JP2009174496A - Tandem valve type throttle body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the entire length of a throttle body, excellent in assemblability and conveyance property, and increasing an air amount of a sub-throttle valve well, without generation of turbulence of air flowing in a main intake passage. <P>SOLUTION: The intake passage 2 penetrating the throttle body 1 is formed of the main intake passage 3, an inclined intake passage 5, and a sub-intake passage 4. The main intake passage is opened/closed by a main throttle valve 16 attached/detached to/from a main throttle shaft 15, and the sub-intake passage is opened/closed by the sub-throttle valve 18 attached/detached to/from the sub-throttle shaft 17. An upper enlarged start point 5b1 of the inclined intake passage is arranged aside (X) to be close to an engine side (E) than a lower enlarged start point 5a1 of the inclined intake passage. A distance (Lc) from the upper enlarged start point of the inclined intake passage up to an upper enlarged end point is made the same as a distance (Lb) from the lower enlarged start point of the inclined intake passage up to a lower enlarged end point. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a throttle body that controls the amount of air directed to an engine, and in particular, a main throttle valve that opens and closes an intake passage (main intake passage) that is mechanically operated by an accelerator is disposed in an intake passage that passes through the throttle body. In addition, the present invention relates to a dandem valve type throttle body in which a sub-throttle valve that electrically opens and closes an intake passage (sub-intake passage) upstream of a main throttle valve by an electromagnetic actuator such as a motor is disposed.

A conventional tandem valve type throttle body is disclosed in Patent Document 1.
A description will be given with reference to FIG. 4 created based on the technique disclosed in Patent Document 1. (10) is a throttle body having an intake passage 11 penetrating through the inside to the side, and this intake passage (11) is a main intake passage (continuous to the engine (E) arranged on the left side in the figure). 12), a sub-intake passage (13) connected to the air cleaner (A) arranged on the right side and having a larger diameter than the main intake passage (12), and an end (12a) on the air cleaner side of the main intake passage (12) And an inclined intake passage (14) connecting the engine side end (13a) of the sub intake passage (13).
That is, the intake passage (11) is formed by connecting the main intake passage (12), the inclined intake passage (14), and the sub intake passage (13), and the left end of the main intake passage (12) is the throttle body (10). ) At the left end (10a), and the right end of the sub intake passage (13) is opened at the right end (10b) of the throttle body (10). The main intake passage (12) opened at the left end (10a) of the throttle body (10) is communicated with the engine (E) through an intake pipe (not shown). The sub intake passage (13) opened at the right end (10b) of the throttle body (10) communicates with the air cleaner (A) via a duct (not shown). Reference numeral (15) denotes a main throttle shaft that is rotatably supported by the throttle body (10) across the main intake passage (12). The main intake passage (12) is opened and closed on the main throttle shaft (15). A butterfly type main throttle valve (16) is attached by a screw or the like (not shown).
(17) is a sub-throttle shaft that is rotatably supported by the throttle body (10) across the sub-intake passage (13). The sub-intake passage (13) is opened and closed on the sub-throttle shaft (17). A butterfly-type sub-throttle valve (18) is attached by screws or the like (not shown).
A throttle drum is attached to an end portion of the main throttle shaft (15) protruding from the throttle body (10). The throttle drum is connected to an accelerator grip of a motorcycle via an accelerator wire. Therefore, when the driver operates the accelerator grip, the main throttle shaft (15) is rotated, whereby the main throttle valve (16) mechanically moves the main intake passage (12) according to the operation of the accelerator grip. Open and close. Also, an electromagnetic actuator such as a motor is connected to the end of the sub throttle shaft (17) protruding from the throttle body (10), and the sub throttle shaft (17) is rotated by the electromagnetic actuator. The throttle valve (18) electrically opens and closes the sub intake passage (13) according to the rotation of the electromagnetic actuator.
The throttle drum, accelerator grip, accelerator wire, and electromagnetic actuator are not shown.
Further, (J) is a fuel injection valve that injects fuel whose pressure has been increased through the opening into the main intake passage (12).
The total length (L) along the longitudinal axis of the intake passage (11) in the throttle body (10) is the length (L1) of the main intake passage (12) and the length of the inclined intake passage (14) ( L2) and the sum of the lengths (L3) of the sub-intake passages (13). (L = L1 + L2 + L3)
JP 2006-22703 A

  Here, when such a tandem valve type throttle body is mounted on a motorcycle, it is particularly desirable that the overall length (L) of the throttle body (10) be short. This is because in the motorcycle, the storage space for storing the throttle body is limited to a narrow storage space that is extremely limited as compared with the storage space in the hood of the four-wheeled vehicle.

