JP4042488B2 - Anti-slip device for V-belt type continuously variable transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for preventing slippage of a V belt in a V belt type continuously variable transmission.
[0002]
[Prior art]
Generally, a V-belt type continuously variable transmission is configured such that a V-belt is stretched between a pair of mutually aligned pulleys, and power can be transmitted between both pulleys via the V-belt.
In such a transmission during power transmission, the transmission hydraulic pressure is applied to one pulley (usually the output side pulley) as it is, and the V-belt is clamped with the corresponding force, and the transmission control valve The created speed change control pressure corresponding to the gear ratio command is applied to the other pulley (usually the input pulley), and the V belt is clamped with the corresponding force, and the above difference is caused by the difference in the V belt clamping pressure between these pulleys. Realizes gear ratio command.
[0003]
By the way, if the shift hydraulic pressure used for the above-mentioned shift control is insufficient with respect to the input torque of the transmission, slip occurs between the V-belt and the pulley, resulting in power loss or damage to the belt friction surface. It causes a decline in sex.
However, if the transmission hydraulic pressure is increased excessively with respect to the transmission input torque, the driving load of the oil pump driven by the engine becomes unnecessarily large, and the drivability of the vehicle is impaired.
For this reason, it is conceivable that the transmission hydraulic pressure that satisfies the contradicting conditions is set at a pressure value at which the V-belt type continuously variable transmission does not cause the slip.
[0004]
However, if set with the above-mentioned marginal shift hydraulic pressure, the start-up of the hydraulic pressure is delayed with respect to a sudden change in input torque, as in the case where the driver depresses the accelerator pedal greatly, and slippage of the V-belt type continuously variable transmission occurs. Sometimes.
[0005]
In order to solve this problem, conventionally, as described in, for example, Japanese Patent Laid-Open No. 9-53695, the margin ratio of the transmission hydraulic pressure is further increased so that the V-belt continuously variable transmission does not slip even due to the above factors. Technology is proposed,
Further, as described in Japanese Patent Application Laid-Open No. 8-258595, a technique for limiting the time change rate under a situation where the transmission input torque is suddenly changed has been proposed.
[0006]
[Problems to be solved by the invention]
However, since the former countermeasure technology always increases the margin ratio of the shift hydraulic pressure, the shift hydraulic pressure is increased until it is not necessary, and the load on the oil pump driven by the engine increases, resulting in deterioration of fuel consumption. This causes a decrease in vehicle driving performance.
In the latter countermeasure technology, when the driver depresses the accelerator pedal greatly in hope of rapid acceleration, the transmission input torque cannot be increased with a time-series change commensurate with the accelerator pedal operation. The acceleration performance of the vehicle cannot be obtained, and the acceleration performance of the vehicle is greatly sacrificed.
[0007]
The present invention is intended to solve the above-mentioned problem when the accelerator pedal is depressed particularly during constant speed traveling, and the slip of the V-belt continuously variable transmission at this time causes the accelerator pedal to be depressed. Based on the fact that it is caused by a sudden increase in vehicle driving force,
First, the vehicle driving force is prevented from changing suddenly when the accelerator pedal is depressed, and the shift hydraulic pressure is set to a high value during which no belt slip occurs even when the driving force changes suddenly.
When the accelerator pedal is depressed during constant speed driving, the shift hydraulic pressure can be kept low for as long as possible. However, when the vehicle driving force suddenly increases as the accelerator pedal is depressed, the shift hydraulic pressure is reduced. The purpose is to eliminate the problems related to the deterioration of fuel consumption, the decrease in vehicle driving performance, and the sacrifice of acceleration performance, which were caused by the above-mentioned conventional technology, by ensuring that the belt slip prevention is set to a high value. .
[0008]
[Means for Solving the Problems]
For this purpose, an anti-slip device for a V-belt type continuously variable transmission according to the present invention is as described in claim 1.
Constant speed running control device Target driving force for constant speed driving And depending on the amount of accelerator pedal depression Accelerator target driving force Whichever is larger Target driving force of the vehicle As a configuration used for driving force control,
During constant speed running control Target driving force for constant speed driving But Accelerator target driving force Further, it is configured to issue a command to lower the transmission hydraulic pressure when the amount is more than a predetermined amount.
