JP4690949B2 - Engine intake system - Google Patents

Description

The present invention provides a throttle body having an intake passage, a throttle valve supported by the throttle body for opening and closing the intake passage, a bypass bypassing the throttle valve and connected to the intake passage, and opening of the bypass In order to adjust the degree, a bypass valve that is slidably fitted in a valve hole of a valve body portion provided continuously with the throttle body, and an output shaft is connected to the bypass valve to operate the bypass valve. be an actuator attached to, the actuator, the inner end surface of the output shaft side, it was charged via an annular seal member between the valve body portion opposing to an improvement of the 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 device, the actuator is fitted in the mounting hole formed in the valve body portion, and the first close to the outer peripheral surface of the output shaft between the bottom surface of the mounting hole and the inner end surface of the actuator. A sealing member is provided in a watertight manner, and a lid for holding the actuator is screwed into the mounting hole via the second sealing member. With such a structure, the outer surface and the inside of the actuator are waterproofed, keeping.

  However, in the above structure, in addition to the first seal member for waterproofing the inside of the actuator, the second seal member for waterproofing the outer surface of the actuator is required. Have difficulty.

  The present invention has been made in view of such circumstances. The engine intake device for an engine, which does not require a sealing member for waterproofing the outer surface of the actuator, has a small number of parts, has a simple structure, and has a small number of assembly steps. The purpose is to provide.

To achieve the above object, the present invention provides a throttle body having an intake passage, a throttle valve supported by the throttle body for opening and closing the intake passage, and bypassing the throttle valve and connected to the intake passage. A bypass valve, a bypass valve slidably fitted in a valve hole of a valve body portion connected to the throttle body to adjust the opening degree of the bypass, and an output to operate the bypass valve by connecting the shaft becomes an actuator attached to the valve body, the actuator, the inner end surface of the output shaft side, it was charged via an annular seal member between the valve body portions facing, in an intake device for an engine, in order to constitute the actuator in waterproof, the inner and outer end surfaces and the outer peripheral surface of the stator of the actuator, synthetic resin for covering them face The manufacturing of the covering body is molded bond, and an outer peripheral surface of the covering body, fitted and fixed to a mounting hole formed in the valve body portion, and also between the inner end surface of the bottom and the cover of the mounting hole The first feature is that the outer peripheral portion of a single sealing member having a lip in close contact with the outer peripheral surface of the output shaft is sandwiched in a watertight manner.

  In addition to the first feature, the present invention has a second feature that a coupler for feeding power to the actuator is integrally formed on the covering.

According to the first feature of the present invention, the actuator has a synthetic resin covering body molded and bonded to both the inner and outer end faces and the outer peripheral face of the stator, and the outer peripheral face of the covering body is attached to the mounting hole of the valve body portion. fitted and secured to, and also watertight outer peripheral portion of the single seal member having between the inner end surface of the bottom and the cover of the mounting hole, the lip close contact with the outer peripheral surface of the output shaft to the inner periphery As a result, it is possible to form a waterproof type, and thus prevent rusting due to water immersion of the outer surface of the stator. That is, the seal member alone serves not only to prevent water from entering from the outer peripheral surface of the output shaft to the inside of the actuator but also to prevent water from entering between the inner end of the cover and the outer surface of the stator. Therefore, a seal member that prevents water from entering the mounting hole (that is, for waterproofing the outer surface of the actuator) is not required, the number of parts and the number of assembly steps can be reduced, and the cost can be reduced.

  According to the second feature of the present invention, since a coupler for supplying power to the actuator is integrally formed on the cover, the mounting flange integrated with the cover is used not only for the actuator but also for mounting the coupler. As a result, the number of parts and the number of assembly steps can be further reduced.

