JP2016124489A - Saddle-riding type vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit vibrations of an engine and a muffler which are transmitted to a rear fender lower.SOLUTION: A cooling unit 31 for cooling an engine 11 is attached to an engine unit 3 of a scooter 1. Further, the scooter 1 has a rear fender lower 61 covering an area ranging from the upper side to the front side of a rear wheel 25. The rear fender lower 61 is supported by a fan cover 33 of the cooling unit 31. Vibrations of the engine 11 are transmitted to the rear fender lower 61 through the fan cover 33. Since the vibrations of the engine 11 are damped in the fan cover 33, the vibrations of the engine 11 which are transmitted to the rear fender lower 61 are inhibited.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a straddle-type vehicle such as a scooter.

  A straddle type vehicle such as a scooter includes a unit swing type engine unit. The engine unit includes an engine and a power transmission mechanism that transmits engine power to the rear wheels, and is attached to the body frame so as to be swingable in the vertical direction. A rear wheel is supported at the rear of the engine unit. Further, a muffler, an air cleaner, and the like are attached to the engine unit. The engine unit, rear wheel, muffler, and air cleaner swing together.

  Further, the saddle riding type vehicle includes a rear fender that suppresses splashes of mud, stones, water, and the like due to rotation of the rear wheels. The rear fender is attached to the rear part (rear frame) of the vehicle body frame, and is mainly attached to the rear fender upper covering the wide range from the upper side of the rear wheel to the rear side, and the engine unit side. Or there is a rear fender lower covering the narrow area on the front side. Normally, the rear fender upper is arranged at a position far away from the rear wheel upward, whereas the rear fender lower is arranged at a lower position closer to the rear wheel than the rear fender upper. Since the rear fender lower is attached to the engine unit side, it swings integrally with the engine unit, the rear wheel, the muffler, and the like. Some types of straddle-type vehicles have only a rear fender upper and do not have a rear fender lower. A straddle-type vehicle having a rear fender lower is described in, for example, Patent Documents 1 to 3 below.

JP-A-6-270868 Japanese Patent Laid-Open No. 11-301553 JP-A-10-7058

  As described in Patent Documents 1 to 3, the rear fender lower according to the prior art is supported by a transmission case that houses a power transmission mechanism in the engine unit, or is supported by a muffler attached to the engine unit. . Some rear fender lowers according to the prior art are supported by an engine crankcase in an engine unit.

  Such a support structure for a rear fender lower according to the prior art has the following problems. In other words, the support structure for supporting the rear fender lower on the muffler has a problem that the vibration of the muffler is transmitted to the rear fender lower, and the rear fender lower vibrates, thereby radiating sound from the rear fender lower. In addition, the support structure for supporting the rear fender lower on the crankcase of the engine has a problem that the vibration of the engine is transmitted to the rear fender lower and the rear fender lower vibrates, thereby radiating sound from the rear fender lower. The support structure that supports the rear fender lower to the transmission case is not as great as the support structure that supports the rear fender lower to the crankcase of the engine, but the engine vibration is transmitted to the rear fender through the transmission case, which causes the rear fender lower to vibrate. However, there is a problem that sound is emitted from the rear fender lower.

  The present invention has been made in view of the above-described problems, for example, and an object of the present invention is to provide a straddle-type vehicle capable of suppressing vibrations of an engine and a muffler transmitted to a rear fender (rear fender lower). There is.

  In order to solve the above problems, a saddle-ride type vehicle according to the present invention includes an engine and a power transmission mechanism that transmits the power of the engine to a rear wheel. A unit swing type engine unit that supports the rear wheel, a cooling fan provided on one side in the vehicle width direction of the crankcase of the engine, and a fan cover attached to the crankcase so as to cover the cooling fan A cooling unit that cools the engine with cooling air generated by the cooling fan, and a rear fender that covers at least the upper side or the front side of the rear wheel, and the rear fender is supported by the fan cover. To do.

  Thus, by supporting the rear fender on the fan cover, the vibration of the engine is transmitted from the crankcase to the rear fender via the fan cover. Engine vibration is attenuated when it travels through the fan cover. Therefore, the vibration of the engine transmitted to the rear fender can be suppressed. Further, since the rear fender is not supported by the muffler, the vibration of the muffler transmitted to the rear fender can be suppressed.

