JPH0735851B2 - Method and apparatus for shifting control of automatic transmission - Google Patents

Description

Detailed Description of the Invention a. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for performing shift control by controlling clutch actuation of an automatic transmission, and more specifically, a one-way clutch and a one-way clutch locked in a power transmission path of this transmission. The present invention relates to a shift control method and device for an automatic transmission having an embrace clutch to be held.

(Prior Art) An automatic transmission is configured to automatically change gears in accordance with a traveling state to obtain desired traveling characteristics. As such an automatic transmission, for example, Japanese Patent Publication No. −21131
Japanese Patent Laid-Open No. 61-189354 discloses an example of control of such an automatic transmission.

In such a transmission, a one-way clutch may be provided in the power transmission path for the purpose of improving shift characteristics. However, the one-way clutch allows power transmission in the driving direction but does not transmit power in the opposite direction, and if this route is selected, engine braking cannot be obtained, so the input side and output of the one-way clutch cannot be obtained. In many cases, an embrace clutch that connects the sides directly and holds the one-way clutch locked is also provided. In such a case, control is performed such that the engine clutch is operated under a predetermined condition so that engine braking is obtained, and the engine clutch is released under another condition.

Incidentally, the condition for operating and non-operating the emblem clutch is conventionally a shift range (for example, D, 2,1) determined by a manual valve operated according to a shift lever.
It was set uniquely corresponding to the range). Specifically, for example, in the D range, the engine clutch is disengaged to set a one-way power transmission path without engine braking action, and in the 2 and 1 ranges, the engine clutch is engaged to engage the engine braking power. It was supposed to set the transmission route.

(Problems to be Solved by the Invention) Here, for example, the shift range is changed from the D range to the 2 or 1 range by a shift lever operation, and the downshift is performed while the accelerator pedal is depressed (when the power is on). In the case of such a gear shift, if the gear shift is performed via the one-way clutch, the power transmission will be started via this one-way clutch after the input and output rotations of the gear shift clutch are synchronized, so a smooth gear shift is possible. Is obtained. However, in the above-mentioned conventional setting, since the operation / non-operation of the emblem clutch is determined for each shift range determined by the shift lever position, the above-mentioned shift is performed with the emblem clutch engaged. Therefore, the emblem clutch is engaged before the input and output rotations of the shift clutch are synchronized, and a shift shock may occur.
The shifting feel may be impaired.

For this reason, conventionally, an accumulator is arranged in the hydraulic oil pressure supply passage to the emblem clutch to prevent the engagement of the emblem clutch from becoming too rapid, thereby reducing shift shock. However, in this case, an accumulator is required for the control valve, which causes a problem that the control valve becomes complicated and large.

The present invention has been made in view of the above problems, and provides a gear shift control method capable of performing smooth gear shift without gear shift shock in the case of gear shift to a power transmission path in which an embrace clutch is engaged. It is an object of the present invention to further provide a shift control device capable of performing such shift control.

B. Structure of the Invention (Means for Solving the Problems) As means for achieving the above object, in the present invention,
When shifting is performed by switching from one of the power transmission paths to the one-way power transmission path in which the embroidery clutch operates, after the shift is started, the engine speed is changed until the input / output rotation of the transmission means for selecting the one-way power transmission path is synchronized. The clutch is held in the non-engaged state, and after the input / output rotation is synchronized, the emblem clutch is engaged.

Then, as a device for performing the shift control as described above,
The control device of the present invention has a control solenoid valve that generates a predetermined control hydraulic pressure, and is configured to control the operation of the emblem clutch using the control hydraulic pressure from this control solenoid valve. As the control solenoid valve, a solenoid valve that is on / off controlled or a duty-controlled solenoid valve may be used.

(Operation) When the shift control is performed by the shift control device,
For example, when the shift lever is operated while the accelerator pedal is being depressed (when the power is on) to shift down to the gear position (power transmission path) at which the engine clutch is operated, the gear shift is performed. From the start to the time when the input / output rotation of the speed change means (for example, the speed change clutch) for setting the above speed change step is synchronized, the emblem clutch is OFF (non-engaged) and the speed change via the one-way clutch is performed. After that, when the input and output rotations of the shift clutch are synchronized with each other, the emblem clutch is engaged to set the shift speed at which the engine brake works. Therefore, the gear shift at this time is a smooth gear shift using the one-way clutch.

