JPS5822653B2 - Hydraulic control device for vehicle automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic control device for an automatic transmission for a vehicle such as an automobile, and particularly relates to a hydraulic control device for an automatic transmission for a vehicle such as an automobile, and more particularly, it relates to a hydraulic control device for an automatic transmission for a vehicle such as an automobile, and more particularly, a hydraulic control device for an automatic transmission for a vehicle such as an automobile. The present invention relates to a hydraulic control device that controls shift timing when an engagement device shifts.

In general, in this type of automatic transmission for vehicles, engine power is transmitted even during up or down shifts, so if the shift timing is inappropriate, the engine speed may rise or torque fluctuations may increase. This causes a shock and a bad feeling.

Therefore, in order to perform such a shift smoothly, a method has been proposed in the past in which one-way clutches are engaged, and this method has actually been used to
However, if it were used to shift all gears, the automatic transmission would become larger and more expensive.

Furthermore, since the one-way clutch spins during reverse rotation and engine braking becomes ineffective, a separate means for engine braking is required, which complicates the structure of the hydraulic control device.

Therefore, in view of the engine braking action, it is preferable to not use the one-way clutch at all, but to engage or release the clutch friction engagement device and the brake friction engagement device in a timely manner to perform a shift.

In order to satisfy such conditions, the first friction engagement device for obtaining the first gear and the second friction engagement device for obtaining the second gear are provided at the same input element, and the first and second friction engagement devices are provided at the same input element. In the brake-side friction engagement device of the two friction engagement devices, a holding member that holds one friction element movably in the axial direction is configured to be able to rotate slightly relative to the case of the automatic transmission, and hydraulic control is performed. In the equipment, a switching valve is installed in the line hydraulic oil supply and drainage path leading from the transmission valve to the friction engagement device, and in order to guide the line hydraulic pressure to the friction engagement device during engine coasting, a switching valve is installed in the line hydraulic oil supply and drainage path that branches off from the line hydraulic oil supply and drainage path to the friction engagement device. A delay control valve is installed in the branch oil path leading to the coupling device, and detects the direction of 1 to 1 torque acting on the holding member that holds the friction element of the friction engagement device during an upshift, and detects the direction of the torque acting on the holding member that holds the friction element of the friction engagement device during a downshift. The direction of relative slip between the friction elements is detected and the switching valve is operated, an orifice is provided in the branch oil passage, and the delay control valve is delayed by the pressure difference in the line oil pressure, thereby controlling the oil pressure of the friction engagement device during gear shifting. The hydraulic control device to be controlled is based on Japanese Patent Application No. 51-109679 (filed date: September 1978) filed by the same applicant as the applicant of the present application.
13th of May).

The present invention is based on the aforementioned Japanese Patent Application No. 51-109679 (Application H:
The purpose is to provide a hydraulic control device for automatic transmissions for vehicles that is further improved in the structure related to the switching valve of the hydraulic control device proposed in the 13th September 1976. The purpose is to increase the oil pressure of the second frictional engagement device to achieve a low speed gear in a timely manner when the vehicle is coasting.

In the present application, a first frictional engagement device for obtaining a first gear and a second frictional engagement device for obtaining a second gear are provided in the same input element of a planetary gear device, and In the friction engagement device on the brake side of the friction engagement device, a holding member that holds one friction element movably in the axial direction is configured to be able to rotate slightly with respect to the case of the automatic transmission, and the hydraulic control device A switching valve is installed in the line hydraulic oil supply and drainage path from the transmission valve to the frictional engagement device, and in order to guide the line hydraulic pressure to the frictional engagement device when the engine coasts, the line hydraulic oil supply and drainage path is branched from the frictional engagement device. A coast valve is installed in the branch oil path leading to the device, and the direction of torque acting on the friction element holding member of the friction engagement device is detected during an upshift, and the direction of the torque acting on the friction element holding member of the friction engagement device is detected during an upshift. The direction of relative slip between the friction elements of the engagement device is detected and the switching valve is operated, and the coast valve is switched and controlled by the acting force of the throttle oil pressure corresponding to the engine output and the governor oil pressure corresponding to the vehicle speed, and the coast valve is controlled to switch during gear shifting. The present invention relates to a hydraulic control device that controls hydraulic pressure of a frictional engagement device.

