JP3802148B2 - Motorcycle travel speed detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motorcycle traveling speed detection device using a sensor for detecting a change in magnetic flux.
[0002]
[Prior art]
As a conventional traveling speed detection device of this type, for example, there is one disclosed in JP-A-4-163286. The traveling speed detection device disclosed in this publication employs a structure that detects the rotation of the output shaft of a mission that rotates with the rear wheels by a sensor that detects a change in magnetic flux.
[0003]
More specifically, this travel speed detecting device has a bracket attached to a portion of the engine mission case where the output shaft of the mission protrudes, and the sensor is attached to the bracket. The sensor includes a permanent magnet disk that engages with and rotates with the output shaft, and a pickup IC that faces the outer peripheral surface of the disk, and an electric pulse is generated when the output shaft rotates. It is configured.
[0004]
In addition, this traveling speed detection device is provided with a cover for protecting the sensor from pebbles, muddy water, and the like that the front wheels have jumped up on the transmission case.
[0005]
[Problems to be solved by the invention]
However, the conventional traveling speed detection device configured as described above has a large number of parts for detecting the rotation of the output shaft, and has a limit in reducing the cost. The rotation detection parts include a permanent magnet disk, a part for engaging the disk with an output shaft, and a part for rotatably supporting the disk. In addition, the fact that a cover for protecting the sensor must be provided also causes an increase in cost.
[0006]
Such a problem can be solved to some extent by fixing a permanent magnet disk to the end of the output shaft. However, since the bracket is interposed between the pickup IC and the transmission case, a new problem that the position of the pickup IC is easily displaced with respect to the permanent magnet disk fixed to the output shaft supported by the transmission case. Occurs. That is, when the mounting position of the bracket with respect to the transmission case and the mounting position of the pickup IC with respect to the bracket are slightly deviated from the design position due to manufacturing errors or the like, and the interval between the pickup IC and the permanent magnet disk is out of the specified range, The accuracy of the traveling speed detected by this sensor decreases.
[0007]
As a sensor for detecting a change in magnetic flux, there is a structure for rotating the permanent magnet as described above, and a structure for causing the detection portion to face the irregularities on the surface of the rotating body. The same problem arises even if diverted to the travel speed detection device.
[0008]
The present invention has been made to solve such problems, and it is possible to reduce the number of parts while reducing the number of parts while keeping the distance between the detection part of the sensor and the detected object within a specified range. An object of the present invention is to provide a motorcycle traveling speed detection device.
[0009]
[Means for Solving the Problems]
A traveling speed detection device for a motorcycle according to the present invention includes an engine including a cylinder and a crankcase, a carburetor disposed at the rear of the cylinder and provided on an upper portion of the crankcase, and attached to the crankcase. A sensor including a detection unit for detecting a change in magnetic flux;
A crankshaft supported by the crankcase, an intermediate shaft connected to the crankshaft located on the rear side of the crankshaft, a magnetic gear provided on the intermediate shaft, and a vehicle body from the intermediate shaft A traveling speed detection device for a motorcycle, comprising a rear side and an output shaft that is positioned at substantially the same height, is connected to an intermediate shaft, and rotates together with the rear wheel, the rear side of the vehicle body from the cylinder in the crankcase An upper wall that is inclined rearwardly downward is provided above the intermediate shaft and the output shaft and below the carburetor, and the sensor is attached to the upper wall so as to be inclined forwardly downward, and a detection portion of the sensor Is opposed to the teeth of the magnetic gear .
According to the present invention, a sensor and a magnetic gear can be supported on one crankcase. In addition, since the magnetic gear as the detected object detected by the sensor can be configured using the gear in the crankcase, a rotating body that is used only for detecting rotation is required. do not do.
[0010]
Further , according to the present invention, the cylinder blocks the pebbles and muddy water splashed by the front wheels from hitting the sensor .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a motorcycle traveling speed detection device according to the present invention will be described in detail with reference to FIGS.
FIG. 1 is a side view of a traveling speed detection device according to the present invention, which is a partially broken view of an engine. FIG. 2 is a longitudinal sectional view showing an enlarged main part, and FIG. 3 is a transverse sectional view of the mission part. In FIG. 3, the fracture position in FIGS. 1 and 2 is indicated by the line II-II.
[0012]
In these drawings, reference numeral 1 represents a two-cycle engine for a motorcycle according to this embodiment, 2 represents a cylinder disposed on the front side of the vehicle body of the engine 1, 3 represents a crank for rotatably supporting a crankshaft 4. Show the case. This crankcase 3 employs a left and right split type, and supports the balancer shaft 5 and the intermediate shaft 7 and output shaft 8 of the transmission 6 on the rear side of the vehicle body from the cylinder 2 so as to be rotatable. The reference numeral 9 provided at the upper part of the crankcase 3 is a vaporizer.
