JP2839031B2 - Shift control device for automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a second coast brake for locking front and rear sun gears (hereinafter, referred to as front and rear sun gears) when switching the shift of an automatic transmission. In particular, the present invention relates to a control device for a cutoff valve that supplies hydraulic pressure to a hydraulic servo that engages and disengages a second coast brake.

(Prior Art) Conventionally, an automatic transmission for an automobile is provided with a multi-plate clutch or a brake for engaging and disengaging various shafts, gears, etc. when switching gears of the automatic transmission. Have been. For example, the forward clutch is used to connect the input shaft and the front ring gear, the direct clutch is used to connect the input shaft and the rear sun gear, the second coast brake locks the front and rear sun gear, and the second brake is used for the front & rear sun gear. Fast & reversal brakes are used to lock the rear planetary carrier to lock the left rotation of the rear sun gear.

The second coast brake receives a hydraulic pressure from a 1-2 shift valve via a second coast modulator valve. When the vehicle shifts from the 1st speed to the 2nd speed in the case of 2nd range driving, and D
Engage when manual down from range driving to 2nd range to lock the front & rear sun gear.

(Problems to be solved by the invention) However, when the vehicle is traveling in the second range as described above,
In the case of shifting up from the second speed to the second speed, the second brake and the second coast brake are in the released state in the first speed state, whereas both brakes are simultaneously engaged in the second speed state. In many cases, the driver performs the upshifting while stepping on the accelerator, so that the shock caused by the engagement of the two brakes is considerably large.

Also, when driving downhill while driving in the D range, the driver may manually shift down to the 2nd range, but in this case, only the second brake was engaged until then. On the other hand, the second coast brake is also engaged by the downshift. The driving situation occurs when it is necessary to apply the engine brake on a steep downhill or the like, but it is desirable that the second coast brake be engaged quickly. If the engagement is slow, the vehicle coasts, giving the driver a sense of idle running.

The present invention solves the above-mentioned problems of the conventional automatic transmission, and suppresses the occurrence of a shock due to the engagement of the friction engagement element when performing acceleration while shifting while the accelerator is on. It is another object of the present invention to provide a shift control device for an automatic transmission that can prevent a vehicle from coasting when performing speed change while decelerating with an accelerator off.

(Means for Solving the Problems) For this purpose, the shift control device in the automatic transmission according to the present invention is arranged to achieve a predetermined shift speed in the transmission gear mechanism and to achieve the shift speed during engine braking. The present invention is applied to an automatic transmission including a provided friction engagement element, a hydraulic servo that disengages the friction engagement element, and a shift valve that supplies and discharges hydraulic pressure to and from the hydraulic servo.

A cut-off valve is provided between the hydraulic servo and the shift valve. The cut-off valve receives two positions in response to a throttle oil pressure that changes according to depression of an accelerator pedal. The port connecting the shift valve side and the hydraulic servo side is narrowed when the accelerator is off.

In the shift control device for another automatic transmission according to the present invention, the cutoff valve may further include a first port connected to the shift valve, a second port connected to the shift valve, and a third port connected to the hydraulic servo. And a position where the second port and the third port communicate with each other when the accelerator is on, and the first and the second ports when the accelerator is off.
A position where the second port and the third port communicate with each other is taken.

(Operation and Effect of the Invention) According to the present invention, as described above, the shift control device of the automatic transmission achieves a predetermined shift speed in the speed change gear mechanism and achieves the shift speed during engine braking. The present invention is applied to an automatic transmission that includes a friction engagement element disposed in a hydraulic servo, a hydraulic servo that disengages the friction engagement element, and a shift valve that supplies and discharges hydraulic pressure to and from the hydraulic servo.

A cut-off valve is provided between the hydraulic servo and the shift valve, and the cut-off valve takes two positions in response to a throttle oil pressure that changes according to the depression of an accelerator pedal. The port connecting the shift valve side and the hydraulic servo side is narrowed when the accelerator is off.

In this case, when shifting and accelerating while the accelerator is on, for example, when traveling in the second range and shifting up to a predetermined gear, the port connecting the shift valve side and the hydraulic servo side is not connected. Since the throttle is squeezed, the engagement of the friction engagement element is delayed.

