JPH02256965A - Lockup device in torque converter - Google Patents

Abstract

PURPOSE:To surely prevent a torque transmitting capacity from decreasing by connecting an oil chamber to communicate with an oil line system directly by an orifice provided in a rotary member and extending this orifice in a diametric direction of the rotary member. CONSTITUTION:The first and second oil chambers 25 and 26 are formed being partitioned by a lockup piston 21. An orifice 36, connecting the second oil chamber 26 or the second oil line system B to communicate with the first oil line system A, is formed in a driven side rotary shaft 20 forming the first oil line system A. The first oil chamber 25 is prevented from directly communicating with the second oil chamber 26 by this orifice 36. In this way, not only a shock at the time of releasing a lockup is relaxed but also a transmitting torque capacity can be surely prevented from decreasing.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to (1) a hydraulic torque converter used in, for example, a vehicle transmission, and in particular, a hydraulic torque converter for mechanically directly connecting a driving side and a driven side. This invention relates to a lockup device in a torque converter.

(Prior Art) In general, such a lock-up device connects a driven-side lock-up clutch piston and a driving-side converter via, for example, a friction material provided on the lock-up clutch piston, so that the driving-side member and the driven side member are directly mechanically connected. In this case, the operation of the lock-up piston is controlled by appropriately controlling each oil pressure in a first oil chamber and a second oil chamber that are partitioned on both sides by a clutch plate. When the lock-up device is directly connected, power from the engine is transmitted with almost no loss due to slippage.

By the way, in such a lock-up device, a shock occurs when the lock-up device is brought into a direct connection state (lock-up on) or when it is brought into a direct connection release state (lock-up off), but in that case, the shock when the lock-up device is turned on is not so great. While this has no effect, the shock when locking up and off is relatively large, which is unfavorable for the driving feeling.

Therefore, conventionally, as shown in Japanese Patent Publication No. 63-5625, for example, a lock-up clutch piston is generally provided with an orifice that communicates the first oil chamber with the second oil chamber. According to such an orifice, a part of the hydraulic oil supplied to the first oil chamber when locking up and off flows through this orifice to the second oil chamber side.
Since the direct connection state is gradually released, the shock at lock-up-off can be alleviated.

(Problem to be Solved by the Invention) However, if the orifice is provided in the lock-up clutch piston in this way, even in the lock-up state, the first oil chamber and the second oil chamber are connected through the orifice. will be in direct communication. Therefore, in the lock-up-on state, the pressure in the second oil chamber leaks through the orifice, reducing the pressure difference between the second oil chamber and the first oil chamber, and reducing the transmission torque capacity of the cock-up clutch. There is a problem.

The present invention has been made in view of these problems, and its purpose is to reduce the shock as much as possible when locking up and off, while also making it possible to reduce the impact on both sides of the lockup piston in the lockup on state. It is an object of the present invention to provide a lock-up device for a torque converter, which can suppress a decrease in pressure difference between oil chambers as much as possible to reliably prevent a decrease in transmission torque capacity.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention, for example, as shown with reference to FIG. (21) into a first oil chamber (25) and a second oil chamber (26). The output shaft (20), which is the driven side, has a first oil chamber (2
5), an oil passage (32) is formed to supply and discharge hydraulic oil, and this oil passage (32) communicates with the lock-up relay valve (28) via the oil passage (31, 29). ing.

In addition, the sleeve (2C) of the power transmission case (2), which is the drive side connected to the engine output shaft (Ea), and the stator (
A fixed sleeve (3) rotatably supports the sleeve (13) in one direction.
0), an oil passage (34) communicating with the second oil chamber (26) and supplying and discharging hydraulic oil is formed between the oil passage (34
) is also in communication with the lock-up relay valve (28).

The output shaft (20) has an orifice (36) connected to the oil passage (32).
) and the outer circumferential surface of the output shaft (20), and this orifice (36) communicates with the turbine hub (19).
) through the oil passage (37) formed in the second oil chamber (
26).

