JPS6026838A - Hydraulic control device for automatic speed change gear - Google Patents

Abstract

PURPOSE:To moderate any shock produced upon changing a speed by providing an orifice for delaying the stroke of a plug of a shift valve in an oil passage for applying downward hydraulic pressure to said plug for controlling a speed change between No.n+1 and No.n speeds. CONSTITUTION:When a manual valve 4 is positioned in a D range and a car speed is high, respective 2-3, 3-4 shift valves 22, 24 are pushed up to up-positions by governor pressure PG applied to respective ports 122j, 124k. Accordingly, a clutch C2 and a brake B2 are engaged to permit an automatic change gear to stay on a fourth speed state. In this state, changing-over of the manual valve 4 to a II range (engine brake to running) causes the spool 224 of the 3-4 shift valve 24 to be pushed down while line pressure in an oil passage 414 is supplied to the 2-3 shift valve 22 via an orifice 690. Thus, with a plug 223 or a spool 222 gradually pushed down, any shock produced upon changing a speed can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a hydraulic control device 1 for an automatic transmission.

(b) Prior art - FJ'; i In an automatic transmission, gear changes are performed by switching the operating states of two friction elements, but if the timing of switching between the two friction elements is not the same, a large shift occurs. Shock, engine blowing, etc. occur. In particular, when changing gears by switching between two multi-disc clutches, it is difficult to gently control the engagement or release speed of the multi-disc clutches, making it very difficult to adjust the timing. Therefore, for example, in an automatic transmission with four forward speeds, the state of the fourth speed in the D range (automatic shift driving range) is y.
C1 to II range (2nd speed engine brake running range) When it is necessary to engage one clutch and release the other clutch when shifting to the 2nd speed state, conventionally, for example, As shown in No. 24249, the timing is adjusted by providing a timing valve (downshift control valve) in the oil path where pressure oil is supplied in the low speed fixed range of the manual valve, and the timing is adjusted from D range 4th gear to D range 4th gear. I was trying to shift from 3rd gear to II range 2nd gear. However, with such a timing valve, the entire device becomes large due to the valve and the large number of oil passages required for it, and the small diameter of the valve makes it prone to sticking and lacks operational stability. There were some problems. These are particularly important in the case of automatic transmissions used in automobiles.

(C) Purpose of the Invention The present invention provides a method for changing the gear stage to 1 when the manual valve is switched from the automatic transmission range to the engine brake range.
The object of the present invention is to provide a hydraulic control device for an automatic transmission which can prevent the occurrence of shift shock and drying when shifting over a gear, is compact, and improves reliability.

(D) Structure of the Invention The present invention provides, for example, in the case of an automatic transmission with four forward speeds, when shifting from the D range 4th speed to the II range 2nd speed, the 3rd speed is changed for a short time.
The above object is achieved by intervening the speed state (that is, changing the speed from 4 to 3 to 2). That is, the hydraulic control device for an automatic transmission according to the present invention
When the manual valve is selected to the nth engine brake drive range while driving at high speed, the n+1st and f
It is characterized by an orifice that retards the stroke of the plug in the oil passage that applies hydraulic pressure toward the down position to the plug of the shift valve that controls the shift between 5n and 5n speeds.

(e) Examples Examples of the present invention will now be described with reference to FIGS. 1 to 3 of the accompanying drawings.

FIG. 1 shows a schematic diagram of a power transmission mechanism of an automatic transmission with four forward speeds and one rear selection speed with overdrive. This power transmission mechanism consists of an input shaft (■) to which the rotational force from the engine output shaft E is transmitted via the torque converter T/C, an output +11+O which transmits the driving force to the final drive device, and a first
Planetary gear set Gl, second planetary gear set G2, first clutch c
1, a second clutch C2, a third clutch C3, a first brake B1, a second brake B2, and a one-way clutch owC. The first planetary gear set G1 includes a sun gear S1, an internal gear R1, and both gears S1 and R1.
The planetary gear set G2 is composed of a carrier Pct that supports the pinion gear P1 that meshes at the same time, and a planetary gear set G2.
Sun gear S2, internal gear R2, both gears S2
and a carrier PC2 that supports the pinion gear P2 that meshes with R2 at the same time. Career P'C
I can be connected to the input axle load via clutch C2,
Further, the sun gear S1 can be connected to the input axle load via the clutch c1. Carrier Pct can also be connected to internal gear R2 via clutch C3. Sun gear S2 is always connected to the input shaft load, and internal gear R1 and carrier PC2 are always connected to output shaft 0. Brake B1 can fix carrier PCI, and brake B2 can fix sun gear S1. The one-way clutch OWC has a structure that allows forward rotation (rotation in the same direction as the engine output shaft E) of the carrier Pct, but does not allow reverse rotation (rotation in the opposite direction to the forward rotation) (i.e., a structure that acts as a brake only during reverse rotation). It's Toshide.

