JPS62188843A - Control device for automatic transmission - Google Patents

Abstract

PURPOSE:To prevent the deceleration because of undue shift-down, by reliably detecting engine brake operation by a driver and effecting the shift-down operation only when the engine brake is necessary. CONSTITUTION:An engine speed is measured by a turbine rotating speed sensor 9, and a throttle opening angle is read from a throttle opening angle sensor 7. Then, a turbine rotating speed at a first speed position is obtained from a turbine rotating speed map 4a. Then, according to a difference between the engine speed and the turbine rotating speed, it is calculated whether overrun occurs or not. If the overrun occurs, a shift processing to a second speed is carried out. If the overrun does not occur, a shift processing to a first speed is carried out. Accordingly, overdrive is canceled to effect the shift-down. Thus, undue shift-down may be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for an automatic transmission in an automobile or the like.

[Prior Art] An automatic transmission having a conventional overdrive stage (iii
In modern automobiles, when driving in overdrive, the overdrive is automatically released and the gear is downshifted due to the need to apply strong engine braking, for example when driving downhill.

As this control device, for example, Japanese Patent Application Laid-Open No. 58-22105
As shown in No. 2, it is possible to detect that the driver has stepped on the brake pedal and automatically downshift, or to adjust the accelerator return time. The engine was controlled by applying a strong engine braking effect.

[Problems to be Solved by the Invention] Therefore, with conventional control devices, overdrive is immediately released and downshift is performed simply when the brake pedal is depressed or when the accelerator is released quickly. Therefore, there were problems as described below.

For example, in addition to decelerating when descending from a board, when following on a flat road, even a slight press of the brake pedal causes a downshift, which is undesirable from the standpoint of driving feeling.

Furthermore, in a similar case, simply releasing the accelerator pedal would result in an automatic downshift, which inevitably worsened the driving feeling.

[Means for solving problems]

The present invention has been made in view of the above-mentioned problems, and includes a negative pressure detection means for detecting that the negative pressure in the intake pipe of the carrot is equal to or higher than a predetermined value, and a negative pressure detection means for detecting that the negative pressure in the carrot intake pipe is equal to or higher than a predetermined value. and an overdrive release means that receives signals from both detection means, releases the overdrive stage, and shifts down.

[Operations] With this configuration, overdrive is released only when strong engine braking is required, for example, when there is a deceleration operation such as the brake being stepped on while descending, and when downshifting is truly necessary. This will prevent unnecessary downshifts.

[Example] Hereinafter, an example according to the present invention will be described in detail with reference to the drawings.

[Basic configuration] FIG. 1 shows a basic schematic configuration of an embodiment according to the present invention.

In FIG. 1, 1 is the engine body, 2 is a multi-speed gear device having an overdrive stage (hereinafter referred to as "transmission"), 3 is a hydraulic control circuit that hydraulically controls the gears of the transmission 2, and 4 is described later. 5 is a lock-up control means for controlling the lock-up according to the procedure shown in FIG. 7, which will be described later. This is a forced release means for overdrive.

Further, 7 is a throttle opening sensor that detects the throttle opening of the engine 1, 8 is a negative pressure sensor installed in the intake pipe of the engine 1 that detects the intake pipe negative pressure, and 9 is a sensor that detects the rotation speed of the turbine. This is a turbine speed sensor.

[Basic configuration of transmission mechanism] An outline of the transmission 2 and hydraulic control circuit 3 is shown in FIG.

In FIG. 2, numeral 11 indicates the crankshaft of the engine 1, which is the human power shaft to the transmission mechanism, and this crank! TiIh1
A torque converter 12 and a transmission gear 2 are arranged coaxially with the engine 1 in order from the engine side.

The torque converter 12 includes a pump 13, a turbine 14, and a stator 15, and the pump 13 is fixed to the crankshaft 11. The stator 15 is connected to a fixed shaft 17 that is integrated with the case 2a of the transmission 2 via a one-way clutch 16 that allows rotation only in the same direction as the pump 13. Rotate only.

The center @h18 of the transmission 2 has its base end fixed to the crank @11, extends through the center of the transmission 2, and has its tip connected to the oil pump P disposed on the side wall of the device 2. It is driving P.

Outside of this center @18, the base end is the torque converter 1
A hollow turbine shaft 19 is connected to the turbine 14 of the transmission 2, and its tip extends to the side wall of the transmission 2, and is rotatably supported by the side wall. turbine shaft 1
A Ravigneau type planetary gear unit 30 is provided on the 9, and this planetary gear unit 30 includes a small diameter sun gear 35, a large diameter sun gear 36, and a small diameter sun gear 36 in order from the engine 1 side.
It consists of a long pinion gear 37, a short pinion gear 38, and a ring gear 39. Furthermore, on the side of the planetary gear unit 14 further away from the engine 1, first and second clutch devices 20, 21 are arranged in parallel. The first clutch device 20 is a clutch for forward running, and connects and disconnects power transmission between the small diameter sun gear 35 and the turbine shaft 19 via the first one-way clutch 22. On the other hand, like the first clutch device 2o, the second clutch device 21 also connects and disconnects power transmission between the small diameter sun gear 35 and the turbine shaft 19, but is directly connected to the small diameter sun gear 35. A first brake device 23 having a band brake structure is disposed radially outward of the second clutch device 21.

