JPH07145858A - Torque converter with multi-disc lockup clutch - Google Patents

Abstract

PURPOSE:To reduce the occurrence of dragging torque during release of lockup, in a torque converter with a multi-disc lockup clutch in which a multi-disc lockup clutch having a plurality of fastening surfaces. CONSTITUTION:A multi-disc lockup clutch 10 is provided with brag preventing structure comprising a first annular groove part 106 formed in the side of the outside diameter part of a facing 105; and a first communicating groove part 107 having one end communicated with a first communicating groove part 107 and the other end opened to the end face of the inside diameter part of the facing 105.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque converter with a multi-plate lock-up clutch having a built-in multi-plate lock-up clutch having a plurality of fastening surfaces.

[0002]

2. Description of the Related Art Conventionally, as a torque converter with a multi-plate lockup clutch, for example, Japanese Patent Laid-Open No. 55-5475.
The one described in Japanese Patent No. 8 is known.

The above-mentioned conventional source shows a torque converter with a multi-disc lockup clutch in which a multi-disc lockup clutch having a plurality of fastening surfaces is arranged between a converter cover and a clutch piston.

[0004]

However, in the above-mentioned conventional torque converter with a multi-plate lock-up clutch, since the multi-plate lock-up clutch has a plurality of engaging surfaces, the lock-up oil chamber is released from the lock-up oil chamber when the lock-up is released. Even if you try to separate multiple fastening surfaces at the same time by supplying the hydraulic oil, the separation force on one fastening surface is the pressing force on the adjacent fastening surface due to the variation in the pressure distribution between the inner diameter part and the outer diameter part of the facing. Therefore, a problem peculiar to the multi-plate lockup clutch having a plurality of fastening surfaces occurs that drag torque increases when the lockup is released. As a result, the torque increasing action of the torque converter is reduced, heat is generated at the time of stall or sudden start, and the clutch durability reliability is deteriorated.

That is, the clutch disc has a slight taper on its facing due to manufacturing variations. A clutch disc with such a taper
As shown in FIG. 18, when incorporated in a torque converter,
The pressure distribution acting from the facing inner-diameter position B to the outer-diameter position A of the first clutch disc when releasing the lockup for releasing the engagement of the clutch by supplying hydraulic oil PB from the lockup oil chamber is shown in FIG. As shown in (1), on the left side, it mainly drops near point B, and on the right side, it mainly drops near point A. Therefore, in this case, the first clutch disc is pushed to the left in the drawing, the gap between the first clutch disc and the clutch piston widens, and conversely the gap between the first clutch disc and the second clutch disc becomes narrower. , Both clutch discs come into contact with each other, and drag torque is generated.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a torque converter with a multi-plate lock-up clutch having a built-in multi-plate lock-up clutch having a plurality of fastening surfaces. The purpose is to reduce the drag torque when releasing the lockup.

[0007]

To achieve the above object, in a torque converter with a multi-plate lock-up clutch according to the present invention, a converter cover connected to an input member and a clutch piston provided on an output member so as to be movable in an axial direction. A multi-disc lockup clutch having at least one clutch disc having a plurality of fastening surfaces, the clutch disc being disposed between the converter cover and the clutch piston, the clutch disc having a facing surface on one side or both sides; Applying differential pressure to the clutch piston by supplying the working oil to the converter oil chamber on the blade element side and the lock-up oil chamber on the converter cover side, and the converter oil chamber that is defined, and removing the working oil from the lock-up oil chamber. By engaging the multi-plate lockup clutch, hydraulic oil is supplied to the lockup oil chamber to convert it. Lockup control means for releasing the multi-plate lock-up clutch by removing the hydraulic oil in the oil chamber and applying a differential pressure to the clutch piston; and the clutch disc provided at the multi-plate lock-up clutch, when the lock-up is released. And a drag prevention structure for suppressing a change gradient of the pressure distribution from the pressure acting on the inner diameter side to the pressure acting on the outer diameter side to a small value.

Here, the drag prevention structure means, for example,
They are as listed below.

(1) A first annular groove portion formed on a side surface of an outer diameter portion of the facing, and a first communicating groove portion having one end communicating with the first annular groove portion and the other end opened to an end surface of an inner diameter portion of the facing. Due to.

