JPS62255652A - Toroidal type continuously variable transmission - Google Patents

Abstract

PURPOSE:To prevent the generation of a shock in the starting time and to perform a speed change as predetermined in the time of advancing and reversing, by arranging a forward-reverse switching mechanism in the front stage of an input cone disc and performing the displacement in the axial line direction of a cone roller in its oscillation to be reversed in the advancing time from in the reversing time. CONSTITUTION:Since a forward-reverse switching mechanism 4 exists in the front stage of an input cone disc 5, in the neutral condition that no power is transmitted in said mechanism 4, no rotation is generated in the input cone disc 5, cone rollers 9 and an output cone disc 8 which provide large rotating inertia. As the result, said mechanism 4, when it is placed in a forward or reverse select condition for starting, enables the generation of a large shock to be prevented. While in the time of advancing and reversing, when an oscillating turn due to the displacement in the axial line direction of the cone roller in its oscillation is reversed by reversing rotation of the both cone discs and the cone rollers, a cone roller displacement direction switching means 29 reverses the displacement in the axial direction of the cone roller oscillation. Consequently, a speed change can be performed as predetermined in the both advancing and reversing.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a toroidal continuously variable transmission.

(Prior art) A toroidal continuously variable transmission consists of an input cone disc that receives power manually, an output cone disc that is coaxially arranged with the input cone disc that outputs power, and frictionally engages the opposing cone surfaces of these discs. It is equipped with a cone roller that transmits power between both cone discs, and rotates the cone roller around an oscillation axis that is orthogonal to the rotation axis of the cone roller (oscillation).
Usually, the configuration is such that the gears are changed by shifting the gear.

By the way, when a cone roller is offset in the direction of the swing axis from a neutral position where its rotation axis intersects with the cone disc rotation axis, it receives a swing component force from the cone disc according to the offset direction and rotates around the swing axis by itself. . Therefore, in the past, speed change control performed by swinging the cone roller was generally performed using the configuration described in, for example, Japanese Patent Application Laid-open No. 160663/1983.

(Problems to be Solved by the Invention) On the other hand, when a continuously variable transmission is used in a vehicle, a forward/reverse switching mechanism for switching the transmission output rotation direction is required. The conventional transmission control device described above is intended for a transmission in which the forward/reverse switching mechanism is located downstream of the output cone disk.

By the way, in this transmission, even in the neutral state in which the forward/reverse switching mechanism does not transmit power, the input cone disc, cone roller, and output cone disc with large rotational inertia are rotating, so the forward/reverse switching mechanism is not used at the time of starting. When the vehicle is placed in the forward selection state or reverse selection state, the above-mentioned large rotational inertia causes a large shock.

For this reason and for layout reasons, it is better to provide the forward/reverse switching mechanism at the front stage of the input cone disk.

However, in this case, the input cone disc, cone roller, and output cone disc rotate in opposite directions between the forward selection state and the reverse selection state of the forward/reverse switching mechanism. If it is designed to work effectively in the forward selection state, a problem arises in that, in the reverse selection state, the gear is shifted in the opposite direction to the command from the transmission control device.

(Means for Solving the Problems) In view of the above-mentioned requirements, the present invention arranges a forward/reverse switching mechanism in the front stage of the input cone disc, and by this arrangement, both the cone discs and the cone roller can be switched during forward movement and reverse movement. A cone roller displacement direction switching means is provided for reversing the axial displacement of the cone roller during forward movement and backward movement so that when the rotation is reversed, the speed change control device can operate effectively in both forward and reverse movement. It was established.

(Function) The power that reaches the input cone disk through the forward/reverse switching mechanism is transmitted to the output cone disk through the rotation of the cone roller. During this power transmission, when the cone roller is displaced from the neutral position in the direction of the swing axis,
The cone roller oscillates by receiving the oscillation component force from both cone disks in a direction that depends on the rotational direction of both cone disks and the cone roller and the direction of displacement of the cone roller, which is determined by whether the forward/reverse switching mechanism is selecting forward or reverse movement. It rotates around the axis and can perform continuously variable speed.

