JPS62204064A - Direct coupling mechanism control method for fluid type power transmission of automatic transmission for vehicle - Google Patents

Abstract

PURPOSE:To simplify the device construction and enhance the operating characteristics by dividing a certain period of time into a plurality of stages, setting the time for one stage as minimum valve opening period, and emitting valve open signals only during period corresponding to the stage to be controlled. CONSTITUTION:A specific period for which the transmission capacity of a direct coupling clutch Cd is determined, is divided into a plurality of stages, and period for one stage is set as minimum valve open period, and for every minimum valve open period, valve open signals are emitted for a time corresponding to the stage to be controlled. After passage of a time corresponding to the stage to be controlled, a valve close signal is emitted, and a duty control signal for a solenoid valve to be controlled is now emitted. This allows elimination of use of any external counter to control the open and close times of a solenoid valve which controls the optimum transmission capacity, so that the operating characteristics can be enhanced while the construction is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for controlling a direct coupling mechanism of a fluid power transmission device for an automatic transmission for a vehicle.

(Prior art and its problems) In general, vehicles equipped with automatic transmissions use a fluid power transmission device, such as a fluid torque converter, to provide sufficient driving force and a smooth and easy driving feeling with a small number of gears. On the other hand, the practical fuel efficiency is poor due to the fluid slippage loss in the torque converter, and the engine rotational speed increases by the amount of fluid slippage, making the operation louder and less quiet.

For this reason, when there is no need to expect the torque amplification function of the torque converter, a direct coupling clutch mechanism called a lock-up mechanism is used, which mechanically connects the torque converter's output member and the output member to improve power transmission efficiency. (
A direct-coupling mechanism (hereinafter referred to as a direct-coupling mechanism) has been developed and has already been put into practical use, and since it can obtain favorable effects from improving power transmission characteristics and fuel efficiency, the direct-coupling mechanism is operated from as low a speed range as possible. It is desirable to do so. However, if the torque converter is completely directly connected in the low-speed operating range where the engine speed is also low, there are drawbacks such as large fluctuations in engine torque, which may cause vibration and noise in the vehicle body, or deteriorate driving performance. .

Therefore, instead of directly connecting the torque converter in such a low-speed operating range, for example, the rotational speed of the input member and output member of the torque converter should be Calculate the ratio e or slip ratio (=1-〇), etc., and in the above low-speed operation range, the rotation speed ratio C is 1 or the slip ratio is O.
The transmission capacity of the direct coupling mechanism is controlled by adopting the optimum transmission capacity from among the plurality of transmission capacities (engaging forces) of the direct coupling mechanism while feeding back the actual measured value of the rotational speed ratio e or slip ratio so as to avoid this. It is possible that

In such a case, if an attempt is made to control the opening and closing periods (duty ratio) of the electromagnetic valve that controls the transmission capacity in order to control the optimum transmission capacity, a separate external counter is required. In addition to providing data for commands to turn on (open) and off (close) the solenoid valve that controls the transmission capacity to the counter, for example, when a new optimum transmission capacity is given in the low speed operating range, It is necessary to output the opening/closing period of the electromagnetic valve corresponding to the transfer capacity from the counter and control the electromagnetic valve according to the transfer capacity.

However, when such a control method is implemented, the following problems occur. That is, for example, in an embodiment of the present invention to be described later, the transmission capacity is the maximum capacity of the control system when the electromagnetic valve that controls the transmission capacity is off, that is, when the valve is closed.

) is set relatively at the injection port, the control is performed smoothly and no vibration or noise is generated in the vehicle body, but the fuel consumption is poor (on the contrary, in order to improve fuel efficiency, the transmission When the capacity is set relatively finely, the rotation speed ratio e sometimes becomes 1.
, or the slip ratio approaches 0, but the rotational speed ratio e=1 or the slip ratio becomes O instantly, causing vibrations and noise in the vehicle body.

This is because no matter how electronic control technology is used, calculating the rotational speed ratio e or slip ratio takes a certain amount of time, including data sampling time, and the feedback system includes mechanical parts such as hydraulic equipment. , there is a physical limit to the response time of a control system that cannot be accelerated beyond a certain value, whereas if the transmission capacity is set in detail, the speed of transition in the direction of direct connection (direction of increasing transmission capacity) increases, causing a delay in control and causing the rotational speed ratio e or slip ratio to exceed the reference range value. Reflecting this result, the transmission capacity is then reduced more than necessary in order to return to the reference range value. Since the control is started in such a way that the rotational speed ratio e or the slip ratio decreases significantly again and falls below the reference range value, the operation repeats, and in the worst case, it diverges.

For the above reasons, the actual measured value of a predetermined parameter value representing the relative slip amount of the input and output members is compared with a predetermined reference range value set in advance, and the predetermined period to be implemented from now on is based on the comparison result. There is a method for determining the transfer capacity of . In order to control this transmission capacity, in the same way as above, if you try to control the opening/closing period of the solenoid valve that controls this transmission capacity, you will need a separate external counter that corresponds to the transmission capacity. The counter outputs the opening/closing period of the solenoid valve, and the solenoid valve is controlled according to the transmission capacity.

Note that if the response time of the entire control system is shortened, there is no risk of the above-mentioned problem occurring even when the transmission capacity is set to be strong, but in reality, there is a limit to the shortening of the response time.

(Object of the Invention) The present invention has been made in view of the above circumstances, and has a simple configuration that does not require an external counter to control the opening/closing period of a solenoid valve that controls the optimum transmission capacity. Moreover, even if the transmission capacity of the direct coupling mechanism is set to be strong,
Only in the driving range where it is necessary to accurately control the transmission capacity without causing divergence, this is controlled to the optimum value to suppress the generation of vehicle body vibration and noise, and to improve fuel efficiency and power transmission characteristics. Another object of the present invention is to provide a direct-coupling mechanism control method for a fluid power transmission device of an automatic transmission for a vehicle, which allows an extremely smooth and comfortable driving feeling to be obtained.

(Means for Solving the Problems) In order to solve the above-mentioned problems, in the present invention, predetermined actual values and preset values of predetermined parameter values representing the relative slip amounts of the output member and the output member of the hydraulic power transmission device are provided. Based on the comparison result, the transmission capacity of the direct coupling mechanism for the predetermined period to be implemented is determined, and the predetermined period is divided into multiple stages, and the period per stage is set to the minimum. For each minimum valve opening period, a valve opening signal is output for a period corresponding to the control stage, and after the period corresponding to the control stage has elapsed, the minimum valve opening period A duty control signal for the solenoid valve to be controlled is output by outputting a valve closing signal for a period corresponding to the control stage for each minimum valve closing period corresponding to the minimum valve closing period, thereby controlling the duty of the solenoid valve. It is something.

(Example) An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an outline of a vehicle automatic transmission to which the present invention can be applied, in which the output of the engine E is transmitted from its crankshaft 1 to a torque converter T as a fluid power transmission device, an auxiliary transmission M, and a differential device Df. The diameter of the left and right drive wheels w, w'
and drive them.

The torque converter T includes a pump impeller 2 which is an input member connected to a crankshaft 1, a turbine impeller 4 which is an output member connected to an input shaft 3 of an auxiliary transmission M, and a rotatable member on the input shaft 3. The stator wheel 5 is connected to a stator shaft 5a supported by a stator shaft 5a via a one-way clutch 6. The torque transmitted from the crankshaft l to the pump wheel 2 is hydrodynamically transmitted to the turbine wheel 4, and when the torque is amplified during this time, the stator wheel 5 acts as a reaction force. bear the burden.

A pump drive gear 7 for driving the hydraulic pump P shown in FIG. 2 is provided at the right end of the pump impeller 2, and a stator shaft 5a
A stator arm 5b that controls the regulator valve Vr shown in FIG. 2 is fixed to the right end of the stator arm 5b.

A roller-type direct coupling clutch Cd is provided between the pump impeller 2 and the turbine impeller 4 as a direct coupling mechanism capable of mechanically coupling these. To explain this in detail with reference to FIGS. 2 and 3, an annular drive member 9 having a drive conical surface 8 on the inner circumference is spline-fitted to the inner peripheral wall 2a of the pump impeller 2.

Further, an annular driven member 11 having a driven conical surface 1° facing parallel to the driving conical surface 8 on its outer periphery is spline-fitted to the inner circumferential wall 4a of the turbine impeller 4 so as to be slidable in the axial direction. Ru. A piston 12 is integrally formed at one end of this driven member 11, and this piston 12 is slidably engaged with a hydraulic cylinder 13 provided on the inner periphery 94a of the turbine wheel 4.
The internal pressure of the cylinder 13 and the internal pressure of the torque converter T are simultaneously received on both left and right end surfaces.

A cylindrical clutch o is provided between the driving and driven conical surfaces 8 and 10.
- A clutch roller 14 is interposed, and this clutch roller 14 is connected to a third clutch roller 14.
As shown in the figure, the annular glue retainer 15 is arranged so that its central axis 〇 is inclined at a constant angle θ with respect to the generatrix g of the virtual conical surface 1c (see FIG. 2) passing through the center between the hundred conical surfaces 8 and 10. Retained.

Therefore, when a hydraulic pressure higher than the internal pressure of the torque converter T is introduced into the hydraulic cylinder 13 at a stage when the torque amplification function of the torque converter T is no longer required, the piston 12, that is, the driven member 11 is pushed toward the drive member 9. Ru. As a result, the clutch roller 14 is pressed against the hundred conical surface 8.10. At this time, when the driving member 9 is rotated in the X direction in FIG. 3 with respect to the driven member 11 by the output torque of the engine E, the clutch roller 14 rotates. Since 0 is tilted as described above, its rotation imparts a relative axial displacement to both members 9.11 that brings them closer together. As a result, the clutch roller 14 has a hundred conical surface 8.10
It bites in between the two members 9 and 11, that is, the pump wheel 2 and the turbine wheel 4 to be mechanically connected. Even during such operation of the direct coupling clutch Cd, if the output torque of the engine E exceeds the coupling force and is applied between the two wing wheels 2 and 4, the clutch roller 14 is moved between each conical surface 8. slipping occurs with respect to to, and the above torque is divided into two, with some torque being mechanically transmitted via the direct coupling clutch Cd, and the remaining torque being transmitted hydrodynamically from the pump impeller 2 to the turbine impeller 4. The ratio of the former torque to the latter torque changes depending on the degree of slippage of the clutch roller 14.

