JP3050040B2 - Shift control device for toroidal type continuously variable transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toroidal type continuously variable transmission, and more particularly to a transmission control device for the same.

[0002]

2. Description of the Related Art A toroidal type continuously variable transmission is usually constructed as described in, for example, Japanese Patent Application Laid-Open No. 3-89066.
As shown in FIGS. 9 and 10, the toroidal type continuously variable transmission has input / output cone disks 2, 3 rotatably supported on an input shaft 1 and arranged coaxially, and a frictional engagement between the input / output cone disks. A toroidal transmission unit having a power roller 4 for transferring power as a main component in some cases, and a shift control device as described later are provided.

First, an input cone disk 2 is rotated via a loading cam 6 by a drive plate 5 integrally connected to an input shaft 1, and this rotation is output via a power roller 4 to an output cone disk. After being transmitted to 4, it is taken out from the output gear 7. During this time, the loading cam 6 generates a thrust corresponding to the transmission torque, and this thrust causes the power roller 4 to rotate.
Is sandwiched between the input and output cone disks 2 and 3 to enable the above-described transmission.

Here, each power roller 4 is rotatably supported on an individual trunnion 8, and these trunnions are rotatably supported at their upper ends by upper links 9 and at their lower ends by lower links 10, respectively. By being supported movably, the strokes are synchronized in opposite directions. To perform the stroke, each trunnion 8
Is further provided with a piston 11.

[0005] The speed change control device comprises a step motor 12.
And the outer valve 13b of the inner and outer valve bodies 13a and 13b of the shift control valve 13 is switched to a position corresponding to the gear shift command (target gear ratio) by a gear shift command (target gear ratio) from the step motor. By displacing the inner valve body 13a relatively from the neutral position, the two trunnions 8 and the power roller 4 are operated with the working fluid from the shift control valve 13 according to the opening degree of the shift control valve 13 determined by the amount of the displacement. Piston 1
1 is displaced in the vertical direction of FIG. 10 at a speed corresponding to the opening degree of the shift control valve 13 in the opposite direction. As a result, the two power rollers 4 are offset at the above-mentioned speeds in opposite directions from the position in FIG. 10 where the rotation axis O ₁ intersects with the rotation axis O ₂ of the input and output cone disks 2 and 3. Is its own rotation axis O ₁ by the component force from the input and output cone disks 2 and 3.
It is possible to perform continuously variable being tilted about the swing axis O ₃ that is perpendicular to the.

When the above-mentioned shift command is achieved by such a continuously variable shift, the inner valve element 13a of the shift control valve 13, which feeds back the offset and tilt of the power roller 4 via the precess cam 14 and the shift link 15, is provided. ,
It returns to the initial neutral position relatively to the outer valve body 13b,
The achievement state of the shift command can be maintained.

However, it is necessary to periodically adjust the initial position of the transmission link 15 with respect to the transmission control valve 13, so that the end of the transmission link 15 opposed to the inner valve body 13a of the transmission control valve 13 is screwed in and adjusted. The adjusting screw 16 is screwed in so as to be adjustable, and the tip of the adjusting screw 16 is brought into contact with the inner valve body 13 a of the transmission control valve 13.

[0008]

However, in such a conventional shift control device, when the relative stroke amount of the inner and outer valve bodies of the shift control valve 13 is determined due to the structure of the shift link 15, the offset of the trunnion 8 is determined. The decision needs to be made taking into account the amount and the amount of the tilt.

Here, the offset amount of the trunnion 8 occurs in response to the shift speed during the shift transition, and the tilt amount occurs in response to the shift result. Therefore, if only the steady state after the shift is completed, the stroke of the shift control valve 13 can be a stroke obtained by multiplying the cam lead of the precess cam 14 by the lever ratio of the shift link 15, but the stroke of the shift control valve 13 during the shift transition period is sufficient. Needs to be obtained by adding a stroke obtained by multiplying the offset amount of the trunnion 8 by the lever ratio of the transmission link 15. Then, the stroke of the shift control valve is not determined unless the latter is determined by assuming the latter shift transition period in which the stroke becomes large. In addition, at the time of the rapid shift at which the offset of the trunnion 8 becomes maximum and the tilting becomes maximum. It is necessary to determine the stroke of the shift control valve 13 in consideration of the maximum speed change ratio, which is given by the following formula. In addition, the shift control valve 13 has a margin so as to be safe even if the offset amount and the tilt amount vary. It is necessary to determine the stroke of the valve 13. Taking these into consideration, the stroke of the transmission control valve 13 becomes considerably large, and it is unavoidable to increase its size.