  Further, in the saddle riding type vehicle according to the present invention, the fan cover is provided with an arm portion extending from the fan cover toward the rear fender, and a front end side of the arm portion is on one side in the vehicle width direction of the rear fender. It is desirable that a connecting portion to be connected is provided.

  In this way, by supporting the rear fender to the fan cover via the arm portion, the vibration transmitted to the fan cover is transmitted to the rear fender via the arm portion. Since the vibration transmitted to the fan cover is further attenuated by the arm portion, the effect of suppressing the engine vibration transmitted to the rear fender can be enhanced.

  Further, in the saddle riding type vehicle according to the present invention, a muffler disposed on one side in the vehicle width direction of the rear wheel, and a muffler suspension bracket that supports the muffler on one side in the vehicle width direction of the crankcase of the engine. Preferably, the arm portion extends inward in the vehicle width direction and is connected to the connection portion of the rear fender at a position on the inner side in the vehicle width direction than the muffler and the muffler suspension bracket.

  In the straddle-type vehicle according to the present invention, the position on the inner side in the vehicle width direction from the muffler and the muffler suspension bracket is a position close to the rear wheel. By extending the arm part from the fan cover to a position close to the rear wheel and connecting the rear fender to the tip side of the arm part, the support position of the rear fender can be set to a position close to the rear wheel. By setting the support position of the rear fender close to the rear wheel, it is not necessary to form a long arm part or a long protruding part for supporting the rear fender in the rear fender, and the width dimension of the rear fender is set to the rear wheel. There is no need to make it too large to exceed the width dimension. As a result, the rigidity of the rear fender can be increased. Therefore, the support of the rear fender can be strengthened, and the displacement of the rear fender can be suppressed. Furthermore, it is easy to form an arm portion having high rigidity on the fan cover, and because the fan cover is firmly fixed to the crankcase in a stable state, the tip of the arm portion extending from the fan cover It is also easy to position the side position at a predetermined position with high accuracy. Therefore, by connecting the rear fender to the front end side of the arm portion extending from the fan cover, the rear fender can be firmly supported, and the displacement of the rear fender can be suppressed.

  In the straddle-type vehicle of the present invention, the muffler suspension bracket extends from the muffler to the crankcase at an upper portion of the muffler, and an upper mounting portion having a tip portion attached to the crankcase, and a lower portion of the muffler When the vehicle is viewed from one side in the vehicle width direction of the saddle riding type vehicle from the outside of the saddle riding type vehicle, including a lower attachment portion that extends from the muffler to the crank case and has a tip portion attached to the crank case. In addition, a portion where the connecting portion of the rear fender and the distal end side of the arm portion are connected to each other is located between the upper mounting portion and the lower mounting portion, and constitutes the saddle type vehicle. It is desirable to face the outside of the saddle riding type vehicle without being blocked by any part.

  According to the saddle riding type vehicle of the present invention, an operator who manufactures, repairs, or maintains the saddle riding type vehicle can easily visually check the connection point between the rear fender and the arm portion. Further, the operator can easily insert the tool into the connection portion between the rear fender and the arm portion. Thereby, the operator can easily attach or remove the rear fender. Therefore, the workability of manufacturing, repairing or maintaining the saddle riding type vehicle can be improved.

  In the saddle riding type vehicle of the present invention, one side in the vehicle width direction of the rear fender is supported by the fan cover, and the other side in the vehicle width direction of the rear fender is disposed on the other side in the vehicle width direction of the rear wheel. It is desirable to be supported by an air cleaner that purifies the air supplied into the cylinder of the engine.

  Both engine vibration and muffler vibration are attenuated as they travel through the air cleaner. Therefore, the effect of suppressing the vibrations of the engine and the muffler transmitted to the rear fender can be enhanced.

  According to the present invention, vibrations of the engine and the muffler transmitted to the rear fender (rear fender lower) can be suppressed.