(Examples) Hereinafter, preferred examples of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing a power transmission system of an automatic transmission AT controlled by a control device according to the present invention. The automatic transmission AT includes a torque converter 5 and a transmission mechanism 10. .

The torque converter 5 includes a pump 6a connected to the engine output shaft 1 and a turbine 6b connected to an output shaft (transmission mechanism input shaft) 11.
And a stator 6c fixedly held, and further, a lockup mechanism 7 capable of engaging and disengaging the pump 6a and the turbine 6b.
Have.

The speed change mechanism 10 is an input shaft integrated with the torque converter output shaft.
11 has a counter shaft 12 and an output shaft 13 which are parallel to this. Between the input shaft 11 and the counter shaft 12, there are five sets of gear trains that mesh with each other, that is, first-speed gear trains 21a, 21.
b 2nd gear train 22a, 22b, 3rd gear train 23a, 23b, 4th gear train 2
4a, 24b and reverse gear trains 25a, 25b, 25c are arranged. Hydraulic actuating clutches 14 to 18 for selecting each gear train are provided as drive gears or driven gears of each gear train, and by selectively actuating these hydraulic actuating clutches 14 to 18 The power transmission path is selectively switched, and gear shifting is performed.

Output gear trains 29a, 29b are arranged between the counter shaft 12 and the output shaft 13, and the power changed as described above is transmitted to the output shaft via the output gear trains 29a, 29b. .

The first-speed driven gear 21b and the second-speed driven gear 22b allow power transmission in the driving direction from the engine, but do not allow power transmission in the opposite direction (engine braking action direction) to be performed by idling. Clutch 26 and 27 are attached. The first speed one-way clutch 26 attached to the first speed driven gear 21b has its input side connected to the first speed driven gear 21b and its output side connected to the input side of the second speed one way clutch 27 attached to the second speed driven gear 22b. There is. Also, 2
The input side of the high speed one-way clutch 27 is further connected to the second speed driven gear 22b, and the output side thereof is connected to the counter shaft 12.

Further, an emblem clutch 19 for locking and holding the one-way clutches 26, 27 is provided. The emblem clutch 19 is a clutch for engaging and disengaging the input side of the first speed one-way clutch 26 and the output side of the second speed one-way clutch 27, depending on whether it is ON (engaged) or OFF (non-engaged). The power transmission will be described separately.

First, the case where the emblem clutch 19 is OFF (non-engaged) will be described. In this case, when the first speed clutch 14 is engaged, the engine output transmitted to the input shaft 11 is transmitted to the counter shaft 12 via the first speed gear trains 21a and 21b and both one-way clutches 26 and 27. . On the other hand, in the deceleration state in which power is transmitted from the wheel side (output shaft 13) side to the engine side, the one-way clutches 26, 27 run idle, so that the counter shaft 12
Is not transmitted from the input shaft 11 to the input shaft 11, and no engine braking action occurs.

When the engine clutch 19 is off and the second speed clutch 15 is on (engaged), the engine output is transmitted from the input shaft 11 to the counter shaft 12 via the second speed gear trains 22a, 22b and the second speed one-way clutch 27. However, the reverse power transmission is blocked by the idling of the one-way clutch 27, and the engine braking action does not occur.

Next, a case where the emblem clutch 19 is ON (engaged) will be described. In this case, the engine output is transmitted from the input shaft 11 to the counter shaft 12 when the first speed clutch 14 is ON or the second speed clutch 15 is ON
And the one-way clutches 26 and 27, respectively.