(2) An intermittent first annular groove portion formed on a side surface of an outer diameter portion of the facing, and one end communicates with the intermittent first annular groove portion, and the other end is opened to an end surface of the inner diameter portion of the facing. Due to the first communication groove portion.

(3) By a communication groove portion formed from the inner diameter end to the outer diameter portion on the side surface of the facing.

(4) A second annular groove portion formed at a position corresponding to the facing outer diameter portion of the fastening surface facing the facing,
One of the second communicating groove portions has one end communicating with the second annular groove portion and the other end opening at a position corresponding to the inner diameter portion of the facing.

(5) A taper surface having a thicker outer diameter side and a thinner inner diameter side of the facing.

(6) By arranging the clutch discs in a slanted manner, a fastening surface taper space is provided in which the facing inner diameter side clearance of the fastening surface is wide and the facing outer diameter side clearance is narrow.

(7) The first facing having a large porosity attached to the facing inner diameter side and the second facing having a small porosity attached to the facing outer diameter side.

(8) By a through hole that penetrates the facing and the clutch disc in the axial direction.

(9) With a sealing material that seals the position closest to the clutch piston at the outer diameter position of the clutch disc.

[0018]

When lockup is required, the lockup control means controls the supply of hydraulic oil to the converter oil chamber and the removal of hydraulic oil from the lockup oil chamber.
The multiple disc lockup clutch is engaged by applying a force due to the differential pressure to the clutch piston. By this clutch engagement, the converter cover and the clutch piston are integrally connected via the multi-plate lockup clutch, and a lockup state in which the input member and the output member are directly connected is realized.

When the lock-up is released, the lock-up control means controls the supply of the working oil to the lock-up oil chamber and the removal of the working oil from the converter oil chamber. The multi-plate lockup clutch is released. In order to suppress the generation of drag torque when the clutch is released, it is necessary to flow hydraulic oil from the lockup oil chamber to the converter oil chamber via all the fastening surfaces. On the other hand, due to the drag prevention structure provided in the multi-plate lock-up clutch, the change gradient of the pressure distribution from the pressure acting from the lock-up oil chamber to the inner diameter side of the clutch disc to the pressure acting to the outer diameter side is kept small. Therefore, the balanced axial force secures the gaps through which the hydraulic oil flows to the plurality of fastening surfaces, and prevents the drag torque from being generated.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) First, the structure will be described.

FIG. 1 is a sectional view showing an essential part of a torque converter with a multi-plate lock-up clutch according to a first embodiment of the present invention, and FIG. 2 shows a facing of the multi-plate lock-up clutch. FIG. 3 and FIG. 3 are overall sectional views of the torque converter with a multi-plate lockup clutch of the first embodiment.

In FIG. 3, 1 is a converter cover, and 2
Is a pump impeller, 3 is a turbine runner, 4 is a stator, 5 is a turbine hub, 6 is a transmission input shaft, 7 is a one-way clutch, 8 is a clutch piston, 9 is a torsion spring, 10 is a multi-plate lock-up clutch, and 11 is Converter oil chamber, 12 lockup oil chamber, 13 oil pump, 14 lockup control valve, 15 reserve tank, 16 pump suction oil passage, 17 pump discharge oil passage, 18 drain oil passage, 19 Lockup oil passage,
Reference numeral 20 is a lockup release oil passage.

The converter cover 1 is connected to an engine crankshaft (input member) not shown.

The clutch piston 8 is provided on the turbine hub 5 (output member) so as to be movable in the axial direction.

The multi-plate lockup clutch 10 is arranged between the converter cover 1 and the clutch piston 8.

A converter oil chamber 11 for accommodating the pump impeller 2, which is a blade element, the turbine runner 3, and the stator 4.
And the lock-up oil chamber 12 on the converter cover 1 side,
It is defined by the clutch piston 8.

The hydraulic oil is supplied to the converter oil chamber 11 by the oil pump 13 to the lock-up releasing oil passage 20 to remove the hydraulic oil from the lock-up oil chamber 12, and the differential pressure in the left direction in the drawing is applied to the clutch piston 8. By engaging the multi-plate lockup clutch 10, the lockup oil chamber 1
A lock-up control means for releasing the multi-plate lock-up clutch 10 by supplying the hydraulic oil to the valve 2 and removing the hydraulic oil in the converter oil chamber 11 to exert a differential pressure on the clutch piston 8 in the right direction in the drawing is configured. .

