JPH03234922A - Hydrauric oil circuit for hydraulic operating frictional joint device - Google Patents

Abstract

PURPOSE:To facilitate arrangement of a bypass control valve by arranging a bypass passage bypassing an orifice and a bypass control valve in the piston of accumulator. CONSTITUTION:An accumulator 55 for damping a shock at engaging a reverse clutch 34 (friction coupling element) is arranged on a reverse clutch line 107, a one-way orifice 54 is arranged on the upper stream of the accumulator, and a bypass passage is constituted out of a passage 68 bypassing the orifice 54, an input port 58, an annular chamber 64, a communicating hole 67, a valve fitting hole 66, a pressure chamber 62, and a pressure port 57. A bypass control valve 70 for opening/closing the bypass passage 68 is received in a piston 60. Hereby, the valve 70 is effectively arranged, utilizing the dead space in the accumulator 55, and hence arrangement of the valve 70 is facilitated.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a hydraulic circuit for a friction engagement device that engages and operates a friction engagement element such as a clutch using hydraulic pressure, and in particular, the present invention relates to a hydraulic circuit for a friction engagement device that engages and operates a friction engagement element such as a clutch using hydraulic pressure. Concerning things that create pressure.

(Prior Art) In general, in a hydraulic automatic transmission in a vehicle, when engaging various clutches (for example, a reverse clutch for reversing) as a friction engagement element, the hydraulic pressure acting on the hydraulic actuator of the clutch is In this method, the pressure is increased early until the actual engagement state is reached, and then the pressure is maintained at a substantially constant level for a predetermined period of time, thereby placing the clutch in a so-called half-clutch state, thereby reducing the shock at the time of engagement. There is.

In order to maintain a constant tank pressure while increasing the oil pressure, conventionally, as disclosed in Japanese Patent Publication No. 52-27311, an accumulator is provided in the hydraulic circuit of the clutch, and an orifice is installed on the upstream side of the accumulator. A bypass control valve is provided to bypass the orifice, and by opening the bypass control valve at the initial stage of engagement of the clutch, hydraulic oil is supplied to the clutch bypassing the orifice, and after a predetermined period of time, the oil pressure is reduced. When the temperature rises, the bypass control valve is closed, supplying hydraulic oil through the orifice and
It has been proposed to create the tank pressure.

(Problems to be Solved by the Invention) In this proposal, the bypass control valve plays an important role in quickly creating hydraulic tank pressure when the clutch is engaged. However, it is necessary to take into consideration the space for arranging the bypass valve, and there is a problem in its arrangability, especially when space is limited, such as in a vehicle transmission.

The present invention has been made in view of the above, and an object thereof is to facilitate the arrangement of the bypass control valve by devising a location where the bypass control valve is arranged.

(Means for Solving the Problem) In order to achieve the above object, the invention according to claim (1) focuses on the fact that the bypass control valve is provided in the hydraulic circuit near the accumulator. It was housed inside the piston.

That is, the present invention provides a hydraulically operated friction engagement device including an accumulator disposed in a hydraulic circuit for operating a friction engagement element such as a clutch, and an orifice disposed in the hydraulic circuit upstream of the accumulator. The piston of the accumulator is characterized in that a bypass passage that bypasses the orifice and a bypass control valve that opens the bypass passage at the initial stage of engagement of the frictional engagement element and closes the bypass passage thereafter.

(Function) With the above configuration, in this invention, the space formed in the piston of the accumulator is a dead space, and the bypass control valve is housed in this dead space, so the bypass control valve can be operated independently. Compared to the case where the device is provided, there is no need to consider the placement space, and the placement is easier.

(First example) Embodiments of the present invention will be described below based on the drawings.

FIG. 3 shows an automatic transmission A for an automobile according to a first embodiment of the present invention, and this transmission A includes a torque converter 10, a speed change gear mechanism 20 driven by the output of the torque converter 0, It has a plurality of frictional engagement elements 31 to 36 and one-way clutches 41 and 42 for switching the transmission path of the transmission gear mechanism 20, and these elements serve as a driving range, 2.1 and R ranges, and D range. 1 to 4 speeds in , 1 to 3 speeds in 2 ranges, 1 in lungi
speed and second speed are available.

