JP2007040216A - Throttle device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a throttle device for an internal combustion engine, capable of preventing water dropping on a throttle body from staying near a vent hole. <P>SOLUTION: The throttle body 10a has extension portions 62 along an outside line 30a of an opening portion 30, more specifically, four extension portions 62a, 62b, 62c, 62d. On the extension portion 62a, a protrusion 62a1 is formed which extends downward from a lower end 30b of the opening portion 30 in the direction of the gravity during mounting on the internal combustion engine. At least one-side edges 62a2, 62b2, 62c2, 62d2 of the extension portions are inclined to a line 30c perpendicular to the outside line 30a of the opening portion 30 and formed on both sides of the vent hole 60. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a throttle device for an internal combustion engine, and more specifically to a throttle device for an internal combustion engine that prevents water from entering the throttle body.

  The throttle valve is usually housed in the throttle body and attached to the intake pipe of the internal combustion engine together with the throttle body, and is mechanically connected to the accelerator pedal, and opens and closes according to the operation of the accelerator pedal. The throttle body has an opening formed on a side surface, and a throttle opening sensor is attached to the throttle body so as to protrude from the throttle body. The opening is covered with a cover.

  In such a throttle device, as shown in Patent Document 1 below, in order to discharge water that has entered the throttle body, water is placed in the vicinity of the opening (the mating surface of the throttle body and the cover). A punch hole is provided. The technique described in Patent Document 1 arranges four drain holes at intervals of 90 degrees to increase the degree of freedom in the mounting direction to the internal combustion engine, and prevents the intrusion of the throttle body into the inner part of the maze structure. It is configured.

  In recent years, a throttle device for a so-called DBW (Drive By Wire) type internal combustion engine, in which the accelerator pedal is mechanically disconnected and driven by connecting an actuator such as an electric motor to the throttle valve shaft via a gear mechanism. However, even in the case of such a structure, an opening is formed on the side of the throttle body where the gear mechanism and the throttle opening sensor are arranged, and is covered with a cover.

In the case of a DBW-type throttle device, ozone is generated by the electric sparks of the brush of the electric motor. When the gear of the gear mechanism is made of a resin material, this ozone deteriorates the gear and is used for sealing the opening. In addition to deteriorating the O-ring and the like, it is necessary to promptly release the generated ozone to the outside in order to promote rusting of other metal parts. Furthermore, the strength of the resin gear is reduced by water immersion. Therefore, the above-mentioned drain hole is made to function also as a ventilation hole, and ventilation with the outside is aimed at.
JP 2002-309968 A

  In an internal combustion engine, water dripped from above the throttle body usually flows down along the surface of the throttle body. However, water flows along the opening (the mating surface between the throttle body and the cover) and reaches the vicinity of the ventilation hole (drainage hole) drilled below, where it accumulates due to capillary action or the throttle body. As the internal pressure drops, it may enter the inside of the throttle body from the ventilation hole.

  Accordingly, an object of the present invention is to provide a throttle device for an internal combustion engine that solves the above-described problems and prevents water dropped on the throttle body from being stored in the vicinity of a ventilation hole.

  In order to solve the above-mentioned object, according to claim 1, a throttle valve connected to an intake passage of an internal combustion engine for opening and closing the intake passage, an actuator, and a shaft of the throttle valve through the shaft of the throttle valve. The throttle mechanism includes at least a gear mechanism that transmits a driving force to the throttle valve, and includes a throttle body having an opening formed on the gear mechanism side, and a cover that covers the opening. In a throttle device for an internal combustion engine in which a ventilation hole is formed at a lower position in the direction of gravity when mounted on an engine, at least one of the throttle body and a cover is provided with an extending portion along the outline of the opening In addition, the lower end of the opening in the direction of gravity when the extension is mounted on the internal combustion engine, in other words, And as configured to form a protrusion extending downward from pores.

  In the throttle device for an internal combustion engine according to claim 2, at least one edge portion of the extending portion is configured to be inclined with respect to a line orthogonal to the outline of the opening.

