JP2005257053A - Controller of toroidal type continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the responsiveness of the gear shift control of a toroidal type CVT. <P>SOLUTION: A tilt angle control means 82 calculates a tilt angle control instruction value Cθ×Δθ obtained by multiplying a feedback gain Cθ by a deviation Δθ between a target tilt angle θr and a detected tilt angle θ. A target offset amount calculation means 83 calculates the target offset amount xr of a roller rotating shaft based on the target tilt angle θr by using an approximation expression of an equation for the tilting motion of a roller corresponding the roller tilt angle θ to the offset amount x of a roller rotating shaft. An offset amount control means 85 calculates an offset amount control instruction value Cx×Δx obtained by multiplying a feedback gain Cx by a deviation Δx between the target offset amount xr and the detected offset amount x of the roller rotating shaft. Then, the driving control of a flow control valve 108 is performed by using a control instruction value Cθ×Δθ+Cx×Δx outputted from an adder 86. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a control device for a toroidal CVT (continuously variable transmission), and in particular, changes the gear ratio by offsetting the roller rotation shaft from a position where the roller rotation shaft and the input / output disk rotation shaft are orthogonal to each other. The present invention relates to a control device for a toroidal CVT.

  An example of this type of toroidal CVT control device is disclosed in Japanese Patent Laying-Open No. 2003-56885 (Patent Document 1). In Patent Document 1, the spool of the shift control valve is displaced by a step motor to offset the rotation shaft of the roller and tilt the roller. At that time, the tilt angle of the roller and the offset amount of the roller rotation shaft are mechanically fed back to the spool of the shift control valve via the cam and the link, so that the displacement of the spool given by the step motor moves to the neutral position. Acts to be returned. Further, the offset amount of the roller rotation shaft is calculated, and the feedforward control command value to the step motor is corrected according to the offset amount. As a result, the responsiveness of the shift control is improved.

  In addition, a control device for a toroidal CVT disclosed in Patent Document 2 is disclosed.

JP 2003-56785 A JP 2003-336732 A

  In Patent Document 1, the tilt angle of the roller and the offset amount of the roller rotation shaft are mechanically fed back to the spool of the shift control valve via the cam and the link. This mechanical feedback is based on the displacement of the spool. Since it acts to return to the neutral position, that is, to return the offset amount of the roller rotation shaft to 0, the stability of the shift control is improved, but the response is deteriorated. For this reason, in Patent Document 1, the responsiveness of the shift control is improved by correcting the feedforward control command value to the step motor in accordance with the offset amount of the roller rotation shaft. However, the basic feedback control does not change in the direction in which the responsiveness of the shift control is deteriorated, so that a sufficient improvement effect of the responsiveness of the shift control cannot be obtained. Therefore, Patent Document 1 has a problem that it is difficult to improve the response of the shift control.

  An object of the present invention is to provide a control device for a toroidal CVT capable of improving the responsiveness of shift control.

  A control device for a toroidal CVT according to the present invention includes a toroidal transmission member having an input / output disk and a roller for transmitting power between the input / output disks by friction engagement between the input / output disk, a rotating shaft of the roller, and an input / output disk. A toroidal CVT gearshift control unit having a gearshift control unit that controls a gear ratio by changing a tilt angle of the roller by offsetting the roller rotation shaft from a position at which the rotation shafts are orthogonal to each other. A target offset amount calculating means for calculating a target offset amount of the roller rotation shaft, and an offset amount control means for calculating an offset amount control command value for causing the offset amount of the roller rotation shaft to follow the target offset amount. The shift control unit controls a gear ratio based on the offset amount control command value, and the target offset amount calculating means Calculating the target offset amount based on at least one of the target tilt angle and the target speed ratio of the roller, using a roller tilt motion equation that associates the la tilt angle with the offset amount of the roller rotation shaft. The gist.

  In the present invention, using a roller tilting motion equation that associates the roller tilting angle with the offset amount of the roller rotating shaft, the roller rotating shaft is detected based on at least one of the target tilting angle and target speed ratio of the roller. By calculating the target offset amount, it is possible to appropriately set the target offset amount of the roller rotation shaft necessary for the target tilt angle of the roller and the target gear ratio. Then, during the shift control, by controlling the offset amount of the roller rotation shaft to follow the target offset amount, the offset amount of the roller rotation shaft is controlled so that the roller tilt angle and the gear ratio follow the target value. Since it can be performed appropriately, according to the present invention, the response of the shift control can be improved.

