Throttle device and intake system of internal combustion engine

Abstract

A throttle device is provided which is capable of recovering fuel evaporative gas and generating a swirling flow in a combustion chamber, while reducing the number of parts, simplifying the structure, making it smaller, and reducing costs. [Solution] The engine comprises a body 10 which defines a main passage 11a which is part of the main intake passage, a sub-passage 15 which is part of the sub-intake passage, and a purge passage 16 which is part of the gas passage, a throttle valve 30 which opens and closes the main passage, a throttle shaft 20 which fixes the throttle valve and is rotatably supported on the body, a first regulating valve 25 which adjusts the flow rate of the sub-passage, and a second regulating valve 26 which adjusts the flow rate of the purge passage, the first regulating valve 25 and the second regulating valve 26 rotating integrally with the throttle shaft 20 to be driven to open and close.

Description

[Technical Field]

[0001] The present invention relates to a throttle device applied to an internal combustion engine of a vehicle, such as a motorcycle, and an intake system of the internal combustion engine. [Background technology]

[0002] A known intake system for a conventional internal combustion engine includes an inlet pipe that defines the intake passage, an intake valve that opens and closes the intake passage at a position facing the combustion chamber, an injector provided in the inlet pipe to inject fuel midway through the intake passage, a throttle valve provided in the inlet pipe and driven by a drive mechanism to open and close the intake passage, a partition plate downstream of the throttle valve that separates the intake passage into an upper intake passage and a lower intake passage, and an intake distribution valve provided in the inlet pipe downstream of the throttle valve and adjacent to the upstream edge of the partition plate and driven by a separate drive mechanism; the intake distribution valve is rotated appropriately to change the ratio of air flowing through the upper intake passage and the lower intake passage (see, for example, Patent Document 1). However, the above-described intake system requires a drive mechanism for driving the throttle valve and a drive mechanism for driving the intake distribution valve, which increases the number of parts, complicates the structure, increases the size, and increases the cost.

[0003] Other known intake systems include a canister arrangement structure or a fuel vapor recovery device that includes a canister that temporarily stores fuel vapor generated in the fuel tank, a purge pipe that directs the vapor from the canister to the intake passage of the internal combustion engine, and a purge valve equipped with a dedicated drive source downstream of the canister or midway through the purge pipe, and that appropriately controls the purge valve with the dedicated drive source so that the vapor in the canister is introduced into the intake passage at a desired flow rate (see, for example, Patent Document 2 and Patent Document 3). However, the above-described canister arrangement structure or fuel evaporative gas recovery device requires a purge valve equipped with a dedicated drive source, which leads to an increase in the number of parts, an increase in size, and an increase in cost.

[0004] Furthermore, as another intake system, an intake system control device is known that includes a throttle valve that opens and closes the intake passage, a throttle body that includes the intake passage, a bypass passage, and a purge passage, a flow path switching mechanism that switches the blocked state of the bypass passage and the purge passage by the driving force of the throttle valve, and a flow control valve that adjusts the flow rate of the bypass passage or the purge passage (see, for example, Patent Document 4). However, in the above-mentioned intake system control device, the flow control valve is driven by a driving force separate from the driving force of the throttle valve, so a dedicated driving source is required, which results in an increase in the number of parts, a complex structure, an increase in size, and high costs. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5925878 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-7537 [Patent Document 3] Japanese Patent Application Laid-Open No. 2016-8014 [Patent Document 4] Japanese Patent Application Laid-Open No. 2010-19185 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above circumstances, and its object is to provide a throttle device and an intake system for an internal combustion engine that can recover fuel evaporative gas and generate swirling flows such as swirl flows and tumble flows in the combustion chamber, while reducing the number of parts, simplifying the structure, reducing costs, and making the system smaller. [Means for solving the problem]

[0007] The throttle device of the present invention is a throttle device applied to the intake system of an internal combustion engine which includes a main intake passage that leads intake air to the combustion chamber, an auxiliary intake passage that branches off midway from the main intake passage and joins the main intake passage near the combustion chamber, and a gas passage that leads fuel evaporative gas to the main intake passage or the auxiliary intake passage, and is equipped with a body that defines the main passage that is part of the main intake passage, the auxiliary passage that is part of the auxiliary intake passage, and the purge passage that is part of the gas passage, a throttle valve that opens and closes the main passage, a throttle shaft to which the throttle valve is fixed and which is rotatably supported on the body, a first regulating valve that adjusts the flow rate of the auxiliary passage, and a second regulating valve that adjusts the flow rate of the purge passage, and the first regulating valve and second regulating valve rotate integrally with the throttle shaft to be driven to open and close.

[0008] In the above throttle device, the sub-passage and the purge passage may be formed so as to intersect with the axis of the throttle shaft.

[0009] In the above throttle device, the first adjusting valve may include a first lightening portion formed on the throttle shaft in a region facing the auxiliary passage, and the second adjusting valve may include a second lightening portion formed on the throttle shaft in a region facing the purge passage.

[0010] In the above throttle device, a configuration may be adopted in which the body includes a cylindrical portion extending in the direction of a predetermined center line to define a main passage, the sub-passage is formed as a through-hole extending parallel to the center line adjacent to the cylindrical portion and with a first adjustment valve interposed midway, and the purge passage is formed as a through-hole extending parallel to the center line adjacent to the cylindrical portion and with a second adjustment valve interposed midway.

[0011] In the above throttle device, the first cutout portion may be a notched groove formed by cutting out the throttle shaft, and the second cutout portion may be a through-hole that passes through the throttle shaft.

[0012] In the above throttle device, a configuration may be adopted in which the body includes a shaft hole through which the throttle shaft passes, the sub-passage and the purge passage are formed to communicate with the shaft hole, and the throttle shaft is provided with sealing members that are in tight contact with the shaft hole at least on both sides of the purge passage.

[0013] In the above throttle device, the body may include a cylindrical portion extending in the direction of a predetermined center line to define a main passage, the sub-passage being formed as a through-hole extending parallel to the center line adjacent to the cylindrical portion and with a first adjusting valve interposed midway, and the purge passage may include an upstream purge passage formed upstream of the second adjusting valve and extending parallel to the center line adjacent to the cylindrical portion so as to have a second adjusting valve interposed midway, and a downstream purge passage formed downstream of the second adjusting valve and communicating with the through-hole downstream of the first adjusting valve.

[0014] In the throttle device including the above-mentioned upstream purge passage and downstream purge passage, a configuration may be adopted in which the first hollowed-out portion is a notched groove cut out of the throttle shaft, the second hollowed-out portion is an open hole that opens the throttle shaft in the radial direction, and the downstream purge passage is formed in the throttle shaft in a region extending from the downstream end of the open hole to the notched groove.

[0015] In the throttle device including the upstream purge passage and the downstream purge passage, the body may include a shaft hole through which the throttle shaft passes, the sub-passage and the upstream purge passage are formed to communicate with the shaft hole, and the throttle shaft may be provided with sealing members that are in tight contact with the shaft hole on at least both sides of the upstream purge passage and the sub-passage.

[0016] The above throttle device may also employ a configuration that includes a connecting shaft connected to an end of the throttle shaft so as to rotate integrally with the throttle shaft and rotatably supported on the body, the first adjusting valve including a first lightening portion formed on the connecting shaft in a region facing the auxiliary passage, and the second adjusting valve including a second lightening portion formed on the connecting shaft in a region facing the purge passage.

[0017] In the throttle device including the connecting shaft, the body may include a cylindrical portion extending in the direction of a predetermined center line to define a main passage, the sub-passage extending parallel to the center line adjacent to the cylindrical portion and formed as a through hole with a first adjustment valve interposed midway, and the purge passage extending parallel to the center line adjacent to the cylindrical portion and formed as a through hole with a second adjustment valve interposed midway.

[0018] In the throttle device including the connecting shaft, the first lightening portion may be a notched groove formed by cutting out the connecting shaft, and the second lightening portion may be a through-hole that passes through the connecting shaft.

[0019] In the throttle device including the connecting shaft, the body may include a shaft hole through which the throttle shaft passes, and a second shaft hole formed coaxially and continuously with the shaft hole and through which the connecting shaft passes, the sub-passage and the purge passage are formed to communicate with the second shaft hole, and the connecting shaft may be provided with sealing members that come into tight contact with the second shaft hole on at least both sides of the purge passage.

[0020] In the throttle device including the connecting shaft, a configuration may be adopted in which the throttle shaft is made of a metal material and the connecting shaft is made of a resin material.

[0021] The above throttle device may also employ a configuration that includes a drive unit that rotates and drives the throttle shaft, the drive unit including a drive motor fixed to the body, a drive gear fixed to the rotary shaft of the drive motor, and a gear train interposed between the drive gear and the throttle shaft.

[0022] In the throttle device including the drive unit, the sub-passage and the purge passage may be formed between the cylindrical portion and the gear train in the axial direction of the throttle shaft.

[0023] In the throttle device including the drive unit, the sub-passage and the purge passage may be formed on the opposite side of the cylindrical portion from the gear train in the axial direction of the throttle shaft.

[0024] In the above throttle device, when the throttle valve changes from a low opening to a medium opening and then to a high opening, the first adjusting valve opens the bypass passage in the low to medium opening range and closes the bypass passage in the high opening range, and the second adjusting valve closes the purge passage in the low opening range and opens the purge passage toward the high opening range.

[0025] In the above throttle device, the auxiliary passage may define a portion of the auxiliary intake passage branching off from the main intake passage upstream of the throttle valve, and the purge passage may define a portion of the gas passage joining the main intake passage downstream of the throttle valve or a portion of the gas passage joining the auxiliary passage downstream of the first adjustment valve.