  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 and 4 projecting outward are formed on opposite side walls of the throttle body 1 in the horizontal direction. 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 intake negative temperature 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 of 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 opens to the upper part of the upstream end face of the throttle body 1 and extends along the intake passage 2, 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 intermediate 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 horizontal 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 horizontal 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 with 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 portion 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 is formed on the second end surface 16b of the valve body portion 16 so as to be coaxial with the fixed metering hole 15c. 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 15 b is disposed above the axis A of the intake passage 2 and on the opposite side of the bypass port 15 f 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 metal stator 27a of the stepping motor 27 is mold-bonded with a synthetic resin coating 28 covering both the inner and outer end surfaces and the outer circumferential surface, and the coating 28 protrudes 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 surface 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. , the outer peripheral portion of the plate-shaped sealing member 29 provided in the inner peripheral portion of the lip 29a to close contact with the outer peripheral surface of the output shaft 27b is interposed watertight. 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 have their end faces facing 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 central portion of the bypass valve 20, and the bypass valve 20 can be lifted (opened / 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, and the like, and controls the operation of the stepping motor 27 in accordance with 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 greatly adjusts the communication area between the fixed metering hole 15c and the movable metering hole 21. 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 by the control unit 32 in a direction to push down the bypass valve 20, and the communication area between the fixed metering hole 15 c 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 vertical key groove 24 on the side wall thereof and the key 23 fixed to the valve body portion 16. The opposed relationship between the valve 21 and the fixed metering hole 15c of the throttle body 1 can be properly maintained, and the adjustment of the intake air amount can be stabilized.

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

  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 assembling steps. Therefore, even when the surroundings of the engine are small like a motorcycle, the installation can be easily performed.

  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 with the valve shaft 7a interposed therebetween, 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 place, and the distance between the valve hole 15b and the outlet port 15f can be secured long enough. Therefore, when the engine blows back, the blown-back gas flows into the outlet port 15f. However, 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 blown-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 to the upper part of the upstream end face of the throttle body 1, so that it faces the flow of intake air. The intake air is smoothly taken into the valve hole 15b, and the idling of the engine is stabilized. Can contribute.

  The stepping motor 27 has a synthetic resin cover 28 molded and bonded to both the inner and outer end faces and the outer peripheral face of the stator 27a, and the outer periphery of the output shaft between the inner end face of the cover 28 and the bottom face of the mounting hole 25. 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 sealing 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.

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

  Further, 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 the number of assembly steps.

  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 present invention can also be applied to a downdraft type throttle body in which the intake passage is set up in the vertical direction. Further, the valve body portion 16 may be configured separately from the throttle body 1 and joined to the throttle body 1.

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.

DESCRIPTION OF SYMBOLS 1 ... Throttle body 2 ... Intake passage 7 ... Throttle valve 15 ... Bypass 15b ... Valve hole 16 ... Valve body part 20 ... Bypass Valve 25 ··· Mounting hole 27 ··· Actuator (stepping motor)
27a ... Stator 27b ... Output shaft 28 ... Cover 29 ... Seal member
29a ... Lip

Claims (2)

A throttle body (1) having an intake passage, a throttle valve (7) supported by the throttle body (1) for opening and closing the intake passage (2), and bypassing the throttle valve (7), the intake passage The bypass (15) connected to (2) and the valve hole (15b) of the valve body (16) connected to the throttle body (1) are slid to adjust the opening of the bypass (15). A bypass valve (20) that is movably fitted, and an actuator (27) that is attached to the valve body portion (16) by connecting the output shaft (27b) thereto to operate the bypass valve (20). with it, this actuator (27), was charged via an annular sealing member (29) between the inner end surface of the output shaft (27b) side, it valve body portion facing (16), an engine In the intake system,
To construct the actuator (27) in waterproof, the inner and outer end surfaces and the outer peripheral surface of the stator (27a) of the actuator (27), made of a synthetic resin coating for covering them surface (28) molded bonded The outer peripheral surface of the covering body (28) is fitted and fixed in a mounting hole (25) formed in the valve body portion (16) , and the bottom surface of the mounting hole (25) and the covering body (28) are fixed. The outer peripheral portion of a single sealing member (29) having a lip (29a) in close contact with the outer peripheral surface of the output shaft (27b) between the inner end surface of the output shaft (27b) is watertight. An engine intake system. The engine intake device according to claim 1, wherein
An intake device for an engine, wherein a power supply coupler (31) to an actuator (27) is integrally formed on the cover (28).

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