  In the toroidal CVT control device according to the present invention, the target offset amount calculating means includes at least one of a target tilt angle and a target speed ratio of the roller, a target tilt angular speed of the roller and a time change rate of the target speed ratio. The target offset amount may be calculated based on at least one and at least one of an input disk angular velocity, an output disk angular velocity, and a roller angular velocity. By so doing, it is possible to appropriately calculate the target offset amount of the roller rotation shaft necessary for the target tilt angle of the roller and the target gear ratio.

In the toroidal CVT control device according to the present invention of this aspect, the target offset amount calculation means includes a target tilt angle of the roller θr, a target tilt angular velocity of the roller δθr, an output disk angular velocity ωo, and the target offset When the amount is xr, the half apex angle of the roller is Θ, the cavity radius is Ro, and the value obtained by dividing the distance from the rotation center of the input disk to the oscillation center of the roller by the cavity radius is 1 + k0,
It is also possible to calculate the target offset amount using an equation represented by: In this way, it is possible to easily and accurately calculate the target offset amount of the roller rotation shaft necessary for the target tilt angle of the roller.

In the toroidal CVT control device according to the present invention of this aspect, the target offset amount calculation means includes a target tilt angle of the roller θr, a target tilt angular velocity of the roller δθr, an input disk angular velocity ωi, and the target offset. When the amount is xr, the half apex angle of the roller is Θ, the cavity radius is Ro, and the value obtained by dividing the distance from the rotation center of the input disk to the oscillation center of the roller by the cavity radius is 1 + k0,
It is also possible to calculate the target offset amount using an equation represented by: In this way, it is possible to easily and accurately calculate the target offset amount of the roller rotation shaft necessary for the target tilt angle of the roller.

  In the toroidal CVT control device according to the present invention, the offset amount control means calculates the offset amount control command value as a feedback control command value based on a deviation between the offset amount of the roller rotation shaft and the target offset amount. It can also be.

  In the toroidal CVT control device according to the present invention, the control device includes a tilt angle control means for calculating a tilt angle control command value for causing a roller tilt angle to follow the target tilt angle, and the shift control unit includes: The gear ratio may be controlled based on the offset amount control command value and the tilt angle control command value. In the toroidal CVT control device according to the present invention of this aspect, the tilt angle control means uses the tilt angle control command value as a feedback control command based on a deviation between a roller tilt angle and the target tilt angle. It can also be calculated as a value.

  The toroidal CVT control device according to the present invention further includes a transmission ratio control means for calculating a transmission ratio control command value for causing the transmission ratio to follow the target transmission ratio, and the transmission control unit includes the offset amount control unit. The gear ratio may be controlled based on the command value and the gear ratio control command value. In this aspect of the toroidal CVT control device according to the present invention, the transmission ratio control means calculates the transmission ratio control command value as a feedback control command value based on a deviation between the transmission ratio and the target transmission ratio. It can also be.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

  FIG. 1 shows the overall configuration of the toroidal CVT according to the embodiment. That is, two sets of input disks 30a and 30b are coupled to the input shaft 10 that is rotated based on the rotation of the engine. Each of the input disks 30a and 30b has an opening formed in the center, and has a shape that gradually protrudes from the outside toward the center, and the inclined surface has a substantially arc-shaped cross section in the axial direction. Further, the input disk 30a is located on the left side in the figure, the input disk 30b is located on the right side in the figure, and both projecting centers are located so as to face the inside. The input disks 30a and 30b are arranged so that output disks 40a and 40b having substantially the same shape face each other. That is, the input disk 30a and the output disk 40a are arranged to face each other, and the input disk 30b and the output disk 40b are arranged to face each other. Accordingly, in the cross section in the axial direction, the inclined surfaces of the input disk 30a and the output disk 40a form a pair of semicircles, and the input disk 30b and the output disk 40b form another pair of semicircles.

  Rollers 35a-1 and 35a-2 are sandwiched between the input / output disks 30a and 40a, and rollers 35b-1 and 35b-2 are sandwiched between the input / output disks 30b and 40b. That is, one side of the rollers 35a-1, 35a-2, 35b-1, 35b-2 contacts the input disks 30a, 30b, the other side contacts the output disks 40a, 40b, and the rotational torque of the input disks 30a, 30b is increased. This is transmitted to the output disks 40a and 40b. The rollers 35a-1 and 35a-2 are supported by trunnions 36a-1 and 36a-2, respectively, and the rollers 35b-1 and 35b-2 are supported by trunnions 36b-1 and 36b-2, respectively. The trunnions 36a-1, 36a-2, 36b-1, and 36b-2 each have an axis in a direction perpendicular to the paper surface in the drawing, can move in the axial direction, and can rotate about the axis. ing. The radial positions of the trunnions 36a-1, 36a-2, 36b-1, and 36b-2 are fixed, and the rollers 35a-1, 35a-2, 35b-1, and 35b-2 are input and output. The discs 30a, 40a, 30b, and 40b are not separated from each other.

