JPH0121382B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an improvement in a lock-up automatic transmission. 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, slippage between the pump impeller and the turbine runner cannot be avoided during operation of the torque converter, and although automatic transmissions equipped with 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, the lock-up region of the automatic transmission in which the torque converter with the direct coupling clutch is brought into the lock-up state when the vehicle speed exceeds a set vehicle speed (lock-up vehicle speed) for each shift position is as shown in FIG. 7, for example.
This figure shows the shift pattern of an automatic transmission with three forward speeds. In the figure, V ₁ , V ₂ , and V ₃ are the lock-up vehicle speeds in 1st, 2nd, and 3rd gears, and A, B, and C are the lock-up vehicle speeds in 1st, 2nd, and 3rd gears. 1st
This is the lock-up area at 1st, 2nd, and 3rd speeds. In the case of an automatic transmission that performs lock-up at a lock-up vehicle speed or higher at each shift position,
When the vehicle shifts automatically while the accelerator pedal is pressed down to a relatively large degree (with the throttle opening still wide), the lock-up areas A to C contact each other in sequence, so the torque converter remains in the lock-up state during gear changes. become. However, if a shift is performed with the torque converter in the locked-up state as described above, the torque converter will not be able to absorb torque fluctuations, resulting in a large shift shock. Therefore, in this type of lock-up automatic transmission, even in the above-mentioned lock-up region, the lock-up is released and the torque converter state is maintained during gear shifting. For this purpose, a shift detection circuit is provided that issues a shift signal indicating that the shift is in progress for a predetermined period of time after a shift command is issued, and is configured to temporarily suspend the lock-up state even in the lock-up region while the shift signal is issued from this circuit. It was normal to do so. However, conventionally, the shift signal output time of the shift detection circuit is constant, and therefore, the lock-up interruption performed in response to this signal is only carried out for a fixed period of time regardless of the type of shift command.
However, the time required for the actual gear shifting operation depends on the type of gear shifting command, that is, which shifting positions are the shifting between, and whether shifting between the same shifting positions is an upshift?
The configuration of the hydraulic circuit differs depending on whether it is a downshift. Furthermore, the above-mentioned shift operation time varies depending on the magnitude of the engine load. In other words, the line pressure for operating the friction elements that select each gear shift position changes depending on the magnitude of the engine load, and as the engine load increases, the line pressure increases, and the switching operation of the friction elements due to this, that is, the actual Shifting operations are performed within a short period of time, and the lock-up interruption time, which should correspond to the shifting operation time, is not constant as in the past.
This lock-up interruption time only corresponds to the shift operation time during a specific shift, and at other shifts, it becomes longer or shorter than the shift operation time, causing engine racing and shift shock, which impairs driving feeling. From this point of view, the present invention includes a shift type determination circuit that discriminates the types of the shift commands and issues signals corresponding to these types, and a shift type determination circuit that classifies the magnitude of the engine load into a plurality of stages according to the magnitude of the engine load. and an engine load determination circuit that generates a signal, and the shift detection circuit is provided to respond to corresponding signals from the shift type determination circuit and the engine load determination circuit, respectively, for each type of shift command and the number of engine load classification stages. , the shift signal output time of each shift detection circuit is set to match the shift operation time of the automatic transmission according to the type of the corresponding shift command and the size of the engine load. Even under engine load,
It is an object of the present invention to provide a lock-up type automatic transmission in which the above-mentioned lock-up interruption time coincides with the shift operation time, thereby solving the above-mentioned problems of the conventional structure. Hereinafter, embodiments of the present invention will be described in detail based on the drawings. 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 The torque is further transmitted by the input shaft 7 to the transmission gear train. The stator wheel 9 is a one-way clutch 10
is placed on the sleeve 12 via. 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. The first planetary gear group 110 is connected to the intermediate shaft 109
an internal gear 117 fixed to the hollow conductive shaft 118, a sun gear 119 fixed to the hollow conduction shaft 118, and an internal gear 1
17 and sun gear 119, and a planetary gear support 121 that is fixed to the output shaft 112 and supports the planetary gear 120. The second planetary gear group 111 rotates and revolves while meshing with the internal gear 122 fixed to the top shaft 112, the sun gear 123 fixed to the hollow conduction shaft 118, the internal gear 122, and the sun gear 123, respectively. The planetary gear support 125 supports the planetary gear 124 and the planetary gear 124. The front clutch 104 is connected to the input shaft 7 driven by the turbine wheel 8 and both sun gears 119, 123.