Further, a brake drum 23-1 is connected to the large-diameter sun gear 36, and a brake band 23-2 is hung on this brake drum 23-1. radially outward of the first clutch device 20 and the first brake device 23
A third clutch device 24 for reverse running is disposed on the side of the brake device 23, and the third clutch device 24 is connected to the large diameter sun gear 36 via the brake drum 23-1 of the first brake device 23. power transmission between the turbine shaft 19 and the turbine shaft 19.

On the radially outward side of the planetary gear unit 30 described above, a carrier 30 of the planetary gear unit 30 is provided.
A second brake device 25 is arranged to engage and disengage the case 2b of the transmission 2 and the case 2b of the transmission 2. Between the first and second brake devices 23 and 25, the second brake device 25
A second one-way clutch device 26 that engages and disengages the carrier 30a and the case 2b is arranged in parallel with the carrier 30a.

Furthermore, a fourth clutch device 27 is disposed on the side of the planetary gear unit 30 on the engine side, which connects and disconnects power transmission between the carrier 30a of the planetary gear unit 30 and the turbine shaft 19. An output gear 28 connected to a ring gear 39 is disposed on the side of the fourth clutch device 27 on the engine side, and the output gear 28 is attached to an output shaft (not shown). In addition, the reference numeral 29 in the figure indicates a lock-up clutch for directly connecting the turbine shaft 13 and the crankshaft 1 without using the torque converter 2. This lock-up clutch 29 is controlled by the lock-up control means 5.

[Functions of Transmission 2] The transmission 2 having the structure described above has four forward speeds including an overdrive speed and one reverse speed, and has first, first and second speeds.
Second, third and fourth clutch devices 20, 21, 24 and 27 and first and second brake devices 23 and 2
By operating 5 appropriately, a desired gear stage can be obtained.

In the above configuration, the operational relationship between each gear stage, clutch, and brake is shown in the table below.

(Margin below) (0) Transmission on the drive side [3 hydraulic control circuits] Next, details of the hydraulic control circuit 3 are shown in FIG.

The hydraulic control circuit 3 has an oil pump 100 driven by the engine output shaft shown in FIG.
Hydraulic oil is discharged from 00 to pressure line 101. The hydraulic fluid discharged from the pump 100 to the pressure line 101 is guided to the pressure regulating valve 102, where the pressure is regulated by the throttle pressure, throttle modulator pressure, and backup pressure, and then supplied to the boat g of the select valve 103. This select valve 103 is a manual shift valve, and is shifted to each range of P-R-N-D, 2, and 1 according to the operating position of a manually operated shift lever, and is shifted from boat g to each range. Supply regulated operating pressure to each corresponding predetermined boat. When the select valve 103 is set to lunge, boat g is in communication with boats a, d, and e, and when the select valve 103 is set to range 2, it is connected to boat a.

When the D range is set, the ports a and C are in communication, and the select valve 10 is in communication with the boats a and C.
3 is set to the R range, it is in communication with boat f.

The boat a of the select valve 103 is connected to the 1-2 shift valve 110, and hydraulic oil acts on the 1-2 shift valve 110 against an internally installed spring 110a. -2 solenoid valve 110b is O
1st speed when FF, drain hydraulic oil and 2nd speed when ON
It is controlled to be in a state of high speed.

The 1-2 shift valve 110 also includes a select valve 10.
3 is set to the D range, the select valve 10
Hydraulic oil is supplied from boat a of No. 3, and when the solenoid valve 110b for 1-2 is turned on to shift from the first speed to the second speed, the hydraulic oil is supplied to the apply side 23a of the first brake equipment 23.
-4 Hydraulic oil is supplied through the shift valve 130. In addition,
In D range, solenoid valve 110b for 1-2 is OFF.
At the time of F, the operating pressure from boat a bypassing the 1-2 shift valve 110 is supplied to the clutches 201 and 21 to achieve the first speed state.