  The input shaft 10 is connected to a hydraulic pressure (end load) mechanism 20. The end load mechanism 20 receives hydraulic pressure inside and presses the input disks 30a and 30b toward the output disks 40a and 40b, thereby applying a narrow pressure between the input / output disks 30a and 40a and the input / output disks 30b and 40b. As a result, the rollers 35a-1, 35a-2, 35b-1, and 35b-2 are respectively sandwiched between the input / output disks 30a, 40a, 30b, and 40b with a predetermined pressure. As a result, slip between the input / output disks 30a, 40a, 30b, 40b and the rollers is prevented, and the traction state is maintained. The shaft 25 rotates in the same manner as the input shaft 10, and the input disks 30 a and 30 b are rotated by the shaft 25. The input disks 30a and 30b are connected to the shaft 25 via a thrust bearing and are movable in the axial direction of the shaft 25.

  The output disks 40a and 40b are rotatably supported on the shaft 25 via bearings. An output gear 45 is connected between the output disks 40a and 40b and rotates together with the output disks 40a and 40b. A counter gear 60 is engaged with the output gear 45, and an output shaft 70 is connected to the counter gear 60. Accordingly, the output shaft 70 rotates as the output disks 40a and 40b rotate.

  Further, the toroidal CVT is provided with a hydraulic piston chamber. The trunnions 36a-1, 36a-2, 36b-1, and 36b-2 are displaced in the trunnion axial direction by the hydraulic pressure from the hydraulic piston chamber ( Trunnion stroke: roller offset amount) is controlled. The gear ratio is changed by controlling the trunnion strokes (roller offset amounts) of the trunnions 36a-1, 36a-2, 36b-1, and 36b-2. The strokes (roller offset amounts) of the trunnions 36a-1 and 36a-2 are complementarily performed so that the line connecting the centers of the trunnions 36a-1 and 36a-2 passes through the centers of the input / output disks 30 and 40. The trunnion strokes (roller offset amounts) of the trunnions 36b-1 and 36b-2 are complementarily performed so that the line connecting the centers of the trunnions 36b-1 and 36b-2 passes through the centers of the input / output disks 30 and 40. .

  Here, the change of the gear ratio will be described with reference to FIG. FIG. 2 is a view of the input disk 30 as viewed from the output disk 40. Only one input disk 30 and one roller 35 are shown. FIG. 2A shows the case where the roller 35 is not displaced (trunion stroke = 0), and the rotational axis of the roller 35 passes through the center of the input disk 30. When shifting, the trunnion 36 is offset in the axial direction. For example, as shown in FIG. 2B, the input disk 30 is offset in the rotating direction (upper side in the figure). As a result, the roller 35 receives a force in the circumferential direction of the input disk 30 at the moved position, and the roller 35 receives a force (tilting force) that moves to the peripheral side of the input disk 30. When the offset amount (trunnion stroke) of the roller 35 returns to 0, the position of the roller 35 that contacts the input disk 30 is displaced outward in the radial direction. As a result, the contact position of the roller 35 with the output disk 40 is displaced radially inward, and the gear ratio is changed (upshifted). It should be noted that the trunnion 36 is tilted in the opposite direction by down-shifting by offsetting the trunnion 36 in the downward direction (the side from which the input disk moves away) in the figure.

  FIG. 3 shows a configuration for this gear ratio control. In FIG. 3, one input disk 30, two rollers 35-1, 35-2, and two trunnions 36-1, 36-2 are shown.

  Thus, the hydraulic piston chamber 50 has a pair of piston chambers 50-1 and 50-2 in order to make the trunnions 36-1 and 36-2 operate in a complementary manner. A flow rate control valve 52 is connected to the piston chambers 50-1 and 50-2, and the amount of oil supplied to the hydraulic piston chambers 50-1 and 50-2 is controlled by the control of the flow rate control valve 52. Then, the strokes (roller offset amounts) of the trunnions 36-1 and 36-2 are controlled.

  Then, the tilt angle θ of the trunnion 36 is detected by the tilt angle sensor 37, and the stroke x is detected by the stroke sensor 38 and supplied to the controller 80. Here, if the contact position between the roller 35 and the input / output disks 30 and 40 is known, the relationship between the transmission gear ratio and the tilt angle is a correspondence determined only by the geometric shape. Therefore, the gear ratio can be detected by detecting the tilt angle θ. Further, instead of detecting the tilt angle θ by the tilt angle sensor 37, the tilt angle θ is also obtained by obtaining the tilt angle corresponding to the speed ratio obtained from the input shaft rotational speed and the output shaft rotational speed. can do.

