JP2004257458A - Belt-type continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt-type continuously variable transmission which enhances steering stability by disposing a clutch mechanism on a drive side and integrating the clutch mechanism with a transmission, and reliably generates an engine brake during the deceleration by fitting a torque cam mechanism to a pulley. <P>SOLUTION: In the belt type continuously variable transmission, a torque cam mechanism sliding on a rotary shaft is disposed on a pulley on the clutch coupling side. In the torque cam mechanism, a torque cam of the drive pulley slides on the rotary shaft in the retracting direction from the pulley by the torque input from a wheel when a throttle is returned in a running condition of a vehicle. By the slide of the torque cam of the pulley in the retracting direction, shift-down is performed to obtain an engine brake effect. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a belt-type continuously variable transmission applied to a vehicle such as a scooter.
[0002]
[Prior art]
Vehicles such as scooters are equipped with a V-belt continuously variable transmission, and the speed of the vehicle can be adjusted only by controlling the engine rotation.
In this continuously variable transmission, for example, as shown in FIG. 13, two drive pulleys 71 are attached to an output shaft 70 of the engine. One of the drive pulleys 71 is a centrifugal roller 72 that is movable in the axial direction. Is installed.
[0003]
On the other hand, one of the two pulleys 73 attached to the driven pulley is biased by a spring 74 in a direction to reduce the interval between the two pulleys. The V-belt 75 is wound between the drive pulley 71 and the driven pulley 73.
The driven pulley 73 includes a centrifugal clutch 76 that is automatically connected when the rotation increases from idling to a certain rotation, and is connected to wheels via a gear transmission 77.
[0004]
When the drive pulley 71 starts rotating, the interval between the two drive pulleys 71 is wide and the winding diameter of the V-belt 75 is small, while the two driven pulleys 73 are pressed by a spring and the interval is small, With the winding diameter of the V-belt increased, the rotation is transmitted to the wheels at a low speed.
As the rotation of the drive pulley 71 increases, the centrifugal roller 72 expands, and the interval between the two drive pulleys 71 decreases, thereby increasing the winding diameter of the V-belt 75 and the two The distance between the driven pulley 73 and the spring 74 is increased, the winding diameter of the V-belt 75 is reduced, the rotation of the driven pulley 73 is increased, and the rotation of the wheel is also increased to increase the speed.
As a technology related to such a belt-type continuously variable transmission, a technology described in Japanese Patent Application Laid-Open No. 9-57138 is known.
[0005]
[Patent Document 1]
JP-A-9-57138
The operation of the conventional belt type continuously variable transmission will be described with reference to FIG.
(A) At the time of idling, the drive pulley 71 is rotating because it is directly connected to the output shaft 70. In conjunction with this, the belt 75 and the driven pulley 73 rotate.
(B) When the rotation is increased, the clutch is engaged by the centrifugal force, and the wheels rotate through the speed reducer.
(C) In middle-speed running, the centrifugal force of the centrifugal roller 72 gradually narrows the interval between the drive pulleys 71 and shifts up.
(D) Further, when the upshift is performed and the throttle is closed during high-speed running, torque from the engine is released, the belt 75 and the pulleys 71 and 73 rotate due to the inertia of the wheels, and the engine brake is not applied and the upshift is performed. Would.
[0007]
In the conventional belt type continuously variable transmission, when the throttle is returned, torque from the belt 75 is lost as shown in FIG. Since the function of the torque cam of the driven pulley 73 is lost and the gear is shifted up by the centrifugal transmission, there is a problem that the gear ratio is increased and the engine brake is not effective.
In addition, there is a problem that it takes a long time to shift down to a state suitable for acceleration because the speed is shifted up to a high speed ratio after re-acceleration after deceleration.
[0008]
Further, in the conventional belt type continuously variable transmission, since the clutch 76 is mounted on the driven pulley 73, a portion far from the suspension pivot becomes heavy, resulting in poor balance and adversely affecting maneuverability.
Further, since the centrifugal clutch 76 operates in the circumferential direction, the clutch spring deteriorates and breaks, and the clutch is directly connected.
[0009]
In the conventional type, an explosion accident of the centrifugal clutch 76 has occurred. However, it is an accident in a special situation where a scooter chained up for a race is turned up to 14000 rpm with an idle blow.