(Operation and Effects of the Invention) In the lock-up device for the torque converter according to the present invention configured as described above, - From the illustrated state, hydraulic oil is supplied to the second oil chamber (26) through the oil passage (34). At the same time, the hydraulic oil in the first oil chamber (25) flows through the oil passage (32
) so that the lock-up relay valve (
28) is switched, the pressure in the first oil chamber (25) becomes lower than the pressure in the second oil chamber (26), and a pressure difference occurs between the compartments. Due to this pressure difference, the lock-up piston (21) moves to the left in the figure.
The clutch facing (24) fixed to this piston (21) is connected to the 7-inch mount cover (2) of the power transmission case (2).
2a). In that case, a part of the hydraulic oil supplied to the second oil chamber (26) flows into the oil passage (32) through the orifice (36), so that the clutch facing (2
4) and the front cover (2a) come to engage while sliding, and the shock at the time of engagement comes to be alleviated. In this way, the torque converter (1) enters a lock-up state in which the driving side and the driven side are directly connected.

In this lock-up-on state, the second oil chamber (26) and the oil passage (32) communicate with each other via the orifice (36), and the hydraulic oil in the second oil chamber (26) flows through the orifice (32).
6) and leaks to the oil path (32) side. However, since this orifice (36) is not provided in the piston (21), the first oil chamber (25) and the second oil chamber (26) are not in direct communication. Therefore, even if such hydraulic oil leaks, the pressure in the first oil chamber (25) is hardly affected by the leak, and the pressure in the second oil chamber (26) and the first oil chamber
There is almost no drop in the pressure difference between the oil chamber (25) and the oil chamber (25). Therefore, since the transmission torque capacity hardly decreases, the engine drive torque input to the power transmission case (2) is transferred to the output shaft (20) on the driven side with almost no loss.
be able to communicate to. In particular, when the lock-up-on state is established, high-speed rotation is often performed, so a relatively large centrifugal force is applied to the hydraulic fluid, and the hole of the orifice 36 extends at least in the radial direction of the output shaft 20. If the hole is drilled so that the oil comes out, this centrifugal force will flow from the second oil chamber 26 toward the oil passage 32 and into the orifice 36.
Since the pressure difference between the second oil chamber 26 and the oil passage 32 is counteracted by the flow of the hydraulic oil flowing through the orifice 36, leakage of the hydraulic oil through the orifice 36 is suppressed. This further suppresses a decrease in the transmission torque capacity.

On the other hand, from this lock-up state, the hydraulic oil flows into the oil path (3
2) to the first oil chamber (25) and the second oil chamber (25).
When the lock-up relay valve (28) is switched and set so that the hydraulic oil in the oil chamber (26) is discharged through the oil passage (34), the hydraulic oil is supplied to the first oil chamber (25). In that case, the clutch facing (24) is connected to the front cover (
2a), the oil flows to the second oil chamber (26) via the orifice (36), so the pressure in the first oil chamber (25) gradually increases. Therefore, the shock when the fifth clutch facing (24) separates from the front cover (2a), that is, the shock when lockup is released, is alleviated. This makes it possible to reliably prevent the drive feeling from being impaired due to this shock.

As described above, according to the present invention, the orifice not only alleviates the shock when the lockup is released, but also reliably prevents the transmission torque capacity from decreasing due to pressure leakage through the orifice in the lockup-on state. It becomes like this.

Note that the symbols in parentheses are for referring to the drawings and do not limit the structure of the present invention in any way.

(Example) Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a longitudinal sectional view of a torque converter provided with an embodiment of a lockup device according to the present invention.

As is clear from Fig. 1, the torque converter 1 is
It is composed of a power transmission case 2 which is a case of this torque converter 1, and a fluid transmission part 3 which transmits power via hydraulic oil within this power transmission case 2.
It is housed in a transmission case 4. A lock-up device 5 is disposed between the power transmission case 2 and the fluid transmission section 3. Further, the inside of the transmission case 4 is separated from, for example, an automatic transmission and the like by a partition wall 6.

