JP2001324002A - Variable speed control device of troidal type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change the feedback amount of axial displacement of a trunnion according to a tilting angle to the optimum value while the relationship between the driving amount o an actuator and the tilting angle of a power roller is kept substantially constant. SOLUTION: This variable speed control device is formed by a variable speed control valve 100 for controlling oil pressure to a hydraulic cylinder for driving the trunnion, a step motor 11 for driving the variable control valve 100 through a variable speed link 4, and a feedback means for transmitting displacement of the trunnion round the axis and the axial displacement thereof through a variable speed link to the variable speed control valve 100. The feedback means is formed by a cam plate 2, an L link 7 for transmitting the axial displacement of the trunnion, and a feedback link 3 connecting the cam plate 2 and the L link 7 and connected to the variable speed link 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a shift control device for a toroidal type continuously variable transmission employed in a vehicle or the like, and more particularly to a mechanism for feeding back a tilt angle of a power roller.

[0002]

2. Description of the Related Art Conventionally, a toroidal type continuously variable transmission used for a vehicle includes a transmission control valve driven by an actuator and a mechanism for feeding back a tilt angle of a power roller to the transmission control valve. Known, for example, Japanese Patent Application Laid-Open Nos. 10-148244 and 7-29
No. 3654 and the like.

[0003] One end of an L-shaped and swingable feedback link is in sliding contact with a precess cam provided on a trunnion supporting the power roller, and the tilt angle of the power roller (displacement of the trunnion about the axis of the trunnion). ) And the axial displacement of the trunnion are transmitted to the shift control valve.

Here, the former will be described as an example. FIGS. 8 and 9 show that the speed change control is performed by independent speed change control valves at the time of forward movement and at the time of reverse movement, respectively. At the lower part of the trunnion that supports the power roller, a precess cam 92 for forward movement,
A recessed precess cam 93 is formed.

[0005] The precess cam 92 for advance has a predetermined inclined surface (not shown) formed therein, and determines the tilt angle of the power roller (= displacement around the axis of the trunnion, equivalent to the gear ratio) and the axial displacement of the trunnion. L link 5 formed in L shape
4 drives one end of the speed change link 9. The L link 54 swings around the Y axis in the figure by a swing shaft 57, and engages with the forward precess cam 92 at one end and engages with the engaging portion 90 of the speed change link 9 at the other end. The L link 54 has a predetermined lever ratio L1 / L2, and drives the engaging portion 90 of the transmission link 9 according to the displacement of the precess cam 92.

An engaging portion 9 provided at the other end of the transmission link 9
1, a step motor 50 is connected, and drives a spool of a shift control valve 100 provided in the middle of the shift link 9 in the X-axis direction in the figure. The spool of the transmission control valve 100 is driven by the feedback from the 92 and the L link 54, and a predetermined tilt angle = speed ratio is maintained.

On the other hand, the recessed precess cam 93 has L
One end of the link 154 is engaged, and the spool of the reverse speed change control valve (not shown) connected to the other end of the L link 154 is driven in accordance with the displacement of the reverse precess cam 93. The L link 154 is also used for the forward L link 54.
And is oscillated about the Y axis in the figure.

The transmission control valve, the step motor 50,
The valve body 80 supporting the feedback mechanism includes:
In order to attach the L links 54 and 154 which swing while engaging with the precess cams 92 and 93, a notch portion 81 is formed in the peripheral edge portion to smoothly swing the L links 54 and 154.

[0009]

However, in the above conventional example, a large space is required to secure the movable range of the L links 54 and 154 swinging around the Y axis in FIG. In particular, the axial dimension of the trunnion (FIG. 8)
(Z axis direction), the swing angle of the L links 54 and 154 must be increased unless the arm length L1 of the L links 54 and 154 is set to be large to some extent.

When the swing angle of the L-links 54 and 154 increases, the displacement of the speed change link 9 on the side of the engagement portion 90 shown in FIG. 8 and the engagement portion connected to the step motor 50 corresponding to the speed change command. The non-linearity in the relationship of the displacement of the speed change link 9 on the 91 side increases.