hollow conduction shaft 118 that rotates in unison with
The rear clutch 105 serves to connect the input shaft 7 and the internal gear 117 of the first planetary gear group 110 via the intermediate shaft 109. The second brake 106 fixes both sun gears 119 and 123 by winding and tightening a drum 126 fixed to a hollow conductive shaft 118, and the low reverse brake 107 fixes both sun gears 119 and 123 to the planetary gear support of the second planetary gear group 111. It works to fix 125. 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. First governor valve 113 and second governor valve 114
is fixed to the output shaft 112 and generates governor pressure according to vehicle speed. Next, a description will be given of the power transmission train when the gear shift lever 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 through the rear clutch 105 to the internal gear 117 of the first planetary gear group 110. The internal gear 117 rotates the planetary gear 120 in the normal direction. Therefore, the sun gear 119 rotates in reverse, and the planet gears 124 of the second planet gear group 111 rotate in the normal direction to reverse the sun gear 123 of the second planet gear group 111, which rotates integrally with the sun gear 119. 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, the vehicle speed increases and the second
When the brake 106 is engaged, the input shaft 7 is moved to the rear clutch 1 as in the first gear.
05 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. For this reason, the planetary gear 120 revolves around the stationary sun gear 119 while rotating, and therefore the planetary gear support 121 and the output shaft 112 integrated therewith
Although it is decelerated, it rotates normally at a faster speed than in the case of the first speed, 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, the power transmitted to the input shaft 7 is
One side passes through the rear clutch 105 to the internal gear 11.
7 and the other is transmitted to the sun gear 119 via the front clutch 104. Therefore, the internal gear 117 and the sun gear 119 are interlocked, and together with the planetary gear support 121 and the output shaft 112, they all rotate normally at the same rotational speed to obtain the third forward speed. In this case, the input clutches are the front clutch 104 and the rear clutch 105, and since no torque is increased by the planetary gear, neither reaction brake is activated. 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 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 pressure regulating 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 increase valve 129. The resulting force opposes line pressure acting above spool 172 through orifice 175 from circuit 144 and pressure acting from circuit 176. The operating oil pressure of the torque converter 1 is supplied from the circuit 144 to the line pressure regulating valve 128.
The oil introduced into the circuit 145 via the hydraulic oil inflow passage 50 flows into the torque converter 1 and is then removed via the hydraulic oil outflow passage 51 and the pressure holding valve 146. is maintained. Above a certain pressure, the pressure retention valve 146
is opened and oil is further routed from 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, the front lubricating section of the power transmission mechanism has circuit 1.
