JPS5944537B2 - Automobile continuously variable transmission speed ratio automatic control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic speed ratio control device for controlling the speed ratio of a continuously variable transmission so that the operating state of the engine is in a predetermined operating state in an automobile equipped with a continuously variable transmission.

If there is no intermediate torque loss between the engine output torque TE and the torque consumed by driving the vehicle, the following equation (1) holds true.

TE-(J, n2+An22+B)×e・・・・・・
・・・・・・・・・(I)e: =n2/nl ””
””””””””'°=−−−− °−=−=′−−−
-°-(2) n2: Output shaft rotational speed J: Output inertia A: Windage resistance B: Slope resistance nl: Input shaft rotational speed On the other hand, the output characteristics of an automobile prime mover, particularly a gasoline engine, are shown in Fig. 10. It can be expressed by equation (3).

TE--K(θ)n1+α(θ)・・・・・・・・・
(31) The speed ratio change rate 6 is calculated from equation (1) (2X3) as follows.

By the way, the conventional general speed ratio control method was based on equation (4).

1 in δ- (nl-no)・・・・・・・・・・・・・・・
・・・・・・・・・Smell) no: 1 for the engine target rotation speed: When comparing the constant formula (4) and the formula <X, I noticed the letter (.

In other words, n is the equivalent term below the second term in the right-hand side () of equation (3).

It was set to fit under normal driving conditions.

However, in such a system, in a car where e is changing and the rate of change is large, the speed ratio change rate at the time of start (i.e., e; 0) is naturally insufficient.
Engine output and torque could not be absorbed, resulting in a rapid increase in engine speed, causing a problem in which the target value (nQ) was exceeded.

This was not only unfavorable for the passenger's feeling, but also caused a decline in the starting acceleration ability.

The present invention attempts to deal with this problem by providing means for changing the gain of the speed ratio change rate according to the displacement of the speed ratio control actuator of the continuously variable transmission, and when the speed ratio is small, the speed ratio change rate - When the speed ratio is large, the gain of the speed ratio change rate 5 is made small.

Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, an engine E is connected via a flywheel 1 to an input shaft 2 of a mechanical-hydraulic transmission H, which is a continuously variable transmission. Hydraulic pump P that applies constant line pressure to P2
A governor valve G1 is installed to adjust the line pressure to a hydraulic pressure according to the rotational speed of the engine E and apply it to the oil passage P7.

Further, a gear 2a is fixed to the right end of the input shaft 2, and a gear 3a fixed to the rotation shaft 3 of the first hydraulic pump motor M1 of the rotary displacement type is meshed with the gear 2a.

A gear 4 spline-coupled to the rotating shaft 3 so as to be slidable in the axial direction has a dog gear 4a at its right end, and is pushed left and right by the forward/reverse switching fork CF to the right end stop position. It meshes with the dog gear 5a of the gear 5 rotatably mounted on the rotating shaft 3, and also meshes with the left gear 6a of the reversing shaft 6 at its right end stop position.

The gear 5 and the right gear 6b of the reversing shaft 6 are constantly meshing with the gear 7a of the intermediate shaft 7, which is a component of the differential gear mechanism.

The differential gear mechanism includes a first planetary gear mechanism D1 and a second planetary gear mechanism D2.

The sun gear 8a of the first planetary gear mechanism D1 is the first reaction shaft 8
The left end of the first reaction shaft 8 has a gear 8b that meshes with the output gear 12a of the low range clutch LC.
is fixed to the right end of the first reaction shaft 8, and a ring gear 8c of the second planetary gear mechanism D2 is fixed to the right end of the first reaction shaft 8.

The ring gear 9a of the first planetary gear mechanism D2 is fixed to a second reaction shaft 9 which is rotatably mounted on the intermediate shaft γ, and the left end of the second reaction shaft 9 is equipped with]・Irange clutch HC A gear 9b that meshes with the output gear 13a is fixed to the second reaction shaft 9, and a sun gear 9c of the second planetary gear mechanism D2 is fixed to the right end of the second reaction shaft 9.

The planetary gear 7b of the first planetary gear mechanism D1 is the first reaction shaft 8
The planetary gear 10a of the second planetary gear mechanism D2 rotates on a carrier 10b provided on the left end of the output shaft 10. It can be installed freely.