Furthermore, this 1-2 shift valve 110 supplies hydraulic oil from the boat e of the select valve 103 to the brake device 25 via the low pressure reducing valve 140 at the time of lunge 2'a, and at the same time supplies signal pressure to the throttle backup 141. It is now possible to send

Boat a of the select valve 103 is also a 2-3 shift valve 1
The 2-3 shift valve 120 is also connected to the 2-3 solenoid valve 120, and hydraulic oil acts against the internally installed spring 120a, so that the 2-3 solenoid valve 120
Control is performed so that when b is ON, the hydraulic oil is drained and the gear is in second speed, and when b is off, it is in third gear. Note that when shifting from 2nd speed to 3rd speed, hydraulic oil from boat c of select valve 103 is transferred to servo control valve 142.2.
-3 It is ultimately supplied to the clutch 27 via the timing valve 143 to activate it, and is also supplied to the release side 23b of the brake device 23 to deactivate it.

Similarly to the 1-2 shift valve 110 and the 2-3 shift valve 120, the 3-4 shift valve 130 is supplied with hydraulic oil from the boat a of the select valve 103 in opposition to a spring 130a, Solenoid valve 130 for 3-4
Control is such that when b is OFF, the gear is set to third speed, and when b is ON, the hydraulic oil is drained and the gear is set to fourth speed, which is an overdrive stage. To shift from the third speed state to the fourth speed state, the hydraulic fluid that has passed through the 1-2 shift valve 110 is transferred to the apply side 23 of the brake device 23 without going through the orifice.
The hydraulic oil from boat a of the select valve 103 bypassing the 1-2 shift valve 110 is supplied to
-4 shift valve 130 and N-D accumulator 144
This is achieved by supplying it to the clutch 21 via the.

When the 3-4 solenoid valve 130b is turned ON and the hydraulic oil is drained, the shift operation from 3rd speed to 4th speed is performed as described above, and the operation via the 1-2 shift valve 110 is performed. Oil is supplied to the apply side 23a of the brake device 23 via a circuit 145 with orifices and check valves. At the same time, the release of the brake device 23 (111123b is drained through the orifice and the 3-4 capacity control valve 145, and the brake device 23 is activated, and at the same time, the hydraulic oil that was acting on the clutch 21 is also drained. be done.

The low pressure reducing valve 140 is intended to alleviate shift shock by reducing the pressure of the hydraulic oil, and when the select valve 103 is set to lunge, it receives the hydraulic oil from the boat e of the select valve 103 and self-regulates the pressure. The pressure of this hydraulic oil is reduced and supplied to the 1-2 shift valve 110. In the first speed state, this hydraulic fluid is supplied to the brake device 25 through the 1-2 shift valve 110 to alleviate the shift shock. Note that this port-pressure reducing valve 140 does not operate in the D range. Further, the hydraulic oil that has passed through the 1-2 shift valve 110 is supplied to the throttle backup valve 141 as a signal pressure.

The throttle backup valve 141 is the low pressure reducing valve 1
The signal pressure from the select valve 103 is supplied to the regulator valve 102 or cut off depending on whether the signal pressure is ON or OFF. That is, when the select valve 103 is set to range or 2 range and is not receiving signal pressure, the throttle backup valve 141 transfers the hydraulic oil from the boat d of the select valve 103 to the regulator valve. 102 to increase its pressure and ensure engine braking capacity.

A throttle valve 146 is connected to the regulator valve 102 via a thrower modulator valve 147. The throttle valve 146 operates in response to the accelerator opening and generates a hydraulic pressure proportional to the accelerator opening, and the modulator valve 147 appropriately reduces this hydraulic pressure and supplies it to the regulator valve 103. Obtain hydraulic oil with a pressure that matches the engine torque.

The servo control valve 142 and the 2-3 timing valve 143 are for alleviating the shift shock that occurs when shifting from second speed to third speed. For this reason,
When shifting from 2nd speed to 3rd speed, the clutch 27 may be engaged and the brake device 23 may be inactive, and the clutch 27 and the release 23b of the brake device 23 may be inactivated.
I'J] Just supply oil. However, in order to reduce the engagement shock of the clutch 27, the clutch 27 and the brake device 23 are provided with an orifice and an accumulator 148.
If hydraulic oil is supplied to the release side 23b of the clutch 27, the rise of the oil pressure of the clutch 27 will be delayed due to the action of the orifice and the resistance of the pipe, and the neutral time will be lengthened by that much, and it is conceivable that blow-up will occur.

Therefore, a servo control valve 142 is arranged in the hydraulic oil supply line to the release side 23 of the brake device 23, and the operating pressure of the clutch 27 is applied to this valve 142, so that the hydraulic oil of the clutch 27 is raised to a certain degree of pressure. Until then, the supply line is cut off to prevent the release pressure from rising. The 2-3 timing valve 143 also controls the clutch 2 according to the accelerator opening degree.
7 and has the function of alleviating shift shock that cannot be controlled by the servo control valve 142. That is, in the upshift from 2nd speed to 3rd speed, which occurs when the accelerator is momentarily returned to the low opening side when the accelerator opening is small, the clutch z
If 7 is suddenly engaged, it is easy to feel a shift shock. For this reason, the 2-3 timing valve 143 controls the slip time at the time of engagement to be long when the accelerator opening is small, and short when the accelerator opening is large.

