JPS6318052B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lock-up automatic transmission, and particularly to an improvement proposal for a lock-up control section thereof.

Automatic transmissions generally include a torque converter in the power transmission system for the purpose of increasing torque from the engine. A normal torque converter uses an engine-driven pump impeller to circulate hydraulic oil within the torque converter, and this hydraulic oil rotates the turbine runner while increasing the torque under the reaction force of the stator (torque converter state). . Therefore, the torque converter cannot avoid slipping between the pump impeller and the turbine runner during operation, and although automatic transmissions that include a torque converter in the power transmission system are easy to operate, they have poor power transmission efficiency. It has the disadvantage of poor fuel efficiency. For this reason, in the relatively high vehicle speed range where engine torque fluctuations are not a problem, the turbine runner is directly connected to the pump impeller (lock-up state), thereby eliminating slip between the two. A lock-up automatic transmission equipped with this type of torque converter in the power transmission system has been put into practical use in some vehicles.

By the way, in the case of conventional lock-up automatic transmissions, the torque converter with a direct coupling clutch is placed in the lock-up state when the vehicle speed exceeds a set value (lock-up vehicle speed) at each gear position, or the torque converter is locked up at a specific gear position. Regardless of whether the torque converter with the direct coupling clutch is placed in the lock-up state when the vehicle speed exceeds a set value (lock-up vehicle speed), the lock-up vehicle speed is a fixed constant value. In addition, it has been common practice to set the lock-up vehicle speed to a value suitable for operation after the engine has been warmed up.

However, during operation when the engine has not warmed up yet, its combustion is unstable and the operating condition is similar to when the engine load is excessive. When the torque converter is locked up, it not only impairs drivability due to insufficient torque, but also increases unburned harmful components in the exhaust gas.

Furthermore, even after warm-up is completed, if the lock-up vehicle speed is constant as in the conventional case, the lock-up vehicle speed cannot be suitable for both cases where the engine load is large and cases where the engine load is small; In this case, it becomes a sacrifice. In other words, if the lock-up vehicle speed is set based on a case where the engine load is heavy and the lock-up vehicle speed is set to be suitable for this, if the engine load is small, the lock-up vehicle speed will be unnecessarily high, and the lock-up automatic transmission's intention of improving fuel efficiency will be defeated. If the lock-up vehicle speed is set to be suitable for the case where the engine load is low, if the engine load is large, the lock-up vehicle speed will be too low and the drivability will be impaired due to lack of torque, and the exhaust gas will be reduced. Increases the unburned components inside.

Therefore, it is necessary to set the lock-up vehicle speed relatively high while the engine has not yet completed warming up to effectively utilize the torque increasing effect of the torque converter in order to avoid the above-mentioned problem of insufficient torque. There is. Also, the lockup vehicle speed is
Even after the engine has warmed up, the lock-up vehicle speed is different during high-load operation and low-load operation,
During high-load operation, the lock-up vehicle speed is set relatively high to effectively utilize the torque increasing effect of the torque converter to avoid the above-mentioned torque shortage problem, and conversely, during low-load operation, when the torque shortage is not so much of a problem, the lock-up vehicle speed is set relatively high. It is better to improve fuel efficiency by keeping the torque relatively low and locking up the torque converter with a direct coupling clutch early.

The first object of the present invention is to provide a lock-up automatic transmission in which the lock-up vehicle speed can be changed during engine warm-up and after the engine has warmed up, so as to satisfy the former requirement, and to satisfy the latter requirement. The second object of the present invention is to provide a lock-up automatic transmission that can change the lock-up vehicle speed between high-load operation and low-load operation even after the engine has warmed up. This was done in an attempt to solve the problems of conventional lock-up automatic transmissions all at once.

Hereinafter, the present invention will be explained in detail based on each illustrated embodiment, and its effects will be mentioned.

Fig. 1 schematically shows the internal power transmission part of a lock-up automatic transmission with three forward speeds and one reverse speed. Lockup torque converter 1, input shaft 7, front clutch 104, rear clutch 105, second brake 106, low reverse brake 107,
One-way brake 108, intermediate shaft 109, first planetary gear group 110, second planetary gear group 111, output shaft 112, first governor valve 11
3. Second governor valve 114, oil pump 13
It consists of The torque converter 1 consists of a pump impeller 3, a turbine impeller 8, and a stator impeller 9. The pump impeller 3 is driven by a crankshaft 4 and rotates the torque converter hydraulic oil contained therein to the input shaft 7. Torque is applied to the turbine wheel 8 fixed to the Torque is transmitted by the input shaft 7 to the transmission gear train.
The stator wheel 9 is placed on the sleeve 12 via a one-way clutch 10. The one-way clutch 10 has a structure that allows the stator wheel 9 to rotate in the same direction as the crankshaft 4, that is, in the direction of the arrow (hereinafter referred to as normal rotation), but does not allow rotation in the opposite direction (hereinafter referred to as reverse rotation). ing. 1st
The planetary gear group 110 includes an internal gear 117 fixed to the intermediate shaft 109, a sun gear 119 fixed to the hollow conduction shaft 118, and two planetary gears that can rotate and revolve simultaneously while meshing with the internal gear 117 and the sun gear 119, respectively. The second planetary gear group 111 is an internal gear fixed to the output shaft 112. 122, a sun gear 123 fixed to a hollow conductive shaft 118, a planetary gear 1 consisting of two or more small gears that can rotate and revolve simultaneously while meshing with each of the internal gear 122 and the sun gear 123;
24, it is composed of a planetary gear support 125 that supports the planetary gear 124. front clutch 10
4 connects an input shaft 7 driven by a turbine impeller 8 and a hollow transmission shaft 118 which rotates together with both sun gears 119 and 123 via a drum 126, and a rear clutch 105.
is connected to the input shaft 7 and the internal gear 117 of the first planetary gear group 110 via the intermediate shaft 109.
It functions to combine. Second brake 1
06 fixes both sun gears 119 and 123 by wrapping and tightening a drum 126 fixed to the hollow conduction shaft 118, and a low reverse brake 107 fixes the planetary gear support 125 of the second planetary gear group 111. work to do. The one-way brake 108 has a structure that allows the planetary gear support 125 to rotate in the normal direction, but not in the reverse direction. A first governor valve 113 and a second governor valve 114 are fixed to the output shaft 112 and generate governor pressure according to vehicle speed.