In FIG. 1, a multi-plate lockup clutch 10 is fixed to a converter cover 1, is fixed to a first annular member 101 having spline teeth formed on the inner surface thereof, and a clutch piston 8, and has spline teeth formed on the outer surface thereof. Second annular member 102, a first clutch disc 103 splined to the first annular member 101, a second clutch disc 104 splined to the second annular member 102, and the first clutch disc 103
Has a facing 105 attached to both surfaces of the second clutch disc 104 and one face on the cover side of the second clutch disc 104. The facing 105 and the inner face 1a of the cover, the facing 105 and the disc side face 104a, the facing 105 and the clutch piston side face 8a. Each has three fastening surfaces.

As shown in FIGS. 1 and 2, the facing 105 has a first annular groove 106 formed on a side surface of an outer diameter portion of the facing 105, and one end of the first annular groove 106 communicates with the first annular groove 106. However, a drag preventing structure is provided by the first communication groove portion 107 whose other end is open to the end surface of the inner diameter portion of the facing 105.

Next, the operation will be described.

[Lock-up] When lock-up is required, the converter oil chamber 1 is switched through the lock-up oil passage 19 by switching operation by the lock-up control valve 14.
1, the hydraulic oil is supplied to the lockup oil chamber 12, and the hydraulic oil in the lockup oil chamber 12 is removed via the lockup release oil passage 20 and the drain oil passage 18 to exert a force on the clutch piston 8 by a differential pressure. The clutch piston 8 is shown in Fig. 3
Stroke to the left of the multi-plate lockup clutch 1
0 is concluded. By this clutch engagement, the converter cover 1 and the clutch piston 8 are integrally connected via the multi-plate lockup clutch 10, and a lockup state in which the engine crankshaft and the transmission input shaft are directly connected is realized. In this lockup state, the transmission torque capacity can be increased as compared with the lockup clutch having one engagement surface by being engaged with the three engagement surfaces of the multi-plate lockup clutch 10.

[Release of Lockup] When releasing the lockup, the switching oil is supplied to the lockup oil chamber 12 via the lockup release oil passage 20 by the switching operation by the lockup control valve 14. Control is performed to remove the hydraulic oil via the lock-up oil passage 19 and the drain oil passage 18, and the clutch piston 8 strokes to the right in FIG. Plate lockup clutch 10
Is released.

When the clutch is disengaged, it is necessary to flow the working oil from the lockup oil chamber 12 to the converter oil chamber 11 via all three fastening surfaces in order to suppress the generation of drag torque.

That is, the pressure distribution acting from the facing inner diameter position B1 to the facing outer diameter position A1 on the one of the three fastening surfaces where a clearance is secured when the clutch is released is as shown in FIG. 4 (a). , Lock-up oil chamber 1
The curve 1 gradually decreases from the hydraulic pressure PB of 2 to the hydraulic pressure PA of the converter oil chamber 11.

On the other hand, the pressure distribution on the fastening surface where no clearance is secured when the clutch is disengaged is such that when there is no drag prevention structure, the pressure drops sharply at the facing inner diameter position B1 as described in the prior art. In the case of the first embodiment, since the drag prevention structure is provided by the first annular groove portion 106 and the first communication groove portion 107, as shown in FIG. From the inner diameter position B1 to the first annular groove portion 106, the pressure drop is suppressed by the first communication groove portion 107, and the first annular groove portion 1
From 06 to the facing outer diameter position A1, there is a drop in pressure.
The curve 2 shows the characteristic of decreasing.

Therefore, as shown in the upper part of FIG. 4 (b), the hatched portion has the effect of widening the gap between the fastening surfaces that are narrowed, and when the gap between the fastening surfaces is secured,
The hydraulic pressure distribution characteristics are shown in the upper part of (a), and the axial forces are almost balanced. As described above, when there are variations in the gaps between the three fastening surfaces, the clutch discs move in a direction to eliminate the variations,
This suppresses the generation of drag torque.

Incidentally, the experimental results of drag torque are shown in FIG.

In the characteristics of FIG. 5, the ring groove is the first annular groove portion 106, and the numbers 2, 4, ... Are the numbers of the first communicating groove portions 107 in the radial direction.

