EP2032300A1

EP2032300A1 - Hydrodynamic torque converter and method for producing the same

Info

Publication number: EP2032300A1
Application number: EP07725282A
Authority: EP
Inventors: Bernd Koppitz; Rudolf Reinhardt; Heinz Schultz; Bernhard Ziegler
Original assignee: Daimler AG
Current assignee: Mercedes Benz Group AG
Priority date: 2006-06-23
Filing date: 2007-05-16
Publication date: 2009-03-11
Also published as: US20090139821A1; DE102006028771A1; WO2007147464A1; JP2009541668A

Abstract

The invention relates to a hydrodynamic torque converter (1) and to a method for producing the same. In order to facilitate assembly, the turbine (37) is riveted by means of a plurality of hot rivets (7), or welded, to the torsional damper (17).

Description

Hydrodynamic torque converter and method of making such

The invention relates according to the one-part claim 1 a hydrodynamic torque converter and according to the one-part claim 6, a method for producing such.

The not previously published DE 102005006253.9-34 already relates to a hydrodynamic torque converter, in the production of which a hot-riveting method is used. This hydrodynamic torque converter has a torsional damper.

In DE 19826351 C2, a hydrodynamic torque converter with a torsion damper and a turbine is shown.

In principle, hot riveting methods with a hot rivet having a head are already known from US 2005/0161442 A1, GB 1 528 730 and DE 31 40 368 A1.

The object of the invention is to provide a hydrodynamic torque converter or a method for producing such, which allows a connection of the turbine after assembly of the torsion damper. This object is achieved with the features of device claim 1 and the features of method claim 6.

According to an advantage of the invention, it is possible to completely complete the torsion damper and, if necessary, to check on function and to fix the turbine on the torsion damper by means of hot rivets in rotation from one side. For this purpose, the large head of the hot rivet is provided on the axial side of the turbine, whereas the narrow bolt of the hot rivet is inserted through a recess of this turbine and is riveted warm with a carrier part of the torsion damper. This assembly from one side ensures that the turbine can only be attached to the torsion damper after the torsion damper has been installed. Indeed, such pre-assembly of turbine and torsion damper can prove costly if the turbine is manufactured at a different production location than the torsion damper. For example, the turbine and the torsion damper would first have to be brought together in one place for assembly and, if appropriate, subsequently be moved to another location for installation with the housing. This problem is exacerbated when the individual components are produced by different manufacturers - in particular OEM (Original Equipment Manufacturer) and suppliers. By contrast, the supply of the entire components to a location at which at the same time also large parts of the components are manufactured, represents the lowest manufacturing / assembly costs.

When hot riveting a method is used in a particularly advantageous manner, as this is already shown in the not previously published DE 102005006253.9-34. In addition to the above-mentioned advantage, another advantage of this method is that no burnup is released, which would be in the oil circuit at first commissioning of the hydrodynamic torque converter. This will also make the oil kept clean circuit of the transmission, which usually has a common oil circuit with the hydrodynamic torque converter. The burnup - ie spatter - can namely be withheld during hot riveting in a special catchment area, which can be designed, for example, as a ring pocket or hole reveal.

The connection with hot rivets, for example, over the rotationally fixed connection with a splined shaft has the advantage that it is a solid connection without backlash, so it can not come to noise due to resonant vibrations.

The turbine can be riveted directly to a plate of the torsion damper, so that this metal sheet forms the said carrier part. However, a turbine made of very thin sheet metal is advantageous in terms of weight and dynamics, which in turn makes the connection with the hot riveting method problematic. For this reason, a special carrier may be provided as the carrier part, which may in particular be designed as an annular carrier. The hot rivets are welded onto the carrier. Thus, the plate of the torsion damper and the thin turbine between the carrier and the head of the hot rivet is braced.

This carrier can be made so thick or sufficiently stiff that it can absorb the forces required for welding and riveting. Furthermore, the carrier can take over a centering function for the turbine and / or a spring carrier of the torsion damper. This carrier may have a blind hole for receiving the burn-up. Since the carrier can be designed in particular as a rotating part, an annular groove can also be provided for the circumferentially distributed hot rivets. The depth of the annular groove advantageously determines the hot riveting length. Thus, a particularly long hot rivet can be provided, whose shrinkage is also correspondingly large, so that a high tensile stress is achieved. These high tension a particularly good positive connection.

