JP2012206694A - Two-wheeled motor vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve engine maintainability while securing the straight advancing stability and operation stability of a vehicle and the strength and rigidity of a vehicle body frame.SOLUTION: The two-wheeled motor vehicle includes, in a frame head part 12 located in a vehicle front part: a vehicle body frame 11 to which the front ends of a pair of main tubes 13 extending to a vehicle body rear side are connected; an engine 17 mounted on the vehicle body frame 11; and an air box 18 disposed on the upper part of the engine 17 to guide intake air to the engine 17. The frame head part 12 of the two-wheeled motor vehicle has: a shaft support part 19 for supporting a steering shaft; and a box-shaped box part 20 fixed to the shaft support part 19, the front ends of the main tubes 13 being connected to the box part 20. In the box part 20 of the frame head part 12, in a vehicle plan view, a recess 54 is formed in a region roughly overlapping the axis P of an ignition plug 44 disposed in the cylinder head 36 of the engine 17.

Description

  The present invention relates to a motorcycle, and more particularly to a motorcycle having an improved structure of a frame head portion of a body frame.

  In the motorcycle, in order to improve the intake efficiency, as described in Patent Document 1, a traveling wind is taken from the opening at the tip of the upper cowl, and this traveling wind (air) is passed through the duct to the frame head portion of the vehicle body frame. An intake passage structure has been proposed that leads to the (head box) and bypasses the shaft support portion (hollow columnar portion) in the frame head portion and leads from the rear end of the frame head portion to the air cleaner.

JP 2001-71968 A

  However, in the above-described intake passage structure, since it is necessary to secure an intake passage in the frame head portion and to ensure the strength and configuration of the frame head portion, the size of the frame head portion is increased. Therefore, for example, in an engine in which the cylinder assembly is greatly inclined forward, the frame head portion is positioned on the extension line of the axis of the spark plug provided in the cylinder head, and the spark plug and the plug cap attached to the spark plug are There is a risk that the maintenance of the engine may be impaired due to the frame head portion being hindered during attachment / detachment.

  In order to solve this problem, it is necessary to move the mounting position of the engine rearward or to reduce the size of the periphery of the shaft support portion of the frame head portion. In this case, the following issues arise.

  First, when the engine mounting position is moved rearward, the load sharing ratio of the front wheels is lowered, and there is a risk that the straight running stability and the steering stability of the vehicle are impaired. Next, when the size of the frame head portion is reduced, the strength and rigidity of the frame head portion may be reduced, and steering stability may be impaired, or a necessary intake passage area may not be ensured.

  An object of the present invention has been made in consideration of the above-described circumstances, and provides a motorcycle that can improve engine serviceability while ensuring the straight running stability and steering stability of the vehicle and the strength and rigidity of the body frame. It is to provide.

  Another object of the present invention is to provide a motorcycle capable of improving engine maintainability while ensuring the straight running stability and steering stability of the vehicle, the intake efficiency of the engine, and the strength and rigidity of the body frame. It is in.

  The present invention relates to a vehicle body frame in which front end portions of a pair of main tubes extending rearward of the vehicle are coupled to a frame head portion located at the vehicle front portion, an engine mounted on the vehicle body frame, and an upper portion of the engine And an air box for guiding intake air to the engine. The frame head portion is fixed to the shaft support portion for supporting the steering shaft, and the front end portion of the main tube is coupled to the shaft support portion. A box-shaped box part, wherein the box part of the frame head part is recessed in a region substantially overlapping with an axis of a spark plug provided in the cylinder head of the engine in plan view of the vehicle. Is provided.

  According to the present invention, even in a motorcycle in which the cylinder head of the engine and the vehicle body frame are close to each other, the engine is kept mounted on the vehicle body frame by using the recess provided in the box portion of the frame head portion of the vehicle body frame. The spark plug and the plug cap attached to the spark plug can be attached and detached. This improves engine serviceability and eliminates the need to move the engine mounting position to the rear, ensuring that the load sharing ratio of the front wheels is optimized to ensure straight running stability and steering stability. it can. Further, since it is not necessary to reduce the size of the frame head portion in order to improve the serviceability of the engine, the strength and rigidity of the frame head portion can be ensured.