On the other hand, the lever ratio represented by the ratio of the shift control valve side arm length to the precess cam side arm length of the speed change link 15 is well known in the prior art. It is preferable to increase the value. However, when increasing the lever ratio of the transmission link 15, the transmission control valve 13 is increased due to the increase in the feedback amount.
It is necessary to ensure a larger stroke, so that the size of the transmission control valve 13 is further increased, which is too large to fit in the transmission case.

Therefore, the transmission control valve 13 must be maximized within an allowable range, and the lever ratio of the transmission link 15 must be determined in accordance with the maximum, so that the lever ratio cannot be sufficiently increased. The stability was sacrificed.

However, the lever ratio of the transmission link 15 is
When the required speed change control stability is increased to ensure the required speed change control valve 13, the speed change control valve 13 is
Although the stroke range capable of performing the shift control function is limited, the amount of feedback to the inner valve body 13a increases, the amount of feedback operation increases, and the shift control whose position is determined by a shift command (target gear ratio) is performed. The relative stroke amount of the valve 13 with respect to the outer valve body 13b is determined by the shift control valve 1
There is a concern that the number 3 may increase so that it cannot fulfill the shift control function. According to the present invention, the feedback operation amount of the valve body of the shift control valve to receive the feedback is stopped within a range in which the shift control valve can perform a predetermined shift control function, and the lever ratio of the shift link is increased as described above. In this case, the shift control valve body operation amount is not limited, and the operation of the precess cam that feeds back the offset and tilt of the power roller via the shift link is not limited, while avoiding the concern that the shift control cannot be performed. In other words, the shift control device is prevented from failing, so that even when the shift control valve is limited in size as described above, the shift is controlled so that the required shift control stability is achieved. To propose a shift control device for a toroidal type continuously variable transmission that can increase the link lever ratio,
It is intended to realize the above-mentioned problem solving.

[0013]

SUMMARY OF THE INVENTION To this end, a transmission control apparatus for a toroidal-type continuously variable transmission according to the first invention is provided with an input / output cone disk coaxially arranged and a power input through frictional engagement between the input / output cone disks. A toroidal transmission unit consisting of a power roller and a transfer roller for transferring one of the inner and outer valve bodies of the shift control valve to a position corresponding to a shift command, and from a neutral position relative to the other valve body. By displacing the power roller, the working fluid from the transmission control valve causes the power roller to be offset from a position where the rotation axis of the power roller intersects the rotation axis of the input / output cone disk. In addition to allowing the power roller to tilt around the oscillating axis orthogonal to its own rotation axis, the stepless transmission is performed, When the speed change command is achieved by the continuously variable transmission, the offset and tilt of the power roller are fed back to the other valve body via a precess cam and a speed change link, and the other valve body is moved to the one valve body. In a toroidal-type continuously variable transmission having a shift control device that is relatively returned to a neutral position and maintains a state in which the shift command is achieved, the feedback operation amount of the other valve element by the shift link is changed by shifting. A relief for limiting the amount of operation in which the control valve can perform the shift control function is provided, and after the stopper restricts the operation of the other valve body, a relief allowing displacement of the precess cam due to offset and tilt of the power roller. A mechanism is provided.

A shift control device for a toroidal-type continuously variable transmission according to a second invention is characterized in that the stopper restricts the rotation of the shift link to limit the feedback operation amount of the other valve body. It is assumed that.

In a third aspect of the present invention, the shift control device for a toroidal type continuously variable transmission is characterized in that the stopper directly limits the feedback operation amount of the other valve body.

According to a fourth aspect of the present invention, in the transmission control device for a toroidal-type continuously variable transmission, the transmission link is divided into a link member on the side of the precess cam and a link member on the side of the transmission control valve. The relief mechanism is constructed by pivotally supporting a link member and a transmission control valve side link member on a common axis and elastically supporting a relative rotation position so as to form a predetermined transmission link shape. is there.