In other words, in order to ensure the stability of the speed change control, the displacement of the spool of the speed change control valve must be increased, and accordingly, the displacement of both ends of the speed change link 9 must also be increased. Therefore, if the arm length L1 of the L link 54 connected to the precess cam 92 is short, the L link 5
4, the displacement of the speed change link 9 on the engagement portion 90 side increases near the speed ratio = 1, while
The ratio becomes smaller at the maximum (lowest Lo) speed ratio or the minimum (highest Hi) speed ratio, and the non-linearity increases with respect to the displacement of the engaging portion 90 on the side of the step motor 50 driven at a substantially constant ratio.

The non-linearity between the drive amount of the step motor 50 and the feedback amount from the L-link 54 needs to be compensated by a control unit using a map or a function.

Further, even when the outer diameter of the spool of the transmission control valve 100 cannot be made sufficiently large, the displacement of the transmission link 9 can be increased by setting the arm length L1 of the L link 54 larger than L2. However, it is necessary to increase the stroke gain of the spool to ensure the stability of the speed change control.

As described above, in order to ensure the stability of the shift control, the arm length L1 of the L link 54 must be increased, and the dimension in the Z-axis direction of FIG. The machine becomes larger.

In order to avoid this enlargement, as shown in FIG. 9, a notch 81 is provided in accordance with the swing range of the L-links 54, 154, and the arrangement positions of the L-links 54, 154 are changed. The lever ratio L1 / L2 of the L-links 54, 154 is secured close to the trunnion (precess cams 92, 93) side. However, the provision of the notch 81 reduces the volume of the valve body 80, The arrangement of each control valve becomes difficult, and there is a problem that a sufficient oil passage cross-sectional area may not be secured.

Accordingly, the present invention has been made in view of the above problems, and prevents a reduction in the volume of a valve body and facilitates the layout of a control valve and an oil passage while ensuring a sufficient amount of feedback from a precess cam. Thus, it is an object to maintain the stability of the shift control.

[0017]

According to a first aspect of the present invention, a power roller sandwiched by an input / output disk and rotatably supported is rotatably supported, and is rotatable about a predetermined axis and axially displaceable. A trunnion, a shift control valve that controls the hydraulic pressure to a hydraulic cylinder that drives the trunnion in the axial direction, an actuator that drives the shift control valve through a shift link, and a displacement of the trunnion about an axis and an axial direction of the trunnion. And a precess cam for transmitting the displacement of the to the transmission control valve to the transmission control valve via the transmission link.
A cam surface is formed on the side surface, and the cam surface slides on the speed change link.

According to a second aspect of the present invention, in the first aspect, the cam surface has a distance from the axis of the trunnion to the distance from the axis of the trunnion in accordance with displacement about the axis of the trunnion at a position in sliding contact with the speed-change link. And the distance of the transmission link from the axis of the trunnion according to the axial displacement of the trunnion.

In a third aspect based on the second aspect, the cam surface changes its radius in accordance with displacement of the trunnion about an axis at a position where the cam surface is in sliding contact with the speed change link, and the cam surface is aligned with the axis of the trunnion. It has an angle set in advance.

In a fourth aspect based on the first aspect, the speed change link is connected to an actuator and a speed change control valve and is capable of swinging. The movable second speed change link is connected to the first and second speed change links.

According to a fifth aspect of the present invention, in the first aspect, the speed change control valve comprises a forward speed change control valve and a reverse speed change control valve. A reversing cam surface is formed on each side surface, and the forward shift control valve is driven by a forward shifting link that is connected to the actuator and slides on the forward cam surface.
The reverse shift control valve is driven directly or indirectly via a reverse cam surface.

[0022]

Therefore, according to the first aspect of the present invention, the transmission link swings in accordance with the drive amount of the actuator, which is a transmission command, and drives the transmission control valve to control the hydraulic pressure of the hydraulic cylinder to thereby control the trunnion. Displace and tilt the power roller. The precess cam is also displaced in accordance with the tilt angle of the power roller (displacement around the axis of the trunnion) and the axial displacement of the trunnion, and the speed change link that slides on a cam surface formed on the side surface of the precess cam is driven to control the speed change. The tilt angle of the power roller and the axial displacement of the trunnion are fed back to the valve.

