JPH0222266B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a variable pulley device with a variable effective diameter that is used as a part of a transmission in automobiles, agricultural machinery, etc. This relates to a mechanism that automatically adjusts the effective diameter according to the tension of the belt depending on the force.

(Prior art) Conventionally, as a belt-type transmission using belt transmission, a pair of input and output shafts arranged parallel to each other has been provided with a shaft that rotates integrally with and cannot slide relative to each of the input and output shafts. A variable pulley consisting of a fixed sheave fixed to the shaft, and a movable sheave that is rotatably and slidably supported on each axis so as to be opposed to each other so as to form a V-shaped belt groove between the movable sheaves. At the same time, a belt member is wound between the belt grooves of both variable pulleys, and the movable sheave of each variable pulley is moved in the axial direction to approach and separate from the fixed sheave, and the belt is wound around the belt groove between both the sheaves. It is well known that the gear ratio between the input and output shafts is variably controlled by changing the effective radius of the member.

Usually, the variable pulley on the input shaft is used as a drive pulley, and the effective diameter of the drive pulley is changed by moving its movable shaft in the axial direction using, for example, hydraulic pressure, while the variable pulley on the output shaft is used as a driven pulley. The movable sheave is biased toward the fixed sheave by a spring, and the effective diameter of the driven pulley is automatically adjusted in accordance with the positional change of the belt member caused by the change in the effective diameter of the drive pulley. being done.

By the way, when applying a biasing force to the movable sheave in the driven pulley using a spring, a predetermined designed spring force is set to act while the interval between the belt grooves between the two sheaves is narrowed.
However, since the spring force of this spring is constant, when the effective diameter of the pulley increases and the interval between the belt grooves widens, the spring is compressed and deformed accordingly, and the spring force increases beyond the target value. As a result, the belt member is strongly pressed and held between the two shafts, resulting in problems such as deterioration of the durability of the belt member and reduction of power transmission efficiency.

Therefore, conventionally, as shown in Japanese Patent Application Laid-Open No. 58-46250, the seat of the spring that urges the movable shaft toward the fixed shaft is loosely fitted onto the rotating shaft, and the spring seat is fitted with a The tip of a shift fork that can swing around a shift axis in a direction perpendicular to the rotation axis is connected, and the swing of this shift fork causes the spring seat to move around the rotation axis in accordance with changes in the interval between belt grooves. It has been proposed that the biasing force acting on the movable shaft of the spring can be adjusted to be substantially constant at all times by moving it in the axial direction.

(Problem to be Solved by the Invention) However, in this proposal, since the spring seat is moved in the axial direction of the rotating shaft by the swinging of the shift fork, the movable range of the spring seat is limited to the arcuate movement of the shift fork. This is limited to a small range where the locus and the linear motion locus of the spring seat almost overlap. For this reason, the maximum distance between the belt grooves between the two shaves cannot be made very large, and there is a limit to increasing the speed ratio of the variable pulley, and the adjustment range of the spring force is also limited. It was hot.

Further, since the spring seat is moved and adjusted by a shift fork, there is an unavoidable problem that the adjustment accuracy of the spring force of the spring is low.

The present invention was made in view of these points,
The purpose of this is to adjust the urging force of the spring against the movable sheave by screw feeding the spring seat on the rotating shaft, thereby improving the durability of the belt member, while also improving the durability of the spring seat. Increasing the movable range on the rotating shaft and increasing the accuracy of its movement adjustment, thereby increasing the speed ratio of the variable pulley, expanding the spring force adjustment range of the spring, and improving the adjustment accuracy. It lies in trying to understand.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a fixed shaft that is rotatably fixed to the rotating shaft in a non-slidable manner, and a fixed shaft that is slidably and rotatably fixed to the rotating shaft in the axial direction. The object of the present invention is a variable pulley device comprising a movable sheave that is integrally supported, and that changes speed by moving the movable sheave towards and away from a fixed sheave and changing the effective radius of a belt member wound between both the sheaves. .

In this variable pulley device, a spring seat supported on the rotating shaft and movable in the axial direction by screw feeding by relative rotation with the rotating shaft, and a spring seat between the spring seat and the movable sheave. A spring is provided which is compressed and biases the movable sheave toward the fixed sheave.

