Secondary air supply system

Abstract

To provide a structure capable of reducing the number of components to enable reduction in the size of a system, cost reduction and the like in a secondary air supply system.SOLUTION: In a secondary air supply system for an engine for supplying air in an air cleaner 10 to an exhaust passage via an internal passage 21 of an on-off valve V1, the air cleaner 10 includes a penetration passage 11a penetrating through a wall part 11d thereof, and the on-off valve V1 is fixed adjacent to an outer wall surface of the air cleaner 10 so as to cause air to directly pass from a region of the penetration passage 11e through the internal passage 21.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a secondary air supply system for supplying air that has passed through an air cleaner to an exhaust passage in an intake and exhaust system of an engine mounted on a vehicle, particularly a motorcycle or the like. [Background technology]

[0002] A known conventional secondary air supply system is configured between the air cleaner and exhaust pipe of an engine mounted on a motorcycle, and includes a solenoid valve (opening / closing valve) fixed to the outer wall of the air cleaner, a reed valve fixed to the outer wall of the air cleaner, upstream piping connecting the air cleaner and the solenoid valve to allow air to pass through, intermediate piping connecting the solenoid valve and the reed valve to allow air to pass through, and downstream piping connecting the reed valve and the exhaust pipe to allow air to pass through (see, for example, Patent Document 1).

[0003] In this secondary air supply system, the solenoid valve and air cleaner are connected by dedicated piping, which requires dedicated piping space, reducing layout freedom, increasing the number of parts and costs, and making it difficult to consolidate the installed parts.

[0004] Another known secondary air supply system is one that is located between the air cleaner and exhaust pipe of an engine mounted on a motorcycle and includes a secondary air valve (open / close valve) fixed to the air cleaner in an area facing the top surface of the cylinder head cover, a secondary air intake hose that connects the secondary air valve to the air cleaner to allow air to pass through, and a secondary air supply hose that connects a connector provided on the cylinder head cover to communicate with the exhaust port of the engine and the secondary air valve to allow air to pass through (see, for example, Patent Document 2).

[0005] In this secondary air supply system, as in the case described above, the secondary air valve and the air cleaner are connected by a dedicated pipe (secondary air intake hose), which requires dedicated piping space, reduces layout freedom, increases the number of parts and costs, and makes it difficult to consolidate the installed parts. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-180812 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-59923 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in consideration of the above circumstances, and its purpose is to provide a secondary air supply system that can reduce the number of parts, lower costs, and increase layout freedom, etc. [Means for solving the problem]

[0008] The secondary air supply system of the present invention is a secondary air supply system for an engine that supplies air in an air cleaner to an exhaust passage via an internal passage of an on-off valve, wherein the air cleaner includes a through passage penetrating its wall, and the on-off valve is fixed adjacent to the outer wall surface of the air cleaner so as to pass air directly from the area of ​​the through passage into the internal passage.

[0009] In the secondary air supply system, a configuration may be adopted in which an internal opening end of the through passage is provided vertically above a bottom surface of the air cleaner.

[0010] In the secondary air supply system, the internal opening end of the through passage may be formed at a position protruding inward from the inner wall surface of the wall portion of the air cleaner.

[0011] The secondary air supply system may have a configuration including a pipe that connects the internal passage of the on-off valve with the exhaust passage.

[0012] In the above secondary air supply system, the on-off valve may have a configuration including a main body defining an internal passage, a fixing portion fixed to the outer wall surface of the air cleaner, and a pipe portion to which piping is connected, a valve body that opens and closes the internal passage, and a drive portion that drives the valve body.

[0013] In the above secondary air supply system, the air cleaner may include a joining surface formed on the outer wall surface around the through passage and to which the fixing portion is joined, the main body may include a cylindrical fitting portion that defines a part of the internal passage and is fitted into the through passage, and a sealing member may be arranged between the cylindrical fitting portion and the through passage.

[0014] In the above secondary air supply system, the air cleaner may have a configuration in which it includes a joint surface formed on the outer wall surface around the through passage and to which the fixing portion is joined, and a sealing member is arranged between the fixing portion and the joint surface.

[0015] In the above secondary air supply system, a configuration may be adopted in which the air cleaner includes a female threaded hole in the area of ​​the joint surface, the main body includes a circular hole in the fixing portion through which a screw is passed to be screwed into the female threaded hole, and the opening / closing valve is fixed to the air cleaner by passing a screw through the circular hole and screwing it into the female threaded hole.

[0016] In the above secondary air supply system, the main body may have a circular hole in the fixing portion through which a tapping screw passes, and the opening / closing valve may be fixed to the air cleaner by passing the tapping screw through the circular hole and screwing it into the area of ​​the joint surface of the air cleaner.

[0017] In the above secondary air supply system, a configuration may be adopted in which the air cleaner includes two protruding mating pins in the area around the joint surface, the main body includes two annular elastic members at the fixing portion into which the protruding mating pins are fitted, and the opening / closing valve is fixed to the air cleaner by fitting the protruding mating pins into the annular elastic members.

