Patent Description:
In a torque converter assembled in a vehicle automatic transmission, a front cover constituting a front part of a converter housing is rotationally driven on a crankshaft, a torque is transmitted between blades on a pump impeller side of the converter housing and blades on a turbine runner side, and the torque is transmitted from the output shaft driven by the turbine runner to the input shaft of the transmission.

In addition, the torque converter operates a lock-up clutch by using a lock-up piston to promote fuel consumption and a lock-up device transmitting the torque of the crankshaft of the engine to the transmission through a torsion spring (an elastic body) for absorbing an impact (a torsional vibration).

Here, in order to speed up a response (separation) speed of the lock-up piston when the lock-up clutch operation is stopped, a spring pack with a built-in spring between the clutch support and the lock-up piston may be used.

For example, <CIT> discloses a technical idea of installing a coil spring on an inner circumference side of an engaging portion in which a flange member installed on a piston member is protruded. According to this, it is shown that the piston member is pressed by the coil spring in the direction that the clutch is disengaged, which accelerates the response when the clutch is disconnected.

However, according to this technical idea, since the spring is mounted on the piston itself, it does not consist of an independent unit called a spring pack, and an assembly adjustment becomes difficult.

<CIT> describes a torque converter comprising a clutch having a plurality of clutch plates supported by a clutch supporting member, and a piston configured for pressurizing the plates. A spring pack is provided between the piston and a member to which the clutch supporting member is fixed, wherein the spring pack applies a force to separate the piston and the clutch plates The spring pack includes a retainer plate and a plurality of spring supporters.

The present invention seeks to solve such a conventional art problems existing in a lock-up device consisting of a lock-up clutch, a lock-up piston, an input side clutch support, etc.. It is one of the objects of the invention to provide a lock-up device with excellent assemblability and simultaneously reducing a mutual rotation between the lock-up piston and the input side clutch support, which simultaneously increases the response of the lock-up piston.

In order to solve such a problem the invention provides a lock-up device for a torque converter according to claim <NUM>.

In this way, since the spring pack presses the lock-up piston in the direction of releasing the clutch, the response speed at the time of the clutch release is accelerated, and simultaneously, the mutual rotation of the lock-up piston and the input side clutch supporter generated during the rapid acceleration may be prevented by the mutual rotation prevention mechanism. In addition, since the spring pack is composed as an independent unit, it is possible to be assembled to the torque converter after being externally assembled and adjusted, which helps to improve efficiency such as a number reduction of an assembling adjustment process.

In addition, according to the present invention, the spring pack includes:.

In this way, after assembling the spring pack at the outside, it is possible to fix the first retainer plate to the lock-up piston by rivet combination and the effect of the number reduction of the assemble process described above is realized.

According to the present invention, the mutual rotation prevention mechanism has:.

In this way, by a simple structure of the outer gear and the inner gear, the spring pack and the input side clutch supporter are free to move in the axis direction, but the mutual rotation is prevented, and therefore, the mutual rotation between the lock-up piston fixed to the spring pack and the input side clutch supporter is also prevented.

According to a further exemplary embodiment, and it may provided that an exterior circumference portion of the second retainer plate has a shape that is bent toward the input side and is in contact with input side clutch supporter on a front end surface.

Here, the front end surface refers to contacting the exterior circumference portion of the second retainer plate by an L-shaped bent end or a Z-shaped bent small area, not the contact by the wide side without bending of the second retainer plate.

In this way, the spring pack may be mounted more compactly than when contacting on the wide surface, thereby reducing the entire space of the torque converter.

According to an embodiment, the lock-up piston includes a plurality of rivets for fixing the first retainer plate and the lock-up piston, and the coil spring is not disposed at the fixing position of the rivet.

In this way, since the coil spring is not disposed near the rivet fixing position, the rivet fixing position may be close to the exterior circumference of the first retainer plate, thereby the first retainer plate may be down-sized, and also as the rivet fixing position and the spring position are close, the occurrence of a rotation moment or a bending stress may be reduced, and even pressure may be applied.

According to an embodiment, an exterior circumference portion of the lock-up piston is bent to the output side in the axis direction and is supported by the piston guide at that portion.

In this way, the exterior circumference of the lock-up piston may be reduced, and a larger torsion damper or pendulum may be installed on the outside of the lock-up piston while maintaining the entire size of the torque converter, and the entire size of the torque converter may be compacted if the torsion damper is used as in the conventional art.

