JP2012127251A - Intake valve device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intake valve device capable of sustaining the safe operation of an engine by providing a relief valve function to a shaft which rotatably operates a resin valve element and opening the relief valve if back fire occurs to forcibly release high temperature and high pressure combustion gas through the relief valve so as to maintain the state in which a suction air amount can be controlled by the resin valve element even if back fire occurs.SOLUTION: A fluid path 34 is provided to the inside of the shaft 33 which rotatably operates the resin valve element 32. A relief valve mechanism 40 for releasing a fluid pressure on the intake air downstream side by displacing to the second hole 36 side by only a fluid pressure acting from a first hole 35 toward a second hole 36 is disposed in the fluid path 34 between the first hole 35 and the second hole 36. The relief valve mechanism 40 is opened by the high temperature and high pressure combustion gas reversely flowing from the intake air downstream side to quickly release the high temperature and high pressure combustion gas so as to protect the resin valve element 32 even if back fire occurs.

Description

  The present invention relates to an intake valve device for an internal combustion engine (hereinafter referred to as an engine) mounted on a vehicle such as an automobile, and more particularly to a resin as a valve body for directly controlling the amount of air taken into a combustion chamber of the engine. The present invention relates to an intake valve device of a type in which a valve body is used.

(Conventional technology)
As an intake valve device for an engine mounted on a vehicle such as an automobile, various configurations have been conventionally known. In the case of a throttle valve as a representative example, a type as shown in FIG. 1 is generally used. Is. Briefly referring to FIG. 1, a valve 3 for opening / closing or adjusting the opening of the intake passage 2 is provided in the intake passage 2 that guides combustion air toward the combustion chamber 1 a of the engine 1. The valve 3 basically includes a housing 31 that forms part of the intake duct 4, a valve body 32, and a shaft 33 that rotates the valve body 32, and the passage area of the intake passage 2 is increased according to the operating conditions of the engine 1. The flow of intake air as indicated by arrow A, that is, the amount of intake air of the engine 1 is controlled by increasing and decreasing.
However, in recent years, a so-called resin valve device in which at least the valve body 32 to be rotated is made of resin instead of metal has been widely used for this type of intake valve device in order to reduce cost and weight. It has come to be.

However, the engine 1 generates a combustion pressure, that is, a so-called backfire, accompanied by a flame directed from the downstream side of the intake passage 2 (downstream side of the intake air) to the upstream side of the intake passage 2 (upstream side of the intake air) as indicated by an arrow B depending on operating conditions. Although the high-temperature and high-pressure combustion gas and flame generated by the backfire instantaneously flow back in the intake passage 2, the valve 3 mounted in the intake passage 2, particularly the resin valve body 32, is As a result, the surface of the valve element 32 may be melted. In particular, during start-up and idle operation, the valve 3 is in a slightly opened state, and a slight gap is formed in the intake passage 2, so that high-temperature and high-pressure combustion gas and flame due to the backfire are As a result of instantaneously concentrating in the gap as the escape path, there is a concern that the entire valve body 32 may be melted and further, the valve body 32 may be welded to the inner wall of the housing 31 forming the intake passage 2.
As described above, when an accident such as melting of the valve body 32 is caused, the amount of intake air becomes uncontrollable, and safe driving is hindered due to dangerous behavior such as sudden start of the vehicle due to engine overrun.

Therefore, in this type of intake valve device, when the valve body 32 is made of resin, a proposal has been made to mount a heat-resistant protective layer on the surface of the valve body 32 (see, for example, Patent Document 1). .
This structure is intended to protect the surface of the valve body from high-temperature combustion gas by providing a heat-resistant plating layer or providing (attaching) a heat-resistant material on the surface of the resin valve body.

(Problems of conventional technology)
However, attaching any protective means to the resin valve body not only increases the weight and goes against the weight reduction, but also the backfire is high temperature and high pressure as described above. When this occurs, there is a problem that the valve body itself is made of resin and has low strength, which eventually causes damage (breakage, breakage, etc.) of the valve body.
If the valve body itself is damaged in this way, the amount of intake air becomes uncontrollable, and in addition to the same problem as the above-mentioned melting damage that causes troubles in safe operation such as engine overrun, If inhaled into the engine, there is a risk of serious damage to the engine.