In a particularly advantageous manner, between the sheets to be joined by means of hot rivets - i. the sheet metal of the torsion damper and the turbine - be provided an embossing. Such embossing forms time before riveting a rotation of the sheets against each other. This embossing can be provided in particular in the area of the hot rivet.

The subject matter of patent claim 4 advantageously ensures, as an additional function by means of the carrier part, axial positioning of the torsion damper to the transmission input shaft hub.

The indirect welding of at least two rivets at the same time ensures that the main flow does not flow over mutually movable parts, so that it can not come to side welds and / or surface damage. At least two evenly distributed around the circumference of welding electrodes provide a security against tilting.

Further advantages of the invention will become apparent from the other claims, the description and the drawings.

The invention is explained below with reference to several illustrative embodiments illustrated.

Showing:

1 shows a hydrodynamic torque converter 1 with hot rivets in a half section, Fig. 2 to Fig. 4 in a detail of the hydrodynamic torque converter according to FIG. 1 a

Manufacturing method for connection in the area of the hot rivet,

5 in an alternative embodiment, a hot rivet with conical geometry,

Fig. 6 shows a clamping of a structural unit of the hydrodynamic torque converter on a machine for hot riveting and

FIG. 7 and FIG. 8 analogous to FIG. 2 to FIG. 4

Process steps for hot riveting an alternative hot rivet.

Fig. 1 shows a hydrodynamic torque converter 1 in a half section. This hydrodynamic torque converter 1 is connected on the input side via a screw connection with a partially flexible driver disk (not shown in more detail) and a crankshaft of a drive motor. Two alternative ways of screwing are shown in the drawing.

On the output side, the hydrodynamic torque converter 1 is connected via a spline toothing 52 to a coaxially arranged transmission input shaft of a transmission (not shown). The transmission input shaft, the hydrodynamic torque converter 1 and a

Crankshaft flange are arranged coaxially to a central axis 25.

The hydrodynamic torque converter 1 comprises the housing 50, a pump shell 35, a turbine 37 and a stator 38. The following detailed description of the embodiment follows the power flow from the crankshaft to the housing 50. From the housing 50, the power flow to the pump shell 35. In hydrodynamic power transmission of the power flow from this pump shell 35 to the turbine 37 and a torsion damper 17 on the said transmission input shaft transmitted. By contrast, the power flow is transmitted at an engaged lock-up clutch 18 from the housing 50 via the lock-up clutch 18 to the torsion damper 17 and then to the transmission input shaft.

The turbine 37 is arranged next to the pump shell 35 on its side facing the drive motor. Axially between the pump shell 35 and the turbine 37, the stator 38 is disposed radially inwardly, which is supported in a conventional manner on a freewheel 39.

An inner hub 40 of the freewheel 39 is rotatably connected by means of an internal toothing with a stator shaft, not shown.

The turbine 37 has radially inwardly a plurality of evenly distributed on the circumference round recesses 5a, which are shown in more detail in FIG. 2 to FIG. 4. Warm rivets 7, which comprise a head 15 and a shaft 13, are inserted into these recesses 5 a from the turbine 37 side. The heat rivets 7 clamp a spring carrier 44 against an annular carrier 43. The production of this connection is explained in more detail below in FIGS. 2 to 4. The spring carrier 44 is limited against the torsional stiffness of the torsion damper 17 rotatable to a support plate 46th arranged. For this purpose, bow springs 47, 14 of the torsion damper 17 are received in recesses into the sheet

the support plate 46,

- The spring carrier 44 and

- A non-rotatably riveted with the latter clutch plate 53 are incorporated.

