JP2012077626A - Intake device of multicylinder internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intake device of a multicylinder internal combustion engine capable of reducing influence of bypass air extraction when detecting the condition of intake air passing through an intake duct, and reducing influence on each sensor.SOLUTION: In this intake device of a multicylinder internal combustion engine including a plurality of throttle bodies 61A, B including one or more intake ducts 71-74 connected to respective cylinders and also including bypass passages 101-104 connecting the upstream sides to the downstream sides of the intake ducts by bypassing throttle valves 81-84 and having a bypass valve 100 interposed, a sensor unit 120 is arranged in any one of the intake ducts; a bypass valve is arranged in the throttle body 61A without including the intake duct arranged with the sensor unit; and the bypass passages include the bypass passages 103, 104 for connecting the throttle body arranged with the bypass valve to the throttle body 61B arranged with the sensor unit.

Description

  The present invention relates to an improvement in an intake device for a multi-cylinder internal combustion engine, and more particularly to an intake device for a multi-cylinder internal combustion engine having a bypass passage that bypasses a throttle valve in an intake pipe connected to each cylinder.

  Conventionally, in an intake device of an internal combustion engine having a single intake pipe provided with a throttle valve in a single throttle body, the intake air temperature, intake pressure, etc. of the intake air passing through the intake pipe in the intake pipe In order to detect the state, a sensor unit provided with a throttle sensor for detecting the opening of the throttle valve is provided in the throttle body so that the detection unit protrudes into the intake pipe or the detection port is opened. There is a throttle body provided with a bypass passage that bypasses the valve and communicates immediately upstream and downstream, and a bypass valve that controls opening and closing of the bypass passage (for example, Patent Document 1 below). The detection signal of the intake air state and the detection signal of the throttle opening are input to the electronic control unit, whereby the electronic control unit controls the bypass valve and also controls the operation of the fuel injection valve.

  When an intake device having such a bypass passage is to be adopted in a multi-cylinder internal combustion engine, the bypass air taken out from the intake pipe of the throttle body provided with the sensor unit to the bypass passage passes through a single bypass valve. Thus, the downstream end of the branched bypass passage is connected to the intake pipe of the throttle body of each cylinder on the downstream side of the throttle valve.

  However, in a multi-cylinder internal combustion engine, the amount of exhaust increases, so the amount of bypass air taken out from one intake pipe also increases. As described above, when a sensor unit is provided in the throttle body in which the bypass valve is disposed to detect the intake air state in the intake pipe, the amount of bypass air taken out to the bypass passage is large. The disturbance factor with respect to the intake air state increases, and there is a problem that the detection state of the sensor may be affected.

  On the other hand, in a multi-cylinder internal combustion engine, the intake pressure (Pb) is obtained by providing intake pressure tubes connected to the intake pipes of the respective cylinders, joining them with a merging member, and then connecting them to an intake pressure sensor. The intake air temperature (Ta) is detected by an intake air temperature sensor provided in an air cleaner upstream of the throttle body, and the throttle opening (Th) is detected by a throttle sensor provided at the end of the throttle shaft. Some sensors are distributed. In such a case, the arrangement, attachment, piping, and arrangement of the wiring cord from each sensor to the electronic control unit are complicated, resulting in an increase in the number of parts, assembly man-hours, and maintenance man-hours.

Japanese Patent Laid-Open No. 2007-332827 (FIGS. 2 to 7)

  The present invention can reduce the influence of bypass air extraction when detecting the state of intake air passing through an intake pipe in an intake device of a multi-cylinder internal combustion engine. In addition to reducing the fluctuation of the sensor, the influence on the detection status of each sensor can be reduced, and the placement, installation, piping, and wiring code from each sensor when sensors that detect the status of intake air are distributed It is an object of the present invention to provide an intake device for a multi-cylinder internal combustion engine that can eliminate the complexity of the arrangement of the engine and reduce the number of parts, the number of assembly steps, and the number of maintenance steps.

  In order to achieve the above object, the invention according to claim 1 includes a plurality of throttle bodies including one or a plurality of intake pipes connected to each cylinder of a multi-cylinder internal combustion engine, The multi-cylinder internal combustion engine is provided with a bypass passage that bypasses the throttle valve and connects the upstream side and the downstream side of the intake pipe, and a bypass valve that controls the amount of bypass air that is circulated is interposed in the bypass passage In the intake device, a sensor unit is provided in any one of the intake pipes, and the bypass valve is provided in a throttle body other than the throttle body provided with the intake pipe provided with the sensor unit. The bypass passage includes a bypass passage connecting a throttle body provided with the bypass valve and a throttle body provided with the sensor unit. This is an intake device for a multi-cylinder internal combustion engine.

  According to a second aspect of the present invention, in the intake system for a multi-cylinder internal combustion engine according to the first aspect, each of the bypass passages has a downstream end branched via the bypass valve and each intake pipe line downstream of the throttle valve. In the throttle body provided with the bypass valve, the upstream end is opened in the intake pipe upstream of the throttle valve or in the intake passage upstream of the intake pipe. .

  According to a third aspect of the present invention, in the intake device for a multi-cylinder internal combustion engine according to the first or second aspect, the sensor unit includes a protrusion detection portion that protrudes into the intake pipe upstream of the throttle valve. It is characterized by having.

  According to a fourth aspect of the present invention, in the intake device for a multi-cylinder internal combustion engine according to the third aspect, the protrusion detection unit is an intake air temperature sensor that measures an intake air temperature.

  According to a fifth aspect of the present invention, in the intake system for a multi-cylinder internal combustion engine according to any one of the first to fourth aspects, the sensor unit is detected to communicate with the intake pipe downstream of the throttle valve. And an intake pressure sensor that directly detects only the intake pressure of the intake pipe.

  According to a sixth aspect of the present invention, in the intake device of the multi-cylinder internal combustion engine according to the fifth aspect, the detection port in the intake pipe of the intake pressure sensor, and an outlet of the bypass passage in the intake pipe Are arranged at positions facing each other.

  According to a seventh aspect of the present invention, in the intake system for a multi-cylinder internal combustion engine according to any one of the first to sixth aspects, the sensor unit includes a throttle having an intake pipe provided with the sensor unit. There is a bulging portion that bulges along the mounting direction of the auxiliary device attached to the throttle body outside the mounting portion to the body, and the bulging portion is at least a part of the auxiliary device in a side view. It is characterized by covering.

  According to an eighth aspect of the present invention, in the intake device for a multi-cylinder internal combustion engine according to any one of the first to seventh aspects, the coupler of the sensor unit is attached to an intake pipe provided with the sensor unit. The fuel injection valve is disposed toward the opposite side.

