JP2010038042A - Throttle device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a throttle device for an internal combustion engine, preventing operation failure of a throttle valve by suppressing adhesion and freeze of condensate water around the throttle valve. <P>SOLUTION: This throttle device 1 includes a throttle body 2 forming an intake passage 3, and the plate-like throttle valve 4 arranged rotatably around a rotating shaft 41 for opening/closing the intake passage 3. A variable plate 5 deformable in accordance with a change in temperature of intake air G or the throttle valve 2 is provided upstream of the opposite inner wall surface 211 of the throttle body 2 with the outer peripheral end 42 of the throttle valve opposed when the throttle valve 4 is closed. The variable plate 5 is configured to be substantially in close contact with the inner wall surface 21 of the throttle body 2 when the temperature of the intake air G or the throttle body 2 exceeds a predetermined temperature and to be deformed in order to be separated from the inner wall surface 21 of the throttle body 2 according as it approaches a downstream side when the temperature of the intake air G or the throttle body 2 reaches the predetermined temperature or lower. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a throttle device for an internal combustion engine that controls an intake air amount to the internal combustion engine by opening and closing a throttle valve.

2. Description of the Related Art Conventionally, a throttle device that controls the amount of air (intake amount) taken into a combustion chamber by opening and closing a throttle valve provided in an intake passage of an internal combustion engine is known. An air cleaner is usually provided at the inlet of the intake passage of the internal combustion engine. However, depending on the use environment, condensed water may be generated in the intake passage. When the condensed water adheres to the vicinity of the throttle valve (the inner wall surface of the throttle body that forms the intake passage), for example, when the internal combustion engine is stopped and the temperature becomes low (below freezing point), the condensed water freezes. There has been a problem that operation failure occurs due to the biting of ice by the throttle valve.
Therefore, Patent Document 1 proposes a device provided with a hot water heating device having a hot water passage for circulating hot water for heating the throttle body in order to prevent freezing of moisture in the intake air at a low temperature.

JP-A-10-317998

  However, since the structure in which the throttle body is heated with warm water is accompanied by a reduction in intake air density due to the intake air heating, it is necessary to suppress the upper limit of the temperature. For this reason, in particular, when the internal combustion engine is operating under a low outside temperature, when the icing on the throttle device occurs, it is unavoidable that a malfunction may occur due to the ice biting by the throttle valve temporarily. .

  The present invention has been made in view of such conventional problems, and it is intended to provide a throttle device for an internal combustion engine that can suppress the adhesion and freezing of condensed water around the throttle valve and prevent malfunction of the throttle valve. It is what.

The present invention includes a throttle body that forms an intake passage of an internal combustion engine, and a plate-like throttle valve that is rotatably disposed around a rotation shaft so as to open and close the intake passage inside the throttle body. In a throttle device for an internal combustion engine,
On the upstream side of the opposing inner wall surface, which is the inner wall surface of the throttle body, which faces the outer peripheral end of the throttle valve in the closed state of the throttle valve, a variable plate that can be deformed according to intake air or temperature change of the throttle body Part is arranged,
The variable plate portion is substantially in close contact with the inner wall surface of the throttle body when the intake air or the temperature of the throttle body exceeds a predetermined temperature, and on the downstream side when the temperature is equal to or lower than the predetermined temperature. The throttle device for an internal combustion engine is configured to be deformed so as to move away from the inner wall surface of the throttle body as it goes to (Claim 1).

In the throttle device according to the present invention, the variable plate portion that can be deformed according to intake air or a temperature change of the throttle body has an inner portion of the throttle body facing the outer peripheral end of the throttle valve when the throttle valve is closed. It is arranged on the upstream side of the wall surface.
When the intake air or the throttle body becomes a predetermined temperature or lower, the variable plate portion cools, for example, moisture in the intake air flowing through the intake passage and becomes condensed water, and freezes on the inner wall surface of the throttle body. Under easy conditions, as it goes downstream, it deforms away from the inner wall surface of the throttle body.