1 is a left side view showing a motorcycle according to the present invention. FIG. 2 is a left side view showing a body frame and the like in the motorcycle of FIG. 1. FIG. 2 is a left side view showing an engine and an air box in the motorcycle of FIG. 1. The top view which shows the vehicle body frame of FIG. 2, an air box, and an air duct, and removes the box cover of an air box. Sectional drawing which follows the VV line | wire of FIG. Fig. 2 is a plan view showing a body frame and an engine of the motorcycle shown in Fig. 1. Sectional drawing which follows the VII-VII line of FIG. Sectional drawing which follows the VIII-VIII line of FIG. FIG. 3 is a left side view showing the periphery of the frame head portion of the body frame of FIG. 2. Sectional drawing which follows the XX line of FIG. The XI arrow perspective view of FIG. FIG. 12 is a perspective view showing a state in which a rectifying member is attached to the frame head portion of FIG. 11. Sectional drawing corresponding to FIG. 10 equipped with the rectifying member of FIG. The rectification | straightening member of FIG.12 and FIG.13 is shown, (A) is a surface side perspective view, (B) is a back surface side perspective view. Sectional drawing which follows the XV-XV line | wire of FIG. Sectional drawing which follows the XVI-XVI line | wire of FIG. Sectional drawing which follows the XVII-XVII line of FIG. The XVIII arrow directional view of FIG. 5 which mounted | wore the air duct and the box body of the air box to the flame | frame head part of FIG. The expanded sectional view of the XIX part of FIG. The perspective view which shows the deformation | transformation form of an air duct visually from diagonally upward. FIG. 21 is a perspective view showing the air duct of FIG. 20 as viewed from obliquely below. Sectional drawing corresponding to FIG. 5 which shows the vehicle body frame etc. with which the air duct of FIG.20 and FIG.21 was mounted | worn. The expanded sectional view of the XXIII part of FIG. Sectional drawing corresponding to FIG. 10 which shows the deformation | transformation form of a frame head part.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, the present invention is not limited to these embodiments. FIG. 1 is a left side view showing a motorcycle according to the present invention. FIG. 2 is a left side view showing the body frame and the like in the motorcycle of FIG. In this embodiment, front / rear, left / right, and upper / lower expressions are based on the driver when riding the vehicle.

  A motorcycle 10 shown in FIG. 1 is a so-called sports motorcycle. In the motorcycle 10, as shown in FIGS. 1 and 2, the front end portions of a pair of left and right main tubes 13 extending obliquely downward and rearward of the vehicle are coupled to a frame head portion 12 positioned above the front portion of the vehicle. A pair of left and right pivot brackets 14 are coupled to the rear end of each main tube 13, and a pair of left and right seat rails 15 extend obliquely upward to the rear of the vehicle at the top of each pivot bracket 14. A frame 11 is configured.

  A fuel tank 16 is disposed above the main tube 13, and an engine 17 is disposed below the main tube 13. The engine 17 is sandwiched between the left and right main tubes 13 and positioned in front of the pivot bracket 14, and is suspended from the main tube 13 and the pivot bracket 14. As shown in FIG. 3, an air box 18 that guides intake air (air) to the engine 17 is disposed on the upper portion of the engine 17. The air box 18 is positioned below the fuel tank 16 shown in FIG.

  As shown in FIGS. 4 to 7, the frame head portion 12 includes a cylindrical shaft support portion 19 that supports a steering shaft (not shown) that is not shown, and is fixed to the periphery of the shaft support portion 19 to the rear of the vehicle. It has a box-shaped box portion 20 that extends. A front end portion of the main tube 13 is coupled to the box portion 20.

  The steering shaft is rotatably supported by a shaft support portion 19, and as shown in FIG. 1, a handle 22 is provided at the upper portion of the steering shaft portion 21 including the steering shaft, and a pair of left and right front forks 23 are provided at the side portions. Installed. A front wheel 24 is rotatably supported at the lower part of these front forks 23. By operating the handle 22, the front wheel 24 is steered left and right around the steering shaft.