The invention will now be described by way of example with reference to the accompanying figures.

First, the automatic transmission for a vehicle according to the present invention will be explained with reference to FIG.
This input shaft 3 is coupled to a first intermediate shaft 5 via a front clutch 4, and coupled to a second intermediate shaft 7 (input element) via a rear clutch 6 (first friction engagement device). has been done.

These intermediate shafts 5 and 7 are connected to an output shaft 9 via a Simpson-type planetary gear 8 (gear group), and a front brake 10 ( A one-way clutch 11 and a rear brake 12 are provided on a carrier 8b that supports a pinion 8a of a planetary gear 8.

In this way, the engine power from the engine output shaft 1 is transmitted to the human power shaft 3 via the torque converter 2, and further, when the front clutch 4 is engaged, the power is transmitted to the first intermediate shaft 5, and then the front clutch 4 and the rear clutch 6 are engaged. As a result, the signal is transmitted to the planetary gear 8 via the second intermediate shaft 7.

Further, by engagement of the front brake 10, the common sun gear 8c (input element) of the planetary gear 8 is fixed together with the rear clutch drum 6as second intermediate shaft 7, and the one-way clutch 1
The carrier 8b is fixed by the action of 1 or the engagement of the carrier brake 12, and is moved forward by the planetary gear 8 by selectively engaging the clutch 46.11 and the brake 10.12 of these frictional engagement devices. A gear shift of one reverse gear is performed, and the power of each gear is taken out to the output shaft 9.

That is, the first speed is obtained by engaging the front clutch 4 and the action of the one-way clutch 11, and the second speed (second gear stage) is obtained by engaging the front brake 10 instead of the one-way clutch 11. Rear clutch 6 instead of front brake 10
When the rear clutch 6 and the rear brake 12 are engaged, the third speed (second gear) is obtained, and when the rear clutch 6 and the rear brake 12 are engaged, the reverse gear is obtained.

In such automatic transmissions for vehicles, it is applied to the front brake 10 that obtains the second speed and the rear clutch 6 that obtains the third speed. When downshifting from 2 to 2nd speed, the front brake 10 is controlled to be released or engaged in a timely manner.

Therefore, as shown in FIGS. 2 and 3, a relatively wide spline 14 is formed on the inner circumference of the transmission case 13, and a spline narrower than the spline 14 is formed on the outer circumference of the drum 15 of the front brake 10. 16 is formed, and by the engagement of these splines 14 and 16, the drum 15 (holding member) is assembled to the transmission case 13 (case of automatic transmission) so that it can rotate forward and reverse by a gap a (forward rotation is the same direction of rotation as the engine).

The rod 17 is attached to the drum 15 rotatably assembled in this way, and a friction engagement plate 18 (first friction element) and a reaction plate 19 are spline-coupled as in the conventional case, and a piston 20 in a hydraulic servo to be described later is mounted to move against the force of spring 21.

L/h 18,') Between the action plays 1 and 19, there is a lining plate 22 (second (friction element) is interposed, and by pressing these plays 1-18, 19, and 22 and bringing them into integral frictional contact, the front brake 10 is
The rotation of the drum 6as bub 6b of the rear clutch 6 is restrained, and the sun gear 8c of the planetary gear 8 is fixed.

On the other hand, the drum 15 is always given a spring force in the opposite direction to the engine rotation direction by a spring 24 between the rod 17 and the spring receiver 23, and a timing valve 25 (switching valve) is attached to the drum 15 on the side of the rod 17 facing the spring 24. It is provided so as to be interlocked with the rotation of 15.

Further, referring to FIG. 4, a hydraulic control system including a coast valve of the present invention will be explained.A hydraulic pressure source 26, a pressure regulating valve 27, a 1-2 shift valve 28, a 2-3 shift valve 29 (speed change valve), or an oil passage 30. They are connected in series by 30a and 30b.

