JP3656482B2 - Shift control device for continuously variable transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a continuously variable transmission having a manual shift mode function, and more particularly to a shift control technique at an initial stage of switching from an automatic shift mode to a manual shift mode.
[0002]
[Prior art]
Conventionally, as a transmission control device for a continuously variable transmission having a manual mode function, for example, those described in JP-A-9-196156 and JP-A-9-264416 are known.
[0003]
The former publication aims to smoothly switch from the automatic shift mode to the manual shift mode without giving the driver a sense of incongruity, and reaches the input shift on the downshift side closest to the actual input rotation at the time of switching. Are selected, and the shift speed that is the closest input rotation on the upshift side closest to the actual input rotation at the time of switching is described.
[0004]
The latter publication aims to allow the driver to experience switching from the automatic transmission mode to the manual transmission mode, and to satisfy the driver's request to apply the engine brake by switching the transmission mode. When the shift speed initial value line is set in the shift diagram and the automatic shift mode is switched to the manual shift mode, the shift speed initial value corresponding to the vehicle speed is calculated, and the current shift speed is determined based on the shift speed initial value. Is greater than the initial value of the gear position and is on the high speed side, the gear position after switching is set to the initial value of the gear position, and when the current gear position is smaller than the initial value of gear position, the gear position after the switching is The shift speed in the downshift direction is set by setting the speed position closest to the low speed position to the initial speed value.
[0005]
[Problems to be solved by the invention]
However, in the former prior art, the purpose of the driver actually switching from the automatic transmission mode to the manual transmission mode is to downshift to prepare for the next acceleration or downshift to apply the engine brake. Since this is an expectation, a downshift operation must be performed after the mode switching operation, and there is a problem that the operation is troublesome.
[0006]
In the latter prior art, for example, when the current gear position is slightly larger than the gear position initial value and is on the high speed side, the gear position after switching is set to the gear position initial value. Therefore, although a downshift occurs at the time of shifting the speed change mode, the expected engine braking force does not occur due to a small change in rotation, and when the accelerator is turned off, which requires many engine brakes, the rotation changes even with a downshift with the same gear ratio range. There is a problem that the expected engine braking force is not generated. In other words, the driver's request that acceleration or engine braking is applied by mode switching cannot be satisfied only by setting the downshift direction at the time of shift mode switching.
[0007]
The present invention has been made paying attention to the above-mentioned problems, and when switching from the automatic transmission mode to the manual transmission mode, expecting a downshift for acceleration or applying an engine brake by only one mode switching operation. It is an object of the present invention to provide a transmission control device for a continuously variable transmission that can reliably meet the driver's request for downshift expectations.
[0008]
[Means for Solving the Problems]
In the invention according to claim 1 of the present invention, an automatic transmission control means for setting an automatic transmission mode for automatically changing the transmission ratio according to the driving state;
Manual shift control means for manual shift mode in which a fixed gear ratio can be selected sequentially from a plurality of shift stages by manual operation;
Shift mode switching means for selectively switching between the automatic shift mode and the manual shift mode;
In a continuously variable transmission shift control device comprising:
When the automatic transmission mode is switched to the manual transmission mode by the operation of the transmission mode switching means, the initial transmission ratio immediately after the switching is changed to the transmission input rotational speed at the transmission ratio in the automatic transmission mode before the switching. On the other hand, there is provided an initial gear ratio setting means for setting an increasing gear ratio that increases at least a predetermined number of revolutions set in advance.
[0009]
According to a second aspect of the present invention, in the transmission control device for a continuously variable transmission according to the first aspect,
The manual shift control means has a fixed gear ratio for each of a plurality of shift stages,
When the initial speed ratio setting means is switched from the automatic speed change mode to the manual speed change mode, the highest speed among the speeds that increase to the input speed that is equal to or higher than the predetermined speed relative to the current transmission input speed. It is characterized in that it is a means for setting the stage.
[0010]
Operation and effect of the invention
According to the first aspect of the present invention, when the automatic transmission mode is selected by the transmission mode switching means, the automatic transmission control means changes the speed according to the driving state such as the vehicle speed and the throttle opening. The ratio changes automatically. On the other hand, when the manual speed change mode is selected by the speed change mode switching means, the manual speed change control means can select the fixed speed ratio sequentially from a plurality of speed stages by manual operation.
[0011]
When the automatic transmission mode is switched to the manual transmission mode by the operation of the transmission mode switching means, the initial transmission ratio immediately after the switching is changed in the automatic transmission mode before the switching by the initial transmission ratio setting means. With respect to the transmission input rotation speed in the ratio, it is set to an increase-side transmission ratio that increases at least by a preset predetermined rotation speed.
[0012]
That is, at the time of switching from the automatic transmission mode to the manual transmission mode, a downshift in which the transmission input rotational speed is always increased by a predetermined rotational speed or more is performed. The change in the input speed of the transmission is ensured, and the engine braking force expected by the driver is generated.
[0013]
Therefore, when switching from the automatic transmission mode to the manual transmission mode, the downshift expectation for acceleration or the downshift expectation for applying the engine brake is required without requiring a downshift operation with only one mode switching operation. The driver's request can be met reliably.
[0014]
According to a second aspect of the present invention, when the initial transmission ratio setting means is switched from the automatic transmission mode to the manual transmission mode, the manual transmission having a fixed transmission ratio for each of a plurality of shift stages. On the control means side, the highest shift speed is set among the shift speeds that increase to an input speed that is equal to or higher than a predetermined speed relative to the current transmission input speed.