Assuming that the gear ratio at high speed is 1: 3, when the rotation speed of the engine, that is, the drive pulley is 14,000, the driven pulley and the centrifugal clutch rotate at an ultra-high speed of 42,000, which is three times as large as that of the engine. An accident has occurred in which the clutch housing could not withstand the severe centrifugal force and broke, and the clutch shoe crushed the aluminum cast material case and jumped out.
[0010]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION The present invention has been made to solve the conventional problems, and an object of the present invention is to dispose a clutch mechanism on a drive side and integrally configure a clutch mechanism and a transmission to improve steering stability. It is another object of the present invention to provide a belt-type continuously variable transmission in which a torque cam mechanism is mounted on a pulley to surely generate an engine brake during deceleration.
[0011]
[Means for Solving the Problems]
In the belt-type continuously variable transmission according to claim 1, as a means for achieving the object, a drive pulley disposed on an output shaft side, adjusting a diameter by separating and separating a gap between pulleys, and a transmission. In a belt-type continuously variable transmission including a driven pulley connected to wheels and a belt wound between the pulleys, a clutch plate that is separated from and connected to the outer periphery of the pulley is provided on one side on a rotation shaft of a drive pulley. The clutch plate is disposed with a centrifugal roller, and the centrifugal force acting on the centrifugal roller causes the clutch plate to slide in the axial direction and transmit power to the drive pulley, and the clutch plate is connected to the pulley. After that, when the rotation of the engine rises, the clutch plate further presses the pulleys so that the pulleys approach each other to shift the speed. The pulley is provided with a torque cam mechanism that slides on the rotating shaft. When the throttle is returned during traveling of the vehicle, the torque cam of the drive pulley causes the torque cam of the drive pulley to move away from the pulley on the rotating shaft in response to torque input from the wheels. The pulley slides in the separating direction to shift down, thereby obtaining an engine braking effect.
[0012]
In the belt-type continuously variable transmission according to the second aspect, in the belt-type continuously variable transmission according to the first aspect, the torque cam mechanism is configured by a movable face (pulley) that is mounted on a rotating shaft so as to be capable of spirally turning. Then, it is configured to slide in the axial direction while spirally moving by the torque input from the wheel side.
[0013]
In the belt-type continuously variable transmission according to the third aspect, in the belt-type continuously variable transmission according to the first or second aspect, a torque cam mechanism is also provided on the driven pulley, and when the throttle is opened, the torque cam of the driven pulley is set. Operates to enable smooth acceleration.
[0014]
In the belt-type continuously variable transmission according to the fourth aspect, in the belt-type continuously variable transmission according to the first, second or third aspect, a clutch plate that slides on a rotary shaft and a slide portion of a pulley that slides on the rotary shaft. A bearing is arranged on the shaft to reduce sliding resistance with the rotating shaft.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
1 is a plan sectional view of a belt type continuously variable transmission, FIG. 2 is a plan view of a belt type continuously variable transmission, FIG. 3 is a sectional view near a drive pulley, FIG. 4 is a plan view near a drive pulley, and FIG. 6 is an exploded view of the drive pulley, and FIG. 7 is an exploded view of the driven pulley.
In addition, the groove of the torque cam of the drive pulley is drawn perpendicular to the axis for easy understanding.
As shown in FIGS. 1 and 2, a belt-type continuously variable transmission according to one embodiment of the present invention includes a drive pulley 1 connected to an engine side, a clutch mechanism 2 separated from and connected to the drive pulley 1, and a clutch mechanism. 2, a centrifugal transmission 4 integrally formed with the clutch mechanism 2, a driven pulley 5 connected to the wheel side, and a bridge between the drive pulley 1 and the driven pulley 5. The main structure of the belt 6 is as follows.
[0016]
As shown in FIGS. 3 and 4, the centrifugal transmission includes a shallow conical clutch friction plate (clutch plate 8) to which a friction material is fixed, and a centrifugal roller 3 for moving the transmission by centrifugal force. The housing 9 is configured to be fastened by a spring 10.
When the rotation of the output shaft increases, the clutch mechanism 2 rotates, the centrifugal roller 3 moves outward, and the clutch friction plate 8 is pressed against the pulley 1a against the spring 10.
Then, the pulley 1a gradually rotates due to the contact with the clutch plate 8, and as the speed increases, the centrifugal roller 3 moves further outward to further press the pulley 1a, and the interval between the pulleys 1 is reduced to achieve high-speed running. Become.