[0018] In the above secondary air supply system, the drive unit may be a solenoid-type electromagnetic actuator, and the valve body may be directly connected to a mover of the electromagnetic actuator.

[0019] In the above secondary air supply system, a configuration may be adopted in which the drive unit is a solenoid-type electromagnetic actuator, the valve body is directly connected to the movable element of the electromagnetic actuator, the main body includes a connector that electrically connects a coil included in the electromagnetic actuator, and the connector and the pipe unit are formed to extend parallel to each other on the same side.

[0020] In the above secondary air supply system, a configuration may be adopted in which the main body includes a cylindrical fitting portion that defines a portion of the internal passage and is fitted into the through passage, and the cylindrical fitting portion is formed to extend parallel to the connector portion and the pipe portion on the opposite side.

[0021] In the above secondary air supply system, the valve body may be configured to open the internal passage when the electromagnetic actuator is in a non-energized state.

[0022] In the secondary air supply system, a check valve for preventing backflow of air may be disposed between the pipe and the exhaust passage.

[0023] In the secondary air supply system, the air cleaner may include a filter member disposed therein, and the through passage may lead to a region downstream of the filter member. [Effects of the Invention]

[0024] According to the secondary air supply system having the above configuration, it is possible to achieve a reduction in the number of parts, a reduction in costs, and an increase in the degree of freedom in layout. It is possible. [Brief explanation of the drawings]

[0025] [Figure 1]1 is a system diagram showing an intake and exhaust system of a motorcycle equipped with a secondary air supply system according to the present invention. [Figure 2] 1 is an external perspective view showing an air cleaner, an on-off valve, and piping in a secondary air supply system according to a first embodiment of the present invention. [Figure 3] 1 is an exploded perspective view of an air cleaner, an on-off valve, and piping in a secondary air supply system according to a first embodiment of the present invention. FIG. [Figure 4] 1 is a partial cross-sectional view showing an air cleaner, an on-off valve, and piping in a secondary air supply system according to a first embodiment of the present invention. [Figure 5] 1 is a partial cross-sectional view showing an air cleaner, an on-off valve, and piping in a secondary air supply system according to a first embodiment of the present invention. [Figure 6] 1 is a plan view showing an on-off valve included in a secondary air supply system according to a first embodiment of the present invention. [Figure 7] 1 is a perspective view showing a drive unit and a valve body that form part of an on-off valve included in a secondary air supply system according to a first embodiment of the present invention. FIG. [Figure 8] FIG. 10 is an external perspective view showing an on-off valve in a secondary air supply system according to a second embodiment of the present invention. [Figure 9] FIG. 5 is a partial cross-sectional view showing an air cleaner, an on-off valve, and piping in a secondary air supply system according to a second embodiment of the present invention. [Figure 10] FIG. 6 is a partial cross-sectional view showing an air cleaner, an on-off valve, and piping in a secondary air supply system according to a second embodiment of the present invention. [Figure 11] FIG. 10 is an external perspective view showing an air cleaner, an on-off valve, and piping in a secondary air supply system according to a third embodiment of the present invention. [Figure 12] FIG. 10 is an exploded perspective view of a secondary air supply system according to a third embodiment of the present invention, in which an air cleaner, an on-off valve, and piping are disassembled. [Figure 13] FIG. 10 is a partial cross-sectional view showing an air cleaner, an on-off valve, and piping in a secondary air supply system according to a third embodiment of the present invention. [Figure 14] FIG. 10 is an external perspective view showing an on-off valve in a secondary air supply system according to a third embodiment of the present invention. [Figure 15] FIG. 10 is a plan view showing an on-off valve in a secondary air supply system according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. As shown in FIG. 1, the intake and exhaust system of an engine equipped with a secondary air supply system according to the present invention includes an engine body 1, an intake manifold 2, a throttle device 3, an intake duct 4, an outside air introduction duct 5, an exhaust manifold 6, an exhaust pipe 7, an air cleaner 10, an on-off valve V1 fixed directly to the air cleaner 10, a pipe P, and a check valve RV. Here, the secondary air supply system according to the first embodiment is made up of an air cleaner 10, an on-off valve V1, a pipe P, and a check valve RV.