Conventionally, a first method shown in FIG. 5 is conceivable as a method for shortening the overall length (L) of the throttle body (10).
Since the configuration is the same as in FIG. 4, the same reference numerals are used and the description thereof is omitted.
In this first method, the left end (10a) of the throttle body (10) is shortened (a) from the left end (10a) shown in FIG. 4, and the right end (10b) of the throttle body (10) is shown in FIG. (B) is shorter than the left end (10b).
According to the above, the total length (L ′) corresponding to the shortened portion (a + b) can be shortened with respect to the total length (L) of the conventional throttle body (10) shown in FIG.
(The total length (L ') of the throttle body (10) according to the first method is the length of the conventional total length L- (a + b))
However, according to the first conventional method, the upper end (16a) of the main throttle valve (16) projects laterally from the left end (10a) of the throttle body (10) when the main throttle valve (1b) is fully opened. . In the sub-throttle valve (18), when the sub-throttle valve (18) is fully opened, the lower end (18a) projects sideways from the right end (10b) of the throttle body (10). (This state is indicated by a dotted line in FIG. 5)
According to the above, when the throttle body (10) is assembled, it is necessary to work carefully so that the projecting ends (16a) and (18a) do not come into contact with other members to be deformed, and the working efficiency cannot be improved. Also, it is necessary to carefully perform the work even when the throttle body (10) is being transported or stored, and it is difficult to efficiently perform the packing work and the transporting work of the throttle body.

Next, a second method for shortening the overall length (L) of the throttle body (10) and a method shown in FIG. 6 are conceivable.
Since the configuration is the same as in FIG. 4, the same reference numerals are used.
In the second method, the length (L2) of the inclined intake passage (14) of the conventional throttle body (10) shown in FIG. 4 is shortened corresponding to (c).
This is indicated as (L2 ') in FIG. (The length (L2 ′) of the inclined intake passage (14) according to the second method is the length L2-c of the conventional inclined intake passage (14).)
According to the second method, the total length (L ″) of the throttle body (10) can be shortened corresponding to the shortened length (c) of the inclined intake passage (14).
The overall length (L ″) of the throttle body (10) according to the second method is the length of the conventional overall length Lc.
According to the second method, as described above, the length of the inclined intake passage (14) is shortened corresponding to (c), so that it flows from the sub intake passage (13) toward the main intake passage (12). The air flow is abruptly contracted. According to this, a vortex may be generated in the air flow flowing in the main intake passage (12), and the fuel injected from the fuel injection valve (omitted in FIG. 6). This is not preferable because it disturbs the flow.

Further, as a third method for shortening the overall length (L) of the throttle body (10), a method shown in FIG. 7 is conceivable.
Since the configuration is the same as in FIG. 4, the same reference numerals are used.
In the third method, the center (17a) of the sub-throttle shaft (17) shown in FIG. 4 is moved to the engine side (left side in FIG. 7) corresponding to (d). In FIG. 7, the conventional sub-throttle shaft (17) and its center (17a) are indicated by dotted lines, and the sub-throttle shaft (17 ') and its center (17a') in the state of being moved (d) to the engine side are solid lines. Indicated by
According to the third method, the right end (10b) of the throttle body (10) can be shortened corresponding to the lateral movement (d) of the sub-throttle shaft (17), whereby the overall length of the throttle body (10) can be reduced. Can be shortened to (L ′ ″).
The total length (L ′ ″) of the throttle body (10) according to the third method is the length of the conventional total length Ld. According to the third method, when the sub-throttle valve (18) moves in the opening direction, which rotates counterclockwise in FIG. 7, the main intake passage ( 12) The amount of air flowing in toward 12) cannot be increased satisfactorily according to the movement in the opening direction.
Referring to FIG. 7, the upper end (18b) of the sub-throttle valve (18) is disposed close to the upper inclined intake passage (14a) from the initial opening stage to the middle stage from the fully closed state of the sub-throttle valve (18). Thus, it moves in a state of being close along the upper inclined intake passage (14a), thereby forming between the upper end (18b) of the sub-throttle valve (18) and the upper inclined intake passage (14a). The gap (19) to be produced cannot be increased in response to the opening of the sub-throttle valve (18). (In other words, the increase in the gap (19) cannot be increased relative to the degree of opening of the sub-throttle valve (18))

