JP4879927B2 - Engine idle intake control device - Google Patents

Description

  The present invention relates to a throttle body having an intake passage connected to an intake port of an engine and a throttle valve for opening and closing the intake passage, a bypass that bypasses the throttle valve and is connected to the intake passage, and a bypass valve that adjusts the bypass in an adjustable manner. The engine is provided with a dust trap for preventing dust from entering the bypass valve from the intake passage.

Conventionally, in an idle intake control device for such an engine, the dust trap is composed of a plurality of passages connected in a crank shape, and the direction of the intake air flowing through the bypass is changed to a right angle to separate the dust from the intake air. (See Patent Document 1) and a structure in which a dust trap is configured in a swirling chamber that applies a swirling flow to the intake air and centrifuges dust from the intake air (Patent Document 2).
JP 2001-115931 A Japanese Patent Laid-Open No. 3-264769

  By the way, in the trap described in Patent Document 1, the effect of separating dust from the intake air is weak only by changing the direction of the intake air in the bypass to a right angle, and in the trap of Patent Document 2, the swirl flow is effective in the intake air. In order to provide the same, it is necessary to form a large-diameter swirl chamber in the throttle body, and there is little room for forming it in a small throttle body for motorcycles and the like.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an idle intake control device for an engine having a dust separation effect and a compact dust trap.

  In order to achieve the above object, the present invention provides a throttle body having an intake passage connected to an intake port of an engine and a throttle valve for opening and closing the bypass, a bypass bypassing the throttle valve and connected to the intake passage, and the bypass In an idle intake control system for an engine, provided with a dust trap for preventing dust from entering from the intake passage to the bypass valve, the dust trap is disposed on the intake passage side. A first trap chamber in which a bypass trap inlet hole is opened; a second trap chamber adjacent to the first trap chamber with a partition wall therebetween; and a bypass trap outlet hole on the bypass valve side; The first feature is that the two trap chambers are formed in a U-shaped cross section with a reversing chamber communicating with one end of the partition wall. .

  In addition to the first feature of the present invention, the second feature is that a step portion is formed between the reversing chamber and the second trapping chamber so that the bottom surface of the second trapping chamber is higher than the bottom surface of the reversing chamber. To do.

  In addition to the first or second feature, the present invention further includes forming the first trap chamber, the second trap chamber, and the reversing chamber by molding from one side surface of the throttle body. The third feature is that the remaining punching hole is closed with a closing plug.

  Furthermore, the present invention is characterized in that, in addition to the third feature, the trap inlet hole is opened in the bottom surface of the first trap chamber.

  Furthermore, in addition to the fourth feature of the present invention, the trap outlet hole is opened on the inner surface of the second trap chamber, the axis of the trap outlet hole is made parallel to the axis of the valve shaft of the throttle valve, A fifth feature is that a valve hole for mounting the bypass valve is arranged on the same line as the trap outlet hole.

  According to the first aspect of the present invention, when air or gas passing through the bypass flows toward the bypass valve through the trap, first, when flowing into the first trap chamber from the trap inlet hole, the air or gas passes through the partition into the reversing chamber. In this reversal chamber, the reversal chamber is reversed by approximately 180 °, is directed to the second trap chamber, and flows out to the trap outlet hole. Therefore, the dust contained in the air or gas is effective when the reversal is approximately 180 °. As a result, the dust that reaches the trap outlet is drastically reduced. Therefore, dust can be prevented from accumulating around the bypass valve, and the adjustment function of the bypass valve can always be stabilized. Moreover, the U-shaped dust trap including the first trap chamber, the second trap chamber, and the reversing chamber is compact and can be easily formed in a small throttle body for a motorcycle or the like.