In addition, in the lock-up piston, since the exterior circumference portion is supported by the piston guide with a bending structure on the bending surface thereof, it may avoid unintentional deformation of the lock-up piston, and it may have many effects such as maintaining good centering.

Further, it may be provided that a plurality of hole portions are installed to the first retainer plate as a part of the spring pack, and a plurality of extrusion rivets as a part of the lock-up piston are protruded in the spring pack direction, wherein the extrusion rivets are capable of being inserted into the hole portions of the first retainer plate.

In other words, since a cylindrical rivet-shaped part (referred to as an extrusion rivet) is formed in a form of protruding the flat part of the lock-up piston at the same radius part at the axial center of the lock-up piston and the part as a rivet is inserted into the hole portion of the first retainer plate, the rivet as a separate member as described so far becomes unnecessary, and thus the structure may be simplified, the number of parts and the number of the assembling processes may be reduced, and further, the reduction in manufacturing cost may be expected.

In addition, the extrusion rivet part is integrally molded and does not have a rivet hole, which is a separate member, so there is no risk of liquid leakage from this part, and thus, the piston may be operated stably for a long time without deteriorated pressure.

It is also desirable to disable a movement in the axis direction by caulking the extrusion rivet head part (the part protruded from the first retainer plate).

However, without caulking the head part, it may be fixed by force-fitting or a spring force, or it may be moved in the axis direction. The stabilization in the axis direction may be maintained by a compressing spring force between the spring pack and the lock-up piston.

According to a further embodiment, the coil spring is not disposed at the position of the extrusion rivet of the lock-up piston which is inserted into the hole portion of the first retainer plate.

In this way, as in the case of the fifth aspect, by not disposing the coil spring near the extrusion rivet position, the extrusion rivet position may be close to the exterior circumference of the first retainer plate, thereby down-sizing the first retainer plate, and in addition, as the extrusion rivet position and the spring position are close together, the occurrence of a rotation moment or bending stress may be reduced, and even pressure may be applied.

According to the present invention, it is possible to provide the lock-up device simultaneously having excellent assembly performance while reducing mutual rotation between the lock-up piston and the input side clutch supporter, which simultaneously increases the response of the lock-up piston in the lock-up device.

In addition, in the sixth aspect of the present invention, it is possible to provide the torque converter that may effectively utilize the outside of the lock-up piston exterior circumference portion.

Hereinafter, a form for carrying out the present invention will be described with reference to the drawings. In addition, in the following, a range required for explanation for achieving the object of the present invention is schematically shown, and a range required for explanation of the corresponding part of the present invention is mainly described, and a part to which the description is omitted will be made by known technology.

<FIG> is a longitudinal cross-sectional view of a torque converter including a lock-up device according to an exemplary embodiment of the present invention, in which an upper par is only shown and a lower part is omitted, and <FIG> is a top plan view of a lock-up device according to an exemplary embodiment of the present invention.

A torque converter <NUM> is a device for transmitting a torque from a crankshaft of an engine to an input shaft of a transmission. The engine that is not shown is disposed on the right side of the drawing, and the transmission that is not shown is disposed on the left side of the drawing. A-A' shown in the drawing is a rotation axis of the torque converter <NUM>.

In addition, unless otherwise specified, the input side represents the right side of the drawing (front cover side), and the output side represents the left side of the drawing opposite to the input side. Also, the inside or inner circumference refers to the side closer to the rotation axis, and the outside or outer circumference refers to the side far from the rotation axis. Further, the axis direction is assumed to indicate the direction in which the rotation axis extends.

As shown in <FIG>, a torque converter <NUM> mainly includes a front cover <NUM> and three type impellers (pump impellers) <NUM>, a turbine runner <NUM>, stator blades <NUM>, a lock-up device <NUM>, and a vibration absorption device <NUM> including members such as a retainer plate <NUM>, an outer elastic member <NUM>, an inner elastic member <NUM>, a centrifugal pendulum <NUM>, and a turbine hub <NUM> that receives power from the front cover <NUM>.

Here, when the lock-up device <NUM> is not operating, the power from the front cover <NUM> is fluidly transmitted to the turbine hub <NUM> via the impeller.

On the other hand, when the lock-up device <NUM> is in operation, the power from the front cover <NUM> is transferred mechanically to the turbine hub <NUM>.

The lock-up device <NUM> includes a lock-up clutch <NUM> made of a lock-up plate of a multi-layered plate disposed between the front cover <NUM> and the turbine hub <NUM>, an input side clutch supporter <NUM> and an output side clutch supporter <NUM> supporting the lock-up clutch <NUM>, a lock-up piston <NUM>, a piston guide <NUM>, a spring pack <NUM> installed between the lock-up piston <NUM> and the input side clutch supporter <NUM>, and a drive plate <NUM> fixed and coupled to the output side clutch supporter <NUM>.