  Therefore, the condensed water that is generated in the intake passage and travels along the inner wall surface of the throttle body by the flow of the intake air moves along the shape of the variable plate portion provided on the front side of the throttle valve. The condensed water separated from the inner wall surface and then separated from the variable plate portion flows along with the intake air in a state separated from the inner wall surface of the throttle body. Thereby, adhesion and freezing of condensed water in the vicinity of the opposed inner wall surface of the throttle body can be suppressed. Therefore, it is possible to prevent the ice from being caught by the throttle valve and the operation failure associated therewith.

On the other hand, the variable plate portion is substantially in close contact with the inner wall surface of the throttle body when the temperature of the intake air or the throttle body exceeds a predetermined temperature, for example, under the condition that the condensed water flowing through the intake passage hardly freezes. It will be in the state.
For this reason, the variable plate portion does not serve as a resistance for intake air flowing through the intake passage. Thereby, there is almost no influence on the intake air amount and the output of the internal combustion engine due to the arrangement of the variable plate portion.

  As described above, according to the present invention, it is possible to provide a throttle device for an internal combustion engine that can suppress the adhesion and freezing of condensed water around the throttle valve and prevent malfunction of the throttle valve.

In the present invention, the throttle device can be employed in an internal combustion engine such as a gasoline engine or a diesel engine.
Further, the opposed inner wall surface of the throttle body is a region having a certain width including the portion of the inner wall surface of the throttle body that faces the outer peripheral end of the throttle valve when the throttle valve is closed. Say.
The predetermined temperature refers to a temperature range from the start of deformation of the variable plate portion to the completion thereof.

Further, as described above, the variable plate portion is disposed on the upstream side of the opposed inner wall surface of the throttle body. At this time, the variable plate portion is disposed at a position where it does not interfere with the throttle valve.
In addition, it is preferable that the arrangement position of the variable plate portion is a position that does not interfere with the throttle valve on the upstream side of the opposed inner wall surface of the throttle body and is the most downstream side thereof. Thereby, the effect of suppressing the adhesion and freezing of condensed water in the vicinity of the opposed inner wall surface of the throttle body by the variable plate portion can be further exhibited.

Further, the variable plate portion may be disposed upstream of a portion of the opposed inner wall surface of the throttle body where ice is likely to be caught by the throttle valve when condensed water adheres and freezes. preferable.
For example, the arrangement position of the variable plate portion in the circumferential direction of the throttle body is upstream of a portion of the opposed inner wall surface at which the apex portion farthest from the rotation shaft at the outer peripheral end portion of the throttle valve is opposed. It is preferable that it is the side (Claim 2).
That is, of the opposed inner wall surfaces of the throttle body, the portion of the throttle valve that faces the apex of the outer peripheral end of the throttle valve is particularly engulfed by the throttle valve when condensed water adheres and freezes. easy. Therefore, by disposing the variable plate portion on the upstream side of such a portion, it is possible to further prevent the biting of ice by the throttle valve and the operation failure associated therewith.

Further, when there are a plurality of vertex portions at the outer peripheral end portion of the throttle valve, the variable plate portion is located upstream of the portion of the opposed inner wall surface of the throttle body that is opposed to at least one vertex portion. What is necessary is just to arrange | position.
Furthermore, it is preferable that the throttle valve is disposed upstream of a portion facing the apex portion on the side where a large amount of intake air flows when the intake valve is opened and closed by rotating the throttle valve. Since this portion is a portion where condensed water is likely to adhere and freeze, the effect of disposing the variable plate portion can be further exhibited.

Further, the variable plate portion can be disposed by a method such as welding, sticking or fixing with a bolt on the inner wall surface of the throttle body.
The variable plate portion can be disposed on the inner wall surface of the throttle body, or can be embedded in the inner wall surface of the throttle body so as to be exposed to the intake passage.
The variable plate portion can be configured to be deformable so that the downstream portion is separated from the inner wall surface of the throttle body by fixing only the upstream portion thereof to the inner wall surface of the throttle body.

