JP2007120366A - Intake device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make an output gear of a drive source side and a drive gear of a valve element side appropriate mesh. <P>SOLUTION: A drive shaft 33 of a rotary valve 21 is externally fitted on a based end side part 61 of a drive gear 59. The base end side part 61 is rotatably supported by a cover member 45 of an intake casing 3. A tip end side part 63 of the drive gear 59 is projected in a housing 49 attached on an outside of the cover member 45. An extended shaft part 67 of the drive shaft 33 is projected in the housing 49 with penetrating a rotation center of the drive gear 59 in the axial direction. The extended shaft part 67 is fitted in and is supported by a recess part 69 of the housing under a condition where the same rotatably slides and contact, and a center of the recess part is made to match with an axial center of the extended shaft part 67. Teeth part 57a of an output gear 57 of a drive motor 53 stored in the housing 4 and teeth part 63a of the drive gear 59 are meshed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an improvement of an intake device for an engine, and particularly relates to a power transmission system that rotates a valve body disposed in an intake casing.

  In Patent Document 1, a butterfly valve is provided at a branch point of an intake passage formed for each cylinder of a multi-cylinder engine, and the butterfly valve is switched according to the operating state of the engine to thereby change the effective length of each intake passage. An intake device is disclosed in which the flow of intake air is variably adjusted by changing the air flow.

In Patent Document 1, a drive gear is integrally connected to one end of a drive shaft that supports a valve body, and a housing that houses a drive motor is attached to an intake manifold so as to cover the drive gear. The housing is provided with a boss-like support portion projecting toward the drive gear side so as to coincide with the rotation center of the drive gear, while a concave portion is formed at the center of the drive shaft on the drive gear support portion side. The housing is recessed so as to coincide with the center, and the front end of the support portion of the housing is fitted into the recess of the drive gear so that the drive gear does not move in the axial direction of the drive shaft. The coupled output gear is meshed with the drive gear. Then, the rotational torque of the drive motor is transmitted to the output gear, the drive gear, and the drive shaft, so that the valve body is rotated, and the flow of intake air is variably adjusted according to the operating state of the engine.
JP 2004-124933 A (pages 5-7, FIG. 4)

  However, in the above-mentioned Patent Document 1, when the center of the recess of the drive gear is eccentric with respect to the axis of the drive shaft due to a manufacturing error, the housing support portion is fitted into the recess of the drive gear and the housing is taken in. When attached to the manifold, the output gear connected to the output shaft of the drive motor does not mesh properly with the drive gear, thereby hindering the rotation of the valve body.

  The present invention has been made in view of this point, and an object of the present invention is to appropriately mesh the output gear on the drive source side with the drive gear on the valve body side.

  In order to achieve the above object, the present invention is characterized in that the drive shaft for rotating the valve body is directly supported by the housing on the drive source side.

  Specifically, in the present invention, the valve body is disposed in the intake casing so as to be rotatable around a drive shaft integral with the valve body, and an output gear connected to a drive source is connected to the drive shaft. The valve body is rotated by meshing with the gear and transmitting the rotational torque of the drive source to the output gear, drive gear and drive shaft, and the flow of intake air is variably adjusted according to the operating state of the engine. The following measures were taken for the engine intake system.

  That is, according to the present invention, the drive source is housed in a housing attached to the outside of a lid member that closes an end portion on the drive shaft side of the intake casing, and the drive gear has a base end side portion that is driven by the drive member. A tooth portion that is externally fitted so as to rotate integrally with the shaft and is rotatably supported by the lid member and that meshes with a tooth portion of the output gear is formed on the tip side portion. An extension shaft portion that penetrates the rotation center of the drive gear in the axial direction and protrudes into the housing is formed, and the housing is a recess that is slidably contacted and supported by the extension shaft portion. Is formed so that the center of the recess coincides with the axial center of the extension shaft portion.

