JP2001132426A - Blow-by gas recirculation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a passage structure for a blow-by gas recirculation device capable of eliminating the demerits of installation space, the number of parts, and assemblage manhour caused by provision of a dedicated hose for sending blow-by gas. SOLUTION: A head cover part 3 comprising a head cover and an air cleaner lower case integrally molded with each other, and an intake passage part 5 integrally molded with an air cleaner cap 4 are provided, the intake passage part 5 is directly connected to the head cover part 3 through a seal part 8a to compose a blow-by gas passage 21, and the seal part 8a is composed by extending part of an element 8. Blow-by gas 30, therefore, passes through the blow-by gas passage 21 to be circulated to the upstream side of a throttle valve 12, and the passage of this blow-by gas circulation device is composed without providing a dedicated hose.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blow-by gas recirculation device for an internal combustion engine, and more particularly to a flow path structure thereof.

[0002]

2. Description of the Related Art In an internal combustion engine for an automobile or the like, blow-by gas leaks from a combustion chamber into a crankcase through a gap between a piston and a cylinder wall. The main component of the blow-by gas is an unburned gas containing a large amount of HC, and it is not preferable to release it into the atmosphere from the viewpoint of environmental protection.

[0003] For this reason, as a conventional blow-by gas recirculation device, for example, as disclosed in Japanese Utility Model Laid-Open No. 5-50014, a blow-by gas recirculation device using a hose for passing blow-by gas is often used. Have been. This blow-by gas recirculation device is, as shown in FIG. 3, a blow-by gas 104 generated from the internal combustion engine 100 side.
The first blow-by hose 102 is provided to return the air to the upstream side 106 of the throttle valve 101, and the second blow-by hose 103 is provided to return the downstream side 107 of the throttle valve 101. The blow-by gas 104 is recirculated into the air 105.

[0004]

However, in the structure of the conventional blow-by gas recirculation device, a dedicated hose for passing the blow-by gas is provided, and a space for arranging the dedicated hose is required. However, there is a problem in that the number of installation steps in a small engine room is increased.

An object of the present invention has been made in view of the above points, and provides a blow-by gas recirculation device which can easily realize a reduction in mounting space, a reduction in the number of parts, and a reduction in the number of assembly steps. It is in.

[0006]

According to a first aspect of the present invention, there is provided a blow-by gas recirculation apparatus according to the first to third aspects of the present invention. An intake passage that guides intake air upstream of the throttle valve of the internal combustion engine can be configured at an adjacent position, and a blow-by gas passage can be configured by directly connecting the intake passage and the head cover. With this, a hose is conventionally used to recirculate the blow-by gas to the upstream side of the throttle valve, and a passage is configured. However, in the present invention, a hose or the like for passing the blow-by gas is not provided, and the inside of the head cover portion is not provided. Can be directly recirculated into the intake air in the intake passage, so that the mounting space can be reduced, the number of parts can be reduced, and the number of assembly steps can be reduced.
In addition, by forming the blow-by gas passage as a molded body integrally formed with the intake passage portion, the number of parts can be reduced without adding a part for connection. Further, when the air passage or the air cleaner case and the head cover are connected via a seal, the blow-by gas can be easily prevented from leaking out of the blow-by gas passage.

According to the blow-by gas recirculation device according to the fourth aspect of the present invention, the molded body of the blow-by gas passage integrally formed with the intake passage portion or the air cleaner case is integrally formed of resin to form a complicated shape. Can be performed easily, and the weight can be reduced, which contributes to the requirement that the vehicle as a whole be reduced in weight for improving fuel efficiency.