The above power transmission mechanism operates the planetary gear set G by operating clutches C1, C2 and C3, brake Bl (one-way clutch 0WC) and B2 in various combinations.
1 and each element of G2 (Sl, B2, R1, R2, Pct
, and PO2) can be changed, thereby making it possible to variously change the rotational speed of the output shaft O relative to the rotational speed of the input shaft. Clutches C1, C2 and C3
, and brakes B1 and B2 in combination as shown in the table below, four forward speeds and one rear speed can be obtained.

(Space below) In the above table, O marks indicate operating clutches and brakes, and C1 and C2 are internal gear R1, respectively.
The gear ratio is the ratio of the number of teeth of sun gear S1 and B2 to the number of teeth of R2, and the gear ratio is the ratio of the number of rotations of input shaft (2) to the number of rotations of output shaft O. Also, under B1 (OWC
) indicates that the first speed can be obtained by the one-way franchise OWC even when the brake B1 is not activated. However, in the first speed in this case, it is not possible to drive from the output shaft O side (i.e.,
(engine brake does not work).

FIG. 2 is a hydraulic circuit diagram of a hydraulic control device that controls the power transmission mechanism.

This hydraulic control device includes a regulator valve 2, a manual valve 4, a throttle valve 6, a throttle failsafe valve 8, a throttle modulator valve 10,
Pressure modifier valve 12, cutback valve 14, line pressure booster/help 16, governor valve 18.1-2 shift valve 20.2-3 shift pal 2
J 2.3-4 shift valve 24.2-4 timing/
Round Lube 26.2-3 Timing Valve 28.3-4 Timing Valve 30.3-2 Timing/Help 32, l
Speed fixed range pressure reducing valve 34, torque converter pressure reducing valve 36.1-2 accumulator 38.4-3 accu rake 40. These valves are connected to each other as shown in FIG. 2, and the oil pumps O/P, l, and
Lucon Bark T/C, clutches C1, C2 and C3,
It is also connected to brakes B1 and B2 as shown. The brake B2 has a servo apply chamber S/A, which is a hydraulic chamber for applying the brake, and a servo release chamber S/R, which is a hydraulic chamber for releasing the brake. Since the area is larger than the pressure receiving area of servo apply "MS/A", if hydraulic pressure is not supplied to servo release chamber S7R, brake B2 will be released even if hydraulic pressure is supplied to servo apply chamber S/A. ).The overdrive inhibitor solenoid 42 is electrically connected to the overdrive inhibit switch SW and is set to "V". With this configuration, the clutches C1, C2, and C3 and the brakes B1 and B2 operate as shown in the table above, depending on the vehicle speed and the throttle opening of the engine.

In the following explanation, the parts directly related to the present invention will be mainly explained, and the detailed explanation of other parts will be omitted. It is similar to that disclosed in No. 036606, and the name of the member indicated by each reference symbol is written in place of #. Code 102, 104, 106, 10
8゜110.112,114,116,120,122
．． 124. l'26,128,130,132°134
and 136 are helf holes, symbols 102a-j, 104
a-f, 106a-f, 108a-e, 11
0a-e, 112a-e, 114a-g, 1.16
a-f, 120a-, 122a-j, 124a
~k, 126a-e, 130a-e, L
32a-e, 134a-e and 136a-e are ports, 138 and 140 are cylinder holes, 202. '
203,204.206.210.212,214,2
15,216.220°221.222,224,22
6,228.230.232, 234 and 236 are spools, symbols 202a-d, 203a-b, 204a
-b, 206a-c, 208a, 210a-c, 21
2a-b, 214a-c, 215a-b, 216a
~c, 220a-c, 22.1a-d, 222a-e
, 224a-d, 226a-c, 228a-c,
230a-c, 232a-c, 234a-b and 236
a - b is a land, -÷207 is a plunger, 208 is a sleeve, 209 is a plug, 223 and 225 are plugs, 238 and 240 are pistons,
252 is a sleeve, 252a-c are ports I,
254 is a spring seat, 302, 306,
307, 308. 310, 312, 316, 320, 3
22゜324.328,330,332,334,33
6.338 and 340 are springs, code 4°2.40
4,406,408,409,410°4 ], 1.
, 4. 1 2, 4 1 4, 4 1 6
, 4 1 8 , 4 20.422,424,42
6.42'8,430°432.434,436,43
8,440,442.444, j4s, 448 and 450 are oil passages, codes 502, 504, 506 and 508
are shuttle valves, codes 602, 604, 606, 60
8.610,612.6'14,616,618°62
0.622.624.626.628.630.650
, 652, 654. ' 56 and 658 are orifices,
Reference numerals 750, 752, 754, 756 and 758 indicate check valves, respectively.