According to a fifth aspect of the present invention, there is provided a transmission control device for a toroidal-type continuously variable transmission, wherein the relief mechanism is constituted by supporting a pivot point of the transmission link at a fixed position.

A shift control device for a toroidal-type continuously variable transmission according to a sixth invention is characterized in that the pivot point of the shift link is elastically supported at a fixed position by a spring.

According to a seventh aspect of the present invention, there is provided a transmission control apparatus for a toroidal type continuously variable transmission, wherein a pivot point of the transmission link is supported at a fixed position by fluid pressure.

An eighth aspect of the present invention is a shift control device for a toroidal-type continuously variable transmission, which is provided at an end of the shift link near the shift control valve and adjusts a position between the shift control valve and the shift link. The relief mechanism is constructed by elastically supporting a predetermined position on the end of the speed change link.

[0021]

According to the first aspect of the invention, the power roller transfers power by frictional engagement between the input and output cone disks arranged coaxially. At the time of shifting, one of the inner and outer valve bodies of the shift control valve is switched to a position corresponding to a shift command and displaced from a neutral position relative to the other valve body. As a result, the working fluid from the shift control valve forms a power roller to offset the rotation axis from a position where the rotation axis intersects the rotation axis of the input / output cone disk. Is
Tilt around the swing axis orthogonal to the axis of rotation of the self,
The transmission ratio between the input and output cone disks, that is, the gear ratio, can be changed steplessly. Then, when the shift command is achieved by the continuously variable shift, the offset and tilt of the power roller are fed back to the other valve element of the shift control valve via a precess cam and a shift link to switch the other valve element. It returns to the neutral position relative to the one valve body, and maintains the state of achieving the shift command.

In the first invention, a stopper is provided for limiting the amount of feedback operation of the other valve element by the transmission link to an amount of operation by which the transmission control valve can perform the transmission control function. Since the relief mechanism that allows the displacement of the precess cam due to the offset and tilting of the power roller even after the movement of the body is restricted, the following operation and effect can be particularly obtained. That is, first, according to the former stopper, it is possible to prevent the other valve body from performing a large feedback operation with respect to the one valve body to a region where the shift control valve cannot perform the shift control function, Without worrying about the excessive feedback operation, the lever ratio represented by the ratio of the shift control valve side arm length to the precess cam side arm length of the shift link is adjusted so that the required shift control stability is secured. Can be bigger. Here, the operation amount restriction of the other valve element is originally intended to prevent the further rotation of the transmission link after the restriction, so that the displacement of the precess cam due to the offset and tilting of the power roller is reduced. However, it is possible to prevent the latter escape mechanism from permitting the displacement of the precess cam to reach a locked state in which the precess cam cannot be displaced, so that the configuration of the transmission control device cannot be established. Absent. For this reason, it is not necessary to reduce the lever ratio of the speed change link in view of the above-mentioned locked state. Can be.

The stopper may be constituted by a stopper for limiting the rotation of the speed change link as in the second invention,
Further, it can be constituted by a stopper for limiting the operation of the shift control valve itself as in the third invention.

In the fourth aspect of the invention, the operation of the shift control valve is restricted by the stopper, and even if the shift control valve side link member of the shift link stops rotating about the common axis, the precess cam side link member is not moved. It continues to resist the elastic force and can be rotated around the common axis with the displacement of the precess cam so as not to hinder the displacement of the precess cam. Therefore, whatever the displacement amount of the precess cam, the configuration of the shift control device can be established, and the shift ratio can be freely increased by freely increasing the lever ratio of the shift link without increasing the size of the shift control valve. The above-mentioned effects, such as realization of stability, can be achieved. In addition, according to the configuration of the escape mechanism, a large escape stroke can be ensured, and the operation and effect can be completed.

Instead of this, as the escape mechanism, a structure in which the pivot point of the speed change link is elastically supported at a fixed position as in the fifth invention can be adopted. Or fluid pressure as in the seventh invention. In the relief mechanism of the fifth invention, the relief stroke is slightly reduced, but an inexpensive structure can be achieved. In the sixth invention, the cost can be further reduced. In the seventh invention, the elastic force of the transmission link pivot point is reduced. Can be relatively large.