  Further, the shape of the variable plate portion may be a shape that can be deformed so as to move away from the inner wall surface of the throttle body as it goes downstream when the temperature of the intake air or the throttle body becomes equal to or lower than the predetermined temperature. is necessary. For example, when the inner wall surface of the throttle body is a curved surface, it is preferable that the variable plate portion also has a shape having a curved surface corresponding to the curved surface so that it can be easily deformed by making a notch (slit) or the like.

Further, it is preferable that the width of the variable plate portion is 1/6 or more of the circumferential length of the outer peripheral end portion of the throttle valve.
In this case, the adhering of the condensed water to the vicinity of the opposed inner wall surface of the throttle body can be sufficiently suppressed by the variable plate portion.

Moreover, it is preferable that the said variable board part is a bimetal comprised by laminating | stacking the some material from which a thermal expansion coefficient differs (Claim 4).
In this case, the variable plate portion can be easily and accurately deformed according to the intake air or the temperature of the throttle body.

Moreover, the said bimetal can employ | adopt an already well-known general thing.
For example, when two materials having different thermal expansion coefficients are overlapped, a material having a relatively low thermal expansion coefficient may be adopted for one and a material having a relatively high thermal expansion coefficient for the other. Invar (Ni—Fe alloy) or the like can be used as the material having a lower coefficient of thermal expansion, and austenite Ni—Cr—Fe alloy or Ni—Mn—Fe as the material having a higher coefficient of thermal expansion. An alloy or the like can be used.
A combination of a plurality of materials having different thermal expansion coefficients can be appropriately selected in consideration of the temperature (predetermined temperature) at which the variable plate portion is deformed, the amount of deformation, and the like.

The throttle body is provided with a hot water passage for preventing the cooling of the throttle body by flowing hot water at least at a position where the outer peripheral end of the throttle valve faces when the throttle valve is closed. And
The variable plate portion is connected to a hot water valve that opens and closes the hot water passage, and is deformed to move the position of the hot water valve so that the hot water passage can be switched from a closed state to an open state. It is preferable to be configured (Claim 5).
That is, when the intake air or the throttle body becomes equal to or lower than the predetermined temperature, the variable plate portion is deformed to suppress the adhesion of condensed water near the opposed inner wall surface of the throttle body. At the same time, the warm water passage is switched to the open state by moving the warm water valve in conjunction with the deformation of the variable plate portion. And the freezing of the condensed water in the vicinity of the opposed inner wall surface can be suppressed by circulating the warm water through the warm water passage and warming the throttle body. As a result, it is possible to further prevent the ice from being caught by the throttle valve and the operation failure associated therewith.

Further, it is preferable that the hot water passage is disposed in a portion where ice is easily caught by the throttle valve when condensed water adheres to the throttle body and freezes.
For example, in the closed state of the throttle valve in the throttle body, it is preferable that the outermost end portion is disposed at a portion where the apex portion farthest from the rotation shaft is opposed.
That is, when the condensed water adheres and freezes at the portion where the apex portion opposes, the ice biting by the throttle valve is particularly likely to occur. Therefore, by disposing the warm water passage in such a portion, it is possible to further suppress freezing of condensed water near the opposed inner wall surface of the throttle body.

Further, the hot water passage may be disposed over the entire circumference of the throttle body at a position where the outer peripheral ends thereof face each other in the closed state of the throttle valve.
In this case, the freezing of condensed water in the vicinity of the opposed inner wall surface of the throttle body can be sufficiently suppressed.

Example 1
A throttle device according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the throttle device 1 of this example is for controlling the amount of air (intake amount) taken into the combustion chamber of an engine (internal combustion engine), and forms part of the intake passage 3. A cylindrical throttle body 2 and a disc-shaped butterfly throttle valve 4 disposed inside the throttle body 2 are provided. The throttle body 2 is connected to an intake pipe (not shown) on the upstream side and the downstream side of the intake passage 3.