According to the blow-by gas recirculation device according to the fifth aspect of the present invention, the seal portion is not provided separately,
By extending a part of the seal part formed on the element, the seal part between the head cover part and the intake passage part is integrated with the element seal part, reducing the number of parts and the number of assembly steps. The flow path structure of the blow-by gas recirculation device that has become possible becomes possible.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the blow-by gas recirculation device of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 and 2 show an embodiment of the present invention. FIG. 1 is a sectional view showing a flow path structure of a blow-by gas recirculation device of an internal combustion engine and the periphery of the engine. FIG.
FIG. 4 is a plan view of an element 8 in the blow-by gas recirculation device shown in FIG. The configuration of the flow path structure of the blow-by gas recirculation device in FIG. 1 will be described. The internal combustion engine 1 is provided with a closed cam chamber 26 in which the camshaft 2 is disposed. A head cover 3 in which a head cover 3b and an air cleaner lower case 3c are integrally formed of resin are provided above the cam chamber 26, and a throttle valve 1 of the internal combustion engine.
(2) An air cleaner cap 4 integrally formed of resin with an intake passage portion 5 for guiding the intake air 31 is provided upstream.
The head cover 3 and the air cleaner cap 4 constitute an air cleaner case, and an element 8 for filtering air taken in from the outside is arranged inside the air cleaner case. In FIG. 1, outside air intake air 31 is guided from below with the element 8 inside the air cleaner case as a boundary, and the intake air 31 filtered by the element 8 is guided to the upper part. In this case, a blow-by gas passage 21 communicating with a cam chamber 26 inside the head cover 3 adjacent to the intake passage 5 is integrally formed with the intake passage 5 integrally formed with the air cleaner cap 4. Have been. At the position of the upper surface of the cam chamber 26 of the head cover 3, the head cover 3 has a receiving port 3 a through which the blow-by gas passage 21 can be inserted, and is formed integrally with the head cover 3. A blow-by gas passage 21 integrally formed with the air cleaner cap 4 is inserted into the receiving port 3a. Further, in order to prevent the blow-by gas 30 passing through the inside of the blow-by gas passage 21 from leaking into the atmosphere, the seal portion 8a is connected to the head cover portion 3 and the intake passage portion 5.
, Is arranged on the outer periphery of the receiving port 3a. Seal part 8
2, a is an integral structure formed by extending an element seal portion 8b formed on the element 8, as shown in FIG. 2, and hermetically seals the space between the head cover portion 3 and the intake passage portion 5 from the outside. . As a result, the blow-by gas passage 2 connecting the cam chamber 26 and the upstream side of the throttle valve 12
1 is completed. Here, the blow-by gas passage 21 can be configured at a position other than the position described above. In this case, the flow of the intake air 31 inside the air cleaner case guides the external intake air 31 from the upper portion of the element 8 and guides the intake air 31 filtered by the element 8 to the lower portion. With this configuration, a passage for passing the blow-by gas can be provided in the head cover portion 3 which is a boundary portion between the cam chamber 26 and the filtered suction air side below the element 8. Here, an appropriate hole for passing blow-by gas may be formed. On the other hand, the cam chamber 26 and the downstream side of the throttle valve 12 are connected to the blow-by gas outlet 9 through the blow-by gas hose 9 and the PCV (“Positive Crankcase Ventil”).
ation ”, the same applies hereinafter). The valve 10, the blow-by gas hose 11, and the blow-by gas inlet 25 communicate with each other. The PCV valve 10 adjusts the flow area of the blow-by gas 30 from the cam chamber 26 to the blow-by gas inflow port 25 with the passage area adjusted according to the intake negative pressure of the surge tank, and recirculates the flow.

Next, the operation of the blow-by gas recirculation device of this embodiment will be described.

The blow-by gas 30 leaked from the combustion chamber (not shown) of the internal combustion engine 1 into the crankcase through the gap between the piston and the cylinder wall flows into the cam chamber 26, and from the cam chamber 26 to the upstream side of the throttle valve 12, And the intake air 3 is returned to the downstream side of the throttle valve 12 respectively.
Mix with 1. The intake air 31 guides outside air to the element upstream chamber 22, reaches the element downstream chamber 23 through the element 8 that filters foreign substances in the air sucked from outside, and surges through the inside of the intake passage section 5 and the inside of the throttle valve body 6. It is supplied to the tank 7. In order to recirculate the blow-by gas 30 from the cam chamber 26 to the upstream side of the throttle valve 12, the blow-by gas 30 passes through the blow-by gas passage 21 which is inside the extension passage 5 a connecting the cam chamber 26 and the intake passage inside 24. On the other hand, in order to recirculate the blow-by gas 30 from the cam chamber 26 to the downstream side of the throttle valve 12, the blow-by gas hose 9, the PCV
It passes through a path leading to the valve 10, the blow-by gas hose 11, and the blow-by gas inlet 25.

As described above, according to the embodiment of the present invention shown in FIG. 1, a dedicated hose for passing the blow-by gas 30 is provided in the path for returning the blow-by gas 30 to the upstream side of the throttle valve 6. Thus, the blow-by gas passage 21 can be configured without using any other means, and a flow path structure of the blow-by gas recirculation device that can easily realize a reduction in mounting space, a reduction in the number of parts, and a reduction in the number of assembly steps can be realized. The head cover 3 and the intake passage 5 are provided on the element seal 8b.
Since the sealing portion 8a between the two is integrated,
This contributes to a reduction in the number of parts and the number of assembly steps.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a flow path structure of a blow-by gas recirculation device according to an embodiment of the present invention and the periphery of an engine.

FIG. 2 is a plan view of an element of a flow path structure of the blow-by gas recirculation device shown in FIG.

FIG. 3 is a schematic configuration diagram showing a flow path structure and a periphery of an engine of a conventional blow-by gas recirculation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Internal combustion engine 3 Head cover part 3b Head cover 3c Air cleaner lower case 4 Air cleaner cap 3, 4 Air cleaner case 5 Intake passage part 8 Element 8a Seal part 12 Throttle valve 21 Blow-by gas passage 26 Cam chamber 31 Intake air

Claims (5)

[Claims] 1. An air cleaner case comprising an air cleaner cap and a head cover portion in which a head cover of an internal combustion engine and a part of an air cleaner case are integrally formed or directly fixed, and an air cleaner cap is provided. An element for filtering intake air taken in from the outside, an intake passage for guiding the intake air to an upstream side of a throttle valve of the internal combustion engine through the element, and a blow-by connecting the intake passage with a cam chamber in the head cover. A blow-by gas recirculation device comprising a gas passage. 2. The blow-by gas recirculation device according to claim 1, wherein the blow-by gas passage is a molded body integrally formed with the intake passage portion. 3. The air conditioner according to claim 1, wherein a seal portion is provided at a portion where the blow-by gas passage is provided to make a space between the intake passage portion and the head cover portion airtight. Blow-by gas recirculation device. 4. The blow-by gas recirculation device according to claim 2, wherein the molded body is integrally molded with a resin. 5. The blow-by gas recirculation device according to claim 3, wherein the seal portion is configured by extending a part of a seal portion formed on the element.