[0009]
【The invention's effect】
According to the configuration of the present invention, when the accelerator pedal is depressed during constant speed traveling, the constant speed traveling control device is Target driving force for constant speed driving When Accelerator target driving force Whichever is larger Target driving force of the vehicle As the driving force control,
When the accelerator pedal is depressed Accelerator target driving force Is still small for the time being Target driving force for constant speed driving Will be used for driving force control, and the vehicle driving force will not rapidly increase when the accelerator pedal is depressed.
[0010]
Here, for example, even when a command to increase the shift hydraulic pressure is issued when the accelerator pedal is depressed, the shift hydraulic pressure actually increases after a response delay of the hydraulic pressure.
However, according to the present invention, as described above, since the vehicle driving force does not increase immediately when the accelerator pedal is depressed, there is a situation in which the vehicle driving force increases rapidly during the hydraulic response delay and belt slip occurs. It can be prevented from occurring.
As a result, when the accelerator pedal is depressed during constant speed travel, Accelerator target driving force But Target driving force for constant speed driving Thus, there is a time margin until the moment exceeding 1, the transmission hydraulic pressure can be increased by the scheduled instant, and the transmission hydraulic pressure can be kept low for as long as possible.
[0011]
afterwards, Accelerator target driving force But Target driving force for constant speed driving By crossing Accelerator target driving force Even if the vehicle driving force suddenly changes due to contributing to the driving force control, according to the present invention, in order to issue a command to increase the transmission hydraulic pressure, Accelerator target driving force But Target driving force for constant speed driving The shifting hydraulic pressure is already high due to the response delay at the moment when the vehicle driving force changes suddenly beyond this, and even if there is a sudden increase in driving force at that moment, belt slippage is reliably prevented. can do.
As described above, according to the present invention, the transmission hydraulic pressure can be kept low for as long as possible, and this also reliably prevents the occurrence of belt slip. It is possible to prevent belt slip without causing problems related to deterioration of fuel consumption, deterioration of vehicle driving performance, and sacrifice of acceleration performance.
[0012]
In addition , In the present invention, as described in claim 2, Target driving force for constant speed driving Is the target driving force for constant speed driving to maintain the vehicle speed, the accelerator target driving force is the accelerator target driving force corresponding to the accelerator required load obtained from the accelerator pedal depression amount and vehicle speed, and is constant with respect to the accelerator target driving force. It is preferable that the driving target driving force is equal to or greater than a predetermined value.
In this case, depending on how the predetermined value is given, the low pressure time of the shift hydraulic pressure can be extended to the limit in relation to the response delay of the hydraulic pressure.
[0013]
Also , In the present invention, as described in claim 3, Target driving force for constant speed driving Is set as the target driving force for constant speed driving to maintain the vehicle speed, and the target driving force for constant speed driving is set with the accelerator target driving force as the accelerator target driving force corresponding to the accelerator required load obtained from the accelerator pedal depression amount and vehicle speed. When the condition that it is greater than the value and the condition that the accelerator pedal depression amount is greater than or equal to the set value are aligned, Issue the command to lower the shift hydraulic pressure May be.
[0014]
Furthermore, in the present invention, as described in claim 4, Accelerator target driving force Instead of depressing the accelerator pedal Use ,Also Target driving force for constant speed driving Instead of Target driving force for the constant speed running When the accelerator pedal depression amount is converted to the accelerator pedal depression amount, and the accelerator pedal depression amount approaches the accelerator pedal depression amount conversion value to the set value. Issue a command to increase the shift hydraulic pressure be able to.
In this case, a separate throttle actuator for constant speed running control is added to an engine control system that does not have an electronically controlled throttle valve, and the throttle opening by the throttle actuator and the throttle opening corresponding to the accelerator pedal depression amount The present invention can also be applied to a conventional constant speed travel control device in which the larger one is mechanically selected to obtain the throttle opening.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 to 5 show a slip prevention device for a V-belt continuously variable transmission according to an embodiment of the present invention. FIG. 1 shows a vehicle equipped with a V-belt continuously variable transmission equipped with the slip prevention device. The power train is composed of an engine 1 and a V-belt continuously variable transmission 2.
Although the engine 1 is an internal combustion engine such as a gasoline engine, the throttle valve 3 is not mechanically connected to the accelerator pedal 4 operated by the driver, and is separated from the throttle pedal 3 by the throttle actuator 5 to electronically adjust the opening degree of the throttle valve 3. Control it.
