JP2568787Y2 - Blow-by gas processing device for vehicular internal combustion engine - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for sucking blow-by gas in a cylinder head cover of an internal combustion engine mounted on a vehicle into an intake system of the internal combustion engine for processing.

[0002]

2. Description of the Related Art In one type of blow-by gas processing apparatus, the inside of a cylinder head cover communicates with a portion of an intake system upstream of a throttle valve through a first blow-by gas passage, and a second blow-by gas is provided. In the operating range where the opening of the throttle valve is small, the blow-by gas in the cylinder head cover is passed through the second blow-by gas passage to the intake system through the passage. On the other hand, by introducing atmospheric air into the cylinder head cover through the first blow-by gas passage, ventilation in the cylinder head cover is performed, and in an operating range where the opening of the throttle valve is large, The blow-by gas in the cylinder head cover is supplied to both the first blow-by gas passage and the second blow-by gas passage. There is configured to draw in more air intake system.

However, in this system, a large amount of air and blow-by gas is sucked into the intake system through the second blow-by gas passage in a low-load operation range where the opening of the throttle valve is small, so that the low-load operation range is reduced. , The rotation becomes unstable.
As described in Japanese Patent No. 4514, etc., when the intake negative pressure downstream of the throttle valve becomes larger on the vacuum side during the second blow-by gas passage from inside the cylinder head cover to the downstream side of the throttle valve, the second P acting to reduce the cross-sectional area of the blow-by gas passage
By providing a CV valve, it is configured to stabilize low overload operation.

[0004]

However, since the air or the blow-by gas containing water flows in the second blow-by gas passage, the inside of the PCV valve in the second blow-by gas passage is formed. Since moisture is attached, when the blow-by gas processing device equipped with the PCV valve is applied to an internal combustion engine mounted on a vehicle, the PCV valve is exposed to cold running wind in winter, The water in the PCV valve freezes,
There is a problem that the PCV valve malfunctions.

According to the present invention, a DOHC type internal combustion engine is used in a recent vehicle, and a waterproof cover for covering an ignition system electric wiring to a spark plug of each cylinder is provided on an upper surface of a cylinder head cover in the DOHC type internal combustion engine. It is a technical problem to take note of the fact that the PCV valve in the blow-by gas passage is free from the occurrence of freezing without increasing the cost. It is assumed that.

[0006]

SUMMARY OF THE INVENTION In order to achieve this technical object, the present invention relates to a DOHC type internal combustion engine having a waterproof cover for the ignition system electric wiring to each cylinder on the upper surface of a cylinder head cover. In the internal combustion engine, the crank axis is mounted sideways, while the cylinder head cover is provided in a blow-by gas passage from the cylinder head cover to the intake system at a position behind the waterproof cover with respect to the traveling direction of the vehicle. The PCV valve was installed.

[0007]

[Work] With this configuration, the waterproof cover projecting from the upper surface of the cylinder head cover serves as a wind shield for the PCV valve on the rear side of the waterproof cover, and the traveling wind directly hits the PCV valve. That
On the other hand, since the heat in the cylinder head cover is transmitted to the PCV valve, the freezing of the PCV valve in the blow-by gas passage is prevented.
No. 313, an electric heater is provided on the PCV valve, or, as described in Japanese Utility Model Application Laid-Open No. 64-15710, lubricating oil in an internal combustion engine is sprayed on the PCV valve. Without such a configuration, it is possible to reliably prevent the problem.

[0008]

Therefore, according to the present invention, there is an effect that the prevention of freezing of the PCV valve in the blow-by gas passage can be surely achieved without increasing the cost.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. In the figure, reference numeral 1 denotes a vehicle body frame of a vehicle, and a DOHC-type internal combustion engine 3 has a crank axis 3a in a plan view in an engine room 2 formed in a front portion of the vehicle body frame 1. A cylinder head cover 5 that covers the intake valve camshaft 15 and the non-exhaust valve camshaft 16 and the like is attached to the upper surface of the cylinder head 4 of the internal combustion engine 3, and the upper surface of the cylinder head cover 5 In addition, a waterproof cover 7 for covering the ignition system electric wiring 6 to each cylinder in the internal combustion engine 3 is attached.

An exhaust manifold 8 is mounted on a front longitudinal side surface of the internal combustion engine 3, and an intake manifold 9 having a throttle valve 10 is mounted on a rear longitudinal side surface. Further, a gas-liquid separation chamber 5a formed in the cylinder head cover 5 is connected to a portion of the intake system upstream of the throttle valve 10 via a first blow-by gas passage 15 and a second blow-by gas. The gas passage 12 is connected to a portion downstream of the throttle valve 10.

Reference numeral 11 denotes a PCV valve provided in the second blow-by gas passage 12, and the PCV valve 11
The valve body 11b is provided in the valve box 11a, and the valve body 11b
Is urged by a spring 11c to close the blow-by gas inlet pipe 11d into the valve box 11a, while the valve box 11a
Is provided with a blow-by gas outlet pipe 11e. The opening of the blow-by gas outlet pipe 11e into the valve box 11a has a passage cross-sectional area when the valve body 11b moves upward against its spring 11c. Is provided with a valve seat 11f that reduces the size of the valve seat.

That is, when the intake negative pressure downstream of the throttle valve is close to the atmospheric pressure, the PCV valve 11 closes the blow-by gas inlet pipe 11d by pressing the valve body 11b by the spring 11c. When the negative pressure increases toward the vacuum side, the valve element 11b rises against the spring 11c to increase the passage cross-sectional area, and when the intake negative pressure further increases, the valve element 11b approaches the valve seat 11f. , So as to reduce the cross-sectional area of the passage.

A mounting hole 13 is formed in the cylinder head cover 5 at a position behind the waterproof cover 7 with respect to the running direction of the vehicle.
In the ring-shaped grommet 14 mounted in 3, the P
The PCV valve 11 is attached to the cylinder head cover 5 by inserting the blow-by gas inlet pipe 11d of the CV valve 11 such that the blow-by gas inlet pipe 11d communicates with the gas-liquid separation chamber 5a of the cylinder head cover 5. It is.

With this configuration, the waterproof cover 7 projecting from the upper surface of the cylinder head cover 5 serves as a wind shield for the PCV valve 10 on the rear side of the waterproof cover 7, and the traveling wind for the PCV valve 10. Can be prevented by the waterproof cover 7, while the heat in the cylinder head cover 5 is transmitted to the PCV valve 10.
The freezing of the CV valve 10 can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along line II-II of FIG.

FIG. 3 is an enlarged sectional view of a PCV valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body frame 2 Engine room 3 Internal combustion engine 4 Cylinder head 5 Cylinder head cover 5a Gas-liquid separation chamber 6 Ignition system electric wiring 7 Waterproof cover 10 PCV valve 11 Blow-by gas passage 12 Mounting hole 13 Grommet

Claims (1)

(57) [Scope of request for utility model registration] 1. A DOHC type internal combustion engine having a waterproof cover for an ignition system electrical wiring to each cylinder protruding from an upper surface of a cylinder head cover is mounted on a vehicle so that a crank axis of the internal combustion engine is oriented sideways. Wherein a PCV valve provided in a blow-by gas passage from a cylinder head cover to an intake system is attached to a portion behind the waterproof cover with respect to a traveling direction of the vehicle. Gas treatment equipment.