JPS60135335A - Constant-speed running device for automobiles with cvt - Google Patents

Abstract

PURPOSE:To improve the controlling accuracy of a constant-speed running device by providing a means for correcting the transmission gear ratio of a CVT in relation to electric signals in means for controlling conducted current. CONSTITUTION:A CVT computer 114 comprises an input circuit 116 for receiving pulse signals from a driving circuit 90 and so on, an A/D converter for receiving analogue signals from a throttle opening sensor 52 and so on, a ROM120, a RAM122, a CPU 124 and an output circuit 126. The output circuit 126 controls the current conducted in solenoids 128 and 130 of a pressure-regulating valve 32 and a flow-controlling valve 38 based on the data from the CPU. The CTV computer 114 corrects the transmission gear ratio gamma based on the duty ratio D of the driving pulse signal.

Description

[Detailed description of the invention] Technical field The present invention relates to a continuously variable transmission (hereinafter referred to as [CV1'J).

) related to a constant speed running device (auto drive device) for a vehicle.

Background Art A constant speed driving device has a negative pressure actuator that operates a throttle valve in an intake passage to control the throttle opening θ, and during a constant speed driving period, the set vehicle speed V′ and the actual vehicle speed V
The supply of negative pressure to the negative pressure actuator is controlled based on the difference between the two. When climbing, the throttle opening θ increases and the negative pressure in the intake pipe, which serves as a source of negative pressure, decreases, so the actual vehicle speed V drops significantly from the set vehicle speed V', making it necessary to increase the throttle opening θ. However, there is a problem that the throttle opening degree 0- cannot be increased sufficiently.

Therefore, in the previous Japanese Patent Application No. 57-207736, the present applicant proposed that when v'-v>c (where C is a constant), CVT
(or increase the target engine rotational speed N' to increase T) C
A constant speed traveling device for a vehicle with a VT has been disclosed as an example.

However, in that device, if v' - v < c, the vehicle speed V
The gear ratio T or the target engine speed N' is not corrected due to the deviation in the gear ratio T or the target engine speed N' when v' - v > c.
-It was uniform regardless of the value of v. Therefore v'
- In the case of v≦C, there is a problem that the actual vehicle speed V cannot be sufficiently increased to the set vehicle speed V', and v'
- When v > c, the amount of correction of the gear ratio T or target engine speed N' may be too small and the vehicle speed V cannot be increased sufficiently, or may be too wide, increasing noise and worsening the fuel consumption rate. There is a problem.

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a constant speed traveling device for a vehicle equipped with a CVT that can eliminate these problems and improve control accuracy.

In order to achieve this object, the present invention provides a CVT provided in the power transmission path of the engine, an actuator that controls the throttle opening degree 0 by operating the throttle valves 1 to 1 of the intake gas passage 1B, and a constant During the high-speed running period, in a constant-speed running system for a vehicle equipped with a CVT, which is equipped with an energizing current control means that controls the actuator energizing current in relation to the difference between the set vehicle speed V' and the actual vehicle speed V, the energizing current or The corresponding communication 'I'
I! Modification means are provided for modifying the transmission ratio γ of the CVT in relation to the electrical signal in the current control means.

Since the CVT transmission ratio can be corrected regardless of whether v'-v>c or apricot, it is possible to accurately match the actual vehicle speed V to the set vehicle speed V' even during the period when v'-v≦C. can.

Since the energizing current or the electrical signal corresponding to it is a function of v'-v, as a result of modifying the gear ratio γ in relation to the energizing current or the electrical signal corresponding to it, the amount of correction becomes v
' -v is reflected, and the vehicle speed V can be appropriately brought closer to the target engine rotational speed V'.

In a preferred embodiment, the gear ratio γ of the CVT is modified by modifying the target engine rotational speed N' of the engine, and the energizing current control means forms the energizing current of the actuator as a drive pulse signal with a varying duty ratio.

Example The present invention will be described in detail with reference to the drawings.