The reverse power transmission, that is, the transmission of the driving force from the wheel side such as deceleration of the vehicle, is performed via the emblem clutch 19 and the first gear trains 21b and 21a when the first gear clutch 14 is ON. Be seen. When the second speed clutch 15 is ON, it is performed via the emblem clutch 19, the first speed one-way clutch 26 and the second speed gear trains 22b and 22a. Although the power is transmitted through the first-speed one-way clutch 26, the power transmission in the first-speed one-way clutch 26 in this case is transmission in the driving direction, and the power transmission is performed through the one-way clutch 26. Therefore, when the emblem clutch 19 is ON, the power transmission path in which the engine braking is effective is set in both the first speed and the second speed.

The operation control of the lockup mechanism 7 and the operation control of each clutch 14 to 19 of the speed change mechanism 10 of the automatic transmission AT having the above-mentioned configuration are
It is performed by a control valve CV whose hydraulic circuit is shown in FIG.

This control valve CV is a line valve that uses a regulator valve 32 that regulates the hydraulic oil sent from the charge pump 30 to a predetermined line pressure P _L , a modulator valve 34 that creates a modulated pressure P _M from this line pressure, and a linear solenoid. It has a throttle valve 36 that converts P _L into throttle pressure P _TH . The control valve CV is
Have the following valve, the line pressure P _L, modulator pressure
The operation of the lockup mechanism 7 and each clutch is controlled by appropriately using P _M and the throttle pressure P _TH .

First, the control valve of the lockup mechanism 7 will be briefly described. As this valve, L / C on-off valve 4
0, L / C shift valve 42, L / C control valve 44, L / C
Timing valve 46 and duty solenoid valve
There are 155. The L / C on / off valve 40 is a valve for ON / OFF controlling the supply of the line pressure P _L to the line 101, by which ON / OFF control of the lockup mechanism 7 is performed. The remaining valves are valves that control the engagement capacity of the lockup mechanism 7 when the lockup mechanism 7 is turned on by the L / C on / off valve 40. Since this operation is already well known, its explanation is omitted.

The return oil of the torque converter 5 is regulated by the relief valves 48a, 48b, 48c shown in the figure, used for lubrication, cooled through the cooler 49, and then returned to the oil tank.

Next, a valve for controlling the operation of each clutch 14 to 19 in the speed change mechanism 10 to change the speed will be described.

As a valve for this purpose, first, there is a manual valve 50 having a spool 51 which is moved in response to a shift lever operation by a driver. The spool 51 can be moved to seven positions P, R, N, D, 3, 2, and 1 corresponding to the shift lever position, and the line pressure P _L from the line 102 is predetermined corresponding to each position. Supply to the port.

1-2 shift valve 60 for controlling the shift between the first speed and the second speed,
2-3 shift valve 62 for controlling the shift between the 2nd and 3rd speeds and 3-4 shift valve for controlling the shift between the 3rd and 4th speeds
64 is also included in the control valve CV, and the operation of these is controlled by the first and second on / off solenoid valves 151, 152.
It is controlled by the modulating pressure P _M selectively supplied by the ON-OFF operation of.

It also has a clutch pressure control valve 55 and four orifice control valves 56-59. The clutch pressure control valve 55 is a valve that converts the operating pressure of each clutch 14-18 into a pressure corresponding to the throttle pressure P _TH . The orifice control valves 56 to 59 are valves that allow the hydraulic pressure of the front clutch to be released at the same time as the hydraulic pressure of the rear clutch is increased during gear shifting. The 4-3 and 3-4 orifice control valves 56 and 57 release the hydraulic pressures of the 3rd and 4th clutches during the shifting from the 4th to the 3rd and the 3rd to the 4th, respectively. -2 Orifice control valve
58 and 59, respectively from 2nd to 1st and 1st to 2nd
The hydraulic pressure of the 1st and 2nd speed clutches is released when shifting to the 1st speed.

Furthermore, a switching valve 70 that switches between control of the emblem clutch 19 and control of the lockup mechanism 7, an emblem timing valve 75 that controls operation of the emblem clutch 19, the lockup mechanism 7 and the emblem clutch.
3rd on-off solenoid valve used to control 19 15
3 are also provided. These will be described later.

Each clutch 14 to 18 has an accumulator.
81 to 85 are connected to smooth the fluctuations in hydraulic pressure when the clutches 14 to 18 are engaged and to perform smooth gear shifting.