Therefore, it is possible to suppress the occurrence of a shock due to the engagement of the friction engagement element.

When the vehicle is decelerated by shifting while the accelerator is off, for example, when driving in the D range and downshifting to a predetermined gear, the port is not throttled. It will be faster.

Therefore, the engine brake can be applied quickly with the shift, so that the vehicle can be prevented from coasting, and the driver is not given a feeling of idling.

In the shift control device for another automatic transmission according to the present invention, the cutoff valve may further include a first port connected to the shift valve, a second port connected to the shift valve, and a third port connected to the hydraulic servo. And a position where the second port and the third port communicate with each other when the accelerator is on, and the first and the second ports when the accelerator is off.
A position where the second port and the third port communicate with each other is taken.

In this case, when the accelerator is on, the second port and the third port
The port is connected to the first port, so that the amount of oil supplied to the hydraulic servo is reduced.
Since the second port and the third port are communicated,
The amount of oil supplied to the hydraulic servo increases.

(Example) Hereinafter, an example of a shift control device in an automatic transmission of the present invention will be described in detail with reference to the drawings.

2 and 3, the automatic transmission 1 includes a torque converter 2, a planetary gear transmission gear mechanism 3, and a hydraulic control device 5, and includes a converter housing 6, a case 7, and an extension housing 9, respectively. Are housed in the valve body 10 and the oil pan 11.

The torque converter 2 is provided with a lock-up clutch 12 for improving power transmission efficiency, and the rotational power of the input member 13 is indirectly transmitted by an oil flow in the torque converter 2 or the lock-up clutch 12 It is transmitted directly to the input shaft 15 of the transmission gear mechanism 3 by the engagement.

The transmission gear mechanism 3 has an overdrive planetary gear unit 17 and a front planetary gear unit 19 and a rear planetary gear unit 20.
And a main transmission unit 21 composed of

Here, the overdrive planetary gear unit
17 is connected to the input shaft 15 and the planetary pinion 22
Carrier 24 supporting the sun gear 2 surrounding the input shaft 15
3, and a ring gear 25 connected to the input shaft 26 of the main transmission unit 21. Also, carrier 24 and sun gear
Between 23, an overdrive direct clutch C ₀ and a one-way clutch F ₀ are interposed,
Overdrive brake B ₀ is disposed between the sun gear 23 and the case 7.

Next, the front planetary gear unit 19 is connected to the output shaft 27.
Be connected to a carrier 29 that supports the planetary pinion 28, and 30a that are configured with the sun gear 30b integral with the rear planetary gear unit 20 with surrounding the output shaft 27, the forward clutch C ₁ on the input shaft 26 And a ring gear 31 which is connected through the ring gear 31. A direct clutch C ₂ is provided between the input shaft 26 and the sun gear 30a,
Second coast brake B ₁ consisting of a band brake is interposed between the sun gear 30a and the case 7. Between the sun gear 30a and the case 7, further second brake B ₂ is disposed consisting of multi-plate via a one-way clutch F _1.

The rear planetary gear unit 20 includes a carrier 33 that supports the planetary pinion 32, a sun gear 30b, and a ring gear 35 that is directly connected to the output shaft 27. A 1st & Rev brake B ₃ is provided between the carrier 33 and the case 7. the one-way clutch F ₂ are arranged in parallel with. The second
In the figure, reference numeral 36 denotes a hydraulic pump.

Here, as shown in FIG. 2, in the overdrive planetary gear unit 17, the boss portion 23 of the sun gear 23 is provided.
a is extending in the axial direction, the one-way clutch F ₀ between the sleeve 24a fixed to the boss portion 23a and the carrier 24 are interposed.

Further, a flange portion 40 constituting a cylinder extends from the boss portion 23a, and a piston 41 is formed on the flange portion 40.
There constitute a hydraulic actuator for overdrive direct clutch C ₀ fitted. Then, between the flange portion 40 inner peripheral surface and the casing 7 and overdrive brake B ₀ is provided, an annular flange portion 42 extending radially outward is fixed to the outer periphery of the flange portion 40 You.

