JPH0332939A - Transmission shock reducing device of automatic transmission - Google Patents

Abstract

PURPOSE:To reduce transmission shock by carrying out control of an engaging force of a clutch to the size between an engaged state and a released state prior to a lowering control of an engine output at the time of transmission of the automatic transmission having a torque converter with lock-up clutch. CONSTITUTION:An automatic transmission 20 has a torque converter 24, and the converter is equipped with a turbine runner to which generation torque of an engine is transmitted through a drive plate 32 rotated integrally with a crank shaft 10c and a pump impeller 34. A lock-up clutch 22 is arranged between the drive plate 32 and the turbine runner 36, and a transmission mechanism 26 is connected to the turbine runner 36 through a hollow output shaft 39. At the time of transmission operation of this automatic transmission 20, when transmission shock is reduced by lowering an engine output through control such as changing an ignition timing to the delay side, etc., an engaging force of the lock-up clutch 22 is controlled in advance to the size between an engaged state and a released state.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an automatic transmission that changes the output of an engine during a gear shifting operation of an automatic transmission equipped in a vehicle to reduce the shock accompanying the gear shifting operation. This invention relates to a gear shift shock reduction device.

[Conventional technology]

Automatic transmissions installed in automobiles are generally constructed by combining a torque converter consisting of a pump impeller, a turbine runner, a stator, etc., and a multi-stage gear type transmission mechanism connected to the turbine runner of the torque converter. has been done. Such automatic transmissions are usually equipped with a hydraulic control device whose main component is a hydraulic circuit, and this hydraulic control device controls hydraulically operated friction engagement elements such as clutches and brakes in the transmission mechanism. The holding state is switched, and the gear shifting operation is thereby performed.

When a gear change operation is performed in an automatic transmission, although the vehicle speed hardly changes due to the inertia of the vehicle, the engine speed changes rapidly in response to changes in the gear ratio in the automatic transmission. A sudden torque fluctuation occurs on the output shaft of the automatic transmission, and this sudden torque fluctuation on the output shaft causes a sudden change in the acceleration of the vehicle body, which is a so-called shift shock. As a measure to reduce such shift shock, for example, it is possible to control the hydraulic pressure supplied to the frictional engagement elements so that the frictional engagement elements in the transmission mechanism are smoothly released and engaged. However, if this is done, the period in which the frictional engagement elements are kept in a sliding state becomes longer, and there is a risk that the frictional engagement elements may seize or become more abraded. occurs.

Therefore, as disclosed in Japanese Patent Publication No. 63-14173, for example, it has been proposed to reduce the engine output and reduce the shift shock when a shift operation is performed in an automatic transmission. ing. In such shift shock reduction control, when one of the control targets that changes the engine output, for example, ignition timing, is selected, the ignition timing is delayed from the reference ignition timing corresponding to the reference control amount. Change to the side, standard system? A correction amount for the II amount (hereinafter referred to as shift correction amount) is set,
The ignition system is operated with a tie corresponding to the effective ignition advance value set using this shift correction amount.

[Problem to be solved by the invention]

However, when the output of the engine is reduced with the shift operation as described above, the engine speed may drop by the time the shift operation is completed and the engine output is restored to its original level. Therefore, there is a problem that the acceleration of the vehicle body may take a breather or the vehicle speed may not change smoothly.

[Means for Solving the Problems] In order to solve the above problems, the automatic transmission shift shock reduction device of the present invention includes a torque converter in which a pump impeller is connected to an output shaft of an engine, and a turbine of the torque converter. a transmission mechanism connected to a turbine output shaft connected to the runner; a lock-up clutch that engages and releases the pump impeller of the torque converter and the turbine runner; an output control means that reduces engine output during gear shifting; and a slip control means for controlling the engagement force of the lock-up clutch to be between an engaged state and a released state, prior to the reduction of engine output by the output control means. There is.

[For production]

According to the above configuration, even if the engine output is reduced due to the gear shifting operation, the rotational force from the gear shifting mechanism is transmitted to the output shaft of the engine via the lock-up clutch under the control of the slip control means. . Therefore, it is possible to prevent the engine speed from dropping. Moreover, since the engagement force of the lock-up clutch is controlled to be between the engaged state and the released state, an excessive shift shock will not occur.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

The shift shock reduction device for an automatic transmission according to this embodiment is as follows:
As shown in Figure 2, it is mounted on a front engine/front drive vehicle.