  The above problem has been described in detail with respect to a case of a throttle valve, which is a typical example of an intake valve device. However, in recent engines, in FIG. 1, each branch pipe 4a of the intake duct 4 to each intake port 1b of each cylinder is shown. Some tumble valves and swirl valves are installed to change the flow of intake air into a more suitable flow. The impact is exactly the same.

  The present inventors have conducted various experiments and researches in order to investigate such a problem, and as described above, backfire is a phenomenon that occurs instantaneously as described above. It has been found that the direct influence of the backfire can be eliminated by preventing the resin valve body itself from being exposed to the high-temperature combustion gas.

JP 2008-23001A

  The present invention has been made in view of the above investigation results. The purpose of the present invention is to incorporate a relief valve mechanism in a shaft for rotating a resin valve body so that when a backfire occurs. The relief valve mechanism is opened using high combustion pressure, and after the high-temperature and high-pressure combustion gas is once removed, the relief valve mechanism is restored to the initial state. An object of the present invention is to provide an intake valve device capable of maintaining a controllable intake air amount and maintaining a safe operation of an engine.

[Means of claim 1]
According to the first aspect of the present invention, the shaft for rotating the resin valve body is a cylindrical body having a fluid passage extending in the axial direction therein, and the valve body is opened so that the intake passage is closed. When one of the fluid passages is rotated, the pressure introduction hole opens at one end of the fluid passage to the intake downstream side of the intake passage, and the other end of the fluid passage opens at a location other than the intake downstream side of the intake passage. A pressure relief hole, and the fluid passage is displaced between the pressure introduction hole and the pressure relief hole only by the fluid pressure directed from the pressure introduction hole to the pressure relief hole, and the intake passage A relief valve mechanism is provided for releasing the downstream fluid pressure.
Therefore, when a backfire occurs, the relief valve mechanism instantaneously receives a high combustion pressure (fluid pressure) and displaces (opens) to the pressure relief hole side. Therefore, the resin valve body is not continuously exposed to high temperatures, and the valve body is not melted.
Moreover, since the relief valve mechanism can be arranged by skillfully utilizing the dead space of the shaft, a backfire countermeasure structure can be realized while maintaining the weight reduction of the valve body itself to be rotated.

  Furthermore, the relief valve mechanism can immediately return to the initial state when the backfire disappears, so the intake passage can be closed by the valve body and the intake air volume can be continuously controlled, and the engine can be operated safely and continuously. can do. Therefore, the vehicle can be moved and repaired at least to the nearest repair shop.

[Means of claim 2]
According to the second aspect of the present invention, the pressure relief hole opens to the intake upstream side of the intake passage when the shaft rotates the valve body to the opening position where the intake passage is closed.
By adopting such a configuration, it is possible to quickly and surely release the high-temperature and high-pressure combustion gas or flame caused by the backfire to the intake upstream side to protect the resin valve body.

[Means of claim 3]
According to the third aspect of the present invention, the shaft has a communication hole opened to the outside of the housing at a portion supported by the housing, and a pressure relief hole is formed in the communication hole.
According to this configuration, the high-temperature and high-pressure combustion gas or flame caused by the backfire can be quickly and surely released to the outside of the housing to protect the resin valve body.

[Means of claim 4]
According to the fourth aspect of the present invention, a plurality of pressure introducing holes and a plurality of pressure relief holes are provided.
According to such a configuration, in addition to the effect of the first aspect of the invention, the pressure loss at the time of pressure relief can be reduced, so that the pressure can be reduced more quickly.

[Means of claim 5]
According to the fifth aspect of the present invention, the valve body and the shaft are integrally provided by a common resin material.
With this configuration, the valve body and the shaft can be integrally formed with the same molding die, and the manufacturing cost of the intake valve device can be reduced.

