JP2007332829A - Intake device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake device for an engine which prevents blow back gas of an engine from reaching a bypass valve and realizes excellent productivity even though its size is small. <P>SOLUTION: In an intake device for an engine equipped with a bypass 15 which detours a throttle valve 7 to be connected to an intake passage 2 and with a bypass valve 20 for adjusting an opening of the bypass 15, at least a part of the bypass 15 is composed of an inlet port 15a provided to a throttle body 1 so as to open to an intake passage 2 upstream from the throttle valve 7, a valve hole 15b provided to the throttle body 1 so as to fit the bypass valve 20 thereto, and an outlet port 15f provided to the throttle body 1 so as to open to the intake passage 2 downstream from the throttle valve 7. The valve hole 15b is arranged above the outlet port 15f on the opposite side to the outlet port 15f sandwiching the throttle valve and in parallel to bearing holes 5, 6 for supporting a valve shaft 7a of the throttle valve 7. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a throttle body having an intake passage, a throttle valve that supports a valve shaft in a bearing hole formed in the throttle body and opens and closes the intake passage, and bypasses the throttle valve and is connected to the intake passage. And a bypass valve that adjusts the opening of the bypass, an actuator that operates the bypass valve, and a throttle sensor that is attached to one side wall of the throttle body and detects the opening of the throttle valve. , It relates to improvement of engine intake system.

Such an intake device for an engine is already known as disclosed in Patent Document 1.
JP 2003-74444 A

  In the conventional engine intake system, a bypass valve for adjusting the opening of the bypass and its actuator are attached to the control block joined to the throttle body, so that the assembly on the throttle body side and the assembly on the control block side are performed. Since the bypass valve provided in the control block can be performed in parallel and is inevitably far from the outlet port of the bypass opening downstream of the intake passage, the engine blow-back gas reaches the bypass valve. There is also an advantage that it is difficult.

  However, since the throttle body combined with the control block tends to be large as a whole, it is not suitable for installing the throttle body in a narrow space around the engine like a motorcycle.

  The present invention has been made in view of such circumstances, and the engine blow-back gas is difficult to reach the bypass valve while being small, and the machining of the valve hole in which the bypass valve is fitted can be easily performed. It is an object of the present invention to provide an engine intake device having a good quality.

  To achieve the above object, the present invention provides a throttle body having an intake passage, a throttle valve that supports a valve shaft in a bearing hole formed in the throttle body and opens and closes the intake passage, and the throttle valve. A bypass that bypasses and is connected to the intake passage, a bypass valve that adjusts the opening of the bypass, an actuator that operates the bypass valve, and an opening of the throttle valve that is attached to one side wall of the throttle body. An intake device for an engine comprising a throttle sensor configured to provide an inlet port provided in a throttle body so as to open at least a part of a bypass to an intake passage upstream of the throttle valve, and a throttle for fitting the bypass valve. A valve hole provided in the body and a throttle body that opens to the intake passage downstream of the throttle valve. Constituted by an outlet port which is, the valve hole, the first, characterized in that it arranged parallel to and the bearing hole above the outlet port at an opposite side to the outlet port across the throttle valve.

  According to the second aspect of the present invention, in addition to the first feature, the valve hole is disposed above the axis of the throttle body, and the outlet port is disposed below the coaxial line and parallel to the bearing hole. It is characterized by.

  Furthermore, in addition to the first or second feature, the third feature of the present invention is that the inlet port is disposed so as to open above the upstream end surface of the throttle body.

  Furthermore, in addition to any one of the first to third features, the present invention is characterized in that a sensor box for holding the throttle sensor and the actuator are attached to an end surface facing the same direction of the throttle body. It is characterized by.

  According to the first feature of the present invention, the bypass valve is fitted in a valve hole formed in the throttle body, and an actuator for operating the bypass valve is also attached to the throttle body. The overall size can be reduced, and therefore, even when the surroundings of the engine are small like a motorcycle, the installation can be easily performed.

  In addition, the valve hole in which the bypass valve is fitted is disposed above the outlet port on the opposite side of the outlet port with the throttle valve interposed therebetween. Therefore, even if the engine blowback enters the outlet port, it does not reach the valve hole easily, and the bypass valve is not fixed due to freezing of moisture in the blowback gas or adhesion of carbon. Can be prevented.