As shown in the figure, the engine 10 has four cylinders 9, and each cylinder 9 includes a throttle valve 11 and a fuel injection valve 13 that injects fuel supplied from a fuel injection pump 12. The air-fuel mixture is supplied through the intake passage 14 in which the air-fuel mixture is provided. The air-fuel mixture supplied into the cylinders 9 is controlled in a predetermined order within each cylinder 9 by the operation of the ignition system, which is composed of spark plugs 15, distributor 16, ignition coil section 17, ignition control section 18, etc. , and the resulting exhaust gas is discharged into the exhaust passage 19.

The combustion of the air-fuel mixture causes the crankshaft 10c, which is the output shaft of the engine 10, to rotate, and the torque of the engine 10 obtained from the crankshaft 10c is transmitted to the automatic transmission 2o, the differential gear unit 111, the axle 112, etc. The power is transmitted to the front wheels 113 via a power transmission path consisting of.

The automatic transmission 20 includes speed change control solenoid valves 1 to 4;
A hydraulic circuit section 30 is provided, which includes a lock-up control solenoid valve 6 and a pressure regulating solenoid valve 7, and supplies hydraulic pressure used to control a torque converter 24 and a transmission mechanism 26, which will be described later.

Further, as shown in FIG. 3, the automatic transmission 20 includes a torque converter 24, a multi-gear type transmission mechanism 26, and an oil pump 45 connected to the crankshaft 10c via a pump drive shaft 116. It is provided.

The torque converter 24 rotates integrally with the crankshaft 10c via the output section 10a of the engine 10, as shown in detail in FIG. Drive plate 32 to be driven and drive plate 32
The pump impeller 34 is connected to and is rotationally driven integrally with the pump impeller 34, and the torque generated by the engine 10 is connected to the pump impeller 34.
4, a stator 35 disposed between the pump impeller 34 and the turbine runner 36, and a case 121 disposed between the stator 35 and the fixed part of the torque converter 24. , and a one-way clutch 38 that can rotate the stator 35 in the same direction as the pump impeller 34 and the turbine runner 36. The turbine runner 36 is connected to the transmission mechanism 26 via a hollow turbine output shaft 39, and is also connected to the output section 10a of the engine 10 via the lockup mechanism 21.

The lock-up mechanism 21 is disposed between the drive plate 32 and the turbine runner 36 in the torque converter 24, and is connected to the torsion damper 23 spline-fitted to the turbine output shaft 39 and the torsion damper 23 via a coil spring 23a. The lock-up clutch 22 has been warned. The lock-up mechanism 21 is
The entire structure is movable in the axial direction relative to the turbine runner 36, and rotates integrally with the turbine runner 36.

The lock-up clutch 22 is interposed between the drive plate 32 and the turbine runner 36 in the torque converter 24, so that a back pressure chamber 43 and an internal pressure chamber 44 are provided.
The back pressure chamber 43 is supplied with hydraulic pressure from the hydraulic circuit section 3o through the oil passage 42 to press the lock-up clutch 22 in the direction of disengaging from the drive plate 32. Hydraulic pressure for pressing the lock-up clutch 22 in the direction toward the drive plate 32 is supplied from the hydraulic circuit section 3o through the oil passage 41.

When the oil pressure value in the internal pressure chamber 44 is higher than the oil pressure value in the back pressure chamber 43 by a predetermined value or more, the lock-up mechanism 21 is pushed to the right in FIG. When the pump impeller 34 and the turbine runner 36 are engaged, and the pump impeller 34 and the turbine runner 36 are engaged, the hydraulic pressure in the internal pressure chamber 44 is lower than the hydraulic pressure in the back pressure chamber 43 by a predetermined value or more. , in FIG. 4, it is pushed to the left to release the frictional engagement state with the drive plates 1 and 32, and assumes a released state in which the pump impeller 34 and the turbine runner 36 are disengaged. There is.

Furthermore, the lock-up mechanism 21 has a drive that allows relative rotation between the pump impeller 34 and the turbine runner 36 when the differential pressure between the oil pressure in the internal pressure chamber 44 and the oil pressure in the back pressure chamber 43 is within a predetermined range. It assumes a state of slip engagement with the plate 32, and the larger the differential pressure, the stronger the frictional engagement force with the drive plate 32. The internal pressure chamber 44 also has a check valve 46.
It is connected to an oil cooler 48 through an oil passage 47 in which a is arranged.

A lock-up shift valve 5.11 is included in a portion of the hydraulic circuit section 30 that is involved in controlling the operation of the torque converter 24.
A zero pull-up pressure regulating valve 52, a lock-up control solenoid valve 6, and a pressure regulating solenoid valve 7 are provided.

The lock-up shift valve 51 has land portions 56a and 56.
a first spool 56 provided with a spool b, and a land portion 57 whose pressure receiving area is equal to that of the land portions 56a and 56b.
a, 57b, and a second spool 57 provided with a land portion 57c having a larger pressure-receiving area than these, and a spring 58 that urges the first spool 56 to the right in FIG. Ports opened and closed by the first spool 56 and the second spool 57) a, b, c, de, f
, g and h, and three drain boats.

