JP4310083B2 - Engine blow-by gas processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes a supercharger provided upstream of a throttle valve in an intake passage, a first blow-by gas passage connecting the upstream position of the intake passage supercharger to the inside of the crankcase, and an intake passage. A second blow-by gas passage connecting the position downstream of the throttle valve to the inside of the crankcase, and provided in the second blow-by gas passage and opened by intake negative pressure, from the crankcase side to the downstream position side of the intake passage The present invention relates to a blow-by gas processing apparatus for an engine provided with a flow rate control valve that allows movement of the blow-by gas.
[0002]
[Prior art]
Such an engine blow-by gas processing apparatus is known from Japanese Utility Model Laid-Open No. 5-87213.
[0003]
The conventional blow-by gas processing apparatus for an engine includes an auxiliary valve provided with a check valve at a position on the crankcase side of the flow control valve in the second blow-by gas passage and a position on the upstream side of the supercharger in the intake passage. Connected by blow-by gas passage. At low load when the turbocharger does not operate, the intake negative pressure generated on the downstream side of the throttle valve sucks fresh air in the intake passage upstream of the supercharger into the valve chamber through the first blow-by gas passage. At the same time, the blow-by gas in the crankcase is sucked into the downstream side of the throttle valve through the second blow-by gas passage where the flow control valve is opened for ventilation. Due to the negative pressure generated upstream of the machine, the blow-by gas in the crankcase is sucked into the intake passage through the auxiliary blow-by gas passage opened by the check valve, and the blow-by gas in the valve operating chamber is drawn into the first blow-by gas passage. The air is sucked into the intake passage through the air and ventilated.
[0004]
[Problems to be solved by the invention]
By the way, the conventional blow-by gas processing device for an engine requires an auxiliary blow-by gas passage provided with a check valve in addition to the first and second blow-by gas passages. In addition to an increase in the number of parts, there is a problem that a space is required for the auxiliary blow-by gas passage. When the auxiliary blow-by gas passage is abolished, the flow control valve of the second blow-by gas passage is closed when the supercharger is operated, and therefore ventilation in the crankcase cannot be performed.
[0005]
The present invention has been made in view of the above circumstances, and it is an object of the present invention to reliably ventilate blow-by gas both when the turbocharger is not operating and when it is operating, while avoiding an increase in the number of parts. And
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, there is provided a supercharger provided upstream of the throttle valve in the intake passage, and a position upstream of the supercharger in the intake passage inside the crankcase. engine comprising a first blow-by gas passage, and a second blow-by gas passage connecting a downstream position than the throttle valve in the intake passage inside the crankcase, and a flow control valve for opening and closing the second blow-by gas passage connecting to In the blow-by gas processing apparatus of the present invention, there is provided control means for controlling the opening degree of the flow control valve according to the supercharging pressure of the supercharger and closing the flow control valve when the maximum supercharging pressure is detected. blow-by gas treatment device for an engine, wherein the Ru been proposed.
[0007]
According to the above configuration of the first aspect of the invention, when the supercharger is not in operation, the control means opens the flow rate control valve provided in the second blow-by gas passage, and is located upstream of the supercharger in the intake passage. Fresh air is drawn to a position downstream of the throttle valve in the intake passage through the first blow-by gas passage, the inside of the crankcase and the second blow-by gas passage in which the flow control valve is opened, and the blow-by gas in the crankcase is ventilated. Is done. When the supercharger is activated and supercharging pressure is generated, the control means opens the flow control valve provided in the second blow-by gas passage to a predetermined opening, and the supercharging pressure causes the control valve to open more than the throttle valve in the intake passage. The fresh air at the downstream position flows into the crankcase through the flow rate control valve opened at the predetermined opening provided in the second blow-by gas passage, and from there through the first blow-by gas passage and upstream of the intake passage throttle valve By flowing to the position, the blow-by gas in the crankcase is ventilated. In addition, since an auxiliary blow-by gas passage is unnecessary in addition to the first and second blow-by gas passages, it is possible to contribute to the reduction of the number of parts and space. Furthermore, by controlling the opening degree of the flow rate control valve by the control means, the flow rate control according to the supercharging pressure becomes possible. In addition, when the maximum supercharging pressure of the supercharger is detected, the flow rate control valve is closed, so that the reduction of the maximum supercharging pressure can be prevented and the engine output can be increased to the maximum.
[0008]
According to a second aspect of the invention, in addition to the feature of the first aspect of the invention, the control means is configured to perform a predetermined time after the flow rate control valve is closed when the maximum boost pressure is detected. An engine blow-by gas processing device is proposed in which the flow rate control valve is controlled to open to a predetermined opening when the time elapses. According to the configuration, acceleration performance by supercharging is ensured when the vehicle is accelerated. However, it is possible to ventilate the crankcase.
