JPH09296860A - Continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable speed change in upshifting and speed change in downshifting to be bodily sensed, to prevent speed change shock from being generated, and to improve durability. SOLUTION: A continuously variable transmission is provided with a continuously variable transmission 12, an actuator for changing the gear ratio of the continuously variable transmission 12, and a gear shift mode judging means for judging whether the steplessly variable mode is shifted to the step gear shift mode or not. When the stepless variable mode is shifted to the step gear shift mode, a target gear ratio determining means 253 fixes the gear ratio calculated by a reference gear ratio calculating means 251 as the target gear ratio and then determines the target gear ratio corresponding to the command of upshift transmission and the command of downshift transmission from a plurality of gear ratios calculated by a gear ratio line calculating means 252. In the step gear shift mode, the difference between the gear ratio of respective mutually adjacent gear shift stages is made proper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuously variable transmission.

[0002]

2. Description of the Related Art Conventionally, a V-belt type continuously variable transmission (CV
In the continuously variable transmission using T), a V-belt is stretched between the primary pulley and the secondary pulley, and the interval between the "V" -shaped grooves of the primary pulley and the secondary pulley is changed. By changing the effective diameter of the primary pulley and the secondary pulley,
It is designed to perform gear shifting with a stepless gear ratio. In addition,
In this case, the gear ratio is a value obtained by dividing the rotation speed of the primary pulley by the rotation speed of the secondary pulley.

In a continuously variable transmission capable of selecting between the continuously variable transmission mode and the continuously variable transmission mode, when the continuously variable transmission mode is selected, the primary pulley of the primary pulley is made to correspond to the engine load. The target rotation speed is set, and the gear ratio is changed so that the target rotation speed is achieved. Further, when the stepped shift mode is selected, the driver operates a shift lever or the like to sequentially select a plurality of preset gear ratios.

Further, when shifting from the continuously variable transmission mode to the continuously variable transmission mode, the gear ratio when the continuously variable transmission mode has been selected is once fixed, and the driver operates the shift lever or the like. When an upshift is performed by operation, the gear ratio of the upper gear is selected, and when a downshift is performed, the gear ratio of the next lower gear is selected.

If the difference between the fixed gear ratio and the gear ratio of the gear above one is small and falls within a predetermined range, the gear ratio of the gear above one is selected, and the same. To
When the difference between the fixed gear ratio and the gear ratio of the next lower gear is small and falls within a predetermined range, the gear ratio of the one further lower gear is selected.

[0006]

However, in the above-mentioned conventional continuously variable transmission, when a gear ratio of a gear position one step higher or a gear ratio one step lower is selected, a fixed gear shift is performed. The driver may not be able to experience an upshift or downshift because the difference between the ratio and the selected gear ratio is not sufficient.

Further, when the gear ratio of the gear position one stage higher or the gear ratio of the gear stage one lower is selected, the difference between the fixed gear ratio and the selected gear ratio becomes too large. ,
A shift shock will occur. Moreover, the driver determines whether or not the difference between the fixed gear ratio and the gear ratio of the gear that is one step higher is small, and whether the difference between the fixed gear ratio and the gear ratio of the gear that is one gear lower is small. I don't know how to select the gear ratio of the upper gear or the gear ratio of one lower gear, or select the gear ratio of one gear higher or one gear lower. It cannot be expected that the gear ratio will be selected.

Furthermore, in the stepped speed change mode, one of a plurality of preset speed ratios is selected, so that the V-belt always contacts the same portion of the primary pulley and the secondary pulley. Therefore,
The primary pulley and the secondary pulley are locally worn, and the durability of the continuously variable transmission is reduced. The present invention solves the above-mentioned problems of the conventional continuously variable transmission, allows the user to experience upshifting or downshifting, and predicts the selected gear ratio without causing a gearshift shock. It is an object of the present invention to provide a continuously variable transmission that is capable of improving the durability.