[0015]
That is, the gear position of the closest shift line that is equal to or larger than the rotation speed obtained by adding a predetermined rotation speed to the current transmission input rotation speed (actual input rotation speed or input rotation speed corresponding to the target speed ratio before switching). Set to
[0016]
Therefore, if a shift map for manual shift mode that defines a steady target input rotation speed with respect to the output rotation speed of the transmission is prepared, mode switching can be performed by a simple process that does not convert the input rotation speed into a gear ratio. At this time, it is possible to set a speed ratio that increases to an input rotational speed greater than or equal to a predetermined rotational speed with respect to the current transmission input rotational speed.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
A transmission control device for a continuously variable transmission according to the present invention will be described in detail with reference to the drawings.
[0018]
[Configuration of continuously variable transmission transmission unit and transmission control device]
1 and 2 show a toroidal continuously variable transmission including a transmission control device for a continuously variable transmission according to the present invention, FIG. 1 is a longitudinal side view showing a transmission unit of a toroidal continuously variable transmission, and FIG. It is a figure which shows the transmission control apparatus of a toroidal type continuously variable transmission.
[0019]
First, a transmission unit that is a main part of a toroidal-type continuously variable transmission will be described with reference to FIG. This transmission unit includes an input shaft 20 to which rotation from an engine (not shown) is transmitted. As shown in FIG. 1, the input shaft 20 has an end portion far from the engine in a transmission case 21 via a bearing 22. The central portion is supported rotatably in the intermediate wall 23 of the transmission case 21 via a bearing 24 and a hollow output shaft 25.
[0020]
The input cone disk 1 is supported by the input shaft 20, the output cone disk 2 is supported by the hollow output shaft 25, and the input / output cone disks 1 and 2 have their toroidal curved surfaces 1a and 2a facing each other. Coaxially arranged.
[0021]
A pair of power rollers 3 and 3 disposed on both sides of the input shaft 20 are interposed between the opposing toroidal curved surfaces 1a and 2a of the input / output cone disks 1 and 2, respectively. The following configuration is adopted in order to clamp the disk between the input / output cone disks 1 and 2.
[0022]
That is, a loading nut 26 is screwed onto the bearing 22 side end of the input shaft 20, the cam disk 27 is prevented from coming off by the loading nut 26 and is rotationally engaged on the input shaft 20, and the toroid of the input cone disk 1. A loading cam 28 is interposed between the end surface far from the curved surface 1a, and the rotation from the input shaft 20 to the cam disk 27 is transmitted to the input cone disk 1 through the loading cam 28.
[0023]
Here, the rotation of the input cone disk 1 is transmitted to the output cone disk 2 through the rotation of both power rollers 3 and 3, and during this transmission, the loading cam 28 generates a thrust proportional to the transmission torque, and the power roller 3 , 3 is narrowed between the input / output cone disks 1 and 2 to enable the power transmission.
[0024]
The output cone disk 2 is wedged on the output shaft 25, and an output gear 29 is fitted on the output shaft 25 so as to rotate integrally therewith.
[0025]
The output shaft 25 is further rotatably supported in an end cover 31 of the transmission case 21 via a radial / thrust bearing 30, and the input shaft 20 is separately received in the end cover 31 via a radial / thrust bearing 32. Support for rotation. Here, the radial and thrust bearings 30 and 32 are aligned with respect to the corresponding output gear 29 input shaft 20 so that the spacers 33 start to abut against each other so as not to approach each other and cannot be displaced relative to each other. Impetus in the direction.
[0026]
With the above configuration, the thrust acting between the input / output cone disks 1 and 2 by the loading cam 28 becomes an internal force that sandwiches the spacer 33 and does not act on the transmission case 21.
[0027]
As shown in FIG. 2, the power rollers 3 and 3 are rotatably supported by trunnions 41 and 41, and the trunnions 41 and 41 are respectively rotatable at both ends of the upper link 43 by spherical joints 42. The lower end is connected to both ends of the lower link 45 by a spherical joint 44 so as to be freely swingable and swingable.
[0028]
The upper link 43 and the lower link 45 are supported at the center by the spherical joints 46 and 47 so that the transmission case 21 can swing in the vertical direction, and both trunnions 41 and 41 are moved up and down in synchronization with each other in opposite directions. To get.
[0029]
A shift control apparatus that shifts the speed by moving both the trunnions 41 and 41 up and down in synchronization with each other in the opposite direction will be described with reference to FIG.
[0030]
Each trunnion 41, 41 is provided with pistons 6, 6 for individually moving these trunnions in the vertical direction, and upper chambers 51, 52 and lower chambers 53, 54 are defined on both sides of both pistons 6, 6, respectively. . A shift control valve 5 is installed to control the strokes of the pistons 6 and 6 in opposite directions.
[0031]
Here, the shift control valve 5 is configured such that a spool-type inner valve body 5a and a sleeve-type outer valve body 5b are slidably fitted to each other, and the outer valve body 5b is slidable on a valve case 5c. Fit and configure.
[0032]
The shift control valve 5 has an input port 5d connected to the pressure source 55, one communication port 5e connected to the piston chambers 51 and 54, and the other communication port 5f connected to the piston knows 52 and 53, respectively.
