JP2936860B2 - Centrifugal oil pressure cancel mechanism for rotary clutch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary clutch that can rotate itself, such as a clutch that changes the transmission path by changing the torque transmission path in an automatic transmission.
In particular, the present invention relates to a cancel mechanism that cancels out hydraulic pressure caused by centrifugal force in a rotary clutch that is engaged and released by hydraulic pressure.

[0002]

2. Description of the Related Art As is well known, an automatic transmission is configured to set a plurality of gears by changing the transmission path of power in a gear train by appropriately engaging or releasing a clutch or a brake. . These clutches and brakes are generally configured to be engaged by a hydraulic servo mechanism that drives a piston by hydraulic pressure,
These clutches and brakes not only transmit torque and give a reaction force, but also absorb the inertial energy associated with shifting to reduce shift shocks.Therefore, the clutch and brake are operated by a hydraulic servo mechanism. Proper control of the timing of engagement or disengagement is an important requirement for reducing shift shock.

[0003] The timing of engagement and disengagement of the clutch and brake by the hydraulic servo mechanism is substantially determined by the degree of increase or decrease of the hydraulic pressure supplied to and discharged from the hydraulic servo mechanism. In such a case, it may be difficult to control as expected due to the influence of the centrifugal force.

That is, since a clutch is a joint for transmitting torque from a rotating member such as an input shaft to another rotating member, a hydraulic servo mechanism for engaging the clutch also rotates. Therefore, the centrifugal force according to the rotation speed and the radius of rotation acts on the oil supplied to the hydraulic servo mechanism, so even if the hydraulic servo mechanism is depressurized to release the clutch, the hydraulic pressure based on the centrifugal force is applied to the piston. Act,
Release of the clutch is delayed.

In order to eliminate such inconvenience, a check ball valve is provided in a piston chamber for supplying hydraulic pressure for driving the piston, and the check ball valve is opened when the pressure is released. It is being promoted.

However, since the check ball valve may not easily open due to the centrifugal force, various canceling mechanisms (balance mechanisms) for more aggressively avoiding the influence of the centrifugal oil pressure have been tried. One example is described in JP-A-62-52249.

In this method, a working hydraulic pressure chamber for supplying a high-pressure liquid to advance the piston toward the clutch and a centrifugal hydraulic pressure chamber for supplying a liquid at substantially atmospheric pressure are formed with the piston interposed therebetween. By balancing the pressure generated in the hydraulic fluid chamber due to the pressure and the pressure generated by the centrifugal force in the centrifugal pressure chamber, the operation of the piston, that is, the engagement of the clutch
It is configured to eliminate the effect of centrifugal force on release.

[0008]

In the above-described canceling mechanism, the volume of the centrifugal hydraulic chamber increases and decreases as the piston advances and retreats. Therefore, conventionally, an oil passage branched from the main oil passage along the axis of the input shaft is opened to the inner peripheral portion of the centrifugal hydraulic pressure chamber, and the liquid (oil) in the centrifugal hydraulic pressure chamber is discharged to the main oil passage, or It is supplied from the main oilway.

However, the main oil passage is for supplying oil to a large number of locations such as bearings, and is large enough to contain an amount of oil equal to the change in volume due to the operation of the hydraulic servo mechanism. No capacity. Therefore, in the conventional cancel mechanism described above, when the piston retreats to the working hydraulic pressure chamber side and the volume of the centrifugal hydraulic pressure chamber increases, the amount of oil supplied to the centrifugal hydraulic pressure chamber becomes insufficient, and as a result,
There is a high possibility that a cavity will be formed in the centrifugal pressure chamber.

That is, in the conventional canceling mechanism, a cavity is formed in the centrifugal hydraulic chamber, and the so-called centrifugal hydraulic pressure (centrifugal hydraulic pressure) generated here is significantly lower than the centrifugal hydraulic pressure in the working hydraulic chamber. In some cases, the effect of the centrifugal force on the operation of the piston cannot always be sufficiently eliminated. In such a case, the timing of engaging or disengaging the clutch becomes inappropriate, and the shift shock may increase. there were.

The present invention has been made in view of the above circumstances, and provides a centrifugal hydraulic pressure canceling mechanism capable of reliably eliminating the effect of centrifugal force on engagement / disengagement of a clutch and preventing deterioration of shift shock. It is intended to do so.

