JPS60253876A - Wheel angular velocity reduction sensor - Google Patents

Abstract

PURPOSE:To maintain a specified performance of a sensor avoiding the resonance by setting the natural frequency of a wheel angular velocity reduction sensor in the axial direction of a flywheel as provided in the support system of a wheel less than that in the direction of longitudinally bending the support system. CONSTITUTION:A wheel angular velocity reduction 21 is made up of an acceleration gear unit 45 and a cam mechanism 73 arranged inside and outside a box body 22a respectively, a fly wheel 72 and an output lever mechamism 74. Then, the natural frequency of a sensor 21 in the axial direction of the fly wheel 72 determined by the angle of inclination of the bottom in a cam concave, the rotary radius of a thrust ball 84, the lever ratio when a lever 91 is swung with a press plate 89 on a valve bdy 67 as fulcrum, the spring constant of a spring 94 and the like is set less enough than that in the direction of longitudinally bending a front fork 9. Thus, the sensor function can be fully performed avoiding resonance with the support system at the braking without adding a special member.

Description

Detailed Description of the Invention A1 Purpose of the Invention (1) Industrial Application Field The present invention is used in anti-lock control devices for motorcycles, automobiles, etc. to detect angular deceleration of a wheel exceeding a certain value. A wheel angular deceleration sensor, in particular a flywheel rotatably and slidably supported on a drive shaft interlocked with the wheel; transmits the rotational torque of the drive shaft to the flywheel, and When angular deceleration occurs, the support system for the wheel is composed of a cam mechanism that causes overrun rotation in the flywheel and gives it an axial displacement, and a return spring that applies an axial retraction force to the flywheel. The present invention relates to a wheel angular deceleration sensor installed in a vehicle.

(2) Prior art This type of wheel angular deceleration sensor is known, for example, from Japanese Patent Application Laid-open No. 56-1
This is already known as described in Japanese Patent No. 20440.

(3) Problems to be Solved by the Invention Conventional sensors of this type may suffer from performance deterioration during wheel braking, and the inventors have discovered the following as one of the causes. That is, if the anti-lock control device is repeatedly activated and released while the wheels are being braked, the wheel support system will bend backwards when the braking force is applied, and will bend backwards when the braking force is released. Due to the elasticity of the wheel, it is bounced forward, and this causes rotational fluctuations in the wheels, so similar rotational fluctuations, or vibrations, are applied to the drive shaft of the sensor that is linked to the wheels, and the sensor resonates with the vibrations. At that time, its performance deteriorates.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a simple and effective sensor capable of maintaining a predetermined performance even if longitudinal vibration occurs in a wheel support system.

B0 Structure of the Invention (1) Means for Solving Problems The present invention is characterized in that the natural frequency of the sensor in the flywheel axial direction is set to be smaller than the natural frequency of the wheel support system in the longitudinal bending direction. shall be.

(2) Effect Even if the supporting system of the working wheel bends back and forth, causing rotational fluctuations in the wheel, and the drive shaft is vibrated, the sensor, whose natural frequency is smaller than that of the supporting system, will experience only a small amount of vibration. , and no resonance occurs.

(3) Examples An embodiment of the present invention will be described below with reference to the drawings.

First, in FIG. 1, the motorcycle 1 is equipped with a pair of left and right front wheel brakes 3f, 3f for braking the front wheels 2'', and one rear wheel brake 3r for braking the rear wheel 2r. Axial brake 3f.

3f is operated by the output hydraulic pressure of the front mask cylinder 5f operated by the brake lever 4, and the rear wheel brake 2r is operated by the output hydraulic pressure of the front mask cylinder 5f operated by the brake pedal 6.
It is operated by the output hydraulic pressure of r, but especially the front wheel brake 3
The braking oil pressure of f, 3 (is controlled by an anti-lock control device 7).