If a reverse load is applied to the torque converter T in the operating state of the direct coupling clutch Cd, the rotational speed of the driven member 11 becomes higher than the rotational speed of the driving member 9. The clutch roller 14 rotates in the Y direction in FIG. 3, and the clutch roller 14 rotates in a direction opposite to the previous direction, thereby applying a relative axial displacement to the members 9 and 11 to separate them from each other. As a result, the clutch roller 14 is released from being wedged between the 100-conical surfaces 8 and 1o, and enters an idling state. Therefore, the turbine wheel 4
The transmission of the reverse load from to the pump wheel 2 takes place only hydrodynamically.

When the hydraulic pressure of the hydraulic cylinder 13 is released, the piston 12'
receives the internal pressure of the torque converter T and retreats to its initial position, so the direct coupling clutch Cd becomes inactive.

Referring again to FIG. 1, the mutually parallel persons of the auxiliary transmission M,
A first speed gear train G1, a second speed gear train G2, a third speed gear train G3, a fourth speed gear train G4, and a reverse gear train Gr are provided in parallel between the output shafts 3 and 16. The first speed gear train G1 is
a drive gear 17 connected to the input shaft 3 via a first speed clutch C1; and a one-way latch C meshing with the gear 17 and connected to the output shaft 16.

and a driven gear 18 that can be connected via. The second speed gear train G2 consists of a driving gear 19 that can be connected to the input shaft 3 via a second speed clutch C2, and a driven gear 20 that is fixed to the output shaft 16 and meshes with the gear 19. The third speed gear train G-1 consists of a driving gear 21 fixed to the input shaft 3 and a driven gear 22 connected to the output shaft 16 via a third speed clutch C3 and capable of meshing with the gear 21. . Further, the fourth speed gear train G4 includes a driving gear 23 connected to the input shaft 3 via a fourth speed clutch C4, and a driven gear 24 connected to the output shaft 16 via a switching clutch Cs and meshing with the gear 23. It consists of Further, the reverse gear train Gr includes a driving gear 25 provided integrally with the driving gear 23 of the fourth speed gear train G4, a driven gear 26 connected to the output shaft 16 via the switching clutch Cs, and both gears 25. .26 and an idle gear 27 that meshes with the gear. The switching clutch Cs connects the driven gear 24 of the fourth speed gear train G4 and the idle gear 27.
By shifting the selector sleeve S of the clutch C3 to the forward position on the left or the reverse position on the right in FIG.
7 can be selectively coupled to the output shaft 16. The one-way clutch Co transmits only the drive torque from the engine E to the drive wheels W, W'', and does not transmit torque in the opposite direction.

Thus, when the selector sleeve S is held in the forward position as shown in FIG. A gear train G1 is established, and torque is transmitted from the input shaft 3 to the output shaft 16 via this gear train G1. Next, the first
While the speed clutch C1 remains connected, the second speed clutch C2
When connected, the drive gear 19 is connected to the input shaft 3 to establish the second speed gear train G2, and torque is transmitted from the input shaft 3 to the output shaft 16 via this gear train G2. At this time, the first speed clutch C1 is also engaged, but due to the action of the one-way clutch CO, the first speed is not established, but the second speed gear train G2 is established, which is connected to the third and fourth speeds. The same goes for when. Release the second gear clutch C2 and apply the third gear clutch C3.
When the driven gear 22 is connected to the output shaft 16, the third speed gear train G3 is established, and when the third speed clutch C3 is released and the fourth speed clutch C4 is connected, the driven gear 22 is connected to the output shaft 16 and the third speed gear train G3 is established. 23 is connected to the input shaft 3 and the fourth speed gear train G4
is established. Furthermore, if the selector sleeve S of the switching clutch Cs is moved to the right in FIG. The reverse gear train Gr is established, and the output shaft 1 is connected from the input shaft 3 to the output shaft 1 via this gear train Gr.
Reverse torque is transmitted to 6.

The torque transmitted to the output shaft 16 is transmitted from the output gear 28 provided at the end of the shaft 16 to the large diameter gear DG of the differential device Df. One end of a speedometer cable 30 is fixed to the gear 29 meshing with the gear Ds fixed to the gear DC, and the speedometer 3 is connected to the other end of the speedometer cable 30 via a magnet 31a of a vehicle speed detector 31.
2 is connected, and the speedometer 32 is connected to the gear Ds, 29
and a cable 30 to display the vehicle speed.

The vehicle speed detector 31 includes the magnet 31a and a reed switch 31b, for example, which is driven by the magnet 31a.
1b is opened and closed, and on and off signals accompanying this opening and closing are supplied to an electronic control device 33, which will be described later.

FIG. 2 shows a hydraulic control circuit for a vehicle automatic transmission to which the present invention is applied.

In the figure, a hydraulic pump P whose suction port is connected to an oil tank R is connected via an oil path 300 to an inlet boat 60a of a regulator valve Vr, a pilot pressure introduction boat 60b, and a port of a manual shift valve (hereinafter simply referred to as a manual valve) Vm). 70
b and the inlet boat 80a of the governor valve Vg, respectively. Ports 70a and 70c of manual valve Vm are connected to port 9 of servo piston 90 via oil passages 301 and 302, respectively.
0C290b, the port 70c is further connected to the port 70d of the manual valve Vm, the inlet boat 270a of the pressure reducing valve 270, and the port 100a of the throttle valve Vt via the oil passage 303.
, the port 70e is connected to the manual valve Vm via the oil passage 304.
port 70g of the timing valve 210, port 210d of the timing valve 210
, are connected to the port 170a of the first accumulator 170 and the second speed clutch C2, respectively. Also, the manual valve Vm port? Of has a throttle 350 and one-way valve 38 in the middle
0 is connected in parallel to the port 130b of the second shift valve v2, and the port 70h is connected to the oil path 31 in which a throttle 359 and a one-way valve 383 are provided in parallel in the middle.
3 to the first speed clutch C1, respectively. The oil passage 313 is connected to the two inlet bows (400a, 400) of the flow rate regulating valve 400 via the oil passage 307 provided with a throttle 369.
One outlet boat 400d of the flow rate regulating valve 400 is connected to the port 1-120b of the first shift valve 1 through an oil passage 307a. A throttle 3 is provided between the first inlet boat 400a of the flow rate adjustment valve 400 and the oil passage 307.
70 is interposed.

The bow) 70i of the manual valve Vm is connected to the port 90a of the servo piston 90 through the oil passage 308, and the bow) 70 is connected to the port 21 of the timing valve 210 through the oil passage 309.
0 e, port 190a of second accumulator 190
and 4th speed clutch C4, bow 110m is oil path 310
port 70n1 of manual valve Vm through port 130d of second shift valve v2.

and 160b of the first control valve 160, respectively. Oil passage 310 and port 130 of second shift valve V2
A throttle 356 and a one-way valve 381 are arranged in parallel with each other between the valve and the valve d.

Port of throttle opening responsive valve Vt) 100 b.

and 100C each port 170b of the first to third accumulators 170, 190, 180 via an oil path 311,
190b, 180b, port 2 of modulator valve 220
20f, port 230c of the on-off valve 230, port 400c of the flow rate adjustment valve 400, port 160a of the first control valve 160, and port 20 of the second control valve 200
0a, and a throttle 352 is interposed between the port 100b of the throttle opening responsive valve Vt and the oil passage 311. The port 100d of the throttle opening response valve Vt is connected to the port 130g of the second shift valve ■2 via the oil passage 312.
and the drain EX, and the oil passage 312 and the drain E
A diaphragm 353 is interposed between the X and X. Third control valve 1
The port 110a of No. 10 is connected to the port 120a of the first shift valve 1 and the drain EX via an oil passage 315, and a throttle 354 is connected between the oil passage 315 and the drain EX.
is interposed.

Port 120c, 120 of first shift valve ■1
d is connected to the second shift valve ■ via oil passages 316 and 317, respectively.
The port 120e is connected to the port 160c of the first control valve 160 via the oil passage 318.
and a drain EX, and a throttle 355 is interposed between the oil passage 318 and the drain EX. The port 130e of the second shift valve (2) is connected to the port 200C of the second control valve 200 and the drain EX via an oil passage 319, and a throttle 357 is connected between the oil passage 319 and the drain EX.
is interposed. The port 130f of the second shift valve 2 is connected to the port 200 of the second control valve 200 via an oil passage 320 in which a throttle 358 and a one-way valve 382 are connected in parallel.
0 b, port 180a of third accumulator 180
and third speed clutch C3. In addition, the second
A throttle 356a is interposed in one of the two EX ports of the shift valve (2).

The bow) 120f of the first shift valve 1 is connected to the inlet boat 140a of the first solenoid valve 140 via an oil passage 340, and the oil passage 340 is connected to the pressure reducing valve 270 via an oil passage 341 provided with a throttle 361. is connected to the exit boat 270b. The port 130h of the second shift valve 2 is connected to the inlet port 150a of the second solenoid valve 150 via an oil passage 322a, and the oil passage 322a is connected to the oil passage 3 through a throttle 362.
22, and this oil passage 322 is connected to the outlet boat 80b of the governor valve Vg.

Each valve body 141 of the first and second solenoid valves 140, 150.
151 is the deenergization (off) of solenoids 142 and 152, respectively.
At times, the spring force of the springs 143 and 153 closes the inlet boats 140a and 150a, and the solenoid 14
When energized (on) of 2,152, it is attracted against the spring force and the large opening 140a.

150a is opened. That is, the first and second solenoid valves 14
0 and 150 are closed when the solenoids 142 and 152 are deenergized, and opened when the solenoids are energized.