  Furthermore, since the valve hole is arranged in parallel with the bearing hole that supports the valve shaft of the throttle valve, the valve hole can be processed together with the bearing hole by a multi-axis drilling machine, and productivity can be improved.

  According to the second feature of the present invention, the vertical distance between the valve hole and the outlet port can be more sufficiently ensured, and the engine blowback gas can be effectively prevented from reaching the valve hole. In addition, the outlet port is arranged in parallel with the bearing hole in the same manner as the valve hole, so that the outlet port can be processed together with the valve hole and the bearing hole at once by a multi-axis drilling machine, thereby improving productivity. Can do.

  According to the third feature of the present invention, the inlet port opens at the upper part of the upstream end face of the throttle body, so that it faces the flow of intake air. It can contribute to stabilization of idling.

  According to the fourth feature of the present invention, the sensor box and the actuator can be easily attached to the throttle body from the same direction without changing the direction thereof, and the productivity can be further increased.

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

  1 is a plan view of an intake system for an engine according to the present invention, FIG. 2 is a sectional view taken along line 2-2 in FIG. 1, FIG. 3 is a sectional view taken along line 3-3 in FIG. 5 is a sectional view taken along line 5-5 in FIG. 4, FIG. 6 is a sectional view taken along line 6-6 in FIG. 1, and FIG. 7 is a sectional view taken along line 7-7 in FIG.

  1 to 4, the intake device of the present invention is mainly used for an engine of a motorcycle, and includes a throttle body 1 attached to the engine. The throttle body 1 has a horizontal intake passage 2 connected to an intake port (not shown) in an attached state to the engine. First and second bearing bosses 3, 4 projecting outward are formed on both side walls facing in the horizontal direction of the throttle body 1, and the horizontal directions aligned coaxially with the bearing bosses 3, 4. The valve shaft 7a of the butterfly throttle valve 7 that opens and closes the intake passage 2 is rotatably supported by the bearing holes 5 and 6. A throttle drum 8 is fixed to one end portion of the valve shaft 7 a that protrudes outward from the first bearing boss 3, and a return spring 9 that biases the throttle drum 8 in the closing direction of the throttle valve 7 is provided in the first bearing boss 3. It is attached to.

  A sensor box 10 integrally provided with a coupler 14 is fixed to the end face of the second bearing boss 4 by a plurality of screws 35, 35..., And this sensor box 10 allows a throttle sensor 11, an intake air temperature sensor 12, a boost negative pressure sensor. 13 etc. are held. The throttle sensor 11 detects the rotation angle of the valve shaft 7 a as the opening degree of the throttle valve 7, and the intake air temperature sensor 12 passes through the through hole 33 on the side wall of the throttle body 1 so that the tip part faces the intake passage 2. The boost negative pressure sensor 13 detects the boost negative pressure of the engine from a detection hole 34 (see FIG. 7) opened in the intake passage 2 downstream from the throttle valve 7. It has become.

  The throttle body 1 is provided with a bypass 15 that bypasses the throttle valve 7 and is connected to the intake passage 2. The bypass 15 has an inlet port 15a (see FIG. 4) that extends along the intake passage 2 and opens at the upper end of the upstream end surface of the throttle body 1, and a cylindrical valve hole 15b that rises from the downstream end of the inlet port 15a. (See FIG. 5), a fixed metering hole 15c (see FIG. 5), which is perpendicular to the middle portion of the valve hole 15b and extends along the intake passage 2, and has a smaller diameter than the valve hole 15b, and downstream of the fixed metering hole 15c. A lateral hole 15d rising from the end and opening in the end surface of the second bearing boss 4 and a groove-shaped intermediate bending path 15e formed between the joint surfaces of the second bearing boss 4 and the sensor box 10 and connected to the lateral hole 15d (see FIG. 6) and an outlet port 15f (see FIGS. 2 and 3) communicating with the downstream end of the intermediate bent path 15e and opening to the intake passage 2 downstream of the throttle valve 7.