[0033]
Then, the inner valve body 5a is caused to cooperate with the cam surface of the recess cam 7 fixed to the lower end of one trunnion 41 via a bell crank type shift lever 8, and the outer valve body 5b is used as a step motor 4 as a shift actuator. And drivingly engaged with a rack and pinion model.
[0034]
The operation command for the speed change control valve 5 is given as a stroke to the outer valve body 5b via the rack and pinion by the step motor 4 that responds to the actuator drive position command Asstep (step position command).
[0035]
With this operation command, when the outer valve body 5b of the shift control valve 5 is displaced from the neutral position relative to the inner valve body 5a, for example, to the position shown in FIG. The fluid pressure (line pressure PL) is supplied to the chambers 52 and 53, while the other chambers 51 and 54 are drained, and the outer valve body 5b of the speed change control valve 5 is relative to the inner valve body 5a. When the shift control valve 5 is opened in the reverse direction from the neutral position, the fluid pressure from the pressure source 55 is supplied to the chambers 51 and 54, while the other chambers 52 and 53 are drained, and both trunnions 41 and 41 are supplied. Is displaced by fluid pressure through the pistons 6 and 6 in the corresponding up and down directions in the drawing.
[0036]
As a result, both the power rollers 3 and 3 ₁ Is the rotation axis O of the input / output cone disks 1 and 2 ₂ Is offset (offset amount y) from the illustrated position intersecting with the power, and the power rollers 3 and 3 are swung from the input / output cone disks 1 and 2 by the nuclear offset, so that their own rotation axis O ₁ Swing axis O ₃ Is continuously tilted (tilt angle φ) and continuously variable.
[0037]
During such a shift, the recess cam 7 coupled to the lower end of one trunnion 41 shifts the above-described vertical movement (offset amount y) and tilt angle φ of the trunnion 41 and the power roller 3 via the shift link 8. Feedback is given mechanically to the inner valve body 5a of the valve 5 as indicated by x.
[0038]
When the gear ratio command value corresponding to the actuator drive position command Asstep for the step motor 4 is achieved by the continuously variable transmission, the mechanical feedback via the recess cam 7 is changed to the inner valve of the shift control valve 5. The body 5a is returned to the initial neutral position relative to the outer valve body 5b. At the same time, both the power rollers 3 and 3 ₁ Is the rotation axis 0 of the input / output cone disks 1 and 2 ₂ By returning to the illustrated position that intersects with the speed ratio, the achieved state of the gear ratio command value can be maintained.
[0039]
Since the purpose of the control is to set the power roller tilt angle φ to a value corresponding to the gear ratio command value, the recess cam 7 basically needs to feed back only the power roller tilt angle φ. The reason why the power roller offset amount y is also fed back is to avoid the hunting phenomenon of the shift control by providing a damping effect that prevents the shift control from becoming oscillating.
[0040]
An actuator drive position command Astep to the step motor 4 is set by the controller 61.
[0041]
For this purpose, as shown in FIG. 2, the controller 61 has a signal from the throttle opening sensor 62 for detecting the engine throttle opening TVO, a signal from the vehicle speed sensor 63 for detecting the vehicle speed VSP, and the rotational speed of the input cone disk 1. A signal from the input rotation sensor 64 for detecting Ni (which may be the engine rotation speed Ne), a signal from the output rotation sensor 65 for detecting the rotation speed No of the output cone disk 2, and an oil temperature for detecting the transmission operating oil temperature TMP. Signal from sensor 66, line pressure P from hydraulic source 55 _L (Normally, the line pressure P _L Is detected by an internal signal of the controller 61 because it is controlled by the controller 61), a signal from the engine rotation sensor 68 that detects the engine speed Ne, and a signal about range information from the inhibitor switch 60. , UP / DOWN information signal from UP / DOWN switch 69, selection mode signal from mode selection switch 70, torque down permission signal from engine control device 310, ABS control from anti-skid control device (ABS) 320 A signal, a TCS control signal from the traction control device (TCS) 330, and an ASCD cruise signal from the constant speed traveling device 340 are input.
[0042]
The controller 61 sets the actuator drive position command Asstep (shift command value) to the step motor 4 by the following calculation based on the various input information.
[0043]
[About controller configuration]
In the present embodiment, the controller 61 is configured as shown in FIG.
[0044]
The shift map selection unit 71 selects a shift map according to various conditions such as the oil temperature TMP detected by the sensor 66 in FIG. 2 and whether the exhaust purification catalyst is being activated.
[0045]
The reaching input rotation speed calculation unit 72 will be described with respect to the case where the shift map selected in this way is as shown in FIG. 4, for example. The throttle opening TVO detected by the sensors 62 and 63 in FIG. From the vehicle speed VSP, based on the shift map corresponding to the shift diagram of the figure, the reached input rotational speed Ni to be the steady target input rotational speed in the current operating state ^* Search for and ask.
[0046]
The reaching speed ratio calculating unit 73 is configured to input the reaching input rotational speed Ni. ^* Is divided by the transmission output rotational speed No detected by the sensor 65 of FIG. ^* Reaching speed ratio i which is a steady target speed ratio corresponding to ^* Ask for.
[0047]
The shift time constant calculation unit 74 includes a selection range (forward normal travel range D, forward sport travel range Ds), vehicle speed VSP, throttle opening TVO, engine speed Ne, accelerator pedal operation speed, torque down control device (not shown). ) To change the speed according to various conditions such as a torque down amount signal, a torque down permission signal, an anti-skid control signal, a traction control signal, a constant speed travel signal, and a speed ratio deviation RtoERR with a target speed ratio Ratio0 described later. The first speed change time constant Tg1 and the second speed change time constant Tg2 of the control are set, and the ultimate speed ratio i ^* And the deviation Eip between the target gear ratio Ratio0.