The power transmission case 2 is composed of a front cover 2a that houses the lockup device 5, a jacket cover 2b welded to the front cover 2a, and a sleeve 2c welded to the rear cover 2b. front cover 2
a is the engine crankshaft Ea and drive plate Eb
are connected via. The sleeve 2c is rotatably supported within a cylindrical portion 6a formed to protrude forward of the partition wall 6 via a metal bearing 7 and an oil seal 8, and furthermore, the rear end of the sleeve 2c is connected to the partition wall 6 and the rear cover. It is coupled by a key means to a slot of an external gear 10a of a gear oil pump 10 disposed in an oil pump housing formed by 9 and 9.

The fluid transmission part 3 is integrally formed with the rear cover 2b, and is provided opposite to the pump impeller 11, which causes hydraulic oil to flow from the inner circumferential side to the outer circumferential side by centrifugal force as the rear cover 2b rotates. A turbine impeller 12 receives the hydraulic oil that the pump impeller 11 has flowed toward the outer circumference, and transmits the rotation of the pump impeller 11 by making it flow toward the inner circumference again, and the pump impeller 11 and the turbine impeller. car 1
The stator 13 changes the flow direction of hydraulic oil between the inner circumferential sides of the rotor 2 and increases the transmitted torque. An outer race 14a of a one-way clutch 14 rotatable in only one direction is fixed to the inner periphery of the stator 13 by casting. Further, the inner race 14b of the one-way clutch 14 is spline-fitted to the front end outer circumference of a fixed sleeve 15 connected to a rear cover 9 forming an oil pump housing. When the flow velocity of the hydraulic oil flowing through the stator 13 exceeds a certain value, the one-way clutch 14 causes the stator 13 to rotate in one direction. When the stator 13 rotates, the torque converter 1 no longer increases torque and performs a simple fluid coupling operation.

Turbine flange 12a supporting turbine impeller 12
are fixed to a turbine hub 19 by rivets 18, and this turbine hub 19 is fitted with metal bearings 16. at the front and rear ends of the inner periphery of the fixed sleeve 15.
The output shaft 20 of the torque converter 1 is rotatably supported via a spline 17 and fixed in the axial direction.

The lock-up device 5 includes a lock-up piston 21 consisting of an inner cylindrical portion 21a, an outer cylindrical portion 21b, and an annular plate portion 21c. is fitted onto the outer periphery of the turbine hub 19 via a seal ring 22 so as to be slidable in the axial direction.

Further, the lock-up piston 21 is provided with a damper mechanism 23, and this damper mechanism 23 includes a group of dampers 23a made of compression coil springs, and this damper 23a.
a driven plate 23d, which also serves as a first guide plate 23b and a second guide plate 23c, which encloses the guide plate 23a and slidably holds it in the circumferential direction;
1b, and is held slidably in the circumferential direction between the first guide plate 23b and the second guide plate 23c.
The drive plate 23f has a damper biasing window 23e that biases the damper 3a by sliding of the driven plate 23d. The first guide plate 23b is fastened together with the turbine flange 12a to the turbine hub 19 by rivets 18. Further, the first and second guide plates 23b, 23c are connected to each other by a rivet 23g. Furthermore, lock-up piston 2
A clutch facing 24 is fixed to the first annular plate portion 21c.

Further, the lock-up piston 21 defines a first oil chamber 25 and a second oil chamber 26 on both sides of the lock-up piston 21.

When the oil pressure in the first oil chamber 25 is higher than the oil pressure in the second oil chamber 26, the lock-up piston 2
1 is located at a retreated position relative to the front cover 2a,
Clutch facing 24 does not engage front cover 2a. In this state, the drive side of the torque converter 1,
In other words, there is no engagement between the pump side and the driven component, ie, the turbine side.

