JPH09177958A - Hydraulic pressure control device of automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow an operating oil to be fed to a friction engaging element directly, and to set a running stage to secure a certain level of running function of a vehicle, by applying the output hydraulic pressure of a change-over valve to a control valve in the direction communicating the output hydraulic pressure and the friction engaging element. SOLUTION: At first, by communicating an oil passage 12 and an oil passage 80 in a manual valve 20, an operation hydraulic pressure having a line pressure is fed to the oil passage 80. And the oil passage 80 is communicated to an oil passage 82 in a delivery shift valve 32, and the oil passage 82 is communicated to the right side end of a pressure delivery valve. As a result, the line pressure is operated to the right side end of the pressure delivery valve, and the spool of the pressure delivery valve which was moving to the right before in a D range moves to the left so as to communicate an oil passage 70a and another oil passage. Consequently, by turning on a solenoid valve SE, a second brake B2 is engaged and operated by its output pressure, and an engine brake can be operated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic control system for an automatic transmission, and more specifically, in an automatic transmission mounted on a vehicle, it supplies a hydraulic pressure to a friction engagement element for setting a speed stage. It relates to a device for controlling.

[0002]

2. Description of the Related Art An automatic transmission has a plurality of gear trains having different gear ratios between its input and output. These gear trains are controlled by hydraulically engaging and disengaging frictional engagement elements such as clutches and brakes. The gear train used for power transmission is selected from among the above, and the output rotation of the engine is changed in speed and transmitted to the drive system of the vehicle.

FIG. 15 shows an example of a hydraulic circuit of a conventional device for hydraulically controlling the automatic transmission as described above. In the conventional device as shown in FIG. 15, a plurality of solenoid valves (A '...
E ′) is provided, and the frictional engagement elements (K1 ′, K2 ′, K3 ′, B1 ′, B) are provided by this solenoid valve.
2 ') is directly controlled to control the shift of the operating oil pressure. The frictional engagement element K1 'will be described below as an example.

The engagement state of each friction engagement element of this hydraulic circuit at each gear is as shown in FIG.
In FIG. 16, the right half shows the energization state at each shift stage to the electromagnetic solenoid provided in each solenoid valve),
As shown in FIG. 16, only the friction engagement element K1 ′ is engaged when the first speed (1ST) is set. Referring to FIG. 15 again, the supply of hydraulic oil to K1 ′ at the time of setting the first speed will be described. First, the hydraulic oil supplied to the regulator valve 512 from the pump 510 and adjusted to a predetermined line pressure is , Solenoid valve A ′ through oil passage 514
Leads to. As described above, the solenoid valve A'is in the non-energized state when the first gear is set, and the solenoid valve A'is a normally open type (the valve is open when not energized and is closed when energized). The operating oil passes through the solenoid valve A ′ and is supplied to the manual valve 518 through the oil passage 516.

The spool 5 of the manual valve 518
The state shown in FIG. 15 of FIG. 20 is in the N and P positions, which is a state when the N (neutral) range or the P (parking) range is selected by the shift lever (not shown).

Here, the D (drive) range is selected by the shift lever, and the spool 5 of the manual valve 518 is selected.
When 20 moves from the illustrated state to the right and moves to the position D, the oil passage 516 communicates with the oil passage 522, and the hydraulic oil is supplied to the friction engagement element K1 ′ located at the end of the oil passage 522, and Engage. At the same time, another solenoid valve B ',
Turn off the power supply to the electromagnetic solenoids D'and E ',
If the energization state to C'is turned on, detailed description will be omitted, but other friction engagement elements K2 ', K3', B1 ', B
2'is in the non-engaged state, and the first speed (1ST) is set.

[0007]

In the hydraulic circuit of the conventional hydraulic control system for an automatic transmission shown in FIG. 15, when the manual valve 518 is selected in the D position, the operating hydraulic pressure is supplied to the friction engagement element K1 '. Is a solenoid valve A '
Directly controlled by the solenoid valve A '
However, there was a problem that if it failed, only the highest speed stage could be formed.

That is, in the conventional hydraulic control system for an automatic transmission, when a solenoid valve is provided and the output hydraulic pressure directly controls the operating hydraulic pressure supply to each friction engagement element to control the shift, the solenoid valve However, when there is a malfunction, the gear shift malfunctions in which a predetermined shift speed cannot be set, and there is a problem that the vehicle drivability is deteriorated.

In view of such a problem, there has been proposed a technique for directly supplying the working hydraulic pressure from the manual valve to the friction engagement element without using the solenoid valve when the lowest position (1 position) of the manual valve is selected. This will be described with reference to FIGS. 17 and 18.

17 and 18 respectively show respective parts of the hydraulic circuit, and these two figures constitute one hydraulic circuit. In each figure, an oil passage with a circled alphabet at the end is connected to an oil passage with the same circled alphabet in the other figure.

Although a plurality of solenoid valves (A "to E") are also provided in the hydraulic circuits shown in FIGS. 17 and 18, the frictional engagement element K1 "will be taken as an example to explain the engagement.

The engagement state of each friction engagement element provided in the hydraulic circuit shown in FIGS. 17 and 18 at each gear is as follows.
This corresponds to the one shown in FIG. Therefore, only the friction engagement element K1 ″ is engaged when the first speed (1ST) is set. Here, the supply of hydraulic oil to the friction engagement element K1 ″ when the first speed is set will be described first. The hydraulic oil supplied from the pump 610 to the regulator valve 612 and adjusted to a predetermined line pressure reaches the manual valve 616 through the oil passage 614. Shown here (Fig. 1
The state of 8) is the spool 61 of the manual valve 616.
8 is in the N and P positions. When this moves to the 1st position by moving 2 positions to the right, the oil passage 614 and the oil passage 620 communicate with each other to cause the underdrive engagement control valve 622.
To reach the oil passage 624.

This oil passage 624 is provided with a manual valve 61.
When one position 6 is selected, it is connected to the frictional engagement element K1 ″ by communicating with the oil passage 626, so that the hydraulic pressure is supplied to the frictional engagement element K1 ″. On the other hand, although description is omitted, when the manual valve 616 is selected at one position, K2 ″, K3 ″, and B1 ″ are in the disengaged state without being supplied with the operating oil pressure, and B2 ″ is supplied with the operating oil pressure. Therefore, the first speed stage (1ST) is set.

As described above, in the hydraulic circuit of the hydraulic control system for the automatic transmission shown in FIGS. 17 and 18, when the manual valve 616 is set to one position, the friction engagement element K1 ″ is directly connected to the friction engagement element K1 ″ without the solenoid valve. Therefore, it is possible to avoid the occurrence of the problem that the solenoid valve A cannot be formed except for the highest speed stage, which has occurred in the device shown in FIG.

Here, in the hydraulic circuit of the hydraulic control system for an automatic transmission shown in FIGS. 17 and 18, the underdrive engagement control valve 622 is a friction engagement element K.
It is provided to alleviate the shock when the 1 "is engaged.

However, with the underdrive engagement control valve 622 as shown, the oil passage 62
Since the hydraulic pressure of the hydraulic oil supplied to the frictional engagement element K1 ″ via No. 4 is regulated by the flow rate passing through the orifice 628, the oil temperature characteristic is very unstable with respect to the temperature fluctuation of the hydraulic oil. In addition, the frictional engagement element K1 ″
There is a problem in that it is not possible to freely adjust the supply pressure to, and it is very difficult to achieve high-quality shift quality.