It is explanatory drawing which shows the vehicle body frame, engine unit, cooling unit, rear wheel, muffler, air cleaner, rear fender upper, rear fender lower, etc. of the scooter according to the embodiment of the present invention. FIG. 2 is an enlarged view showing a portion where a rear fender lower is provided in the scooter shown in FIG. 1. FIG. 3 is a cross-sectional view showing a crankcase, a fan cover, a muffler suspension bracket, a rear fender lower, and the like as seen from the direction of arrows III-III in FIG. 2. It is explanatory drawing which shows the air cleaner, rear wheel, rear fender lower, etc. of the scooter by embodiment of this invention. It is explanatory drawing which shows the engine unit, the cooling unit, the rear wheel, the air cleaner, the rear fender lower, etc. of the scooter by embodiment of this invention. It is explanatory drawing which looked at the rear fender lower of the scooter by embodiment of this invention from the top. It is explanatory drawing which looked at the rear fender lower of the scooter by embodiment of this invention from the right. It is explanatory drawing which shows the example of the support structure of the rear fender lower of the scooter by embodiment of this invention. It is explanatory drawing which shows the other example of the support structure of the rear fender lower of the scooter by embodiment of this invention. It is explanatory drawing which shows the measuring method of the vibration transmitted to the rear fender lower of the scooter by embodiment of this invention. It is a graph which shows the measurement result of the vibration transmitted to the rear fender lower of the scooter by embodiment of this invention, and the measurement result of the vibration transmitted to the rear fender lower of the scooter by a comparative example.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a scooter body frame, an engine unit, a cooling unit, a rear wheel, a muffler, an air cleaner, a rear fender upper, a rear fender lower, and the like, which are an embodiment of a saddle riding type vehicle of the present invention. FIG. 2 is an enlarged view of a portion where the rear fender lower 61 is provided in the scooter 1 in FIG. FIG. 3 shows the crankcase 12, the fan cover 33, the muffler suspension bracket 52, the rear fender lower 61, and the like as seen from the direction of arrows III-III in FIG. 4 shows the air cleaner 41, the rear wheel 25, the rear fender lower 61, etc. of the scooter 1 in FIG. FIG. 5 schematically shows the engine unit 3, the cooling unit 31, the rear wheel 25, the air cleaner 41, the rear fender lower 61, and the like of the scooter 1 in FIG. In the following description, front, rear, left, and right refer to front, rear, left, and right, respectively, for a person facing the forward direction of the scooter 1.

  As shown in FIG. 1, the scooter 1 includes a body frame 2, and the body frame 2 is provided with a unit swing type engine unit 3. The engine unit 3 is attached to an engine suspension bracket 4 fixed to the vehicle body frame 2 so as to be swingable in the vertical direction about a pivot shaft 5. The engine unit 3 includes an engine 11 and a power transmission mechanism 21 (see FIG. 5).

  As shown in FIG. 5, the engine 11 is disposed in the front portion of the engine unit 3 and in the center portion in the left-right direction (vehicle width direction). The engine 11 is, for example, a forced air-cooled four-cycle single cylinder engine. The engine 11 includes a crankcase (engine case) 12, a cylinder 13, and a cylinder head 14. A crankshaft or the like is provided in the crankcase 12, and a piston or the like is provided in the cylinder 13. The crankcase 12, the cylinder 13, and the cylinder head 14 are made of a metal material such as an aluminum alloy. The axis AA in FIG. 5 indicates the axis of the crankshaft. A head cover 15 is attached to the cylinder head 14.

  The power transmission mechanism 21 is a mechanism that transmits engine power to the rear wheels 25, and includes a transmission, a deceleration transmission device, and a rear axle shaft (none of which are shown). The power transmission mechanism 21 is disposed on the left side of the rear part of the engine unit 3. The power transmission mechanism 21 includes a metal transmission case 22 formed integrally with the crankcase 12, and the transmission mechanism and the like are accommodated in the transmission case 22. A rear wheel 25 is supported on the rear axle shaft. An axis BB in FIG. 5 indicates the axis of the rear axle shaft.

  A cooling unit 31 is provided on the right side of the crankcase 12 of the engine 11. The cooling unit 31 is a device that cools the engine 11 by blowing cooling air mainly on the cylinder 13 and the cylinder head 14. As shown in FIG. 5, the cooling unit 31 includes a cooling fan 32, a fan cover 33, and a cooling air cowling 34 as a cooling air passage forming unit.

  The cooling fan 32 is connected to the crankshaft, and is rotated by the power of the engine 11 to generate cooling air.

  The fan cover 33 is attached to the right side of the crankcase 12 so as to cover the cooling fan 32. The fan cover 33 is made of a resin material. As shown in FIG. 2, the fan cover 33 is formed in a cylindrical shape with a lid, and an air inlet 35 is formed in the center of the lid portion. Further, on the outer peripheral side of the fan cover 33, a fixing portion 33A for fixing the fan cover 33 to the crankcase 12 via a bolt or the like is provided. The fan cover 33 is firmly fixed to the crankcase 12 by fastening bolts or the like to the crankcase 12 via the fixing portion 33A. An arm portion 36 for supporting the rear fender lower 61 is provided on the outer peripheral side of the fan cover 33. The arm part 36 will be described in detail later.

