JP2011196250A - Vehicle speed sensor mounting structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle speed sensor mounting structure for mounting a vehicle speed sensor by means of a simple configuration to a place in which maintenance is easy while protecting the vehicle speed sensor.SOLUTION: The vehicle speed sensor 77 is secured to a crankcase 64 by fastening the same together with a protector 83, which covers the upper part of the vehicle speed sensor 77, by means of a fastening member 81 while the axis O of an almost cylindrical body 78 is tilted by a predetermined angle θ towards the rear side of a vehicle body as viewed in a vehicle body lateral side, at a position on the vehicle body upper side of a sub-shaft 35 and on the vehicle body rear side of a shift drum 150. The body 78 of the vehicle speed sensor 77 is constructed so that when it is inserted into a through hole 73 formed in the crankcase 64, the detection part 78a of the vehicle speed sensor 77 faces the tooth tip of a second-speed driven gear G2. The through hole 73 into which the body 78 is thrusted and a fastening hole 74 into which the fastening member 81 is inserted are provided in a fastening seat 72 formed on the crankcase 64. The fastening hole 74 is disposed on the outside in the vehicle width direction of the through hole 73.

Description

  The present invention relates to a vehicle speed sensor mounting structure, and more particularly to a vehicle speed sensor mounting structure for mounting a vehicle speed sensor to an engine crankcase.

  2. Description of the Related Art Conventionally, a structure is known in which a vehicle speed sensor is attached to a crankcase of an engine in order to detect the vehicle speed based on the number of rotations of a countershaft (counter shaft) of a transmission.

  In Patent Document 1, the detection part of the vehicle speed sensor is directed to the front of the vehicle body, and the detection part faces the tooth tip of the gear that rotates integrally with the auxiliary shaft of the transmission, so that the wall surface on the vehicle body rear side of the crankcase is disclosed. Discloses a vehicle speed sensor mounting structure in which a vehicle speed sensor is mounted.

JP 2000-87780 A

  However, since a vehicle body frame, an engine hanger, a swing arm pivot, and the like are concentratedly arranged close to the crankcase on the rear surface portion of the crankcase, the frame and the vehicle speed sensor are arranged in the vehicle speed sensor mounting structure described in Patent Document 1. However, once the vehicle is assembled, it may be difficult to remove and maintain the vehicle speed sensor. Furthermore, since a movable member such as a shift drum or a drive sprocket is disposed close to the transmission shaft in the crankcase, the mounting structure of the vehicle speed sensor not only protects the vehicle speed sensor but also has a structure. Simplification and space saving are also required.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle speed sensor mounting structure that solves the above-described problems of the prior art, and that protects the vehicle speed sensor and attaches the vehicle speed sensor to a place where maintenance is easy with a simple structure. .

  In order to achieve the above object, the present invention includes a crankshaft (33) oriented in the vehicle width direction, a main shaft (34), and a sub shaft (35) disposed on the vehicle body rear side of the main shaft (34). An engine (23) in which a transmission (GR) having a plurality of transmission gear trains disposed therein and a shift drum (150) for shifting the transmission (GR) are accommodated above the auxiliary shaft (35). In the vehicle speed sensor mounting structure in which the vehicle speed sensor (77) is mounted on the crankcase (64) of the crankshaft (64) so as to face a tooth tip of a predetermined driven gear (G2) on the countershaft (35). The machine (GR) and the shift drum (150) are housed on the rear side of the crankcase (64), and the vehicle speed sensor (77) uses the axis (O) of the cylindrical main body (78). Predetermined angle (θ) on the rear side of the vehicle in side view An upper portion of the vehicle speed sensor (77) is formed using a fastening member (81) at a position inclined to the upper side of the vehicle body of the auxiliary shaft (35) and the rear side of the vehicle body of the shift drum (150). The first feature is that it is configured to be fixed to the crankcase (64) by being fastened together with a protector (83) that covers the cover.

  Further, by inserting the cylindrical main body part (78) of the vehicle speed sensor (77) into a through hole (73) formed in the upper part of the crankcase (64), the detection part ( The second feature is that 78a) is plunged downward in the front of the vehicle body and is opposed to the tooth tip of the predetermined driven gear (G2).

  The crankcase (64) is provided with a fastening seat (72) for mounting the vehicle speed sensor (77) and the protector (83). The fastening seat (72) is provided with the vehicle speed sensor (77). ) And a fastening hole (74) into which the fastening member (81) is inserted. The fastening hole (74) is provided in the through-hole (73). ) Has a third feature in that it is provided on the outer side in the vehicle width direction.

  In addition, a plurality of ribs (65, 66, 69) formed substantially radially around the auxiliary shaft hole (35a) for projecting one end of the auxiliary shaft (35) from the crankcase (64) are provided in the vehicle width. A fourth point is that the fastening seat (72) is disposed so as to be located inside an end face on the outer side in the vehicle width direction of the rib (65, 66, 69). There are features.

  The predetermined driven gear (G2) has a fifth feature in that it is a second speed driven gear (G2).