[0016]
The throttle actuator 5 responds to a target throttle opening TVOo (described later) from the engine controller 6 so that the opening TVO of the throttle valve 3 coincides with the target throttle opening TVOo, and the output of the engine 1 is basically changed. Although control is performed so as to be a value corresponding to the depression amount APO of the accelerator pedal 4, details can be controlled by factors other than the operation of the accelerator pedal depending on how to give an engine torque command value to be described later.
[0017]
The V-belt type continuously variable transmission 2 is a well-known general one, and includes an input-side primary pulley 8 that is drive-coupled to the output shaft of the engine 1 via a torque converter 7, and an output side that is aligned with the primary pulley 8. Secondary pulley 9 and a V-belt 10 spanned between these pulleys.
The left and right drive wheels 12 (only one is shown in FIG. 1) are drivingly coupled to the secondary pulley 9 via a final drive gear set 11 including a differential gear device, and the power from the engine 1 is transmitted to the V-belt continuously variable transmission. 2 and the final drive gear set 11 are transmitted to the left and right drive wheels 12 to drive the vehicle.
[0018]
The speed change operation of the continuously variable transmission 2 is such that, among the flanges forming the V-grooves of the primary pulley 8 and the secondary pulley 9, one movable flange is brought relatively close to the other fixed flange to make the V-groove width. The width of the V-belt 10 around the pulleys 8 and 9 is changed by increasing the width of the V-groove by narrowing the distance or conversely.
The stroke positions of the movable flanges of the pulleys 8 and 9 are determined by the primary pulley pressure Ppri and the secondary pulley pressure Psec from the transmission control hydraulic circuit 13.
[0019]
The shift control hydraulic circuit 13 uses the hydraulic oil from the engine-driven oil pump 14 as a medium to create a shift hydraulic pressure that matches the target shift hydraulic pressure Po described later in detail from the transmission controller 15, and uses this as it is as the secondary pressure. The pulley pressure Psec is supplied to the secondary pulley 9.
The shift control hydraulic circuit 13 is not shown because it is not related to the invention, but the shift control valve is caused to respond to the gear ratio command from the transmission controller 15 and the shift hydraulic pressure set to the target value Po is used as the original pressure. A primary pulley pressure Ppri corresponding to the gear ratio command is created and supplied to the primary pulley 8.
The V-belt type continuously variable transmission 2 generates a gear shift by the difference in the clamping pressure of the V-belt 10 by the secondary pulley pressure Psec and the primary pulley pressure Ppri, and can achieve the above-described gear ratio command.
A signal related to the target transmission hydraulic pressure Po from the transmission controller 15 is also supplied to the transmission control hydraulic circuit 13 and the oil pump 14, and the flow rate supplied from the oil pump 14 to the pulleys 8 and 9 needs to correspond to the target transmission hydraulic pressure Po. It is also used to reduce the pump load by controlling the flow rate to a minimum.
[0020]
When the engine controller 6 obtains the target throttle opening TVOo or the transmission controller 15 obtains the target transmission hydraulic pressure Po, information (transmission input limit torque Tic, While passing the engine torque command value Tes and the low hydraulic pressure permission flag FLAG) and receiving information on the target driving force Tdc for constant speed traveling from the cruise controller 16, the target throttle opening TVOo and the target speed change hydraulic pressure will be described later. Demand Po.
The engine controller 6 also includes an accelerator pedal depression amount sensor that detects information related to the transmission ratio (input / output rotation speed ratio) i of the transmission 2 obtained by the transmission ratio calculation unit 17 and the accelerator pedal 4 depression amount APO. 18 and the signal from the vehicle speed sensor 19 that detects the vehicle speed VSP.
A signal from the vehicle speed sensor 19 is also input to the transmission controller 15 and the cruise controller 16.
[0021]
The engine controller 6 and the transmission controller 15 are configured as shown in FIG. 2, the engine controller 6 executes the control program shown in FIG. 3 to obtain the target throttle opening TVOo, and the transmission controller 15 controls the control shown in FIG. The target transmission hydraulic pressure Po is obtained by executing the program.
[0022]
First, the engine controller 6 will be described in detail with reference to FIGS. 2 and 3. As shown in FIG. 2, the accelerator controller 6 calculates an accelerator target driving force calculating unit 21, a target driving force determining unit 22, a target engine torque calculating unit 23, The engine torque command value determination unit 24, the target throttle opening calculation unit 25, and the cruise control state estimation unit 26 are configured.