Further, when the oil pressure in the first oil chamber 25 decreases and a predetermined pressure difference occurs with respect to the oil pressure in the second oil chamber 26, the lock-up piston 21 moves toward the front cover 2a due to the pressure difference. The clutch facing 24 slides and comes into contact with the front cover 2a. In this state, the pump side and the turbine side come to engage.

Next, the hydraulic oil supply means 27 that supplies hydraulic oil to the first oil chamber 25 and the second oil chamber 26 will be explained.

The hydraulic oil supply means 27 is provided in the rear cover 9 of the oil pump housing, has an oil passage 29 that communicates with the lock-up relay valve 28, and is formed between the output shaft 20 and the fixed sleeve 15, and communicates with this oil passage 29. An oil passage 30 is formed at the axis of the output shaft 20, an oil passage 32 communicates with the oil passage 29 via an oil passage 31, the front cover 2a and the turbine hub 1.
Race 3 on the front cover 2a side of the thrust bearing 39, which communicates with the oil passage 32 and is disposed between the front cover 2a and the turbine hub 19.
A first oil passage system A consisting of an oil passage 33 communicating with the first oil chamber 25 via an oil passage formed in 9a, and a lock-up relay valve 28 formed between the sleeve 2c and the fixed sleeve 15. A communicating oil passage 34 is formed between the sleeve 2c and the one-way clutch 14.
A second oil passage 35 that communicates the oil chamber 26 and the oil passage 34
It is equipped with an oil line system B.

Switching between supply and discharge of hydraulic oil between the first oil passage system A and the second oil passage system B is controlled by the lock-up relay valve 28 described above.

On the other hand, an oil passage 32 and an output shaft 20 are provided at the front end of the output shaft 20.
An orifice 36 communicating with the outer peripheral surface is formed, and this orifice 36 is constituted by a radial hole. In that case, since the output shaft 20 is drilled with several other holes, this orifice 36 hole can sometimes be drilled together. The orifice 36 can be easily formed without requiring any process.

Further, the turbine hub 19 has this orifice 36 and a second
An oil passage 37 communicating with the oil chamber is formed. In that case, this oil passage 37 opens into the thinned portion 19a of the turbine hub 19.

The thinned portion 19a forms an oil passage that communicates the oil passage 37 with the second oil chamber. By utilizing the thinned portion 19a as a part of the oil passage in this manner, the oil passage 37 can be formed relatively easily. In this way, the oil passage 32 of the first oil passage system A and the second oil chamber 26 communicate with each other via the orifice 36.

The operation of the lockup device 5 in the torque converter 1 configured as described above will be explained.

When the lock-up relay valve 28 is set so that the lock-up device 5 is in the lock-up off state: At this time, hydraulic oil is supplied to the first oil chamber 25 in the power transmission case 2 via the first oil passage system A. and the second
It is set to form a circulating oil passage through which hydraulic oil is discharged from the oil chamber 26 via the second oil passage system B.

In this setting state, hydraulic oil is supplied into the power transmission case 2 via between the front cover 2a and the lock-up piston 21, so that the first oil chamber 25 and the second oil chamber 26 are Due to the pressure difference, the lock-up piston 21 moves to the right in the figure, separating the clutch facing 24 and the front cover 2a. That is, there is no frictional engagement between the clutch facing 24 and the front cover 2a, and the lockup device 5 enters the lockup-off state.