  Further, the transmission (GR) is a four-speed transmission type, and the four transmission gear pairs between the main shaft (34) and the sub shaft (35) are the second speed, the fourth speed, the third speed from the left side in the vehicle width direction. There is a sixth feature in that they are arranged in the order of speed and speed.

  The engine (23) is fixed to the center frame (4) of the vehicle body frame (2) by three hanger bosses (64a, 64b, 64c) formed from the upper part to the rear part of the crankcase (64). Among the three hanger bosses (64a, 64b, 64c), the middle hanger boss (64b) located at the center in the vertical direction and in the center in the front-rear direction is over the vehicle rear side of the vehicle speed sensor (77) in the side view of the vehicle body. There is a seventh feature in that they are arranged close to each other so as not to wrap.

  The crankcase (64) includes a left case half (64L) on the left side in the vehicle width direction and a right case half (64R) on the right side in the vehicle width direction. The left case half (64L) and the right case half (64L) A fastening bolt (75) oriented in the vehicle width direction for coupling with the case half (64R) overlaps the vehicle speed sensor (77) when viewed from the side of the vehicle body, and the vehicle body front of the middle hanger boss (64b). There is an eighth feature in that it is disposed on the side.

  The engine (23) is a single-cylinder engine mounted horizontally between a crankshaft and disposed between a rear end portion of a front wheel (WF) and a front end portion of a rear wheel (WR). A ninth feature is that the cylinder (24) of 23) is arranged to face the front of the vehicle body.

  The protector (83) includes a flat plate portion (87) through which the fastening member (81) penetrates to fasten the extension portion (80) of the vehicle speed sensor (77), and the vehicle speed sensor (77). ) When the output wiring passage portion (85) through which the output wiring (77a) passes and the vehicle speed sensor (77) are fastened together, an opening (for preventing relative rotation between the vehicle speed sensor (77) and the protector (83)). 86) and an eaves part (84).

  Furthermore, an eleventh feature is that an O-ring (79) is attached to the cylindrical main body (78) of the vehicle speed sensor (77) to maintain a sealing property with the crankcase (64). There is.

  According to the first feature, the transmission and the shift drum are housed on the rear side of the crankcase body, and the vehicle speed sensor is arranged at a predetermined angle toward the rear side of the vehicle body when the axis of the cylindrical main body is viewed from the side of the vehicle body. It is fixed to the crankcase by tilting it together with a protector that covers the upper part of the vehicle speed sensor using a fastening member at a position above the vehicle body of the counter shaft and on the rear side of the vehicle body of the shift drum. Therefore, the vehicle speed sensor is disposed on the upper side of the vehicle body of the countershaft and on the rear side of the shift drum, and the vehicle speed sensor is disposed on the rear surface of the crankcase while effectively utilizing the dead space. The maintainability of the vehicle speed sensor can be improved as compared with the structure in which is attached. In addition, the protector protects the vehicle speed sensor, and the number of fastening members can be reduced by fastening together with the protector, so that interference is not noted when the engine is assembled to the vehicle body frame.

  According to the second feature, the cylindrical body portion of the vehicle speed sensor is inserted into a through-hole formed in the upper portion of the crankcase, so that the detection portion of the vehicle speed sensor enters the vehicle body downwardly downward, and a predetermined driven gear is provided. Therefore, the amount of protrusion of the vehicle speed sensor from the crankcase surface is reduced, and the influence of traveling wind can be reduced. In addition, the vehicle speed sensor can be accessed from above the vehicle body, and the maintainability is improved.

  According to the third feature, the crankcase is provided with a fastening seat for attaching the vehicle speed sensor and the protector, and a through hole into which the main body of the vehicle speed sensor enters and a fastening member are inserted into the fastening seat. Since the fastening hole is provided outside the through hole in the vehicle width direction, the vehicle speed sensor and the protector can be easily positioned and can be stably fixed to the crankcase. Further, since the fastening hole is positioned outside the through hole in the vehicle width direction, the vehicle speed sensor can be easily protected.

  According to the fourth feature, the plurality of ribs formed in a substantially radial manner are formed in the vehicle width direction around the auxiliary shaft hole for projecting one end portion of the auxiliary shaft from the crankcase. Since the seat is arranged so that it fits inside the end surface of the rib in the vehicle width direction outside, the drive sprocket attached to the end of the countershaft and the drive chain wrapped around this are attached to the fastening seat and the vehicle speed. Interference with the sensor can be prevented.

  According to the fifth feature, since the predetermined driven gear is a second-speed driven gear, it is possible to stably detect the vehicle speed using the second-speed driven gear that has a relatively large diameter and does not move in the axial direction. Become.

  According to the sixth feature, the transmission is a four-speed transmission, and the four transmission gear pairs between the main shaft and the sub-shaft are second speed, fourth speed, third speed, first speed from the left side in the vehicle width direction. Therefore, the vehicle speed sensor is positioned closer to the left end of the crankcase in the vehicle width direction, and the maintainability of the vehicle speed sensor can be further enhanced.