[0026] The intake system of an internal combustion engine of the present invention comprises a main intake pipe that defines a part of the main intake passage that leads intake air to the combustion chamber of the internal combustion engine, a fuel injection valve that injects fuel into the main intake passage or the combustion chamber, an auxiliary intake pipe that defines a part of the auxiliary intake passage that branches off from the main intake passage midway and joins the main intake passage near the combustion chamber, a gas pipe that defines a part of the gas passage that leads fuel evaporative gas in the fuel tank to the main intake passage or the auxiliary passage, and a throttle device arranged in the main intake pipe, wherein the throttle device is a throttle device having any of the above configurations. [Effects of the Invention]

[0027] The throttle device and intake system for an internal combustion engine configured as described above can reduce the number of parts, simplify the structure, make it smaller, and reduce costs, while recovering evaporated fuel gas and generating swirling flows such as swirl flows and tumble flows in the combustion chamber, thereby contributing to improved combustion efficiency. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a system diagram showing an intake system of an internal combustion engine according to one embodiment, which is equipped with a throttle device of the present invention. [Figure 2] 1 is a perspective view of a throttle device according to a first embodiment, viewed obliquely from the upstream side in the flow direction of intake air. FIG. [Figure 3] 1 is a perspective view of a throttle device according to a first embodiment, viewed obliquely from the downstream side in the flow direction of intake air. FIG. [Figure 4] 1 is a cross-sectional view of a throttle device according to a first embodiment, taken along a plane including the axis of a throttle shaft and the center line of a main passage. [Figure 5] 1 is an exploded perspective view of a throttle device according to a first embodiment, viewed from one side. [Figure 6] FIG. 3 is an exploded perspective view of the throttle device according to the first embodiment, viewed from the other side. [Figure 7] 1 is a perspective view showing a part (drive gear, gear train) of a drive unit that rotationally drives a throttle shaft in a throttle device according to a first embodiment. FIG. [Figure 8] FIG. 2 is a perspective view showing a throttle shaft included in the throttle device according to the first embodiment. [Figure 9] 1 is a cross-sectional view of the throttle device according to the first embodiment, taken along a plane perpendicular to the axis of the throttle shaft and passing through an auxiliary passage that forms part of an auxiliary intake passage. [Figure 10] 1 is a cross-sectional view of a throttle device according to a first embodiment, taken along a plane perpendicular to the axis of a throttle shaft and passing through a purge passage that forms part of a gas passage. [Figure 11] 4 is a table showing the relationship between the opening degree of the throttle valve and the opening degree of the first adjusting valve and the opening degree of the second adjusting valve in the throttle device according to the first embodiment. [Figure 12] 4 is a graph showing the flow rate through the main passage, the flow rate through the sub-passage, and the flow rate through the purge passage relative to the opening degree of the throttle valve in the throttle device according to the first embodiment. [Figure 13]FIG. 10 is a perspective view of a throttle device according to a second embodiment of the present invention, viewed obliquely from the upstream side in the flow direction of intake air. [Figure 14] FIG. 10 is a perspective view of a throttle device according to a second embodiment, viewed obliquely from the downstream side in the flow direction of intake air. [Figure 15] FIG. 10 is a cross-sectional view of a throttle device according to a second embodiment, taken along a plane including the axis of a throttle shaft and the center line of a main passage. [Figure 16] FIG. 10 is an exploded perspective view of a throttle device according to a second embodiment, viewed from one side. [Figure 17] FIG. 10 is an exploded perspective view of the throttle device according to the second embodiment, viewed from the other side. [Figure 18] FIG. 10 is a perspective view showing a throttle shaft included in a throttle device according to a second embodiment. [Figure 19] 10 is a cross-sectional view of a throttle device according to a second embodiment, taken along a plane perpendicular to the axis of the throttle shaft and passing through an auxiliary passage that forms part of the auxiliary intake passage. FIG. [Figure 20] FIG. 10 is a cross-sectional view of a throttle device according to a second embodiment, taken along a plane perpendicular to the axis of a throttle shaft and passing through a purge passage that forms part of a gas passage. [Figure 21] FIG. 10 is a cross-sectional view of a throttle device according to a third embodiment of the present invention, taken along a plane including the axis of a throttle shaft and the center line of a main passage. [Figure 22] FIG. 10 is an exploded perspective view showing a throttle shaft and a connecting shaft included in a throttle device according to a third embodiment. [Figure 23] FIG. 11 is an exploded perspective view showing a modified example of a throttle shaft and a connecting shaft included in the throttle device according to the third embodiment. [Figure 24] FIG. 10 is a system diagram showing an intake system of an internal combustion engine according to another embodiment, which is provided with a throttle device of the present invention. [Figure 25] FIG. 10 is a perspective view of a throttle device according to a fourth embodiment, viewed obliquely from the downstream side in the flow direction of intake air. [Figure 26]FIG. 10 is a cross-sectional view of a throttle device according to a fourth embodiment, taken along a plane including the axis of a throttle shaft and the center line of a main passage. [Figure 27] FIG. 10 is a perspective view showing a throttle shaft included in a throttle device according to a fourth embodiment. [Figure 28] FIG. 10 is a perspective cross-sectional view of a throttle shaft included in a throttle device according to a fourth embodiment, cut along a plane including the axis. [Figure 29] 10 is a cross-sectional view of a throttle device according to a fourth embodiment, taken along a plane perpendicular to the axis of the throttle shaft and passing through an auxiliary passage that forms part of an auxiliary intake passage and a first adjusting valve. FIG. [Figure 30] 10 is a cross-sectional view of a throttle device according to a fourth embodiment, taken along a plane perpendicular to the axis of the throttle shaft and passing through an upstream purge passage that forms part of a gas passage and a second adjustment valve. FIG. [Figure 31] 10 is a table showing the relationship between the opening degree of the throttle valve and the opening degree of the first adjusting valve and the opening degree of the second adjusting valve in a throttle device according to a fourth embodiment. [Figure 32] FIG. 10 is a system diagram showing an intake system of an internal combustion engine according to still another embodiment, which is provided with a throttle device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The throttle device of the present invention is incorporated into the intake system of an internal combustion engine mounted on a motorcycle, for example. As shown in Figure 1, the motorcycle is equipped with an internal combustion engine E, a fuel tank T, and other components (not shown).

[0030] The internal combustion engine E includes a cylinder block 1, a piston 2, a cylinder head 3, an intake valve 4a, an exhaust valve 4b, an exhaust pipe 5, an intake system IS, and the like. The cylinder head 3 cooperates with the upper surface of the piston 2 to define the combustion chamber C, and has an intake port 3a that forms part of the main intake passage, a secondary port 3b that forms part of the secondary intake passage, and an exhaust port 3c.It also houses a drive mechanism (not shown) that opens and closes the intake valve 4a and the exhaust valve 4b, an ignition plug (not shown), etc.

[0031] The auxiliary port 3b is formed to merge with the intake port 3a immediately upstream of the intake valve 4a. That is, the auxiliary intake passage (auxiliary port 3b) has a merging port 3b1 that merges with the main intake passage (intake port 3a) upstream of the intake valve 4a. The confluence port 3b1 of the sub-port 3b is oriented in a direction that generates a swirl flow (lateral vortex) inside the combustion chamber C. Specifically, the confluence port 3b1 of the sub-port 3b is formed so that the intake air joins the intake port 3a at an angle and flows in a tangential direction to the inner wall surface of the combustion chamber C.

[0032] The intake system IS includes an intake port 3a and an auxiliary port 3b of the cylinder head 3, an air cleaner Ac that draws in outside air, a main intake pipe Ip, an auxiliary intake pipe Sp, a fuel injection valve Iv located downstream of the main intake pipe Ip, a throttle device M located midway in the main intake pipe Ip upstream of the fuel injection valve Iv, a gas pipe Gp that connects the fuel tank T and the throttle device M, and a canister Ca located in the intermediate region of the gas pipe Gp.

[0033] The main intake pipe Ip is formed from a metal or resin material, etc., and defines a main intake passage Ip1 having a substantially circular cross section to allow the intake air drawn in by the air cleaner Ac to pass through, and is positioned so as to be interposed between the air cleaner Ac and the intake port 3a of the cylinder head 3. Here, the main intake pipe Ip is composed of a main intake pipe Ipu arranged on the upstream side of the throttle device M and a main intake pipe Ipd arranged on the downstream side.

[0034] The auxiliary intake pipe Sp is made of metal, resin, rubber, or the like, and defines an auxiliary intake passage Sp1 having a circular cross section for allowing intake air to pass through. The auxiliary intake pipe Sp has its upstream end connected to the main intake pipe Ipu upstream of the throttle valve 30, and its downstream end connected to a connector (not shown) that leads to the auxiliary port 3b of the cylinder head 3. The auxiliary intake pipe Sp is composed of an auxiliary intake pipe Spu disposed on the upstream side of the throttle device M and an auxiliary intake pipe Spd disposed on the downstream side thereof. That is, the auxiliary intake pipe Sp branches off from the main intake pipe Ipu located upstream of the throttle valve 30 and is connected so that the auxiliary passage 15 of the throttle device M is interposed midway.

[0035] The gas pipe Gp is ​​made of an oil-resistant and corrosion-resistant metal, resin, rubber, or other material, and defines a gas passage Gp1 having a circular cross section for allowing fuel vapor to pass through. The gas pipe Gp is ​​connected from the fuel tank T to a main intake pipe Ipd located downstream of the throttle device M, with the canister Ca and throttle device M interposed therebetween. Here, the gas pipe Gp is ​​composed of a gas pipe Gpu arranged on the upstream side of the throttle device M and a gas pipe Gpd arranged on the downstream side. That is, the gas pipe Gp is ​​connected between the canister Ca and the main intake pipe Ipd located downstream of the throttle valve 30 so that the purge passage 16 of the throttle device M is interposed therebetween.

[0036] The fuel injection valve Iv is disposed in the main intake pipe Ip and injects fuel into the main intake passage Ip1 near the intake port 3a. The canister Ca contains activated carbon that temporarily adsorbs the fuel vapor guided from the fuel tank T, guides the stored fuel vapor to the gas passage Gp1, and also takes in outside air depending on the internal pressure.