Further, the lock-up pressure regulating valve 52 has land portions 60a, 6
0b and 60c, a spring 62 that biases the spool 60 to the right in FIG.
, m and n, and two drain boats.

In the lock-up shift valve 51, the boats a and boats 1-d each have a pressure regulating solenoid valve 7.
The oil pump 45 is connected to the constant pressure control section 75 through an oil passage 63 and an oil passage 65 in which a valve 63 and an oil passage 65 are arranged.
It is connected to the. Further, boat b is connected to boats j and k in lock-up pressure regulating valve 52 via oil passage 64, boat c is connected to back pressure chamber 43 via oil passage 42, and boats e and f are connected to oil road 66 and oil road 6
7 is connected to an oil cooler 48, and port +-g is connected to a regulator valve 49 via an oil path 68.

On the other hand, in the lock-up pressure regulating valve 52, the boat i is connected via an oil path 71 to a throttle pressure forming section 61 that forms a throttle pressure that takes a lower value as the opening degree of the throttle valve 11 is smaller. m are connected to the regulator valve 49 via oil passages 72 and 73, respectively,
A boat n is connected via an oil passage 74 to the downstream side of the oil passage 63 from a portion where the pressure regulating solenoid valve 7 is disposed. The throttle pressure forming section 61 is connected to the regulator valve 49, and the regulator valve 49 and the constant pressure forming section 75 are connected to the oil pump 45. Further, each oil passage 63, 65, 66, 69, 71 and 74 is provided with an orifice at a predetermined position.

The transmission mechanism 26 of the automatic transmission 20 includes a planetary gear unit 124 for obtaining four forward speeds and one reverse speed. The planetary gear unit 124 includes a small diameter sun gear 125, a large diameter sun gear 126, a long pinion gear 127, a short pinion gear 12B, and a ring gear 129. A forward clutch 131 for forward running and a coasting clutch 133 are arranged in parallel between the small diameter sun gear 125 and the turbine output shaft 39.
A one-way clutch 132 is interposed between the two. A reverse clutch 135 for backward running is provided between the large diameter sun gear 126 and the turbine output shaft 39, and a 2-4 brake 136 is also provided. A 3-4 clutch 138 is provided therebetween. The long pinion gear 127 is connected to a transmission case 142 via a carrier 139 and a one-way clutch 141, and the carrier 139 and the transmission case 142 are engaged and disengaged by a low reverse brake 144.

The ring gear 129 is connected to the output gear 147 via an output shaft 145, and the torque obtained from the output shaft 145 is transmitted to the differential gear unit 111 via an idler or the like (not shown).

In the multi-stage gear type transmission mechanism 26 having the above configuration, a forward clutch 131, a coasting clutch 133, a reverse clutch 135, 2-4 brake 1
36.3-4 By selectively operating the clutch 138 and the low reverse brake 144, respectively, the P range (parking range), R range (reverse range), N range (N range), F range (
It is possible to obtain each of the D range (drive range), 2 range, and I range constituting the forward range, and each gear stage of 1st to 4th speed in the F range.

Each clutch 1 for obtaining each of these ranges and gears
31, 133.138 and 135, and brake 1
Table 1 shows the operational relationship of clutches 36 and 144 and the operational states of one-way clutches 132 and 141 when each range and gear position are obtained.

[Space below] Table 1 (○ indicates a engaged state, Δ indicates that it is operating but is not involved in power transmission.) With the operating relationship shown in Table 1, each clutch 131・133
- The hydraulic pressure for operating the brakes 138, 135 and the brakes 136, 144 is supplied from the hydraulic circuit section 30.

The vehicle also includes an output control means that controls the operation of the engine 10 and the automatic transmission 20 having the above-described configuration, and that reduces the torque generated by the engine 10 to reduce the output when changing gears, and the engine 10 when changing gears. A control unit 100 is provided which acts as a slip control means to control the engagement force of the lock-up clutch 22 to be between the engagement state and the release state before the output of the lock-up clutch 22 is reduced.