A 3-4 capacity valve 145 is provided to reduce shift shock when shifting up from third speed to fourth speed. By turning on the 3-4 solenoid valve 130b, the hydraulic oil is drained and the 3-4 shift valve 130 is switched to the fourth shift valve 130.
When moving to the first speed side, the hydraulic oil on the release side 23b of the clutch 21 and brake 23 is drained, but the drain on the release side 23b at this time is controlled by this 3-4 capacity valve 145, and the third This reduces the shock of shifting from 4th gear to 4th gear.

In this 3-4 capacity valve 145, at the initial stage of the drain on the release side 23b, the operating pressure and self-pressure of the clutch 21 oppose and overcome the internal spring force, so that the spool is at the position shown in the figure. The lines 1 and 2 shown in the figure are connected and drained straight. Once the water has drained to a certain extent, the internal spring force forces the spool to move in the direction of the arrow shown in the figure, and the line 11. Cut off communication with fL2. This results in draining only through the orifice. That is, the release side 23b of the brake device 23
The operating pressure at the time of draining drops rapidly in the early stage of draining, and gradually decreases in the latter half of draining.If the engagement pressure of the brake device 23 is set to the same pressure value as the appropriate pressure in the latter half of draining, The sliding time becomes longer and the fastening shock is alleviated.

In addition, in order to reduce the shift shock when shifting from 3rd speed to 2nd speed according to the throttle opening, the 3-2 capacity valve 149 and the 3-2 timing valve 150 are
is provided. Throttle modulator pressure acts on the 3-2 capacity valve 149 against the internal spring force and self pressure, that is, pressure added to the release drain pressure. Similar to the capacity valve 145, the drain is passed through the bypass during the initial stage of draining, that is, when the pressure is high, and thereafter, the drain is drained via the orifice. Draining of the 3-2 capacity valve 149 is performed by the 2-3 shift valve 120 via the 3-2 timing valve 150. In this 3-2 timing valve 150, the throttle modulator pressure acts against the internal spring force, and when the modulator pressure is higher than the spring force, it passes through the orifice, and when it is lower, it is bypassed and drained. do.

This is because when the modulator pressure is high, the throttle opening is small and the engine speed is high, so by draining through the orifice, the brake device 2
3. Slow down the release of release pressure. In other words, by forcing the brake device to engage, sudden engagement is prevented,
Acts to prevent shock.

Further, the N-D accumulator 144 is provided in the hydraulic oil passage of the clutch 20, and its function is the same as that of other accumulators.
The timing of supplying hydraulic oil to clutch 1 is slightly advanced from the timing of supplying hydraulic oil to clutch 20.

This is because when the clutch 21 only has capacity for engine braking, for example, when shifting from the N range to the D range while the accelerator is pressed, the clutch 21 will engage first, causing abnormal wear. This is to prevent

On the other hand, a lock-up control valve 151 is provided in the hydraulic oil path of the lock-up clutch 29. This lock-up control valve 151 is operated by the spring force of an internal spring and the clutch 2.
The lock-up solenoid valve 1 acts against the pressure added to the working pressure of 0, and the hydraulic oil is controlled as described below.
By turning ON the drain 51a, the supply of hydraulic oil is switched from the release chamber side to the engagement chamber side, the release chamber pressure is drained, and the lockup is turned ON.

Further, the hydraulic oil passage 3 of the first clutch 20, which is a forward clutch, is connected to the hydraulic oil passage 4 connected to the boat a of the select valve 103, and the hydraulic oil passage 3 connected to the boat a of the select valve 103. A neutral valve 160 is provided to switch between the hydraulic oil passage 5 connected to the boat d where oil pressure rises in the range (range). This neutral valve 160 has a pressure line 10
Hydraulic oil is supplied from 1 against a spring 160a installed internally, and the idle cut solenoid valve 161
When is OFF, the spool 160b is positioned at the right end position shown in the figure by the action of the supplied hydraulic oil, and 1. The oil road 3 is connected to the oil road 4, and as a result, boat a
Hydraulic oil is supplied to the clutch 20 from.

On the other hand, when the select valve 103 is selected to the N range and the idle cut solenoid 161 is ON, the hydraulic oil acting against the spring 160a is drained, so the spool 160b moves to the left in the figure. As a result, the oil passage 23 is cut off from communicating with the Yujiko 4 and is now communicated with the Yujiri 5. In this way, Yuro Bun 5
When the select valve 103 is set to the D range, the boat d to which the boat d is connected drains the hydraulic oil of the clutch 20 and releases the clutch 20, thereby preventing the occurrence of vibration.