[0037] As shown in FIGS. 2 to 6, the throttle device M includes a body 10, a throttle shaft 20 extending on an axis S, a throttle valve 30, a drive motor 40 and a gear train Gt as a drive unit, and a sensor unit U. Here, the gear train Gt is made up of a two-stage gear 50 (large diameter gear 51, small diameter gear 52) and a throttle gear 60, as shown in FIG. As shown in FIG. 6, the sensor unit U includes a case U1, a joint surface U2, a terminal U3 for connecting the drive motor 40, a fitting receiving portion U4 for fitting the end of the support shaft 12b1 and for slidably receiving the end face of the double gear 50, an angular position sensor 70, a pressure sensor 80, a temperature sensor 90, and a circuit board (not shown) on which various electronic components are mounted.

[0038] The body 10 is formed from a metal material such as aluminum or a resin material, and as shown in Figures 2 to 6, 9 and 10, is provided with a cylindrical portion 11, a flange portion 12, a motor accommodating portion 13, a shaft hole 14 through which the throttle shaft 20 passes, a sub-passage 15, a purge passage 16, a recess 17, a communication passage 18, and an insertion hole 19.

[0039] The cylindrical portion 11 extends in the direction of the center line L, defines a main passage 11a, and has an upstream connection portion 11b and a downstream connection portion 11c at both ends. The main passage 11a functions as a part of a main intake passage that guides intake air to the combustion chamber C, and is formed in a cylindrical shape with a circular cross section centered on the center line L. The upstream connection portion 11b is connected to the upstream main intake pipe Ipu connected to the air cleaner Ac, and the downstream connection portion 11c is connected to the downstream main intake pipe Ipd connected to the surrounding area of ​​the intake port 3a of the cylinder head 3 of the internal combustion engine E.

[0040] As shown in Figures 4 and 5, the flange portion 12 is an area to which the sensor unit U is joined and fastened, and which houses the gear train Gt inside, and is provided with a joining surface 12a, a recess 12b, a recess 12c, and a recess 12d. The joint surface 12a is a flat surface to which the joint surface U2 of the sensor unit U is joined, and includes four screw holes 12a1 into which the screws b1 are screwed. Also, an insertion hole 19 through which the temperature sensor 90 is inserted is opened in the joint surface 12a. The recess 12b is an area that rotatably accommodates the double gear 50 that forms part of the gear train Gt, and is provided with a support shaft 12b1 that supports the double gear 50. The recess 12b also has, around the cylindrical recess 13a, two screw holes 12b2 into which screws b2 that fix the flange portion 42 of the drive motor 40 are screwed. The recess 12c is an area that rotatably accommodates a throttle gear 60 that is fixed to one end 24 of the throttle shaft 20 and forms part of the gear train Gt. The recess 12d is an area facing the pressure sensor 80 of the sensor unit U, and the communication passage 18 opens therein.

[0041] The motor accommodating portion 13 is an area that accommodates the drive motor 40, and includes a cylindrical recess 13a that extends parallel to the axis S. That is, the cylindrical recess 13a extends in a direction (the direction of the axis S) perpendicular to the extension direction (the center line L) of the cylindrical portion 11, and is disposed adjacent to the cylindrical portion 11. This allows the motor accommodating portion 13 to be disposed on the same side of the flange portion 12 as the cylindrical portion 11, which contributes to making the body 10 more compact and integrated.

[0042] As shown in Figure 4, the shaft hole 14 is formed as a circular hole through which the throttle shaft 20 passes and which supports the throttle shaft 20 so that it can rotate freely on the axis S. Three lip-type seals Rs serving as sealing members are arranged in close contact with the shaft hole 14. If necessary, a dedicated bushing or the like may be arranged in the shaft hole 14 as a bearing to support the throttle shaft 20.

[0043] 4 and 9, the sub-passage 15 forms part of the sub-intake passage, and is formed adjacent to the cylindrical portion 11 as a through-hole with a circular cross section, extending parallel to the center line L and perpendicularly intersecting the axis line S, and communicating with the axial hole 14. The sub-passage 15 also defines an upstream connection port 15a and a downstream connection port 15b. An auxiliary intake pipe Spu is connected to the upstream connection port 15a via a connecting pipe (not shown) fitted to the body 10, and an auxiliary intake pipe Spd is connected to the downstream connection port 15b.

[0044] The purge passage 16 forms part of the gas passage that guides fuel evaporation gas to the main intake passage, and as shown in Figures 4 and 10, it is formed adjacent to the cylindrical portion 11 and the sub-passage 15, extending parallel to the center line L and intersecting the axis line S perpendicularly, as a through-hole with a circular cross section that communicates with the axial hole 14. The purge passage 16 also defines an upstream connection port 16a and a downstream connection port 16b. A gas pipe Gpu is connected to the upstream connection port 16a via a connection pipe (not shown) fitted to the body 10, and a gas pipe Gpd is connected to the downstream connection port 16b.

[0045] 4, the sub-passage 15 and the purge passage 16 are adjacent to the cylindrical portion 11 and to each other, and are formed as linear through-holes extending parallel to the center line L. The sub-passage 15 and the purge passage 16 are also formed between the cylindrical portion 11 and the gear train Gt in the direction of the axis S of the throttle shaft 20.

[0046] 4, the recess 17 is formed contiguous with the end of the shaft hole 14 on the opposite side of the main passage 11a from the sub-passage 15 and the purge passage 16, and has an inner circumferential surface 17a with a larger diameter than the shaft hole 14 and a fitting surface 17b with a larger diameter than the inner circumferential surface 17a. The recess 17 is closed by fitting a cap 17c onto the fitting surface 17b. A bearing such as a bush may be fitted onto the inner circumferential surface 17a, and the end of the throttle shaft 20 may be rotatably supported by the bearing.

[0047] As shown in Figures 3 and 5, the communication passage 18 is open to the recess 12d to connect the pressure sensor 80 to the main passage 11a, and has an opening 18a that opens to the main passage 11a downstream of the throttle valve 30. As shown in Figures 2 and 5, the insertion hole 19 allows the temperature sensor 90 to be inserted so that the tip region of the temperature sensor 90 protrudes into the main passage 11a, and has an opening 19a that opens into the main passage 11a upstream of the throttle valve 30.

[0048] The throttle shaft 20 is made of a metal material and is formed so as to have a circular cross section and extend in the direction of the axis S, as shown in Figures 4, 7, and 8, and is equipped with a slit 21, a two-face width portion 22, two screw holes 23, one end portion 24, a first adjustment valve 25, a second adjustment valve 26, and three annular grooves 27.

[0049] The slit 21 is an area in which the throttle valve 30 is fitted in the central area. The two-flat width portion 22 is formed on the outer periphery of the region of the slit 21 in order to reduce the passage resistance in the main passage 11a. A screw b3 for fastening the throttle valve 30 fitted in the slit 21 is screwed into the screw hole 23. The one end 24 is an area where a throttle gear 60, which is part of the gear train Gt, is fitted and fixed.

[0050] As shown in FIGS. 4 and 9, the first adjustment valve 25 is driven to open and close to adjust the flow rate of the secondary passage 15, and is formed in a region facing the secondary passage 15 to form a substantially U-shaped notched groove as a first lightening portion. As shown in Figures 4 and 10, the second adjustment valve 26 is driven to open and close to adjust the flow rate of the purge passage 16, and is formed to form a through hole as a second hollowed-out portion in the area facing the purge passage 16. That is, the first regulating valve 25 and the second regulating valve 26 rotate integrally with the throttle shaft 20 to be driven to open and close, with the first regulating valve 25 adjusting the flow rate of intake air flowing through the secondary passage 15 and the second regulating valve 26 adjusting the flow rate of fuel evaporative gas flowing through the purge passage 16.

[0051] The three annular grooves 27 are regions into which lip seals Rs serving as sealing members are fitted. As shown in FIG. 4, the three lip seals Rs are arranged so as to be in close contact with the axial hole 14 on both sides of the sub-passage 15 and on both sides of the purge passage 16. That is, the throttle shaft 20 is provided with seal members (lip-type seals Rs) that come into close contact with the shaft hole 14 at least on both sides of the purge passage 16. In particular, by arranging sealing members (lip-type seals Rs) on both sides of the purge passage 16, leakage of fuel evaporative gas through the axial hole 14 is prevented, and the fuel evaporative gas can be reliably guided to the main intake passage Ip1.

[0052] The throttle valve 30 is a butterfly valve made of a metal material or the like and formed in a substantially circular disk shape, and as shown in FIGS. 4 and 7, is provided with a circular hole 31 through which a screw b3 passes. After the throttle shaft 20 is passed through the shaft hole 14, the throttle valve 30 is passed through the slit 21 and fixed to the throttle shaft 20 by a screw b3, and is disposed so as to open and close the main passage 11a.

[0053] As shown in FIG. 5, the drive motor 40 includes a main body 41, a flange portion 42, a rotary shaft 43, a drive gear 44 fixed to the rotary shaft 43, and a terminal 45 connected to the terminal U3 of the sensor unit U. The main body 41 is formed in a cylindrical shape with a bottom that extends parallel to the axis S so as to be fitted into the cylindrical recess 13a. The flange portion 42 has two circular holes 42a through which the screws b2 pass, and when the main body 41 is inserted into the cylindrical recess 13a and abutted against the bottom wall of the recess 12b around the cylindrical recess 13a, the screws b2 are screwed into the screw holes 12b2 of the body 10 to fasten and fix it.

[0054] The double gear 50 is made of a resin material, and as shown in FIG. 7, includes a large diameter gear 51 and a small diameter gear 52 that are integral with each other. The double gear 50 is rotatably supported by a support shaft 12b1 parallel to the axis S in the area of ​​the recess 12b of the body 10, with the large diameter gear 51 meshing with the drive gear 44 of the drive motor 40 and the small diameter gear 52 meshing with the throttle gear 60.