The outlet port 60c of the regulator valve Vr is connected to the port 210a of the timing valve 210 through the oil passage 325.
Each port 230d of the off valve 230 is connected to the port 230d. The port 210b of the timing valve 210 has a throttle 371 in the middle.
The port 210c is connected to the port 220d of the modulator valve 220 via an oil path 321 provided with a 220, the port 210c is connected to the port 220a of the modulator valve 220 via an oil path 327, and the port 210f is connected to the port 220a of the modulator valve 220 through an oil path 501a provided with a throttle 375 in the middle. and are connected to the oil passages 501, respectively. Modulator valve 22
The port 220b of port 220b is connected to the oil path 326 via an oil path 326a provided with a throttle 372 in the middle.
0c is connected to the port 230b of the on-off valve 230 via an oil passage 353 with a throttle 373 in the middle, and to the port 220e.
are connected to oil passages 322 each having a throttle 366a in the middle. Port 230a of on-off valve 230 is connected to oil passage 32
6, the port 230e is connected to the oil passage 334 via an oil passage 501 provided with a throttle 374 in the middle.

The inlet port 240a of the third solenoid valve 240 has a throttle 367
It is connected to the oil passage 326 via. This third solenoid valve 2
When the solenoid 242 is deenergized (off), the valve body 241 of 40 is pressed by the spring force of the spring 243, and the valve body 241 of the inlet boat 2
40a, and when the solenoid 242 is energized (on), it is sucked against the spring force and opens the inlet port 240a. That is, the third solenoid valve 240 is closed when the solenoid 242 is deenergized, and opened when the solenoid 242 is energized.

The port Ta of the torque converter T is connected to the oil passage 325 through the oil passage 334 provided with the throttle 368, the port Tb is connected to the oil passage 326, and the port Tc is connected to the pressure holding valve 2 through the oil passage 335.
50 inlet boats 250a. This pressure holding valve 2
The pilot pressure introduction port 250b of No. 50 is connected to the upstream side of the throttle 366a of the oil passage 322 via the oil passage 336, and the outlet boat 250C is connected to the drain EX via the oil passage 337 and the oil cooler 260, respectively. Each drain EX is connected to an oil tank R, respectively.

Each solenoid 142, 152, 242 of the first to third solenoid valves 140, 150, 240 is connected to a signal line 142a, 1
It is connected to the electronic control device 33 via 52a and 242a, respectively. The electronic control device 33 operates in accordance with a predetermined shift map based on input signals from a vehicle speed detector 31, an engine speed detector 34, a gear position detector 35, etc.
Then, the second solenoid valves 140 and 150 are controlled to control the engagement and disengagement (disengagement) of the first to fourth gear clutches C1 to C4, thereby controlling the speed change. Further, the electronic control device 33 actually measures a predetermined parameter value representing the relative slip amount of the output member of the torque converter T, for example, the speed ratio e, and compares the measured value e with a predetermined reference value, Based on the comparison result, the engagement force (transmission capacity) of the direct coupling clutch CdO is determined and the third solenoid valve 240 is controlled to control the direct coupling clutch CdO.
control the engagement force of

The operation of the above-mentioned hydraulic circuit will be explained below.

The hydraulic pump P sucks and pressurizes the hydraulic oil in the oil tank R, adjusts the pressure to a predetermined pressure (hereinafter referred to as line pressure P1) using the regulator valve Vr, and then pumps it to the oil path 300. The stator arm 5b (see Fig. 1) is in contact with the spring receiver 61 of the regulator valve Vr, and when the reaction force of the stator wheel 5 of the torque converter T exceeds a predetermined value, the spring 62 is compressed and the hydraulic pump P Increase the discharge pressure. Such hydraulic control is detailed in Japanese Patent Publication No. 45-30861. A part of the hydraulic oil whose pressure is regulated by the regulator valve Vr is sent into the torque converter T through an inlet oil passage 334 having a throttle 368, and after pressurizing the inside thereof to prevent cavitation, the pressure holding valve 250, Tank R via oil cooler 260
is refluxed to. In the pressure holding valve 250, as the vehicle speed U increases, the spool 251 opens to the right side R in the figure against the spring 252 due to the governor pressure Pc. In other words, the pressure holding valve 250 works to lower the internal pressure of the torque converter T in proportion to the vehicle speed U, and since its spool 251 is operated by the differential pressure with the governor pressure Pc, the transmission capacity of the direct coupling clutch Cd increases. The maximum transmission capacity of the direct coupling clutch Cd is increased on the side.

The manual valve Vm is switched by manual switching operation of the shift lever; P (parking), R (reverse), N (neutral), D4 (4-speed forward automatic transmission), D:] (3-speed forward automatic transmission except TOP). ), 2 (2ND hold), and an operation mode corresponding to each shift position can be arbitrarily selected.

When the spool 71 of the manual valve Vm is in the illustrated N position, the port 70b connected to the oil passage 300 is blocked by the spool 71 of the manual valve Vm, and the other ports 70a, 70c to 70n are all connected to the drain EX. The four clutches 01 to C4 of the first to fourth speeds are all disengaged, and therefore engine torque is not transmitted to the drive wheels W, W' (see figure ffi1).

When the spool 71 of the manual valve Vm moves one frame to the left from the illustrated position and is at the D4 position, both the oil passages 302 and 313 communicate with the oil passage 300, and pressure oil is supplied to the oil passage 30.
5,304 communicate with each other. Further, the oil passage 309 is communicated with the oil passage 310, but is isolated from the drain EX and the oil passage 308, respectively, and the oil passage 301 continues to communicate with the drain EX. As a result, at the D4 position (range), the servo piston 90 for moving the selector sleeve S (see Fig. 1) receives the line pressure PR in its spring chamber 92, and the spool 91 also receives the hydraulic pressure. fixed in the position shown,
The selector sleeve S is held in the position shown in FIG. 1 by a shift fork 39 fixed to one end of the spool 91. As a result, the fourth speed driven gear 24 is engaged with the switching clutch C8, and the reverse driven gear 26 is placed in a freely rotatable state.

Even if the spool 71 of the manual valve Vm is further shifted one frame to the left from this state and placed in the D3 position, the manual valve Vm remains the same except that the oil passage 310 is connected to the drain EX via the boats 70m and 70n. The connection relationship between the connected oil passages does not change. These 2. At the Dl and D4 positions, pressure oil is sent to the throttle opening responsive valve Vt via the oil passage 303.

The throttle opening response valve Vt is a parameter representing the load of the engine E, and is proportional to the amount of depression of the throttle pedal (not shown), that is, the valve opening of the throttle valve (not shown) provided in the intake system of the engine E. The left spool 101 is moved to the left by receiving the displacement of the cam 104 which rotates counterclockwise from the illustrated position via the spring 103, and the boat 10
0a to the open side, and the discharge pressure of its output port 100c,
Through the throttle 352, the boat 100b and the spool 101 are moved to the right to drive the boat 100a to the closing side, and a pressure proportional to the opening degree of the throttle valve (hereinafter referred to as throttle pressure Pt) is applied to the output oil passage 311. )
to occur. In addition, the counterclockwise rotation of the cam 104 moves the right spool 102 to the left, continuously restricts the communication between the boat 100d and the drain EX, and kicks down from 3rd speed (3RD) to 2nd speed (2ND). Alleviates the shock of shifting gears.

Cam 113 of third control valve 110 interlocking with cam 104
is rotated counterclockwise according to the opening degree of the throttle valve to move the spool 111 to the left against the spring force of the spring 112, thereby continuously restricting the communication between the port 1-110a and the drain EX, Alleviates shift shock when kicking down from 4th gear (TOP) to 3rd gear (3RD). Further, the throttle pressure pt is sent to the boat 400c of the flow rate regulating valve 400 via the oil passage 311 to control the valve 400. That is, when the flow rate adjustment valve 400 is in the state shown in the figure, the flow rate adjustment valve 400 passes only through the first inlet boat 400a provided with the throttle 370 from the oil passage 307, and from the outlet boat 400d through the oil passage 307a to the first shift valve 1. When hydraulic pressure is sent to the boat 120b and the throttle pressure pt increases to overcome the force of the spring 402, the spool 401 moves to the left and passes through both the first and second inlet ports 400a and 400b, thereby opening its outlet. Increase the amount of pressure oil supplied from the port 400d to the oil passage 307a, and when the throttle valve opening is small, the clutches will engage together (the state will be such that two clutches are engaged together,
Energy is consumed in both clutches, causing the vehicle to drop below its previous speed. ), the next clutch is not engaged until one clutch is completely disengaged, thereby alleviating the shock of, for example, upshifting when the accelerator is released, or downshifting when stopping the vehicle.

The oil discharged from the hydraulic pump P is fed to the inlet boat 80 of the governor valve Vg.
a, the governor valve Vg is rotated by its own shaft 82 at a speed proportional to the vehicle speed by a gear 81 meshing with the large-diameter gear DG shown in FIG. A pressure proportional to (hereinafter referred to as governor pressure Pc) is output.

When the first shift valve (1) is in the first position shown, the input oil passage 307a is connected to the output oil passage 316, and another output oil passage 317- is connected to the drain EX via the oil passage 318. The valve body 121 of the first shift valve (1) is shifted to the first position by the spring 122. The first shift valve v1 is activated by the spring 122 due to the hydraulic pressure reduced to a pressure lower than the line pressure Pβ introduced from the pressure reducing valve 270 through the oil passage 341, the throttle 361, and the oil passage 340 into the chamber 120A facing the right end surface of the first shift valve v1. It can be moved to the left against the force and assume a second position, and when in this second position, the output oil passage 316 is connected to the oil passage 315.
Another output oil passage 317 is separated from the oil passage 318 and connected to the input oil passage 307a.

When the first shift valve (1) is in either the first or second position, the oil passage 313 is connected to the first speed (LOW) clutch C1, so that the manual valve Vm is in the D position.
When in the 3 or D4 position, the first speed clutch C1 is always pressurized and engaged. The spool 121 of the first shift valve 1 is controlled by a first solenoid valve 140, and when the solenoid valve 140 is closed, the second position is set by the pressure introduced into the chamber 120A, and when the solenoid valve 140 is opened, the spool 121 is set to the second position by the spring 1.
22 to assume the first position.