45, the front lubricating valve 149 is opened and lubricating oil is supplied. 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. The hydraulic pressure passes through the circuit 151 from port a, and part of it acts on the lower part of the second lock valve 135, and the spring 17
The spool 178, which is pressed upward by the spool 9, is lowered by the hydraulic pressure acting from the port b through the circuit 152, so that the conductive circuits 161 and 162 are not cut off, and a part of the spool 178 is pressed upward by the orifice 166. From circuit 167 to 2-
3 shift valve 132, and from port c, circuit 1
53 and reaches the second governor valve 114, rear clutch 105 and 1-2 shift valve 131, and the transmission is in the first forward speed state. In this state, when the vehicle speed reaches a certain speed, the spool 160 of the 1-2 shift valve 131, which is pressed to the right by the spring 159, moves to the left due to the governor pressure of the circuit 158, shifting from the first forward speed to the second forward speed. Automatic gear shifting is performed, and the circuit 153 and circuit 161 are brought into conduction, and the hydraulic pressure reaches the engagement-side hydraulic chamber 169 of the servo 141 via the second lock valve 135, and the second brake 106 is engaged. forward 2nd
Be in a state of speed. In this case, the 1-2 shift valve 13
1 is compact, the spool 160 moves to the left at the required speed without increasing the speed at the shift point, and an automatic shift action from forward first speed to second speed is performed. When the vehicle speed increases further and reaches a certain speed, the governor pressure of the circuit 158 overcomes the spring 163 and becomes 2-
3 Press the spool 164 of the shift valve 132 to the left to connect the circuit 167 and the circuit 168 so that the hydraulic pressure is partially transferred from the circuit 168 to the release side hydraulic chamber 1 of the servo 141.
70, the second brake 106 is released, a portion reaches and engages the front clutch 104, and the transmission is in third forward gear. Furthermore, when the driver depresses the accelerator pedal until the throttle opening is close to full throttle while driving in the D position, desiring a large acceleration force, the kick-down switch is turned on and the solenoid down shift valve 137 is turned on. A down shift solenoid 137a disposed opposite to the down shift solenoid 137a is energized by energization. As a result, the spool 190 of the solenoid downshift valve 137 is pushed downward by the spring 191 from the upwardly locked position in FIG. At this time, the kickdown circuit 180 that was connected to the circuit 154 is connected to the line pressure circuit 144, and the line pressure is applied to the circuit 14.
4,180 and 1-2 shift valve 131 and 2-
3 shift valve 132 is supplied opposite the governor pressure. At this time, if the vehicle is running in third gear, the spool 164 of the 2-3 shift valve 132 is forcibly pushed from the leftward position by the line pressure to the rightward position against the governor pressure. A forced downshift from third gear to second gear is performed within vehicle speed limits, and sufficient acceleration force is obtained. By the way, the second
If the above-mentioned kickdown is performed while running at a high speed, the load is large at this time and the speed is low, so the governor pressure is also low, so the line pressure led to the circuit 180 is also It is moved 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 Lockup control valve 30, lockup solenoid 31, and lockup mechanism 17
Details of the attached torque converter 1 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-way 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 is coupled to the pump impeller 3 via a hollow shaft 52 so as to be driven by an engine. Hollow shaft 52
The sleeve 12 is wrapped around the sleeve 12 to define the annular hydraulic oil supply passage 50 between the two, and the input shaft 7 is loosely passed through the sleeve 12 to define the annular hydraulic oil discharge passage 51 between the two. to be accomplished. Note that the sleeve 12 is integrally molded with the pump 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, etc., 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 welded to the lock-up clutch piston 20, and its pawl 22a is drivingly engaged with the notch 23a of the drive plate 23, thereby connecting the driven plate 26 to the turbine wheel 8. The lockup chamber 27 is communicated with a lockup passage 16 formed in the input shaft 7, and this passage is connected to the lockup control device 100 as described below.
to relate to. 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 via a passage 56, the port 30e communicates with the torque converter hydraulic oil supply passage 50 via 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, the right half is in the protruding position and the branch passage 55
so that it can be closed. When the plunger 31a opens the branch passage 55 when the solenoid 31 is deenergized, this branch passage communicates with the drain port 59. At this time, the rear clutch pressure flowing toward 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 because the spool 30a is placed in 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. 1 can perform normal power transmission in the 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 runner 8, a locked-up state is obtained in which the pump impeller 3 and the turbine runner 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, 60 is a 1-2 shift switch, 61 is a 2-3 shift switch, and 62 is a vehicle speed sensor. 1-2 shift switch 60 and 2-
The 3-shift switch 61 is assembled into the 1-2 shift valve 131 and the 2-3 shift valve 132, for example, as clearly shown in FIG.