The torque converter 0 includes a pump 12 connected to an engine output shaft 1 via a case 11;
a turbine 13 disposed opposite to the pump 12 and driven by the pump 12 via hydraulic oil; the turbine 13 and the pump 12;
A stator 15 is arranged between the case 11 and the turbine 13, and is fixed to the case 2 of the transmission A via a one-way clutch 14 to increase torque. A lock-up clutch 16 is directly connected to a turbine 13 via a cylindrical turbine shaft 7. The turbine 13 is connected to a speed change gear mechanism 20 via a cylindrical turbine shaft 7. Further, an oil pump 4 is drivingly connected to the engine output shaft 1 via a pump shaft 12 passing through the turbine shaft 17 .

The speed change gear mechanism 20 is composed of a Ravigneau type planetary gear mechanism. That is, this speed change gear mechanism 20 includes a small sun gear 21 rotatably supported by a turbine shaft 17, and a turbine shaft 17 located behind the small sun gear 21 (to the left in the figure).
A large sun gear 22 rotatably supported by the small sun gear 21, a plurality of short pinions 23, 23, . A plurality of long pinions 24, 24°...
and the short pinion 23. 23. ... and long pinions 24, 24. ... and a ring gear 26 that meshes with the front half of each of the long pinions 24.

Further, a forward clutch 31 and a first one-way clutch 41 are arranged in series between the turbine shaft 17 and the small sun gear 21, and a coast clutch 32 is arranged in parallel with both clutches 31 and 41. Also,
A 3-4 clutch 33 is disposed between the turbine shaft 17 and the pinion carrier 25, and the turbine shaft 1
7 and large sun gear 22 is a reverse clutch 3.
4 are arranged. A 2-4 brake 35 consisting of a band brake for fixing the large sun gear 22 is provided between the large sun gear 22 and the reverse clutch 34, and a pinion brake 35 is provided between the pinion carrier 25 and the case 2 of the transmission A. A second one-way clutch 42 that receives and stops the reaction force of the carrier 25 and a low reverse brake 36 that fixes the pinion carrier 25 are provided in parallel.

Further, the ring gear 26 is connected to an output gear 5, and the output gear 5 is connected to left and right drive wheels via a differential device (not shown).

Frictional engagement elements 31 such as clutches and brakes
36 and one-way clutches 41 and 42 and the relationship between the gears. First, in the first gear,
The forward clutch 31 is turned on, and the first and second one-way clutches 41 and 42 are locked. Therefore, the output rotation of the torque converter 10 is input from the turbine shaft 17 to the forward clutch 31 and the small sun gear 21 of the transmission gear mechanism 20 . Since the pinion carrier 25 is fixed by the second one-way clutch 42, the transmission gear mechanism 20 is a fixed type that does not perform a differential operation that transmits rotation from the small sun gear 21 to the ring gear 26 via the short pinion 23 and the long pinion 24. The gear train operates as a large gear train, and a large reduction ratio corresponding to the ratio of the diameters of the small sun gear 21 and the ring gear 26 can be obtained.

In 2nd gear, in addition to the above 1st gear condition, the 2-4 brake 35
is activated, the large sun gear 22 is fixed, and the second one-way clutch 42 is idled. Therefore, the rotation transmitted from the turbine shaft 17 to the small sun gear 21 is transmitted to the long pinion 24 via the short pinion 23. Since the long pinion 24 is fixed to the large sun gear 22 that meshes with the long pinion 24, it revolves on the large sun gear 22, and the pinion carrier 25 rotates.

Therefore, compared to the 1st speed state, the rotation needle of the pinion carrier 25 (the amount of revolution of the long pinion 24) is the same as that of the ring gear 2.
The rotation speed of No. 6 is increased, and the reduction ratio becomes smaller than that of the first speed.

In 3rd gear, the 2-4 brake 35 is turned to O from the above 2nd gear state.
The 3-4 clutch 33 is turned on. Therefore, the rotation of the turbine shaft 17 is input to the small sun gear 21 via the forward clutch 31 and the first one-way clutch 41, and at the same time the 3-4 clutch 3
It is also input to the pinion carrier 25 via 3. As a result, the entire transmission gear mechanism 20 rotates integrally, and the ring gear 26 rotates at the same speed as the turbine shaft 17.