[0055] The throttle gear 60 is made of a resin material, and as shown in FIGS. 4 and 7, is integrally provided with a tooth row 61, a cylindrical fitting portion 62, and an annular recess 63. The tooth row 61 is formed as a sector gear and meshes with the small diameter gear 52 of the double gear 50. The fitting portion 62 is a region into which one end 24 of the throttle shaft 20 is fitted. The annular recess 63 has a permanent magnet (not shown) embedded in its inner circumferential surface, and is formed to receive the angular position sensor 70 of the sensor unit U in a non-contact manner. Here, because the throttle gear 60 is formed as a sector gear partially having a tooth row 61, it is possible to eliminate portions that do not function as a gear and achieve a reduction in size of the gear itself. Therefore, the throttle gear 60 can be housed in a narrow area (recess 12c) of the body 10, and the throttle device M as a whole can be made smaller.

[0056] As shown in FIGS. 4 and 6, the angular position sensor 70 is provided in the sensor unit U and is a non-contact sensor formed in a cylindrical shape with a Hall element embedded therein, and detects the rotation angle of the throttle shaft 20 in cooperation with a permanent magnet (not shown) disposed in the annular recess 63 of the throttle gear 60 fixed to the throttle shaft 20.

[0057] As shown in FIG. 6, the pressure sensor 80 is provided in a sensor unit U, and includes a pressure receiving portion such as a diaphragm equipped with a semiconductor strain gauge, a protective cover, and the like. The pressure sensor 80 detects the pressure of the intake air through a connecting passage 18 that leads to the main passage 11a, with the connecting surface U2 of the sensor unit U joined to the connecting surface 12a of the body 10 and the periphery of the recess 12d sealed by a sealing member Sr.

[0058] As shown in FIG. 6, the temperature sensor 90 is provided in the sensor unit U and is a lead-type sensor including a temperature-sensitive element such as a thermistor. The temperature sensor 90 is housed in a cylindrical portion protruding from the joint surface U2 of the sensor unit U, and is positioned so as to protrude into the main passage 11a through the insertion hole 19 upstream of the throttle valve 30, as shown in FIG. 2, to detect the temperature of the intake air.

[0059] Next, the operation of the internal combustion engine E equipped with the intake system IS including the throttle device M according to the first embodiment will be described with reference to FIG. First, when the internal combustion engine E is in the idle operating range, the throttle valve 30 is in a closed state in which the main passage 11a is closed, the first adjusting valve 25 opens the sub-passage 15, and the second adjusting valve 26 closes the purge passage 16. Therefore, the intake air drawn in through the air cleaner Ac flows through the main intake passage (main intake passage Ip1, main passage 11a), then flows through the auxiliary intake passage (auxiliary passage 15, auxiliary intake passage Sp1, auxiliary port 3b) bypassing the throttle valve 30, and flows again into the downstream main intake passage (intake port 3a), and flows into the combustion chamber C as an air-fuel mixture together with the fuel injected by the fuel injection valve Iv in the main intake passage Ip1. As a result, a swirl flow (lateral vortex) is generated in the mixture of intake air and injected fuel flowing through the auxiliary intake passage (auxiliary intake passage 15, auxiliary intake passage Sp1, and auxiliary port 3b) when the mixture flows into the combustion chamber C. This swirl flow promotes atomization of the fuel and homogenization of the mixture of intake air and fuel, resulting in stable idle operation with a small amount of fuel.

[0060] When the internal combustion engine E is in the low to medium load operating range, the throttle valve 30 opens in the low opening range (10° to 30°) to open the main passage 11a. On the other hand, the first adjusting valve 25 fully opens the secondary passage 15 when the throttle valve 30 is positioned at a low opening (10°), and starts to throttle the secondary passage 15 when the throttle valve 30 is positioned at a medium opening (20° to 30°).The second adjusting valve 26 starts to open the purge passage 16 when the throttle valve 30 is positioned at a low opening (10°), and fully opens the purge passage 16 when the throttle valve 30 is positioned at a medium opening (20° to 30°). As a result, the amount of intake air flowing through the main intake passage (main intake passage Ip1, main passage 11a, main intake passage Ip1) increases, and the amount of intake air flowing through the auxiliary intake passage (auxiliary passage 15, auxiliary intake passage Sp1, auxiliary port 3b) also increases, and fuel vapor flows into the main intake passage (main passage 11a) via the gas passage (gas passage Gp1, purge passage 16), creating a swirl flow (lateral vortex) in the air-fuel mixture flowing into the combustion chamber C. This swirl flow promotes atomization of the fuel and homogenization of the air-fuel mixture in the low to medium load operating range, improving combustion efficiency.

[0061] When the internal combustion engine E is in a high load operating range, the throttle valve 30 opens at a large opening (40° or more) to open the main passage 11a. On the other hand, the first adjusting valve 25 closes the sub-passage 15 when the throttle valve 30 is positioned at a large opening (40° or more). The second adjusting valve 26 keeps the purge passage 16 fully open when the throttle valve 30 is positioned at a large opening (40° or more). As a result, in the high-load operating range, fuel vapor flows into the main intake passage (main passage 11a) via the gas passage (gas passage Gp1, purge passage 16), maximizing the amount of intake air flowing through the main intake passage (main intake passage Ip1, main passage 11a, main intake passage Ip1), increasing the combustion speed and promoting efficient combustion.

[0062] That is, as shown in FIG. 12, when the throttle valve 30 opens from the fully closed position to the fully open position, in the low to medium load operating range (where the opening angle of the throttle valve 30 is in the range of 0° to 20°), the proportion of intake air flowing through the auxiliary intake passage (auxiliary passage 15, auxiliary intake passage Sp1, auxiliary port 3b) increases. Furthermore, in the medium to high load operating range (throttle valve 30 opening range of 30° to 40°), the proportion of intake air flowing through the auxiliary intake passages (auxiliary intake passage 15, auxiliary intake passage Sp1, auxiliary port 3b) decreases, and the proportion of intake air flowing through the main intake passages (main intake passage Ip1, main passage 11a, main intake passage Ip1) increases. Furthermore, in the low-load to high-load operating range, the flow rate of fuel evaporation gas introduced from the gas passage (gas passage Gp1, purge passage 16) to the main intake passage (main passage 11a) gradually increases. Therefore, in the low-load to medium-load operating range, a swirl flow is generated in the combustion chamber C, improving combustion efficiency. Also, in the high-load operating range, the flow rate of high-speed intake air that mainly flows through the main passage 11a increases, increasing the combustion speed and promoting efficient combustion.

[0063] In short, with regard to the mutual opening and closing timing of the throttle valve 30, the first adjusting valve 25, and the second adjusting valve 26, when the throttle valve 30 moves from a low opening to a medium opening and then to a high opening, the first adjusting valve 25 opens the secondary passage 15 in the low to medium opening range and closes the secondary passage 15 in the high opening range, and the second adjusting valve 26 closes the purge passage 16 in the low opening range and opens the purge passage 16 toward a high opening.

[0064] The throttle device M having the above-described configuration comprises a body 10 that defines a main passage 11a that forms part of the main intake passage, a sub-passage 15 that forms part of the sub-intake passage, and a purge passage 16 that forms part of the gas passage, a throttle valve 30 that opens and closes the main passage 11a, a throttle shaft 20 that is rotatably supported on the body 10 and to which the throttle valve 30 is fixed, a first regulating valve 25 that adjusts the flow rate of the sub-passage 15, and a second regulating valve 26 that adjusts the flow rate of the purge passage 16, and the first regulating valve 25 and the second regulating valve 26 rotate integrally with the throttle shaft 20 to be driven to open and close. As a result, the first adjusting valve 25 and the second adjusting valve 26 rotate integrally with the throttle shaft 20, and the driving force of the throttle shaft 20 can be shared. Compared to the conventional case in which multiple electric actuators are used and driven individually, this reduces the number of parts, simplifies the structure, reduces costs, etc., while recovering fuel evaporative gas and generating a swirling flow in the combustion chamber, thereby improving combustion efficiency.

[0065] Furthermore, since the sub-passage 15 and the purge passage 16 are formed so as to intersect with the axis S of the throttle shaft 20, the first adjusting valve 25 and the second adjusting valve can be arranged in a concentrated configuration on or near the throttle shaft 20, thereby achieving a more concentrated, compact, and simplified structure. Specifically, the first adjusting valve 25 includes a first cutout portion formed on the throttle shaft 20 in the area facing the secondary passage 15, and the second adjusting valve 26 is formed to include a second cutout portion formed on the throttle shaft 20 in the area facing the purge passage 16. According to this, by appropriately selecting the positions of the first and second cutout portions on the throttle shaft 20, the phases of the opening and closing timing of the first adjusting valve 25 and the opening and closing timing of the second adjusting valve 26 can be appropriately selected according to the specifications of the intake control of the internal combustion engine E, and the opening and closing timings of each can be linked to the opening and closing operation of the throttle valve 30. In particular, the first adjustment valve 25 has a notched groove cut out of the throttle shaft 20 as the first lightening portion, and the second adjustment valve 26 has a through-hole passing through the throttle shaft 20 as the second lightening portion, so that it is possible to adopt a form that corresponds to the flow rate of the fluid flowing through the secondary passage 15 and the flow rate of the fluid flowing through the purge passage 16, while also ensuring mechanical strength.

[0066] The sub-passage 15 and the purge passage 16 extend parallel to the center line L adjacent to the cylindrical portion 11 and are formed as through-holes with a first adjusting valve 25 and a second adjusting valve 26 interposed therein, respectively. This contributes to the miniaturization and integration of the body 10, simplifies hole processing, and also allows the connection of the sub-intake pipes Spu, Spd and the gas pipes Gpu, Gpd by easily fitting them together.

