JPS6235161A - Control device for lockup in automatic transmission - Google Patents

Abstract

PURPOSE:To reduce a speed change shock, by actuating a lockup control valve through a spool while performing a line pressure control through lockup valves and switching the both valves through a passage selector valve. CONSTITUTION:A transmission actuates a lockup control valve 78, which controls the pressure of working fluid to be supplied to a lockup means, by a spool 78a displaced in accordance with a line pressure. The transmission, controlling the line pressure by lockup valves 76, 77, alternatively switches communication of the lockup control valve 78 with the lockup valves by a shuttle valve 87 which connects lines 125, 126. While the line pressure is controlled in accordance with a throttle opening. Consequently, the transmission, in which a lockup can be released when the throttle opening is in a small degree, enables a speed change shock to be reduced in the transmission when it performs a speed change.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a hydraulic control device for an automatic transmission having a torque converter and a speed change gear mechanism. The present invention relates to a lock-up control device that controls the operation of a lock-up device.

(Prior art) Most automatic transmissions for automobiles that have been commonly used in the past are of the type in which a torque converter is combined with a multi-speed gear mechanism, and this multi-speed gear mechanism has multiple gear trains. By selectively operating the combined brakes and clutches of each gear in this gear train,
Power is transmitted through a predetermined gear train, and a predetermined gear stage is selected. Generally speaking, a lock-up mechanism is provided in the torque converter, and in a region where the output rotation is high, the lock-up mechanism is operated to directly connect the engine output shaft and the multi-speed gear mechanism input shaft to improve fuel efficiency.

When such a lock-up mechanism is installed, if the gear is shifted with the lock-up still in place, the engine and gear gear f
Since it is directly connected to the ffi structure, there is a problem that shift shock is not generated. Therefore, when shifting, the lock-up is temporarily released and the torque fluctuation caused by shifting is absorbed by the torque converter, thereby reducing the shift shock. Efforts are being made to reduce this. For example, as proposed in Japanese Patent Application No. 59-144768 by the present applicant, oil passages from two lock-up valves are connected to a lock-up control valve via passage switching valves, and the oil passages from the passage switching valves are controlled by the passage switching valves during gear shifting. Some gears temporarily release lock-up by switching the supply of lock-up hydraulic oil to suppress shift shock.

On the other hand, when the lock-up valve is operated to directly connect the engine output shaft and the transmission input shaft, engine vibrations are directly transmitted to the transmission, which tends to lead to an increase in cabin vibration and noise. In particular, engine vibration tends to become a problem in a region where the throttle opening is small, so it is desirable to be able to release the lockup when the throttle opening is small.

(Object of the Invention) The present invention has been made in view of the above circumstances, and provides an automatic transmission that has a relatively simple configuration and is capable of releasing lock-up during gear shifting and in the low throttle opening range. The object of the present invention is to provide a lock-up control device.

(Structure of the Invention) The lock-up control device of the present invention includes a torque converter,
In an automatic transmission comprising a transmission gear mechanism, a lock-up means, and a hydraulic control valve for transmission control, the lock-up control valve is provided with a spool that is displaced according to the transmission control line pressure, and the lock-up control valve is displaceable according to the displacement of the spool. The hydraulic pressure supply to the lock-up means is controlled, and the line pressure supply to the lock-up control valve is controlled using a plurality of lock-up valves that operate corresponding to each gear position requiring lock-up. None, a passage switching valve interposed in a passage that communicates the plurality of lock-up valves and the lock-up control valve selectively allows communication between the plurality of lock-up valves and the lock-up control valve through the passage. The line pressure is regulated by a throttle modulator valve in accordance with the throttle opening, so that when the throttle opening is small, the line pressure is also small.

(Embodiment) Hereinafter, one embodiment of a lock amplifier control device for an automatic transmission according to the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing the structure of an automatic transmission that is automatically shifted by the lock-up control device of the present invention.

A torque converter 2 and a multi-speed gearing device 10 are sequentially arranged from the engine side coaxially with an engine flywheel 1 that is integrally attached to the output shaft of the engine. The torque converter 2 includes a pump 3 , a turbine 4 and a stator 5 , and the pump 3 is identified with the flywheel 1 . The stator 5 rotates via a one-way clutch 6 on a fixed shaft 7 that is integrated with the case 11 of the multi-speed gear device 10 . The one-way clutch 6 allows the stator 5 to rotate in the same direction as the pump 3, but does not allow rotation in the opposite direction.