The second hydraulic pump motor M2 is of a fixed displacement type, and the oil path P
.

and Pl to the first hydraulic pump motor M1, and a low range clutch LC and a high range clutch HC are mounted on the rotating shaft 11.

The low range clutch LC has an output shaft 12 rotatably mounted on the rotary shaft 11 of the second hydraulic pump motor M2, and the output shaft 12 is rotatably mounted on the rotary shaft 11 of the second hydraulic pump motor M2. The output shaft 12 is rotated integrally.

Like the low range clutch LC, the high range clutch HC has an output shaft 13 rotatably mounted on the rotating shaft 11.
The output shaft 13 is rotated integrally with the rotating shaft 11 in response to line pressure being applied to the oil passage P16.

In this mechanical-hydraulic transmission H, when the dog gears 4a and 5a are engaged and the range clutch LC or the bi-range clutch HC is operated, the output shaft 10 is rotated 20 times to rotate the input shaft 2. The gears 4 and 6a are engaged with each other, and the low range clutch LC or bi-range clutch HC is rotated in the same direction.
When the output shaft 10 is activated, the output shaft 10 can be rotated in the opposite direction to the input shaft 2 by the rotation of the input shaft 20.

A state in which dog gears 4a and 5a are engaged and low range clutch LC is activated is a forward high speed ratio range transmission state, and a state in which dog gears 4a and 5a are engaged and bi-range clutch HC is activated is in a forward high speed ratio region. A transmission state in which gears 4 and 6a are engaged and the low range clutch LC is activated is a reverse high speed ratio transmission state, and a state in which gears 4 and 6a are engaged and the low range clutch HC is activated. is the reverse high speed ratio range transmission state.

The first hydraulic pump motor M1 in each of their transmission states
The relationship between the discharge volume V, the forward speed ratio e, and the reverse speed ratio -e of the hydraulic pump motor M1 is as follows.

Considering oil leakage inside M2, it becomes band-shaped as shown with diagonal lines in FIG.

In addition, the solid line in FIG. 3 shows the case where there is no oil leakage, and the broken line shows the case where the oil leakage is maximum.

Next, a control device for the mechanical-hydraulic transmission H as described above will be explained.

The manual shift valve 20 on the lower right side of Fig. 1 is the oil path P.
3. P4. It controls the state of communication between P, oil passage P2, and reservoir Re, and has three positions: neutral, forward, and reverse.

At the forward position, the oil passage P3 is cut off from the reservoir Re and communicated with the oil passage P2, and both the oil passage P4°P is cut off from both the oil passage P2 and the reservoir Re.

Further, in the forward position, the oil passage P3 is cut off from the oil passage P2 and communicated with the reservoir Re, and the oil passages P4 and P5 are communicated with the oil passage P2 and the reservoir Re, respectively.

Furthermore, in the reverse position, the oil passage P3 is cut off from the oil passage P2 and communicated with the reservoir Re, and the oil passages P4 and P5 are communicated with the reservoir Re and the oil passage P2, respectively.

The oil passages P4 and P are used to move the forward/reverse switching fork CF of the actuator 30 connected to it left and right, and when the manual shift valve 20 is shifted to the forward position, line pressure is applied to the oil passage P4. In this case, the gear 4 is positioned at the right end stop position via the forward/reverse switching fork CF, the dog gears 4a and 5a are engaged, and the manual shift valve 20 is shifted to the reverse position, thereby applying line pressure to the oil passage P. When this is applied, the gear 4 is positioned at the left end stop position via the forward/reverse switching fork CF and meshed with the gear 6a.

A valve 40 provided at the left end of the forward/reverse switching fork CF temporarily connects the oil passage P6 to P2 during the stroke when the gear 4 is moved between its left end stop positions.

Oil road P3. P6. The bypass clutch valve 50 to which P7 is connected is the oil path P.

An oil passage P8 that communicated with the oil passage P8 and an oil passage P9 that communicated with the oil passage P1
When line pressure is applied to oil passage P3 by shifting the manual shift valve 20 to the neutral position, oil passages P8 and P are communicated with each other to perform mechanical-hydraulic gear shifting. Even when machine H is in a neutral state, engine E is rotating at idle, and no line pressure is applied to oil passage P6, oil passages P8 and P9 are
communicate with.