In the fourth speed, the 2-4 brake 35 is turned on again. Therefore, the rotation of the turbine shaft 17 is 3=4 clutches 3
3 to the pinion carrier 25, and the long pinion 24 revolves. However, since the large sun gear 22 is fixed by the 2-4 brake 35, the long pinion 24 rotates while revolving together with the pinion carrier 25.

Therefore, the ring gear 26 rotates the long pinion 24 according to the rotation of the pinion carrier 25 (rotation of the turbine shaft 17).
Only the rotating bones of the body rotate at an increased speed, resulting in an overdrive state. At this time, the forward clutch 31 is in the ON state, but the first one-way clutch 4 directly connected to the forward clutch 31 is in the ON state.
1 idles, the rotation of the turbine shaft 17 is not input to the small sun gear 21.

Further, at reverse speed, the reverse clutch 34 and the low reverse brake 36 are turned on, the rotation of the turbine shaft 17 is input to the large sun gear 22, and the pinion carrier 25 is fixed. For this reason, the large sun gear 22 is connected to the ring gear 26 via the long pinion 24.
The rotation is transmitted through a fixed gear train leading to the large sun gear 22 and the ring gear 26, and a reduction ratio corresponding to the diameter ratio of the large sun gear 22 and the ring gear 26 is obtained. At the same time, the rotational direction of the ring gear 26 is opposite to the rotational direction of the turbine shaft 17 or large sun gear 22.

Note that the first one-way clutch 41, which transmits rotation in 1st to 3rd gears, and the second one-way clutch 42, which receives no reaction force in 1st gear, spin idle during coasting, so engine braking is not applied in these gears. Become.

However, in the 3rd gear of the D range, the 2nd and 3rd gears of the 2nd range, and the 1st and 2nd gears of the lunge, the coast clutch 32 disposed in parallel with the first one-way clutch 41 is not turned on.
Also, in the first gear of the lunge, the second one-way clutch 4
Since the low reverse clutch 34 parallel to 2 is turned on, engine braking is obtained in 3rd gear of the D range, 2nd and 3rd gears of the 2 range, and 1st and 2nd gears of lunge.

In this embodiment, the present invention is applied to the hydraulic circuit for operating the reverse clutch 34 among the hydraulic circuits for operating the plurality of frictional engagement elements 31 to 36. Therefore, here, the description will be limited to the hydraulic circuit that mainly operates the reverse clutch 34 with reference to FIG.

This hydraulic circuit includes a regulator valve 50 that adjusts the pressure of the hydraulic oil discharged from the oil pump 4 to the main line 100 to a predetermined line pressure, and a regulator valve 50 that sends the line pressure to each hydraulic line according to the selected range. A manual valve 51 is provided. This manual valve 51 has one input port 51b and first to fifth output ports 51c to 51g, and line pressure is introduced from the main line 100 into the input port 51b. On the other hand, the output ports 51c to 51g each have a first
-Fifth output lines 101-105 are connected, and these lines 101-105 are connected to hydraulic actuators of valves and other frictional engagement elements (not shown). As the spool 51a moves, the input port 51b becomes the first and second output ports 51c and 51d in the D range, and the second
In the range, the first to third output ports 51c to 51e, and in the lunge, the first, third, and fourth ports 51c
+ 51 e +' 51 f, and in the R range, the fifth output port 51g.

The fifth output line 105 includes a low reverse brake line 106 that connects to the hydraulic actuator 36a of the low reverse brake 36 via a one-way orifice 52 and a shuttle valve 53, and a one-way orifice 54.
Hydraulic actuator 3 of reverse clutch 34 via
4a is connected to the reverse clutch line 107, and in the R range, the low reverse brake 36 and reverse clutch 34 are simultaneously engaged.

The reverse clutch line 107 is provided with an N-R accumulator 5 that buffers the impact when the reverse clutch 34 is engaged.
5 is arranged, and the upstream side of this accumulator 55 (fifth
The above one-way orifice 54 is installed on the output line 105 side).
is installed.