  In the throttle device for an internal combustion engine according to a third aspect, the extending portion is composed of a plurality of extending portions, and the plurality of extending portions are formed on both sides of the ventilation hole.

  The throttle device for an internal combustion engine according to claim 1, wherein at least one of the throttle body and the cover is provided with an extending portion along the outline of the opening, for example, on the throttle body, and is mounted on the internal combustion engine. Since it is configured to form a protrusion extending downward from the lower end of the opening in the direction of gravity, water flows down through the protrusion extending downward from the lower end of the opening, so that water is stored near the ventilation hole. Therefore, it is possible to avoid entering the inside of the throttle body from the ventilation hole. Moreover, draining or draining can be improved by flowing water along the extending portion.

  In the throttle device for an internal combustion engine according to claim 2, since at least one edge of the extending portion is inclined with respect to a line orthogonal to the outline of the opening, for example, inclined in the direction of gravity. By doing so, draining or draining can be further improved, and water can be more effectively prevented from being stored in the vicinity of the ventilation hole.

  In the throttle device for an internal combustion engine according to claim 3, since the extending portion is composed of a plurality of extending portions and formed on both sides of the ventilation hole, the drainage or drainage is further improved. Thus, the amount of water dripping near the ventilation hole can be reduced, and water can be more effectively prevented from being stored near the ventilation hole.

  The best mode for carrying out a throttle device for an internal combustion engine according to the present invention will be described below with reference to the accompanying drawings.

  1 is a front view of a throttle device for an internal combustion engine according to a first embodiment of the present invention, FIG. 2 is a side view thereof, FIG. 3 is a longitudinal sectional view of the throttle device shown in FIG. 1, and FIG. It is the side view which took the cover and looked at the opening part side.

  In the following, mainly referring to FIG. 3, as shown in the figure, the throttle device 10 has a generally box shape and is attached to an intake pipe (not shown) continuous from an air cleaner (not shown) of an internal combustion engine (not shown). The throttle valve 12 for adjusting the intake air amount (air amount) flowing through the intake passage formed inside the intake pipe is configured to open and close by an electric motor (actuator) 14.

  Specifically, the throttle device 10 cuts out the intake pipe and attaches a valve body (butterfly valve) 12a of the throttle valve 12 to the cut-out intake pipe portion, and a valve shaft (shaft) 12b and an electric motor 14 are attached thereto. The throttle body 10a is configured as an attachment. In the throttle body 10a, a valve shaft 12b that supports the valve body 12a is rotatably supported by a bearing 16.

  A motor housing chamber 20 for housing the electric motor 14 is formed in the lower portion of the throttle body 10a, and a gear chamber 22 is formed on the side surface (right side surface in FIG. 1), and a gear mechanism (reduction gear mechanism) is formed therein. 24 and a throttle opening sensor 26 comprising a hall element is accommodated. As shown in FIG. 4, the gear chamber 22 is opened, and an opening 30 is formed. The opening 30 is covered with a cover 32. A gasket 34 is disposed in the vicinity of the opening 30. Reference numeral 36 denotes a pipe that connects a flow path for circulating cooling water to the throttle body 10a.

  Although detailed illustration is omitted, the electric motor 14 is a DC motor (with a brush). The electric motor 14 rotates when energized, and the rotational force is taken out from the output shaft 14a.

  The output shaft 14a of the electric motor 14 extends to the gear chamber 22, and a small-diameter drive gear 40 is attached to the tip thereof. On the other hand, in the upper part of the throttle body 10a, the valve shaft 12b extends through the seal member 42 toward the gear chamber 22, and a return spring 44 is inserted in the middle to urge the throttle valve 12 in the closing direction. At the same time, a default spring 46 is inserted to urge the throttle valve 12 toward a default opening (about 7 degrees when the fully opened opening is 90 degrees).