In FIGS. 2 and 3, the hub 8 of the front wheel 2f is supported on an axle 10 fixed to the lower end of the front fork 9 via a bearing 11.11. A pair of front wheel brakes 3f, 3f arranged on both sides of the front wheel 2f are both
It consists of a brake disc 12 fixed to the end face of the hub 8 and a brake caliper 14 supported by the front fork 9 via a bracket 13 while straddling the brake disc 12.The brake caliper 14 has an input port 1. When the output hydraulic pressure of the mask cylinder 5f is supplied to the mask cylinder 5f, the mask cylinder 4a is activated to clamp the brake disc 12 and apply braking force to the front wheel 2f. Thus, the front wheel 2f corresponds to the wheel of the present invention, and the front fork 9 corresponds to its support system.

An anti-lock control device 7 is interposed in a hydraulic conduit 15 connecting the output port 5fa of the front mask cylinder 5f and the manual boat 14.21 of each brake caliper 14.

The anti-lock control device 7 has a hydraulic pump 16 driven by the front wheel 2f during braking, and a control hydraulic chamber 18 into which the discharge pressure of the hydraulic pump 16 is introduced, and the hydraulic conduit 15
A modulator 17 interposed between the control hydraulic chamber 18 and the oil tank 19, a normally-closed exhaust pressure valve 20 interposed in the communication path between the control hydraulic chamber 18 and the oil tank 19, and a front wheel 2 detecting that a lock state is approaching. The main component is an inertial wheel angular deceleration sensor 21 that opens the exhaust pressure valve 20 when the exhaust pressure valve 20 opens.

The casing 22 includes a cup-shaped housing 22a and this housing 2.
A lid body 22 that fits into the open end of 2a and is fixed with screws 23
b, the casing 22a is disposed so as to fit in a recess 8a formed on one end surface of the hub 8, and a lid 22b
is connected to the axle 10 via a cylindrical shaft Z4 fixed at its center.
The front fork 9 is supported by the front fork 9 and connected to the front fork 9 by a rotation preventing means so as not to rotate around the axle 10.

The rotation preventing means is arbitrary, but for example, a bolt 25 for fixing the bracket 13 to the front fork 9
(See Figure 2) is appropriate.

The hydraulic pump 16 includes a camshaft 26 disposed parallel to the axle 10, a bushing rod 27 disposed with its inner end facing an eccentric cam 26a formed on the camshaft 26, and q
The pump piston 28 contacts the outer end of the bushing rod 27, the actuating piston 29 contacts the outer end of the pump piston 28, and the return spring 30 biases the bushing rod 27 away from the eccentric cam 26a. configured.

The bushing rod 27 and the pump piston 28 are slidably fitted into a first ring hole 33 formed in the lid body 22b so as to define an inlet chamber 31 and an outlet chamber 32 on their respective outer peripheries. Further, a plug body 34 is fitted into the outer end of the first cylinder hole 33 so as to define a pump chamber 35 between it and the pump piston 28, and a hydraulic chamber 36 is defined in the plug body 34. The actuating piston 29 is slidably engaged with the actuating piston 29 .

The inlet chamber 31 communicates with the oil tank 19 via a conduit 37, and also communicates with the pump chamber 35 via a suction valve 38, and the pump chamber 35 communicates with the outlet chamber 32 via a one-way seal member 39 having a discharge valve function. will be communicated to. Further, the hydraulic chamber 36 is connected to the upstream pipe 15a of the hydraulic conduit 15 so as to constantly communicate with the output pump 5fa of the front mask cylinder 5[.

As shown in FIG. 4, the camshaft 26 is supported by the lid body 22b via hair rings 40, 40', and rotatably supported on the cylindrical shaft 24 via hair rings 41, 41. The drive shaft 42 is driven by a pair of gears 43 and 44, and the drive shaft 42 is driven by the front wheels 2f via a speed increasing gear device 45, which will be described later. in the end,
The camshaft 26 is driven at an increased speed by the front wheel 2f.

A meter drive gear 49 is fixed to the outer end of the camshaft 26 opposite to the gear 44, and this gear 4 meshes with a driven gear 50 connected to an input shaft of a speedometer 51 of the motorcycle.

The modulator 17 includes a decompression piston 46, a fixed piston 47 that receives one end of the decompression piston 46 and restricts its retraction limit, and a fixed piston 47 that connects the decompression piston 46 to the fixed piston 47.
Both pistons 46 and 47 are slidably fitted into a second cylinder hole 52 formed adjacent to the first cylinder hole 33 in the lid body 22b.