  According to a ninth aspect of the present invention, in the intake device for a multi-cylinder internal combustion engine according to any one of the first to eighth aspects, the intake pipe is configured so that the multi-cylinder internal combustion engine is mounted on a vehicle. Oriented in the longitudinal direction of the vehicle, the coupler of the sensor unit extends downward, and the harness extends from the coupler toward the center in the lateral direction of the vehicle via the harness side coupler connected to the coupler. It extends below the throttle body.

According to the intake device of the multi-cylinder internal combustion engine of the first aspect, the bypass valve is provided in the throttle body where the sensor unit is not arranged, the throttle body provided with the bypass valve, and the sensor unit are provided. Since it has a bypass passage that connects to the throttle body, in the intake pipe line where the sensor unit is provided, the intake air is prevented from fluctuating due to a large amount of bypass air taken out, and the influence on the detection state of the sensor unit is reduced. Is done.
Moreover, wiring etc. are collected by consolidating a sensor in a sensor unit.

  According to the invention of claim 2, in addition to the effect of the invention of claim 1, the upstream end of the bypass passage is located at the upstream side of the throttle valve in the throttle body where the sensor unit is not disposed. By opening in the intake passage upstream of the passage, fluctuation due to intake air is reliably reduced in the intake pipe provided with the sensor unit.

  According to the invention of claim 3, in addition to the effect of the invention of claim 1 or 2, the protrusion detection part of the sensor detects when the bypass air is taken out in the same intake pipe line due to the fluctuation of the intake air. Although it is easily affected, since the bypass air is not taken out by the intake pipe provided with the sensor unit, the influence on the detection by the protrusion detection unit can be suppressed.

  According to the fourth aspect of the present invention, in the case of temperature detection by the protrusion detection unit, there is a concern about the influence of the fluctuation of the intake air, but the effect of the third aspect of the invention is effective in the measurement of the intake air temperature. .

  According to the invention of claim 5, in addition to the effect of any of the inventions of claims 1 to 4, in a multi-cylinder internal combustion engine, an intake pressure sensor built in the sensor unit allows a single intake pipe to Since the intake pressure is directly detected, piping for detecting intake pressure from a plurality of intake pipes can be omitted.

  According to the sixth aspect of the invention, in addition to the effect of the fifth aspect of the invention, the detection port of the intake pressure sensor and the outlet of the bypass passage are disposed at positions facing each other. It is possible to make it difficult for the influence of the pressure fluctuation at the time of inflow to be transmitted to the intake pressure sensor.

  According to the invention of claim 7, in addition to the effect of the invention of any one of claims 1 to 6, the auxiliary machine is protected using the sensor unit.

  According to the invention of claim 8, in addition to the effect of the invention of any one of claims 1 to 7, the harness side coupler connected to the coupler can be obtained by making the direction of the coupler opposite to the fuel injection valve. Interference with the fuel injection valve can be prevented.

  According to the invention of claim 9, in addition to the effect of the invention of any one of claims 1 to 8, the harness extending from the sensor unit is arranged toward the vehicle center through the lower part of the throttle body, so that the harness Is difficult to be exposed, is inconspicuous, and enhances the appearance.

1 is a left side view of a motorcycle equipped with a multi-cylinder internal combustion engine according to an embodiment of the present invention. FIG. 2 is an enlarged left side view showing the intake device of the multi-cylinder internal combustion engine of the present embodiment and its periphery in FIG. It is the perspective view which took out the intake device of this embodiment shown by FIG. 2, and looked back diagonally from front left. It is the perspective view which took out the air intake apparatus of this embodiment shown by FIG. 2, and looked from the diagonal left side toward the right side. It is the schematic diagram which took out the suction device periphery of this embodiment, and looked forward from the back. In addition, piping and valves show the communication relationship, and the arrangement in the vertical direction differs from the actual arrangement. FIG. 5 is an upstream side elevation view of the vicinity of the throttle body on the side where the bypass valve of the intake device of the present embodiment is provided and viewed from the rear to the front. It is the downstream elevation which took out the intake device of this embodiment, and looked toward the back from the front, and was notched partially. It is an elevational sectional view along a pipe axis of an intake pipe provided with a sensor unit of this embodiment. FIG. 9 is a plan cross-sectional view of the intake pipe line as viewed in the direction of arrows IX-IX in FIG. 8. FIG. 10 is a partial cross-sectional view of the intake pipe line as viewed in the direction of arrows XX in FIG. It is sectional drawing of Example 1 of the connection member of the discharge piping of the evaporated fuel processing apparatus in this embodiment. Similarly it is sectional drawing of Example 2 of a connection member. It is a perspective view of the modification of Example 2 of a connection member similarly. It is sectional drawing of the other modification of Example 2 of a connection member similarly. Similarly it is sectional drawing of Example 3 of a connection member. Similarly it is sectional drawing of the modification of Example 3 of a connection member.

Hereinafter, an intake system for a multi-cylinder internal combustion engine according to an embodiment of the present invention will be described with reference to FIGS.
In the present invention, the term “intake device” means, in a narrow sense, a device mainly composed of a throttle body connected to the downstream side of the air cleaner and provided between the cylinder portion of the internal combustion engine.

The directions such as front, rear, left, right, up and down in the description and claims of the present specification refer to the direction of the vehicle when the multi-cylinder internal combustion engine according to the present embodiment is mounted on a vehicle, particularly a small vehicle such as a motorcycle. Shall be followed. In the figure, arrow FR indicates the front of the vehicle, LH indicates the left side of the vehicle, RH indicates the right side of the vehicle, and UP indicates the upper side of the vehicle.
Further, in the figure, the white arrow added indicates the flow direction of the bypass air in the intake device, and the small black arrow indicates the flow direction of the air containing the fuel-containing gas (hereinafter referred to as “fuel-containing air”), This is schematically shown, and the internal flow of equipment, pipes, etc. is also indicated by solid lines.

FIG. 1 shows a left side surface of a motorcycle 1 as a vehicle according to the present embodiment. The motorcycle 1 includes a so-called double cradle-type body frame 2.
The vehicle body frame 2 includes a head pipe 3 disposed at a front end portion thereof, and a pair of left and right sides extending from the head pipe 3 to the left and right, extending slowly rearward and rearward, and extending substantially downward via the curved portion 4a. A pair of left and right main frames 4, which branch from the head pipe 3 to the left and right, extend rearward and obliquely downward, extend rearward substantially horizontally through the curved portion 5 a, and are connected to the lower ends of the pair of left and right main frames 4. The down pipe 5 is provided.

