JPH10280982A - Intake device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intake device for an internal combustion engine which prevents a throttle valve and an ISC valve from causing icing and sticking. SOLUTION: A housing 10 forming an intake path 100 consists of an inner tube member 11 and an outer tube member 12, and both ends of the inner tube member 11 is surrounded by the outer tube member 12. Gaps 40, 41 are circumferentially between the inner tube member 11 and the outer tube member 12. An inlet 33a and an outlet 33b of a bypass 33 are opened in the inner peripheral surface of the inner tube member 11. When liquid water or oil intends to enter into the inner tube member 11 toward a throttle valve 20, the water or oil is accumulated in the gap 40 or 41, and therefore, it cannon enter into the inner tube member 11. Therefore, the throttle valve 20 and an ISC valve 32 are prevented from causing icing and sticking.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine (hereinafter referred to as "internal combustion engine").
The present invention relates to an intake device for an "internal combustion engine".

[0002]

2. Description of the Related Art Heretofore, a PCV (Positive Crankcase Ventiration) system for recirculating blow-by gas leaked into a crankcase from a combustion chamber through a sliding portion between a piston and a cylinder from an intake passage to a combustion chamber for combustion processing. Is required. However, the blow-by gas recirculated to the combustion chamber via the intake passage contains moisture,
Oil etc. are mixed. If the water, oil, etc. contained in the recirculated blow-by gas liquefies on the inner wall of the intake passage at a low temperature, the water freezes and the throttle valve and the ISC valve freeze on the wall, causing icing. This may cause the valve to stick to the wall. As an intake device that solves such a problem, an intake control device disclosed in Japanese Utility Model Laid-Open No. 2-46074 and a throttle valve device disclosed in Japanese Patent Application Laid-Open No. 9-32590 are known.

In the intake control apparatus disclosed in Japanese Utility Model Laid-Open Publication No. 2-46074, a hollow portion is provided outside an intake wall forming an intake passage, and the hollow portion is formed on an intake wall upstream of a throttle valve on the intake side. The opening at the top allows the intake passage to communicate with the cavity, and the bypass passage of the ISC device to communicate with the cavity. Since the cavity is opened above the inner peripheral surface of the intake wall, liquefied water and oil do not enter the cavity and the bypass passage, thereby preventing the ISC valve from icing or sticking.

Further, in the throttle valve device disclosed in Japanese Patent Application Laid-Open No. 9-32590, liquefied water or oil is contained in the inner pipe by forming the throttle body into a double pipe structure comprising an inner pipe and an outer pipe. A blocking recess for preventing intrusion is formed between the inner tube and the outer tube to prevent icing and sticking of the throttle valve.

[0005]

However, in the intake control device disclosed in Japanese Utility Model Laid-Open Publication No. 2-46074, liquefied water or oil does not enter the bypass passage, but the inlet on the outer peripheral side that forms the hollow portion. Since the side wall portion and the cylindrical portion on the inner peripheral side are connected by an annular member on the upstream side of the throttle valve, liquefied water or oil penetrates into the cylindrical portion along the annular member, and the throttle valve may cause icing or the like. There is a risk of sticking.

In the throttle valve device disclosed in Japanese Patent Application Laid-Open No. 9-32590, liquefied water or oil can be prevented from entering the inner pipe, but the inlet and outlet of the bypass passage are connected to the inner pipe. Since the opening is provided between the outer pipe and the outer pipe, liquefied water or oil may enter the bypass passage through the inner wall of the outer pipe, causing icing or sticking of the ISC valve.

An object of the present invention is to provide a throttle valve and an IS
An object of the present invention is to provide an intake system for an engine which prevents icing and sticking of a C valve.

[0008]

According to the first aspect of the present invention, the outer tubular member is provided on at least one of the upstream side and the downstream side of the inner tubular member according to the mounting state of the intake unit. Is formed between the outer tubular member and the inner tubular member, liquefied water, oil, and the like which are to enter the inner annular member are accumulated in the gap formed between the outer tubular member and the inner tubular member. Therefore, icing and sticking of the throttle valve can be prevented, so that the intake flow rate can be controlled regardless of the ambient temperature.

Further, if at least one of the inflow port and the outflow port of the bypass passage is provided in the inner tubular member according to the mounting state of the intake device, liquefied water, oil and the like can be prevented from entering the bypass passage. it can. Therefore, it is possible to prevent icing and sticking of the ISC valve, so that it is possible to control the intake air flow during idle operation regardless of the ambient temperature.