In the cam surface formed on the side surface of the precess cam,
Since the speed change link is driven, the swinging feedback arm as in the conventional example can be eliminated, and the feedback mechanism can be reduced in the axial direction of the trunnion. In addition to promoting the miniaturization of the valve body, the notch of the valve body for swinging the arm as in the above-described conventional example is not required, and the volume of the valve body is prevented from being reduced, and the layout of each control valve and the oil passage is prevented. Can be easily performed, and the degree of freedom in design can be improved.

According to a second aspect of the present invention, the cam surface changes the distance of the transmission link from the axis of the trunnion in accordance with displacement around the axis of the trunnion at a position where the cam surface is in sliding contact with the transmission link, and the cam surface is disposed in the axial direction of the trunnion. Since the cam surface 2 is formed so as to change the distance of the speed change link from the axis of the trunnion in accordance with the displacement, the cam surface 2 gives feedback to the speed change link in accordance with the tilt angle in the radial direction, and provides The corresponding feedback can be given to the speed change link, and the displacement of the speed change link, while suppressing the relationship between the drive amount of the actuator and the tilt angle from becoming non-linear,
In other words, it is possible to secure a sufficient amount of driving of the shift control valve to ensure the stability of the shift control.

According to a third aspect of the present invention, the cam surface changes its radial direction in accordance with the displacement of the trunnion around the axis.
The feedback according to the tilt angle is given to the transmission link 4,
Feedback is provided to the transmission link in accordance with the axial displacement of the trunnion at an angle with respect to the axis of the trunnion.

According to a fourth aspect of the present invention, a speed change link is connected to an actuator and a speed change control valve so as to be swingable, and a second speed change link is slidably contacted with a precess cam.
By dividing the speed change link and connecting the first and second speed change links, the feedback amount from the precess cam can be amplified according to the lever ratio of the second speed change link, and the displacement amount of the speed change link, in other words, the speed change speed It is possible to secure a sufficient amount of drive of the control valve and to secure the stability of the shift control.

According to a fifth aspect of the present invention, the speed change control valve is divided into a forward movement and a reverse movement, and a forward cam surface and a reverse movement cam surface are formed on a side surface of the precess cam, respectively. The shift control valve is driven by a forward shift link that is connected to the actuator and slidably contacts the forward cam surface, while the reverse shift control valve is driven directly or indirectly through the reverse cam surface. Because the cam surface for driving the reverse shift control valve is provided on the same precess cam as the forward cam surface, the axial dimension of the trunnion is reduced even when the forward and backward shift control valves are used. The volume of the valve body can be ensured while reducing the size and promoting downsizing, and the drive amount of the forward and backward shift control valves can be sufficiently ensured to maintain the stability of the shift control in forward and backward traveling.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 to 3 show an example in which the present invention is applied to a shift control device of a half toroidal type continuously variable transmission.
In response to a command from a control unit (not shown), the stepping motor 11 drives the speed change control valve 100 via the speed change link 4.
And the power roller 20
The axial displacement (= tilt angle) and the axial displacement of the trunnion 23 that supports the shaft are fed back to the spool 10 via the speed change link 4.

At one end of the speed change link 4, a pin 15 protruded from a slider 14 driven in the axial direction by a step motor 11 as an actuator via a speed reduction mechanism 13.
An engaging portion 41 is formed which engages with.

Further, at a predetermined position in the middle of the speed change link 4, as shown in FIG. 2, a spool 10 sliding on the inner periphery of the speed change control valve 100 via a pin 17 of the connecting member 16.
Rod 101 is connected.

As shown in FIGS. 2 and 3, the shift control valve 10
Reference numeral 0 denotes a port 100L communicating with the oil chamber 30A of the hydraulic cylinder 30 for driving the trunnion 23 in the axial direction, a port 100H also communicating with the oil chamber 30B, and a hydraulic supply source formed between the ports 100L and 100H. 100P and a drain port disposed next to the ports 100L and 100H, respectively.