It is configured to open and close depending on the position of 164. For this purpose, the valve spool 1 is mounted on the side plate 64.
Fixed contact 6 so as to directly face the end face of 60, 164
5 and 66 are provided, and these fixed contacts are electrically insulated from the side plate 64 by insulators 67 and 68,
The valve spools 160, 164 function as movable contacts. Since the shift valves 131 and 132 are grounded to the vehicle body, by connecting the fixed contacts 65 and 66 to the power supply +V via the lead wire 69 and the resistors 72 and 73, respectively, the fixed contacts 65 and the valve spool 160 -2 shift switch 60,
Also, the fixed contact 66 and the valve spool 164 allow 2-
Three shift switches 61 can be configured respectively. As is clear from the above, in the first speed, both the valve spools 160 and 164 are connected to the fixed contacts 65 and 6.
The 1-2 shift switch 60 and the 2-3 shift switch 61 each output a low (L) level signal. At the second speed, only the valve spool 160 moves to the left in FIG.
5, the 1-2 shift switch 60 outputs a high (H) level signal. Further, at the third speed, the valve spool 164 also moves to the left in FIG. 5, away from the fixed contact 66, and the 2-3 shift switch 61 also outputs an H level signal. The vehicle speed sensor 62 outputs a current proportional to the vehicle speed, which is passed through the resistor 74 when the transistor 78 is conductive.
and the emitter-collector path of transistor 78 in order to be grounded, and when transistor 78 is non-conductive, it is grounded in order through resistors 74 and 75. When the circuit including resistor 74 and the emitter-collector path of transistor 78 is closed, resistor 74
When a voltage corresponding to the vehicle speed determined only by . The signals from the 1-2 shift switch 60 and 2-3 shift switch 61 are transmitted to the gear position determination circuit 2.
01, and the gear position determination circuit determines the corresponding gear position (shift position) based on the combination of signal levels from both shift switches 60 and 61 shown in the following table.
Determine.

[Table] Then, the gear position determination circuit 201 receives an H level signal from only the gate' when in first gear, only from gate' when in second gear, and only from gate' when in third gear. AND gate 202-20
4 to one of the input terminals. Vehicle speed sensor 62
The vehicle speed signal V is input to the vehicle speed determination circuit 205, and the vehicle speed determination circuit converts the vehicle speed signal V into the lock-up vehicle speed V ₁ for the first gear, the lock-up vehicle speed V 2 for the second gear, and the lock-up vehicle speed V ₂ for the third gear as described above with reference to FIG. Compared to the lock-up vehicle speed V ₃ , from the gate when V > V ₁ ,
When V>V ₂ , an H level signal is output from the gate, and when V>V ₃ , an H level signal is output from the gate, and these signals are
It supplies the remaining input terminals of AND gates 202-204. Thus, AND gates 202-204
take the AND of the above H level signals, AND
The gate 202 is H in the lockup region A of FIG.
The AND gate 203 outputs an H level signal in the lockup area B of FIG. 7, and the AND gate 204 outputs an H level signal in the lockup area C of FIG. OR gate 206 is connected to these AND gates 202 to 204
In response to the output, a lockup permission signal S _L of H level is output in any of the lockup areas A, B, or C in FIG. This H-level lock-up permission signal S _L is applied to the base of the transistor 78 to turn it off, and at this time, as mentioned above, the vehicle speed signal is kept at a constant level determined by the resistance value of the resistor 75 below the level corresponding to the actual vehicle speed. As a result, the lock-up release vehicle speed becomes relatively lower than the lock-up vehicle speeds V ₁ , V ₂ , and V ₃ as shown in a', b', and c' in FIG. 7, and hysteresis is set between them. Can be done. The signal from the 1-2 shift switch 60 is 1←2
Shift detection circuits 207a, 207b, 207c and 1→2 shift detection circuits 208a, 208b, 208
The signal from the 2-3 shift switch 61 is also input to the 2←3 shift detection circuit 218a, 218b,
218c and 2→3 speed change detection circuit 219a, 21
Also input to 9b and 219c. The circuits 207a, 207b, and 207c each receive a 1←2 speed change command, as shown in FIG.