In the eighth invention, the operation of the shift control valve is restricted by the stopper, and even if the adjusting screw stops,
The speed change link continues to resist the elastic force and can be rotated with the displacement of the precess cam so as not to hinder the displacement of the precess cam. Therefore, whatever the displacement amount of the precess cam, the configuration of the shift control device can be established,
It is possible to achieve the above-described operation and effect that the lever ratio of the transmission link is freely increased to realize the stability of the transmission control without increasing the size of the transmission control valve. In addition, according to the configuration of the escape mechanism, the escape mechanism can be embodied with an inexpensive measure simply by changing the mounting structure of the existing adjustment screw to the speed change link.

[0027]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIGS. 1 to 4 show a shift control device for a toroidal type continuously variable transmission according to an embodiment of the present invention. In these figures, the same parts as those in FIGS. 9 and 10 are denoted by the same reference numerals. In this example, as shown in the assembly diagram of FIG.
And a transmission control valve side link member 22 and a leaf spring 23, which are pivotally connected to a valve outer casing 25 into which the transmission control valve 13 is to be inserted via a common pivot pin 24.

The precess cam side link member 21, as best shown in FIG. 2, has a hole 21a to be inserted a pivot pin 24, as shown in the boss portion 21b to drilling the hole in W _1, the remainder of the precess cam Reduce the thickness of the contact portion 21c to half. On the outer periphery of the boss 21b, a rotation stopper 21d offset from the boss in the axial direction of the pin hole 21a.
To protrude.

As shown in FIG. 3, the shift control valve side link member 22 has a hole 22a into which the pivot pin 24 is to be inserted. excision of the side opposite to the part 21b, as shown by W _1, to half the thickness of the remainder of the shift control valve abutment portion 22c. Then, on the outer periphery of the boss portion 22b, a rotation stopper 22d facing the rotation stopper 21d of the precess cam side link member 21 is provided in a protruding manner.

[0030] As the leaf spring 23 is clearly shown in FIG. 4, the boss portion 23b which has a hole 23 to be inserted a pivot pin 24 and U-shaped cross section, further to the inner width 2W _1, link member The boss portions 21b and 22b of the 21 and 22 can be sandwiched in a state of being coaxially superposed. The leaf spring 23 further bends the end 23c far from the boss 23b along the shift control valve contact portion 22c of the shift control valve side link member 22, and the distal end 23d of the end 23d to the shift control valve contact portion 22c. Is formed into a U-shaped cross-section so that is held.

The precess cam side link member 21, the speed change control valve side link member 22, and the leaf spring 23
As shown in FIG. 1, a common pivot pin 24 is used to
The transmission link 15 is formed by pivotally connecting the link members 5, and at this time, the leaf spring 23 elastically supports the link members 21 and 22 with each other at a relative rotation position where the respective rotation stoppers 21d and 22d abut. And The speed change link 15 is used for practical use by causing the contact portion 21 c of the link member 21 to cooperate with the precess cam 14 and causing the adjustment screw 16 to contact the speed change control valve 13.

In this embodiment, different from the one described above with reference to FIG. 10, the shift control valve 13 receives a shift command to the inner valve body 13a and feeds back the displacement of the precess cam 14 to the outer valve body 13b. The adjusting screw 16 is brought into contact with the outer valve body 13b of the transmission control valve 13.

A stopper 25a for restricting the rotation of the link member 22 when the transmission control valve side link member 22 pushes the outer valve body 13b of the transmission control valve 13 is set on the valve outer casing 25, and this restricted position is set. The shift control valve 13 is made to correspond to the limit position of the feedback operation amount of the outer valve body 13b that can perform a predetermined shift control function.

The operation of the above embodiment will now be described. The toroidal continuously variable transmission performs the transmission and shifting described above with reference to FIGS. 9 and 10, during which the trunnion 8 is tilted about an axis in response to the shifting result and an axial offset in response to the shifting speed during the shifting transition. These offsets and tilts cause the precess cam 14 and the transmission link 1
5, and is fed back to the inner valve body 13a of the shift control valve 13 to be subjected to the shift control described above with reference to FIGS.