[0027] The engine body 1 includes a cylinder block CB and a cylinder head CH, and is equipped with a piston 1a, an intake valve 1b, an exhaust valve 1c, an ignition plug 1d, a pipe section 1e, a drive system (not shown) for the piston 1a, and drive systems for the intake valve 1b and the exhaust valve 1c. The engine body 1 also includes an exhaust port Ep in the cylinder head CH downstream of the exhaust valve 1c, which forms part of an exhaust passage, and a communication passage Cp that leads from the pipe section 1e to the exhaust port Ep and has a check valve RV disposed midway. The intake manifold 2 includes a surge tank and a plurality of branch pipes, and the branch pipes are equipped with fuel injection valves 2a. The throttle device 3 is connected to a surge tank of the intake manifold 2 and includes a butterfly valve that opens and closes the intake passage. The intake duct 4 is connected between the throttle device 3 and the air cleaner 10 to define an intake passage for introducing the intake air that has passed through the air cleaner 10 . The outside air intake duct 5 is connected to the connection portion 12b of the air cleaner 10 and guides the outside air into the air cleaner 10. The exhaust manifold 6 is connected between the engine body 1 and an exhaust pipe 7, and defines an exhaust passage through which exhaust gas discharged from the exhaust port Ep of the engine body 1 passes. The exhaust pipe 7 is connected to the exhaust manifold 6 to define an exhaust passage, and is provided with a catalyst 7a in the middle thereof.

[0028] 2 to 5, the air cleaner 10 includes a case body 11, a case cover 12 that covers the case body 11, and a filter member 13 housed in the internal space. Here, the case body 11 and the case cover 12 are molded from a resin material.

[0029] The case body 11 includes a connecting flange portion 11a that connects the case cover 12, a holding portion 11b that holds the filter member 13, a bottom wall portion 11c, a side wall portion 11d, a through passage 11e that penetrates the side wall portion 11d, a joint surface 11f formed on the outer wall surface of the side wall portion 11d, two female screw holes 11g formed in the area of ​​the joint surface 11f, and a connecting portion 11h (see Figure 1) that connects the upstream end of the intake duct 4.

[0030] The through passage 11e is formed as a cylindrical hole penetrating the side wall portion 11d so that the cylindrical fitting portion 23 of the on-off valve V1 can be fitted therein, and is formed at a position higher than the bottom wall portion 11c in the vertical direction Vd. That is, the through passage 11e is provided above the bottom surface 11c1 of the air cleaner 10. Furthermore, the inner opening end 11e1 of the through passage 11e is formed at a position protruding inward from the inner wall surface of the side wall portion 11c.

[0031] The joining surface 11f is formed on the outer wall surface of the side wall portion 11d around the through passage 11e so that the fixing portion 22 of the on-off valve V1 is joined thereto. The two female screw holes 11g are formed in the region of the joining surface 11f at positions corresponding to the circular holes 22a formed in the fixing portion 22 of the on-off valve V1.

[0032] The case cover 12 includes a connecting flange portion 12a that is connected to the connecting flange portion 11a of the case body 11, and a connecting portion 12b that connects the downstream end of the outside air intake duct 5 (see FIG. 1). The filter member 13 is held by the holding portion 11b of the case body 11 and housed in the internal space, and serves to filter dust and the like from the air introduced from the outside air introduction duct 5. The air filtered by the filter member 13 is supplied to the intake duct 4 and the on-off valve V1. That is, the through passage 11e is formed so as to communicate with an area downstream of the filter member 13 in the internal space of the air cleaner 10, as shown in FIG.

[0033] As shown in FIGS. 2 to 7, the on-off valve V1 includes a main body 20, a valve element 30 that reciprocates in the direction of an axis S, a biasing spring 40, and a drive unit 50. The main body 20 is molded from a resin material, has an elongated shape in the direction of the axis S, and includes an internal passage 21, a fixing portion 22, a cylindrical fitting portion 23, a pipe portion 24, an enclosing portion 25, and a connector 26.

[0034] The internal passage 21 is a passage through which air passes within the air cleaner 10, and is bent in a crank shape to include an intermediate passage extending in the direction of the axis S in which the spring 40 is housed, an upstream passage extending within the cylindrical fitting portion 23, and a downstream passage extending within the pipe portion 24. The internal passage 21 also has a seating surface 21a on which the valve body 30 seats in the direction of the axis S to close the valve, a receiving surface 21b that receives one end 41 of the biasing spring 40 in the direction of the axis S, and a stopper 21c that stops the valve body 30 in the fully open position.

[0035] The fixing portion 22 is an area that is joined and fixed to the joining surface 11f of the air cleaner 10, and is formed as a long, flat flange in the direction L1 perpendicular to the axis S, and has two circular holes 22a through which the screws B are passed. The cylindrical fitting portion 23 is formed in a cylindrical shape extending from the central region of the fixing portion 22 in the direction of a straight line L2 perpendicular to the axis S, and defines a part of the internal passage 21 and has an annular groove 23a on its outer periphery into which the sealing member Sr is fitted. The cylindrical fitting portion 23 is adapted to be fitted into the through passage 11e of the air cleaner 10 with the seal member Sr fitted into the annular groove 23a.