The support plate 46 is provided radially outwardly of the bow springs 47, 14 in Umfangsriehtung with curved lugs 49 which guide the bow springs 14. The support plate 46 is radially inwardly rotatably connected to a transmission input shaft hub 51. This transmission input shaft hub 51 is rotatably connected by means of the aforementioned spline 52 with the transmission input shaft. The carrier 43 is guided radially and axially by means of a sliding bearing on the transmission input shaft hub 51. For lubrication of the axial sliding surface pairing, a lubricant channel 70 is provided. This lubricant channel 70 opens into a lubricant channel 71, which is provided for lubrication of the radial sliding surface pairing. This lubricant channel 70 simultaneously ensures the circulation of the converter cooling circuit. The support member 43 is axially supported by an axial rolling bearing 72 on an axial securing ring 73. This axial securing ring 73 is in turn axially supported on an outer ring 74 - i. Clamping ring - of the freewheel 39 from.

The coupling plate 53 is immovably connected to an inner plate carrier 54. The inner plate carrier 54 halter via an axial toothing inner clutch plates of the lock-up clutch 18. These clutch plates are rotatably and axially displaceable relative to the inner plate carrier 54. Likewise, outer clutch plates on a fixedly connected to the housing 50 outer plate carrier 57th rotatably supported and axially displaceable. For this purpose, an axially aligned internal toothing is incorporated into the outer disk carrier 57, in which an external toothing of the outer clutch plates engages. The outer disk carrier 57 extends coaxially with the housing 50 and is friction welded to this movement. The outer and inner clutch plates engage radially with each other. In this case, the inner clutch plates 55 friction linings, which are fixed on both sides firmly on a base body. These friction linings are on both sides of the outer clutch plates and on one side to the frontmost clutch plate and an abutment disc 63 at. In this case, a friction torque is transmitted to the contact surfaces. A piston 64 is provided to disengage and engage the lock-up clutch 18.

In the manufacturing process described below with reference to Figs. 2 to 4, the transmission side - i. in the drawing plane from the right - a pressure in the hot rivet 7 introduced to weld the hot rivet 7 with the annular support 43 and then to compress. For this purpose, a structural unit 100 is first mounted as shown in FIG. 6, which

the inner plate carrier 54,

the torsion damper 17,

- The annular support 43 and

- Includes the Getriebeeinganswellennabe 51. The transmission input shaft hub 51 is inserted in a receptacle 101 of a machine and the turbine 37 is used together with the hot rivets 7 in the assembly 100. Subsequently, the hot-riveting method is carried out by means of at least two electrodes 102a, 102b distributed uniformly around the circumference, as described in detail with reference to a single hot rivet in FIGS. 2 to 4. The forces when pressing the heat rivets 7 are about the carrier 43 and the transmission input shaft hub 51 at the Recording 101 supported. According to the arrows of Fig. 9 is welded indirectly. In this case, the welding current flows through an electrode 102a into another electrode 102b. Thus, the main current flows relatively directly through the heat rivets 7, the carrier 43 and the transmission input shaft hub 51. This ensures that touching - but against each other movable - parts of the assembly 100 are not welded together and the surface of these components is protected.

FIGS. 2 to 4 show in a detail of the hydrodynamic torque converter 1 according to FIG. 1 the production method of the connection in the region of the hot rivet 7. The detail is shown rotated in relation to FIG.

Fig. 2 shows the turbine 37 and the spring carrier 44, which are to be attached to the not shown in Fig. 2 annular support 43. The turbine 37 and the spring carrier 44 have continuous round recesses 5a, 5b. Furthermore, the hot rivet 7 with the shaft 13 and the head 15 is shown. In this case, the recesses 5a, 5b have a larger diameter than the shaft 13, so that the hot rivet 7 in assembly position play against the recesses 5a, 5b. In this embodiment, the end face 9 of the hot rivet 7 facing away from the head 15 is designed in the form of a point 16. For example, the hot rivet 7 is made of a low-carbon steel to ensure high toughness. The recess 5b in the spring carrier 44 is provided on its side facing away from the head 15 with a shoulder which increases the recess 5b on this side in a collecting area 23. The function of this catchment area 23 will be described below. The collecting area 23 is cylindrical in this exemplary embodiment. and can be described as a ring bag. The collecting area 23 can also have a different geometry.

