JPH0972927A - Rear-wheel rotary-speed detector of motor-bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the increase in new manufacturing processes and number of parts for detecting the speed of rear wheels and the production of detection errors. SOLUTION: A sensor 81 is brought close to a tooth surface 71a of a first rear gear 71 on the side of a drive shaft 30 constituting a bevel gear 70 on the rear side linking the drive shaft 30 and rear wheels and mounted on a gear case 50. The first rear gear 71 on the side of the drive shaft 30 is made to be the variation element of the rotary speed of the rear wheel. Thus, the increase in manufacturing steps and number of parts is suppressed, and the detection errors are made hard to produce.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear wheel rotation speed detecting device for a motorcycle, which is used for an anti-skid device, a vehicle speed meter, etc., and particularly to an automatic device 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 on the basis of the rotational speed of a rear wheel, which is a driving wheel, and changes in the rotational speed to prevent the rear wheel from slipping during sudden braking. Some vehicle speed meters display the vehicle speed based on the rotational 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 been conventionally used. However, this method
This has led to an increase in the number of parts, such as providing a rotor for detecting the rotation speed on the rear wheel and requiring a member for mounting the sensor. In addition, it is necessary to adjust the relative positional relationship between the sensor and the rotor each time maintenance of the rear wheels such as tire replacement is performed, which causes a decrease in detection accuracy. As described above, the method of directly detecting the rotation speed of the rear wheel has various problems.

Therefore, a technique for solving such a problem is disclosed in Japanese Utility Model Publication No. 51-68576 and Japanese Patent Publication No. 5-426.
No. 31 is proposed. All of these are applied to motorcycles equipped with a shaft drive type transmission mechanism for secondary transmission. The former is a sensor that detects the rotational speed of the gear on the rear wheel side in the bevel gear that connects the drive shaft and the rear wheel ( It is detected by the electromagnetic pickup). Further, in the latter case, a sensor detects the rotation speed of a rotary shaft interposed between the output shaft of the engine and the drive shaft. In either case, the rotation speed of the rear wheel is indirectly detected and the maintenance of the rear wheel is not affected.

[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 circumference of the gear on the rear wheel side, and these teeth are used as a variable element of the rotational speed. That is, a large number of teeth for detecting the rotation speed must be newly formed on the outer circumference of the gear. Therefore, the number of manufacturing processes 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, it easily bends when the rotational speed suddenly changes. When the gear is deformed in this way, the distance between the sensor and the tooth surface changes, which causes a detection error, albeit instantaneously.

On the other hand, in the latter case, a rotor having a large number of teeth with a constant pitch formed on the outer circumference as a variable element of the rotation speed is provided on the rotation shaft interposed between the output shaft of the engine and the drive shaft. It must be fixed, and an increase in the number of parts cannot be denied. Further, since the meshing portion of the gear and the cross joint are provided between the rear wheel and the sensor, a detection error is likely to occur due to the backlash and the slight clearance that they have.

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

[0007]

The present invention has been made to achieve the above object. According to the invention of claim 1, the drive shaft rotating with the rotation of the engine is provided with a bevel gear. It is characterized in that a rotation speed detection sensor, which is connected to the rear wheel and faces the tooth surface of the drive shaft side gear of the bevel gear, detects the rotation speed of the gear. The invention according to claim 2 is characterized in that the bevel gear is covered with a gear case, and the rotation speed detection sensor is detachably attached to the gear case.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. A. One Embodiment A-1. Configuration of Motorcycle FIG. 1 is an overall side view of a motorcycle 1 equipped with a rear wheel rotation speed detection device according to an embodiment of the present invention. In this case, the forward direction (front) of the motorcycle 1 is the left side. In FIG. 1, reference numeral 2 is a vehicle body frame, and a vertically installed 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 vehicle body frame 2 from the front via a bracket (not shown). A vehicle speed meter 7 is attached to the front part of the fuel tank 4. A front fork 8 incorporating a front cushion unit (not shown) is rotatably attached to the front end of the body frame 2. A handle 9 is attached to the upper end of the front fork 8.
Is fixed, and the front wheel 10 is rotatably supported at the lower end.

As shown in FIG. 2, a pair of left and right rear forks 12 are provided at the rear of the body frame 2 via a pivot 11.
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 rear cushion unit 15 damps the swing of the rear wheel 13.

FIG. 3 shows a part of a constant mesh type transmission 20 which is connected to the engine 3.
This transmission 20 has a transmission case 21.
The main shaft 22 and the mission drive shaft 23 rotatably supported by the two shafts 22 and 23.
Sets of drive gears 2 that are incorporated into and mesh with each other
4 and driven gear 25, and a change mechanism (not shown). The main shaft 22 is connected to a clutch (not shown), and the rotation of the engine 3 is transmitted when the clutch is engaged and rotates. The rotation is transmitted to the mission drive shaft 23 through the meshing of the drive gear 24 and the driven gear 25. The change mechanism changes the transmission path from the drive gear 24 to the driven gear 25 to change the rotation speed of the mission drive shaft 23.

For the secondary transmission of power from the transmission 20 to the rear wheels 13, a shaft drive type transmission mechanism using a drive shaft 30 is adopted. 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 the first, second, and third drive shafts 31, 3 from the upstream side (front side of the vehicle body).
It is divided into 2 and 33, and these are connected. At the end of the mission drive shaft 23,
The first drive shaft 31 is connected via the middle-side bevel gear 40.