As shown in the figure, the throttle valve 4 is disposed so as to be rotatable about a rotating shaft 41 supported by the throttle body 2. Further, the throttle valve 4 is configured to be able to open and close the intake passage 3 by rotating around the rotary shaft 41 inside the throttle body 2.
The throttle valve 4 is connected to an actuator (not shown) such as a step motor, and is configured to be rotationally driven by this actuator. The actuator can be controlled by a signal sent from an ECU (not shown).

In addition, the variable plate portion 5 is disposed on the upstream side of the opposed inner wall surface 211 that is the inner wall surface 21 of the throttle body 2 that faces the outer peripheral end 42 in the closed state of the throttle valve 4.
Here, the closed state of the throttle valve 4 refers to the apex portion 421a and the intake passage 3 located on the downstream side of the intake passage 3 among the apex portions farthest from the rotating shaft 41 at the outer peripheral end portion 42 of the throttle valve 4. This is a state in which the distance between the apex portion 421b located on the upstream side of the throttle body 2 and the inner wall surface 21 of the throttle body 2 is minimized, and the flow passage cross-sectional area of the intake G in the intake passage 3 is minimized (FIG. 1). The state of the solid line portion of the throttle valve 4).
The opposed inner wall surface 211 refers to a region having a certain width including the portion of the inner wall surface 21 of the throttle body 2 that faces the outer peripheral end 42 when the throttle valve 4 is closed.

  In this example, the arrangement position of the variable plate portion 5 in the circumferential direction of the throttle body 2 is a portion of the opposed inner wall surface 211 facing the apex portion 421a as shown in FIGS. 2 (b) and 3 (b). On the upstream side. That is, except for the fully opened state of the throttle valve 4, it is upstream of the portion where the apex portion 421a on the side where a large amount of intake air G circulates. Of course, it can also be set as the structure arrange | positioned in the upstream of the part which both the vertex parts 421a and 421b oppose.

  Further, as shown in FIG. 1, the variable plate portion 5 is disposed at a position where it does not interfere with the throttle valve 4, that is, a position where the rotation of the throttle valve 4 is not affected. In this example, the variable plate portion 5 is a position that does not interfere with the throttle valve 4 on the upstream side of the opposed inner wall surface 211 in the axial direction of the throttle body 2 and is the most downstream side (the position closest to the throttle valve 4). ).

  Further, the variable plate portion 5 of this example is a bimetal configured by superposing two materials having different thermal expansion coefficients. The variable plate portion 5 employs a material having a relatively low coefficient of thermal expansion on one side and a material having a relatively high coefficient of thermal expansion on the other side. Invar (Ni-Fe alloy) is used as the material with a low thermal expansion coefficient, and austenitic Ni-Cr-Fe alloy is used as the material with a high thermal expansion coefficient.

The variable plate portion 5 is configured to be deformable in accordance with the temperature change of the throttle body 2. Specifically, the variable plate portion 5 is fixed by welding only the upstream portion (fixed portion 51) on the inner wall surface 21 of the throttle body 2.
As will be described later, when the intake air G (or the throttle body 2) exceeds a predetermined temperature, as shown in FIGS. 2 (a) and 2 (b), it is substantially in close contact with the inner wall surface 21 of the throttle body 2. It becomes a state.
Further, when the intake air G (or the throttle body 2) becomes a predetermined temperature or lower, as shown in FIGS. 3A and 3B, the intake G (or the throttle body 2) moves away from the inner wall surface 21 of the throttle body 2 as it goes downstream. Deform.

That is, a downstream portion (deformation portion 52) of the variable plate portion 5 that is not fixed to the inner wall surface 21 of the throttle body 2 bends inward from a bent portion 53 that is a boundary between the fixation portion 51 and the deformation portion 52. The distance from the inner wall surface 21 of the throttle body 2 is gradually increased as it goes downstream.
Here, the predetermined temperature refers to a temperature region from the start of deformation of the variable plate portion 5 to completion, that is, a region from a deformation start temperature to a deformation completion temperature described later.

