JP2007113556A - Control device for pcv valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for a PCV valve stably changing a flow rate characteristic of blowby gas from immediately after the start of an internal combustion engine. <P>SOLUTION: The PCV valve 1 becomes a closed state after the stop of the internal combustion engine. The PCV valve is controlled by a controller so that its open/close operations are performed three times up to a position where a passage opening area of a blowby gas passage 2 is changed to the maximum, immediately before the start of the internal combustion engine and when an outside temperature detection signal is a low temperature signal. The PCV valve 1 is controlled to perform open/close operations three times each for after a lapse of one hour, after a lapse of three hours, and after a lapse of six hours, since the controller has stopped the internal combustion engine. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a control device for a PCV valve used in a blow-by gas reduction device for an internal combustion engine (hereinafter referred to as a PCV (positive crankcase ventilation) device), and more particularly to a stable control immediately after the start of the internal combustion engine. It relates to measures to change the flow rate characteristics of blow-by gas.

  In general, an internal combustion engine is provided with a PCV device for guiding blow-by gas blown into a crankcase through a gap between a cylinder and a piston to an intake system. That is, with this PCV device, blow-by gas containing carbon monoxide, hydrocarbons, etc. is sent to the combustion chamber through the intake system of the internal combustion engine to prevent the blow-by gas from being released into the atmosphere and stored in the oil pan. To prevent the deterioration of the oil.

The PCV device is provided with a PCV valve that changes the flow rate characteristic of the blowby gas by changing the passage opening area of the blowby gas passage that guides the blowby gas to the intake system. As an example of this PCV valve, as disclosed in Patent Document 1 below, a PCV valve is configured by an electromagnetic valve, and by opening and closing the PCV valve, the blow-by gas is controlled according to the operating state of the internal combustion engine. What has been controlled so as to change the flow characteristics has been conventionally employed, and the recirculation amount (flow characteristics) of blow-by gas to the intake system is adjusted by opening and closing the PCV valve.
JP-A-8-33822

  Incidentally, foreign substances such as oil and sludge may be mixed in the blow-by gas flowing in the blow-by gas passage.

  In that case, when the PCV valve is closed after the internal combustion engine is stopped, the foreign matter in the blow-by gas that has come down in the blow-by gas passage is blocked by the PCV valve due to the height difference between the crankcase and the intake system. This may cause the PCV valve to adhere to the closed position (closed state). For this reason, even if an attempt is made to open and close the PCV valve so that the opening degree of the PCV valve becomes a subtle opening when changing the flow rate characteristic of the blow-by gas after the internal combustion engine is started, the opening degree of the PCV valve cannot be adjusted, and the internal combustion engine is started. The flow rate characteristic of blow-by gas cannot be changed stably immediately after.

  The present invention has been made in view of this point, and an object of the present invention is to provide a control device for a PCV valve capable of changing the flow rate characteristic of blow-by gas stably immediately after the start of the internal combustion engine. There is.

  In order to achieve the above object, the present invention is premised on a control device for a PCV valve that changes the flow rate characteristic of blowby gas by changing the passage opening area of the blowby gas passage. Then, the PCV valve is controlled to open and close to a position where the opening area of the blow-by gas passage is changed to the maximum immediately before starting the internal combustion engine.

  Because of this specific matter, the PCV valve is controlled to open and close to a position that changes the passage opening area of the blow-by gas passage to the maximum immediately before starting the internal combustion engine. Even if the PCV valve adheres to the PCV valve, the foreign matter is splashed by the PCV valve that opens and closes to a position where the opening area of the blow-by gas passage is changed to the maximum immediately before the internal combustion engine is started. The sticking is eliminated, and the opening degree of the PCV valve can be finely adjusted immediately after the internal combustion engine is started, so that the flow rate characteristic of the blow-by gas can be changed stably.

  In particular, the following configurations are listed as specifying timing for opening and closing the PCV valve immediately before starting the internal combustion engine.

  That is, the PCV valve opening / closing operation immediately before the start of the internal combustion engine is controlled to be performed only during cold weather.