Next, a description will be given of the power transmission train when the speed selection rod is set to the D (forward automatic shifting) position.

In this case, only the rear clutch 105, which is the forward input clutch, is initially engaged. Power from the engine via the torque converter 1 is transmitted from the input shaft 7 to the internal gear 117 of the first planetary gear group 110 through the rear clutch 105. The internal gear 117 rotates the planetary gear 120 in the normal direction. Therefore, the sun gear 119 rotates in reverse, and the second
The planetary gears 124 of the planetary gear group 111 rotate normally.
One-way brake 108 prevents sun gear 123 from reversing planetary gear support 125 and acts as a forward reaction brake. Therefore, the internal gear 122 of the second planetary gear group 111 rotates normally. Therefore, the output shaft 112, which rotates integrally with the internal gear 122, also rotates in the normal direction, and the reduction ratio of the first forward speed is obtained. In this state, when the vehicle speed increases and the second brake 106 is engaged, the input shaft 7 is moved from the rear clutch 10 as in the case of the first gear.
5 is transmitted to the internal gear 117.
The second brake 106 fixes the drum 126, prevents rotation of the sun gear 119, and acts as a forward reaction brake. Therefore, the sun gear 11 is stationary.
The planetary gear 120 revolves around the planetary gear 9 while rotating, and therefore the planetary gear support 121 and the output shaft 112 integrated therewith are decelerated, but at a higher speed than in the first speed. The motor rotates forward in the normal direction, and the reduction ratio of the second forward speed is obtained. When the vehicle speed increases further and the second brake 106 is released and the front clutch 104 is engaged, one side of the power transmitted to the input shaft 7 is transmitted to the internal gear 117 via the rear clutch 105, and the other is transmitted to the internal gear 117. It is transmitted to the sun gear 119 via the front clutch 104. Therefore, the internal gear 11
7. Sun gear 119 is interlocked, planetary gear support 121 and output shaft 1
12, all rotate forward at the same rotation speed and move forward No. 3
You can get speed. In this case, the input clutches are the front clutch 104 and the rear clutch 105, and since the planetary gear does not increase the torque, the reaction brake does not act.

Next, the power transmission train when the speed selection rod is set to the R (reverse travel) position will be explained.

In this case, the front clutch 104 and the low
Reverse brake 107 is engaged. The power from the engine passes through the torque converter 1 and is transferred from the input shaft 7 to the front clutch 104.
Sun gears 119, 123 through drum 126
be guided by. At this time, since the rear planet carrier 125 is fixed by the low reverse brake 107, the sun gears 119, 1
The internal gear 122 is decelerated and reversed by the forward rotation of the internal gear 23, and a backward reduction ratio is obtained from the output shaft 112 that rotates integrally with this internal gear.

Figure 2 shows the hydraulic system of the speed change control device related to the above-mentioned automatic transmission.
3. Line pressure adjustment valve 128, pressure increase valve 129, torque converter 1, speed selection valve 130, first governor valve 113, second governor valve 114, 1-2 shift valve 131, 2-3 shift valve 132, throttle pressure reduction Valve 133, cut-down valve 134, second lock valve 135, 2-3 timing valve 13
6, solenoid down shift valve 137, throttle back up valve 138, vacuum
Throttle valve 139, vacuum diaphragm 140, front clutch 104, rear clutch 105, second brake 106, servo 1
41, a low reverse brake 107 and a hydraulic circuit network. The oil pump 13 is driven by the prime mover via the drive shaft 4 and the pump impeller 3 of the torque converter 1, and during engine operation, the oil pump 13 always sucks up oil from a reservoir 142 through a strainer 143, from which harmful debris has been removed, and is transferred to a line pressure circuit. 144.