The control unit 100 includes detection signals Sn and Sc that indicate the engine speed and crank angle obtained from a rotation speed sensor 81 and a crank angle sensor 82 provided in the distributor 16, and a water temperature sensor 83 provided in the engine block 10b. and detection signals Sw and Sk that detect the cooling water temperature Tw and knocking intensity of the engine 10 obtained from the knocking sensor 84,
Detection signal St obtained from a throttle opening sensor 85 as a throttle opening detection means arranged in relation to the throttle valve 11, throttle valve 11 in the intake passage 14
A detection signal sb obtained from an intake negative pressure sensor 86 disposed further downstream, a detection signal Sm obtained from a turbine rotation speed sensor 87 as a rotation speed detection means of the turbine runner 36, and a detection signal obtained from a vehicle speed sensor 88. Sv,
Shift position sensor 89 as gear shift operation detection means
Detection signal Ss corresponding to the range position of the shift lever obtained from the automatic transmission 2o, and detection signal Su obtained from the oil temperature sensor 9o that detects the temperature of the hydraulic oil supplied to the automatic transmission 2o.
is supplied, and the engine 10 and automatic transmission 8
Other detection signals Sx required for control of 20 are also supplied.

Based on these various detection signals, the control unit 100 sets an effective ignition advance value θ that determines the ignition timing, forms an ignition timing control signal Cq with a timing corresponding to the effective ignition advance value θ, and controls the ignition timing control signal Cq. is supplied to the ignition control section 18. As a result, a secondary side high voltage pulse is obtained from the ignition coil section 17 at a time corresponding to the ignition timing control signal Cq, and this pulse is transmitted to the ignition plug 1 via the distributor 16.
5... is supplied.

The control unit 100 also determines an appropriate fuel injection amount based on the various detection signals and the like, and supplies an injection amount control signal Ci to the fuel injection pump 12.

The control unit 100 further generates drive pulse signals Ca, Cb-CC- based on the various detection signals described above.
CD, and select these as the shift control solenoid valves 1 to 4 that regulate the hydraulic pressure supplied to the various clutches 131, 133, 138, and 135 built into the shift mechanism 26, and the brakes 136 and 144. By supplying the signals to the automatic transmission 20, the automatic transmission 20 is controlled to change gears, and the drive pulse signals Ce-Cf are also transmitted to the control mechanism 2 built in the hydraulic circuit section 30.
Lockup control in the automatic transmission 20 is performed by supplying the lockup control solenoid valve 6 that switches between supplying and discharging hydraulic pressure to the automatic transmission 20 and the pressure regulating solenoid valve 7 that controls the engagement force.

Through such control, various clutches 131 and 133
・138, 135, and brakes 136, 144,
As shown in Table 1, the Ronocqua knob clutch 22 is selectively engaged or disengaged, and the desired shift range and gear position are obtained, and the Ronocqua knob clutch 22 is selectively engaged or disengaged.
Alternatively, it is placed in a released state, or in a slip state where the fastening force is between the fastened state and the released state.

When the control unit 100 performs shift control of the automatic transmission 20 and operation control of the lock-up clutch 22, a map shown in FIG. 5 stored in the built-in memory of the control unit 100 is used. This map shows the opening degree T of the throttle valve 11 on the vertical axis.
The shift pattern is represented by h and the vehicle speed V on the horizontal axis.

Then, the control unit 100 controls the shift lines Ua, Ub, tJc, Dd in the above shift pattern.
, De, and DI are compared with the opening degree of the throttle valve 11 at which the detection signal St occurs and the vehicle speed at which the detection signal SV occurs, and it is determined whether the shift amplifier condition or the shift down condition is satisfied.

Then, the control unit 100 selectively sends drive signals Ca, Cb, Cc, and Cd in order to switch the gear position in the transmission mechanism 26 when it is detected that the shift-up condition or the shift-down condition is satisfied. The automatic transmission 20 is also configured to perform gear change control.

Further, the lock-up operation lines Lg and Ll and the lock-up release lines Lh and Lj are compared with the opening degree of the throttle valve 11 at which the detection signal St occurs and the vehicle speed at which the detection signal Sv occurs, and the lock-up operation condition or lock-up operation condition is determined. It is determined whether the cancellation condition is satisfied.

Furthermore, the slip control execution line Rj, the slip control release line Rk, and the throttle valve 11 to which the detection signal St is applied
The opening degree of the slip nottle valve 11 and the vehicle speed are compared with the vehicle speed to determine whether the slip control conditions for the lock-up clutch 22 are satisfied. . In addition, the slip control conditions are
In addition to being determined based on the above-mentioned MA knob, it is also determined that the condition holds true when changing gears, which will be described later.

Note that the shift lines Ua, Ub, and U shown in FIG.
c is respectively from 1st gear to 2nd gear, from 2nd gear to 3rd gear, and 3rd gear.
This relates to upshifting from 1st to 4th gear, and the shift lines Dd, De, and Dr are, respectively, from 2nd to 1st gear.
This relates to downshifting from 3rd gear to 2nd gear and from 4th gear to 3rd gear. In addition, the lock-up operating line Lg and Li
are related to the lockup operation in the third and fourth speeds, respectively, and the lockup release lines Lh and Lj are related to the release of the lockup in the third and fourth speeds, respectively. Furthermore, the slip control execution line Rj is
The slip control release line Rk is used to determine whether to start slip control on the lock-up clutch 22, and the slip control release line Rk is used to determine whether to release the slip control on the lock-up clutch 22 after it has been started.