As a feature of the present invention, a bypass passage 693 is provided that bypasses the one-way orifice 54, and a portion of this bypass passage 69 is formed within the accumulator 55. That is, as shown in enlarged detail in FIG. 1, the accumulator 55 includes a closed cylindrical casing 56 as a cylinder, and this casing 56 has a pressure port that opens at one end in the length direction (the left end in the figure). 57 and an input port 5 opening in the center
8 and a drain port 59 that opens at the other end (the right end in the figure). Above input port 58
There is a passage 68 in the line 107 upstream of the orifice 54.
The pressure port 57 is connected to the actuator 34a of the reverse clutch 34. A piston 60 is slidably disposed within the casing 56, and the space within the casing 56 is
It is divided into a spring chamber 61 on the right side in the figure that is always in communication with the drain port 59, and a pressure chamber 62 on the left side that is always in communication with the pressure port 57. The spring chamber 61 has two accumulator springs 63a, 63 with a large diameter and a small diameter.
b is compressed, and the piston 60 is urged toward the pressure chamber 62 by the springs 63a and 63b.

Further, an annular chamber 64 is formed on the outer periphery of the piston 60 and is in constant communication with the input port 58, and an annular chamber 64 is formed in the center of the end surface of the piston 60 on the side of the pressure chamber 62 and is in constant communication with the pressure chamber 62 via a communication passage 65. A bottom valve fitting hole 66 is provided. Further, this valve fitting hole 66 has a communication hole 67,
It communicates with the annular chamber 64 on the outer periphery of the piston 60 via 67, . . .
, the communication hole 67, the valve fitting hole 66, the pressure chamber 62, and the pressure port 57 constitute a bypass passage 69 that bypasses the orifice 54.

A bypass control valve 70 for opening and closing the bypass passage 69 is accommodated in the piston 60.

This bypass control valve 70 has a valve body 71 that is slidably inserted into the valve fitting hole 66, and the space inside the valve fitting hole 66 is constantly communicated with the pressure chamber 62 by this valve body 71. The chamber 72 on the hole opening side (left side in the figure) and the bottom side (right side in the figure)
It is divided into spring chambers 73 and 5. The valve body 71 is restricted from moving to the left in the figure by a stopper 74 made of a ring attached to the inner periphery of the valve fitting hole 66. Further, a valve opening that communicates with the chamber 72 through an orifice 75 is opened on the outer periphery of the valve body 71, and this valve opening and the piston 6
When the bypass passage 69 is opened and closed by communicating with and blocking the communication with the communication hole 67 of 0, and the valve body 7] moves to the left in the figure to the position where it is regulated by the stopper, as shown in the upper half of the figure, the valve The mouth part communicates with the communication hole 67 and the bypass passage 69
opens, and when the valve body 71 moves to the right as shown in the lower half of the figure, communication with the communication hole 67 of the valve opening is cut off and the bypass passage 69 is closed.

Further, a valve spring 77 is compressed in the spring chamber 73, and the valve body 77 is compressed by the valve spring 77.
1 is biased to open toward the pressure chamber 62 side. Therefore, the bypass control valve 70 is controlled by the valve spring 77.
At the initial stage of engagement of the reverse clutch 34, the valve is opened to open the bypass passage 69 until the oil pressure in the line 107 rises to a predetermined value, and then when the line pressure rises to a predetermined value, the valve body 71 is moved to the right. When the valve is moved, the valve is closed and the bypass passage 69 is closed.

Reference numeral 78 denotes a communication hole formed through the bottom wall of the valve fitting hole 66, which allows the spring chambers 61 and 73 to communicate with each other so as not to inhibit the movement of the valve body 71.

Next, the operation of the above embodiment will be explained.

When the manual valve 51 is switched to the R range, the oil pressure of the reverse brake line 106 and the reverse clutch line 107 increases, and each actuator 36a
, 34a is supplied with hydraulic oil and the low reverse brake 3 is activated.
6 and reverse clutch 34 are engaged.

At this time, at the initial stage when the reverse clutch 34 is engaged, the bypass control valve 70 is open, as shown in the upper half of FIG. Since the openings communicate with the communication holes 67, 67, . . . , the bypass passage 69 is opened. By opening the bypass passage 69, the hydraulic oil bypasses the one-way orifice 54 and reaches the actuator 34.
supplied to a. Therefore, as shown by the line L1 in FIG. 4, the oil pressure in the line 107 can quickly rise to a predetermined value.