A number of holes or notches are formed in the flange portion 42, and a non-contact type sensor 45 such as light or magnetism is provided on the case 7 so as to face the holes or notches. The sensor
45, when connecting the overdrive direct clutch C _0, i.e. the first speed, second speed, the third speed, for detecting the rotational speed of the flange portion 42 integral with the input shaft 15.

On the other hand, a vehicle speed sensor 46 for detecting rotation of the output shaft 27 is disposed in the extension case 9, and signals from the vehicle speed sensor 46 and the sensor 45 are sent to a control unit together with signals from other sensors, Hydraulic control device 5 to be described later
The solenoid valves S ₁ , S ₂ , S ₃ and S ₄ (see FIG. 4) are controlled.

Next, the hydraulic control device 6 will be described with reference to FIG.

In the drawing, C ₀ , C ₁ , and C ₂ are hydraulic servos of the respective clutches, and B ₀ , B ₁ , B ₂ , and B ₃ are hydraulic servos of the respective brakes. 2 is a torque converter, 36 is a hydraulic pump, and 37 is a strainer.

Reference numeral 51 denotes a manual valve which is operated when the driver performs a shift shift.The manual valve is connected to a shift lever in the driver's seat via a push-pull cable, and each position P, R, N, and Switch to D, 2nd, L,
The line pressure port p communicates with each of the ports a, b, c, d as shown by the circles in FIG.

Reference numeral 52 denotes a primary regulator valve that regulates a line pressure by a throttle modulator pressure and a line pressure at the time of reverse, and supplies the regulated oil to a lock-up relay valve 57 and a secondary regulator valve 55 described later.

Reference numeral 53 denotes a throttle valve, which compresses the upper and lower two springs according to the degree of depression of the accelerator pedal, and obtains a throttle pressure corresponding to the engine output by a cutback pressure from a cutback valve 59 described later. belongs to.

Reference numeral 55 denotes a secondary regulator valve which adjusts the hydraulic pressure from the primary regulator valve 52 to provide lubricating hydraulic pressure and supplies the lubricating hydraulic pressure to a lock-up relay valve 57.

Reference numeral 56 denotes a lock-up control valve, which adjusts a hydraulic pressure related to a valve tip of the lock-up relay valve 57. Further, the lock-up relay valve 57 is operated by a signal pressure from the linear solenoid valve S ₃ and the solenoid relay valve 58, is to disengage the lock-up clutch 12 of the torque converter 2.

Reference numeral 59 denotes a cutback valve, which applies cutback pressure to the throttle valve 53 to regulate the pressure of the throttle pressure. The cutback valve
59, when other than L range or R-range is operated by hydraulic pressure supplied to the second coast brake B ₁ and second brake B _2.

60 is a 1-2 shift valve for switching between a first speed and the second speed, they become as oil pressure of the solenoid valve S ₂ is supplied to the tip, the valve 60 takes the right half position when the first speed, Takes the left half position at 2,3,4th speed. In other words, it is in the right half position in the first gear, and the second coast brake
B ₁ , the hydraulic pressure supply to the second brake B ₂ is constantly stopped,
Hydraulic pressure supply to the 1st & Rev brake B ₃ only when the L-range is to be carried out. Then, the second speed when the valve is in the left-half position, so that the hydraulic pressure from the manual valve 51 is supplied to the second brake B _2. In the 2nd and L ranges, 2-
Receiving the hydraulic pressure from 3 shift valve supplies the second coast brake B ₁ via the second coast modulator valve 66 this.

Further, 61 is a 2-3 shift valve for switching between a second speed and third speed, hydraulic pressure of the solenoid valve S ₁ at the tip is not to be supplied, the valve 61 is the right half the time 2 speed Take the position and take the left half position at 3rd and 4th speed. Ie 1,2
Supply of hydraulic pressure to the direct clutch C ₂ which has been stopped when fast is, so the valve becomes the third speed is performed by the left-half position.

Then, 62 is a 3-4 shift valve for switching between a third speed and the fourth speed, they become as oil pressure of the solenoid valve S ₂ is supplied to the tip, the valve 62 at the time of 1, 2, 3 speed Take the right half position and take the left half position at 4th speed. That is, the hydraulic pressure to the overdrive direct clutch C ₀ which has been supplied at the time of 1, 2, 3 speeds are taken to the fourth speed is not supplied by the valve is in the left-half position, whereas when the 1,2,3-speed so the supply of hydraulic pressure is conducted to the overdrive brake B ₀ which has been stopped.