[0009]
The compressor 13 of the embodiment corresponds to the supercharger of the present invention, and the electronic control unit U of the embodiment corresponds to the control means of the present invention.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on reference examples shown in the accompanying drawings and examples of the present invention.
[0011]
1 to 4 show a first reference example , FIG. 1 is an overall configuration diagram of a blow-by gas processing apparatus for an automobile engine, FIG. 2 is an enlarged view of a main part of FIG. 1, and FIG. FIG. 4 is a cross-sectional view taken along line -3, and FIG. 4 is an operation explanatory view corresponding to FIG.
[0012]
As schematically shown in FIG. 1, an air cleaner 12, a turbocharger compressor 13, a throttle valve 14, and an intake air are provided in an intake passage 11 of an automobile engine E from the upstream side to the downstream side of the intake air flow. A manifold 15 is arranged. The intake manifold 15 includes a single pipe portion 15a... And a collecting portion 15b, and a flow control valve 19 including a check valve in a second blow-by gas passage 18 that connects the collecting portion 15b and the flow control valve chamber 17 of the engine E. Is placed. Further, the compressor inlet 13 a of the turbocharger and the breather chamber 20 of the engine E are connected by a first blow-by gas passage 21. The inside of the crankcase 22 of the engine E in which blow-by gas containing NOx accumulates communicates with the flow control valve chamber 17 and the breather chamber 20.
[0013]
As shown in FIGS. 2 and 3, a valve seat 34 on which a valve body 33 urged by a valve spring 32 can be seated is provided inside the valve chamber 31 of the flow control valve 19. Is constituted by an annular projecting portion projecting from the inner wall of the valve chamber 31 toward the valve body 33. As shown in FIGS. 1 to 3, the surface of the valve body 33 that faces the valve seat 34 is formed in a spherical shape having a center on the axis of the valve seat 34. Further, a plurality (eight in the reference example) of notches 34a... Are formed on the top surface of the valve seat 34 at equal intervals in the circumferential direction. The flow control valve 19 comprising a check valve opens when the collecting portion 15 b of the intake manifold 15 becomes lower in pressure than the flow control valve chamber 17, and the collecting portion 15 b of the intake manifold 15 is more than the flow control valve chamber 17. Closes when high pressure is reached.
[0014]
Therefore, as shown in FIG. 1, when the engine E is low and the throttle valve 14 is closed and the turbocharger is inoperative, fresh air is introduced into the air cleaner 12 and the compressor 13 by the intake negative pressure generated by the engine E. Then, the air is sucked into the engine E through the throttle valve 14 and the intake manifold 15. At this time, since the flow control valve 19 is opened by the intake negative pressure acting on the collecting portion 15b of the intake manifold 15, a part of the fresh air that has passed through the air cleaner 12 passes from the compressor inlet 13a to the first blow-by gas passage 21, the breather. The air is drawn into the engine E through the chamber 20, the crankcase 22, the flow control valve chamber 17, the second blow-by gas passage 18, and the intake manifold 15. At that time, the blow-by gas in the crankcase 22 is sucked into the engine E together with the fresh air, so that the crankcase 22 is ventilated and the deterioration of the lubricating oil of the engine E due to NOx contained in the blow-by gas is minimized. It can be suppressed to the limit.
[0015]
As shown in FIG. 4, when the engine E in which the throttle valve 14 is opened and the turbocharger is operated has a high load, a supercharging pressure is generated in the intake manifold 15 provided in the intake passage 11 on the downstream side of the compressor 13. Therefore, the internal pressure of the intake manifold 15 becomes higher than the internal pressure of the crankcase 22, and the flow control valve 19 provided in the second blow-by gas passage 18 is closed. However, at the time of supercharging by the turbocharger, both sides of the flow control valve 19, that is, the 19 upstream side (intake passage 11 side) and the downstream side (crankcase 22 side) of the flow control valve are communicated to crank from the intake passage 11 side. A notch 34a that allows a predetermined amount of fresh air to move toward the case 22 is provided in the valve seat 34 of the flow control valve 19, so that the valve element 33 of the flow control valve 19 is seated on the valve seat 34. , High-pressure fresh air in the intake manifold 15 passes through the notches 34a of the valve seat 34, and further passes through the flow control valve chamber 17, the crankcase 22, the breather chamber 20, and the first blow-by gas passage 21 to the compressor inlet 13a. Reflux. At that time, the blow-by gas in the crankcase 22 is returned to the intake passage 11 together with the fresh air and sucked into the engine E, whereby the crankcase 22 is ventilated and the engine E by NOx contained in the blow-by gas. The deterioration of the lubricant is minimized. Further, since the amount of fresh air passing through the notches 34a of the flow control valve 19 is set to the minimum amount necessary for ventilating the crankcase 22, there is almost no decrease in supercharging pressure due to the turbocharger.