-2 The edge trigger circuit detects the fall of the signal from the shift switch 60, and the circuits 218a,
218b and 218c are also similar edge trigger circuits as shown in the same figure by the suffix 218, and detect the fall of the signal from the 2←3 shift command, that is, the 2-3 shift switch 61. It shall be in operation. In addition, circuit 2
08a, 208b, and 208c are the numerals 208 in FIG.
219a, 219b,
219c is also a similar edge trigger circuit, as shown in the same figure with the suffix removed from the reference numeral 219, and is activated by detecting the 2→3 shift command, that is, the rise of the signal from the 2-3 shift switch 61. shall be. For these purposes, the circuit 20 shown in FIG.
7,218 is NOT gate 209 and resistor 210
, a capacitor 211, and a NOR gate 212, the circuit 208 (219) shown in FIG.
is composed of a NOT gate 213, a resistor 214, a capacitor 215, and an AND gate 216. When the signal level from the 1-2 shift switch 60 falls from the H level to the L level, that is, 1←2
When a gear shift command is issued, the 1←2 gear shift detection circuit 20
7a, 207b, and 207c each output an H level signal (1←2 speed change signal) until the NOR gate 212 completes charging the capacitor 211, that is, for the time constant of the RC circuits 210, 211. OR gate 237,2 for the level signal
38,239. Further, when the signal level from the 1-2 shift switch 60 rises from the L level to the H level, that is, when a 1→2 shift command is issued, the 1→2 shift detection circuits 208a, 208b, 2
08c individually, since the AND gate 216 outputs an H level signal (1→2 speed change signal) for the time constant of the RC circuits 214 and 215 due to the charge of the capacitor 215, this H level signal is sent to the OR gate 2.
37,238,239. And 1←
2 speed change detection circuits 207a, 207b, 207c and 1→2 speed change detection circuits 208a, 208b, 20
8c continues to supply an L level signal to the corresponding OR gates 237 to 239 regardless of the signal level from the 1-2 shift switch 60 in a steady state other than the above. When the signal level from the 2-3 shift switch 61 falls from the H level to the L level, that is, 2←3
When a gear shift command is issued, the 2←3 gear shift detection circuit 21
8a, 218b, 218c are individually NOR21
2 outputs an H level signal (2←3 speed change signal) until the capacitor 211 is fully charged, that is, for the time constant of the RC circuits 210 and 211, so this H level signal is supplied to OR gates 237 to 239. . Also, when the signal level from the 2-3 shift switch 61 rises from the L level to the H level,
That is, when a 2→3 shift command is issued, the 2→3 shift detection circuits 219a, 219b, and 219c individually
Since the AND gate 216 outputs an H level signal (2→3 speed change signal) for the time constant of the RC circuits 214 and 215 due to the charge of the capacitor 215, this H level signal is supplied to the OR gates 237 to 239. And 2←3 speed change detection circuit 218a,
218b, 218c and 2→3 speed change detection circuit 21
9a, 219b, and 219c are OR gates 2 that correspond to L level signals regardless of the signal level from the 2-3 shift switch 61 in steady states other than the above.
Continue to supply 37-239. Thus, the speed change detection circuits 207a, 207b, 2
07c, 208a, 208b, 208c, 218
a, 218b, 218c, 219a, 219b,
219c, when the shift switches 60 and 61 are kept in the on or off state in a normal operating state other than during gear shifting, the L level signal is sent to the OR gates 237 to 239 regardless of the signal level from these shift switches. continues to output to OR gate 2
37 to 239 correspond to L level signals during this period.
