JP2008025458A - Scooter type motorcycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify pipe layout structure by shortening the length of a secondary air supply passage from a secondary air control valve to an exhaust system of an engine. <P>SOLUTION: In this scooter type motorcycle having a power unit comprising an engine and a transmission device transmitting the power of the engine to a rear wheel swingingly supported by a body frame and having an intake system including an air cleaner arranged above a transmission case storing the transmission device at an upstream end connected to the upper side surface of a cylinder head, the length of the secondary air supply passage from the secondary air supply passage to the exhaust system of the engine is shortened by arranging a secondary air control valve sufficiently close to an engine body. The secondary air control valve 35 controlling a flow rate of secondary air supplied to the exhaust system of the engine from the air cleaner 27 is arranged at a position in front of the air cleaner 27, above the engine body 19 and at the side of an intake passage forming means 26 in such a manner that at least a part thereof is overlapped with the intake passage forming means 26 in a side view. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  According to the present invention, a power unit composed of an engine in which a cylinder axis of an engine body is tilted forward and a transmission device that transmits the output of the engine to a rear wheel is swingably supported on a vehicle body frame. The rear wheel is pivotally supported by the rear part of the transmission case that is continuously provided and extends to the side of the rear wheel and accommodates the transmission device, and the upstream end is connected to an air cleaner disposed above the transmission case The present invention relates to a scooter type motorcycle in which a downstream end of a sunk intake passage forming means is connected to an upper side surface of a cylinder head constituting a part of the engine body.

Such a scooter type motorcycle is known from Patent Document 1, in which secondary air for controlling the amount of secondary air supplied to the engine exhaust system from a sub air cleaner different from the air cleaner of the intake system. The control valve is disposed on the side of the intake system so as to be positioned above the intake system in a side view.
JP 2002-235535 A

  By the way, if the secondary air control valve is located relatively far from the engine, the length of the secondary air supply passage from the secondary air control valve to the engine exhaust system becomes long, and the piping structure is complicated. Become. In addition, since the power unit is swingably supported on the vehicle body frame, when the secondary air control valve is supported on the vehicle body frame side, the pipe connecting the secondary air control valve and the power unit against It is necessary to ensure sufficient escape. For this reason, it is desirable to arrange the secondary air supply control valve as close as possible to the engine side.

  The present invention has been made in view of such circumstances, and provides a scooter-type motorcycle in which a secondary air control valve is disposed sufficiently close to an engine body to solve the above-described problem. Objective.

  In order to achieve the above object, a power unit comprising an engine in which a cylinder axis of an engine body is tilted forward and a transmission that transmits the output of the engine to a rear wheel is provided in a vehicle body frame. The rear wheel is pivotally supported by a rear portion of the transmission case that is supported by the engine body and extends rearward to the side of the rear wheel. In the scooter type motorcycle, in which the downstream end of the intake passage forming means having the upstream end connected to the air cleaner disposed above is connected to the upper side surface of the cylinder head constituting a part of the engine body, the air cleaner A secondary air control valve that controls the flow rate of secondary air supplied to the exhaust system of the engine overlaps at least a part of the intake passage forming means in a side view. Unishi Te, characterized in that it is arranged on the side of the intake passage forming means in front of and above the engine body than the air cleaner.

  According to a second aspect of the invention, in addition to the configuration of the first aspect of the invention, the secondary air control valve and the ignition coil are commonly supported by a stay that is elastically supported by the engine body or the vehicle body frame. It is characterized by that.

  Furthermore, the invention described in claim 3 is characterized in that, in addition to the configuration of the invention described in claim 2, the secondary air control valve is elastically supported by the stay.

  According to the first aspect of the present invention, the secondary air control valve overlaps at least a part of the intake passage forming means in a side view, and is located in front of the air cleaner and above the engine body on the side of the intake passage forming means. Therefore, the secondary air control valve can be disposed as close as possible to the engine body and effectively disposed in the space on the side of the intake passage forming means. The length of the secondary air supply passage can be shortened to simplify the piping structure, and even if the secondary air control valve is supported on the body frame side, the secondary air control valve and power unit It is possible to reduce the escape against the swing of the power unit of the piping connecting the pipes. In addition, since the engine body is located below the secondary air control valve, the secondary air control valve can be effectively protected against mud and water splashing when the scooter type motorcycle is traveling.