  Due to this specific matter, because the air is often placed in a position where it can come into contact with the outside air due to restrictions on placement, moisture in the blow-by gas is condensed in the blow-by gas passage during cold weather when the temperature suddenly drops after the internal combustion engine stops operating. Even if the condensed water accumulates in the vicinity of the PCV valve and freezes, the condensed water frozen by the PCV valve that opens and closes to a position where the passage opening area of the blow-by gas passage is changed to the maximum immediately before starting the internal combustion engine. PCV valve sticking due to the frozen condensed water is crushed and fine adjustment of the opening of the PCV valve immediately after the start of the internal combustion engine in cold weather is possible, and the flow rate characteristics of the blow-by gas stably Can be changed.

  Furthermore, when the PCV valve is controlled to open and close after a predetermined time has elapsed since the internal combustion engine stopped, the internal combustion engine is often disposed at a position where it comes into contact with the outside air due to restrictions on the arrangement. PCV valve that opens and closes after a predetermined time has elapsed since the internal combustion engine stopped even if moisture in the blowby gas has condensed in the blowby gas passage where the temperature drops after the engine stops and the condensed water has accumulated near the PCV valve Thus, the dew condensation water collected in the vicinity of the PCV valve is smoothly circulated each time, and it becomes possible to more effectively prevent the PCV valve from adhering due to adhesion of foreign matters such as oil and sludge or freezing of dew condensation water.

  In short, in short, by controlling the PCV valve so as to open and close to a position where the passage opening area of the blow-by gas passage is changed to the maximum immediately before starting the internal combustion engine, the blow-by gas passage of the internal combustion engine is started. The PCV valve that opens and closes to a position that changes the passage opening area to the maximum is allowed to jump off foreign matter adhering to the PCV valve to eliminate the PCV valve sticking, and the PCV valve is opened slightly after the internal combustion engine is started. The flow rate characteristics of the blow-by gas can be changed stably by adjusting the degree.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a longitudinal sectional view of a PCV valve. The PCV valve 1 is in the middle of a blow-by gas passage 2 that guides blow-by gas blown into a crankcase from a gap between a cylinder and a piston of an internal combustion engine to an intake manifold. Is interposed. The blow-by gas passage 2 is divided into an upstream passage portion 21 whose upstream end is connected to the crankcase, and a downstream passage portion 22 whose downstream end is connected to the intake manifold. The downstream end of the upstream passage portion 21 of the blow-by gas passage 2 is connected to the upstream connection portion 12 (lower side in FIG. 1) of the body 11 of the PCV valve 1, and the upstream end of the downstream passage portion 22 is connected to the PCV valve 1. Each is connected to a downstream side connection portion 13 (right side in FIG. 1) of the body 11. In this case, the blow-by gas passage 2 has a height difference between the crankcase and the intake manifold, and is disposed at a position where the blow-by gas passage 2 comes into contact with the outside air due to restrictions in arrangement.

  Further, in the intersecting space 14 where the upstream connecting portion 12 and the downstream connecting portion 13 intersect in the body 11 of the PCV valve 1, a cylindrical valve body 15 having a conical tip is formed in the axial direction. It is arrange | positioned so that it can move to the downstream connection part 13 side. When the valve body 15 moves to the downstream side connection portion 13 side, the tip end portion thereof abuts against the base end (left end in FIG. 1) of the downstream side connection portion 13 so as to close the intersection space 14. ing. That is, the valve body 15 is configured to vary the passage opening area of the blow-by gas passage 2 (intersection space 14) according to the movement position.

  A shaft 16 is integrally provided on the end face of the valve body 15 in the body 11 of the PCV valve 1 (the end face on the left side in FIG. 1), and the end of the shaft 16 is ferromagnetic. A cylindrical plunger 17 made of metal is fixed. In this case, the inside of the body 11 of the PCV valve 1 is supported by a support member 19 that slidably supports the valve body 15, in each of the connection portions 12 and 13, the intersection space 14, the shaft 16, the plunger 17, and the coil 18 ( It is partitioned into a base end side space 10 for housing (described later).