  As shown in FIGS. 2 and 5, the valve hole 15 b and the fixed metering hole 15 c are formed by drilling in the valve body portion 16 formed integrally with the throttle body 1 adjacent to the second bearing boss 4. . That is, the valve hole 15b is drilled in parallel to the bearing holes 5 and 6 from the first end surface 16a of the valve body portion 16 parallel to the end surface of the second bearing boss 4, and the fixed metering hole 15c is Drilling is performed in parallel with the axis A of the intake passage 2 from the second end face 16b of the valve body 16 parallel to the upstream end face of the throttle body 1 so as to cross 15b. When the fixed metering hole 15c is processed, a processing port 17 arranged coaxially with the fixed metering hole 15c is formed on the second end surface 16b of the valve body portion 16. The processing port 17 is hermetically closed by a plug 18 that is press-fitted or screwed into the processing port 17. Thus, the first and second bearing holes 5 and 6 and the valve hole 15b which are parallel to each other are processed at once by a multi-axis drilling machine.

  The valve hole 15b is disposed close to the second end face 16b so that the length L1 of the machining port 17 is sufficiently shorter than the length L2 of the fixed measuring hole 15c. By doing so, it is possible to extend the service life of the drill by reducing the machining amount of the machining port 17 as much as possible.

  Further, as shown in FIG. 2, the valve hole 15b is disposed above the axis A of the intake passage 2 and on the opposite side of the bypass port 15f of the bypass 15 with the throttle valve 7 interposed therebetween. On the other hand, the outlet port 15 f is disposed below the axis A of the intake passage 2. At that time, both the valve hole 15b and the outlet port 15f are arranged in parallel with the first and second bearing holes 3 and 4.

  In FIG. 5 again, a hollow cylindrical bypass valve 20 is slidably fitted into the valve hole 15. This bypass valve 20 has a movable measuring hole 21 facing the upstream end of the fixed measuring hole 15c on one side wall, and the communication area of the movable measuring hole 21 and the fixed measuring hole 15c is bypassed by raising and lowering the bypass valve 20. The opening is adjusted to 15 degrees.

  Between the bypass valve 20 and the valve body portion 16, there is provided a detent means 22 that allows the bypass valve 20 to be raised and lowered while holding the movable measuring hole 21 at a position facing the fixed measuring hole 15c. The anti-rotation means 22 includes a vertical key groove 24 provided on the other side wall of the bypass valve 20 on the side opposite to the movable measuring hole 21, and a pin protruding integrally with the central portion of the inner end surface of the plug body 18. It is comprised with the key 23 of a shape.

  The valve body portion 16 is provided with a mounting hole 25 having a diameter larger than that of the valve hole 15b so as to open to the first end face 16a. A stepping motor 27 as an actuator for opening and closing the bypass valve 20 is mounted in the mounting hole 25 with its output shaft 27b protruding toward the bypass valve 20 side. The metallic stator 27a of the stepping motor 27 is molded with a synthetic resin coating 28 covering both the inner and outer end surfaces and the outer circumferential surface, and the coating 28 is projected from the outer circumferential surface. A mounting flange 28a and a power feeding coupler 31 for the stepping motor 27 protruding from the outer end face of the mounting flange 28a are integrally formed. When the stepping motor 27 is mounted in the mounting hole 25, the outer peripheral surface of the covering body 28 is fitted to the inner peripheral surface of the mounting hole 25 and between the inner end surface of the covering body 28 and the bottom surface of the mounting hole 25. A plate-like sealing member 29 having a lip 29a in close contact with the outer peripheral surface of the output shaft 27b is interposed. The mounting flange 28 a is fixed to the first end surface 16 a of the valve body portion 16 by a plurality of screws 36. At that time, no sealing member is interposed between the mounting flange 28a and the first end face 16a.

  Thus, the valve body portion 16 and the second bearing boss 4 are adjacent to each other and their end faces are directed in the same direction, and the stepping motor 27 and the sensor box 10 are attached to these end faces. The mounting operation can be easily performed without changing the direction of the throttle body 1 and can contribute to the improvement of the assembly work efficiency.