The engine controller 6 having such a configuration reads the accelerator pedal depression amount APO, the vehicle speed VSP, and the gear ratio i in step S1 of FIG. 3, and then, in step S2, a transmission input limit torque Tic (described later) from the transmission controller 15; And the above-mentioned constant driving target driving force Tdc from the cruise controller 16 is received.
[0023]
As shown in step S3 of FIG. 3, the accelerator target driving force calculation unit 21 determines the accelerator target drive requested by the driver by operating the accelerator pedal from the accelerator pedal depression amount APO and the vehicle speed VSP based on the planned map. Find the force Tdn by searching. The target driving force determination unit 22 compares the accelerator target driving force Tdn and the constant speed traveling target driving force Tdc and selects the larger one (select high) as shown in steps S4 to S6 of FIG. Then, the selected driving force is finally determined as the target driving force Tdo.
That is, when Tdc> Tdn is determined in step S4, Tdo = Tdc is set in step S5, and when Tdc <Tdn is determined in step S4, Tdo = Tdn is determined in step S6.
[0024]
As shown in step S7 of FIG. 3, the target engine torque calculation unit 23 calculates the target engine torque Teo for achieving the target driving force Tdo from the target driving force Tdo and the gear ratio i determined as described above. calculate.
The engine torque command value determination unit 24 is also shown in steps S8 to S10 in FIG. 3, but the transmission input limit torque Tic from the transmission controller 15 (V-belt type continuously variable transmission based on the selected transmission hydraulic pressure). Compare the target engine torque Teo calculated above and select the smaller one (select low), and finally select the selected torque as the engine torque command. Let the value Tes.
That is, when it is determined that Tic> Teo in step S8, Tes = Tic is set in step S9, and when Tic <Teo is determined in step S8, Tes = Teo is determined in step S10.
[0025]
The target throttle opening calculation unit 25 also converts the target throttle opening TVOo for achieving the engine torque command value Tes determined as described above by searching from a planned map, as shown in step S11 of FIG. This is also shown in step S12 of FIG. 3, and is output to the throttle actuator 5 to feedback control the throttle actuator 5 so that the throttle opening TVO matches the target throttle opening TVOo.
The cruise control state estimation unit 26 also shows the target driving force deviation ΔTd = Tdc−Tdn between the constant speed traveling target driving force Tdc and the accelerator target driving force Tdn, which is also shown in steps S13 and S14 of FIG. The cruise control state is estimated based on whether the value is greater than or less than the set value ΔTds.
[0026]
As shown in FIG. 4, the cruise control state is estimated by depressing the accelerator pedal from the release state at the instant t1 during cruise control where the constant speed driving target driving force Tdc is determined (idle determination is ON → OFF) Explaining that the accelerator target driving force Tdn increases from the instant t1 as shown in the figure, it is equivalent to estimating whether the target driving force deviation ΔTd is before or after the instant t2 when the target driving force deviation ΔTd decreases to the set value ΔTds. For example, this means that it is estimated whether or not the accelerator target driving force Tdn has approached the target driving force Tdc for constant speed travel to the set value ΔTds.
[0027]
Note that the final target driving force Tdo obtained by the target driving force determining unit 22 is the select high of the constant speed traveling target driving force Tdc and the accelerator target driving force Tdn, as described above. Since the driving force of the vehicle suddenly increases at the instant t3 when the target driving force Tdn increases so as to coincide with the target driving force Tdc for constant speed running, the transmission hydraulic pressure of the V-belt continuously variable transmission 2 causes the belt slip. It needs to be raised so that it doesn't happen.
By the way, there is a response delay Δt of the hydraulic pressure when the transmission hydraulic pressure increases, so that ΔTds = ΔTds is determined just at the transmission hydraulic pressure increase command instant t2 necessary to make the transmission hydraulic pressure increase at the instant t3. Determine.
[0028]
The cruise control state estimator 26 is also shown in steps S14 to S16 in FIG. 3. As long as the target driving force deviation ΔTd is equal to or larger than the set value ΔTds, that is, at the shift hydraulic pressure increase command optimum instant t2 in FIG. Before reaching, the low oil pressure permission flag FLAG is set to 1 because it is determined that the shift oil pressure increase command should not be issued, and after the target driving force deviation ΔTd becomes less than the set value ΔTds, After reaching the shift hydraulic pressure increase command optimum instant t2 in FIG. 4, it is determined that the shift hydraulic pressure increase command should be issued, the low hydraulic pressure permission flag FLAG is reset to 0, and the low hydraulic pressure permission flag FLAG thus determined is set. In step S17, the data is output to the transmission controller 15.