  According to the second aspect of the present invention, the number of parts required to support the ignition coil and the secondary air control valve can be reduced by commonly supporting the ignition coil and the secondary air control valve on the stay. The stay can be attached to the engine main body or the vehicle body frame with the ignition coil and the secondary air control valve supported by the stay, and the assembly work can be simplified. Moreover, because the stay is elastically supported by the engine body or the body frame, the stay with the ignition coil and secondary air control valve attached has a relatively large weight, which reduces the natural frequency and improves the vibration isolation performance. be able to.

  Further, according to the third aspect of the present invention, the secondary air control valve is elastically supported by the engine body or the vehicle body frame with a double vibration isolating structure, and the vibration transmitted to the secondary air control valve is more effectively prevented. Can be suppressed.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

  1 to 8 show an embodiment of the present invention, FIG. 1 is a left side view of a scooter type motorcycle, and FIG. 2 is a perspective view of the engine as viewed from the right front side with the cover removed. 3 is a right side view of a part of FIG. 2 as viewed from the direction of the arrow 3 with the cover attached, FIG. 4 is an enlarged cross-sectional view taken along line 4-4 of FIG. 3, and FIG. 3 is an enlarged view of the main part of FIG. 3, FIG. 6 is a view corresponding to FIG. 5 with the ignition coil removed, FIG. 7 is a perspective view of the stay and the secondary air control valve as seen obliquely from the lower left front, and FIG. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 4.

  First, in FIG. 1, a vehicle body frame F of a scooter type motorcycle having a low floor type floor 11 includes a head pipe 13 that supports a front fork 12 that pivotally supports a front wheel WF, and a front end mounted on the head pipe 13. A pair of left and right side frames 14 to which the portions are joined. The side frame 14 is formed such that a down frame portion 14a hanging downward from the head pipe 13 is connected to a lower end of the down frame portion 14a and extends rearward below the floor 11 and a rear half portion is inclined rearwardly upward. The lower frame portion 14b, the rising frame portion 14c that is connected to the rear end of the lower frame portion 14b and rises upward at the rear of the floor 11, and the rear end of the rising frame portion 14c to support the vehicle seat 15. A single pipe is bent and formed integrally with a seat rail portion 14d extending in the direction.

  Between the rear part of the lower frame part 14b ... in the side frame 14 ... and the front part of the seat rail part 14d ..., it is located below the lower frame part 14b ... in the side frame 14 ... and behind the rising frame part 14c ... The rear sub-frames 16 are provided, and the pivot plates 17 are provided between the side frames 14 and the rear sub-frames 16.

  A power unit P composed of an engine E arranged on the front side of the rear wheel WR and a transmission device M arranged on the left side of the rear wheel WR swings up and down on the pivot plate 17 provided in the body frame F. The rear wheel WR is pivotally supported on the rear portion of the power unit P. The rear wheel WR is supported by the link mechanism 18 so as to be able to move. The transmission device M includes a V-belt type continuously variable transmission (not shown) and a reduction gear train (not shown) that decelerates the output of the continuously variable transmission and transmits it to the axle of the rear wheel WR. .

  In FIG. 2, an engine body 19 of the engine E, which is a single-cylinder water-cooled four-cycle engine, includes a crankcase 20 formed by connecting left and right crankcase halves 20L and 20R divided into left and right parts, and the crankcase 20 A cylinder block 21 coupled to the cylinder block 21, a cylinder head 22 coupled to the cylinder block 21, and a head cover 23 coupled to the cylinder head 22. The transmission device M is housed in a transmission case 25 (see FIG. 1) that is connected to the crankcase 20 and extends to the left side of the rear wheel WR. A rear cushion unit 24 is provided between the rear portion of the seat rail portion 14 d and the rear portion of the transmission case 25.

  Connected to the upper side surface of the cylinder head 22 in the engine body 19 is a downstream end of an intake passage forming means 26 that is disposed above the transmission case 25 and has an upstream end connected to an air cleaner 27 supported by the transmission case 25. The intake passage forming means 26 includes an inlet pipe 28 whose upstream end is connected to the air cleaner 27, and a throttle body 29 provided between the downstream end of the inlet pipe 28 and the cylinder head 22. A fuel injection valve 30 that injects fuel into the air that has passed through the throttle body 29 is attached to the cylinder head 22.

