JP3209663B2 - Motorcycle rear wheel rotational speed detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle rear wheel rotational speed detecting device used for an anti-skid device, a vehicle speed meter, and the like, and more particularly, to an automatic vehicle equipped with a shaft drive type power transmission mechanism for secondary transmission. The present invention relates to a detection device suitable for a motorcycle.

[0002]

2. Description of the Related Art An anti-skid device for a motorcycle is a device that controls a brake based on the rotation speed of a rear wheel, which is a driving wheel, and changes in the rotation speed, thereby preventing the rear wheel from slipping during sudden braking. In some vehicle speed meters, the vehicle speed is displayed based on the rotation speed of the rear wheels. When it is necessary to detect the rotation speed of the rear wheel as described above, a method of directly detecting the rotation speed of the rear wheel with a sensor has conventionally been adopted. However, this method
This increases the number of parts, such as providing a rotor for detecting the rotation speed on the rear wheel and requiring a member for attaching a sensor. In addition, every time maintenance is performed on the rear wheels such as tire replacement, it is necessary to adjust the relative positional relationship between the sensor and the rotor, which causes a reduction in detection accuracy. As described above, there are various problems in the method of directly detecting the rotation speed of the rear wheel.

A technique for solving such a problem is disclosed in Japanese Utility Model Laid-Open Publication No. Sho 51-68576 and Japanese Patent Publication No. 5-426.
No. 31 has proposed this. Each of these is applied to a motorcycle equipped with a shaft drive type transmission mechanism for secondary transmission, and the former detects a rotational speed of a gear on the rear wheel side in a bevel gear connecting the drive shaft and the rear wheel ( (Electromagnetic pickup). In the latter, the rotation speed of a rotating shaft interposed between the output shaft of the engine and the drive shaft is detected by a sensor. In any case, the rotational speed of the rear wheel is indirectly detected and is not affected by the maintenance of the rear wheel.

[0004]

However, in the former case, the sensor is brought close to a large number of teeth having a constant pitch formed on the outer periphery of the gear on the rear wheel side, and these teeth are used as a variable element of the rotational speed. That is, a number of teeth for detecting the rotational speed must be newly formed on the outer periphery of the gear. Therefore, the number of manufacturing steps is increased. Further, since the gear on the rear wheel side has a disk shape whose thickness is relatively thin with respect to the diameter, the gear easily bends when the rotational speed fluctuates rapidly. If the gear is deformed in this way, the distance between the sensor and the tooth surface changes, and although momentary, a detection error occurs.

[0005] On the other hand, in the latter case, a rotor having, for example, a large number of teeth having a constant pitch on its outer periphery is formed on a rotating shaft interposed between an output shaft of an engine and a drive shaft as a rotating speed variable element. It must be fixed, and the increase in the number of parts cannot be denied. In addition, since a gear meshing portion and a cross joint are interposed between the rear wheel and the sensor, a detection error is likely to occur due to backlash or slight clearance of the gear.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a rear wheel rotational speed detecting device for a motorcycle in which an increase in the number of manufacturing processes and the number of parts is suppressed and a detection error is less likely to occur. I have.

[0007]

Means for Solving the Problems The present invention has been made to achieve the above object, and the invention according to claim 1 has a drive shaft rotating with the rotation of the engine via a bevel gear. A rotation speed detection sensor connected to the rear wheel and facing the tooth surface of the gear on the drive shaft side of the bevel gear and detecting the rotation speed of the gear is provided. The invention described in claim 2 is characterized in that the bevel gear is covered with a gear case, and the rotation speed detection sensor is detachably mounted on the gear case.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. A. Embodiment A-1. Configuration of Motorcycle Fig. 1 is an overall side view of a motorcycle 1 provided with a wheel rotational speed detecting device after the one embodiment of the present invention. In this case, the forward direction (forward) of the motorcycle 1 is the left side. In FIG. 1, reference numeral 2 denotes a vehicle body frame, and a vertical V-type engine 3 is mounted inside the vehicle body frame 2. A fuel tank 4, a driver's seat 5, and a passenger's seat 6 are attached to the upper part of the body frame 2 from the front via a bracket (not shown). A vehicle speed meter 7 is attached to the front of the fuel tank 4. A front fork 8 containing a front cushion unit (not shown) is rotatably attached to a front end of the body frame 2. At the upper end of this front fork 8 is a handle 9
Is fixed, and a front wheel 10 is rotatably supported at the lower end.