[0009]

To this end, in a continuously variable transmission according to the present invention, a continuously variable transmission that changes gears at a continuously variable transmission ratio, and an actuator that changes the gear ratio of the continuously variable transmission. A shift mode determining means for determining whether or not the stepless shift mode has changed to the stepped shift mode, and a reference gear ratio calculation means for calculating a gear ratio when the stepless shift mode has changed to the stepped shift mode. A gear ratio sequence calculating means for calculating a plurality of gear ratios suitable for performing an upshift gearshift and a downshift gearshift with reference to the gear ratio calculated by the reference gear ratio calculating means, and a continuously variable transmission mode. From the stepped speed change mode to the stepped speed change mode, the speed change ratio calculated by the reference speed change ratio calculating means is fixed as the target speed change ratio, and then the plurality of speed change speeds calculated by the speed change ratio sequence calculating means From a target gear ratio determining means for determining a target gear ratio corresponding to an upshift gearshift instruction and a downshift gearshift instruction, and an actuator operation for operating the actuator so that the target gear gear ratio is achieved. And means.

In another continuously variable transmission according to the present invention, the gear ratio sequence calculating means may further include an upshift gearshift constant and a downshift gearshift constant based on the gear ratio calculated by the reference gear ratio calculating means. The plurality of gear ratios are calculated by multiplying by.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a functional block diagram of a continuously variable transmission according to an embodiment of the present invention. In the figure, 12 is a continuously variable transmission that performs gear shifting at a continuously variable gear ratio, 43 is a hydraulic actuator as an actuator that changes the gear ratio of the continuously variable transmission 12, and 205
Is a position sensor that sends a stepped speed change mode detection signal to be described later to the control unit 206.

Then, the control unit 206 determines a shift mode determining means 250 for determining whether or not the stepless shift mode is changed to the stepped shift mode, and a gear ratio when the stepless shift mode is changed to the stepped shift mode. And a plurality of gear ratios α suitable for performing upshift gearshifts and downshift gearshifts with reference to the gear ratio α _M calculated by the reference gear ratio calculation unit 251. _The gear ratio sequence calculating unit 252 for calculating _i fixes the gear ratio α _M calculated by the reference gear ratio calculating unit 251 as the target gear ratio α when the continuously variable gear shifting mode is changed to the stepped gear shifting mode. After that, from the plurality of gear ratios α _i calculated by the gear ratio sequence calculating means 252,
A target speed ratio determining means 253 for determining a target speed ratio α corresponding to an upshift speed change instruction and a downshift speed change instruction, and the hydraulic actuator 43 is operated so that the target speed ratio α is achieved. And actuator actuating means 254.

FIG. 2 is a schematic diagram of the continuously variable transmission according to the embodiment of the present invention. In the figure, reference numeral 11 denotes a continuously variable transmission, which comprises a V-belt type continuously variable transmission 12, a forward / reverse mode switching device 13, a torque converter 16, a counter shaft 17, and a differential device 19. Have. Then, the torque converter 1
6 is the engine output shaft 20 through the front cover 27.
A pump impeller 21 which is connected to the engine 10 and is rotated by an engine (not shown), a turbine runner 23 which is connected to the input shaft 22, a stator 26 which is supported by the case 10 through a one-way clutch 25, the front cover 27 and the input shaft 22. And a lock-up clutch 15 disposed between and.

Reference numeral 30 is a damper spring disposed between the lockup clutch plate 15a and the input shaft 22, and 31 is an oil pump connected to the pump impeller 21 and driven by the rotation from the engine. Is. The continuously variable transmission 12 includes a primary shaft 32.
Fixed sheave 33 fixed to the primary shaft 32 and a movable sheave 35 slidably mounted on the primary shaft 32, a primary pulley 36, a fixed sheave 39 fixed to a secondary shaft 37, and the secondary shaft. It has a secondary pulley 41 composed of a movable sheave 40 slidably arranged with respect to 37, and a metallic V belt 42 stretched between the primary pulley 36 and the secondary pulley 41.

Further, on the back surface of the movable sheave 35 of the primary pulley 36, a hydraulic actuator 43 having a double piston structure and a movable sheave 40 of the secondary pulley 41 are provided.
The hydraulic actuators 45 having a single-piston structure are arranged on the back surface of each. The hydraulic actuator 43 on the primary pulley 36 side includes a cylinder member 46 and a reaction force support member 47 fixed to the primary shaft 32, and a tubular member 4 fixed to the movable sheave 35.
9 and a piston member 50, and the cylindrical member 4
9, the reaction force support member 47 and the back surface of the movable sheave 35 form a first hydraulic chamber 51, and the cylinder member 46 and the piston member 50 form a second hydraulic chamber 52.