In the second cylinder hole 52 , the pressure reducing piston 46 defines a control hydraulic chamber 18 between the inner end wall of the second cylinder hole 52 and an output hydraulic chamber 55 between the fixed piston 47 and the inner end wall of the second cylinder hole 52 .
The fixed piston 47 also defines an input hydraulic pressure chamber 54 on its outer periphery.

The input hydraulic chamber 54 communicates with the hydraulic chamber 36 of the hydraulic pump 16 via an oil passage 56, and the output hydraulic chamber 55 communicates with the hydraulic conduit 15 so as to constantly communicate with the input port 14a of the front wheel brakes 3f, 3f. is connected to the downstream pipe 15b of
The control hydraulic chamber 18 is connected to the hydraulic pump 16 via an oil passage 57.
It communicates with the outlet chamber 57 of.

The fixed piston 47 includes a valve chamber 58 that constantly communicates with the input hydraulic pressure chamber 54 and a valve hole 59 that communicates the valve chamber 58 with the output hydraulic chamber 55. A valve body 60 to be obtained and a valve spring 61 that biases the valve body 60 toward the closing side are housed. A valve opening rod 62 for opening the valve body 60 is provided protruding from one end surface of the pressure reducing piston 46, and this valve opening rod 62 opens the valve body 60 when the pressure reducing piston 46 is located at the backward limit. keep it in good condition.

The outer opening of the second cylinder hole 52 is closed with an end plate 63 fixed to the lid body 22b, and the fixed piston 47 is operated by the elastic force of the return spring 48 or the output hydraulic chamber 54.5.
The hydraulic pressure introduced into the end plate 5 keeps the end plate 63 in contact with the end plate 63 at all times.

The hydraulic pump 16 and modulator 17 are arranged on the rear side of the front fork 9, like the brake caliper 14, in order to protect them from obstacles from the front of the vehicle.

The exhaust pressure valve 20 is composed of a valve seat member 65 fitted into a stepped cylinder hole 64 of the lid body 22b, and a valve body 67 that slides onto the valve seat member 65 to open and close the valve hole 66 thereof. be done. The valve seat member 65 defines an artificial chamber 68 in the small diameter part of the stepped cylinder hole 64 and an outlet chamber 69 in the large diameter part, and both chambers 6
8.69 are communicated through the valve hole 66. Further, the inlet chamber 68 communicates with the control hydraulic chamber 18 of the modulator 17 via an oil passage 20, and the outlet chamber 69 communicates with the inlet chamber 31 of the hydraulic pump 16 via an oil passage 71. in the end,
The outlet chamber 69 is in communication with the oil tank 19.

The wheel angular deceleration sensor 21 includes a speed increasing gear device 45 manually operated by the front wheel 2f, a flywheel 72 rotated by the speed increasing device 45, and converts overrun rotation of the flywheel 72 into an axial displacement. The exhaust pressure valve 2 is operated in response to the axial displacement of the cam mechanism 73 and the flywheel 72.
an output lever mechanism 74 capable of operating 0;
The speed increasing gear device 45 is disposed on the outer side of the rear wall of the housing 22a,
The cam mechanism 73, flywheel 72, and output reno mechanism 74 are arranged within the housing 22a.

The speed increasing gear device 45 includes a ring gear 76 spline-fitted to the inner peripheral surface of an annular support portion 75 protruding from the outer surface of the rear wall of the housing 22a, and a rotatably supported shaft 77 on the knob 8. A plurality of planetary gears 78 that mesh with the ring gear 76
and a sun gear 79 formed at one end of the drive shaft 42 and meshing with the planetary gear 78, forming a planetary gear type configuration.

A sealing member 89 is interposed between the back wall of the housing 22a and the drive shaft 42 passing through it, and a sealing member 81 is also interposed between the hub 8 of the annular support portion 75 of the housing 22a. be done.

In order to prevent rotation of the front wheels 2f from being hindered even if the drive shaft 42 becomes stuck for some reason, at least one of the constituent gears of the speed increasing gear device 45, for example, the planetary gear 78, is set to a specified value. It is made of synthetic resin and has a fuse function that ruptures when it is subjected to excessive torque.