According to the second aspect of the present invention, since both the upstream end and the downstream end of the inner tubular member are surrounded by the outer annular member, and a gap is formed between the outer tubular member and the inner tubular member. In addition, liquefied water, oil, or the like that tends to enter the inner annular member regardless of the mounted state of the intake device is stored in a gap formed between the outer tubular member and the inner tubular member. Therefore, icing and sticking of the throttle valve can be prevented, so that the intake flow rate can be controlled regardless of the ambient temperature and the mounting state of the intake device.

According to the third aspect of the present invention, since both the inflow port and the outflow port of the bypass passage are open to the inner peripheral surface of the inner tubular member, regardless of the mounting state of the intake apparatus. Liquefied water or oil can be prevented from entering the bypass passage. Therefore, ISC
Since the valve can be prevented from icing and sticking,
It is possible to control the intake flow rate during idle operation regardless of the ambient temperature and the mounting state of the intake device.

According to the fourth aspect of the present invention, since the inner tubular member and the outer tubular member are integrally formed, the number of parts of the intake device is reduced, and the number of assembling steps is reduced. According to the intake device for an engine according to the fifth aspect of the present invention, the throttle body is formed as an inner tubular member, and the air duct and the intake manifold are formed as outer tubular members. By adjusting the diameter of the member, it is possible to provide a gap for preventing intrusion of liquefied water, oil, or the like at a connection portion of each member.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a plurality of examples showing embodiments of the present invention will be described. (First Embodiment) FIGS. 1 and 2 show an intake system for an engine according to a first embodiment of the present invention. In the intake device 1, the ISC device 30 controls the intake flow rate during idle operation.

Housing 10 forming intake passage 100
Consists of an inner tubular member 11 and an outer tubular member 12 and are integrally formed of resin. The outer diameter of the inner tubular member 11 is smaller than the inner diameter of the outer tubular member 12, and the upstream end 11 a and the downstream end 11 b of the inner tubular member 11 are surrounded by the outer tubular member 12. Gaps 40 and 41 are formed in the circumferential direction between the inner tubular member 11 and the outer tubular member 12, and the partition walls 13 and 1 are provided between the gap 40 and the gap 41.
Blocked at 4.

The throttle valve 20 is rotatably accommodated in the inner tubular member 11, and a throttle shaft 21 that rotates together with the throttle valve 20 is supported by the inner tubular member 11 and the outer tubular member 12. The intake flow rate in the intake passage 100 is controlled according to the opening of the throttle valve 20. ISC
The housing 31 of the device 30 is made of resin and attached to the outer wall of the outer tubular member 12 by heat welding or the like. ISC
The valve 32 is rotatably accommodated in the housing 31. A bypass passage 33 that avoids the throttle valve 20 and allows the intake passage 100 on the upstream side of the throttle valve 20 to communicate with the intake passage 100 on the downstream side is formed in the inner tubular member 11, the outer tubular member 12, and the housing 31. I have.
The inflow port 33 a and the outflow port 33 b of the bypass passage 33 are open on the inner peripheral surface of the inner tubular member 11. ISC valve 3
The amount of auxiliary air passing through the bypass passage 33 is adjusted according to the opening degree of the second.

Next, the operation of the intake device 1 will be described. During normal running of the vehicle, the throttle valve 20 is operated in accordance with the engine operating state based on detection signals input from various sensors.
The opening degree of the ISC valve 32 is determined by an engine control device (not shown) (hereinafter, the “engine control device” is referred to as an ECU), and a stable operation state of the vehicle is maintained.

When the vehicle is idling, the throttle valve 20
Is in the fully closed position shown in FIG. 1 and the total amount of air taken into the engine is controlled by the ISC valve 32. Here, for example, P
Moisture and oil contained in the blow-by gas returned to the combustion chamber via the intake passage 100 by the CV system are liquefied at a low temperature, and the liquefied water and oil are discharged from the upstream side or downstream side of the intake device 1 to the outer tubular member 12. Trying to flow along the inner wall of the
The liquefied water or oil is stored in the gap 40 or 41 formed between the outer tubular member 12 and the inner tubular member 11 and does not enter the inner tubular member 11. Therefore, the icing that causes the throttle valve 20 and the inner wall of the inner tubular member 11 to freeze at a low temperature due to the water that has entered the inner tubular member 11 occurs, or the oil that has entered the inner tubular member 11 solidifies, and the solidified oil causes Throttle valve 2
0 and the inner wall of the inner tubular member 11 can be prevented from sticking to each other.