[0036] The pipe portion 24 is formed in a cylindrical shape that extends from the region where the valve body 30 is housed in the direction of a straight line L3 perpendicular to the axis S and defines a part of the internal passage 21. The pipe portion 24 is adapted to be connected to a piping P. The surrounding portion 25 is an area that houses the drive unit 50, and is molded during resin molding so as to embed and surround the stator (first yoke 53 and second yoke 54), bobbin 51, and coil 52 of the drive unit 50. The connector 26 is formed to extend in the direction of a straight line L4 perpendicular to the axis S so as to expose and surround the terminal 52a connected to the coil 52 of the drive unit 50 for electrical connection to the outside.

[0037] Here, the relationship between the tubular fitting portion 23, the pipe portion 24, and the connector 26 is such that the connector 26 and the pipe portion 24 extend parallel to the same side of the axis S (the lines L4 and L3 are parallel), and the tubular fitting portion 23 extends parallel to the connector 26 and the pipe portion 24 on the opposite side of the axis S (the lines L2, L3, and L4 are parallel). This arrangement facilitates the installation of the on-off valve V1 to the air cleaner 10, the installation of the piping P to the pipe section 24, and the connection of an external connector to the connector 26. Furthermore, the layout of the wiring connected to the piping P and the external connector can be simplified.

[0038] As shown in Figures 4 and 7, the valve body 30 has a metal reinforcing plate 31 and a rubber part 32 molded to embed the reinforcing plate 31, and is formed in a circular plate shape and directly connected to the movable element 55 of the drive part 50. The rubber portion 32 includes an annular seal portion 32 a that seats on a seating surface 21 a of the internal passage 21 to close the internal passage 21 , and a receiving surface 32 b that receives the other end 42 of the biasing spring 40 .

[0039] The biasing spring 40 is a coil-type compression spring, and as shown in Figure 4, is arranged in an intermediate passage of the internal passage 21 that extends in the direction of the axis S, with one end 41 abutting against the receiving surface 21b and the other end 42 abutting against the receiving surface 32b of the valve body 30, biasing the valve body 30 in the valve-opening direction.

[0040] As shown in Figures 4 and 7, the drive unit 50 is a solenoid-type electromagnetic actuator and includes a bobbin 51, an excitation coil 52, a first yoke 53 and a second yoke 54 as stators, and a mover 55 that reciprocates in the direction of the axis S.

[0041] The bobbin 51 is made of a resin material and is formed to include a cylindrical portion 51a that guides the mover 55 in the direction of the axis S, a flange portion 51b on one end side, and a flange portion 51c near the other end side. Coil 52 is wound around cylindrical portion 51a of bobbin 51, and a metal terminal 52a is connected to one end of coil 52. Terminal 52a is embedded in a region where the base connected to coil 52 is continuous with flange 51c of bobbin 51. The first yoke 53 is made of a magnetic material and includes a bottomed cylindrical portion 53a that is fitted onto the cylindrical portion 51a from the flange portion 51b side of the bobbin 51, and a flat portion 53b to which the second yoke 54 is connected. The second yoke 54 is made of a magnetic material and is bent into an approximately U-shape, and includes a flat portion 54a having a fitting hole 54a1 that fits into the cylindrical portion 51a from the flange portion 51c side of the bobbin 51, and an arm portion 54b that extends from the flat portion 54a outside the coil 52 in the direction of the axis S and to which the first yoke 53 is connected. The mover 55 is made of a magnetic material and includes a bottomed cylindrical portion 55a disposed within the cylindrical portion 51a, and a rod portion 55b extending from the bottomed cylindrical portion 55a in the direction of the axis S and connecting the valve body 30 at its tip.

[0042] The on-off valve V1 having the above-described configuration is set so that when the coil 52 is not energized, the internal passage 21 is opened by the biasing force of the biasing spring 40, and when the coil 52 is energized, the annular seal portion 32a of the valve body 30 seats on the seating surface 21a against the biasing force of the biasing spring 40, thereby closing the internal passage 21.

[0043] The pipe P is a rubber hose made of a rubber material or the like, and its upstream end is connected to the pipe portion 24 of the on-off valve V1, and its downstream end is connected to the pipe portion 1e of the cylinder head CH. That is, the pipe P connects the internal passage 21 of the on-off valve V1 to the exhaust port Ep of the cylinder head CH, which forms part of the exhaust passage, via the communication passage Cp of the cylinder head CH.

[0044] The check valve RV is a cantilever-shaped reed valve located midway in the connecting passage Cp of the cylinder head CH. It is closed when the engine body 1 is stopped, and bends and opens when the engine body 1 starts and the negative pressure in the exhaust passage exceeds a predetermined level.

[0045] The installation work of the on-off valve V1 having the above configuration is completed by fitting the sealing member Sr into the annular groove 23a, fitting the cylindrical fitting portion 23 into the through passage 11e of the air cleaner 10, joining the fixing portion 22 to the joining surface 11f, and then inserting the screw B into the circular hole 22a and screwing it into the female threaded hole 11g. As a result, the on-off valve V1 is fixed so as to face an area downstream of the filter member 13 arranged inside the air cleaner 10. Then, the air inside the air cleaner 10, from which dust and the like have been filtered by the filter member 13, is passed directly from the area of ​​the through passage 11e to the internal passage 21.