By the way, the speedometer 51 is connected to the speed increasing gear device 4.
5, so if the synthetic resin gear 78 were to break, the speedometer 51 would not operate despite the rotation of the front wheels 2f. From this, the above-mentioned failure can be known.

The cam mechanism 73 is connected to the drive shaft 42 as shown in FIG.
a driving cam plate 82 fixed to the drive cam plate 82; a driven cam plate 83 disposed opposite to the driving cam plate 82 so as to be relatively rotatable;
Cam recesses 82a and 83a on opposing surfaces of both cam plates 82 and 83
The thrust hole 84 is engaged with the thrust hole 84. The force J/recess 82a of the drive cam plate 82 is inclined so that its bottom surface becomes shallow toward the rotation direction 85 of the drive shaft 42, and the cam recess 83a of the driven cam plate 83 is inclined so that its bottom surface becomes shallow toward the rotation direction 85 of the drive shaft 42. It slopes downward.

Therefore, in the normal case where the driving cam plate 8 takes a position on the driving side with respect to the driven cam plate 83, the thrust ball 84 is engaged with the deepest part of both the cam recesses 82a, 82a, and the driving cam plate 82 simply transmits the rotational torque received from the drive shaft 42 to the driven cam plate 83 and does not cause relative rotation between the two cam plates 82 and 83. When you run,
Relative rotation occurs between both cam plates 82 and 83, and the thrust ball 84 rolls up the sloped bottom surfaces of both cam recesses 82a and 83a, applying thrust to both cams 82 and 83, thereby causing the driven cam plate to rotate. 82 is caused to undergo axial displacement in the direction away from the drive cam plate 82.

The thrust pole 84 suddenly moves into the cam recess 82a.

In order to reduce the impact when the rolling ratio of 83a is reached,
At least one component of the cam mechanism 73 is made of synthetic resin, and in the illustrated example, the driven cam plate 83 and the thrust pole 84 are made of synthetic resin. As a result, vibration of the cam mechanism 73 due to impact is prevented and its durability is improved.

The flywheel 72 has its boss 72a connected to the drive shaft 4.
The driven cam plate 83 is rotatably and slidably supported on the boss 72a via a bush 86, and the driven cam plate 83 is rotatably supported on the boss 72a, and is attached to one side of the flywheel 72 via a friction clutch plate 87. is engaged with. A pressing plate 89 is attached to the other side of the flywheel 72 via a thrust bearing 88.

The output lever mechanism 74 swings in the axial direction of the axle 10 by a support shaft 90 protruding from the inner surface of the lid body 22b at an intermediate position between the axle 10 and the exhaust pressure valve 20, and a neck 90a at the tip of the support shaft 90. A lever 91 is freely supported, and a certain amount of play 92 is provided between the neck 90a and the lever 91 in the swinging direction of the lever 91. The lever 91 includes a long first arm 91a that extends from the support shaft 90, bypassing the drive shaft 42, and
The first arm 91a has a short second arm 91a extending toward the exhaust valve 20, and an abutment part 93 that comes into contact with the outer surface of the press plate 89 is formed in a raised chevron shape at the middle part of the first arm 91a. ing.

A spring 94 is compressed between the tip of the first arm 91 and the lid body 22b, and the tip of the second arm 91b is attached to the valve body 6 of the exhaust pressure valve 20.
7 Abuts on the outer end.

The elastic force of the spring 94 acts on the lever 91, and the first arm 91
The contact portion 93 of a is pressed against the pressing plate 89, and the valve body 67 of the exhaust pressure valve 20 is normally pressed to keep the valve closed.

The pressing force that the pressing plate 89 receives from the spring 94 is applied to the flywheel 72, the friction clutch plate 87, and the driven cam plate 8.
3, and both cam plates 8
2. Add approach power to 83.

' The frictional engagement force is set so that when a rotational torque of a certain value or more is applied between the driven cam plate 83 and the flywheel 72, the friction clutch plate 87 slips.

In the present invention, the natural frequency fO of the sensor 21 in the axial direction of the flywheel 72 is the natural frequency f in the longitudinal bending direction of the front 1-fork 9.

is set to be sufficiently smaller than ro, that is, ro<<f.