The oil is regulated to a predetermined pressure by the line pressure regulating valve 128 and sent to the torque converter 1 and the speed selection valve 130 as working oil pressure. The line adjustment valve 128 consists of a spool 172 and a spring 173.
In addition to the spring 173, the throttle pressure of the circuit 165 and the line pressure of the circuit 156 act on the spool 172 through the spool 174 of the pressure booster valve 129, and the force generated by these is applied above the spool 172 from the circuit 144 through the orifice 175. It counteracts the applied line pressure and the pressure applied from circuit 176. The hydraulic pressure of the torque converter 1 is determined by the hydraulic oil outflow passage 51 and the pressure holding valve after the oil introduced into the circuit 145 from the circuit 144 via the line pressure regulating valve 128 flows into the torque converter 1 through the hydraulic oil inflow passage 50. 146, the pressure is maintained within a certain pressure by a pressure holding valve 146. Above a certain pressure, the pressure holding valve 146 is opened and oil is sent further from the circuit 147 to the rear lubrication section of the drive train. When this lubricating oil pressure is too high, the relief valve 148 opens and the pressure is lowered.
On the other hand, lubricating oil is supplied from the circuit 145 to the front lubricating section of the power transmission mechanism by opening the front lubricating valve 149. The speed selection valve 130 is a manually operated fluid direction switching valve, and is composed of a spool 150, which is connected to a speed selection rod (not shown) via a linkage, and the spool 150 moves with each speed selection operation to change the line. This is for switching the pressure feeding passage of the pressure circuit 144. The condition shown in FIG. 2 is the N (neutral) position, with line pressure circuit 144 open to ports d and e. The first governor valve 113 and the second governor valve 114 are shifted to the 1-2 shift valve 131 and the 2-3 shift valve by the governor pressure generated during forward travel.
The shift valve 132 is actuated to perform automatic gear shifting and also controls the line pressure, and the speed selection valve 130
When is in each position D, and, the oil pressure reaches the second governor valve 114 from the line pressure circuit 144 through port c of the speed selection valve 130, and when the car is running, the pressure is regulated by the second governor valve 114. The governor pressure thus generated is sent to the circuit 157 and the first governor valve 1
13, and when the vehicle speed reaches a certain speed, the spool 177 of the first governor valve 113 moves and the circuit 157
is connected to the circuit 158 to generate governor pressure, and the governor pressure from the circuit 158 is transferred to the 1-2 shift valve 131,
2-3 shift valve 132 and cut-down valve 13
counterbalanced by respective springs acting on each end face of 4 and urging each of these valves to the right. Also, from port c of speed selection valve 130 to circuit 153 and circuit 16
1 and second brake 1 via circuit 162
Fastening side hydraulic chamber 1 of servo 141 that tightens 06
1-2 shift valve 1 in the middle of the hydraulic circuit reaching 69
31 and a second lock valve 135 are provided separately,
Furthermore, a circuit 152 extending from port b of the speed selection valve 130 to the second lock valve 135 is provided.

Therefore, when the speed selection rod is set to the D position, the spool 150 of the speed selection valve 130 moves and the line pressure circuit 1
44 leads to ports a, b, and c. Hydraulic pressure passes through circuit 151 from port a, and part of it is sent to the second
The spool 178, which acts on the lower part of the lock valve 135 and is pressed upward by the spring 179, is lowered by the hydraulic pressure acting from the port b through the circuit 152, so that the circuit 16 becomes conductive.
1 and 162 are not cut off, a portion reaches the 2-3 shift valve 132 from the circuit 167 via the orifice 166, and the circuit 153 from port c.
through the second governor valve 114, rear clutch 1
The transmission reaches the 05 and 1-2 shift valves 131 and enters the first forward speed state. In this state, when the vehicle speed reaches a certain speed, the governor pressure in the circuit 158 causes
1- being pressed to the right by spring 159
The spool 160 of the second shift valve 131 moves to the left to perform an automatic gear change operation from the first forward speed to the second forward speed, and the circuit 153 and the circuit 161 are brought into conduction, and the hydraulic pressure is transferred from the circuit 162 to the servo via the second lock valve 135. 141, the second brake 106 is engaged, and the transmission enters the second forward speed. In this case, since the 1-2 shift valve 131 is miniaturized, the speed at the shift point does not increase, and the spool 160 moves to the left at the required speed to perform an automatic shift action from forward first speed to second speed. will be held. When the vehicle speed increases further and reaches a certain speed, circuit 15
The governor pressure of 8 overcomes the spring 163 and pushes the spool 164 of the 2-3 shift valve 132 to the left, and the circuit 167 and circuit 168 are brought into contact and the hydraulic pressure is transferred to the circuit 16.
8 to a part is the release side hydraulic chamber 170 of the servo 141
, the second brake 106 is released, and a portion reaches and engages the front clutch 104, placing the transmission in third forward gear.

Additionally, when the driver presses the accelerator pedal hard until the throttle opening is close to full throttle while driving in the D position, desiring a large acceleration force, the kick-down switch (not shown) that responds to this turns ON. Then, the downshift solenoid 137a, which is disposed opposite to the solenoid downshift valve 137, is energized by energization. This causes the spool 190 of the solenoid down shift valve 137 to
91, it is pushed downward from the locked position upward in FIG. At this time, the kickdown circuit 180 connected to the circuit 154 is connected to the line pressure circuit 144.
1 through circuits 144 and 180.
It is supplied to the -2 shift valve 131 and the 2-3 shift valve 132 so as to correspond to the governor pressure. At this time, if you are driving in 3rd gear, first shift valve 1 to 2-3.
32 spool 164 is forcibly pushed from the leftward position by the line pressure to the rightward position against the governor pressure, and a forced downshift from 3rd gear to 2nd gear is performed within a certain vehicle speed limit. and sufficient acceleration force can be obtained. By the way, if the above-mentioned kickdown is performed while running in second gear, the load is large and the speed is low at this time, so the governor pressure is also low.
The line pressure led to the circuit 180 also causes the spool 160 of the 1-2 shift valve 131 to move from the leftward position to the right against the governor pressure. Therefore, in this case, a forced downshift from second speed to first speed is performed, and a stronger acceleration force corresponding to a large load can be obtained.