[0046] According to the secondary air supply system of the first embodiment, after the engine body 1 is started, the check valve RV opens in response to the negative pressure in the exhaust passage (exhaust port Ep), and air in the air cleaner 10 is supplied from the area of ​​the through passage 11e to the exhaust passage (exhaust port Ep) through the internal passage 21 of the on-off valve V1, the passage of the piping P, and the connecting passage Cp of the cylinder head CH. This allows unburned HC and CO to be re-burned, reducing the amount of HC and CO that is emitted. On the other hand, when the throttle (accelerator) is suddenly released to decelerate, the coil 52 is energized and the on-off valve V1 closes the internal passage 21 in order to prevent self-ignition (afterfire) from occurring when the unburned gas is concentrated in the exhaust passage.

[0047] According to the secondary air supply system of the first embodiment, the on-off valve V1 is fixed adjacent to the outer wall surface (joint surface 11f of side wall portion 11d) of the air cleaner 10 so as to pass air directly from the area of ​​the through passage 11e of the air cleaner 10 to the internal passage 21. This eliminates the need for piping connecting the air cleaner and the on-off valve as in the prior art, thereby reducing the number of parts and achieving lower costs, and also increasing the freedom of layout due to the increased free space.

[0048] Furthermore, the internal opening end 11e1 of the through passage 11e, which serves as the air inlet, is located above the bottom surface 11c1 of the air cleaner 10 in the vertical direction Vd, so that even if water droplets generated by condensation or the like in the internal space of the air cleaner 10 accumulate on the bottom surface 11c1, the water droplets can be prevented from flowing into the internal passage 21 of the opening / closing valve V1. In particular, the internal opening end 11e1 of the through passage 11e is formed at a position that protrudes inward from the inner wall surface of the side wall portion 11d, which serves as a wall portion, and therefore water droplets and the like adhering to the inner wall surface of the side wall portion 11d can be prevented from penetrating into the through passage 11e as they flow down toward the bottom surface 11c1.

[0049] Furthermore, when attaching the on-off valve V1 to the air cleaner 10, the cylindrical fitting portion 23 is fitted into the through passage 11e to prevent it from falling off, and the fixing portion 22 is joined to the joining surface 11f, and the screw B is passed through the circular hole 22a and screwed into the female screw hole 11g, thereby making it possible to easily perform the installation work (fixing work). Furthermore, since the pipe portion 24 and the connector 26 extend parallel to each other on the same side, the installation of the piping P and the connection of the external connector can be easily performed.

[0050] 8 to 10 show a secondary air supply system according to a second embodiment of the present invention, and the same components as those in the first embodiment are given the same reference numerals and descriptions thereof will be omitted. The secondary air supply system according to the second embodiment is made up of an air cleaner 10, an on-off valve V2, a pipe P, and a check valve RV.

[0051] The on-off valve V2 includes a main body 120, a valve element 30 that reciprocates in the direction of an axis S, a biasing spring 40, and a drive unit 50. The main body 120 is molded from a resin material, has an elongated shape in the direction of the axis S, and includes an internal passage 121, a fixing portion 122, a pipe portion 24, an enclosing portion 25, and a connector 26.

[0052] The internal passage 121 is a passage through which air passes within the air cleaner 10, and is bent in a crank shape to include an intermediate passage extending in the direction of the axis S in which the spring 40 is housed, an upstream passage extending through the fixed portion 122, and a downstream passage extending within the pipe portion 24. The internal passage 121 also has a seating surface 21a on which the valve body 30 seats in the direction of the axis S to close the valve, a receiving surface 21b that receives one end 41 of the biasing spring 40 in the direction of the axis S, and a stopper 21c that stops the valve body 30 in the fully open position.

[0053] The fixing portion 122 is an area that is joined and fixed to the joining surface 11f of the air cleaner 10, and is formed as a long, flat flange in the direction L1 perpendicular to the axis S, and is equipped with two circular holes 122a for passing the screws B, a joining surface 122b, and an annular groove 122c. The joining surface 122b is formed as a flat surface that is intimately joined to the joining surface 11f of the air cleaner 10. The annular groove 122c is formed around the upstream opening end of the internal passage 121 on the joining surface 122b to fit the seal member Sr.

[0054] The on-off valve V2 having the above-described configuration does not have anything equivalent to the cylindrical fitting portion 23 of the on-off valve V1 described above, and therefore can achieve a corresponding simplification of the structure and miniaturization. According to the secondary air supply system of the second embodiment, the on-off valve V2 is fixed adjacent to the outer wall surface (joint surface 11f of side wall portion 11d) of the air cleaner 10 so as to pass air directly from the area of ​​the through passage 11e of the air cleaner 10 to the internal passage 121. This eliminates the need for piping connecting the air cleaner and the on-off valve as in the prior art, thereby reducing the number of parts and achieving lower costs, and also increasing the freedom of layout due to the increased free space.

