JP2005273647A - By-pass set screw and by-pass passage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bypass set screw and a bypass passage capable of decreasing the frequency of idle adjustment, by suppressing adhesion of deposit. <P>SOLUTION: The bypass set screw 10 has a screw main body portion 15 screwed with a passage wall 9 of the bypass passage 6 bypassing a throttle valve opening/closing an intake passage 2 of an internal combustion engine, and a valve portion 18 opening/closing the bypass passage 6 by advancing/retracting of the screw main body 15. The valve portion 18 opens/closes the bypass passage 18 in a state forming a passage cross section 27 forming a single pipe-shaped passage wall surface. The valve portion 18 opens/closes the bypass passage 6 in a diameter direction by axial movement. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bypass set screw and a bypass passage provided in an intake system of an internal combustion engine in a vehicle such as an automobile or a motorcycle.

  2. Description of the Related Art Conventionally, there has been known one in which a bypass set screw for opening and closing a bypass passage is screwed to a passage wall of a bypass passage that bypasses a throttle valve that opens and closes an intake passage of an internal combustion engine. Then, the bypass passage is opened and closed by screwing or unscrewing of the bypass set screw, whereby the idle speed of the internal combustion engine can be adjusted (referred to as “idle adjustment”).

For example, as shown in FIG. 20A, such a bypass set screw is formed by screw main body 115 screwed into the passage wall 109 of the bypass passage 106 and screwing or screwing of the screw main body 115. And a valve portion 118 for opening and closing the bypass passage 106. The valve portion 118 is formed with a tip portion 122 having a tapered shape.
The bypass passage 106 extends in the direction of the axis L of the bypass set screw (denoted by reference numeral 110) and has a vertical passage portion 108 having a measuring port 125 corresponding to the tip 122 of the bypass set screw 110, and its measuring port. A horizontal passage portion 107 intersecting with the vertical passage portion 108 is provided near the upper portion of 125.

The bypass set screw 110 reduces the passage cross-sectional area due to the annular gap formed between the measuring port 125 and the front end portion 122 by closing the measuring port 125 by a screwing operation (see FIGS. 20A and 20B). b)), conversely, the passage cross-sectional area is increased by opening the measuring port 125 by a retraction operation (see FIGS. 20C and 20D).
In the initial stage of use, the bypass set screw 110 is placed in a state where the passage cross-sectional area is adjusted so that the intake air flowing through the bypass passage 106, that is, idle air, becomes a predetermined amount (see FIG. 20B).
An example of this type of bypass set screw is an idle speed adjusting valve described in Patent Document 1.

JP 7-279696 A

  Incidentally, blow-back gas (for example, blow-by gas) from the combustion chamber of the internal combustion engine may flow into the bypass passage 106. Then, foreign matters such as oil, fuel (for example, gasoline), carbon, etc. contained in the blow-by gas adhere to the passage wall surfaces of the passage portions 107 and 108 of the bypass passage 106 and the surface of the valve portion 118 of the bypass set screw 110. It becomes a deposit by depositing. As the deposit increases, the amount of idle air decreases, and consequently the idle speed decreases. For this reason, it is necessary to readjust the idle air amount by screwing the bypass set screw 110 (see FIGS. 20C and 20D).

However, the valve portion 118 of the bypass set screw 110 opens and closes the measuring port 125 of the bypass passage 106 in the axis L direction by movement in the axial direction (vertical direction in FIG. 20A). Accordingly, the bypass passage 106 is opened and closed with the passage section 127 that forms a double tubular passage wall surface by the tip portion 122 and the metering port 125 of the valve portion 118 (see FIGS. 20B and 20D).
Thus, in the passage cross section 127 that forms the double tubular passage wall surface, the passage width (radial width) is narrowed, so the flow of idle air is likely to be impaired. That is, the flow coefficient decreases, and peeling phenomenon and stagnation are likely to occur. For this reason, deposits tend to adhere to the bypass passage 106 and the distal end portion 122 of the valve portion 118, and as a result, the frequency of idle adjustment of the bypass set screw 110 increases.
In addition, since the total area in contact with the air is large in the measuring portion including the tip portion 122 of the valve portion 118 and the metering port 125, deposits easily adhere to the tip portion 122 and the metering port 125 of the valve portion 118, and idle adjustment is performed. The frequency of increases.
If the frequency of adjusting the bypass set screw 110 is high, not only will the load on the user increase, but the screw on the screw side and the thread on the passage wall 109 side may be crushed due to erroneous operation of the bypass set screw 110 or the like. There is a risk of chipping. Furthermore, when it is severe, it is not preferable because parts on the bypass set screw 110 and / or the passage wall 109 side (for example, the throttle body 1 must be replaced).

  An object of the present invention is to provide a bypass set screw and a bypass passage that can reduce the frequency of idle adjustment by suppressing deposit adhesion.

The above-mentioned problem can be solved by a bypass set screw and a bypass passage having the structure described in the claims.
That is, according to the bypass set screw according to claim 1 of the claims, the valve portion opens and closes the bypass passage by screwing or screwing of the screw main body portion, so that the idle adjustment of the internal combustion engine can be performed.
By the way, since the valve portion opens and closes the bypass passage with a passage cross section forming a single tubular passage wall surface, idle air can flow smoothly, the flow coefficient increases, and the peeling phenomenon and stagnation are reduced. Thereby, adhesion of the deposit with respect to a valve part and a bypass passage can be controlled, and the frequency of idle adjustment of a bypass set screw can be reduced.

  According to the bypass set screw according to claim 2 of the claims, the valve portion bypasses with a passage cross section forming a single tubular passage wall surface by opening and closing the bypass passage in the caliber direction by movement in the axial direction. The passage can be opened and closed.

  According to the bypass set screw according to claim 3 of the claims, the valve section forms a single tubular passage wall surface by opening and closing the bypass passage in the caliber direction by pivoting around the axis. Can open and close the bypass passage.

In addition, according to the bypass set screw according to claim 4 of the claims, the adhesion of deposits to the valve portion can be suppressed by the oil-repellent coating applied to the valve portion.
Further, if the coating having water repellency has lubricity, it is effective for improving the operability of the valve portion and suppressing wear of the sliding portion due to the operation of the valve portion.

According to the bypass set screw according to claim 5 of the claims, the valve body is moved in the axial direction in conjunction with the screwing or screwing of the screw body, and the bypass passage is opened and closed, whereby the internal combustion engine. Idle adjustment can be performed.
By the way, since the valve body opens and closes the bypass passage with a passage cross section forming a single tubular passage wall surface, idle air can flow smoothly, the flow coefficient increases, and the peeling phenomenon and stagnation are reduced. Thereby, adhesion of deposit to the valve body and the bypass passage can be suppressed, and the frequency of idle adjustment of the bypass set screw can be reduced.

  According to the bypass set screw according to claim 6 of the claims, since the valve body is tilted with a predetermined declination by the tilting means, the tip of the valve body is eccentrically brought into contact with the passage wall surface. Thereby, adhesion of the deposit with respect to the clearance gap between a valve body and a channel | path wall surface can be suppressed. At the same time, rattling of the valve body due to vibration or the like can be suppressed.

In addition, according to the bypass set screw according to claim 7 of the claims, the adhesion of deposits to the valve body can be suppressed by the oil-repellent coating applied to the valve body.
Further, if the coating having water repellency has lubricity, it is effective for improving the operability of the valve body and suppressing wear of the sliding portion due to the operation of the valve body.

Further, according to the bypass passage according to claim 8 of the claims, the oil-repellent coating applied to the passage wall surface suppresses the adhesion of deposits to the passage wall surface and reduces the frequency of idle adjustment of the bypass set screw. can do.
Moreover, if the coating having water repellency has lubricity, it is effective for improving the operability of the bypass set screw and for suppressing the wear of the sliding portion due to the operation of the bypass set screw.