[0048]
Here, the first shift time constant Tg1 and the second shift time constant Tg2 set to correspond to the secondary delay system of the toroidal-type continuously variable transmission are determined by the ultimate transmission ratio i. ^* The target speed ratio calculating unit 75 sets the speed change response to the target speed ratio i. ^* Is calculated with a transitional time target speed ratio Ratio0 and an intermediate speed ratio Ratio00 for realizing the above with a speed change response determined by the first speed change time constant Tg1 and the second speed change time constant Tg2, and only the target speed ratio Ratio0 is calculated. Is output.
[0049]
The input torque calculation unit 76 obtains the transmission input torque Ti by a known method. First, the engine output torque is obtained from the throttle opening TVO and the engine speed Ne, and then the input / output speed (Ne, The torque ratio t of the torque converter is obtained from the speed ratio which is the Ni) ratio, and finally the transmission input torque Ti is calculated by multiplying the engine output torque by the torque ratio t.
[0050]
The torque shift compensation gear ratio calculation unit 77 is a torque shift for eliminating a torque shift (an incorrect gear ratio) peculiar to the toroidal type continuously variable transmission from the transient target gear ratio Ratio0 and the transmission input torque Ti. A compensation gear ratio TSrto is calculated.
[0051]
Here, the torque shift of the toroidal-type continuously variable transmission will be supplementarily explained. During the transmission of the toroidal-type continuously variable transmission, the power rollers 3, 3 are placed between the input / output cone disks 1, 2 as described above. Due to the pinching, the trunnion 41 is deformed, whereby the position of the recess cam 7 at the lower end of the trunnion is changed to cause a change in the path length of the mechanical feedback system composed of the recess cam 7 and the speed change link 8. The torque shift is generated.
[0052]
Therefore, the torque shift of the toroidal continuously variable transmission differs depending on the target gear ratio Ratio0 and the transmission input torque Ti, and the torque shift compensation gear ratio calculation unit 77 searches the torque shift compensation gear ratio TSrto from these two-dimensional maps. Ask for.
[0053]
The actual transmission ratio calculation unit 78 calculates the actual transmission ratio Ratio by dividing the transmission input rotational speed Ni by the transmission output rotational speed No detected by the sensor 65 of FIG. The gear ratio deviation calculation unit 79 subtracts the actual gear ratio Ratio from the target gear ratio Ratio0 to obtain a gear ratio deviation RtoERR (= Ratio0-Ratio) between the two.
[0054]
The first feedback (FB) gain calculating unit 80 calculates a gear ratio feedback correction amount by a well-known PID control (P is proportional control, I is integral control, and D is differential control) according to the gear ratio deviation RtoERR. The first proportional control feedback gain fbpDATA1, the integral control feedback gain fbiDATA1, and the differential control feedback gain to be set according to the transmission input rotational speed Ni and the vehicle speed VSP among the feedback gains of the respective controls. Each of fbdDATA1 is obtained.
[0055]
The first feedback gains fbpDATA1, fbiDATA1, and fbdDATA1 are determined in advance as a two-dimensional map of the transmission input rotational speed Ni and the vehicle speed VSP, and based on this map, the transmission input rotational speed Ni and the vehicle speed VSP are obtained by inspection. Suppose you want.
[0056]
The second feedback (FB) gain calculation unit 81 includes the transmission hydraulic oil temperature TMP and the line pressure P among the feedback gains used when calculating the gear ratio feedback correction amount by the PID control. _L The second proportional control feedback gain fbpDATA2, the integral control feedback gain fbiDATA2, and the differential control feedback gain fbdDATA2 to be set in accordance with are respectively obtained.
[0057]
These second feedback gains fbpDATA2, fbiDATA2, and fbdDATA2 are determined by the hydraulic oil temperature TMP and the line pressure P. _L As a two-dimensional map, the hydraulic oil temperature TMP and the line pressure P are determined based on this map. _L It shall be obtained by searching from
[0058]
The feedback gain calculation unit 83 multiplies corresponding ones of the first feedback gain and the second feedback gain to obtain a proportional control feedback gain fbpDATA (= fbpDATA1 × fbpDATA2) and an integral control feedback gain fbiDATA ( = FbiDATA1 × fbiDATA2) and a differential control feedback gain fbdDATA (= fbdDATA1 × fbdDATA2).
[0059]
In order to calculate the gear ratio feedback correction amount FBrto by the PID control according to the gear ratio deviation RtoERR, the PID control unit 84 uses the feedback gain obtained as described above.
The speed ratio feedback correction amount by the proportional control is obtained by RtoERR × fbpDATA,
Next, a gear ratio feedback correction amount by integral control is obtained by ∫RtoERR × fbiDATA,
Further, a gear ratio feedback correction amount by differential control is obtained by (d / dt) RtoERR × fbdDATA,
Finally, the sum of these three values is set as a gear ratio feedback correction amount FBrto (= RtoERR × fbpDATA + ∫RtoERR × fbiDATA + (d / dt) RtoERR × fbdDATA) by PID control.
[0060]
The target speed ratio correction unit 85 corrects the target speed ratio Ratio0 by the torque shift compensation speed ratio TSrto and the speed ratio feedback correction amount FBrto to obtain a corrected target speed ratio DsrRTO (= Ratio0 + TSrto + FBrto).