The following description will be made based on FIG. 3 in which only the manual valve 4.2-3 shift valve 22 and 3-4 shift valve 24 are shown separately for ease of understanding.

The oil passage 414 connected to the port 104e of the manual valve 4 is connected to the port 104e of the 2-3 shift valve 22.
It is connected to 2a. An orifice 690 is provided at the entrance of the port 122a of the oil passage 414. The spool 204 of the manual valve 4 is connected to this oil passage 414.
Line pressure is supplied when switched to I range or range range. Note that the oil passage 414 is connected to the 3-4 shift valve 24.
It is also connected to port 1-124b. The 2-3 shift valve 22 includes a spool 222, a plug 223, and a spring 332 interposed between the two. The plug 223 is for holding the spool 222 in the down position in the engine braking range,
Pressure receiving surface J! The port 122a described above is arranged to apply hydraulic pressure to the upper side of the plug 223 in the figure.

Next, the operation of this embodiment will be explained. When the manual valve 4 is in the D range (automatic shift driving range) and the heavy speed is high, the 2-3 shift pulso 22 and 3-4 shift/slip 24 are controlled by the governor pressure PG acting on the ports 122j and 124k, respectively. Up position (
They are pushed up to the positions shown in the left half of FIG. 3, respectively.

Therefore, the port 122f and the port 122g of the 2-3 shift pulso 22 communicate with each other, the line pressure of the oil passage 432 is supplied to the oil passage 434, and the clutch c2 is engaged.

On the other hand, the port 124g of the 3-4 shift valve 24 communicates with the port 1-124f, and the flange c3 is connected to the oil passage 442.
, port 1-124g, and port 124f. Therefore, clutch c2 and brake B2 are engaged (line pressure is supplied to servo apply chamber S/A from oil passage 432 to brake B2, and line pressure is supplied to servo apply chamber S/A from oil passage 444, port 1-124d, and port 1
24c), the automatic transmission is in fourth gear. When the manual valve 4 is switched from this state to the II range (engine brake running range), line pressure acts on the oil passage 414. The line pressure of the oil passage 414 immediately acts on the port 124b of the 3-4 shift valve 24, and forcibly pushes the spool 224 of the 3-4 shift valve 24 down to the down position (the position shown in the right half of the figure). Therefore, the port 124g and the port 124h of the 3-4 shift valve 24 communicate with each other, the line pressure of the oil passage 412 is supplied to the oil passage 442, and the clutch C3 is engaged. At the same time, oil passage 434 and oil passage 4
44 and po l= 124 e and po 1-124
d, and hydraulic pressure is supplied to the servo release chamber S/R, so that the brake B2 is released. On the other hand, the line pressure of the oil passage 414 is also applied to the port 122a of the 2-3 shift valve 22 through the orifice 690.