[0016]
As described above, the fresh air is circulated in the crankcase 22 of the engine E through the first and second blowby gas passages 21 and 18 to effectively ventilate the blowby gas in the crankcase 22 and The deterioration of the lubricating oil can be suppressed. Moreover, since an auxiliary blow-by gas passage is unnecessary in addition to the first and second blow-by gas passages 21 and 18, the number of parts and space can be saved.
[0017]
In addition, since the valve seat 34 of the flow control valve 19 is formed by an annular projecting portion that projects toward the valve body 33, not only the rigidity of the valve seat 34 is improved, but also the notch 34a ... Is formed as the communication hole of the flow rate control valve 19, so that the communication hole can be easily formed. Further, since the notches 34a of the valve seat 34 are arranged symmetrically with respect to the axis of the valve seat 34 and the valve body 33, it is possible to prevent a biased load from acting on the flow control valve 19 and to reduce the ventilation amount of blow-by gas. It can be stabilized.
[0018]
Next, a second reference example will be described based on FIGS.
[0019]
The flow control valve 19 of this reference example does not include the notches 34a in the valve seat 34. Instead, a plurality of (four in the reference example) notches 33a are formed on the side surface of the valve body 33 at intervals of 90 °. Is done. The notch 33a of the valve body 33 of the second reference example allows the crankcase 22 to pass through a predetermined amount of fresh air when the flow control valve 19 is closed, similar to the notch 34a of the valve seat 34 of the first reference example. These notches 33a... Are arranged symmetrically with respect to the axis of the valve seat 34 and the valve body 33, thereby preventing a biased load from acting on the flow control valve 19. The ventilation volume of blow-by gas can be stabilized.
[0020]
Next, a third reference example will be described based on FIG. 7 and FIG.
[0021]
In the flow control valve 19 of the third reference example, notches 33a..., 34a... Are not formed in the valve body 33 or the valve seat 34. Instead, the flow control valve 19 penetrates to the flow control valve chamber 17 in the wall surface of the valve chamber 31. A plurality of through holes 31 a are formed, and these through holes 31 a bypass the flow control valve 19. The through holes 31a of the third reference example have a function of ventilating the crankcase 22 by passing a predetermined amount of fresh air when the flow rate control valve 19 is closed, like the notches 34a of the first reference example. Yes.
[0022]
Next, the actual施例of the present invention will be described with reference to FIGS. 9 to 11.
[0023]
Although the flow control valve 19 of the reference example is constituted by a check valve, the flow control valve 19 of this embodiment is constituted by a solenoid valve. The flow control valve 19 is urged in the direction in which the valve element 33 is seated on the valve seat 34 by the elastic force of the valve spring 32, and a signal from the pressure sensor 36 provided in the collecting portion 15 b of the intake manifold 15 is input. The electronic control unit U can arbitrarily control the opening degree of the flow control valve 19 by exciting the solenoid 37.
[0024]
When the pressure of the collecting portion 15b of the intake manifold 15 detected by the pressure sensor 36 is negative, that is, when the turbocharger is not operating, the flow control valve 19 is held open and is generated in the collecting portion 15b of the intake manifold 15. By flowing fresh air from the first blow-by gas passage 21 side to the second blow-by gas passage 18 side with the intake negative pressure, the blow-by gas in the crankcase 22 can be ventilated.
[0025]
On the other hand, when the turbocharger is activated and the pressure of the collecting portion 15b of the intake manifold 15 detected by the pressure sensor 36 becomes a positive supercharging pressure, the opening degree of the flow control valve 19 is controlled according to the supercharging pressure. The That is, if the supercharging pressure is detected by the pressure sensor 36 in step S1 of the flowchart of FIG. 10 and the supercharging pressure is not the maximum supercharging pressure in step S2, the electronic control unit U increases the supercharging pressure in step S3. Accordingly, a signal for increasing the opening degree of the flow control valve 19 is output, and the opening degree of the flow control valve 19 is controlled in step S5 and supplied to the crankcase 22 for ventilation from the second blow-by gas passage 18. Is increased (see FIG. 11). Thereby, flow control according to supercharging pressure is attained. On the other hand, if the pressure detected by the pressure sensor 36 in step S2 is the maximum supercharging pressure, a signal for fully closing the flow control valve 19 is output in step S4, and the flow control valve 19 is fully closed in step S5. Then, the ventilation in the crankcase 22 is stopped. As described above, when the maximum supercharging pressure is detected, the flow control valve 19 is fully closed to prevent the supercharging pressure from being lowered, so that the effect of increasing the engine output by the turbocharger can be maximized. .