  According to the present invention, the extension shaft portion of the drive shaft, to which the drive gear is fitted, is rotated so that the shaft center of the extension shaft portion and the center of the recess coincide with the recess portion of the housing in which the drive source is accommodated. Since the drive gear and the output gear on the drive source side are properly engaged with each other without being displaced, the valve body can be smoothly rotated without sliding.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  2 and 3 show an intake device 1 according to an embodiment of the present invention. The intake device 1 includes an intake casing 3 made of resin, and the intake casing 3 is mounted on an engine 5 provided with two cylinders (not shown) arranged in a direction in which a crankshaft (not shown) extends. ing. An intake passage 7 is formed in the intake casing 3 for each cylinder of the engine 5, and an upper flange 9 is integrally formed on the outer periphery of the upstream end of the intake passage 7. The lower flange 11 having an annular seal groove 11a on the lower surface is integrally formed to project. In addition, two boss portions 13 having bolt insertion holes 13 a are integrally formed on the outer periphery of the intake casing 3 at the front and rear portions corresponding to the intake passages 7. Further, an intake manifold 15 connected to a surge tank (not shown) is disposed on the upstream side of the intake casing 3, and a flange 17 is provided at the lower end of the intake manifold 15 at the upper flange 9 of the intake casing 3. It is formed as an integral overhang so as to correspond to An attachment hole (not shown) is formed in the flange 17 and the upper flange 9 of the intake casing 3 so as to correspond to the bolt insertion hole 13a of the boss portion 13. While the lower flange 11 is overlapped and the upper flange 9 of the intake casing 3 is overlapped with the flange 17 of the intake manifold 15, a bolt (not shown) is inserted through the mounting hole of the intake manifold 15, and then the intake casing 3 The intake manifold 15 and the intake casing 3 are integrally assembled with the engine 5 by being inserted into a bolt insertion hole 13a of the boss portion 13 and screwed into a screw hole (not shown) formed in the engine 5.

  The intake casing 3 is formed with a circular valve insertion hole 19 extending in the cylinder row direction and crossing the intake passages 7 when viewed from the cylinder row direction. A resin rotary valve 21 is rotatably inserted so as to variably adjust the flow of intake air according to the operating state of the engine 5. A boss 23 having a mounting hole 23a is integrally formed at the lower end of the intake casing 3, and the fuel injection nozzle 25 is connected to the injection hole 25a at the downstream end of the intake passage 7 below the valve insertion hole 19 in the mounting hole 23a. It is attached at an angle so that it can face.

  On the side of the fuel injection nozzle 25 at the downstream end of each intake passage 7, a flat plate-like partition wall 27 is disposed close to the intake flow direction, and the downstream end side of the intake passage 7 below the rotary valve 21 is arranged, The partition wall 27 divides the first passage 7a having a large passage cross-sectional area and the second passage 7b having a narrow passage cross-sectional area that is arranged in parallel with the first passage 7a and faces the fuel injection nozzle 25.

  As shown in FIG. 4, the rotary valve 21 includes two columnar valve bodies 29 disposed in the valve insertion holes 19 so as to correspond to the intake passages 7. A connecting portion 31 having the same diameter as the valve main body 29 is integrally connected. A drive shaft 33 is integrally projected from one end surface (right side in FIG. 4) of each valve main body 29 in the cylinder row direction, and the other end surface (see FIG. 4) a driven shaft 35 is integrally projected.