  A large-diameter driven gear 50 is attached to the tip of the valve shaft 12b. The driven gear 50 has a fan shape in the lower side view, and teeth are formed only in the lower fan-shaped portion. A shaft 52 is disposed between the driven gear 50 and the drive gear 40 mounted on the output shaft 14a of the electric motor 14, and a large-diameter intermediate gear 54a and a small-diameter intermediate gear 54b are integrated with the shaft 52. It can be mounted freely. The large diameter intermediate gear 54 a meshes with the drive gear 40, and the small diameter intermediate gear 54 b meshes with the driven gear 50.

  As described above, the output shaft 14a of the electric motor 14 is transmitted to the valve shaft 12b via the gear mechanism 24 including the drive gear 40 and the like, and opens and closes the throttle valve 12. More specifically, the throttle opening is determined based on the operating state of the internal combustion engine obtained from an accelerator opening sensor (not shown) or the like in an electronic control unit (not shown) and detected from the throttle opening sensor 26. The drive of the electric motor 14 is controlled so that the actual opening degree to be achieved becomes the determined throttle opening degree.

  FIG. 5 is a perspective view of the throttle body 10a, and FIG. 6 is an explanatory view showing a case where the throttle device 10 shown in FIG. FIG. 6 shows a case where the throttle device 10 is mounted (installed) on the internal combustion engine obliquely in the direction of gravity.

  Referring to FIGS. 4, 5 and 6, the opening 30, more specifically, the mating surface of the throttle body 10 a and the cover 32, when mounted on the internal combustion engine, is at a lower position in the direction of gravity. The ventilation hole 60 is formed, and at least one of the throttle body 10a and the cover 32, more specifically, the throttle body 10a has an extending portion 62 along the outline (contour line) 30a of the opening 30. Provided. Although the detailed illustration is omitted, the ventilation hole 60 is formed by keeping the throttle body 10a side flat and forming the corresponding position of the cover 32 and forming a groove there. Is done.

  In the illustrated example, a plurality of extending portions 62 are formed of four extending portions 62a, 62b, 62c, and 62d. Of the four extending portions 62, the extending portion 62a formed close to the ventilation hole 60 extends below the lower end 30b of the opening 30 in the direction of gravity when mounted on the internal combustion engine. A protrusion 62a1 is formed.

  As shown in FIG. 4, the four extending portions 62 include at least one edge portion, more specifically, the edge portions 62 a 2, 62 b 2, 62 c 2, and 62 d 2 positioned on the lower side on the outline 30 a of the opening 30. It is configured to be inclined in the direction of gravity with respect to the orthogonal line 30c.

  Further, the four extending portions 62 are formed on both sides of the ventilation hole 60, that is, the extending portions 62a and 62b are formed on the right side of the ventilation hole 60 and the extending portions 62c and 62d are formed on the left side in the positional relationship shown in FIG. Is done.

  Since the throttle device 10 according to this embodiment is configured as described above, it is possible to reliably prevent water from being stored near the ventilation hole 60. That is, although the arrows in FIG. 6 indicate the flow of water, as shown in the drawing, the water flows along the extended portion 62 and flows down through the protrusion 62a1 extending below the lower end 30b of the opening 30. There is no accumulation near the hole 60.

  Further, since at least one edge 62 a 2, 62 b 2, 62 c 2, 62 d 2 of the four extending portions 62 is configured to be inclined in the direction of gravity with respect to the line 30 c perpendicular to the outline 30 a of the opening 30. Further, drainage can be further improved, and water can be more effectively prevented from being stored in the vicinity of the ventilation hole 60.

  Further, since the water is diverted along the four extending portions 62a2, 62b2, 62c2, and 62d2 formed on both sides of the ventilation hole 60, the amount of water reaching the vicinity of the ventilation hole 60 is further reduced. Storage in the vicinity of the hole 60 can be more effectively prevented.

  FIG. 7 is an explanatory diagram showing a case where the throttle device 10 is mounted (or installed) in parallel (in other words, vertically) on the internal combustion engine in the direction of gravity. In this case as well, the water flows along the extension 62 and flows down through the protrusion 62a1 extending downward from the lower end 30b of the opening 30, and therefore does not accumulate in the vicinity of the ventilation hole 60. Further, since water flows along the four extending portions 62 formed on both sides of the ventilation hole 60, the water does not reach the vicinity of the ventilation hole 60 and is not stored in the vicinity of the ventilation hole 60.