In the control valve CV configured as described above, the operation of the manual valve 50 by operating a shift lever (not shown) and the first to third solenoid valves 151,
The valves are operated by ON-OFF operations of 152 and 153, the hydraulic pressure supply to the clutches 14 to 19 is controlled to perform automatic gear shift, and the operation of the lockup mechanism 7 is controlled.

Depending on the combination of ON / OFF of the normally closed type (normally closed type) first and second solenoid valves 151, 152 and the position of the manual valve 55, the gear position is the third speed.
It is set as shown in the figure. In this figure, LOW
Means power transmission through the first speed gear train, and among the gears, the gears surrounded by circles are gears where the engine brake works.

The shift lever is in the D position and the manual valve 50 is in the D position.
For range, first and second solenoid valves 15
Corresponding to four combinations of 1,152 ON-OFF, as shown in the figure, 1st speed (LOW), 2nd speed (2ND), 3rd speed (3RD) and 4th speed (4
(TH) each gear is set. Also a manual valve
When 50 is in the 3 range, the first speed (LOW), the second speed (2ND) and the third speed (3RD) are shown as shown in the figure corresponding to the four combinations of ON-OFF of the first and second solenoid valves 151, 152. )
Each gear stage of is set. In the D and 3 ranges, the power transmission path with one way, that is, the 1st and 2nd speeds, is the gear stage in which the engine clutch is not effective because the engine clutch is off. However, the third and fourth speeds are direct power transmission paths, and the engine braking is always effective.

On the other hand, when the manual valve 50 is in the 2 or 1 range with the shift lever in the 2 or 1 position, it corresponds to the four combinations of ON-OFF of the first and second solenoid valves 151, 152, as shown in the two ranges. Then 1st speed (LO
W), 2nd speed (2ND) and 3rd speed (3RD) are set, and 1st range is set to 1st speed (LOW) and 2nd speed (2ND). In these 2 and 1 ranges, the 1st speed and the 2nd speed are gear stages where the engine clutch is effective and the engine clutch is ON.

As described above, the selection and switching of the shift speed set corresponding to the ON-OFF combination of the solenoid valves 151 and 152 is performed by the shift map set corresponding to the engine throttle opening θ _TH and the vehicle speed V for each range. Based on. This shift map is shown in FIGS. 4A to 4D, which shows the D range,
It is a shift map for 3 ranges, 2 ranges, and 1 range.

The shift map for the D range has three shift-up lines U1, U2,
It has U3 and three downshift lines D1, D2, D3. U1 and D1 are shift lines from 1st to 2nd and 2nd to 1st, U2
And D2 are shift lines from 2nd speed to 3rd speed and 3rd speed to 2nd speed, U3 and D3 are shift lines from 3rd speed to 4th speed and 4th speed to 3rd speed, and throttle opening θ _TH and vehicle speed V When a point on the map defined by the above-mentioned crosses the shift line, a predetermined shift is performed. Map for 3 ranges (Fig. 4B) is 3
There are no lines U3 and D3 for shifting between 1st and 4th speeds
This is the same as the case of the D range except that the gear is changed up to the high speed.

The two-range shift map has one shift-up line U1 and two shift-down lines D1 and D2 as shown in FIG. 4C. Here, there is no shift-up line U2 from the 2nd speed to the 3rd speed, but this is for basically performing the shift between the 1st speed and the 2nd speed in the 2nd range. However, for example, when the shift lever is operated to switch to the 2nd range from the 3rd speed running state in the 3rd range, the downshift from the 3rd speed to the 2nd speed is performed by the shift down line D2 of the map in FIG. 4C. , I try not to shift down to the 2nd speed where the engine brake works at a too high vehicle speed.

The map shown in Fig. 4D is used for the 1st range. In this case, the gear is basically fixed to the 1st speed (LOW), and this map is used for downshifting when switching to the 1st range by operating the shift lever. The shift bounce line D1 is used to prevent downshifting to the 1st speed where engine braking works at too high a vehicle speed.