[0067] The body 10 also includes a shaft hole 14 through which the throttle shaft 20 passes, and the secondary passage 15 and purge passage 16 are formed to communicate with the shaft hole 14. The throttle shaft 20 is provided with sealing members (lip-type seals Rs) that fit tightly against the shaft hole 14 on at least both sides of the purge passage 16, thereby preventing fuel vapor from leaking out through the shaft hole 14 and ensuring that it is introduced into the main intake passage Ip1.

[0068] It also includes a drive unit that rotates and drives the throttle shaft 20, and the drive unit includes a drive motor 40 fixed to the body 10, a drive gear 44 fixed to the rotating shaft 43 of the drive motor 40, and a gear train Gt interposed between the drive gear 44 and the throttle shaft 20, and the secondary passage 15 and the purge passage 16 are formed between the cylindrical portion 11 and the gear train Gt in the direction of the axis S of the throttle shaft 20. This allows the protruding area of ​​the throttle device M to be reduced on the side opposite to the side on which the gear train Gt is arranged relative to the cylindrical portion 11 in the direction of the axis S of the throttle shaft 20, thereby achieving a reduction in the overall size of the throttle device M.

[0069] In addition, the auxiliary passage 15 defines a portion of the auxiliary intake passage Sp1 that branches off from the main intake passage Ip1 upstream of the throttle valve 30, and the purge passage 16 defines a portion of the gas passage Gp1 that merges with the main intake passage Ip1 downstream of the throttle valve 30. This allows the intake air flowing through the main intake passage Ip1 to be guided to the combustion chamber C through the sub-passage 15 even when the throttle valve 30 is closed, and also allows fuel vapor to be introduced into the main intake passage Ip1 through the purge passage 16 depending on the opening degree of the throttle valve 30.

[0070] As described above, the throttle device M of the first embodiment can achieve a reduction in the number of parts, a simplified structure, a smaller size, a lower cost, etc., while recovering evaporated fuel gas and generating a swirl flow (rotating flow) in the combustion chamber C, thereby contributing to improving the combustion efficiency of the internal combustion engine E.

[0071] 13 to 20 show a throttle device M2 according to a second embodiment, and the same components as those in the throttle device M according to the first embodiment are given the same reference numerals and the description thereof will be omitted. The throttle device M2 according to the second embodiment includes a body 110, a throttle shaft 120 extending on an axis S, a throttle valve 30, a drive motor 40 and a gear train Gt as a drive unit, and a sensor unit U.

[0072] The body 110 is formed from a metal material such as aluminum or a resin material, and as shown in Figures 13 to 17, it is equipped with a cylindrical portion 11, a flange portion 12, a motor accommodating portion 13, a shaft hole 114 through which the throttle shaft 120 passes, a sub-passage 115, a purge passage 116, a recess 17, a communication passage 18, and an insertion hole 19.

[0073] 15, the shaft hole 114 is formed as a circular hole through which the throttle shaft 120 passes and which supports the throttle shaft 120 rotatably on the axis S. Two lip-type seals Rs serving as sealing members are arranged in close contact with the shaft hole 114. If necessary, a dedicated bush or the like may be arranged in the shaft hole 114 as a bearing for supporting the throttle shaft 120.

[0074] 15 and 19, the sub-passage 115 forms part of the sub-intake passage, and is formed adjacent to the cylindrical portion 11 as a through-hole with a circular cross section that extends parallel to the center line L, intersects the axis line S perpendicularly, and communicates with the axial hole 114. The sub-passage 115 also defines an upstream connection port 115a and a downstream connection port 115b. An auxiliary intake pipe Spu is connected to the upstream connection port 115a via a connecting pipe (not shown) fitted to the body 110, and an auxiliary intake pipe Spd is connected to the downstream connection port 115b.

[0075] 15 and 20, the purge passage 116 is a part of the gas passage that guides fuel evaporation gas to the main intake passage, and is formed as a through-hole with a circular cross section adjacent to the cylindrical portion 11 and the sub-passage 115, extending parallel to the center line L and intersecting the axis line S perpendicularly, and communicating with the axial hole 114. The purge passage 116 also defines an upstream connection port 116a and a downstream connection port 116b. A gas pipe Gpu is connected to the upstream connection port 116a via a connection pipe (not shown) fitted to the body 110, and a gas pipe Gpd is connected to the downstream connection port 116b.

[0076] 15, the sub-passage 115 and the purge passage 116 are formed as linear through-holes adjacent to the cylindrical portion 11 and extending parallel to the center line L. The sub-passage 115 and the purge passage 116 are formed on the opposite side of the cylindrical portion 11 from the gear train Gt in the direction of the axis S of the throttle shaft 120.

[0077] The throttle shaft 120 is made of a metal material or the like and is formed to have a circular cross section and extend in the direction of the axis S, as shown in Figures 15, 18 to 20, and is provided with a slit 21, a two-face width portion 22, two screw holes 23, one end portion 24, a first adjustment valve 125, a second adjustment valve 126, and two annular grooves 127.

[0078] As shown in Figures 15 and 19, the first adjustment valve 125 is driven to open and close to adjust the flow rate of the secondary passage 115, and is formed in the area facing the secondary passage 115 to form a notched groove cut out in an approximately U-shape as a first lightening portion. As shown in Figures 15 and 20, the second adjustment valve 126 is driven to open and close to adjust the flow rate of the purge passage 116, and is formed to form a through hole as a second hollowed-out portion in the area facing the purge passage 116. That is, the first adjusting valve 125 and the second adjusting valve 126 rotate integrally with the throttle shaft 120 to be driven to open and close, with the first adjusting valve 125 adjusting the flow rate of intake air flowing through the secondary passage 115 and the second adjusting valve 126 adjusting the flow rate of fuel evaporative gas flowing through the purge passage 116.

[0079] The two annular grooves 127 are regions into which lip seals Rs serving as sealing members are fitted. The two lip seals Rs are arranged so as to be in close contact with the shaft hole 114 on both sides of the purge passage 116. That is, the throttle shaft 120 is provided with sealing members (lip seals Rs) that are in close contact with the shaft hole 114 on at least both sides of the purge passage 116. By providing sealing members (lip seals Rs) on both sides of the purge passage 116 in this way, it is possible to prevent fuel evaporation from leaking through the shaft hole 114 and to reliably guide the fuel evaporation to the main intake passage Ip1.

[0080] Furthermore, the operation and flow characteristics of an internal combustion engine E equipped with an intake system IS including a throttle device M2 according to the second embodiment are similar to those of an internal combustion engine E equipped with an intake system IS including a throttle device M according to the first embodiment, as shown in Figures 11 and 12, and therefore will not be described here.

[0081] The throttle device M2 having the above-described configuration includes a body 110 that defines a main passage 11a that forms part of the main intake passage, a sub-passage 115 that forms part of the sub-intake passage, and a purge passage 116 that forms part of the gas passage, a throttle valve 30 that opens and closes the main passage 11a, a throttle shaft 120 that is rotatably supported on the body 110 and to which the throttle valve 30 is fixed, a first regulating valve 125 that adjusts the flow rate of the sub-passage 115, and a second regulating valve 126 that adjusts the flow rate of the purge passage 116, and the first regulating valve 125 and the second regulating valve 126 rotate integrally with the throttle shaft 120 to be driven to open and close. With this, the first adjusting valve 125 and the second adjusting valve 126 rotate integrally with the throttle shaft 120, and the driving force of the throttle shaft 120 can be shared. Compared to the conventional case in which multiple electric actuators are used and driven individually, this reduces the number of parts, simplifies the structure, reduces costs, etc., while also recovering fuel evaporative gas and generating a swirling flow in the combustion chamber, thereby improving combustion efficiency.

[0082] Furthermore, since the sub-passage 115 and the purge passage 116 are formed so as to intersect with the axis S of the throttle shaft 120, the first adjusting valve 125 and the second adjusting valve 126 can be arranged in a concentrated configuration on or near the throttle shaft 120, thereby achieving the consolidation, miniaturization, simplification, etc. of the structure. Specifically, the first adjusting valve 125 includes a first cutout portion formed on the throttle shaft 120 in the area facing the secondary passage 115, and the second adjusting valve 126 is formed to include a second cutout portion formed on the throttle shaft 120 in the area facing the purge passage 116. According to this, by appropriately selecting the cutting positions of the first cutout portion and the second cutout portion, the phases of the opening and closing timing of the first adjusting valve 125 and the opening and closing timing of the second adjusting valve 126 can be appropriately selected according to the specifications of the intake control of the internal combustion engine E, and the opening and closing timings of each can be linked to the opening and closing operation of the throttle valve 30. In particular, first adjustment valve 125 has a first cutout portion formed as a notched groove cut into throttle shaft 120, and second adjustment valve 126 has a second cutout portion formed as a through-hole passing through throttle shaft 120. Therefore, it is possible to adopt a configuration suited to the flow rate of the fluid flowing through sub-passage 115 and the flow rate of the fluid flowing through purge passage 116, while also ensuring mechanical strength.

[0083] The sub-passage 115 and the purge passage 116 extend parallel to the center line L adjacent to the cylindrical portion 11 and are formed as through-holes with a first adjusting valve 125 and a second adjusting valve 126 interposed therein, respectively. This contributes to the miniaturization and integration of the body 110, simplifies hole processing, and also allows the connection of the sub-intake pipes Spu, Spd and the gas pipes Gpu, Gpd by easily fitting them together.

[0084] Furthermore, the body 110 includes an axial hole 114 through which the throttle shaft 120 passes, and the secondary passage 115 and the purge passage 116 are formed to communicate with the axial hole 114. The throttle shaft 120 is provided with sealing members (lip-type seals Rs) that fit tightly against the axial hole 114 on at least both sides of the purge passage 116, thereby preventing fuel evaporative gas from leaking out through the axial hole 114 and ensuring that it is introduced into the main intake passage Ip1.