The multi-speed gear device 10 has a base end connected to the flywheel 1.
The solid shaft 12 is fixed to the multi-speed gearing device, and has a solid shaft 12 whose tip extends through the center of the multi-speed gearing device and is connected to the pump P for driving an oil pump P disposed on the side wall of the device. On the outside of this solid shaft 12, a hollow shaft is connected at its base end to the turbine 4 of the torque converter 2, and whose distal end extends to the side wall of the multi-speed gear unit 10, and is rotatably supported by the side wall. A turbine shaft 13 is provided. A Ravigneau-type planetary gear unit 14 is provided on the turbine shaft 13, and this planetary gear unit 14 includes a small-diameter sun gear 15, a large-diameter sun gear 16 disposed on the side of the small-diameter sun gear 15 far from the engine, The planetary gear unit 1 consists of a long pinion gear 17, a small diameter sun gear 15, a short pinion gear 18 (not shown) that meshes with the long pinion gear 17, and a ring gear 19.
First and second clutch devices 20, 21 are arranged in parallel on the side far from the engine of No. 4. The first clutch device 20 is a clutch for forward running, and connects and disconnects secondary power transmission between the small diameter sun gear 15 and the turbine shaft 73 via the first one-way clutch 22. On the other hand, the second clutch device 2
1 is connected in parallel with the first clutch device 20 to connect and disconnect power transmission between the small diameter sun gear 15 and the turbine shaft 13. A first brake device 23 is arranged radially outward of the second clutch device 21 . This first brake device 23 is a band brake, and includes a brake drum connected to the large-diameter sun gear 16 and a brake band applied to the brake drum. A third clutch device 24 is disposed radially outward of the first clutch device 20 and on the side of the first brake device W123. , is a clutch for traveling backward, and is used to connect and disconnect power transmission between the large-diameter sun gear V16 and the turbine shaft 13 via the brake drum of the first brake device 23.

Radially outward of the planetary gear unit 14,
A second brake device 25 is arranged to engage and disengage the carrier 14a of the planetary gear unit 14 and the case 10a of the multi-speed gear device 10. 1st and 2nd above
Between the brake devices 23 and 25, the carrier 14a and the case 10a are arranged in parallel with the second brake device 25.
A second one-way clutch device 26 is arranged to engage and disengage the two. A fourth clutch device 27 is disposed on the side of the planetary gear unit 14 on the engine side to connect and disconnect power transmission between the carrier 14a of the planetary gear unit and the turbine shaft 13. An output gear 28 connected to the ring gear 19 is disposed on the side of the fourth clutch device 27 on the engine side, and this gear A728 is connected to the output shaft 2.
8a).

The symbol @29 in the figure indicates a lock-up clutch for directly connecting the turbine shaft 13 and the crankshaft 1 without going through the torque converter 2. The lock-up clutch is operated by supplying and discharging lock-up hydraulic oil through the line 37, and when the lock-up hydraulic oil is supplied through the line 37, the clutch plate is pushed to the left in the figure. Lock-up is now turned off.

The multi-speed gear device 10 having the structure described above has four forward speeds and one reverse speed, and has first, second, third and fourth clutch devices 20.21.2'4. and 27, and the first and second brake devices 23 and 25, by appropriately operating the line pressures sent through the oil passages 31 to 35, a desired gear position can be obtained. In the above configuration, the operational relationship between each gear stage, clutch, and brake is shown in the table below.

Hydraulic Control Circuit Next, a hydraulic control circuit that supplies line pressure to each clutch and brake in order to operate the clutches and brakes as described above is shown in FIG. 2, and this hydraulic control circuit will be described.

This control valve 50 includes a plurality of valves shown below,
The above-mentioned first to fourth clutch devices 20.21.24 are connected via lines 31 to 35 by the operation of these plurality of valves.
．． 27 and the first and second brake devices 23 and 25, and operate each clutch and brake device according to each speed stage as shown in the previous person. ing.