In the above configuration, first, the control unit 10
The operation of the hydraulic circuit section 30 under the control of 0 will be explained.

The control unit 100 stops supplying the drive signal Ce to the lock-up control solenoid valve 6 when it is detected that neither the lock-up operating condition nor the slip control condition described below is satisfied.
The supply of the drive signal Cf to the pressure regulating solenoid valve 7 is stopped. As a result, the lock amplifier control solenoid valve 6 is closed, and the oil pressure from the oil pump 45 is supplied to the boat h in the lock up shift valve 51 through the oil passage 69 without being reduced. At the same time, the pressure regulating solenoid valve 7 is closed, and the oil pump 45 is connected to the boat a in the lock-up shift valve 51 through the oil passage 63 and to the boat n in the lock-up pressure regulating valve 52 through the oil passage 74. The hydraulic pressure is supplied at a constant pressure via the constant pressure forming part 75.

As a result, the land portion 57c of the lock-up shift valve 51 is removed from the other land portions 56a, 56b, 57a and 57.
Since the pressure-receiving area is larger than that shown in FIG. In addition, since the oil pressure supplied to the boat n in the lock-up pressure regulating valve 52 is higher than the oil pressure supplied to the boat i in the lock-up pressure regulating valve 52 from the throttle pressure forming part 61, the spool 6
0 is moved in a direction against the biasing force of spring 62 and assumes a first position as shown by the solid line in FIG.

As a result, the boat b in the lockup shift valve 51 and the port C communicate with each other, and the port in the lockup pressure regulating valve 52 communicates with the boat l, so that the hydraulic pressure regulated by the regulator valve 49 is directly transferred to the oil passage 72.
, is supplied to the back pressure chamber 43 through the oil passage 64 and the oil passage 42, and the boat e and boat f in the lock-up shift valve 51 communicate with each other. The oil is discharged to the oil cooler 48. Therefore, in this case, the lock-up clutch 22
is separated from the drive plate 32 and placed in a released state, and the torque converter 24 assumes a converter state in which power is transmitted via fluid.

Further, when it is detected that the lock-up operating condition is satisfied, the control unit 100 supplies the drive signal Ce to the lock-up control solenoid valve 6, and also supplies the drive signal C to the pressure regulating solenoid valve 7. As a result, the lock-up control solenoid valve 6 is opened, and the hydraulic pressure supplied to port hh in the lock-up shift valve 51 is reduced, and the pressure regulating solenoid valve 7 is closed. As a result, the oil pressure is supplied to the boat a in the lockup shift valve 51 and the boat n in the lockup pressure regulating valve 52 without being reduced.

As a result, the first and second spools 56 and 57 of the lock-up shift valve 51 are moved in a direction according to the biasing force of the spring 58, and assume a second position as shown by the dashed line in FIG. Further, the spool 60 in the lock-up pressure regulating valve 52 is moved in a direction that resists the biasing force of the spring 62, and assumes the first position. As a result, the bow 1□ at the lock amplifier shift valve 51
g and boat e communicate with each other, and the boat and boat e in the lock-up pressure regulating valve 52 communicate with each other, and the hydraulic pressure regulated by the regulator valve 49 is supplied to the internal pressure chamber 44 through the oil passages 68 and 41, and the back pressure is The hydraulic pressure in the chamber 43 is discharged through the oil passage 42 to the oil tank from the drain boat which is opened and closed by the land portion 56b.

Therefore, in this case, the lock-up clutch 22 is pressed against the drive plate 32 and placed in the engaged state, and the torque converter 24 enters the lock-up state in which the pump impeller 34 and the turbine runner 36 are engaged.

On the other hand, the control unit 100 determines the opening degree and vehicle speed of the throttle valve 11 in response to the detection signals St and Sv.
It is detected that the shift pattern is in the region defined by the slip control execution line Rj and the slip control release line Rk in the shift pattern as shown in FIG. is within the range of , and it is detected that the lock-up activation condition is not established, and the steady-state slip control condition is established,
If it is detected that the shift up condition is satisfied based on the opening degree of the throttle valve 11 and the vehicle speed, and the shift slip control condition is satisfied, and based on the detection signals St and Sn. In each case, when the throttle valve 11 is fully closed and the engine 10 is detected to be in a deceleration state where the engine speed is equal to or higher than a predetermined value, and the deceleration slip control condition is satisfied, the torque In order to perform slip control on the lock-up clutch 22 in the converter 24, a drive signal Ce is supplied to the lock-up control solenoid valve 6, and a drive signal Cf having a duty set to a predetermined value of 20% or more is formed. Then, it is supplied to the pressure regulating solenoid valve 7.