  Information about the accelerator opening and the vehicle speed is also supplied to the controller 80. The controller 80 determines a target tilt angle θr corresponding to the target gear ratio based on the accelerator opening and the vehicle speed, and this target tilt. The flow rate command value is calculated based on the deviation between the angle θr and the tilt angle θ detected by the tilt angle sensor 37. The stroke x of the trunnion 36 is controlled by drivingly controlling the flow control valve 52 with the flow command value. Thus, the gear ratio control is performed so that the tilt angle θ follows the target tilt angle θr. In this embodiment, the stroke x is also controlled so that the stroke x detected by the stroke sensor 38 follows the target stroke xr.

  FIG. 4 shows a configuration for shift control in the controller 80. As shown in FIG. 4, the controller 80 includes subtracters 81 and 84, a tilt angle control unit 82, a target offset amount calculation unit 83, an offset amount control unit 85, and an adder 86. Yes.

  As described above, the target tilt angle θr is determined based on the accelerator opening and the vehicle speed, and the target tilt angle θr is input to the subtractor 81. The tilt angle θ detected by the tilt angle sensor 37 is also input to the subtracter 81. The subtractor 81 calculates and outputs a deviation Δθ between the target tilt angle θr and the detected tilt angle θ.

  A deviation Δθ calculated by the subtractor 81 is input to the tilt angle control means 82. Then, the tilt angle control means 82 calculates and outputs the tilt angle control command value Cθ × Δθ by multiplying the deviation Δθ by a predetermined feedback gain Cθ. In this way, the tilt angle control means 82 calculates the tilt angle control command value Cθ × Δθ for causing the detected tilt angle θ to follow the target tilt angle θr as a feedback control command value based on the deviation Δθ. .

  The target tilt amount calculation means 83 receives the target tilt angle θr and the angular velocity ωo of the output disk 40 detected by a sensor (not shown). Then, the target offset amount calculation means 83 uses the approximate equation of the tilt motion equation of the roller 35 that associates the roller tilt angle θ with the offset amount (stroke of the trunnion 36) x of the roller rotation shaft, and uses the target tilt angle. Based on θr, a target offset amount (target stroke of trunnion 36) xr of the roller rotation shaft is calculated and output. The details of the approximate expression used to calculate the target offset amount xr of the roller rotation shaft will be described later.

  The subtracter 84 receives the target offset amount xr calculated by the target offset amount calculation means 83 and the roller rotation shaft offset amount x detected by the stroke sensor 38. The subtractor 84 calculates and outputs a deviation Δx between the target offset amount xr of the roller rotation shaft and the detected offset amount x.

  The offset amount control means 85 receives the deviation Δx calculated by the subtractor 84. Then, the offset amount control means 85 calculates and outputs an offset amount control command value Cx × Δx by multiplying the deviation Δx by a predetermined feedback gain Cx. Thus, the offset amount control means 85 calculates the offset amount control command value Cx × Δx for causing the detected offset amount x to follow the target offset amount xr as a feedback control command value based on the deviation Δx.

  The adder 86 receives the tilt angle control command value Cθ × Δθ calculated by the tilt angle control means 82 and the offset amount control command value Cx × Δx calculated by the offset amount control means 85. . The adder 86 calculates and outputs the sum of the tilt angle control command value Cθ × Δθ and the offset amount control command value Cx × Δx. The control command value Cθ × Δθ + Cx × Δx output from the adder 86 is supplied to the flow control valve 108 as a control command value for performing drive control of the flow control valve 108. Then, the drive control of the flow control valve 108 is performed based on the control command value Cθ × Δθ + Cx × Δx output from the adder 86, so that the drive control of the trunnion 36 in the toroidal CVT 110 is performed, and the gear ratio is changed. Control is performed.

  As disclosed in Japanese Patent Application Laid-Open No. 2003-336732 (Patent Document 2), the feedback gains Cθ and Cx may be changed according to the operating conditions of the toroidal CVT 110. For example, the feedback gains Cθ and Cx may be changed based on any one or more of input / output disk pressing force (or input torque), input rotational speed, and tilt angle (or speed change ratio).

In addition, as for the tilt angle control means 82 and the offset amount control means 85, the case where the feedback control command value by the proportional term is calculated has been described, but the feedback control command value that also considers the integral term and the differential term may be calculated. Good. Alternatively, a feedback control command value derived by a dynamic controller such as ^H∞ control may be calculated.

  As described above, in the speed change control of the present embodiment, the target offset of the roller rotation shaft is calculated using the approximate equation of the tilting motion equation of the roller 35 that associates the roller tilt angle θ with the offset amount x of the roller rotation shaft. The quantity xr is calculated. Hereinafter, the derivation of this approximate expression will be described.