Note that such first and second solenoid valves 151,
When setting the shift speed corresponding to the ON / OFF combination of 152, when the system is down, that is, both solenoid valves
When 151 and 152 are turned off, the maximum speed stage in each range is set, and it is aimed to prevent sudden engine braking force from being generated by shifting to the low speed stage when the system is down. At the same time, the shift lever can be manually operated to change the speed from the 4th speed to the 2nd speed for fail-safe operation.

Further, in the R range, the reverse stage is set, and although not shown, in the P and N ranges, both clutches are disengaged and are in a neutral state.

In the above, the first and second solenoid valves 151,
Setting of shift speed by 152, that is, each shift clutch 1
Although the operation control of 4 to 18 has been described, in the automatic transmission AT, the embrace clutch 19 and the lockup mechanism 7 are used.
It is also necessary to control the operation of, which will be described with reference to FIG.

This control includes ON-OFF operation of the normally closed type third solenoid valve 153 and the first solenoid valve 15
Made in response to one actuation. First, D range or 3
In the case of the range, as can be seen from FIG. 3, the emblem clutch 19 may always be OFF (non-engaged), so the lockup mechanism 7 is activated according to ON / OFF of the third solenoid valve 153.
ON-OFF control. On the other hand, in the case of 2 range or 1 range, the lockup mechanism 7 is always turned off, and the first
Further, the emblem clutch 19 is ON / OFF controlled according to ON / OFF of the third solenoid valves 151, 153.

As described above, the third solenoid valve 153 is used to control the operation of the lockup mechanism 7 in the D or 3 range, and is used to control the operation of the emblem clutch in the 2 range or the 1 range. A hydraulic control circuit portion for this purpose is taken out from the circuit of FIG. 2 and shown in FIG. 6, and its operation will be described below with reference to FIG. As shown in the figure, this control requires a manual valve 50, L / C
The on / off valve 40, the switching valve 70, the engine timing valve 75, and the third solenoid valve 153 are used.

First, the case of the D range or the 3 range will be described. At this time, the spool 51 of the manual valve 50 moves rightward from the N position shown in the drawing to the D or 3 position. In the D or 3 position, the ports 50c and 50d of the valve 50 communicate with the port 50a, and the line pressure P _L from the line 102 changes to the lines 111 and
It acts on both ends of the switching valve 70 via 115.
For this reason, the spool 71 of the switching valve 70 is pushed by the spring 72 and is in the left movement position as illustrated.

The line pressure P _L supplied to the line 102 is from the line 102b to the groove of the spool 71 of the switching valve 70 and the line 10.
It acts on the left end of the engine timing valve 75 through 3. When the spool 76 of the valve 75 receives the line pressure P _L , it is moved to the right against the spring 77, and the line 109 to which the line pressure P _L is supplied and the line 1 connected to the emblem clutch 19 are connected.
10 and 10 are cut off by the land portion of the spool 76. Therefore, the emblem clutch 19 is OFF (non-engaged). As will be described later, when the third solenoid valve 152 is turned off, the modulated pressure P _M supplied to the line 105 acts on the right end of the spool 76, but the line pressure P _L is the modulated pressure. It is considerably higher than P _{M, and} even if the modulating pressure P _M acts in this way, the spool 76 remains moved to the right and the emblem clutch 19 remains OFF.

3rd solenoid valve in D or 3 range
Reference numeral 153 is used for ON-OFF control of the lockup mechanism 7.
In the line 108 communicating with the third solenoid valve 153, the modulating pressure P _M supplied to the line 105 is supplied to the orifice 107a.
Is supplied through a line 107 having a line, and when the normally closed type third solenoid valve 153 is OFF, a modulated pressure P _M is generated in the line 108, and when it is ON, the pressure in the line 108 is made substantially zero. . Line 108 is the first spool 4 of the L / C on / off valve 40 via line 108b.
It is connected to the right end of 1a, and the third solenoid valve 153 is O
When FF, the modulating pressure P _M acts on the right end of the first spool 41a and moves the spool 41a left as shown in the figure. As a result, the line 112 communicates with the drain, and the lockup mechanism 7 is turned off.