Note that the above-mentioned natural frequency of the sensor 21 is the same as that of the cam recess 82a.
, the inclination angle of the bottom surface of s3a, the transfer radius of the thrust ball 84, the lever ratio at which the pressing plate 89 swings the lever 91 about the valve body 67, the spring constant of the spring 94, etc.

This output lever mechanism 74 is checked to confirm its normal operation.
A verification device 95 is connected for checking. This confirmation device 9
Reference numeral 5 denotes a switch holder 96 fixed to the lid body 22b and protruding into the coil portion of the spring 94, a reed switch 97 held by the switch holder 96 within the coil portion of the spring 94, and the reed switch 97 corresponding to the reed switch 97. First arm 91a
A permanent magnet 98 attached to the first arm 91
When a swings toward the lid 22b by a predetermined angle, the permanent magnet 98 is moved to the closed position of the reed switch 97.

A display circuit 99 is connected to the reed switch 97. The display circuit 99 is configured as shown in FIG. When the main switch 100 is closed, current flows from the power supply 101 to the transistor 10 through the main switch 100, resistors 102 and 103.
4, the transistor 104 becomes conductive, and as a result, the indicator lamp 105 switches to the main switch 1.
It is energized through 00 and turns on. In this state, when the reed switch 97 is once closed by the approach of the permanent magnet 98, the reed switch 97 passes through the reed switch 97, and the
Since current is passed through the gate of 06, Cyrisk 106
becomes conductive, and a large amount of the current passing through the resistor 102 flows toward the cyrisk 106, causing the transistor 10 to become conductive.
Step 4 is a cut-off state, and indicator lamp 105 is turned off. Therefore, by turning off the light, it can be confirmed that the lever 91 has swung toward the lid 22b against the elastic force of the spring 94. Thereafter, even if the reed switch 97 is opened by the return operation of the lever 91, the extinguished state of the indicator lamp 105 is maintained by the cyrisk 106 until the main switch 100 is opened and closed again.

As the main switch 100, an ignition switch or a brake switch of a motorcycle can be used.

Further, as shown in FIG. 7, an induction coil 107 may be used in place of the main switch 100. That is, the primary side of the induction coil 107 is connected to the REET switch 97, and the secondary side thereof is connected to the gate of the SIRISK 106.

The rest of the configuration is the same as that in FIG. Positive and negative pulses are generated alternately on the side, which causes the thyristor 106 to repeat the conduction and cutoff states, and the indicator lamp 1
05 flashes. Therefore, the operation of the lever 91 can be confirmed by this blinking.

Next, the operation of this embodiment will be explained.

While the vehicle is running, the speed increasing gear device 4 is connected to the rotating front wheels 2F.
5, the drive shaft 42 is driven to increase the speed, and then the flywheel 72 is driven via the cam mechanism 73 and the friction clutch plate 87.
rotates faster than. Therefore, flywheel 7
2. It can have a large rotational inertia.

At the same time, the camshaft 26 and speedometer 5
1 is also driven by the drive shaft 42.

Now, if the front mask cylinder 5f is operated to brake the front wheel 2f, the output oil pressure will be transferred to the upstream pipe 1 of the hydraulic conduit 15.
5a, hydraulic chamber 3G of hydraulic pump 16, modulator 17
Input hydraulic chamber 54, valve chamber 58, valve hole 59, output hydraulic chamber 5
5 and the downstream pipe 15b of the hydraulic conduit 15, the brake force is transmitted to the front wheels 1-3f and 3f in order, and by operating these, braking force can be applied to the front wheel 2f.

On the other hand, in the hydraulic pump 16, since the output hydraulic pressure of the front mask cylinder 5f is introduced into the hydraulic chamber 36, the hydraulic pressure acts on the operating screw 1 and the eccentric cam 29.
The lifting action of 6a on the bushing rod 27 provides a reciprocating motion to the pump piston 28. and,
In the suction stroke in which the pump piston 28 moves toward the bushing rod 27, the suction valve 38 opens τ, and the oil in the oil tank 19 is sucked into the pump chamber 35 from the conduit 37 via the population chamber 1.
During the discharge stroke in which the pump piston 28 moves toward the working piston 29 side, the one-way seal member 39 opens the valve, and the oil in the pump chamber 35 flows into the outlet chamber 32 through the oil passage 57 to the control hydraulic pressure of the modulator 17. It is pumped into chamber 18. Then, when the pressure in the outlet chamber 32 and the control hydraulic chamber 18 rises to a predetermined value, the pump piston 28 is held in the abutting position with the stopper 34 by the pressure in the outlet chamber 32.