The vehicle body frame 2 further includes a pair of left and right seat rails 6 extending rearward and slightly rearward from the vicinity of the curved portions 4a of the pair of left and right main frames 4, and a pair of left and right pivot plates attached to the lower portions of the main frames 4. 7 and a pair of left and right reinforcing stays 8 extending obliquely rearward from the pivot plate 7 and connected to the seat rail 6 respectively.
A rear cushion mounting bracket 8 a for supporting the upper end portion of the rear cushion 19 is provided in the vicinity of the connecting portion between the reinforcing stay 8 and the seat rail 6. A pivot 9 is provided on the pair of left and right pivot plates 7.

A pair of left and right front forks 10 are rotatably supported on the head pipe 3, and a steering handle 12 is attached to the upper end of the front fork 10 by a top bridge 11.
A meter 13 and a headlight 14 are mounted near the top of the front fork 10, and a front wheel 16 integrated with a brake disk 15 is rotatably supported at the lower end of the front fork 10. A front fender 17 that covers the upper side of the front wheel 16 is fixed on the upper side.

  A rear swing arm 18 is supported on the pivot plate 7 of the vehicle body frame 2 via a pivot 9 so as to be swingable in a substantially vertical direction. A rear cushion 19 is interposed between the rear end of the rear swing arm 18 and the seat rail 6, and a brake disc 20 and an integrated rear wheel 21 are rotatably supported at the rear end of the rear swing arm 18. ing.

A step holder 22 extending rearward is fixed to the pivot plate 7, and foldable driver and passenger steps 23 and 24 are attached to the front and rear portions of the step holder 22. ing.
In FIG. 1, reference numerals 27 and 28 denote a foldable main stand and a side stand attached to the lower part of the vehicle body frame 2.

A fuel tank 25 is disposed above the pair of left and right main frames 4 so as to straddle the main frame 4. A driver's and passenger's seat 26 is attached to the upper portion of the seat rail 6 behind the fuel tank 25 so as to cover the seat rail 6 from above.
Also, a pair of knee covers 29 are provided below the rear portion of the fuel tank 25 in order to bring a portion below the driver's knee into contact when the driver takes a sitting posture.

  A side cover 30 is disposed behind the knee cover 29. A grab bar 31 and a rear turn signal 32 that are held by the passenger are attached to the rear portion of the seat rail 6, and a substantially arc-shaped rear fender 33 is attached as an exterior product in a side view. A tail lamp 34 and a license plate 35 are attached to the rear fender 33.

A multi-cylinder internal combustion engine (hereinafter simply referred to as “internal combustion engine”) 40 according to the present embodiment is disposed below the fuel tank 25, that is, between the main frame 4 and the down pipe 5 in a side view of the body frame 2. Has been.
The internal combustion engine 40 is an air-cooled in-line four-cylinder four-stroke cycle internal combustion engine having a crankshaft 41 oriented in the vehicle width direction of the motorcycle 1, that is, the left-right direction.

Hereinafter, the periphery of the internal combustion engine 40 will be described with reference to FIG.
The internal combustion engine 40 is disposed below the main frame 4 and supported by an engine mount 5b and the like fixed to the down pipe 5. The internal combustion engine 40 includes a crankcase 42, a cylinder block 43 connected to the upper front part of the crankcase 42 with a slight forward inclination, a cylinder head 44 connected to the upper part of the cylinder block 43, and an upper part of the cylinder head 44. The cylinder head cover 45 is connected to the cylinder head cover 45. Around the cylinder block 43 and the cylinder head 44, cooling fins 46 for air cooling are provided.
In addition, 47 in FIG. 1 is an oil cooler and is attached to the front side of the down pipe 5 ahead of the cylinder head 44.

A cylinder is provided in the cylinder block 43, and a piston is reciprocally accommodated in the cylinder. A crankshaft 41 connected to the piston via a connecting rod and an output shaft 48 of the internal combustion engine are supported in the crankcase 42, and a power transmission mechanism is configured between the crankshaft 41 and the output shaft 48. A clutch mechanism and a transmission mechanism are housed.
A drive chain (not shown) is bridged between the drive sprocket 49 attached to the output shaft 48 and the driven sprocket 50 attached to the rear wheel 21, and the rotation of the internal combustion engine 40 causes the power transmission mechanism or the like to rotate. Via the rear wheel 21.

  An exhaust pipe 52 extending downward from each exhaust port 51 on the front side is connected to the cylinder head 44, and an exhaust muffler 53 is connected to the exhaust pipe 52. The exhaust muffler 53 extends from the lower side of the vehicle body frame 2 to the right side of the vehicle body and extends obliquely rearward.

  The intake ports 54 on the rear side of the cylinder head 44 are connected to the intake air of the throttle body 61 (the first throttle body 61A and the second throttle body 61B) constituting the intake device 60 of the present embodiment via an annular insulator 55. Downstream ends 71b to 74b of the pipe lines 71 to 74 are attached (see FIGS. 3 and 5).

Further, the upstream ends 71a to 74a of the intake pipes 71 to 74 of the throttle body 61 (only the upstream ends 71a and 72a of the intake pipes 71 and 72 of the first throttle body 61A are shown in FIG. 6) are sealed around them. It is fastened to the downstream end face of the air cleaner case 56a (see FIG. 2) so as to communicate with the inside of the air cleaner 56 through 62.
In the fastened state, the region surrounded by the seal 62 forms an upstream intake passage for intake air that is in communication with the inside of the air cleaner 56 on the upstream side of the intake pipes 71 to 74. FIG. 6 shows the upstream intake passage 75A of the first throttle body 61A.
In FIG. 1, the air cleaner 56 is covered with the knee cover 29 and the side cover 30.

That is, in the present embodiment, the intake device 60 is connected to the downstream side of the air cleaner 56 and mainly includes a throttle body 61 (61A, 61B) provided between the cylinder portion (cylinder head 44) of the internal combustion engine 40. Refers to the device.
The air purified by the air cleaner 56 is sent into the cylinder head 44 of the internal combustion engine 40 via the intake device 60, the insulator 55, and the intake port 54.

As shown in FIGS. 3 to 5, the intake device 60 of the present embodiment is an intake device for an in-line four-cylinder internal combustion engine, and includes first and second throttle bodies 61A and 61B arranged in parallel. Yes. Each of the throttle bodies 61A and 61B is provided with a pair of intake pipes 71, 72, 73 and 74 which are parallel to each other and have downstream ends 71b to 74b facing the internal combustion engine 40 (see FIGS. 1 and 2) substantially forward. The air cleaner case 56a is constructed so that the upstream ends 71a to 74a of the intake pipes 71, 72, 73, 74 communicate with the interior of the air cleaner 56 at the rear ends of the throttle bodies 61A, 61B. (See FIG. 2).
The two throttle bodies 61A and 61B are integrally connected to each other by a connecting bolt 63, and the pair of intake pipes 71, 72, 73 and 74 are arranged symmetrically.