  For example, as shown in FIG. 5, the cooling air cowl ring 34 is attached to the engine 11 so as to cover a part of the cylinder 13 and the cylinder head 14. The cooling air cowling 34 and the fan cover 33 are each formed with a communication port (not shown) communicating with each other, and the cooling air generated by the cooling fan 32 passes through the communication port and the cylinder 13 and the cylinder head. 14 side.

  An air cleaner 41 is attached to the engine unit 3. The air cleaner 41 is a device that purifies the air supplied into the cylinder 13 of the engine 11. As shown in FIG. 5, the air cleaner 41 is disposed on the rear left side of the engine unit 3 and above the transmission case 22. The air cleaner 41 is located on the left side of the rear wheel 25. As shown in FIG. 4, the air cleaner 41 includes a resin cleaner case 42, and an air filter or the like is accommodated in the cleaner case 42. The cleaner case 42 is attached to the upper surface of the transmission case 22 via cushion rubber. As shown in FIG. 2, the air purified by the air cleaner 41 is supplied to the carburetor 44 through the connecting tube 43, mixed with fuel by the carburetor 44, and sucked into the cylinder 13 of the engine 11 through the intake pipe 45. Is done.

  Further, the engine unit 3 is provided with a muffler 51 that reduces exhaust noise of the engine 11. As shown in FIG. 5, the muffler 51 is arranged on the rear right side of the engine unit 3. Further, the muffler 51 is located on the right side of the rear wheel 25.

  The muffler 51 is supported on the right side of the crankcase 12 via a muffler suspension bracket 52. The muffler suspension bracket 52 includes a bifurcated mounting portion that is divided into upper and lower portions. That is, as shown in FIG. 2, the muffler suspension bracket 52 extends from the muffler 51 to the crankcase 12 at the upper portion of the muffler 51, and has an upper attachment portion 52 </ b> A having a tip portion attached to the crankcase 12 and a lower portion of the muffler 51. A lower attachment portion 52B that extends from the muffler 51 to the crankcase and has a tip attached to the crankcase 12 is provided. The upper attachment portion 52A and the lower attachment portion 52B are firmly fixed to the crankcase 12 via bolts or the like. An exhaust pipe 53 is connected between the engine 11 and the muffler 51.

  As shown in FIG. 1, a rear fender upper 55 is provided at the rear portion (rear frame) of the vehicle body frame 2 of the scooter 1. The rear fender upper 55 is disposed above the rear wheel 25 and covers a wide area from the upper side to the rear side of the rear wheel 25. The rear fender upper 55 mainly suppresses splashing of mud, stones, or water toward the body of the scooter 1, the driver, or the following vehicle.

  The scooter 1 is provided with a rear fender lower 61. The rear fender lower 61 is disposed on a part of the outer peripheral side of the rear wheel 25 and covers a portion from the upper side to the front side of the rear wheel 25. Compared with the rear fender upper 55, the rear fender lower 61 is disposed at a lower position close to the rear wheel 25 and covers a narrow range of the rear wheel 25. As shown in FIG. 5, the rear fender lower 61 is disposed between the crankcase 12 and the rear wheel 25 of the engine 11. The rear fender lower 61 is located in the center of the scooter 1 in the left-right direction, and is disposed between the air cleaner 41 and the muffler 51. The rear fender lower 61 mainly suppresses the splash of mud, stones, or water toward the engine unit 3 and components provided therein.

  6 and 7 show the rear fender lower 61. The rear fender lower 61 is made of a resin material. Focusing on the circumferential shape of the rear fender lower 61, when the front end portion of the outermost peripheral portion of the rear wheel 25 is 0 degrees, the upper end portion is 90 degrees, the rear end portion is 180 degrees, and the lower end portion is 270 degrees, the rear fender lower As shown in FIG. 2 or FIG. 7, 61 extends in the range of approximately 0 to approximately 75 degrees of the rear wheel 25 while curving along the circular outer shape of the rear wheel 25.