[0085] The sub-passage 115 and the purge passage 116 are formed on the opposite side of the gear train Gt across the cylindrical portion 11 in the direction of the axis S of the throttle shaft 120. This allows the auxiliary intake pipes Spu, Spd and gas pipes Gpu, Gpd to be easily piped by utilizing the end area in the axial direction S of the body 110 when the space between the cylindrical portion 11 and the gear train Gt is narrow or when there are constraints due to the relationship with other parts.

[0086] In addition, the auxiliary passage 115 defines a portion of the auxiliary intake passage Sp1 that branches off from the main intake passage Ip1 upstream of the throttle valve 30, and the purge passage 116 defines a portion of the gas passage Gp1 that merges with the main intake passage Ip1 downstream of the throttle valve 30. This allows the intake air flowing through the main intake passage Ip1 to be guided to the combustion chamber C through the sub-passage 115 even when the throttle valve 30 is closed, and also allows fuel vapor to be introduced into the main intake passage Ip1 through the purge passage 116 depending on the opening degree of the throttle valve 30.

[0087] As described above, the throttle device M2 according to the second embodiment can reduce the number of parts, simplify the structure, make it smaller, and reduce costs, while recovering evaporated fuel gas and generating a swirl flow (rotating flow) in the combustion chamber C, thereby contributing to improving the combustion efficiency of the internal combustion engine E.

[0088] 21 and 22 show a throttle device M3 according to a third embodiment, and the same components as those in the throttle device M2 according to the second embodiment are given the same reference numerals and the description thereof will be omitted. The throttle device M3 according to the third embodiment includes a body 110, a throttle shaft 220 extending on an axis S, a connecting shaft 230, a throttle valve 30, a drive motor 40 and a gear train Gt as a drive unit, and a sensor unit U.

[0089] The throttle shaft 220 is made of a metal material and is formed so as to have a circular cross section and extend in the direction of the axis S, as shown in Figures 21 and 22, and is equipped with a slit 21, a two-face width portion 22, two screw holes 23, one end portion 24, the other end portion 226, and one annular groove 227. The other end 226 is provided with a cylindrical fitting hole 226a with a bottom extending in the direction of the axis S for connecting the connecting shaft 230, and a fitting hole 266b that penetrates in the radial direction for fitting the pin P therein. The annular groove 227 is an area into which a lip seal Rs serving as a sealing member is fitted.

[0090] The connecting shaft 230 is formed from a resin material so as to have a circular cross section and extend in the direction of the axis S, as shown in Figures 21 and 22, and is equipped with one end 231, a first adjusting valve 232, a second adjusting valve 233, two annular grooves 234, and the other end 235.

[0091] One end 231 is an area that is connected to the other end 226 of the throttle shaft 220, and is formed as a cylindrical mating protrusion that is fitted into the mating hole 226a, and also has a through hole 231a that penetrates radially to allow the pin P to pass through. As shown in FIG. 21, the first adjustment valve 232 is driven to open and close to adjust the flow rate of the secondary passage 115, and is formed in the area facing the secondary passage 115 to form a substantially U-shaped notched groove as a first lightening portion. As shown in FIG. 21, the second adjustment valve 233 is driven to open and close to adjust the flow rate of the purge passage 116, and is formed to form a through-hole as a second lightening portion in the area facing the purge passage 116.

[0092] The two annular grooves 234 are regions into which lip seals Rs serving as sealing members are fitted. The two lip seals Rs are arranged so as to be in close contact with the shaft hole 114 on both sides of the purge passage 116. In other words, the throttle shaft 220 is provided with sealing members (lip seals Rs) that are in close contact with the shaft hole 114 on at least both sides of the purge passage 116. By providing sealing members (lip seals Rs) on both sides of the purge passage 116 in this way, it is possible to prevent fuel evaporation from leaking through the shaft hole 114 and to reliably guide the fuel evaporation to the main intake passage Ip1. The other end 235 has a circular flat surface perpendicular to the axis S, and is disposed so as to face the cap 17c fitted into the recess 17 with a gap in the direction of the axis S.

[0093] The connecting shaft 230 is rotatably passed through the shaft hole 114 through which the throttle shaft 220 is passed, that is, through the shaft hole 114 serving as a second shaft hole located in an area outside the other end 226 . That is, the first regulating valve 232 and the second regulating valve 233 rotate integrally with the throttle shaft 220 to be driven to open and close, with the first regulating valve 232 adjusting the flow rate of intake air flowing through the secondary passage 115 and the second regulating valve 233 adjusting the flow rate of fuel evaporative gas flowing through the purge passage 116.

[0094] Furthermore, the operation and flow characteristics of an internal combustion engine E equipped with an intake system IS including the throttle device M3 of the third embodiment are similar to those of an internal combustion engine E equipped with an intake system IS including the throttle devices M, M2 of the first and second embodiments, as shown in Figures 11 and 12, so explanations here will be omitted.

[0095] The throttle device M3 having the above-described configuration not only exhibits the same effects as the throttle device M2 according to the second embodiment described above, but also has a connecting shaft 230 connected to the throttle shaft 220, and a first adjusting valve 232 and a second adjusting valve 233 formed on the connecting shaft 230. Therefore, by appropriately changing the connecting shaft 230, it is possible to adjust the flow rate of intake air flowing through the secondary passage 115 and the flow rate of fuel evaporative gas flowing through the purge passage 116 in accordance with the specifications of the internal combustion engine E.

[0096] FIG. 23 shows a modified example of the throttle shaft 220 and the connecting shaft 230 in the throttle device M3 according to the third embodiment. In this modified example, the throttle shaft 220 has an other end 228 instead of the other end 226. The other end 228 has a fitting groove 228a cut out in the radial direction. The connecting shaft 230 has one end 236 instead of the one end 231 and the other end 237 instead of the other end 235 . The one end 236 has a two-face width portion 236a that fits into the fitting groove 228a of the other end 228. The other end 237 has a gripping portion 237a that can be grasped with a tool or the like, and a thrust surface 237b that abuts against the cap 17c in the direction of the axis S.

[0097] According to this modified example, the connecting shaft 230 can be changed as appropriate after the throttle shaft 220 is assembled to the body 110, and therefore, by changing only the connecting shaft 230, the connecting shaft 230 can be rearranged according to the specifications of the internal combustion engine E.

[0098] Figures 24 to 30 show the throttle device M4 of the fourth embodiment and an intake system for an internal combustion engine of another embodiment equipped with the throttle device M4, and the same components as those of the intake system IS of the above-mentioned embodiment and the throttle device M1 of the first embodiment are given the same symbols and will not be described. In this intake system IS, the fuel vapor in the fuel tank T is led to the sub-passage 15 downstream of the first adjusting valve 325. The auxiliary intake pipe Spd is made of an oil-resistant and corrosion-resistant metal, resin, rubber, or the like, in order to allow not only intake air but also fuel vapor to pass through.

[0099] The throttle device M4 according to the fourth embodiment includes a body 210, a throttle shaft 320 extending on an axis S, a throttle valve 30, a drive motor 40 and a gear train Gt as a drive unit, and a sensor unit U.

[0100] The body 210 is formed from a metal material such as aluminum or a resin material, and as shown in Figures 25, 26, 29 and 30, is provided with a cylindrical portion 11, a flange portion 12, a motor housing portion 13, a shaft hole 14 through which the throttle shaft 320 passes, a sub-passage 15, an upstream purge passage 216 which forms part of the purge passage, a recess 17, a communication passage 18, and an insertion hole 19.

[0101] The upstream purge passage 216 forms part of the gas passage that guides fuel evaporation gas to the auxiliary intake passage, and is formed adjacent to the cylindrical portion 11 and the auxiliary passage 15, extending parallel to the center line L and intersecting the axis line S perpendicularly, with its downstream end formed as a cylindrical hole with a circular cross section that communicates with the axial hole 14. The upstream purge passage 216 also defines an upstream connection port 216a. A gas pipe Gpu is connected to the upstream connection port 216a via a connection pipe (not shown) fitted to the body 210.

[0102] The throttle shaft 320 is made of a metal material and is formed so as to have a circular cross section and extend in the direction of the axis S, as shown in Figures 26 to 28, and is provided with a slit 21, a two-face width portion 22, two screw holes 23, one end portion 24, a first adjustment valve 325, a second adjustment valve 326, a downstream purge passage 327 that forms part of the purge passage, and two annular grooves 328.

[0103] As shown in Figures 26 and 29, the first adjustment valve 325 is driven to open and close to adjust the flow rate of the secondary passage 15, and is formed in the area facing the secondary passage 15 to form a notched groove cut out in an approximately U-shape as a first lightening portion.

[0104] As shown in Figures 26 and 30, the second adjustment valve 326 is driven to open and close to adjust the flow rate of the purge passages (the upstream purge passage 216 and the downstream purge passage 327), and in the area facing the purge passage (the upstream purge passage 216), it is formed as a second lightening portion, opening the throttle shaft 320 radially and extending to a position beyond the axis S, but forming an opening hole that does not pass through. As shown in Figures 26 and 28, the downstream purge passage 327 is formed as a cylindrical hole extending along the axis S in the region from the downstream end of the opening hole as the second adjustment valve 326 to the notched groove as the first adjustment valve 325. Specifically, the downstream purge passage 327 is formed by drilling from one end 24 side of the throttle shaft 320 in the direction of the axis S to form a machined hole extending to the downstream end of the opening hole serving as the second adjustment valve 326, and a plug Cp is pressed into the opening of the one end 24 to seal it. That is, the downstream purge passage 327 is formed downstream of the second adjustment valve 326 and is formed so as to communicate with the sub-passage 15 (through-hole) downstream of the first adjustment valve 325.