  The pivot bracket 14 includes a pivot (swinging shaft) 25 extending in parallel with the vehicle width direction, and a swing arm 26 is pivotally supported on the pivot 25 so as to swing in the vertical direction. A rear wheel 27 is pivotally supported on the rear portion of the swing arm 26. The rear wheel 27 is rotationally driven by a drive chain 28 that is spanned between the rear portion of the engine 17.

  The exterior component that covers the entire vehicle includes a front cowl 29A that covers the front of the vehicle, a side cowl 29B that is connected to the lower portion of the front cowl 29A and covers the side of the vehicle, and a rear cowl 29C that covers the seat rail 15. Configured.

  The engine 17 is a V-type engine (in this embodiment, a V-type four-cylinder engine) as shown in FIGS. 2 and 3, and the front cylinder assembly 32F and the rear cylinder assembly 32R are V-shaped before and after the crankcase 31. It is arranged and arranged. Specifically, cylinder blocks 35 and 38 are integrally provided on the upper part of an upper case 33 as an upper half of the crankcase in the crankcase 31 so as to be integrated with each other, and a cylinder head 36 and a head cover 37 are sequentially coupled to the cylinder block 35. Thus, a front cylinder assembly 32F is formed, and a cylinder head 39 and a head cover 40 are sequentially coupled to the cylinder block 38 to form a rear cylinder assembly 32R.

  A lower case 34 which is a lower half of the crankcase is coupled to the lower surface of the upper case 33 of the crankcase 31, and an oil pan 41 for storing engine oil is coupled to the lower surface of the lower case 34. Further, a crankshaft 43 is disposed in the crankcase 31 at the position of the mating surface 42 between the upper case 33 and the lower case 34.

  A piston (not shown) moves up and down in the cylinder 30 (FIG. 7) of the cylinder blocks 35 and 38, and the crankshaft 43 connected to the piston is rotatably supported by the crankcase 31. A valve operating device (not shown) is disposed in the cylinder head 39 and the head cover 40, and an ignition plug 44 (FIG. 7) is attached to the cylinder heads 36, 39 to constitute the engine 14.

  As shown in FIGS. 2 and 3, the air box 18 is disposed above the engine 14 including the space between the front cylinder assembly 32F and the rear cylinder assembly 32R of the engine 14 thus configured. . The air box 18 is configured by attaching a box cover 46 to the upper part of the box body 45 and joining side covers 47 to the left and right sides of the lower part of the box body 45. The side cover 47 is also joined to the cylinder head 36 and the head cover 37 of the front cylinder assembly 32F and the cylinder head 39 and the head cover 40 of the rear cylinder assembly 32R, respectively.

  As shown in FIGS. 2 to 5, an air duct 48 is connected to the front of the box body 45, and this air duct 48 is connected to an intake passage 50 (detailed later) formed in the box portion 20 of the frame head portion 12. The In the air box 18, a fuel supply device such as a fuel injection device (not shown) is arranged. Traveling wind (air) during traveling of the vehicle is introduced into the air box 18 from the intake passage 50 of the frame head portion 12 through the air duct 48. This air is mixed with the fuel from the fuel supply device in the air box 18 and supplied to the intake ports 51 (FIG. 7) of the cylinder heads 36 and 39 in the engine 17 shown in FIG. Further, the exhaust from the engine is discharged from the exhaust ports 52 of the cylinder heads 36 and 39 through an exhaust pipe (not shown).

  As shown in FIGS. 7 and 9 to 11, the intake passage 50 in the box portion 20 of the frame head portion 12 extends from the front opening 53 in front of the vehicle in the box portion 20 to both sides or one side of the shaft support portion 19. This is provided so as to penetrate substantially in the front-rear direction of the vehicle until it reaches the center of the rear end of the box portion 20 by bypassing the direction (both sides in the present embodiment). A recess 54 is formed in a part of the box portion 20 constituting the intake passage 50.