[0013]
In this embodiment, the balancer shaft 5 adopts a structure in which a columnar body having a semicircular cross section that is horizontally mounted on both lateral walls of the crankcase 3 rotates, and a driven gear 10 fixed to the right end of the vehicle body is provided. It is meshed with the drive gear 11 on the crankshaft 4 side.
In the transmission 6, the rotation of the crankshaft 4 is transmitted to the end of the intermediate shaft 7 on the right side of the vehicle body via a clutch (not shown), and the rear wheel (not shown) is output from the end of the output shaft 8 on the left side of the vehicle body. ), And a gear group 12 having a dog clutch is provided as shown in FIGS. In addition, what is shown with the code | symbol 6a, 6b in FIG. 2 is the shift fork for driving the said dog clutch. In this embodiment, the transmission 6 employs a gear having 6 speeds.
[0014]
The intermediate shaft 7 and the output shaft 8 are rotatably supported by bearings 13 to 16 on the left half 3a and right half 3b of the crankcase 3, respectively. The intermediate shaft 7 has a right end of the vehicle body projecting laterally from the right half 3b in order to connect the clutch. The output shaft 8 has a left end of the vehicle body projecting laterally from the left half 3a, and a sprocket 17 is attached to the projecting end. A rear wheel drive chain (not shown) is wound around the sprocket 17. That is, when the output shaft 8 rotates, the rear wheels also rotate.
[0015]
The gear group 12 includes movable gears 12a to 12c that are spline-fitted to the intermediate shaft 7 and the output shaft 8 and moved by the shift forks 6a and 6b in the axial direction, and the movement in the axial direction is restricted and the intermediate shaft 7 and the fixed position gears 12A to 12F that are rotatable with respect to the output shaft 8.
Among these gears, the motorcycle is located above the position fixed gear 12B on the intermediate shaft 7 side that meshes with the movable gear 12c provided on the output shaft 8 and on the side opposite to the shift forks 6a, 6b (upward). A sensor 18 for detecting the traveling speed is provided. The fixed position gear 12B is formed of a magnetic material such as a steel material, and is formed to have the largest diameter among the gears mounted on the intermediate shaft 7. That is, the gear 12B constitutes a 6-speed pinion in the transmission 6.
[0016]
The sensor 18 is a sensor configured to generate a magnetic pulse by detecting a change in magnetic flux passing through the tip surface of the columnar detection unit 18a, and the tip surface of the detection unit 18a is radially directed to the teeth of the gear 12B. Are attached to the left half 3a of the crankcase 3 so as to face each other. The sensor mounting portion forms a cylindrical portion 20 that extends forwardly downward from the upper wall 19 of the left half 3a below the carburetor 9 and at a position on the rear side of the vehicle body from the cylinder 2 and the balancer shaft 5. A structure in which the detection unit 18a is fitted in the unit 20 is adopted.
[0017]
The cylindrical portion 20 is inclined forward and downward so that the tip surface of the detection portion 18a approaches the tooth tip of the gear 12B while avoiding interference between the balancer shaft 5 and the sensor 18 positioned above the gear 12B. This is to make it happen. Further, in this embodiment, in order to avoid interference between the detection unit 18a and another gear (position-fixed gear 12F on the output shaft 8 side shown in FIG. 3), the front end of the detection unit 18 is directed toward the front end. Therefore, it is formed to become gradually thinner.
[0018]
In order to fix the sensor 18 to the crankcase 3, a structure is adopted in which a flange 18b at the top of the sensor is brought into contact with the upper surface of the upper wall 19 and the flange 18b is fastened to the upper wall 19 with a fixing bolt (not shown). . An O-ring 21 attached to the upper wall 19 is pressed against the lower surface of the flange 18b.
[0019]
In this embodiment, as described above, the sensor 18 is fixed to the crankcase 3 so that the distance between the tip surface and the tooth tip of the gear 12B falls within a predetermined specified range.
[0020]
When the sensor 18 is attached to the crankcase 3 as described above, the position on the intermediate shaft 7 side is fixed together with the movable gear 12c that is spline-fitted to the output shaft 8 during traveling, that is, when the output shaft 8 of the transmission 6 rotates. The type gear 12B rotates, and the magnetic flux passing through the front end surface of the detection unit 18b changes. The sensor 18 converts the change in the magnetic flux into an electric pulse and outputs it to a travel speed calculation / display device (not shown) via the wiring 22 (see FIGS. 1 and 2).