Therefore, the driving torque of the engine is the crankshaft Ea
The power is transmitted to the pump impeller 11 via the drive plate Eb and the power transmission case 2, and the impeller 11 rotates. Due to this rotation of the pump impeller 11, the hydraulic oil in the power transmission case 2 flows from the pump impeller 11 through the turbine impeller 12 and the stator 13, and then returns to the pump impeller 11.
It circulates and flows. The turbine impeller 12 receives a force due to the circulating flow of the hydraulic oil, so that the turbine impeller 12 rotates. In that case, the driving torque is increased and transmitted by the stator 13. This rotation of the turbine impeller 12 causes the output shaft 20 to rotate via the turbine hub 19, and its driving torque is further transmitted to, for example, an automatic transmission OD (not shown). In this way, the torque converter 1 increases torque and performs fluid transmission, which is what is called a converter operation. When the rotational speed of the turbine impeller 12 exceeds a predetermined speed, the flow direction of the hydraulic oil flowing out from the turbine impeller 12 changes beyond the inclination direction of the blades of the stator 13, and the hydraulic oil flows onto the back surface of the blades of the stator 13. Since they come into contact with each other, the stator 13 begins to idle. Therefore, the torque converter 1 performs normal fluid coupling operation without increasing torque.

In this way, no torque transmission takes place via the lockup device 5.

When the lock-up relay valve 28 is set so that the lock-up device 5 is in the lock-up state; the hydraulic oil supply means 27 supplies the hydraulic oil to the second oil in the power transmission case 2 via the second oil passage system B. It is supplied to the chamber 26 and discharged from the first oil chamber 25 via the first oil path system A. As a result, the pressure in the second oil chamber 26 increases, and the pressure in the first oil chamber 25 decreases, creating a pressure difference between the second oil chamber 26 and the first oil chamber 25. This pressure difference causes the lockup piston 21 to slide to the left in the figure, and the tarp facing 24 comes into contact with the front cover 2a. That is, the power transmission case 2 on the driving side and the output shaft 20 on the driven side are directly connected to each other in a lock-up state.

In that case, an orifice 36 that communicates the second oil chamber 26 and the oil passage 32 is formed in the output shaft 20, and the second oil chamber 26 and the oil passage 32 are connected to each other.
6 and the first oil chamber 25, the influence of leakage of hydraulic oil through the orifice 36 can be reduced from the effect that the orifice 36 is provided on the lock-up piston 21 and the second oil chamber 26 and the first oil chamber 25 are not in direct communication with each other. 1 oil chamber 25, which is in direct communication with the lock-up device of a torque converter. Therefore, the transmission torque capacity of the lockup device 5 hardly decreases. In particular, when the lock-up-on state is established, the hydraulic oil is often rotated at high speed, so a relatively large centrifugal force is applied to the hydraulic fluid. If the holes are drilled along the radial direction of
Since the pressure difference between the second oil chamber 26 and the oil passage 32 is counteracted by the flow of the hydraulic oil flowing through the orifice 36, leakage of the hydraulic oil through the orifice 36 is suppressed.

This further suppresses a decrease in the transmission torque capacity.

In this lock-up-on state, the driving torque from the engine is directly transmitted from the power transmission case 2 to the output shaft 20 with almost no loss.

When the lock-up relay valve 28 is switched from the lock-up on state to the lock-up off state, hydraulic oil is supplied to the first oil chamber 25 through the first oil passage system A. In that case, until the clutch facing 24 separates from the front cover 2a, a portion of the hydraulic oil flows into the second oil chamber 26 via the orifice 36, so the pressure increase in the first oil chamber 25 is relatively slow. It will be held in For this reason,
The shock that occurs when the clutch facing 24 and the front cover 2a disengage is now alleviated, and the drive feeling is almost never impaired.

Further, the hydraulic oil flowing through the orifice 36 effectively lubricates the bearing 38 interposed between the turbine hub 19 and the stator 13. That is, the thinned portion 19a of the turbine hub 19 becomes an oil reservoir, and the hydraulic oil stored here flows into the bearing 38 to lubricate the bearing 38.

Note that the present invention is not limited to the above-described embodiments, and various design changes are possible.

For example, in the embodiment described above, the orifice 36
Although the orifice 36 is provided so as to extend in a radial direction with respect to the axis of the orifice 36, it is not necessarily necessary to provide the orifice 36 in a radial direction. In other words, it can be provided so as to extend in the axial direction and also in the radial direction. Furthermore, it may be provided so as to extend along the circumferential direction of the output shaft 20 and also to extend in the radial direction. In short, it is only necessary to form the orifice 36 so that an appropriate amount of centrifugal force due to the rotation of the output shaft 20 is applied to the hydraulic oil.