It continues to output to AND gates 234-236. Therefore, AND gates 234 to 236 set all input signal levels of NOR gate 217 to L, and from this
Since the H level signal is continuously supplied to the AND gate 228, the AND gate 228 outputs an H level or L level signal depending on the presence or absence of the lockup permission signal S _L (H level) from the OR gate 206. When the AND gate 228 receives the lockup permission signal S _L and outputs an H level signal,
The signal is applied to the base of transistor 230 through bias resistor 229, which makes it conductive and energizes lock-up solenoid 31 with power supply +V, allowing torque converter 1 to be placed in lock-up as described above. Furthermore, if the AND gate 228 does not receive the lock-up permission signal S _L and outputs an L level signal, the transistor 2
30 is rendered non-conductive, lock-up solenoid 31 is deenergized, and torque converter 1 can be placed in the torque converter state as described above. Thus, the torque converter 1 operates in areas A, B, and
It is controlled to be in the lock-up state at C, and to be in the torque converter state at other times. In the present invention, an idle switch 70 and a full throttle switch 71 are added. These switches are linked to the accelerator pedal, and the idle switch 70 is turned on when the amount of depression of the accelerator pedal is below a certain value (light load area), and the full throttle switch 71 is turned on when the amount of depression of the accelerator pedal is below a certain value (light load area). (high load area). And switch 70, 71
are connected to the power supply +V via resistors 76 and 77, respectively, and when the switch 70 detects light load operation including engine idling and closes, it is connected to L from now on.
A level signal is output, and when the switch 71 detects heavy load operation of the engine and closes, these L level signals are output, and when the engine is operated with a medium load with the throttle opening between these levels, both switches 71
0 and 71 are both open and can each output an H level signal. The signals from the idle switch 70 and the full throttle switch 71 are sent to a NAND gate 231,
The signal is supplied to the AND gate 232 and the NAND gate 233, and when the switch 70 is closed during light load operation of the engine where the amount of depression of the accelerator pedal is below a certain level, the L level signal from the switch is
Let the NAND gate 231 output an H level signal,
If the switch 71 is closed while the engine is operating under heavy load by pressing down on the accelerator pedal more than a certain level, the L level signal from the switch will cause the NAND
When the engine is operated at a medium load while the gate 233 is outputting an H level signal and the accelerator pedal is operated between these two switches, and both switches 70 and 71 are open and outputting an H level signal, these AND gate 23 that ANDs the H level signal
2 to output an H level signal. In other words,
NAND gate 231, AND gate 232 and
The NAND gate 233 selectively sends an H level signal to the AND gates 234, 235, 236, depending on the load state of the engine. supply to. And circuits 207a, 208a, 218a,
219a is a shift detection circuit for light loads, circuits 207b, 208b, 218b, and 219b are shift detection circuits for medium loads, and circuits 207c,
208c, 218c, and 219c are high-load speed change detection circuits, respectively. In this configuration, lock-up control in a steady state (non-shifting) is as described above, but lock-up control during shifting is performed as follows.
When changing gears, that is, when shifting from 1st gear to 2nd gear, from 2nd gear to 3rd gear, and from 3rd gear to 2nd gear.
When downshifting from 2nd speed to 1st speed, the corresponding shift switch 60 or 61 is turned on or off, and this is detected by the shift detection circuits 207a, 20.
7b, 207c, or 208a, 208b, 20
8c or 218a, 218b, 218c, or 219a, 219b, 219c detects by the above-mentioned action and outputs an H level signal (shift signal) to the corresponding OR gates 237-239 for a certain period of time. This H level signal is the corresponding OR gate 2
AND gates 234-236 via 37-239
is fed to one input of The other inputs of these AND gates 234 to 236 are as described above.
NAND gate 231, AND gate 232,
The output signal of the NAND gate 233 is supplied, and as mentioned above, only one of the gates 231 to 233 becomes H level depending on the engine load, so it receives this H level signal.