[Means of claim 6]
According to the invention described in claim 6, the shaft is composed of a metal pipe having an U-shaped axial section having an open end at one end, and a plug fitted to the open end. The stopper is fitted after the relief valve mechanism is assembled from the open end side.
With this configuration, a general-purpose metal pipe can be used as a shaft, and a one-way assembly of a relief valve mechanism to the shaft is possible, thereby reducing the manufacturing cost of the intake valve device. it can.

[Means of Claim 7]
According to the seventh aspect of the present invention, the relief valve mechanism includes a valve body and a restoring spring, the valve body is a ball valve or a conical valve, and the restoring spring is a coil spring.
According to such a configuration, a relief valve mechanism itself having a simple structure and a low cost can be used, and the relief valve mechanism can be easily maintained and inspected despite being incorporated in the shaft.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing a part of a general engine provided with an intake device and an exhaust device as an engine for applying an intake valve device of the present invention. The principal part of the valve apparatus for intake air of Example 1 of this invention is shown in a partial cross section, (a) is a typical longitudinal cross-sectional view, (b) is a typical cross-sectional view. 2A and 2B are diagrams for explaining the operation of the intake valve device shown in FIG. 2, in which FIG. 2A is a schematic sectional view of a shaft, and FIG. 2B is an XX sectional view of FIG. The principal part of the valve apparatus for intake air of Example 2 of this invention is shown with a partial cross section, (a) is a typical longitudinal cross-sectional view, (b) is a typical cross-sectional view. FIGS. 4A and 4B are used to explain the operation of the intake valve device shown in FIG. 4. FIG. 4A is a schematic sectional view of a shaft, and FIG. 4B is a YY sectional view of FIG. It is a typical cross section which shows the principal part of the valve apparatus for intake air of Example 3 of this invention.

  The best mode for carrying out the present invention is to rotate the resin valve body in order to protect the resin valve body from the instantaneous high temperature and high pressure phenomenon that occurs by backflow in the intake passage by the backfire. This was realized by incorporating a relief valve mechanism in the shaft, and opening the relief valve mechanism using the high pressure during backfire and then restoring it after removing the high pressure.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted.

[Example 1]
FIGS. 1 to 3 are for explaining the first embodiment of the present invention. First, based on FIG. 1, the basic configuration of a general engine in which the intake valve device is applied as a throttle valve is outlined. After that, the first embodiment of the intake valve device of the present invention will be described in detail with reference to FIGS.

(Description of applicable engine 1)
The engine 1 is mounted on a vehicle such as an automobile, and the intake passage 2 that leads combustion air toward the combustion chamber 1a of the engine 1 is opened and closed or opened as an intake valve device. A valve 3 for adjusting the degree is provided. The valve 3 is basically interposed in the intake duct 4, and a housing 31 that presents the outline of the device, a valve body 32 that is accommodated in the housing 31, and the valve body 32 are rotated. It comprises a shaft 33, and controls the flow of intake air (intake air amount of the engine 1) as indicated by the arrow A by increasing or decreasing the passage area of the intake passage 2 in accordance with the operating conditions of the engine 1.

The engine 1 is usually composed of multiple cylinders, and the combustion chamber 1a of each cylinder is connected to each branch pipe 4a of the intake duct 4 from the intake port 1b. An air filter 5 is provided at the air intake 4b of the intake duct 4, and air purified by the air filter 5 flows as indicated by an arrow A and is guided to the combustion chamber 1a. A passage from the air intake 4b of the intake duct 4 to the intake port 1b forms the intake passage 2 described above.
Each branch pipe 4a of the intake duct 4 is provided with a fuel injection valve 6, and a mixture of fuel and air injected from the fuel injection valve 6 is introduced into the combustion chamber 1a via the intake valve 1c. Therefore, the gas ignited and burned by the spark plug 1d is discharged from the exhaust port 1f to the exhaust pipe 7 through the exhaust valve 1e.

(Description of the valve 3 constituting the intake valve device)
The valve 3 is disposed in the intake duct 4 forming the intake passage 2 as described above. As shown in FIG. 2, the cylindrical housing 31 constituting a part of the intake duct 4 and the intake passage 2 are arranged. And a metal valve body 32 for opening / closing or adjusting the opening of the intake passage 2 and rotatably supported by the housing 31 and for rotating the valve body 32 inside the intake passage 2. The shaft 33 made of is provided as a basic configuration.