  Moreover, according to the bypass passage concerning Claim 9 of a claim, providing a bypass passage provided with the bypass set screw which has an effect | action and effect as described in any one of Claims 1-7 is provided. it can.

  According to the bypass set screw and the bypass passage of the present invention, the frequency of idle adjustment of the bypass set screw can be reduced by suppressing the adhesion of deposits.

  Next, the best mode for carrying out the present invention will be described with reference to examples.

A first embodiment of the present invention will be described. As shown in FIG. 1, an intake passage 2 is formed in the throttle body 1. The throttle body 1 forms a series of intake passages that communicate with the internal combustion engine together with an intake manifold and a surge tank (not shown). Further, the intake air flows in the intake passage 2 in a predetermined direction (for example, see the arrow Y1 in FIG. 1).
Further, the throttle body 1 is provided with a throttle shaft 3 penetrating the intake passage 2 so as to be rotatable. A plate-like throttle valve 4 that opens and closes the intake passage 2 is fixed to the throttle shaft 3 with a screw 5. The throttle valve 4 is opened and closed in conjunction with the accelerator operation of the vehicle.

The throttle body 1 is provided with a bypass passage 6 that bypasses the throttle valve 4. The bypass passage 6 extends in the lateral direction (rightward in FIG. 1) from the center portion of the vertical passage portion 8, which joins the intake passage 2 in an inverted T shape downstream of the throttle valve 4. The side passage portion 7 branches from the intake passage 2 on the upstream side of the throttle valve 4.
In the idling state of the internal combustion engine, the throttle valve 4 is closed to an idling opening amount of a predetermined air amount, so that the intake air flowing through the intake passage 2 is a lateral passage portion of the bypass passage 6 as shown by an arrow Y2 in FIG. 7 flows to the intake passage 2 through the vertical passage portion 8. The intake air flowing through the bypass passage 6 is referred to as “idle air”.

The bypass wall 6 of the bypass passage 6 of the throttle body 1 is provided with a bypass set screw 10 for adjusting the amount of intake air flowing through the bypass passage 6 (referred to as idle air amount).
On the passage wall 9 where the bypass set screw 10 is provided, as shown in FIG. 2A, on the axis L of the vertical passage portion 8 of the bypass passage 6, a female screw hole 12 extending above the vertical passage portion 8, And the attachment hole 13 extended above the internal thread hole 12 is formed. The mounting hole 13 is formed with a larger hole diameter than the female screw hole 12.

As shown in FIG. 2A, the bypass set screw 10 has a screw main body 15 and a valve portion 18 extending below the screw main body 15 on the same axis L. .
The screw main body portion 15 has a head portion 16 and a screw shaft portion 17 continuous below the head portion 16 on the same axis L. The head portion 16 is formed with an outer diameter that can be fitted into the mounting hole 13 of the bypass passage 6. On the upper surface of the head 16, an engagement groove 19 that can engage a tool such as a flathead screwdriver is formed. An annular groove 20 is formed on the outer peripheral surface of the head 16. An O-ring (O-ring) 21 for sealing is attached to the annular groove 20. The screw shaft portion 17 is formed so as to be able to be screwed into the female screw hole 12 of the bypass passage 6.
The valve portion 18 is formed in a cylindrical shaft shape having an outer diameter that can be inserted almost densely into the vertical passage portion 8 of the bypass passage 6. The lower end portion of the valve portion 18 is a distal end portion 22 having a flat distal end surface 23 orthogonal to the axis L (see FIG. 2 (e)).

  2A, in the bypass set screw 10, the valve portion 18 is inserted into the vertical passage portion 8 of the bypass passage 6 through the mounting hole 13 and the female screw hole 12, and the screw shaft portion 17 is inserted into the female screw hole 12. And is provided on the passage wall 9 of the throttle body 1. The head portion 16 is positioned in the attachment hole 13 of the bypass passage 6, and the space between the head portion 16 and the hole wall surface of the attachment hole 13 is sealed by an O-ring 21.

The bypass set screw 10 is moved downward by the screwing operation of the screw main body 15 from the state shown in FIG. Thereby, the front-end | tip part 22 of the valve | bulb part 18 closes the opening end surface, ie, a measurement opening | mouth (code | symbol, 25) of the horizontal channel | path part 7 of the bypass channel 6, ie, reduces a channel cross-sectional area (FIG. , (B)).
On the other hand, the screw body 15 is moved upward by the screwing operation from the state of FIG. Thereby, the front-end | tip part 22 of the valve | bulb part 18 opens the measurement opening | mouth 25 of the side passage part 7 of the bypass passage 6, ie, a passage cross-sectional area is increased (refer FIG.2 (c), (d)).
Thus, the measuring port 25 of the bypass passage 6 is opened and closed by the axial movement (the vertical movement in FIG. 2A) of the valve section 18 by the screwing or screwing of the screw body section 15. As a result, the amount of idle air flowing through the bypass passage 6 can be adjusted, and consequently the idle adjustment of the internal combustion engine can be performed.

In the initial stage of use, the bypass set screw 10 is adjusted so that the amount of idle air flowing through the bypass passage 6 becomes a predetermined amount (see FIGS. 2A and 2B).
When the deposit is attached to the passage wall surfaces of the passage portions 7 and 8 of the bypass passage 6 and the surface of the valve portion 18 of the bypass set screw 10 by use, and the deposit increases, the amount of idle air decreases. As a result, the idling speed decreases. For this reason, the idle air amount may be readjusted by screwing the bypass set screw 10 (see FIGS. 2C and 2D). Thereby, the idle adjustment of the internal combustion engine can be performed.

According to the bypass set screw 10 described above, the passage cross-section forming a single tubular passage wall surface by the tip surface 23 of the tip portion 22 of the valve portion 18 and the metering port 25 (reference numerals in FIGS. 2B and 2D) The bypass passage 6 is opened and closed. For this reason, compared with a prior art example (refer FIG. 20 (a)-(d)), idle air can flow smoothly, a flow coefficient rises, and a peeling phenomenon and stagnation decrease. Thereby, adhesion of deposits to the valve portion 18 (specifically, the surface of the tip portion 22) and the bypass passage 6 (specifically, the wall surface of the passage) can be suppressed, and the frequency of idle adjustment of the bypass set screw 10 can be reduced. .
In addition, according to the present embodiment, compared with the conventional example (see FIGS. 20A to 20D), the total area in contact with air is reduced in the measuring portion including the tip portion 22 of the valve portion 18 and the measuring port 25. can do. Also by this, it is possible to suppress deposits from adhering to the distal end portion 22 of the valve portion 18 and the metering port 25 and to reduce the frequency of idle adjustment of the bypass set screw 10.

FIG. 3 shows the relationship between the elapsed time for use and the amount of idle air. In FIG. 3, the horizontal axis indicates the elapsed time, and the vertical axis indicates the idle air amount. The characteristic line A in FIG. 3 shows the characteristic according to this embodiment, and the characteristic line B shows the characteristic according to the conventional example.
As is apparent from FIG. 3, according to the present embodiment (see characteristic line A), the idle air amount is less decreased due to deposit adhesion with the passage of time than in the conventional example (see characteristic line B). Lowering of the required flow rate to the lowest line is delayed. Therefore, since the time until readjustment is required is delayed to point b as compared to point a in the conventional example, the frequency of idle adjustment of the bypass set screw can be reduced.

  Further, the valve portion 18 opens and closes the measuring port 25 of the bypass passage 6 in the diametrical direction by moving in the axial direction (moving up and down in FIGS. 2A and 2C), thereby forming a single tubular passage wall surface. The bypass passage 6 can be opened and closed with a passage section 27 (see FIGS. 2B and 2D).