[0055] Furthermore, the internal opening end 11e1 of the through passage 11e, which serves as the air inlet, is located above the bottom surface 11c1 of the air cleaner 10 in the vertical direction Vd, so that even if water droplets generated by condensation or the like in the internal space of the air cleaner 10 accumulate on the bottom surface 11c1, the water droplets can be prevented from flowing into the internal passage 121 of the opening / closing valve V2. In particular, the internal opening end 11e1 of the through passage 11e is formed at a position that protrudes inward from the inner wall surface of the side wall portion 11d, which serves as a wall portion, and therefore water droplets and the like adhering to the inner wall surface of the side wall portion 11d can be prevented from penetrating into the through passage 11e as they flow down toward the bottom surface 11c1.

[0056] 11 to 15 show a secondary air supply system according to a third embodiment of the present invention, and the same components as those in the first embodiment are given the same reference numerals and descriptions thereof will be omitted. The secondary air supply system according to the third embodiment is made up of an air cleaner 100, an on-off valve V3, a pipe P, and a check valve RV.

[0057] The air cleaner 100 includes a case body 101, a case cover 12 that covers the case body 101, and a filter member 13 housed in the internal space. Here, the case body 101 and the case cover 12 are molded from a resin material.

[0058] The case body 101 includes a connecting flange portion 11a, a holding portion 11b, a bottom wall portion 11c, a side wall portion 11d, a through passage 11e relating to the side wall portion 11d, a joint surface 101f formed on the outer wall surface of the side wall portion 11d, two protruding mating pins 101g around the joint surface 101f, and a connection portion 11h (see Figure 1).

[0059] The joint surface 101f is formed on the outer wall surface of the side wall portion 11d around the through passage 11e so that the joint portion 227 of the on-off valve V3 is joined thereto. The two protruding fitting pins 101g are formed in a cylindrical shape protruding perpendicularly to the joining surface 101f on both sides in the direction L1 sandwiching the joining surface 101f, and have a fitting portion 101g1 in a tip side region that fits into the annular elastic member (grommet 260) of the on-off valve V3. The fitting portion 101g1 is formed as a small diameter portion to prevent it from falling off from the annular elastic member (grommet 260).

[0060] The on-off valve V3 includes a main body 220, a grommet 260 as an annular elastic member, a valve element 30 that reciprocates in the direction of an axis S, a biasing spring 40, and a drive unit 50. The main body 220 is molded from a resin material, has an elongated shape in the direction of the axis S, and includes an internal passage 21, a fixing portion 222, a cylindrical fitting portion 23, a pipe portion 24, a surrounding portion 25, a connector 26, and a joint portion 227.

[0061] The fixing portion 222 has two fitting and holding portions 222a arranged in the horizontal direction L1 with the through passage 11e in between. The fitting and holding portion 222a has a cutout portion cut out in a C-shape, into which the grommet 260 can be fitted. The joint portion 227 is formed in a rectangular parallelepiped shape in the base region of the cylindrical fitting portion 23, and has a joint surface 227a that is joined to the joint surface 101f of the air cleaner 100.

[0062] The grommet 260 is molded into a circular ring shape using a rubber material, and includes a fitting hole 261 into which the protruding fitting pin 101g is fitted, and a small diameter portion 262 into which the fitting holding portion 222a is fitted.

[0063] The installation work of the on-off valve V3 having the above configuration is such that, with the sealing member Sr fitted into the annular groove 23a and the grommet 260 fitted into the fitting holding portion 222a, the cylindrical fitting portion 23 is fitted into the through passage 11e of the air cleaner 100, the two protruding fitting pins 101g are fitted into the grommet 260 (fitting hole 261) of the fixing portion 222, and the joining surface 227a of the joining portion 227 is joined to the joining surface 101f. As a result, the on-off valve V3 is fixed so as to face an area downstream of the filter member 13 arranged inside the air cleaner 100. Then, the air inside the air cleaner 100, from which dust and the like have been filtered by the filter member 13, is passed directly from the area of ​​the through passage 11e to the internal passage 21.

[0064] According to the on-off valve V3 having the above-described configuration, the on-off valve V3 is directly fixed to the air cleaner 100 via the annular elastic member (grommet 260), so that vibrations and the like transmitted from the air cleaner 100 side to the on-off valve V3 can be absorbed or mitigated by the annular elastic member (grommet 260). According to the secondary air supply system of the third embodiment, the on-off valve V3 is fixed adjacent to the outer wall surface (joint surface 101f of the side wall portion 11d) of the air cleaner 100 so as to pass air directly from the area of ​​the through passage 11e of the air cleaner 100 to the internal passage 21. This eliminates the need for piping to connect the air cleaner and the on-off valve as in the prior art, thereby reducing the number of parts and achieving lower costs, and also increasing the freedom of layout due to the increased free space.