Furthermore, a movable shaft is disposed on the back side of the spring catch so that it can move in a direction parallel to the rotation axis, and the spring catch is braked by contact with the spring catch to rotate relative to the rotation axis in one direction. A spring seat position adjusting means is provided, which includes a clutch pad that is screwed toward the side, and a moving member that adjusts the position of the clutch pad by moving it in response to a speed change operation so that the biasing force of the spring is approximately constant. do.

(Function) With this configuration, in the present invention, the seat of the spring that urges the movable shift toward the fixed shift is threadedly supported on the rotating shaft, and the position of the spring seat is adjusted according to the speed change operation. By adjusting the position by feeding the screw while rotating it relative to the rotating shaft using means, the biasing force of the spring against the movable shaft is adjusted and maintained at a substantially constant level. In other words, the clutch pad moves parallel to the rotation axis by driving the moving member in response to the gear shifting operation.
For example, when the movable shaft approaches the fixed shaft, the distance between the movable shaft and the spring seat widens, and the spring force of the spring is about to decrease, the moving member moves the clutch pad toward the movable shaft and the spring seat. It contacts the back of the seat and brakes its rotation. Therefore, the spring seat is rotated relative to the rotating shaft in one direction and is screwed so that it approaches the movable shaft.
This maintains the spring force. On the other hand, when the movable shaft moves away from the fixed shaft, the distance between the movable shaft and the spring seat becomes smaller, and the spring force of the spring is about to increase, the clutch pad simultaneously moves away from the movable shaft. For this reason, the spring seat is pushed by the spring that is trying to increase, and is screwed away from the movable shaft while rotating in the other direction relative to the rotation axis, and this restores the spring force of the spring. It is maintained.

In order to improve the durability of the belt member in this way, when the spring force of the spring is kept approximately constant, the spring seat that adjusts the biasing force of the spring is moved in the axial direction while being screwed on the rotating shaft. Because of this, the movable range of the spring catch can be expanded, and thereby the spring force adjustment range of the spring can be expanded, and
By increasing the movable range of the movable sheave relative to the fixed sheave, it is possible to cope with an increase in the speed ratio of the variable pulley.

In addition, since the spring catch is screw-fed and moves on the rotating shaft, the ratio of the angle at which the spring catch rotates relative to the rotating shaft increases relative to the distance the spring catch is moved and fed in the axial direction of the rotating shaft. , linear motion is extended to rotational motion. Therefore, by adjusting the relative rotational difference of the spring seat with respect to the rotating shaft, the spring force of the spring seat can be adjusted with high precision.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

1 and 2 show the overall configuration of a pulley type transmission according to an embodiment of the present invention, in which 1 is an input shaft;
Reference numeral 2 denotes an output shaft, which serves as a rotating shaft in the present invention, and is disposed and supported in parallel with the input shaft 1. A drive pulley 3 is provided on the input shaft 1. This drive pulley 3 includes a flange-shaped fixed sheave 5 that is rotatably and non-slidably fixed to the input shaft 1 with a screw 4, and a boss portion 6a that is attached to the input shaft 1 so as to face the fixed sheave 5. It consists of a flange-shaped movable sheave 6 which is slidably and rotatably spline-coupled, and a belt groove 7 is formed between these two sheaves 5 and 6.

On the other hand, a driven pulley 8 is provided on the output shaft 2. This driven pulley 8 includes a flange-shaped fixed sheave 10 that is rotatably and non-slidably fixed to the output shaft 2 with a screw 9, and a fixed sheave 5 of the drive pulley 3 on the input shaft 1 connected to the fixed sheave 10. It consists of a flange-shaped movable sheave 11 that is slidably and rotatably splined to the output shaft 2 so as to face the movable sheave 6 in a direction opposite to that of the movable sheave 6. A belt groove 12 is formed. A V-belt 13 as a belt member is wound between the belt groove 7 of the drive pulley 3 and the belt groove 12 of the driven pulley 8, and the movable sheave 6 of the drive pulley 3 is connected to the fixed sheave 5. When the movable sheave 6 of the drive pulley 3 approaches the fixed sheave 5, the effective radius of the drive pulley 3 is increased. The movable sheave 11 of the driven pulley 8 is fixed by the tension of the V-belt 13.
The movable sheave 6 of the drive pulley 3 is separated from the fixed sheave 5 by making the effective radius of the driven pulley 8 smaller, thereby creating a high-speed mode that increases the gear ratio between the input and output shafts 1 and 2. Sometimes, the effective radius of the drive pulley 3 is made small and V
A low-speed mode is achieved in which the movable sheave 11 of the driven pulley 8 approaches the fixed sheave 10 by the tension of the belt 13 to increase the effective radius of the driven pulley 8, thereby reducing the gear ratio between the input and output axes 1 and 2. is configured to do so.