  The resin valve body 32 has a disk shape corresponding to the cross-sectional shape of the intake passage 2 as a whole, and is supported on the metal shaft 33 by an annular portion 32a extending in the diameter direction at the center of rotation. The valve body 32 and the shaft 33 can be easily manufactured (integrated) by, for example, an insert molding technique by exposing both end portions 33a and 33b of the shaft 33 from the valve body 32. At this time, by forming an uneven surface on the outer peripheral surface of the shaft 33 by a satin finish or the like, the resin valve body 32 can be firmly fixed to the metal shaft 33. Further, as the resin material of the valve body 32, for example, a thermosetting resin such as PPS is used.

Both end portions 33a and 33b of the metal shaft 33 are rotatably supported by the bulging portions 31a and 31b of the housing 31 via bearings 8 and 9, respectively. One end portion 33b is a drive source. 10 is connected. As is well known, the drive source 10 receives a control signal corresponding to the operating state of the engine 1 from an electronic control device (not shown) and rotates the shaft 33 to a predetermined position, and is constituted by a motor or the like.
A seal cap 11 is fitted into the bulging portion 31a of the housing 31 that supports the other end portion 33a (open end, counter drive source side) of the shaft 33 in order to maintain airtightness.

As shown in FIG. 3, the metal shaft 33 as a whole presents a pipe (cylindrical body) having an U-shaped cross section with an open end 33 a opened, and extends in the axial direction inside. A fluid passage 34, a first hole 35 provided in the radial direction and opening one end side of the fluid passage 34 to the outside, a second hole 36 opening the other end side of the fluid passage 34 to the outside, and an open end 33a And a plug 37 that seals the fluid passage 34.
The first hole 35 and the second hole 36 are spaced apart in the axial direction but opposed in the radial direction. As shown in FIG. 2A, the annular portion 32a of the valve body 32 is provided. Is opened to the outside of the valve body 32.
The fluid passage 34 is displaced (opened) between the first hole 35 and the second hole 36 toward the second hole side only by the fluid pressure from the first hole 35 toward the second hole 36. By doing so, a relief valve mechanism 40 is provided for allowing the first hole 35 and the second hole 36 to flow.

In this embodiment, the metal shaft 33 is formed into a pipe shape by machining a cylindrical metal rod (for example, stainless steel material or heat-resistant steel material), and the fluid passage 34 has an open end 33a side. The large-diameter hole 34a has a two-step hole structure with a small-diameter hole 34b on the side opposite to the open end, and a relief valve mechanism 40 is disposed at this stepped portion.
The relief valve mechanism 40 includes a ball valve 41 that forms a valve body, a valve seat 42, a coil spring 43 that presses the ball valve 41 against the valve seat 42 to form a restoring spring, and a spring receiver 44. The spring receiver 44 has a plurality of communication grooves 44a on the outer periphery, and ensures the communication state of the large-diameter hole 34a.
When the relief valve mechanism 40 is assembled to the shaft 33, the valve seat 42, the ball valve 41, the coil spring 43, and the spring receiver 44 are inserted into the large-diameter hole 34 a of the fluid passage 34 from the stepped portion toward the open end 33 a. Can be completed by sequentially loading and plugging the plug 37 into the open end 33a. A one-way assembly is thus achieved.
In the fluid passage 34, the first hole 35 communicates with the small diameter hole 34 b and the second hole 36 communicates with the large diameter hole 34 a before and after the relief valve mechanism 40 is disposed.