[0012]

According to a first aspect of the present invention, in order to achieve the above object, the first cylindrical body is disposed concentrically with respect to the inner peripheral surface of the first cylindrical body and the first cylindrical body. Friction plates that are frictionally pressed against each other and transmit torque are attached to the outer peripheral surface of the second cylindrical body having a smaller diameter than the body, and pistons that frictionally press these friction plates are arranged to move back and forth with respect to the friction plates. A centrifugal hydraulic pressure of the rotary clutch, in which a hydraulic chamber is formed on the opposite side of the piston to the friction plate and a cancel chamber capable of supplying and discharging hydraulic pressure is formed on the opposite side of the piston from the hydraulic chamber. In the cancellation mechanism ,
An auxiliary oil chamber located on the rotation center side of the cancel chamber
The auxiliary oil chamber and the cancellation chamber are
Auxiliary oil formed in a direction along the radial direction of the first cylindrical body
It is characterized by being connected by an oil passage having a smaller volume than the inner volume of the chamber . The invention of claim 2 is
In addition to the configuration of claim 1, the auxiliary oil chamber is adjacent in the axial direction.
Connect to the other space on the wall that separates from the other space
Through which an auxiliary oil chamber is provided.
To form another space that is arranged in the axial direction
The further space portion and the auxiliary oil chamber are connected to each other.
The oil passage provided on the inner peripheral side of the space and the auxiliary oil chamber
To the further space portion of the oil passage
The radius of the opening end from the center of rotation and the opening formed on the wall
The radius of the mouth from the center of rotation must be set equal.
It is characterized by the following.

[0013]

According to the present invention, by supplying the pressure oil to the hydraulic chamber, the piston advances toward the friction plate, and the friction plates are pressed against each other to bring the clutch into an engaged state. Conversely, if the pressure is released from the hydraulic chamber, the piston is retracted and the clutch is released.

Since the oil supplied through the oil passage is contained in the cancel chamber on the opposite side of the hydraulic chamber with the piston interposed therebetween, the cancel chamber rotates along with the piston and the like to cause centrifugal movement into the cancel chamber. Hydraulic pressure is generated, which acts to offset the centrifugal hydraulic pressure in the hydraulic chamber.

The volume of the cancel chamber increases when the piston retreats to the hydraulic chamber side. In this case, the cancel chamber is connected to an auxiliary oil chamber formed closer to the rotation center side through an oil passage. And the auxiliary oil chamber has a sufficient volume for the increased volume of the cancel chamber, so that a sufficient amount of oil does not flow into the cancel chamber and a cavity is not formed. Therefore, the effective radius of the cancel chamber increases toward the inner circumference, and as a result, the centrifugal hydraulic pressures of the hydraulic chamber and the cancel chamber balance with each other, and the influence of the centrifugal hydraulic pressure on the operation of the piston is eliminated or slightly reduced. can do. Claim 2
According to the invention, the cancellation chamber is associated with the advance of the piston.
Moves to the auxiliary oil chamber via the oil passage. Its supplement
The lubrication chamber is axially aligned with the other space adjacent to it.
Still communicates with the other space, but the other space
The radius from the center of rotation of the opening with respect to
The radius from the center of rotation of the open end to the space is equal
So the auxiliary oil from the cancellation chamber with the advance of the piston
The oil discharged into the chamber is further discharged from the auxiliary oil chamber.
It is easily discharged to the peripheral side.

[0016]

Next, the present invention will be described based on embodiments. FIG. 1 is a sectional view showing an embodiment of the present invention.
The upper half from the central axis is shown. That is, the rotary clutch 1 shown in FIG. 1 has a plurality of clutch plates 3 spline-fitted to the inner peripheral surface of a clutch drum 2 which is a first cylindrical body, and a clutch disk 4 sandwiched between the clutch plates 3. To the clutch drum 2
The clutch plate 3 and the clutch disk 4 are spline-fitted to the outer peripheral surface of the clutch hub 5 which is a second cylindrical body having a smaller diameter, and the clutch plate 3 and the clutch disk 4 are frictionally pressed to transmit torque.

The hydraulic servo mechanism 6 for engaging or disengaging the clutch 1 is configured to rotate integrally with the clutch drum 2. That is, the clutch drum 2 is integrated with the piston housing 7, and the piston housing 7 is provided with a boss 8 having a diameter much smaller than that of the clutch drum 2 on the inner peripheral side. Are linked. Also, the piston housing 7
The boss portion 8 is rotatably supported by rotatably fitting the outer periphery of the fixed boss portion 10. As the fixed boss 10, for example, a boss projecting from an oil pump cover (not shown) is used.