The technique disclosed in Japanese Patent Application Laid-Open No. 1-299351 discloses a friction element B which is engaged at the time of setting the first speed stage when switching from the N (neutral) range to the L (first speed) range.
In order to directly supply the working hydraulic pressure to -2, a device is provided in which a low modulator valve 11 is provided midway and a feedback pressure is introduced to the low modulator valve 11, thereby adjusting the supply pressure. However, it did not propose a technique for more positively adjusting the supply pressure.

Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks of the prior art. When an operation failure occurs in the valve for controlling the operation oil pressure supply to the friction engagement element, the operation oil pressure is not operated. It is possible to directly supply the frictional engagement element without passing through the generated valve, so that it is possible to set a traveling stage that can secure at least a certain traveling performance of the vehicle, and it is possible to appropriately control the hydraulic pressure supply to the frictional engagement element. It is an object of the present invention to provide a hydraulic control device for such an automatic transmission.

[0019]

In order to achieve the above object, a hydraulic control device for an automatic transmission according to a first aspect of the present invention is provided with a switching valve for controlling supply / discharge of hydraulic pressure to / from a friction engagement element, and the friction engagement element. In a hydraulic control device for an automatic transmission including a control valve that controls the hydraulic pressure of the friction engagement element installed between the coupling element and the switching valve, the control valve supplies the friction engagement element with the output hydraulic pressure of a solenoid valve. In addition to controlling the hydraulic pressure to be applied to the control valve, the output hydraulic pressure of the switching valve is applied to the control valve in a direction in which the output hydraulic pressure of the switching valve and the friction engagement element communicate with each other.

According to a second aspect of the present invention, the output hydraulic pressure of the switching valve and the output hydraulic pressure of the solenoid valve communicate with each other through an orifice.

According to a third aspect of the present invention, a one-way valve is provided between the solenoid valve and the control valve to enable a hydraulic pressure to be supplied from the solenoid valve to the control valve.

According to a fourth aspect of the present invention, the output hydraulic pressure of the switching valve is applied to both ends of the control valve via an orifice.

According to a fifth aspect of the present invention, the automatic transmission inputs rotation of an output shaft of an engine mounted on a vehicle, and the switching valve is a manual valve which is switched by operating a manual shift lever. Configured as it is.

[0024]

As described above, according to the first aspect of the present invention, in the hydraulic control device for the automatic transmission, the control valve is configured to control the hydraulic pressure supplied to the friction engagement element by the output hydraulic pressure of the solenoid valve. Since the output hydraulic pressure of the switching valve is configured to be applied to the control valve in the direction in which the output hydraulic pressure of the switching valve and the friction engagement element communicate with each other, that is, Since the output hydraulic pressure is applied and the output hydraulic pressure of the solenoid valve is separately applied, even when the solenoid valve fails (in both closing failure and opening failure), the friction engagement element is applied to the friction engagement element. The operating oil pressure can be supplied, and therefore, the setting of the predetermined shift speed of the automatic transmission can be ensured.

On the other hand, when the solenoid valve is in the normal state (non-failure), it is possible to improve the rise delay of the hydraulic pressure supplied to the friction engagement element when the hydraulic oil temperature is low, and when the hydraulic oil is at normal temperature. In-gear shock can be reduced. Further, in normal times, even if the transmission input shaft speed is suddenly increased immediately after the switching valve is switched at normal temperature of the hydraulic oil and the hydraulic oil is supplied from the switching valve to the friction engagement element, Accordingly, the transmission input shaft rotation speed can be controlled so as to be promptly reduced to a predetermined rotation speed.

According to the second aspect of the present invention, the output hydraulic pressure of the switching valve and the output hydraulic pressure of the solenoid valve are configured to communicate with each other through the orifice. The hydraulic pressure can be supplied while controlling the supply timing with the solenoid valve, and even when the control valve fails, the frictional engagement element can be engaged by the output hydraulic pressure of the switching valve, and at a predetermined shift speed. It is possible to secure the traveling of.

According to the third aspect of the present invention, since it is configured as described above, it is possible to prevent the output hydraulic pressure of the switching valve from leaking when the solenoid valve fails.
Therefore, it is possible to supply the hydraulic pressure to the friction engagement element, and it is possible to ensure traveling at a predetermined gear.

According to the fourth aspect of the present invention, since it is configured as described above, it is possible to freely control the hydraulic pressure supplied to the friction engagement element during normal operation, and the hydraulic pressure supplied when the hydraulic oil temperature is low. Rise of the hydraulic oil, in-gear shock of hydraulic oil at room temperature, and when switching the switching valve to supply hydraulic oil from the switching valve to the friction engagement element, the transmission input shaft speed increases suddenly after the switching. It is possible to effectively deal with the increase in the transmission input shaft rotational speed that occurs when the transmission is operated as described above, and to freely control these.

According to the fifth aspect of the present invention, since it is configured as described above, the working hydraulic pressure is supplied to the friction engagement element even when the solenoid valve fails (both the closing failure and the opening failure). Therefore, it is possible to secure the setting of the predetermined shift speed of the automatic transmission and maintain the running performance of the vehicle to some extent. On the other hand, at normal times, the rise delay of the hydraulic pressure supplied to the friction engagement element can be improved when the hydraulic oil temperature is low, and the in-gear shock can be reduced at normal temperature of the hydraulic oil. It is possible to obtain a good in-gear shock without a pleasant feeling. Furthermore, during normal operation, even if the accelerator is immediately depressed immediately after switching the manual valve at normal temperature of the hydraulic oil and supplying the hydraulic oil from the manual valve to the friction engagement element, the engine speed rise is prevented from occurring. can do.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic explanatory view showing the structure of a hydraulic control device for an automatic transmission according to the present invention.

This transmission includes a torque converter 8 connected to an output shaft 9 of an internal combustion engine 9a, and a transmission having a transmission input shaft 8a connected to a turbine (not shown) of the torque converter 8. Become.

This transmission has first, second and third planetary gear trains G1, G arranged in parallel on the transmission input shaft 8a.
2, G3. Each planetary gear train has first to third sun gears S1, S2, and S3 located at the center, and first to third planetary pinion P1 that revolves while rotating around the first to third sun gears S1, S2, and S3. , P2
P3 and the first to third carriers C1, C2, C that rotatably hold the pinion and rotate in the same way as the revolution of the pinion.
3 and first to third having inner teeth that mesh with this pinion
It is composed of ring gears R1, R2 and R3.

The first planetary gear train G1 and the second planetary gear train G
2 is a double pinion type planetary gear train, and the first pinion P1 and the second pinion P2 are respectively 2 as shown.
It is composed of individual pinion gears P11, P12 and P21, P22.

The first sun gear S1 is always connected to the input shaft, and the first carrier C1 is always fixed. The first ring gear R1 is connected to the second sun gear S via a third clutch K3.
2 and the second sun gear S2 can be fixedly held by the first brake B1. Second carrier C
2 is connected to the third carrier C3 and the output gear 8b
The rotations of the second carrier C2 and the third carrier C3 are output rotations of the transmission. The second ring gear R2 is directly connected to the third ring gear R3, and both ring gears R2 and R3 can be integrally fixed and held by the second brake B2, and can be disengaged from the transmission input shaft via the second clutch K2. It is freely connected. The third sun gear S3 is detachably connected to the transmission input shaft via the first clutch K1. Here, a one-way brake B3 is arranged in parallel with the second brake B2. The first clutch K1 corresponds to the "friction engagement element" in the claims.