Here, the relationship between the first and second holes 35 and 36 and the opening position of the valve body 32 will be supplementarily described with reference to FIG. The valve body 32 exhibits an inclined state in which the valve body 32 obliquely crosses the intake passage 2 and closes in the fully closed state (fully closed position) in which the outer peripheral edge is in contact with the inner wall of the housing 31 (intake duct 4). The intake passage 2 is gradually opened (opened) by being rotated counterclockwise as indicated by an arrow C, and the maximum valve opening (fully opened state) at a horizontal position along the intake passage 2 is performed. Fully open position).
In the first and second holes 35 and 36, in the fully closed position of the valve body 32, the first hole 35 opens to the intake downstream side, and the second hole 36 opens to the intake upstream side. The hole 35 serves as a pressure introduction hole, and the second hole 36 serves as a pressure relief hole.

(Background of Example 1)
The engine 1 has a backfire depending on operating conditions. This backfire is a phenomenon in which incomplete combustion gas explodes and burns due to, for example, a deviation in the opening / closing timing of the intake valve 1c of the engine 1 or a deviation in the ignition timing by the spark plug 1d. In addition to the vicinity of the port 1b, the intake passage 2 may flow backward (in the direction of arrow B in FIGS. 1 and 2) to reach the vicinity of the air filter 5.
Therefore, the valve 3 disposed in the intake passage 2 is exposed to high-temperature and high-pressure combustion gas or flame. At this time, when the engine 1 is idling or the like and the valve body 32 is fully closed or close to it, the entire valve body 32 receives the high-temperature and high-pressure combustion gas.

(Characteristics of Example 1)
In order to solve the above problem, the following technique is adopted in the valve 3 of the first embodiment.
That is, the shaft 33 incorporates the relief valve mechanism 40. When the high pressure of the backfire is received as shown by the arrow B in FIG. 2 with the valve body 32 fully closed, as shown in FIG. The ball valve 41 separates (opens) from the valve seat 42 against the coil spring 43 by the pressure introduced from the pressure introduction hole) into the small diameter hole 34 b of the fluid passage 34. Thereby, the flow path (path | route of the arrow D shown in FIG.3 (b)) from the 1st hole 35 (pressure introduction hole) to the 2nd hole 36 (pressure relief hole) can be formed.
Thus, using this flow path as an escape path, high-temperature and high-pressure combustion gas and flame instantaneously escape (exit) from the intake downstream side to the intake upstream side. Therefore, the resin valve body 32 is not continuously exposed to the high-temperature and high-pressure combustion gas or flame, and the valve body 32 can be prevented from being melted.

On the other hand, when the backfire disappears, the relief valve mechanism 40 causes the ball valve 41 to be seated (closed) on the valve seat 42 by the coil spring 43. The flow path (the path indicated by the arrow D shown in FIG. 3B) from the first hole 35 (pressure introduction hole) to the second hole 36 (pressure relief hole) is blocked.
As a result, the valve body 32 can perform the original function of the valve, control the intake air amount, and the engine 1 can be operated continuously without fear of overrun. Therefore, the vehicle can be safely moved to the nearest repair shop by safe driving.

Although it is conceivable to incorporate the relief valve mechanism 40 in the valve body 32, in this case, the relief valve mechanism 40 becomes a weight by attaching the relief valve mechanism 40 to the valve body 32. Unbalance the weight. For this reason, an unbalanced load is generated when the valve body 32 rotates, and the responsiveness deteriorates. In addition, the valve body 32 itself may be damaged by the centrifugal force due to the rapid rotation.
The present embodiment has the following characteristics that do not cause any such problems.
That is, the shaft 33 needs to have a predetermined thickness for the operation of the valve body 32, and the relief valve mechanism 40 can be arranged by effectively utilizing this thickness (dead space). Since it is located at the center of movement, there is no particular load or deterioration in responsiveness even when the valve body 32 is rotated, and it is completely affected by the centrifugal force due to a sudden rotation. Absent.

[Example 2]
4 and 5 are for explaining the second embodiment of the present invention, and schematically show the main part of an intake valve device applied as the valve 3 of FIG.
In the present embodiment, the relief valve mechanism 40 is built in the metal shaft 33 and the relief valve mechanism 40 is disposed between the first hole 35 and the second hole 36. Although it is the same as that of Example 1, it has the characteristics in the escape structure of the combustion gas at the time of backfire.