2-3 The shift valve 29 moves in accordance with the relationship between the governor oil pressure corresponding to the vehicle speed acting on the ports 31 to 33, the drain ports 34, 35, and the port 90, and the throttle oil pressure corresponding to the throttle valve opening acting on the port 100. It has a spool 36 that performs a switching operation, and in the case of second speed, the spool 36 moves downward to connect the ports 31 and 32, and when the vehicle speed increases and the vehicle reaches third speed, the spool 36 moves upward. It operates to connect ports 31 and 33.

A check valve 38 and an accumulator 39 are connected to the oil passage 37 from the port 33 of the 2-3 shift valve 29.
A check valve 41 is connected to the hydraulic servo of the rear clutch 6, and a check valve 41 is also connected to the oil passage 40 from the port 32.
An accumulator 42 is provided, which is connected to the timing valve 25 before the hydraulic servo 10' of the front brake 10.

The timing valve 25 has a port 43 connected to the oil passage 40.
, a port 45 and a port 46 connected to the oil passage 44 from the hydraulic servo 10' of the front brake 10, a spool 47 that is in contact with the aforementioned rod 17 and moves as the rod 17 swings;
The spool 47 has a spring 48 facing the rod 17 and applying a spring force, and performs a switching operation to connect the ports 43 and 45 or 45 and 46, or reduces the opening of the port 43 and acts as a throttle.

Further, an oil passage 49 that branches off from the upstream side of the check valve 41 of the oil passage 40 is connected to a coast valve 51 .

The line hydraulic oil supply and drainage passages are oil passages 40 and 44.

The coast valve 51 includes a valve spool 55 having a large-diameter valve brand 52, 53 and a small-diameter valve brand 54, a spring that presses the valve spool 55 in one direction, and is provided at one end of the coast valve 51 to adjust the output of the engine. A port 56 on which a corresponding throttle oil pressure acts;
A port 57 that is provided between the valve brands 53 and 54 and receives governor hydraulic pressure corresponding to the vehicle speed, and a branch oil path 49.
a port 58 that communicates with
0 and a drain port 62 provided at the other end of the coast valve 51.

The valve spool 55 performs a switching operation by moving depending on the magnitude relationship between the throttle hydraulic pressure and the governor hydraulic pressure acting on the ports 56 and 57.

In the area above the coast valve operating line X shown in FIG. 7, the valve spool 55 moves to the left from the state shown in FIG. It operates so that the hydraulic pressure acting on the timing valve 10' can be discharged via the timing valve 25.

Further, in the region below the coast valve operating line X shown in FIG. 7, the valve spool 55 moves to the state shown in FIG.
It operates so that hydraulic pressure can be supplied to the hydraulic servo 10' via the branch oil passage 59 and the timing valve 25.

As a result, when the vehicle is in an engine coast state, hydraulic pressure is supplied to the hydraulic servo 10' despite the movement of the timing valve 25 to the left, enabling the engine brake running state.

To explain the hydraulic control device configured in this way using the diagrams in FIGS. 5 and 6, first, in the case of second speed, the drum 15 of the brake 10 is transferred to the front 1 in the same way as in the first speed. As shown in FIG. 3, the rod 17 rotates in the opposite direction to the engine rotation direction, and the rod 17 becomes as shown by the solid line in FIG.
4 communicates with the hydraulic servo 10' of the front brake 10.
On the other hand, the hydraulic servo 6' of the rear clutch 6 is supplied with hydraulic pressure to
The pressure is exhausted by 5.

Therefore, during an upshift from 2nd speed to 3rd speed, the 2-3 shift valve 29 changes the oil pressure in the oil passage 30 to the oil passage 3.
7, the oil passage 40 communicates with the drain port 34.

Therefore, the hydraulic servo C of the rear clutch 6 is supplied with oil, and the hydraulic pressure rises as shown by the curve B at 1 in a of FIG. The pressure is exhausted and the oil pressure decreases as shown by curve A due to the action of the check valve 41 and accumulator 42.

Therefore, the rear clutch 6 is engaged to transmit engine power, and the front brake 10 is disengaged to release the restraint of the drum 6a of the rear clutch 6.
At the beginning of the gear shift, the engagement force of the front brake 10 is greater than the hydraulic pressure of the hydraulic servo 10', so no power is transmitted while the friction retaining piston of the rear clutch 6 is moving.