  Focusing on the shape of the rear fender lower 61 in the left-right direction, the rear fender lower 61 covers the entire left and right direction of the outer peripheral surface of the rear wheel 25 as shown in FIG. 4 or FIG. The rear fender lower 61 also covers a part of the right side surface of the rear wheel 25 and a part of the left side surface of the rear wheel 25. Further, the position of the right edge 61A of the rear fender lower 61 is set to a position close to the right side surface of the rear wheel 25, and the position of the left edge 61B of the rear fender lower 61 is set to a position close to the left side surface of the rear wheel 25. Has been.

  Further, as shown in FIG. 6, a right connection portion 62 for supporting the rear fender lower 61 to the fan cover 33 is provided at the right edge portion 61 </ b> A of the rear fender lower 61. The right connection portion 62 is disposed at the front portion of the rear fender lower 61. The right connection portion 62 is integrally formed of the same material as the main body portion of the rear fender lower 61. As shown in FIG. 7, the right connection portion 62 protrudes forward from the right edge portion 61 </ b> A of the rear fender lower 61, and the right side surface thereof is an abutment surface 62 </ b> A that abuts on the distal end side of the arm portion 36. The length of the right connecting portion 62 protruding forward is short, and the contact surface 62A can be secured. Further, the right connection portion 62 is formed with an insertion hole 62B through which a bolt 65 (see FIG. 8) for fixing the right connection portion 62 to the distal end side of the arm portion 36 is passed.

  As shown in FIG. 6, a left side connection portion 63 for supporting the rear fender lower 61 to the air cleaner 41 is provided on the left side of the rear fender lower 61. The left connection part 63 is disposed at the rear part of the rear fender lower 61.

  The right side of the rear fender lower 61 is supported by the fan cover 33 and the left side is supported by the air cleaner 41. A first example of a structure for supporting the rear fender lower 61 on the fan cover 33 is as shown in FIG.

  That is, in FIG. 8, the rear fender lower 61 is connected to the distal end side of the arm portion 36 of the fan cover 33. More specifically, an arm portion 36 extending toward the rear fender lower 61 is formed on the outer peripheral portion of the fan cover 33 and facing rearward. The arm portion 36 is formed integrally with the fan cover 33 using the same material as the fan cover 33. The arm portion 36 extends rearward and leftward (inward in the vehicle width direction) from the fan cover 33.

  The arm portion 36 is formed in a plate shape, and as shown in FIG. 2, the base end side of the arm portion 36 is wider than the distal end side of the arm portion 36 (the vertical dimension is larger). Thereby, the arm part 36 is firmly supported on the main body side of the fan cover 33.

  As shown in FIG. 8, the distal end side of the arm portion 36 is bent so that the left side surface thereof is opposed to and parallel to the contact surface 62 </ b> A of the right connection portion 62 of the rear fender lower 61. In addition, an insertion hole 36 </ b> A for allowing the bolt 65 to pass is formed on the distal end side of the arm portion 36. The rear fender lower 61 is formed on the distal end side of the insertion hole 62B formed in the right connection portion 62 and the distal end side of the arm portion 36 with the contact surface 62A of the right connection portion 62 abutting on the left side surface on the distal end side of the arm portion 36. The bolt 65 is inserted into the insertion hole 36 </ b> A from the right side, and then the nut 66 is fastened to the bolt 65, thereby connecting and fixing to the distal end side of the arm portion 36.

  As shown in FIG. 5, the connecting portion between the right connecting portion 62 of the rear fender lower 61 and the distal end side of the arm portion 36 is located on the left side (inward in the vehicle width direction) with respect to the muffler 51 and the muffler suspension bracket 52. 51 and the muffler suspension bracket 52 are closer to the rear wheel 25 in the left-right direction.

  Further, as shown in FIG. 3, the arm portion 36 is disposed between the upper mounting portion 52A and the lower mounting portion 52B of the muffler suspension bracket 52, and the upper mounting portion 52A and the lower side of the muffler suspension bracket 52 are arranged. It passes between the mounting portion 52B and extends leftward toward the rear fender lower 61.