In this way, each element (first to third sun gear S
1 to S3, first to third carriers C1 to C3, and first to third
The third ring gears R1 to R3), the transmission input shaft 8a, and the output gear 8b are connected to each other.
3rd clutch K1-K3 and 1st, 2nd brake B1,
By performing the engagement / disengagement control of B2, it is possible to set the speed stage and control the shift. Specifically, if engagement / disengagement control is performed as shown in Table 1, the fifth forward speed (1ST, 2ND, 3
RD, 4TH and 5TH) and reverse first speed (RVS) can be set. The speed reduction ratio (ratio) at each gear shifts depending on the number of teeth of each gear, and Table 1 shows an example of this ratio for reference.

[0037]

[Table 1]

In Table 1, the second brake B2 in 1ST is shown in parentheses because the one-way brake B3 transmits power to the drive side without engaging the second brake B2. is there. That is,
If the first clutch K1 is engaged, power transmission on the drive side at a gear ratio of 1ST is possible without engaging the second brake B2, and 1ST is set. However, it is not possible to transmit power in the opposite direction to the drive side, and therefore the second brake B
When 2 is engaged, the 1st speed where the engine brake is effective becomes, and 1ST where the second brake B2 is disengaged becomes the 1st speed where the engine braking is not effective.

A controller 200 including a microcomputer is provided to control the hydraulic pressure supply to the friction engagement element. The controller 200 includes a magnetic pickup, which is arranged near the transmission input shaft 8a and detects a transmission input rotation speed.
Similarly, a rotation speed sensor 2 which is made of a magnetic pick and is arranged in the vicinity of the output gear 8b to detect the transmission rotation speed of the transmission.
04, and the output of a range selector switch 206 that is connected near the shift lever 208 arranged near the driver's seat and detects the gear range selected by the driver.

Further, in the controller 200, an engine speed sensor 210 arranged near the crankshaft (not shown) of the internal combustion engine 9a for detecting the engine speed and a throttle valve (not shown) are provided. A throttle position sensor 212 arranged to detect the engine load through the throttle opening.
Then, the output of a vehicle speed sensor 214, which is arranged near a drive shaft (not shown) and detects the vehicle speed of the vehicle in which the transmission is mounted, is input.

Based on the detected parameters, the controller 200 energizes (ON) or de-energizes (OFF) the solenoid valves SA to SE, and the hydraulic control circuit 3
At 00, the hydraulic pressure supply to the friction engagement element is controlled. In the hydraulic control circuit 300, there are five hydraulic pressure sensors PS
Is detected via the, and the detected value is also sent to the controller 200.

Next, a hydraulic control circuit 300 for performing engagement / disengagement control of the first to third clutches K1 to K3 and the first and second brakes B1 and B2 will be described with reference to FIGS. 2 and 3 show respective parts of the hydraulic control circuit, and these two figures constitute one hydraulic control device.

Incidentally, the circled alphabet at the end of the oil passages in each drawing indicates that the oil passages are connected to the oil passages having the same circled alphabet in the other drawings. Also,
A cross indicates that the port opens to the drain.

The operation control of the brakes and clutches for shift control is carried out by utilizing the hydraulic pressure of the hydraulic oil supplied from the pump 10 from the tank shown in the lower part of FIG. Pump 10
The hydraulic oil discharged from the oil passage 12 acts on the regulator valve 14 to regulate a predetermined line pressure. It should be noted that a part of the oil discharged from the pump 10 is part of the oil passage 12 as described above.
But the rest is regulator valve 1
4 is sent to the oil passage 16. The hydraulic oil sent to the oil passage 16 is supplied for lockup control of the torque converter (not shown). Further, the hydraulic oil sent to the oil passage 18 returns to the tank via a relief valve (not shown).

The oil passage 12 adjusted to the line pressure as described above.
Is supplied to the corresponding parts of the hydraulic circuit for the shift control of the transmission. In these parts,
A manual valve 20 connected to a shift lever 208 arranged near the driver's seat and operated by a driver's manual operation, and five duty ratio control solenoid valves on / off controlled by a controller 200 detecting the manual operation. SA to SE, operation of these manual valves 20 and solenoid valves SA to S
Six hydraulically actuated valves 2 that operate according to the actuation of E
2, 24, 26, 28, 30, 32, four accumulators 34, 36, 38, 40 and five hydraulic pressure sensors P
And S are provided. The above manual valve 20
Corresponds to the "switching valve" in the claims, and the solenoid valve SA corresponds to the "solenoid valve".

The solenoid valves SA and SC are normally open type valves, which are opened when the electromagnetic solenoids provided therein are turned off. On the other hand, the solenoid valves SB, SD and SE are normally closed type valves, and are closed when the electromagnetic solenoids provided therein are deenergized.

Each of these valves 20, SA to SE, 22,
The shift control and the operation control of the lockup clutch of the torque converter are performed by the supply control of the hydraulic oil by 24, 26, 28, 30, 32, and are set in accordance with the operation of each solenoid valve SA to SE and this operation. Table 2 shows the relationship with the speed stage. The ON / OFF in Table 2 indicates ON (energization) / OFF (non-energization) of the electromagnetic solenoid provided in each solenoid valve SA to SE. When the solenoid is ON during gear shifting, The solenoid is controlled based on the duty ratio so that desired shift characteristics can be obtained.

[0048]

[Table 2]

The shift control will be described below.
First, the case where the D range is selected by the shift lever and the spool 20a of the manual valve 20 moves to the D position will be described. In FIG. 3, when the hook portion at the right end of the spool 20a is moved to the position indicated by D (3, 2) to the D position and the spool 20a is in the D position, the hydraulic oil adjusted to the line pressure as described above is supplied. The oil passage 12 communicates with the oil passage 42. Since the oil passage 12 is connected to the solenoid valve SC and the oil passage 42 is connected to the solenoid valve SE,
The line pressure always acts on the solenoid valves SC and SE. Further, the oil passage 42 is
Since it is also connected to the solenoid valve SA, the line pressure always acts on the solenoid valve SA. In this specification, the directions such as left, right, up and down are used to indicate the directions in the attached drawings.

The oil passage 12a branched from the oil passage 12 is branched to the right end oil chamber of the reverse pressure switching valve 22, the oil passage 12b branched from the oil passage 12 is branched to the left end oil chamber of the pressure release valve 24, and the oil passage 42 is branched. The oil passages 42a are connected to the right end oil chambers of the out gear control valve 26, respectively. Therefore, the reverse pressure switching valve 22 and the out gear control valve 26 are constantly pressed to the left, and the pressure release valve 24 is always pressed to the right by the line pressure.

When the D range is selected, the speed stage is determined according to the relationship with the engine load and the vehicle speed, and Table 2 shows the operation of each solenoid valve SA to SE so as to obtain this speed stage. Controlled to Hereinafter, the operation of the clutch and the brake associated with the operation of the solenoid valve at each speed stage will be described.

First, the case where the first speed stage (1ST) is set as the speed stage will be described. In this case, as shown in Table 2, only the solenoid valve SC is on and the other four are off. Therefore, at this time, the solenoid valve SA
Only the other valve is opened and the other solenoid valves are closed.