At this time, from the oil pump 45, the constant pressure forming part 7
The first spool 56 of the lock-up shift valve 51 is moved to the first position as shown by the solid line in FIG. At the same time, the second spool 57 assumes the second position as shown by the dashed line in FIG. 4, and the spool 6o in the lock amplifier pressure regulating valve 52 The duty of the drive signal Cf supplied to n is moved to the right from the first position as shown by the solid line in FIG. , the effective opening area of port 2 is reduced. As a result, the regulator valve 4 is located in the internal pressure chamber 44.
While the hydraulic pressure regulated by the regulator valve 9 is supplied as is through the oil passage 68, the back pressure chamber 43 is provided with the regulator valve 4.
The hydraulic pressure regulated by 9 is reduced in pressure by the lock amplifier pressure regulating valve 52 according to the duty of the drive pulse signal Cf and is supplied to the lock-up clutch 22.
The rotation speed difference ΔN between the pump impeller 34 and the turbine runner is applied to the drive plate 32 according to the differential pressure ΔP obtained by subtracting the hydraulic pressure supplied to the back pressure chamber 43 from the extraction pressure supplied to the internal pressure chamber 44. 36, a slip engagement state is established.

In this case, the back pressure chamber 43 is
The differential pressure ΔP obtained by subtracting the oil pressure supplied to the lock-up pressure regulating valve 52 is the throttle pressure supplied to the boat i at the lock-up pressure regulating valve 52, Pd, the duty control pressure supplied to the boat n at the lock-up pressure regulating valve 52, and the spring 6.
If the biasing force of 2 is Fa, then the formula: P=C, (Pt-P
d)+Fa/Cz (However, C and C2 are constants)
Hail to you. Therefore, the differential pressure ΔP is the throttle pressure p
t and duty control pressure Pd. In this case, the throttle pressure pt is formed to take a lower value as the opening degree of the throttle valve 11 becomes smaller, and the duty control pressure Pd takes a smaller value as the duty d of the drive signal Cf becomes larger. It is formed like this. Therefore, the differential pressure ΔP takes on a larger value as the opening degree Th of the throttle valve 11 becomes larger, and as the duty d of the drive signal Cf becomes larger, the differential pressure ΔP takes on a larger value.

In addition, the lock-up clutch 22 is connected to the drive plate 3.
The maximum torque (hereinafter referred to as transmittable torque) Ts that can be transmitted from the pump impeller 34 to the turbine runner 36 via the lock-up clutch 22 when the lock-up clutch 22 is frictionally engaged with the lock-up clutch 22 is determined by the friction coefficient of the lock-up clutch 22 and the effective torque. If the radii are U and r, respectively, and the engagement area between the lock-up clutch 22 and the drive plate 32 is A, then the formula: Ts = ΔPXuXrXA can be obtained, and as is clear from this formula, the transmittable torque Ts
is assumed to take a larger value as the differential pressure ΔP becomes larger. When the input torque Ti of the torque converter 24, which is equal to the torque Te generated by the engine 10 and transmitted to the drive plate 32, is larger than the transmittable torque Ts, the pump impeller 34 and the turbine runner 36 A rotational speed difference ΔN will occur between the two. In that case, the rotational speed difference ΔN increases as the input torque Ti increases and as the differential pressure ΔP decreases.

Next, the torque down control and slip control performed by the control unit lOO when shifting the automatic transmission 20 will be explained based on the flowchart shown in FIG. 1.

First, in Sll, the map shown in FIG.
It is checked whether a shift flag, which is set when a shift condition is satisfied, has risen based on the vehicle speed expressed by v.

When it is determined that the shift flag has risen at Sll, S
12, it is determined whether or not slip control in which the lock-up clutch 22 is in a slip-engaged state was performed before the gear change. If it is determined in S12 that slip control is being performed, the process advances to S13 and the duty d is
After setting the value yfi-1 to the value immediately before the shift, the process advances to S20.

On the other hand, if it is determined in S12 that slip control was not performed before the gear shift, the process proceeds to S14, where the generated torque TeO value of the engine IO is detected as the opening degree of the throttle valve 11 when the detection signal St is detected. The signal Sn is set based on the expected engine rotation speed. The value of the generated torque Te of the engine 1o is, for example, determined in advance according to the opening degree of the throttle valve 11 and the engine rotation speed, and a detection signal St is obtained from a map stored in a memory built into the control unit 100. It is obtained by reading a value corresponding to the opening degree of the throttle valve 11 and the engine rotational speed at which the detection signal Sn occurs.