  Further, as shown in FIG. 2, when the right side of the scooter 1 is viewed from the outside of the scooter 1, the connecting portion P between the right connecting portion 62 of the rear fender lower 61 and the distal end side of the arm portion 36 is a muffler suspension bracket. 52 is located between the upper mounting portion 52A and the lower mounting portion 52B, and faces the outside of the scooter 1 without being blocked by any portion constituting the scooter 1. Thereby, the worker who manufactures, repairs, or maintains the scooter 1 can easily visually check the connection location between the rear fender lower 61 and the arm portion 36. In addition, the operator can easily insert the tool into the connection portion (bolt 65 or the like) between the rear fender lower 61 and the arm portion 36. Thereby, the operator can easily attach or remove the rear fender lower 61. Therefore, the workability of manufacturing, repairing or maintaining the scooter 1 can be improved.

  A second example of the structure for supporting the rear fender lower 61 on the fan cover 33 is as shown in FIG. Although the scooter 1 employs the first example shown in FIG. 8, the second example shown in FIG. 9 may be employed instead of the first example. In the second example, as shown in FIG. 9, the distal end side of the arm portion 37 extends to the left beyond the right connection portion 62 of the rear fender lower 61 and then bends. The left side surface of the right side connection portion 62 of the rear fender lower 61 is in contact with the left side surface. Further, a connecting hole 37A that is threaded on the inner peripheral side is formed on the distal end side of the arm portion 37, and the bolt 65 inserted into the insertion hole 62B of the right connecting portion 62 of the rear fender lower 61 is connected to the arm portion 37. It is fastened to a connection hole 37A formed on the tip side of the. According to such a configuration, the nut 66 can be eliminated, and since it is not necessary to prevent the nut 66 from rotating when the bolt 65 is tightened, the tightening operation of the bolt 65 can be simplified.

  On the other hand, the structure for supporting the rear fender lower 61 on the air cleaner 41 is as shown in FIG. That is, the left side connection portion 63 of the rear fender lower 61 is bolted to an attachment member 64 that is integrally formed with the cleaner case 42 of the air cleaner 41.

  As described above, according to the scooter 1 according to the embodiment of the present invention, the vibration of the engine 11 can be attenuated in the fan cover 33 by supporting the right side of the rear fender lower 61 on the fan cover 33, and the rear fender lower 61 The vibration of the engine 11 transmitted to can be suppressed. Thereby, the sound radiated from the rear fender lower 61 can be reduced.

  The fan cover 33 is made of a resin material. Compared to metal materials, resin materials have a higher effect of damping vibrations. Therefore, by supporting the right side of the rear fender lower 61 with the fan cover 33 formed of a resin material, the effect of suppressing the vibration of the engine 11 transmitted to the rear fender lower 61 can be enhanced.

  Further, by supporting the right side of the rear fender lower 61 on the fan cover 33 via the arm portion 36, the vibration of the engine 11 can be further damped in the arm portion 36, and the vibration of the engine 11 transmitted to the rear fender lower 61 can be reduced. The effect which suppresses can be heightened.

  Here, the suppression effect of the vibration of the engine 11 transmitted to the rear fender lower 61 by the scooter 1 of the embodiment of the present invention will be specifically described with reference to FIGS. 10 and 11. FIG. 10 shows a method for measuring the vibration transmitted to the rear fender lower 61. FIG. 11 shows measurement results of vibration transmitted to the rear fender lower 61 of the scooter 1 according to the embodiment of the present invention and measurement results of vibration transmitted to the rear fender lower of the scooter according to the comparative example.

  Experiments were performed on the scooter 1 according to the embodiment of the present invention and the scooter according to the comparative example by the following procedure. That is, the scooter 1 according to the embodiment of the present invention in which the rear fender lower 61 is supported by the fan cover 33 is prepared, and a vibration pickup meter 67 is attached to a part of the rear fender lower 61 of the scooter 1 as shown in FIG. It was. Then, the engine 11 was driven, and vibration generated in the rear fender lower 61 was measured by a vibration pickup meter 67. A scooter having the same configuration as that of the scooter 1 according to the embodiment of the present invention is prepared except that the rear fender lower is supported by the crankcase of the engine, and a vibration pickup meter is provided on a part of the rear fender lower of the scooter. Attached. Then, the engine was driven and the vibration generated in the rear fender lower was measured with a vibration pickup meter.

  In the graph of FIG. 11, the solid characteristic line indicates the measurement result in the scooter 1 according to the embodiment of the present invention, and the broken characteristic line indicates the measurement result in the scooter according to the comparative example. Each characteristic line shows the relationship between the frequency (horizontal axis) and the vibration value (vertical axis). As can be seen from FIG. 11, at most frequencies, the vibration value of the scooter 1 according to the embodiment of the present invention is lower than the vibration value of the scooter according to the comparative example. From the above experiment, it was confirmed that the engine vibration was suppressed by supporting the rear fender lower 61 on the fan cover 33.