Since the line pressure acts on the solenoid valve SA from the oil passage 42, the working oil having this line pressure reaches the manual valve 20 via the oil passage 44 after passing through the solenoid valve SA. Here, when the spool 20a of the manual valve 20 is in the D position, the oil passage 44 communicates with the oil passage 46, so that hydraulic oil having a line pressure is supplied to the first clutch K1 via the oil passage 46,
The first clutch K1 is engaged. The oil passage 44 is connected to the oil pressure sensor PS. Further, the oil passage 46 is connected to the right end portion of the first accumulator 34, and the first accumulator 34 has a function of suppressing a sudden increase in the operating hydraulic pressure supplied to the first clutch K1 and reducing a shock.

The oil passage 46 acts on the right end of the pressure release valve 24 via the oil passage 46a. on the other hand,
At the left end of the pressure release valve 24, the oil passage 12
Although the line pressure acts via b, the spool 24a of the pressure release valve 24 moves rightward from the state shown in the figure because the hydraulic pressure acting via the oil passage 12b is predominant due to the difference in pressure receiving area. The oil passage 42a branched from the oil passage 42 and the oil passage 48 connected to the solenoid valve SD are in communication with each other.

On the other hand, the oil passage 5 connected to the second clutch K2
0 is connected to the output side of the solenoid valve SB, but since this solenoid valve SB is closed,
The oil passage 50 is connected to the drain through the inside of the valve SB, and the second clutch K2 is released. In addition, oil passage 5
0 is connected to the pressure switch PS and the right end of the second accumulator 36.

The oil passage 52 connected to the third clutch K3 is connected to the right end oil chamber of the pressure release valve 24 via the oil passage 52a and to the left end oil chamber of the reverse pressure switching valve 22 via the oil passage 52b.
On the other hand, the oil passage 52 is also connected to the output side of the solenoid valve SC, but since the solenoid valve SC is closed as described above, the oil passage 52 is connected to the valve S.
It connects to the drain through the inside of C. Therefore, the third clutch K3 is also in the released state. The oil passage 52 is connected to the hydraulic sensor PS and the right end portion of the fourth accumulator 40.

The oil passage 54 connected to the first brake B1 is connected to the output side of the solenoid valve SD, but since the solenoid valve SD is closed, the oil passage 5
4 is connected to the drain through the inside of this valve SD,
The first brake B1 is also released. The oil passage 54a branched from the oil passage 54 is connected to the right end portion of the pressure release valve 24 via the shuttle valve 56, and is connected to the left end portion of the pressure delivery valve 28 via the oil passage 54b. The oil passage 54 is connected to the hydraulic switch PS, and the oil passage 54b is connected to the right end portion of the third accumulator 38.

The oil passage 58 connected to the second brake B2 is connected to the oil passage 62 or the oil passage 64 via the shuttle valve 60. The oil passage 62 is the manual valve 20 and the oil passage 66.
This oil passage 66 communicates with the oil passage 68 by the out gear control valve 26, and this oil passage 68 is connected to the underdrive engagement control valve 30. However, when the D position of the manual valve 20 is selected, Underdrive engagement control valve 30
Since the working oil pressure is not supplied to the oil passage 58, the working oil pressure is not supplied to the oil passage 58 via the oil passage 66.

Further, the oil passage 64 communicates with the oil passage 70a through the pressure delivery valve 28, and the oil passage 70a reaches the manual valve 20, but when the manual valve 20 is in the D range position, it is closed there.

Therefore, the hydraulic pressure controlled by the solenoid valve SE is not supplied to the second brake B2, and the second brake B2 is also released. Therefore,
In the first speed (1ST) of the D range, engine braking cannot be applied. The underdrive engagement control valve 30 corresponds to the "control valve" in the claims.

Next, the case of shifting to the second speed will be described. In this case, only the solenoid valve SD is switched from off to on. Comparing this state with the state of the first speed, the only difference is that the solenoid valve SD is opened, and the first clutch K1 remains engaged. on the other hand,
The spool 24a of the pressure release valve 24 is moved to the right by the hydraulic oil having the line pressure supplied to the left end portion of the pressure release valve 24 via the oil passage 12b, so that the manual valve 20 moves to the oil passage 42 and the oil. The hydraulic oil having the line pressure reaching the pressure release valve 24 via the passage 42a reaches the solenoid valve SD via the oil passage 48 and the solenoid valve SD is opened, so that the operating hydraulic pressure is applied to the first brake B1. Supplied and engaged. At this time, the engagement shock is reduced by the action of the third accumulator 38. In this way, the first clutch K1 and the first brake B1 are engaged and the second speed is set.

By opening the solenoid valve SD,
Line pressure acts on the left end portion of the pressure delivery valve 28 via the oil passage 54, the oil passage 54a, and the oil passage 54b,
The spool 28a of the pressure delivery valve 28 moves right. As a result, in the pressure delivery valve 28, the oil passage 76 and the oil passage 74 connected to the lockup control circuit described above communicate with each other, but the oil passage 74 is connected to the output side of the solenoid valve SE in the manual valve 20. It communicates with 70. Therefore, as shown in parentheses in Table 2, when the solenoid valve SE is turned on, the lockup clutch can be controlled by the output pressure thereof.

The spool 28a of the pressure delivery valve 28 is moved to the right so that the oil passage 42a is moved to the oil passage 7a.
8 communicating with the pressure delivery valve 28
The line pressure acts on the left end portion of the spool 28a, and the right movement of the spool 28a is maintained even if the line pressure from the oil passage 54b disappears.

Next, the case of shifting to the third speed will be described. In this case, the solenoid valves SC and SD are switched from on to off, and all the solenoid valves are turned off. As a result, from the state of the second gear, the solenoid valve SC is opened and the solenoid valve SD is closed. Since the solenoid valve SA is open, the first clutch K1 remains engaged. Also,
Since the solenoid valve SD is closed, the oil passage 54 communicates with the drain through the inside of the solenoid valve SD, so that the first brake B1 is released.

On the other hand, when the solenoid valve SC is opened, hydraulic oil having a line pressure is supplied to the oil passage 52, and the third clutch K3 communicating with this is engaged. At this time, the shock is reduced by the action of the fourth accumulator 40. In this way, the first clutch K1 and the third clutch K3 are engaged to set the third speed.

In the third speed, the solenoid valve S
When D is closed, the hydraulic pressure acting on the left end portion of the pressure delivery valve 28 via the oil passage 54 and the oil passage 54b becomes zero. However, as described above, the operating hydraulic pressure supplied through the oil passage 78 maintains the state where the spool 28a is moved to the right. Therefore, if the solenoid valve SE is turned on as in the case of the second speed, the lockup clutch can be controlled by the output pressure thereof.

Next, the case of shifting from the third speed to the fourth speed will be described. In this case, only the solenoid valves SB and SC are switched from off to on. This makes 3
From the speed state, the solenoid valve SB is opened and the solenoid valve SC is closed. Since the solenoid valve SA is open, the first clutch K1 remains engaged. When the solenoid valve SC is closed, the line pressure supply to the third clutch K3 is cut off and released, contrary to the case of the third speed.

Since the oil passage 48a branched from the oil passage 48 is connected to the solenoid valve SB, the working oil having the line pressure is supplied to the second clutch K2, and the second clutch K2 is supplied.
Engages. At this time, the shock is reduced by the action of the second accumulator 36. In this way, the first clutch K1 and the second clutch K2 are engaged, and the fourth speed is set.

