JPS62258254A - Toroidal continuously variable transmission - Google Patents

Abstract

PURPOSE:To prevent slippage of a cone roller by varying the pushing force of the cone roller according to the transmission torque and the swing angle of the cone roller. CONSTITUTION:The swing angle of a cone roller 23 determines the rotary position of a cam 35 so as to cause an angle-hydraulic pressure converting section 36 to provide a hydraulic pressure corresponding to the swinger angle to a circuit 39 from which the hydraulic pressure is fed to a torque-hydraulic pressure converting section 40. The working oil in a circuit 38 is provided with such hydraulic pressure as corresponding with the transmission torque by means of a diaphragm 41 functionable in response to the transmission torque thus producing a hydraulic pressure combined with that fed from the circuit 39. Consequently, the pushing hydraulic pressure Pa in the circuit 38 corresponds to the swing angle of the cone roller and the transmission torque and fed to a hydraulic chamber 19. Said hydraulic pressure Pa energizes a hydraulic piston 18, and a cylinder 17 in the separating direction with a pushing force Fa so as to approach an input cone disc 12 and an output cone disc 13 each other with the pushing force Fa. Consequently, slippage or power loss of the cone roller can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a toroidal continuously variable transmission, and particularly to a cone roller "pressing structure" thereof.

(Prior art) Toroidal type continuously variable transmissions are conventionally known, for example, as disclosed in Japanese Patent Application Laid-Open No. 59-6
This is well known from Japanese Patent No. 5654, and it was common to have a configuration as shown in FIG.

That is, an input cone disk 1 for inputting power and an output cone disk 2 for outputting power are coaxially provided, and a cone roller 3 is provided in frictional engagement between these cone disks. The cone roller 3 is rotatable around an axis 4 and transmits power to the input cone disc 1 to the output cone disc 2. During this power transmission, the cone roller 3 is oscillated around an axis 5 perpendicular to the rotational axis 4 (the oscillation angle is indicated by ψ). The matching point can be changed continuously and the speed can be continuously changed.

By the way, in order to compensate for the above power transmission, it is necessary that the frictional engagement force between the cone roller 3 and the cone disk 1.2, that is, the pressing force, be greater than a predetermined value. It was normal for it to increase in size as it grew.

(Problems to be Solved by the Invention) However, the required pressing force not only changes depending on the transmitted torque, but also changes depending on the swing angle ψ of the cone roller 3, as described below.

That is, the required value of the pressing force Fa is as shown by a in FIG. 5 when the transmitted torque is maximum, and as the transmitted torque decreases, not only does the characteristic at the minimum transmitted torque decrease; The value of the cone roller swing angle ψ. It is known that it is maximum at , and decreases as you move away from it.

However, in a conventional system that only increases the pressing force Fa as the transmitted torque increases, when the transmitted torque is at its maximum, the fifth
The pressing force is set as shown in C in the figure. Because of this, each transmitted torque and each oscillation ψ. When , the pressing force matches the required value, but the swing angle is ψ. The pushing force becomes excessive as it moves away from the contact point, which not only causes a deterioration in transmission efficiency due to an increase in power loss, but also significantly reduces the lifespan of the parts that support the pushing reaction force, resulting in poor durability.

(Means for Solving the Problem) The present invention achieves the above-mentioned problem by making the cone roller pressing force changeable not only according to the transmitted torque but also according to the cone roller swing angle so that it always matches the required value. It is designed to provide a first pressurizing means that generates a force corresponding to the transmitted torque, and a second pressurizing means that generates a force corresponding to the swing angle of the cone roller, so that both pressurizing means generate The above-mentioned pressing is performed using the applied force.

(Function) Power to the input cone disc can be transmitted to the output cone disc, which is also frictionally engaged with the input cone disc, via the rotation of the cone roller that is frictionally engaged with the input cone disc with the push.

By swinging the cone roller around an oscillation axis perpendicular to its rotational axis during power transmission, the frictional engagement points of the cone roller with both cone disks are continuously changed, and continuously variable speed can be achieved.