While any one of the AND gates 234, 235 or 236 is present, the NOR gate 21
7 is supplied with H level. At this time, the NOR gate 217 outputs an L level signal to the AND gate 228, and the lock-up solenoid 31 is deactivated to interrupt the lock-up even while the lock-up permission signal S _L is present, and the torque converter 1 remains in the lock-up state. It is possible to prevent a large shift shock from occurring when the gear is changed. Note that the speed change detection circuit becomes H after the above-mentioned certain period of time has elapsed.
When the level shift signal is no longer output, the output signal level of all OR gates 237 to 239 is changed to L, and the output signal level of AND gates 234 to 236 also becomes L, causing NOR gate 217 to output an H level signal. Therefore, lockup control is performed in a steady state. By the way, in the present invention, the speed change detection circuit 207
a, 207b, 207c, 208a, 208b,
208c, 218a, 218b, 218c, 21
9a, 219b, and 219c, and adjust the time constant of the RC circuit in each shift detection circuit to adjust the output time of the shift signal (lock-up interrupt signal) from these to achieve different shifts depending on the type of shift command and the size of the engine load. Since the structure can be adjusted individually to match the operating time, the lock-up interruption time performed by the shift signal can be adjusted to match the shift operating time at any shift time and under any engine load, so that the engine does not start revving. The intended purpose of preventing gear shift shock from occurring can be completely achieved.

[Brief explanation of drawings]

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 the lock-up control section, FIG. 5 is a sectional view of a shift valve showing an example of the configuration of a shift switch, and FIGS. 7 are shift pattern diagrams showing the lock-up region of the automatic transmission of the present invention. 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, 60...
1-2 shift switch, 61...2-3 shift switch, 62...vehicle speed sensor, 63...converter chamber,
64... Side plate, 65, 66... Fixed contact,
67, 68...Insulator, 70...Idle switch,
71...Full throttle switch, 78,230...
Transistor, 100...Lockup control device,
104...Front clutch, 105...Rear clutch, 106...Second brake, 107...Low reverse brake, 108...One-way brake, 11
0...first planetary gear group, 111...second planetary gear group,
131...1-2 shift valve, 132...2-3 shift valve, 160, 164...valve spool, 201...gear position determination circuit, 205...vehicle speed determination circuit, 207
a, 207b, 207c...1←2 speed change detection circuit,
208a, 208b, 208c...1→2 speed change detection circuit, 218a, 218b, 218c...2←3 speed change detection circuit, 219a, 219b, 219c...2
→3 speed change detection circuit, 217...NOR gate, 23
1,233...NAND gate, 232,234~
236, 228...AND gate, 237-239
...OR gate.

Claims (1)

[Claims] 1. A lock-up determination circuit that issues a lock-up permission signal when the vehicle speed exceeds the lock-up vehicle speed at each shift position, and a shift detection circuit that issues a shift signal indicating that a shift is in progress for a predetermined period of time after a shift command, and lock-up permission is determined from the lock-up decision circuit. In the lock-up type automatic transmission, the torque converter with a direct coupling clutch is switched from a lock-up state to a torque converter state to eliminate a shift shock while a shift signal is issued from the shift detection circuit even if a shift signal is issued. A shift type determination circuit that determines the types of shift commands and issues signals corresponding to these types; and an engine load determination circuit that classifies the magnitude of the engine load into multiple levels and issues signals according to the magnitude of the engine load. and the shift detection circuits are arranged to individually respond to corresponding signals from the shift type determination circuit and the engine load determination circuit for the type of shift command and the number of engine load classification stages, and the shift detection circuits are configured to respond to corresponding signals from the shift type determination circuit and the engine load determination circuit, and A lock-up automatic transmission characterized in that the output time is set to match the shift operation time of the automatic transmission according to the type of the corresponding shift command and the magnitude of the engine load.