  In the vehicle plan view shown in FIG. 6, the intake passage 50 is provided in a region that substantially overlaps the axis P of the spark plug 44 (FIG. 7) provided in the cylinder head 36 in the front cylinder assembly 32 </ b> F of the engine 17. The spark plug 44 of this embodiment is a direct ignition type spark plug in which an ignition coil 55 is installed for each spark plug 44. Accordingly, the ignition coil 55 is integrally provided on the plug cap 56 attached to the cylinder heads 36 and 39 corresponding to each spark plug 44. When attaching and detaching the spark plug 44 and the plug cap 56, a large-diameter tool space for rotating a tool or the like is required. In particular, as shown in FIG. 8, the recess 54 is provided in the box portion 20 of the frame head portion 12 which is enlarged by forming an intake passage 50 therein to secure the tool space. .

  As shown in FIGS. 12, 13, and 15, the recess 54 formed in the box portion 20 of the frame head portion 12 closes the recess 54 and rectifies the intake air flowing into the intake passage 50. 57 is fitted, and this rectifying member 57 is detachably fixed to the box portion 20 of the frame head portion 12 using fixing means such as screws 49 and bolts.

  The flow regulating member 57 is made of resin or metal and includes a tongue piece portion 57A and a fixing portion 57B as shown in FIG. A fitting projection 58 is provided on the back surface of the tongue piece portion 57A along the side edge, and the fitting projection 58 is fitted in a recess 54 in the box portion 20 of the frame head portion 12 as shown in FIG. Match. 14 is formed with a mounting hole 59. As shown in FIG. 17, a screw 49 is inserted into the mounting hole 59 so that the rectifying member 57 is inserted into the box section 20 of the frame head section 12. Fixed.

  In order to make it easy to insert or remove the screw 49 into the mounting hole 59 of the rectifying member 57, as shown in FIGS. 12 and 15, the box portion 20 of the frame head portion 12 has a lower rear end to which the rectifying member 57 is fixed. The portion 60 is configured to extend rearward of the vehicle from the upper rear end portion 61, and the lower rear end portion 60 is exposed upward.

  The lower rear end portion 60 and the upper rear end portion 61 of the box portion 20 are mounted on the box portion 20 of the frame head portion 12 in a state where the rectifying member 57 is fitted and attached to the recess 54 of the box portion 20. As shown in FIGS. 5 and 18, the air duct 48 is inserted into the rear opening 67 provided. Accordingly, the intake passage 50 in the box portion 20 of the frame head portion 12 is connected to the air box 18 via the air duct 48. At this time, a part of the rectifying member 57 (that is, a fixing portion 57B on the rear side of the stepped portion 62 (described later) in the rectifying member 57) is covered with the air duct 48, pressed downward, and held in the box portion 20.

  As shown in FIG. 14, the rectifying member 57 is provided with a stepped portion 62 at the boundary between the tongue piece portion 57 </ b> A and the fixing portion 57 </ b> B, and a seal is formed on the surface of the fixing portion 57 </ b> B adjacent to the stepped portion 62. A groove 64 is formed. As shown in FIGS. 12, 13, and 15, the stepped portion 62 is formed on the inner wall surface of the intake passage 50 in the box portion 20 with the rectifying member 57 mounted on the box portion 20 of the frame head portion 12. It is formed so as to be continuous with the substantially elliptical stepped portion 63 formed. As shown in FIGS. 18 and 19, the front end surface 48 </ b> A of the air duct 48 comes into contact with these stepped portions 62 and 63, and the inner surface of the air duct 48 is the inner wall surface of the intake passage 50 in the box portion 20 and the rectifying member 57. Smoothly continues to the surface of the tongue piece portion 57A.

  As shown in FIGS. 12, 13, and 15, the seal groove 64 of the rectifying member 57 is formed so that the rectifying member 57 is attached to the box portion 20 of the frame head portion 12 and the intake passage 50 in the box portion 20. The inner wall surface is formed to be continuous with a substantially oval seal groove 65 formed in parallel with the stepped portion 63. A ring-shaped seal member 66 made of an elastic material such as rubber is fitted into the seal grooves 64 and 65 as shown in FIGS. The seal member 66 seals the gaps between the box portion 20 and the rectifying member 57 of the frame head portion 12 and the air duct 48, and the air duct 48 and the rectifying member 57 are box portions of the frame head portion 12 by the elastic force of the seal member 66. 20 is held.

  With the configuration as described above, according to the present embodiment, the following effects (1) to (7) are obtained.