A second embodiment of the present invention will be described. In addition, since a present Example adds a change to a part of said Example 1 (refer FIG. 2 (a)-(e)), a changed part is demonstrated and the overlapping description is abbreviate | omitted. In the following embodiments, the same description will be omitted.
As shown in FIG. 4 (e), the present embodiment is a cross-sectional view of the side portion of the tip 22 of the valve portion 18 in the bypass set screw 10 of the first embodiment (see FIGS. 2 (a) to 2 (e)). A split-shaped recess 30 is formed (see FIGS. 4A, 4B, 4C, and 4D).

The bypass set screw 10 is rotated about 90 ° in the direction around the axis (for example, clockwise in the plane) by the screwing operation of the screw main body 15 from the state shown in FIG. Thereby, the front-end | tip part 22 of the valve | bulb part 18 closes the measurement port 25 of the bypass passage 6, ie, reduces a passage cross-sectional area (refer FIG. 4 (a), (b)).
Conversely, the screw main body 15 is turned about 90 ° in the direction around the axis (for example, counterclockwise in the plane) by the screwing operation of the screw main body 15 from the state of FIG. Thereby, the front-end | tip part 22 of the valve | bulb part 18 opens the measurement opening | mouth 25 of the side passage part 7 of the bypass passage 6, ie, a passage cross-sectional area is increased (refer FIG.2 (c), (d)).
Thus, the metering port 25 of the bypass passage 6 is opened and closed by the rotation of the valve portion 18 in the direction around the axis by the screwing or screwing of the screw main body 15. As a result, the amount of idle air flowing through the bypass passage 6 can be adjusted, and consequently the idle adjustment of the internal combustion engine can be performed.

In the initial stage of use, the bypass set screw 10 is adjusted so that the amount of idle air flowing through the bypass passage 6 becomes a predetermined amount (see FIGS. 4A and 4B).
When the deposit is attached to the passage wall surfaces of the passage portions 7 and 8 of the bypass passage 6 and the surface of the valve portion 18 of the bypass set screw 10 by use, and the deposit increases, the amount of idle air decreases. As a result, the idling speed decreases. For this reason, the idle air amount may be readjusted by screwing the bypass set screw 10 (see FIGS. 4C and 4D). Thereby, the idle adjustment of the internal combustion engine can be performed.

According to the bypass set screw 10 described above, the passage cross section (FIGS. 4B, 4C, and 4D) that forms a single tubular passage wall surface by the recess 30 and the metering port 25 of the distal end portion 22 of the valve portion 18. ) Is designated by reference numeral 32. The bypass passage 6 is opened and closed.
Therefore, the same functions and effects as those of the first embodiment (see FIGS. 2A to 2E) can be obtained by the bypass set screw 10 of the present embodiment.

A passage section 32 (FIGS. 4B, 4C, and 4D) that forms a single-walled passage wall surface by opening and closing the bypass passage 6 in the diametrical direction by the valve portion 18 turning around the axis. The bypass passage 6 can be opened and closed.
Further, since the valve portion 18 opens and closes the bypass passage 6 in the diametrical direction by turning around the axis, the bypass passage 6 is compared with the first embodiment (see FIGS. 2A to 2D). The amount of operation of the screw main body 15 required to open and close the measuring port 25 is small.

  A third embodiment of the present invention will be described. In the present embodiment, as shown in FIG. 5 (e), the shape of the recess 30 of the second embodiment (see FIGS. 4 (a) to 4 (e)) is changed to a recess 34 having a U-shaped cross section. It is. (See FIGS. 5A, 5B, 5C and 5D).

Similarly to the second embodiment (see FIGS. 4 (a) to 4 (d)), the bypass set screw 10 described above also has a single tubular shape due to the recess 34 and the metering port 25 of the distal end portion 22 of the valve portion 18. The bypass passage 6 is opened and closed with a passage cross section forming the passage wall surface (reference numeral 36 is attached to FIGS. 5B, 5C, and 5D).
Therefore, the same operation and effect as the second embodiment (see FIGS. 4A to 4D) can be obtained by the bypass set screw 10 of the present embodiment.
In addition, according to the present embodiment, the tip of the valve portion 18 is compared with the first embodiment (see FIGS. 2A to 2E) and the second embodiment (see FIGS. 4A to 4E). In the measuring part including the part 22 and the measuring port 25, the total area in contact with air is increased by the formation of the recess 34. However, it is assumed that the volume in the recess 34 is secured so that the amount of idle air is affected even if deposit is attached to the wall surface of the passage in the recess 34.

  Embodiment 4 of the present invention will be described. In this embodiment, as shown in FIG. 6 (e), the tip 22 of the valve portion 18 in the bypass set screw 10 of the first embodiment (see FIGS. 2 (a) to 2 (e)) An open hollow portion 38 is formed. Furthermore, an opening groove 39 that opens the hollow portion 38 is formed on the side surface of the distal end portion 22. That is, the shape of the recess 30 of the second embodiment (see FIGS. 4A to 4E) is changed to a composite recess having a hollow portion 38 and an opening groove 39 (FIG. 6A). , (B), (c), (d)).

Also with the above-described bypass set screw 10, similarly to the second embodiment (see FIGS. 4A to 4D), a recessed portion having a composite shape formed by the hollow portion 38 and the opening groove 39 of the distal end portion 22 of the valve portion 18. And the metering port 25 open and close the bypass passage 6 with a passage cross section forming a single tubular passage wall surface (reference numeral 40 is attached to FIGS. 6B and 6D).
Therefore, the same operation and effect as the second embodiment (see FIGS. 4A to 4D) can be obtained by the bypass set screw 10 of the present embodiment.
In addition, also in the present Example, the said Example 1 (refer FIG. 2 (a)-(e)) and the said Example 2 (FIG. 5) like the said Example 3 (refer FIG. 5 (a)-(e)). 4 (a) to 4 (e)), the total area in contact with air in the measuring portion by the tip portion 22 and the measuring port 25 of the valve portion 18 is widened by the formation of the hollow portion 38. However, it is assumed that the volume in the hollow portion 38 is secured so that the amount of idle air is affected even if deposit is attached to the wall surface of the passage in the hollow portion 38.

  A fifth embodiment of the present invention will be described. In this embodiment, as shown in FIG. 7 (e), instead of the opening groove 39 of the valve portion 18 in the bypass set screw 10 of the embodiment 4 (see FIGS. 6 (a) to (e)), a circular shape is used. Opening holes 42 are formed (see FIGS. 6A, 6B, 6C, and 6D).

Also with the above-described bypass set screw 10, similarly to the fourth embodiment (see FIGS. 6A to 6D), a recess having a composite shape formed by the hollow portion 38 and the opening hole 42 of the distal end portion 22 of the valve portion 18. And the metering port 25 open and close the bypass passage 6 with a passage cross-section (denoted by reference numeral 43 in FIGS. 7B and 7D) forming a single tubular passage wall surface.
Therefore, the same operation and effect as the fourth embodiment (see FIGS. 6A to 6D) can be obtained by the bypass set screw 10 of the present embodiment.

Embodiment 6 of the present invention will be described. As shown in FIG. 8E, the present embodiment is flat on the lower end portion of the distal end portion 22 of the valve portion 18 in the bypass set screw 10 of the first embodiment (see FIGS. 2A to 2E). Instead of the leading end surface 23, a hemispherical leading end surface 45 is formed.
Further, the vertical passage portion 8 of the bypass passage 6 in the first embodiment (see FIGS. 2A to 2D) is communicated with the horizontal passage portion 7 so as to be continuous (FIG. 8 ( a) and (c)).