According to the displacement of the spool 10, the port 100
By supplying the supply pressure of P to one oil chamber and connecting the other oil chamber to the drain to change the pressure difference between the front and back of the piston 31, the trunnion 23 is driven in the axial direction and the power roller 2 is driven.
Tilt 0.

As shown in FIG. 3, the arrangement of the oil chambers 30A, 30B of the hydraulic cylinder 30 for driving the opposing trunnions 23, 23 is reversed.
When the hydraulic pressure Plo from L rises, the trunnion 23 on the right side in the figure rises, while the trunnion 23 on the left side in the figure falls and is pinched between the input disk 21 and the output disk 22,
When the input disk 21 rotates as shown in FIG. 3, the pressed power roller 20 tilts to the Lo side (large side) of the gear ratio.

Conversely, when the hydraulic pressure Phi from the port 100H increases, the trunnion 23 on the right side in the figure decreases while the trunnion 23 on the left side in the figure increases, and the power roller 20 changes the Hi ratio (small) of the gear ratio. Side).

Next, a feedback mechanism for transmitting the tilt angle of the power roller 20 and the axial displacement of the trunnion 23 to the shift control valve 100 will be described.

On the other end of the speed change link 4 connected to the step motor 11, an engagement portion 3 is formed which is in sliding contact with a cam surface 2A formed on the side surface of the precess cam 2.

The precess cam 2 and the shift control valve 10
A spring 5 (elastic member) that urges the engaging portion 3 toward the cam surface 2A is disposed between the spring 5 and the cam surface 2A.

Here, the cam surface 2A of the precess cam 2 is
First, as shown in FIGS. 1 and 2, the tilt angle of the power roller (= displacement around the axis of the trunnion 23) changes from the Hi side (lower gear ratio side) to the Lo side (larger gear ratio side). As a result, a spiral shape is formed so that the distance from the axis 23C of the trunnion 23 to the position where the engaging portion 3 of the transmission link 4 abuts is continuously increased. When a displacement (feedback) is given and the tilt angle becomes Hi, the end of the transmission link 4 on the engagement portion 3 side is driven downward in FIG. The end of the transmission link 4 on the part 3 side is driven upward in FIG.

By setting the radial shape of the cam surface 2A so as to change at a constant rate corresponding to the change in the tilt angle, the relationship between the drive amount of the step motor 11 and the tilt angle is determined. Non-linearity can be suppressed.

On the other hand, the cam surface 2A is
1 and 3, the trunnion 23 having the precess cam 2 is set in the L direction as shown in FIGS.
When the spool 10 is displaced toward the o-side (upward in FIG. 3), the end of the transmission link 4 slidingly contacting the cam surface 2A via the engaging portion 3 is moved to the Lo side in the drawing (the left side of FIG. When the shift link 4 is displaced to the Hi side (downward in FIG. 3), the end of the transmission link 4 closes the spool 10 that opens to the Hi side (right side in FIG. 3). ), The cam surface 2A has a predetermined angle with respect to the axis of the trunnion 23.

The angle of the cam surface 2A with respect to the axis 23C determines the amount of feedback to the transmission link 4 with respect to the axial displacement of the trunnion, and can be changed on the Hi and Lo sides of the tilt angle. For example, the feedback gain for the axial displacement of the trunnion can be set according to the tilt angle.

As described above, since the cam surface 2A is formed on the side surface of the precess cam 2 and the speed change link 4 is brought into direct sliding contact with the engagement portion 3, the feedback arm which swings as in the conventional example described above. Can be eliminated, the feedback mechanism can be reduced in the axial direction of the trunnion 23, and the miniaturization of the toroidal-type continuously variable transmission can be promoted, and the arm is attached to the valve body as in the conventional example. Notches are not required to swing the valve, preventing a reduction in the volume of the valve body, making it easier to lay out each control valve and oil passage, and improving design flexibility. it can.