Inside the piston housing 7, a piston 11 having a liquid-tight seal between the outer peripheral surface of the boss portion 8 and the inner peripheral surface of the piston housing 7 is provided with respect to the clutch plate 3 and the clutch disk 4. It is housed to move back and forth. A hydraulic chamber 12 is formed on the back side of the piston 11, that is, on the side opposite to the clutch plate 3 and the clutch disk 4 (right side in FIG. 1). The hydraulic chamber 12 feeds a predetermined pressure of oil to advance the piston 11, and thereby the clutch 1
The oil passage 13 formed in the boss 8 and the oil passage 14 formed in the fixed boss 10 are provided as oil passages for supplying and discharging oil to and from the hydraulic chamber 12. I have.

The front side of the piston 11, that is, the hydraulic chamber 12
The balance piston 15 is arranged on the opposite side (left side in FIG. 1). The balance piston 15 is an annular member having a cross-sectional shape as shown in FIG. 1, and is fitted to the outer peripheral surface of the boss 8 at the inner peripheral edge and to the inner peripheral surface of the piston 11 at the outer peripheral edge. Each of these inner and outer peripheral edges is sealed by a sealing material 16 in a liquid-tight state. Further, the balance piston 15 is fixed by a snap ring 17 fitted into the boss portion 8.

Therefore, the inner and outer peripheral edges of the balance piston 15 are sealed, and the inner peripheral portion of the piston 11 is
, A space that can be filled with oil, that is, a cancel chamber 18, is formed between the balance piston 15 and the piston 11. 1 indicates a return spring, which is attached to the inner peripheral surface of the balance piston 15 so as to press the piston 11 toward the hydraulic chamber 12.

A space is provided on the inner peripheral side of the boss portion 8 and on the distal end side of the fixed boss portion 10, and a partition plate 21 for partitioning the auxiliary oil chamber 20 is provided in this space.
The partition plate 21 is an annular member having a cross-sectional shape shown in FIG. 1. The partition plate 21 is fitted on the inner peripheral side of the boss 8 and is fixed by a snap ring 22. The inner peripheral edge of the partition plate 21 is close to the input shaft 9 to the extent that a slight gap is formed between the partition plate 21 and the outer peripheral surface of the input shaft 9. Accordingly, the auxiliary oil chamber 20 is defined as an oil chamber having a slight opening between the input chamber 9 and the inner peripheral side of the cancel chamber 18.

A portion of the input shaft 9 on the inner peripheral side of the hydraulic servo mechanism 6 and the rotary clutch 1 is hollow, and an intermediate shaft 23 is inserted therein. A main oil passage 24 whose front end is sealed with a plug is formed on the intermediate shaft 23 along the center axis, and a branch oil passage 25 extending from the main oil passage 24 to the outer peripheral surface of the intermediate shaft 23 is formed. I have.

On the other hand, a hollow portion of the input shaft 9 has a first oil passage 26 opening from the inner periphery to the auxiliary oil chamber 20 and an opening extending from the inner periphery to the drain space Sd where the clutch hub 5 is located. A second oil passage 27 is formed. Of these oil passages 26 and 27, the dimension R from the rotation center of the opening end of the second oil passage 27 on the drain space Sd side is equal to the dimension R from the rotation center of the inner peripheral edge of the partition plate 21. ing. That is, the centrifugal oil pressure increases in accordance with the turning radius, but the turning radius of the inner peripheral edge of the partition plate 21 which is the opening on the inner peripheral side of the auxiliary oil chamber 20, and the drain space Sd of the second oil passage 27
If the turning radius of the opening end to the
Since the centrifugal oil pressure in the sixth oil passage 27 is equal to the centrifugal oil pressure in the second oil passage 27, the oil is easily discharged from the auxiliary oil chamber 20 to the inner peripheral side. Further, a communication hole 28 for communicating the auxiliary oil chamber 20 and the cancel chamber 18 is formed in the boss portion 8 of the piston housing 7 . The communication hole 28 is
It corresponds to the oil passage in the invention of claim 1. Also, the first oil passage
26 and the second oil passage 27 are oil passages according to the second aspect of the present invention.
Is equivalent to

Next, the operation of the above-described centrifugal hydraulic pressure canceling mechanism will be described. The state shown in FIG. 1 is a state in which the rotary clutch 1 is released. When the pressure is released from the hydraulic chamber 12, the piston 11 is pressed by the return spring 19 and retreats.

When a predetermined valve (not shown) is switched to supply oil to the hydraulic chamber 12 through the oil passage 14 in the fixed boss 10 and the oil hole 13 in the boss 8, the piston 11
Moves forward while compressing the return spring 19 by the hydraulic pressure. In this case, since the volume of the cancel chamber 18 is reduced, the oil inside the cancel chamber 18 is pushed toward the inside of the input shaft 9 through the communication hole 28, the auxiliary oil chamber 20, and the first oil passage 26. The centrifugal oil pressure acts as a resistance to the oil discharge performed in this manner, but as described above, the radial position of the inner peripheral edge of the partition plate 21 and the open end of the outer peripheral side of the second oil passage 27 And the centrifugal oil pressure in the first oil passage 26 opening to the auxiliary oil chamber 20 and the centrifugal oil pressure in the second oil passage 27 opening to the drain space Sd become equal. Therefore, oil is easily discharged to the drain space Sd.
The discharge of oil from 8 occurs smoothly.