  On the other hand, by extending the arm portion 36 to a position close to the rear wheel 25 and connecting the right side of the rear fender lower 61 to the front end side thereof, the rigidity of the rear fender lower 61 can be increased and the positional deviation of the rear fender lower 61 can be reduced. Can be suppressed. That is, the fan cover 33 is firmly connected to the crankcase 12 via the fixing portion 33A, and the base end side of the arm portion 36 provided on the fan cover 33 is connected to the main body portion of the fan cover 33 as described above. It is firmly fixed. Therefore, the distal end side of the arm portion 36 does not wobble, and the right side of the rear fender lower 61 can be stably supported. Since the front end side of the arm portion 36 that is formed so strong extends to a position close to the rear wheel 25, the rear fender lower 61 is formed with a long protrusion or arm portion for supporting the rear fender lower 61. It is not necessary, and it is not necessary to increase the horizontal dimension of the rear fender lower 61 so as to greatly exceed the horizontal dimension of the rear wheel 25. Therefore, the shape of the rear fender lower 61 can be simplified, and the rigidity of the rear fender lower 61 can be increased. Then, by connecting the highly rigid rear fender lower 61 to the sturdy arm portion 36, it is possible to suppress the displacement of the rear fender lower 61.

  Further, since the rear fender lower 61 is not supported by the muffler 51, the vibration of the muffler 51 transmitted to the rear fender lower 61 can be suppressed, and this also reduces the sound radiated from the rear fender lower 61. .

  Further, by supporting the left side of the rear fender lower 61 to the air cleaner 41, the effect of suppressing the vibration of the engine 11 and the muffler 51 transmitted to the rear fender lower 61 can be enhanced. As described above, since the air cleaner 41 is attached to the transmission case 22 via the cushion rubber, vibration transmitted from the transmission case 22 to the air cleaner 44 is greatly suppressed. Therefore, the vibration suppressing effect obtained by supporting the left side of the rear fender lower 61 to the air cleaner 41 is high.

  In the above-described embodiment, the case where the right connection portion 62 of the rear fender lower 61 is formed in a plate shape that expands in one plane is taken as an example, but the shape of the right connection portion 62 of the rear fender lower 61 is limited to this. Not. For example, the front side (projecting side) of the right connection portion 62 may be bent leftward, and the tip of the bent portion may be joined to the main body portion of the rear fender lower 61. With such a configuration, when the rear fender lower 61 is viewed from the front or the rear, the shape of the right connection portion 62 and its peripheral portion is generally substantially cylindrical. Stiffness can be increased.

  Further, in the above-described embodiment, the case where the right connection portion 62 of the rear fender lower 61 and the arm portion 36 are connected using the bolt 65 or the like is taken as an example, but the right connection portion 62 and the arm portion 36 of the rear fender lower 61 are exemplified. The connection method is not limited to this. When both the right connecting portion 62 and the arm portion 36 of the rear fender lower 61 are formed of a resin material, a tapping screw, a push rivet, or the like can be used as a connecting member for both. Thereby, the connection work of the rear fender lower 61 and the arm part 36 can be simplified.

  In the above-described embodiment, the rear fender lower 61 covers the range from the front side to the upper side of the rear wheel 25 (for example, approximately 0 to 75 degrees). The range which covers is not limited to this. For example, the length of the rear fender lower 61 in the circumferential direction may be extended rearward, and the rear fender lower 61 may cover the range from the upper side to the rear side of the rear wheel 25.

  In the above-described embodiment, the case where the arm portion 36 (37) is integrally formed with the fan cover 33 has been described as an example. However, the method of forming the arm portion 36 (37) is not limited to this. The arm portion 36 (37) may be a separate member independent of the fan cover 33 and may be attached to the fan cover 33 with bolts or screws. Further, in the above-described embodiment, the case where the right connecting portion 62 of the rear fender lower 61 is integrally formed with the rear fender lower 61 is described as an example, but the method of forming the right connecting portion 62 is not limited to this. The right connection portion 62 may be a separate member independent of the main body portion of the rear fender lower 61 and may be attached to the main body portion of the rear fender lower 61 with bolts, screws, or the like. The same applies to the left connection part 63.