When the feedback is large, the speed control valve side link member 22 comes into contact with the stopper 25a as shown in FIG. Therefore, the outer valve element 13b of the shift control valve 13 is not operated in the same direction relative to the inner valve element 13a any more (the above feedback is not accepted). Accordingly, the shift control valve 13 is moved to a stroke range where the shift control valve 13 cannot perform the shift control function.
This does not cause a problem that the outer valve body 13b performs a feedback operation relative to the inner valve body 13a. When the feedback from the precess cam 14 to the link member 21 is further performed even after the shift control valve side link member 22 abuts against the stopper 25a, the link member 21 flexes the leaf spring 23 and responds to the reaction force. Pin 24 against resistance alone
Keep turning around. Therefore, the action of the escape mechanism that allows feedback from the further precess cam 14 to the link member 21 is obtained.

Therefore, the transmission link 1 can be used without worrying that the outer valve body 13b performs a feedback operation up to a stroke region where the transmission control valve 13 cannot perform the transmission control function.
The lever ratio represented by the ratio of the shift control valve side arm length to the precess cam side arm length of No. 5 can be increased so that the required shift control stability is realized. Even if the shift control valve side link member 22 abuts against the stopper 25a after the feedback operation restriction of the shift control valve 13 to prevent further rotation, the precess cam side link member 21 is moved by the action of the relief mechanism. 14
Since the rotation of the precess cam 14 due to the offset and the tilt of the power roller is not hindered, the rotation of the precess cam 14 is not hindered. This can be avoided, and there is no possibility that the configuration of the shift control device cannot be established. For this reason, there is no need to reduce the lever ratio of the transmission link 15 because of concern about the above-mentioned locked state. In this regard, too, the lever ratio of the transmission link 15 is increased to achieve the required stability of the transmission control. can do.

In the above example, there is a structural advantage that the stroke of the escape mechanism can be increased. However, when it is desired to configure the escape mechanism at a lower cost, the escape mechanism is configured as shown in FIGS. be able to. In these examples, the transmission link 15 is basically made the same as the conventional one in FIGS. 9 and 10 to reduce the cost.

In the example of FIG. 6, the block 31 is
And the transmission link 1 is connected to the block via a pin 24.
Pivot 5 By the way, in this pivot, pin 24
The precess cam 14 can be displaced in the axial direction by passing through the long hole 31 a formed in the block 31. Then, the pin 24 is connected to the slot 31 close to the precess cam 14 by the spring 32.
Press against the end of “a” and support it at this position. According to such a relief mechanism, when further receiving feedback from the precess cam 14 even after the transmission link 15 abuts against the stopper 25a, the transmission link 15 is displaced together with the pin 24 against the spring force of the spring 32. The action of the relief mechanism that allows feedback from the further precess cam 14 to the speed change link 15 is obtained.

The medium that presses the pin 24 against the end of the elongated hole 31a near the precess cam 14 is a spring 32 shown in FIG.
Instead, fluid pressure can be used as shown in FIG.
In this case, a piston 33 is provided so as to be slidably fitted in the cylinder chamber 31b of the block 31, and a fluid regulated to a constant pressure is supplied into the cylinder chamber 31b. According to such an escape mechanism, when further receiving feedback from the precess cam 14 even after the transmission link 15 abuts against the stopper 25a, the transmission link 15 is displaced together with the pin 24 against the fluid pressure in the cylinder chamber 31b. And the action of the escape mechanism is obtained. In this example, the elastic force for pressing the pin 24 against the end of the long hole 31a is applied to the cylinder chamber 31b.
Optionally, an advantage can be obtained which can be larger than in FIG. 6, depending on the internal pressure.