By the way, the pressing of the cone roller for compensating the power transmission is performed by the force generated by the first pressure means in accordance with the transmission torque and the force generated by the second pressure means in accordance with the swing angle of the cone roller. Therefore, the corn roller pressing force takes into account not only the transmitted torque but also the corn roller swing angle, and the corn roller pressing force can be matched to different required values depending on the transmitted torque and the corn roller swing angle. . This prevents the above-mentioned pressing force from becoming excessive in areas where the cone roller swing angle (speed ratio) is relatively small or relatively large. It is possible to prevent the durability from being deteriorated due to a significant decrease in service life at the parts that support the parts.

(Example) Hereinafter, the present invention will be described in detail based on illustrated embodiments.

Figure 1 shows an embodiment of the toroidal continuously variable transmission of the present invention.
For convenience, a sectional view taken along the line ■-I on the right side of this figure is shown on the left side of the same figure.

Reference numeral 10 denotes a transmission case, in which an input shaft 11 is rotatably provided. An input cone disk 12 is integrally connected on an input shaft 11, and an output cone disk 13 is provided coaxially with the input cone disk. An output cone disk 13 is integrally coupled onto a hollow output shaft 14, and the hollow output shaft is rotatably supported on the input shaft 11.

Further, on the output shaft 14, an output gear 15 and an inner race 16a of a thrust bearing 16 are drivingly coupled so as to be immovable in the axial direction, and an outer race 16b of the thrust bearing 16 is connected to the output shaft 14 so as to be immovable in the axial direction.
is fitted into the cylinder 17 attached to the transmission case 10.

A hydraulic piston 18 is slidably fitted into the cylinder 17 to define a hydraulic chamber 19. An outer race 20a of a thrust bearing 20 is applied coaxially to the side of a hydraulic piston 18 far from a hydraulic chamber 19, and this outer race is fitted to a partition wall 21 attached to a transmission case 10 so as to be slidable in the axial direction. In addition, the inner race 2 of the thrust bearing 20
0b is coupled via a ring 22 onto the input shaft ll.

A pair of cone rollers 23 are provided between the input cone disk 12 and the output cone disk 13 in frictional engagement with the opposing cone surfaces 12a and 13a, respectively.

These cone rollers are connected to the input shaft 1 so that they can rotate around a common axis 23a that is perpendicular to the center axis of the input shaft 11.
1, and each cone roller 23 is supported by an individual swing shaft 24. The shaft 24 has a corresponding cone roller 23
Both ends are supported by radial bearings 25 and 26 so as to be able to rotate around a swing axis MA 23 b that is perpendicular to the rotation axis of They are connected by tie rods 27 and 28, respectively.

The centers of the tie rods 27 and 28 are respectively connected to the transmission case 10 via joints 29 and 30, and one of the swing shafts 24 is raised and lowered in the direction of the swing axis 23b by hydraulic pistons 31 and 32 provided at both ends thereof. possible. The piston 31.32 thus fits into the transmission case 10 to define a hydraulic chamber 33.34.

A rod 24a extending in the direction of the axis 23b is provided at the upper end of the one swing shaft 24, and a cam 35 is fixed to the tip thereof. The cam 35 is associated with an angle-to-hydraulic converter 36;
This includes a spool 36a, a spring 36b and a plunger 36.
A spool valve consisting of c is used to supply hydraulic oil from the pump 37 to the circuit 38, and the hydraulic pressure corresponding to the spring force of the spring 36b is supplied to the circuit 3.
9. The spring force of the spring 36b is the cam 3
It is determined by the amount of plunge + 36c pushed by 5. By the way, the cam 35 is the shaft 24, and therefore the cone roller 2.
Since the rotational position is determined by the swing angle of the cone roller 3, the spring force of the spring 36c, and therefore the output pressure to the circuit 39, is a value corresponding to the swing angle of the cone roller, and the cam surface shape of the cam 35 is as shown in FIG. The cone roller swing angle is ψ in accordance with the required characteristics shown by the dotted line. The shape is selected so that the spring force of the spring 36b is maximized when .