As described above, the spool 28a of the pressure delivery valve 28 includes the oil passage 78 and the oil passage 42a.
Since the hydraulic pressure of the line pressure supplied via the valve keeps moving to the right, the solenoid valve S
When E is turned on, the lockup clutch can be controlled by the output pressure.

Next, the case of shifting from the 4th speed to the 5th speed will be described. In this case, the solenoid valve SA is switched from off to on and the solenoid valve SC is switched from on to off. As a result, the solenoid valve SA is closed from the state of the fourth speed, and the solenoid valve S
C is released. When the solenoid valve SA is closed, the line pressure supply from the oil passage 46 is cut off, and the first clutch K1 is released. By closing the solenoid valve SA, the oil pressure in the oil passage 46a becomes zero, and the spool 24a of the pressure release valve 24 remains in the right-handed state. Therefore, the communication state between the oil passage 42a and the oil passage 48a in the pressure release valve 24 does not change, the line pressure continues to be supplied to the input side of the solenoid valve SB, and at the same time, the solenoid valve SB remains open. Two
The clutch K2 is maintained in the engaged state.

On the other hand, when the solenoid valve SC is opened, the line pressure is supplied to the third clutch K3 via the oil passage 52 to engage it, as described above.
In this case also, the shock is reduced by the action of the fourth accumulator 40. As described above, the second clutch K2 and the third clutch K3 are engaged to set the fifth speed.
The lockup clutch can be controlled in the fifth gear as well as in the fourth gear.

Next, by operating the shift lever, the shift range is switched to 1 range.
The case of selecting a position will be described. In this case, the spool 20a of the manual valve 20 is moved rightward so that its end connecting hole moves from the D position to the 1 position. As a result, the oil passage 12 to which the line pressure is supplied when one range is selected is supplied not only to the oil passage 42 but also to the oil passage 80 in the manual valve 20.

When one range is selected, the gear is controlled so as to be fixedly held at the first speed. Therefore, the electromagnetic solenoids of the solenoid valves SA to SE are set to 1S in Table 2.
On / off is set to correspond to T.

Here, first, when the oil passage 12 and the oil passage 80 communicate with each other in the manual valve 20, the working oil pressure having the line pressure is supplied to the oil passage 80. Further, the oil passage 80 communicates with the oil passage 82 in the delivery shift valve 32, and the oil passage 82 communicates with the right end portion of the pressure delivery valve 28. Therefore, the pressure delivery valve 2
The line pressure acts on the right end portion of 8, and the spool 28a of the pressure delivery valve 28, which has been moved to the right in the D range earlier, is moved to the left to be in the state shown in the drawing, and the oil passage 70a and the oil passage 64 are communicated with each other. Will be done. Here, the oil passage 64 is connected to the oil passage 58 connected to the second brake B2 via the shuttle valve 60, while the oil passage 70a communicates with the oil passage 70 when the spool 20a of the manual valve 20 is in the 1 position, and is connected to the solenoid valve. Connected to the output side of SE.

Therefore, as shown in parentheses in Table 2, when the solenoid valve SE is turned on, the output pressure of the solenoid valve SE engages the second brake B2 to actuate the engine brake.

The engagement of the second brake B2 and the engagement of the first clutch K1 described below reliably set the first speed in which the engine brake acts.

Next, the engagement operation of the first clutch K1 which is characteristic of the present invention will be described. In this device, when the spool 20a of the manual valve 20 is moved to the 1 position, the line pressure is directly supplied to the first clutch K1 without passing through the solenoid valve SA, and the engagement at that time is also performed. An underdrive engagement control valve 30 having a shock absorbing function is provided.

More specifically, the output hydraulic pressure of the solenoid valve SA is supplied to the back pressure chamber of the underdrive engagement control valve 30 via an oil passage, and a check valve is provided in this communication oil passage. That is, the oil passage 12 communicates with the oil passage 80 when the spool 20 a of the manual valve 20 is in the 1 position and branches from the oil passage 80.
Is underdrive engagement control valve 30
In communication with the oil passage 68a branched from the oil passage 68,
The oil passage 68 is connected to the oil passage 6 by the out gear control valve 26.
6 to reach the manual valve 20, and then to the oil passage 46 to connect to the first clutch K1.

On the other hand, in the oil passage 44 on the output side of the solenoid valve SA, the spool 20a of the manual valve 20 is 1
When in the position, it communicates with the oil passage 86, and the oil passage 86 is connected to the upper back pressure chamber of the underdrive engagement control valve 30.
8 are provided.

The oil passage 86 and the oil passage 68a are connected to the oil passage 90.
The oil passage 90 is provided with an orifice 92 in the middle thereof.

In the above configuration, the oil passage 68a communicates with the lower end of the underdrive engagement control valve 30, so that the underdrive engagement control valve 30 is responsive to the hydraulic pressure of the hydraulic oil passing through 68a.
The position of the spool 30a of the
The flow rate of the hydraulic oil flowing from the a to the oil passage 68a can be adjusted.

On the other hand, since the output hydraulic pressure of the solenoid valve SA is supplied to the upper back pressure chamber of the underdrive engagement control valve 30 via the oil passage 86, the spool 30a is responsive to the output hydraulic pressure of the solenoid valve SA.
It is possible to adjust the precompression amount of the spring 30b that presses down, so that the pressure adjustment value of the underdrive engagement control valve 30 can be adjusted.

Engagement of the first clutch K1 at the time of selecting one range in the hydraulic control apparatus for an automatic transmission according to this embodiment configured as described above will be described with reference to FIG.

In FIG. 4, the first "range selection signal" in the figure
As shown in the graph, when the travel range is switched from the N range to the 1 range, the duty ratio of the energizing current of the electromagnetic solenoid of the solenoid valve SA is changed to the second "SA drive signal" graph from the top in the figure. By controlling, the output pressure of the solenoid valve SA, which is the control back pressure of the underdrive engagement control valve 30, can be operated as shown in the third “SA output pressure” graph from the top in the figure, and thus the first clutch K1 can be operated. The supply timing of the engagement pressure can be controlled as shown in the fourth "K1 pressure" graph from the top of the drawing. Therefore, the first clutch K1
The acceleration generated in the vehicle body due to the engagement shock of 1 can be suppressed to a small value as shown in the "vehicle body G" graph at the bottom of the figure.

The fifth "clutch slip ratio" graph from the top of the figure represents the slip of the transmission input shaft rotation speed (torque converter turbine rotation speed) with respect to the transmission output shaft rotation speed. The fact that this becomes zero means that the slip between them becomes zero and the frictional engagement elements interposed between them become completely engaged (shift completion). Called time. In the hydraulic control system for the automatic transmission according to this embodiment, the in-gear time can be controlled by controlling the supply timing of the engagement pressure of the first clutch K1 as described above. It is possible to prevent the engine from blowing up even when the accelerator is immediately depressed when selecting one range.

The above is a description of when one range is selected when the solenoid valve SA is in a normal state (non-failure). On the other hand, when an electrical or mechanical failure such as an electromagnetic solenoid energization failure of the solenoid valve SA occurs and the solenoid valve SA sticks in the closed state (close stick), the first clutch in the D range is detected. It becomes impossible to engage K1. Therefore, in this case, in the D range, from the first speed to 4
Since it is not possible to set the speed stage, only the 5th speed stage can be set, and the drivability of a vehicle equipped with this transmission is significantly deteriorated.