  According to the seventh feature, the engine is fixed to the center frame of the vehicle body frame by three hanger bosses formed from the upper part to the rear part of the crankcase. The central hanger boss located in the center is located close to the rear side of the vehicle speed sensor so that it does not overlap in the side view of the vehicle body, so that the engine can be removed from the vehicle body frame without removing the vehicle speed sensor from the crankcase. It becomes possible.

  According to an eighth feature, the crankcase includes a left case half on the left side in the vehicle width direction and a right case half on the right side in the vehicle width direction, and connects the left case half and the right case half. The fastening bolts that are oriented in the vehicle width direction are arranged at positions that overlap the vehicle speed sensor when viewed from the side of the vehicle body and on the front side of the vehicle body of the middle hanger boss, so when disassembling the left and right crankcases, Although it is necessary to remove the vehicle speed sensor, it is not necessary to remove the vehicle speed sensor when the engine is attached to or detached from the vehicle body frame, and the vehicle speed sensor can be attached or detached while the engine is mounted on the vehicle body frame.

  According to a ninth feature, the engine is a single-cylinder engine with a crankshaft placed between the rear end of the front wheel and the front end of the rear wheel. Therefore, the maintainability of the vehicle speed sensor can be improved even in an engine type vehicle that requires less space on the back side of the crankcase as compared with an engine type in which the cylinder stands upright.

  According to the tenth feature, the protector includes a flat plate portion through which the fastening member passes to fasten the extension portion of the vehicle speed sensor, an output wiring passage portion through which the output wiring of the vehicle speed sensor passes, and the vehicle speed sensor. When tightening, it is equipped with an opening and eaves that prevent relative rotation between the vehicle speed sensor and the protector, so that the protector can be prevented from rotating at the same time with a simple shape, facilitating assembly work. Can do.

  According to the eleventh feature, since the O-ring for maintaining the sealing performance with the crankcase is attached to the cylindrical main body portion of the vehicle speed sensor, the vehicle speed sensor can be simply inserted into the through hole. And the crankcase can be sealed.

1 is a side view of a motorcycle to which a vehicle speed sensor mounting structure according to the present invention is applied. It is a partial enlarged view of an engine. It is a top view sectional view of an engine. It is a perspective view of the left-side case half with the vehicle speed sensor unit attached. It is a perspective view of the left-side case half body with the vehicle speed sensor unit removed. It is a perspective view of a vehicle speed sensor unit. It is a side view of a vehicle speed sensor unit. It is a top view which shows the engagement relationship between a hanger plate and an engine. FIG. 5 is an enlarged arrangement view of the vehicle speed sensor unit as viewed from above in the axial direction.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view of a motorcycle 1 to which a vehicle speed sensor mounting structure according to the present invention is applied. The body frame 2 of the motorcycle 1 includes a head pipe 3 at the front end of the body, a main frame 8 extending rearward from the head pipe 3, and a pair of left and right seat rails connected to the rear end of the main frame 8 and extending rearward. 5, a pair of left and right down frames 22 connected to the front end portion of the main frame 8 and extending downward, and a pair of left and right centers extending downward from the rear portion of the main frame 8 and connected to the rear end portion of the down frame 22 The frame 4 is composed of a pair of left and right subframes 6 that connect the seat rail 5 and the center frame 4. A center stand 53 is rotatably attached to the lower end portion of the center frame 4.

  A front fork 9 that rotatably supports a front wheel WF is steerably attached to the head pipe 3, and a fuel tank 41 is attached to the main frame 8 so as to cover from above. The engine 23 as a power source is suspended by a pair of left and right hanger plates 100 </ b> L, R coupled to the center frame 4. The engine 23 and the hanger plates 100L and 100R are connected by three support portions A, B, and C. A swing arm 38 that rotatably supports the rear wheel WR is swingably attached to the vehicle body frame 2 by a pivot 37 provided on the hanger plates 100L and 100R.

  The pair of left and right front forks 9 are connected by a top bridge 10 and a bottom bridge 11. A handle bar 12 and a handle lock device 13 are attached to the top bridge 10. A cowl support stay 17 is attached to the top bridge 10 and the bottom bridge 11, and the cowl support stay 17 allows the front cowl 15, the meter device 14, the inner cowl 16, the support stay 20 of the pair of left and right winker devices 19, and front use. Each license plate 21 is supported. A headlamp 18 is attached to the front cowl 15, and a front fender 9a is disposed above the front wheel WF.

  The engine 23 disposed between the front wheel WF and the rear wheel WR is a crank horizontal type single-cylinder engine in which the crankshaft 33 is oriented in the vehicle width direction, and the cylinder 24 is oriented forward of the vehicle body. Suspended by frame 2. An intake device is attached to the upper side of the vehicle body and an exhaust device is attached to the lower side of the vehicle body in the cylinder head 25 that is attached to the cylinder 24 and houses the intake / exhaust valve mechanism.