The operation of each valve will be explained below. Pressure line 1 from pump P driven by engine via solid shaft 12
The hydraulic oil discharged to line 101 is regulated to a predetermined line pressure (Pln) by a regulator valve 51 that operates according to the throttle modulator pressure (Psm) from line 102 and the backup pressure from line 103, and this line pressure (Pln) is supplied to the boat 52a of the manual valve 52 via the line 71. The manual valve 52 is operated in conjunction with a lever on the driver's seat, and is shifted to each of P, R, N, D, and 2.1 travel ranges according to the lever operation, and is supplied to the boat 52a according to each range position. It is designed to supply hydraulic pressure to other boats.

The throttle modulator pressure (PSm) is regulated by the throttle modulator valve 65, and the throttle modulator valve 65 has governor pressure (Pct) from a governor valve 79 that generates hydraulic pressure corresponding to the transmission output rotation speed, and Throttle pressure (Pth) from the throttle valve 64 that generates oil pressure corresponding to the throttle opening is connected to lines 104 and 105, respectively.
The throttle modulator pressure (Psm) is determined according to the governor pressure (Pa) and throttle pressure (Pth).

The operation of this throttle modulator valve 65 will be explained with reference to FIGS. 3 to 5. FIG. 3 is an enlarged view of the throttle modulator valve 65, which includes:
The first spool 65b is slidable within the first sleeve 65a.
and a second spool 6 that is slidable inside the second sleeve 65C.
5d, a second spring 65e located between the first spool 65b J5 and the second spool 65d, and a second spring 65 that biases the second spool 65d to the left in the figure.
f. First, for the sake of explanation, we will start with the governor pressure (Pc
Consider the case where t> is zero. At this time, the spring force (Fl) of the first spring 65e is smaller than the spring force (F2) of the second spring 65f, and the second spool 65d is shifted to the left, causing the line 105
b and the line 102b communicate with each other via a groove in the second spool 65d, and the throttle pressure (Pth) supplied to the line 105 is supplied to the line 102 as is. Therefore, the throttle modulator pressure (Psm) and the throttle pressure (Pth) become equal. However, line 1
The throttle pressure (Pth) of 05 acts on the second pressure receiving part Δ2 of the second spool 65d through the line 105a, and the second
The spool 65f is biased to the left, while the throttle modulator pressure (Psm) in the line 102 is
acts on the first pressure receiving part A1 of the second spool 65d through the pressure receiving part A1 of the second spool 65d to urge the second spool 65d to the right, and since the area of both pressure receiving parts is Al>A2, the throttle When the pressure increases beyond a predetermined value, the second spool 65d moves to the right, reducing the throttle modulator pressure (Psm).
The relationship between and throttle pressure is PsmxAl = PthxA
2+, (F2-Fl). This is shown graphically in Figure 4. As can be seen from this figure, the throttle pressure becomes an oil pressure that is linearly proportional to the throttle opening, and the throttle modulator pressure (Psm) changes in the region where the throttle opening is small. Although it is equal to the throttle pressure (Pth), when the throttle opening exceeds a predetermined value, the oil pressure becomes smaller than the throttle pressure. When the throttle modulator pressure (Psm) obtained in this way is applied to the throttle valve 51 through the line 102, the line pressure (Pb) becomes a hydraulic pressure proportional to the throttle modulator pressure (PSm), which causes the transmission to The line pressure (Pin) corresponding to the input torque can be obtained.

