be stably collected.

As mentioned above, although embodiment of this invention was described, the said embodiment can also be changed and implemented as follows.

(1) In this embodiment, an example of the oil separation structure used for the gas heat pump engine is shown, but the oil separation structure of the present invention is not limited to the case used for the gas heat pump engine. However, since the oil separation structure of the present invention can separate oil satisfactorily, the filter is less clogged and the maintenance frequency can be reduced or maintained free, so that the engine for a gas heat pump for a long time of continuous operation is assumed. Particularly preferred.

(2) In this embodiment, as shown in FIG. 1, although it is set as the external installation type oil separation structure, it is of course possible to make the said filter 4 into the engine main body, and to set it as the engine built-in oil separation structure. As a specific structure, the blow which passed the filter 4, for example, provided the filter 4 in the head cover, connecting the space in the crankcase and the inner space of the head cover (upper space of the filter 4). It is conceivable to configure the gas to be led to the intake side and return the oil dropped from the filter 4 to the locker chamber into the crankcase. In this case, a compact structure with space saving can be realized. In addition, in the present invention, since the filter 4 can be formed in a simple and compact shape (for example, a rectangular parallelepiped shape), it is also easy to provide an oil separation structure inside the engine.

In this case, when the engine is built-in type, a constitution for solving a problem occurring when the oil separation structure is disposed outside the engine (for example, to prevent condensate generation during cold operation such as JP-A-7-269326) It is not necessary to form a heater or to employ an integrally molded resin housing in order to improve the airtightness of the housing of the oil separation structure as in Japanese Patent Laid-Open No. 2002-266621). In addition, in the built-in type, the maintenance of the filter 4 becomes slightly difficult. However, in the present invention, since the replacement frequency of the filter 4 can be made very small as described above, this is not a problem.

(3) The gas inlet 3 is not limited to being formed on the upper surface of the case 2, and may be formed on the side surface of the case 2 as long as it is the upper side of the filter 4. Similarly, the structure may be formed in the lower side of the side without forming the oil outlet 5 in the bottom face of the case 2.

According to the structure of this invention, the oil separability of a filter element becomes very favorable, the number of maintenance processes can be made small or zero (maintenance free), and the shape of a filter element can be comprised, for example in simple cuboid shape. It is easy to compact the oil separation structure.

In addition, the resistance when the blow-by gas passes through the filter element is equalized to allow the blow-by gas to pass through the entire area of the filter element. Therefore, the pressure loss is not excessive and the blockage is small, so that the oil mist can be stably collected.

In addition, the oil separability of the filter element is very good, so that the number of maintenance steps can be reduced or zero (maintenance free).

In addition, it is possible to avoid the oil from being mixed again by the blow-by gas, and the space below the filter element can be used as the passage of the oil and the passage of the blow-by gas, and no special configuration is required to distinguish the two passages. Simple and compact oil separation structure can be realized.

In addition, the present invention can realize a compact engine having a low load on the environment and a low sediment problem.

Claims (8)

With the case, A filter element supported to partition the space inside the case up and down to separate oil; A gas outlet formed on a side of the case below the filter element and connected to an intake side of the engine; The blow-by gas passes through the filter element from top to bottom, and then returns to the intake side through the gas outlet. 2. The oil separation structure of blow-by gas according to claim 1, wherein the filter element is formed in a shape having substantially the same thickness in the vertical direction. With the case, A filter element supported to partition the space inside the case up and down to separate oil; A gas outlet formed on a side of the case below the filter element and connected to an intake side of the engine; The blow-by gas oil passing through the inside of the filter element exits from the lower surface of the filter element in a direction substantially similar to the direction of gravity, and then passes through the gas outlet to return to the intake side. Separation structure. The method according to any one of claims 1 to 3, Blowing gas oil separation structure, characterized in that the gas inlet is formed on the upper surface of the case. The method according to any one of claims 1 to 3, An oil separation structure of blow-by gas, which is used in an engine for a gas heat pump. An internal combustion engine characterized by having an oil separation structure of blow-by-gas according to any one of claims 1 to 3, wherein said filter element is built in an engine main body. An internal combustion engine, wherein the oil separation structure of the blow-by gas according to any one of claims 1 to 3 is provided outside the engine body. 4. The oil separation structure of blow-by gas according to any one of claims 1 to 3, wherein the filter element is cuboid.

Images