By the way, since the forward/reverse switching mechanism exists in the front stage of the input cone disk, in the neutral state where the mechanism does not transmit power, the input cone disk, cone roller, and output cone disk with large rotational inertia do not rotate, causing the mechanism to It is possible to prevent a large shock from occurring when the vehicle is set to go forward or backward when starting.

Furthermore, due to the arrangement of the forward/backward switching mechanism, when the rotation of both cone disks and the cone roller is reversed during forward movement and reverse movement, and the oscillation rotation due to the axial displacement of the cone roller is reversed, The cone roller displacement direction switching means reverses the oscillating axial displacement of the cone roller. Therefore, the oscillation of the cone roller is not reversed when moving forward and when moving backward, and it is possible to perform a predetermined speed change in both forward and backward movement.

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

Figure 1 shows an embodiment of the toroidal type non-operational transmission of the present invention.
In the figure, 1 indicates an input shaft, and 2 indicates an output shaft.

Engine power is input to the human power shaft 1 via a fluid coupling 3, and an input cone disk 5a is drivingly connected via a forward/reverse switching mechanism 4.

The forward/reverse switching mechanism 4 is a well-known double pinion type planetary gear, the sun gear 4S of which is coupled to the input shaft 1, and the ring gear 4. a first pinion 4.1 meshing with the first pinion 4.1;
A second pinion 4 meshing with the pinion and sun gear 4S,
A carrier 4C rotatably supporting the input cone disk 2 and the input cone disk 5 is coupled to the input cone disk 5. The forward/reverse switching mechanism 4 is further provided with a forward clutch 6 that connects the sun gear 4S to the carrier 4C and directly connects the input shaft 1 to the input cone disc 5, and also includes a forward clutch 6 that connects the sun gear 4S to the carrier 4C and directly connects the input shaft 1 to the input cone disc 5. A reverse brake 7 is provided to fix the. When the forward clutch 6 is engaged, the 10 revolutions of the human shaft are directly transmitted to the input cone disc 5, allowing the vehicle to travel forward, and when the reverse brake 7 is engaged, the rotation of the input shaft 1 is reversed and transmitted to the input cone disc 5, allowing the vehicle to travel in reverse. It is possible to drive.

An output cone disk 8 is disposed coaxially opposite to the input cone disk 5, and this output cone disk is coupled to the output shaft 2. A pair of cone rollers 9 are provided on both sides of the rotation axis of the cone disk by frictional coupling to the opposing cone surfaces 5a and ga of the disks 5 and 8, and each cone roller is rotated around an oscillation axis 9b perpendicular to the rotation axis 9a. By changing the point of frictional engagement with the cone disc 5.8, continuously variable speed is possible.

A structure for performing such a speed change is shown in FIG.

This FIG. 2 corresponds to a cross-sectional view taken from the line ■-■ in FIG.
Rotatably supported in the middle. The shaft 10 is supported at both ends by bearings 11 and 12 so as to be able to rotate around the swing axis 9b of the corresponding cone roller 9, and the bearings 11 and 12 at the upper end and the lower end of the rainyuki furisode lO are respectively supported. It is articulated by tie rods 13 and 14.

The quirods 13, 14 are connected at their centers to the transmission case 15 via joints 16, 17, and one of the oscillating shafts 10 is raised and lowered in the direction of the oscillating axis 9b by hydraulic pistons 18, 19 provided at both ends thereof. The other swing shaft is controlled to move up and down in conjunction with the tie rods 13 and 14. Note that the hydraulic pistons 18 and 19 are fitted into the transmission case 15 so as to face the hydraulic chambers 20 and 21.