In this case, the first hydraulic chamber 51 and the second hydraulic chamber 51
Of the hydraulic actuator 4 on the secondary pulley 41 side are communicated with each other through the communication hole 47a.
When receiving the same hydraulic pressure as 5, double the axial force. On the other hand, the hydraulic actuator 45 on the secondary pulley 41 side has a reaction force support member 53 fixed to the secondary shaft 37 and a tubular member 55 fixed to the back surface of the movable sheave 40. A hydraulic chamber 56 is formed by the tubular member 55. A spring 57 for preloading is provided between the movable sheave 40 and the reaction force support member 53, and the movable sheave 40 is fixed to the stationary sheave 3.
Bias towards 9.

The forward / reverse mode switching device 13 is
It comprises a double pinion planetary gear 60 for switching between forward and reverse, a reverse brake B ₁ , a first clutch (D range clutch) C ₁ , a second clutch (L range clutch) C ₂ and a one-way clutch F. Then, the first clutch C ₁ and the one-way clutch F are arranged in series,
Fixed sheave 3 of the input shaft 22 and the primary pulley 36
The first clutch C ₁ and the one-way clutch F and the second clutch C ₂ are arranged in parallel with the third clutch C ₃ .

In the planetary gear 60, the sun gear S is attached to the input shaft 22, the carrier CR supporting the first pinion P ₁ and the second pinion P ₂ is attached to the fixed sheave 33 of the primary pulley 36, and the ring gear R is attached. Each of them is connected to the reverse brake B ₁ . A large gear 61 and a small gear 62 are fixed to the counter shaft 17, and the large gear 61 and a gear 63 fixed to the secondary shaft 37 are meshed with each other. The gear 65 of the differential device 19 is engaged.

The differential device 19 includes a differential case 76 to which the gear 65 is fixed, and the differential case 7
6 has a differential gear 66 supported by 6 and left and right side gears 67, 69, and the rotation transmitted to the differential case 76 via the gear 65 is differentiated by the differential gear 66 and the side gears 67, 69 to produce left and right axles. 70,
71 is transmitted. In addition, 200 is an engine speed sensor, 201 is an input shaft speed sensor, and 202 is a vehicle speed sensor.

Next, the hydraulic circuit of the continuously variable transmission 11 having the above construction will be described. FIG. 3 is a hydraulic circuit diagram of the continuously variable transmission according to the embodiment of the present invention. In the figure, 3
1 is an oil pump, 80 is an oil pump control valve, 81 is a solenoid valve for the control valve,
Reference numeral 82 is a primary regulator valve, 83 is a secondary regulator valve, 85 is a line pressure control linear solenoid valve, and 86 is a solenoid valve modulator valve.

Numeral 87 is a manual valve, which is operated by the driver to switch the hydraulic pressure of the line pressure port 1 to the port 2 or 3 as shown in the table in the figure. 89 is a modulator valve, 90 is a C2 control valve, 91 is a duty control solenoid valve,
C1 is the hydraulic servo of the first clutch C ₁ (FIG. 2), C2
Is a hydraulic servo of the second clutch C ₂ , B _{1 is} a hydraulic servo of the reverse brake B ₁ , 100 is an accumulator for the hydraulic servo B ₁ , and 101 is an accumulator for the hydraulic servo C 1.

Further, 102 is a ratio control valve for controlling the gear ratio, 103 is a linear solenoid valve for adjusting the control oil pressure supplied to the ratio control valve 102, 43 is a hydraulic actuator on the side of the primary pulley 36, and 45 is a hydraulic actuator. Is a hydraulic actuator on the secondary pulley 41 side. Further, 16 is a torque converter, 105 is a lockup control valve,
106 is a lock-up relay valve, 107 is a linear solenoid valve for lock-up control, and 109 is a cooler.