3 additionally shows the annular carrier 43 to which the turbine 37 and the spring carrier 44 are to be permanently attached by means of the hot rivet 7. For this purpose, first of all the hot rivet 7 is inserted into the recesses 5a, 5b by means of a welding electrode, not shown here, with which the head 15 of the hot rivet 7 is firmly but detachably connected. This connection of the head 15 with the welding electrode is made for example by a negative pressure. Alternatively, the head 15 may be connected to the welding electrode by mechanical clamping. Alternatively, the recess 5a or 5b may be equipped with the hot rivets before, so that the position of turbine 37 is fixed to spring carrier 44.

Then the hot rivet 7 is welded with its end face 9 to the surface 10 of the carrier 43. This happens here, for example, by a resistance welding process. However, all electrical welding processes are suitable. Under the resistance welding process here in particular a projection welding method is used. For this purpose, the end face 9 of the hot rivet 7 is shaped accordingly as a tip 16. The welding is done by an electrical welding pulse. The pulse has in this embodiment on the order of magnitude of a length of 30-60 milliseconds, a customary at the frontal resistance welding of hot rivets 7 value. An alternative to electrical resistance welding is, for example, an arc-bolt welding method. However, this is less suitable here, since in this method the arc would jump over to the other side, which is undesirable. In Fig. 4, the permanent connection of the carrier 43 is shown with the turbine 37 and the spring carrier 44 after performing the next and last process step. In this step, the hot rivet 7 is plastically deformed. This plastic deformation is generated by applying a second electrical pulse, which follows the first welding pulse in a short time interval. This second low-current pulse is significantly longer than the first welding pulse. For example, it can be 1000 milliseconds. By the second pulse of the heated rivet 7 is heated and softened.

At the same time a force is exerted in the longitudinal direction 8 of the hot rivet 7, which leads to a plastic deformation in the form of a compression of the shaft 13 of the hot rivet 7. The compression force may have the same height as the welding force or lower or higher than this. This compression movement is performed until the head 15 of the hot rivet 7 at least partially rests with its underside 12 on the surface 11 of the turbine 37. The compressed during upsetting to the sides of the material of the shaft 13 fills the recesses 5a, 5b now partially in Umfangsriehtung completely. The resulting during welding of the end face 9 of the hot rivet 7 on the surface 10 of the support member 43 spatters and displaced in this collection area during compression material are received in the collecting area 23 of the recess 5b, so that both between the support 43 and the spring support 44, as well there is a clean, smooth contact surface between the spring carrier 44 and the turbine 37. The weld spatters can thus not reach the oil circuit of the hydrodynamic torque converter or, if necessary, the transmission as burnup. Characterized in that in this method, only between the hot rivet 7 and the carrier 43, a welded connection is made, it is possible to attach the spring carrier 44 and the turbine 37 to the carrier 43, which need not be weldable. For example, the spring carrier 44 and the turbine 37 components of aluminum, surface-coated steel - in particular nitrated -, ceramic or plastic - in particular fiber reinforced plastics - and composites of such components. Only the hot rivet 7 and the support member 43 must be made of a weldable material.

By virtue of the fact that the hot rivet 7 has play relative to the bore 5 before the method is carried out, the end face 9 of the hot rivet 7 can continue to be welded onto the carrier 43 without a short circuit even in the connection of electrically conductive materials for the carrier 43. since the welding current is passed only through the hot rivet 7 itself. The high electrical resistance required for welding occurs in each case between the end face 9 of the hot rivet 7 and the surface 10 of the carrier 43.

After performing the process, the hot rivet 7 shrinks due to the previous thermal deformation. In this way, there is an additional distortion of the compound, which has a high strength result.

Furthermore, the welding and the subsequent plastic deformation are carried out in one operation on a standard welding press, without additional Umrüst- or Umspann- measures are required. The hardening of the weld zone 30 possibly caused by the welding is reduced by the subsequent heating during the plastic deformation.

In addition to the above-described cylindrical geometry of the recess 5b, it is possible to provide a conical geometry, as shown in Fig. 5. A conical recess, for example, when using a casting as a spring carrier 44 or as a turbine 37 easier to produce than a cylindrical. The diameter of the recess increases with increasing distance from the carrier 43. The opening angle a can vary, in this example, it is approximately 01 = 25 °. It can be seen that the material displaced during the compression of the shaft 13 presses against the wall of the recesses in the spring carrier 44 and thus almost completely fills these recesses. Furthermore, in this embodiment, on the underside 98 of the head 15 of the hot rivet 7, a circumferential sealing ring 27 is formed. This sealing ring 27 is located after the upsetting operation on the surface 11 of the spring carrier 44 and seals the connection in addition. Alternatively, a similar circumferential sealing ring on the surface 11 of the spring carrier 44 may be provided, which then performs the same function.