63 when the vehicle speed is more than 9km / h for example, actuated by the solenoid valve S ₂ is opened, a reverse inhibit valve for stopping the oil pressure to the direct clutch C _2.

Reference numeral 65 denotes a low coast modulator valve, and 66 denotes a second coast modulator valve, which is activated when the engine brake is applied.

Each of the clutches C ₀ , C ₁ , C ₂ and the brakes B ₀ , B ₂ is provided with an accumulator. That is, 67 C ₀ accumulator 68 is C ₁ accumulator, the 69 B ₀ accumulator, the C ₂ accumulator 70, 71 is an accumulator for B _2. The B ₀ accumulator 69, the back pressure chamber of the C ₂ accumulator 70 and B ₂ accumulator 71 69
An accumulator control valve 72 is provided for adjusting the hydraulic pressure communicating with a, 70a, and 71a, and for adjusting the low coast modulator valve 65 and the second coast modulator valve 66.

Then, S ₁ and S ₂ are solenoid valves for switching and controlling the 1-2 shift valve 60,2-3 shift valve 61,3-4 shift valve 62 as described above, S ₃ and S ₄ are linear solenoid valves The hydraulic pressure adjusted by the solenoid modulator valve 73 is supplied.

74 is an orifice control valve, and 75 is a cutoff valve.

In the hydraulic control circuit, in the case of the shift control device for an automatic transmission according to the present invention, the second coast brake B ₁
A cut-off valve 75 is provided between the 1-2 shift valve 60 and the hydraulic servo to supply and discharge the hydraulic pressure to and from the hydraulic servo operating the.

That is, in the 1-2 shift valve 60, the port e
There have been connected to the solenoid S _2, the 1-2 shift valve 60 takes the right half position when the first speed, second speed, third speed, take left half position when the fourth speed. The port f is connected to the port b of the manual valve 51 via the 2-3 shift valve 61, and receives the line pressure in the 2nd and L ranges. The line pressure is 1-2 shift valve 60
Is connected to port g when it is at the left half position, and supplies hydraulic pressure to port g 'of second coast modulator valve 66. Port h is connected to the port a of the manual valve 51, and supplies the line pressure to the second brake B ₂ via the port i.

The second coast modulator valve 66 connected to the 1-2 shift valve 60 via the port g 'supplies the adjusted hydraulic pressure to the cutoff valve 75 via the port j.

The cutoff valve 75 has a port k and a port 1 that receive a hydraulic pressure according to the acceleration / deceleration state of the vehicle, for example, a hydraulic pressure from the throttle valve 53. The right half position is taken when the accelerator is on, and the left half position is taken when the accelerator is off. Therefore, when the accelerator is turned on, the oil pressure of the port j of the second coast modulator valve 66 is supplied only via the port J ₂ as a second port, the second coast brake B ₁ from a port m of the third port will sent by that, operation of the second coast brake B ₁ represents slower. On the other hand, when the accelerator is turned off, the oil pressure of the port j of the second coast modulator valve 66, the port J ₂ not only, first
As much oil is supplied via port j ₁ as port, much oil is supplied via port m to second coast brake B ₁
And its operation becomes faster.

Incidentally, the port n is an accelerator is in communication with the port p in the off, is for supplying a back pressure to the overdrive direct clutch C ₀ accumulator. And
In order to provide a snap action to the cutoff valve 75 at this time, two ports k and l for receiving hydraulic pressure from the throttle valve 53 are provided.

Here, each solenoid valve S ₁ , S
₂ , S ₃ , S ₄ , clutches C ₀ , C ₁ , C ₂ , brakes B ₀ , B ₂ , B ₃ and one-way clutches F ₀ , F ₁ , F ₂ are respectively positioned P, R, R (V
≧ 9), the 6th gear at N, D, 2nd, L
The control is performed as shown in the operation table shown in FIG.