Next, the control device of the continuously variable transmission 11 having the above-mentioned structure will be described. FIG. 4 is a block diagram of a control device for a continuously variable transmission according to an embodiment of the present invention, and FIG. 5 is a schematic diagram of a speed selecting device according to an embodiment of the present invention. In the figure, reference numeral 206 denotes a control unit (E
CU), and the control unit 206 includes an engine speed sensor 200 for detecting the engine speed, and a speed of the primary pulley 36 (FIG. 2), that is, an input shaft speed sensor for detecting the speed of the input shaft 22. 201, a rotation speed of the secondary pulley 41, that is, a vehicle speed sensor 202 that detects a vehicle speed, an accelerator sensor 203 that detects an accelerator depression amount, that is, a throttle opening, and a position sensor 205 are connected.

In this embodiment, the speed selecting device is shown in FIG.
A shift lever 301 as shown in FIG. 3 is operated, and by operating the shift lever 301, each switch (not shown) constituting the position sensor 205 is turned on / off. That is, by moving the shift lever 301 in the continuously variable transmission mode guide groove 302, the shift lever 301 can be set at the parking range position P, the reverse traveling range position R, the neutral range position N, the forward traveling range position D and the low range position L. You can
When the shift lever 301 is placed at the forward drive range position D, the continuously variable transmission mode is set.

Then, the shift lever 301 is moved to the stepped speed change mode guide groove 304 via the mode shift groove 303 and moved in the stepped speed change mode guide groove 304, whereby the upshift position + and the downshift position are set. -Can be placed in In addition, the control unit 206
The solenoid valve 81 for the control valve
A pump solenoid 381 for controlling (FIG. 3),
A line pressure solenoid 385 for controlling the line pressure control linear solenoid valve 85, a C ₂ solenoid 391 for controlling the duty control solenoid valve 91, a shift solenoid 403 for controlling the linear solenoid valve 103, and Lock-up solenoids 407 for controlling the linear solenoid valves 107 are respectively connected.

Next, the operation of the continuously variable transmission 11 having the above construction will be described. First, when the rotation of the engine (not shown) is transmitted to the oil pump 31, the oil pump 31
A predetermined hydraulic pressure is generated by. Then, the control unit 206 sends a signal SG1 calculated based on the engine load to the line pressure solenoid 385, and causes the line pressure control linear solenoid valve 85 to generate a control hydraulic pressure. Then, when the control hydraulic pressure is sent to the primary regulator valve 82, the primary regulator valve 82 regulates the hydraulic pressure generated by the oil pump 31 into a line pressure.

When the driver selects the forward drive range or the low range in the continuously variable transmission mode and places the shift lever 301 at the forward drive range position D or the low range position L, the line pressure port 1 of the manual valve 87 is set.
Is supplied to the hydraulic servo C1 via the port 2, and the first clutch C ₁ is engaged. as a result,
The rotation of the engine output shaft 20 depends on the torque converter 16,
It is transmitted to the primary pulley 36 via the input shaft 22, the one-way clutch F, and the first clutch C _1, and is transmitted at a predetermined gear ratio in the continuously variable transmission 12 to be transmitted to the secondary pulley 41. And the secondary pulley 4
The rotation of 1 is transmitted to the left and right axles 70, 71 via the counter shaft 17 and the differential device 19. When the forward drive range is selected, only the first clutch C ₁ is engaged via the one-way clutch F, so the engine brake does not operate during coasting.

When the low range is selected, the shift
It is positive that the lever 301 is in the low range position L.
Detected by the motion sensor 205, the control unit 206
La C _TwoThe duty signal SG3 is sent to the solenoid 391 for
Can be And the solenoid valve 9 for duty control
1 is controlled, C2 control valve 90 is switched
Is supplied to the hydraulic servo C2, and the second clutch
Chi C_TwoAre engaged. As a result, when the coast
The gin brake can be activated.

When the driver selects the reverse drive range in the continuously variable transmission mode and places the shift lever 301 in the reverse drive range position R, the hydraulic pressure from the port 1 of the manual valve 87 is transmitted via the port 3. are supplied to a servo B1, the reverse brake B ₁ is engaged. At this time, the ring gear R of the planetary gear 60 is fixed, and the rotation input from the input shaft 22 to the sun gear S is output as the reverse rotation from the carrier CR and transmitted to the primary pulley 36.