The line pressure P _L supplied from the line 113 acts on the spool 41a so as to push it to the right. However, since the pressure receiving area is small, regardless of the action of the line pressure P _L , the line pressure P _L When the modulating pressure P _M acts, the spool 41a
Is moved to the left. However, the third solenoid valve 153 is O
When it becomes N and the hydraulic pressure in the line 108b becomes zero, the first spool 41a is moved to the right by the line pressure P _L from the line 113. This right movement makes line 112 line 106
The lockup mechanism 7 is turned on by the modulating pressure P _M supplied from the line 106 to the line 112.

As described above, in the D or 3 range, the emblem clutch 19 is always off, and the third solenoid valve 1
The ON-OFF control of the lock-up mechanism 7 is performed by the ON-OFF control of 53.

Next, the case of two ranges or one range will be described. At this time, the spool 51 of the manual valve 50 moves further to the right and is located at the 2 or 1 position. In the 2 or 1 position this valve 50
Port 50c remains connected to line 102 through the groove of spool 51, but port 50d connects to the drain. Line 1 via line 111 at the left end of switching valve 70
The line pressure P _L remains acting from 02, but line 11
The hydraulic pressure acting from 5 to the right end becomes zero. Therefore, the spool 71 of the switching valve 70 is moved rightward against the spring 72.

When the spool 71 is moved to the right, the land portion of the spool 71 blocks the communication between the line 102b and the line 103, and the line 103 communicates with the drain. As a result, the spool 76 of the engine timing valve 75 is moved to the left by the urging force of the spring 77 and enters the state shown in the drawing.
The line 109 and the line 110 are communicated with each other through the groove. Therefore, the line pressure P _L from the line 109 is supplied to the emblem clutch 19 to bring the clutch 19 into the N (engaged) state.

However, the spool 76 has the first solenoid valve 151 turned off.
In response to the operation, the modulated pressure P _M acts from the line 114 so as to move the spool 76 to the left. When the third solenoid valve 153 is ON, the spool 7 moves from the line 108a.
If the pressure acting on the right end of 6 is zero, this spool 76
Is moved to the left, and the emblem clutch 19 is turned off. In addition,
This condition is also shown in FIG. 4, and as can be seen from this, in the 1st and 2nd ranges, the 1st and 3rd
The operation of the emblem clutch 19 is controlled according to ON / OFF of the solenoid valves 151, 153.

In the case of 1 range or 2 ranges,
The port 50b of the manual valve 50 is communicated with the port 50a, and the line pressure from the line 102 is L / C via the line 104.
It acts on the right end of the second spool 41b of the on / off valve 40. As a result, the second spool 41b moves to the left, and the first spool 41a is held at the left position (the illustrated position). Therefore, the line 112 is always in communication with the drain,
The lockup mechanism 7 is always off. That is, in the 1 or 2 range, the lockup mechanism 7 of the torque converter 5 is always turned off.

To summarize the above control contents, first, D range and 3
In the case of the range, the emblem clutch 19 is always OFF, and the emblem does not work, that is, the shift stage is set through the one-way clutch, and at the same time, the operation control of the lockup mechanism is performed by the third solenoid valve. . On the other hand, in the case of the 1st range and the 2nd range, the lockup mechanism is always OFF, the operation control of the emblem clutch is performed by the third solenoid valve, and normally, the gear stage is set with the emblem clutch ON. .

Shift control by the shift control device of the automatic transmission AT having the above-described configuration will be described.

FIG. 7 shows various signals and clutches when the shift lever is switched to the 2nd range and downshifted to the 2nd speed while the accelerator pedal is depressed while traveling in the 4th speed in the D range. It shows changes over time in hydraulic pressure and clutch input / output speed, and one example of shift control will be described based on this graph.

Here, the shift lever is operated at time t _{1 and the} range determined by the manual valve 50 is switched from the D range to the 2 range. Simultaneously with this range switching, both solenoid outputs are changed so as to shift down the gear set by the first and second solenoid valves 151, 152 from the 4th speed to the 2nd speed. Along with this, the shift valve is actuated, and the clutch hydraulic pressure P ₄ of the fourth speed clutch 17
Is drained and drops rapidly. However, since the emblem clutch 19 is OFF in the D range, the second speed clutch 15 is always ON (engaged). Therefore, in this shift, the second speed clutch hydraulic pressure P ₂ is the predetermined hydraulic pressure (line pressure). ) Is maintained.

