JPS6233052Y2 - - Google Patents

Description

[Detailed explanation of the idea]

This invention relates to a blowby gas recirculation device for a diesel engine that appropriately returns blowby gas leaking into the engine to the intake pipe and effectively removes lubricating oil contained in the gas. In general, diesel engines take in much more air during combustion than gasoline engines, so until now, unlike gasoline engines, special measures have been taken to deal with the unburned gas that leaks into the engine, so-called blow-by gas. There was no need to take this into account, but as exhaust regulations for vehicle engines have become stricter, measures have been taken to treat blow-by gas even in vehicle diesel engines. A reflux device with a built-in valve body operated by negative pressure in the manifold, or a diaphragm biased by a spring installed between the cover and the diaphragm to the blow-by gas pressure. Some models have a reflux device that can be pushed up and mounted directly on the head cover. However, in the former case, when the engine rotates at high speeds when the intake negative pressure increases, it is necessary to replenish the intake of outside air from an air cleaner, etc., and extra piping is required for this, and the performance of the air cleaner is affected. In addition, the latter has the disadvantage that there are limits to the selection of springs and it cannot be expected to operate at gas pressure close to atmospheric pressure.
Furthermore, these devices only recirculate gas and cannot treat oil contained in the gas, requiring a separate device to separate the oil. Therefore, this idea was devised to eliminate the above-mentioned inconvenience, and allows a certain amount of blow-by gas to be smoothly returned to the crank chamber even when the engine is running at high speed, eliminating the need for replenishment of outside air or the difficult selection of springs. Moreover, the present invention provides a reflux device that can efficiently separate oil in blow-by gas and return it to the engine.A partition wall is provided in the main body of the device to divide the reflux chamber into a separation chamber. The reflux chamber is connected to the engine head cover through a center hole, and the reflux chamber is provided with an inlet pipe that protrudes from the partition wall, and the partition wall is provided with an orifice that communicates with the separation chamber.The front end of the reflux chamber is provided with a diaphragm that opens and closes the inlet pipe. In the separation chamber, perforated plates with many pores and filter members made of a porous material such as metal are erected in multiple stages at alternating intervals, and an outlet pipe is installed at the rear end of the separation chamber. It is characterized by having an oil return pipe and a cover plate attached to the top end. The embodiment will be explained with reference to the drawings.
In FIGS. 1 and 2, reference numeral 1 denotes the main body of the apparatus, which has a reflux chamber A in the front (on the left side in the figure) that is almost lappa-shaped and a rectangular parallelepiped in the rear (on the right side) due to a partition wall 1a in the middle. It is divided into a separation chamber B with an open upper end, and a circular flange 2 is located on the lower side of the reflux chamber A, and a diesel engine head cover C is provided.
The center hole 2a is aligned with the through hole Ca of the head cover C, and an inlet pipe 3 is provided in the reflux chamber A and projects forward from the partition wall 1a. A diaphragm 4 is removably fixed together with a cover 5, and the center of the diaphragm 4 normally comes into contact with the front end of the inlet pipe 3 to close it, and a partition wall 1a that is located below the proximal end of the inlet pipe 3 An orifice 6 communicating with the separation chamber B is provided in the portion. On the other hand, the separation chamber B is equipped with an outlet pipe 7 at the rear end and an oil return pipe 8 at the side of the bottom wall.
A groove 11 for flowing the separated oil is provided in the central longitudinal direction of the bottom wall 10, and a plurality of ribs 12 and lateral grooves 13 are alternately provided perpendicular to the groove 11, and a first lateral groove in the front 13 is formed wider than the others. FIG. 3 shows a plurality of perforated plates 14 in separation chamber B.
The first perforated plate 14 at the front has a large number of pores 14a on the left half, and a pair of spacers 14c protruding rearward at the center of the lower end. are provided on both sides of the upper end, and locking pieces 14b are provided on both sides of the upper end to protrude rearward and laterally to the same extent as the spacer 14c, while the first filter member 15 is made of a porous body (made of a metal melt-treated with foamed resin). It is made of a so-called CELMET or a porous material having the same effect, and is formed into a thick plate shape with a flat front surface and a thick wall except for the peripheral edge, and is provided with locking pieces 15b on both sides of the upper end. The first perforated plate 14 and the first filter member 15 are connected to the locking piece 14b of the perforated plate and the spacer 14.
abut the front surface of the filter member 15 on the back surface of c;
Their overlapping lower ends were fitted into the first horizontal groove 13 and erected close to the bottom wall 10, and the locking pieces 14b and 15b on both sides of each upper end were formed on the upper surface of the side wall of the separation chamber B. It is engaged in the recess 16. In addition, a second perforated plate 14 having the same shape as the first perforated plate 14 is turned over and its lower end is fitted into a narrow second horizontal groove 13 formed at the rear of the first horizontal groove 13. Similarly, the locking pieces 14b on both sides of the upper end are engaged with the second recesses 16 on the upper surface of the side wall. Therefore, the positions of the pores 14a of the first and second perforated plates 14 are different on the left and right sides. Furthermore, a first filter member 15 is provided in the third horizontal groove 13 at the rear.
The same filter member is used as a second filter member, and its lower end is fitted, and the upper end locking piece 15b is engaged with the third recess 16 on the upper surface of the side wall. Thus, the upper end opening of the separation chamber B is covered with an elastic plate 17 made of rubber, synthetic resin, etc., and the upper end of each perforated plate 14 and the filter member 15 is covered with a plurality of concave protrusions 17a provided on the lower surface of the elastic plate 17. is fitted, a cover plate 18 is applied thereon, and the cover plate 18 is detachably attached to the separation chamber B with screws. In its use, the outlet pipe 7 is connected to the intake pipe by a pipe, and the return pipe 8 is connected to the crank chamber. Here, in diesel engines for vehicles, the negative pressure in the intake manifold changes greatly depending on the rotation speed.