When the speed selection rod is set to the (second forward speed fixed) position, the spool 150 of the speed selection valve 130 moves and the line pressure circuit 144 communicates with ports b, c, and d.
Oil pressure reaches the same locations from ports b and c as in case D, engaging the rear clutch 105, while the lower part of the second lock valve 135 is not receiving oil pressure in this case and the spool 178 circuit. Since the areas of the lands above and below the part that opens at 152 and where hydraulic pressure is applied are larger at the bottom, the spool 178 of the second lock valve 135 is pushed down against the force of the spring 179, and the circuits 152 and 16
2 becomes conductive, the hydraulic pressure reaches the engagement-side hydraulic chamber 169 of the servo 141, engages the second brake 106, and the transmission enters the second forward speed state. From port d, hydraulic pressure passes through circuit 154 to solenoid down.
Shift valve 137 and throttle back up valve 138 are reached. There is a disconnection between port a of the speed selection valve 130 and the line pressure circuit 144, and the hydraulic pressure has not reached the 2-3 shift valve 132 from the circuit 151, so the second brake 106 is released and the front clutch 104 is released. The engagement is not performed and the transmission is not in the third forward speed state, and the second lock valve 135 works in conjunction with the speed selection valve 130 to fix the transmission in the second forward speed state. . When the speed selection rod is set to the (first forward speed fixed) position, the line pressure circuit 144 is connected to ports c, d and e.
Leads to. Hydraulic pressure reaches the same location from ports c and d, engaging the rear clutch 105, and from port e, from circuit 155, through the 1-2 shift valve 131, and from circuit 171, partially at low
The low reverse brake 10 reaches the reverse brake 107 and acts as a forward reaction brake.
7, the transmission is in the first forward speed state, and a portion reaches the left side of the 1-2 shift valve 131 and the spring 1
59 to press the spool 160 to the right, and the first forward speed is fixed.

In FIG. 2, reference numeral 100 indicates a lock-up control device according to the present invention, which includes a lock-up control valve 30 and a lock-up solenoid 31.
It consists of The details of the torque converter 1 with the lockup control valve 30, the lockup solenoid 31, and the lockup mechanism (direct clutch) 17 will be explained below with reference to FIG.

The pump wheel 3 of the torque converter 1 is connected via a converter cover 6 to a drive plate 5, which in turn is connected to the engine crankshaft 4. Further, the turbine wheel 8 is splined to the input shaft 7 via a hub 18, and the stator wheel 9 is further connected to the sleeve 12 via a one-wear clutch 10. The torque converter 1 is surrounded by a converter housing 28, and the converter housing is connected to the transmission case 29 with the pump housing 1.
4 and pump cover 11. The oil pump 13 is housed in a chamber defined by the pump housing 14 and the pump cover 11, and the pump is connected to the pump impeller 3 by a hollow shaft 52.
It is connected to the engine so that it can be driven by the engine. The hollow shaft 52 encloses the sleeve 12 to define the annular hydraulic oil supply passage 50 therebetween, and the sleeve 12
The input shaft 7 is loosely passed through the input shaft 7 to define an annular hydraulic oil discharge passage 51 therebetween. In addition,
The sleeve 12 is integrally molded with the cover 11.

The lockup mechanism 17 has the following configuration. A lock-up clutch piston 20 is slidably fitted onto the hub 18 and is housed within the converter cover 6. An annular clutch facing 19 is provided on the surface of the lock-up clutch piston 20 facing the end wall of the converter cover 6, and when this clutch facing contacts the end wall of the converter cover 6, a lock-up chamber is formed on both sides of the lock-up clutch piston 20. 2
7 and a torque converter chamber 63 are defined.

A lock-up clutch piston 20 is drivingly coupled to the turbine wheel 8 via a torsional damper 21. The torsional damper 21 is of a type used in dry clutches and the like, and is composed of a drive plate 23, a torsional spring 24, a rivet 25, and a driven plate 26. An annular member 22 is attached to the lock-up clutch piston 20.
Weld the claw 22a to the drive plate 23
The driven plate 26 is connected to the turbine wheel 8 by driving engagement with the notch 23a of the notch 23a. The lockup chamber 27 is communicated with a lockup passage 11 formed in the input shaft 7, and this passage is connected to the lockup control device 10 as described later.
Relate to 0.

The lock-up control valve 30 includes a spool 30a which, when moved by a spring 30b to the position shown in the upper half of FIG.
When the oil pressure inside the port is set to the lower half position, the port 30d
It functions to allow the drain port 30f to communicate with the drain port 30f. The port 30d communicates with the lockup passage 16 through a passage 56, the port 30e communicates with the torque converter hydraulic oil supply passage 50 through a passage 57 as shown in FIG. It communicates with the rear clutch pressure passage 153 as shown in FIG.