  1, the exhaust system 31 connected to the lower side surface of the cylinder head 22 is connected to the lower portion of the cylinder head 22 and extends from the lower right side of the engine body 19 to the right side of the rear wheel WR. The exhaust pipe 32 includes an exhaust muffler 33 connected to the exhaust pipe 32 and disposed on the right side of the rear wheel WR.

  3 to 5 together, the air purified by the air cleaner 27 is supplied to the exhaust system 31 of the engine E through the secondary air control valve 35. The secondary air control valve 35 and the ignition coil 36 are supported in common by a stay 37 that is elastically supported by the engine body 19 or the vehicle body frame F. In this embodiment, a crank in the engine body 19 is used. The secondary air control valve 35 and the ignition coil 36 are commonly supported by a stay 37 elastically supported by a right cover 38 coupled to the right side surface of the case 20. Thus, the stay 37 is arranged in front of the air cleaner 27 and next to the inlet pipe 28, and the bolts 46 and 47 inserted from the side of the engine body 19 through the mount rubbers 42 and 43. It is attached to the engine body 19.

  Referring to FIGS. 6 and 7 together, the stay 37 is formed by joining first and second support plates 39 and 40 by welding. The first support plate 39 is divided into front and rear mounting leg portions 39a and 39b extending vertically, and a connecting plate portion 39c that is connected to the upper ends of both mounting leg portions 39a and 39b and bent at right angles to the inner side. A rising plate portion 39d that rises upward from the inner end of the connecting plate portion 39c, a lower support portion 39e that protrudes inward from the lower portion of the rising plate portion 39d, and an outward portion from the intermediate portion in the vertical direction of the rising plate portion 39e. The intermediate support portion 39f protruding inward and the upper support portion 39g bent inward from the upper end of the rising plate portion 39e are integrally formed, and a single steel plate is bent.

  The lower support portion 39e is formed in a substantially L shape in a horizontal plane so as to cut and raise a part of the lower portion of the rising plate portion 39d inward, and corresponds to the lower support portion 39e. A rectangular opening 41 is formed below the rising plate portion 39d. Further, the intermediate support portion 39f protrudes outward from the rising plate portion 39d so as to form a right angle with the rising plate portion 39d. The upper support portion 39g is formed in a substantially L shape in a vertical plane orthogonal to the rising plate portion 39d and extends further upward from the upper end of the rising plate portion 39d.

  Further, the second support plate 40 has a mounting plate portion 40a which is brought into contact with the mounting leg portions 39a and 39b of the first support plate 39 from the outside and welded to the mounting leg portions 39a and 39b, and a mounting plate portion. A pair of support arm portions 40b and 40c that are bent outward at right angles from the front and rear portions of the upper end of 40a and extend outward are integrally formed by bending a single steel plate.

  The mounting legs 39 a and 39 b of the stay 37 are attached to the right cover 38 of the engine body 19 via mount rubbers 42 and 43. That is, a cylindrical collar 44 having one end of a collar portion 44a sandwiched between the right cover 38 and one end of the mount rubber 42 is inserted into the mount rubber 42 attached to the mounting leg 39a. A washer 45 is in contact with the other end. Thus, a bolt 46 inserted through the washer 45 and the collar 44 is screwed into the right cover 38, and a flange portion sandwiching the washer 45 between the other end of the mount rubber 42 is attached to the bolt 46. 46a is provided integrally.

  The mounting leg 39b has the same structure as the mounting structure of the mounting leg 39a to the right cover 38, and is attached to the right cover 38 using the mount rubber 43 and the bolt 47.

  The ignition coil 36 is attached to both support arm portions 40 b and 40 c of the stay 37. That is, the case 48 of the ignition coil 36 is disposed between the support arm portions 40b and 40c, and both ends of the core 49 protruding from both ends of the case 48 are fastened to the support arm portions 40b and 40c with bolts 50 and 51. The Thus, weld nuts 52 and 53 to which the bolts 50 and 51 are screwed are fixed to the lower surfaces of the both support arm portions 40b and 40c.

  The high tension cord 54 extending forward from the case 48 of the ignition coil 36 is extended to the engine body 19 side of the engine E.

  The valve housing 55 of the secondary air control valve 35 is formed in a stepped cylindrical shape extending vertically, and a support arm that faces the lower support portion 39e of the stay 37 from the inner side is provided at the lower portion of the valve housing 55. A portion 56 is provided, and the support arm portion 56 is supported by the lower support portion 39e via the mount rubber 57.