However, if the neutral valve 160 fails while draining the hydraulic oil of the clutch 20 and becomes stuck, it becomes impossible for the vehicle to travel forward at all because the clutch 20 is a forward clutch. I end up. Therefore, the select valve 103 is
When in a forward travel range other than range, for example, lunge and 2 range in the case of the embodiment, boat d is communicated with boat g, which is a hydraulic oil supply boat,
As a result, the oil pressure of the boat d is raised, and this oil pressure is then supplied to the oil passage J13 via the oil passage intersection 5, and the clutch 20 is engaged, allowing the vehicle to travel forward.

In this case, the boat d is cut off from communication with the drain path.

As described above, in this embodiment, the pressure regulating valve 102 is connected to the throttle backup valve 141 and the throttle modulator valve 147, and receives the throttle backup pressure from the valve 141 and the throttle modulator pressure from the valve 147. It has become.

Therefore, these backup pressure and modulator pressure are
In order to prevent interference in the pressure regulating valve 102, the valve 102 has the following structure.

That is, the spool of this pressure regulating valve 102 is composed of a first spool 102a, a second spool 102b, and a third spool 102C, which are separate from each other, and the backup pressure from the thrower 1 to the backup valve 141 is
The modulator pressure from the throttle modulator valve 147 is introduced between the spool 102b and the third spool 102C, and the modulator pressure is applied to the right side of the figure of the third spool 102C, i.e.
It is adapted to be introduced on the opposite side of the second spool 102b. Therefore, the backup pressure is
2b can be actuated by directly acting on the right end face of the valve 2b, while the modulator pressure is applied by moving the third spool 102C six times to the left to combine with the second spool valve 102b,
As a result, the first spool valve is actuated, and the first spool 102a is actuated according to the respective pressures, and the pressure regulating valve 102 is actuated.
to perform pressure regulating action. Further, the second spool 102b on which the throttle modulator pressure acts and the third spool 102C on which the backup pressure acts are separated, and the third
Since the spool 102C is a free piston type, the hydraulic action area of both spools is the same, that is, the spool diameter can be made the same, so compared to an integrated spool structure with a difference in area, it is more compact in the axial and radial directions. The structure can be simplified. Further, the oil pressures of the throttle backup pressure and the throttle modulator pressure can be lowered.

[Control operation of hydraulic control circuit] Next, the solenoid valve 110b for 1-2, the solenoid valve 120b for 2-3, and the solenoid valve 130b for 3-4 of the hydraulic control circuit 3 having the above configuration are controlled by the speed change control means 4, The lockup solenoid valve 151a is controlled by the overdrive release means 6, and the lockup solenoid valve 151a is controlled by the lockup control means 5. This control will be explained below with reference to flowchart 1 in FIGS. 4 to 7.

FIG. 4 is a flowchart showing the overall control procedure of the hydraulic control circuit 3.

In the figure, when the ignition switch is turned on and power is supplied from the battery to each of the control means 4 to 6, hydraulic control corresponding to the shift lever position and driving condition is performed. First, in step S1, each of the control means 4 to 6 is set to an initial state, and in subsequent step S2, it is checked whether the shift lever is in the N (neutral) range or the P (parking) range. If the N range or P range is selected, wait until the shift lever is set to another range. If the shift lever is set to another range, the process proceeds from step S2 to step S3, where it is checked whether the shift lever is set to the 1st speed range, and if it is set to the 1st speed range, step S4 is performed. Then, the lock-up control means 5 instructs the lock-up solenoid 151a to be turned on to release the lock-up, and the lock-up control means 5 turns the lock-up solenoid 151a to 0F.
FL, the supply of hydraulic oil for the lock-up clutch 29 is switched from the engagement chamber side to the release chamber side, and the lock-up is turned off. Subsequently, in step S5, the shift control means 4 calculates whether or not the current clutch engagement state will be downshifted to the first speed and the engine will overrun and an overload will be applied to the engine. Specifically, the turbine rotation speed sensor 9
The turbine rotation speed, that is, the engine rotation speed is measured, and the throttle opening is read from the throttle opening sensor 7, and the throttle opening is read from the built-in throttle-to-throttle general constant turbine rotation speed map (hereinafter abbreviated as "map") 4a. Find the turbine rotation speed when the first speed is set. Then, based on the difference between the two rotational speeds, it is calculated whether or not the engine will overrun. If the result is an overrun, the process proceeds from step S6 to step 37, where a shift process to second speed is performed. If overrun does not occur, step S
6, the process proceeds to step S8, and a shift process to 1st speed is performed. Then, the process returns to step S2 and prepares for the next shift process.

Next, in step S3, if the shift lever position is not in range, the process proceeds to step S9 to check whether it is in the 2nd range.