An orifice 54 is provided in the middle of the passage 53, and a branch passage 55 is provided in the passage 53 between this orifice and the chamber 30c. The branch passage 55 has an orifice 58 therein and communicates with a drain port 59, and the lock-up solenoid 31 is used to open and close the branch passage 55. For this purpose, the lock-up solenoid 31 has a plunger 31a, which is normally kept in the left half position in FIGS.
When energized in step 1, the right half is in the protruding position and the branch passage 5
5 can be closed.

When the plunger 31 a opens the branch passage 55 by the activation of the solenoid 31 , this branch passage communicates with the drain port 59 . At this time, the rear clutch pressure directed to the chamber 30c via the passage 53 is extracted from the drain port 59, and the lock-up control valve 30 is operated to connect the port 30d to the port 30d since the spool 30a is set to the upper half position in FIG. 3 by the spring 30b. 3
Pass it to 0e. Therefore, the internal pressure of the torque converter led to the passage 57 is transferred to the ports 30e and 30e.
0d, via passages 56 and 16 to lockup room 27
The lockup chamber 27 has the same pressure as the converter chamber 63. As a result, the lock-up clutch piston 20 is moved to the right from the position shown in FIG. Converter 1 can perform normal power transmission in a torque converter state.

When the plunger 31a closes the branch passage 55 due to the activation of the lock-up solenoid 31, the passage 53
As the spool 30a moves left from the upper half position to the lower half position in FIG. 3, the lock-up control valve 30 connects the port 30d to the drain port. 3
Connect to 0f. As a result, lockup room 2
7 is lockup passage 16, passage 56, port 3
It communicates with the drain port 30f via 0d and is brought into a pressureless state. Thus, the lock-up clutch piston 20 is moved to the left in FIG.
By being pressed against the end wall of the pump impeller 3 and the turbine impeller 8, a locked-up state is obtained in which the pump impeller 3 and the turbine wheel 8 are directly connected.

In the present invention, the lock-up solenoid 31 is turned on and off by an electronic circuit as shown in FIG. In this figure, 200 is a vehicle speed sensor that detects the vehicle speed and outputs a corresponding signal, 201 is a 1-2 shift switch, 202 is a 2-3 shift switch, and 203 is a shift switch when the automatic transmission is changing gears. A shift determination circuit 204 detects changes in signals from switches 201 and 202, and a shift switch 204 detects which gear position the automatic transmission is in.
1, 202 is a gear position determination circuit that makes decisions based on signals from 202, 205 is a vehicle speed comparison circuit A, 206 is a vehicle speed comparison circuit B, 210 is a vehicle speed comparison circuit selection section, 21
Reference numeral 1 denotes a temperature sensor that responds to, for example, the engine cooling water temperature in order to detect whether the engine is being warmed up or has been warmed up.

For example, the 1-2 shift switch 201 closes when the valve spool 160 of the 1-2 shift valve 131 (see FIG. 2) is in the lower half position (downshift position) in FIG. A switch such as a reed switch installed in the 1-2 shift valve 131 is used so as to open when the shift valve reaches the upper half position (upshift position) in FIG. Further, as the 2-3 shift switch 202, for example, the 2-3 shift valve 13
Closed when the valve spool 164 of No. 2 is in the lower half position (downshift position) in FIG.
A switch such as a reed switch installed in the 2-3 shift valve 132 is used so as to open when the shift valve 4 reaches the upper half position (upshift position) in FIG. Further, the temperature sensor 211 is open while the engine cooling water temperature is at a low temperature corresponding to the warm-up operation of the engine.
It is designed to close when the engine warm-up is completed and the cooling water temperature reaches the set value.

As is clear from the above regarding Figure 2,
In the first gear position, the valve spool 160 of the 1-2 shift valve 131 and the valve spool 164 of the 2-3 shift valve 132 are both in the downshift position,
Both the 1-2 shift switch 201 and the 2-3 shift switch 202 are closed. At this time, both shift switches 201 and 202 are connected to the voltage of the power supply +V,
In other words, the high (H) level signal is sent to the gear position determination circuit 204.
This circuit determines from these input signals that it is the first gear position, and outputs an H level signal to gate a. 1-2 in 2nd gear position
The valve spool 160 of the shift valve 131 is in the upshift position to open the 1-2 shift switch 201, but the valve spool 164 of the 2-3 shift valve 132 is in the upshift position.
remains in the downshift position and the 2-3 shift switch 202 remains closed. At this time, the 1-2 shift switch 201 cannot input the voltage of the power supply +V to the gear position determination circuit 204, and the signal from the 1-2 shift switch 201 to the gear position determination circuit 204 is switched to a low (L) level. . However, the 2-3 shift switch 202 still inputs the H level signal to the gear position determination circuit 204, and this circuit determines that it is in the second gear position based on the combination of both input signal levels, and gates b. outputs an H level signal. Further, in the third gear position, the valve spool 160 of the 1-2 shift valve 131 maintains the upshift position to keep the 1-2 shift switch 201 open, and the valve spool 16 of the 2-3 shift valve 132 remains in the upshift position.
4 becomes the upshift position and opens the 2-3 shift switch 202. At this time, both shift switches 2
01 and 202 no longer input the voltage of the power supply +V, that is, the H level signal, to the gear position determination circuit 204, and this circuit determines that it is the third gear position based on the combination of the levels of these input signals, and gate c. outputs an H level signal.