A cylindrical driven cam 14 is externally fitted onto the boss portion 6a of the movable sheave 6 in the driving pulley 3 via a bearing 15 so as to be rotatable and non-slidable. A cylindrical sleeve 16 is rotatably fixed on the input shaft 1 on the opposite side of the fixed sheave 5 to the movable sheave 6 by means of screws 17, and a cylindrical drive shaft is fixed on the sleeve 17. A cam 18 is externally fitted via a bearing 19 so as to be rotatable and non-slidable. The drive cam 18 and the driven cam 14 each include cam portions 18b and 14b that protrude from their main bodies 18a and 14a in the direction toward the other side, and these cam portions 1
8b and 14b are provided in the same shape as each divided portion when the cylinder is diagonally cut and divided at an intermediate position,
Slanted cam surfaces 18c, 14c are formed at the tips of each cam portion 18b, 14b to make cam contact with each other. Although not shown, the drive cam 18 is rotated by switching operation of a switching lever, and by operating the switching lever, the drive cam 18 is rotated around the input shaft 1, and the cam portion 18b is rotated. The cam portion 1 of the driven cam 14 is connected to the inclined cam surface 18c at the tip.
By pressing the inclined cam surface 14c at the tip of the drive pulley 4b, the driven cam 14 is moved in the axial direction of the input shaft 1 together with the movable sheave 6 of the drive pulley 3, thereby increasing and changing the effective radius of the drive pulley 3. has been done.

Furthermore, as a feature of the present invention, as shown in an enlarged view in FIG. The shaped spring seat 20 moves in the axial direction so as to move toward the driven pulley 8 side (rightward in the figure) during relative rotation with the output shaft 2, for example, in the deceleration direction. A spring 21 is mounted between the spring seat 20 and the back surface of the movable sheave 11 to bias the movable sheave 11 toward the fixed sheave 10. still,
FIG. 3 shows a state in which the movable sheave 11 of the driven pulley 8 approaches the fixed sheave 10 in the upper half, and a state in which the movable sheave 11 is separated from the fixed sheave 10 in the lower half.

Further, a spring seat position adjusting means 25 for adjusting the position of the spring seat 20 is provided. This spring seat position adjustment means 2
5 includes a clutch pad 22 movably disposed on the back side of the spring seat 20 (on the opposite side from the spring 21) in parallel with the output shaft 2, and a connecting rod 24 as a moving member for moving the clutch pad 22. Become. The clutch pad 22 is
The clutch pad 22 is in the form of a disc ring that contacts the back surface of the spring seat 20 to brake its rotation and rotate the spring seat 20 relative to the output shaft 2 in one direction. (only shown in FIG. 1) so as to be slidably movable in the axial direction of the output shaft 2. On the other hand, the connecting rod 24 is composed of a rigid rod member that is slidably supported in a direction parallel to the input/output shafts 1 and 2, and one end of the connecting rod 24 is connected to the driven cam 14 on the input shaft 1, and The other ends are connected and fixed to clutch pads 22, respectively. The coupling rod 24 moves the clutch pad 22 in response to the shift operation of the driven cam 14, that is, the movement of the V-belt 13 associated with control of the effective radius of the drive pulley 3, so that the biasing force of the spring 21 is approximately constant. When the movable sheave 11 of the driven pulley 8 moves to the fixed sheave 10 side in the high speed mode,
Accordingly, the clutch pad 22 is moved to the driven pulley 8.
The spring seat 20 is brought close to the rear surface of the spring seat 20 to perform braking, and this braking causes the spring seat 20 to rotate relative to the output shaft 2 and screw feed the driven pulley 8 in the direction toward the movable sheave 11 side.
Movable sheave 11 of driven pulley 8 in low speed mode
When the clutch pad 22 is separated from the fixed shaft 10, the clutch pad 22 is moved away from the driven pulley 8, and the spring seat 20 is moved away from the spring 21.
The screw is configured to be fed in a direction away from the driven pulley 8 by the biasing force of.

Next, the operation of the above embodiment will be explained.