  The output shaft 27b of the stepping motor 27 is screwed into a female screw member 30 attached to the center portion of the bypass valve 20, and the bypass valve 20 can be raised and lowered (opened and closed) by forward and reverse. An electronic control unit 32 that controls energization to the stepping motor 27 is connected to a terminal in the coupler 31. The electronic control unit 32 receives detection signals from the throttle sensor 11, the intake air temperature sensor 12, the boost negative pressure sensor 13, etc., and controls the operation of the stepping motor 27 according to these signals. It also controls the operation of the injection valve.

  Next, the operation of this embodiment will be described.

  During operation of the engine with the throttle valve 7 fully closed, the intake air that has flowed into the intake passage 2 bypasses the throttle valve 7, that is, an inlet port 15a, a valve hole 15b, a fixed metering hole 15c, an intermediate It is supplied to the engine through the bent path 15e and the outlet port 15f. At this time, if the engine is in a warm-up operation state, the stepping motor 27 is actuated in the direction of pulling up the bypass valve 20 by the control unit 32, and the communication area between the fixed metering hole 15c and the movable metering hole 21 is greatly adjusted. , The intake air is increased and the engine is in the first idling state. Further, after the warm-up operation, the stepping motor 27 is operated in a direction to push down the bypass valve 20 by the control unit 32, and the communication area between the fixed metering hole 15c and the movable metering hole 21 is reduced, so that the intake air is reduced, The engine is in a normal idling state.

  The bypass valve 20 ascending / descending as described above is prevented from rotating by the engagement between the longitudinal key groove 24 on the side wall and the key 23 fixed to the valve body portion 16, so that the movable metering hole of the bypass valve 20 is provided. It is possible to stabilize the adjustment of the intake air amount by appropriately maintaining the opposing relationship between the valve 21 and the fixed metering hole 15c of the throttle body 1.

  In particular, the key 23 is formed integrally with the plug body 18 that closes the processing port 17 when the fixed metering hole 15c is drilled in the valve body portion 16, so that the fixed metering hole 15c and the key 23 are connected to each other. A fixed positional relationship can be easily and accurately maintained in a mass-produced engine intake device, and can greatly contribute to stabilization of engine idling characteristics.

  In addition, since the plug 18 has the key 23, it is not necessary to attach a special key to the valve body portion 16, and accordingly, the number of parts and the number of assembling steps can be reduced, and the cost can be reduced.

  Further, the valve body portion 16 that forms the valve hole 15b is formed integrally with the throttle body 1, in other words, the valve hole 15b is formed in the throttle body 1, and the bypass that is fitted into the valve hole 15b. The stepping motor 27 that operates the valve 20 is also attached to the valve body portion 16, that is, the throttle body 1, thereby further reducing the number of parts and the number of assembly steps, and reducing the size of the entire throttle body 1 with the bypass valve 20 and the stepping motor 27. Therefore, even when the engine periphery is narrow like a motorcycle, the installation can be performed easily.

  In addition, since the valve hole 15b, the mounting hole 25, and the outlet port 15f are arranged in parallel with the first and second bearing holes 5 and 6 of the valve shaft 7a, the valve hole 15b, the mounting hole 25, and the outlet port 15f are connected to each other. The first and second bearing holes 5 and 6 can be processed together with a multi-axis drilling machine, which also reduces the number of processing steps.

  Moreover, the valve hole 15b is disposed above the axis A of the intake passage 2 and on the side opposite to the outlet port 15f of the bypass 15 across the valve shaft 7a, while the outlet port 15f is connected to the intake passage 2. Since it is disposed below the axis A, the valve hole 15b is disposed at a high position, and a sufficiently long distance can be secured between the valve hole 15b and the outlet port 15f. Therefore, when the engine is blown back, the blown-back gas flows into the outlet port 15f. Even if it enters, it does not easily reach the valve hole 15b, and it is possible to prevent the bypass valve 20 from sticking due to freezing of moisture in the blow-back gas or adhesion of carbon or the like. In particular, in the throttle body 1, unlike a carburetor with a bypass, no fuel flows into the bypass 15, and therefore no foreign substance cleaning action occurs around the valve hole 15 b, so that the foreign substance enters the valve hole 15 b. Prevention is extremely important.