In FIG. 1, the CVTIO has an input shaft 12 and an output shaft 14 that are parallel to each other. The input shaft 12 is the engine I6
The crankshaft 18 is provided coaxially with the crankshaft 18, and is connected to the crankshaft 18 through a clutch 20. The input pulleys 22a and 22b are provided opposite to each other, and one of the input pulleys 22a is provided as a movable pulley on the input shaft 12 so as to be movable in the axial direction and fixed in the rotational direction.
The other input side pulley 22b is a fixed pulley that connects the input shaft 1.
It is fixed at 2. Similarly, output side pulley 24g, 2
4b are also provided facing each other, and one output side pulley 2
4a is fixed to the output shaft 14 as a fixed pulley, and the other output side pulley 24b is provided as a movable pulley on the output shaft 14 so as to be movable in the axial direction and fixed in the rotational direction. Opposing surfaces of the input pulleys 22a, 22b and the output pulleys 24a, 24b are tapered, and the belt 26 with an isosceles trapezoid cross section is connected to the input pulleys 22a, 22b.
and the output pulleys 24a, 24b. The oil pump 28 pumps oil from the oil sump 3o to the pressure regulating valve 32.
send to The pressure regulating valve 32 is composed of an electromagnetic relief valve, and controls the line pressure of the oil passage 36 by changing the amount of oil released to the drain 34, and the line pressure of the oil passage 36 is controlled by the hydraulic cylinder of the output pulley 24b and the flow rate. It is sent to the control valve 38. The flow control valve 38 controls the flow rate of oil supplied from the oil path 36 to the oil path 4o connected to the hydraulic cylinder of the input pulley 22a, and the flow rate of oil discharged from the oil path 4o to the drain 34. Input side pulleys 22a, 22b and output side pulley 24 with respect to belt 26
The pressing force of a, 24b is controlled by the oil pressure of the input side hydraulic cylinder and the output side hydraulic cylinder, and in relation to this pressing force, the belt 26 on the tapered surface of the input side pulleys 22IlI, 22b and the output side pulleys 241I, 24b is controlled. The engagement radius changes, and as a result, the gear ratio of CVT 10 is 7 (
= Nin / Nout, where Nout is output shaft 1
4 rotation speed, Nin is the input shaft] 2 rotation speed,
In this embodiment, Nin=engine rotation speed Ne. ) changes. In order to suppress drive loss of the oil pump 28, the line pressure of the output side hydraulic cylinder is controlled to the minimum necessary value that can avoid slipping of the belt 26 and ensure power transmission, and is controlled by the oil pressure of the input side hydraulic cylinder. The lower gear ratio is controlled. Note that the hydraulic pressure of the input side hydraulic cylinder ≦ the hydraulic pressure of the output side hydraulic cylinder, but since the pressure receiving area of the input side hydraulic cylinder > the pressure receiving area of the output side hydraulic cylinder, the pressing force of the input side pulleys 22a and 22b is calculated from the output side pulley. 24a+
It can be made larger than the pressing force of 24b. The input side rotation angle sensor 42 and the output side rotation angle sensor 44 measure the rotational speed N l n of the input shaft 12 and output shaft 14, respectively.
+ NO 12L is detected, and the water temperature sensor 46 is connected to the engine 16.
Detects the cooling water temperature. An accelerator pedal 50 is provided in the driver's seat 48, a throttle valve in the intake passage is interlocked with the accelerator pedal 50, and a throttle opening sensor 52 detects the throttle opening θ. A shift position sensor 54 detects the shift range of a shift lever located near the driver's seat.

FIG. 2 shows the electronic control unit.

The vehicle speed sensor 56 consists of a reed switch that generates a pulse signal proportional to the vehicle speed V, and its output is sent to the F-V conversion circuit 60 of the constant speed running computer 98 and converted into a voltage proportional to the vehicle speed V. The PL-V conversion circuit 60 is
A constant voltage is supplied from a constant voltage circuit 64 that is turned on and off by a main S/W (S/W: abbreviation for switch) 62,
It operates only while the main switch 62 is on. The AND circuit 66 cooperates with the low-speed limiter circuit 76 to open and close the analog S/W 74 in relation to the logical product of the output of the set S/W 68 and the output of the high-speed limiter circuit 72 sent via the NOT circuit 70. control. Therefore, the analog S/W 74 is, for example, 40 Km/h < V <
It closes when the set S/W 68 is turned on during a period of 100 Km/h, and the vehicle speed V at this time is the set vehicle speed V'
It is stored in the storage circuit 78 as . Comparison circuit 80 compares set vehicle speed V' and actual vehicle speed V' and generates a logic signal corresponding to the comparison result. The phase compensation circuit 82 corrects the output of the comparator circuit 80 in consideration of play in the accelerator system in order to quickly correct fluctuations in the traveling vehicle speed V. If the set S/W 6g is turned on during the period h, the instruction to execute constant speed driving is retained even after the set S/W 68 is turned off, and when the cancel 57W86 is turned on, the instruction to execute constant speed driving is retained. discard.