  The engine 23 is provided with respective axes in the order of a crankshaft 33, a transmission main shaft (main shaft) 34, and a transmission sub shaft (counter shaft) 35 from the front side of the vehicle body. A drive sprocket around which a drive chain 39 that transmits driving force to the rear wheel WR is wound is attached to the countershaft 35, and a sprocket cover 36 is disposed on the left side in the vehicle width direction.

  The intake device includes a carburetor 27 connected via an intake pipe 26 and an air cleaner 30 connected to the carburetor 27 via a connecting tube 28. The air cleaner 30 is disposed in a space surrounded by the seat rail 5, the center frame 4, and the sub frame 6. An intake port 31 is connected to the upper rear portion of the air cleaner 30.

  Connected to the carburetor 27 is a throttle cable 56 coupled to a throttle grip (not shown) attached to the handle bar 12. The engine 23 is connected to a clutch cable 57 coupled to a clutch lever (not shown) attached to the handle bar 12. A battery 29 is disposed at a position near the center of the air cleaner 30 in the vehicle width direction. The carburetor 27 may be replaced with an injector and a throttle body of the fuel injection device.

  The exhaust device includes an exhaust pipe 32 connected to the lower portion of the cylinder head 25 and a muffler 40 attached to the rear end of the exhaust pipe 32. The muffler 40 is supported by a bar member 7 extending rearward and obliquely downward from the subframe 6 via a muffler stay 52.

  The swing arm 38 is suspended from the vehicle body frame 2 by a pair of left and right rear cushion units 51. The upper end portion of the rear cushion unit 51 is attached to a rail lower bracket 62 provided at the lower portion of the seat rail 5.

  A storage box 54 attached to the lower part of the main frame 8 via a bracket 55 is disposed below the fuel tank 41 and on the left side of the carburetor 27 in the vehicle width direction. The storage box 54 includes a case 58 having an opening and a lid (not shown) that closes the opening, and an extension 60 extending rearward from the case 58 covers the lower side of the fuel tank 41, and further on both sides. Are respectively covered with a left cover 59 and a right cover (not shown).

  The seat 42 is fixed by engaging the insertion portion provided in the lower part of the rear part with the engaging part provided in the seat rail 5 and bolting a pair of left and right mounting pieces 63 provided in the lower part of the front part to the seat rail 5. Has been. A grab rail 43 and a rear fender 49 are attached to the seat rail 5. A support stay 47 that supports the rear cover 44, the tail lamp device 45, and the winker device 46 is attached to the rear fender 49.

  A side guard member 50 is disposed behind the rear cushion unit 51. The side guard member 50 is supported by the seat rail 5 and the bar member 7, and a pair of left and right tandem steps 61 are attached in the vicinity of the connecting portion with the bar member 7. A helmet holder 48 is attached to the upper part of the side guard member 50.

  In the vehicle speed sensor mounting structure according to the present invention, the vehicle speed sensor 77 for detecting the vehicle speed of the motorcycle 1 is positioned above the vehicle body of the countershaft 35 of the transmission and in front of the vehicle body of the support portion B of the hanger plates 100L, R. It is characterized in that it is attached to 23 crankcases.

  FIG. 2 is a partially enlarged view of the engine 23. This figure shows a state where various covers, a generator, and a sprocket cover 36 (see FIG. 1) are removed. As described above, the engine 23 is supported by the center frame 4 of the body frame 2 by fastening hanger bolts (not shown) to the support portions A, B, C of the pair of left and right hanger plates 100L, R. The hanger plates 100L, R are composed of a left-right plate 100L and a right-side plate 100R that are substantially left and right symmetrically arranged in the vehicle width direction.

  The support portions A, B, and C are provided on the front portion 100a, the middle portion 100b, and the rear portion 100c of the hanger plates 100L and 100R. The support part B is disposed between the support part A and the support part C in the longitudinal direction of the vehicle body and between the support part A and the support part B in the vertical direction of the vehicle body. The crankcase 64 of the engine 23 is formed with a front hanger boss 64a constituting the support portion A, a middle hanger boss 64b constituting the support portion B, and a rear hanger boss 64c constituting the support portion C.

  A through hole 100d through which the pivot 37 of the swing arm 38 (see FIG. 1) passes is provided in the hanger plates 100L and 100R, and is supported on the rear side of the support portion A and the support portion B in the vehicle longitudinal direction and in the vehicle vertical direction. It is disposed between the part B and the support part C.

  A crankshaft 33 is disposed on the vehicle body front side of the crankcase 64, and a transmission including a main shaft (main shaft) 34 and a counter shaft (counter shaft) 35 is disposed on the vehicle body rear side. Thus, the respective shafts are arranged in the order of the crankshaft 33, the main shaft 34, and the auxiliary shaft 35 from the front side of the vehicle body. The crankshaft 33 and the subshaft 35 are disposed at substantially the same height in the vertical direction when viewed from the side of the vehicle body, and the main shaft 34 is disposed offset to a position slightly higher than the shafts 33 and 35. .