In the example of FIG. 8, instead of directly attaching the adjusting screw 16 installed on the speed change link 15 and abutting against the outer valve body 13b of the speed change control valve 13, to the speed change link 15,
The escape mechanism is configured by attaching to the speed change link 15 via the sleeve 34. That is, the adjusting screw 16 is screwed into the sleeve 34, and the sleeve is slidably fitted to the corresponding end of the transmission link 15. At the time of this fitting, the insertion position of the sleeve 34 in the direction toward the shift control valve 13 is limited by the flange 34a of the sleeve 34, and the spring 3
At 5, the sleeve 34 is supported in this position. In addition, in this embodiment, as the stopper for limiting the operation amount of the shift control valve 13, the stopper 25 a for limiting the rotation of the shift lever 15 as in each of the above-described embodiments is replaced by a shift control valve provided in the valve outer casing 25. A stopper 36 for directly limiting the stroke of the thirteen outer valve body 13b is provided.

According to this relief mechanism, the shift control valve 13
Further, when the transmission link 15 receives feedback from the precess cam 14 even after the outer valve body 13b abuts against the stopper 36, the transmission link 15 resists the spring force of the spring 35 relative to the adjusting screw 16 and the sleeve 34. Then, the rotation is continued around the pin 24, and the action of the escape mechanism is obtained. In the escape mechanism of the present example, the escape mechanism can be obtained by an inexpensive measure only by changing the mounting structure of the existing adjustment screw 16 and is practical.

[0042]

As described above, according to the first aspect of the present invention, there is provided a transmission control apparatus for a toroidal type continuously variable transmission, wherein a feedback operation amount of a transmission control valve body by a transmission link is controlled by a transmission control valve. Since a stopper for limiting the amount of operation capable of performing the control function is provided, and an escape mechanism for allowing the displacement of the precess cam due to offset and tilting of the power roller even after the operation of the shift control valve body is limited by the stopper, In particular, the following effects can be obtained. That is, first, the former stopper can prevent the above-mentioned shift control valve element from performing a feedback operation up to an operation amount range where the shift control valve cannot perform the shift control function. Without concern, the lever ratio represented by the ratio of the shift control valve side arm length to the precess cam side arm length of the shift link can be increased so as to ensure the required shift control stability. Here, the feedback operation amount limitation of the speed change control valve body originally prevents the further rotation of the speed change link after the limit, and therefore, the displacement of the precess cam due to the offset and tilt of the power roller. While the latter escape mechanism allows the displacement of the precess cam to avoid a locked state where the precess cam cannot be displaced, so that the configuration of the shift control device cannot be established. There is no. For this reason, there is no need to reduce the lever ratio of the speed change link in view of the above-mentioned locked state. Can be.

The stopper may be constituted by a stopper for restricting the rotation of the speed change link as in the second aspect of the present invention, or may be constituted by a speed change link as in the third aspect of the present invention. It can be configured with a stopper that limits the operation itself of the control valve.

According to a fourth aspect of the present invention, in the transmission control device for a toroidal-type continuously variable transmission, when the relief mechanism is configured, the speed change link includes a precess cam side link member and a speed control valve side link member. Since these link members are pivotally supported on a common axis line and are elastically supported at a relative rotation position so as to have a predetermined transmission link shape, a large relief stroke can be secured. (1) The operation and effect of the invention can be made more complete.

[0045] Instead of this, the escape mechanism may be configured as in claim 5
According to a fifth aspect of the present invention, it is possible to adopt a configuration in which the pivot point of the speed change link is elastically supported at a fixed position. At the time of the elasticity, a spring is provided as in the sixth aspect of the present invention. Although the fluid pressure can be used or the fluid pressure can be used as in the seventh aspect of the present invention, the relief mechanism of the fifth aspect of the invention has a slightly smaller relief stroke, but can be configured at a low cost. In the sixth invention, the cost can be further reduced, and in the seventh invention, the elastic force of the transmission link pivot point can be made relatively large.

According to an eighth aspect of the present invention, a transmission control device for a toroidal type continuously variable transmission is provided at an end of the transmission link close to the transmission control valve. Since the relief mechanism is configured by elastically supporting an adjustment screw for adjusting the position between the transmission link and a fixed position on the end of the transmission link, it is inexpensive enough to change the mounting structure of the existing adjustment screw to the transmission link. By coping, the escape mechanism can be embodied.

[Brief description of the drawings]

FIG. 1 is a detailed view of a main part showing a transmission control device of a toroidal type continuously variable transmission according to an embodiment of the present invention.