The operation of the centrifugal roller 3 causes the clutch and the speed change to be performed, and the clutch mechanism 2 and the centrifugal transmission 4 are integrally formed.
[0017]
The clutch reflection plate 8 is provided with external teeth 11 and the housing 9 is provided with splines of internal teeth so that the clutch reflection plate 8 can slide in the axial direction while transmitting power.
The clutch reflection plate 8 is provided with a wall for preventing the centrifugal roller 3 from jumping out and a reinforcing rib on the wall.
A spring 10 holding the clutch reflection plate 8 and the housing 9 prevents the clutch reflection plate 8 from contacting the pulley 1 at the time of stopping, idling, or starting the engine.
By separating the centrifugal transmission, the independent drive pulley 1 is floated by bearings and passed through the output shaft.
As described above, the centrifugal transmission 4 having the clutch mechanism 2 is fixed to the tip of the drive pulley 1 that passes through the output shaft.
[0018]
The drive pulley 1 is composed of a movable drive face 1a and a drive face 1b. The movable drive face 1a suppresses belt slippage, smoothes gear shifting, and changes the characteristics of the transmission by inputting torque from the belt. The groove 12 for the torque cam is opened so as to be inclined backward with respect to the rotation direction, the guide pin 13 is set up on the drive face 1b, and a cover is attached to the removable drive face 1a so that the guide pin 13 does not come off.
The guide pin 13 is arranged in a state fixed to the drive shaft of the drive face 1b, and the guide pin 13 and the groove 12 can be slid obliquely. That is, the removable drive face 1a is mounted on the drive shaft in such a manner that the movable drive face 1a is capable of spirally turning.
When the throttle is released, the torque of the wheels, not the engine, is transmitted to the movable drive face 1a via the belt, and the movable drive face 1a spirally moves to expand the space between the pulleys 1.
[0019]
Next, FIG. 7 is an exploded view of the driven pulley.
The driven pulley 5 also has a torque cam function, and a groove 15 that is inclined backward in the rotation direction is opened in the movable driven face 5a, so that the driven pulley 5 slides along a guide pin 16. Further, a spring 17 for keeping the transmission at a low speed ratio is attached.
The structure itself is the same as that of the drive pulley 1, except that there is no bearing on the inner diameter and the shaft is fixed.
A drive gear is attached to the shaft, and the transmission is constructed by reducing the idle gear and final gear. Wheels are mounted on a drive shaft fixed to the final gear.
[0020]
In general, a belt-type continuously variable transmission has a pair of detachable drive pulleys attached to an output shaft, a pair of detachable passive pulleys attached to a passive shaft, and a bridge between them. It is constituted by a belt. The belt is configured so that the rotation of the output shaft can be steplessly changed by a belt and transmitted to the passive shaft, and a torque cam mechanism is provided on the movable pulley of the passive pulley in order to apply tension to the belt during shifting and the like. Is provided.
The torque cam mechanism of the present invention is mounted so as to be capable of spirally rotating with respect to an axis by guide pins 13 and 16 and grooves 12 and 15 cut obliquely.
[0021]
Next, the operation of the present invention will be described with reference to FIGS.
(A) During idling, the output shaft and the centrifugal transmission with clutch directly connected to the output shaft rotate. The drive pulley 1, the driven pulley 5, and the belt 6 are in a stopped state.
The driven pulley 5 is pressed by a spring 17 while the drive pulleys 1 are separated from each other.
[0022]
(B) When the throttle is opened, the rotation increases, and the centrifugal roller 3 in the housing moves outward in the circumferential direction by centrifugal force, pressing the clutch retraction plate 8 against the removable drive face 1a and rotating to the drive pulley 1. Tell
At this time, since the torque cam mechanism of the drive pulley 1 is not an input from the belt but is floating by the bearing, it works only to the extent that the belt is lightly pressed to suppress slippage.
[0023]
(C) When the clutch is engaged, the drive pulley 1 starts rotating, and the rotational force is transmitted to the driven pulley through the belt.
Since the driven face is directly connected to the wheels via the transmission and cannot be moved immediately, the movable driven face 5a leads by the torque cam, and the movable driven face 5a tightens the belt to shift down. While maintaining the speed, the transmission decelerates, the rotation is transmitted to the wheels, and the vehicle moves forward.