Similarly to the first embodiment (see FIGS. 2A to 2D), the bypass set screw 10 described above also has a single tubular shape due to the distal end surface 45 of the distal end portion 22 of the valve portion 18 and the measuring port 25. The bypass passage 6 is opened and closed with a passage cross section forming the passage wall surface (reference numeral 46 is attached to FIGS. 8B and 8D).
Therefore, the same operation and effect as in the first embodiment (see FIGS. 2A to 2D) can be obtained also by the bypass set screw 10 of the present embodiment.
Further, since the hemispherical tip surface 45 is formed at the tip portion 22 of the valve portion 18, idle air can flow more smoothly around the tip surface 45, the flow rate coefficient increases, peeling phenomenon and stagnation Less. This is effective for suppressing deposit adhesion to the valve portion 18 and the bypass passage 6.
Further, since the vertical passage portion 8 of the bypass passage 6 is continuous with the horizontal passage portion 7, the idle air can flow smoothly from the horizontal passage portion 7 to the vertical passage portion 8, the flow coefficient increases, and the separation occurs. The phenomenon and stagnation are reduced. This is effective for suppressing deposit adhesion to the valve portion 18 and the bypass passage 6.
In addition, the bypass set screw 10 of a present Example is applicable also to the bypass path 6 in the said Example 1 (refer FIG. 2 (a)-(d)).

A seventh embodiment of the present invention will be described. In this embodiment, as shown in FIGS. 9 and 10A, a bypass set screw (reference numeral 47) is a two-body structure of a screw body 48 and a valve body 49.
As shown in FIGS. 11A and 11B, the screw main body 48 has the same axis L as the head 16 and the screw shaft portion 17 as in the first embodiment (see FIGS. 2A to 2E). Have on. An extension shaft portion 50 that forms the same axis L is formed at the lower end portion of the screw body 48. A columnar engagement convex portion 51 having the same axis L is projected from the lower end surface of the extending shaft portion 50 (see FIGS. 11B and 11C).

  Further, as shown in FIGS. 12B and 12D, the valve body 49 is mainly formed of the same valve portion 18 as that of the first embodiment (see FIGS. 2A to 2E). . The distal end surface of the distal end portion 22 of the valve portion 18 is formed as a convex curved inclined surface 53 (see FIG. 12B). Moreover, the flange part 54 which protrudes on the outer periphery is formed in the upper end part of the valve | bulb part 18 (refer FIG. 12 (a)-(d)). The flange portion 54 is formed with an outer diameter substantially the same as the outer diameter of the extending shaft portion 50 (see FIG. 11B) of the screw body 48. A hollow cylindrical engaging recess 55 having the same axis L is formed on the upper end surface of the valve portion 18 (see FIGS. 12A and 12B). Moreover, the linear protrusion 56 extended in the axis line L direction is formed in the side surface of the upper half part of the valve | bulb part 18 (refer FIG.12 (b), (c), (d)).

Further, as shown in FIGS. 10 (a) and 10 (c), a convex strip 56 of the valve body 49 is slidably engaged with the upper end portion of the vertical passage portion 8 in the longitudinal direction (vertical direction in the drawing). A groove 58 is formed. The groove 58 is formed on the wall surface of the vertical passage portion 8 on the side of the horizontal passage portion 7 (the right side in FIGS. 10A and 10C).
Further, an intermediate hole 59 having a step surface 59a at the lower end is formed between the vertical passage portion 8 and the female screw hole 12.

The valve body 49 rotates in the direction around the axis by inserting the valve portion 18 into the vertical passage portion 8 of the bypass passage 6 through the mounting hole 13 and the female screw hole 12 and engaging the protrusion 56 with the groove 58. It is provided so as to be movable in the axial direction (vertical direction in FIGS. 10A and 10C) in a stopped state. At the same time, the convex curved inclined surface 53 of the valve body 49 faces the vertical passage portion 8 and the horizontal passage portion 7 of the bypass passage 6 in an inclined state. Further, the extending shaft portion 50 and the flange portion 54 are fitted into the intermediate hole 59 of the passage wall 9 in a loose fit.
A coil spring 60 is interposed between the step surface 59 a of the intermediate hole 59 and the flange portion 54 of the valve body 49. The coil spring 60 is fitted to the valve portion 18 and always urges the valve body 49 toward the screw body 48, that is, upward.

  Next, as shown in FIGS. 10A and 10C, the screw body 48 is engaged with the passage wall 9 of the throttle body 1 by screwing the screw shaft portion 17 into the female screw hole 12 of the passage wall 9. Is provided. The screw body 48 compresses the coil spring 60 by pressing the valve body 49 downward. Further, the engagement concave portion 55 of the valve body 49 is engaged with the engagement convex portion 51 of the screw body 48 so as to be rotatable about the axis. Accordingly, the valve body 49 can move in the axial direction (vertical direction in FIGS. 10A and 10C) in conjunction with the screwing or screwing of the screw body 48.

In the bypass set screw 47, the screw body 48 is screwed from the state shown in FIG. 10C, so that the valve body 49 is prevented from rotating about the axis by the ridge 56 and the groove 58. Moved. Thereby, the front-end | tip part 22 of the valve body 49 closes the measurement opening | mouth 25 of the horizontal passage part 7 of the bypass passage 6, ie, reduces a passage cross-sectional area (refer FIG. 10 (a), (b)).
On the other hand, in the state where the valve body 49 is prevented from rotating about the axis by the protrusion 56 and the groove 58 by the screwing operation of the screw main body 48 from the state of FIG. Is moved upward by the elastic restoring force of the coil spring 60. Thereby, the front-end | tip part 22 of the valve body 49 opens the measurement opening | mouth 25 of the horizontal channel | path part 7 of the bypass channel 6, ie, increases a channel cross-sectional area (refer FIG.10 (c), (d)).
In this way, the valve body 49 is moved in the axial direction in conjunction with the screwing or screwing of the screw main body 15 (moving up and down in FIGS. 10A and 10C), whereby the bypass passage 6 The measuring port 25 is opened and closed. As a result, the amount of idle air flowing through the bypass passage 6 can be adjusted, and consequently the idle adjustment of the internal combustion engine can be performed.

According to the bypass set screw 47 described above, the passage cross section forming the single tubular passage wall surface by the inclined surface 53 of the tip end portion 22 of the valve body 49 and the measuring port 25 (reference numerals in FIGS. 10B and 10D) The bypass passage 6 is opened and closed. For this reason, compared with a prior art example (refer FIG. 20 (a)-(d)), idle air can flow smoothly, a flow coefficient rises, and a peeling phenomenon and stagnation decrease. Thereby, deposit adhesion to the valve body 49 (specifically, the surface of the tip portion 22) and the bypass passage 6 (specifically, the passage wall surface) can be suppressed, and the frequency of idle adjustment of the bypass set screw 47 can be reduced. .
In addition, compared with the conventional example, the total area in contact with air can be reduced in the measuring portion including the distal end portion 22 of the valve body 49 and the measuring port 25. Also by this, it is possible to suppress deposits from adhering to the distal end portion 22 of the valve portion 18 and the metering port 25 and to reduce the frequency of idle adjustment of the bypass set screw 10.

  Further, the valve body 49 opens and closes the measuring port 25 of the bypass passage 6 in the diametrical direction by moving in the axial direction (up and down movement in FIGS. 10A and 10C), thereby forming a single tubular passage wall surface. The bypass passage 6 can be opened and closed with the passage section 62 (see FIGS. 2B and 2D).