The movable shaft 6 and sleeve 16 of the drive pulley 3 supported on the input shaft 1 rotate integrally with the input shaft 1. Further, the driven cam 14 on the boss portion 6a of the movable shaft 6 and the drive cam 18 on the sleeve 16 do not rotate following the input shaft 1 but are stopped. On the other hand, under normal conditions, the spring seat 20 on the output shaft 2 is in contact with the clutch pad 22 to the extent that it is not affected by braking and rotates together with the output shaft 2. Therefore, the spring seat 20 on the output shaft 2 It is stopped moving in the axial direction with respect to axis 2,
A constant spring force from a spring 21 acts on the movable shaft 11 of the driven pulley 8.

From this state, for example, when increasing the gear ratio between the input and output shafts 1 and 2 to enter the high-speed mode, if the switching lever is positioned at the high-speed position, as the switching lever is switched, as shown in FIG. The drive cam 18 rotates in one direction (for example, clockwise) on the input shaft 1, and as the drive cam 18 rotates, the inclined cam surface 18 at the tip of each cam portion 18b, 14b
The driven cam 14 that is in contact with each other is pushed and moves on the input shaft 1 in the direction away from the drive cam 18 (leftward in the figure), and the driven cam 14 moves integrally with the driven cam 14 via a bearing 15. The movable sheave 6 of the connected drive pulley 3 moves in the same direction and approaches the fixed sheave 5, thereby reducing the distance between the belt grooves 7 of the drive pulley 3, that is, the V-belt 1.
The effective radius for 3 is increased. Additionally, as the effective radius of the drive pulley 3 increases, the V-belt 1
3 is drawn toward the driving pulley 3 as a whole, and due to the movement of the V-belt 13, the movable sheave 11 of the driven pulley 8 moves on the output shaft 2 in the direction away from the fixed sheave 10 (leftward in the figure), and the driven The effective radius of pulley 8 is reduced. As a result, the effective radius of the driving pulley 3 becomes larger than that of the driven pulley 8, and the rotation of the input shaft 1 is accelerated and transmitted to the output shaft 2.

Further, as the movable sheave 11 of the driven pulley 8 moves on the output shaft 2 in a direction away from the fixed sheave 10, the driven cam 14 is pressed by the drive cam 18 and moves on the input shaft 1. The clutch pad 22, which is movably connected to the clutch pad 22 via the connecting rod 24, moves to the left in the figure and is released from contact with the spring seat 20. As a result, the spring seat 20 is pressed by the spring force of the spring 21 and rotates on the output shaft 2 relative to the output shaft 2, for example, in the speed increasing direction, until it contacts the clutch pad 22 again. The spring seat 20 moves in conjunction with the movement of the movable sheave 11, so that the spring force of the spring 21 against the movable sheave 11 is kept approximately constant. Ru.

On the other hand, when lowering the gear ratio between the input and output shafts 1 and 2 to set the low speed mode, if the switching lever is positioned at the low speed position, the switching operation of the switching lever causes the Above drive cam 1
8 rotates on the input shaft 1 in the other direction (for example, counterclockwise), and due to this rotation of the drive cam 18, the pressure on the driven cam 14 is removed, and the driven cam 14 approaches the drive cam 18 ( As the driven cam 14 moves, the movable sheave 6 of the drive pulley 3 moves in the same direction and separates from the fixed sheave 5. This causes the V of the drive pulley 3 to The effective radius for belt 13 is reduced. Further, as the effective radius of the driving pulley 3 decreases, the V-belt 13 is entirely moved around the driven pulley 8 due to the biasing force of the spring 21 in the direction of increasing the effective radius of the driven pulley 8.
As the V-belt 13 moves, the movable sheave 11 of the driven pulley 8 moves to the fixed sheave 10.
The effective radius of the driven pulley 8 increases as the driven pulley 8 moves on the output shaft 2 in a direction approaching (rightward in the figure). As a result, the effective radius of the driving pulley 3 becomes smaller than that of the driven pulley 8, and the rotation of the input shaft 1 is decelerated and transmitted to the output shaft 2.