  In this embodiment, as described above, the throttle valve 12, which is connected to the intake passage of the internal combustion engine and opens and closes the intake passage, the actuator (electric motor) 14, and the shaft (valve shaft) 12b of the throttle valve is used. It includes at least a gear mechanism 24 that transmits the driving force of the actuator to the throttle valve, and includes a throttle body 10a having an opening 30 formed on the gear mechanism 24 side, and a cover 32 that covers the opening 30. In addition, in the throttle device 10 for an internal combustion engine in which the opening 30 is formed with a ventilation hole 60 at a lower position in the direction of gravity when mounted on the internal combustion engine, at least one of the throttle body 10a and the cover 32. For example, the throttle body 10 a is aligned with the outline 30 a of the opening 30. The extension portion 62, more specifically, four extension portions 62a, 62b, 62c, and 62d are provided, and the opening portion 30 in the gravity direction when mounted on the internal combustion engine is provided on the extension portion 62a. In other words, the projection 62a1 extending downward from the ventilation hole 60 is formed.

  Further, at least one edge 62a2, 62b2, 62c2, 62d2 of the extending portions 62a, 62b, 62c, 62d is configured to be inclined with respect to a line 30c orthogonal to the outline 30a of the opening 30.

  In addition, the extension portion 62 includes a plurality of extension portions 62, more specifically, four extension portions 62 a, 62 b, 62 c, and 62 d, and the plurality of extension portions are formed on both sides of the ventilation hole 60. It was configured as follows.

  In the above description, the extending portion 62 is provided in the throttle body 10a. However, as shown by an imaginary line in FIG. 1, the extending portion 62 may be formed on the cover 32 (only the extending portion 62d is shown).

  Further, although four extending portions are provided as the extending portion 62, one or five or more may be formed.

1 is a front view of a throttle device for an internal combustion engine according to a first embodiment of the present invention. FIG. 2 is a side view of the throttle device shown in FIG. 1. It is a longitudinal cross-sectional view of the throttle device shown in FIG. FIG. 3 is a side view of the throttle body viewed from the opening side with the cover removed in FIG. 2. It is a perspective view of the throttle body shown in FIG. It is explanatory drawing which shows the case where the throttle device shown in FIG. 1 etc. is mounted in an internal combustion engine. Similarly, it is explanatory drawing which shows the case where the throttle device shown in FIG. 1 etc. is mounted in an internal combustion engine.

Explanation of symbols

  10 throttle device, 10a throttle body, 12 throttle valve, 12b valve shaft (shaft), 14 electric motor (actuator), 24 gear mechanism, 26 throttle opening sensor, 30 opening, 30a outline, 30b lower end, 30c line, 32 cover, 60 ventilation hole, 62 (62a, 62b, 62c, 62d) extension part, 62a1 protrusion, 62a2, 62b2, 62c2, 62d2 edge part

Claims (3)

  A throttle valve connected to an intake passage of an internal combustion engine for opening and closing the intake passage; an actuator; and a gear mechanism for transmitting a driving force of the actuator to the throttle valve via a shaft of the throttle valve; A throttle body having an opening formed on the gear mechanism side and a cover that covers the opening, and a ventilation hole is formed in the opening at a lower position in the direction of gravity when mounted on the internal combustion engine. In the internal combustion engine throttle device, at least one of the throttle body and the cover is provided with an extending portion along the outline of the opening, and the extension portion is gravity when mounted on the internal combustion engine. A protrusion extending in a direction below the lower end of the opening is formed. Liter unit.   2. The throttle device for an internal combustion engine according to claim 1, wherein at least one edge of the extending portion is inclined with respect to a line orthogonal to the outline of the opening.   3. The throttle device for an internal combustion engine according to claim 1, wherein the extending portion includes a plurality of extending portions, and the plurality of extending portions are formed on both sides of the ventilation hole.

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