  A coil 18 is provided on the outer peripheral portion of the plunger 17 with a gap, and the coil 18 is electrically connected to the control unit 3. The control unit 3 is electrically connected to an outside air temperature sensor 4 that detects the outside air temperature, and an outside air temperature detection signal from the outside air temperature sensor 4 is input to the control unit 3. Further, the control unit 3 is supplied with a just-starting state detection signal from a just-starting state detection sensor 5 that detects a just-starting state of the internal combustion engine. The state detection sensor 5 immediately before starting detects that an operation that is first performed when starting the internal combustion engine, such as inserting an ignition key or a card key, is performed. The PCV valve 1 changes the flow rate characteristics of the blow-by gas by changing the passage opening area of the blow-by gas passage 2 by changing the introduction amount when the blow-by gas containing a large amount of HC (hydrocarbon) is led to the intake manifold by negative pressure. The change of the passage opening area of the blow-by gas passage 2 by the PCV valve 1 is controlled by the control unit 3. The control unit 3 has a timer function.

  Next, control of the PCV valve 1 when the internal combustion engine is started by the control unit 3 will be described based on the flowcharts of FIGS. 3 and 4.

  First, in step ST1 of the flowchart of FIG. 4, it is determined whether or not the internal combustion engine is in a stopped state. If the determination in step ST1 is YES where the internal combustion engine is in a stopped state, the ignition is determined in step ST2. It is determined whether or not a key or a card key has been inserted. Specifically, it is determined whether or not a just-starting state detection signal from the immediately-starting state detection sensor 5 that detects a state immediately before starting the internal combustion engine is input. If the determination in step ST2 is YES when an ignition key or a card key is inserted (time A shown in FIG. 3), the outside temperature detection signal input from the outside temperature sensor 4 is cold in step ST3. It is determined whether it is a temperature signal (for example, a cold temperature signal of 10 ° C. or less).

  If the determination in step ST3 is YES when the outside air temperature detection signal from the outside air temperature sensor 4 is a cold temperature signal, in step ST4, as shown in FIG. 3, the blow-by gas passage 2 immediately before the start of the internal combustion engine is performed. The PCV valve 1 is operated before starting (for example, three opening / closing operations) to a position where the passage opening area of the (intersection space 14) is changed to the maximum. In this case, the PCV valve 1 immediately before the start of the internal combustion engine is controlled so as to be opened and closed three times at a frequency of about 10 Hz.

  Then, in step ST5, after the ignition is turned on (time B shown in FIG. 3), the internal combustion engine is started in step ST6. In this case, the PCV valve 1 immediately after the start of the internal combustion engine is controlled so as to be opened and closed in a frequency band of about 20 Hz.

  Here, the control of the PCV valve 1 after the internal combustion engine is stopped by the control unit 3 will be described based on the flowchart of FIG.

  First, in step ST11 of the flowchart of FIG. 5, it is detected whether or not the internal combustion engine has stopped. If this determination is YES, the timer function in the control unit 3 is activated in step ST12. Operate.

  In step ST13, when one hour has passed since the internal combustion engine was stopped by the timer function, in step ST14, the passage opening area of the blow-by gas passage 2 (intersection space 14) is changed to the maximum. The PCV valve 1 is opened / closed to a position (for example, three opening / closing operations).

  Thereafter, in step ST15, the timer in the control unit 3 is reset and the timer function is restarted. In step ST16, when the timer reset in step ST15 has passed 2 hours (when 3 hours have elapsed since the internal combustion engine stopped), in step ST17, the passage of the blow-by gas passage 2 (intersection space 14). The PCV valve 1 is opened / closed (for example, opened / closed three times) to a position where the opening area can be changed to the maximum.

  Then, in step ST18, the timer in the control unit 3 is reset and the timer function is reactivated. In step ST19, when the timer reset in step ST18 has elapsed for 3 hours (when 6 hours have elapsed since the internal combustion engine stopped), in step ST20, the passage of the blow-by gas passage 2 (intersection space 14). The PCV valve 1 is opened / closed (for example, opened / closed three times) to a position where the opening area can be changed to the maximum.

  That is, the PCV valve 1 is controlled to open and close three times each after 1 hour, 3 hours, and 6 hours after the internal combustion engine stops.