  A cylindrical shift drum 150 that performs a shifting operation by operating a shift fork (not shown) that engages with a gear of the transmission is disposed above a substantially intermediate position between the main shaft 34 and the sub shaft 35. . A neutral switch 67 that detects the neutral state of the transmission based on the rotation angle of the shift drum 150 is provided on the axis of the shift drum 150. The neutral switch 67 is attached to the crankcase 64 by attachment bolts 68.

  A drive sprocket 127 around which the drive chain 39 is wound is attached to the left end in the vehicle width direction of the auxiliary shaft 35 protruding from the crankcase 64. Three ribs 65, 66, and 69 are provided substantially radially around the auxiliary shaft hole 35a (see FIG. 4) formed in the crankcase 64 and through which the left end portion of the auxiliary shaft 35 passes.

  A vehicle speed sensor unit 76 including a vehicle speed sensor 77 that detects the vehicle speed based on the rotational speed of a transmission gear provided on the auxiliary shaft 35 is attached above the auxiliary shaft 35 in a side view of the vehicle body. The vehicle speed sensor unit 76 is disposed between the shift drum 150 and the middle hanger boss 64b in a state where the axis O is inclined by a predetermined angle θ with respect to the line P perpendicular to the horizontal direction. .

  FIG. 3 is a top sectional view of the engine 23. The same reference numerals as those described above denote the same or equivalent parts. The engine 23 includes a crankcase 64, a cylinder 24 that is coupled to the crankcase 64 and protrudes forward, and a cylinder head 25 that is joined to the front end of the cylinder 24. The crankcase 64 includes a left case half 64L and a right case half 64R that are divided into left and right in the vehicle width direction, and the crankshaft 33 that is arranged in the left and right horizontal direction includes a pair of left and right bearings 117 and 118. And is supported by both case halves 64L and 64R. A piston 112 that slides in a cylinder bore formed in the cylinder 24 is connected to the crankshaft 33 via a connecting rod 114.

  The cylinder head 25 is formed with a combustion chamber 111 where the top surface of the piston 112 faces, an intake port and an exhaust port (not shown) that are connected to the combustion chamber 111 and open in the vertical direction of the vehicle body of the cylinder head 25. Intake and exhaust valves (not shown) for opening and closing are mounted. A valve operating mechanism 102 for opening and closing the intake / exhaust valves is installed in the valve operating chamber 103 of the cylinder head 25, and a cylinder head cover 101 is attached to the upper part thereof.

  The valve mechanism 102 includes a cam shaft 106 that is supported by bearings 104 and 105 at an intermediate portion between the intake valve and the exhaust valve, a rocker arm (not shown) that transmits the operation of the cam shaft 106 to the intake and exhaust valves, and intake and exhaust. Each valve consists of a valve spring (not shown) that urges the valve in the closing direction. A spark plug 110 connected to the plug cap 109 is attached to the lower side of the valve mechanism 102 in the figure.

  A rotational driving force of the crankshaft 33 is transmitted to the camshaft 106 via the cam chain 108. The power transmission to the camshaft 106 is transmitted to the drive sprocket 123 fixed to the crankshaft 33 adjacent to the left side of the bearing 117 in the figure, the driven sprocket 107 fixed to one end of the camshaft 106, and both sprockets 123 and 107. The rotation of the crankshaft 33 is reduced by half and transmitted to the camshaft 106. The cam chain 108 is accommodated in a chain passage 113 formed on one side wall of the cylinder 24.

  The rotor 120 of the generator 121 is key-connected to the left end of the crankshaft 33 in the vehicle width direction, and the rotor 120 and a starter gear 124 rotatably supported on the crankshaft 33 are connected via a one-way clutch 119. Connected. The left side of the generator 121 in the vehicle width direction is covered with a generator cover 122 attached to the left case half 64L.

  The one-way clutch 119 transmits a rotational force in only one direction from the starting gear 124 to the rotor 120. A starter motor (not shown) that drives the starter gear 124 via a reduction gear train is attached to the front side of the crankcase 64 and above the vehicle body of the crankcase 64. The front hanger boss 64a for suspending the engine is disposed on the rear side of the vehicle body of the starting motor.

  A four-speed transmission GR having a main shaft 34 and a sub shaft 35 disposed in parallel with the crankshaft 33 is accommodated on the vehicle body rear side of the crankcase 64. The main shaft 34 is pivotally supported on the crankcase 64 via bearings 125 and 126, and the auxiliary shaft 35 is pivotally supported on the crankcase 64 via bearings 128 and 129.

  As described above, the auxiliary shaft 35 is disposed on substantially the same horizontal plane as the crankshaft 33. The main shaft 34 is offset above the crankshaft 33 and the subshaft 35 and is disposed at an intermediate position between the shafts 33 and 35. A shift drum 150 (see FIG. 2) for selecting a transmission gear train corresponding to the first to fourth gears is disposed on the upper side of the vehicle body of the main shaft 34 and the sub shaft 35.