When line pressure is applied to oil passage P6, oil passage P8
and P9, and also when line pressure is not applied to oil passage P3 and the engine speed becomes faster than the idle link rotation speed, oil passages P8 and P9 are also shut off.

The detailed structure of the manual shift valve 20.7 described above, the valve 40, and the bypass clutch valve 50 is disclosed in Japanese Patent Application No. 51-101.27 (Japanese Unexamined Patent Publication No. 52-9386).
It is the same as that of Publication No. 9).

Next, a structure for controlling the supply of hydraulic oil to the actuator AC, the low range clutch LC, and the high range clutch HC will be explained.

In FIGS. 1 and 3, a potentiometer PM in a control circuit X is connected to an engine throttle S, and the positive potential output from the potentiometer PM decreases as the engine throttle opening increases.

As shown in FIG. 4, the function conversion circuit 300 which receives the output of the potentiometer PM as an input has analog-to-digital converters A to D, lead-on memory R<IJM, and digital to
It mainly consists of an analog converter DA, which outputs a positive potential indicating the target engine speed corresponding to the engine throttle opening, and the output is connected to a resistor 321 as shown in FIG.
It passes through a well-known first-order delay circuit 320 consisting of a capacitor 322 and an impedance conversion arithmetic element 323, and becomes the positive input of an adder/subtractor 330.

The negative input of the adder/subtractor 330 is the positive potential ne formed by the rotation speed sensor S1 attached to the input shaft 2 and the frequency-potential converter F-V (responsive to the engine rotation speed).
It is.

This positive potential ne and the output positive potential of the function conversion circuit 300 match when the engine rotation speed is the engine rotation speed target value, and the relationship between the engine throttle opening and the engine rotation speed target value is The engine speed target value also increases as the opening degree increases.

The output of the adder/subtractor 330 is applied to the servo valve 360 through a polarity inversion circuit 400, a gain adjustment circuit 500, and a servo amplifier 350 in this order.

The servo valve 360 blocks both the oil passage P22 and the oil passage P23 of the actuator AC from the oil passage P2 and the reservoir Re when the applied electric potential is zero, and when the applied electric potential is a positive electric potential, the oil passage is closed. P23 and P22 as oil path P2
and the reservoir Re, and the degree of communication is set to have a thickness corresponding to the height of the positive potential applied,
When the applied potential is a negative potential, the oil passages P2□ and P23 are communicated with the oil passage P2 and the reservoir Re, respectively, and the degree of communication thereof is set to a size corresponding to the height of the applied negative potential.

As shown in FIG.
An inverting element 401 that inverts the polarity of the output of 0, a normally open contact 402 that inputs the output of the inverting element 401 to an adder 402 by driving a node relay 405, and an adder/subtractor 330
The adder 402 is provided with a normally closed contact 406 that inputs the output of the adder 402 to the adder 402 .

Normally closed contacts 406 are opened by reed relay 405 .

) The node relay 405 is activated by the conduction of the transistor T6, which is connected to the clutch control circuit 200 shown in detail in FIG. When either one of the normally closed contacts 409, which opens only when the no-range clutch HC is activated by interlocking with the electromagnetic switch 218, is closed, the exclusive OR circuit 408 conducts the contact.

In such a polarity reversal circuit 400, when the manual shift valve 20 is shifted to the forward position and the low range clutch LC is operated, and when it is shifted to the reverse position and the high range clutch HC is operated, T
6 is in a non-conducting state, so the normally closed contact 406 is closed and the normally open contact 403 is open, so the output of the adder/subtractor 330 is directly applied to the gain adjustment circuit 500.

In addition, when the manual shift valve 20 is shifted to the forward position and the low range clutch is operating, and when the manual shift valve 20 is shifted to the reverse position and the low range clutch LC
is in operation, the transistor T6 is conductive, the normally open contact 403 is closed, and the normally closed contact 403 is open, so that the output of the adder/subtractor 330 is applied to the gain adjustment circuit 500 with its polarity reversed.

Note that when the normally open contact 403, the normally closed contacts 406 and 409, and the switch 40γ are open, the terminals are grounded.