Further, at this time t ₁ (shift start time), the third
The solenoid valve 153 is turned on, and the engine clutch 1
Set 9 to OFF (not engaged). After this, when the predetermined time T has elapsed, the third solenoid valve 153 is turned off and the emblem clutch 19 is engaged. The predetermined time T is set equal to or longer than the time until the input / output rotation of the second speed clutch 15 is synchronized, and the emblem clutch 19 is set when the input / output rotation of the second speed clutch 15 is synchronized or thereafter. Is engaged with.

As a result, in shifting in this case, when the engagement of the 4th speed clutch is released, the one-way clutch 27 idles until the input / output rotation of the 2nd speed clutch is synchronized. Since power transmission is started, smooth gear shifting is performed. Since the emblem clutch 19 is engaged after waiting for this synchronization, smooth gear shifting is not impaired.

As can be seen from this, in this case, there is no problem even if the engagement clutch 19 is suddenly engaged. For this reason, as shown in the circuit diagram of FIG.
It is not necessary to connect the accumulators 81-85, which are connected to ~ 18, to the emblem clutch 19.

It should be noted that the predetermined time T from the start of gear shifting until the emblem clutch is turned on is measured using the timer in the above example, but this predetermined time is the time until the input / output rotation of the gear clutch is synchronized. Yes, the input / output rotational speed of the speed change clutch is directly detected, and the synchronization is detected by detecting the time when the input / output rotational speed ratio becomes 1.0, as shown in the graph at the bottom of FIG. The emblem clutch may be turned on at this point.

The control method described above is not limited to the above case, and switching from the D or 3 range to the 2 or 1 range is performed with the accelerator pedal depressed (power-on state). It can be used in all cases where the speed is changed from the second speed to the first speed, and all of these speed changes can be smoothly performed.

Furthermore, not only the shift accompanying the shift lever operation, but also the shift from the 3rd speed to the 2nd speed in the 2nd range,
Even in the case of shifting to the high speed, it is possible to perform control such that the emblem clutch is temporarily released to perform smooth shifting.

However, to change from 2nd speed to 1st speed, use the 2-1 orifice control valve 58 to change from 1st speed to 2nd speed.
The shift timing is controlled by the -2 orifice control valve 59 so that smooth shift with little shift shock can be performed even when the shift clutch 19 is engaged.

The control described above is performed in the case of downshifting in the power-on state. However, in the case of downshifting in the power-off state (state in which the accelerator pedal is returned), the input / output rotation of the speed change clutch is set to the far side. Because of the change, it is necessary to engage the emblem clutch 19 immediately after the engagement of the fourth speed clutch. In this case, it is preferable that the engagement clutch is gently engaged in order to improve the shift feeling.

Therefore, for example, as shown in FIG. 8, instead of the third solenoid valve 153, the duty control solenoid valve 253
It is also possible to use the above and replace the emblem timing valve 75 with the illustrated emblem control valve 275. In this configuration, the spool 276 of the engine control valve 275 receives the control pressure converted by the duty control solenoid valve 253 at the left end,
The right end receives the pushing force of the spring 227 and the embrace clutch pressure.
The hydraulic pressure acting on the embrace clutch 19 from 109 is controlled via a line 220. Therefore, the engagement of the emblem clutch 19 can be arbitrarily controlled, and the shift feeling can be improved.

This control can be performed without using the engine control valve 275, as shown in FIG.
It is also possible to directly control the hydraulic pressure to be supplied to the embrace clutch 19 by using 3.