Further, the inflow port 33a of the bypass passage 33
Further, since the outlet 33b is open to the inner peripheral surface of the inner tubular member 11, it is possible to prevent liquefied water or oil from entering the bypass passage 33. Therefore, the ISC valve 32
Icing and sticking can be prevented. In the first embodiment, since the inner tubular member 11 and the outer tubular member 12 are integrally formed of resin, the number of components is reduced, and the number of assembling steps is reduced.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
Shown in Components substantially the same as those in the first embodiment are denoted by the same reference numerals. An intake passage 100 of the intake device is formed by a throttle body 50, an air duct 60, and an intake manifold 61. A throttle body 50 made of resin as an inner tubular member includes a tubular portion 51 and a tubular portion 51.
Annular flanges 52 and 5 extending radially outward on the upstream and downstream sides of the intake air, respectively.
And 3. The resin housing 31 of the ISC device 30 is attached to the outer peripheral wall of the cylindrical portion 51 between the flange 52 and the flange 53 by heat welding or the like.

The upstream side of the tubular portion 51 is fitted into an air duct 60 as an outer tubular member, and the air duct 60 surrounds the upstream end 51a of the tubular portion 51. Thus, the tubular portion 51 and the air duct 60 have a double pipe structure.
The fitting amount of the throttle body 50 into the air duct 60 is defined by the flange 52 abutting on the opening-side end surface of the air duct 60.

The cylindrical portion 51 is fitted into the air duct 60 to form a cylindrical gap 40 between the outer peripheral wall of the cylindrical portion 51 and the inner peripheral wall of the air duct 60.
A lip seal 42 as a sealing member disposed between the outer peripheral wall of the cylindrical portion 51 and the inner peripheral wall of the air duct 60 is sealed. When the intake passage 100 becomes negative pressure due to the intake air flow, the lip seal 42 expands, and seals between the outer peripheral wall of the cylindrical portion 51 and the inner peripheral wall of the air duct 60.

If water or oil liquefied from the air duct 60 side tries to enter the throttle body 50 side, water or oil is accumulated in the gap 40, so that the throttle body 1
It is possible to prevent water or oil from entering the inside. Tube part 5
1 is fitted into an intake manifold 61 as an outer tubular member, and the intake manifold 6
Reference numeral 1 surrounds the downstream end 51b of the tubular portion 51. Thus, the tubular portion 51 and the intake manifold 61 have a double pipe structure. The amount of fitting of the throttle body 50 into the intake manifold 61 is defined by the flange 53 being in contact with the end face on the opening side of the intake manifold 61. The protrusion 61 a formed on the opening-side end face of the intake manifold 61 is fitted into the through hole 54 formed on the flange 53, thereby positioning the throttle body 50 and the intake manifold 61 in the circumferential direction. As for the fitting relationship between the concave portion and the convex portion for positioning the throttle body 50 and the intake manifold 61 in the circumferential direction, the convex portion may be formed in the throttle body 50 and the concave portion may be formed in the intake manifold 61.

The cylindrical portion 51 is fitted into the intake manifold 61 to form a cylindrical gap 41 between the outer peripheral wall of the cylindrical portion 51 and the inner peripheral wall of the intake manifold 61. Lip seal 4
Reference numeral 2 seals between the outer peripheral wall of the cylindrical portion 51 and the inner peripheral wall of the intake manifold 61. When the intake passage 100 becomes negative pressure due to the intake air flow, the lip seal 42 expands, and seals between the outer peripheral wall of the cylindrical portion 51 and the inner peripheral wall of the intake manifold 61.

Even if water or oil liquefied from the intake manifold 61 side tries to enter the throttle body 50, water or oil is accumulated in the gap 41, so that water or oil can be prevented from entering the throttle body 50. The clamps 62 made of a leaf spring are arranged so as to be located on both sides of the throttle shaft 21, avoiding both ends of the throttle shaft 21. One end of the clamp 62 is swingably supported by a pin 63 attached to the intake manifold 61. The other end of the clamp 62 can be fitted into the through hole 54 in a state where the cylindrical portion 51 is fitted into the intake manifold 61. When the other end of the clamp 62 is fitted into the through hole 54, the throttle body 50 and the intake manifold 61 are axially held by the clamp 62 and pressed against each other. Does not rattle.

In the second embodiment, the upstream side and the downstream side of the cylindrical portion 51 are fitted in the air duct 60 and the intake manifold 61, respectively, so that the cylindrical portion 51 and the intake manifold 61 are located between the cylindrical portion 51 and the air duct 60. The gaps 40 and 41 are formed between them. Therefore, liquefied water or oil flowing from the air duct 60 and the intake manifold 61 to the throttle body 50 accumulates in the gaps 40 and 41 and does not enter the throttle body 50. Therefore, the throttle valve 20
Can prevent icing and sticking of the throttle valve, so that the smooth rotation of the throttle valve 20 can be maintained and the intake air flow rate can be appropriately controlled.