As shown in FIGS. 3 and 6, throttle valve shafts 64A and 64B traversing the respective intake pipes 71, 72, 73, and 74 are rotatably supported by the throttle bodies 61A and 61B. Throttle valves 81, 82, 83, 84 for opening and closing the pipe lines 71, 72, 73, 74 are attached to the throttle valve shafts 64A, 64B.
Both throttle valve shafts 64A and 64B are arranged coaxially, and their opposite ends are connected to each other via a throttle drum 65, and the throttle drum 65 is rotated by a throttle wire 66 (see FIG. 5). As a result, all the throttle valves 81, 82, 83, 84 can be opened and closed simultaneously.

  Fuel injection for injecting fuel into each intake port 54 of the internal combustion engine 40 through the intake pipes 71, 72, 73, 74 on the downstream side of the throttle valves 81, 82, 83, 84 to the throttle bodies 1A, 1B. Valves 91, 92, 93, 94 are mounted. A fuel supply pipe 95 is connected to each fuel injection valve 91-94.

  As shown in FIG. 5, in the intake device 60, a bypass passage that bypasses the throttle valves 81 to 84 in the intake pipes 71 to 74 and connects the upstream side and the downstream side of the intake pipes 71 to 74. 101 to 104 are respectively provided, and the bypass passages 101 to 104 are provided with a single bypass valve 100 for controlling the amount of bypass air flowing therethrough.

The bypass valve 100 is provided in the first throttle body 61A, not the second throttle body 61B provided with an intake pipe 74 provided with a sensor unit 120 described later.
As shown in FIG. 6, the rear end surface 61Aa of the first throttle body 61A on the air cleaner 56 side is surrounded by the above-described seal 62, and in the upstream intake passage 75A communicating with the inside of the air cleaner 56, a pair of intake pipes A bypass air inlet chamber 76 opened between the upstream ends 71a and 72a of the 71 and 72 is formed.
A bypass valve introduction passage 77 is formed in the bypass air inlet chamber 76 so as to open, and the bypass valve introduction passage 77 is connected to the inlet side of the bypass valve 100 provided in the first throttle body 1A.

The bypass air inlet chamber 76 formed on the rear end surface 61Aa of the first throttle body 1A is connected to the upstream end 71a, 72a of the intake pipes 71, 72 and the upstream side as the intake passage upstream of the intake pipes 71, 72. It communicates with the intake passage 75A and further communicates with the inside of the air cleaner 56 on the upstream side.
Therefore, the bypass air inlet chamber 76 and the bypass valve introduction path 77 constitute a single bypass upstream passage 110 on the upstream side of the bypass valve 100 that controls the amount of bypass air.

  As shown in FIG. 5, a pair of bypass downstream passages 111, 112, 113, 114 extend from the bypass valve 100, and one set of bypass downstream passages 111, 112 extends from the throttle valve 81, 82 of the first throttle body 61 </ b> A. The other downstream bypass passages 113 and 114 open to the intake pipes 71 and 72 downstream, and the other downstream bypass passages 113 and 114 open to the intake pipes 73 and 74 downstream of the throttle valves 83 and 84 of the second throttle body 61B. .

Bypass upstream passage 110 and bypass downstream passages 111, 112, 113, 114 are bypass passages 101, 102, 103, 104 connected to intake pipes 71, 72, 73, 74, bypassing throttle valves 81, 82, 83, 84, respectively. The bypass upstream passage 110 is configured as a single upstream passage common to all the bypass passages 101, 102, 103, and 104.
The bypass valve 100 distributes the bypass air introduced into the single bypass upstream passage 110 to the bypass downstream passages 111, 112, 113, 114, and passes the bypass air through the bypass downstream passages 111, 112, 113, 114 to the intake pipes 71, 72, In addition to supplying to 73 and 74 respectively, it has a function to control the amount of bypass air at the same time.

  The bypass valve 100 itself is a known one, and detailed description is omitted. However, bypass air that has entered the cylindrical valve chamber 105 shown in FIG. From the measured holes 107A1, 107A2, 107B3, 107B4, the flow rate is adjusted from fully closed to fully open by the valve body 106 that is controlled to slide in the valve chamber 105 in the axial direction, and flows into the bypass downstream passages 111, 112, 113, 114. .

As shown in FIG. 5, the downstream end portions of the bypass downstream passages 111, 112, 113, 114 opened downstream of the intake pipes 71, 72, 73, 74 of the first and second throttle bodies 61A, 61B Restriction holes 108A1, 108A2, 108B3, 108B4 are provided, respectively.
The throttle holes 108B3 and 108B4 on the second throttle body 1B side without the bypass valve 100 are formed to have larger diameters than the throttle holes 108A1 and 108A2 on the first throttle body 1A side including the bypass valve 100. The difference in diameter between the throttle holes 108A1 and 108A2 and the throttle holes 108B3 and 108B4 is determined by the difference in length between the bypass downstream passages 111 and 112 and the bypass downstream passages 113 and 114 corresponding thereto.

That is, on the first throttle body 61A side, the bypass valve 100 supported by the bypass valve 100 is disposed at a relatively short equidistant position with respect to the pair of intake pipes 71, 72. The lengths of the bypass downstream passages 111 and 112 are set to be relatively short and equal to each other. Therefore, the throttle holes 108A1 and 108A2 are formed to have a relatively small diameter.
On the other hand, on the second throttle body 61B side that does not have the bypass valve 100, the lengths of the bypass downstream passages 113 and 114 from the bypass valve 100 to the intake pipes 73 and 74 are inevitably long. Therefore, the throttle holes 108B3 and 108B4 Is formed with a relatively large diameter.

  On the other hand, as shown in FIGS. 3 to 5, in the intake device 60 of the present embodiment, the bypass upstream passage 110 and the bypass valve 100 are not provided, that is, the upstream ends of the bypass passages 101, 102, 103, and 104 are not provided. 2 In the throttle body 61B, on the left side of the intake pipe 74 at the left end, an intake pressure sensor 121 for detecting the intake pressure (Pb), an intake air temperature sensor 122 for detecting the intake air temperature (Ta), and a throttle opening ( There is provided a sensor unit 120 that is also provided with a throttle sensor 123 for detecting Th).

  As shown in FIG. 5, in the sensor unit 120, a throttle sensor 123 is attached to the left end portion of the throttle valve shaft 64B of the second throttle body 61B, and the intake air temperature of the intake air passing through the intake pipe 74 is detected. For this purpose, an intake air temperature sensor 122 having a protrusion detection part 122a protruding in the intake pipe line 74 is provided, and in order to detect the intake pressure, the intake pressure sensor is opened to open the detection port 121a. 121 is provided.