[0105] Here, the purge passage includes an upstream purge passage 216 formed upstream of the second regulating valve 326, adjacent to the cylindrical portion 11 and extending parallel to the center line L, so that the second regulating valve 326 is interposed in the middle, and a downstream purge passage 327 formed downstream of the second regulating valve 326 and communicating with the through hole (secondary passage 15) downstream of the first regulating valve 325. That is, the first regulating valve 325 and the second regulating valve 326 rotate integrally with the throttle shaft 320 and are driven to open and close, with the first regulating valve 325 adjusting the flow rate of intake air flowing through the secondary passage 15 and the second regulating valve 326 adjusting the flow rate of fuel evaporative gas flowing through the purge passages (the upstream purge passage 216 and the downstream purge passage 327).

[0106] The two annular grooves 328 are regions into which lip seals Rs serving as sealing members are fitted. As shown in Fig. 26, the two lip seals Rs are arranged so as to be in close contact with the axial hole 14 on both sides of the upstream purge passage 216 and the sub-passage 15. That is, sealing members (lip-type seals Rs) that come into close contact with the shaft hole 14 are arranged on the throttle shaft 320 at least on both sides of the upstream purge passage 216 and the auxiliary passage 15. This prevents the fuel vapor from leaking through the shaft hole 14, and ensures that the fuel vapor is guided to the auxiliary intake passage Sp1.

[0107] Next, the operation of the internal combustion engine E equipped with the intake system IS including the throttle device M4 according to the fourth embodiment will be described with reference to FIG. First, when the internal combustion engine E is in the idle operating range, the throttle valve 30 is in a closed state in which the main passage 11a is closed, the first adjusting valve 325 opens the sub-passage 15, and the second adjusting valve 326 closes the upstream purge passage 216. Therefore, the intake air drawn in through the air cleaner Ac flows through the main intake passage (main intake passage Ip1, main passage 11a), then flows through the auxiliary intake passage (auxiliary passage 15, auxiliary intake passage Sp1, auxiliary port 3b) bypassing the throttle valve 30, and flows again into the downstream main intake passage (intake port 3a), and flows into the combustion chamber C as an air-fuel mixture together with the fuel injected by the fuel injection valve Iv in the main intake passage Ip1. As a result, a swirl flow (lateral vortex) is generated in the mixture of intake air and injected fuel flowing through the auxiliary intake passage (auxiliary intake passage 15, auxiliary intake passage Sp1, and auxiliary port 3b) when the mixture flows into the combustion chamber C. This swirl flow promotes atomization of the fuel and homogenization of the mixture of intake air and fuel, resulting in stable idle operation with a small amount of fuel.

[0108] When the internal combustion engine E is in the low to medium load operating range, the throttle valve 30 opens in the low opening range (10° to 30°) to open the main passage 11a. On the other hand, the first adjusting valve 325 fully opens the secondary passage 15 when the throttle valve 30 is positioned at a low opening (10°), and starts to throttle the secondary passage 15 when the throttle valve 30 is positioned at a medium opening (20° to 30°). The second adjusting valve 326 starts to open the upstream purge passage 216 when the throttle valve 30 is positioned at a low opening (10°), and fully opens the upstream purge passage 216 when the throttle valve 30 is positioned at a medium opening (20° to 30°). As a result, the amount of intake air flowing through the main intake passage (main intake passage Ip1, main passage 11a, main intake passage Ip1) increases, and the amount of intake air flowing through the auxiliary intake passage (auxiliary passage 15, auxiliary intake passage Sp1, auxiliary port 3b) also increases, and fuel vapor flows into the auxiliary intake passage Sp1 via the gas passage (gas passage Gp1, upstream purge passage 216, and downstream purge passage 327) and the auxiliary passage 15, generating a swirl flow (lateral vortex) in the air-fuel mixture flowing into the combustion chamber C. This swirl flow promotes atomization of the fuel and homogenization of the intake air-fuel mixture in the low to medium load operating range, improving combustion efficiency.

[0109] When the internal combustion engine E is in a high load operating range, the throttle valve 30 opens at a large opening (40° or more) to open the main passage 11a. On the other hand, the first adjusting valve 325 closes the secondary passage 15 when the throttle valve 30 is at a large opening (40° or more). The second adjusting valve 326 keeps the upstream purge passage 216 fully open when the throttle valve 30 is at a large opening (40° or more). As a result, in the high-load operating range, fuel vapor flows into the auxiliary intake passage Sp1 via the gas passages (gas passage Gp1, upstream purge passage 216, and downstream purge passage 327) and the auxiliary passage 15, and the amount of intake air flowing through the main intake passages (main intake passage Ip1, main passage 11a, main intake passage Ip1) becomes maximum, increasing the combustion speed and promoting efficient combustion. The flow rate characteristics of the fluid flowing through the main passage 11a, the sub-passage 15, and the purge passages (the upstream purge passage 216 and the downstream purge passage 327) are substantially the same as those shown in FIG. 12, although there is a slight change in the flow rate through the purge passages when the throttle valve 30 is fully open.

[0110] In short, with regard to the mutual opening and closing timing of the throttle valve 30, the first adjusting valve 325, and the second adjusting valve 326, when the throttle valve 30 moves from a low opening to a medium opening and then to a high opening, the first adjusting valve 325 opens the secondary passage 15 in the low to medium opening range and closes the secondary passage 15 in the high opening range, and the second adjusting valve 326 closes the purge passage (upstream purge passage 216) in the low opening range and opens the purge passage (upstream purge passage 216) toward a high opening.

[0111] The throttle device M4 having the above-described configuration includes a body 210 that defines a main passage 11a that forms part of the main intake passage, a sub-passage 15 that forms part of the sub-intake passage, and a purge passage 316 that forms part of the gas passage, a throttle valve 30 that opens and closes the main passage 11a, a throttle shaft 320 that fixes the throttle valve 30 and is rotatably supported on the body 210, a first regulating valve 325 that adjusts the flow rate of the sub-passage 15, and a second regulating valve 326 that adjusts the flow rate of the purge passages (the upstream purge passage 216 and the downstream purge passage 327), and the first regulating valve 325 and the second regulating valve 326 rotate integrally with the throttle shaft 320 to be driven to open and close. As a result, the first adjusting valve 325 and the second adjusting valve 326 rotate integrally with the throttle shaft 320, and the driving force of the throttle shaft 320 can be shared. Compared to the conventional case in which multiple electric actuators are used and driven individually, this reduces the number of parts, simplifies the structure, reduces costs, etc., while recovering fuel evaporative gas and generating a swirling flow in the combustion chamber, thereby improving combustion efficiency.

[0112] Furthermore, the body 210 includes a cylindrical portion 11 extending in the direction of the center line L and defining the main passage 11a, and the secondary passage 15 is formed as a through hole extending parallel to the center line L adjacent to the cylindrical portion 11 and with a first adjustment valve 325 interposed midway, and the purge passage includes an upstream purge passage 216 formed upstream of the second adjustment valve 326 and extending parallel to the center line L adjacent to the cylindrical portion 11 so that the second adjustment valve 326 is interposed midway, and a downstream purge passage 327 formed downstream of the second adjustment valve 326 and communicating with the through hole (secondary passage 15) downstream of the first adjustment valve 325, so that within the body 210, the purge passage can be merged with the secondary passage 15 and fuel vapor can be guided upstream of the vicinity of the combustion chamber C via the secondary passage 15.

[0113] Furthermore, the first adjusting valve 325 has a notched groove cut out of the throttle shaft 320 as the first lightening portion, and the second adjusting valve 326 has an open hole that opens the throttle shaft 320 radially as the second lightening portion, and the downstream purge passage 327 is formed in the throttle shaft 320 in the region extending from the downstream end of the open hole (second adjusting valve 326) to the notched groove (first adjusting valve 325), so there is no need to provide a downstream purge passage in the body 210, and the structure can be simplified. The downstream purge passage is not limited to the form provided in the throttle shaft 320 (downstream purge passage 327), but may be provided in the body with the second adjustment valve formed as a through-hole.

[0114] As described above, in the intake system IS equipped with the throttle devices M, M2, M3 according to the first to third embodiments, the confluence port 3b1 of the auxiliary intake passage (auxiliary port 3b) is oriented upstream of the intake valve 4a in a direction that generates a swirl flow in the combustion chamber C, but this is not limited to this. For example, as shown in Figure 32, a configuration may be adopted in which the fuel injection valve Iv is positioned to inject fuel directly into the combustion chamber C, and the confluence port 113b1 of the auxiliary intake passage (auxiliary port 113b) is oriented upstream of the intake valve 4a in a direction that generates a tumble flow (vertical vortex) in the combustion chamber C. This allows for a reduction in the number of parts, simplification of the structure, miniaturization, and cost reduction, while also recovering evaporated fuel gas and generating a swirling flow as a tumble flow in the combustion chamber C, thereby contributing to improving the combustion efficiency of the internal combustion engine E. Incidentally, the intake system IS equipped with the throttle device M4 according to the fourth embodiment may also employ a configuration for generating a tumble flow in the combustion chamber C as shown in FIG.

[0115] In the above embodiment, the drive motor 40 and the gear train Gt are shown as the drive unit that generates the rotational drive force, but this is not limited to this. A pulley may be fixed to one end of the throttle shaft and a wire may be wound around the pulley, or a drive mechanism of other forms may be used.

[0116] In the above embodiment, the first and second adjusting valves 25, 125, 232, 325 and the second adjusting valves 26, 126, 233, 326 are formed by providing hollowed-out portions in a cylindrical member of the same diameter that outlines the throttle shaft 20, 220, 320, but this is not limited to this. For example, it is also possible to adopt a configuration in which the body is divided into two parts at the shaft hole and the throttle shaft is assembled, a shaft member with multiple diameter stages including a large diameter and a small diameter is used as the throttle shaft, the first and second adjusting valves are formed in the large diameter section, and the sub-passage and purge passage are formed offset from the axis of the throttle shaft.

[0117] In the above embodiment, the auxiliary passage and purge passage are shown as through holes extending parallel to the center line L of the cylindrical portion 11, but this is not limited to this, and the auxiliary passage and purge passage may be oriented in a twisted direction relative to the center line L.