Further, as shown in FIGS. 2B and 3B, the variable plate portion 5 has a rectangular shape and a plate shape, and the lateral width thereof is the length in the circumferential direction of the outer peripheral end portion 42 of the throttle valve 4. About 1/6.
In addition, the position, thickness, and shape of the two types of materials constituting the variable plate portion 5 are deformed so that the variable plate portion 5 is deformed when the temperature of the intake air G (or throttle body 2) becomes equal to or lower than the deformation start temperature. Etc. have been adjusted.

Next, the effect of the throttle device 1 of this example will be described.
During engine operation, when the temperature of the intake G (or throttle body 2) becomes equal to or lower than the deformation start temperature (about 5 ° C.), the deformation of the variable portion 5 starts (state of FIG. 2 → state of FIG. 3). At this time, as shown in FIGS. 3 (a) and 3 (b), the deformable portion 52 of the variable plate portion 5 bends inward starting from the bent portion 53, and with the inner wall surface 21 of the throttle body 2 as it goes downstream. The distance is gradually increased. When the temperature of the intake air G (or throttle body 2) reaches the deformation completion temperature (about 0 ° C.), the deformation is completed such that the variable plate portion 5 moves away from the inner wall surface 21 of the throttle body 2 as it goes downstream. (State of FIG. 3).

  In this way, when the temperature of the intake air G (or throttle body 2) becomes equal to or lower than the predetermined temperature, as shown in FIG. 3 (a), it occurs in the intake passage 3, and the throttle body 2 is caused by the flow of the intake air G. Condensed water W that travels along the inner wall surface 21 moves away from the inner wall surface 21 of the throttle body 2 along the shape of the variable plate portion 5 provided on the front side of the throttle valve 4, and then leaves the variable plate portion 5. The condensed water W flows along with the intake air G in a state of being separated from the inner wall surface 21 of the throttle body 2. Thereby, the adhesion and freezing of the condensed water W in the vicinity of the opposed inner wall surface 211 of the throttle body 2 can be suppressed under conditions where the condensed water W flowing through the intake passage 3 is likely to freeze. Therefore, it is possible to prevent the ice of the throttle valve 4 and the accompanying malfunction.

  The condition where the condensed water W is likely to freeze is below the deformation completion temperature (about 0 ° C.). However, in an environment where the outside air temperature gradually decreases, the throttle body 2 or the throttle valve can be used even when the temperature is above the deformation completion temperature. It is preferable that adhesion of the condensed water W to 4 is suppressed. Therefore, in this example, the deformation of the variable plate portion 5 is set to start from the deformation start temperature (about 5 ° C.) higher than the deformation completion temperature.

  On the other hand, when the temperature of the intake G (or throttle body 2) exceeds the deformation completion temperature (about 0 ° C.), the variable portion 5 starts to return to the original position (state of FIG. 3 → state of FIG. 2). When the temperature of the intake air G (or throttle body 2) reaches the deformation start temperature (about 5 ° C.), the variable plate portion 5 returns to the original position (the state shown in FIG. 2).

  In this way, when the temperature of the intake G (or throttle body 2) exceeds the predetermined temperature, that is, under the condition where the condensed water W flowing through the intake passage 3 is unlikely to freeze, as shown in FIG. As described above, the variable plate portion 5 is in close contact with the inner wall surface 21 of the throttle body 2. For this reason, the variable plate portion 5 does not become a resistance of the intake air G flowing through the intake passage 3. Thereby, there is almost no influence on the intake air amount and the engine output due to the arrangement of the variable plate portion 5.

Further, the arrangement position of the variable plate portion 5 in the circumferential direction of the throttle body 2 is the apex portion (in this example, the intake air in the outer peripheral end portion 42 of the throttle valve 4) farthest from the rotation shaft 41. The apex 421a) located on the downstream side of the passage 3 is the upstream side of the facing portion.
That is, the portion of the opposed inner wall surface 211 of the throttle body 2 that is opposed to the apex portion 421a of the outer peripheral end portion 42 of the throttle valve 4 tends to concentrate the flow of the intake air G. Condensed water W flowing along the wall surface 21 is also likely to collect, and when the ice is frozen, the ice biting by the throttle valve 4 is particularly likely to occur. Therefore, by disposing the variable plate portion 5 on the upstream side of such a portion, it is possible to further prevent the biting of ice by the throttle valve 4 and the operation failure associated therewith.