The cam surface 2A of the precess cam 2 is
Feedback corresponding to the tilt angle in the radial direction is given to the transmission link 4, and the trunnion 23 is angled with respect to the axis 23 </ b> C.
Can be applied to the transmission link 4 in accordance with the axial displacement of the motor, and the relationship between the drive amount of the step motor 11 and the tilt angle can be suppressed from being non-linear.
Thus, it is possible to secure a sufficient amount of displacement of the transmission link 4, in other words, a sufficient stroke of the spool 10 of the transmission control valve 100, thereby ensuring stability of the transmission control.

FIG. 4 shows a second embodiment, in which the first embodiment is used.
The recessed cam surface 2B is provided on the precess cam 2 of the embodiment, and the rest is the same as the first embodiment.

The cam surface 2A, the speed change link 4, and the step motor 11 shown in the first embodiment constitute a forward speed change control unit, and the reverse cam surface 2 added to the precess cam 2 is provided.
B, reverse speed change link 140, reverse speed change control valve 200
, A reverse speed change control unit is formed.

The reversing speed change link 140 is slidably contacted with the reversing cam surface 2B by an engagement portion 143 provided at one end, while the other end is supported on the valve body (not shown) side and the trunnion 2 is supported.
3 oscillates according to the axial displacement and the axial displacement.

The spool 201 of the reverse speed change control valve 200 is connected to the middle of the reverse speed change link 140, and the spool 201 is driven in the axial direction in accordance with the displacement of the trunnion 23.

In this case, when the reversing cam surface 2B is provided with a forward / reverse switching mechanism (not shown) in front of the input disk 21, the rotation direction of the input disk 21 reverses with respect to the forward direction when reversing. Therefore, the Hi side of the tilt angle and L
The relationship on the o side is also set in reverse.

Since the cam surface 2B for driving the reverse shift control valve 200 is provided on the same precess cam 2 as the forward cam surface 2A, even when the forward and backward shift control valves are used, the trunnion 23 can be used. While promoting downsizing by reducing the size in the axial direction, the volume of the valve body can be ensured in the same manner as described above, and the strokes of the spools of the forward and reverse shift control valves 100 and 200 are sufficiently ensured for shifting. Control stability can be maintained.

FIG. 5 shows a third embodiment, in which the second embodiment is used.
The reverse speed change link 40 is omitted, and the reverse speed change control valve 2 is directly provided on the reverse cam surface 2B of the precess cam 2.
The spool 201 of No. 00 is driven, and the other components are the same as those of the second embodiment.

Spool 201 of reverse speed change control valve 200
An engagement portion 202 is formed at an end of the spool 201 so as to slidably contact the retreat cam surface 2B,
Is driven directly.

In this case, since there is no reverse speed change link, the layout of the valve body can be easily performed, and the number of parts can be reduced.

FIG. 6 shows a fourth embodiment, in which the first embodiment is used.
The transmission link 4 of the embodiment is divided into two parts, a first transmission link 4 ′ connected to a step motor 11 and a spool 10 of a transmission control valve 100, and a precess cam 2 at one end.
And a second speed change link 6 which is provided with an engaging portion 62 which is in sliding contact with the cam surface 2A and which is supported halfway by a swing shaft 63 at each end. The other portions are the same as those of the first embodiment. The same is true.

A first motor connected at one end to the step motor 11
A pin 42 is provided at the other end of the speed change link 4 ′, and the other end of the second speed change link 6 slidably contacting the cam surface 2 A at one end is engaged with the pin 42 of the first speed change link 4 ′. A part 61 is formed.

The second transmission link 6 has a cam surface 2A of the precess cam 2 with a lever ratio corresponding to the distance from the engaging portion 62 to the swing shaft 63 and the distance from the swing shaft 63 to the engaging portion 61.
Amplifying the amount of feedback from the first transmission link 4 '
Can be transmitted to

In this case, the stroke gain of the shift control valve 100 can be set to be large, and the outer diameter of the spool 10 is reduced by the increased stroke of the spool 10 to reduce the leakage flow rate of the shift control valve 100. You can.