On the other hand, in the hydraulic chamber 12, the rotation of the hydraulic chamber 12 causes centrifugal hydraulic pressure to be generated in the oil inside the hydraulic chamber 12. Further, the oil is filled in the auxiliary oil chamber 20 located on the inner peripheral side of the cancel chamber 18, and the centrifugal oil pressure by the oil is added to the oil pressure in the cancel chamber 18.
In addition, the centrifugal oil pressure is canceled according to the pressure receiving area in the cancel chamber 18.

Therefore, the effect of the centrifugal hydraulic pressure on the forward movement of the piston 11 is negligible or negligible. The piston 11 moves forward in accordance with the pressure of the oil supplied to the hydraulic chamber 12, and presses the clutch plate 3 and the clutch disk 4 into contact. Let it. That is, the engagement timing or torque capacity of the rotary clutch 1 is controlled as expected by the hydraulic pressure supplied to the hydraulic chamber 12.

Even when the rotary clutch 1 is engaged, the cancel chamber 18 and the auxiliary oil chamber 20 are filled with oil. When the pressure is released from the hydraulic chamber 12 to release the rotary clutch 1 from this state, the piston 11 is pushed back by the return spring 19. In this case, the centrifugal oil pressure is generated inside the hydraulic chamber 12 due to the rotation of the hydraulic servo mechanism 6, but the centrifugal oil pressure against the centrifugal oil is generated in the cancel chamber 18.
Retreats according to the degree of decrease in the hydraulic pressure in the hydraulic chamber 12.

Since the volume of the cancel chamber 18 increases as the piston 11 retreats, oil is supplied to the cancel chamber 18 through a communication hole 28 on the inner peripheral side thereof. The oil is supplied from an auxiliary oil chamber 20 formed adjacent to the cancel chamber 18 on the inner peripheral side thereof.
Since a sufficient amount of oil is already stored in the cancel chamber 18, the necessary and sufficient amount of oil corresponding to the increase in the volume of the cancel chamber 18 is quickly supplied.

Therefore, in the above canceling mechanism,
Since the amount of oil in the cancel chamber 18 is not sufficient to form a cavity and the centrifugal hydraulic pressure is not reduced, the timing of releasing the rotary clutch 1 or the torque capacity is determined by the hydraulic pressure in the hydraulic chamber 12. Controlled on time.

In the above-described embodiment, the auxiliary oil chamber 20 is defined by fitting the partition plate 21 into the inner peripheral portion of the boss 8. However, the structure of the auxiliary oil chamber in the present invention is different from that of the above-described embodiment. However, the present invention is not limited to the structure shown in FIG. That is, FIG. 2 is an example of forming an auxiliary oil chamber without using the septal wall plate 2 1 above. In the following description, the same members or portions as those shown in FIG. 1 are denoted by the same reference numerals in FIG. 2 as those in FIG. 1 and the description thereof is omitted.

In FIG. 2, a flange 9a is formed at the distal end of the input shaft 9 near the distal end surface of the fixed boss 10, and the boss 8 of the clutch drum 2 is formed on the outer peripheral end of the flange 9a. It is fixed. The boss 8 extends to the tip (left side in FIG. 2) from the portion fixed to the flange 9a to form a cylindrical portion 8a. On the other hand, a cylindrical portion 5b having a wall surface 5a fitted to the inner peripheral side of the cylindrical portion 8a is formed in the inner peripheral portion of the clutch hub 5, and the outer peripheral surface of the cylindrical portion 5b and the boss portion are formed. 8 and the cylindrical portion 8a are sealed in a liquid-tight state by a seal ring 29. Oil passages 30, 31 having the same radial position from the center of rotation are formed on the flange 9a of the input shaft 9 and the wall surface 5a of the clutch hub 5. Thus among the space portions partitioned by the flanges 9a and Class Tchido ram second cylindrical portion 8a and the cylindrical portion 5b of the clutch hub 5 of the input shaft 9, the portion of the outer peripheral side of the oil passage 30 and 31 and the auxiliary oil chamber 20 Has become. The auxiliary oil chamber 20 and the cancel chamber 18 communicate with each other through a communication hole 28.