Further, since the tip end portion 22 of the valve body 49 is formed with a convex curved inclined surface 53 that faces the vertical passage portion 8 and the horizontal passage portion 7 of the bypass passage 6 in an inclined state, idle air is laterally transmitted. It can flow smoothly from the passage portion 7 to the longitudinal passage portion 8, the flow coefficient is increased, and the peeling phenomenon and stagnation are reduced. This is effective in suppressing deposit adhesion to the valve body 49 and the bypass passage 6.
The convex curved inclined surface 53 of the distal end portion 22 is a flat surface perpendicular to the axis L, like the distal end portion 22 of the valve body 49 in the first embodiment (see FIGS. 2A to 2E). It is possible to replace the leading end surface 23. Further, the convex curved inclined surface 53 of the distal end portion 22 is formed into a spherical distal end surface 45 like the distal end portion 22 of the valve body 49 in the sixth embodiment (see FIGS. 8A to 8E). Can be replaced.

Embodiment 8 of the present invention will be described. In this embodiment, as shown in FIG. 13E, the convex curved inclined surface 53 of the valve body 49 in the bypass set screw 47 of the seventh embodiment (see FIGS. 10A to 10D) is used. Instead, a flat inclined surface 63 is formed (see FIGS. 13A, 13B, 13C, and 13D).
According to the bypass set screw 10 of the present example, the passage cross-section that forms a single tubular passage wall surface by the inclined surface 63 of the distal end portion 22 of the valve body 49 and the metering port 25 (reference numerals in FIGS. 13B and 13D). , 64), the bypass passage 6 is opened and closed.
Accordingly, the bypass set screw 10 of the present embodiment can provide the same operations and effects as those of the seventh embodiment (see FIGS. 10A to 10D).

Embodiment 9 of the present invention will be described. In the present embodiment, as shown in FIG. 14 (e), the inclined surface 53 of the tip 22 of the valve body 49 in the bypass set screw 47 of the seventh embodiment (see FIGS. 10 (a) to 10 (d)), It replaces with the flat front end surface 65 orthogonal to the axis L (refer Fig.14 (a)).
Moreover, the hollow part 66 opened to the front end surface 23 is formed in the front-end | tip part 22 of the valve body 49 similarly to the hollow part 38 of the front-end | tip part 22 in the said Example 5 (refer Fig.7 (a)-(e)). Has been. Further, a vertically long opening hole 67 that opens the hollow portion 66 is formed on the side surface of the distal end portion 22 (see FIGS. 14A, 14B, 14C, and 14D).

According to the bypass set screw 47 described above, a passage that forms a single tubular passage wall surface by the opening hole 67 and the metering port 25 of the tip 22 of the valve body 49 and the tip surface 65 and the metering port 25 of the tip 22. The bypass passage 6 is opened and closed with a cross section (the reference numeral 68 is attached to FIGS. 14B and 14D).
Accordingly, the bypass set screw 47 of this embodiment can provide the same operations and effects as those of the seventh embodiment (see FIGS. 10A to 10D).
In addition, according to the present Example, compared with the said Example 7 (refer FIG. 10 (a)-(d)) and the said Example 8 (refer FIG. 13 (a)-(e)), the front-end | tip of the valve | bulb body 49. FIG. In the measuring part by the part 22 and the measuring port 25, the total area in contact with air is widened by the formation of the hollow part 66. However, it is assumed that the volume in the hollow portion 66 is secured so that the amount of idle air is affected even if deposit is attached to the wall of the passage in the hollow portion 66.

A tenth embodiment of the present invention will be described. In this embodiment, as shown in FIG. 15 (e), instead of the opening hole 67 of the valve body 49 in the bypass set screw 47 of the embodiment 9 (see FIGS. 14 (a) to (e)), a circular shape is used. An opening hole 69 is formed (see FIGS. 15A, 15B, 15C, and 15D).
According to the bypass set screw 10 of the present example, the passage cross section forming the single tubular passage wall surface by the opening hole 69 and the metering port 25 of the distal end portion 22 of the valve body 49 (reference numerals in FIGS. 15B and 15D). 70, the bypass passage 6 is opened and closed.
Therefore, also by the bypass set screw 10 of the present embodiment, the same operation and effect as those of the ninth embodiment (see FIGS. 14A to 14E) can be obtained.

Embodiment 11 of the present invention will be described. In this embodiment, as shown in FIGS. 16A and 16C, the vertical passage portion 8 of the bypass passage 6 in the seventh embodiment (see FIGS. 10A to 10E) is replaced with the horizontal passage portion 7. Are communicated to form a continuous shape.
Accordingly, the bypass set screw 47 of this embodiment can provide the same operations and effects as those of the seventh embodiment (see FIGS. 10A to 10D).
Further, since the vertical passage portion 8 of the bypass passage 6 is continuous with the horizontal passage portion 7, the idle air can flow smoothly from the horizontal passage portion 7 to the vertical passage portion 8, the flow coefficient increases, and the separation occurs. The phenomenon and stagnation are reduced. This is effective in suppressing deposit adhesion to the valve body 49 and the bypass passage 6.

A twelfth embodiment of the present invention will be described. In the present embodiment, as shown in FIG. 17A, the valve body 49 of the bypass set screw 47 in the seventh embodiment (see FIGS. 10A to 10D) is tilted with a predetermined deviation angle θ. Is.
That is, a hemispherical projection 71 is projected from the upper end surface of the valve body 49 (see FIG. 17B). The protrusion 71 is formed at a position eccentric to the side passage portion 7 side. As shown in FIG. 17B, the projecting portion 71 contacts the lower end surface 48a of the screw body 48, thereby tilting the valve body 49 with a predetermined deviation angle θ (see FIG. 17A). The protrusion 71 corresponds to the “tilting means” in this specification. Further, it is assumed that the valve body 49 is inclined by utilizing a gap formed between the valve portion 18 and the vertical passage portion 8.
As a result, as shown in FIG. 17C, the distal end portion (lower end portion) of the distal end portion 22 of the valve body 49 comes into contact with the passage wall surface (reference numeral 8a) of the longitudinal passage portion 8.

According to the bypass set screw 47 of the present embodiment, the valve body 49 is inclined with the predetermined deviation angle θ by the projection 71, so that the distal end portion 49 a of the valve body 49 comes into contact with the passage wall surface 8 a of the vertical passage portion 8. . Thereby, the adhesion of the deposit to the gap between the valve body 49 and the passage wall surface 8a can be suppressed. At the same time, rattling of the valve body 49 due to vibration or the like can be suppressed.
The protrusion 71 can be provided on the lower end surface of the screw body 48 instead of the valve body 49. Further, as the tilting means, in addition to the protrusion 71, an inclined surface 53 formed on the upper end surface of the valve body 49 or the lower end surface of the screw body 48, and between the upper end surface of the valve body 49 and the lower end surface of the screw body 48. It is conceivable to use an interposed spacer or the like.

  A thirteenth embodiment of the present invention will be described. In this embodiment, as shown in FIG. 18, the surface of the valve body 49 in the bypass set screw 47 of the embodiment 7 (see FIGS. 10A to 10D) has an oil-repellent coating (see FIG. 18). (Refer to the colored portion). In addition, as coating, fluororesin coating, such as PTFE, PFA, FEP, can be considered, for example.

According to the bypass set screw 47 of the present embodiment, deposits on the valve body 49 can be suppressed by the oil-repellent coating applied to the valve body 49.
Further, since the fluororesin coating has lubricity, it is effective for improving the operability of the valve body 49 and suppressing wear of the sliding portion due to the operation of the valve body 49.

In addition, the coating having water repellency may be applied to at least the surface of the tip portion 22 of the valve body 49.
Moreover, the valve part 18 of the bypass set screw 47 in Examples 1 to 6 or the valve body 49 of the bypass set screw 47 in Examples 8 to 12 can be coated with water repellency.