Also, as described above, in conjunction with the movement of the movable sheave 11 of the driven pulley 8 on the output shaft 2 in the direction approaching the fixed sheave 10, the drive cam 18 moves on the input shaft 1 toward the drive cam 18 side. Followed cam 1
Clutch pad 22, which is connected to 4 through a connecting rod 24, moves rightward in the figure to press and brake the spring seat 20. The spring seat 20 receiving the braking force from the clutch pad 22 rotates relative to the output shaft 2 in the deceleration direction while moving toward the right in the figure on the output shaft 2 until the contact state with the clutch pad 22 returns to a steady state. The movement of the spring seat 20 maintains a constant distance between the spring seat 20 and the movable shaft 11, and the movement of the spring seat 20 in conjunction with the movable shaft 11 causes the spring 21 to move against the movable shaft 11. The force is held approximately constant as above.

Therefore, in this embodiment, the spring seat 20 moves in conjunction with the movement of the movable sheave 11 of the driven pulley 8, and the biasing force of the spring 21 against the movable sheave 11 changes as the effective diameter of the driven pulley 8 changes. Since it remains approximately constant regardless of the input/output axis 1,
The power transmission efficiency between the two can be increased, and the life of the V-belt 13 can be extended.

In that case, the spring seat 20 is moved in the axial direction by the relative rotation difference with respect to the output shaft 2, and the spring force of the driven pulley 8 against the movable sheave 11 is kept constant. The adjustable range of the spring force of the spring 21 against the movable sheave 11 of the driven pulley 8 can be expanded accordingly, and the maximum distance between the belt grooves 12 of the driven pulley 8 can be increased to 8 speed ratio can be set to a large value.

Moreover, since the spring seat 20 is moved in the axial direction by screw feeding, the ratio of the rotation angle to the axial movement distance becomes large.
The spring force can be adjusted with high precision.

In the above embodiment, the movable shaft 6 of the drive pulley 3 on the input shaft 1 is moved in the axial direction by a cam mechanism consisting of the drive cam 18 and the driven cam 14, but other mechanisms, such as input shaft 1 It is also possible to move the movable shaft by means of a screw member or the like that is screw-fed by relative rotation with the movable shaft.

Further, in the above embodiment, the movable shaft 11 of the driven pulley 8 provided on the output shaft 2 is biased by the spring 21, but conversely, a spring may be provided on the drive pulley side on the input shaft. It may be changed to , and the same effect as the above embodiment can be obtained.

(Effects of the Invention) As explained above, according to the present invention, the seat of the spring that biases the movable sheave of the pulley on the rotating shaft in the direction toward the fixed sheave is screw-fed by relative rotation with the rotating shaft. The belt member is movable in the axial direction, and the spring seat is rotated relative to the rotating shaft so that the urging force of the spring against the movable shaft is always approximately constant, thereby improving the durability of the belt member. While aiming at this, it is possible to expand the movable range of the spring catch and expand the adjustment range of the spring force of the spring, and it is also possible to increase the speed ratio by widening the maximum interval between the belt grooves in the variable pulley. Furthermore, the spring force of the spring can be adjusted with high precision, which is an excellent practical effect.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is an overall configuration diagram of the transmission in high speed mode, FIG. 2 is an overall configuration diagram of the transmission in low speed mode, and FIG. 3 is an enlarged cross section showing the main parts. It is a diagram. 1...Input shaft, 2...Output shaft, 3...Drive pulley, 8...Driven pulley, 10...Fixed shaft,
11...Movable shield, 13...V belt, 20
... Spring catch, 21 ... Spring, 22
...Clutch pad, 24...Connection rod, 25
...Spring catch position adjustment means.

Claims (1)

[Scope of Claims] 1. A fixed shaft rotatably and non-slidably fixed to a rotating shaft, and a movable shaft rotatably and slidably supported in the axial direction, the movable In a variable pulley device that changes speed by moving a sheave toward and away from a fixed sheave and changing the effective radius of a belt member wound between both sheaves, the variable pulley device is supported on the rotating shaft and rotates relative to the rotating shaft. a spring catch that is screw-fed and movable in the axial direction; and a spring that is compressed between the spring seat and the movable shake and biases the movable shake toward the fixed shake; It is arranged on the back side of the catch so that it can move in a direction parallel to the rotating shaft, and when it comes into contact with the spring catch, the spring catch is braked and rotated relative to the rotating shaft in one direction, which feeds the screw to the movable shaft side. A variable pulley comprising a spring seat position adjusting means comprising a clutch pad that moves the clutch pad and a moving member that adjusts the position of the clutch pad by moving it in response to a speed change operation so that the biasing force of the spring becomes substantially constant. Device.