By the way, in the continuously variable transmission 12, the line pressure from the primary regulator valve 82 is supplied to the hydraulic actuator 45 of the secondary pulley 41, and the belt clamping force according to the load torque is generated by the hydraulic actuator 45. Is generated. On the other hand, the linear solenoid valve 103 is controlled based on the shift signal SG4 sent from the control unit 206 to the shift solenoid 403, and the control hydraulic pressure is generated. The ratio control valve 1 is controlled by the control oil pressure.
02 is controlled, and the apply hydraulic pressure controlled by the ratio control valve 102 is applied to the hydraulic actuator 4
3 is supplied. As a result, the gear ratio of the continuously variable transmission 12 is determined.

In this case, for example, in the control unit 206, the best fuel consumption primary pulley rotation corresponding to the throttle opening detected by the accelerator sensor 203 based on the best fuel consumption power line capable of driving the engine with the best fuel consumption. The number is calculated, and the best fuel consumption primary pulley rotation speed is set as the target rotation speed. Then, the actual input shaft rotational speed detected by the input shaft rotational speed sensor 201 is compared with the target rotational speed, and when the actual input shaft rotational speed is higher than the target rotational speed, the apply hydraulic pressure is increased. As a result, the effective diameter of the primary pulley 36 increases and the gear ratio of the continuously variable transmission 12 decreases,
Upshift shifting is performed. Further, when the actual input shaft rotation speed is lower than the target rotation speed, the apply hydraulic pressure is lowered. As a result, the effective diameter of the primary pulley 36 becomes smaller and the gear ratio of the continuously variable transmission 12 becomes larger,
Downshifting is performed.

When the stepped shift mode is selected when the forward drive range of the stepless shift mode is selected, the position sensor 205 causes the shift lever 301 to move to the stepped shift mode guide groove 304. Detect that
The stepped speed change mode detection signal SG5 is sent to the control unit 206.
Shift mode determination means 250 of the control unit 206 (FIG. 1)
When the position sensor 205 sends the stepped speed change mode detection signal SG5, it is determined that the stepless speed change mode is changed to the stepped speed change mode. Then, the control unit 206
Reference gear ratio calculating means 251, the reference change gear ratio alpha _M gear ratio when the transition from the continuously variable transmission mode to the stepped shift mode
Is calculated as Here, when the rotation speed and the vehicle speed of the input shaft 22 at the time of shifting from the continuously variable transmission mode to the stepwise transmission mode are N _I and N _O , respectively, α _M = N _I / N _O.

Then, the control unit 206 sets the reference gear ratio α _M to the target gear ratio α,
Fix the gear ratio to α _M. Next, when the reference gear ratio is α _M , the gear ratio sequence calculating means 252 of the control unit 206 performs the upshift gearshift and the downshift gearshift on the basis of the reference gear ratio α _M. A plurality of suitable gear ratios α _i (i = 1, 2, ..., N) are calculated, and the gear ratios α _i are stored in a memory (not shown) built in the control unit 206.

In this case, 1 / r (where r <1) is preset as the gear ratio constant for upshifting and r is preset as the gear ratio constant for downshifting, and the gear ratio constant is set to the reference gear ratio α _M. By repeatedly multiplying 1 / r and r by the number of times corresponding to the gear stage, the gear ratio α
_i can be calculated. For example, with respect to the reference gear ratio α _M , the gear ratio α _iUP for upshift corresponding to each gear is α _iUP = α _M · r, α _M · r ² , ..., α _M · r ^{n / 2} , And the downshift gear ratio α _iDOWN is _calculated as α _iDOWN = α _M / r, α _M / r ² , ..., α _M / r ^{n / 2} .

Next, the control section 206 judges whether or not the gear shift is instructed in the stepped gear shift mode based on the gear shift operation detection signal SG6 sent from the position sensor 205, and if the gear shift is instructed, It is determined whether an upshift is instructed. In this case, the shift lever 3 moved to the stepped shift mode guide groove 304
When 01 is moved in the stepped shift mode guide groove 304 and placed in the upshift position +, it is determined that the upshift gearshift has been instructed, and when the 01 is placed in the downshift position −, the downshift gearshift is performed. It is determined that the instruction has been given.