In the case of the 2nd range, the process proceeds from step S9 to step 310, where the lock-up is released in the same manner as step S4, and in the subsequent step Sll, a shift process to 2nd speed is performed, and the process returns to step S2.

On the other hand, if it is determined in step S9 that the shift lever is not in the 2nd range, it means that the shift lever is in the D (drive) range, and the process proceeds to step S12, where the shift-up control shown in the flowchart of FIG. 5, which will be described later, is executed. Step S1
In step S4, the lock-up control shown in FIG. 7 is executed by the lock-up control means, and the process returns to step S2.

Next, the upshift process by the shift control means 4 in step S12 will be explained with reference to the flowchart of FIG.

When the shift lever is set to D range,
Transmission 2 according to turbine rotation speed and accelerator pedal status
must be set to an appropriate state, and first the upshift process shown in FIG. 5 is performed. In step S20, it is checked whether the current gear position is the fourth gear, and if it is the fourth gear, the highest speed has been set, so the process ends without doing anything and returns.

Here, if the state is other than the fourth speed, the process advances to step S21, and the throttle opening sensor 7 reads the current throttle opening. Then, in the following step 322, the map 4a is
As shown in the solid line (LU) in Figure 8, the pre-stored turbine rotation speed (Tmap) is adjusted according to the throttle opening.
), and in step S23, the actual turbine (engine) rotation speed (T) is read by the turbine rotation speed sensor 9. Next, in step S24, this turbine rotation speed (T) is compared with the set turbine rotation speed (T+nap), and if the turbine rotation speed (T) is larger, the process proceeds to step S25, and the built-in shift up flag F1 is set. Check to see if it is. If the upshift flag F1 is set, it means that the upshift has been carried out, so the process ends. If the upshift flag F1 is not set, it is necessary to upshift, so the process advances from step S25 to step S26. , sets the shift-up flag F1, and continues in step S27.
At this point, the hydraulic control circuit 3 is controlled to shift up one gear from the current one, and the gear stage is shifted up one gear, and the process ends.

On the other hand, if the turbine rotation speed (T) is not larger than the set turbine rotation speed (Tmap) in step S24, the process advances from step S24 to step S30, where (Tmap)
= (Tmap) The turbine rotation speed (T) measured by the number sensor 9 is compared. Here, the turbine rotation speed (T
) is larger, the process ends without doing anything, and if the turbine rotational speed (T) is not larger, the shift-up flag (Fl) is reset in the subsequent step S32, and the process ends.

Next, details of the downshift control in step S13 in FIG. 4 will be explained below with reference to the flowchart in FIG.

First, in step S40, it is determined whether or not the vehicle is currently running in the first gear. If the vehicle is in the first gear, there is no need to downshift and the process ends. If it is not the first speed, step S4
0, the process proceeds to step S41, and the throttle opening sensor 7
Read the throttle opening. Then, in the following step S42, it is checked whether the throttle is fully closed (whether it is necessary to apply engine braking). Here, if the throttle is not fully closed, the process proceeds to step S43, where the set turbine rotation speed (Tmap) stored in advance according to the throttle opening is read from the map 4a as shown by the solid line (Ld) in FIG. 9, and the following step In S44, the actual turbine rotation speed (T) is read by the turbine rotation speed sensor 9. Then, in step S45, (T) < (Tmal)
), and if (T) < (Tmap), the process advances to step S46, and it is checked whether a shift down flag F2 (not shown) is set. If the downshift flag F2 is set, the process ends without doing anything, and if the downshift flag F2 is reset, the process advances to step S47, where the downshift flag F2 is reset.
is set, and in the subsequent step 348, a one-stage downshift is performed.

On the other hand, in step S45, (T) < (Tmap)
If not, the process proceeds from step S45 to step S50, where (Tmap) - (Tmap), 'o, a, the current (Tmap) 10°8 is set to the new set turbine rotation speed (broken line (Ld' in Figure 9)). value). Then, in the following step S51, (T) <
<Tmap).

Here, if (T) < (Tmap), the process ends, and if (T) < (Tmap), the process proceeds to step S5.
1, the shift down flag F2 is reset and the process ends.

Further, if the throttle is fully closed in step S42, the process proceeds to step S53, where the negative pressure in the intake pipe is read by the negative pressure sensor 8, and in the subsequent step S54, this intake pipe negative pressure is set to a predetermined negative pressure setting value. Check whether the above is true or not. Here, if the negative pressure is not equal to or higher than the set value, the process proceeds to step S43, and no downshift is performed. If the negative pressure is equal to or higher than the set value, it is determined in step S55 whether the current gear is 4th gear, the overdrive is canceled, and the process proceeds to step 348 to apply engine braking, and a one-stage downshift is performed. This is because the load applied to the engine is smaller when driving downhill than when driving on flat ground or uphill, so the negative pressure in the inlet manifold is high at the same throttle valve opening.