The target step number (actuator target drive position) calculation unit 86 obtains the target step number (actuator target drive position) DsrSTP of the step motor (actuator) 4 for realizing the corrected target gear ratio DsrRTO by map search.
[0061]
The step motor drive position command calculation unit 87 is configured so that the step motor 4 can perform the target step number DsrSTP in one control cycle even at the limit drive speed of the step motor 4 set by the step motor drive speed setting unit 88 from the transmission hydraulic fluid temperature TMP or the like. When the step motor 4 cannot be displaced, the feasible limit position that can be realized at the limit drive speed of the step motor 4 is set as the drive position command Asstep to the step motor 4, and the step motor 4 performs the target step number DsrSTP in one control cycle. When the target step number DsrSTP can be displaced as it is, the target position number DsrSTP is directly used as the drive position command Astep for the step motor 4.
[0062]
Therefore, the drive position command Asstep can always be regarded as the actual drive position of the step motor 4.
[0063]
The step motor 4 is displaced in a direction and a position corresponding to the drive position command Astep and strokes the outer valve body 5b of the shift control valve 5 via the rack and pinion, so that the toroidal continuously variable transmission has already been described. The gears can be shifted as prescribed.
[0064]
When the gear ratio command value corresponding to the drive position command Step is achieved by this speed change, the mechanical feedback via the recess cam 7 causes the inner valve body 5a of the speed change control valve 5 to be relative to the outer body 5b. At the same time, the power rollers 3 and 3 are rotated at the rotational axis 0 at the same time. ₁ Is the rotation axis 0 of the input / output cone disks 1 and 2 ₂ By returning to the illustrated position that intersects with the speed ratio, the achieved state of the gear ratio command value can be maintained.
[0065]
In the present embodiment, a step motor followability determination unit 89 is additionally provided.
[0066]
The step motor followable determination unit 89 determines whether or not the step motor 4 can follow the target number of steps (actuator target drive position) DsrSTP corresponding to the corrected target speed ratio DsrRTO.
[0067]
That is, the determination unit 89 first obtains a step number deviation (actuator drive position deviation) ΔSTP between the target step number (actuator target drive position) DsrSTP and the drive position command Astep that can be regarded as the actual drive position.
[0068]
Then, the determination unit 89 detects the step number deviation (actuator drive) that the step motor 4 cannot resolve in one control cycle even at the limit drive speed of the step motor 4 set as described above by the step motor drive speed setting unit 88. Lower limit value of position deviation) △ STP _LIM Step number deviation (actuator drive position deviation) ΔSTP is smaller (ΔSTP <ΔSTP) _LIM ), Determining that the step motor 4 can follow the target number of steps (actuator target drive position) DsrSTP corresponding to the corrected target speed ratio DsrRTO,
Conversely, △ STP ≧ △ STP _LIM When it is, it is determined that the step motor 4 cannot follow the target number of steps (actuator target drive position) DsrSTP.
[0069]
When the determination unit 89 determines that the step motor 4 can follow the target step number (actuator target drive position) DsrSTP corresponding to the corrected target speed ratio DsrRTO, the PID control unit 84 performs the PID as described above. The calculation of the gear ratio feedback correction amount FBrto by the control is continued.
[0070]
In this way, when it is determined that the step motor 4 cannot follow the target number of steps (actuator target drive position) DsrSTP, the gear ratio feedback correction amount ∫RtoERR × fbiDATA by integral control is held at the value at the time of the determination. The PID control unit 84 is instructed to do so.
[0071]
Further, in the present embodiment, when the step motor drive position command calculation unit 87 does not allow the step motor 4 to be displaced to the target step number DsrSTP during one control cycle even at the limit drive speed of the step motor 4, the limit of the step motor 4 is reached. The feasible limit position that can be realized at the driving speed is set as the driving position command Asstep to the step motor 4, and the driving position command Asstep is used as the actual driving position of the step motor 4 to determine whether the step motor can follow the step motor 4. Because we decided to contribute
The actual drive position of the step motor 4 necessary for performing such followable determination is detected by the drive position command Step from the transmission control device to the step motor 4. This can be done inexpensively without relying on actual measurement of the actual drive position.
[0072]
In the present embodiment, step motor followability determination unit 89 determines step number deviation (actuator drive position deviation) between target step number (actuator target drive position) DsrSTP and actual drive position (drive position command) Asstep. △ STF is the follow-up determination standard deviation △ STP determined for each limit drive speed of the step motor 4 _LIM Less than (△ STP <△ STP _LIM ), It is determined that the step motor 4 can follow the target step number (actuator target drive position) DsrSTP corresponding to the corrected target gear ratio DsrRTO, and on the contrary, ΔSTP ≧ ΔSTP _LIM In order to determine that the step motor 4 cannot follow the target number of steps (actuator target drive position) DsrSTP,
Whether the step motor 4 can follow can be reliably determined regardless of the limit drive speed of the step motor 4 that varies depending on the oil temperature TMP or the like.
[0073]
[Overall shift control]
When the controller 61 of FIG. 2 is configured by a microcomputer, the shift control described with reference to FIG. 3 is executed by the programs of FIGS.