C. EFFECTS OF THE INVENTION As described above, according to the present invention, for example, the state in which the accelerator pedal is depressed (when the power is on)
In the case where the shift lever is operated with the shift lever to shift down to the shift stage (power transmission path) in which the embrace clutch is operated, the shift means for setting the shift stage from the start of the shift (for example, The emblem clutch is off until the input / output rotation of the gear shift clutch) is synchronized.
(Non-engaged), the gear shift is performed via the one-way clutch, and when the input / output rotations of the gear shift clutch are synchronized thereafter, the emblem clutch is engaged to set the gear stage at which the engine brake works. . Therefore, the gear shift at this time is a smooth gear shift using the one-way clutch, and the shift feeling can be improved. Furthermore, since the engagement of the emblem clutch at this time does not cause any problem, an accumulator for the emblem clutch is not required, and the hydraulic control valve and the like can be reduced in size and weight accordingly.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a power transmission system of an automatic transmission AT controlled by a control method according to the present invention, FIG. 2 is a hydraulic circuit diagram of a control valve as a control device according to the present invention, and FIG. A table showing the relationship between the operation and manual valve positions of the first and second solenoid valves and the shift speed, FIGS. 4A to 4D are graphs showing a shift map used for shifting by the control device, and FIG. 5 is A table showing the relationship between the operation of the first and third solenoid valves and the operation of the emblem clutch and the lockup mechanism. FIG. 6 is a hydraulic circuit diagram showing a part of the circuit of FIG. 2 and FIG. FIG. 8 and FIG. 9 are graphs showing changes over time of various shift command signals, clutch pressure, and clutch input / output speed ratio when the shift control according to the present invention is performed. It is a hydraulic circuit diagram showing an example. 5 ... Torque converter, 7 ... Lock-up mechanism 10 ... Transmission mechanism, 19 ... Emble clutch 26, 27 ... One-way clutch 32 ... Regulator valve 34 ... Modulator valve 40 ... L / C on / off valve 50 ... … Manual valve 70… Switching valve 75… Emble timing valve 151, 152, 153… Solenoid valve AT… Automatic transmission CV… Control valve

Claims (4)

[Claims] 1. An automatic transmission that shifts gears by switching and selecting a plurality of power transmission paths having different gear ratios, wherein the power transmission path includes a one-way clutch that allows only power transmission in a driving direction. In an automatic transmission including at least one one-way power transmission path having an embrace clutch that locks this one-way clutch, from one of the power transmission paths to the one-way clutch power transmission path where the emble clutch operates. When the gear is changed by switching, the emblem clutch is kept in the non-engaged state from the start of the gear shift until the input / output rotation of the gear shifting means for selecting the one-way power transmission path is synchronized, and the input / output rotation is synchronized. After that, the automatic clutch is characterized in that the embrace clutch is engaged. Shift control method of. 2. An automatic transmission that shifts gears by switching and selecting a plurality of power transmission paths having different gear ratios, wherein the power transmission path includes a one-way clutch that allows only power transmission in a driving direction. An automatic transmission including at least one one-way power transmission path having an embrace clutch for locking the one-way clutch, wherein the automatic transmission has a manual valve for setting a plurality of ranges and an operation of the manual valve. And a shift lever for manually switching the range to perform range switching, the range switching is performed by manual operation of the shift lever, and the one-way power transmission path in which the embrace clutch operates from any one of the power transmission paths. When the gear is changed by switching to, the one-way The emblem clutch is kept in the disengaged state until the input / output rotations of the speed change means for selecting the power transmission path are synchronized, and after the input / output rotations are synchronized, the emblem clutch is engaged. And a shift control method for an automatic transmission. 3. An automatic transmission that shifts gears by switching and selecting a plurality of power transmission paths having different gear ratios, wherein the power transmission path includes a one-way clutch that allows only power transmission in a driving direction. In an automatic transmission that includes at least one power transmission path with a one-way that has an embrace clutch that locks this one-way clutch, a control solenoid valve that generates a predetermined control hydraulic pressure independent of the shift control hydraulic pressure is included. The shift control device for an automatic transmission is characterized in that the control hydraulic pressure from the control solenoid valve can be used to independently control the operation of the emblem clutch. 4. The shift control device for an automatic transmission according to claim 3, wherein the control solenoid valve is a duty-controlled solenoid valve.