The lunoid valve 220 controlled by the clutch control circuit 200 normally communicates the oil passage P1□ with the oil passage P2 by the force of a spring, and connects the oil passage P16 with the reservoir Re.
When the lunoid 225 is energized, the oil passage P16 is communicated with the oil passage P2, and the oil passage P1□ is communicated with the reservoir Re.

The clutch control circuit 200 includes an integrating circuit 201 that multiplies the positive potential ne (positive potential generated by 20 revolutions of the input shaft) by a speed ratio e2*, an integrating circuit 202 that multiplies the positive potential ne by a speed ratio e1*, Comparison circuit 2 that compares the output positive potential ne-e2* determined by the circuit 201 with the output positive potential nd from the rotation speed sensor S2 attached to the output shaft 10
03, the output positive potential nd from the rotation speed sensor S2, and the output positive potential ne'el* determined by the integration circuit 202.
and a comparison circuit 204 for comparing the two.

Therefore, in the comparison circuit 203, an output positive potential is applied to the transistor T1 of the relay drive circuit 205 when ne-e2*>nd, and in the comparison circuit 204, when nd>
ne −e ]*, the output positive potential is applied to the transistor T2 of the relay drive circuit 208.

Furthermore, when a positive potential is applied to the transistor T1, the normally open contact 207 is closed via the reed relay 206, and when a positive potential is applied to the transistor T2, the reed relay 207 closes.
A normally open contact 210 is configured to close via 09.

Therefore, when a positive potential is applied to both transistors TI and T2 and both normally open contacts 207 and 210 are closed, a circuit C2 connecting the drive circuit C3 of the solenoid valve 220 and the adder/subtractor 330 is closed.

As a result, when the adder/subtracter 330 outputs a negative potential, a potential is applied to the transistor T3 of the relay drive circuit 211, the normally open contact 213 is closed via the relay 212, and the adder/subtracter 330 outputs a positive potential. Inversion element 2140
Due to the action, transistor T4 of relay drive circuit 215
A potential is applied to the reed relay 216 to open the normally closed contact 217 .

In other words, in this clutch control circuit 200,
If the speed ratio e is between e1* and e2*, both normally open contacts 207 and 210 installed in the circuit C2 close, and if a negative potential is output from the adder/subtractor 330 at this time, the normally open contacts in the drive circuit C3 close. 213 closes solenoid valve 220 solenoid 2
25 is energized, and this energization is self-maintained by the action of an electromagnetic switch 218 interposed in the drive circuit C3.

In addition, both normally open contacts 207 and 210 inserted in the circuit C2
If a positive potential is output from the adder/subtractor 330 in the closed state,
Normally closed contact 217 in drive circuit C3 opens solenoid 2
25 is cut off, and electromagnetic switch 218 is also opened.

The gain adjustment circuit 500 forms a main part of the present invention, and will be explained with reference to FIG.

In FIG. 7, the output UD of the polarity inversion circuit 400 becomes an input to an arithmetic element 5010, and the output of the arithmetic element 501 is applied to a movable terminal 502a of a potentiometer 502.

A movable terminal 502a of this potentiometer 502 is interlocked with the piston of actuator AC, and
C is the discharge volume V of the first hydraulic pump motor M1 -VM
In the state where the movable terminal 502a is the fixed terminal 502
b, and in a state where the actuator AC is making the discharge volume V of the first hydraulic pump motor M1 +vM, the movable terminal 502a comes closest to the fixed terminal 502c.

Either one of the fixed terminals 502b and 502c, the resistor 506, and the parallel branch point of the normally closed contact 503 are connected via a contact 505.

Contact 505 is operated by reed switch 405 of a signal inversion device.

When reed relay 405 is activated, contact 505 is connected to fixed end 502c of potentiometer 502.

Also, when the reed relay 405 is not operating, the contact 50
5 is connected to the fixed end 502b of the potentiometer 502.

A normally closed contact 503 connected in parallel with resistor 506 is opened by electromagnetic switch 218 of the clutch control circuit.

At this time, the open end of the normally closed contact 503 is not grounded as is normally done.

Note that when the normally closed contact 503 is closed, the current flows through the resistor 5.
06, but instead flows toward the normally closed contact 503.