[0026]
As mentioned above, although the Example of this invention was explained in full detail, this invention can perform a various design change in the range which does not deviate from the summary.
[0027]
For example, in the above embodiment, after the pressure sensor 36 detects the maximum boost pressure and fully closes the flow control valve 19, the flow control valve 19 is opened to a predetermined opening when a predetermined time has elapsed. Thus, the crankcase 22 can be ventilated. If it does in this way, it will become possible to ventilate the crankcase 22 while ensuring acceleration performance by supercharging when the vehicle is accelerated.
[0028]
Further, any supercharger such as a supercharger can be used in place of the turbocharger.
[0029]
The present invention can also be applied to a marine vessel propulsion engine such as an outboard motor having a crankshaft arranged in the vertical direction.
[0030]
【The invention's effect】
As described above , according to the present invention, when the supercharger is not in operation, the control means opens the flow rate control valve provided in the second blow-by gas passage so that the fresh air at a position upstream of the supercharger in the intake passage. Is sucked to a position downstream of the throttle valve in the intake passage through the first blowby gas passage, the inside of the crankcase and the second blowby gas passage in which the flow control valve is opened, and the blowby gas in the crankcase is ventilated. . When the supercharger is activated and supercharging pressure is generated, the control means opens the flow control valve provided in the second blow-by gas passage to a predetermined opening, and the supercharging pressure causes the control valve to open more than the throttle valve in the intake passage. The fresh air at the downstream position flows into the crankcase through the flow rate control valve opened at the predetermined opening provided in the second blow-by gas passage, and from there through the first blow-by gas passage and upstream of the intake passage throttle valve By flowing to the position, the blow-by gas in the crankcase is ventilated. In addition, since an auxiliary blow-by gas passage is unnecessary in addition to the first and second blow-by gas passages, it is possible to contribute to the reduction in the number of parts and space. Furthermore, by controlling the opening degree of the flow rate control valve by the control means, the flow rate control according to the supercharging pressure becomes possible. In addition, since the flow rate control valve is closed when the maximum supercharging pressure of the supercharger is detected, it is possible to prevent the maximum supercharging pressure from decreasing and increase the engine output to the maximum.
[0031]
According particularly to the second aspect of the invention, the valve opening control of the flow amount control valve to a predetermined opening degree when a predetermined time has elapsed since the flow control valve is closed when the top serious errors supply pressure is detected Therefore, it is possible to ventilate the crankcase while ensuring acceleration performance by supercharging when the vehicle is accelerated.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an automotive engine blow-by gas processing apparatus according to a first reference example . FIG. 2 is an enlarged view of a main part of FIG. 1. FIG. FIG. 5 is a diagram corresponding to FIG. 2 according to a second reference example. FIG. 6 is a sectional view taken along line 6-6 in FIG. 5. FIG. 7 is a diagram corresponding to a third reference example. Figure 8 overall configuration diagram of a blow-by gas processing apparatus for an automobile engine according to the actual施例the cross-sectional view taken along line 8-8 of FIG. 7 and FIG. 9 of the present invention corresponding to 2 [10] flow control valve Flow chart explaining opening control [Fig. 11] Graph showing the relationship between supercharging pressure and fresh air flow [Explanation of symbols]
11 Intake passage 13 Compressor (supercharger)
14 throttle valve 18 second blow-by gas passage 19 flow control valve 21 first blow-by gas passage 22 crankcase U electronic control unit (control means)

Claims (2)

Throttle valve of the air intake passage (11) (14) supercharger provided upstream position than (13),
A first blow-by gas passage (21) connecting an upstream position of the intake passage (11) with respect to the supercharger (13) to the inside of the crankcase (22);
A second blow-by gas passage (18) for connecting a position downstream of the throttle valve (14) of the intake passage (11) to the inside of the crankcase (22);
In the blow-by gas treatment device for an engine provided with a flow control valve (19) the <br/> for opening and closing the second blow-by gas passage (18),
Control means (U) controls the opening degree of the flow control valve (19) according to the supercharging pressure of the supercharger (13) and controls the flow control valve (19) to close when the maximum supercharging pressure is detected. ) blow-by gas treatment device for an engine characterized by comprising a. The control means (U) opens the flow control valve (19) at a predetermined opening when a predetermined time elapses after the flow control valve (19) is closed when the maximum supercharging pressure is detected. characterized by valve opening control, the blow-by gas treatment device for an engine according to claim 1.

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