Thereafter, when the oil pressure in the line 107 rises to a predetermined value, the pressure in the chamber 72 increases and the valve body 71 moves to the right in the figure while contracting the valve spring 77, as shown in the lower half of FIG. However, the valve opening is removed from the communication hole 67, the bypass control valve 70 is closed, and the bypass passage 69 is closed. Therefore, the hydraulic oil flows through the one-way orifice 54.
L is supplied to the actuator 34a through L in FIG.
As shown by the two lines, the line pressure of the line 107 is maintained at a substantially constant value, making it possible to form a hydraulic tank pressure. This hydraulic tank pressure brings the reverse clutch 34 into a half-clutch state, which can reduce shock when the reverse clutch 34 is engaged.

When the line pressure further increases as time passes, the pressure in the pressure chamber 62 increases, causing the piston 60 of the accumulator 55 to move.
moves to the right in the figure while contracting, the hydraulic pressure to the actuator 34a increases as shown by the line L3 in FIG. 4, and the clutch 34 is completely engaged.

Therefore, in this embodiment, the bypass control valve 70 is housed in the piston 60 of the accumulator 55, so that when the bypass control valve 70 is provided separately from the accumulator, the bypass control valve 70 is The bypass control valve 70 can be effectively arranged by utilizing the dead space within the accumulator 55, and the bypass control valve 70 can be easily arranged.

(Second Embodiment) FIG. 5 shows a second embodiment. The same parts as in FIG.
In the first embodiment, the bypass control valve 70 is closed by moving the valve body 71, whereas in this embodiment, the piston 60 of the accumulator 55 is moved to close the bypass control valve 70. It is designed to close the valve.

That is, in this embodiment, there is one accumulator spring 63 that biases the piston 60 of the accumulator 55 toward the pressure chamber 62, and its spring force is smaller than that of the valve spring 77. As shown in the upper half of the figure, in a normal state, the bypass control valve 70 is open and the valve opening of the valve body 71 is in communication with the communication hole 67 of the accumulator 55. When the line pressure increases during fastening, the piston 60 of the accumulator 55 moves to the right in the figure while contracting the accumulator spring 63, as shown in the lower half of the figure.

On the other hand, the valve body 71 of the bypass control valve 70 does not follow the piston 60 and stops while expanding the valve spring 77. As a result, communication between the valve opening and the communication hole 67 is cut off, the bypass control valve 70 is closed, and the bypass passage 69 is closed. Therefore, this embodiment can also achieve the same functions and effects as those of the first embodiment.

0 The above embodiments are applied to the hydraulic pressure circuit of the reverse clutch 34 in the automatic transmission A of an automobile, but the present invention is applicable to other clutches and friction engagement devices other than the automatic transmission A. Of course, the present invention can also be applied to hydraulic hydraulic circuits.

(Effects of the Invention) As explained above, according to the present invention, the bypass control valve that bypasses the orifice is accommodated in the piston of the accumulator disposed in the hydraulic pressure circuit of the frictional engagement element. can be effectively arranged by utilizing the dead space within the accumulator, and the bypass control valve can be easily arranged.

[Brief explanation of drawings]

1 to 4 show a first embodiment of the present invention, FIG. 1 is an enlarged sectional view of an accumulator, FIG. 2 is a hydraulic circuit diagram of the main parts of an automatic transmission, and FIG. 3 is a diagram of an automatic transmission. The skeleton diagram, FIG. 4, is a characteristic diagram showing the rise characteristics of the hydraulic pressure to the actuator when the clutch is engaged. FIG. 5 is a first diagram showing the second embodiment. A... Automatic transmission 34... Reverse clutch (frictional engagement element) 34a.
・Hydraulic actuator 54 ・One-way orifice 55 ・Accumulator 69 ・Bypass passage 70 ・Bypass control valve 2

Claims (1)

[Claims] (1) In a hydraulically operated friction engagement device comprising an accumulator disposed in a hydraulic circuit that operates a friction engagement element, and an orifice disposed in the hydraulic circuit upstream of the accumulator, a piston of the accumulator , a hydraulically actuated friction engagement device comprising: a bypass passage that bypasses the orifice; and a bypass control valve that opens the bypass passage at the initial stage of engagement of the friction engagement element and then closes the bypass passage. Actuation hydraulic circuit.