The metal shaft 33 is provided with a fluid passage 34 extending in the axial direction therein, but is a short fluid passage 34 extending from the open end 33a side to approximately half the axial length of the shaft 33. A first hole 35 forming a pressure introduction hole is formed in the small diameter hole 34b forming one end side of the fluid passage 34, and a pressure releasing hole is formed in the large diameter hole 34a forming the other end side of the fluid passage 34. Each hole 36 is provided.
The first hole 35 passes through the annular portion 32a of the valve body 32 and opens to the outside of the valve body 32 as in the first embodiment. However, the second hole 36 is centered on the center of the plug body 37. A communication hole is provided penetrating in the direction to open the large-diameter hole 34 a to the bulging portion 31 a of the housing 31.
In the relief valve mechanism 40, the plug body 37 also serves as the spring receiver 44 of the coil spring 43.
Note that a seal cap 11 is fitted into the open end of the bulging portion 31a of the housing 31 by press-fitting in order to keep it airtight. Press-fit strength is selected.

According to this embodiment, when a backfire occurs, the valve body 31 receives a reverse flow (arrow B) from the intake downstream side, the relief valve mechanism 40 is opened as in the first embodiment, and the second The seal cap 11 is detached from the bulging portion 31 a of the housing 31 by the fluid pressure ejected from the hole 36 (pressure relief hole). Thereby, the flow path (path | route of the arrow D shown in FIG.5 (b)) from the 1st hole 35 (pressure introduction hole) to the 2nd hole 36 (pressure relief hole) can be formed.
Thus, using this flow path as the escape path, the high-temperature and high-pressure combustion gas or flame follows the path indicated by the arrow D from the intake downstream side and escapes (exits) instantly out of the housing 31. Therefore, the resin valve body 32 is not continuously exposed to the high-temperature and high-pressure combustion gas or flame, and the valve body 32 can be prevented from being melted.

[Example 3]
FIG. 6 is for explaining the third embodiment of the present invention, and schematically shows the main part of the intake valve device applied as the valve 3 of FIG.
In the present embodiment, the relief valve mechanism 40 is built in the metal shaft 33 and the relief valve mechanism 40 is disposed between the first hole 35 and the second hole 36. Although it is the same as that of Examples 1 and 2, it has the characteristic in the escape structure of the combustion gas at the time of backfire.

The metal shaft 33 is provided with a fluid passage 34 extending in the axial direction therein, and a first small diameter hole 34b forming one end of the fluid passage 34 (the non-opening side end) forms a pressure introduction hole. A plurality of holes 35 (three in the illustrated example) are provided, and a plurality of second holes 36 (two in the illustrated example) forming pressure relief holes are provided in the large-diameter hole 34a forming the other end of the fluid passage 34. ing.
The first hole 35 penetrates the annular portion 32a of the valve body 32 and opens to the outside of the valve body 32 as in the first embodiment, but the second hole 36 is located at the open end 33a of the shaft 33 ( In particular, a penetrating hole is provided in a radial direction on the tip side of the portion supported by the bearing 8 so as to open the large-diameter hole 34 a to the bulging portion 31 a of the housing 31.
As in the second embodiment, in the relief valve mechanism 40, the plug body 37 also serves as the spring receiver 44 of the coil spring 43, and the open end of the bulging portion 31 a of the housing 31 is kept airtight. Therefore, the seal cap 11 is fitted by press-fitting, but the press-fitting strength is selected so that the seal cap 11 can be pulled out by the fluid pressure from the second hole 36.
The relief valve mechanism 40 includes a conical valve 45 as a valve body.

  According to this embodiment, when a backfire occurs, the valve body 32 receives a reverse flow from the intake downstream side, and the relief valve mechanism 40 is opened and ejected from the second hole 36 (pressure relief hole). The seal cap 11 is detached from the bulging portion 31 a of the housing 31 by the fluid pressure. As a result, the flow path from the first hole 35 (pressure introduction hole) to the second hole 36 (pressure relief hole) can be formed, as in the second embodiment, but the first hole There are a plurality of each of the 35 and the second holes 36, and the total opening area can be increased. Therefore, the pressure loss during the pressure relief can be reduced by that amount, and the pressure can be reduced more quickly.