  A through passage 37 is formed in each valve body 29 in a substantially circular shape when viewed from the intake flow direction so as to communicate the upstream side and the downstream side of each intake passage 7. A valve piece portion 41 that variably adjusts the flow of intake air according to the operating state of the engine 5 is provided on a valve body portion 39 (hereinafter referred to as “circular wall portion 39”) on both sides in the axial direction of the valve body. It extends in the main body axial direction and is integrally connected. The circular wall portions 39 are integrally bridged so that a flat plate-shaped reinforcing bridge portion 43 is positioned on the center line of the valve body 29 and parallel to the valve piece portion 41. The length of the reinforcing bridge portion 43 in the direction orthogonal to the valve body axis is set to be shorter than the outer diameter of the rotary valve 21, and one end portion 43 a of the reinforcing bridge portion 43 in the direction orthogonal to the valve body axis is rotary. While located on substantially the same plane as the outer peripheral surface of the valve 21, the other end 43 b is spaced inward from the outer peripheral surface of the rotary valve 21. Thus, the circular wall portions 39 are connected at two locations by the reinforcing bridge portion 43 and the valve piece portion 41, and the rigidity of the valve body 29 is enhanced. The valve piece 41 closes the first passage 7a during low-speed operation of the engine 5, and the first passage 7a is disconnected from the intake passage 7 upstream of the rotary valve 21 (FIG. 3B). In addition, the first passage 7a is opened during high-speed operation of the engine 5, and the first passage 7a communicates with the intake passage 7 upstream of the rotary valve 21 (see FIG. 3A). . Further, the second passage 7 b is always in communication with the upstream side of the intake passage 7 without being opened and closed by the rotation of the valve body 29 in the entire operation region of the engine 5. The rotary valve 21 is provided with a seal member that is in sliding contact with the inner surface of the valve insertion hole 19 of the intake casing 3, but is omitted in the drawing.

  The end of the intake casing 3 on the driven shaft 35 side is closed by a flat resin lid member 45 attached by a bolt (not shown). The end portion on the drive shaft 33 side of the intake casing 3 is also closed by a resin lid member 46. The lid member 46 includes two flange portions 46a and 46b arranged in parallel, and the intake casing 3 3 is closed by attaching one flange portion 46 a with a bolt 47. In addition, a resin housing 49 including an accommodation portion 49a and a flange portion 49b is disposed outside the lid member 46 on the drive shaft 33 side of the intake casing 3, and the housing 49 covers the flange portion 49b with the lid. It is attached to the outer side of the lid member 46 by overlapping with the flange portion 46 b of the member 46 and fastening with a bolt 51. As shown in an enlarged detail in FIG. 1, the housing portion 49 a of the housing 49 accommodates a conventionally known electric drive motor 53 as a drive source, and an output shaft 55 of the drive motor 53 has an outer periphery. A resin output gear 57 having a plurality of tooth portions 57a is integrally connected. The drive motor 53 is connected to an engine control device (not shown). This engine control device detects the rotation speed of the engine 5 and determines whether the engine 5 is in a low-speed operation state near the idle rotation speed or a high-speed operation state higher than the idle rotation speed. It is configured as follows. Based on this determination result, the engine control device switches the operation of the drive motor 53 and rotates the rotary valve 21.

  On the other hand, a resin drive gear 59 is connected to the drive shaft 33 of the rotary valve 21. Specifically, the drive gear 59 includes a cylindrical proximal end side portion 61 and a distal end side portion 63, and a tooth portion 63 a that meshes with a tooth portion 57 a of the output gear 57 at the distal end of the distal end side portion 63. Is formed over a predetermined range in the circumferential direction. On the inner peripheral surface of the base end side portion 61, a plurality of concave ridge portions 61a are formed in parallel along the rotation center line direction of the drive gear 59, while a plurality of ridges are formed on the outer peripheral surface of the drive shaft 33. The portion 33 a is formed in parallel along the axial direction of the drive shaft 33. Further, a shaft insertion hole 65 is formed between the base end side portion 61 and the distal end side portion 63. Then, the concave portion 61a of the base end side portion 61 is externally fitted to the protrusion 33a of the drive shaft 33, and both are spline-coupled so that the drive gear 59 and the drive shaft 33 rotate integrally. Yes. A base end side portion 61 of the drive gear 59 is inserted into a shaft hole 46d of a boss portion 46c formed substantially at the center of the lid member 46 and is rotatably supported. Projecting into the housing 49. As a result, the drive shaft 33 is drivingly connected to the drive motor 53, and the rotary torque of the drive motor 53 is transmitted to the output gear 57, the drive gear 59 and the drive shaft 33, so that the rotary valve 21 is moved into the intake casing 3. And the flow of intake air is variably adjusted by changing the cross-sectional area of the intake passage 7 in accordance with the operating state of the engine 5.