  According to the second feature of the present invention, since the bottom surface of the second trap chamber is one step higher than the bottom surface of the reversing chamber through the stepped portion, the air or gas reversed approximately 180 ° in the reversing chamber is After colliding with the stepped portion and changing the course upward, it moves to the second trap chamber and flows out to the trap outlet hole. Therefore, the dust contained in the air or gas can be separated by specific gravity difference when changing the course by colliding with the stepped part immediately before moving from the reversing chamber to the second trap chamber, and the trap dust separation. Function can be enhanced.

  According to the third aspect of the present invention, the trap is formed by molding from one side of the throttle body, and the mold release hole remaining on one side of the throttle body is closed with a closing plug. At the same time, the dust trap can be formed, and it is not necessary to apply special processing to the dust trap, which can contribute to a reduction in manufacturing cost.

  According to the fourth feature of the present invention, since the trap inlet hole is opened in the bottom surface of the first trap chamber, the trap inlet hole can be easily formed by molding from the die punching hole or drilling. In addition, the air or gas that has flowed into the first trap chamber is allowed to collide with the stepped portion after the lower portion of the first trap chamber is turned over and reversed in the reversing chamber. It is possible to enhance the dust separation effect.

  According to the fifth aspect of the present invention, the trap outlet hole and the valve hole, and the valve shaft hole of the throttle valve can be machined in parallel with the throttle body, so that the production efficiency of the throttle body can be improved. .

  Embodiments of the present invention will be described based on preferred embodiments of the present invention shown in the accompanying drawings.

  1 is a longitudinal side view of a throttle body equipped with an idle intake control device for an engine of the present invention, FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 1, FIG. 3 is a sectional view taken along line 3-3 of FIG. FIG. 4 is a sectional view taken along line 4-4 of FIG.

  First, in FIG. 1, a throttle body T is attached to a motorcycle engine (not shown), and a horizontal intake passage 1 connected to an intake port of the engine is formed at the center, and the intake passage 1 is opened and closed. A valve shaft 2 a of the butterfly throttle valve 2 is supported by the throttle body T. An electromagnetic fuel injection valve 4 capable of injecting fuel toward the intake passage 1 downstream of the throttle valve 2 is mounted on the upper wall of the throttle body T.

  As shown in FIGS. 1 and 2, the throttle body T is provided with a bypass 5 that bypasses the upper side of the throttle valve 2 and is connected to the intake passage 1. The bypass 5 can be adjusted in the middle of the bypass 5. And a dust trap 7 for preventing dust from entering the bypass valve 6 from the upstream side of the intake passage 1. The dust includes atmospheric dust sucked into the intake passage 1 and combustion soot that flows back to the intake passage 1 during backfire of the engine.

  The bypass 5 opens upward at the lower end on the upstream side of the intake passage 1 and extends upward, and a trap inlet hole 10 reaching the dust trap 7, and a trap extending in parallel with the valve shaft 2 a of the throttle valve 2 from one side of the dust trap 7. An outlet hole 11, a measuring hole 12 that communicates perpendicularly to the trap outlet hole 11 and extends in parallel with the axis X of the intake passage 1, and the measuring hole 12 is bent into a crank shape that communicates with the downstream side of the intake passage 1. And the bent path 13.

  As clearly shown in FIG. 2, the throttle body T is provided with a valve hole 15 disposed coaxially with the trap outlet hole 11 with the metering hole 12 interposed therebetween, and the bypass valve 6 is attached to the valve hole 15. . The valve hole 15 includes a small-diameter guide hole 16 that opens to the measuring hole 12, a larger-diameter screw hole 17 that is continuous with the small-diameter guide hole 16, and a large-diameter guide that is continuous with the screw hole 17 and has a larger diameter. It consists of a hole 18. On the other hand, the bypass valve 6 is freely rotatable and slidable in the small diameter guide hole 16 so as to be rotatably and slidably fitted in the small diameter guide hole 16, the screw shaft portion 21 screwed into the screw hole 17, and the large diameter guide hole 18. And a head 22 with a tool groove 23 that is fitted together, and the outer peripheral groove 22 a of the head 22 holds a seal member 24 that is in close contact with the inner peripheral surface of the large-diameter guide hole 18. The In addition, a coil spring 25 for preventing the bypass valve 6 from rotating is contracted in the large diameter guide hole 18.