The resistor 504 is connected to the negative input terminal of the arithmetic element 508, and the output of the arithmetic element 508 is connected to the feedback resistor 509.
is fed back to the negative input terminal via.

The output of the arithmetic element 508 is sent to the arithmetic element 51 via a resistor 510.
1, and the output UD' of the arithmetic element 511 is fed back to the negative input terminal via the feedback resistor 512, and the output '[JD' is applied to the servo amplifier 350.

The operation of the above configuration will be explained next.

When the engine E is stopped, the solenoid 225 of the solenoid valve 220 is not energized, so the solenoid valve 225 is not energized.
0 communicates the oil passage P1□ and the oil passage pia with the oil passage P2 and the reservoir Re, respectively.

Therefore, when the manual shift valve 20 in FIG. 1 is shifted to the neutral position and the engine E is started, line pressure is applied to the oil passage P2 by the operation of the hydraulic pump P in FIG. 1, and this line pressure is applied to the solenoid. The oil is applied to the low range clutch LC through the oil passage P1□ by the valve 220, and the low range clutch LC is operated.

Also, the line pressure of oil path P2 is the manual shift valve 2.
0 is applied to the bypass clutch valve 50 through the oil passage P3, and the bypass clutch valve 50 communicates the oil passages P8 and P9 to bring the mechanical-hydraulic transmission H into a neutral state.

After that, when the manual shift valve 20 is shifted to the forward position for forward driving, the line pressure of the oil passage P2 changes to the oil passage P2.
4, and the actuator 30 operates to engage the dog gears 4a and 5a of the mechanical-hydraulic transmission H, and the line pressure of the oil Mp3 is discharged to the reservoir Re by the manual shift valve 20.

In addition, the polarity inversion circuit 400 is in a state where the output of the adder/subtractor 330 is directly applied to the gain adjustment circuit 500, and in the gain adjustment circuit 500, the normally closed contact 503 is closed, and one end of the contact 505 is connected to the potentiometer 50 by the reed relay 405 of the polarity inversion circuit 400.
2 fixed end 502b.

After that, until the accelerator pedal is depressed, the positive potential applied from the function conversion circuit 300 to the adder/subtractor 330 through the first-order lag circuit 320 is applied to the rotation speed sensor S1.
Since it is higher than the positive potential ne applied to the adder/subtractor 330 from the side, the output of the adder/subtractor 330 becomes a positive potential with a height corresponding to the difference in power between the two people, and this positive potential is applied to the polarity inverting circuit 4.
00 and is applied to the gain adjustment circuit 500.

The positive potential applied to the gain adjustment circuit 500 is applied to the arithmetic element 5
01, potentiometer 502, movable end 502a, fixed end 502b, contact 505, normally closed contact 503, resistor 50
4 sequentially, enters the arithmetic element 508, and this arithmetic element 50
After being inverted and amplified by 8, it is passed through a resistor 510 to the arithmetic element 5.
11, is inverted and amplified again by this arithmetic element 511, and enters the servo amplifier 350.

Therefore, a positive potential is applied to the servo valve 360, the servo valve 360 communicates the oil passages P23 and P2□ with the oil passage P2 and the reservoir Re, respectively, and the actuator AC is operated to increase the discharge volume V of the first hydraulic pump motor M1. −V
M, and the speed ratio e is set to zero.

As described above, when the actuator AC sets the discharge volume V of the first hydraulic pump motor M1 to -VM, the movable terminal 50 of the potentiometer 502 of the gain adjustment circuit 500
2a is closest to the fixed terminal 502b.

When the access pedal is depressed to increase the engine throttle opening, the output positive potential of the potentiometer PM decreases in conjunction with this increase in the engine throttle opening.
The function conversion circuit 300 increases its output positive potential, and the positive input of the adder/subtractor 330 gradually increases due to the action of the first-order lag circuit 320.

Further, due to an increase in the engine throttle opening degree, the engine rotational speed starts to increase, and the negative input of the adder/subtractor 330 increases.

Therefore, the positive potential output by the adder/subtractor 330 gradually becomes lower, and the negative input of the adder/subtracter 330 becomes thicker than the positive input (if the output of the adder/subtractor 330 reaches a negative potential of a height corresponding to the difference in power between the two persons) becomes.