  That is, a cylindrical collar 58 having one end of a collar portion 58a sandwiched between one end of the lower support portion 39e and the mount rubber 57 is inserted into the mount rubber 57 attached to the support arm portion 56. A washer 59 is in contact with the other end. Thus, a bolt 60 inserted through the washer 59 and the collar 58 is screwed into a weld nut 61 fixed to the lower support portion 39e, and the other end of the mount rubber 57 is connected to the bolt 60. The flange portion 60a sandwiching the washer 59 is integrally provided therebetween.

  Referring also to FIG. 8, a dish-like cap 62 made of an elastic material such as rubber is mounted on the upper portion of the valve housing 55 of the secondary air control valve 35, and the valve housing 55 is interposed via the cap 62. The holding member 63 that holds the upper portion is supported by the upper support portion 39g via the mount rubber 64.

  The holding member 63 includes a tightening portion 63a formed in an arc shape so as to surround the outer periphery of the cap 62 over almost the entire periphery, and a pair of opposing protrusions protruding outward from both ends of the tightening portion 63a. The opposing plate portions 63b and 63c are integrally formed. When the opposing plate portions 63b and 63c are brought close to each other, the tightening portion 63a comes into close contact with the outer periphery of the cap 62, so that the upper portion of the valve housing 55 is formed. Is held by the holding member 63.

  The holding member 63 is disposed so that one of the opposing plate portions 63b and 63c faces the upper support portion 39g. The mount rubber 64 is attached to the upper support portion 39g, and a cylindrical collar 66 having at one end a collar portion 66a sandwiched between the opposing plate portion 63b of the holding member 63 and one end of the mount rubber 64 is mounted on the mount rubber 64. The washer 67 is brought into contact with the other end of the mount rubber 64. Thus, a nut 65 is screwed into a bolt 68 inserted through the washer 67, the collar 66, and the opposing plate portions 63b and 63c. The bolt 68 is connected to the other end of the mount rubber 64. A flange portion 68a sandwiching the washer 67 is integrally provided.

  Thus, the secondary air control valve 35 is elastically supported by the lower support part 39e and the upper support part 39g of the stay 37, and is elastically supported by the stay 37 elastically supported by the right cover 38 of the engine body 19. The secondary air control valve 35 is disposed in front of the air cleaner 27 and on the side of the intake passage forming means 26 above the engine body 19 so as to at least partially overlap the intake passage forming means 26 in a side view. Thus, in this embodiment, the secondary air control valve 35 is disposed on the side of the intake passage forming means 26 in the vicinity of the connection portion between the inlet pipe 28 and the throttle body 29.

  A downstream end of an upstream rubber hose 70 having an upstream end connected to the air cleaner 27 is connected to an upper portion of the valve housing 55 in the secondary air control valve 35, and a downstream rubber hose 71 connected to the lower portion of the valve housing 55 is connected. The engine E is extended to the engine body 19 side to supply secondary air to the exhaust system 31 of the engine E. A breather hose 81 for guiding blow-by gas from the engine body 19 is connected to the air cleaner 27 so as to straddle the upstream rubber hose 70.

  Incidentally, as clearly shown in FIGS. 3 and 4, the ignition coil 36 supported by the stay 37 and the vicinity of the connection portion of the upstream hose 70 to the air cleaner 27 are covered with a cover 72. The rear part is fastened to the air cleaner 27 with a bolt 73 (see FIG. 3). Further, the cover 72 is supported on the intermediate support portion 39 f of the stay 37 via a mount rubber 74.

  That is, a cylindrical collar 75 having one end of a collar portion 75 a sandwiched between the intermediate support portion 39 f and one end of the mount rubber 74 is inserted into the mount rubber 74 attached to the cover 72. A washer 76 is brought into contact with the end. Thus, a bolt 77 inserted through the washer 76 and the collar 75 is screwed into a weld nut 78 fixed to the intermediate support portion 39f, and the other end of the mount rubber 74 is connected to the bolt 77. The flange portion 77a sandwiching the washer 76 is integrally provided there between.

  4 and 7, a grommet 79 made of an elastic material is attached to the tip of the support arm portion 40b of the stay 37. As shown in FIG. 4, the grommet 79 comes into contact with the grommet 79 from above. In this manner, the support boss 80 provided integrally with the cover 72 is integrally provided with a pin 80 a that elastically fits the grommet 79. That is, the cover 72 is detachably attached to the air cleaner 27 and the stay 37.