In order to avoid this inconvenience, in the hydraulic control system for the automatic transmission according to this embodiment, as described above, when the solenoid valve SA fails to close, the shift lever is operated to move the manual valve 20 to the D range. By switching from the position to the 1-range position, the operating hydraulic pressure is supplied to the first clutch K1 without passing through the solenoid valve SA, and the first speed stage is established. Engagement of the first clutch K1 when one range is selected when the solenoid valve SA fails to close will be described with reference to FIG.

FIG. 5 is an explanatory view similar to FIG. 4, but
When the shift range is switched from N to 1 as shown in the "range selection signal" graph at the top of the figure, the line pressure is directly passed through the manual valve 20, that is, through the solenoid valve SA that has malfunctioned. Instead, it is supplied to the first clutch K1. At this time, the orifice 9
Since the operating oil pressure is supplied to the oil passage 86 side via 2 as shown in the "K1 pressure" graph, the oil pressure supply to the first clutch K1 is slightly delayed as shown in the figure, resulting in the "clutch slip ratio" graph. Although the in-gear time becomes long as shown, the first clutch K1 can be engaged. Therefore, it is possible to reliably ensure the engagement of the predetermined shift speed,
It is possible to avoid a significant decrease in driving performance.

When the solenoid valve SA has an open failure, it is possible to set from the 1st speed to the 4th speed even in the D range. However, since the output pressure of the solenoid valve SA cannot be throttled at the time of opening failure, the supply pressure to the first clutch K1 rises rapidly, and the shock at the time of switching from the N range to the D range and 1 range is large. Become.
Regarding this, FIG. 6 (an explanatory view similar to FIGS. 4 and 5 shown above) shows a state when the N range is switched to the 1 range.

In the apparatus according to this embodiment, the one-way valve 88 is provided in the middle of the oil passage 86, so that the solenoid valve SA has a close stick (close failure).
Then, the oil passage 44 connected to the output side is opened to the drain inside the solenoid valve SA, and the oil passage 86 communicating with this is provided.
It is possible to prevent the hydraulic pressure supplied to the first clutch K1 from leaking through the oil passage 90 and the oil passage 68a, that is, the first speed is surely established when the solenoid valve SA fails.

As described above, in the device according to this embodiment, when the solenoid valve SA is implemented as a countermeasure against failure and when one range is selected by the shift lever at the normal time (when the solenoid valve SA is not failing). The control of the supply timing of the supply pressure to the first clutch K1 in (1) to reduce the in-gear shock makes both of them compatible.

When the underdrive engagement control valve 30 provided in the device according to the present embodiment fails, the shift lever 1
An additional description will be made regarding the engagement of the first clutch K1 when the range is selected. When the underdrive engagement control valve 30 fails to open, the oil passage 80a and the oil passage 68a communicate with each other. Therefore, as described above, the line pressure of the oil passage 12 is supplied to the first clutch K1 to engage it. The speed is set. At this time, since the pressure regulating action of the underdrive control valve 30 cannot be expected, the shift shock becomes large, but the first speed setting at the time of switching one range can be secured.

On the other hand, when the under control valve 30 fails to close, the communication between the oil passage 80a and the oil passage 68a is stopped, so that the line pressure of the oil passage 12 cannot be supplied to the first clutch K1. . However, at this time, the solenoid valve SA supplied through the oil passage 44
The output pressure of the spool 20a of the manual valve 20 is 1
When in the position, the oil is supplied to the oil passage 86. Oil passage 86 here
Communicates with the oil passage 68 through the orifice 92,
The output pressure of the solenoid valve SA can be supplied to the first clutch K1. However, the action of the orifice makes it possible to delay the rise of the supplied hydraulic pressure and reduce the in-gear shock, but the in-gear time becomes long when the oil temperature is low.

As described above, even when the underdrive engagement control valve 30 provided in the device according to this embodiment fails, the first clutch K1 can be engaged when one range is selected. The speed can be set.

FIG. 7 is a partial view of a hydraulic circuit of a hydraulic control device for an automatic transmission, showing a second embodiment of the present invention. The configuration of the hydraulic circuit of FIG. 7 is the same as that of the hydraulic circuit shown in FIGS. 2 and 3 according to the first embodiment except the portion shown in FIG. 7, and performs the same operation. In the following, the description will focus on the parts of different configurations shown in FIG. 7.

In the hydraulic circuit of FIG. 7, the case where one position is selected to switch the shift range to one range by operating the shift lever will be described. As a result, the spool 20a of the manual valve 20 is moved to the right from the illustrated N and P positions so that its end connecting hole moves to the 1 position. As a result, when one range is selected, the oil passage 12 to which the line pressure is supplied is connected not only to the oil passage 42 but also to the oil passage 80. This point is not different from that of the first embodiment.

In this embodiment, when the spool 20a of the manual valve 20 is moved to the 1 position, the line pressure is directly supplied to the first clutch K1 without passing through the solenoid valve SA. Is provided with a circuit provided with an underdrive control valve 96 which has a function of reducing the shock of the shock absorber.

That is, paying attention to the fact that the solenoid valve SA does not function in the conventional device shown in FIGS. 17 and 18 when the manual valve 20 is in the 1 position, the underdrive control valve 96 outputs the solenoid valve SA output. Oil passage 44, oil passage 86 and oil passage 86
It is configured so that it can be guided to the lower end of the underdrive control valve 96 via a, and the supply pressure to the first clutch K1 can be freely raised or lowered according to the output pressure of the solenoid valve SA.

More specifically, the oil passage 12 communicates with the oil passage 80 when the spool 20a of the manual valve 20 is in the 1 position, and the operating hydraulic pressure having a line pressure is applied to the oil passage 80 and the oil passage 8.
Underdrive control valve 96 via 0b
Is supplied to the upper end of the spool and pushes the spool 96a downward to move it. As a result, the oil passage 80c becomes the oil passage 68b.
An oil passage 68c, which communicates with the oil passage 68b and is connected to the lower end of the underdrive control valve 96, presses the spool 96a upward. However, due to the difference in the pressure receiving area, the operating oil pressure is supplied from the oil passage 80b. The downward pressing force by is larger. Oil passage 68b and oil passage 68
The oil passage 68 connected to c returns to the manual valve 20 by communicating with the oil passage 66 at the out gear control valve 26, communicates with the oil passage 46 there, and connects to the first clutch K1.

On the other hand, the oil passage 86a connected to the lower end of the underdrive control valve 96 communicates with the oil passage 44 in the manual valve 20 via the oil passage 86,
The oil passage 44 is connected to the output side of the solenoid valve SA.

The out gear control valve 26
Is for controlling how to disengage the first clutch K1 oil pressure from the oil passage 98 depending on how the third clutch K3 oil pressure is disengaged when the manual valve 20 is switched from the R range position to the N range position. This is to prevent the occurrence of shock during out gear (when switching from the R range position to the N range position and when switching from the D range position to the N range position).