  FIG. 5 is the same as the diagram on the right side of FIG. 2 and shows only the input disk and one roller. In the following description, the suffix “i” of the parameter name indicates the input disk side, and the suffix “o” indicates the output disk side. The time derivative of the variable is represented by adding a dot on the variable.

  When the rotation center axis of the input disk 30 and the rotation center axis of the roller are offset from each other, the force acting on the roller 35 from the input disk 30 at the contact point (strictly, the position of the center of gravity of the contact surface) It acts as a disk rotation direction force Fdi having an angle with the tilt direction. Therefore, the driving force Fti that is the rotation direction and the tilting force Fθi orthogonal to the driving force Fti are applied to the roller 35.

  The equation of motion in the direction of tilting (transmission) of the trunnion is as shown in equation (1) by considering the relationship between the disc rotational direction force Fdi and the tilting force Fθi shown in FIG. 5 and the rotational moment I around the trunnion center in FIG. Call it.

  Here, Fθi: input side tilting force, Fθo: output side tilting force, Fdi: input disk rotation direction force, Fdo: output disk rotation direction force, Ro: cavity radius (from roller tilt center to contact point) Distance), ηi: angle measured in a clockwise direction from the prescribed direction of the input disk (the direction from the center to the left in the figure) connecting the center of the input disk and the rocking center of the roller (see FIG. 5), ηo Is the same angle as ηi, Fci is the normal force at the input disk contact point, Fco is the normal force at the output disk contact point, Sci is the input side tilt direction slip ratio, Sco is the output side tilt direction slip ratio, μi : Input side traction coefficient, μo: Output side traction coefficient, θ: Tilt angle.

  The normal force at the contact point is the same for both input and output, and can be expressed by equation (2).

    Fci = Fco = Fa / (nrc · sin (Θ + θ)) (2)

  Here, Fa: end load (clamping pressure), nrc: number of rollers in the cavity, Θ: half of the angle of the contact point with the input disk and the contact point with the output disk as viewed from the center of the roller swing, that is, the roller The half apex angle (see FIG. 6).

  Substituting equation (2) into equation (1) yields equation (3).

  Here, as represented by the traction characteristics in FIG. 7, the traction coefficient μ increases with the slope Δμ as the slip ratio Sd increases, and becomes a peak immediately before reaching μmax, and becomes maximum at μmax. Then gradually decrease. Therefore, the traction coefficient μ in the actual use range can be expressed linearly. Furthermore, in the formula (3), it can be considered that I: very small (≈0) and μi≈μo. That is, in the present embodiment, the moment of inertia in the tilt direction of the roller 35 is ignored, and the traction characteristics regarding the tilt direction at the contact portion between the disk and the roller 35 are considered to be the same on the input disk side and the output disk side.

That means
μi (Sci) ≈ΔμSci, μo (Sco) ≈ΔμSco (4) Assuming that (42)
Δμ (Sci + Sco) = 0 ⇒ Sci + Sco = 0 (5) Here, the input / output side tilt direction slip ratios Sci and Sco can be expressed by equations (6) and (7), respectively.

  Here, ri: input disk contact point rotation radius, ro: output disk contact point rotation radius, ωi: input disk angular velocity, ωo: output disk angular velocity, ωr: roller angular velocity, Rr: roller rotation radius (= Rosin Θ).

  Furthermore, when the equations (6) and (7) are substituted into the equation (5) and expanded as follows, the equation (8) can be derived.

  Assuming that the slip at the input / output contact point is very small, riωi≈roωo≈Rrωr.

It can be expressed as

  As shown in FIG. 8, when considering the plane passing through the contact point and orthogonal to the disc rotation axis, the stroke xi and xo of the contact point between the input / output disc and the roller by the trunnion stroke x can be expressed by the equation (9). it can.

  Here, x: roller rotation center offset amount, xi: input disk contact point offset amount, xo: output disk contact point offset amount, k0 = Eo / Ro, Eo: from the rotation center of the input disk to the lowest point of the input disk , That is, a distance obtained by subtracting the cavity radius Ro from the distance from the center of rotation of the input disk to the center of oscillation of the roller (see FIG. 6). Therefore, the distance from the rotation center of the input disk to the rocking center of the roller is Eo + Ro, and a value obtained by dividing the distance Eo + Ro by the cavity radius Ro is 1 + k0.

  Further, sin ηi and sin ηo are expressed by equation (10) from the relationship shown in FIG.

  Further, the output disk contact point rotation radius ro can be expressed by equation (11).

  Substituting the expressions (10) and (11) into the expression (8), the expression (12)

Sin (Θ + θ) + sin (Θ−θ) = 2 sinΘ Can be derived.