Note that the above signals from the shift switches 201 and 202 are also input to the speed change determination circuit 203. However, this shift judgment circuit 203 continues to output an H level signal in a steady state, regardless of the combination of signal levels from the shift switches 201 and 202.
After the gear change is performed, shift switches 201 and 202 are activated.
At the beginning of switching from close to open or from open to close, an L level signal is output for a set time corresponding to the shift operation time.

While the temperature sensor 211 detects that the engine is warming up from the engine cooling water temperature and is open, the voltage of the power supply +V, that is, the H level signal is applied to the AND gate 213 and the NAND gate 21 via the resistor 212.
4 is input. At this time, the AND gate 213 supplies an H level signal to the A vehicle speed comparison circuit 205 to activate it, and the NAND gate 214 supplies an L level signal to the A vehicle speed comparison circuit 205 to activate it.
A level signal is supplied to the B vehicle speed comparator circuit 206 to keep it inactive. Conversely, while the temperature sensor 211 detects the completion of engine warm-up from the engine cooling water temperature and closes, the voltage of the power supply +V is grounded via the temperature sensor 211, and the AND gate 2
The input signals to NAND gate 13 and NAND gate 214 are respectively switched to L level. At this time, the AND gate 213 outputs an L level signal to deactivate the vehicle speed comparison circuit 205, and the NAND gate 214 outputs an H level signal.
A level signal is output to activate the vehicle speed comparison circuit 206. In this way, the vehicle speed comparison circuit selection unit 210 selects the vehicle speed comparison circuit A 205 when the engine is warming up, and selects the vehicle speed comparison circuit 206 B when the engine has been warmed up. It can be operated automatically.

Vehicle speed comparison circuit 205 provides relatively high lock-up vehicle speeds for each of first, second, and third gear positions.
V _1H , V _2H , V _3H (see Figure 6) are stored,
The vehicle speed signal V supplied from the vehicle speed sensor 200 is compared with these lockup vehicle speeds V _1H , V _2H , and V _3H . Note that the lock-up vehicle speeds V _1H , V _2H , and V _3H are the same as those in 1st gear, 2nd gear, and V 3H, respectively, even when the engine is warmed up.
Corresponds to the lower limit of the vehicle speed range that does not cause a torque shortage during lock-up at each gear position of 3rd gear, and the lock-up vehicle speed for each gear position after warm-up.
Set relatively higher than V _1L , V _2L , and V _3L (see Figure 6). The vehicle speed comparison circuit 205 includes the vehicle speed sensor 2
Vehicle speed signal V from 00 and the above lock-up vehicle speed
From the comparison results with V _1H , V _2H , and V _3H , when V > V _1H , an H level signal is output only to gate d, and V >
When V _2H , an H level signal is output only to the gate e, and when V>V _3H , an H level signal is output only to the gate f.

The vehicle speed comparison circuit 206 selects the normal relatively low lock-up vehicle speed V _1L , which is considered preferable after the engine has warmed up, at each of the first, second, and third gear positions.
V _2L and V _3L (see FIG. 6) are stored, and the vehicle speed signal V supplied from the vehicle speed sensor 200 is compared with these locked-up vehicle speeds V _1L , V _2L and V _3L . From this comparison result, the vehicle speed comparison circuit 206 determines that V>V _1L
When , an H level signal is output only to gate g, and V
When V>V _2L , an H level signal is output only to the gate h, and when V>V _3L , an H level signal is output only to the gate i.

During warm-up operation of the engine, when the vehicle speed signal V exceeds the lock-up vehicle speed _V1H in the first gear position, the AND gate 230 outputs the signal H from gates a and b.
AND the level signals and send H to OR gate 236.
Next, the OR gate 238 outputs a H level signal, and this is output to the AND gate 240.
is supplied to one input terminal of the Here, if the gear shift operation is not in progress, the gear shift determination circuit 203 inputs an H level signal to the other input terminal of the AND gate 240, and the AND gate 240 outputs an H level signal, and this signal is sent to the amplifier 241. By being supplied to the lock-up solenoid 31 through
By energizing the solenoid, a lock-up condition can be obtained as described above.

During warm-up of the engine, when the vehicle speed signal V exceeds the lock-up vehicle speed _V2H in the second gear position, the AND gate 231 outputs the signal H from gates b and e.
AND the level signals and send H to OR gate 236.
Next, the OR gate 238 outputs a H level signal, and this is output to the AND gate 240.
is supplied to one input terminal of the Here, if the gear shift operation is not in progress, the gear shift determination circuit 203 inputs an H level signal to the other input signal of the AND gate 240, and the AND gate 240 outputs an H level signal, and this signal is sent to the amplifier 241. By being supplied to the lock-up solenoid 31 through
By energizing the solenoid, a lock-up condition can be obtained as described above.

During warm-up of the engine, when the vehicle speed signal V exceeds the lock-up vehicle speed _V3H in the third gear position, the AND gate 232 outputs the signal H from gates c and f.
AND the level signals and send H to OR gate 236.
Next, the OR gate 238 outputs a H level signal, and this is output to the AND gate 240.
is supplied to one input terminal of the Here, if the gear shift operation is not in progress, the gear shift determination circuit 203 inputs an H level signal to the other input terminal of the AND gate 240, and the AND gate 240 outputs an H level signal, and this signal is sent to the amplifier 241. By being supplied to the lock-up solenoid 31 through
By energizing the solenoid, a lock-up condition can be obtained as described above.