  Embodiment 14 of the present invention will be described. In the present embodiment, as shown in FIG. 19, a coating having oil repellency is provided on the passage wall surface of each passage portion 7, 8 in the bypass passage 6 of the seventh embodiment (see FIGS. 10A to 10D). The colored portion in FIG. 19 is applied). In addition, as coating, fluororesin coating, such as PTFE, PFA, FEP, can be considered, for example.

According to the bypass passage 6 of the present embodiment, the oil-repellent coating applied to the passage wall surfaces of the passage portions 7 and 8 suppresses adhesion of deposits to the passage wall surfaces, and the frequency of idle adjustment of the bypass set screw 47 is reduced. Can be reduced.
Further, since the fluororesin coating has lubricity, it is effective for improving the operability of the bypass set screw 47 and suppressing wear of the sliding portion due to the operation of the bypass set screw 47.
Further, according to the present embodiment, the bypass passage 6 including the bypass set screw 47 having the effects and effects described in the seventh embodiment (see FIGS. 10A to 10D) can be provided.

In addition, the coating having water repellency may be applied to at least the peripheral portion of the distal end portion 22 of the passage wall surfaces of the passage portions 7 and 8.
In addition, by applying a water-repellent coating to the passage wall surfaces of the passage portions 7 and 8 of the bypass passage 6 in Examples 1 to 6 and 8 to 12, the examples 1 to 6 and 8 to 12 are applied. It is possible to provide the bypass passage 6 including the bypass set screw 10 (or 47) that exhibits the described operations and effects.

  Further, the bypass set screw 10 and the bypass passage 6 according to each of the above-described embodiments are suitable for a motorcycle using fuel injection as a fuel supply device in a vehicle.

A fifteenth embodiment of the present invention will be described. In this example, a deposit adhesion test was performed according to the shape of the tip of the bypass set screw.
First, a bypass set screw 10 (see FIGS. 1 and 2A to 2E) that opens and closes a bypass passage with a passage section forming a single tubular passage wall surface described in the first embodiment is a sample 10A. .
Further, the bypass set screw 47 (see FIGS. 9 and 10A to 10D) that opens and closes the bypass passage with the passage section forming the single tubular passage wall surface described in the seventh embodiment is referred to as a sample 47B. .
Further, three bypass set screws 110 (see FIGS. 20 (a) to (d)) that open and close the bypass passage with a passage cross section forming a double tubular passage wall surface described in the conventional example are used as samples 110C1, 110C2, 110C3.

  The samples 10A, 47B, 110C1, 110C2, and 110C3 are set in a dummy body having a bypass passage, and the exhaust gas of the engine using a fuel containing a solvent that easily causes a deposit is caused to flow through the bypass passage of the dummy body. A test was conducted. And the change of the amount of bypass air which flows through a bypass passage was measured for every predetermined time (in this example, every hour). The samples 10A, 47B, 110C1, 110C2, and 110C3 have the same conditions except that the shape of the tip is different.

When the results of the deposit adhesion test are summarized, the characteristic diagram shown in FIG. 21 is obtained. In FIG. 21, the horizontal axis indicates the test time [hr], and the vertical axis indicates the bypass air amount [m ³ / h].
In FIG. 21, a characteristic line A1 including a point ◯ indicates a measurement result by the sample 10A, and a characteristic line A2 including a point Δ indicates a measurement result by the sample 47A. A characteristic line B1 including a point ● indicates a measurement result by the sample 110C1, a characteristic line B2 including a point ▲ indicates a measurement result by the sample 110C2, and a characteristic line B3 including the point ■ indicates a measurement result by the sample 110C3. Yes.

As is clear from FIG. 21, with the passage of time, the decrease (decrease) in the amount of bypass air is large for the samples 110C1, 110C2, and 110C3 in a relatively short time, whereas the samples 10A and 47B are considerably long. It can be seen that there is almost no decrease in the amount of bypass air over time.
Therefore, according to the samples 10A and 47B, there is almost no deposit on the valve portion, and the frequency of idle adjustment of the bypass set screws 10 and 47 can be greatly reduced, so-called life extension effect is improved by about 2 to 3 times. can do. For example, for samples 110C1, 110C2, and 110C3, if idle adjustment is required every 4 hours in the test time, according to samples 10A and 47B, only idle adjustment is required every 12 hours in the test time.
Further, if the samples 10A and 47B (that is, the bypass set screws 10 and 47 that open and close the bypass passage with a passage section forming a single tubular passage wall surface), it can be determined that there is almost no difference in the life extension effect. . However, as the test time becomes longer, the sample 47B can obtain better results than the sample 10A.

Further, based on the test result (see FIG. 21) of the deposit adhesion test, the relationship between the deposit thickness due to the deposit adhesion and the passage area was examined on a desk, and the characteristic diagram shown in FIG. 22 was obtained. In FIG. 22, the horizontal axis represents the deposit thickness [mm], and the vertical axis represents the passage area [mm ² ] in the passage control unit by the bypass set screw.
Further, in this case, the inner diameter of the vertical passage portion 8 (see FIG. 1) of the bypass passage 6 of the first embodiment in which the negative pressure is 60 kPa and the flow rate is 1.7 m ³ / h is φ1.8 mm. In addition, let passage sectional area S of the longitudinal passage part 8 be an area in a state where the bypass set screw 10 is omitted.
On the other hand, the passage cross-sectional area forming the double-circular tubular passage wall surface in the vertical passage portion 108 of the bypass passage 106 of the conventional example (see FIGS. 20A to 20D) is the passage cross-sectional area S of the sample 6A. Same as At this time, if the diameter d ₁ of the outer wall surface in the double-circular tubular passage wall surface is φ3.5 mm, the diameter d ₂ of the inner wall surface in the double-circular passage wall surface is calculated by the following equation.
S = π (1.8 / 2) ²
S = π {(3.5 / 2 ) 2 - (d 2/2) 2}
d ₂ = 3.00017

In FIG. 22, a characteristic line C indicated by a solid line indicates a result of desk study using the sample 6A, and a characteristic line D indicated by a dotted line indicates the result of desk study by the sample 106C.
As is clear from FIG. 21, it is considered that the passage area of the sample 106C (refer to the characteristic line D) decreases as the deposit thickness increases. On the other hand, regarding the sample 6A (see the characteristic line C), it is considered that the reduction in the passage area is small even if the deposit deposition thickness is increased. From this, according to the sample 6A, it is presumed that the reduction (decrease) in the amount of bypass air due to deposit adhesion can be reduced.

Next, an example of a motorcycle internal combustion engine system to which the bypass set screw 10 of the first embodiment is applied will be described.
As shown in FIG. 23, the engine system mounted on a motorcycle includes a fuel tank 210 that stores fuel. A fuel pump 211 disposed in the fuel tank 210 sucks and pressurizes fuel stored in the fuel fuel tank 210 through a fuel filter 212 and discharges the fuel to an injector 216 (described later). Note that the pressure of the fuel supplied to the injector 216 is adjusted to a predetermined pressure by the pressure regulator 213.

  An injector 216 is provided in a reciprocating type single-cylinder engine 201 that is an internal combustion engine. The fuel discharged from the fuel pump 211 is supplied to the injector 216 through a fuel hose 218 that is a fuel passage. The fuel supplied to the injector 216 is injected into the intake passage 2 in the intake manifold 202 by operating the injector 216. Further, air is taken into the intake passage 2 from the outside through the air cleaner element 217a of the air cleaner 217. Then, the air taken into the intake passage 2 and the fuel injected from the injector 216 form a combustible mixture and are sucked into the combustion chamber 227.