As shown in more detail in FIGS. 8 and 9, an intake air temperature sensor protruding into the intake pipe 74 is provided upstream of the throttle valve 84 of the intake pipe 74 provided with the sensor unit 120 of the present embodiment. 122 protrusion detection parts 122a are provided.
A throttle sensor 123 that detects the throttle opening is provided at the left end of the throttle valve shaft 64B of the second throttle body 61B.
As shown in FIG. 9, an outlet 114 a of the bypass passage 104 (bypass downstream passage 114) into which bypass air flows is opened on the right bottom surface of the intake pipe 74 on the downstream side of the throttle valve 84.

Further, as shown in FIG. 10 which shows a cross section of the intake pipe line 74 at the same position as the downstream end 114a of the bypass downstream path 114, the detection port 121a of the suction pressure sensor 121 is provided on the upper surface of the intake pipe line 74. Is provided.
That is, the detection port 121a of the intake pressure sensor 121 and the outlet 114a in the intake pipe 74 of the bypass passage 104 are disposed at positions facing each other.
The detection port 121a communicates with the suction pressure sensor 121 provided in the sensor unit 120, and the suction pressure sensor 121 directly detects only the intake pressure of the intake pipe 74 provided with the sensor unit 120. .

Further, as shown in FIG. 4, the sensor unit 120 of the present embodiment is disposed on the throttle body 61B outside the attachment portion 120a to the second throttle body 61B having the intake pipe 74 attached thereto. It has a bulging portion 120b that bulges along the mounting direction of the fuel injection valves 93 and 94, which are attached accessories, and the bulging portion 120b is at least part of the fuel injection valves 93 and 94 in a side view. Covering.
The wiring coupler 124 of the sensor unit 120 is disposed on the opposite side of the fuel injection valve 94 attached to the intake pipe 74 where the sensor unit 120 is provided.

Further, in a state where the internal combustion engine 40 of the present embodiment is mounted on the motorcycle 1, the intake pipes 71 to 74 are oriented in the front-rear direction of the motorcycle 1, and the coupler 124 of the sensor unit 120 faces downward. It extends to.
A harness 126 connecting the sensor unit 120 and the electronic control unit 125 (see FIG. 2) is directed toward the center in the left-right direction of the motorcycle 1 from the coupler 124 via a harness-side coupler 127 connected to the coupler 124. Thus, it extends below the throttle body 61 (see FIG. 3).

In the intake system for a multi-cylinder internal combustion engine of the present embodiment configured as described above, when the internal combustion engine 40 is warmed up, the electronic control unit 125 supplies a current corresponding to the temperature of the internal combustion engine 40 to the electric actuator of the bypass valve 100. Therefore, when the internal combustion engine 40 is at a low temperature, the valve body 106 is moved largely to adjust the opening degree of the measuring holes 197A1, 107A2, 107B3, 107B4. Therefore, in a state where the throttle valves 81, 82, 83, 84 are fully closed, the bypass air (first idle air) supplied to the internal combustion engine 40 through the bypass passages 101, 102, 103, 104 is the measurement holes 197A1, 107A2, 107B3, 107B4. At the same time, fuel corresponding to the degree of opening of the bypass valve 100 is injected from the fuel injection valves 91, 92, 93, 94 toward the downstream side of the intake pipes 71, 72, 73, 74, The internal combustion engine 40 can maintain an appropriate first idling rotational speed so as to promote warm-up operation.
When the temperature of the internal combustion engine 40 increases due to the progress of the warm-up operation, the opening degree of the bypass valve 100 is decreased accordingly, and when the temperature of the internal combustion engine 40 reaches a predetermined high temperature, the bypass valve 100 is closed.

The intake device 60 of the present embodiment has the following characteristics.
In the intake device 60, the bypass valve 100 is provided not in the second throttle body 61B including the intake pipe line 74 provided with the sensor unit 120 but in the other first throttle body 61A.
The upstream ends of the bypass passages 101, 102, 103, 104 are first intake passages upstream of the throttle valves 81, 82 as the single bypass upstream passage 110 in the first throttle body 61 A provided with the bypass valve 100. It opens to an upstream side intake passage 75A formed in the throttle body 61A, and further communicates with the outlet of the air cleaner 56.

The downstream ends of the bypass downstream passages 111 to 114 branched through the bypass valve 100 are connected to the intake pipes 71 to 74 on the downstream side of the throttle valves 81 to 84, respectively.
That is, the bypass passages 103 and 104 are provided to connect the first throttle body 60A provided with the bypass valve 100 and the second throttle body 60B provided with the sensor unit 120.

  In addition, the detection of the intake pressure and intake air temperature states of the intake air passing through the intake pipes 71 to 74 does not include the bypass upstream passage 110 and the bypass valve 100, and does not include the upstream ends of the bypass passages 101, 102, 103, and 104. 2. This is performed in the sensor unit 120 provided in the intake pipe 74 of the throttle body 61B.

  Therefore, when detecting the intake air pressure and intake air temperature, it is possible to reduce the influence of taking out a large amount of bypass air for 71 to 74 minutes for all intake pipes, and to suppress fluctuations in the intake air. The influence on the detection state of each sensor is reduced.

  In addition, since the sensor unit 120 is provided in one intake pipe 74 among the plurality of intake pipes 71 to 74 and is collectively detected by one sensor unit 120, the arrangement, attachment, and The arrangement of wiring, piping, etc. from each sensor can be consolidated and organized, eliminating the complexity, and reducing the number of parts, assembly man-hours, and maintenance man-hours.

Further, the sensor unit 120 has a protrusion detection part 122 a that protrudes into the intake pipe 74 on the upstream side of the throttle valve 84. The sensor protrusion detection unit 122a is susceptible to detection due to fluctuations in the intake air if the bypass air is taken out in the same intake pipe 74, but the bypass air is taken out by the intake pipe 74 provided with the sensor unit 120. Therefore, the influence on the detection by the protrusion detection unit 122a can be suppressed.
In the case of temperature detection by the protrusion detection unit 122a, there is a particular concern about the influence of fluctuations in the intake air. However, as described above, the bypass air is not taken out by the intake pipe 74 provided with the sensor unit 120. The effect is effective in measuring the intake air temperature.

  Further, the sensor unit 120 includes a detection port 121a communicating with the intake pipe 74 on the downstream side of the throttle valve 84, and the intake pressure sensor 121 incorporated in the sensor unit 120 allows only the single intake pipe 74 to be connected. Since the intake pressure is directly detected, piping for taking out and detecting the intake pressure individually from the plurality of intake pipes 71 to 74 in the internal combustion engine 40 can be omitted.