The lock-up piston <NUM> is disposed inside the output side clutch supporter <NUM> between the front cover <NUM> and the vibration absorption device <NUM>. The lock-up piston <NUM> is formed in an annular shape, and includes a pressing part <NUM> protruding on the input side.

In addition, the disk-shaped inner circumferential portion of the lock-up piston <NUM> is fixed to the cover hub <NUM>, and the disk-shaped exterior circumference portion has a cylindrical edge portion <NUM> that is opened from the axis direction to the output side.

As above-described, if the exterior circumference portion of the lock-up piston <NUM> is bent in the axis direction output side and is supported to the piston guide <NUM> at that portion, the exterior circumference of the lock-up piston <NUM> may be reduced, and instruments such as a larger torsional damper and a pendulum may be installed on the outside of the lock-up piston <NUM> while maintaining the entire size of the torque converter <NUM>, or if the torsion damper or the like is conventionally used, the entire size of the torque converter <NUM> may be compact.

In addition, the lock-up piston <NUM> is supported by the piston guide <NUM> on the bent surface with the structure in which the exterior circumference portion is bent, so that unintended deformation of the lock-up piston <NUM> may be avoided and a lot of effects such as a good maintenance of centering may be obtained.

In addition, around the central portion of the lock-up piston <NUM>, six holes <NUM> for fixing rivets are installed evenly on the circumference.

The piston guide <NUM> is equally formed in an annular shape on the output side of the lock-up piston <NUM>, the inner circumference side of the disk shape is firmly bonded to the cover hub <NUM>, and the outer circumference portion of the disk shape is in contact with the inner surface side of the edge portion <NUM> of the lock-up piston <NUM> by interposing an O-ring <NUM> as a sealing member disposed on the recessed portion <NUM>.

The lock-up piston <NUM> and piston guide <NUM> move in the axis direction input side by the pressure due to the internal oil of the torque converter <NUM>. By this movement, the pressing part <NUM> presses the multi-layered plate clutch <NUM> and establishes a lock-up state.

<FIG> is a perspective view of a spring pack of a lock-up device according to an exemplary embodiment of the present invention, <FIG> is a top plan view of a first retainer plate of a device according to an exemplary embodiment of the present invention, <FIG> is a top plan view of an input side clutch supporter of a device according to an exemplary embodiment of the present invention, and <FIG> is a longitudinal cross-sectional view of an input side clutch supporter of a device according to an exemplary embodiment of the present invention.

The spring pack <NUM> includes a first retainer plate <NUM> installed between the lock-up piston <NUM> and the input side clutch supporter <NUM> and fixed to the lock-up piston <NUM>, a second retainer plate <NUM> installed at the input side clutch supporter <NUM> side, a plurality of first spring supporters <NUM> installed at the surface facing the second retainer plate <NUM> of the first retainer plate <NUM>, a plurality of second spring supporters <NUM> installed at the surface facing the first retainer plate <NUM> of the second retainer plate <NUM>, and a coil spring <NUM> sandwiched between the first spring supporter <NUM> and the second spring supporter <NUM>.

The first retainer plate <NUM> has an approximate ring shape, and a thin plate shape, has a plurality of protruded portions, that is an external gear <NUM> on a most of the exterior circumference thereof, and has a plurality of first spring supporters <NUM> (<NUM> in the present exemplary embodiment) formed by a burring process, and protruded to the second retainer plate <NUM> and fitted with the interior diameter of the coil spring.

In addition, the inner periphery of the first retainer plate <NUM> has six tongue portions <NUM> protruded inward, and the central portion thereof has a rivet fixing hole <NUM>.

Also, the first spring supporter <NUM> is installed evenly on the circumference, but it is not installed where the tongue portion <NUM> is located. Therefore, the spring supporters <NUM> that must be installed in <NUM> places originally are formed in <NUM> places.

The reason is that if the first spring supporter <NUM> is installed in the place where the tongue portion <NUM> is located, the rivet hole <NUM> of the tongue portion <NUM> must be installed further inside and the size of the first retainer plate <NUM> increases, and in addition, if the first retainer plate <NUM> is fixed to the lock-up piston <NUM> with the rivet, there is a risk of generating unnecessary rotation moment or bending stress during the operation or releasing of the lock-up.