  The tandem valve type throttle body according to the present invention is made in view of the above-mentioned problems, has excellent assembly workability and transportability, and increases the amount of air flowing toward the main intake passage according to the degree of opening of the sub-throttle valve. Providing a tandem valve type throttle body that can be performed well and does not disturb the air flow flowing through the main intake passage and can reduce the overall length of the throttle body, and is therefore preferable for mounting on a motorcycle. The main purpose is to provide a valve-type throttle body.

In order to achieve the above object, the tandem valve type throttle body according to the present invention has an intake passage that penetrates the throttle body, which has a main intake passage that opens to the engine side and an air cleaner side that has a larger diameter than the main intake passage. Are connected by an inclined intake passage that communicates an end of the main intake passage on the air cleaner side and an end of the sub intake passage on the engine side,
The main intake passage is opened and closed by a butterfly type main throttle valve attached to the main throttle shaft, and the sub intake passage is opened and closed by a butterfly type sub throttle valve attached to the sub throttle shaft,
Furthermore, in the tandem valve type throttle body in which the fuel injection valve is arranged to open toward the main intake passage,
When the main throttle valve is fully closed, the lower end is disposed on the air cleaner side from the center of the main throttle shaft and the upper end is disposed on the engine side from the center.
The sub-throttle valve, when fully closed, has a lower end disposed on the air cleaner side from the center of the sub-throttle shaft and an upper end disposed on the engine side from the center.
Also, the upper expansion starting point of the inclined intake passage is shifted to the engine side from the lower expansion starting point of the inclined intake passage,
Further, the first feature is that the distance from the upper expansion start point of the inclined intake passage to the upper expansion end point and the distance from the lower expansion start point of the inclined intake passage to the lower expansion end point are the same distance. To do.

  According to the present invention, in addition to the first feature, the opening of the fuel injection valve is connected to a lower main intake passage connected to a lower inclined intake passage extending from a lower expansion start point to a lower expansion end point. The opening is a second feature.

According to the first feature of the present invention, the overall length of the throttle body is shortened correspondingly to the amount of the upper expansion starting point of the inclined intake passage positioned closer to the engine than the lower expansion starting point of the inclined intake passage. This makes it possible to provide a tandem valve type throttle body that can be easily mounted on a motorcycle. Further, at this time, when the main throttle valve is fully opened, the upper end of the main throttle valve can be arranged inside the left end of the throttle body. On the other hand, the sub-throttle shaft including the sub-throttle valve is offset by the upper inclined intake passage. Since it can be shifted to the inclined intake passage side corresponding to the minute, even when the throttle body is shortened, the sub-throttle valve can be disposed at the lower end of the throttle body at the right end of the throttle body when fully opened. As a result, the assembly workability and transportability of the tandem valve type throttle body can be improved.
In addition, since the sub throttle shaft including the sub throttle valve can be shifted in correspondence with the offset of the upper inclined intake passage, the positional relationship between the inclined intake passage and the sub throttle valve can be set and arranged as usual. Thus, it is possible to satisfactorily increase the air amount toward the main intake passage according to the degree of opening of the sub-throttle valve.
In addition, since the upper intake passage length and the lower intake passage length constituting the inclined intake passage are formed as the same distance, the air flow supplied from the inclined intake passage to the main intake passage is not disturbed, The fuel flow injected from the fuel injection valve into the main intake passage is not obstructed.

  Further, according to the second feature of the present invention, without changing the position of the fuel injection valve relative to the conventional one, the intersection of the fuel injection valve spray center and the line along the upper inclined intake passage, Since the engine can be located on the upper main intake passage side and away from the main throttle shaft, the fuel injected from the fuel injection valve with respect to the air flow flowing in the main intake passage is better in the main intake passage. It is preferable for improving the operability of the engine.