  In the above-described embodiment, the left side of the rear fender lower 61 is supported by the air cleaner 41. However, the left side of the rear fender lower 61 may be supported by other parts of the scooter 1 excluding the crankcase and the muffler. Good. For example, the left side of the rear fender lower 61 may be supported by the transmission case 22. When the left side of the rear fender lower 61 is supported by the transmission case 22, the vibration of the engine 11 transmitted to the rear fender lower 61 becomes larger than when the left side of the rear fender lower 61 is supported by the air cleaner 41. However, since the scooter 1 according to the embodiment of the present invention has a configuration in which the right side of the rear fender lower 61 is supported by the fan cover 33, this configuration can suppress vibration of the engine 11 transmitted to the rear fender lower 61. Overall, the engine vibration suppression effect can be enhanced as compared with the prior art.

  Further, the scooter 1 of the above-described embodiment has the rear fender upper 55 and the rear fender lower 61, but the present invention is a scooter having only one rear fender equivalent to the rear fender lower 61 in terms of function, shape and arrangement. Can also be applied. The present invention can be applied not only to a scooter type motorcycle but also to a scooter type motorcycle, and other straddle type vehicles having the same structure with respect to the arrangement of a rear fender lower, a cooling unit, and the like. It can also be applied to.

  Further, the present invention can be appropriately changed without departing from the spirit or idea of the invention which can be read from the claims and the entire specification, and a straddle-type vehicle accompanied with such a change is also applicable to the technology of the present invention. Included in thought.

DESCRIPTION OF SYMBOLS 1 Scooter 2 Body frame 3 Engine unit 11 Engine 12 Crankcase 13 Cylinder 14 Cylinder head 21 Power transmission mechanism 22 Transmission case 25 Rear wheel 31 Cooling unit 32 Cooling fan 33 Fan cover 34 Cooling wind cowling 35 Inlet 36, 37 Arm part 36A Insertion hole 37A Connection hole 41 Air cleaner 42 Cleaner case 51 Muffler 52 Muffler suspension bracket 52A Upper attachment part 52B Lower attachment part 61 Rear fender lower 62 Right connection part 63 Left connection part

Claims (5)

A unit swing type engine unit that is attached to the body frame so as to be swingable in the vertical direction, includes an engine and a power transmission mechanism that transmits the power of the engine to a rear wheel, and supports the rear wheel;
A cooling fan and a fan cover attached to the crankcase so as to cover the cooling fan are provided on one side of the engine crankcase in the vehicle width direction, and the engine is driven by cooling air generated by the cooling fan. A cooling unit for cooling;
A rear fender covering at least the upper side or the front side of the rear wheel,
The straddle-type vehicle, wherein the rear fender is supported by the fan cover. The fan cover is provided with an arm portion extending from the fan cover toward the rear fender,
The straddle-type vehicle according to claim 1, wherein a connecting portion to which a tip end side of the arm portion is connected is provided on one side in the vehicle width direction of the rear fender. A muffler disposed on one side in the vehicle width direction of the rear wheel;
A muffler suspension bracket that supports the muffler on one side in the vehicle width direction of the crankcase of the engine;
The scissors according to claim 2, wherein the arm portion extends inward in the vehicle width direction, and is connected to the connection portion of the rear fender at a position on the inner side in the vehicle width direction than the muffler and the muffler suspension bracket. Ride type vehicle. The muffler suspension bracket extends from the muffler to the crankcase at an upper part of the muffler, and an upper end part attached to the crankcase at a tip part, and extends from the muffler to the crankcase at a lower part of the muffler. A lower mounting portion attached to the crankcase,
When the one side in the vehicle width direction of the saddle riding type vehicle is viewed from the outside of the saddle riding type vehicle, the portion where the connection part of the rear fender and the tip side of the arm part are connected to each other is the upper side 4. The vehicle is located between an attachment portion and the lower attachment portion and faces the outside of the saddle riding type vehicle without being blocked by any part constituting the saddle riding type vehicle. The saddle riding type vehicle described in 1.   One side in the vehicle width direction of the rear fender is supported by the fan cover, and the other side in the vehicle width direction of the rear fender is disposed on the other side in the vehicle width direction of the rear wheel, and purifies the air supplied into the cylinder of the engine The straddle-type vehicle according to any one of claims 1 to 4, wherein the straddle-type vehicle is supported by an air cleaner.

Images