  (1) As shown in FIG. 7, the cylinder head 36 in the front cylinder assembly 32F of the engine 17 and the frame head portion 12 of the vehicle body frame 11 are close to each other, and an intake passage 50 is provided in the box portion 20 of the frame head portion 12. Also in the formed motorcycle 10, by using the recess 54 provided in the box part 20 of the frame head part 12, the cylinder in the front cylinder assembly 32F of the engine 17 remains mounted on the vehicle body frame 11 while the engine 17 is mounted. A spark plug 44 provided on the head 36 and a plug cap 56 attached to the spark plug 44 can be attached and detached. As a result, the maintainability of the engine 17 can be improved, and it is not necessary to move the mounting position of the engine 17 rearward. Therefore, the load sharing ratio of the front wheels 24 is optimized, and the vehicle travels straight and is stable. Can be secured.

  (2) Since the box portion 20 of the frame head portion 12 is provided with the recess 54 for improving the serviceability of the engine 17, the frame head portion 12 of the vehicle body frame 11 is mounted to improve the serviceability of the engine 17. There is no need to downsize. As a result, the degree of freedom in designing the frame head portion 12 is increased, and the strength and rigidity of the frame head portion 12 can be ensured.

  (3) Even when the intake passage 50 is formed in the box portion 20 of the frame head portion 12, the box portion 20 of the frame head portion 12 constituting the intake passage 50 has a recess for improving the maintainability of the engine 17. 54 is provided, it is not necessary to reduce the size of the frame head portion 12 in order to improve the maintainability of the engine 17. As a result, the degree of freedom in designing the frame head portion 12 is increased, and the intake passage area of the frame head portion 12 can be optimized, so that the intake efficiency of the engine 17 can be ensured.

  (4) As shown in FIGS. 5 and 18, an intake passage 50 is provided in the box portion 20 of the frame head portion 12, and a depression 54 formed in a part of the box portion 20 constituting the intake passage 50 is rectified. The member 57 is closed. Therefore, the inner wall surface of the intake passage 50 is smooth even by the presence of the recess 54, and the intake air (air) flowing through the intake passage 50 is not rectified and disturbed by the rectifying member 57, so that the intake efficiency is improved. Can be made.

  (5) As shown in FIGS. 12 and 13, since the rectifying member 57 is detachably fixed to the box portion 20 of the frame head portion 12 using fixing means (screw 49 or the like), the rectifying member 57 is removed. This can be prevented and the rectifying member 57 can be easily removed.

  (6) Further, as shown in FIGS. 5 and 19, a part of the rectifying member 57 is covered with the air duct 48 and is pressed and held by the box portion 20. Can be prevented from falling off.

  (7) As shown in FIGS. 15 and 19, the seal member 66 is fitted into the seal grooves 65 and 64 formed continuously from the inner wall surface of the intake passage 50 and the rectifying member 57 in the box portion 20 of the frame head portion 12. The seal member 66 seals the gap between the box portion 20 and the rectifying member 57 and the air duct 48. For this reason, even when the surface roughness of the box part 20 is large, the sealing performance of the connection part between the box part 20 and the rectifying member 57 and the air duct 48 can be improved. Further, the air duct 48 and the rectifying member 57 can be reliably held in the box portion 20 of the frame head portion 12 by the elastic force of the seal member 66.

  As mentioned above, although this invention was demonstrated based on the said embodiment, this invention is not limited to this, A various deformation | transformation can be made in the range which does not deviate from the main point of this invention. For example, in the above-described embodiment, the seal member 66 has been described as being provided in the box portion 20 and the rectifying member 57 of the frame head portion 12, but in the air duct 48, the outer periphery of the portion overlapping the box portion 20 and the rectifying member 57. It may be provided on the surface.

  As shown in FIGS. 20 to 22, the rectifying member 70 that closes the recess 54 formed in the box portion 20 of the frame head portion 12 may be integrally formed with the air duct 48. The rectifying member 70 corresponds to the tongue piece portion 57A of the rectifying member 57 of the embodiment. Even when the rectifying member 70 is integrally formed with the air duct 48 as described above, the same effects as the effects (1) to (4) of the above-described embodiment can be obtained, and the rectifying member 70 can be replaced with the box portion of the frame head portion 12. Since fixing means (screw 49 etc.) for fixing to 20 is unnecessary, the maintainability of the engine 17 which attaches / detaches the spark plug 44 and the plug cap 56 can be improved.