Hereinafter, an embodiment of a tandem valve type throttle body according to the present invention will be described with reference to FIG. 1 (the fuel injection valve is omitted in FIG. 1).
(1) is a throttle body (referred to as a tandem valve type throttle body) in which an intake passage (2) penetrates the inside. In FIG. 1, the intake passage (2) is the throttle body (1). Drilled from the left end (1a) toward the right end (1b). The intake passage (2) has a main intake passage (3) that opens to the left end (1a) and a sub intake passage (4) that opens to the right end (1b) and has a larger diameter than the main intake passage (3). And an inclined intake passage (5) connecting the end (3a) on the air cleaner side of the main intake passage (3) and the end (4a) on the engine side of the sub intake passage (4).
The inclined intake passage (5) is enlarged from the end (3a) on the air cleaner side of the main intake passage (3) to the end (4a) on the engine side of the sub intake passage (4). The throttle body shown in FIG. 2 is the same as that shown in FIG. 4, and is prepared for easy explanation.
In the main intake passage (3), the same main throttle shaft (15) as shown in FIG. 2 and a butterfly type main throttle valve (16) are arranged.
Here, the passage length (La) of the lower main intake passage (3b) located below the main intake passage (3) is the passage length (L1) of the main intake passage (12) shown in FIG. ).
The distance (g) from the left end (1a) of the throttle body (1) to the center (15a) of the main throttle shaft (15) is also the same as in FIG. When the main throttle valve (16) is fully closed, the upper end (16a) of the main throttle valve (16) is located on the engine (E) side (leftward in FIG. 1) from the center (15a) of the main throttle shaft (15). ) And the lower end (16b) is located on the air cleaner (A) side (right side in FIG. 1) from the center (15a).
According to the above, when the main throttle valve (16) is fully opened, its upper end (16a) is outward from the left end (1a) of the throttle body (1), like the main throttle valve (16) shown in FIG. Does not protrude.

The sub-intake passage (4) is provided with the same sub-throttle shaft (17) and butterfly-type sub-throttle valve (18) as shown in FIG.
At this time, the position of the center (17a) of the sub-throttle shaft (17) is not specified. (This center (17a) will be specified later)
When the sub-throttle valve (18) is fully closed, the lower end (18a) is disposed closer to the air cleaner (A) than the center (17a) of the sub-throttle shaft (17) and the upper end (18b) is the center (17a). ) On the engine (E) side.

The inclined intake passage (5) is formed by:
The inclined intake passage (5) includes a lower inclined intake passage (5a) located below in FIG. 1 and an upper inclined intake passage (5b) located above.
The lower inclined intake passage (5a) extends from the lower enlarged starting point (5a1) located at the air cleaner side end (3a) of the lower main intake passage (3b) to the lower sub intake passage (4b). Is enlarged toward the lower enlargement end point (5a2) located at the engine end (4a). The length (Lb) of the lower inclined intake passage (5a) from the lower enlarged starting point (5a1) to the lower enlarged end point (5a2) is equal to that of the inclined intake passage (14) shown in FIG. The same length (L2) was formed.
The upper inclined intake passage (5b) extends from the upper enlarged starting point (5b1) located at the air cleaner side end (3d) of the upper main intake passage (3c) to the engine side of the upper sub intake passage (4c). An enlargement is formed toward the upper enlargement end point (5b2) located at the end (4d).
In the above description, the upper expansion start point (5b1) of the upper inclined intake passage (5b) is closer to the engine (E) side (FIG. 1) than the lower expansion start point (5a1) of the lower inclined intake passage (5a). (X) to the left).
In the upper inclined intake passage (5b), the length (Lc) of the upper inclined intake passage (5b) from the upper enlarged starting point (5b2) to the upper enlarged end point (5b2) is the lower inclined angle. It was formed to be the same as the length (Lb) of the intake passage (5a).
According to the above, the engine side end (4d) of the upper sub-intake passage (4c) (including the upper enlarged starting point (5b2)) is located on the engine side of the lower sub-intake passage (4b). The end portion (4a) is positioned on the engine (E) side corresponding to the shift (X).