From the results of this experiment, first, it can be seen that the drag torque is greatly reduced as compared with the case of the facing without a groove. In particular, in the region where the flow rate is 2 to 5 L / min, the larger the number of the first communication groove portions 107, the higher the effect. In this case, it can be seen that a large thrust in the axial direction for pushing back the clutch disc is generated.

Next, the effect will be described.

In a torque converter with a multi-disc lock-up clutch having a multi-disc lock-up clutch 10 having three fastening surfaces, a first annular groove portion 106 formed on a side surface of an outer diameter portion of a facing 105 and the first annular groove portion 106. 1 Since the multi-plate lockup clutch 10 is provided with the drag prevention structure by the first communication groove portion 107, one end of which communicates with the annular groove portion 106 and the other end of which is opened to the end face of the inner diameter portion of the facing, the drag torque is reduced when the lockup is released. Can be achieved.

When the first communication groove portion 107 is formed in the facing 105 in a tunnel shape, a large fastening contact area can be secured, which is preferable in terms of facing durability.

(Second Embodiment) FIG. 6 is a sectional view showing an essential part of a torque converter with a multi-plate lock-up clutch according to a second embodiment of the present invention, and FIG. 7 is a multi-plate lock. It is a figure which shows the facing of an up clutch.

In the facing 105 of the second embodiment, as shown in FIGS. 6 and 7, the intermittent first annular groove portion 10 formed on the side surface of the outer diameter portion of the facing 105.
6'and the first communication groove 107 having one end communicating with the intermittent first annular groove 106 'and the other end opened to the end face of the inner diameter portion of the facing 105 is provided with a drag preventing structure. The other structure is similar to that of the first embodiment.

Further, in terms of operation and effect, the annular groove portion is intermittent, so that the facing 105 does not come apart during manufacture or when it is attached to the clutch disc by baking or the like, and the durability of the facing 105 is improved. Can be improved in addition to the function and effect of the first embodiment.

FIG. 8 shows the experimental results of drag torque when the T-shaped groove of the second embodiment is provided. The effect of drag torque reduction in the first embodiment is almost the same level. I understand that.

(Third Embodiment) FIG. 9 is a diagram showing the facing of a torque converter with a multi-plate lockup clutch according to a third embodiment of the present invention.

In the facing 105 of the third embodiment, as a drag preventing structure, communication groove portions 108, 109, 110 formed from the inner diameter end to the outer diameter portion (not reaching the outer diameter end) on the side surface of the facing 105. 111 is provided. The communication groove portion 108 is formed by a vertical groove in the radial direction, as shown in FIG. 9 (a). Communication groove 109
Is due to the vertical and horizontal crossing grooves as shown in FIG. 9 (b). The communicating groove portion 110 is formed by a large number of arcuate grooves intersecting with each other, as shown in FIG. 9 (c). Communication groove 1
As shown in FIG. 9 (d), reference numeral 11 is due to a plurality of vertical grooves and horizontal grooves provided at equal intervals in the divided area.

In operation, the drag torque is reduced by the same operation as in the first and second embodiments. Incidentally, the characteristic connecting the black squares in FIG. 8 is the drag torque characteristic when eight communication groove portions 108 shown in FIG. 9A are provided.

(Fourth Embodiment) FIG. 10 is a sectional view showing a main part of a torque converter with a multi-plate lockup clutch according to a fourth embodiment of the present invention.

In this fourth embodiment, the facing 105
As shown in FIG. 10, on each of the cover inner surface 1a, the disk side surface 104a, and the clutch piston side surface 8a facing each other, a second annular groove portion 112 formed at a position corresponding to the facing outer diameter portion and the second annular groove portion 112 are formed. A drag prevention structure is provided by the second communication groove portion 113 having one end communicating and the other end opening at a position corresponding to the inner diameter portion of the facing 105.

In operation, the groove portion 11 is different from that of the first embodiment.
2, 113 have a relative positional relationship when viewed from the fastening surface, and the drag torque is reduced by the same action as in the first embodiment.

Incidentally, the drag preventing structures by the groove portions of the second and third embodiments are the same as in the fourth embodiment, and the facing 105
Can be provided on the surface facing.