FIG. 7 shows a fifth embodiment, in which the first
The steep slope portions 21 and 22 in which the feedback gain sharply increases are provided on both sides of the cam surface 2A shown in the embodiment.

The steep slope portions 21 and 22 are used to increase the feedback gain when the tilt angle of the power roller 20 becomes excessive, as in Japanese Patent Application Laid-Open No. 11-325210 proposed by the present applicant. And power roller 2
This is to prevent the trunnion 23 supporting 0 from colliding with a stopper (not shown).

In the above embodiment, the arrangement of the feedback mechanism, the step motor 11, and the shift control valve is as follows.
The position is not limited to the above position, and can be arbitrarily combined.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a shift control device of a toroidal-type continuously variable transmission, showing an embodiment of the present invention.

FIG. 2 is a schematic plan view of the transmission control device.

FIG. 3 is a conceptual diagram of a toroidal type continuously variable transmission.

FIG. 4 is a schematic plan view of a shift control device of the toroidal-type continuously variable transmission, showing the second embodiment.

FIG. 5 is a schematic plan view of a shift control device for a toroidal-type continuously variable transmission, showing a third embodiment.

FIG. 6 is a schematic plan view of a shift control device for a toroidal-type continuously variable transmission, showing a fourth embodiment.

FIG. 7 shows a fifth embodiment, and is a perspective view of a precess cam.

FIG. 8 is a schematic perspective view of a shift control device for a toroidal-type continuously variable transmission, showing a conventional example.

FIG. 9 is a plan view of a main part of a transmission control device, similarly showing a conventional example.

[Explanation of symbols]

 2 Precess cam 2A, 2B Cam surface 3 Engagement part 4 Speed change link 6 Second speed change link 7 L link 10 Spool 11 Step motor 20 Power roller 23 Trunnion

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3J051 AA03 BA03 BB02 BD02 BE09 CA03 CA05 CB04 CB07 DA02 DA05 FA01 3J552 MA09 NA01 NB01 PA14 PA54 PA67 QA24C QB07 QB09 SA45 SB02 TA02 VA24W VA24Y VA74W VA74Y

Claims (5)

[Claims] 1. A trunnion rotatably supporting a tiltable power roller sandwiched between an input / output disk and rotatable about a predetermined axis and displaceable in an axial direction, and a trunnion extending in the axial direction. A shift control valve for controlling oil pressure to a hydraulic cylinder to be driven; an actuator for driving the shift control valve via a swingable shift link; and a displacement about an axis of the trunnion and an axial displacement.
A transmission control device for a toroidal-type continuously variable transmission including a precess cam transmitting to the transmission control valve via the transmission link, wherein the precess cam forms a cam surface on a side surface, and the cam surface and the transmission link are A transmission control device for a toroidal-type continuously variable transmission, wherein the transmission is in sliding contact. 2. The cam surface changes the distance of the transmission link from the axis of the trunnion in accordance with the axial displacement of the trunnion at a position in sliding contact with the transmission link, and changes the distance of the transmission link in the axial direction of the trunnion. The shift control device for a toroidal-type continuously variable transmission according to claim 1, wherein the distance of the shift link from the axis of the trunnion is changed. 3. The cam surface changes its radius at a position where the cam surface is in sliding contact with the speed change link in accordance with displacement of the trunnion about an axis, and has a predetermined angle with respect to the axis of the trunnion. The shift control device for a toroidal-type continuously variable transmission according to claim 2. 4. The first transmission link, which is connected to an actuator and a transmission control valve and is swingable, wherein the first transmission link is swingable.
The speed change control device for a toroidal-type continuously variable transmission according to claim 1, wherein a second speed change link slidably in contact with the precess cam and the first and second speed change links are connected. 5. The speed change control valve comprises a forward speed change control valve and a reverse speed change control valve.
A forward cam surface and a reverse cam surface are formed on respective side surfaces, and the forward speed change control valve is driven by a forward speed change link which is connected to the actuator and slidably contacts the forward cam surface. The speed change control device for a toroidal-type continuously variable transmission according to claim 1, wherein the speed change control valve is driven directly or indirectly via a reverse cam surface.