[0024]
(D) In middle-speed running, the rotation gradually increases, the centrifugal force increases, and the force of the centrifugal roller 3 pressing the movable drive face 1a exceeds the force of the torque cam, thereby narrowing the width of the drive pulley 1. Thereby, the drive diameter increases.
On the other hand, the driven pulley 5 pulls the belt 6, so that the distance between the driven pulleys 5 is expanded, the belt moves inward, the passive diameter decreases, and the gear ratio increases to shift up.
[0025]
(E) In high-speed running, the rotation further increases, and the belt moves to the outermost periphery of the drive pulley 1 and the innermost periphery of the driven pulley 5.
[0026]
(F) When the throttle is closed, the drive from the engine is cut off, and the drive of the tires is input to the drive pulley 1 from the belt 6.
[0027]
(G) When the driving of the tire is input from the belt 6, the drive face of the drive pulley 1 moves along the groove of the torque cam to open the movable drive face 1a. As a result, the movable pulley 1a of the driven pulley 1 To shift down. This downshift is transmitted to the engine through a transmission integrally formed with the clutch, and is used as an engine brake.
That is, the torque cam of the drive pulley 1 is spirally moved by the torque input from the wheels, and slides on the rotating shaft in the direction away from the pulley, so that the downshift is performed and the engine brake operates.
[0028]
(H) When the throttle is opened, the drive of the engine is transmitted to the movable drive face 1a, the torque cam of the driven pulley 5 operates, and the vehicle immediately enters an acceleration state.
In the re-acceleration in this state, the shift to the engine has already been shifted down, so that the load on the engine is reduced, and wasteful fuel is not consumed.
[0029]
Next, FIG. 10 is a cross-sectional view near the drive pulley according to the second embodiment.
The grooves and bearings of the torque cam are drawn perpendicular to the axis for easy understanding.
In FIG. 10, a bearing 20 is disposed on a clutch plate that slides on the rotating shaft and a sliding portion of a pulley that slides on the rotating shaft to reduce sliding resistance with the rotating shaft.
It should be noted that the same configuration is adopted when a bearing is provided on a driven pulley.
By arranging the bearing 20 in this manner, the clutch mechanism and the speed change mechanism can be smoothly operated even when receiving large power and torque.
[0030]
Next, FIG. 11 is an exploded view near the drive pulley according to the third embodiment.
FIG. 11 shows a configuration in which an oblique slide groove 21 is formed in a screw turning portion as a torque cam mechanism, and a bearing 22 is disposed in the groove.
FIG. 12 is an exploded view when the bearing 22 is provided on the driven pulley.
By arranging the bearing 22 in the torque cam mechanism in this manner, the torque cam operates smoothly even in a heavy vehicle.
[0031]
The embodiment of the present invention has been described above. However, the specific configuration of the present invention is not limited to the present embodiment, and even if there is a design change or the like within a range not departing from the gist of the present invention, the present invention is not limited thereto. Included in the invention.
For example, the belt-type continuously variable transmission of the present invention can be applied to four-wheeled vehicles, radio-controlled cars, radio-controlled bikes, and vehicles using electric motors in addition to two-wheeled vehicles such as scooters.
As the belt, a metal belt can be used in addition to the resin belt.
[0032]
【The invention's effect】
In the belt-type continuously variable transmission according to the first aspect of the present invention, a clutch plate that comes into contact with and separates from the outer periphery of the pulley is disposed on one side of the rotation shaft of the drive pulley, and a centrifugal roller is disposed on the clutch plate. Due to the centrifugal force acting on the roller, the clutch plate slides in the axial direction and power is transmitted to the drive pulley.After the clutch plate is connected to the pulley, the rotation of the engine causes the clutch plate to further pull the pulley. Since the speed is shifted by pressing the pulleys so as to approach the pulleys, the clutch mechanism and the transmission are integrally formed.
When the present invention is applied to a swing unit or a semi-swing unit which is a general suspension type of a scooter, a portion far from the suspension pivot is lightened because the clutch is integrated with the transmission. As a result, the load on the shock absorber is reduced, and the riding comfort and the following ability on the road surface are improved.
Further, a torque cam mechanism that slides on a rotating shaft is provided on the pulley on the clutch contact side, and the torque cam mechanism is configured such that when the throttle is returned during traveling of the vehicle, the torque cam of the drive pulley is input by torque input from wheels. Since the configuration is such that the pulley slides on the rotating shaft in the direction away from the pulley, the pulley slides in the direction away from the pulley, whereby a downshift is performed and an engine braking effect is obtained.