  As described above, in the above-described embodiment, the PCV valve 1 that is closed after the internal combustion engine is stopped is input with the just-starting state detection signal from the just-starting state detection sensor 5 by inserting the ignition key or the card key. When the internal combustion engine is in a state immediately before starting and the outside air temperature detection signal from the outside air temperature sensor 4 is a cold temperature signal, the passage opening area of the blow-by gas passage 2 (intersection space 14) is changed to the maximum. Since it is controlled so that the opening / closing operation is performed three times to such a position, the temperature is drastically lowered after the operation of the internal combustion engine is stopped because it is often arranged at a position where it comes into contact with the outside air due to arrangement restrictions. Even if the moisture in the blow-by gas condenses in the blow-by gas passage 2 when it is cold and the condensed water accumulates near the PCV valve 1 and freezes, The frozen condensed water is crushed by the PCV valve 1 that opens and closes to a position that changes the passage opening area of the blowby gas passage 2 to the maximum immediately before the movement, and the PCV valve 1 is prevented from sticking due to the frozen condensed water. Is done. Moreover, foreign matter such as oil mist and sludge in the blow-by gas that has come down in the blow-by gas passage 2 (downstream passage portion 22) due to the height difference between the crankcase and the intake manifold is blocked by the PCV valve 1. Even if they are attached, the PCV valve 1 that opens and closes to a position that changes the passage opening area of the blow-by gas passage 2 to the maximum immediately before starting the internal combustion engine causes the foreign matter to jump off and the PCV valve 1 due to the foreign matter. The sticking of is also eliminated. As a result, the opening degree of the PCV valve 1 can be finely adjusted immediately after the internal combustion engine is started, and the flow rate characteristic of the blow-by gas can be changed stably.

  In the above embodiment, the PCV valve 1 opens and closes three times each after a predetermined time has elapsed since the internal combustion engine stopped (after 1 hour, 3 hours, and 6 hours). Even if the moisture in the blowby gas is condensed in the blowby gas passage 2 (in the downstream passage portion 22) and the condensed water is collected near the PCV valve 1, the internal combustion engine is stopped. After 1 hour, 3 hours, and 6 hours, the PCV valve 1 that opens and closes three times each time causes the condensed water accumulated in the vicinity of the PCV valve 1 to flow smoothly each time. It is possible to more effectively prevent the PCV valve 1 from adhering due to adhesion or freezing of condensed water.

  In addition, this invention is not limited to the said embodiment, The other various modifications are included. For example, in the above-described embodiment, when the internal combustion engine is in a state immediately before starting and the outside air temperature detection signal is a cold temperature signal, three times until the position where the passage opening area of the blow-by gas passage 2 is changed to the maximum are obtained. Although the PCV valve 1 is controlled so as to perform the opening / closing operation, the opening / closing operation is performed to a position where the passage opening area of the blow-by gas passage can be changed to the maximum if it is in a state immediately before starting the internal combustion engine regardless of the cold time. The PCV valve may be controlled to do so.

  In the above embodiment, the PCV valve 1 is controlled to open and close three times after one hour, three hours, and six hours after the internal combustion engine has stopped, but the internal combustion engine stops. The PCV valve may be controlled to open and close only once after a predetermined time has elapsed (for example, after one hour has elapsed).

  Further, in the above embodiment, the PCV valve 1 is controlled to open and close three times immediately before the internal combustion engine is started. However, the PCV valve is controlled to open and close once or twice before the internal combustion engine is started. Of course.

It is sectional drawing in the obstruction | occlusion state of the PCV valve concerning embodiment of this invention. It is sectional drawing in the open state of a PCV valve | bulb. It is a time chart which shows the control state of the opening / closing operation | movement of the PCV valve at the time of start-up of the internal combustion engine at the time of cold. It is a flowchart figure which shows the flow of control of the PCV valve at the time of starting of the internal combustion engine by a control unit. It is a flowchart figure which shows the control flow of the PCV valve after the internal combustion engine stop by a control unit.

Explanation of symbols

1 PCV valve 2 Blow-by gas passage 3 Controller (control device)

Claims (3)

A control device for a PCV valve that changes a flow rate characteristic of a blowby gas by changing a passage opening area of the blowby gas passage,
The PCV valve is controlled so as to be opened and closed up to a position where the opening area of the blow-by gas passage is changed to the maximum immediately before starting the internal combustion engine. In the control device for a PCV valve according to claim 1,
An apparatus for controlling a PCV valve, wherein the PCV valve opening / closing operation immediately before the start of the internal combustion engine is controlled only when it is cold. In the control device for a PCV valve according to claim 1 or 2,
The PCV valve is controlled such that the PCV valve is opened and closed after a predetermined time has elapsed since the internal combustion engine stopped.

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