Next, in S15, a correction coefficient K is set based on the temperature of the hydraulic oil at which the detection signal Su occurs, and in S16, the transmission torque T' is set by the formula: Tr=TeXK. For example, if the temperature of the hydraulic oil is 90'
C, it is set to 1, and the higher the temperature is than 90°C, the larger the value is, and the lower the temperature is 90'C, the smaller the value is. Then, by multiplying the value of the generated torque Te of the engine IO by this correction coefficient K, the value of the transmission torque Tr is set.

Then, in step 317, a differential pressure ΔP that provides a predetermined rotational speed difference ΔN is set based on the transmission torque Tr, and
Proceed to. That is, between the pump impeller 34 and the turbine runner 36 in the torque converter 24, the energy loss in the torque converter 24 is reduced, the torque fluctuations generated by the engine 1o are absorbed, and the rotational force from the transmission mechanism 26 is reduced. is transmitted to the engine 10 via the lock latch 22, thereby preventing the rotational speed of the engine 10 from dropping when torque down control of the engine 10, which will be described later, is performed. A predetermined rotation speed difference ΔN, for example, 80
The value of the differential pressure ΔP is set so as to produce (rpm). Note that the value of the rotational speed difference ΔN is read out from a map in which the relationship between the input torque Ti, the rotational speed difference ΔN, and the differential pressure ΔP is written in advance, depending on, for example, the operating state of the engine lO, the running state of the vehicle, etc. It is obtained by each time.

At 318, the drive signal Cr causing the differential pressure ΔP
The value y, , of the duty d of is calculated, and in S19 this value yf
Set i as duty d and proceed to S20. Above differential pressure Δ
The value of the duty d of the drive signal Cf that generates P can be obtained, for example, by reading from a map in which the relationship between the differential pressure ΔP and the duty d is written.

Further, in S20, the drive signal Ce is supplied to the lock-up control solenoid valve 6, and in the following S21, a drive signal Cf having the duty d set in S13 or 319 is formed and is applied to the pressure regulating solenoid valve 6. It is supplied to the valve 7 and the process proceeds to S24.

That is, as shown in FIG. 6, the shift operation of the automatic transmission 20 is started, and the lock-up clutch 22 is
Slip control is performed to control the fastening force to be between the fastened state and the released state, and the torque down control of the engine 10 prevents the rotational speed of the engine 10 from dropping.

Further, if it is determined that the shift flag has not risen in the Sll, that is, after the shift operation is once started and slip control is performed as described above, the process moves to 322 and the turbine rotational speed is sensor 8
It is checked whether the turbine rotational speed change ITTREVO value obtained based on the detection signal Sm from 7 is negative. That is, there is a time lag between the start of the shift operation and the actual shift due to the characteristics of the hydraulic path in the hydraulic circuit section 30. Therefore, it is checked whether or not a gear shift has actually been performed, depending on the sign of the value of the turbine rotational speed change 1iVTREV.

If it is determined in S22 that the value of the turbine rotational speed change amount TTREV is not negative, the process directly proceeds to S24. Further, if it is determined in S22 that the value of the turbine rotational speed change TTREV is negative, the process proceeds to S23, and the amount of fuel injected into the intake passage 14 via the fuel injection pump 12 is determined in advance by the engine. After starting the torque down control to reduce the torque to the amount set according to the operating state of No. 10, the process proceeds to step 524. That is, the engine output is reduced along with the shift operation, so that the shift shock is reduced.

In S24, it is determined whether the turbine rotational speed 1'REV obtained from the detection signal Sm from the turbine rotational speed sensor 87 is smaller than the sum of the rotational speed TTREV at the time of completion of the shift operation and a preset value 0FTI. Find out. That is, it is checked whether the shift operation is near completion. The rotational speed TTREV at the time of completion of the shift operation is determined, for example, based on the detection signal Sv from the vehicle speed sensor 88 and the gear ratio at the new gear position.

In S24, the turbine rotation TTREV is set to the rotation speed TTREV at the time of completion of the shift operation and a preset value 0FT.
If it is determined that the value is not smaller than the sum of I and I, the slip control and torque down control are continued,
Return as is.

In S24, the turbine rotation TTREV is set to the rotation speed TTREV at the time of completion of the shift operation and a preset value 0FT.
When it is determined that the value is smaller than the sum of I and
Proceeding to S25, the amount of fuel injected into the intake passage 14 is returned to the initial value obtained according to the opening degree of the throttle valve 11 based on the map shown in Table 2 below.