  In addition, since the detection port 121a in the intake pipe 74 of the intake pressure sensor 121 and the outlet 114a in the intake pipe 74 of the bypass passage 104 are arranged to face each other, the detection port 121a of the intake pressure sensor 121 and the bypass Since the outlet 114 a of the passage 104 is disposed at a position facing away from the passage 104, the influence of pressure fluctuation when the bypass air flows into the intake pipe 74 is difficult to be transmitted to the intake pressure sensor 121.

  Further, the sensor unit 120 is a fuel that is an auxiliary machine attached to the second throttle body 61B outside the attachment portion 120a to the second throttle body 61B having the intake pipe line 74 provided with the sensor unit 120. Since the bulging portion 120b bulges along the mounting direction of the injection valves 93 and 94, and the bulging portion 120b covers at least a part of the fuel injection valves 93 and 94 in a side view, the sensor unit 120 is used. Thus, the fuel injection valves 93 and 94 are protected.

  Further, since the coupler 124 of the sensor unit 120 is disposed toward the opposite side of the fuel injection valve 94 attached to the intake pipe 74 provided with the sensor unit 120, the direction of the coupler 124 is changed to the fuel injection valve. By making it opposite to 94, interference between the harness-side coupler 127 connected to the coupler 124 and the fuel injection valve 94 can be prevented.

  Further, in a state where the internal combustion engine 40 is mounted on the motorcycle 1, the intake pipes 71 to 74 are oriented in the front-rear direction of the motorcycle 1, the coupler 124 of the sensor unit 120 extends downward, and the coupler 124 Since the harness 126 is extended downward from the coupler 124 toward the center in the left-right direction of the motorcycle 1 via the harness-side coupler 127 connected to the vehicle, the harness 126 extending from the sensor unit 120 is provided. Since the harness 126 is disposed toward the center of the vehicle through the lower part of the throttle body 61, the harness 126 is difficult to be exposed and hardly noticeable, and the appearance is improved. Further, the detection signals detected by the sensor unit can be connected to the electronic control unit 125 (see FIG. 2) inconspicuously and simply by the harness 126 gathered together through one coupler 124.

The intake device 60 of the internal combustion engine 40 according to the present embodiment can detect the intake state by the single intake pipe 74 provided with the sensor unit 120, since disturbance elements due to bypass air extraction are particularly suppressed. ing.
That is, when detecting the intake pressure, an intake pressure tube connected to and connected to the intake pipe of each cylinder is provided, which is often seen in a multi-cylinder internal combustion engine. Since the method of detecting by connecting to the pressure sensor is not adopted, the suction device 60 of this embodiment eliminates the suction pressure tube.
As a result, a configuration was obtained in which the evaporated fuel processing device was connected to the intake device 60 in a simple and effective manner as described below.

In FIG. 5, the evaporative fuel processing connected to the intake device 60 of this embodiment is shown above the first throttle body 61A and the second throttle body 61B (in the drawing, not the actual direction of the device). Device 130 is schematically illustrated.
The evaporative fuel processing apparatus 130 in the present embodiment is a well-known one whose outline is generally configured as follows.

Reference numeral 131 in FIG. 5 denotes a fuel gas generation source such as a fuel tank. From the viewpoint of environmental protection, the gas gf containing fuel generated from the fuel gas generation source 131 is required to be processed without being directly discharged into the atmosphere, and an evaporative fuel processing apparatus incorporating an adsorbent such as activated carbon It is sent to 130 canisters 132 and adsorbed by the adsorbent.
The gas gf containing the adsorbed fuel is separated from the adsorbent by the purge air pa, and the air af containing the gas gf containing the recovered fuel (hereinafter simply referred to as “fuel-containing air af”) is evaporated fuel processing. Gas is purified by passing through the discharge pipe 133 of the apparatus 130 and returning to the intake pipes 71 to 74 and burning in the internal combustion engine 40.

As shown in FIG. 5, the evaporated fuel processing apparatus 130 includes a discharge pipe 133 that sends fuel-containing air af from the canister 132 to the intake pipes 71 to 74.
The discharge pipe 133 is configured by connecting a single upstream pipe 140 and a plurality of branch pipes 141 to 144 serving as downstream pipes via a connecting member 134. The downstream ends of the branch pipes 141 to 144 are connected to and opened on the downstream side of the throttle valves 81 to 84 of the intake pipes 71 to 74, respectively.

As shown in FIG. 7, each of the branch pipes 141 to 144 has a downstream end standing on each intake pipe 71 to 74 and a joint member 151 serving as a connecting portion communicating with each intake pipe 71 to 74. It connects with each intake pipe 71-74 via ~ 154.
That is, the discharge pipe 133 of the evaporative fuel processing apparatus 130 that recovers the fuel-containing air af containing gas containing fuel and returns the recovered fuel-containing air af to the intake pipes 71 to 74 via the discharge pipe 133. Are connected to the intake pipes 71-74.
As described above, the joint members 151 to 154 of the present embodiment are conventionally detected by connecting the intake pressure tubes connected to the intake pipes of the respective cylinders and connecting them to the intake pressure sensors. The suction pressure tube joint member is provided instead.

That is, in the intake device 60 of the present embodiment, since the intake pressure is detected at one location of the sensor unit 120, there is no need to provide a suction pressure tube, and a location where a suction pressure tube joint member has conventionally been erected is used. Then, the joint members 151 to 154 for connecting the branch pipes 141 to 144 of the discharge pipe 133 of the evaporated fuel processing apparatus 130 are erected, and the evaporated fuel processing apparatus 130 can be easily changed without changing the conventional apparatus. Can be configured.
However, it is not always necessary to use the portion where the suction pressure tube joint member of the conventional intake device is erected. In the newly manufactured intake device, the branch pipes 141 to 144 of the discharge pipe 133 are used. Needless to say, the joint members 151 to 154 for connecting the members may be newly provided at the locations.

  In addition, in the case of the conventional suction pressure tube joint member, it has a throttle structure for detecting the intake pressure, and even in the case of the branch pipes 141 to 144 of the discharge pipe 133 of the present embodiment, In order to send the fuel-containing air af into the intake pipes 71 to 74, it is necessary to provide some kind of restriction for adjusting the flow rate. However, the joint members 151 to 155 of the present embodiment have a restriction. It does not have a straight pipe line.

That is, the downstream ends of the branch pipes 141 to 144, which are downstream pipes branched by the connection member 134 of the discharge pipe 133 of the evaporated fuel processing device 130, are connected to the intake pipes 71 to 74 to each cylinder of the internal combustion engine 40. In each of the joint members 151 to 154, no restriction is provided, and a restriction is provided in the connection member 134 that branches the discharge pipe 133.
Therefore, the number of members provided with the diaphragm is reduced, and the diaphragm only needs to be provided on the connection member 134. In addition to facilitating the molding of the diaphragm, versatility can be obtained and the cost can be reduced. This makes it possible to reduce the stroke, and consequently, the molding and processing costs of the throttle bodies 61A and 61B having the intake pipes 71 to 74 can be reduced.