Next, the throttle pressure (Pth) is constant and line 104
We will explain the operation when the governor pressure (PI) from
When the pressure is low, the first spool 65b receives the spring force (
F2-Fl) remains shifted to the right. Governor pressure (Pq) increases and spring force (F2-Fl)
When the pressure (PQl) that overcomes this governor pressure (PQl) is reached, this governor pressure (PQl) is reached.
CIt), the first spool 65b moves to the right. As a result, the spring force F1 of the first spring 65e increases, and therefore the throttle modulator pressure (ps
m) becomes low even if the throttle pressure (Pth) is constant. The governor pressure (PQ) further increases, and the first spool 65
b comes into contact with the second sleeve 65c, the governor pressure is 2g2), and no matter how much the governor pressure (Pg) rises, the first spool 65b does not move to the right and the throttle modulator pressure (Psm) remains constant. It will be done. Governor pressure at this time (
The graph in Figure 5 shows the relationship between the throttle pressure (Pth) and the throttle modulator pressure (Psm).
) is constant, it changes along the three straight lines in this figure. Note that the governor pressure (Pg) is a hydraulic pressure that changes depending on the transmission output rotation, that is, the vehicle speed, and the vehicle speed may be plotted on the horizontal axis instead of the governor pressure (Pq). Furthermore, when the throttle pressure (Pth) changes, the straight line in Figure 5 moves up and down in response to the opening, and as the throttle opening increases, this straight line moves upward (in the direction of arrow B).
(If the throttle opening becomes smaller, it will move downward in the direction of arrow C)
do. As shown in Figure 5, the throttle modulator pressure (PS
By controlling the line pressure (Pln), the line pressure (Pln) also becomes a hydraulic pressure proportional to this, and it is possible to create a line pressure corresponding to the input torque of the transmission.

In this way, by using the throttle modulator 65, the line pressure can be regulated in accordance with the throttle opening degree and vehicle speed with a relatively simple configuration, and the torque range of the clutch and brake in the transmission can be set to a necessary and sufficient value. I can do it.

The line pressure regulated as described above is appropriately supplied to each valve shown in the hydraulic control circuit 52 in FIG. (Pth) and the positive governor pressure (Pa) from the governor valve 79, and supplies appropriate line pressure to the lines 31 to 35 in order to operate predetermined clutches and brakes according to the vehicle speed and throttle opening. . Most of this hydraulic control circuit 52 is conventionally known, and a description of its operation will be omitted.

The names and roles of each valve are briefly explained below.

The throttle backup valve 57 is a valve for optimizing operation when the vehicle is in the 2nd range or lunge, and the 1-2 shift valve 53 is a valve for automatically shifting between 1st speed and 2nd speed. 2-3 shift valve 58
is a valve for automatically shifting between 2nd and 3rd speeds,
The 3-4 shift valve 55 is a valve for automatically shifting between 3rd speed and 4th speed. Low reducing valve 5
6 is a valve for reducing shift shock when shifting from 2nd gear to 1st gear while the J3 is in lunge, and 2-3 timing valve 60 is used to reduce shift shock from 2nd gear to 3rd gear. The bypass valve 61 is a valve for controlling the timing when the second speed is changed to the third speed.
The coasting bypass valve 62 is a valve for controlling the engagement timing of the coasting clutch.
-2 capacity valve 63 is a valve for controlling the 8 mother of 2-4 brakes when shifting from 3rd speed to 2nd speed in 2 range, and 3-2 timing valve 73 is in 2 range. This valve is used to control the timing when shifting from 3rd speed to 2nd speed. Furthermore, the N-D accumulator 54 is connected from the N range to the D range.
The N-R accumulator 67 is a valve for reducing the shock when shifting from the N range to the R range, and the 1-2 accumulator 66 is a valve for reducing the shock when shifting from the N range to the R range. This is a valve to reduce the shift shock when shifting from to 2nd gear.
The 2-3 accumulator 69 is a valve for reducing shift shock when shifting from 2nd speed to 3rd speed. The lock-up control valve 78 is a valve for controlling the operation of the lock-up clutch in the torque converter, and the servo control valve 59 is a valve for controlling the timing when shifting from 2nd speed to 3rd speed. The kickdown valve 72 is a valve that shifts down when the accelerator pedal is suddenly depressed greatly while the vehicle is running.

Next, a hydraulic control circuit for controlling the operation of the lock-up clutch 29 will be explained. This control is performed by the OD/lockup valve 76.3RD/lockup valve 77, lockup control valve 78J5, and rotor up accumulator 68 shown in Fig. 2, so these valves and their circuit system are enlarged in Fig. 6. The operation control of the lock-up clutch 29 will be explained using this circuit diagram.