When the second shift valve V2 is in the first position shown, it blocks the input oil passage 316, connects the output port 130d to the drain EX, connects the input oil passage 317 to the output oil passage 305,
Further, the output oil passage 320 is connected to the drain EX via the oil passage 312. The spool 131 of the second shift valve ■2 is the spring 1
32 to the first position. This shift valve■2
is moved to the left against the spring force of the spring 132 by the governor pressure Po introduced from the port 130h into the chamber 130A facing the right end surface of the spool 131 via the oil passage 322, the throttle 362, and the oil passage 322a, and is moved to the second position. and when it is in the second position, drain the outlet hole 30d.
It is disconnected from the input oil passage 316 and connected to the output oil passage 30.
5 is connected to the drain EX via the oil passage 319, the remaining output oil passage 320 is separated from the oil passage 312, and the input oil passage 317 is connected to the drain EX through the oil passage 319.
Switch to connect.

The spool 131 of the second shift valve v2 is controlled by a second solenoid valve 150, and when the solenoid valve 150 is closed, the second shift valve v2 is controlled by the governor pressure Pc introduced into the chamber 130A.
The position is set to the first position by the spring 132 when the valve is opened.

Further, the second shift valve (2) is particularly provided with a click motion mechanism 133 so that its switching operation is performed in an on-off manner. This click motion mechanism 133
is the governor pressure Pc even when the second solenoid valve 150 is closed.
In response to the change in , the spool position of the shift valve v2 is limited to either the first or second position.

Now, as long as the engine E is rotating, the hydraulic oil pressurized by the hydraulic pump P is sent to the governor valve Vg.
g, the pressure is regulated as a signal pressure proportional to the vehicle speed U and guided to the chamber 130A of the second shift valve 2, and the pressure reducing valve 27
The pressure is reduced at 0 and guided to the chamber 120A of the first shift valve (1). To maintain these two shift valves Vl and V2 in the first switching position shown when the manual valve ■m is in the D4 (or D3) position, the solenoids 142 and 152 of the two solenoid valves 140 and 150 are attached together. All you have to do is force the valve open. As a result, each clutch 02-C of 2nd speed to 4th speed
4 is not pressurized, only the first speed clutch C1 is engaged under pressure, and the first speed reduction ratio is established. This first gear generally covers the low speed range, so
In this low speed region, the governor pressure Pc itself is low pressure, and the loss flow rate of the pressure oil discarded from the second solenoid valve 150 to the oil tank R via the throttle 362 is correspondingly small (this is economical. This is particularly advantageous when the pressure of the entire system must be maintained significantly higher than the normal pressure level (line pressure P1), such as when starting from a stall (vehicle speed=0).

Next, the solenoid 152 of the second solenoid valve 150 is energized to maintain the solenoid valve 150 in the open state, and the solenoid 142 of the first solenoid valve 140 is deenergized to keep the solenoid 150 open.
When valve 0 is closed, hydraulic pressure reduced by the pressure reducing valve 270 is generated in the chamber 120A of the first shift valve 1, and this causes the spool 12 of the shift valve 1 to resist the spring force of the spring 122.
1 moves to the left. Due to this leftward movement of the spool 121, the oil path 3
07a is connected to the oil passage 305 through the oil passage 317, and when the oil passage 305 is in the D4 position, it is connected to the oil passage 304 through the port 70f of the manual valve Vm, the notch 71a of the spool 71, and the port 70g, and when it is in the D3 position. 70
f, annular groove 71b of spool 71;

are respectively connected to the oil passages 304 via ports 70e,
The speed clutch C2 is engaged under pressure. Therefore, D4 or D
In the 3rd position, the first gear clutch c1 and the second gear clutch C2
are engaged under pressure. However, as shown in FIG. 1, a one-way clutch CD is interposed between the first driven gear 18 and the output shaft 16, which transmits torque only in the direction of the driving torque from the engine E. A speed reduction ratio is established.

Next, with the solenoid 142 of the first solenoid valve 140 deenergized and the solenoid valve 140 closed, the second solenoid valve 150 is opened.
When the solenoid 152 is deenergized and the solenoid valve 150 is closed, the governor pressure PG at that time is generated in the chamber 130A of the second shift valve 2, and the resistance force by the spring 132 and the click motion mechanism 133 is suppressed by the governor. The spool 131 moves to the left and assumes the second position only when the left power generated by the pressure Pc exceeds the left power. Due to this leftward movement of the spool 131, the oil passage 305 is connected to the drain EX via the oil passage 319, and the engagement of the second speed clutch C2 is released, and at the same time, the oil passage 320 is connected to the oil passage 317, which is a hydraulic pressure source. 3rd gear clutch C3
are engaged under pressure. At this time as well, the first gear clutch C1 is pressurized and engaged, but due to the action of the one-way clutch CO, the third gear clutch
A speed reduction ratio is established.

Next, the solenoid 152 of the second solenoid valve 150 is held in a de-energized state, and the solenoid 14 of the first solenoid valve 140 is held in a de-energized state.
2 is energized again to open the solenoid valve 140, the spool 121 of the first shift valve 1 moves to the right and returns to the illustrated position, connecting the oil passage 317 to the drain EX via the oil passage 318. Then, the third speed clutch C3 is disengaged, and at the same time, the oil passage 316 is connected to the hydraulic pressure source 307a, and pressure oil is supplied to the oil passage 310.

Cough oil passage 310 is operated by manual valve Vrn when in D4 shift position.
It is connected to the oil passage 309 via the boats 70m and 70k, and the fourth speed clutch C4 is engaged under pressure. At this time also the first
Although the speed clutch C1 is engaged under pressure, the fourth speed reduction ratio is established by the action of the one-way latch CO, as described above. In this manner, automatic gear shifting from first to fourth gears is performed.

Each reduction ratio of these 1st speed to 4th speed and the 1st speed. The relationship between the second solenoid valves 140 and 150 and the respective solenoids 142 and 152 is shown in Table 9J1.

On the other hand, the hydraulic pump P discharged from the regulator valve Vr
A part of the working oil pressure flows into the torque converter T through an oil passage 334 provided with a throttle 368 to increase its internal pressure and is sent to the timing valve 210 and the on-off valve 230. This timing valve 210 has chambers 210A and 210B introduced with oil pressure to be applied to a second speed clutch C2 and a fourth speed clutch C4, respectively, and a spool 211 has a second speed or fourth speed reduction ratio established. Sometimes the spring 212
The spring 212 moves to the left against the spring force of the spring 212 to reach the second switching position, and when the first or third speed reduction ratio is established.
The spool 212 is moved to the right by the spring force of
takes the switching position.

When the timing valve 210 is in either of these two switching positions, it connects the input oil passage 325 to the output oil passage 327 and also connects the drain oil passage 32 of the modulator valve 220.
1 to the drain EX, but during the transition to both switching positions, the output oil passage 327 is cut off from the input oil passage 325, and the drain oil passage 321 of the modulator valve 220 is cut off from the drain EX. The oil pressure in the output oil passage 327 of the timing valve 210 is input to the modulator valve 220, modulated, and output to its output oil passage 353. The modulator valve 220 modulates the hydraulic pressure using the governor pressure PG and the throttle pressure pt to create an engagement force for the direct coupling clutch Cd, and has oil passages 3 in the chambers 22OA and 220B, respectively.
Governor pressure PG, throttle pressure Pt via 22, 311
is introduced, and these two pressures and the spring force of the spring 222 move the spool 221 to the left toward the valve opening side, and the feedback pressure of the output oil passage 326 is applied to the oil passage 326a and the throttle 372.
The governor pressure Pc is received by the left end surface of the spool 221 via
, the spool 221 is moved to the right toward the valve closing side against the throttle pressure Pt and the spring force of the spring 222. As a result, a pressure proportional to the vehicle speed U and the opening degree of the throttle valve appears in the output oil passage 353.

When the pressure output from the modulator valve 220 becomes too high, the spool 221 of the modulator valve 220 moves to the right in the figure against the resultant force of the governor pressure Pc, throttle pressure pt, and spring 222 due to feedback pressure, causing the pressure to increase. is drained to drain EX via the timing valve 210. And when the gear is not changing, the timing valve 21
The drain oil passage 321 of the modulator valve 220 is always connected to the drain EX through the is not drained anywhere.

The reason for this is that it is necessary to control the engagement force (transmission capacity) of the direct coupling clutch Cd only by the third solenoid valve 240, and to prevent the engagement force of the direct coupling clutch Cd from decreasing excessively during gear shifting. This is to do so. During a shift, the accumulator moves in connection with the shift, so the line pressure Pl decreases and the throttle pressure pt also momentarily decreases. For this reason, the spool 221 of the modulator valve 220 moves to the right in the figure, and if the drain oil passage 321 is connected to the drain EX at this time, the engagement force of the direct coupling clutch Cd itself decreases. Therefore, during gear shifting, the drain oil passage 321 of the modulator valve 220 is shut off from the drain EX in conjunction with the timing valve 210 to prevent pressure oil from escaping anywhere, thereby reducing the engagement force of the direct coupling clutch CdO during gear shifting. can be prevented.

The pressure in the output oil passage 353 of the modulator valve 220 is
73, the oil is guided from the boat 230a of the on-off valve 230 to the cylinder 13 of the direct coupling clutch Cd in the torque converter T via the oil passage 326. Therefore, the engagement force (transmission capacity) of the direct coupling clutch Cd is strengthened according to the vehicle speed U and the opening degree of the throttle valve when the third electromagnetic valve 240 is closed. The on-off valve 230 receives the throttle pressure pt through the oil passage 311 in the chamber 230A, and at the throttle pressure pt, the spool 231 moves to the left in the figure against the spring force of the spring 232 to open the input oil passage 353. It is connected to the output oil passage 326, and when there is no throttle pressure pt, that is, when the throttle valve opening is at the idle position, the spool 231 moves to the right by the spring force of the spring 232 and is held in the position shown in the figure, draining the oil passage 326. It connects to EX and also serves to connect oil passage 325 and oil passage 501. This on-off valve 230 is connected to the direct clutch Cd when the valve opening of the throttle valve is at the idle position.
This is to release the engagement. At this idle position, the oil passage 325 and the oil passage 501 are connected, so that the amount of oil flowing into the torque converter T from the inlet boat Ta of the torque converter T increases, and the pressure inside the torque converter T increases. Since the piston 13 is pushed to the left in the figure, it is in the idle position (when the accelerator pedal is released)
The disengagement of the direct coupling clutch Cd can be reliably performed.