(Fifth Embodiment) FIG. 11 is a sectional view showing an essential part of a torque converter with a multi-disc lockup clutch according to a fifth embodiment of the present invention.

In this fifth embodiment, the facing 105
A drag prevention structure is provided by a tapered surface 105a having a large thickness on the outer diameter side and a small thickness on the inner diameter side.

Operationally, when the lockup is released, the tapered surface 105a has a large opening area at the inner diameter end of the facing 105 on the lockup oil chamber 12 side at the fastening surface with a narrow clearance, and the facing surface has a large opening at the outer diameter portion of the facing 105. A fastening surface taper space that gradually narrows toward the front side is formed, and this space serves as a communication groove, and a thrust force is generated in the axial direction that separates by the action described in the first embodiment, and drag torque is reduced.

(Sixth Embodiment) FIG. 12 is a sectional view showing an essential part of a torque converter with a multi-plate lockup clutch according to a sixth embodiment of the present invention.

In the sixth embodiment, the first clutch disc 103 and the second clutch disc 104 are the first clutch discs 103 ', 10 of the dish plate type.
3 ″ and the second clutch disc 104 ′, which are arranged in an inclined manner, are provided with a drag preventing structure by a fastening surface taper space in which the facing inner diameter side gap of the fastening surface is wide and the facing outer diameter side gap is narrow.

The drag torque reducing action is similar to that of the fifth embodiment, but at the time of lockup, the first clutch discs 103 ', 103 "and the second clutch disc 10 are operated.
By securing the fastening surface by the facing 105 by the deformation of 4 ', the taper angle α can be set large.

(Seventh Embodiment) FIG. 13 is a sectional view showing an essential part of a torque converter with a multiple disc lockup clutch according to a seventh embodiment of the present invention.

In the seventh embodiment, the first facing 105 'having a large porosity is attached to the facing inner diameter side.
Further, a drag prevention structure is provided by the second facing 105 ″ having a small porosity, which is attached to the facing outer diameter side.

In operation, when the lockup is released, the pores of the first facing 105 'serve as oil communication holes on the fastening surface with a narrow clearance, and the oil flows through the pores, so that the oil pressure on the inner diameter side of the facing is increased. The hydraulic pressure difference from the hydraulic pressure on the outer diameter side of the facing is suppressed to a low level, the axially separating thrust force is generated by the action described in the first embodiment, and the drag torque is reduced.

(Eighth Embodiment) FIG. 14 is a sectional view showing an essential part of a torque converter with a multi-plate lockup clutch according to an eighth embodiment of the present invention.

In this eighth embodiment, the facing 105
Further, a through hole 114 penetrating the clutch disks 103 and 104 in the axial direction is provided with a drag preventing structure. Further, the through holes 114 are provided at three different positions in the radial direction.

Operationally, when the lockup is released, the oil pressure flows through the through holes 114 so that the hydraulic pressure levels of the adjacent fastening surfaces become the same, that is, the pressure distributions of the respective fastening surfaces become the same. By the adjustment, the variation in the clearance of the fastening surface is corrected, the proper clearance that the facing 105 does not contact is secured, and the drag torque is reduced.

(Ninth Embodiment) FIG. 15 is a sectional view showing an essential part of a torque converter with a multiple disc lockup clutch according to a ninth embodiment of the invention as defined in claims 1 and 10.

In the ninth embodiment, the clutch piston 8
On both sides of the outer diameter position of the first clutch disc 103 close to, a seal material 115 is attached to the side surface of the cover and a stopper 116 is attached to the side surface of the piston to provide a drag prevention structure. The seal material 115 is the first
The stopper 11 moves together with the clutch disc 103.
6 is fixed to the first annular member 101.

In operation, when the lockup is released, when the oil flows from the lockup oil chamber 12 toward the converter oil chamber 11, the clutch piston 8 moves rightward in the drawing due to the force due to the pressure difference between the chambers 11 and 12. Move to a predetermined position. At this time, looking at the hydraulic pressures at the portions A, B, C, and D in FIG. 15, the portions A and C existing inside the facing 105 become the hydraulic pressure P2 of the lockup oil chamber 12, and Second
The B portion existing on the outer diameter portion of the clutch disc 104 is cut off from the communication with the converter oil chamber 11 by the seal material 115, and becomes the hydraulic pressure P2 of the lockup oil chamber 12 as in the A and C portions. The D portion existing on the outer peripheral portion of the clutch piston 8 becomes the hydraulic pressure P1 of the converter oil chamber 11 by communicating with the converter oil chamber 11.