Then, the driver operates the shift lever 301.
Is set to the upshift position +, the target gear ratio determining means 253 of the control unit 206 determines that the gear position one step higher is selected, and α is set as the value of the gear ratio α _iUP from the memory.
_The value of _M · r is read out and the value α _M · r is set to the target gear ratio α. When the driver places the shift lever 301 in the downshift position-, the target gear ratio determining means 253 of the control unit 206 determines that the gear position one step lower is selected, and the gear ratio α is stored in the memory. α _M as the value of _iDOWN
/ R is read and the value α _M / r is set to the target gear ratio α.

Subsequently, the control unit 206 determines whether the target gear ratio α is greater than the minimum gear ratio α _{MIN and} less than the maximum gear ratio α _MAX so as not to reduce the engine efficiency. That is, it is determined whether or not the condition of α _MIN <α <α _MAX (1) is satisfied. Then, when the condition of the expression (1) is not satisfied, the control unit 206 does not permit the shift.

The control unit 206 also calculates the engine speed N _e corresponding to the target gear ratio α, and the engine speed N _e is less than the minimum speed N _MIN that causes the engine to stall. High, and the maximum number of revolutions N that causes engine overrevolution
_It is determined whether it is lower than _MAX , that is, whether the condition of N _MIN <N _e <N _MAX (2) is satisfied. Then, when the condition of the expression (2) is not satisfied, the control unit 206 does not permit the shift.

When the equations (1) and (2) are satisfied, the control section 206 sets the target gear ratio α. Subsequently, the actuator actuating means 254 of the control unit 206 calculates the target rotation speed based on the target gear ratio α and the actual input shaft rotation speed detected by the input shaft rotation speed sensor 201, and calculates the actual rotation speed. The input shaft speed is compared with the target speed, and if the actual input shaft speed is higher than the target speed, the apply hydraulic pressure is increased. As a result, the effective diameter of the primary pulley 36 is increased, the actual gear ratio of the continuously variable transmission 12 is reduced, and upshifting can be performed.

Further, the control unit 206 uses the actual input shaft
If the rotation speed is lower than the target rotation speed, the apply hydraulic pressure
Lower. As a result, the effective diameter of the primary pulley 36
Becomes smaller and the gear ratio of the continuously variable transmission 12 becomes larger,
Downshifting can be performed. in this way,
Place the shift lever 301 in the upshift position +
Then, the gear ratio α_iUPThe value of α_M・ R is set to the target gear ratio α
The upshift is performed and the shift
When the bar 301 is placed in the downshift position-, the gear ratio
α _iDOWNThe value of α_M/ R is set to the target gear ratio α
Downshifting is performed.

After that, when the shift lever 301 is again placed in the upshift position +, the value α _M · r ² of the gear ratio α _iUP of the gear one step higher is set to the target gear ratio α and up. When the shift gear shift is performed and the shift lever 301 is again placed in the downshift position −, a further 1
The value α _M / r ² of the gear ratio α _iDOWN of the lower gear is set to the target gear ratio α and downshifting is performed.

In this case, in the stepped shift mode, the difference between the gear ratios α _i of the adjacent gears becomes appropriate, so that the driver can always feel the upshift or downshift. . Further, it is possible to prevent a shift shock from occurring. Then, the driver can expect the speed change ratio α _i when the upshift or downshift is performed.

Moreover, since the plurality of gear ratios α _i are calculated by multiplying the gear ratio α _M by the gear ratio r for upshifting and the gear ratio 1 / r for downshifting, the gear ratio of each gear is changed. The difference between the ratios α _i becomes constant. Therefore, the shift feelings of the upshift and downshift are constant.

Further, in the stepped speed change mode, the speed ratio α when the stepless speed change mode is shifted to the stepped speed change mode.
_Since a plurality of gear ratios α _i are calculated on the basis of _M , the gear ratio α _i constantly fluctuates. Therefore, since the V belt 42 does not always hit the same portion of the primary pulley 36 and the secondary pulley 41, the primary pulley 36 and the secondary pulley 41
It is possible to improve the durability of the continuously variable transmission 11 without any local wear.