Plug 2 is activated by the hydraulic pressure acting on Ho 1-122 a.
23 is pushed down in the figure, but port 1-122
Since hydraulic pressure is supplied to a through the orifice 690 and the plug 223 has a relatively large diameter, the plug 22
3 is pushed down gently. Plug 223 If spool 222 is pushed down together, and after a predetermined period of time, spool 222 is completely switched to the down position. After a predetermined period of time, the 2-3 shift valve 22 is switched to the down position shown in the right half of the figure. 2-3 shift valve 22
is switched to the down position, the 3-4 shift valve 24 is in the down position and the 2-3 shift valve 22 is in the amplifier position, clutch C2 remains engaged and brake B2 remains released. . Therefore, the automatic transmission is in the third speed state where clutches C2 and C3 are engaged. After a predetermined period of time as shown in L, 2-3
The shift valve 22 is switched to the town position and the port 12
2g and 122h communicate with each other, and the hydraulic pressure of the clutch C2 is discharged from the drain boat 122h via the oil passage 434 and port 1-122g. Also, the servo release chamber S/
R also oil passage 444, port 1-124 d, and port) 12
Since it communicates with the oil passage 434 via 4e, it is also first discharged. Therefore, clutch C3 and brake B2 are engaged, and the automatic transmission enters the second speed state. In the end, when the manual valve 4 is switched to the II range while driving in the D range and 4th gear, the 3-4 shift valve 24 is immediately switched from the up position to the town position, the automatic transmission is in the 3rd gear state, and then After a predetermined period of time during which the plug 223 strokes, the 2-3 shift valve 22 is switched from the up position to the town position, and the automatic transmission enters the second speed state. That is, when the manual valve 4 is switched from the D range to the II range, the gear is first shifted from the fourth gear to the third gear, and after reaching the third gear, the gear is shifted from the third gear to the second gear. . Since the rotational speed fluctuations and drive l/lux fluctuations during 4-3 and 3-2 speed changes are smaller than in the case of direct 4-2 speed change, the speed change can be reduced. Also, during 4-3 shifting and 3-2 shifting,
Since the brake B2 is released and engaged, the hand servo is operated, and the shift timing can be adjusted relatively easily.

(f) As described in detail, according to the present invention, at least two
Shift I valves, when the first shift valve (2-3 shift valve 22 in the illustrated embodiment) and the second shift valve (3-4 shift valve 24) are both in the up position. When the first shift valve is in the up position and the second shift valve is in the down position, the n+1th gear is set, and the first shift valve and the second shift/help are both down. When the manual valve is in the position, it becomes the nth gear, and when the manual valve is selected from the automatic shift driving range (D range) to the engine brake driving range (II range), both the first and second shift valves are forced to the down position. In a hydraulic control system for an automatic transmission with 3 or more forward speeds, a plug is provided with a spring interposed on the up position side of the first shift valve. The oil passage to which hydraulic pressure is applied when the brake driving range is selected is connected to a port that pushes the plug toward the down position when hydraulic pressure is applied, and the port entrance of this oil passage has an orifice that delays the stroke of the plug. is provided, so when shifting from the n+2nd speed (4th speed) of the automatic transmission range to the nth speed (2nd speed) of the engine brake driving range, the nth
+1 speed (third speed) can be interposed, and the occurrence of shift shock and engine revving can be prevented. In addition, since only a plug and an oriice are used, the number of parts and oil passages are not only compact, but also the operation of the plug is stable, so reliability can be improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a power transmission mechanism of an automatic transmission, FIG. 2 is a diagram showing the entire hydraulic control device for an automatic transmission to which the present invention is applied, and FIG. 3 is a diagram showing a hydraulic control device according to the present invention. be. 4, Φ, manual pal 7', 2'2-ψ-2-3 shift valve, 24, fist, 3-4 shift valve, 223φφ
Fist plug, 414/Fist/oil passage, 690/Oφ orifice. Patent applicant: Nissan Motor Co., Ltd. Representative Patent attorney: Toshiyuki Miyauchi

Claims (1)

[Claims] It has at least two shift I valves, and when the first shift valve and the second shift valve are both in the up position, the n+2th gear is set, and the first shift valve is in the up position and the second shift valve is in the up position. When the shift valve is in the down position, the n+2th gear is set, and when both the first shift valve and the second shift valve are in the down position, the nth gear is set, and the manual valve is moved from the automatic shift driving range. In a hydraulic control device for an automatic transmission with three or more forward speeds, which forcibly moves both the first and second shift valves to the down position when the engine brake driving range is selected, the first shift valve is moved to the up position. A plug is installed on the position side with a spring interposed, and when the manual valve is selected to the engine braking range, the oil passage where hydraulic pressure acts pushes the plug to the down position side. A hydraulic control device for an automatic transmission, characterized in that the oil passage is connected to a port, and an orifice for delaying the flow of a plug is provided at an inlet of the port of the oil passage.