[0033]
In the belt-type continuously variable transmission according to the second aspect, the torque cam mechanism is constituted by a movable face (pulley) which is mounted on the rotating shaft so as to be capable of spirally rotating. Since it is configured to slide in the axial direction, when the throttle is returned, the torque input from the wheels is received and the space between the pulleys is automatically expanded.
[0034]
In the belt-type continuously variable transmission according to the third aspect, the torque cam mechanism is also provided on the driven pulley, so that when the throttle is opened, the torque cam of the driven pulley operates to enable smooth acceleration.
[0035]
In the belt-type continuously variable transmission according to the fourth aspect, the bearing is disposed on the clutch plate that slides on the rotating shaft and the sliding portion of the pulley that slides on the rotating shaft, so that the sliding resistance with the rotating shaft is reduced. Even if a large power and torque are received, the clutch mechanism and the shift function can be operated smoothly.
[Brief description of the drawings]
FIG. 1 is a plan sectional view of a belt-type continuously variable transmission.
FIG. 2 is a plan view of the belt-type continuously variable transmission.
FIG. 3 is a sectional view near a drive pulley.
FIG. 4 is a plan view near a drive pulley.
FIG. 5 is an exploded view of a clutch mechanism and a transmission.
FIG. 6 is an exploded view of a drive pulley. FIG. 7 is an exploded view of a driven pulley.
FIG. 8 is an explanatory diagram showing the operation of the present invention in the order of (A) to (D).
FIG. 9 is an explanatory diagram showing the operation of the present invention in the order of (E) to (H).
FIG. 10 is a sectional view near a drive pulley according to a second embodiment.
FIG. 11 is an exploded view of a drive pulley according to a third embodiment.
FIG. 12 is an exploded view when a bearing is provided on a driven pulley.
FIG. 13 is an explanatory diagram of a belt-type continuously variable transmission according to a conventional example.
FIG. 14 is an explanatory diagram showing the operation of a belt-type continuously variable transmission of a conventional example in the order of (A) to (D).
[Explanation of symbols]
REFERENCE SIGNS LIST 1 drive pulley 2 clutch mechanism 3 centrifugal roller 4 transmission 5 driven pulley 6 belt 8 clutch plate 9 housing 10 spring 11 external teeth 12 groove 13 guide pin 14 cover 15 groove 16 guide pin 17 spring 20 bearing 21 slide groove 22 bearing

Claims (4)

A drive pulley that is arranged on the output shaft side and adjusts the diameter by separating and spacing the pulleys, a driven pulley connected to wheels via a transmission, and a belt wound around the pulleys In belt type continuously variable transmissions,
On one side of the rotation axis of the drive pulley, a clutch plate that is separated from and attached to the outer periphery of the pulley is arranged, and a centrifugal roller is arranged on the clutch plate, and the clutch plate slides in the axial direction due to centrifugal force acting on the centrifugal roller. Power is transmitted to the drive pulley, and after the clutch plate is connected to the pulley, the clutch plate presses the pulley by the rotation of the engine, and the pulley is moved closer to change the speed.
A torque cam mechanism that slides on a rotating shaft is provided on the pulley on the clutch contact side, and the torque cam mechanism is configured such that when the throttle is returned during running of the vehicle, the torque cam of the drive pulley is rotated by a torque input from wheels to rotate the rotating shaft. The upper part slides in the pulley separation direction,
A belt-type continuously variable transmission characterized in that the pulley slides in the separating direction to shift down to obtain an engine braking effect. The torque cam mechanism is constituted by a movable face (pulley) mounted on the rotating shaft so as to be capable of turning in a spiral manner, and slides in the axial direction while rotating in a spiral manner by a torque input from a wheel side. Item 2. A belt-type continuously variable transmission according to item 1. 3. The belt-type continuously variable transmission according to claim 1, wherein a torque cam mechanism is also provided on the driven pulley, and when the throttle is opened, the torque cam of the driven pulley operates to enable smooth acceleration. . 4. A clutch plate that slides on a rotating shaft and a sliding portion of a pulley that slides on the rotating shaft are provided with bearings to reduce sliding resistance with the rotating shaft. The belt-type continuously variable transmission as described in the above.

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