A throttle body 1 including a throttle valve 4 that is operated by a predetermined accelerator device (not shown) is incorporated in the intake passage 2. By opening and closing the throttle valve 4, the amount of intake air taken into the combustion chamber 227 through the intake passage 2 is adjusted.
The throttle body 1 is provided with a bypass passage 6 that bypasses the throttle valve 4. A bypass set screw 10 for performing idle adjustment of the engine 201 is provided on the passage wall 9 of the bypass passage 6 of the throttle body 1 as in the first embodiment.

  The engine 201 is provided with a spark plug 208 that faces the combustion chamber 227. The spark plug 208 performs a spark operation in response to the ignition signal output from the ignition coil 207. The combustible air-fuel mixture sucked into the combustion chamber 227 through the intake passage 2 explodes and burns by the spark operation of the spark plug 208. As the combustible air-fuel mixture burns in the combustion chamber 227, the piston 203 moves and the crankshaft 228 rotates, so that a driving force for running the motorcycle is obtained. Further, the exhaust gas after combustion is discharged from the combustion chamber 227 to the outside through the exhaust passage 229 in the exhaust manifold 204.

  In addition, the motorcycle is provided with an ignition switch 225 for starting the engine 201. The motorcycle is provided with an ECU 230 that is an electronic control unit that performs various controls of the engine 201. A battery 219 as a power source is connected to the ECU 230 via an ignition switch 225. When the ignition switch 225 is turned on, electric power is supplied from the battery 219 to the ECU 230.

Various sensors 206, 209, 214, and 215 provided in the engine 201 are for detecting various operation parameters related to the operation state of the engine 201, and are connected to the ECU 230, respectively.
That is, the crank angle sensor 206 provided in the engine 201 detects the rotational speed (engine rotational speed) of the crankshaft 228 and outputs an electrical signal corresponding to the detected value to the ECU 230. Specifically, a signal rotor 205 having crank angle teeth 205 a arranged on the outer periphery is attached to the crankshaft 228. The crank angle sensor 206 detects the rotation speed of the crankshaft 228 by detecting the passage of the crank angle teeth 205a of the signal rotor 205 as the crankshaft 228 rotates, and outputs an electrical signal corresponding to the detected value. Output to ECU 230.
Further, a water temperature sensor 209 provided in the engine 201 detects the temperature (cooling water temperature) of engine cooling water flowing through a cooling water channel (not shown) called a water jacket, and outputs an electrical signal corresponding to the detected value to the ECU 230.
A throttle position sensor 214 provided in the throttle body 1 detects the opening degree of the throttle valve 4 and outputs an electric signal corresponding to the detected value to the ECU 230.
An intake pressure sensor 215 provided in the intake manifold 202 detects the intake pressure in the intake passage 2 downstream of the throttle valve 4 and outputs an electric signal corresponding to the detected value to the ECU 230.

  The ECU 230 performs fuel pressure detection control, fuel injection control, ignition timing control, and the like based on signals output from the various sensors 206, 209, 214, 215, and the like. The ignition coil 207 and the like are respectively controlled. Here, the intake pressure detection control is control for obtaining a detected value of the intake pressure excluding the influence of the intake pulsation based on the intake pressure detected by the intake pressure sensor 215. Further, the fuel injection control is to control the fuel injection amount by the injector 216 and the injection timing thereof according to the operating state of the engine 201. The ignition timing control is to control the ignition timing by each spark plug 208 by controlling the ignition coil 207 in accordance with the operating state of the engine 201.

  As is well known, the ECU 230 includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), a backup RAM, an external input circuit, an external output circuit, and the like. The ECU 230 constitutes a logical operation circuit formed by connecting a CPU, a ROM, a RAM, a backup RAM, an external input circuit, an external output circuit, and the like through a bus. The ROM stores a predetermined control program related to various controls of the engine 201 in advance. The RAM temporarily stores the calculation results of the CPU. The backup RAM stores data stored in advance. In addition, the CPU executes the above-described various controls according to a predetermined control program based on the detection signals of the various sensors 206, 209, 214, and 215 input through the input circuit.

In addition, the voltage of the battery 219 is applied to the fuel pump 211 via an ignition switch 225 and a fuel pump relay 220. The ignition switch 225 is a switch that is turned ON / OFF by operating an ignition key (not shown).
The fuel pump relay 220 is an electromagnetic relay that is controlled to be opened and closed by the ECU 230.
The ECU 230 controls energization of the electromagnetic coil (reference number omitted) of the fuel pump relay 220 based on the signal of the ignition switch 225.

  Specifically, when the ignition switch 225 is turned on, energization of the electromagnetic coil of the fuel pump relay 220 is started, and the contact (reference number omitted) of the fuel pump relay 220 is closed. Thereby, the voltage of the battery 219 is applied to the fuel pump 211, whereby the fuel pump 211 is started. Thereafter, if the engine has not been started even after a predetermined time has elapsed, the energization of the electromagnetic coil of the fuel pump relay 220 is cut off and the fuel pump 211 is stopped. However, if the engine 201 has been started within the predetermined time, the fuel pump 211 is operated by continuing energization of the electromagnetic coil of the fuel pump relay 220 until the engine 201 is stopped thereafter.

  By the way, in the case of a motorcycle, the distance between the cylinder head of the engine 201 and the throttle body 1 must be close because the arrangement space of parts related to the engine is considerably restricted as compared with a four-wheeled vehicle. For this reason, the deposit caused by the return from the combustion chamber 227 tends to adhere to the valve portion 18 of the bypass set screw 10, and the frequency of idle adjustment of the bypass set screw 110 has to be increased.

  In view of the problems peculiar to the motorcycle, the present invention proposes a bypass set screw that opens and closes the bypass passage with a passage section in which the valve portion forms a single-walled passage wall surface. Therefore, according to the present invention, it is possible to effectively suppress deposits from being attached to the valve portion and the bypass passage with a simple configuration, and to reduce the frequency of idle adjustment of the bypass set screw. For this reason, a bypass set screw suitable for a motorcycle can be provided.

Further, technical matters grasped from the embodiment will be described together with their effects.
(1) A screw body that is screwed into a passage wall of a bypass passage that bypasses a throttle valve that opens and closes an intake passage of an internal combustion engine for a motorcycle, and the bypass passage is opened and closed by screwing or screwing of the screw body. A bypass set screw having a valve portion to perform,
The bypass set screw, wherein the valve portion opens and closes the bypass passage with a passage cross section forming a single tubular passage wall surface.
According to this configuration, the idle adjustment of the motorcycle internal combustion engine can be performed by opening and closing the bypass passage by the valve portion by the screwing or screwing of the screw main body portion.
By the way, since the valve portion opens and closes the bypass passage with a passage cross section forming a single tubular passage wall surface, idle air can flow smoothly, the flow coefficient increases, and the peeling phenomenon and stagnation are reduced. Thereby, adhesion of the deposit with respect to a valve part and a bypass passage can be controlled, and the frequency of idle adjustment of a bypass set screw can be reduced.
Moreover, since the frequency of idle adjustment of the bypass set screw for a motorcycle can be reduced with a simple configuration, a bypass set screw suitable for a motorcycle can be provided.

(2) The bypass set screw according to any one of claims 1 to 7, wherein the internal combustion engine for motorcycles is opened and closed by opening and closing a bypass passage that bypasses a throttle valve that opens and closes an intake passage of the internal combustion engine for motorcycles. A bypass set screw for motorcycles, characterized in that idle adjustment is performed.
According to this configuration, since the frequency of idle adjustment of the bypass set screw for motorcycles can be reduced with a simple configuration, a bypass set screw suitable for motorcycles can be provided.