In the above, the oil passage 68c and the oil passage 80b
Since the orifices 100 and 102 are provided in the valve, the increase in hydraulic pressure when the manual valve 20 is selected at one position can be moderated. Then, the output oil pressure of the solenoid valve SA is supplied to the lower end portion of the underdrive control valve 96 via the oil passage 44, the oil passage 86, and the oil passage 86a, and the output oil pressure of the solenoid valve SA rises to move the spool 96a. When it is displaced upward, the communication between the oil passage 80c and the oil passage 68b is hindered, and the hydraulic pressure supplied to the first clutch K1 via the oil passage 46 is reduced.

That is, the pressure adjusting characteristic of the underdrive control valve 96 can be set so that the relationship between the output pressure of the solenoid valve SA and the K1 clutch supply pressure is inversely proportional as shown in FIG. .

The engagement of the first clutch K1 when the underdrive control valve 96 is operating normally and when one range is selected in the hydraulic control system having the hydraulic circuit configured as described above will be described. 9 (Fig. 4
(The same explanatory view as the above) will be described.

In FIG. 9, when one position is selected as shown in the "range selection signal" graph, the duty ratio of the energizing current of the electromagnetic solenoid of the solenoid valve SA is controlled as shown in the "SA drive signal" graph. The output pressure of the solenoid valve SA, which is the control back pressure of the underdrive control valve 96, is controlled as "SA output pressure", and the hydraulic pressure supplied to the first clutch K1 is freely controlled as shown in the "K1 pressure" graph. Therefore, the in-gear time can be shortened even when the oil temperature is low, or the engine speed can be prevented from rising even when the N → 1 switching is immediately stepped on, and a good in-gear shock can be obtained.

Further, as described in the first embodiment, when the solenoid valve SA fails, the shift lever is operated to switch the manual valve 20 to the 1-range position, so that the line pressure is transmitted through the manual valve 20. It is possible to supply the first clutch K1 to engage the first clutch K1 directly, that is, without passing through the solenoid valve SA that has malfunctioned. As a result, it is possible to set the first speed, and it is possible to ensure the traveling of the vehicle at the first speed even when the solenoid valve SA malfunctions.

This point will be described with reference to FIGS. FIG. 10 is an explanatory diagram similar to FIG. 4, showing a case where the shift range is switched from the N range to the 1 range to secure traveling at the 1st speed stage when the solenoid valve SA fails to close. When the solenoid valve SA fails to close, the engagement hydraulic pressure to the first clutch K1 is entirely supplied by the output hydraulic pressure of the solenoid valve SA in the D range. Therefore, it is impossible to establish the first to fourth speed stages in the D range. is there. Therefore, by switching the shift lever to the 1 range as shown in the "range selection signal" graph, the line pressure is supplied to the first clutch K1 without passing through the solenoid valve SA, and the vehicle travels at the first speed. At this time, since the pressure control of the underdrive control valve 96 by the solenoid valve SA cannot be performed, the shift shock becomes large ("vehicle body G" graph).

On the other hand, when the solenoid valve SA has an open failure, switching to the 1 range makes it impossible to control the output pressure of the solenoid valve SA, and the underdrive control valve 96 always has a solenoid valve SA at its lower end. The output pressure of will act. As a result, the spool 96a cannot be displaced downward and the oil passage 80c and the oil passage 68b cannot communicate with each other, so that the engagement pressure cannot be supplied to the first clutch K1.

However, even in this case, if the range is switched to the D range as shown in the "range selection signal" graph of FIG. 11 (an explanatory view similar to FIG. 4), the hydraulic oil is supplied to the first range without the intervention of the underdrive control valve 96. 1 clutch K
It can be supplied to the first gear, and the first gear can be set.
However, in this case, the output pressure of the solenoid valve SA cannot be regulated, and therefore, the in-gear shock becomes large ("vehicle body G" graph), but traveling at the first speed can be ensured.

In the device according to the second embodiment,
Underdrive control valve 96 configured as described above
Since the solenoid valve SA is normally provided, it is possible to freely control the engagement pressure of the first clutch K1 by the output hydraulic pressure control of the solenoid valve SA to obtain a good in-gear shock. Can ensure the setting of the first speed stage, and can ensure a certain running performance.

Further, if the relationship between the output pressure of the solenoid valve SA and the supply pressure to the first clutch K1 is inversely proportional as shown in FIG. 8, the solenoid valve SA has a hydraulic open side and a hydraulic close side. Even if a failure occurs in either direction, as shown in FIG. 12, it is possible to travel in a range other than the maximum speed stage in either the D range or the 1 range by the range selection operation. When the closing failure of the solenoid valve SA shown in the lower part of the figure, the normal friction engagement elements shown in Table 1 and the solenoid valves at that time shown in Table 2 are engaged. The setting for fail does not depend on the operation of.

Here, in order to compare and contrast with the control results in the devices according to the first and second embodiments, in the hydraulic control device according to the prior art shown in FIGS. 17 and 18, from the N range. First when switching to 1 range
The engaged state of the clutch K1 ″ is shown in FIGS.

FIG. 13 shows the case where the hydraulic oil is at a low temperature. When the N range is switched to the 1 range as shown in the "range selection signal" graph, the engagement pressure of the first clutch K1 "is" K1 ". As shown in the "pressure" graph, it does not rise easily, so that the in-gear time becomes long as shown in the "clutch slip ratio" graph. This is because in the conventional device shown in FIGS. 17 and 18, the flow resistance of the orifice 628 (FIG. 18) is too large and the underdrive engagement control valve 6 is operated at a low oil temperature.
Since the operating oil pressure is not easily supplied to the back pressure chamber of No. 22, the spool 622a does not move to the left, and therefore the first clutch K
This is because the hydraulic pressure supplied to 1 "does not rise.

On the other hand, in the devices according to the first and second embodiments of the present invention described above, as described above with reference to FIGS. 4 and 9, the first embodiment Then, by controlling the supply timing of the engagement hydraulic pressure of the first clutch K1 with the solenoid valve SA, and by freely controlling the engagement hydraulic pressure of the first clutch K1 in the second embodiment, the hydraulic oil is lowered. In-gear time can be shortened even when the oil temperature is high.

On the other hand, FIG. 14 shows the case where the hydraulic oil is at room temperature. When the N range is switched to the 1 range as shown in the "range selection signal" graph, the first clutch K
As shown in the "K1" pressure "graph, the engagement pressure of 1" increases at a dash. Therefore, although the in-gear time is short as shown in the "clutch slip ratio" graph, it is large as shown in the "body G" graph. Shift shock occurs. The occurrence of such a large shift shock is as shown in FIGS.
In the prior art hydraulic control device of No. 1, only the flow path resistance of the orifice 628 (FIG. 18) relaxes the supply pressure to the first clutch K1 ″ at the time of switching one range, so that the clutch engagement pressure can be freely adjusted. Because you cannot do it.

On the other hand, in the above-described apparatus according to the first embodiment of the present invention, as described above with reference to FIG. 4, the supply timing of the engagement pressure of the first clutch 1K1 is changed. By controlling, the in-gear shock can be reduced. Further, also in the device according to the second embodiment, as described above with reference to FIG. 9, the engagement hydraulic pressure of the first clutch K1 is freely controlled, so that the hydraulic oil is kept at room temperature. In-gear shock can be reduced.

In each of the above-mentioned embodiments, the case where the setting of the first speed stage is ensured by the engagement of the first clutch K1 when the solenoid valve SA fails is explained, but the invention is not limited to this. is not. It may be configured to ensure setting of a predetermined shift speed by engagement of a predetermined friction engagement element (including a brake) when another solenoid valve fails.