[0065] Furthermore, the internal opening end 11e1 of the through passage 11e, which serves as the air inlet, is located above the bottom surface 11c1 of the air cleaner 100 in the vertical direction Vd, so that even if water droplets generated by condensation or the like in the internal space of the air cleaner 100 accumulate on the bottom surface 11c1, the water droplets can be prevented from flowing into the internal passage 21 of the opening / closing valve V3. In particular, the internal opening end 11e1 of the through passage 11e is formed at a position that protrudes inward from the inner wall surface of the side wall portion 11d, which serves as a wall portion, and therefore water droplets and the like adhering to the inner wall surface of the side wall portion 11d can be prevented from penetrating into the through passage 11e as they flow down toward the bottom surface 11c1.

[0066] In the above embodiment, as a configuration in which air is passed directly from the area of ​​the through passage 11e to the internal passage 21, the tubular fitting portion 23 is fitted partway into the through passage 11e, and the air that has passed through the through passage 11e is passed to the internal passage 21. However, this is not limited to this, and the concept of "from the area of ​​the through passage" also includes a configuration in which the upstream end of the tubular fitting portion 23 is extended to the internal opening end 11e1 of the through passage 11e, and the air is passed directly from the internal opening end 11e1 to the internal passage 21.

[0067] In the above embodiment, a solenoid-type electromagnetic actuator having a movable element 55 that reciprocates in the direction of the axis S is shown as the driving unit included in the on-off valves V1, V2, and V3, but this is not limited to this, and an on-off valve having a rotary drive source as the driving unit or an on-off valve of other form may be used as long as it is an on-off valve that can open and close the internal passages 21 and 121 on and off.

[0068] In the above embodiment, the side wall 11d of the air cleaner 10, 100 is used as the wall to which the on-off valves V1, V2, and V3 are attached. However, this is not limited thereto. A through-passage may be provided in the bottom wall 11c, and the on-off valves may be fixed to the outer wall surface of the bottom wall 11c. In this case, the internal opening end of the through-passage is formed at a position that protrudes inward (upward) from the inner wall surface (bottom surface 11c1) of the bottom wall 11c so as to be located vertically above the bottom surface 11c1. This prevents water droplets adhering to or accumulating on the bottom surface 11c1 of the bottom wall 11c from entering the internal passages of the on-off valves through the through-passage.

[0069] In the above embodiment, in the on-off valves V1, V2, and V3, the pipe section 24 and the connector 26 extend in the same direction on the same side, but this is not limited to this, and a form in which they extend in a desired direction may be adopted depending on the required wiring layout.

[0070] In the above embodiment, the method of fixing the on-off valves V1, V2 to the air cleaner 10, 100 is such that the air cleaner 10, 100 includes a pre-formed female threaded hole 11g in the area of ​​the joint surface 11f, the main body 20, 120 of the on-off valves V1, V2 includes circular holes 22a, 122a at the fixing portions 22, 122 through which screws B are passed to be screwed into the female threaded hole 11g, and the on-off valves V1, V2 are fixed to the air cleaner 10, 100 by passing the screws B through the circular holes 22a, 122a and screwing them into the female threaded hole 11g, but this is not limited to this. For example, a structure may be adopted in which the main body of the on-off valve includes a circular hole at the fixing portion through which a tapping screw (also called a tapping screw or tap screw) passes, the air cleaner has an area in the area of ​​the joint surface into which the tapping screw is screwed, and the on-off valve is fixed to the air cleaner by passing the tapping screw through the circular hole and screwing it into the area of ​​the joint surface of the air cleaner. Furthermore, although a fitting structure including a protruding fitting pin 101g and an annular elastic member (grommet 260) has been shown as a method for fixing the on-off valve V3 to the air cleaner 100, this is not limited to this and other forms of fitting structures may be adopted, and other methods may also be adopted as long as they can directly fix the on-off valve to the air cleaner.

[0071] In the above embodiment, a configuration has been shown in which the check valve RV included in the secondary air supply system is arranged midway through the communicating passage Cp formed in the cylinder head CH to supply air to the exhaust port Ep, but this is not limited to this, and as long as required conditions are met, a configuration in which the check valve RV is arranged midway through the passage member leading from the piping P to the exhaust pipe 7 to supply air to the exhaust pipe 7 further downstream may also be adopted.