Table 2 Also, in S26, the amount of fuel injected into the intake passage 14 is increased by an increment value obtained from the map in the same manner as the initial value described above each time injection is performed, for example, 06
After a predetermined period of time, such as 2 seconds, has elapsed, the injection amount is returned to normal according to the opening degree of the throttle valve 11, and the torque down control is ended. However, the above 525 and 32
6, after the injection amount returns to the normal injection amount, the injection amount remains at the normal injection amount.

Next, in S27, the turbine rotation TTREV obtained from the detection signal Sm from the turbine rotation speed sensor 87 is smaller than the sum of the rotation speed TTREV at the time of completion of the gear shifting operation and the preset 410 F T 2. Find out if. That is, it is checked whether the shift operation is closer to completion than when the torque down control is finished.

In S27, the turbine rotational speed TREV is set to the rotational speed TTREV at the time of completion of the shift operation and a preset value 0FT.
If it is determined that the value is not smaller than the sum of 2 and 2, the process returns and the slip control continues.

In S27, the turbine rotational speed TREV is set to the rotational speed TTREV at the time of completion of the shift operation and a preset value 0FT.
If it is determined that the value is smaller than the sum of 2 and 2, then 3
2B, the supply of the drive signal Ce to the lock-up control solenoid valve 6 is stopped, and in the subsequent S29, the supply of the drive signal Cf to the pressure regulation solenoid valve 7 is also stopped,
Terminate torque down control.

In this manner, since torque down control is performed during gear shifting, the gear shift shock that occurs during gear shifting is reduced.

Moreover, even if the engine output decreases, slip control is performed prior to torque down control, so the rotational force from the transmission mechanism is transmitted to the engine output shaft via the lock-up clutch. This prevents the engine speed from dropping.

Note that in this embodiment, the time point at which the shift is actually performed and the time point at which the shift operation is completed is determined based on the rotation speed of the turbine runner 36 of the torque converter 24, but the present invention is not limited to this. Instead, the completion point of the upshift operation may be predicted based on the engine speed N, etc., or may be predicted based on the elapse of a predetermined time from the start of the shift. good.

Furthermore, in the above example, the control target in torque down control is the fuel injection amount, but the control target is not limited to this, and the control target can change engine output such as ignition timing and intake air amount. Alternatively, these controls may be combined to increase the rate of torque reduction.

〔Effect of the invention〕

As described above, the shift shock reduction device for an automatic transmission of the present invention includes a torque converter in which a pump impeller is connected to an output shaft of an engine, and a shift shock reduction device in which a pump impeller is connected to a turbine output shaft connected to a turbine runner of the torque converter. a lock-up clutch that engages and releases the mechanism, the pump impeller of the torque converter, and the turbine runner;
output control means for reducing engine output during gear shifting;
The structure includes slip control means for controlling the engagement force of the lock-up clutch to be between an engaged state and a released state during gear shifting, prior to a reduction in engine output by the output control means. .

This prevents the engine speed from dropping even if the engine output is reduced during gear shifting, thereby reliably reducing the shock caused by gear shifting, and allowing the vehicle to take a break from accelerating. This has the effect of preventing the vehicle from stalling or from not changing smoothly in vehicle speed.

[Brief explanation of drawings]

1 to 6 show one embodiment of the present invention. FIG. 1 is a flowchart showing operations performed by a control unit in a shift shock reduction device for an automatic transmission according to the present invention. FIG. 2 is an overall configuration diagram of a shift shock reduction device for an automatic transmission. FIG. 3 is a schematic explanatory diagram of the automatic transmission shown in FIG. 2. FIG. 4 is an explanatory diagram showing the configuration of a portion related to control of the lock-up clutch in the hydraulic circuit section. FIG. 5 is a characteristic diagram used to explain the gear shifting operation of the automatic transmission based on the vehicle speed and the opening degree of the throttle valve. Figure 6 shows the turbine rotation speed, fuel injection amount, and
and a time chart showing the relationship between the presence and absence of slip control. 10 is an engine, 10a is a crankshaft (output shaft of the engine), 22 is a lock-up clutch, 24 is a torque converter, 26 is a transmission mechanism, 34 is a pump impeller, 36
39 is a turbine output shaft, and 100 is a control unit (output control means, slip control means).

Claims (1)

[Claims] 1. A torque converter in which a pump impeller is connected to an output shaft of an engine; a transmission mechanism connected to a turbine output shaft connected to a turbine runner of the torque converter;
A lock-up clutch that engages and releases the pump impeller and turbine runner of the torque converter, an output control means that reduces the engine output during gear changes, and a lock-up clutch that reduces the engine output during gear changes before the output control means lowers the engine output. 1. A shift shock reduction device for an automatic transmission, comprising slip control means for controlling the engagement force of a clutch to be between an engaged state and a released state.