FIG. 2A is a front view showing a precess cam side link member of the speed change link in the same example, and FIG. 2B is a plan view of the precess cam side link member viewed from the direction of arrow B in FIG. It is.

3A is a front view showing a speed change control valve side link member of the speed change link in the same example, and FIG. 3B is a sectional view of the speed change control valve side link member taken along line AA in FIG. FIG.

FIG. 4A is a front view of a leaf spring that forms a part of the speed change link in the example, and FIG. 4B is a plan view of the leaf spring when viewed from the direction of arrow C in FIG. is there.

FIG. 5 is an explanatory diagram of the operation of the transmission control device of the example.

FIG. 6 is a main part detailed view showing another example of the transmission control device of the present invention.

FIG. 7 is a detailed view of a main part showing still another example of the transmission control device of the present invention.

FIG. 8 is a main part detailed view showing still another example of the transmission control device of the present invention.

FIG. 9 is a cross-sectional plan view of a toroidal-type continuously variable transmission including a conventional shift control device.

FIG. 10 is a vertical sectional front view of the toroidal-type continuously variable transmission.

[Explanation of symbols]

 8 trunnion 13 speed change control valve 14 precess cam 15 speed change link 16 adjusting screw 21 precess cam side link member 22 speed control valve side link member 23 leaf spring 24 speed change link pivot support pin 25 valve outer casing 25a stopper 31 block 32 spring 33 piston 34 sleeve 35 Spring 36 Stopper

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16H 15/38 F16H 21/00 F16H 61/00

Claims (8)

(57) [Claims] 1. An input / output cone disk arranged coaxially,
It has a toroidal transmission unit consisting of a power roller that transfers power by frictional engagement between these input and output cone disks, and switches one of the inner and outer valve bodies of the shift control valve to a position corresponding to the shift command. By displacing the power roller from the neutral position relative to the other valve body, the power roller is offset from the position where the rotation axis of the power roller intersects with the rotation axis of the input / output cone disk by the working fluid from the transmission control valve. The offset allows the power roller to tilt by a component force from the input / output cone disk about a swing axis orthogonal to its own rotation axis, thereby performing a continuously variable transmission. Is achieved, the offset and tilting of the power roller is controlled by the other valve element via a precess cam and a transmission link. A toroidal-type continuously variable transmission having a shift control device configured to return the other valve body to a neutral position relative to the one valve body by feedback to maintain the state of achieving the shift command. A stopper for limiting the amount of feedback operation of the other valve element by the transmission link to an operation amount at which the transmission control valve can perform the transmission control function; and the operation of the other valve element is restricted by the stopper. A shift control device for a toroidal-type continuously variable transmission, comprising a relief mechanism that allows displacement of the precess cam due to offset and tilting of a power roller. 2. The toroidal-type continuously variable transmission according to claim 1, wherein the stopper is a stopper that restricts the rotation of the speed change link to limit a feedback operation amount of the other valve body. Transmission control device. 3. The shift control device for a toroidal-type continuously variable transmission according to claim 1, wherein the stopper is a stopper that directly limits a feedback operation amount of the other valve body. 4. The precess cam side link member according to claim 1, wherein the speed change link is divided into a link member on the side of the precess cam and a link member on the side of the speed change control valve. Wherein the relief mechanism is constituted by pivotally supporting a transmission control valve side link member on a common axis and elastically supporting a relative rotation position so as to form a predetermined transmission link shape. Transmission control device for transmission. 5. The speed change of a toroidal type continuously variable transmission according to claim 1, wherein the relief mechanism is constituted by supporting a pivot point of the speed change link at a fixed position. Control device. 6. The shift control device for a toroidal-type continuously variable transmission according to claim 5, wherein a pivot point of the shift link is elastically supported at a fixed position by a spring. 7. The shift control device for a toroidal-type continuously variable transmission according to claim 5, wherein a pivot point of the shift link is supported at a fixed position by fluid pressure. 8. An adjusting screw according to claim 1, wherein the adjusting screw is provided at an end of the speed change link near the speed change control valve and adjusts a position between the speed change control valve and the speed change link. A transmission control device for a toroidal-type continuously variable transmission, wherein the relief mechanism is configured to be supported at a fixed position on an end of the transmission link.