  In addition, since the throttle is not provided at the connection part of the branch pipes 141 to 144 of the discharge pipe 133 to the intake pipes 71 to 74, the connection part is provided as a separate joint member 151 to a conventional one as illustrated in FIG. The configuration is not limited to 154. A boss-like connection portion having a flow path that only connects the branch pipes 141 to 144 may be provided on the intake pipe lines 71 to 74 side, and the structure can be simplified and the number of members can be reduced.

FIG. 11 shows a first embodiment of the connecting member 134 and will be described below.
The connection member 161 of Example 1 is the same as the connection member 134 illustrated in FIGS. 5 to 7 in the intake device 60 of the present embodiment.
As shown in FIG. 11, the connection member 161 includes an introduction part 161a to which the upstream pipe 140 of the discharge pipe 133 is connected and into which the fuel-containing air af is introduced, along the introduction pipe line 161b of the introduction part 161a. The branch portions 161c are formed to extend in a plurality of stages in the intersecting direction (the right-angle direction in the embodiment), and a restriction 171 is provided in the branch pipe line 161d of each branch portion 161c.

  The branch pipes 141 are connected to the branch parts 161c. The fuel-containing air af introduced from the upstream side pipe 140 is adjusted in flow rate by the throttle 171, is divided into the branch pipes 141, and is sent to the intake pipes 71 through the joint portions 151. . The fuel-containing air af is sent to each cylinder of the internal combustion engine 40, burned, and processed.

  Therefore, in the connection member 161 of the first embodiment, the connection member 161 provided with the branch portions 161c according to the number of cylinders of the internal combustion engine 40 can be obtained without using a plurality of connection members, so that the number of parts is not increased. The discharge pipe 133 is simplified.

FIG. 12 shows a second embodiment of the connecting member 134 and will be described below.
As shown in FIG. 12, the connection member 162 of the second embodiment includes an introduction portion 162a to which the upstream side pipe 140 of the discharge pipe 133 is connected and into which the fuel-containing air af is introduced, with the introduction portion 162a as the center. The branch parts 162c extend radially in pairs (in the embodiment, in a direction perpendicular to the introduction part 162a), and the restriction 171 is provided in the branch line 162d of the branch part 162c at an equal distance from the introduction pipe line 162b of the introduction part 162a. It is arranged.

  The connection from the connecting member 162 to the branch pipes 141..., The joint members 151..., The connection to the intake pipes 71, and the processing of the fuel-containing air af are the same as described in the first embodiment.

  For this reason, in the connection member 162 of the second embodiment, the throttle 171 is disposed at equal distances in each branch pipe 162d branched from the single introduction pipe 162b, so that the fuel-containing air af in the introduction pipe 162b. Are evenly shunted.

FIG. 13 shows a modification of the connection member 134 according to the second embodiment, which will be described below.
As shown in FIG. 13, in the connection member 163 of the modification of the second embodiment, a plurality of pairs of the branch portions 163c of the connection member 163 are arranged in a radial manner, and other than that, the introduction portion 163a, the introduction pipe line 163b, The branch pipe 163d, a throttle (not shown), and the like are the same as those in the connection member 162 of the second embodiment.

  Therefore, in the connection member 163 of the modification of the second embodiment, in addition to the features of the second embodiment, the single connection member 163 forms a branch portion 163c corresponding to the number of cylinders of the internal combustion engine 40, thereby suppressing an increase in the number of parts. Is done.

FIG. 14 shows another modification of the connecting member 134 according to the second embodiment, which will be described below.
As shown in FIG. 14, the connecting member 164 of another modification of the second embodiment includes an introduction part 164a into which the fuel-containing air af is introduced, and one branch part formed by extending the introduction part 164a straight. 164c1, and an introduction part 164a and another branch part 164c2 formed in the crossing direction (the right-angle direction in the embodiment).
In the introduction part 164a, a drawing hole 174 is formed at the projection position of the branch pipe 164d2 of the other branch part 164c2, and after the drawing of the diaphragm 171 of the other branch part 164c2, the drawing hole 174 becomes a blocking member 175. It is closed and formed.
The branch pipe 164d1 of the one branch part 164c1 is directly connected to the introduction pipe 164b of the introduction part 164a in a straight line, and a restriction 171 is provided.

  Therefore, in the connection member 164 of another modification of the second embodiment, in addition to the features of the second embodiment, the throttle 171 in one branch portion 164c1 is formed through the introduction conduit 164b, and the throttle 171 in the other branch portion 164c2 is After forming through the drawing hole 174, the drawing hole 174 can be closed by the closing member 175, and the connecting member 164 having the drawing 171 is easily formed.

FIG. 15 shows a third embodiment of the connecting member 134 and will be described below.
As shown in FIG. 15, the third embodiment is another example in which the discharge pipe 133 is interposed in the middle of the upstream pipe 140 on the upstream side of the connection members 162 to 164 shown in the second embodiment and the modifications thereof. A connecting member 165 is provided.
The other connecting member 165 includes an introduction portion 165a that is introduced with fuel-containing air af and includes an introduction pipe line 165b, and a delivery pipe line 165f that communicates with the introduction pipe line 165b. The connection members 162 to 164 receive the fuel-containing air af. A delivery part 165e for delivery and a branching part 165c for coupling other downstream pipes are provided. A branch pipe 165d of the branch part 165c communicates with the introduction pipe 165b and has a restriction 171.

  For this reason, in the third embodiment, by adding another connecting member 165 according to the number of cylinders of the internal combustion engine 40, it is possible to add another branch pipe with the restriction 171 interposed, and the evaporated fuel processing in the multi-cylinder internal combustion engine The discharge pipe 133 of the device 130 is configured easily and simply.

FIG. 16 shows a modification of the connection member 134 according to the third embodiment, which will be described below.
As shown in FIG. 16, the other connecting member 166 of the modification of the third embodiment is formed with four pipe lines 166b, 166f, 166d, 166d communicating in a cross shape, and branching a pair of adjacent pipe lines A branch pipe 166d of the portion 166c is provided, and a throttle 171 is provided in the branch pipe 166d.
Other than that, the introduction part 166a, the introduction pipeline 166b, the delivery part 166e, the delivery pipeline 166f, and the like are the same as in the other connection members 165 of the third embodiment.