That is, this is because the engine brake is applied only when the throttle valve is fully closed when the vehicle is descending and the engine brake is highly necessary.

Also, in the above explanation, the throttle is fully closed, and
When the intake pipe negative pressure exceeds a predetermined value, a downshift is performed and the engine brake is applied.In addition, a brake ON detection means (brake switch) is provided to detect when the brake is applied. ON may be changed to a downshift condition. By doing so, engine braking can be applied reliably only when necessary, and unnecessary downshifts can be prevented.

Next, the lock-up control means 5 in step s14 of FIG.
The lockup control will be explained below with reference to the flowchart of FIG.

First, in step S60, the shift up flag F1
Or is the shift down flag F2 set?
1"), and if it is set, step S6
Proceed to step 1, release the lockup, and install the turbine shaft 1.
3 and the crankshaft 1 is released, and both shafts 1.13 are connected via the torque converter 2. Then, the process ends.

If both flags F,..., F2 are not set in step S60, step S60
2, the throttle opening sensor 7 measures the throttle opening, and the turbine rotation speed sensor 9 measures the turbine rotation speed (
Load T). Then, in the following step S63, the set turbine rotation speed (Tmap) corresponding to the throttle opening is determined and read from the lockup release map 5a. Then, in step S64, (T) < (Tmall)
If (T) < (Tmap), the process advances to step S61 and the lockup is released.

On the other hand, if (T) < (Tmap), the process proceeds to step S65, and the set turbine rotation speed (Tmap) corresponding to the throttle opening is determined from the lockup operation map 5b.
') and read it, and in the following step S64 (T)
>(Tmap').

Here, if (T) >(Tmap'), the lock-up clutch 29 is operated in step S67 to directly connect the crankshaft l and the turbine shaft 13. If (T) >(Tma'p'), the process ends without doing anything.

FIG. 10 shows an example of a comprehensive shift diagram based on the respective speed control processes shown in FIG. 4. Here, 81 is a shift up line, 82 is a lock up clutch, 83 is a lock up OFF line, and 84 is a shift down line.

[Other Embodiments] The present invention is not limited to the embodiments described above. For example, in a hydraulic transmission equipped with an overdrive stage, a driver's deceleration operation is detected and automatic fishing is performed to control the overdrive. It can be used as a mechanism to release the drive state.

In this case, for example, an overdrive release solenoid that releases the overdrive when the hydraulic circuit of the transmission is energized is installed using a known method, and the overdrive release solenoid is turned on when the engine intake pipe negative pressure is above a predetermined value and the brake pedal is pressed. When the brake switch is turned on, this overdrive angle ♀ removal solenoid may be controlled to be energized.

An example of an engine incorporating this overdrive release mechanism is shown in FIG. In the figure, 1 is an engine, 2 is a multi-speed gear system, 3 is a hydraulic circuit, 91 is a vacuum switch installed in the intake pipe of the engine 1, and 92 is an overdrive release solenoid installed in the hydraulic circuit 3. . The overdrive release control circuit for the engine shown in FIG. 11 is shown in FIG. TfJ12.

In Figure 12, 93 is ON when the brake pedal is pressed.
94 is the ignition switch,
95 is a relay circuit, which turns on the brake switch 93.
energizes the contact 95a to close the contact 95a.

FIG. 13 shows the operation of the vacuum switch 91 used here. As shown in FIG. 13, the vacuum switch 91 turns OFF from ON when the intake pipe negative pressure of the engine 1 is at a predetermined negative pressure value (BF) that is larger than the negative pressure value (BT) in the idling state. (BF)
When the predetermined value (BO) is greater than OFF,
The switch is in the N state, and these BF and BO are hysteresis to prevent hunting of the switch.

With the above configuration, the ignition switch 9
4 is turned on and the brake pedal is pressed during the operating state, the brake switch 93 is closed and the relay 95 is energized. Then, the relay contact 95a is also closed, and when the vacuum switch 91 is closed, the overdrive release solenoid 92 is energized, and the overdrive is forcibly released.

Therefore, turning off the brake switch 93 can be used as a substitute for turning off the accelerator pedal. It should be noted that the vacuum switch 91 closes only when the engine is decelerating and descending when the intake pipe negative pressure is 8098 or more, and a downshift is not performed when the vehicle is traveling on a flat road.

Determine whether this is deceleration when exiting the vehicle or deceleration when driving on a flat road,
The following methods are available for canceling overdrive.

A slope sensor for detecting the slope of the vehicle may be disposed, and control may be performed so that the downshift is performed when the slope sensor detects a downhill condition of a predetermined level or more. FIG. 14 shows an example in which this gradient sensor is installed in an automobile. FIG. 14 shows an example in which a slope sensor 100 is disposed at the lower part of the vehicle body. As the gradient sensor, in addition to optical or magnetic non-contact sensors, a gradient sensor using a mercury switch or the like can be used. An example in which a photo sensor is used as the gradient sensor is shown in FIGS. 15(A) and 15(B).