  The drive shaft 33 is formed with an extension shaft portion 67 having a circular cross section. The extension shaft portion 67 projects through the center of rotation of the shaft insertion hole 65 of the drive gear 59 in the axial direction and protrudes into the housing 49. On the other hand, a circular recess 69 is formed in the housing 49. The recess 69 is slidably contacted and supported by the extension shaft portion 67 so that the center of the recess matches the axis of the extension shaft portion 67. I am letting. A rubber O-ring 71 is interposed between the intake casing 3 and the flange portion 46 a of the lid member 46, and between the flange portion 46 b of the lid member 46 and the flange portion 49 b of the housing 49. A rubber sealing material 75 is interposed to seal the inside of the intake casing 3 and the outside thereof. Further, a resin sealing material 73 is interposed between the boss portion 46 c of the lid member 46 and the base end side portion 61 of the drive gear 59, and the outer periphery of the base end side portion 61 is rotated by the rotation of the drive gear 59. Prevents wear.

  The intake device 1 configured as described above is assembled as follows.

  First, the rotary valve 21 is accommodated in the intake casing 3. Next, the lid member 45 is attached to the end of the intake casing 3 on the driven shaft 35 side with a bolt (not shown) with an O-ring (not shown) interposed between the lid casing 45 and the intake casing 3. The lid member 46 is also attached to the end portion of the intake casing 3 on the drive shaft 33 side with a bolt 47 with an O-ring 71 interposed between the flange portion 46 a and the intake casing 3. Thereafter, the base end side portion 61 of the drive gear 59 is inserted in a state in which the sealing material 73 is interposed in the shaft hole 46 d of the lid member 46. Thereafter, the housing 49 in which the drive motor 53 is accommodated is attached to the outside of the lid member 46 with bolts 51 in a state where the seal member 75 is interposed between the flange portion 49b and the flange portion 46b of the lid member 46. At this time, the meshing position of the tooth portion 57 a of the output gear 57 and the tooth portion 63 a of the drive gear 59 is adjusted according to the rotation range of the rotary valve 21.

  Next, the operation of the intake device 1 configured as described above will be described.

<During high-speed operation of engine 5>
When the drive motor 53 enters an operating state for high speed by the control signal output from the engine control device, the rotary valve 21 is operated by the operation of the drive motor 53 as shown in FIG. Is positioned in the valve insertion hole 19 to be an open position for opening the first passage 7a. The reinforcing bridge 43 is positioned along the intake flow direction so as not to hinder the intake flow. As a result, the intake air flowing into the intake passage 7 from the intake manifold 15 flows into the first passage 7a and the second passage 7b through the through passage 37, and is mixed with the fuel injected from the fuel injection nozzle 25 to mix the mixture. It flows to an intake port (not shown) of the engine 5 while being generated.

<During engine 5 running at low speed>
When the drive motor 53 enters an operation state for low speed by the control signal output from the engine control device, the rotary motor 21 is operated by the operation of the drive motor 53 as shown in FIG. Is positioned at the engine 5 side to be a closed position for closing the first passage 7a. At this time, the second passage 7b is opened, and a gap S is formed between the other end portion 43b of the reinforcing bridge portion 43 and the inner surface of the valve insertion hole 19. As a result, the intake air that has flowed into the intake passage 7 from the intake manifold 15 flows into the narrow second passage 7b through the gap S to increase the flow velocity, and the mixing with the fuel injected from the fuel injection nozzle 25 is promoted. It flows to an intake port (not shown) of the engine 5 while generating an air-fuel mixture.

  As described above, in this embodiment, the extension shaft portion 67 of the drive shaft 33 to which the drive gear 59 is externally fitted is placed in the recess 69 of the housing 49 in which the drive motor 53 is accommodated, and the axis of the extension shaft portion 67 is aligned. Since it is slidably contacted and supported so as to coincide with the center of the recess 69, the engagement accuracy between the drive gear 59 and the output gear 57 on the drive motor 53 side is increased, and the rotary valve 21 is made smooth. It can be rotated.