By the way, the control hydraulic chamber 18 of the modulator 17 is initially disconnected from the oil tank 19 by closing the exhaust pressure valve 20, so that the hydraulic pressure supplied from the hydraulic pump 16 to the chamber 18 is directly applied to the pressure reducing piston 46. The valve opening rod 62 maintains the valve body 60 in the open state while allowing the output hydraulic pressure of the front mask cylinder 5f to pass through.

Therefore, Gj and front wheel brake 3f at the beginning of braking.

The braking force applied to the cylinder 3f is proportional to the output oil pressure of the front mask cylinder 5r.

When angular deceleration occurs in the front wheels 2r due to this braking, the flywheel 72 senses this and tries to overrun the drive shaft 42 due to its inertial force.

The rotational moment of the flywheel 72 at this time causes relative rotation of both cam plates 82 and 83, and the thrust generated by the displacement of the thrust pole 84 gives an axial displacement to the flywheel 72, causing the press plate 89 to move the lever. Trying to push 91.

Now, if we consider the behavior of the lever 91 when it is pressed by the pressing plate 89, we can see that initially the support shaft 90 and the lever 91
1, the lever 91 is supported by the spring 94, the pressure plate 89, and the valve body 67 of the exhaust valve 20, and when pressed by the pressure plate 89, the lever 91 uses the valve body 67 as a fulcrum. It oscillates as. When such rocking progresses to a predetermined angle, the play 92 between the support shaft 90 and the lever 91 disappears, and the fulcrum on the second arm 91b side moves from the valve body 67 to the support shaft 90 near the contact portion 93. , the lever 91 now swings about the support shaft 90 as a fulcrum.

In this way, when the lever 91 is swung by the pressing plate 89, the lever ratio changes in two stages, so even if the repulsive force of the spring 94 is constant, the lever 91 is initially It swings with a small pushing force, and after the swing fulcrum moves, it does not swing unless the pushing force increases to a predetermined value. Therefore, during braking, when the angular deceleration occurring at the front wheel 2f is relatively small, the lever 91 is moved to the pressing plate 89.
Each time the permanent magnet 98 swings due to the pressing force and approaches the closed position of the reed switch 37, the display circuit 99 is activated as described above to notify the operator that the sensor 21 is operating normally. It can be recognized.

Now, when the front wheel 2f is about to lock up due to excessive braking force or a decrease in the friction coefficient of the road surface, the front wheel 2f
Due to the sudden increase in the angular deceleration of f, the pressing force of the pressing plate 89 exceeds a predetermined value, and the lever 91 swings about the support shaft 90 to further compress the spring 94.
The arm 91b swings away from the valve body 67, and as a result, the exhaust pressure valve 20 becomes open.

When the exhaust pressure valve 20 opens, the oil pressure in the control oil chamber 18 is transferred to the oil passage 70. Entrance chamber 68. Valve hole 66, outlet chamber 69, oil passage 71.
Oil tank 1 via the population chamber 31 of the hydraulic pump 16 and the conduit 37
9, the pressure reducing piston 46 moves toward the control hydraulic chamber 18 against the force of the return spring 48 due to the hydraulic pressure of the output hydraulic chamber 55, thereby retracting the valve opening rod 62 and opening the valve body 60. The valve is closed to cut off communication between the output oil chambers 54 and 55, and increase the volume of the output oil pressure chamber 55.

As a result, the braking oil pressure acting on the front wheel brakes 3f, 3f decreases, the braking force of the front wheel 2r decreases, and the locking phenomenon of the front wheel 2r is avoided. Then, as the rotation of the front wheel 2f accelerates, the pressing force of the pressing plate 89 on the lever 91 is released, so the lever 91 swings back to its original position due to the repulsive force of the spring 940, and closes the exhaust pressure valve 20. Set to valve state. Exhaust pressure valve 20
When the valve is closed, the pressure oil discharged from the hydraulic pump 16 is immediately sealed in the control hydraulic chamber 18, and the pressure reducing piston 4
6 retreats to the output hydraulic chamber 55 side to make the chamber 55 4 pressure,
Restores braking power. By repeating such operations at high speed, the front wheels 2f are efficiently braked.