Further, the inflow port 33a of the bypass passage 33
Since the outlet 33b is open to the inner peripheral surface of the throttle body 50, liquefied water or oil does not enter the bypass passage 32. Therefore, it is possible to prevent icing and sticking of the ISC valve 32, so that it is possible to appropriately control the intake air flow during idling operation. In the second embodiment, the throttle body 50 is used as an inner tubular member, and the air duct 60 and the intech manifold 61 are used as outer tubular members at the connection points between the throttle body 50 and the air duct 60 and the in-tech manifold 61 which need to be connected as an intake system. The formation of the double pipe structure prevents liquefied water or oil from entering the throttle body 50. Therefore, by adjusting the diameter of each member without making the throttle body itself a double pipe structure, newly manufactured parts can be reduced as much as possible, and icing and sticking of the throttle valve 20 and the ISC valve can be prevented.

Further, the throttle body 50, the air duct 60, and the intake manifold 61 are separately formed and connected, and the connection portion is sealed with a lip seal 42.
Since the lip seal 42 expands due to the negative pressure generated by the flow of intake air flowing through the intake passage 100, the throttle body 50, the air duct 60, and the intake manifold 6
Even if there is a processing error at the connection point with the first seal 1, a good seal is provided between the throttle body 50 and the air duct 60 and the intake manifold 61. Therefore, even if a negative pressure is generated in the intake passage 100 due to the intake flow, external air does not flow into the intake passage 100 from a connection point between the throttle body 50, the air duct 60, and the intake manifold 61. The intake flow rate can be controlled with high precision. Further, since it is not necessary to machine the throttle body 50, the air duct 60, and the intake manifold 61 with high precision, machining is facilitated and the number of machining steps is reduced.

In particular, a resin molded throttle body 5
0, air duct 60 and intake manifold 61
Since the processing error and the amount of deformation due to thermal expansion or contraction are large, the lip seal 42 follows the processing error and the amount of deformation due to thermal expansion or contraction, and causes a gap between the throttle body 50 and the air duct 60 and the intake manifold 61. It can be sealed well.

In the second embodiment, the clamp 40 is swingably supported on the intake manifold 61 side, but it is also possible to swingably support the clamp 40 on the throttle body 50 side. In the above-mentioned plurality of examples showing the embodiment of the present invention described above, both the upstream end and the downstream end of the inner tubular member are surrounded by the outer tubular member. It is also possible to adopt a configuration in which only one of the upstream end and the downstream end is surrounded by the outer tubular member.

In the above embodiments, both the inflow port and the outflow port of the bypass passage are opened on the inner peripheral surface of the inner tubular member. Only one of them may be opened on the inner peripheral surface of the inner tubular member, and the other may be opened on the inner peripheral surface of the outer tubular member.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an intake device for an engine according to a first embodiment of the present invention.

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

FIG. 3 is a sectional view showing an intake device for an engine according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Intake device 10 Housing 11 Inner tubular member 11a Upstream end 11b Downstream end 12 Outer tubular member 20 Throttle valve 30 ISC device 32 ISC valve 33 Bypass passage 33a Inlet 33b Outlet 42 Lip seal (seal material) 50 Throttle body (inner tubular) 51a Upstream end 51b Downstream end 60 Air duct (outer tubular member) 61 Intake manifold (outer tubular member) 100 Intake passage

──────────────────────────────────────────────────の Continued on front page (51) Int.Cl. ⁶ Identification code FI F02M 35/10 301Z

Claims (5)

[Claims] 1. A throttle valve for adjusting an intake air flow rate, and at least one of an inlet and an outlet of a bypass passage that avoids the throttle valve and accommodates the throttle valve rotatably. An inner tubular member that is open, and an outer tubular member that surrounds at least one of the upstream end and the downstream end of the inner tubular member and forms a gap between the inner tubular member and the outer tubular member. For an internal combustion engine. 2. The internal combustion engine according to claim 1, wherein the outer tubular member surrounds the upstream end and the downstream end of the inner tubular member and forms a gap between the outer tubular member and the inner tubular member. Air intake device. 3. The intake device for an internal combustion engine according to claim 1, wherein the inflow port and the outflow port of the bypass passage are opened on an inner peripheral surface of the inner tubular member. 4. The intake device for an internal combustion engine according to claim 1, wherein the inner tubular member and the outer tubular member are integrally formed. 5. The apparatus according to claim 1, wherein the inner tubular member and the outer tubular member are separate bodies, and a space between the inner tubular member and the outer tubular member is sealed with a sealing material. 4. The intake device for an internal combustion engine according to 2 or 3.