  The power generated by the crankshaft 33 is transmitted to the main shaft 34 through the centrifugal clutch 116 and the transmission clutch 130, and is transmitted from the main shaft 34 to the sub shaft 35 through one selected transmission gear train. The right side in the vehicle width direction of the centrifugal clutch 116 and the starting clutch 130 is covered with a clutch cover 115 attached to the right case half 64R. An input shaft 131 of a kick starter is pivotally supported below and behind the auxiliary shaft 35 in a side view of the vehicle body.

  The transmission gear train of the transmission GR is arranged in the order of 2nd speed, 4th speed, 3rd speed, and 1st speed from the left side in the vehicle width direction. Corresponding to this arrangement, the four driven gears on the auxiliary shaft 35 are also arranged in the order of the second speed driven gear G2, the fourth speed driven gear G4, the third speed driven gear G3, and the first speed driven gear G1. The vehicle speed sensor unit 76 is disposed so as to face the tooth tip of the second speed driven gear G2 located at the left end in the vehicle width direction among the respective speed driven gears on the auxiliary shaft 35. In the transmission GR according to the present embodiment, the second speed driven gear G2 does not slide in the axial direction and is the gear having the next largest diameter after the first speed driven gear G1, so that stable vehicle speed detection is possible. It is suitable for. In this figure, the attachment position of the vehicle speed sensor unit 76 when viewed from above the vehicle body is indicated by a broken line circle S.

  FIG. 4 is a perspective view of the left case half 64L with the vehicle speed sensor unit 76 attached thereto. FIG. 5 is a perspective view of the left case half 64L with the vehicle speed sensor unit 76 removed. 6 is a perspective view of the vehicle speed sensor unit 76, and FIG. 7 is a side view thereof. A crankshaft hole 33a through which the crankshaft 33 penetrates, a neutral switch hole 67a to which the neutral switch 67 is attached, and a fastening bolt 75 (see FIG. 5) for connecting the left and right case halves are screwed into the left case half 64L. A plurality of holes are formed.

  Of the front hanger boss 64a, the middle hanger boss 64b, and the rear hanger boss 64c for engine suspension, the dimension in the vehicle width direction of the middle hanger boss 64b is set narrower than the other two. Accordingly, in the shape of the hanger plates 100L and 100R, the horizontal interval of the middle portion 100b (see FIG. 2) constituting the support portion B is narrower than other portions.

  A dome-shaped bulging portion 89 that bulges to the left in the vehicle width direction is formed around the auxiliary shaft hole 35a through which the left end portion in the vehicle width direction of the auxiliary shaft 35 passes. The aforementioned ribs 65, 66, 69 are formed so as to stand from the side surface of the left case half 64L and support the side surface of the bulging portion 89.

  The vehicle speed sensor unit 76 is attached to the vehicle body rear side of a rib 69 extending from the bulging portion 89 to the vehicle body upper side. Specifically, like the ribs 65, 66, and 69, it is fixed to a fastening seat 72 (hatched portion in FIG. 5) of the base 90 formed continuously to the bulging portion 89. The tightening seat 72 is provided with a through hole 73 into which a main body portion (the dotted portion in FIG. 4) of the vehicle speed sensor unit 76 is inserted, and a fastening hole 74 for fixing the vehicle speed sensor unit 76.

  Referring to FIGS. 6 and 7, the vehicle speed sensor unit 76 is provided with a protector 83 that protects the vehicle speed sensor 77 on the upper portion of the vehicle speed sensor 77. The vehicle speed sensor 77 and the protector 83 are fastening members made of flange bolts or the like. The threaded portion 82 of 81 is screwed into the fastening hole 74 of the fastening seat 72 to be fastened together with the crankcase 64. The vehicle speed sensor 77 has a substantially cylindrical main body 78 inserted into the through hole 73 and an extending portion 80 through which the fastening member 81 passes. The detection part 78 a of the vehicle speed sensor 77 is provided on the lower surface of the main body part 78.

  According to the above-described configuration, when the vehicle speed sensor unit 76 is attached, the positioning is completed by inserting the main body portion 78 into the through hole 73 and engaging the fastening member 81 with the fastening hole 74. The attachment work of 76 becomes easy. Further, since the fastening hole 74 is located outside the through hole 73 in the vehicle width direction, the vehicle speed sensor 77 can be easily protected. Further, an annular O-ring 79 made of rubber or the like is engaged with the main body 78, and sealing with the crankcase 64 is maintained by inserting the main body 78 into the through hole 73.

  The protector 83 formed of a thin metal plate or the like includes an output wiring through which a fastening member 81 passes and a flat plate portion 87 for fastening the extension portion 80 of the vehicle speed sensor 77 together with an output wiring 77a of the vehicle speed sensor 77. A through portion 85, an eaves portion 84 that prevents the protector 83 from rotating together when the vehicle speed sensor 77 is fastened together, and a substantially rectangular opening 86 are provided.