[0118] In the above embodiment, as an embodiment including a connecting shaft connected to the end of the throttle shaft, a configuration was shown in which part of the shaft hole 114 through which the throttle shaft 220 passes is also used as a second shaft hole through which the connecting shaft 230 passes. However, this is not limited to this, and a configuration may also be adopted in which a second shaft hole is formed coaxially and continuously with the shaft hole and has an inner diameter larger than the inner diameter of the shaft hole, and a connecting shaft having an outer diameter larger than the outer diameter of the throttle shaft is used as the connecting shaft, and the first adjustment valve and the second adjustment valve are formed on this connecting shaft.

[0119] In the above embodiment, the vehicle equipped with an internal combustion engine to which the throttle device and intake system of the present invention are applied is shown to be a motorcycle, but this is not limited to this and the invention may also be applied to internal combustion engines installed in automobiles, etc.

[0120] As described above, the throttle device and intake system for an internal combustion engine of the present invention achieves a reduction in the number of parts, a simplified structure, a smaller size, and lower costs, while recovering evaporated fuel gas and generating swirling flows such as swirl flows and tumble flows in the combustion chamber, contributing to improved combustion efficiency. Therefore, it is not only applicable to internal combustion engines mounted on motorcycles, etc., but is also useful in internal combustion engines mounted on automobiles or internal combustion engines mounted on other vehicles. [Explanation of symbols]

[0121] E. Internal combustion engine T Fuel Tank IS intake system Ip main intake pipe Ip1 main intake passage Sp Auxiliary intake pipe Sp1 auxiliary intake passage Gp gas piping Gp1 gas passage Ca canister IV Fuel Injector C. Combustion chamber 3a Intake port (main intake passage) 3b, 113b Secondary port (secondary intake passage) 3b1, 113b1 auxiliary intake passage junction 4a intake valve M throttle device 10 Body 11 Cylindrical part L center line 11a Main passage (main intake passage) 12 Flange 13 Motor housing 15 Sub-passage (sub-intake passage) 16 Purge passage (gas passage) 18 Communication path 19 Insertion hole 20 Throttle shaft S axis 21 スリット 22 Width across flats 23 screw holes 24 One end 25 First adjusting valve (first hollowed-out portion, notched groove) 26 Second adjustment valve (second hollowed-out portion, through-hole) 27 Annular groove Rs Lip seal (sealing material) 30 Throttle valve 40 Drive motor (drive unit) 43 Rotation axis 44 Drive gear Gt gear train (drive unit) 50 Double gear 60 Throttle gear U Sensor Unit 70 Angular Position Sensor 80 Pressure Sensor 90 Temperature Sensor M2 throttle device 110 Body 114 Shaft hole 115 Auxiliary passage (auxiliary intake passage) 116 Purge passage (gas passage) 120 throttle shaft 125 First adjusting valve (first hollowed-out portion, notched groove) 126 Second adjustment valve (second hollowed-out portion, through hole) 127 Annular groove M3 throttle device 220 throttle shaft 226,228 Other end 227 Circular Groove 230 Connecting shaft 231,236 One end 232 First adjusting valve (first hollowed-out portion, notched groove) 233 Second adjustment valve (second hollowed-out portion, through hole) 234 Circular groove 235,237 Other end M4 Throttle Device 210 Body 216 Upstream purge passage (purge passage) 320 throttle shaft 325 First adjusting valve (first hollowed-out part, notched groove) 326 Second adjustment valve (second cutout, opening hole) 327 Downstream purge passage (purge passage) 328 Circular Groove

Claims

1. A throttle device applied to an intake system of an internal combustion engine, the throttle device including a main intake passage that introduces intake air into a combustion chamber, an auxiliary intake passage that branches off from the main intake passage midway and joins the main intake passage near the combustion chamber, and a gas passage that introduces fuel evaporative gas into the main intake passage or the auxiliary intake passage, a body defining a main passage that forms a part of the main intake passage, a secondary passage that forms a part of the secondary intake passage, and a purge passage that forms a part of the gas passage; a throttle valve that opens and closes the main passage; a throttle shaft rotatably supported by the body and having the throttle valve fixed thereto; a first adjusting valve for adjusting the flow rate of the sub-passage; a second adjusting valve that adjusts the flow rate of the purge passage, the first adjusting valve and the second adjusting valve rotate integrally with the throttle shaft and are driven to open and close; A throttle device characterized by:

2. The sub-passage and the purge passage are formed so as to intersect with the axis of the throttle shaft.

2. The throttle device according to claim 1, wherein:

3. the first adjusting valve includes a first recessed portion formed in the throttle shaft in a region facing the auxiliary passage, the second adjusting valve includes a second lightening portion formed in the throttle shaft in a region facing the purge passage, 3. The throttle device according to claim 2.

4. the body includes a tubular portion extending in a direction of a predetermined centerline and defining the main passage; the sub-passage is formed as a through-hole that extends parallel to the center line adjacent to the cylindrical portion and has the first adjustment valve interposed therein, the purge passage is formed as a through-hole that extends parallel to the center line adjacent to the cylindrical portion and has the second adjustment valve interposed therein.

4. The throttle device according to claim 3.

5. the first recessed portion is a notched groove formed by cutting out the throttle shaft, The second hollowed portion forms a through hole through which the throttle shaft passes.

4. The throttle device according to claim 3.

6. the body includes a shaft hole through which the throttle shaft passes, the sub-passage and the purge passage are formed to communicate with the axial hole, Seal members are disposed on the throttle shaft at least on both sides of the purge passage, the seal members being in close contact with the shaft hole.

4. The throttle device according to claim 3.

7. the body includes a tubular portion extending in a direction of a predetermined centerline and defining the main passage; the sub-passage is formed as a through-hole that extends parallel to the center line adjacent to the cylindrical portion and has the first adjustment valve interposed therein, The purge passage includes an upstream purge passage formed upstream of the second adjustment valve, adjacent to the cylindrical portion, and extending parallel to the center line so that the second adjustment valve is interposed therebetween, and a downstream purge passage formed downstream of the second adjustment valve and communicating with the through-hole downstream of the first adjustment valve.

4. The throttle device according to claim 3.

8. the first recessed portion is a notched groove formed by cutting out the throttle shaft, the second recessed portion is an opening hole that opens radially to the throttle shaft, the downstream purge passage is formed in the throttle shaft in a region extending from the downstream end of the opening hole to the notched groove; 8. The throttle device according to claim 7.

9. the body includes a shaft hole through which the throttle shaft passes, the sub-passage and the upstream purge passage are formed to communicate with the axial hole, Seal members that are in tight contact with the shaft hole are disposed on the throttle shaft at least on both sides of the upstream purge passage and the sub-passage.

8. The throttle device according to claim 7.

10. a connecting shaft connected to an end of the throttle shaft so as to rotate integrally with the throttle shaft and rotatably supported by the body; the first adjusting valve includes a first recessed portion formed in the connecting shaft in a region facing the sub-passage, the second adjusting valve includes a second lightening portion formed in the connecting shaft in a region facing the purge passage, 3. The throttle device according to claim 2.

11. the body includes a tubular portion extending in a direction of a predetermined centerline and defining the main passage; the sub-passage is formed as a through-hole that extends parallel to the center line adjacent to the cylindrical portion and has the first adjustment valve interposed therein, the purge passage is formed as a through-hole that extends parallel to the center line adjacent to the cylindrical portion and has the second adjustment valve interposed therein.

11. The throttle device according to claim 10.

12. the first recessed portion is a notched groove formed by cutting out the connecting shaft, The second hollowed portion forms a through hole that passes through the connecting shaft.

11. The throttle device according to claim 10.

13. the body includes a shaft hole through which the throttle shaft passes, and a second shaft hole formed coaxially and continuously with the shaft hole and through which the connecting shaft passes, the sub-passage and the purge passage are formed to communicate with the second axial hole, The connecting shaft is provided with seal members that are in tight contact with the second shaft hole at least on both sides of the purge passage.

11. The throttle device according to claim 10.

14. The throttle shaft is made of a metal material, The connecting shaft is formed from a resin material.

11. The throttle device according to claim 10.

15. a drive unit that rotationally drives the throttle shaft, the drive unit includes a drive motor fixed to the body, a drive gear fixed to a rotary shaft of the drive motor, and a gear train interposed between the drive gear and the throttle shaft.

5. The throttle device according to claim 4.

16. the sub-passage and the purge passage are formed between the cylindrical portion and the gear train in the axial direction of the throttle shaft, 16. The throttle device according to claim 15.

17. the sub-passage and the purge passage are formed on the opposite side of the cylindrical portion from the gear train in the axial direction of the throttle shaft, 16. The throttle device according to claim 15.

18. When the throttle valve changes from a low opening to a medium opening and then to a high opening, the first adjusting valve opens the bypass passage in the range from the low opening degree to the medium opening degree and closes the bypass passage in the high opening degree range, the second adjusting valve closes the purge passage in the low opening range and opens the purge passage toward the high opening range.

2. The throttle device according to claim 1, wherein:

19. the auxiliary passage defines a portion of the auxiliary intake passage branching off from the main intake passage upstream of the throttle valve, the purge passage defines a portion of the gas passage that merges with the main intake passage downstream of the throttle valve or a portion of the gas passage that merges with the sub-passage downstream of the first adjustment valve; 2. The throttle device according to claim 1, wherein:

20. a main intake pipe defining a part of a main intake passage that guides intake air into a combustion chamber of an internal combustion engine; a fuel injection valve that injects fuel into the main intake passage or the combustion chamber; an auxiliary intake pipe that defines a part of an auxiliary intake passage that branches off from the main intake passage midway and joins the main intake passage near the combustion chamber; a gas pipe defining a part of a gas passage that guides fuel vapor in a fuel tank to the main intake passage or the sub-passage; a throttle device disposed in the main intake pipe, The throttle device is a throttle device according to any one of claims 1 to 19. An intake system for an internal combustion engine.

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