Further, the width of the variable plate portion 5 is about 1/6 of the circumferential length of the outer peripheral end portion 42 of the throttle valve 4. Therefore, the variable plate portion 5 can sufficiently suppress the adhesion of the condensed water W to the vicinity of the opposed inner wall surface 211 of the throttle body 2.
The variable plate portion 5 is a bimetal formed by superposing a plurality of materials having different thermal expansion coefficients. Therefore, the variable plate portion 5 can be easily and accurately deformed according to the temperature of the intake air G (or the throttle body 2).

  As described above, according to this example, it is possible to provide the throttle device 1 that can suppress the adhesion and freezing of the condensed water W around the throttle valve 4 and prevent the malfunction of the throttle valve 4.

(Example 2)
In this example, as shown in FIGS. 4 and 5, a hot water heating device 6 for preventing the cooling of the throttle body 2 is provided in the throttle device 1 of the first embodiment.
As shown in FIG. 4, the throttle device 1 of this example includes a hot water heating device 6. The hot water heating device 6 is disposed inside the throttle body 2 and has a hot water passage 61 for circulating the hot water to prevent the throttle body 2 from being cooled. The hot water passage 61 is disposed at a position where the outer peripheral end 42 thereof faces in the closed state of the throttle valve 4.

  In this example, the hot water passage 61 is disposed at a position where the apex 421 a of the outer peripheral end 42 of the throttle valve 4 in the throttle body 2 faces. That is, the apex portion 421a on the side where a large amount of intake air G circulates except for the fully opened state of the throttle valve 4 is a facing portion. Needless to say, the throttle body 4 may be disposed over the entire circumference of the position where the outer peripheral end 42 faces in the closed state of the throttle valve 4.

  As shown in the figure, the hot water passage 61 is connected to a supply pipe 62 that supplies the hot water passage 61 with hot water and a discharge pipe 63 that discharges the hot water from the hot water passage 61. A supply passage 621 formed in the supply pipe 62 and a discharge passage 631 formed in the discharge pipe 63 communicate with each other via a hot water passage 61 formed in the throttle body 2.

As shown in the figure, the hot water passage 61 is provided with a hot water valve 64 for opening and closing the hot water passage 61. The hot water valve 64 is connected to the variable plate portion 5 via the hot water shaft 65. The hot water valve 64 is configured to be pressed by a valve seat 66 provided at a connection portion between the hot water passage 61 and the supply passage 621 by an urging force of a spring (not shown), so that the hot water passage 61 is closed. .
Other configurations are the same as those in the first embodiment.

Next, the function and effect of this example will be described.
During engine operation, when the temperature of the intake G (or throttle body 2) becomes equal to or lower than the deformation start temperature (about 5 ° C.), the deformation of the variable portion 5 starts (state of FIG. 4 → state of FIG. 5). In this example, as shown in FIG. 5, the hot water valve 64 is moved against the urging force of the spring via the hot water shaft 65 in conjunction with the deformation of the variable plate portion 5 to open the hot water passage 61. The hot water is circulated through the hot water passage 61. When the temperature of the intake air G (or throttle body 2) reaches the deformation completion temperature (about 0 ° C.), the deformation is completed such that the variable plate portion 5 moves away from the inner wall surface 21 of the throttle body 2 as it goes downstream. (State of FIG. 5).

  In this way, when the temperature of the intake air G (or throttle body 2) becomes equal to or lower than the predetermined temperature, the variable plate portion 5 is deformed to condense near the opposed inner wall surface 211 of the throttle body 2 as shown in FIG. At the same time as suppressing the adhesion of water W, warm water can be circulated through the warm water passage 61 to warm the throttle body 2 and to prevent freezing of the condensed water W in the vicinity of the opposed inner wall surface 211. Thereby, it is possible to further prevent the ice from being caught by the throttle valve 4 and the operation failure associated therewith.