After warming up the engine, when the vehicle speed signal V exceeds the lock-up vehicle speed _V1H in the first gear position, the AND gate 233 outputs the H signal from gates a and g.
AND the level signals and send H to OR gate 237.
Next, the OR gate 238 outputs a H level signal, and this is output to the AND gate 240.
is supplied to one input terminal of the Here, if the gear shift operation is not in progress, the gear shift determination circuit 203 inputs an H level signal to the other input terminal of the AND gate 240, and the AND gate 240 outputs an H level signal, and this signal is sent to the amplifier 241. By being supplied to the lock-up solenoid 31 through
By energizing the solenoid, a lock-up condition can be obtained as described above.

After the engine is warmed up, when the vehicle speed signal V exceeds the lock-up vehicle speed _V2L in the second gear position, the AND gate 234 outputs the signal H from gates b and h.
AND the level signals and send H to OR gate 237.
Next, the OR gate 238 outputs a H level signal, and this is output to the AND gate 240.
is supplied to one input terminal of the Here, if the gear shift operation is not in progress, the gear shift determination circuit 203 inputs an H level signal to the other input terminal of the AND gate 240, and the AND gate 240 outputs an H level signal, and this signal is sent to the amplifier 241. By being supplied to the lock-up solenoid 31 through
By energizing the solenoid, a lock-up condition can be obtained as described above.

After warming up the engine, when the vehicle speed signal V exceeds the lock-up vehicle speed _V3L in the third gear position, the AND gate 235 outputs the H signal from gates c and i.
AND the level signals and send H to OR gate 237.
Next, the OR gate 238 outputs a H level signal, and this is output to the AND gate 240.
is supplied to one input terminal of the Here, if the gear shift operation is not in progress, the gear shift determination circuit 203 inputs an H level signal to the other input terminal of the AND gate 240, and the AND gate 240 outputs an H level signal, and this signal is sent to the amplifier 241. By being supplied to the lock-up solenoid 31 through
By energizing the solenoid, a lock-up condition can be obtained as described above.

However, while the engine is operating outside the above-mentioned lock-up region, that is, during engine warm-up, the vehicle speed at each gear position is different from the lock-up vehicle speed V _1H , V _2H , V _{3H .}
In the region where the vehicle speed does not reach the respective lock-up vehicle speeds V _1L , V _2L , V _3L at each gear position after warm-up operation, all AND gates 230 to 2
Since the lock-up solenoid 35 cannot receive H-level signals to its two inputs at the same time, the lock-up solenoid 31 is deenergized and enters the torque converter state as described above.

Also, in the lockup area, the OR gate 23
8 to one input terminal of the AND gate 240.
Even if a level signal is input, if a gear shift operation is in progress at this time, the gear shift judgment circuit 203 detects this by the above-mentioned action and supplies an L level signal to the other input terminal of the AND gate 240, locking up the solenoid. 31, the lockup is released. Therefore, it is possible to prevent a shift shock from occurring due to shifting being performed in the locked-up state.
Further, after the speed change operation is completed, the speed change judgment circuit 203 outputs an H level signal again, and the above-mentioned lock-up control is possible.

Thus, as described above, the lock-up automatic transmission of the present invention allows the lock-up vehicle speed to be relatively high while the engine has not yet been warmed up to effectively utilize the torque increasing effect of the torque converter. It is possible to solve the problem of insufficient torque that conventionally occurred during warm-up operation, and improve drivability and purify exhaust gas. On the other hand, since the lock-up vehicle speed is changed to a relatively high normal value after the engine is warmed up, fuel efficiency can be improved by lock-up early to the extent that drivability is not affected.

FIG. 5 shows another example of the lock-up control circuit used in the automatic transmission of the present invention. In this example, a load sensor 250 for detecting the engine load condition is added to the vehicle speed comparison circuit selection section 210, and the engine load is also controlled by the vehicle speed. This is in addition to the selection elements of comparison circuits 205 and 206.

The load sensor 250 is, for example, an engine throttle opening switch, and is open during low load operation when the throttle opening is below a set value.
It is assumed that the throttle opening is closed during high load operation when the throttle opening exceeds the above set value. Thus, when the load sensor 250 is open during low load operation, the voltage of the power supply +V, that is, the H level signal is applied to the resistor 251.
When the load sensor 250 is closed during high load operation, the +V voltage of the power supply is grounded via this load sensor, and the AND gates 252, 258 and NAND gate 256 are supplied via the An L level signal is now supplied to the NAND gate 256.

In this embodiment, while the temperature sensor 212 detects that the engine is warming up and opens as described above, an H level signal is sent to the AND gate 252 and the inverter 25.
Supply to 7. At this time, if the load sensor is operating at a low load, the load sensor 250 opens and supplies an H level signal to the AND gates 252 and 258. Inverter 25
7 inverts the H level signal from the temperature sensor 211 to make it an L level signal and supplies it to the AND gate 258, so this AND gate cannot output an H level signal, and only the AND gate 252 outputs an H level signal. do. This H level signal causes the OR gate 255 to output an H level signal, and at this time the vehicle speed comparison circuit 205 is activated. Also, when the load sensor 250 closes during high load operation and outputs an L level signal, the NAND gate 256 outputs an H level signal.
The signal is now output to the OR gate 255, and the vehicle speed comparison circuit 205 is activated at this time as well. That is, during engine warm-up, the vehicle speed comparison circuit 205 is selectively activated regardless of the engine load, and the same objective as in the example of FIG. 4 is achieved.