Thereafter, at time t, the oil pressure of the hydraulic servo 6' increases and the engagement force of the rear clutch 6 is increased, so that the drum 6as and the hub 6b are rotated in the same direction as the engine.

On the other hand, in the front brake 10, the hydraulic servo 10'
Although the oil pressure of the drum 1 is decreasing, the plate 18 and the lining plate 22 are still weakly engaged and the rotational torque from the rear clutch 6 is acting on the drum 15.
The restraining force of the drum 15 decreases rapidly as shown in Fig. 5b and eventually becomes zero, and the drum 15 is turned in the same direction as the engine as shown by the arrow in Fig. 3, and the rod 17 is It will look like a dotted chain line.

Then, the spool 47 in the timing valve 25 is moved to the left by the force of the spring 48, and the spool 47 is moved to the left side by the force of the spring 48.
46, the oil passage 44 and the branch oil passage 59 come into communication.

At this time, the coast valve 51 is in the area above the coast valve operating line X in FIG. 7, and is moved to the left from the state in FIG. Since it communicates with the drain port 61, the hydraulic pressure of the front brake side hydraulic servo 10' is connected to the drain port 61 of the coast valve 51.
is discharged from.

As a result, at this time t, the oil pressure of the hydraulic servo 10' suddenly decreases to zero as shown in part X of curve A in Figure 5a, and the front brake 10 is completely released. state, and the gear is shifted to 3rd gear.

Therefore, from this point on, the transmission of engine power by the harrier clutch 6 is not restricted in any way, and the output shaft torque is
The loss is suppressed to the minimum by rising like the partial ridge in the curve C in the figure.

When the front brake 10 is completely released, the plate 18 is separated from the lining plate 22, and the drum 15 is again rotated in the opposite direction to the engine rotation direction by the force of the spring 24, and at the same time the rod 17 is rotated as shown in FIG. Returning to the solid line state, the timing valve 25 is also connected to port 4.
3 and 45 are connected.

Note that the broken lines from a to c in FIG. 5 indicate the case where the shift timing control according to the present invention is not performed, and when the engagement of the front brake 10 is prolonged, the engagement force of the rear clutch 6 is increased and the output is increased. The shaft torque decreases, torque fluctuations increase during gear shifting, and a strong shock occurs when shifting.

Conversely, when downshifting from 3rd gear to 2nd gear, the oil passage 37 is
communicates with the drain port 35, the hydraulic servo 6' discharges pressure, and the hydraulic pressure is transferred to the check valve 38 and the accumulator 3.
9, the rear clutch 6 is released as shown by the curve B in FIG. 6A.

On the other hand, oil is supplied to the hydraulic servo 10' through the oil passage 40, the timing valve 25, and the oil passage 44, and the oil pressure increases. When the oil pressure rises slightly, the plate 18 of the front clutch 10 is rotated by the lining plate. 22 and its drag rotates the drum 15 in the same direction as the engine, so the spool 47 of the timing valve 25 moves slightly to the left together with the rod 17, reducing the opening of the port 43.

Therefore, due to the throttling action of the spool 47 in the port 43, the oil pressure of the hydraulic servo 10' is maintained at a low value as shown in the portion X of the curve A in FIG. 6A.

Then, at time t', when the hydraulic pressure of the hydraulic servo 6' is discharged and becomes zero, and the rear clutch 6 becomes completely released, the rotation of the drum 6a becomes zero as shown in b in Fig. 6. The engine starts to rotate in the opposite direction.

Therefore, the drum 15 of the front brake 10 also rotates in the opposite direction to the engine rotation direction, which moves the spool 47 of the timing valve 25 to the right, almost fully opening the port 43, and the throttling effect of the port 43 is released.

As a result, at time t', the oil pressure of the hydraulic servo 10' rises rapidly as shown in the portion X' of curve A in a of FIG. Ru.

In addition, since the engagement of the front brake 10 is extended until the rear clutch 6 is released in this way, the transmission of engine power by the rear clutch 6 is not restricted in any way.
The output shaft torque only decreases a little for a very short period of time when the hydraulic pressure of the hydraulic servo 6' is almost zero, as shown in part σ of C in FIG. 6.