The center (17a) of the sub-throttle shaft (17) in FIG. 1 is the end (13c) on the engine side of the upper sub-intake passage (13b) in FIG. 2 and the sub-throttle shaft (17) shown in FIG. It is arranged at the same distance (L4) from the center (17a).
That is, the center (17a) of the sub-throttle shaft (17) in the present invention is the engine-side end (4d) of the upper sub-intake passage (4c) (in other words, the upper enlarged end point of the upper inclined intake passage (5b)). (5b2)) to a distance (Ld) corresponding to the distance (L4). (L4 = Ld)
According to the above, the center (17a) of the sub-throttle shaft (17) according to the present invention is shifted to the offset (X) with respect to the center (17a) of the conventional sub-throttle shaft (17) shown in FIG. Correspondingly, it can be arranged on the engine (E) side (left side in FIG. 1). 1 indicates the position of the center (17a) of the sub-throttle shaft (17) in FIG.
Further, the length (Le) from the center (17a) of the sub-throttle shaft (17) in FIG. 1 to the right end (1b) of the throttle body (1) is the same as that of the sub-throttle shaft (17) shown in FIG. It is formed to have the same length (L5) from the center (17a) to the right end (1b) of the throttle body (1).

To summarize the above, the length (Lf) of the upper main intake passage (3c) = La−X:
Length LC of upper inclined intake passage (5b):
The length of the upper sub-intake passage (4c) is Lg = Ld + Le:
Total length of throttle body (1) on the upper side Lha = Lf + Lc + Lg,
In other words, Lha = (La−X) + Lb + (Ld + Le)
In other words, Lha = (La−X) + Lb + (L4 + L5)
In other words, Lha = (L1−X) + L2 + (L4 + L5), and compared with the total length L = L1 + L2 + L4 + L5 of the conventional throttle body shown in FIG. The total length (Lha) of the inclined intake passage (5) can be shortened corresponding to the amount (X) shifted from the lower enlarged starting point (5a1) to the engine side (E).
Further, the length (La) of the lower main intake passage (3b): the length (Lb) of the lower inclined intake passage (5a): the length (L4) of the lower sub intake passage (4b) = Le + (Ld−X):
The total length of the throttle body (1) on the lower side Lha = La + Lb + Le + (Ld−X), in other words, Lha = L1 + L2 + L5 + (L4-X), which is shown in FIG.
Compared to the total length (L) of the conventional throttle body (L1) = L1 + L2 + L4 + L5, the total length (Lhb) can be shortened corresponding to the offset (X) as described above.
As described above, according to the present invention, the total length (L) can be shortened corresponding to the offset (X) as compared with the conventional throttle body, so that the compact tandem valve suitable for mounting on a motorcycle can be used. Type throttle body.

  Further, according to the present invention, in the state where the center (15a) of the main throttle shaft (15) is arranged at the position of the length (g) from the left end (1a) as in FIG. 2) from the position of FIG. 2 to the (X) inclined intake passage (5) side, and the right end (1b) of the throttle body (1) is correspondingly shortened (X). In this state, even if the main throttle valve (16) and the sub throttle valve (18) are kept fully open, the upper end (16a) of the main throttle valve (16) is at the left end of the throttle body (1). (1a) does not protrude laterally, and the lower end (18a) of the sub-throttle valve (18) does not protrude laterally from the left end (1b) of the throttle body (1). Assembling workability of Rottorubode, packaging workability can greatly improve the conveyance workability.

  Further, in the inclined intake passage (5), a length (Lc) from the upper enlarged starting point (5b1) of the upper inclined intake passage (5b) to the upper enlarged end point (5b2), and a lower inclined intake passage ( 5a) Since the length (La) from the lower expansion start point (5a1) to the lower expansion end point (5a2) is formed to be the same length, the inclined intake passage (5) to the main intake passage (3 ), The air flow flowing in toward the main intake passage (3) from the fuel injection valve (not shown) may be disturbed without abruptly contracting the air flow. Absent.

  Further, when the sub-throttle valve (18) is fully closed, the gap between the upper end (18b) of the sub-throttle valve (18) and the vicinity of the special upper enlarged end point (5b2) of the upper inclined intake passage (5b) ( Since a large space can be maintained without bringing S) close to each other, when the sub-throttle valve (18) is released from the fully closed state, the air increase can be performed smoothly and linearly especially at low and medium opening degrees. it can.