[0029]
In step S18 of FIG. 3, the engine torque command value Tes is output to the transmission controller 15 as the engine torque command value determination unit 24 in FIG.
However, the engine torque signal supplied to the transmission controller 15 in step S18 is replaced with the engine torque command value Tes determined by the engine torque command value determination unit 24, and the estimated engine torque value estimated from the engine intake air amount and the engine speed. May be supplied to the transmission controller 15.
[0030]
Next, the transmission controller 15 will be described with reference to FIGS. 2 and 5. As shown in FIG. 2, the transmission controller 15 includes a normal target hydraulic pressure calculation unit 31, a low pressure permission target hydraulic pressure calculation unit 32, and a target hydraulic pressure determination unit 33. And a transmission input limiting torque calculation unit 34.
The transmission controller 15 having such a configuration receives the engine torque command value Tes from the engine controller 6 in step S21 of FIG. 5, and also receives the low hydraulic pressure permission flag FLAG from the engine controller 6 in step S22.
[0031]
As shown in step S23 of FIG. 5, the normal target hydraulic pressure calculation unit 31 also causes the V-belt continuously variable transmission 2 to slip even when sudden acceleration is performed based on the engine torque command value Tes (current engine torque). The normal target hydraulic pressure Pn corresponding to the shift hydraulic pressure without any is calculated.
As shown in step S24 of FIG. 5, the low-pressure allowed target hydraulic pressure calculation unit 32 does not slip the V-belt continuously variable transmission 2 unless it accelerates rapidly based on the engine torque command value Tes (current engine torque). The target oil pressure Pl at the time of low pressure permission corresponding to a certain shift oil pressure (which is naturally lower than the target oil pressure Pn at the normal time) is calculated.
[0032]
The target hydraulic pressure determination unit 33 is also shown in steps S25 to S27 in FIG. 5, but if the low hydraulic pressure permission flag FLAG is 1, that is, as described above, the target driving force deviation ΔTd is equal to or larger than the set value ΔTds, and FIG. If the shift hydraulic pressure increase command optimum moment t2 is not reached, the latter low pressure permitted target hydraulic pressure Pl is selected as the target shift hydraulic pressure Po among the normal target hydraulic pressure Pn and the low pressure permitted target hydraulic pressure Pl, and the low hydraulic pressure permission flag FLAG is set. If it is not 1, that is, if the target driving force deviation ΔTd is less than the set value ΔTds and the shift hydraulic pressure increase command optimum instant t2 in FIG. 4 has been reached, the former normal target hydraulic pressure Pn is selected as the target shift hydraulic pressure Po. The target shift hydraulic pressure Po determined by the above selection is supplied to the shift control hydraulic circuit 13 and the oil pump 14 to be used for the shift hydraulic control.
[0033]
As shown in steps S28 and S29 in FIG. 5, the transmission input limiting torque calculation unit 34 is a V belt under the target transmission oil pressure Po that is set to the target oil pressure Pl when the low oil pressure permission flag FLAG is 1. V-belt under the upper limit value of the input torque range where the continuously variable transmission 2 does not slip, and when the low hydraulic pressure permission flag FLAG is not 1, the target transmission hydraulic pressure Po is set to the high normal target hydraulic pressure Pn. The upper limit value of the input torque range where the variable continuously variable transmission 2 does not slip is obtained as the transmission input limit torque Tic, and this is supplied to the engine controller 6 to contribute to the determination of the engine torque command value Tes.
[0034]
According to the present embodiment configured as described above, when the accelerator pedal is depressed during constant speed traveling, the target driving force determining unit 22 determines whether the constant speed traveling target driving force Tdc and the accelerator target driving force Tdn are In order to use the larger one as the target driving force Tdo of the vehicle (see step S4 to step S6 in FIG. 3 and FIG. 4) for driving force control,
As is clear from FIG. 4, the accelerator target driving force Tdn is still small at the time t1 when the accelerator pedal is depressed, and for the time being, the target driving force Tdc for constant speed traveling will continue to be used for driving force control as the target driving force Tdo. As is apparent from the change with time of the target driving force Tdo in FIG. 4, the vehicle driving force does not increase immediately at the instant t1 when the accelerator pedal is depressed.