That is, when the first speed in the D range or 2nd range, the solenoid valve S ₁ is in an ON state, the result overdrive direct clutch C _0, the one-way clutch F _0, F _2, and the forward clutch C ₁ is engaged, Others are open. Therefore, overdrive planetary gear unit 17, overdrive direct clutch C ₀ and the one-way clutch via the F ₀ has become directly coupled together, the input shaft 26 of the intact primary shifting unit 21 rotates the input shaft 15 Conveyed to. In the main transmission unit 21, the rotation of the input shaft 26 is
C ₁ is transmitted to the ring gear 31 of the front planetary gear unit 19, further transmitted to the carrier 29 and the output shaft 27 integral with the carrier 29, and the carrier 33 of the rear planetary gear unit 20 is transmitted via the sun gear 30. a imparts a rotational force of the left, since the rotation is prevented by the one-way clutch F _2, planetary pinion 32 for transmitting power to the ring gear 35 integral with the output shaft 27 to rotate.

At the 2nd speed in the D range, the solenoid valve
Solenoid valve S ₂ in addition to on the S ₁ is switched on. With this, the overdrive direct clutch
C ₀ , one-way clutch F ₀ , forward clutch C ₁ , one-way clutch F ₁ and second brake B ₂ are engaged,
It becomes another release state. Therefore, the overdrive planetary gear unit 17 is in the directly connected state described above, and the rotation of the input shaft 15 is transmitted to the input shaft 26 of the main transmission unit 21 as it is. Further, speed-change unit 21 is transmitted to the ring gear 31 of the front planetary gear unit 19 through a rotating forward clutch C ₁ of the input shaft 26, imparts a rotational force of the left direction to the sun gear 30 via the planetary pinion 28 , the sun gear 30 is rotated in the said direction is prevented by the one-way clutch F ₁ due to the engagement of the second brake B _2. Therefore, the carrier 29 rotates while the planetary pinion 28 rotates, and the second speed rotation is transmitted to the output shaft 27 via only the front planetary gear unit 19.

Also, at 3rd speed in D range and 2nd range,
Solenoid S ₁ is turned off, overdrive direct clutch C _0, the one-way clutch F _0, the forward clutch
C ₁ , the direct clutch C ₂ and the second brake B ₂ are engaged, and the others are in the released state. Therefore, overdrive planetary gear unit 17 is in a directly coupled state as described above, also the main transmission unit 21, the front planetary gear unit 19 by engaging the forward clutch C ₁ and the direct clutch C ₂ is integral, the input The rotation of the shaft 26 is transmitted to the output shaft 27 as it is.

Then, in a four speed i.e. the highest speed stage in the D range, the solenoid valve S ₂ is also turned off, the forward clutch C _1, the direct clutch C ₂ and the second brake B ₂ is in the engaged state, when the main speed change unit 21 is the third speed Although the same manner directly coupled with the overdrive planetary gear unit 17, overdrive brake B ₀ is changed over to be engaged with overdrive direct clutch C ₀ is released. Accordingly, the sun gear 23 is locked by the over-drive brake B _0, planetary pinion 22 carrier 24 while rotating is being rotated by the power transmitted to the ring gear 25, the input shaft of the main transmission unit 21 in a directly connected state 26
, The rotation of the overdrive is transmitted.

On the other hand, during a downshift in the case of 4-3, overdrive brake B ₀ is released with overdrive direct clutch C ₀ is engaged, and if the 3-2, direct clutch C ₂ is released, 2- 1, the second brake B ₂ is released.

When the manual valve 51 is operated in the second range, the first and third speeds are the same as those in the D range. And in the case of 2nd gear, forward clutch
In addition to C ₁ , the overdrive direct clutch C ₀ and the second brake B ₂ , the second coast brake B ₁ is engaged, and the sun gear 30 of the main transmission unit 21 is locked and the engine brake is activated.

The second speed in the L range is the same as the second speed in the two ranges described above, but in the first speed, the 1st & Rev brake B ₃ is engaged in addition to the forward clutch C ₁ and the overdrive direct clutch C _0. At the same time, the carrier 33 of the rear planetary gear unit 20 is locked, and the engine brake is activated.