This negative potential is applied to the polarity inversion circuit 400 and the gain adjustment circuit 50.
0 to the servo amplifier 350, the servo valve 360 connects the oil passages P2□ and P23 to the oil passage P2 and the reservoir Re, respectively, and the actuator AC increases the discharge volume V of the first hydraulic pump motor M1 toward +vM. The speed ratio e starts to increase.

At this point, the bypass clutch valve 50 is already connected to the oil passage P8.
Since P9 and P9 are cut off, power is transmitted between the engine and the first drive wheel of the vehicle, a load is applied to the engine E, and the vehicle starts again.

The increase in the speed ratio e continues until the output potential of the adder/subtractor 330 becomes zero, and the movable terminal 502a of the potentiometer 502 of the gain adjustment circuit 500 is connected to the fixed terminal 502.
gradually move away from b.

If the output of the adder/subtractor 330 is at a negative potential even when the speed ratio e reaches e1*, the normally open contact 213 of the clutch control circuit 200 closes and energizes the solenoid valve 2200 and the solenoid 225. connects the oil passage P16 to the oil passage P2 and connects the bi-range clutch HC.
At the same time, the oil passage PI7 is communicated with the reservoir Re to release the low range clutch LC.

At the same time, the polarity inversion circuit 400 inverts the polarity of the output of the adder/subtractor 330 and applies it to the gain adjustment circuit 500.
3 is open (along with the polarity reversal circuit 400 and the glue relay 40
5 connects one end of the contact 505 to the fixed end 502c of the potentiometer 502.

The negative potential output from the adder/subtractor 330 has its polarity inverted by the polarity inversion circuit 400 and is applied to the gain adjustment circuit 500 , and is applied to the arithmetic element 501 of the gain adjustment circuit 500 , the movable end 502 a of the potentiometer 502 , and the potentiometer 502 . fixed end 502c, resistor 506, resistor 504
are sequentially passed through to the arithmetic element 508, and this arithmetic element 508
After being inverted and amplified by
11, the arithmetic element 511 inverts and amplifies it again and applies it to the servo amplifier 350. Therefore, a positive potential is applied to the servo valve 360, and the servo valve 360 connects the oil passages P2□ and P23 to the oil passage P2 and the reservoir Re. The actuator AC operates to change the discharge volume V of the first hydraulic pump motor M1 toward -vM, and the speed ratio e increases.

Furthermore, the movable terminal 502a of the potentiometer 502 of the gain adjustment circuit 500 gradually moves away from the fixed terminal 502c as the actuator piston moves, that is, as the speed ratio e increases.

Note that when the speed ratio e'+'e2* is exceeded, the normally open contact 213 of the clutch control circuit 200 opens again, but the solenoid 2250 is normally held by the closed operation of the electromagnetic switch 218.

When the engine throttle opening is decreased while the speed ratio e is larger than e2*, the output positive potential of the potentiometer PM increases, the output positive potential of the function conversion circuit 300 decreases, and the first-order lag circuit 320 The adder/subtractor 330
The positive input of is gradually decreasing.

As a result, the output of the adder/subtractor 330 becomes a negative potential, and a positive potential is applied to the servo valve 360, so that the speed ratio e increases.

As a result, the engine speed decreases, and the adder/subtractor 330
The negative input of decreases.

Therefore, the negative potential output by the adder/subtractor 330 gradually becomes smaller, and when the negative input of the adder/subtractor 330 becomes smaller than the positive input, the output of the adder/subtractor 330 becomes a positive potential, and a negative potential is applied to the servo valve 360. The speed ratio e decreases.

This decrease in the speed ratio e continues until the output potential of the adder/subtractor 330 becomes zero.
gradually approaches o.

Even if the speed ratio e reaches e2*, if the output of the adder/subtractor 330 remains at a positive potential, the normally closed contact 21γ of the clutch control circuit 200 opens to cut off the energization to the solenoid 225 of the solenoid valve 220. Solenoid valve 22
0 communicates oil 1% P17 to P2 to operate the low range clutch LC, and at the same time communicates the oil passage P16 to the reservoir Re to release the high range clutch HC.