  The eaves portion 84 and the opening 86 of the protector 83 have a function of preventing the protector 83 from rotating together with the fastening member 81 when the vehicle speed sensor unit 76 is attached. Specifically, when the protector 83 tries to rotate together with the fastening member 81 in the clockwise direction, the end face of the opening 86 comes into contact with the cylindrical side surface of the vehicle speed sensor 77 and the eaves part is bent downward on the vehicle body. The inner side surface of 84 abuts on the cylindrical side surface of the vehicle speed sensor 77. As a result, the rotation operation of the protector 83 is restricted. Further, since the output wiring through portion 85 is formed in the protector 83, the protector 83 can be attached in a state where the output wiring 77a is connected to the ceiling surface of the vehicle speed sensor 77.

  In the protector 83, a relief portion 88 is formed at the edge of the flat plate portion 87. The escape portion 88 prevents the protector 83 from protruding outward in the vehicle width direction when the vehicle speed sensor unit 76 is attached to a predetermined position. The specific effect will be described later.

  The crankcase 64 is provided with a plurality of fastening bolts 75 that connect the left case half 64L and the right case half 64R in the vehicle width direction. Among these, the fastening bolt 75 disposed on the front side of the vehicle body adjacent to the middle hanger boss 64b is disposed at a position overlapping the vehicle speed sensor unit 76 in a side view of the vehicle body. On the other hand, the middle hanger boss 64b is arranged close to the vehicle speed sensor unit 76 so as not to overlap with the vehicle body side view. Thus, although it is necessary to remove the vehicle speed sensor unit 76 when disassembling the left and right crankcases 64, it is not necessary to remove the vehicle speed sensor unit 76 when the engine 23 is attached to or detached from the vehicle body frame 2, and The vehicle speed sensor unit 76 can be attached and detached while the engine 23 is mounted.

  FIG. 8 is a top view showing the engagement relationship between the hanger plates 100L, 100R and the engine 23. FIG. FIG. 9 is an enlarged layout view of the vehicle speed sensor unit 76 as viewed from above in the axial direction. The same reference numerals as those described above denote the same or equivalent parts. The vehicle speed sensor unit 76 is disposed such that the periphery of the fastening member 81 is exposed from the left hanger plate 100L when viewed from the top of the vehicle body, while the ribs 65, 66, and 69 disposed around the bulging portion 89. 9, the end surface of the relief portion 88 of the protector 83 is positioned inward by the distance S from the end surface in the vehicle width direction of the rib 66 in FIG. 9. Is shown. Further, the escape portion 88 formed in the protector 83 is configured to be directed in the longitudinal direction of the vehicle body when the vehicle speed sensor unit 76 is fixed at a predetermined position. As a result, the protector 83 is prevented from protruding outward in the vehicle width direction, and the drive sprocket 127 attached to the end of the countershaft 35 and the drive chain 39 wound around this interfere with the protector 83 and the vehicle speed sensor 77. Can be prevented.

  As described above, according to the vehicle speed sensor mounting structure according to the present invention, the axis O of the cylindrical main body 78 of the vehicle speed sensor 77 is inclined to the vehicle body rear side by a predetermined angle θ in a side view of the vehicle body. In addition, it is configured to be fixed to the crankcase 64 by being fastened together with a protector 83 and a fastening member 81 covering the upper part of the vehicle speed sensor 77 at a position above the vehicle body of the auxiliary shaft 35 and at the vehicle body rear side of the shift drum 150. Therefore, the vehicle speed sensor 77 is disposed on the vehicle body upper side of the auxiliary shaft 35, and the maintainability of the vehicle speed sensor 77 can be improved as compared with the structure attached to the surface of the crankcase 64 on the vehicle body rear side. Further, the protector 83 protects the vehicle speed sensor 77. Furthermore, by fastening the vehicle speed sensor 77 and the protector 83 together, the number of fastening members 81 can be reduced, and the cost can be reduced.

  The shape of the vehicle and engine, the structure and shaft arrangement of the transmission, the crankcase, the ribs around the bulge, the vehicle speed sensor, the protector, the shape and structure of the shift drum, etc. are not limited to the above embodiment, but various changes can be made. Is possible. The vehicle speed sensor mounting structure according to the present invention can be applied to various vehicles such as a three-wheeled vehicle and a four-wheeled vehicle in addition to a motorcycle.

  DESCRIPTION OF SYMBOLS 1 ... Motorcycle, 2 ... Body frame, 4 ... Center frame, 23 ... Engine, 33 ... Crank shaft, 34 ... Main shaft (main shaft), 35 ... Sub shaft (counter shaft), 35a ... Sub shaft hole, 64 ... Crank Case, 64L ... left case half, 64R ... right case half, 64a, 64b, 64c ... hanger boss, rib ... 65, 66, 69, 72 ... clamping seat, 73 ... through hole, 74 ... fastening hole, 77 ... vehicle speed Sensor, 77a ... Output wiring, 76 ... Vehicle speed sensor unit, 78 ... Body part, 79 ... O-ring, 80 ... Extension part, 83 ... Protector, 84 ... Eaves (hook) part, 85 ... Output wiring through part, 87 ... Flat plate part 89 ... Swelling part 90 ... Pedestal 100L, R ... Hanger plate 150 ... Shift drum G2 ... Second speed driven gear GR ... Transmission, O ... Axis, θ ... Predetermined angle