Therefore, the facing inner diameter portion pressure and the facing outer diameter portion pressure on the two fastening surfaces on the converter cover 1 side are equalized, and the pressure distribution of the facing 105 is equal, as shown in the left part of FIG. It becomes a characteristic by pressure,
A gap is secured between the two fastening surfaces on the converter cover 1 side. Further, as shown in the right part of FIG. 16, the pressure distribution of the facing 105 on the right side of the first clutch disc 103 becomes lower toward the outer diameter side, and the first clutch due to the difference between the left and right pressure distributions. Although a pressing force acts on the right side of the disc 103, the first clutch disc 10
The movement of No. 3 is prevented by the stopper 116, so that the clearance on the piston side is secured. (Tenth Embodiment) FIG. 17 shows a first embodiment of the invention according to claims 1 and 10.
It is sectional drawing which shows the principal part of the torque converter with a multiple disc lockup clutch of 0th Example.

In the tenth embodiment, a drag preventing structure is provided by mounting a seal material 115 sandwiched between stoppers 116, 116 at the outer diameter position of the first clutch disc 103 and at a position close to the clutch piston 8. Is provided. In addition, between the seal material 115 and the upper end of the clutch piston 8, an orifice 117 is formed by a narrow gap when the lockup is released.

In operation, since the orifice 117 is formed, the E portion of the outer peripheral portion of the facing 105 on the right side of the first clutch disc 103 is maintained at a higher hydraulic pressure than the hydraulic pressure P1 of the converter oil chamber 11. As in the ninth embodiment except that the pressing force to the right side as shown in FIG. 16 can be reduced, by preventing the pressure difference between the inner and outer diameters of the facing 105 from occurring, the fastening surface A gap is secured and dragging torque can be reduced.

Although the embodiments have been described above with reference to the drawings, the specific configuration is not limited to the embodiments, and modifications and additions within the scope of the present invention are included in the present invention. Be done.

For example, in the embodiment, the multi-disc lockup clutch has three fastening surfaces, but the fastening surface is two.
Includes one with four or more fastening surfaces.

[0075]

As described above, according to the present invention, in a multi-plate lock-up clutch torque converter having a built-in multi-plate lock-up clutch having a plurality of fastening surfaces, the multi-plate lock-up clutch includes: Since a drag prevention structure that suppresses the change gradient of the pressure distribution from the pressure acting on the inner diameter side of the clutch disc to the pressure acting on the outer diameter side when the lockup is released is provided, it is possible to reduce the drag torque when releasing the lockup. The effect that it can be obtained.

As a result, while using the multi-plate lock-up clutch useful for high torque transmission, it is possible to prevent the torque increasing action of the torque converter from being reduced, and to prevent heat generation during stall or sudden start. Improved durability and reliability can be achieved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a multi-plate lockup clutch portion of a torque converter according to a first embodiment.

FIG. 2 is a diagram showing facing of a clutch according to the first embodiment.

FIG. 3 is an overall sectional view showing a torque converter with a multi-plate lockup clutch according to a first embodiment.

FIG. 4 is an explanatory view of the operation of the first embodiment clutch.

FIG. 5 is a drag torque characteristic diagram of the first embodiment clutch.

FIG. 6 is a sectional view showing a multi-plate lockup clutch portion of a torque converter according to a second embodiment.

FIG. 7 is a view showing a facing of a second embodiment clutch.

FIG. 8 is a drag torque characteristic diagram of the second embodiment clutch.

FIG. 9 is a diagram showing a facing of a third embodiment clutch.

FIG. 10 is a sectional view showing a multi-plate lockup clutch portion of a torque converter according to a fourth embodiment.

FIG. 11 is a sectional view showing a multi-plate lockup clutch portion of a torque converter according to a fifth embodiment.

FIG. 12 is a sectional view showing a multi-plate lockup clutch portion of a torque converter according to a sixth embodiment.

FIG. 13 is a sectional view showing a multi-plate lockup clutch portion of a torque converter according to a seventh embodiment.

FIG. 14 is a sectional view showing a multi-plate lockup clutch portion of a torque converter of an eighth embodiment.