[0072] As described above, the secondary air supply system of the present invention can achieve a reduction in the number of parts, a reduction in costs, and an increase in layout freedom, and is therefore useful not only for motorcycles and the like, but also for other vehicles. [Explanation of symbols]

[0073] 1 Engine body CB cylinder block CH cylinder head Ep exhaust port (exhaust passage) Cp communication path 1a Piston 1b Intake valve 1c Exhaust valve 1d Spark plug 1e Pipe section 2 intake manifolds 2a Fuel injection valve 3 Throttle device 4. Intake duct 5. Outside air intake duct 6 exhaust manifold 7 exhaust pipe 7a catalyst Vd vertical direction 10 Air cleaner 11 Case body 11c Bottom wall (wall) 11c1 bottom 11d Side wall (wall) 11e Passageway 11e1 internal open end 11f Joint surface (exterior wall surface) 11g female screw hole 12 Case cover 13 Filter material P piping RV check valve B screw V1 On-off valve 20 Main Unit 21 Internal passage 22 Fixed part 22a circular hole 23 Cylindrical fitting part 23a Annular groove Sr sealing material 24 Pipe section 25 Surrounding area 26 Connectors 30 Valve body 40 bias spring 50 Drive unit (solenoid type electromagnetic actuator) 51 Bobbin 52 Coil 52a terminal 53 First York 54 Second York 55 Mover 100 air cleaner 101 Case body 101f Joint surface 101g protruding mating pin V2 shut-off valve 120 body 121 Internal passage 122 Fixed part 122a circular hole 122b Joint surface 122c Annular groove V3 On-off valve 220 Main Unit 222 Fixed part 222a Fitting holding part 227 Joint 227a Joint surface 260 Grommet (annular elastic member) 261 Fitting hole 262 Small diameter section

Claims

1. A secondary air supply system for an engine that supplies air in an air cleaner to an exhaust passage through an internal passage of an on-off valve, The air cleaner includes a through passage extending through a wall thereof; The on-off valve is fixed adjacent to an outer wall surface of the air cleaner so as to allow air to pass directly from the through passage area to the internal passage. A secondary air supply system.

2. The inner opening end of the through passage is provided above the bottom surface of the air cleaner in the vertical direction.

2. The secondary air supply system according to claim 1.

3. The inner opening end is formed at a position protruding inward from the inner wall surface of the wall portion.

3. The secondary air supply system according to claim 2.

4. a pipe that connects the internal passage of the on-off valve with the exhaust passage; 2. The secondary air supply system according to claim 1.

5. The on-off valve includes a main body that defines the internal passage, a fixed portion that is fixed to the outer wall surface, and a pipe portion to which the piping is connected, a valve body that opens and closes the internal passage, and a drive portion that drives the valve body.

5. A secondary air supply system according to claim 4.

6. the air cleaner includes a joining surface formed on the outer wall surface around the through-path and to which the fixing portion is joined, the main body includes a cylindrical fitting portion that defines a portion of the internal passage and is fitted into the through passage; A seal member is disposed between the cylindrical fitting portion and the through passage.

6. A secondary air supply system according to claim 5.

7. the air cleaner includes a joining surface formed on the outer wall surface around the through-path and to which the fixing portion is joined, A seal member is disposed between the fixing portion and the joining surface.

6. A secondary air supply system according to claim 5.

8. the air cleaner includes a female threaded hole in the area of ​​the interface; the main body includes a circular hole in the fixing portion through which a screw to be screwed into the female screw hole is passed, The on-off valve is fixed to the air cleaner by passing the screw through the circular hole and screwing it into the female screw hole.

8. A secondary air supply system according to claim 6 or 7.

9. the main body includes a circular hole in the fixing portion through which a tapping screw is inserted; The on-off valve is fixed to the air cleaner by passing the tapping screw through the circular hole and screwing it into the region of the joint surface of the air cleaner.

8. A secondary air supply system according to claim 6 or 7.

10. the air cleaner includes two protruding mating pins in a region around the mating surface; The main body includes two annular elastic members in the fixing portion, into which the protruding fitting pins are fitted, The on-off valve is fixed to the air cleaner by fitting the protruding fitting pin into the annular elastic member.

7. A secondary air supply system according to claim 6.

11. the drive unit is a solenoid-type electromagnetic actuator, The valve element is directly connected to the mover of the electromagnetic actuator.

2. The secondary air supply system according to claim 1.

12. the drive unit is a solenoid-type electromagnetic actuator, The valve element is directly connected to the mover of the electromagnetic actuator, the main body includes a connector that electrically connects a coil included in the electromagnetic actuator; The connector and the pipe portion are formed to extend parallel to each other on the same side.

6. A secondary air supply system according to claim 5.

13. the main body includes a cylindrical fitting portion that defines a portion of the internal passage and is fitted into the through passage; The cylindrical fitting portion is formed so as to extend in parallel to the connector portion and the pipe portion on the opposite side.

13. The secondary air supply system according to claim 12.

14. the valve body is configured to open the internal passage when the electromagnetic actuator is in a non-energized state.

12. The secondary air supply system according to claim 11.

15. A check valve is disposed between the piping and the exhaust passage to prevent backflow of air.

5. A secondary air supply system according to claim 4.

16. The air cleaner includes a filter member disposed therein. The through passage leads to a region downstream of the filter member.

2. The secondary air supply system according to claim 1.

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