In contrast to [Formula], the amount of blow-by gas leaking into the engine does not change much.

[Formula] Generally in the range of 30/min to 40/min. Therefore, when the engine is running and rotating at low speed, the negative pressure in the intake pipe is not so large, so the diaphragm 4 in the recirculation chamber A is pushed forward (to the left) by the pressure inside the engine, and the head cover C hole
Most of the blow-by gas that entered the reflux chamber A through Ca and the central hole 2a passes through the inlet pipe 3, and a portion flows into the separation chamber B through the orifice 6. At times, the negative pressure in the intake pipe becomes high as described above, and the diaphragm 4 is pulled by it to close the inlet end of the inlet pipe 3, so that the blow-by gas in the reflux chamber A is exclusively squeezed through the orifice 6. It will flow into separation chamber B. In this way, the blow-by gas, which leaks in a substantially constant amount, is smoothly moved regardless of the rotation of the engine, and the interior of the engine is maintained at approximately atmospheric pressure. Thus, the blow-by gas that has flowed into the separation chamber B is first accelerated by passing through the pores 14a of the first perforated plate 14, and collides with the filter member 15 located immediately after it, and penetrates into the inside thereof. As a result, oil particles of various sizes present in the gas adhere to the porous internal structure of the filter, and these particles gradually move backwards due to the influence of the gas flow, and in the process, they gradually become coarser, causing the filter member 4 to become coarse. It comes out on the back side, becomes large oil droplets and falls on the bottom wall 10, and
The gas that has passed through the first filter member 4 flows through the pores 14 of the second perforated plate 14 while rotating from the left side to the right side.
a, the separation of the remaining oil particles is promoted by the centrifugal action at that time, and furthermore, the oil particles are accelerated by passing through the pores 14a of the second perforated plate 14 and penetrated into the second filter member 15. The oil capturing operation is repeated, and the gas from which the oil has been sufficiently removed flows from the outlet pipe 7 to the intake pipe. On the other hand, the oil separated from the gas stream is removed from the bottom wall 10.
It collects in the longitudinal groove 11 of and is returned to the crank chamber from the return pipe 8. As described above, in this invention, the main body of the device is divided into a reflux chamber and a separation chamber by a partition wall equipped with an inlet pipe, and a diaphragm is installed in the reflux chamber to open and close the inlet pipe without being biased by a spring. The reflux chamber and the separation chamber are communicated with each other by an orifice, and the separation chamber is constructed with alternating perforated plates and filter members, so that the intake negative pressure during high-speed rotation of the engine is prevented. When the diaphragm closes the inlet pipe, a fixed amount of blow-by gas can smoothly flow through the orifice from the reflux chamber to the separation chamber leading into the crank, and the pressure inside the crank chamber is adjusted without the need for outside air. and,
It is possible to prevent the stuck phenomenon when the diaphragm is closed, the opening and closing operation becomes smooth and stable, and the inside of the engine can be maintained at a state close to atmospheric pressure at all times. In addition, in the separation chamber, the blow-by gas containing many oil particles is accelerated through the pores of the perforated plate, and the oil particles collide with the filter member with force, capturing them and returning them to the engine. Oil can be efficiently removed from gas, and wasteful consumption of oil and increase in pressure loss due to clogging of the filter member can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of this invention. FIG. 2 is a plan view of the device with the lid plate removed. FIG. 3 is a perspective view showing the arrangement of oil separation members. In the figure, 1... device main body, 1a... bulkhead, 2...
Flange, 2a...center hole, 3...inlet pipe,
4...Diaphragm, 5...Cover, 6...Orifice, 7...Outlet pipe, 10...Bottom wall, 11
...Longitudinal groove, 12...Rib, 13...Horizontal groove,
14... Perforated plate, 14a... Pore, 15... Filter member, 17... Elastic plate, 18... Lid plate.

Claims (1)

[Scope of utility model registration request] A partition wall 1a is provided in the device main body 1 to divide it into a reflux chamber A and a separation chamber B, and the reflux chamber A is communicated with the inside of the head cover of the engine through a center hole 2a. An orifice 6 communicating with the separation chamber B is provided in the partition wall 1a, and an inlet pipe 3 is provided at the front end of the reflux chamber A.
A diaphragm 4 for opening and closing is attached, and in the separation chamber B, a perforated plate 14 having a large number of pores 14a and a filter member 15 made of a porous material such as metal are erected in multiple stages at alternate intervals. , an outlet pipe 7 and an oil return pipe 8 at the rear end of the separation chamber B.
A blow-by gas recirculation device for a diesel engine is provided with a cover plate 18 at the upper end.