Connected to the circuits 38 and 39 is a torque-hydraulic converter 40, which is a spool valve that generates hydraulic pressure in accordance with the transmission torque. By the way, since the transmitted torque corresponds to the engine suction negative pressure, the vacuum diaphragm 41, which increases the force in the right direction in the figure as the transmitted torque increases, is connected to the spool 40 of the torque-hydraulic converter 40 in response to this.
a. This torque-hydraulic converter converts the hydraulic oil in the pump circuit 38 into a hydraulic pressure corresponding to the rightward force in the figure of the vacuum diaphragm 41, that is, the transmitted torque, and also receives the hydraulic pressure in the circuit 39 in the rightward direction in the figure on the spool 40a. The oil pressure in the circuit 38 is increased accordingly. Therefore, the torque-hydraulic converter 40 also does not function as an oil-hydraulic summation part that makes the oil pressure Pa in the circuit 38 the sum of the oil pressure corresponding to the transmitted torque and the oil pressure from the circuit 39. ) When Pa is at maximum torque, Figure 5 is solid! ) i d, and at the minimum torque, as shown by the solid line e in the figure (at intermediate torque, it moves up and down between d and e), and is supplied to the hydraulic chamber 19.

The operation of the above embodiment will be explained next.

The power that reaches the input cone disc 12 from the input shaft 11 is transmitted to the output cone disc 13 through the rotation of the cone roller 23, and then transmitted to the output gear 15 via the output shaft 14.

When the swing shaft 24 is moved up and down from the neutral position shown in the figure under hydraulic control in the power transmission chambers 33, 34, the cone roller 23 receives a swing component force from the cone disk 12, 13, and rotates around the axis 23b. to rotate the head in the corresponding direction. As a result, the cone roller 23 is moved to the cone disk 1.
2.13, the frictional engagement point can be changed to change gears. When the desired gear ratio is reached, the oscillating shaft 24 is returned to the neutral position shown in the drawing by hydraulic control in the chamber 33.34, and the cone roller 23 no longer receives the oscillating force from the cone disc 12.13. The changed oscillation angle can be maintained and the gear ratio can be maintained.

On the other hand, the angle-hydraulic converter 36 operates in the circuit 3 due to the above-mentioned action.
At 9, a hydraulic pressure corresponding to the cone roller oscillation angle (maximum when the cone roller oscillation angle is ψ in FIG. 5) is output, and this is supplied to the torque-hydraulic converter 40.

The torque-hydraulic converter (hydraulic summing unit) 40 generates a hydraulic pressure that increases as the transmission transmission torque increases due to the above-mentioned action, and adds the pressing hydraulic pressure Pa in the circuit 38 to the sum of this hydraulic pressure and the hydraulic pressure from the circuit 39. Adjust sip. Therefore, the pressing oil pressure Pa depends on the cone roller swing angle and the transmitted torque, d (at maximum torque) and e (at minimum torque) in Figure 5.
It changes as follows and is supplied to the hydraulic chamber 19.

In the chamber 19, the pressing hydraulic pressure Pa urges the hydraulic piston 1B and the cylinder 17 in the direction of separation with a pressing force Fa.

The pressing force on the piston 18 is applied to the input cone disk 12 via the thrust bearing 20 and the human power shaft 11, and the pressing force on the cylinder 17 is applied to the thrust bearing 16,
It extends to the output cone disc 13 via the output shaft 14, and urges the cone discs 12, 13 toward each other with a pressing force Fa. Because of this, corn roller 2
3 is pressed between cone discs 12 and 13, and the cone roller pressing force Pa against these cone discs is as shown in d (at maximum torque) and e (at minimum torque) in Fig. 5, corresponding to the pressing oil pressure Pa. becomes.