During such braking force control, the front fork 9 is bent backwards when the braking force of the front wheel 2f is applied.
When the braking force is released, the front wheel 2f is bounced forward by its own elasticity, causing rotational fluctuations in the front wheels 2f, and similar rotational fluctuations, that is, vibrations, are also applied to the drive shaft 42. When the transmission rate of the vibration to the sensor 21 was investigated by changing the natural frequency of the sensor 21, it was as shown in FIG. 9.

As is clear from this, the vibration transmission rate to the sensor 21 increases dramatically when the natural frequency of the sensor 21 approaches the natural frequency f1 of the front fork 9, and decreases when it exceeds the natural frequency f. However, it does not fall below the value that it becomes.

By the way, in the sensor 4J°21 of the present invention, its natural frequency is set to [0, which is sufficiently smaller than the natural frequency f1 of the front fork 9, so even if the drive shaft 42 is excited from the front wheel 2f, The sensor 2I receives only a small amount of vibration and can avoid performance deterioration.

FIG. 8 shows a second embodiment of the present invention, in which a ring gear 76 is formed on the input member 11 driven by the hub 8 via the concave-convex engagement means 10 in a speed increasing gear device 45. carrier 112 secured to casing 22
The structure is substantially the same as that of the previous embodiment except that the planetary gear 78 is pivotally supported, and in the drawings, parts corresponding to those of the previous embodiment are designated by the same reference numerals.

C1 Effects of the Invention As described above, according to the present invention, the natural frequency of the sensor in the axial direction of the flywheel is set to be smaller than the natural frequency of the wheel support system in the longitudinal bending direction. Even if the drive shaft is excited by the wheels due to bending vibration,
Resonance of the sensor is avoided and the sensor is able to exhibit a predetermined performance.

Moreover, the sensor does not require any special components and has a simple structure.

[Brief explanation of drawings]

1 to 6 show an embodiment of the present invention,
Fig. 1 is a schematic plan view of a motorcycle equipped with an anti-lock braking device, Fig. 2 is a longitudinal cross-sectional side view of the main part of the anti-lock braking device, and Figs. 5 is an enlarged sectional view taken along line V-V in FIG. 4, FIG. 6 is a wiring diagram of the display circuit in FIG. 2, and FIG. 7 is a wiring diagram showing a modification of the display circuit. 8 is a longitudinal sectional view showing a second embodiment of the present invention, and FIG. 9 is a graph showing the vibration transmission rate from the front fork to the sensor. 2f...Front wheel as a wheel, 3f...Front wheel brake, 7...Anti-lock control device, 8...Hub, 9...
...Front fork as a support system, 10... Axle, 12... Brake disc, 14... Brake caliper, 16... Hydraulic pump, 17... Modulator, 20... Exhaust pressure valve, 21 ...Wheel angle deceleration sensor→
J-122...Casing, 42...Drive shaft, 45
... Speed-up gear device, 72... Flywheel, 73.
...Cam mechanism, 74... Output lever mechanism, 82...
Drive cam plate, 83... Driven force J, plate, 84... Thrust ball, 87... Friction clutch plate, 89... Press plate, 90... Support shaft, 91... Lever, 94・・・
・Spring patent Applicant Honda Motor Co., Ltd. Figure 1 Whistle Figure 9

Claims (1)

[Claims] a flywheel rotatably and slidably supported by a drive shaft interlocking with the wheels; a rotary torque of the drive shaft is transmitted to the flywheel, and when an angular deceleration of a certain value or more occurs in the wheels; A cam mechanism that generates overrun rotation in the flywheel and gives it an axial displacement, and a return spring that gives an axial retraction force to the flywheel, and the wheel angle provided in the support system of the wheel is A wheel angular deceleration sensor, characterized in that the natural frequency of the sensor in the axial direction of the flywheel is set to be smaller than the natural frequency in the longitudinal bending direction of the support system.