At the same time, the polarity inversion circuit 400 is in a state where the output of the adder/subtractor 330 is directly applied to the gain adjustment circuit 500, and in the gain adjustment circuit 500, the normally closed contact 503 is closed and the reed relay 405 of the polarity inversion device 400 is not activated. One end of 505 is potentiometer 50
2 fixed end 502b.

Therefore, a negative potential is continuously applied to the servo valve 360, and the speed ratio e decreases.

Further, the movable terminal 502a of the potentiometer 502 of the gain adjustment circuit 500 changes to the fixed terminal 502a in response to a decrease in the speed ratio e.
Approaching 02b.

Manual shift valve 20 when speed ratio e is zero
When the is shifted to the reverse position, the line pressure of the oil passage P2 is applied to the actuator 30 through the oil passage P, and the operation of the actuator 30 shifts gear 4 of the mechanical-hydraulic transmission H.
is meshed with gear 6.

At the same time, the polarity inversion circuit 400 inverts the polarity of the output of the adder/subtractor 330 and applies it to the gain adjustment circuit 500.

Since the output of the adder/subtractor 330 is at a positive potential until the accelerator pedal is depressed, a negative potential is applied to the servo valve 360, and the actuator AC increases the discharge volume of the first hydraulic pump motor M1 by +VM. and the speed ratio is held at zero.

The contact 505 of the gain adjustment circuit 500 is connected to the polarity inversion circuit 4.
00 reed relay 405, potentiometer 502
is connected to the fixed end 502c of.

Since the normally closed contact 503 is closed, the output of the adder/subtractor 330 is the movable end 502 of the potentiometer, the fixed end 502c,
The signal is input to the arithmetic element 508 via a contact 505, a normally closed contact 503, and a resistor 504.

In the same way as the operation during the forward movement described above, when the erase clutch is activated during the reverse movement, the contact 505 is connected to the polarity reversing device 4.
Since the reed relay 405 of 00 does not work, it is connected to the fixed end 502b of the potentiometer 502.

Then, the normally closed contact 503 is opened by the electromagnetic switch 218 of the clutch control circuit 200.

As a result, the output of the adder/subtractor 330 is the movable end 502a of the potentiometer 502, the fixed end 502b, the contact 505, and the resistor 5.
06, is input to the arithmetic element 508 via the resistor 504.

As in the case of forward movement, the input resistance of the arithmetic element 508 changes as the absolute value of the speed ratio e changes.

Therefore, detailed explanation will be omitted. The subsequent operation will be easily understood from the explanation of the operation during the forward movement described above, so a description thereof will be omitted.

In the speed ratio control operation as described above, when the mechanical-hydraulic transmission H is in the forward low speed ratio driving state, the input resistance of the arithmetic element 508 of the gain adjustment circuit 500 is equal to the resistance value R1 of the resistor 504 and the potentiometer 502. movable terminal 502a
and the fixed terminal 502b, and if the resistance value of the feedback resistor 509 is Rf, then the arithmetic element 5
The output Vot of 03 is expressed by the following formula.

The output UD' of the negotiation gain adjustment circuit 500 is expressed by the following equation.

However, KA is the feedback resistance 512 of the arithmetic element 504.
This is an amplification factor determined by the resistance value of the resistor 510 and the resistance value of the resistor 510.

Further, when the mechanical-hydraulic transmission H is in the forward high speed dead drive state, the input resistance of the arithmetic element 508 of the gain adjustment circuit 500 is the resistance value R1 of the resistor 504 and the potentiometer 5.
It is the sum of the resistance value Rc between the movable terminal 502a and the fixed terminal 5020 of 02 and the resistance value R2 of the resistor 506, Vot,
UD' is expressed by the following formula.

Furthermore, when the mechanical-hydraulic transmission H is in a low reverse speed range, the input resistance of the arithmetic element 508 of the gain adjustment circuit 500 is between the resistance value R1 of the resistor 504 and the movable terminal 502a and fixed terminal 502c of the potentiometer 502. is the sum of the resistance value Re of Vot.

UD' is expressed by the following formula.

When the mechanical-hydraulic transmission H is in a high-speed ratio range, the input resistance of the arithmetic element 508 of the gain adjustment circuit 500 is between the resistance value R1 of the resistor 504 and the movable terminal 502a and fixed terminal 502b of the potentiometer 502. is the sum of the resistance value Rb of the resistor 506 and the resistance value R2 of the resistor 506, and Vot and UD' are expressed by the following equations.