The third solenoid valve 240 controls the engagement force of the clutch Cd by controlling the opening and closing between the oil passage 326 and the drain EX to control the operating pressure of the direct coupling clutch Cd or the pressure of the piston 13. However, when the solenoid 242 of the third electromagnetic valve 240 is energized and opened, the throttle 373
As a result, the oil pressure in the oil passage 326 decreases, and the engagement force (transmission capacity) of the direct coupling clutch Cd is weakened.

The solenoid 242 of this third solenoid valve 240 determines the relative actual speed ratio e between the torque converter T and the output member.
The electronic control unit 33 that measures the speed ratio e is controlled so that the speed ratio e falls within a reference range value, as will be described later. When the solenoid 242 of the third solenoid valve 240 is deenergized and the solenoid valve 240 is closed, the modulator valve 242 is closed.
The output of 0 itself becomes the engagement force of the direct coupling clutch Cd,
The output acts on the hydraulic cylinder 13 via the on-off valve 230 and the oil passage 326, and the operating pressure increases in proportion to the vehicle speed U, as shown by the solid line 3 in FIG. In addition, in FIG. 4, the influence of the throttle pressure pt is omitted to simplify the explanation, and the solid line ! The operating pressure curve shown by is when the valve opening of the throttle valve is at idle, and when the spring 22
This is what happens when 2 is omitted.

On the other hand, when the solenoid 242 of the third solenoid valve 240 is energized and the solenoid valve 240 is open, the hydraulic cylinder 13 is Since it is opened to the drain EX and the pressure decreases, the engagement force of the direct coupling clutch Cd becomes weak or zero, and its operating pressure has the characteristics shown by the broken line (■) in FIG. Therefore, by controlling the duty ratio of the opening time of the third electromagnetic valve 240, the operating pressure of the direct coupling clutch Cd can be created arbitrarily between the solid line (2) and the broken line (2) in FIG.

In this embodiment, between the solid line ■ and the broken line ■ in FIG.
The duty ratio is controlled in 21 stages from 0 to 20%, of which the representative one shown in Figure 4 is on-duty ratio (hereinafter simply referred to as duty ratio) of 60%.
The working pressure when the duty ratio is 30% is shown by the solid line (■), and the solid line (■) is the working pressure when the duty ratio is 30%. In Figure 4, the chain line ■
The straight line shown by indicates the internal pressure PT of the torque converter T, and the differential pressure between the working pressure shown by the solid lines 1 to ■ or the broken line ■ and the internal pressure PT defines the strength of the engagement force of the direct coupling clutch Cd. .

(Operation) FIGS. 5 to 8 are flow charts showing the method of the present invention,
The operation of the method of the present invention will be explained below along with this flowchart.

In FIG. 5, when the ignition switch is first turned on, the CPU of the electronic control unit 33 is initialized (
Step 1): All variables related to transmission capacity control of the direct coupling clutch Cd are set to initial values. Next step 2
Proceed to the vehicle speed detector 31, engine rotation speed detector 34,
Each input data from the gear position detector 35 etc. is read, and in step 3, the time intervals of the vehicle speed pulse signal and the engine rotation speed pulse signal respectively inputted are measured to determine the vehicle speed U,
The engine speed Ne is calculated, and the torque converter T (described later) is operated based on the vehicle speed U and the engine speed Ne.
The speed ratio e between the pump wheel 2 and the turbine wheel 4 (see FIGS. 1 and 2) is calculated (step 4).

This value e is calculated as follows.

When the turbine wheel rotation speed is N2, the speed ratio e of the torque converter T is expressed by the following equation.

- Since it is connected to the cable pulley 30 via a gear train, there is no slippage between them.If the reduction ratio between them is A and the rotation speed of the speedometer cable 30 is N3, then Rotation speed N2 of torque converter output shaft 3
is N2=A-N3 (2). When formula (1) is rearranged using formula (2), the speed ratio e is expressed by the following formula.

Here, when the number of gears of the auxiliary transmission M is four, the value of the reduction ratio A is determined for each detected gear, that is, from 1st gear to
It can take values A1 to A71 corresponding to each reduction ratio of the fourth speed.

Note that a rotation speed detector may be attached to the input shaft 3 of the auxiliary transmission M in order to determine the output side rotation speed of the torque converter T.

After calculating the speed ratio value e in step 4, the process proceeds to step 5, whereupon the direct coupling clutch Cd control o-/l/(Cd, C0NTR0L) routine shown in FIG. 6 is executed.

In FIG. 6, first, in step 1, the engine speed Ne
is larger than a predetermined rotation speed Ne3 (for example, 3.50 rpm), and the answer is affirmative (Yes -).
In this case, proceed to step 16 and turn off or close the third solenoid valve 240 to increase the working oil pressure of the direct coupling clutch Cd.
The engagement force of the direct coupling clutch CdO is strengthened.

This is because if the engine speed Ne is 3.50 Orpm or higher, there is no risk of problems such as vibration occurring, and the direct coupling clutch Cd
By increasing the O engagement force, clutch slippage can be suppressed, and the life and fuel efficiency of the direct coupling clutch Cd can be improved.

At this time, the working oil pressure supplied to the direct coupling clutch Cd is maintained on the solid line ■ in FIG. 4.

If the answer to step 1 is negative (No), it is determined in step 2 whether or not the gear position of the auxiliary transmission M is the fourth speed, and if the answer is affirmative (Yes), step 6 is performed. If the answer is NO, the process proceeds to step 3, where it is determined whether the gear position is the third gear.

If the answer to Step 3 is affirmative (Yes), that is, if the gear position is the third gear, then Step 5 is answered (No).
If so, proceed to step 4.

As a result of the determination in steps 2 and 3, when the vehicle is in fourth gear, the upper limit vehicle speed U32 is changed to the predetermined vehicle speed U432 in step 6.
(for example, 85 km/h), the upper limit vehicle speed U32 is set to the designated vehicle speed U332 (for example, 40 km/h) in step 5 when the vehicle is in 3rd gear, and the upper limit vehicle speed U32 is set to the designated vehicle speed U232 (for example, 40 km/h) in step 4 when the vehicle is in 2nd gear or lower. For example 30
km/h). In this way, the upper limit vehicle speed U32 is set to U232. U332. After setting the vehicle speed to one of U432 and U432, the process proceeds to step 7, where it is determined whether or not the vehicle speed U is greater than the upper limit vehicle speed Uβ set in any of steps 4 to 6, and the answer is affirmative. If (Yes), problems such as vibration will not occur, and the process proceeds to step 16, where the third solenoid valve 240 is closed and the engagement force of the direct coupling clutch CdO is strengthened.

If the answer to step 7 is negative (No), that is, if the vehicle speed U is smaller than the upper limit vehicle speed U32, the process proceeds to step 8 where the vehicle speed U is determined to be the lower limit vehicle speed U31 (for example, 6 km/h).
Determine whether the value is greater than or not. The answer is negative (No),
That is, if the vehicle speed U is lower than the lower limit vehicle speed U3+ and is in a low vehicle speed range that requires the torque amplification function of the torque converter T, the process proceeds to step 18 and the third solenoid valve 240 is turned on, that is, opened. As a result, the operating pressure of the direct coupling clutch Cd is lowered, the engagement force of the direct coupling clutch CdO is weakened, and the function of the torque converter T is utilized. At this time, the working oil pressure supplied to the direct coupling clutch Cd changes along the broken line ■ in FIG. If the answer to step 8 is affirmative (Yes), that is, if the vehicle speed U is greater than the lower limit vehicle speed U3+, the process proceeds to Stellaf 9, and it is determined whether the gear position of the auxiliary transmission M is the fourth gear. do. The answer to step 9 is affirmative (
If the answer is yes, it is determined in step 10 whether the vehicle speed U is greater than a predetermined vehicle speed U3 (for example, 58 km/h), and if the answer is yes, the gear is pressed and the gear is set to fourth gear. When the vehicle speed U is higher than the predetermined vehicle speed U3G, in step 12, the discrimination values e1 (e.g. 92%) and C2 (e.g. 97%) are set in the predetermined speed ratio range.
), ea (e.g. 99.5%), C4 (e.g. 102%
) respectively. The discrimination value e1 is an upper limit value of a region where the engagement force of the direct coupling clutch Cd is weak (hereinafter referred to as a weak engagement force region) and a lower limit value of a region approximated to a reference value (hereinafter referred to as a reference value approximation region). The discrimination value e2 is the upper limit value of the reference value approximation region and the lower limit value of the reference value region (target region). The discrimination value e3 is the upper limit value of the reference value region and the lower limit value of the fine adjustment region. The discrimination value e4 is the upper limit value of the fine adjustment area, and at the same time the solenoid is turned on and the third
This is the lower limit value of the region in which the solenoid valve 240 is opened (hereinafter referred to as the solenoid-on region). If the answer to step 10 is negative (No), that is, if the gear position is the 4th gear and the vehicle speed U is smaller than the predetermined vehicle speed U3G, then step 13 determines the discrimination value e1 (e.g. 88%), C2 (e.g. 9
4%), e+ (e.g. 97.5%), C4 (e.g. 99
%) respectively.

If the answer to step 9 is negative (No), that is, if the gear position is not the fourth gear, the process proceeds to step 11, where it is determined whether the gear position is the third gear. If the answer to step 11 is affirmative (Yes), that is, if the third speed
%), C2 (e.g. 94%), e+ (e.g. 97.5%)
) and C4 (for example, 99%).

If the answer to step 11 is negative (No), and the gear position is neither 4th speed nor 3rd speed, the process moves to step 15, and the determination values e1 (for example, 88%), C
2 (e.g. 94%), C3 (e.g. 97.5%), e,
q (for example, 99%).