Next, the flow chart will be described.
FIG. 6 shows the operation of the continuously variable transmission according to the embodiment of the present invention.
It is a flowchart which shows. The flow chart
Is when the mode is changed from stepless speed change mode to stepped speed change mode.
Of the main routine (not shown)
Then, the shift output process is performed. Step S1 said control
Shift mode determination means 250 (FIG. 1) of the section 206 (FIG. 4)
Indicates whether the mode has changed from stepless speed change mode to stepped speed change mode.
To determine From stepless shifting mode to stepped shifting mode
If it has moved to step S2, if it has not moved to
Go to step S5. Step S2 Base of control unit 206
The quasi-gear-ratio calculation means 251 changes from the continuously variable transmission mode to the stepwise change.
Gear ratio α when shifting to high speed mode_MTo calculate. Stay
Up S3 The control unit 206 changes the gear ratio α to the target gear ratio α.
_MSetting the gear ratio to α_MFixed to
You. Step S4 Gear ratio sequence calculation means 2 of the control unit 206
52 has a reference gear ratio α_MIs the reference gear ratio
α_MUpshift and downshift based on
A plurality of gear ratios α suitable for shifting_iTo calculate.
Step S5 The control unit 206 controls the position sensor 20.
Based on the shift operation detection signal SG6 sent from
Determines if a shift is instructed in the gear shift mode
I do. If gear shifting is instructed, the process proceeds to step S6
If not shown, return. Step S6 system
The control unit 206 determines whether an upshift is instructed.
Judge. If upshifting is instructed
If not instructed in step S7, step S8
Proceed to. Step S7: Determination of target gear ratio by control unit 206
The means 253 is a gear ratio α for upshifting._iUPThe goal of
Set to the gear ratio α. Step S8 of the control unit 206
The target gear ratio determining means 253 is a gear ratio for downshift.
α_iDOWNIs set to the target gear ratio α. Step S9
 The control unit 206 determines that the target gear ratio α is the minimum gear ratio α.
_MINLarger and maximum gear ratio α_MAXLess than
Judge whether or not. The gear ratio α is the minimum gear ratio α_MINGreater than
And maximum gear ratio α_MAXIf smaller, step
In step S10, the gear ratio α is the minimum gear ratio α_MINBelow
Or maximum gear ratio α_MAXLitter if above
On. Step S10 The control unit 206 determines the target gear shift.
Engine speed N corresponding to the ratio α _eTo calculate. Step
The control unit 206 controls the engine speed N_eBut the
Small rotation speed N_MINHigher and maximum speed N_MAXThan
Determine if it is low. Engine speed N_eIs the minimum
Number of turns N_MINHigher and maximum speed N_MAXLower
In the case of step S12, the engine speed N_eIs the best
Small rotation speed N_MINIs less than or equal to the maximum speed N_MAX
If it is more than the above, it returns. Step S12 control
The unit 206 sets the target gear ratio α and returns.

In the present embodiment, the gear ratio α _i is calculated by repeatedly multiplying the reference gear ratio α _M by the gear ratio constants 1 / r and r a number of times corresponding to the gear stage. It is also possible to refer to the map in which the gear ratio α is set in correspondence with the vehicle speed N _O , the gear ratio α, and the engine speed N _e when the continuously variable gear shift mode is changed to the stepped gear shift mode.

[0047]

As described in detail above, according to the present invention, in a continuously variable transmission, a continuously variable transmission that performs gear shifting at a continuously variable gear ratio and a gear ratio of the continuously variable transmission are provided. An actuator to be changed, a shift mode determining means for determining whether or not the stepless shift mode is changed to the stepped shift mode, and a reference gear ratio for calculating a gear ratio when the stepless shift mode is changed to the stepped shift mode. Calculating means, and a gear ratio sequence calculating means for calculating a plurality of gear ratios suitable for performing an upshift gearshift and a downshift gearshift with reference to the gear ratio calculated by the reference gear ratio calculation means, When shifting from the stepless speed change mode to the stepped speed change mode, the speed change ratio calculated by the reference speed change ratio calculating means is fixed as a target speed change ratio, and thereafter, the speed change ratio calculated by the speed change ratio sequence calculating means is fixed. Target gear ratio determining means for determining a target gear ratio corresponding to an upshift gearshift instruction and a downshift gearshift instruction from the gearshift ratio, and operating the actuator so that the target gear ratio is achieved. Actuator actuating means.

In this case, when shifting from the continuously variable transmission mode to the stepped transmission mode, the target transmission ratio determining means fixes the transmission ratio calculated by the reference transmission ratio calculating means as the target transmission ratio, and then the transmission is performed. A target gear ratio corresponding to the upshift gearshift instruction and the downshift gearshift instruction is determined from the plurality of gear ratios calculated by the ratio sequence calculation means.