After the engine is warmed up, the temperature sensor 21
1 is closed and the L level signal is supplied to the AND gate 252 and the inverter 257, the vehicle speed comparison circuits 205 and 206 operate according to the engine load as follows.
can be activated selectively. That is, when the load sensor 250 opens during low load operation and outputs an H level signal, the AND gate 258 ANDs this H level signal and the signal from the temperature sensor 211 which has been inverted by the inverter 257 and has become H level. and activates the vehicle speed comparison circuit 206. In addition, when the load sensor 250 closes during high load operation and outputs an L level signal, this signal causes the NAND gate 256 to output an H level signal, and the OR gate 2
55, the vehicle speed comparison circuit 205 is activated. In other words, after the engine is warmed up, when the engine load is small, the vehicle speed comparison circuit 206 is selectively operated to reduce the lock-up vehicle speed, thereby reducing fuel consumption by locking up early to the extent that engine drivability is not affected. When the load is large, the lock-up vehicle speed is increased by selective operation of the vehicle speed comparison circuit 205, and sufficient acceleration force can be obtained by effectively utilizing the torque increasing effect of the torque converter.

Thus, in this embodiment, the same effects as in the previous embodiment can be obtained, and even after warm-up operation, lock-up control suitable for the engine load can be performed by appropriately selecting the lock-up vehicle speed.

The above-mentioned embodiments were all constructed with general comparison circuits and logic circuits, but these were constructed using a microprocessor to distinguish signals from load sensors and temperature sensors, and to distinguish between vehicle speed signals and standards. It is also possible to store the values necessary for comparison with the vehicle speed in a read-only memory (ROM), and the same effect as described above can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the power transmission system of the automatic transmission of the present invention, FIG. 2 is a shift control circuit diagram of the automatic transmission of the present invention, FIG. 3 is a detailed sectional view of the lock-up control section, and FIG. 4 5 is an electronic circuit diagram of a lock-up control section according to the present invention, FIG. 5 is an electronic circuit diagram for lock-up control similar to FIG. 4 showing another example of the present invention, and FIG. 6 is a lock-up vehicle speed diagram of the automatic transmission of the present invention. FIG. DESCRIPTION OF SYMBOLS 1... Torque converter, 4... Crankshaft, 5... Drive plate, 6... Converter cover, 7... Input shaft, 10... One-way clutch, 11... Pump cover, 12... Sleeve, 13... Oil pump, 14... Pump housing, 16... Lockup passage, 17... Lockup mechanism, 18... Hub, 19... Clutch facing, 20... Lockup clutch piston, 21
...Torsional damper, 27...Lockup chamber,
30... Lock-up control valve, 31... Lock-up solenoid, 50... Torque converter hydraulic oil supply passage, 51... Torque converter hydraulic oil discharge passage,
53... Rear clutch pressure introduction passage, 54, 58... Orifice, 55... Branch passage, 57... Torque converter internal pressure introduction passage, 59... Drain port, 63...
Torque converter chamber, 100... Lockup control device, 104... Front clutch, 105... Rear clutch, 106... Second brake, 107...
Low reverse brake, 108... One-way brake, 110... First planetary gear set, 111... Second planetary gear set, 131... 1-2 shift valve, 132... 2-
3 shift valve, 137... downshift valve, 200...
Vehicle speed sensor, 201...1-2 shift switch, 2
02...2-3 shift switch, 203...speed change judgment circuit, 204...gear position judgment circuit, 205, 20
6...Vehicle speed comparison circuit, 210...Vehicle speed comparison circuit selection section, 211...Temperature sensor, 250...Load sensor.

Claims (1)

[Scope of Claims] 1. In an automatic transmission equipped with a torque converter capable of switching from a torque converter state to a lock-up state upon generation of a lock-up signal, a temperature sensor detects a warm-up state of an engine and a vehicle speed is detected. The vehicle speed comparison circuit includes a vehicle speed sensor and a vehicle speed comparison circuit that compares vehicle speed signals from the vehicle speed sensors with different reference vehicle speeds, and the vehicle speed comparison circuit adjusts the reference vehicle speed as the engine warms up based on the signal from the temperature sensor. while the vehicle speed signal exceeds the selected reference vehicle speed;
A lock-up automatic transmission characterized in that it is configured to output the lock-up signal. 2. In an automatic transmission equipped with a torque converter that can switch from a torque converter state to a lock-up state when a lock-up signal is generated, a temperature sensor that detects the warm-up state of the engine and a load sensor that detects the load state of the engine are used. , a vehicle speed sensor that detects vehicle speed, and a vehicle speed comparison circuit that compares vehicle speed signals from the vehicle speed sensor with different reference vehicle speeds, and the vehicle speed comparison circuit measures the engine temperature based on the signals from the temperature sensor and the load sensor. The lockup is characterized in that as the machine condition progresses or as the engine load decreases, a lower reference vehicle speed is selected, and the lockup signal is output while the vehicle speed signal exceeds the selected reference vehicle speed. automatic transmission.