Further, an orifice 36 is provided at the front end of the output shaft 20, and an oil passage 37 is provided in the turbine hub 19 to communicate this orifice 36 with the second oil chamber 26. 1
It may also be provided at a position (a) that is open between it and 9. In this case, the oil passage 37 provided in the turbine hub 19 can be omitted, but since it is a part that receives a relatively large load due to the transmitted torque, the strength of the output shaft 20 must be adjusted to correspond to the load. It needs to be large enough to allow. The orifice 36 is also defined as an oil passage 30 formed between the output shaft 20 and the fixed sleeve 15, and an oil passage 30 formed between the sleeve 2C and the fixed sleeve 15.
4 may be provided in the fixed sleeve 15 so as to be in communication with the fixing sleeve 15. In short, it is only necessary to provide the orifice 36 so that the first oil chamber 25 and the second oil chamber 26 do not communicate directly.

Moreover, the second oil chamber 26 is connected to the orifice 36 from the oil passage 32.
If a check valve is provided that only allows flow toward It is also possible to reduce the orifice effect, ie to make the orifice 36 a kind of variable orifice. In that case, the check valve may be of a well-known structure as appropriate. By changing the orifice effect in this way, it becomes possible to effectively alleviate the shock even if there is a difference in the magnitude of the impact of the shock, especially when switching between the lock-up on state and the lock-up off state. .

Further, in the above-described embodiment, a lock-up device in which the clutch facing 24 is fixed to the cock-up piston 21 is described, but the present invention can also be applied to a lock-up device in which the clutch facing 24 is attached to the front cover 2a.

As is clear from the above description, according to the present invention, the first
An oil chamber, a second oil chamber, a first oil passage communicating with the first oil chamber and supplying and discharging hydraulic oil, and a second oil passage communicating with the second oil chamber and supplying and discharging hydraulic oil. When the pressure in the second oil chamber is greater than the pressure in the first oil chamber, the lock amplifier clutch piston is actuated by the pressure difference to mechanically directly connect the drive side and the wave side. In the lock-up device for a torque converter, an orifice that communicates the second oil chamber or the second oil passage with the first oil passage is formed on the wave-side rotating shaft in which the first oil passage is formed. Therefore, the first oil chamber and the second oil chamber are no longer in direct communication with each other through this orifice. Therefore, the orifice not only alleviates the shock when the lockup is released, but also makes it possible to reliably prevent the transmission torque capacity from decreasing due to pressure leakage through the orifice in the lockup-on state.

[Brief explanation of drawings]

FIG. 1 is a diagram schematically showing an embodiment of a lock-up device in a torque converter according to the present invention. 1... Torque comparator 2... Power transmission case (drive side member), 5... Lock-up device, 20... Output shaft (driven side member), 21... Lock-up piston, 25... No. 1 oil chamber, 26... 2nd oil chamber, 36... orifice, A... 1st oil passage system mB... 2nd oil passage system Patent applicant Aisin AW Refuru Co., Ltd. (external 1) given name)

Claims (1)

[Claims] (1) A first oil chamber and a second oil chamber defined by a lock-up piston, a first oil passage system communicating with the first oil chamber and supplying and discharging hydraulic oil, and communicating with the second oil chamber and a second oil passage system for supplying and discharging hydraulic oil, and when the pressure in the second oil chamber is greater than the pressure in the first oil chamber, the lock-up piston is actuated by the pressure difference, and the drive side member In the lock-up device for a torque converter that is configured to directly mechanically connect a driven side member and a driven side member, an orifice that directly communicates the second oil chamber or the second oil passage system with the first oil passage system is provided. A lockup device for a torque converter, wherein the orifice is provided in a rotating member and extends in a radial direction of the rotating member.