Claims (11)

A shift in which a plurality of transmission gear trains are disposed between a crankshaft (33) oriented in the vehicle width direction, a main shaft (34), and a counter shaft (35) disposed on the vehicle body rear side of the main shaft (34). The crankshaft (64) of the engine (23) that houses the machine (GR) and the shift drum (150) for shifting the transmission (GR) above the auxiliary shaft (35). 35) In the vehicle speed sensor mounting structure in which the vehicle speed sensor (77) is mounted so as to face the tooth tip of the predetermined driven gear (G2) above,
The transmission (GR) and the shift drum (150) are housed on the vehicle body rear side of the crankcase (64),
The vehicle speed sensor (77) is in a state in which the axis (O) of the cylindrical main body (78) is inclined by a predetermined angle (θ) to the rear side of the vehicle body in a side view of the vehicle body, and of the auxiliary shaft (35). The crankcase is fastened together with a protector (83) covering an upper portion of the vehicle speed sensor (77) using a fastening member (81) at a position above the vehicle body and on the vehicle body rear side of the shift drum (150). (64) The vehicle speed sensor mounting structure characterized by being comprised so that it may be fixed to.   By inserting the cylindrical main body part (78) of the vehicle speed sensor (77) into a through hole (73) formed in the upper part of the crankcase (64), the detection part (78a) of the vehicle speed sensor (77). The vehicle speed sensor mounting structure according to claim 1, wherein the vehicle speed sensor mounting structure is configured to enter the vehicle body downward downward and to face a tooth tip of the predetermined driven gear (G2). The crankcase (64) is provided with a fastening seat (72) for mounting the vehicle speed sensor (77) and the protector (83),
The fastening seat (72) is provided with a through hole (73) into which the main body (78) of the vehicle speed sensor (77) is inserted and a fastening hole (74) into which the fastening member (81) is inserted.
The vehicle speed sensor mounting structure according to claim 1 or 2, wherein the fastening hole (74) is provided outside the through hole (73) in the vehicle width direction. A plurality of ribs (65, 66, 69) formed substantially radially around the auxiliary shaft hole (35a) for projecting one end of the auxiliary shaft (35) from the crankcase (64) are arranged in the vehicle width direction. It is formed upright,
The said fastening seat (72) is arrange | positioned so that it may be settled inside from the end surface of the vehicle width direction outer side of the said rib (65,66,69). Vehicle speed sensor mounting structure.   The vehicle speed sensor mounting structure according to any one of claims 1 to 4, wherein the predetermined driven gear (G2) is a second-speed driven gear (G2).   The transmission (GR) is a four-speed transmission, and the four transmission gear pairs between the main shaft (34) and the sub shaft (35) are second, fourth, third, The vehicle speed sensor mounting structure according to claim 5, wherein the vehicle speed sensor mounting structure is arranged in the order of the first speed. The engine (23) is fixed to the center frame (4) of the vehicle body frame (2) by three hanger bosses (64a, 64b, 64c) formed from the upper part to the rear part of the crankcase (64),
Of the three hanger bosses (64a, 64b, 64c), the middle hanger boss (64b) located in the center in the vertical direction and in the center in the front-rear direction does not overlap the vehicle rear side of the vehicle speed sensor (77) in a side view of the vehicle body. The vehicle speed sensor mounting structure according to any one of claims 1 to 6, wherein the vehicle speed sensor mounting structure is closely arranged. The crankcase (64) includes a left case half (64L) on the left side in the vehicle width direction and a right case half (64R) on the right side in the vehicle width direction.
A fastening bolt (75) oriented in the vehicle width direction for connecting the left case half (64L) and the right case half (64R) overlaps the vehicle speed sensor (77) in a side view of the vehicle body, 8. The vehicle speed sensor mounting structure according to claim 7, wherein the vehicle speed sensor mounting structure is disposed on a front side of a vehicle body of the middle hanger boss (64b). The engine (23) is a single-cylinder engine with a crankshaft placed between a rear end portion of a vehicle body of a front wheel (WF) and a front end portion of a vehicle body of a rear wheel (WR),
The vehicle speed sensor mounting structure according to any one of claims 1 to 7, wherein the cylinder (24) of the engine (23) is disposed so as to be directed forward of the vehicle body. The protector (83)
A flat plate portion (87) through which the fastening member (81) penetrates and fastens the extension portion (80) of the vehicle speed sensor (77);
An output wiring passage portion (85) through which the output wiring (77a) of the vehicle speed sensor (77) passes;
An opening (86) and an eaves part (84) for preventing relative rotation between the vehicle speed sensor (77) and a protector (83) when the vehicle speed sensor (77) is fastened together are provided. Item 10. A vehicle speed sensor mounting structure according to any one of Items 1 to 9.   The O-ring (79) for maintaining a sealing property with the crankcase (64) is attached to the cylindrical main body (78) of the vehicle speed sensor (77). The vehicle speed sensor mounting structure according to any one of Items 10 to 10.

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