[0074]
FIG. 5 shows the entire shift control, and this routine is executed every 10 ms, for example. First, at step 91, the shift time constant calculation unit 74 (FIG. 3) inputs the vehicle speed VSP detected by the vehicle speed sensor 63 (FIG. 2), the engine speed Ne detected by the engine rotation sensor 68 (FIG. 2), and the input. The transmission input rotational speed Ni detected by the rotation sensor 64 (FIG. 2), the throttle opening TVO detected by the throttle opening sensor 62 (FIG. 2), and the range information (automatic shift) from the inhibitor switch 60 (FIG. 2). (D) Range, sports running (S) range, etc.) are read.
[0075]
Next, at step 92, the reached input rotation speed calculation unit 72 (FIG. 3) calculates the actual gear ratio Ratio by dividing the input rotation speed Ni by the transmission output rotation speed No. Next, at step 93, the input input rotational speed Ni is determined from the throttle opening TVO and the vehicle speed VSP based on the shift map as shown in FIG. ^* Search for and ask.
[0076]
Next, at step 94 as the ultimate transmission ratio setting means, the ultimate transmission ratio calculation unit 73 (FIG. 3) determines the ultimate input rotational speed Ni. ^* Is divided by the transmission output rotational speed No to reach the ultimate transmission ratio i ^* Is calculated. Next, at step 95 as the deviation calculating means, the shift time constant calculating unit 74 (FIG. 3) sets the ultimate transmission ratio i. ^* From this, the deviation Eip is calculated by subtracting the target gear ratio Ratio0 calculated in the previous routine (this is calculated in the subsequent step 99).
[0077]
Next, at step 96, it is determined whether or not there is a stepped shift (hereinafter referred to as “switch shift”) by mode switching and manual shift. Specifically, the presence / absence of switching between the power mode and the snow mode is detected in accordance with the selection mode signal from the mode selection switch 70 (FIG. 2), and the manual range signal is output from the inhibitor switch 60 (FIG. 2). It is determined whether or not a signal for UP / DOWN information is detected from the UP / DOWN switch 69 (FIG. 2). Next, at step 97 and step 98 as mode setting means and at step 99 as target speed ratio setting means, the shift time constant calculation unit 74 (FIG. 3) performs the time constant calculation mode and the first and second shift time constants. Tg1 and Tg2, and a target speed ratio Ratio0 and an intermediate speed ratio Ratio00 are calculated.
[0078]
Thereafter, in step 100, the torque shift compensation speed ratio calculating unit 77 (FIG. 3) calculates the torque shift compensation speed ratio TSrto from the map regarding the target speed ratio Ratio0 and the transmission input torque Ti. Next, in step 101, the PID control unit 84 (FIG. 3) calculates a gear ratio feedback correction amount FBrto by PID control. Next, at step 102, the target gear ratio correction unit 85 (FIG. 3) adds the torque shift compensation gear ratio TSrto and the gear ratio feedback correction amount FBrto to the target gear ratio Ratio0 to calculate a corrected target gear ratio DsrRTO. Next, at step 103, a drive position command Asstep to the step motor 4 (FIG. 2) is calculated, and this routine is finished.
[0079]
[Shift control in manual shift mode]
FIG. 6 is an overall flowchart showing a shift control process in the manual shift mode in the shift control program.
[0080]
First, in step 104, the switch state (ON, OFF) of the manual mode switches (inhibitor switch 60 and UP / DOWN switch 69) is input, and the process proceeds to step 105 (see FIG. 8 of JP-A-9-196156). .
[0081]
In step 105, the input state of the control switch signal (M range signal, up signal, down signal, gate signal) is determined, and the process proceeds to step 106. Note that if the abnormal state continues for a set time or longer by determining the input state of the control switch signal, it is determined that the manual mode system switch is abnormal.
[0082]
In step 106, a shift state (initial state, downshift state, upshift state, steady state) in the manual shift mode is determined, and the process proceeds to step 107 and subsequent steps.
[0083]
In step 107, if the previous travel mode is other than the manual shift mode (automatic shift mode) and the current travel mode is the manual shift mode, it is determined that the initial state is immediately after the shift mode is switched to the manual shift mode. Then, the process proceeds to step 108, and the initial process (FIG. 7) is executed.
[0084]
In step 109, a shift state (downshift state, upshift state, steady state) in the manual shift mode is determined based on the combination of the M range signal and the previous and current up signals, down signals, and gate signals.
[0085]
If it is determined in step 109 that the down signal is in the down shift state where the down signal is ON, the process proceeds to step 110, and the down shift state process (FIG. 8) is executed.
[0086]
If it is determined in step 109 that the up-shift state in which the up signal is ON is reached, the process proceeds to step 111, and processing in the up-shift state (FIG. 9) is executed.
[0087]
If it is determined in step 109 that the steady state is neither the downshift state nor the upshift state, the routine proceeds to step 112, where the steady state process (FIG. 10) is executed.
[0088]
[Initial processing in manual shift mode]
FIG. 7 is a flowchart showing an initial process in the manual shift mode in the shift control program (corresponding to the initial gear ratio setting means).
[0089]
In step 113, the input rotation sensor 64 reads the input rotation InpREV (= Ni) of the transmission.
[0090]
In step 114, after switching from the automatic transmission mode to the manual transmission mode, the minimum input rotation to be achieved is calculated by adding the set rotation DMOFST to the input rotation InpREV (InpREV + DMOFST).
[0091]
In step 115, the vehicle speed sensor 63 reads the vehicle speed VspSEN (= VSP).
[0092]
In step 116, the reaching input rotation DsrREVn (= Ni corresponding to the vehicle speed VspSEN at each gear position (n). ^* ) Is calculated.