[0035]
The vehicle driving force increases rapidly at the instant t3 when the accelerator target driving force Tdn exceeds the target driving force Tdc for constant speed running, as is apparent from the change with time of the target driving force Tdo. It needs to be raised to prevent slipping.
By the way, according to the present embodiment, while the cruise control state estimating unit 26 determines that ΔTd ≧ ΔTds is before the shift hydraulic pressure increase command optimum instant t2 in FIG. A command to lower the hydraulic pressure (steps S14 and S15 in FIG. 3), and when it is determined that ΔTd <ΔTds has reached the shift hydraulic pressure increase command optimum instant t2 in FIG. A hydraulic pressure increase command is issued (step S14 and step S16 in FIG. 3).
[0036]
When the shift hydraulic pressure increase command is issued at the instant t2 in FIG. 4, the shift hydraulic pressure increase is completed (at the instant t3) after the response delay time Δt of the hydraulic pressure, so that the driving force increases rapidly at the instant t3 as described above. However, it is possible to prevent the V-belt type continuously variable transmission 2 from slipping.
By the way, the shift hydraulic pressure increase command with the flag FLAG = 0 is delayed until the moment t2 at which the shift hydraulic pressure just finishes increasing at the driving force sudden increase instant t3, so that the shift hydraulic pressure is lowered for as long as possible while performing the slip prevention function. Therefore, slip prevention can be realized without problems associated with the deterioration of fuel consumption, the deterioration of vehicle driving performance, and the sacrifice of acceleration performance, which have occurred in the prior art.
[0037]
FIG. 6 shows another embodiment of the present invention, which replaces step S13 and step S14 in FIG. 3 with step S31.
That is, instead of estimating the cruise control state based on the target driving force deviation ΔTd as in the above-described embodiment, the cruise control state is estimated based on the constant speed traveling target driving force Tdc and the accelerator pedal depression amount APO. It is what I did.
In more detail, the cruise control state estimation unit 26 in FIG. 2 determines that the constant driving speed target driving force Tdc is equal to or greater than the set value Tds illustrated in FIG. 7 in step S31 in FIG. It is estimated whether it is before or after the instant t1 when the condition that the APO is less than the minute set value APOs exemplified in FIG.
That is, here, when the target driving force Tdc for constant speed traveling is equal to or greater than a predetermined value and the accelerator pedal depression amount is small at the same time (= 0 may be used), even if the accelerator pedal is depressed suddenly, the target driving for constant speed traveling is performed. It is assumed that there is a time margin until the power is exceeded.
[0038]
FIG. 7 shows an operation time chart when the accelerator pedal is depressed at a constant speed running instant t1 under the same conditions as in FIG. 4. Until the instant t1 when the above two conditions are met, the low oil pressure permission flag FLAG is shown in step S15. Is set to 1 and the shift hydraulic pressure is set to a low hydraulic pressure, and at the instant t1 when the above two conditions are met, the low hydraulic pressure permission flag FLAG is switched from 1 to 0 at step S16 to command the shift hydraulic pressure to a high hydraulic pressure.
[0039]
In this case, the oil pressure rise margin time in FIG. 7 is set longer than the response delay time Δt of the oil pressure in FIG. 4, and the shift oil pressure is reliably increased at the driving force rapid increase instant t3. It is possible to prevent the V-belt type continuously variable transmission from slipping even if the driving force increases rapidly.
And since it is possible to continue the command to reduce the transmission hydraulic pressure until the instant t1 when the accelerator pedal is depressed, the slip prevention function is not limited to the limit as in the above embodiment. The transmission hydraulic pressure can be kept low over a long period of time while preventing slippage without causing the deterioration of fuel consumption, degradation of vehicle driving performance, and sacrificing acceleration performance. Is possible.
[0040]
Although not shown, the accelerator pedal depression amount APO is used instead of the accelerator target driving force Tdn, and this constant speed traveling target driving force Tdc is used instead of the constant speed traveling target driving force Tdc. When the accelerator pedal depression amount APO approaches the accelerator pedal depression amount conversion value up to the set value corresponding to ΔTds in step S14 in FIG. Even if it emits, the same operation effect as in the embodiment described above with reference to FIGS. 1 to 5 can be achieved.