  FIG. 9 shows the result of verifying the offset amount x of the roller rotation shaft derived from the equation (13) with actual data. Compared with the offset amount (prior application) calculated using the equation shown in Patent Document 1, the offset amount (this application) calculated using the equation (13) is in good agreement with the actual offset amount. I understand that.

  Therefore, in the present embodiment, the target offset amount calculation means 83 performs an operation of substituting the target tilt angle θr, the target tilt angular velocity, and the output disk angular velocity ωo into the following equation (14), thereby the roller rotation shaft: Target offset amount (target stroke of trunnion 36) xr is calculated. Here, the target tilt angular velocity (represented by adding a dot on θr in the equation (14)) can be calculated, for example, from the difference value of the target tilt angle θr.

  Further, the input disk contact point rotation radius ri can be expressed by equation (15).

  Since riωi≈roωo≈Rrωr, the following expression (16) can be obtained by substituting the expressions (10) and (15) into the expression obtained by replacing roωo in the expression (8) with riωi.

  Therefore, the target offset amount calculation means 83 also performs an operation of substituting the target tilt angle θr, the target tilt angular velocity, and the input disk angular velocity ωi (for example, detected by a sensor not shown) into the following equation (17). The target offset amount xr of the roller rotation shaft can be calculated. In the equation (17), the target tilt angular velocity is represented by adding dots on θr.

  Further, the following equation (18) can be obtained by substituting the equation (10) into the equation in which roωo in the equation (8) is replaced with Rrωr (= RoωrsinΘ).

  Therefore, the target offset amount calculation means 83 also performs an operation of substituting the target tilt angle θr, the target tilt angular velocity, and the roller angular velocity ωr (for example, detected by a sensor not shown) into the following equation (19): A target offset amount xr of the roller rotation shaft can be calculated. In the equation (19), the target tilt angular velocity is represented by adding dots on θr.

  Furthermore, the target offset amount calculation means 83 not only calculates the target offset amount xr of the roller rotation shaft by using the equations (14), (17), and (19) alone, but also, for example, (14), (17) Even if the target offset amount xr of the roller rotating shaft is calculated using a plurality of formulas among the formulas (14), (17), and (19), such as taking an average value of the target offset amount xr calculated using the formula. Good.

  As described above, the mechanical feedback of the offset amount of the roller rotation shaft in Patent Document 1 acts to return the offset amount of the roller rotation shaft to zero. Therefore, in Patent Document 1, since the feedback control of the offset amount of the roller rotation shaft necessary for causing the roller tilt angle to follow the target tilt angle is not properly performed, the response of the speed control is improved although the stability is improved. Sex worsens.

  On the other hand, in the present embodiment, the target offset amount xr of the roller rotation shaft is calculated using an approximate expression of the tilting motion equation of the roller 35 that associates the roller tilt angle θ with the offset amount x of the roller rotation shaft. By doing this, it is possible to calculate the target offset amount xr of the roller rotation shaft necessary for causing the roller tilt angle θ to follow the target tilt angle θr in a feed-forward manner. Then, during the shift control, the roller tilt angle θ follows the target tilt angle θr by controlling the offset amount x of the roller rotating shaft to follow the target offset amount xr calculated in a feedforward manner. The offset amount x of the roller rotation shaft can be controlled appropriately. Therefore, according to the present embodiment, it is possible to improve the responsiveness of the shift control.

  In this embodiment, the offset amount x of the roller rotation shaft can be appropriately managed by setting an appropriate target offset amount xr, so that efficiency, stability, and durability can be improved from the design stage of the control system. Can be managed.

  Further, in the present embodiment, the target offset amount xr of the roller rotation shaft is calculated using an approximate expression of the tilting motion equation of the roller 35 represented by the expression (14), (17), or (19). As a result, the target offset amount xr of the roller rotation shaft necessary for causing the roller tilt angle θ to follow the target tilt angle θr can be calculated easily and accurately. Therefore, the responsiveness of the shift control can be further improved.

  Further, as described above, in Patent Document 1, the feedforward control command value to the actuator (step motor) is corrected according to the offset amount of the roller rotation shaft. However, even if the same correction is performed, the toroidal CVT is performed. Variations in the offset amount of the roller rotation shaft occur due to changes in the control system such as the operating conditions and the response characteristics of the actuator system. On the other hand, in the present embodiment, the target offset amount xr of the roller rotation shaft is set using the approximate expression of the tilting motion equation of the roller 35 expressed by the expression (14), (17), or (19). By calculating, the target offset amount xr according to the operating conditions of the toroidal type CVT can be appropriately calculated. Then, by performing electronic feedback control of the offset amount x of the roller rotation shaft based on the offset amount control command value based on the deviation Δx between the target offset amount xr and the detected offset amount x, the operating conditions of the toroidal CVT and the actuator system It is possible to improve the responsiveness of the shift control while adapting to changes in the control system such as the response characteristics. Further, the electronic feedback control command value of the roller tilt angle θ is also performed based on the tilt angle control command value based on the deviation Δθ between the target tilt angle θr of the roller 35 and the detected tilt angle θ. The adaptability to changes in the control system such as operating conditions and response characteristics of the actuator system can be further improved.