  Thus, during idling of the engine with the throttle valve 2 fully closed, the bypass valve 6 is rotated forward and backward by a tool engaged with the tool groove 23 to adjust the amount of protrusion of the valve portion 20 into the measuring hole 12. Thus, the idle intake amount of the engine flowing through the bypass 5 can be adjusted.

  Now, the dust trap 7 will be described with reference to FIGS.

  The dust trap 7 includes a first trap chamber 30, a second trap chamber 31 adjacent to the first trap chamber 30 across a vertically extending partition wall 32 integral with the throttle body T, and the first and second trap chambers. A section U is formed in a U-shaped cross section with a substantially semicircular reversing chamber 33 that communicates with each other so as to go around one end of the partition wall 32. At this time, a step portion 34 is formed between the inversion chamber 33 and the second trap chamber 31 so that the bottom surface of the second trap chamber 31 is higher than the bottom surface of the inversion chamber 33. The trap inlet hole 10 is opened in the bottom surface of the first trap chamber 30, and the trap outlet hole 11 is opened in the inner surface of the second trap chamber 31 facing the partition wall 32.

  The dust trap 7 and the trap inlet hole 10 are formed by molding from the upper surface side of the throttle body T when the throttle body T is cast, and the circular die hole 35 remaining on the upper surface of the throttle body T is formed. Is closed with a closing plug 36.

  In FIG. 2, reference numeral 37 denotes a throttle sensor connected to the valve shaft 2a in order to detect the opening degree of the throttle valve 2.

  Next, the operation of this embodiment will be described.

  During idling of the engine, when the idle intake air of the engine flows from the upstream side of the intake passage 1 to the downstream side of the intake passage 1 via the bypass 5, the dust trap 7 has a bottom surface of the first trap chamber 30 through the trap inlet hole 10. The air that has flowed to the side first moves from the lower portion of the first trap chamber 30 along the partition wall 32 to the reversing chamber 33, and is reversed by approximately 180 ° in the reversing chamber 33 toward the second trap chamber 31. Since the bottom surface of the second trap chamber 31 is one step higher than the bottom surface of the reversing chamber 33 via the step portion 34, the air reversed by about 180 ° below the reversing chamber 33 collides with the step portion 34. After changing the course upward, it moves to the second trap chamber 31 and flows out to the trap outlet hole 11. Therefore, if dust is mixed in the air, the dust is effectively centrifuged from the air when the air is first reversed approximately 180 ° below the reversing chamber 33. Next, immediately before the air moves from the reversing chamber 33 to the second trap chamber 31, the dust is separated from the air due to the difference in specific gravity when it changes the course by colliding with the stepped portion 34.

  Thus, the air from which dust has been removed by the dust trap 7 is directed from the trap outlet hole 11 to the measuring hole 12, the flow rate of which is adjusted by the valve portion 20 of the bypass valve 6, and then through the bent path 13 to the intake passage 1. It flows downstream and is sucked into the engine. Therefore, since clean air always flows through the metering hole 12 and dust is prevented from accumulating around the valve portion 20 of the bypass valve 6, the adjustment function of the bypass valve 6 can always be stabilized.

  By the way, the U-shaped dust trap 7 including the first trap chamber 30, the second trap chamber 31, and the reversing chamber 33 is compact and can be easily formed in a small throttle body T for a motorcycle or the like. In particular, this is formed by molding from the upper side surface of the throttle body T, and the mold release hole 35 remaining on the upper side surface of the throttle body T is closed by the closing plug 36. Therefore, the dust trap 7 is simultaneously formed with the molding of the throttle body T. Therefore, it is not necessary to perform special processing on the dust trap 7, which can contribute to a reduction in manufacturing cost.