In the configuration shown in FIG.
In addition, since the oil filled in the cancel chamber 18 receives centrifugal force and generates centrifugal oil pressure that pushes the piston 11 rightward in FIG. 2, the necessary and sufficient pressure can be obtained without increasing the outer diameter of the balance piston 15. When the rotary clutch 1 is released, the piston 11 is surely pushed back to control the release of the rotary clutch 1 as expected. Further, in the configuration shown in FIG. 2, since the partition plate 21 shown in FIG. 1 is not provided, the space in the axial direction can be omitted, and as a result, the shaft length of the automatic transmission can be shortened. .

In the present invention, a member similar to the partition plate 21 may be formed integrally with the boss portion 8 to form the auxiliary oil chamber, or an appropriate hollow member may be formed in the cancel chamber 1.
8 and the hollow member may be used as an auxiliary oil chamber.

[0035]

As is apparent from the above description , claim 1
According to the centrifugal-pressure canceling mechanism of the invention, through an oil passage
Cancel chamber to form an auxiliary oil chamber communicating with the inner peripheral side of the cancellation chamber, and since it is configured so as to fill a necessary and sufficient oil to the auxiliary oil chamber Te, the inner peripheral substantial effective radius of the cancellation chamber As a result, the centrifugal oil pressure generated in the hydraulic chamber can always be reliably reduced or completely canceled out by the centrifugal oil pressure generated in the cancel chamber, so that the engagement and engagement of the rotary clutch can be reduced.
Release control can be accurately performed without being affected by the centrifugal hydraulic pressure, and deterioration of shift shock can be prevented. Also
According to the invention of claim 2, in the space adjacent to the auxiliary oil chamber,
Radius of rotation of the opening with respect to the auxiliary oil chamber and axial direction
Auxiliary oil chambers for other spaces
The radius of rotation of the open end of the oil passage that communicates through its inner circumference
Are set equal, the hydraulic pressure at these open ends
Are equal, so that when the piston advances,
The oil pushed out from the cancel chamber to the auxiliary oil chamber is
Can be easily discharged further from the lubrication chamber to the inner peripheral side
It will work.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing an embodiment of the present invention.

FIG. 2 is a partial sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotation clutch 2 Clutch drum 3 Clutch plate 4 Clutch disk 5 Clutch hub 6 Hydraulic servo mechanism 11 Piston 12 Hydraulic chamber 18 Cancel chamber 20 Auxiliary oil chamber 24 Main oil path 26 First oil path 28 Communication hole

──────────────────────────────────────────────────続 き Continuing on the front page (72) Mikio Mori, Toyota 1st Toyota Town, Aichi Prefecture, Toyota Motor Corporation (72) Inventor Norihiro Kitamura 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Corporation ( 72) Inventor Yuji Yasuda 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Co., Ltd. (56) References JP-A-1-210623 (JP, A) JP-A 57-184321 (JP, U) JP-A 1-154334 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16D 25/06-25/063

Claims (2)

(57) [Claims] An inner peripheral surface of a first cylindrical body and an outer peripheral surface of a second cylindrical body which is arranged concentrically with respect to the first cylindrical body and has a smaller diameter than the first cylindrical body are frictionally pressed to each other. A friction plate for transmitting torque is attached, a piston for frictionally pressing these friction plates is arranged to move back and forth with respect to the friction plate, and a hydraulic chamber is formed on the opposite side of the piston to the friction plate, In a centrifugal hydraulic pressure canceling mechanism of a rotary clutch having a cancel chamber capable of supplying and discharging hydraulic pressure on the opposite side of the hydraulic chamber with respect to the piston, an auxiliary oil chamber located closer to the rotation center than the cancel chamber is provided.
The auxiliary oil chamber and the cancellation chamber are
Auxiliary oil formed in a direction along the radial direction of the first cylindrical body
A centrifugal hydraulic pressure canceling mechanism for a rotary clutch, wherein the hydraulic pressure is communicated by an oil passage having a smaller volume than the inner volume of the chamber . 2. The other auxiliary oil chamber is axially adjacent to another auxiliary oil chamber.
An opening communicating with the other space on the wall that separates from the space
Part is provided, and the axial direction with respect to the auxiliary oil chamber is
A further space portion arranged side by side is formed, and the further space portion is formed.
The other space and the auxiliary oil chamber are further separated into the other space and
And an oil passage provided on the inner peripheral side of the auxiliary oil chamber.
Rotation of the open end of the oil passage with respect to the further space.
Radius from center of rotation and rotation of opening formed in the wall
The feature is that the radius from the center is set equal
The centrifugal hydraulic cancel of the rotary clutch according to claim 1,
Mechanism.