A rotary valve 22 for controlling hydraulic pressure to the hydraulic chambers 20 and 21 is provided in association with one of the swing shafts 10, and this rotary valve is similar to that shown in the above-mentioned document, JP-A-58-160663. , one of the above swing shafts 1
The outer sleeve 22a is rotatably engaged with the outer sleeve 22a, and the inner sleeve 22b is rotatably inserted into the inner sleeve 22b.The communication circuits 23 and 24 are connected to the drain circuit 25 and the pump pressure circuit 26, respectively, by the relative rotation of both sleeves in one direction. The connection circuits 23, 24 are connected to the pump pressure circuit 26 and the drain circuit 25, respectively, by relative rotation of both sleeves in the other direction. Note that a cone roller displacement direction switching means 29 is provided between the communication circuits 23 and 24 and the connection circuits 27 and 28 of the hydraulic chambers 20 and 21.

This means is a 2-position electromagnetic switching valve, and a reverse travel circuit 23.in which the operation of the reverse brake 7 (see FIG. 1) is detected by a reverse travel sensor 30. ．． 24 to circuits 27.28 and otherwise connect circuits 23.24 to circuits 28.24. ``It shall lead to 27.

The inner sleeve 22b is drive-engaged with a step motor 32 via a gear train 31, and the step motor 32 is drive-controlled by a speed ratio determining circuit 33. The gear ratio determining circuit 33 receives a signal from a throttle sensor 34 that detects the engine throttle opening degree Tll, a signal from a vehicle speed sensor 35 that detects the vehicle speed ■, and a signal from the water temperature sensor 36 that detects the engine cooling water temperature T. The step motor 3 is input so that the optimum gear ratio is determined from this input information, and the inner sleeve 22b is rotated to a position corresponding to this gear ratio.
2 shall be driven and controlled.

The operation of the above embodiment will be explained next.

First, to explain the power transmission function with reference to FIG. 1, the rotation that reaches the human power shaft 1 via the fluid coupling 3 is directly input to the input cone disc 5 when the forward clutch 6 is engaged.
Thereafter, through the rotation of the cone roller 9, the cone reaches the output cone disk 8 and is taken out from the output shaft 2, allowing forward travel.

On the other hand, when the reverse brake 7 is engaged, the rotation of the human power shaft 1 is input to the input cone disc 5 in reverse order, and then follows the same path as above to enable reverse travel.

Next, the speed change operation will be explained with reference to FIG. First, when the forward/reverse switching mechanism 4 (see FIG. 1) is in the forward/forward selection state, the cone roller displacement direction switching means 29 communicates the circuits 23, 24 with the circuits 28, 27. Then, when there is a change in the optimum gear ratio determined by the circuit 33, the step motor 32 rotates the inner sleeve 22b to a corresponding position via the gear set 31. As a result, the relative rotational position between both sleeves 22a and 22b shifts, and the low-return valve 22
The inner sleeve (22b) is connected to the circuit 25 depending on the direction of rotation.
26 or 26.25, and pressurizes one of the hydraulic chambers 21.20 and depressurizes the other through a circuit 28.27. As a result, the swing shaft 10 is raised or lowered in the direction of the axis 9b,
At this time, since the rotation axis 9a of the cone roller 9 is offset from the cone disc rotation axis 0, the cone roller 9 receives a swing component force in the direction corresponding to the offset direction and swings in the same direction around the axis 9b, thereby achieving the above-mentioned optimum. The gear ratio can be changed.

On the other hand, the swinging rotation of the cone roller 9 is fed back to the outer sleeve 22a of the low revalve 22 via the swing sleeve 10, and the outer sleeve 22a is rotated to follow the inner sleeve 22b. When the cone roller 9 continues to receive the swinging force and reaches a swinging angle such that the gear ratio exceeds the optimum gear ratio, the outer sleeve 22a rotates with respect to the inner sleeve 22b beyond the neutral relative rotational position, and as a result, the rotary valve 22 rotates. The connections between circuits 23 and 24 and circuits 25 and 26 are switched, and the cone roller 9 is oscillated in the opposite direction to return to the oscillation position corresponding to the optimum gear ratio. By repeating this action, the cone roller swing angle becomes 1, which corresponds to the optimum gear ratio.
It is possible to maintain this optimum gear ratio.