FIG. 15 is a sectional view showing a multi-plate lockup clutch portion of a torque converter of a ninth embodiment.

FIG. 16 is a pressure distribution characteristic diagram of the first clutch disc when the lockup is released.

FIG. 17 is a sectional view showing a multi-plate lockup clutch portion of the torque converter of the tenth embodiment.

FIG. 18 is a sectional view showing a multi-plate lockup clutch portion of a conventional torque converter.

FIG. 19 is a pressure distribution characteristic diagram of the first clutch disc when the lockup is released.

[Explanation of symbols]

 1 Converter Cover 2 Pump Impeller 3 Turbine Runner 4 Stator 8 Clutch Piston 10 Multi-plate Lockup Clutch 105 Facing 106 First Annular Groove (Drag Prevention Structure) 107 First Communication Groove (Drag Prevention Structure) 11 Lockup Oil Chamber 12 Converter Oil Chamber 14 Lockup control valve

Claims (10)

[Claims] 1. A converter cover connected to an input member, a clutch piston axially movable on an output member, and a clutch cover disposed between the converter cover and the clutch piston and provided with facings on one side or both sides. A multi-plate lockup clutch having at least one clutch disc and a plurality of fastening surfaces; a converter oil chamber on the blade element side and a lockup oil chamber on the converter cover side defined by the clutch piston; The hydraulic oil is supplied to the converter oil chamber, the hydraulic oil in the lock-up oil chamber is removed, and the differential pressure is applied to the clutch piston to engage the multi-plate lock-up clutch and supply the hydraulic oil to the lock-up oil chamber. Multi-plate lock-up clutch by removing hydraulic oil from the oil chamber and applying differential pressure to the clutch piston A lockup control means for releasing the lockup control means, which is provided in the multi-plate lockup clutch and suppresses a change gradient of the pressure distribution from the pressure acting on the inner diameter side of the clutch disc to the pressure acting on the outer diameter side when the lockup is released. A torque converter with a multi-plate lock-up clutch, comprising: a drag prevention structure. 2. The drag prevention structure has a first annular groove portion formed on a side surface of an outer diameter portion of the facing, and one end communicates with the first annular groove portion and the other end is opened to an end surface of an inner diameter portion of the facing. The torque converter with a multi-plate lock-up clutch according to claim 1, wherein the torque converter has a first communication groove. 3. The drag prevention structure includes an intermittent first annular groove formed on a side surface of an outer diameter portion of the facing,
2. The multi-disc lock-up clutch according to claim 1, wherein one end communicates with the intermittent first annular groove portion and the other end is a first communicating groove portion opened to an end surface of an inner diameter portion of the facing. Torque converter. 4. The torque converter with a multi-plate lockup clutch according to claim 1, wherein the drag prevention structure is a communication groove portion formed from an inner diameter end to an outer diameter portion on a side surface of the facing. 5. A second annular groove portion formed at a position corresponding to a facing outer diameter portion of a fastening surface facing the facing and the drag preventing structure, and one end communicating with the second annular groove portion and the other end having an inner diameter of the facing. Second opened to the position equivalent to the section
The torque converter with a multi-plate lock-up clutch according to claim 1, wherein the torque converter has a communicating groove portion. 6. The multi-plate lock-up clutch according to claim 1, wherein the drag-prevention structure is a tapered surface with a thicker outer diameter side and a thinner inner diameter side of the facing. Torque converter. 7. The drag preventing structure is characterized by a fastening surface taper space in which the facing inner diameter side gap of the fastening surface is widened and the facing outer diameter side gap is narrowed by arranging the clutch discs in an inclined manner. Claim 1
Torque converter with multi-disc lock-up clutch described. 8. The drag preventing structure is composed of a first facing having a large porosity attached to the facing inner diameter side and a second facing having a small porosity attached to the facing outer diameter side. A torque converter with a multi-plate lock-up clutch according to claim 1. 9. The torque converter with a multi-plate lock-up clutch according to claim 1, wherein the drag prevention structure includes a facing and a through hole that axially penetrates the clutch disc. 10. The multi-plate lock-up clutch torque according to claim 1, wherein the drag prevention structure is made of a seal material that seals a position closest to the clutch piston at an outer diameter position of the clutch disc. converter.