The middle-side bevel gear 40 includes a first middle gear 41 incorporated at one end of the mission 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. Composed of and. The first middle gear 41 is fixed to one end of the mission drive shaft 23, and is rotatably supported by the mission case 21 together with the mission drive shaft 23 via a bearing 43. The first drive shaft 31 extends rearward in a substantially horizontal direction orthogonal to the mission drive shaft 23, and is rotatably supported by a lid member 26 fitted in the mission case 21 via a bearing 34. . A second drive shaft 32 is swingably connected to a rear end of the first drive shaft 31 via a universal joint 35. At the rear end of the second drive shaft 32, as shown in FIG. 5, a third drive shaft 33 is provided via a gear type flexible shaft coupling 36.
Is connected.

A second drive shaft 32 is housed 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 swing together 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 includes a disc-shaped case main body 51 to which a holding plate 52 is fixed, and a case main body 51 having a cylindrical portion 53 formed at a front end thereof. 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 shaft center of the case body 51 via a sleeve 60. The right end of the axle 61 is fixed to a not-shown right rear fork. A hub 62 that constitutes 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. Has been done. 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 disc shape, and a collar 73 is integrally fitted to the shaft center. The second rear gear 72 itself has a gear case 50.
Through the bearing 74 to the holding plate 52 of the
3 is rotatably supported in the gear case 50 by interposing a 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 portion 76 formed inside is integrally connected to the hub 62. That is, the second rear gear 72 and the rear wheel 13 rotate together.

In the gear case 50, a seal ring 54,
It is liquid-tightly sealed by 55, and the gear case 50 is filled with gear oil. As shown in FIG.
The case main body 51 is formed with a gear oil inlet 57 that 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 Rotational Speed Detection Device The gear case 50 is provided with a rotation speed detection sensor 81 that constitutes a rear wheel rotation speed detection device 80 according to the present invention. As shown in FIGS. 4 and 5, the sensor 81 is inserted into the gear case 50 from the outside at the rear end of the tubular portion 53 of the gear case 50, and is detachably attached by a screw 82. The sensor 81 is attached on a horizontal line passing through the axis of the case body 51, and is located above the injection port 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 attached to the gear case 50 so that the tip of the sensor 81 closely faces the lateral tooth surface 71a of the first rear gear 71. A seal ring 83 liquid-tightly seals between the sensor 81 and the case body 51.

Here, the sensor 81 is 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 constant pitch tooth. In this case, the first rear gear 71
The change in magnetic flux when the teeth of the rear gear 71 cross the sensor 81 due to the rotation of the
Is configured to calculate the rotation speed of the. 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 wheels 13 is displayed on the vehicle speed meter 7. The cable 84 is shown in FIG.
As shown in FIG. 3, the rear fork 12 is connected to the vehicle speed meter 7 after being extended forward along the lower surface of the rear fork 12. Since it is crawled under the rear fork 12, the cable 84
Is less noticeable and is preferable in appearance.

A-3. The rotation of the engine 3 of the embodiment is transmitted to the drive shaft 30 via the transmission 20 and the middle-side bevel gear 40, and the rotation of the drive shaft 30 is transmitted to the rear wheel 13 via the rear-side bevel gear and the rear wheel 13 is rotated. Rear wheel 13
When the vehicle rotates, the motorcycle 1 travels forward.
When the rear wheel 13 swings up and down relative to the body frame 2 following the unevenness of the road surface, the swing is damped by the rear cushion unit 15. Even if 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 rocking of 32 and 33 is permitted via the gear type flexible shaft coupling 36.

The sensor 81 detects the rotational 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 the cable 84 to the vehicle speed meter 7
The vehicle speed based on the rotation speed of the rear wheels 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 used as a variable element for detecting the rotational 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 the increase in the number of parts and the manufacturing process can be suppressed. Further, since the first rear gear 71 has a relatively large thickness with respect to the diameter, the first rear gear 71 does not deform even when the rotational speed changes abruptly. Therefore, the distance between the sensor 81 and the tooth surface 71a is always kept constant. Moreover, only the second rear gear 72 is interposed between the first rear gear 71 and the rear wheel 13,
The rotations of the two are almost directly transmitted to each other. For these reasons, the detection error is unlikely to occur 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 through the inlet 57 is below the inlet 57. Since the sensor 81 is located above the inlet 57, the sensor 81 is not immersed 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. Modifications The present invention is not limited to the above-described embodiment, and various modifications such as the following are possible. The mounting position of the sensor 81 is not limited to the side of the first rear gear 71, but may be above or below. A sensor 81 is provided for the second middle gear 42 that constitutes the middle-side bevel gear 40, and the second middle gear 42 is provided.
Is a variable element of the rotational speed of the rear wheel 13. The sensor 81 is of an optical type including a combination of a light emitting element and a light receiving element. Although the sensor 81 is connected to the vehicle speed meter 7 to detect the vehicle speed, it is used, for example, as a rear wheel rotational speed detecting device when an anti-skid device or a traction control is installed.

[0024]

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

[Brief description of drawings]

FIG. 1 is an overall side view of a motorcycle including a rear wheel rotation speed detection 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 a transmission.

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

5 is a cross-sectional view taken along the line VV of FIG.

[Explanation of symbols]

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

Claims (2)

[Claims] 1. A drive shaft, which rotates with the rotation of an engine, is connected to a rear wheel through a bevel gear, and detects a rotational speed of the gear, facing a tooth surface of the drive shaft side gear of the bevel gear. A rear wheel rotation speed detection device for a motorcycle, comprising a rotation speed detection sensor. 2. The bevel gear is covered with a gear case,
The rear wheel rotation speed detection device according to claim 1, wherein the rotation speed detection sensor is detachably attached to the gear case.