Similarly to the above, the broken lines a and c in FIG. 6 also show the case where the shift timing control according to the present invention is not performed. When the engine power suddenly increases, the torque fluctuates greatly, and conversely, if the rise of the brake pressure A is delayed, the drum 6a rotates in the opposite direction to the engine rotation direction, causing the engine to rev up and causing a strong impact during shifting.

Next, when the engine 2 is in the engine braking state when downshifting from 3rd gear to 2nd gear, when the rear clutch 6 is released, the force acting from the transmission output shaft 9 causes the rear clutch drum 6a to The drum 15 of the brake 10 is forcibly rotated in the same direction as the engine rotation direction.

Accordingly, the rod 17 swings again as shown by the two-dot chain line in FIG. 4, and the spool 47 of the timing valve 25 moves to the left to block the ports 43 and 45, and oil supply through the oil passage 40 is no longer performed.

However, at this time, the throttle oil pressure acting on the port 55 of the coast valve 51 decreases as the throttle opening decreases, and the governor oil pressure acting on the port 57 causes the valve spool 55 to enter the state shown in FIG. is closed, and the hydraulic servo 10' is connected from the branch oil passage 49 to the ports 58 and 53 of the coast valve 51, the branch oil passage 59, and the ports 46. of the timing valve 25.
Hydraulic pressure is supplied via 45.

Therefore, in this case as well, the front brake 10 is engaged, the vehicle is downshifted to the second speed, and the engine brake becomes effective.

FIG. 9 According to another embodiment of the invention in FIG. 8, a coast valve 80 includes a valve spool 83 having valve lands 81, 82 of the same diameter and a spring provided to bias the valve spool 83 to the right. 89, a port 86 at the other end of the coast valve 80 to which throttle oil pressure corresponding to the engine output is supplied, a port 88 communicating with a branch oil passage 59 leading to the timing valve 25 (switching valve), and a branch oil passage 49. When the throttle hydraulic pressure acting on the land 81 of the valve spool 83 against the spring 89 becomes larger than the spring force,
That is, when the throttle opening is in a region above the coast valve operating line y in FIG. The hydraulic pressure of the hydraulic servo 10' accompanying the leftward movement of the valve spool 47 of the timing valve 25 is discharged through ports 45 and 46.
Allows for upshifts.

Also, when the throttle oil pressure acting on the port 86 becomes smaller than the force of the spring 89 acting on the valve spool 83 of the coast valve 80.

That is, when the throttle opening is in the region below the coast valve operating line y in FIG. The oil pressure of the oil passage 49 is transferred to ports 87, 88, branch oil passage 59, and ports 45, 4.
6. Supply the oil to the hydraulic servo 10' via the oil path 44,
Despite the leftward movement of the valve spool 47 of the timing valve 25, hydraulic pressure is supplied to enable engine braking.

The engine coast state of a vehicle begins in proportion to the speed of the vehicle and inversely proportional to the throttle opening.

For this reason, the governor hydraulic pressure and the throttle hydraulic pressure act against each other on the coast valve, thereby alleviating the shift shock during downshifts at all vehicle speeds.

Thus, according to the present invention, a coast valve that operates more reliably is used in a hydraulic control device for a vehicle automatic transmission, and
It will now be appreciated that there is an improved hydraulic control system for a vehicle automatic transmission that cushions the shock of shifting by controlling the line pressure supplied to the second frictional engagement device during upshifts or downshifts.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing an example of an automatic transmission for a vehicle according to the present invention, FIG. 2 is a cross-sectional view showing an enlarged main part of the automatic transmission for a vehicle, and FIG. -DI sectional view, FIG. 4 is a circuit diagram showing an example of a hydraulic control device according to the present invention, a to C in FIG. 5 are line diagrams showing oil pressure characteristics in the case of upshift, a to C in FIG. 7 is a diagram showing the operating characteristics of the coast valve shown in FIG. 4. FIG. 8 is a circuit diagram showing another example of the hydraulic control device according to the present invention. 9 is a diagram showing the operating characteristics of the coast valve shown in FIG. 8. 1...Output shaft, 2...Torque converter, 3...Transmission manual shaft, 4...Front clutch, 5...Torque converter・- intermediate axis, 6...
...Rear clutch, 6'...Hydraulic servo,
6a...Drum, 6b...Bub, 7.
...Second intermediate shaft, 8...Planetary gear, 8
a...Pinion, 8b...Carrier,
8c...Sun gear, 9...Transmission output shaft, 10...Front brake, 10'...
...Hydraulic servo, 13...Mission case, 14...Spline, 17...Rod, 25...Timing valve, 26...
...Hydraulic pressure source, 27...Pressure regulating valve, 28...
...1-2 shift valve, 29...2-3 shift valve, 38,41...check valve,
51,80...Coast valve.

