Blow-by gas processing device

Abstract

A blow-by gas processing device is configured to allow a crankcase and a downstream side of a throttle valve of an intake system to communicate to introduce blow-by gas into the intake system. The device includes a positive crankcase ventilation ( ) valve, a PCV valve cover, and a PCV hose. The valve is attached to a cylinder block and adjusts a flow rate of the blow-by gas. The valve cover is coaxially with the valve and is attached to the cylinder block to cover the valve. The hose is coupled to the valve cover and allows the valve cover and the intake system to communicate. An inner diameter of the valve cover on a tip end side with respect to a plane including a tip end surface of the valve is greater than that on a base end side with respect to the plane.

1 . A blow-by gas processing device configured to allow a crankcase and a downstream side of a throttle valve of an intake system to communicate with each other to introduce blow-by gas into the intake system, the blow-by gas processing device comprising:
 a positive crankcase ventilation valve attached to a cylinder block, the positive crankcase ventilation valve being configured to adjust a flow rate of the blow-by gas according to a pressure of the intake system;   a positive crankcase ventilation valve cover disposed coaxially with the positive crankcase ventilation valve, the positive crankcase ventilation valve cover being attached to the cylinder block so as to cover the positive crankcase ventilation valve; and   a positive crankcase ventilation hose coupled to the positive crankcase ventilation valve cover, the positive crankcase ventilation hose being configured to allow the positive crankcase ventilation valve cover and the intake system to communicate with each other, wherein   an inner diameter of the positive crankcase ventilation valve cover on a tip end side with respect to a plane including a tip end surface of the positive crankcase ventilation valve is greater than an inner diameter of the positive crankcase ventilation valve cover on a base end side with respect to the plane including the tip end surface of the positive crankcase ventilation valve.   
     
     
         2 . The blow-by gas processing device according to  claim 1 , wherein
 the positive crankcase ventilation valve cover comprises a base end portion and a great diameter portion having a greater inner diameter than an inner diameter of the base end portion, and   each of the base end portion and the great diameter portion has a cylindrical shape or a rectangular tubular shape.   
     
     
         3 . A blow-by gas processing device configured to allow a crankcase and a downstream side of a throttle valve of an intake system to communicate with each other to introduce blow-by gas into the intake system, the blow-by gas processing device comprising:
 a positive crankcase ventilation valve attached to a cylinder block, the positive crankcase ventilation valve being configured to adjust a flow rate of the blow-by gas according to a pressure of the intake system;   a tubular positive crankcase ventilation valve cover attached to the cylinder block so as to cover the positive crankcase ventilation valve; and   a positive crankcase ventilation hose coupled to the positive crankcase ventilation valve cover, the positive crankcase ventilation hose being configured to allow the positive crankcase ventilation valve cover and the intake system to communicate with each other, wherein   a center axis of the positive crankcase ventilation valve cover is shifted to a front side of a vehicle with respect to a center axis of the positive crankcase ventilation valve.   
     
     
         4 . The blow-by gas processing device according to  claim 1 , wherein the positive crankcase ventilation valve and the positive crankcase ventilation valve cover are attached to an upper surface of the cylinder block such that an axial line of the positive crankcase ventilation valve and an axial line of the positive crankcase ventilation valve cover are parallel with a vertical direction. 
     
     
         5 . The blow-by gas processing device according to  claim 3 , wherein the positive crankcase ventilation valve and the positive crankcase ventilation valve cover are attached to an upper surface of the cylinder block such that an axial line of the positive crankcase ventilation valve and an axial line of the positive crankcase ventilation valve cover are parallel with a vertical direction. 
     
     
         6 . The blow-by gas processing device according to  claim 4 , wherein the positive crankcase ventilation valve cover has such an inner diameter that an engine is stopped or the engine is not startable when the positive crankcase ventilation valve cover is detached. 
     
     
         7 . The blow-by gas processing device according to  claim 5 , wherein the positive crankcase ventilation valve cover has such an inner diameter that an engine is stopped or the engine is not startable when the positive crankcase ventilation valve cover is detached.