  On the other hand, the inlet port 15a of the bypass 15 opens at the upper end of the upstream end face of the throttle body 1, so that it faces the flow of intake air, and the intake air is smoothly taken into the valve hole 15b to stabilize engine idling. Can contribute.

  Further, the stepping motor 27 molds and bonds a synthetic resin covering 28 to both the inner and outer end faces and the outer peripheral face of the stator 27a, and between the inner end face of the covering 28 and the bottom face of the mounting hole 25, the outer periphery of the output shaft. By interposing the seal member 29 in close contact with the surface, it can be constructed as a waterproof type, and therefore rusting due to water immersion on the outer surface of the stator 27a can be prevented. That is, the single seal member 29 not only prevents water from entering the stepping motor 27 from the outer peripheral surface of the output shaft 27b, but also prevents water from entering between the inner end of the cover 28 and the stator 27a. Since it plays a dual role, a seal member for preventing water from entering the mounting hole 25 is unnecessary, the number of parts and the number of assembly steps are reduced, and the cost can be reduced.

  In addition, since the mounting flange 28a for attaching the stepping motor 27 to the valve body portion 16 is formed integrally with the cover 28, a special lid for holding the stepping motor 27 is not required, and the number of parts is further increased. The cost can be further reduced.

  Furthermore, since the power supply coupler 31 to the stepping motor 27 is integrally formed on the cover 28 so as to protrude outward from the mounting flange 28a, the mounting flange 28a is not only the stepping motor 27 but also the coupler 31. This also contributes to the reduction of the number of parts and assembly man-hours.

  As mentioned above, although the Example of this invention was described, this invention is not limited to it, A various design change is possible in the range which does not deviate from the summary. For example, the mounting flange 28a can be replaced with a pressing plate separate from the cover 28.

The top view of the engine intake device which concerns on this invention. FIG. 2 is a sectional view taken along line 2-2 in FIG. 1. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. FIG. 4 is a view taken in the direction of arrow 4 in FIG. 1. FIG. 5 is a sectional view taken along line 5-5 of FIG. FIG. 6 is a sectional view taken along line 6-6 in FIG. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Throttle body 2 ... Intake passage 7 ... Throttle valve 10 ... Sensor box 11 ... Throttle sensor 15 ... Bypass 15a ... Inlet port 15b ... Valve hole 15f ... Outlet port 20 ... Bypass valve 27 ... Actuator stepping motor)

Claims (4)

A throttle body (1) having an intake passage, and a throttle valve (opening and closing the intake passage (2)) supported by a valve shaft (7a) in bearing holes (5, 6) formed in the throttle body (1) 7), a bypass (15) bypassing the throttle valve (7) and connected to the intake passage (2), a bypass valve (20) for adjusting the opening of the bypass (15), and the bypass Engine intake air comprising an actuator (27) that operates the valve (20) and a throttle sensor (11) that is attached to one side wall of the throttle body (1) and detects the opening of the throttle valve (7). In the device,
An inlet port (15a) provided in the throttle body (1) and a bypass valve (20) are fitted so that at least a part of the bypass (15) is opened to the intake passage (2) upstream of the throttle valve (7). A valve hole (15b) provided in the throttle body (1) and an outlet port (15f) provided in the throttle body (1) so as to open to the intake passage (2) downstream from the throttle valve (7). The valve hole (15b) is disposed above the outlet port (15f) on the opposite side of the outlet port (15f) across the throttle valve (7) and in parallel with the bearing holes (5, 6). An intake system for an engine characterized by The engine intake device according to claim 1,
The valve hole (15b) is disposed above the axis (A) of the throttle body (1), and the outlet port (15f) is disposed below the coaxial line (A) and parallel to the bearing holes (5, 6). An intake system for engines, characterized in that The engine intake device according to claim 1 or 2,
An intake system for an engine, wherein the inlet port (15a) is disposed so as to open at an upper part of an upstream end face of the throttle body (1). The engine intake device according to any one of claims 1 to 3,
An intake system for an engine, wherein the sensor box (10) for holding the throttle sensor (11) and the actuator (27) are attached to an end face of the throttle body (1) facing in the same direction.

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