By the way, when the forward/reverse switching mechanism 4 (see FIG. 1) is in the reverse select state, basically the same speed change control action as in the forward direction is performed. Therefore, when going backward, the input cone disc 5, cone roller 9, and output cone disc 8 are rotating in the opposite direction to when going forward, and with the same speed change control as when going forward, the swinging force applied to the cone roller 9 is also reversed. , the gears are shifted in the opposite direction (for example,
When a high-speed gear ratio is requested, control is performed toward a low-speed gear ratio. However, when moving backward, the cone roller displacement direction switching means 29 switches the circuits 23 and 24 to the circuit 27 in the opposite direction to that when moving forward.
．． Switch connection to 28. Therefore, the swinging sleeve 10 is raised and lowered in the direction opposite to that when moving forward, and despite the above, a predetermined speed change control can be obtained.

In the above example, the cone roller displacement direction switching means 29
was inserted between circuits 23, 24 and 27, 28, but instead of this, drain circuit 25 and pump pressure circuit 2 are inserted as shown in FIG.
6, connect the circuit parts 25b and 26b to the circuit part 261.25a when moving in reverse, and connect the circuit part 2 to the circuit part 2 at other times.
5b, 26b are configured to be connected to the circuit portions 25a, 26a, similar effects can be achieved.

(Effects of the Invention) Thus, the toroidal continuously variable transmission of the present invention has the following effects as described above.
Since the forward/reverse switching mechanism 4 is arranged in front of the input cone disc 5, when the mechanism is in a neutral state (with both the clutch 6 and the brake 7 inactive) where no power is transmitted,
Input cone disc 5 with large rotational inertia,
Since the cone roller 9 and the output cone disk 8 do not rotate, it is possible to prevent a large shock from occurring when the mechanism 4 is set to the forward or reverse selection state at the time of starting.

Also, the swing axis of the cone roller 9 (
Since the means 29 for reversing the displacement in the direction 9b) is provided, the rotation of the cone disc 5.8 and the cone roller 9 is reversed when moving forward and when moving backward due to the above-mentioned arrangement of the forward/reverse switching mechanism 4. If the oscillating rotation associated with the axial displacement of the roller 9 is reversed, the awl can also enable predetermined speed changes in both forward and reverse directions.

[Brief explanation of drawings]

Fig. 1 is a route diagram showing the power transmission train of the toroidal type continuously variable transmission of the present invention, and Fig. 2 is a cross section corresponding to the line ■-■ in Fig. 1 showing the speed change control section of the toroidal type continuously variable transmission of the present invention. 3 are sectional views similar to FIG. 2 showing other examples of the speed change control section. 1... Human power shaft 2... Output shaft 3... Fluid coupling 4... Forward/forward switching mechanism 5... Input cone disc 6... Forward clutch 7... Reverse brake 8.
... Output cone disc 9 ... Cone roller 10 ... Oscillating shaft 13,
14...Tie rod 15...Transmission case 16
, 17...Joint 18.19...Hydraulic piston 22...Lower valve 29...Cone roller displacement direction switching means 30...Backward movement sensor 31...Gear set 32...Step motor 33... - Gear ratio determination circuit 34...Throttle sensor 35...Vehicle speed sensor 36...Water temperature sensor Patent applicant Nissan Motor Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] 1. An input cone disk into which power is input, an output cone disk coaxially arranged therewith and outputting power, and an input cone disk that is frictionally engaged with the opposing cone surfaces of these disks to form a gap between the two cone disks. and a cone roller for transmitting power, the cone roller is displaced in the direction of an oscillation axis perpendicular to the rotation axis of the cone roller, and the cone roller self-rotates around the oscillation axis, thereby changing the speed. , a toroidal continuously variable transmission in which the transmission output rotation direction is switched by a forward/reverse switching mechanism, wherein the forward/reverse switching mechanism is provided at the front stage of the input cone disc, and the forward/reverse switching mechanism is configured to switch between forward and reverse when the forward/reverse switching mechanism is selected. A toroidal type continuously variable transmission characterized in that a cone roller displacement direction switching means is provided for reversing the oscillating axial direction displacement of the cone roller when selected.