However, in the present modification, the pair of adjacent pipe lines of the four pipe lines communicating in a cross shape are the branch pipe lines 166d of the branch portion 166c, so that each branch pipe line 166d is not provided with the restriction 171. Directly connected to the introduction pipe line 166b or the delivery pipe line 166f.
Therefore, in addition to the features in the third embodiment, a tool for forming the restrictor 171 from the end opening of the conduit 166b or 166f of the introduction portion 166a or the delivery portion 166e linearly connected to the branch conduit 166d where the restrictor is provided is provided. Since it can be inserted, the restriction 171 of the branch line 166d is easily formed using the introduction line 166b or the delivery line 166f.

Further, in the first to third embodiments (including modifications), as shown in FIGS. 11 to 16, a retaining member 172 whose part is raised is provided on the outer periphery of the end of each of the branch portions 161 c to 166 c. The stoppers 173 are formed in the introduction parts 161a to 166a, and the stoppers 174 are formed in the delivery parts 165e and 166e so as to prevent the pipes to be connected from coming off.
In particular, the stoppers 172 of the branch portions 161c to 166c are arranged so as to be shifted from the diaphragm 171.
Therefore, when the branch pipes 141... And another branch pipe are connected, the influence of the deformation caused by the branch portions 161c to 166c being compressed by the retaining member 172 is suppressed, and the fuel-containing air af Disturbances in the amount of inflow into each of the intake pipes 71 to 74 are prevented.

As mentioned above, although embodiment of this invention was described, this invention is not limited to it, A various design change is possible in the range which does not deviate from the summary.
For example, the present invention can be applied to a downdraft type throttle body in which the intake pipe is substantially vertical.
Further, in the above embodiment, the upstream ends of the bypass passages 101 to 104, that is, the upstream end of the bypass upstream passage 110, are located on the first throttle body 61A from the intake pipes 71 and 72 upstream of the throttle valves 81 and 82. Although it opens in the upstream intake passage 75A, which is the upstream intake passage, it may be opened in either or both of the intake pipes 81, 82 upstream of the throttle valves 81, 82.

  DESCRIPTION OF SYMBOLS 1 ... Motorcycle (vehicle), 2 ... Body frame, 25 ... Fuel tank, 40 ... Internal combustion engine (multi-cylinder internal combustion engine), 42 ... Crankcase, 43 ... Cylinder block, 44 ... Cylinder head, 51 ... Exhaust port, 54 Intake port, 55 ... Insulator, 56 ... Air cleaner, 60 ... Intake device, 61 ... Throttle body, 61A ... First throttle body, 61B ... Second throttle body, 62 ... Seal, 64A ... Throttle valve shaft, 64B ... Throttle valve Axis 71-74 ... Intake pipe, 75A ... Upstream intake passage, 81-84 ... Throttle valve, 91-94 ... Fuel injection valve (auxiliary), 100 ... Bypass valve, 101-104 ... Bypass passage, 110 ... Bypass upstream passage, 111-114 ... Bypass downstream passage, 114a ... Outlet, 120 ... Sensor unit, 120a ... Mounting portion, 120b ... Swelling portion, 121 ... Intake pressure sensor, 121a ... Detection port, 122 ... Intake temperature sensor, 122a ... Projection detection unit, 123 ... Throttle sensor, 124 ... coupler, 125 ... electronic control unit, 126 ... harness, 127 ... harness side coupler

Claims (9)

The multi-cylinder internal combustion engine (40) has a plurality of throttle bodies (61A, 61B) each having one or a plurality of intake pipes (71 to 74) connected to each cylinder, and the intake pipes (71 to 74) Provided with a bypass passage (101-104) that bypasses the throttle valve (81-84) and connects the upstream side and the downstream side of the intake pipe (71-74), the bypass passage (101-104) Is an intake device of a multi-cylinder internal combustion engine in which a bypass valve (100) for controlling the amount of bypass air flowing is interposed,
A sensor unit (120) is provided in any one of the intake pipe lines (71 to 74).
The bypass valve (100) is provided in the throttle body (61A) other than the throttle body (61B) provided with the intake pipe (74) provided with the sensor unit (120),
The bypass passages (101 to 104) are connected to a throttle body (61A) provided with the bypass valve (100) and a throttle body (61B) provided with the sensor unit (120). And an intake device for a multi-cylinder internal combustion engine. ,
The bypass passages (101 to 104) are connected to the intake pipes (71 to 74) downstream of the throttle valves (81 to 84) at the downstream ends branched through the bypass valves (100), and are connected to the upstream ends. However, in the throttle body (61A) provided with the bypass valve (100), the intake pipe (71, 72) upstream of the throttle valve (81, 82) or the upstream of the intake pipe (71, 72). 2. An intake system for a multi-cylinder internal combustion engine according to claim 1, wherein the intake system is opened in a side intake passage (75A).   The multiple sensor unit (120) according to claim 1 or 2, wherein the sensor unit (120) has a protrusion detection part (122a) protruding into the intake pipe (74) on the upstream side of the throttle valve (84). Intake device for a cylinder internal combustion engine.   The intake device for a multi-cylinder internal combustion engine according to claim 3, wherein the protrusion detection unit (122a) is an intake air temperature sensor (122) for measuring an intake air temperature.   The sensor unit (120) includes a detection port (121a) communicating with the intake pipe (74) on the downstream side of the throttle valve (84), and directly detects only the intake pressure in the intake pipe (74). The intake device for a multi-cylinder internal combustion engine according to any one of claims 1 to 4, further comprising an intake pressure sensor (121).   The detection port (121a) in the intake pipe (74) of the intake pressure sensor (121) and the outlet (114a) in the intake pipe (74) of the bypass passage (104) are in a position facing each other. 6. The intake system for a multi-cylinder internal combustion engine according to claim 5, wherein the intake system is disposed.   The sensor unit (120) has a throttle body (61B) on the outer side of the attachment portion (120a) of the throttle body (61B) provided with the intake pipe (74) provided with the sensor unit (120). ) And a bulging portion (120b) that bulges along the mounting direction of the auxiliary device (93,94), and the bulging portion (120b) of the auxiliary device (93,94) is seen in a side view. The intake device for a multi-cylinder internal combustion engine according to any one of claims 1 to 6, wherein at least part of the intake device is covered.   The coupler (124) of the sensor unit (120) is disposed toward the opposite side of the fuel injection valve (94) attached to the intake pipe (74) provided with the sensor unit (120). The intake device for a multi-cylinder internal combustion engine according to any one of claims 1 to 7.   In the state where the multi-cylinder internal combustion engine (40) is mounted on the vehicle (1), the intake pipes (71 to 74) are oriented in the front-rear direction of the vehicle (1), and the sensor unit (120) The coupler (124) extends downward, and the harness (126) extends from the coupler (124) toward the center in the vehicle left-right direction via the harness-side coupler (127) connected to the coupler (124). The multi-cylinder internal combustion engine intake device according to any one of claims 1 to 8, wherein the intake body extends below the throttle body (61).

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