  On the other hand, when the temperature of the intake G (or the throttle body 2) exceeds the deformation completion temperature (about 0 ° C.), the variable portion 5 starts to return to the original position (state of FIG. 5 → state of FIG. 4). When the temperature of the intake air G (or throttle body 2) reaches the deformation start temperature (about 5 ° C.), the variable plate portion 5 returns to the original position (the state shown in FIG. 4). At this time, in conjunction with the deformation of the variable plate portion 5, the hot water valve 64 is moved to the original position via the hot water shaft 65, the hot water passage 61 is closed, and the flow of hot water is stopped.

In this way, when the temperature of the intake G (or throttle body 2) exceeds the predetermined temperature, that is, under the condition that the condensed water W flowing through the intake passage 3 is unlikely to freeze, as shown in FIG. The plate portion 5 is in a state of being in close contact with the inner wall surface 21 of the throttle body 2. Therefore, also in this example, the variable plate portion 5 does not become a resistance of the intake air G flowing through the intake passage 3. Thereby, there is almost no influence on the intake air amount and the engine output due to the arrangement of the variable plate portion 5.
The other functions and effects are the same as those of the first embodiment.

FIG. 3 is an explanatory diagram illustrating a structure of a throttle device in the first embodiment. Explanatory drawing which shows the normal state of the variable board part in Example 1 ((a) Front sectional drawing, (b) AA sectional view taken on the line A). Explanatory drawing which shows the deformation | transformation state of the variable board part in Example 1 ((a) Front sectional drawing, (b) BB sectional drawing of (a)). Explanatory drawing which shows the throttle apparatus (normal state of a variable plate part) provided with the warm water heating apparatus in Example 2. FIG. Explanatory drawing which shows the throttle apparatus (The deformation | transformation state of a variable board part) provided with the warm water heating apparatus in Example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Throttle device 2 Throttle body 21 Inner wall surface 211 Opposite inner wall surface 3 Intake passage 4 Throttle valve 41 Rotating shaft 42 Outer peripheral end portion 5 Variable plate portion G Intake air

Claims (5)

A throttle of an internal combustion engine having a throttle body that forms an intake passage of the internal combustion engine, and a plate-like throttle valve that is disposed around the rotation shaft so as to open and close the intake passage inside the throttle body In the device
On the upstream side of the opposing inner wall surface, which is the inner wall surface of the throttle body, which faces the outer peripheral end of the throttle valve in the closed state of the throttle valve, a variable plate that can be deformed according to intake air or temperature change of the throttle body Part is arranged,
The variable plate portion is substantially in close contact with the inner wall surface of the throttle body when the intake air or the temperature of the throttle body exceeds a predetermined temperature, and on the downstream side when the temperature is equal to or lower than the predetermined temperature. A throttle device for an internal combustion engine, wherein the throttle device is configured to be deformed so as to move away from the inner wall surface of the throttle body as it goes to.   The position of the variable plate portion in the circumferential direction of the throttle body according to claim 1 is such that at least the apex portion of the opposing inner wall surface that is farthest from the rotation shaft at the outer peripheral end portion of the throttle valve is opposed. A throttle device for an internal combustion engine, characterized by being upstream of the portion.   The throttle device for an internal combustion engine according to claim 2, wherein the width of the variable plate portion is 1/6 or more of the circumferential length of the outer peripheral end portion of the throttle valve.   The throttle device for an internal combustion engine according to any one of claims 1 to 3, wherein the variable plate portion is a bimetal formed by superposing a plurality of materials having different thermal expansion coefficients. 5. The throttle body according to any one of claims 1 to 4, wherein hot water is circulated through the throttle body at least at a position where the outer peripheral end of the throttle valve faces in the closed state of the throttle valve. There is a hot water passage to prevent it,
The variable plate portion is connected to a hot water valve that opens and closes the hot water passage, and is deformed to move the position of the hot water valve so that the hot water passage can be switched from a closed state to an open state. A throttle device for an internal combustion engine, characterized in that it is configured.

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