FIG. 15(A) is a cross-sectional view of the gradient sensor, in which the shielding plate 112 is locked so as to be able to swing on one plane from the center position 113 of the upper part of the gradient sensor, and is opposed to a predetermined position within the swinging range of the shielding plate 112. The light emitting part 111a and the light receiving part 1 of the photosensor 111
11b is installed.

The arrangement position of this photosensor is shown in FIG. 15(B). The shielding plate 112 swings according to the inclination of the car as the car climbs up and down the slope, and FIG. 15(B) shows a photo sensor at the position where the shielding plate 112 swings when the car is climbing and when driving on a flat road. 111 is shown. For this reason,
When the vehicle is in a dismounted state, the shielding plate 112 is in the position shown in the figure, and the photosensor 112 is in a non-blocking state. Therefore, when the photosensor 112 is not shut off, it can be determined that the board is in the down state, and the 12th
Instead of the vacuum switch 91 shown in the figure, it may be configured to turn on at this time and energize the relay 95.

In addition, if a plurality of photo sensors 111 are shielded and arranged in a row within the swinging range of the board 112 and it is determined which photo sensor 111 is in the blocked state, it is possible to easily distinguish between the uphill state, the flat state, and the downhill state. It can also be applied to downshifting from a high gear to a low gear at a more appropriate time. Further, the shielding plate 112 may be made of a magnet, and magnetic sensors may be arranged in a row instead of the photosensor 111.
A magnetically sensitive reed relay may be provided in place of the magnetic sensor to detect the swinging position of the shielding plate 112. By doing so, it is also possible to use the reed relay contact as it is in place of the vacuum switch 91.

[Effects of the Invention] As explained above, according to the present invention, by reliably detecting the engine brake operation of the driver and downshifting only when engine braking is necessary, deceleration due to unnecessary downshifting etc. is prevented. It is possible to provide an automatic transmission control device that provides a good driving feeling.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing the basic configuration of an automatic transmission system according to an embodiment of the present invention, FIG. 2 is a basic configuration diagram of an automatic transmission system of this embodiment, and FIG. 3 is a hydraulic pressure diagram of this embodiment. The circuit diagram of the control device, FIGS. 4 to 7 are automatic transmission control flowcharts of this embodiment, FIGS. 8 to 10 are shift diagrams of the transmission of this embodiment, and FIG. 11 is a diagram of the automatic transmission control of this embodiment. A schematic configuration diagram showing the basic configuration of an automatic transmission system according to another embodiment, FIG. 12 is a circuit diagram of the overdrive forced release section of the other embodiment shown in FIG. 11, and FIG. 13 is a diagram showing the hysteresis of the vacuum switch. FIG. 14 is a diagram showing an example in which a vehicle is equipped with a gradient sensor according to another embodiment of the present invention. FIGS. 15 (A) and (B) are diagrams showing the structure of the gradient sensor. . In the diagram, 1... Engine, 2... Multi-speed gear device, 3
... Hydraulic control circuit, 4... Speed change control means, 5...
Lock-up control means, 6... Overdrive release means, 7... Throttle opening sensor, 8... Negative pressure sensor, 9... Turbine rotation speed sensor, 91... Vacuum switch, 92... Overdrive release solenoid, 93...brake switch, 100...gradient sensor, 111...photo sensor, 112...shielding plate. Patent Applicant: Mazda Co., Ltd.'Zanf""':i:i-' Figure 1 Figure 4 Figure 8 Figure 8 Targo °) Yakubaku-to (Ta - Takagu and Nim Somiden -1) No. Figure 10 Outside betel loin skewer -■ Figure 12 Figure 13 (XD tile)

Claims (3)

[Claims] (1) In an automatic transmission equipped with a speed change gear mechanism having a plurality of speeds including an overdrive speed, the power transmission path of the speed change gear mechanism is switched depending on the running condition of the vehicle to automatically change the speed. a negative pressure detection means for detecting that the intake pipe negative pressure of the engine is equal to or higher than a predetermined value; an operation detection means for detecting a driver operation that causes a deceleration state; An automatic transmission characterized by comprising: an overdrive release means for releasing an overdrive stage of a transmission gear mechanism and downshifting when the occurrence of a deceleration state is detected and a negative pressure of a predetermined value or more is detected by the negative pressure detection means. control device. (2) The automatic transmission control device according to claim 1, wherein the operation detection means is a brake pedal switch that detects a brake pedal depression operation by the driver. (3) The control device for an automatic transmission according to claim 1, wherein the operation detection means is a throttle opening sensor that detects an open state of the accelerator pedal.