After setting the respective discrimination values e1 to e4 in steps 12 to 15, the process proceeds to step 17, where the duty ratio control of the solenoid valve 240 (solenoid valve DUTY C) shown in FIG.
0NTR0L) routine.

In steps 1.2.3 and 7 in FIG. 7, it is determined in which region of the speed ratio range the current speed ratio e falls. First, considering that the speed ratio e changes from the bottom to the top, if the speed ratio e is in the weak engagement force region, it is difficult to determine whether the speed ratio e is larger than the discrimination value e1 in step 7. The answer is negative (No), and in step 8 it is determined whether the timer period T1 has elapsed (T=O).

FIG. 9 shows the duty ratio control state when the speed ratio e passes from the weak engagement force region to the upper reference value approximation region and enters the upper reference value region. As the speed ratio e approaches the reference value region, the rate of increase in the transmission capacity of the direct coupling clutch Cd is controlled to be reduced, that is, the rate of change in the transmission capacity is controlled to be small.

When the speed ratio e is in the weak engagement force region, T1 (for example, 0
．． Every time a period of 2 seconds) elapses, the third solenoid valve 24 is
By controlling the duty ratio of the zero valve opening time, the engagement force of the direct coupling clutch Cd is gradually strengthened. In FIG. 7, if the answer to step 8 is affirmative (Yes), that is, when the timer period (T1) has elapsed (tl in FIG.
.

T2. and time t3) Each time, in step 9, the timer is set to the value T1, and in step 10, the variable value is set to a value (D-x+) smaller than the previous value by xl, and this is stored. The duty ratio control of the opening time of the third electromagnetic valve 240 (steps 8 to 13) is repeated again over the T1 period at the duty ratio at the stage indicated by the value. Note that step 11 is a limit check, and if the variable value becomes smaller than 0, problems will occur in program control, so the variable value should be the minimum D11iI11 (for example, 0).
If the answer is negative (No), that is, if the variable value is smaller than 0, step 12
The value of the variable value is set to the minimum value D41im, and the process moves to step 13. If the answer to step 11 is affirmative (Yes), that is, if the variable value is greater than 0, the process skips step 12 and proceeds to step 13.

In step 13, the value of the variable set in step 10 is stored as a variable D32 for later use in control when the speed ratio e enters the reference value range. After that, proceed to step 14 and set the solenoid valve duty as shown in FIG.
Executes the control cent routine.

Here, the duty ratio refers to the ratio of the energization time to the solenoid 24'2, ie, the valve opening time, to the predetermined period of the third electromagnetic valve 240. The third electromagnetic valve 240 sets how long the solenoid 242 of the electromagnetic valve 240 in the Middle East 3 is energized for a predetermined period and how frequently the cycle repeats. In this case, when the predetermined period is set to 20 stages, that is, when DFQ=20, one stage is set as the minimum valve opening period of the valve opening time. For example, if the minimum valve opening period is 5ms, 5m5X 20 = 1
Set 00 ms as the predetermined period, and set (5ms/
100 ms) x100=5% valve opening ratio, Dl
is displayed. D2 is (5m5X 2 /, 100m5
) Display xioo =to%.

Set the following in order.

Do-10ms 0% Dl-5m5 5% D2-=10m5 10% I) 1o-" 50m5 50% D2o-Looms 100% Above and above, the duty ratio is set in 21 steps by adding Do.

In FIG. 8, it is determined in step 1 whether the ignition switch is turned on or not, and the answer is affirmative (Ye).
In the case of s), proceed to step 6 and open the third solenoid valve 240.
It is determined whether or not the energization time to the solenoid 242, that is, the valve opening time (hereinafter referred to as duty-on time) has elapsed. If the answer is affirmative (Yes), proceed to step 9 to determine whether the de-energization time of the solenoid 242 of the third solenoid valve 240, that is, the valve closing time (hereinafter referred to as duty off time) has elapsed. Determine whether That is, since the ignition switch is on, once the duty on time has elapsed, the duty off time begins to be measured. Since the duty off time has just entered, it is not 0, so the answer is negative (NO) and the process proceeds to step 10.

In this case, the duty off time is set as Da×the minimum unit period, so for example, DFQ=20 is set, and DI+=! In the case of 0, the difference between "10" and "1" is "
9'' and D+=5ms, the off time continues for the remaining 9 x 5m5=45ms. In this case, the duty output remains off, that is, the third solenoid valve 240
The solenoid 242 remains deenergized. below,
Repeat step 11 until you get from "9" to "O".
Proceed to step 12, turn off the solenoid valve 240, and proceed to step 12.
It is determined whether or not the duty off time has elapsed, and if the answer is affirmative (Yes), the process proceeds to step 7 step 13 together with the case where the answer to step 9 is affirmative (Yes),
STb i t is set to O, that is, the ignition switch is turned off, and the answer to step 12 is negative (NO).
), the null control set of the solenoid valve 240 is re-executed.

In step 1, since 5Tbit is not 1, that is, the result is negative (NO), and the process proceeds to step 2, where it is determined whether duty control is to be performed or not, and the result is affirmative (Yes).
), the process proceeds to step 3, where STb i t is set to 1, that is, the ignition switch is turned on, and the process proceeds to step 4. In step 4, a duty on time value (DON Time) is set.

example! If we set t'DFo=20 and D+=5ms when D=10, then [)to=5m5X 10
= 50ms valve opening time. Further, the process proceeds to step 5, where a duty off time value (DOFF Time) is set.

For example, in the above example, DOFF Ti,me is (2
〇-10) X 5m5 = 50ms. After setting the duty off time value, the process proceeds to the steering knob 6 to determine whether or not the duty on time has elapsed. Since the duty control has just started, the answer is negative (No), and the process proceeds to step knob 7, repeats the same operation as step 10, and proceeds to 0. During this time, the third solenoid valve 240 The energization of the solenoid 242 continues, that is, the third electromagnetic valve 240 continues to open. Thereafter, the process proceeds to step 8, where the solenoid valve 240 is turned on, and the solenoid valve duty control set is executed again.

After that, the process returns to step 2 in FIG. 5 and is executed again. Note that the electronic control device 33 repeatedly opens the third solenoid valve 240 at the same duty ratio, that is, at a constant cycle, until the duty ratio of the third solenoid valve 240 is set to a new value.

In this way, when the speed ratio e is in the weak engagement force region, the engagement force of the direct coupling clutch Cd is gradually strengthened toward x1 every period T1.

Next, when the speed ratio e enters the reference value approximation region (times t and 11 in FIG. 9), the answer to step 7 becomes affirmative (Yes), and it is determined in step 15 whether or not the timer period has elapsed. The timer period here is the value T1 set when the speed ratio e is in the weak engagement force region immediately before entering the reference value approximation region, that is, at time t3 in FIG. 9. If the answer to step 15 is negative (No), that is, while the timer period T1 has not elapsed, steps 13 and 14 are executed without executing steps 16 to 19, and the duty ratio set in the weak engagement force region is continued. The third solenoid valve 240 is controlled to open. If the answer to step 15 is affirmative (Yes), that is, when the timer period T1 has elapsed (time t5 in FIG. 9), step 16 sets the timer to a predetermined value larger than the T1 value set in the weak engagement force region. Set T2 (for example, 1 second), and in step 17 set the variable value to X2 from the previous value.
(for example, 1), store this value (D-X2), and change the duty ratio of the opening time of the third solenoid valve 240 over T2 light again at the duty ratio of the stage indicated by the D value. Perform ratio control. Then, timer period T2 again
has passed and the speed ratio e value is still in the reference value approximation region (at time t6 in FIG. 9), step 15 is performed in the same manner as described above.
Repeat steps 19 and 13. Note that step 18 is a limit check similar to step 11, in which it is determined whether the variable value is greater than the minimum value D21im (for example, 0), and if the answer is negative (No), that is, the variable value is When is smaller than 0, the value of the variable is set to the minimum D21im in step 19, and the process moves to step 13.

If the answer to step 18 is affirmative (Yes), that is,
If the variable value is greater than O, the process moves to step 13 without executing step 19.

If the speed ratio e enters the reference value region at time t7 in FIG. 9, the answer to the determination in step 3 as to whether or not the speed ratio e is greater than the discrimination value e2 will be affirmative (Yes), which will be described later in step 20. The flag F1 is set to 0, and the process proceeds to step 21, where it is determined whether or not a flag F3, which will also be described later, is set to 1.

When the speed ratio e enters the reference value region from a smaller value, flags F2 and F3 are both set to 0 (
Steps 5 and 6), the answer to step 21 is negative (N
O), and the answer to the determination as to whether flag F2 is set to 1 in the next step 24 is also negative (No), in which case the process moves to step 26 and it is determined whether or not the timer period has elapsed. The timer period here is the value T2 set when the speed ratio e is in the reference value approximation region, that is, at time tc in FIG. The answer to step 26 is negative (N
o), that is, step 27 until the timer period T2 has elapsed.
Steps 41 to 4 described below without performing steps 41 and 28
Step 6 is followed by step 14, and the third solenoid valve 240 is subsequently controlled to open at the duty ratio set in the reference value approximation region.

If the answer to step 25 is affirmative (Yes), that is,
When the timer period T2 has elapsed (at L8 in FIG. 9),
Once again, in step 27, a unique value when the speed ratio e is in the reference value region, that is, the value T3 (for example, 2 seconds) is entered in the timer, and in step 28, it is stored as the variable value D32 in step 13 in the previous loop. The value set when the speed ratio e is in the reference value approximation region immediately before entering the reference value region (time t6 in FIG. 9) is set as is. In this way, if the speed ratio e falls within the reference value region,
The third solenoid valve is operated until the timer period T3 elapses (at time tS in Figure 9) using the value set just before entering the reference value area (time t6 in Figure 9) without rewriting the value of the variable. The valve opening time of 240 is duty-controlled. Even after time tS, as long as the speed ratio e is within the reference value range, the transmission capacity of the direct coupling clutch Cd is controlled not to be changed.