Claims (1)

[Claims] 1. An output shaft, an input shaft, a first frictional engagement device for connecting one input element of a gear group and the input shaft, and a first frictional engagement device provided on the human power element for fixing the same. and a second frictional engagement device, when the first frictional engagement device is actuated, the first gear is set, and when the second frictional engagement device is actuated, the second gear is set. A vehicular automatic transmission configured as follows: a first friction element of the second friction engagement device; and a second friction element that engages with the first friction element and is provided to be movable in the axial direction on the input element. A holding member that holds the first friction element movably in the axial direction is configured to be able to rotate slightly with respect to the case of the automatic transmission, and the first friction engagement device and the first A line hydraulic oil supply and drainage path that selectively guides the line hydraulic pressure to the second frictional engagement device from a speed change valve that switches the line hydraulic pressure to the second frictional engagement device, and a branch from the middle of the line hydraulic oil supply and drainage path. and a branch oil passage including a coast valve that is switched and actuated by throttle oil pressure and a spring means in order to guide line oil pressure to the second frictional engagement device when the engine coasts, and the line oil pressure oil supply and drainage passage are interposed in the middle. a switching valve that performs switching or pressure regulation control depending on the rotational direction of the holding member due to the relative rotation of the first and second friction elements during operation, and also controls the connection of the branch oil passage to the line hydraulic oil supply and drainage oil passage; 1. A hydraulic control device for an automatic transmission for a vehicle, characterized in that the hydraulic pressure control device for an automatic transmission for a vehicle is provided with, and reduces impact caused by gear shifting by controlling line hydraulic pressure supplied to the second frictional engagement device during upshifting or downshifting. 2. An output shaft, an input shaft, a first frictional engagement device that connects one human-powered element of the float group and the input shaft, and a second frictional engagement device that is provided on the input element and fixes it. and a coupling device, and is configured such that when the first frictional engagement device is actuated, the gear is set to the first gear, and when the second frictional engagement device is actuated, the gear is set to the second gear. In the automatic transmission for a vehicle, the first friction element of the second friction engagement device and the second friction element that engages with the first friction element and is provided to be movable in the axial direction on the input element. A holding member that holds the first friction element movably in the axial direction is configured to be able to rotate slightly with respect to the case of the automatic transmission, and the first friction engagement device and the second friction engagement A line oil pressure oil supply and drainage path that selectively guides line oil pressure to the second frictional engagement device from a transmission valve that switches line oil pressure to the device, and a line oil pressure oil supply and drainage path that branches off from the middle of the line oil pressure oil supply and drainage path to the second friction engagement device, and a A branch oil passage including a throttle hydraulic pressure for guiding the line hydraulic pressure to the second frictional engagement device, a governor hydraulic pressure that acts to oppose the throttle hydraulic pressure, and a coast valve that is switched and actuated by a spring means, and the line hydraulic pressure supply line. The holding member is inserted in the middle of the oil drain path and is switched depending on the rotational direction of the holding member due to the relative rotation of the first and second friction elements during operation;
A switching valve is provided that performs pressure regulation control and controls the connection of the branch oil passage to the line oil pressure supply and drainage oil passage, and controls the line oil pressure supplied to the second frictional engagement device during upshift or downshift. A hydraulic control device for an automatic transmission for a vehicle, which is characterized by controlling the impact caused by gear shifting.