The AND circuit 88 receives input from the phase compensation circuit 82 and the self-holding circuit 84, and its output is sent to the electromagnetic control valve 94 of the negative pressure actuator 92 via the drive circuit 90. FIG. 3 shows the relationship between V'-V and the duty ratio of the drive pulse signal as the output of the drive circuit 90. The electromagnetic control valve 94 opens the negative pressure boat 96 and closes the atmospheric pressure boat 98 when energized, and closes the negative pressure boat 98 when not energized.
6 and the atmospheric pressure boat 98, the energization time of the electromagnetic control valve 94 increases as the duty ratio increases, that is, the pressure chamber of the negative pressure actuator 92 +0
As a result, the diaphragm 102 moves against the spring 104 and the throttle valve 10 is moved through the cable 106.
The opening degree θ of No. 7 increases. When the cancel switch 86 is turned on, a constant speed running cancel signal from the self-holding circuit 84 is sent to the electromagnetic release valve +10 via the drive circuit 108, and the atmospheric boat 112 supplies atmospheric pressure to the negative pressure chamber ioo. Constant speed driving is canceled. FIG. 4 shows the relationship between the negative pressure i 100 of the negative pressure actuator 90 and the amount of movement of the diaphragm 102 to the negative pressure 1100. As the negative pressure increases, the diaphragm 102 deflects toward the negative pressure chamber 100, and the throttle opening θ increases. FIG. 5 shows the relationship between the duty ratio of the drive pulse signal of the S magnetic control valve 94 and the negative pressure of the negative pressure chamber 100 using the negative pressure of the negative pressure source as a parameter. The intake pipe negative pressure as a negative pressure source decreases.
Then, despite the increase in duty ratio, the negative pressure chamber 10
It is not possible to sufficiently increase the zero negative pressure, making it difficult to sufficiently increase the throttle opening θ.

Returning to FIG. 2, the input circuit 116 receives pulse signals from the CVT control computer + 14 drive circuit 90, etc., and the input circuit 116 receives analog signals from the throttle opening sensor 52, etc.
l) (analog/digital) converter +18, RO
M+20. RAM +22. It is equipped with CPt1124° and output circuit +26. The output circuit 126 is C
The energization of the solenoids 128 and 130 of the pressure regulating valve 32 and the flow rate control valve 38 is controlled based on the data from the PU.

Figure 6 shows the flowchart 1 of the CVT j[iU control routine.
− is. The target input side rotation speed Ni'n' (=target engine rotation speed Ne') is determined in relation to the duty ratio of the drive pulse signal sent from the drive circuit 90 to the electromagnetic control valve 94.
is corrected by ΔNin5, thereby changing the flow mu pressure Vf of the solenoid 130 of the flow control valve 38, and the CVT
The gear ratio T of 10 is changed.

As shown in FIG. 3, v' -v is a function of the duty ratio, so by changing the gear ratio T of the CVT 10 in relation to the duty ratio, the intake pipe negative pressure as a negative pressure source can be reduced. Even if the negative pressure actuator 92 does not operate sufficiently due to a decrease in the engine speed, the actual vehicle speed V can be adjusted to the target engine speed V'. Furthermore, in cases where the actual vehicle speed (■) increases further than the set vehicle speed (V') even though the throttle opening θ has already reached 0 due to the operation of the negative pressure actuator 92, such as on a descending road, etc. , the target input (11t1 rotational speed N1n' is corrected by ΔN1nb in relation to the duty ratio, and the CVT
The effectiveness of engine braking is increased by increasing the gear ratio T of 10.

To explain each step in FIG. 6 in detail, in step +31, data such as the throttle opening θ, the input side rotational speed N1n1, the output side rotational speed Nout, and the voltage B of the storage battery are read. In step +32, the duty ratio of the drive pulse signal of the electromagnetic control valve 94 is compared with a predetermined value D1, and D
If >DI, the process proceeds to step 134; if D<DI, the process proceeds to step +38. For example, DI is set to 50%.