[0041]
In this case, a separate throttle actuator for constant speed running control is added to the engine control system that does not have an electronically controlled throttle valve, and the throttle opening by the throttle actuator and the throttle opening corresponding to the accelerator pedal depression amount There is an advantage that the present invention can also be applied to a conventional constant speed traveling control device in which the larger one is mechanically selected to obtain the throttle opening.
[Brief description of the drawings]
FIG. 1 is a schematic system diagram showing a power train of a vehicle including a slip prevention device for a V-belt type continuously variable transmission according to an embodiment of the present invention, together with its control system.
FIG. 2 is a functional block diagram of transmission hydraulic pressure control and engine throttle opening control of a continuously variable transmission executed by an engine controller and a transmission controller in the control system of FIG. 1;
FIG. 3 is a flowchart showing a control program executed by the engine controller in the embodiment.
FIG. 4 is an operation time chart of the slip prevention device according to the embodiment.
FIG. 5 is a flowchart showing a control program executed by the transmission controller according to the embodiment.
FIG. 6 is a flowchart of a control program similar to FIG. 3, showing another embodiment of the present invention.
FIG. 7 is an operation time chart of the slip prevention device according to the embodiment.
[Explanation of symbols]
1 engine
2 V belt type continuously variable transmission
3 Throttle valve
4 Accelerator pedal
5 Throttle actuator
6 Engine controller
7 Torque converter
8 Primary pulley
9 Secondary pulley
10 V belt
11 Final drive gear set
12 driving wheels
13 Shift control hydraulic circuit
14 Oil pump
15 Transmission controller
16 Cruise controller
17 Gear ratio calculator
18 Accelerator pedal depression sensor
19 Vehicle speed sensor
21 Accelerator target driving force calculator
22 Target driving force determination unit
23 Target engine torque calculator
24 Engine torque command value determination unit
25 Target throttle opening calculator
26 Cruise control state estimation unit
31 Normal target hydraulic pressure calculator
32 Target oil pressure calculation section when low pressure is permitted
33 Target hydraulic pressure determination unit
34 Transmission input limit torque calculator

Claims (4)

In a vehicle comprising a V-belt continuously variable transmission that is controlled to change to a gear ratio according to a gear ratio command value based on the gear pressure, and a constant speed travel control device,
The cruise control system and the target driving force for constant-speed driving, of the accelerator target driving force corresponding to the accelerator pedal depression amount, and adapted for use in the driving force control larger one as a target driving force of the vehicle,
A V-belt type continuously variable motor is configured to issue a command to lower the shift hydraulic pressure when the target driving force for constant speed traveling is larger than the accelerator target driving force by a predetermined amount or more during constant speed traveling control. Anti-slip device for transmission. In claim 1, the target driving force for constant speed traveling is a constant driving target driving force for maintaining a set vehicle speed,
The accelerator target driving force is set as the accelerator target driving force corresponding to the accelerator required load obtained from the accelerator pedal depression amount and the vehicle speed,
When the constant driving target driving force for maintaining the set vehicle speed is greater than a predetermined value by the accelerator target driving force corresponding to the accelerator required load, the command to lower the shift hydraulic pressure is issued. Anti-slip device for V-belt type continuously variable transmission. In claim 1, the target driving force for constant speed traveling is set as a target driving force for constant speed traveling for maintaining a set vehicle speed, and the accelerator target driving force is adapted to an accelerator required load determined from an accelerator pedal depression amount and a vehicle speed. Acceleration target driving force
When the condition that the target driving force for constant speed driving for maintaining the set vehicle speed is equal to or greater than the set value and the condition that the accelerator pedal depression amount is equal to or less than the set value are met, the command to lower the shift hydraulic pressure is issued. An anti-slip device for a V-belt continuously variable transmission. In any one of claims 1 to 3, wherein using the accelerator pedal depression amount in place of the accelerator target driving force and in place of the target driving force for the constant speed running, the accelerator target driving force for the constant-speed running Using the accelerator pedal depression converted value converted into the pedal depression amount,
An anti-slip device for a V-belt continuously variable transmission, characterized in that when the accelerator pedal depression amount approaches the accelerator pedal depression amount converted value to a set value, a command to increase the transmission hydraulic pressure is issued .

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