  In the air duct 48 in which the rectifying member 70 is integrated, as shown in FIG. 23, the air duct 48 and the box portion are fitted by the seal member 66 fitted in the seal groove 65 formed in the box portion 20 of the frame head portion 12. The sealing property with 20 is ensured. However, the seal member 66 may be provided on the outer peripheral portion of the air duct 48 that overlaps the box portion 20.

  Further, as shown in FIG. 24, the intake passage 80 provided in the box portion 20 of the frame head portion 12 is approximately on both sides or one side of the shaft support portion 19 in the box portion 20 (both sides in the present embodiment). It may be formed so as to penetrate substantially in the front-rear direction of the vehicle from the front opening 81 formed obliquely forward to the center of the rear end of the box portion 20. Also in this case, a part of the box portion 20 constituting the intake passage 80, that is, similarly to the above-described embodiment, is provided in the cylinder head 36 in the front cylinder assembly 32F of the engine 17 in the vehicle plan view shown in FIG. A depression 54 is formed in a region substantially overlapping with the axis P of the spark plug 44 (FIG. 7). The recess 54 is also closed by the rectifying member 57. Therefore, also in this embodiment, there exists an effect similar to the effect (1)-(7) of the said embodiment.

DESCRIPTION OF SYMBOLS 10 Motorcycle 11 Body frame 12 Frame head part 13 Main tube 17 Engine 18 Air box 19 Shaft support part 20 Box part 44 Spark plug 48 Air duct 49 Screw (fixing means)
50 Intake passage 53 Front opening 54 Recess 56 Plug cap 57 Rectifier 64, 65 Seal groove 66 Seal member 70 Rectifier 80 Intake passage 81 Front opening P Axis

Claims (8)

A vehicle body frame in which front end portions of a pair of main tubes extending rearward of the vehicle are coupled to a frame head portion located at the vehicle front portion, an engine mounted on the vehicle body frame, and the engine disposed on the upper portion of the engine And an air box for guiding intake air to
The frame head portion includes a shaft support portion that supports a steering shaft, and a box-shaped box portion that is fixed to the shaft support portion and to which a front end portion of the main tube is coupled.
The motorcycle according to claim 1, wherein the box portion of the frame head portion is provided with a recess in a region substantially overlapping with an axis of a spark plug provided in a cylinder head of the engine in a plan view of the vehicle. The box portion of the frame head portion is provided with an intake passage that penetrates in a substantially longitudinal direction from the opening in front of the vehicle to the side of the shaft support portion to reach the rear end of the box portion. The motorcycle according to claim 1, wherein a depression is formed in a part of the box portion constituting the intake passage. The box portion of the frame head portion is formed with an opening that is directed substantially obliquely forward to the side of the shaft support portion, and penetrates in a substantially longitudinal direction from the opening portion to the rear end of the box portion. The motorcycle according to claim 1, wherein an intake passage is provided, and a recess is formed in a part of the box portion constituting the intake passage. The dent formed in the box portion of the frame head portion is fitted with a rectifying member that closes the dent and rectifies the intake air flowing into the intake passage. Motorcycle. The motorcycle according to claim 4, wherein the rectifying member is detachably fixed to the box portion of the frame head portion using a fixing means. The motorcycle according to claim 4 or 5, wherein a box portion of the frame head portion is connected to an air box via an air duct, and a part of a rectifying member is covered and held by the air duct. A seal groove is continuously formed in the box portion and the rectifying member of the frame head portion so as to face the intake passage, and a seal member is fitted into the seal groove, and the box portion and the rectifying member are formed by the seal member. The motorcycle according to claim 6, wherein a gap between the air duct and the air duct is sealed. 5. The automatic according to claim 4, wherein a box portion of the frame head portion is connected to an air box via an air duct, and a rectifying member that fits into a depression of the box portion is integrally formed with the air duct. Motorcycle.

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