  Further, since the trap inlet hole 10 is opened in the bottom surface of the first trap chamber 30, the trap inlet hole 10 can be easily formed by molding or drilling from the die punching hole 35, and the first trap After the air flowing into the chamber 30 is swung down the first trap chamber 30 and reversed in the reversing chamber 33, it effectively collides with the stepped portion 34. Can be increased.

  Furthermore, the axis Y2 of the trap outlet hole 11 opened on the inner side surface of the second trap chamber 31 is parallel to the axis Y1 of the valve shaft 2a of the throttle valve 2, and the bypass valve 6 is mounted on the coaxial line Y2 with the trap outlet hole 11. Since the valve hole 15 is arranged, the trap outlet hole 11 and the valve hole 15 and the valve shaft hole of the throttle valve 2 can be machined in parallel with the throttle body T, thereby improving the production efficiency of the throttle body T. be able to.

  In this embodiment, when the combustion gas flows back through the bypass 5 together with dust such as combustion soot during the backfire of the engine, the dust is separated by the curved path 13. As described above, in order to separate dust from the gas flowing backward in the bypass 5, it is effective to provide the dust trap 7 of the present invention in the bypass 5 downstream of the bypass valve 6 instead of the bent path 13.

1 is a longitudinal side view of a throttle body provided with an idle intake control device for an engine according to the present invention. 2-2 line enlarged sectional view of FIG. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. Sectional view along line 4-4 in FIG.

Explanation of symbols

T ... Throttle body 1 ... Intake passage 2 ... Throttle valve 2a ... Valve shaft 5 ... Bypass 6 ... Bypass valve 7 ... .... Dust trap 10 ... Trap inlet hole 11 ... Trap outlet hole 15 ... Valve hole 30 ... First trap chamber 31 ... Second trap chamber 32 ... Partition 33 ... Reversing chamber 34 ... Step part 35 ... Die release hole 36 ... Closing stopper

Claims (5)

A bypass body (T) having an intake passage (1) connected to an intake port of the engine and a throttle valve (2) for opening and closing the intake passage bypasses the throttle valve (2) and is connected to the intake passage (1) ( 5) and a bypass valve (6) for throttleably adjusting the bypass (5), and a dust trap for preventing dust from entering the bypass valve (6) from the intake passage (1) to the bypass (5) In the engine idle intake control system provided with (7),
The dust trap (7) is divided into a first trap chamber (30) in which a trap inlet hole (10) of a bypass (5) on the intake passage (1) side is opened, and a partition wall (32 ) Between the second trap chamber (31) where the trap outlet hole (11) of the bypass (5) on the bypass valve (6) side opens, and between the first and second trap chambers (31). The engine idle intake control device is characterized in that it is formed in a U-shaped cross section with a reversing chamber (33) communicating so as to go around one end of the partition wall (32). The idle intake control device for an engine according to claim 1,
A step portion (34) is formed between the inversion chamber (33) and the second trap chamber (31) so that the bottom surface of the second trap chamber (31) is higher than the bottom surface of the inversion chamber (33). , Engine idle intake control device. The idle intake control device for an engine according to claim 1 or 2,
The first trap chamber (30), the second trap chamber (31), and the reversing chamber (33) are formed by molding from one side of the throttle body (T) and remain on one side of the throttle body (T). An idle intake control device for an engine, characterized in that the punching hole (35) to be closed is closed with a closing plug (36). The idle intake control device for an engine according to claim 3,
An idle intake control device for an engine, wherein the trap inlet hole (10) is opened at a bottom surface of the first trap chamber (30). The idle intake control device for an engine according to claim 4,
The trap outlet hole (11) is opened on the inner side surface of the second trap chamber (31), and the axis (Y2) of the trap outlet hole (11) is the axis of the valve shaft (2a) of the throttle valve (2) ( The engine idle intake control is characterized in that a valve hole (15) for mounting the bypass valve (6) is disposed in parallel with the Y1) and on the coaxial line (Y2) with the trap outlet hole (11). apparatus.

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