[0093]
In step 117, the gear position of the highest gear is selected from the gear positions satisfying DsrREVn ≧ (InpREV + DMOFST).
[0094]
When the automatic shift mode is switched to the manual shift mode by operating the select & shift lever (shift mode switching means) (not shown), the initial process shown in FIG. 7 is executed. The initial gear ratio is set to an increasing gear ratio that increases at least the set rotation DMOFST with respect to the input rotation speed InpREV of the transmission at the gear ratio in the automatic gear shift mode before switching.
[0095]
That is, at the time of switching from the automatic transmission mode to the manual transmission mode, a downshift is always performed in which the input rotational speed InpREV of the transmission increases by more than the set rotation DMOFST. A change in the input rotational speed InpREV equal to or higher than the rotational DMOFST is ensured, and the engine braking force expected by the driver is generated.
[0096]
Incidentally, in the case of selecting the shift stage that is the downshift side reaching input rotation closest to the actual input rotation at the time of the conventional mode switching, as shown in FIG. 12, the actual input is performed in the area indicated by hatching at the time of mode switching. In the present invention, as shown in FIG. 11, for example, when the set rotation DMOFST is set to DMOFST = 500 rpm, hatching is performed at the time of mode switching. When there is an actual input rotation in the area shown in (2), a downshift is made to manual 4th speed. That is, the manual 4th speed is not downshifted to 4th speed but downshifted to 3rd speed even if there is an actual input rotation in the rotation speed region of 500 rpm or less. In particular, the change in the gear ratio increases in the coast region, while the change in the high rotation region is small, indicating that the engine brake request when the accelerator is OFF can be met.
[0097]
Therefore, at the time of switching from the automatic transmission mode to the manual transmission mode, only one mode switching operation to the select & shift lever does not require the downshift operation, and the downshift for acceleration or the engine brake is applied. Therefore, it is possible to reliably meet the driver's demand for downshift expectations.
[0098]
In the initial process of FIG. 7, when the automatic transmission mode is switched to the manual transmission mode, the manual transmission control side having a fixed transmission ratio for each of the plurality of transmission speeds has a current input rotation speed InpREV. On the other hand, since the gear position of the high gear is set in the gear position that rises to the input rotation speed equal to or higher than the set rotation DMOFST, the reaching input to the vehicle speed VSP (= transmission output rotation speed) as shown in FIG. Rotating Ni ^* If a shift map for manual transmission mode that defines (= steady target input rotation) is prepared, the current transmission input rotation at the time of mode switching can be performed by simple processing that does not convert the input rotation speed into a gear ratio. It is possible to set a gear ratio that increases to an input speed equal to or higher than the set speed DMOFST with respect to InpREV.
[0099]
[Processing in downshift state in manual shift mode]
FIG. 8 is a flowchart showing a downshift state process in the manual shift mode in the shift control program.
[0100]
In step 118, it is determined whether or not the vehicle speed VSP is equal to or higher than a predetermined value. If YES, the process proceeds to step 119, and if NO, the process proceeds to step 120.
[0101]
In step 119, when the vehicle speed VSP is equal to or higher than a predetermined value, it is determined whether or not the VDC (vehicle dynamics control) is operated. If the vehicle is operating, the process proceeds to step 122, and downshift is prohibited. Proceed to 120. Here, VDC is a system that automatically adjusts the brake control force according to the difference between the target slip amount and the actual slip amount of the vehicle and controls the engine output to automatically improve the running stability. is there.
[0102]
In step 120, if NO is determined in step 118, or if it is determined not to be operated in step 119, it is determined whether or not the gear position SftPOS is the first speed (minimum speed), and if YES, step 122 is determined. If NO, go to step 121.
[0103]
In step 121, if NO is determined in step 120, it is determined whether or not the target input rotation after the downshift is equal to or greater than a predetermined value of the maximum rotation range. If YES, the process proceeds to step 122 and the downshift is prohibited. Engine overrev (overspeed) is prevented, and if NO, the routine proceeds to step 123.
[0104]
In step 122, if it is determined in step 119 that the VDC operation is performed, if it is determined in step 120 that the gear position is the first speed, and the target input rotation after the downshift is equal to or greater than a predetermined value in the maximum rotation range. If it is determined, the downshift is prohibited (the current gear position is maintained).
[0105]
In step 123, it is determined in step 118 that the vehicle speed VSP is less than the predetermined value, in step 120, the gear position is other than the first speed, and in step 121, the target input rotation after the downshift is less than the predetermined value in the maximum rotation range. In this case, a downshift for shifting to the low speed side by the first speed is executed.
[0106]
[Upshift status processing in manual shift mode]
FIG. 9 is a flowchart showing the upshift state process in the manual shift mode in the shift control program.
[0107]
In step 124, it is determined whether or not the vehicle speed VSP is equal to or higher than a predetermined value. If YES, the process proceeds to step 125, and if NO, the process proceeds to step 126.
[0108]
In step 125, when the vehicle speed VSP is equal to or higher than a predetermined value, it is determined whether or not the VDC is operated. If the vehicle is operating, the process proceeds to step 128, and the upshift is prohibited, and if not, the process proceeds to step 126.
[0109]
In step 126, if NO is determined in step 124, or if it is determined in step 125 that it is not operating, it is determined whether or not the gear position SftPOS is 6th speed (maximum speed). If YES, step 128 is determined. If NO, go to step 127.