FIG. 10 shows a duty ratio control state using a method different from that in FIG. 9 in duty ratio control when the speed ratio e goes from a weak engagement force region to a reference value approximation region and then enters a reference value region as in FIG. 9. . That is, in the case of FIG. 9, xl and x
By keeping the same value for 2 and different values for T+, T2, and T3, the rate of change over time of the speed ratio e becomes smaller as the speed ratio e approaches the reference value region. In the case of , by setting the values of T, , T2, and T3 to be the same, and making the values of x1 and 6x2 different, the time rate of change of the speed ratio e was decreased as the speed ratio e approached the reference value region. It is something.

Figure 11 shows the duty ratio control state when the speed ratio e exceeds the reference value region, enters the fine adjustment region above the reference value region, and returns to the reference value region again without exceeding the fine adjustment region. shows. In this case, if the speed ratio e enters the reference value range from below, the values of all flags Fl, F2, and F3 are O. Therefore, the speed ratio e increases from the time tlo in (a) of FIG.
When the speed ratio e exceeds the reference value region and enters the fine adjustment region directly above it at one point in time, the speed ratio e at step 2 in FIG. 7 becomes the discriminant value e3.
The answer to the determination as to whether it is greater than or not is affirmative (Yes), and the process proceeds to step 29, where the flag F1 is set to 1, and then the process proceeds to step 30. In step 30, the flag F
2 is 0 or not, but since this flag F2 is still set to 0, the answer to the determination is affirmative (Yes), and the process moves to step 31 where the flag F2 is set to 0.
Set 1 to 2.

Next, in step 32, the variable D32 is set as the variable value D33.
Store the value of . This D32 value is the D value used when the speed ratio e is within the reference value region, that is, the D value used in step 28.
This is the same as the D value set in . In addition, FIG. 11 shows a change in the diameter values of D32 and D33 over time together with a change in the speed ratio e. In this case, the diameter values of the variables etc. are shown only as increases and decreases based on the value set when the speed ratio e value is in the reference value region. Then step 3
Set the predetermined value T4 (for example, 0.4 seconds) on the timer in step 3, set the variable value to be used for this control using the steering knob 34, and set the value obtained by adding X6 (for example, 6) to D33 used for the previous control. After setting, steps 41 to 46 described below
and 14, the process returns to step 2 in FIG. 5 and re-executes.

What should be noted here is that when the speed ratio e is in the reference value region immediately before entering the fine adjustment region, that is, (a
), the timer period T3 set at time tlO is t'1
There is no time-up until time 1, but at t1 when the speed ratio e reaches the discriminant value '33, that is, the lower limit value of the fine adjustment region.
At one point in time, the timer is immediately reset to the value T4 (step 33), and control is repeated using the value of D set in step 34 until the T4 period has elapsed. When step 30 is reached through such repetition, step 31 is executed in the previous loop.
Since flag F2 is set to 1, Step 3
If the answer is 0, the process moves to step 35, and since the timer period T4 has not yet expired, the answer to the determination as to whether or not the timer period has elapsed in step 35 becomes negative (No). At step 36, the variable value D32
XI to the 033 value set in step 32 above as
(For example, 1) is added and the value is stored. Since the value D32 was set as the variable value D33 in step 32 in the previous loop, if the value set when the speed ratio e is in the reference value region is set as DO, the value newly stored as the D32 value is this value.

It is equal to the value obtained by adding x3 to

Before the speed ratio e passes the timer period T4, that is,
If it returns to the reference value area again at time t12, the answer in step 3 becomes affirmative (Yes), and step 20
The next step 21 is to set the flag F1 to O.
In this case, since the flag F3 remains set to 0, the process passes through the process and moves to step 24. Since the flag F2 was set to 1 in step 31, the answer to step 24 is affirmative (Yes), and the process moves to step 25, where the flag F2 is set to 1.
Set 2 to O, skip step 26 and go to step 27
Then, the predetermined value T3 is set in the timer. That is, skipping step 26 and proceeding to step 27 means that the timer is reset as soon as the speed ratio e returns to the reference value range.

Next, in step 28, the value D32 stored in step 36 in the previous loop is set as a variable value, and the duty ratio of the opening time of the third solenoid valve 240 is controlled at the duty ratio of the stage indicated by the value of D32.

Then, even at time t13 when the speed ratio e has passed the timer period T3, as long as it is within the reference value range, the T3 value is set in the timer again (step 27) and the D value does not change and remains the same from time t14 onwards. Value D32 (Step 2
8) controls the duty ratio.

In the case of (a) in Fig. 11, the speed ratio e exceeds the reference value region and enters the fine adjustment region for a short period of time (period shorter than the timer period T4).
This is the case when only one person enters. In other words, since the speed ratio e has entered the fine adjustment region, as a result of correction with a large value x6 at time 1++, the timer period T4 does not elapse at t+2.
The fact that it immediately returned to the reference value region at time point means that the x6 value is too large, and therefore, the return to the reference value region at t
At time i2, in the reference value region immediately before exceeding the reference value region, that is, by controlling the duty ratio using the value obtained by adding a small correction value x3 to the variable value set at time 1+a, the speed ratio e is set as the reference value. It is stored in the value area.

In the case of (bl in Fig. 11), the speed ratio e increased from the time t+5 and exceeded the reference value region and entered the fine adjustment region, so correction was applied with a large value x6 at the time t16. , it does not immediately return to the reference value area but stays in the fine adjustment area for a long time.
This is a case where the timer remains (for a time longer than the timer period T4). In this case, immediately before exceeding the reference value area and entering the fine adjustment area, the time period during which the speed ratio e value remains in the fine adjustment area is determined by adding the xc value to the D value set at time t15. The speed ratio e is maintained in the reference value region by controlling the duty ratio using a value added according to the speed ratio.

Therefore, in the case of (b) in FIG. 11, steps 29 to 34 are executed at time t16, similarly to the case at time t11 in (a) of FIG.
-7 until reaching time point 29.30°3.
5 and 36 are executed, respectively. When the time tn is reached, the timer period T1 times up for the first time, so the answer to step 35 becomes affirmative (Yes), and the process moves to step 37, where the flag F3 is set to 1, and then,
In step 38, the value used in the previous loop is stored in D13 as a variable value. Then, in step 39, the timer is set to the T4 value again, and in step 40, the D value is set to the value X3.
Set the value by adding (for example, 1). Steps 29, 30, 35 and 36 are executed again until the timer period T4 is further time-amplified at day t1, and in step 36, the value obtained by adding the value x3 to the D33 value is stored as the D32 value. . If the speed ratio e is still in the fine adjustment region at time t +e, step 37.
38 respectively. The execution of steps 37 and 38 means that the D33 value is updated to a value obtained by adding the value x3, and in step 40, the D value is further updated by the value x3.
is added, the duty value increases again, and duty ratio control is repeated with this value. Then, when the speed ratio e returns to the reference value region at time t19, steps 20 and 2
Execute 1. The answer to step 21 is the answer to step 3.
Since flag F3 was set to 1 at 7, it is affirmative (Yes).
Then, in step 22, the flag F3 is set to 0, and in step 23, the flag F2 is set to 0, and the process skips step 24 and proceeds to step 26, where it is determined whether or not the timer period T4 has timed out. Skipping step 24, ie, not determining flag F2, means that the speed ratio e is changing slowly. If the speed ratio efJ is changing slowly, use the duty value set in the previous loop as is. That is, it waits until the timer period T4 has elapsed, that is, until it reaches the L°19 point, and then performs duty control using the duty value set in the previous loop as is. And t゛191
When the 9th point has passed, the answer to step 26 becomes affirmative (Yes), and in step 27 the timer is set to the T3 value, and in step 28 the value [ ) 32 is set to the variable value. This D3
The binary value is the value set immediately before the fine adjustment area set in step 36 is extracted.

In this way, when the speed ratio e returns to the reference value region, duty ratio control is continued based on the variable value, and as long as the speed ratio e remains within the reference value region, the value is maintained after time t20 and the duty ratio is maintained. Control the ratio.

FIG. 12 shows the control state when the speed ratio e crosses the fine adjustment range from the reference value range, enters the solenoid ON range, and then returns to the reference value range again.

Note that FIG. 12 shows a state in which the speed ratio e is in a range larger than the discrimination value e4, that is, in the solenoid ON region.

In Fig. 12, (al) indicates the case where the speed ratio e passes through the fine adjustment region in a short time and enters the region where the solenoid is turned on.
FIG. 12(b) shows the case where the speed ratio e takes a long time to pass through the fine adjustment region and enters the region where the solenoid is turned on. In both cases (a) and (b) of Fig. 12, the speed ratio e approaches the upper limit value 1.0 (en), so there is a risk of car body vibration, but the duty ratio is the highest, D20.
(The solenoid 242 of the third solenoid valve 240 is turned on and the solenoid valve 240 is opened), but the duty value when the speed ratio e returns from the solenoid on region to the fine adjustment region is In FIG. 12, (a) is set to a larger value than (b).

That is, when the speed ratio e increases from the time t29 in (al in FIG. 12 and enters the fine adjustment region at the time t30), the answer to step 2 in FIG. Steps 29 to 34 are executed in the same manner as described above.At this time, the D value and D33 value are respectively 1×6 (for example, 4) and ±0 with respect to the previous value.

And in the next loop steps 29, 30, 35 and 36
are respectively executed, and in step 36 the D33 value is set to the value)l
The value obtained by adding (for example, 1) is stored as the D32 value. At this time, the flag F3 remains O. In this state, if the speed ratio e exceeds the fine adjustment region before the timer period T4 elapses (at time t31), the answer to the determination as to whether or not the speed ratio e in step 1 of FIG. 7 is greater than the discriminant value e4 is The result is affirmative (Yes), and the process moves to step 47 where flag F is set.
2 is set to 1, and in step 48 it is determined whether the flag F3 is set to 1. As mentioned above, flag F
3 remains at 0 and the speed ratio e leaves the fine adjustment region and enters the solenoid on region, so the answer to step 48 is negative (NO).
), the process moves to step 50 and the value X5 is added to the D33 value.
(For example, 6) is added and the value is stored as the D value. Next, in step 51, it is determined (limit check) whether the D value is greater than the DFO value (=20). If the answer is affirmative (Yes), the D value is set to the value DFO in step 52 and the process moves to step 53. If the answer is negative (NO), step 52 is skipped and the process moves to step 53. In step 53, the D value (for example, +6) set in step 51 is stored as the D32 value, in step 54 the timer is set to 0, and in step 55, the solenoid 2 of the third solenoid valve 240 is
42 is turned on to maintain the solenoid valve 240 in the open state, while at step 56 the electronic control unit 33 stops the valve opening duty ratio control of the third solenoid valve 240, and the fifth solenoid valve 240 is turned on again.
Return to step 2 in the diagram.