As shown in FIG. 2, a pair of left and right rear forks 12 is
Are swingably connected, and a rear wheel 13 is rotatably supported by these rear forks 12. Rear fork 12
Is connected to the vehicle body frame 2 via a link 14 and a rear cushion unit 15, and the swing of the rear wheel 13 is buffered by the rear cushion unit 15.

FIG. 3 shows a part of a constant-mesh transmission 20 connected to the engine 3.
The transmission 20 includes a transmission case 21
Main shaft 22 and transmission drive shaft 23 rotatably supported on the shafts, and both shafts 22, 23
Sets of drive gears 2 incorporated in and meshing with each other
4 and a driven gear 25, and a change mechanism (not shown). The main shaft 22 is connected to a clutch (not shown), and rotates when the rotation of the engine 3 is transmitted when the clutch is connected. The rotation is transmitted to the transmission drive shaft 23 via the engagement between the drive gear 24 and the driven gear 25. The transmission mechanism from the drive gear 24 to the driven gear 25 is converted by the change mechanism, and the rotation of the transmission drive shaft 23 is shifted.

A secondary transmission of the power from the transmission 20 to the rear wheel 13 employs a shaft drive type transmission mechanism using a drive shaft 30. The left one of the pair of left and right rear forks 12 also serves as a cylindrical casing that houses a part of the drive shaft 30. The drive shaft 30 includes first, second, and third drive shafts 31, 3 from the upstream side (the front side of the vehicle body).
2, 33, and these are connected. At the end of the transmission drive shaft 23,
The first drive shaft 31 is connected via a middle bevel gear 40.

The middle side bevel gear 40 includes a first middle gear 41 incorporated at one end of the transmission drive shaft 23 and a second middle gear 42 formed at one end of the first drive shaft 31 and meshing with the first middle gear 41. It is configured with a combination. The first middle gear 41 is fixed to one end of the transmission drive shaft 23, and is rotatably supported by the transmission case 21 via a bearing 43 together with the transmission drive shaft 23. The first drive shaft 31 extends substantially horizontally rearward perpendicularly to the transmission drive shaft 23, and is rotatably supported by a lid member 26 fitted to the transmission case 21 via a bearing 34. . A second drive shaft 32 is swingably connected to the rear end of the first drive shaft 31 via a universal joint 35. As shown in FIG. 5, the third drive shaft 33 is connected to the rear end of the second drive shaft 32 via a gear-type flexible shaft coupling 36.
Is connected.

A second drive shaft 32 is accommodated in the left rear fork 12. The front end of the rear fork 12 is swingably connected to the lid member 26 so as to be swingable with the second drive shaft 32. The rear end of the rear fork 12 is connected to the gear case 50. As shown in FIGS. 4 and 5, the gear case 50 has a holding plate 52 fixed inside a disk-shaped case main body 51 and a cylindrical portion 53 formed at the front end of the case main body 51. The rear end of the rear fork 12 is integrally connected to 53. The third drive shaft 33 is rotatably supported in the cylindrical portion 53 via bearings 37 and 38. The left end of the axle 61 is fixed to the axis of the case body 51 via a sleeve 60. The right end of the axle 61 is fixed to a right rear fork (not shown). A hub 62 that forms the center of the rear wheel 13 is rotatably mounted on the axle 61.