By the way, since the pressing force Fa changes depending on the corn roller swing angle and the transmission transmission torque, it can be made to match the required characteristics a and b for each transmission torque as shown in d and e in Fig. 5. , compensating said power transmission, and
This can prevent poor transmission efficiency and poor durability due to excessive pressing force. When setting the pressing force Pa, set the maximum torque at which the aforementioned transmission efficiency and durability problems become noticeable. Based on the standard, the pressing force Fa is determined as d to match the required characteristic a, so that the pressing force characteristic e (calculated proportionally to d) at the lowest torque is near the cone roller swing angle ψ0. Although this is slightly excessive compared to the required characteristics, since the oscillation angle ψ (intermediate gear ratio) applied at the minimum torque is used infrequently, it does not cause problems with transmission efficiency or durability.

FIG. 2 shows a modification of the torque-hydraulic converter (hydraulic summing unit) 40. In this example, since the transmitted torque also corresponds to the engine throttle opening, the vacuum diaphragm 41 in FIG. A throttle cam 42 that rotates half a rotation in conjunction with the throttle valve is provided, so that the spring force of a spring 40b acting on the spool 40a in the right direction in the figure can be adjusted via the spool 40c. The shape of the cam 42 is selected so that the spring force of the spring 40b increases as the throttle opening increases from fully closed to fully open. Therefore, the torque-hydraulic converter 40 can control the pressing oil pressure Pa in the pump circuit 38 in this example as well in the same manner as in the example shown in FIG.

FIG. 3 shows another example of the present invention. In this example, the pressing force control of the cone roller 23 according to the swing angle of the cone roller is performed by hydraulic pressure using the oil pressure from the angle-hydraulic converter 36, as in the previous embodiment. However, the pressing force control of the cone roller 23 in accordance with the transmitted torque is performed mechanically by the thrust generated by the well-known loading cam 36 in accordance with the transmitted torque.

For this reason, the input cone disc 12 is connected to the input shaft 1.
The output cone disk 13 is rotatable on the output cone disk 1.
A hydraulic piston 44 is slidably fitted to the side of the input cone disk 12 farthest from the input cone disk 12 to define a hydraulic chamber 45, and the hydraulic piston 44 is integrally molded to the human power shaft 11.

A loading cam 43 is interposed between the input cone disk 12 and the hydraulic piston 44 between the hydraulic chambers 45.

The outer races of the thrust bearings 16 and 20 are each slidably fitted into a partition wall 21, and a spacer 4 is fitted between the outer races 16b and 20a.
6 to intervene.

An oil passage 11a communicating with the oil pressure chamber 45 is formed in the input shaft 11, and an angle-hydraulic pressure converter 36 is connected to this oil passage 11a. This angle -
The hydraulic pressure conversion unit 36 is the same as that shown in FIG. 1, but in this example, the pressure pb in the pump circuit 38 is changed to a value corresponding to the swing angle of the corn roller (the same value as the hydraulic pressure to the circuit 39 in FIG. 1). ) is supplied to the hydraulic chamber 45 from the oil passage 11a.

In the configuration of this example, power to the input shaft 11 is transmitted to the input cone disc 12 via the hydraulic piston 44 and the loading cam 43, and thereafter transmitted to the output gear 15 via the same path as shown in FIG.

This power transmission middle opening cam 43 generates a thrust according to the transmitted torque to drive the input cone disc 12.
and urges the hydraulic piston 44 in the direction of separation.

The angle-hydraulic converter 36 supplies a hydraulic pressure Pb corresponding to the swing angle of the cone roller from the circuit 38 to the hydraulic chamber 45, and this hydraulic pressure also urges the input cone disk 12 and the hydraulic piston 44 in the direction of separation.

The biasing force to the input cone disc 12 is exerted by the cone roller 23, the output cone disc 13, and the output shaft 14.
and the spacer 46 via the thrust bearing 16, and the urging force to the hydraulic piston 44 is applied to the spacer 46 via the input shaft 11, the ring 22, and the thrust bearing 20.
Therefore, the re-energizing force is canceled out by the spacer 46 and becomes an internal force in the shaft, so that it does not reach the transmission case.
2.13 is pressed to frictionally engage these cone discs to enable power transmission, but the pressing force is due to the thrust by the loading cam 43 and the force by the hydraulic pressure pb from the angle-hydraulic converter 36. Since it is a summed value, the pressing force control can be performed in the same way as in the previous embodiment, and the same objective can be achieved in this embodiment as well.