  Next, the operation of this embodiment will be described. The secondary air control valve 35 for controlling the flow rate of the secondary air supplied from the air cleaner 27 to the exhaust system 31 of the engine E has the upstream end connected to the air cleaner 27 and the downstream side. It is disposed at the side of the intake passage formation means 26 in front of the air cleaner 27 and above the engine body 19 so that at least a part thereof overlaps the intake passage formation means 26 connected to the engine body 19 in a side view. Therefore, the secondary air control valve 35 can be disposed as close as possible to the engine main body 19 and effectively disposed in the space on the side of the intake passage forming means 26, whereby the exhaust of the engine E is discharged from the secondary air control valve 35. The length of the secondary air supply passage to the system 31 can be shortened to simplify the piping structure. In addition, since the engine body 19 is located below the secondary air control valve 35, the secondary air control valve 35 can be effectively protected against mud and water splashing when the scooter type motorcycle is traveling.

  Further, since the secondary air control valve 35 and the ignition coil 36 are supported in common by the stay 37 supported by the engine body 19, the number of parts required for supporting the ignition coil 36 and the secondary air control valve 35 is reduced. It is possible to attach the stay 37 to the engine body 19 while the ignition coil 36 and the secondary air control valve 35 are supported by the stay 37, and the assembly work can be simplified. In addition, since the stay 37 is elastically supported by the engine body 19, the stay 37 to which the ignition coil 36 and the secondary air control valve 35 are attached has a relatively large weight, so that the natural frequency is reduced and the vibration isolation performance is achieved. Can be increased.

  Further, since the secondary air control valve 35 is elastically supported by the stay 37, the secondary air control valve 35 is elastically supported by the engine body 19 with a double vibration isolation structure, and is transmitted to the secondary air control valve 35. Vibration can be more effectively suppressed.

  As another embodiment of the present invention, the stay 37 may be elastically supported by the vehicle body frame F. In that case, the secondary air control valve 35 is at least partially overlapped with the intake passage forming means 26 in a side view, in front of the air cleaner 27 and above the engine body 19 to the side of the intake passage forming means 26. By being arranged, it is possible to reduce the escape against the swing of the power unit P of the pipe connecting the secondary air control valve 35 and the power unit P.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. It is.

It is a left view of a scooter type motorcycle. It is the perspective view which looked at the engine from the diagonally right front with the cover removed. It is the right view which looked at a part of Drawing 2 from the direction of 3 arrows in the state where the cover was attached. FIG. 4 is an enlarged sectional view taken along line 4-4 of FIG. It is a principal part enlarged view of FIG. 3 in the state which removed the cover. It is a figure corresponding to Drawing 5 in the state where an ignition coil was removed. It is the perspective view which looked at the stay and the secondary air control valve from the left front diagonally downward. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 19 ... Engine main body 22 ... Cylinder head 25 ... Transmission case 26 ... Intake passage formation means 27 ... Air cleaner 31 ... Exhaust system 35 ... Secondary air control valve 36 ... Ignition coil 37 ... Stay E ... Engine F ... Body frame M ... Transmission device P ... Power unit WR ... Rear wheel

Claims (3)

  A power unit (P) comprising an engine (E) in which the cylinder axis of the engine body (19) is tilted forward and a transmission (M) that transmits the output of the engine (E) to the rear wheels (WR). A transmission case that is swingably supported by the vehicle body frame (F), is connected to the engine body (19), extends rearward to the side of the rear wheel (WR), and houses the transmission device (M). (25) The downstream end of the intake passage forming means (26) in which the rear wheel (WR) is pivotally supported at the rear portion and the upstream end is connected to the air cleaner (27) disposed above the transmission case (25). In the scooter type motorcycle connected to the upper side surface of the cylinder head (22) constituting a part of the engine body (19), the air cleaner (27) is connected to the exhaust system (31) of the engine (E). Supplied A secondary air control valve (35) for controlling the flow rate of the secondary air, which is at least partially overlapped with the intake passage forming means (26) in a side view, and forward of the air cleaner (27) and the A scooter type motorcycle, which is disposed above the engine body (19) and to the side of the intake passage forming means (26).   The secondary air control valve (35) and the ignition coil (36) are commonly supported by a stay (37) elastically supported by the engine body (19) or the vehicle body frame (F). The scooter type motorcycle according to claim 1.   The scooter type motorcycle according to claim 2, wherein the secondary air control valve (35) is elastically supported by the stay (37).

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