The second retainer plate <NUM> is formed by a burring process with an approximately ring shape, with a thin plate shape, and has a plurality of second spring supporters <NUM> (<NUM> in the present exemplary embodiment) protruded to the first retainer plate <NUM> side and fitted with the interior diameter of the coil spring <NUM>.

In addition, the outermost circumference of the second retainer plate <NUM> has an edge portion <NUM> that is bent with an L-shape on the input side in the axis direction and is in contact with the cylinder bottom of the input side clutch supporter <NUM> at the front end surface of the edge portion <NUM>.

In addition, the second retainer plate <NUM> may not have the L-shaped edge portion <NUM> formed on the exterior circumference portion, but may have an L-shaped portion formed on the inner circumference, and in any case, it may be in contact with the front cover <NUM> rather than the input side clutch supporter <NUM>.

Alternatively, the second retainer plate <NUM> may have a Z-shaped bend rather than the L-shaped bend, and it may be in contact with the input side clutch supporter <NUM> or the front cover <NUM> in the shorter plane.

In addition, the number of spring supporters, tongue portions, etc. until now is an example, and may be more or less than this, and it is effective depending on the degree.

The input side clutch supporter <NUM> is approximately cylindrical, and one bottom surface is bent to the inner circumference side and fixed to the front cover <NUM> at that part.

In addition, the external circumferential surface of the input side clutch supporter <NUM> is formed with an outer gear <NUM> to support the multi-layered plate clutch plate of the lock-up clutch <NUM>, while the interior circumference of the input side clutch supporter <NUM> is formed with the inner gear <NUM> in a form that is shared with the outer gear <NUM> and is made to engage with the outer gear <NUM> of the first retainer plate <NUM>.

Next, an assembly procedure of the lock-up device of an exemplary embodiment of the present invention will be described.

First, the first retainer plate <NUM> is horizontally disposed, so that the first spring supporter <NUM> faces upward, and is fit to the interior diameter of the coil spring <NUM> thereon.

Next, the second retainer plate <NUM> is mounted so that the second spring supporter <NUM> fits into the interior diameter of the coil spring <NUM>. In this state, the partial assembly of the spring pack <NUM> is completed.

Then, the piston guide <NUM> and the lock-up piston <NUM> are mounted horizontally in this order.

In this state, the partially assembled spring pack <NUM> is mounted upwardly.

After that, the rivet hole <NUM> of the first retainer plate <NUM> of the spring pack <NUM> and the rivet hole <NUM> of the lock-up piston <NUM> are fixed with a rivet. Accordingly, the partial assembly of the lock-up device is completed.

In this way, since the assembling of the spring pack <NUM> may be performed independently in advance, the assembling work may be easily and accurately performed, and an effect of reducing the number of assembling processes may be obtained.

Next, the operation of the lock-up device according to an exemplary embodiment of the present invention is described.

When the lock-up piston <NUM> is hydraulically pressed in the direction of the lock-up clutch <NUM>, the pressing part <NUM> causes the lock-up clutch <NUM> to be connected. As a result, the power from the front cover <NUM> is transmitted to the input side clutch supporter <NUM>, the lock-up clutch <NUM>, the output side clutch supporter <NUM>, and the drive plate <NUM>, and is also transmitted to the output side turbine hub <NUM> via an intermediate member.

At this time, if there is a sudden acceleration on the input side, there is a risk of a mutual rotation between the lock-up piston <NUM> and the input side clutch supporter <NUM> and the front cover <NUM> fixed thereto.

Even in such a state, since the outer gear <NUM> of the external circumferential surface of the first retainer plate <NUM> of the spring pack <NUM> fixed and coupled with the lock-up piston <NUM> and the inner gear <NUM> of the inner circumference side of the input side clutch supporter <NUM> are interlocked, the mutual rotation may be prevented.

In addition, when the connection with the lock-up clutch <NUM> is released, the lock-up piston <NUM> is separated by the elastic force of the coil spring <NUM> embedded in the spring pack <NUM>, and the lock-up state is quickly released.

In addition, the fixing of the first retainer plate <NUM> of the spring pack <NUM> and the lock-up piston <NUM> is performed with a rivet, but since the rivet position is close to the position of the coil spring <NUM> in the radial direction, it is possible to reduce the occurrence of the rotation moment or the bending stress during the locking-up or releasing of the lock-up piston <NUM> and stable operation is possible.

Next, the lock-up device according to another exemplary embodiment of the present invention is described.