[Modification]
Although the three embodiments have been described in detail, the present invention can be implemented in various modifications as described below.
(1) The first and second holes 35 and 36 are preferably circular in terms of production, but are not limited thereto, and the shape and size can be arbitrarily selected.
(2) The shaft 33 can also be manufactured by utilizing a general metal pipe (off-the-shelf product) that is widely used.
(3) If the fluid passage 34 has a stepped hole structure as in the embodiment, it is advantageous in terms of the assembly surface of the relief valve mechanism 40 and the pressure transmission to the relief valve mechanism 40. It is not always necessary.
(4) The relief valve mechanism 40 can be selected from various structures as long as the mechanism is displaced (opened) toward the second hole 36 by the fluid pressure from the first hole 35.
(5) The shaft 33 can also be made of resin. In this case, the shaft 33 and the valve body 32 can be integrally formed of a common resin material.

  In the above example, the application example to the throttle valve has been described in detail. In FIG. 1, the intake flow from each branch pipe 4a of the intake duct 4 to the intake port 1b of each cylinder is changed to a more suitable flow. Needless to say, the structure of the valve body 32 is not limited to the butterfly type having the shaft 33 in the center, and the shaft 33 is provided on one side. It can also be applied to a fan type that opens and closes like a fan. In any case, it is important that the shaft 33 is located at the center of rotation of the valve body 32.

1 engine (internal combustion engine)
2 Intake passage 3 Valve (Intake valve device)
4 Intake duct 31 Housing 32 Resin valve body 33 Metal shaft 33a Open end (the other end)
33b One end 34 Fluid passage 35 First hole (pressure introduction hole)
36 2nd hole (communication hole, pressure relief hole)
37 Plug 40 Relief valve mechanism 41 Ball valve 42 Valve seat 43 Coil spring 44 Spring receiver 45 Conical valve

Claims (7)

A housing having an intake passage for directing combustion air toward the combustion chamber of the internal combustion engine;
A valve body that is disposed inside the intake passage so as to partition an intake upstream side and an intake downstream side, and adjusts the opening of the intake passage;
A shaft that is supported by the housing and that rotates the valve body inside the intake passage;
In the intake valve device in which the valve body is formed of a resin material,
The shaft has a cylindrical body having a fluid passage extending in the axial direction inside, and when the valve body is rotated to an opening position where the intake passage is closed, one end side of the fluid passage is A pressure introduction hole that opens to the intake downstream side of the intake passage, and a pressure relief hole that opens the other end of the fluid passage at a location other than the intake downstream side of the intake passage,
The fluid passage is displaced between the pressure introduction hole and the pressure relief hole only by the fluid pressure from the pressure introduction hole to the pressure relief hole, so that the fluid pressure on the downstream side of the intake air is changed. A relief valve mechanism for releasing air is provided. The intake valve device according to claim 1,
The intake valve device, wherein the pressure relief hole opens to the intake upstream side of the intake passage when the shaft rotates the valve body to an opening position where the intake passage is closed. . The intake valve device according to claim 1,
The shaft has a communication hole that is open to the outside of the housing in a portion supported by the housing;
The intake valve device, wherein the pressure relief hole is formed in the communication hole. The intake valve device according to any one of claims 1 to 3,
The intake valve device, wherein a plurality of the pressure introduction holes and the pressure relief holes are provided. The intake valve device according to any one of claims 1 to 4,
The intake valve device, wherein the valve body and the shaft are integrally provided by a common resin material. The intake valve device according to any one of claims 1 to 4,
The shaft is composed of a metal pipe having an U-shaped axial section having an open end at one end, and a plug fitted to the open end,
The intake valve device, wherein the plug is fitted into the metal pipe after the relief valve mechanism is assembled from the open end side. The intake valve device according to any one of claims 1 to 6,
The relief valve mechanism includes a valve body and a restoring spring,
The intake valve device, wherein the valve body is a ball valve or a conical valve, and the restoring spring is a coil spring.

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