  FIG. 10 shows the effect of improving the responsiveness by the shift control of this embodiment. FIG. 10 shows experimental results comparing the conventional shift control that also performs the feedback control of the trunnion stroke in which the target offset amount xr is set to 0 together with the feedback control of the tilt angle, and the shift control of the present embodiment. As shown in FIG. 10, it is understood that the followability of the actual tilt angle θ with respect to the target tilt angle θr is improved as compared with the conventional shift control in which the target offset amount xr is set to zero. It can be seen that the stroke x of the trunnion 36 converges to 0 earlier than the conventional shift control. In addition, the shift control according to the present embodiment does not cause the tilt angle θ to overshoot or cause the stroke x to vibrate greatly. Therefore, the responsiveness and stability can be improved by the shift control of the present embodiment, and both responsiveness and stability can be achieved.

  In the above description, the target tilt angle θr is set, and the tilt angle control command value is calculated based on the deviation Δθ between the target tilt angle θr and the detected tilt angle θ. However, the target gear ratio Gr may be set instead of the target tilt angle θr. In that case, gear ratio control means for calculating a gear ratio control command value for causing the gear ratio G to follow the target gear ratio Gr and outputting it to the adder 86 is provided instead of the tilt angle control means 82. The speed ratio control means is based on a deviation ΔG between a target speed ratio Gr and a speed ratio G (for example, calculated from an input disk angular speed ωi and an output disk angular speed ωo detected by a sensor not shown) (feedback control command value). Value). The gear ratio is controlled by controlling the flow rate control valve 108 based on the gear ratio control command value and the offset amount control command value.

  Here, the relationship between the tilt angle θ and the gear ratio G (= ωi / ωo) is the relationship shown in FIG. 11, and can be expressed as a formula (20) by a polynomial (for example, second order).

  When this equation (20) is differentiated with respect to time, the following equation (21) is obtained.

  Therefore, when setting the target gear ratio Gr, the target offset amount calculation means 83 uses the following equations (22), (23) and the above-mentioned equation (14) to calculate the target gear ratio Gr, the target gear ratio. The target offset amount xr of the roller rotation shaft can be calculated based on the time change rate of Gr and the output disk angular velocity ωo. Here, the time change rate of the target gear ratio Gr (in the equation (23), represented by adding a dot on Gr) can be calculated, for example, from the difference value of the target gear ratio Gr.

  Further, the target offset amount calculation means 83 uses the equations (22), (23), and the above equation (17) to set the target gear ratio Gr, the time change rate of the target gear ratio Gr, and the input disk angular velocity ωi. Based on this, it is possible to calculate the target offset amount xr of the roller rotation shaft. Further, the target offset amount calculation means 83 is based on the target gear ratio Gr, the time change rate of the target gear ratio Gr, and the roller angular velocity ωr using the equations (22), (23), and the aforementioned equation (19). Thus, the target offset amount xr of the roller rotation shaft can be calculated. As described above, the target offset amount calculation means 83 not only calculates the target offset amount xr of the roller rotation shaft based on the target tilt angle θr and the target tilt angular velocity, but also sets the target gear ratio Gr and its time change rate. Based on this, it is possible to calculate the target offset amount xr of the roller rotation shaft.

  In the above description, the case where the offset amount control unit 85 calculates the feedback control command value based on the deviation Δx between the target offset amount xr of the roller rotation shaft and the detected offset amount x has been described. However, in this embodiment, the relationship between the target offset amount xr and the offset amount control command value, or the time change rate of the target offset amount xr (for example, calculated by the difference value of the target offset amount xr) and the offset amount control command value Is stored in the controller 80 in advance, and the offset amount control means 85 uses this control map to calculate the target offset amount xr or an offset amount control command value corresponding to the rate of change over time. May be. That is, the offset amount control command value may be calculated as a feedforward control command value, and the control for causing the offset amount x of the roller rotation shaft to follow the target offset amount xr can also be performed by feedforward control. Responsiveness can be improved.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to such embodiment at all, and it can implement with a various form in the range which does not deviate from the summary of this invention. Of course.