[0118]

According to the first aspect of the present invention, the hydraulic pressure can be supplied to the friction engagement element even when the solenoid valve fails (both the closing failure and the opening failure). Therefore, the automatic transmission can be provided. It is possible to ensure the setting of the predetermined gear position of. On the other hand, when the solenoid valve is normal (non-failure), the rise delay of the hydraulic pressure supplied to the friction engagement element can be improved when the hydraulic oil temperature is low, and the in-gear shock can be prevented at normal temperature of the hydraulic oil. It can be reduced. Further, in normal operation of the solenoid, even if the switching valve is switched at normal temperature of the hydraulic oil and the transmission input shaft speed is suddenly increased immediately after the hydraulic oil is supplied from the switching valve to the friction engagement element. In response to this, control can be performed so that the transmission input shaft rotation speed can be promptly reduced to a predetermined rotation speed, and the engine does not blow up.

According to the second aspect of the present invention, the same action and effect as those of the first aspect can be obtained, and even when the control valve fails, the frictional engagement element can be engaged by the output hydraulic pressure of the switching valve. Therefore, it is possible to ensure traveling at a predetermined gear.

According to the third aspect of the present invention, it is possible to prevent the output hydraulic pressure of the switching valve from leaking when the solenoid valve fails, so that the operating hydraulic pressure can be supplied to the friction engagement element. Therefore, it is possible to ensure traveling at a predetermined gear.

According to the fourth aspect of the present invention, the hydraulic pressure of the friction engagement element can be freely controlled when the solenoid valve is in the fail state, and the rising delay of the hydraulic pressure supplied when the hydraulic oil temperature is low and the operation can be achieved. In-gear shock of oil at room temperature,
In addition, when hydraulic oil is supplied from the switching valve to the frictional engagement element by switching the switching valve, the transmission input shaft rotational speed when the transmission input shaft rotational speed is operated so as to suddenly increase after the switching. It is possible to control these effectively by coping effectively with blowing up.

According to the present invention, when the solenoid valve fails (both the closing failure and the opening failure).
Also, the working hydraulic pressure can be supplied to the friction engagement element, so that the setting of the predetermined shift speed of the automatic transmission can be ensured and the traveling performance of the vehicle can be maintained to some extent. On the other hand, in the normal state of the solenoid, it is possible to improve the rising delay of the hydraulic pressure supplied to the friction engagement element when the hydraulic oil temperature is low, and it is possible to reduce the in-gear shock when the hydraulic oil is normal temperature. Therefore, a good in-gear shock without discomfort can be obtained. Furthermore, when the solenoid is operating normally, even if the manual valve is switched at normal temperature of the hydraulic oil and the accelerator is immediately depressed immediately after the hydraulic oil is supplied from the manual valve to the friction engagement element, the engine speed will rise. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory diagram showing a configuration of a hydraulic control device for an automatic transmission according to the present invention.

FIG. 2 is a hydraulic circuit diagram showing a part of a hydraulic control device for an automatic transmission according to the first embodiment of the present invention.

FIG. 3 is a hydraulic circuit diagram similar to FIG.

FIG. 4 shows a solenoid valve S in the device according to the first embodiment.
FIG. 7 is an explanatory diagram including graphs showing states of a shift range selection signal, a solenoid drive signal, a solenoid valve output pressure, a clutch pressure, a clutch slip ratio, and a vehicle body acceleration (shift shock) at the time of A (normal time). .

FIG. 5 is an explanatory view similar to FIG. 4, but showing an operating state when the solenoid valve SA has a closing failure.

FIG. 6 is an explanatory view similar to FIG. 4, but showing an operating state when the solenoid valve SA has an open failure.

FIG. 7 is a partial view of a hydraulic circuit diagram showing a part of a hydraulic control device for an automatic transmission according to a second embodiment of the present invention, in which only parts different from the hydraulic circuits of FIGS. 2 and 3 are shown. It is a hydraulic circuit diagram shown.

FIG. 8 is a graph showing an example of pressure regulation characteristics of an under control valve.

FIG. 9 shows a solenoid valve S in the device of the second embodiment.
FIG. 7 is an explanatory diagram including graphs showing states of a shift range selection signal, a solenoid drive signal, a solenoid valve output pressure, a clutch pressure, a clutch slip ratio, and a vehicle body acceleration (shift shock) in the normal state of A;

FIG. 10 is an explanatory view similar to FIG. 9, but showing an operating state at the time of a closing failure of the solenoid valve SA.

FIG. 11 is an explanatory view similar to FIG. 9, but showing the operating state when the solenoid valve SA has an open failure.

FIG. 12 is an explanatory diagram showing a relationship between a shift operation and a travelable range when the solenoid valve SA fails when the pressure control characteristic of the under control valve is set as shown in FIG.

FIG. 13 is a diagram showing a conventional device when the hydraulic oil has a low temperature;
FIG. 6 is an explanatory diagram including graphs showing operating states of a shift range selection signal, clutch pressure, clutch slip ratio, and vehicle body acceleration (shift shock).

FIG. 14 is an explanatory view similar to FIG. 13, but showing the operating state of the hydraulic oil at room temperature.

FIG. 15 is a hydraulic circuit diagram showing a part of a hydraulic control device for an automatic transmission according to a conventional technique.

16 is an explanatory diagram showing an engagement state of each friction engagement element of the hydraulic circuit of FIG. 15 at each shift speed.

17 is a hydraulic circuit diagram showing a part of a hydraulic control device for an automatic transmission according to another conventional technique different from that shown in FIG.

FIG. 18 is a hydraulic circuit diagram similar to FIG.

[Explanation of symbols]

 8 Torque converter 8a Transmission input shaft 9 Engine output shaft 10 Pump PS Oil pressure sensor SA, SB, SC, SD, SE Solenoid valve K1, K2, K3 Clutch BR1, BR2 Brake 20 Manual valve 22, 24, 26, 28, 30 , 96 Hydraulically operated valves 34, 36, 38, 40 Accumulator 200 Controller

Claims (5)

[Claims] 1. An automatic transmission including a switching valve for controlling supply and discharge of hydraulic pressure to and from a friction engagement element, and a control valve installed between the friction engagement element and the switching valve for controlling hydraulic pressure of the friction engagement element. In the hydraulic control device, the control valve is configured to control the hydraulic pressure to be supplied to the friction engagement element by the output hydraulic pressure of a solenoid valve, and the output hydraulic pressure of the switching valve is the same as the output hydraulic pressure of the switching valve. A hydraulic control device for an automatic transmission, characterized in that it is configured to apply to the control valve in a direction in which it communicates with a friction engagement element. 2. The hydraulic control device for an automatic transmission according to claim 1, wherein the output hydraulic pressure of the switching valve and the output hydraulic pressure of the solenoid valve communicate with each other through an orifice. 3. A one-way valve, which allows a hydraulic pressure to be supplied from the solenoid valve in the direction of the control valve, is provided between the solenoid valve and the control valve. Hydraulic control system for automatic transmission. 4. The hydraulic control device for an automatic transmission according to claim 1, wherein the output hydraulic pressure of the switching valve is applied to both ends of the control valve via an orifice. 5. The automatic transmission is for inputting rotation of an output shaft of an engine mounted on a vehicle, and the switching valve is a manual valve that is switched by operating a manual shift lever. Item 2. A hydraulic control device for an automatic transmission according to item 1.