  In this embodiment, the tip side portion 63 of the drive gear 59 is formed in a cylindrical shape, the tooth portion 63a is formed at the tip thereof, and the boss portion in which the recess 69 of the housing 49 is formed is used as the cylindrical tip. The extension shaft portion 67 of the drive shaft 33 is fitted and supported by the recess 69 by being inserted into the recess of the side portion 63, but the tip side portion 63 is a circle having a shorter dimension in the gear rotation center line direction than the embodiment. An extension shaft of the drive shaft 33 is formed in the shape of a plate, the teeth 63a are formed on the outer periphery thereof, and the boss portion in which the recess 69 of the housing 49 is formed is opposed to the end surface of the disc-shaped tip side portion 63. The portion 67 may be fitted and supported by the concave portion 69.

  Furthermore, in this embodiment, although the case where the valve body was the rotary valve 21 was shown, a butterfly valve (throttle valve) may be used.

  Moreover, in this embodiment, although the case where the adjacent valve main bodies 29 were integrally connected by the connection part 31 of the same diameter was illustrated, the shape of the connection part 31 is not restricted to this, For example, in order to achieve weight reduction The adjacent valve main bodies 29 may be integrally connected by a cross-sectional cross-shaped or small-diameter connecting portion 31.

  Furthermore, in this embodiment, as the intake device, the rotary valve 21 inserted in the valve insertion hole 19 of the intake casing 3 is switched to change the cross-sectional area of the intake passage 7 in accordance with the operating state of the engine 5. Although the intake device 1 is illustrated, as in Patent Document 1, an intake air in which an effective length of the intake passage is changed in accordance with an operating state of the engine by switching a butterfly valve provided at a branch portion of the intake passage. The present invention can also be applied to an apparatus.

  In addition, in this embodiment, the case where the intake device 1 is applied to a two-cylinder engine is illustrated, but the present invention can also be applied to an engine having three or more cylinders. In this case, the valve body 29 and the seal member 51 are connected to the cylinder. It may be provided according to the number.

  The present invention is useful as an intake device for an engine provided with a power transmission system for rotating a valve element disposed in an intake casing.

It is sectional drawing by the side of the drive device of the intake device which concerns on embodiment. It is a perspective view of the intake device concerning an embodiment. FIG. 3 is a cross-sectional view taken along line AA of FIG. 2, (a) is a diagram illustrating a high speed operation of the engine, and (b) is a diagram illustrating a low speed operation of the engine. It is a perspective view of the rotary valve of the intake device concerning an embodiment.

Explanation of symbols

1 Intake Device 3 Intake Casing 5 Engine 7 Intake Passage 21 Rotary Valve (Valve)
33 drive shaft 46 lid member 49 housing 53 drive motor (drive source)
55 Output shaft 57 Output gear 57a Tooth part 59 Drive gear 61 Base end side part 63 Tip side part 63a Tooth part 67 Extension shaft part 69 Recessed part

Claims (1)

A valve body is disposed in the intake casing so as to be rotatable around a drive shaft integral with the valve body, and an output gear coupled to the drive source is engaged with a drive gear coupled to the drive shaft so that the drive source An engine intake device configured to rotate the valve body by transmitting rotational torque to an output gear, a drive gear, and a drive shaft, and to variably adjust the flow of intake air according to the operating state of the engine. ,
The drive source is housed in a housing attached to the outside of a lid member that closes an end of the intake casing on the drive shaft side,
The drive gear is externally fitted so that a base end side portion rotates integrally with the drive shaft and is rotatably supported by the lid member and meshes with a tooth portion of the output gear at a distal end side portion. Tooth part to be formed,
The drive shaft is formed with an extension shaft portion that penetrates the rotation center of the drive gear in the axial direction and protrudes into the housing.
The engine is characterized in that the housing is formed with a recess for slidingly fitting the extension shaft portion so as to be able to rotate so that the center of the recess matches the axis of the extension shaft portion. Intake device.

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