It is a figure which shows the structure of the toroidal type CVT of embodiment. It is a figure which shows the speed change mechanism. It is a figure which shows the structure of trunnion stroke and tilt angle control. It is a figure which shows the structure for the shift control in a controller. It is a figure explaining the force which acts between roller discs. It is a figure which shows the tilt angle etc. of a roller. It is a figure which shows the relationship between a slip ratio and a traction coefficient. It is a figure explaining the offset amount of a roller. It is a figure which shows the calculation result of a trunnion stroke. It is a figure which shows the experimental result which compares the conventional transmission control with the transmission control of embodiment. It is a figure which shows the relationship between a tilt angle and a gear ratio.

Explanation of symbols

  10 input shaft, 20 end load mechanism, 30 (30a, 30b) input disk, 35 (35a-1, 35a-2, 35b-1, 35b-2) roller, 36 (36a-1, 36a-2, 36b-) 1, 36b-2) Trunnion, 40 (40a, 40b) Output disk, 45 Output gear, 60 Counter gear, 70 Output shaft, 80 Controller, 81, 84 Subtractor, 82 Tilt angle control means, 83 Target offset calculation Means, 85 offset amount control means, 86 adder.

Claims (9)

A toroidal transmission member having an input / output disk and a roller for transmitting power between the input / output disks by frictional engagement between the input / output disk, and the rotation axis of the roller from a position where the rotation axis of the roller and the rotation axis of the input / output disk are orthogonal to each other. A device that performs shift control of a toroidal CVT having a shift control unit that controls a transmission ratio by changing a tilt angle of a roller by offsetting;
A target offset amount calculating means for calculating a target offset amount of the roller rotation shaft;
An offset amount control means for calculating an offset amount control command value for causing the offset amount of the roller rotation shaft to follow the target offset amount;
Have
The transmission control unit controls a transmission ratio based on the offset amount control command value;
The target offset amount calculating means is based on at least one of the target tilt angle of the roller and the target gear ratio, using a roller tilt motion equation that associates the roller tilt angle with the offset amount of the roller rotation shaft. A control device for a toroidal CVT, wherein a target offset amount is calculated. The toroidal CVT control device according to claim 1,
The target offset amount calculating means includes
At least one of a target tilt angle of the roller and a target gear ratio;
At least one of a target tilt angular velocity of the roller and a time change rate of the target transmission ratio;
At least one of an input disk angular speed, an output disk angular speed, and a roller angular speed;
The target offset amount is calculated based on the toroidal CVT control device. A control device for a toroidal CVT according to claim 2,
The target offset amount calculating means includes
The target tilt angle of the roller is θr, the target tilt angular velocity of the roller is δθr, the output disc angular velocity is ωo, the target offset amount is xr, the half apex angle of the roller is Θ, the cavity radius is Ro, and the rotation center of the input disc is When the value obtained by dividing the distance to the center of oscillation of the roller by the cavity radius is 1 + k0,
A control device for a toroidal CVT, wherein the target offset amount is calculated using an expression represented by: A control device for a toroidal CVT according to claim 2,
The target offset amount calculating means includes
The target tilt angle of the roller is θr, the target tilt angular velocity of the roller is δθr, the input disc angular velocity is ωi, the target offset amount is xr, the half apex angle of the roller is Θ, the cavity radius is Ro, and the rotation center of the input disc is When the value obtained by dividing the distance to the center of oscillation of the roller by the cavity radius is 1 + k0,
A control device for a toroidal CVT, wherein the target offset amount is calculated using an expression represented by: A control device for a toroidal CVT according to any one of claims 1 to 4,
The toroidal CVT control device, wherein the offset amount control means calculates the offset amount control command value as a feedback control command value based on a deviation between an offset amount of a roller rotation shaft and the target offset amount. A control device for a toroidal CVT according to any one of claims 1 to 5,
A tilt angle control means for calculating a tilt angle control command value for causing the roller tilt angle to follow the target tilt angle;
The toroidal CVT control device, wherein the shift control unit controls a gear ratio based on the offset amount control command value and the tilt angle control command value. A control device for a toroidal CVT according to claim 6,
The tilt angle control means calculates the tilt angle control command value as a feedback control command value based on a deviation between a roller tilt angle and the target tilt angle, and controls the toroidal CVT. . A control device for a toroidal CVT according to any one of claims 1 to 5,
Transmission ratio control means for calculating a transmission ratio control command value for causing the transmission ratio to follow the target transmission ratio;
The transmission control unit controls a transmission ratio based on the offset amount control command value and the transmission ratio control command value. A control device for a toroidal CVT according to claim 8,
The control apparatus for toroidal CVT, wherein the speed ratio control means calculates the speed ratio control command value as a feedback control command value based on a deviation between the speed ratio and the target speed ratio.