According to Fig. 3, the duty ratio D = 50% is v' -
The target input side rotational speed N4n' may be corrected by proceeding to step 134 in all cases other than when descending, which requires engine braking. In step 134, the correction amount ΔN1 of the target input side rotational speed Nin'
Calculate the term by setting na as a function fl (D) of D. In step 136, Nip'+ΔN1na is assigned to Nin'. In step 138, the duty ratio and the predetermined value D2 (
D2<DI), and if D<D2, proceed to step 14o; if D>02, proceed to step +46. D2 is, for example, 30%, and according to FIG.
= 02 corresponds to v'-v~-5Km/h. Step 138, along with step 140, is provided to determine whether or not there is a period that requires increased engine braking.

In step 140, it is determined whether the throttle switch included in the throttle opening sensor 52 is on or off. If the throttle switch is on, that is, if the period requires an increase in engine braking, the process proceeds to step 142, and the throttle switch is If the switch is off, that is, if the period does not require an increase in engine braking, the process proceeds to step 146. The throttle switch is on when the throttle valve is at the idling opening, and is off when the throttle valve is opened more than the idling opening. At step +42, the target input side rotation speed Ni
The correction amount ΔN1nb of n' is subtracted as a function f2(I)) of D. In step 144, Nin'+ΔN1nb is substituted for Nin'.

In step 146, the engine torque Te is calculated based on the throttle opening degree 0 and the input side rotational speed Nin. A map is used for this calculation.

At step +48, the engine torque Te and the gear ratio r (=Ni
The control voltage Vf of the solenoid 128 of the four pressure regulating valves 32 is calculated as a function gl(Te, γ) of n/Nout). Output side pulleys 24a and 24b of CVT 10
Since the torque Tout at is a function of Te and Tout, a line pressure Pl related to Tout can be generated by Vr. In step 150, the difference N between the actual input side rotational speed Nin and the target input side rotational speed Nin' is determined.
Function g2 of in -Nin' (Nin -Nin'
), the control voltage Vf of the solenoid 130 of the flow control valve 38 is calculated. The gear ratio γ of the CVT 10 is controlled by Vf.

In the embodiment, the gear ratio T of the CVT 10 is determined based on the duty ratio of the dynamic pulse signal of the CVT computer 114.
However, if the electric signal corresponding to v' - v is in the constant speed running computer 58, for example, the comparator circuit 80
If a subtraction circuit is provided instead of , and an electrical signal corresponding to v' -v is extracted as the output of the subtraction circuit, that electrical signal can be sent to the CvT computer +14 and processed in the same manner as the duty ratio. can.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of the entire CVT, Figure 2 is a configuration diagram of the electronic control unit, and Figure 3 shows the relationship between the deviation from the set vehicle speed and the duty ratio of the drive pulse signal of the electromagnetic control valve of the negative pressure actuator. Figure 4 is a graph showing the relationship between the negative pressure in the negative pressure chamber and the amount of movement of the diaphragm in a negative pressure actuator, and Figure 5 shows the relationship between the duty ratio of the drive pulse signal and the negative pressure using the negative pressure of the negative pressure source as a parameter. FIG. 6, a graph showing the relationship with the negative pressure in the pressure chamber, is a flowchart 1- of the CVT control routine. 10...(VT, 38...flow control valve, 58...
Flying distance computer, 92... Negative pressure actuator, 94... Solenoid control valve, 107... Throttle valve, 114... CVT control computer [CH] - Deviation from set vehicle speed (V'- V) Figure 4 - Negative pressure in the negative chamber

Claims (1)

[Claims] 1. A continuously variable transmission provided in the power transmission path of the engine;
An actuator that controls the throttle opening by operating a throttle valve in an intake passage, and a current control means that controls the current flowing through the actuator in relation to the difference between a set vehicle speed and an actual vehicle speed during a constant speed driving period. A constant speed traveling device for a vehicle with a continuously variable transmission, comprising a correction means for correcting a gear ratio of the continuously variable transmission in relation to an energizing current or an electric signal in the energizing current control means corresponding to the energizing current. A constant speed traveling device for a vehicle equipped with a continuously variable transmission. 2. The constant speed traveling device according to claim 1, wherein the correcting means corrects the gear ratio of the continuously variable transmission by correcting the target engine rotational speed of the engine. 3. The energizing current control means forms the energizing current of the actuator as a drive pulse signal whose duty ratio changes.
Constant speed traveling device as described in section.