When the speed ratio e enters the fine adjustment region again at time t32 in (a) of FIG. 12, the answer to step 2 of FIG. 7 becomes affirmative (Yes), and the flag F1 is set to 1 in step 29. The answer to step 30 is negative because flag F2 was set to 1 in step 47 of the previous loop.
Proceed to step 35.

The answer to step 35 is affirmative (Yes) because the timer was set to 0 in step 54 of the previous loop, flag F3 is set to 1 in step 37, and the D value ( +x5, ie, +6) is stored as the D33 value. Then, in step 39, the timer is set to the predetermined value T4, and in step 40, the value of D+x+ (i.e. +
6+1=+7) is stored as a new value, and in step 36 of the next loop, the value of D33+X3 (hit+6+1=+
7) is stored as a D32 value.

Thereafter, at time t33, the speed ratio e continues to enter the fine adjustment region, so steps 29, 30°35.3
Execute steps 7 to 40, respectively. D value (+7) in step 38
is stored as a 033 value, and in step 40, the value (+8) of D+X] is stored as a D value. Then, the answer to step 35 becomes negative (No) again, and the process moves to step 36.
The D33+XlO value (+8) is stored as the D32 value.

Next, when the speed ratio e enters the reference value region at the time t°33, it is controlled by the same effect as at the time U9 to t°19 in FIG. 11(b) described above, and reaches the time t34. As long as the speed ratio e is within the reference value range, the duty ratio is controlled without changing the D value.

In the case of (b) in FIG. 12, when the speed ratio e enters the fine adjustment region at time t35, steps 29 to 34 in FIG. Then, in step 32, D32, that is, ±O, and in step 34, D33
The value of +x6 (+4) is stored as the D value, and in step 36 of the next loop, D33+X:11 (+1) is stored as D32.
Store as a value. Since the speed ratio e is still in the fine adjustment region at time t3B after the T4 period has elapsed, step 2
9.30. Execute steps 35 and 37 respectively, and then proceed to step 3.
8, store the D value (+4) as the 033 value, and proceed to step 3.
9.40 respectively, and in step 40, the value of D+X3 (+5) is stored as the D value.

And t3? At this point, when the speed ratio e leaves the fine adjustment region and enters the solenoid ON region, the answer to step 1 in FIG. 7 becomes affirmative (Yes), and steps 47 and 48 are executed, respectively. In this case, the speed ratio e changes from the time t35 to the first T
After 4 periods, the next T! t3 in the middle of period 1? Until this point, the speed ratio e has been in the fine adjustment region, so the speed ratio e changes slowly, and the flag F3 is set to 1. Therefore, the answer to step 48 is affirmative (Y
es), the process moves to step 49, where the value of D33+X4, hit, and +5 are set as the D value, and then step 52
If the answer is affirmative (Yes), step 5
If the answer is negative (NO), step 52 is skipped and step 53 is reached. Step 4 in step 53
The D value, strike, and +5 set in step 9 are stored as [) 32 values, and thereafter steps 53 to 56 are executed respectively to obtain the fifth
Return to step 2 in the figure and try again.

Then, when the speed ratio e enters the fine adjustment region again at time t39, steps 29, 30, 35 and 37 are executed, respectively, and the D value (D33+X71=+5) is changed to D3 in the next step 38.
Store as 3 values. Then, in step 40, the D value is set to D.
33+)l=+6 is stored as the D32 value.

Thereafter, when the speed ratio e enters the reference value region at time t39, when the T4 period has not elapsed, the speed ratio e enters the reference value region (t+2 of al in FIG. 11).
The control is performed in the same manner as at time t13 until time t40 is reached and time tat is reached. From then on, as long as the speed ratio e is within the reference value range, the duty ratio is controlled without changing the value of D.

Note that F1=1 in step 4 in FIG. 7 means that the speed ratio e once enters the fine adjustment region from the reference value region, and the speed ratio e in the next loop passes through the reference value region and changes to the lower coefficient. When entering the weak resultant force region, or when the speed ratio e changes rapidly, flag F1 is set to 1, which means that control should be performed using the D value set in the previous fine adjustment region. .

In addition, steps 41 to 46 are limit checks and D
If the diameter values of 32 and D33 are larger than the DFO value (for example, 20), these diameter values are respectively rewritten to the value DFO.

In addition, although the above embodiment describes the case where a fluid torque converter T is employed as the fluid power transmission device, the present invention is applicable to any automatic transmission for a vehicle that is equipped with other types of fluid couplings, etc. It is.

Further, the predetermined parameter representing the relative slippage amount of the human body and the output member of the fluid power transmission device may be the difference between the respective rotational speeds of the human body and the output member.

(Effects of the Invention) As detailed above, according to the direct coupling mechanism control method for a hydraulic power transmission device of an automatic transmission for a vehicle according to the present invention, a predetermined amount of slippage between the output member and the output member of the hydraulic power transmission device is determined. The measured value of the parameter value is compared with a predetermined reference range value set in advance, and based on the comparison result, the transmission capacity of the direct coupling mechanism for a predetermined period to be implemented from now on is determined, and the predetermined period is divided into multiple stages. The period per stage is set as the minimum valve opening period, and for each minimum valve opening period, the valve opening signal is output only for the period corresponding to the relevant controlling stage, and the period corresponding to the relevant controlling stage. After the elapse of time, a duty control signal for the solenoid valve to be controlled is output by outputting a valve closing signal for a period corresponding to the control stage for each minimum valve closing period corresponding to the minimum valve opening period. As a result, there is no need for an external counter to control the opening and closing periods of the solenoid valve that controls the optimum transmission capacity, and the configuration of the device for carrying out the method of the present invention can be simplified. Even if the transmission capacity is set to a fine value, it is possible to stably and quickly control the transmission capacity within the reference value (target value) range without causing divergence, suppressing the generation of vibration and noise in the vehicle body, and reducing the This has the effect of improving fuel efficiency and power transmission characteristics depending on the driving condition, and providing an extremely smooth and comfortable driving feeling.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a vehicle automatic transmission that applies the direct coupling mechanism control method of the present invention, Fig. 2 is a hydraulic control circuit diagram of a dual-purpose automatic transmission, and Fig. 3 is a schematic diagram of the direct coupling clutch shown in Fig. 2. Fig. 4 is a graph showing the relationship between the working oil pressure of the direct coupling clutch and vehicle speed, Fig. 5 is the main flow chart showing the control procedure for the working oil pressure (transmission capacity) of the direct coupling clutch, and Fig. 6 is FIG. 7 is a sub-flowchart showing the control procedure carried out in step 5 of FIG. 6, FIG. 8 is a sub-flowchart showing the control procedure carried out in step 17 of FIG.
FIG. 9 is a sub-flowchart showing the control procedure carried out in step 14 in the figure, in which the duty ratio correction value is the same and the timer period is different, and the speed ratio changes from the weak engagement force region through the reference value approximation region to the reference value. Graph showing the relationship between speed ratio and duty ratio in control when entering the region, 10th
The figure shows the relationship between speed ratio and duty ratio in control when the speed ratio moves from the weak engagement force region through the reference value approximation region and enters the reference value region, with different duty ratio correction values and the same timer period. The graph shown in FIG. 11 shows that the speed ratio exceeds the reference value region and enters the fine adjustment region above the reference value region, and the speed ratio exceeds the reference value region and enters the fine adjustment region above the reference value region. Figure 12 is a graph showing the relationship between the speed ratio and duty ratio in the Mil+ control when returning to the reference value area without exceeding the jIl adjustment area. 12 is a graph showing the relationship between speed ratio and duty ratio in control when returning to a reference value region after entering a region where the vehicle is in the range of the reference value. T...Torque converter (hydraulic power transmission device), 2
... Pump impeller (input member), 4... Turbine impeller (output member), Cd... Direct connection clutch (direct connection mechanism). Applicant Honda Motor Co., Ltd. Agent Patent Attorney Toshihiko Watanabe'IA3 Figure

Claims (1)

[Claims] 1. The predetermined parameter value representing the relative slip amount of the input and output members of a hydraulic power transmission device having an input member and an output member is within a predetermined reference range set in advance. In the direct coupling mechanism control method of a fluid power transmission device for a vehicle automatic transmission, the transmission capacity of the direct coupling mechanism that mechanically engages the input and output members is variably controlled by duty control of a solenoid valve. Compare the actual measured value of the predetermined parameter value with the predetermined reference range value, and based on the comparison result,
The transmission capacity for the predetermined period to be implemented from now on is determined, the predetermined period is divided into multiple stages, each stage is defined as the minimum valve opening period, and for each minimum valve opening period,
A valve opening signal is output only for a period corresponding to the control step, and after the period corresponding to the control step has elapsed, the control step is performed for each minimum valve closing period corresponding to the minimum valve opening period. A fluid power transmission for an automatic transmission for a vehicle, characterized in that the duty control signal of the solenoid valve to be controlled is outputted by outputting a valve closing signal for a corresponding period to control the duty of the solenoid valve. Directly coupled mechanism control method for equipment. 2. Direct coupling mechanism control of a hydraulic power transmission device of an automatic transmission for a vehicle according to claim 1, wherein the predetermined parameter is a ratio of the respective rotational speeds of the input member and the output member. Method. 3. Direct coupling mechanism control of a hydraulic power transmission device for an automatic transmission for a vehicle as set forth in claim 1, wherein the predetermined parameter is a difference between the respective rotational speeds of the input member and the output member. Method.