The third drive shaft 33 is connected to a hub 62 of the rear wheel 13 via a rear bevel gear 70. As shown in FIG. 5, the rear bevel gear 70 includes a first rear gear 71 incorporated at the rear end of the third drive shaft 33, and a second rear gear 72 rotatably provided in the gear case 50. Have been. The first rear gear 71 is formed at the rear end of the third drive shaft 33. The second rear gear 72 has a relatively thin disk shape, and a collar 73 is integrally fitted on the shaft center. The second rear gear 72 itself is the gear case 50.
To the holding plate 52 through the bearing 74 and the collar 7
3 is rotatably supported in the gear case 50 by interposing the bearing 75 in the case body 51. A slight gap is secured between the collar 73 and the sleeve 60. The second rear gear 72 is coaxial with the axle 61, and a flange 76 formed inside is integrally connected to the hub 62. That is, the second rear gear 72 and the rear wheel 13 rotate integrally.

The inside of the gear case 50 includes a seal ring 54,
55, the gear case 50 is filled with gear oil. As shown in FIG.
The case main body 51 has a gear oil inlet 57 which is closed by a cap 56. This inlet 57
Are formed below a horizontal line passing through the axis of the gear case 50.

A-2. Configuration of Rear Wheel Rotation Speed Detecting Device The gear case 50 is provided with a rotation speed detection sensor 81 constituting the rear wheel rotation speed detecting device 80 according to the present invention. As shown in FIGS. 4 and 5, the sensor 81 is inserted into the inside of the gear case 50 from the outside at the rear end of the cylindrical portion 53 of the gear case 50, and is detachably mounted by screws 82. The sensor 81 is mounted on a horizontal line passing through the axis of the case main body 51, and is located above the inlet 57. The tip of the sensor 81 is formed obliquely along the tooth surface 71a of the first rear gear 71 on the drive shaft 30 side of the rear bevel gear 70.
The sensor 81 is mounted on the gear case 50 such that the tip thereof is opposed to the tooth surface 71 a on the side of the first rear gear 71. A space between the sensor 81 and the case main body 51 is hermetically sealed by a seal ring 83.

Here, the sensor 81 is connected to the first rear gear 7.
This is an electromagnetic sensor in which a permanent magnet and a coil are combined so that a closed circuit is sequentially formed by two teeth of one fixed pitch tooth. In this case, the first rear gear 71
A change in magnetic flux when the teeth of the rear gear 71 cross the sensor 81 due to the rotation of the first gear 71 is detected by a coil.
Is calculated. Then, based on the rotation speed of the first rear gear 71 calculated by the sensor 81, the rotation speed of the rear wheel 13 is calculated next. In this case, the output signal of the sensor 81 (the rotation speed of the first rear gear 71) is sent to the vehicle speed meter 7 via the cable 84, and the vehicle speed based on the rotation speed of the rear wheel 13 is displayed on the vehicle speed meter 7. The cable 84 is shown in FIG.
As shown in FIG. 1, the front fork 12 extends forward along the lower surface of the rear fork 12 and is connected to the vehicle speed meter 7. Since the cable is crawled under the rear fork 12, the cable 84
Is not so noticeable and is preferable in appearance.

A-3. The rotation of the operation engine 3 of the embodiment is transmitted to the drive shaft 30 via the transmission 20 and the middle bevel gear 40, and the rotation of the drive shaft 30 is transmitted to the rear wheel 13 via the rear bevel gear, so that the rear wheel 13 rotates. Rear wheel 13
The motorcycle 1 travels forward by the rotation of.
When the rear wheel 13 swings up and down relatively to the vehicle body frame 2 following the unevenness of the road surface, the swing is buffered by the rear cushion unit 15. Even when the drive shaft 30 is rotating, the second drive shaft 32 swings up and down with respect to the first drive shaft 31 via the universal joint 35, and further, the second and third drive shafts Relative swings of the gears 32 and 33 via the gear-type flexible shaft coupling 36 are allowed.