In an alternative embodiment of the invention, the hot rivet is not attached by vacuum to the welding electrode. Furthermore, the hot rivet may also be magnetically or mechanically fastened to the welding electrode.

The recesses in the turbine 37 may be punched or drilled out.

In FIGS. 2 to 4, the recesses 5a, 5b are shown with an exaggerated diameter for better illustration shown. In practice, the bolt 13 has a very small clearance to the recesses 5a, 5b, so that a centering for the preceding welding is achieved. In order to create a receptacle for the material ejection between head and turbine during the hot riveting process at this low clearance, an embodiment according to FIG. 7 and FIG. 8 can be provided.

In this case, FIG. 7 and FIG. 8 show an annular groove 104 at the underside of the head in two method steps. This annular groove 104 receives said material discharge 105a, 105b when the turbine 37 is finish riveted. With this embodiment, in conjunction with a small radial clearance creates a very high radial tension between the pin 113 and the turbine 37 and the spring carrier 44. From the hot rivet 107 can be transmitted in addition to the non-positive connection and shear forces.

The collecting area 123 for receiving the welding spatter is configured differently, as shown in FIG. 2 to. Thus, the collecting area 123 according to FIG. 7 and FIG. 8 is a depression in the annular carrier 143. This depression can be designed as a flat blind hole. However, since the carrier 143 is a rotating part, the recess can also be designed as an annular groove, which is produced in one operation when the carrier 143 is rotated.

The described embodiments are only exemplary embodiments. A combination of the described features for different embodiments is also possible. Further, in particular not described features of the device parts belonging to the invention are to be taken from the geometries of the device parts shown in the drawings.

Claims

claims

1. Hydrodynamic torque converter with a against a coil spring force against the Getriebeeingangswellen- hub (51) rotatable support member (43) and at least one hot rivet (7) having a head (15) and a shaft

(13), wherein a turbine (37) by means of the hot rivet (7) with the support part (43) is riveted warm, wherein the head (15) is arranged on the side of the turbine (37).

2. Hydrodynamic torque converter according to claim 1, characterized in that the carrier part (43) indirectly via a spring carrier (44) on a coil spring (bow springs 47, 14) is supported, which by means of the hot rivet (7) between the turbine (37) and the support member (43) is braced.

3. Hydrodynamic torque converter according to claim 2, characterized in that the carrier part (43) is annular and is supported on the transmission input shaft hub (51).

4. Hydrodynamic torque converter according to claim 2 or 3, characterized in that the carrier part (43) is supported at least indirectly on a stator (38) via an axial roller bearing (72).

5. Hydrodynamic torque converter according to claim 1, characterized in that the carrier part is a spring carrier (44), which is supported on the coil spring (bow springs 47, 14).

6. A method for producing a hydrodynamic torque converter with a against a helical spring force against a transmission input shaft hub (51) rotatable support member

(43), wherein the hot rivet (7) comprises a head (15) and a shaft (13) and is inserted through a recess (5a) of a turbine (37) and with an end face (9) on the surface (10) of the Support member (43) is electrically welded and then plastically deformed, wherein the shaft (13) of the hot rivet (7), is compressed until the bottom (12, 98) of the head (15) partially on the surface (11) of the turbine (37).

7. The method according to claim 6, characterized in that the shaft (13) of the hot rivet (7) is heated by a after a short time interval after welding of the end face (9) applied second electrical pulse and simultaneously compressed.

8. The method according to claim 6 or 7, characterized in that for the welding a projection welding method is used.

9. The method according to any one of the claims 6 to 8, characterized in that the bolt (7) is introduced into the recess (5a) together with a welding electrode, with which it is firmly but detachably connected.

10. The method according to any one of claims 6 to 9, characterized in that the method is carried out on a welding press.

11. The method according to any one of the claims 6 to 10, characterized in that an indirect welding method is used.