[0021]
Further, since the gear 12B as the object to be detected is rotatably supported by the intermediate shaft 7 supported by the crankcase 3, the sensor 18 and the gear 12B can be supported by one crankcase 3. . Therefore, the mounting position of the sensor 18 does not shift with respect to the gear 12B, and the distance between the two is surely within the specified range.
[0022]
Further, since the gear 12B as the object to be detected is a component part of the transmission 6 provided in the crankcase 3, the rotation is detected by the sensor 18 without providing a rotating body used only for detecting the rotation. Can do. That is, parts can be shared.
Furthermore, since the sensor 18 is attached to the rear side of the vehicle body from the cylinder 2 on the upper wall of the left half 3a of the crankcase 3, the cylinder 2 prevents pebbles and muddy water splashed by a front wheel (not shown) from hitting the sensor 18. Can be blocked. In addition, since the sensor 18 is disposed below the vaporizer 9, the sensor 18 is covered by the vaporizer 9 and is protected by this.
[0023]
In addition, when the configuration in which the detection unit 18b is opposed to the gear 12B as shown here, the gear 12B has a relatively large diameter because it forms a 6-speed pinion, and the gear 12B meshes with the gear 12B. Since the diameter of the movable gear 12c is small, the distance between the detection unit 18a of the sensor 18 and the movable gear 12c adjacent thereto is widened, and the arrangement space of the sensor 18 can be increased.
Further, since the distance between the tooth tip and the upper wall 19 of the crankcase 3 is narrower than other gears, a small sensor can be used. Moreover, since the gear 12B is positioned relatively on the left side of the vehicle body, the gear 12B is far away from the clutch provided on the opposite side, and the mounting seat surface of the sensor 18 can be easily processed.
[0024]
In this embodiment, a configuration is adopted in which the detection unit 18a of the sensor 18 is opposed to the gear 12B serving as the 6-speed pinion of the transmission 6. However, the gear that opposes the detection unit 18a rotates with the output shaft 8. Any can be used. That is, it is possible to adopt a configuration in which the sensor 18 detects the rotation of the gear indicated by reference numeral 12A in FIG.
[0025]
【The invention's effect】
As described above, according to the traveling speed detection device for a motorcycle according to the first aspect of the present invention, the sensor and the magnetic gear can be supported on one crankcase. The distance between the two is surely within the specified range. For this reason, the traveling speed can be detected with high accuracy.
In addition, since the magnetic gear as the object to be detected detected by the sensor uses the gear in the crankcase, a rotating body that is used only for detecting rotation is provided as in the prior art. Since it is not necessary, the number of parts is reduced.
[0026]
Therefore, the number of parts can be reduced and the cost can be reduced while keeping the distance between the sensor and the object to be detected within the specified range.
[0027]
Furthermore , according to the traveling speed detection device for a motorcycle according to the present invention , the cylinder blocks the pebbles and muddy water splashed by the front wheels from hitting the sensor. Therefore, a cover for protecting the sensor from the scattered matter is provided. It is not necessary.
Therefore, the manufacturing cost can be further reduced.
[Brief description of the drawings]
FIG. 1 is a side view of a traveling speed detection device according to the present invention.
FIG. 2 is an enlarged longitudinal sectional view showing a main part.
FIG. 3 is a cross-sectional view of a mission unit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Cylinder, 3 ... Crankcase, 3a ... Left half part, 3b ... Right half part, 6 ... Mission, 7 ... Intermediate shaft, 8 ... Output shaft, 12 ... Gear group, 12a-12c ... Mobile type Gears, 12A to 12F ... Position-fixed gears, 18 ... Sensor, 18a ... Detection unit, 19 ... Upper wall.

Claims (1)

An engine including a cylinder and a crankcase;
A carburetor located at the rear of the cylinder and provided at the top of the crankcase;
A sensor attached to the crankcase and including a detector for detecting a change in magnetic flux;
A crankshaft supported by the crankcase;
An intermediate shaft located on the rear side of the crankshaft and connected to the crankshaft;
A magnetic gear provided on the intermediate shaft;
An output shaft positioned on the rear side of the vehicle body and substantially at the same height from the intermediate shaft, connected to the intermediate shaft, and rotating with the rear wheel;
A traveling speed detection device for a motorcycle equipped with
Provided on the rear side of the vehicle body from the cylinder in the crankcase, above the intermediate shaft and the output shaft, and below the carburetor, is provided with an upper wall that slopes rearwardly downward,
The sensor is attached to the upper wall so as to incline forward and downward ,
A traveling speed detecting device for a motorcycle, wherein a detecting portion of the sensor is opposed to teeth of the magnetic gear .

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