  The present invention is not limited to the above-described embodiments, and modifications can be made without departing from the gist of the present invention.

It is sectional drawing which shows the throttle body concerning Example 1 of this invention. The peripheral part of a bypass set screw is shown, (a) is sectional drawing which shows the initial state of a bypass set screw, (b) is the BB sectional drawing of (a), (c) is a re-review of a bypass set screw. Sectional drawing which shows an adjustment state, (d) is the DD sectional view taken on the line of (c), (e) is a perspective view which shows a front-end | tip part. It is a characteristic diagram which shows the relationship between elapsed time and idle air quantity. The surrounding part of the bypass set screw concerning Example 2 of this invention is shown, (a) is sectional drawing which shows the initial state of a bypass set screw, (b) is the BB sectional drawing of (a), ( (c) is sectional drawing which shows the readjustment state of a bypass set screw, (d) is the DD sectional view taken on the line of (c), (e) is a perspective view which shows a front-end | tip part. The periphery part of the bypass set screw concerning Example 3 of this invention is shown, (a) is sectional drawing which shows the initial state of a bypass set screw, (b) is BB sectional drawing of (a), ( (c) is sectional drawing which shows the readjustment state of a bypass set screw, (d) is the DD sectional view taken on the line of (c), (e) is a perspective view which shows a front-end | tip part. The surrounding part of the bypass set screw concerning Example 4 of this invention is shown, (a) is sectional drawing which shows the initial state of a bypass set screw, (b) is BB sectional drawing of (a), ( (c) is sectional drawing which shows the readjustment state of a bypass set screw, (d) is the DD sectional view taken on the line of (c), (e) is a perspective view which shows a front-end | tip part. The surrounding part of the bypass set screw concerning Example 5 of this invention is shown, (a) is sectional drawing which shows the initial state of a bypass set screw, (b) is BB sectional drawing of (a), ( (c) is sectional drawing which shows the readjustment state of a bypass set screw, (d) is the DD sectional view taken on the line of (c), (e) is a perspective view which shows a front-end | tip part. The surrounding part of the bypass set screw concerning Example 6 of this invention is shown, (a) is sectional drawing which shows the initial state of a bypass set screw, (b) is the BB sectional drawing of (a), ( (c) is sectional drawing which shows the readjustment state of a bypass set screw, (d) is the DD sectional view taken on the line of (c), (e) is a perspective view which shows a front-end | tip part. It is sectional drawing which shows the throttle body concerning Example 7 of this invention. The peripheral part of a bypass set screw is shown, (a) is sectional drawing which shows the initial state of a bypass set screw, (b) is the BB sectional drawing of (a), (c) is a re-review of a bypass set screw. Sectional drawing which shows an adjustment state, (d) is the DD sectional view taken on the line of (c). The screw main body is shown, (a) is a top view, (b) is a front view, (c) is a bottom view. The valve body is shown, (a) is a plan view, (b) is a front view, (c) is a bottom view, and (d) is a side view. The surrounding part of the bypass set screw concerning Example 8 of this invention is shown, (a) is sectional drawing which shows the initial state of a bypass set screw, (b) is BB sectional drawing of (a), ( (c) is sectional drawing which shows the readjustment state of a bypass set screw, (d) is the DD sectional view taken on the line of (c), (e) is a perspective view which shows a front-end | tip part. The surrounding part of the bypass set screw concerning Example 9 of this invention is shown, (a) is sectional drawing which shows the initial state of a bypass set screw, (b) is the BB sectional drawing of (a), ( (c) is sectional drawing which shows the readjustment state of a bypass set screw, (d) is the DD sectional view taken on the line of (c), (e) is a perspective view which shows a front-end | tip part. The surrounding part of the bypass set screw concerning Example 10 of this invention is shown, (a) is sectional drawing which shows the initial state of a bypass set screw, (b) is BB sectional drawing of (a), ( (c) is sectional drawing which shows the readjustment state of a bypass set screw, (d) is the DD sectional view taken on the line of (c), (e) is a perspective view which shows a front-end | tip part. The surrounding part of the bypass set screw concerning Example 11 of this invention is shown, (a) is sectional drawing which shows the initial state of a bypass set screw, (b) is the BB sectional drawing of (a), ( (c) is sectional drawing which shows the readjustment state of a bypass set screw, (d) is DD sectional view taken on the line of (c). The surrounding part of the bypass set screw concerning Example 12 of this invention is shown, (a) is sectional drawing, (b) is the B section enlarged view of (a), (c) is the C section expansion of (a). FIG. It is sectional drawing which shows the peripheral part of the bypass set screw concerning Example 13 of this invention. It is sectional drawing which shows the bypass channel concerning Example 14 of this invention. The peripheral part of the bypass set screw concerning a prior art example is shown, (a) is sectional drawing which shows the initial state of a bypass set screw, (b) is a BB sectional drawing of (a), (c) is a bypass. Sectional drawing which shows the readjustment state of a set screw, (d) is the DD sectional view taken on the line of (c). It is a figure which shows the result of having measured the bypass air quantity by the front-end | tip part shape of a bypass set screw for every time. It is a figure which shows the relationship between the deposit thickness of the deposit by the front-end | tip part shape of a bypass set screw, and a passage area. 1 is a schematic configuration diagram showing an example of an engine system mounted on a motorcycle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Throttle body 2 Intake passage 4 Throttle valve 6 Bypass passage 7 Lateral passage portion 7a Passage wall surface 8 Vertical passage portion 8a Passage wall surface 9 Passage wall 10 Bypass set screw 15 Screw main body portion 18 Valve portion 22 Tip portion 25 Measuring port 27 Passage section 32 Passage section 36 passage section 40 passage section 43 passage section 46 passage section 47 bypass set screw 48 screw body 49 valve body 62 passage section 64 passage section 68 passage section 70 passage section 71 protrusion (tilting means)

Claims (9)

A screw main body portion screwed into a passage wall of a bypass passage that bypasses a throttle valve that opens and closes an intake passage of the internal combustion engine, and a valve portion that opens and closes the bypass passage by screwing or unscrewing of the screw main body portion. A bypass set screw,
The bypass set screw, wherein the valve portion opens and closes the bypass passage with a passage cross section forming a single tubular passage wall surface. The bypass set screw according to claim 1,
The bypass set screw characterized in that the valve portion opens and closes the bypass passage in a caliber direction by movement in an axial direction. The bypass set screw according to claim 1,
A bypass set screw, wherein the valve portion opens and closes the bypass passage in a caliber direction by turning around a shaft. The bypass set screw according to any one of claims 1 to 3,
A bypass set screw, wherein the valve portion is coated with oil repellency. A screw body screwed into a passage wall of a bypass passage that bypasses a throttle valve that opens and closes an intake passage of the internal combustion engine;
A valve that is provided on the passage wall so as to be movable in the axial direction while being prevented from rotating in the axial direction, and that opens and closes the bypass passage by moving in the axial direction in conjunction with the screwing or screwing of the screw body. A bypass set screw comprising a body,
The said valve body opens and closes the said bypass channel with the channel | path cross section which forms a single tubular channel | path wall surface, The bypass set screw characterized by the above-mentioned. The bypass set screw according to claim 5,
A bypass set screw characterized in that tilting means for tilting the valve body with a predetermined declination is provided. The bypass set screw according to claim 5 or 6,
A bypass set screw, wherein the valve body is provided with an oil-repellent coating. A bypass passage that bypasses the throttle valve that opens and closes the intake passage of the internal combustion engine and is opened and closed by a bypass set screw,
A bypass passage characterized in that a coating having oil repellency is applied to a passage wall surface. The bypass passage according to claim 8,
A bypass passage, wherein the bypass set screw according to any one of claims 1 to 7 is provided.

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