The above resistance value Rb becomes the minimum when the actuator AC sets the discharge volume V of the first hydraulic pump motor M1 to -VM, and becomes the maximum when the actuator AC sets the discharge volume of the first hydraulic pump motor M1 to +7M.

Moreover, the resistance value Re becomes maximum when the actuator AC sets the discharge volume V of the first hydraulic pump motor M1 to -vM, and becomes the minimum when the actuator AC sets the discharge volume of the first hydraulic pump motor M1 to +7M. .

The maximum resistance value Rb is equal to the sum of the minimum resistance value Re and the resistance value R2.

Therefore, the input resistance of the arithmetic element 508 is 8th with respect to the speed ratio.
As shown in the figure, the (UTjlU I) 7) value changes with respect to the speed ratio as shown in Figure 9.

When the UD'/UDO value changes, it means that the gain of the speed ratio change rate e changes, and when the speed ratio is small, the gain of the speed ratio change rate e increases, and when the speed ratio is large, the gain of the speed ratio change rate e increases. The gain of the speed ratio change rate becomes smaller.

Therefore, the problem of an abnormal increase in engine rotational speed at the time of starting is greatly improved, and the speed ratio control performance during normal driving is also good.

In the embodiments described above, the control target is the engine rotation speed with respect to the engine throttle opening, but as disclosed in Japanese Patent Laid-Open No. 50-48629, for example, the control target is the engine output torque with respect to the engine throttle opening, and the control target with respect to the engine output torque. The present invention can also be applied when the control target is engine rotational speed or engine output torque with respect to engine rotational speed.

Further, in both of the embodiments described above, a mechanical-hydraulic transmission was used as the continuously variable transmission, but other types of continuously variable transmission may be used.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an overview of an embodiment of the present invention, FIG. 2 is a diagram showing the relationship between the speed ratio of the mechanical-hydraulic transmission and the discharge volume V of the first hydraulic pump motor M1, and FIG. The figure is a system diagram showing an overview of the control circuit Figure 6 is a diagram showing details of the clutch control circuit in Figure 3. Figure 7 is a diagram showing details of the gain adjustment circuit in Figure 3. Figure 8 is a diagram showing details of the gain adjustment circuit. FIG. 9 is a diagram showing changes in the input resistance of the arithmetic element 508, FIG. 9 is a diagram showing changes in the input/output ratio of the gain adjustment circuit, and FIG. 10 is a diagram showing the output characteristics of the gasoline engine. E...Engine, ■...Mechanical-hydraulic transmission, 20...Manual shift Harz, 3
0... Actuator for forward/forward switching, AC...
...Actuator for changing the discharge volume of the first hydraulic pump M1, PM... Potentiometer linked to the engine throttle, 300...
・Function conversion circuit, 320...1st order lag circuit, 3
30... Adder/subtractor, SL... Engine rotation speed sensor, 200... Clutch control circuit, 400... Polarity reversal circuit, 350...
...Servo amplifier, 360... Servo valve,
500...gain adjustment circuit, S2...
Output shaft rotation speed sensor.

Claims (1)

[Claims] 1 Engine throttle opening mat, ::- generates an engine rotational speed target value signal corresponding to the engine output torque, or ℃・ generates an engine output torque target value signal corresponding to the engine throttle opening or engine rotational speed. A target value generating section that generates a target value, a detecting section that generates an engine rotation speed signal or an engine output torque signal, and a signal from this detecting section is compared with a signal from the target value generating section and an operation signal is generated in accordance with the deviation. In the speed ratio automatic control device for a continuously variable transmission of an automobile, the speed ratio automatic control device for a continuously variable transmission of an automobile is provided with an operation generating section that generates a signal, and an operation section that changes the speed ratio of the continuously variable transmission in response to a signal from the operation signal generating section. An automobile characterized in that a means is provided for increasing the gain of the speed ratio change rate when the speed ratio is small and decreasing the gain of the speed ratio change rate when the speed ratio is large in response to the displacement of an actuator in the operating part. automatic speed ratio control device for continuously variable transmissions.