Another embodiment of the present invention will be described with reference to FIG.
The same reference numerals are used for the same structural parts as those in FIG.
(J) is a known fuel injection valve, and is sandwiched between the inclined pipe (50) below the throttle body (1). The fuel injection valve (J) has a nozzle hole (Ja) opened at its tip, and the fuel injected from the nozzle hole (Ja) passes through the opening (1g) of the throttle body (1). To the main intake passage (3).
Here, the fuel injection valve (J) is a lower main intake passage (3b) connected to the lower inclined intake passage (5a), and the main intake passage (3b) on the engine side from the main throttle valve (16). It is arranged toward. No fuel injection valve is arranged in the upper main intake passage (3c).
As described above, when the fuel injection valve (J) is arranged at the specified position, the spray center YY of the fuel injected from the fuel injection valve (J) and the upper inclined intake passage (5b) Can be separated from the main throttle valve (16) to the engine (E) side and to the upper position of the main intake passage (3). According to the above, the fuel injected from the fuel injection valve can be mixed well, and the operability of the engine can be further improved.
In the case of the line PP along the conventional upper inclined intake passage (14a) and the upper inclined intake passage (14a) indicated by a one-dot chain line in FIG. 3, the line PP and the fuel spray center Y are shown. It is difficult to bring the intersection (Wa) with -Y to the upper position of the main intake passage (3) like W of the present invention, and it is difficult to desire the effect of the present invention.

  In the description of the present invention, the upper side and the lower side are shown in the drawings, and no limitation is given thereby.

The principal part longitudinal cross-sectional view which shows one Example of the tandem valve type | mold throttle body of this invention. The principal part longitudinal cross-sectional view of the conventional tandem valve type throttle body. The principal part longitudinal cross-sectional view which shows the other Example of the tandem valve type | mold throttle body of this invention. The principal part longitudinal cross-sectional view which shows the conventional tandem valve type | mold throttle body. The principal part longitudinal cross-sectional view which shows the 1st method in the past for solving the malfunction of the conventional tandem valve type | mold throttle body. The principal part longitudinal cross-sectional view which shows the 2nd method in the past for solving the malfunction of the conventional tandem valve type throttle body. The principal part longitudinal cross-sectional view which shows the 3rd method in the past for solving the malfunction of the conventional tandem valve type | mold throttle body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Throttle body 2 Intake passage 3 Main intake passage 5 Inclined intake passage 5a1 Lower expansion start point of inclined intake passage 5a2 Lower expansion end point of inclined intake passage 5b1 Upper expansion start point of inclined intake passage 5b2 Upper inclination start intake passage End point 15 Main throttle shaft 16 Main throttle valve 17 Sub throttle shaft 18 Sub throttle valve A Air cleaner side E Engine side

Claims (2)

An intake passage (2) that penetrates the throttle body (1) opens to the main intake passage (3) that opens to the engine (E) side and to the air cleaner (A) side, and has a larger diameter than the main intake passage (3). The sub-intake passage (4), the end (3a) on the air cleaner (A) side of the main intake passage (3), and the end (4a) on the engine (E) side of the sub-intake passage (4) are connected. Connected to the inclined intake passage (5),
The main intake passage is opened and closed by a butterfly type main throttle valve (16) attached to the main throttle shaft (15), and the sub intake passage (4) is attached to the sub throttle shaft (17). It is opened and closed by the sub throttle valve (18),
Furthermore, in the tandem valve type throttle body in which the fuel injection valve (J) is arranged to open toward the main intake passage (3),
When the main throttle valve (16) is fully closed, the lower end (16b) is disposed closer to the air cleaner (A) than the center (15a) of the main throttle shaft (15) and the upper end (16a) is the center (15a). ) From the engine side (E),
When the sub-throttle valve (18) is fully closed, the lower end (18a) is disposed closer to the air cleaner (A) than the center (17a) of the sub-throttle shaft (17), and the upper end (18b) is the center. (17a) from the engine side (E)
Further, the upper expansion start point (5b1) of the inclined intake passage (5) is shifted (X) to the engine side (E) from the lower expansion start point (5a1) of the inclined intake passage (5).
Further, the distance (Lc) from the upper expansion start point (5b) of the inclined intake passage (5) to the upper expansion end point (5b2) and the lower expansion start point (5a1) below the inclined intake passage (5). A tandem valve type throttle body characterized in that the distance (Lb) to the enlarged end point (5a2) is the same distance.   The lower main intake passage (3b) connecting the opening (1g) of the fuel injection valve to the lower inclined intake passage (5a) from the lower enlarged start point (5a1) to the lower enlarged end point (5a2). The tandem valve type throttle body according to claim 1, wherein the tandem valve type throttle body is opened.

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