(Effects of the Invention) Thus, the toroidal type continuously variable transmission of the present invention has the following effects as described above.
Since the configuration is such that the pressing force Fa of the cone roller 23 against the cone disk 12.13 is changed not only according to the transmitted torque but also according to the corn roller oscillation angle, the corn roller pressing force Pa can be changed to the transmitted torque and the corn roller oscillation angle. It is possible to match different required values accordingly. This not only prevents transmission loss due to corn roller slippage due to insufficient corn roller pressing force Fa, but also reduces transmission efficiency due to excessive corn roller pressing force Fa, resulting in increased power loss. In addition, it is possible to prevent a significant decrease in life and loss of durability at a location that supports a pressing reaction force.

[Brief explanation of drawings]

Fig. 1 is a system diagram showing one embodiment of the toroidal type continuously variable transmission of the present invention, Fig. 2 is a sectional view showing a modification of the torque-hydraulic converter in the same transmission, and Fig. 3 is a system diagram showing an embodiment of the toroidal continuously variable transmission of the present invention. Fig. 4 is a route diagram of a toroidal continuously variable transmission, and Fig. 5 shows a cone roller pressing force change characteristic of the toroidal continuously variable transmission of the present invention compared to a conventional toroidal continuously variable transmission. It is a diagram shown in comparison with that. 10...Transmission case 11...Input shaft 12...
- Input cone disc 13... Output cone disc 14... Hollow output shaft 15... Output gear 16.20... Thrust bearing 17... Cylinder 18... Hydraulic piston 23... Cone roller 24... Swing axis 27
, 28...Tie rod 29.30...Joint 31.32...Hydraulic piston 35...Cam 3
6...Angle-hydraulic conversion section 37...Pump 40...
・Torque-hydraulic converter 41...Vacuum diaphragm 42...Throttle cam 43...Loading cam 44...Hydraulic piston 46...Spacer patent applicant Nissan Motor Co., Ltd. Representative Patent Attorney Hide Sugimura Akihiro Patent attorney Oki Sugimura
Figure 5''-m'ne C dem □ (high school 1 and change d

Claims (1)

[Claims] 1. Power is transmitted from the input cone disk to the output cone disk disposed coaxially therewith through the rotation of cone rollers pressed against the opposing cone surfaces of these cone disks. A tridal type transmission that performs continuously variable transmission by swinging around a swing axis perpendicular to the rotation axis, comprising: a first pressurizing means that generates a force corresponding to a transmitted torque; and a cone roller. The second part generates a force according to the swing angle.
A toroidal continuously variable transmission comprising: a pressurizing means, and the pressing is performed by the force generated by both the pressurizing means. 2. The first pressurizing means includes a torque-hydraulic converter that generates hydraulic pressure according to the transmitted torque, and a hydraulic piston that urges both cone discs toward each other in response to the hydraulic pressure. A toroidal continuously variable transmission according to claim 1. 3. The first pressurizing means is constituted by a loading cam that generates a thrust according to the transmitted torque, and the thrust urges both cone disks in the approaching direction. Toroidal continuously variable transmission. 4. The second pressurizing means includes an angle-hydraulic converter that generates oil pressure according to the swing angle of the cone roller, and a hydraulic piston that urges both cone disks toward each other in response to this oil pressure. A toroidal continuously variable transmission according to any one of claims 1 to 3. 5. A torque-hydraulic converter that generates hydraulic pressure according to the transmitted torque; an angle-hydraulic converter that generates hydraulic pressure according to the oscillation angle of the cone roller; and a hydraulic summing unit that adds up these generated hydraulic pressures; The toroidal continuously variable transmission according to claim 1, further comprising a hydraulic piston that urges both cone discs toward each other in response to the combined oil pressure. 6. The toroidal continuously variable transmission according to any one of claims 2, 4, and 5, wherein the hydraulic piston is a non-rotating member.