Therefore, in the stepped shift mode, the difference in the gear ratio between adjacent gears becomes appropriate, so that the driver can not only experience the upshift or downshift, but also the shift. It is possible to prevent a shock from occurring. Moreover, it is possible to predict the gear ratio when the upshift gearshift or the downshift gearshift is performed.

Further, in the stepped speed change mode, a plurality of speed change ratios are calculated with reference to the speed change ratio at the time of shifting from the stepless speed change mode to the stepped speed change mode. Always fluctuates. Therefore, since the V belt does not always hit the same portion of the primary pulley and the secondary pulley, local wear does not occur on the primary pulley and the secondary pulley, and the durability of the continuously variable transmission can be improved. .

In another continuously variable transmission according to the present invention, the gear ratio sequence calculating means further includes a gear ratio calculated for the reference gear ratio calculating means for the upshift gearshift constant and the downshift gearshift constant. The plurality of gear ratios are calculated by multiplying by. In this case, since the difference in the gear ratio between the shift stages becomes constant, the shift feeling in the upshift and the downshift in the downshift become constant.

[Brief description of drawings]

FIG. 1 is a functional block diagram of a continuously variable transmission according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a continuously variable transmission according to an embodiment of the present invention.

FIG. 3 is a hydraulic circuit diagram of the continuously variable transmission according to the embodiment of the present invention.

FIG. 4 is a block diagram of a control device for a continuously variable transmission according to an embodiment of the present invention.

FIG. 5 is a schematic diagram of a speed selecting device according to an embodiment of the present invention.

FIG. 6 is a flowchart showing an operation of the continuously variable transmission according to the embodiment of the present invention.

[Explanation of symbols]

 11 continuously variable transmission 12 continuously variable transmission 43 hydraulic actuator 205 position sensor 206 controller 250 shift mode determination means 251 reference speed ratio calculation means 252 speed ratio sequence calculation means 253 target speed ratio determination means 254 actuator actuation means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroki Goto 2-19-12 Sotokanda, Chiyoda-ku, Tokyo Equas Research Co., Ltd. (72) Haruki Takemoto 10 Takane, Fujii-cho, Anjo City, Aichi Prefecture Aishi Inside AW Co., Ltd. (72) Inventor Norio Imai 10 Takane, Fujii-cho, Anjo City, Aichi Prefecture Aisin AW Co., Ltd. (72) Inventor Shimizu 10 Takane, Fujii-cho Anjo City, Aichi Prefecture Aisi In-A-W Co., Ltd. (72) Inventor Masayuki Takenaka 10 Takane, Fujii-cho, Anjo-shi, Aichi In-A-W Co., Ltd. (72) Inventor Yuji Takamatsu 20-16 Yatsumen-cho, Nishio-shi, Aichi Prefectural management Yatsumen Residential Building No. 405

Claims (2)

[Claims] 1. A continuously variable transmission that shifts at a continuously variable gear ratio, an actuator that changes the gear ratio of the continuously variable transmission, and a determination as to whether or not the continuously variable gear shift mode has been changed to the stepped gear shift mode. And a reference gear ratio calculation means for calculating the gear ratio when the continuously variable gear mode is changed to the stepped gear ratio mode, and the gear ratio calculated by the reference gear ratio calculation means as a reference, A gear ratio sequence calculating means for calculating a plurality of gear ratios suitable for performing an upshift gearshift and a downshift gearshift, and the reference gear ratio calculating means when shifting from a continuously variable gearshift mode to a stepped gearshift mode. The gear ratio calculated by the above is fixed as the target gear ratio, and thereafter, from the plurality of gear ratios calculated by the gear ratio sequence calculation means, an upshift gearshift instruction and a downshift gearshift instruction are issued. And a actuator actuating means for actuating the actuator so that the target gear ratio is achieved, and a continuously variable transmission device. 2. The gear ratio sequence calculating means calculates the plurality of gear ratios by multiplying the gear ratio calculated by the reference gear ratio calculating means by an upshift gearshift constant and a downshift gearshift constant. The continuously variable transmission according to claim 1.