<FIG> is a top plan view of a lock-up device according to another exemplary embodiment of the present invention, which is a modification of some of the previous exemplary embodiment, and parts common to the previous exemplary embodiment are indicated by the same numbers and detailed description thereof is omitted.

In the central portion of the lock-up piston <NUM>, <NUM> cylindrical extrusion rivets <NUM> are formed evenly on the circumference.

The extrusion rivet <NUM>, also called an extruded rivet or a semi-pierced rivet, is formed in a rivet shape by extruding the flat part of the lock-up piston <NUM> in a cylindrical shape toward the spring pack <NUM> side, and the extrusion part is not penetrated. Therefore, the lock-up piston <NUM> has a structure without a hole portion.

On the other hand, the spring pack <NUM> has the same structure as described so far, and the first retainer plate <NUM> has <NUM> holes <NUM> with an interior diameter that is slightly larger than the exterior diameter of the extrusion rivet <NUM> in the location corresponding to the extrusion rivet <NUM>.

In this state, the lock-up piston <NUM> and the first retainer plate <NUM> are fixed in the axis direction by caulking the protruded head portion of the extrusion rivet <NUM> in the state that the extrusion rivet <NUM> is inserted into the six holes <NUM>.

The advantage of such a fixing method is that it is not necessary to prepare the rivet as a separate member, a member cost may be reduced, and even when assembling, the work such as inserting and a temporary fixing of the rivet is unnecessary, and the number of the work processes may be expected to be reduced.

In addition, since the lock-up piston <NUM> does not have a hole for fastening rivets, power transmission is efficiently performed without causing fluid leakage or a pressure deterioration.

Here, the assembly sequence of another exemplary embodiment of the present invention will be described. <FIG> is an explanatory diagram of a lock-up device according to another exemplary embodiment of the present invention.

First, partial assembling of the spring pack <NUM> is performed by mounting and fitting the coil spring <NUM> and the second retainer plate <NUM> to the first retainer plate <NUM> with <NUM> holes <NUM>.

Meanwhile, six extrusion rivets <NUM> are formed on the lock-up piston <NUM> (<FIG>).

Next, the lock-up piston <NUM> is horizontally disposed, the spring pack <NUM> is lowered from above, and the extrusion rivet <NUM> is inserted into the hole <NUM> of the first retainer plate <NUM> (<FIG>).

Finally, the head portion that the extrusion rivet <NUM> is protruded is caulked (<FIG>). This completes the assembling of the lock-up device.

In addition, it is preferable to caulk the head portion of the extrusion rivet <NUM>, but it may be force-fitted without caulking or may be loosely fitted.

In addition, the present invention is not limited to the above-described exemplary embodiment.

Claim 1:
A lock-up device (<NUM>) for a torque converter (<NUM>), comprising:
an input side clutch supporter (<NUM>) fixed to a front cover (<NUM>) for transmitting power from a drive side;
a lock-up clutch (<NUM>) having a plurality of clutch plates supported by the input side clutch supporter (<NUM>);
a lock-up piston (<NUM>) to pressurize the clutch plates to make the clutch connected;
a piston guide (<NUM>) supporting an end portion of the lock-up piston (<NUM>);
a spring pack (<NUM>) fixed to the lock-up piston (<NUM>) and installed between the lock-up piston (<NUM>) and the input side clutch supporter (<NUM>), the spring pack (<NUM>) including:
a first retainer plate (<NUM>) installed on the side of the lock-up piston (<NUM>) and fixed with the lock-up piston (<NUM>),
a second retainer plate (<NUM>) installed to the input side clutch supporter side,
a plurality of first spring supporters (<NUM>) installed on a surface of the first retainer plate (<NUM>) facing the second retainer plate (<NUM>),
a plurality of second spring supporters (<NUM>) installed on a surface of the second retainer plate (<NUM>) facing the first retainer plate (<NUM>), and
a plurality of coil springs (<NUM>) supported by the first spring supporters (<NUM>) and the second spring supporters (<NUM>), the coil springs (<NUM>) pressing the lock-up piston (<NUM>) in the direction of releasing the clutch (<NUM>); and
a mutual rotation prevention mechanism that prevents mutual rotation between the lock-up piston (<NUM>) and the input side clutch supporter (<NUM>), wherein
the mutual rotation prevention mechanism includes:
an outer gear (<NUM>) installed on the exterior circumference of the first retainer plate (<NUM>) of the spring pack (<NUM>); and
an inner gear (<NUM>) installed in the inner circumference of the input side clutch supporter (<NUM>) and engaged with the outer gear (<NUM>) installed in the exterior circumference of the first retainer plate (<NUM>).