The OD lock-up valve 76 is a valve that performs lock-up control when the gear stage is the fourth speed, and the left end of the spool 76a that can slide left and right receives governor pressure < PQ) supplied via the line 122. The right end of the spool 76a is the 3rd speed line pressure (P3) supplied via the line 123a.
) and the pushing force of spring 76b. The 3rd gear line pressure (P3) is a hydraulic pressure that is equal to the line pressure (Pin) in the 3rd gear and becomes zero in the 4th gear. Therefore, in the 3rd gear, the spool 76a is affected by the pushing force of the spring 76b and the 3rd gear line pressure. (P3) is always shifted to the left side at the receiving end, and the line 125 communicates with the drain side. On the other hand, since the 3rd gear line pressure (P3) is zero in the 4th gear, the governor pressure (PQ)
When the pressure is low, the spool 76a is moved to the left, but when the governor pressure (PQ') is high, the spool 76a is moved to the left.
is shifted to the right so that line 125 communicates with line 124b.

The 3RD lock-up valve 77 is a valve that performs lock-up control during the third speed.
g), the right end of the spool 77a receives the fourth speed line pressure (P4) via the line 124a and the pushing force of the spring 77b.

The 4th gear line pressure (P4) is the line pressure (Pi
n), which is the oil pressure that becomes zero in 3rd gear; therefore,
In the third gear, the line 126 is connected to the drain side, and in the fourth gear, when the governor pressure (Pg) becomes high pressure, the line 126 is connected to the drain side.
26 communicates with line 123b.

Line 125 and line 126 communicate with line 127 via shuttle valve (path switching valve) 87, and line 127b connected to line 127 is connected to the right end side of spool 78a of lock-up control valve 78. A spring 78b is attached to the left end of this spool 78a.
are in contact with each other, and the spool 78a is displaced according to the balance between the pushing force of the spring 78b and the hydraulic pressure acting through the line 127b.

The operation of each valve constructed in this way will be explained.

First, let us consider the case where the gear position is 4th speed. At this time, the 3rd gear line pressure (P3) is zero and the 4th gear line pressure (P4
) becomes equal to the line pressure (Pln), the spool 77a of the 3RD lock-up valve 77 is held in a state of being moved to the left, and the line 126 is communicated with the drain side. The displacement of the spool 76a of the OD/lockup valve 76 is determined by the balance between the pushing force of the spring 76b and the governor pressure (PQ), and when the vehicle speed is below a predetermined value and the governor pressure is low, the spool 76a remains moved to the left. Line 125 also communicates with the drain side. Therefore, the hydraulic pressure acting on the right end of the spool 78a of the lock-up control valve 78 through the line 127b is zero, and the spool 78a moves to the right.
7 is closed. As a result, the hydraulic oil supplied from line 120 is sent to line 37, and the lockup is released. From this state, when the vehicle speed increases and the governor pressure (PO) increases, the spool 76 of the OD/lockup valve 76
a moves to the right, and line 124b and line 125 communicate with each other. Therefore, the 4th speed line pressure (P4) is applied to the line 125 (
This pressure is equal to the line pressure (PIn)), and when this 4th speed line pressure (P4) is supplied to the shuttle valve 87, the ball 87a in the shuttle valve 87 moves to the line 12.
6 is closed, and the lines 125 and 127 are communicated with each other. As a result, the fourth speed line pressure (P4) acts on the right end of the spool 78a of the lock-up control valve 78, and the spool 78a moves to the left. Spool 78a
When the motor moves to the left, line 37 communicates with the drain side to operate the lock-up clutch, line 120 communicates with line 36, and the hydraulic oil supplied to line 120 is sent into the torque converter. In this way, when the vehicle speed becomes higher than a predetermined value in the fourth gear, the lockup is prevented from operating, but the hydraulic pressure acting on the right end of the spool 78a of the lockup control valve 78 is determined by the line pressure (Pln). As shown in Figure 4, this line pressure (Pln) is a hydraulic pressure that changes depending on the throttle opening, so even if the vehicle speed is above a predetermined value, when the throttle opening is close to full open, the spool 78a is moved to the right by the pushing force of spring 78b, and the lockup is released. Thereby, when the throttle opening degree is low, lockup can be released and transmission of engine vibration can be prevented.