The sensor 81 detects the rotation speed of the first rear gear 71 formed at the rear end of the third drive shaft 33. The output signal of the sensor 81 (the rotation speed of the first rear gear 71) is transmitted via a cable 84 to the vehicle speed meter 7
The vehicle speed based on the rotation speed of the rear wheel 13 is displayed on the vehicle speed meter 7.

In this embodiment, the tooth surface 71a of the first rear gear 71 on the drive shaft 30 side of the rear bevel gear 70 is a variable element for detecting the rotation speed of the rear wheel 13. Therefore, it is not necessary to newly provide a variable element for detecting the rotation speed of the rear wheel 13, and an increase in the number of components and manufacturing steps can be suppressed. Further, since the first rear gear 71 has a relatively large thickness with respect to the diameter, no deformation occurs even when the rotational speed fluctuates rapidly. Therefore, the distance between the sensor 81 and the tooth surface 71a is always kept constant. Also, only the second rear gear 72 is interposed between the first rear gear 71 and the rear wheel 13,
Their rotations are transmitted almost directly. For these reasons, a detection error hardly occurs in the sensor 81.

Further, since the sensor 81 is detachably attached to the gear case 50 with the screw 82, maintenance such as inspection and replacement of the sensor 81 can be easily performed.

The oil level of the gear oil filled in the gear case 50 from the inlet 57 is lower than the inlet 57. Since the sensor 81 is located above the injection port 57, the sensor 81 does not immerse in the gear oil filled in the gear case 50. Therefore, the sensor 81 is prevented from being affected by the gear oil and causing a detection error.

B. 4. Modification Examples The present invention is not limited to the above-described embodiment, and for example, various modifications as described below are possible. The mounting position of the sensor 81 is not limited to the side of the first rear gear 71, but may be up or down. A sensor 81 is provided for the second middle gear 42 constituting the middle side bevel gear 40, and the second middle gear 42
Is a variable element of the rotation speed of the rear wheel 13. The sensor 81 is an optical sensor composed of a combination of a light emitting element and a light receiving element. The sensor 81 is connected to the vehicle speed meter 7 to detect the vehicle speed. For example, the sensor 81 is used as a device for detecting the rotation speed of the rear wheel when an anti-skid device or traction control is provided.

[0024]

As described above, according to the present invention, the variable element for detecting the rotation speed of the rear wheel is the gear on the drive shaft side of the bevel gear connecting the drive shaft and the rear wheel, and this gear is rotated. Since the detection is performed by the speed detection sensor, it is possible to suppress the increase in the number of manufacturing processes and the number of parts, and it is possible to prevent a detection error from occurring. Also, maintenance is facilitated by detachably mounting the sensor on a gear case that covers the bevel gear.

[Brief description of the drawings]

FIG. 1 is an overall side view of a motorcycle including a rear wheel rotation speed detecting device according to an embodiment of the present invention.

FIG. 2 is a rear side view of the motorcycle.

FIG. 3 is a partial plan view of the transmission.

FIG. 4 is a side view showing a mounted state of the rear wheel rotational speed detecting device.

FIG. 5 is a sectional view taken along line VV of FIG. 4;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Motorcycle, 3 ... Engine, 30 ... Drive shaft, 33 ... Third drive shaft, 50 ... Gear case, 70 ... Rear bevel gear, 71 ... First rear gear (gear on drive shaft side), 71a ... Tooth surface , 80 ...
Rear wheel rotation speed detection device, 81 ... rotation speed detection sensor.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) G01P 3/488 B60T 8/00 B62M 17/00 B62M 25/00

Claims (2)

(57) [Claims] 1. A drive shaft that rotates with the rotation of an engine is connected to a rear wheel via a bevel gear, and a rotational speed of the gear is detected by opposing a tooth surface of a gear on the drive shaft side of the bevel gear. A rear wheel rotational speed detecting device for a motorcycle, comprising a rotational speed detection sensor. 2. The bevel gear is covered with a gear case,
The rear wheel rotation speed detecting device according to claim 1, wherein the rotation speed detection sensor is detachably mounted on the gear case.