[0110]
In step 127, if NO is determined in step 126, it is determined whether or not the vehicle speed VSP is equal to or higher than the auto-down vehicle speed calculated based on the target shift speed SftPOS. If YES, the process proceeds to step 129. If NO, Proceeding to step 128, prohibiting upshifts prevents up / down shift interference.
[0111]
In step 128, if it is determined in step 125 that the VDC operation is performed, if it is determined in step 126 that the gear position is 6th gear, or if it is determined that the vehicle speed is less than the auto-down vehicle speed, increase Shifting is prohibited (the current gear position is maintained).
[0112]
In step 129, if it is determined in step 124 that the vehicle speed VSP is less than the predetermined value, in step 126 the gear position is other than 6th speed, and in step 127 it is determined that the vehicle speed is equal to or higher than the auto-down vehicle speed, the first speed is shifted to the high speed side. A shift upshift is performed.
[0113]
[Processing in steady state during manual shift mode]
FIG. 10 is a flowchart showing a steady state process in the manual shift mode in the shift control program.
[0114]
In step 130, it is determined whether or not the target input rotation is equal to or higher than the auto-up rotation AUPREV. If YES, the routine proceeds to step 134, and an upshift is automatically performed to prevent engine overrev (overspeed).
[0115]
In step 131, when the target input rotation is less than the auto-up rotation AUPREV, it is determined whether or not the vehicle speed VSP is equal to or higher than the auto-down vehicle speed calculated based on the target shift speed SftPOS. If the gear position is held and the answer is NO, the routine proceeds to step 133, where downshifting is automatically performed. This auto-down control is basically performed for the purpose of returning to the lowest gear position before the stop because the continuously variable transmission cannot shift while it is stopped.
[0116]
The present invention is not limited to the above-described embodiment, and many changes and modifications can be made.
[0117]
For example, in the above embodiment, the case where the shift control device for a continuously variable transmission according to the present invention is applied to a toroidal continuously variable transmission has been described. However, the shift control device of the present invention is applied to a V-belt continuously variable transmission. It can also be applied.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view of a toroidal continuously variable transmission provided with a transmission control device for a continuously variable transmission according to the present invention.
2 is a longitudinal front view showing the toroidal-type continuously variable transmission of FIG. 1 together with its shift control system. FIG.
3 is a functional block diagram of speed change control executed by the controller of FIG. 2. FIG.
FIG. 4 is a shift diagram illustrating a shift pattern of a continuously variable transmission.
FIG. 5 is a flowchart showing the entire shift control program of the shift control device for a continuously variable transmission according to the present invention.
FIG. 6 is an overall flowchart showing a shift control process in a manual shift mode in a shift control program.
FIG. 7 is a flowchart showing an initial process in a manual shift mode in a shift control program.
FIG. 8 is a flowchart showing a downshift state process in a manual shift mode in a shift control program.
FIG. 9 is a flowchart showing processing in an upshift state in a manual shift mode in a shift control program.
FIG. 10 is a flowchart showing a steady state process in a manual shift mode in a shift control program.
FIG. 11 is a diagram showing a manual shift map showing a region to be downshifted to manual shift 4th when the automatic shift mode is switched to the manual shift mode in the present invention.
FIG. 12 is a diagram showing a manual shift map showing a region to be downshifted to manual shift 4th speed when switching from automatic shift mode to manual shift mode in the prior art.
[Explanation of symbols]
1 Input cone disk
2 Output cone disk
3 Power roller
4 Step motor
5 Shift control valve
6 Piston
7 Precess Come
8 Shift link
20 Input shaft
28 Loading cam
41 Trunnion
43 Upper Link
45 Lower link
60 Inhibitor switch
61 controller
62 Throttle opening sensor
63 Vehicle speed sensor
64 input rotation sensor
65 Output rotation sensor
66 Oil temperature sensor
67 Line pressure sensor
68 Engine rotation sensor
69 UP / DOWN switch
70 Mode selection switch
71 Shift map selection section
72 Achieving input rotation speed calculation unit
73 Achieving transmission ratio calculation unit
74 Shift time constant calculator
75 Target gear ratio calculation unit
310 Engine control switch
320 Anti-skid control device
330 Traction control device
340 constant speed travel device

Claims (2)

Automatic transmission control means for automatically changing the transmission ratio according to the driving state, and an automatic transmission mode;
Manual shift control means for manual shift mode in which a fixed gear ratio can be selected sequentially from a plurality of shift stages by manual operation;
Shift mode switching means for selectively switching between the automatic shift mode and the manual shift mode;
In a continuously variable transmission shift control device comprising:
When the automatic transmission mode is switched to the manual transmission mode by the operation of the transmission mode switching means, the initial transmission ratio immediately after the switching is changed to the transmission input rotational speed at the transmission ratio in the automatic transmission mode before the switching. On the other hand, a speed change control device for a continuously variable transmission, comprising an initial speed ratio setting means for setting at least a speed ratio on the increasing side that increases at least a predetermined number of revolutions set in advance. The transmission control device for a continuously variable transmission according to claim 1,
The manual shift control means has a fixed gear ratio for each of a plurality of shift stages,
When the initial speed ratio setting means is switched from the automatic speed change mode to the manual speed change mode, the highest speed among the speeds that increase to the input speed that is equal to or higher than the predetermined speed relative to the current transmission input speed. A speed change control device for a continuously variable transmission, characterized in that it is a means for setting a step.

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