Next, the operation when the gear stage is changed from 4th speed to 3rd speed will be explained. When shifting from 4th speed to 3rd speed, 3rd speed line pressure (P3) becomes equal to line pressure (Pln), and 4th speed line pressure (P4) becomes zero. Therefore, the spool 76a of the OD lock-up valve 76 receives the 3rd speed line pressure (P3) from the line 123a and is kept moving to the left.
25 communicates with the drain side. On the other hand, when the governor pressure (Pg) is above a predetermined value, the spool 77a of the 3rd lock-up valve 77 moves to the right in response to this governor pressure <PQ>, and the line 126 receives the 3rd gear line pressure from the line 123b. (P3) is supplied.

In this case, in the fourth gear, the ball 87a of the shuttle valve 87 moves to the right in the figure and blocks the line 126, so when the gear is shifted to the third gear, the ball 87a of the shuttle valve 87 moves to the right in the figure and blocks the line 126.
7b is first drained via line 125 and then transferred to the 3rd gear line pressure (P
3) moves the ball 87a to the left, and after the ball 87a closes the line 125, the 3rd speed line pressure (P3) acts on the line 127b. Therefore, line 1
The oil pressure at 27b temporarily becomes zero, which allows the lock-up clutch to be temporarily released during gear shifting, thereby suppressing shift shock.

Note that the line 127 communicates with the lock-up accumulator 68 via the line 127a, which is connected to the line 1
This is to allow the accumulator to absorb sudden fluctuations in the oil pressure in the lock-up clutch, thereby ensuring smooth engagement of the lock-up clutch. Also located in lines 88 and 125 are check valves 88 and 86 which allow oil to be slowly supplied to lock-up control valve 78 through an orifice while allowing oil to flow from lock-up control valve 78. This is to ensure rapid discharge, and this allows the lock-up release timing to be adjusted during gear changes.

(Effects of the Invention) As explained above, according to the present invention, the lock-up control valve that controls the supply of hydraulic pressure to the lock-up means of the torque converter is operated by a spool that is displaced in accordance with line pressure. A passage that controls the supply of line pressure to the lock-up control valves by a plurality of lock-up valves that operate corresponding to each gear position requiring lock-up, and that communicates each lock-up valve with the lock-up control valve. A passage switching valve (shuttle valve) installed inside selectively switches the communication between the multiple lock-up valves and the lock-up control valve, and also regulates the line pressure according to the throttle opening. Since the line pressure is made smaller when the throttle opening is small, a relatively simple configuration can release the lock-up when changing gears and when the throttle opening is small, reducing shift shock during gear shifting. It is possible to reduce the amount of engine vibration and prevent the transmission of engine vibrations in a low throttle opening state.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the structure of an automatic transmission that is automatically shifted by the lock-up control device of the present invention, FIG. 2 is a hydraulic control circuit diagram having the lock-up control device of the present invention, and FIG. 3 is the lock-up control device of the present invention. Cross-sectional views of the throttle modulator valve constituting the control device, FIGS. 4 and 5
The figure is a graph showing the oil pressure regulated by the throttle modulator valve, and FIG. 6 is a hydraulic control circuit diagram showing an enlarged part of the circuit diagram of FIG. 2. 2... Torque converter 10... Multi-speed gear device 12... Solid shaft 13... Turbine shaft 14... Planetary gear unit 28... Output gears 31 to 35... Oil passage 52. ...Manual valve 64...Throttle valve 65...Throttle modulator valve 76...O
D・Lockup valve 77...3RD・Lockup valve 78...Lockup control valve 79...Governor valve +04

Claims (1)

[Scope of Claims] A torque converter connected to the output shaft of an engine, a speed change gear mechanism connected to the output shaft of the torque converter, and a lockup means for connecting and disconnecting the input shaft and output shaft of the torque converter. , an automatic transmission comprising: a hydraulic control valve that controls line pressure supply to a clutch/brake group for switching a power transmission path by the speed change gear mechanism to perform speed change; a lockup control valve having a spool that controls the hydraulic pressure supply to the lockup means by displacement of the spool; and a lockup control valve that controls the supply of hydraulic pressure to the lockup means by displacement of the spool; a plurality of lockup valves that operate in correspondence with the respective gear stages to control the supply of the a passage switching valve that selectively switches communication between a plurality of lock-up valves and the lock-up control valve; and a passage switching valve that regulates the line pressure according to the engine throttle opening, and when the throttle opening is small, the line pressure is also adjusted. A lock-up control device for an automatic transmission, comprising a modulator valve for reducing the lock-up.