Next, in the R range, the overdrive direct clutch C ₀ , the one-way clutch F ₀ and the direct clutch C ₂
And engaging the brake B _3, the other is in a released state. Therefore, overdrive planetary gear unit 17 is in a directly connected state, also the main transmission unit 21, rotation of the input shaft 26 is transmitted directly to the sun gear 30 by the direct clutch C _2, and the rotation of the rear carrier 33 by the brake B ₃ Since the sun gear 30 is locked, the rotation of the sun gear 30 is transmitted as reverse rotation to the ring gear 35 via the rotation of the planetary pinion 32, and the output shaft 27 rotates in reverse. Also, manual valve 51
Is operated in the R range, the vehicle speed is a predetermined speed, for example, 9 km /
If there is more than h, it is a solenoid valve S ₂ is turned on,
Since direct clutch C ₂ is in the released state, not in the reverse rotation state. That is, the direct clutch C ₂ is prevented engaged in traveling at a predetermined speed or more speed.

Here, when the vehicle is traveling in the second range and shifting up from the first speed to the second speed, the accelerator is on and the cutoff valve 75 is at the right half position. Therefore, the port j ₁ and port j ₂ of the cut-off valve 75
Only the port j ₂ of the squeezing amount of oil to the second coast brake B ₁ communicates with the port m, the engagement is delayed. Therefore, since the simultaneous engagement of the second brake B ₂ and the second coast brake B ₁ is eliminated, the shock given to the driver by the shift-up is reduced.

Also, when the driver shifts down to the second speed manually while driving in the D range, the accelerator is off and the cutoff valve 75 is in the left half position. Therefore, increasing the amount of oil to the second coast brake B ₁ both ports j ₁ and port j ₂ of the cut-off valve 75 is communicated with the port m, hasten its engagement. Therefore, it will not coast when downshifting,
The feeling of idling given to the driver is eliminated.

It should be noted that the present invention is not limited to the above embodiments, and various modifications are possible based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[Brief description of the drawings]

FIG. 1 is a shift control device for an automatic transmission according to the present invention;
FIG. 2 is an overall sectional view of an automatic transmission to which the present invention is applied, FIG. 3 is a schematic configuration diagram, FIG. 4 is a circuit diagram showing the hydraulic control device, and FIG. 5 is an operation of a manual valve in each range. FIG. 6 is a diagram showing the operating states of the solenoid valve, clutch, brake, and one-way clutch in each range. DESCRIPTION OF SYMBOLS 1 ... Automatic transmission, 2 ... Torque converter, 3 ... Transmission gear mechanism, 5 ... Hydraulic control device, 6 ... Converter housing, 7 ... Case, 10 ... Valve body, 11 ...
Oil pan, 12 Lock-up clutch, 17 Overdrive planetary gear unit, 19 Front planetary gear unit, 20 Rear planetary gear unit, 21 Main transmission unit, 51 Manual valve, 52 … Primary regulator valve, 53 …… Throttle valve, 55 …… Secondary regulator valve,
60 ... 1-2 shift valve, 61 ... 2-3 shift valve, 62 ... 3-4 shift valve, 65 ... low coast modulator valve, 66 ... second coast modulator valve, 73 ... solenoid modulator valve, 75…
… Cutoff valve, B ₁ … Second coast brake, B ₂ … Second brake.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yutaka Taga 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Kunihiro Iwaki 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) References JP-A-60-260751 (JP, A) JP-A-62-93448 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16H 59/00-61 / 12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (2)

(57) [Claims] A friction engagement element provided for achieving a predetermined shift speed in a transmission gear mechanism and for achieving the shift speed during engine braking, and a hydraulic pressure for disengaging the friction engagement element. In a servo and an automatic transmission including a shift valve that supplies and discharges hydraulic pressure to the hydraulic servo, a cutoff valve is provided between the hydraulic servo and the shift valve, and the cutoff valve is The throttle valve takes two positions in response to the throttle oil pressure that changes in accordance with the depression of the accelerator pedal, and when the accelerator is on, the port connecting the shift valve side and the hydraulic servo side is narrowed more than when the accelerator is off. Shift control device for transmission. 2. The cut-off valve has first and second ports connected to the shift valve and one third port connected to the hydraulic servo.
When the accelerator is on, the second port and the third port communicate with each other. When the accelerator is off, the first and second ports are connected.
The shift control device for an automatic transmission according to claim 1, wherein the shift control device takes a position where the third port and the third port communicate with each other.