WO2015007278A2

WO2015007278A2 - Advanced synchronization system for synchronization devices of motor vehicle variable speed transmissions

Info

Publication number: WO2015007278A2
Application number: PCT/DE2014/200244
Authority: WO
Inventors: Reiner Martin; Valerie Mandon
Original assignee: Schaeffler Technologies Gmbh & Co. Kg
Priority date: 2013-07-19
Filing date: 2014-06-04
Publication date: 2015-01-22
Also published as: WO2015007278A3; DE102014203523A1

Abstract

The invention relates to a pressure piece 11 for synchronization devices of motor vehicle variable speed transmissions. The aim of the invention is to modify the structure of previously known pressure pieces in favor of a simple and inexpensive production process without worsening the functional properties of the pressure piece. This is achieved in that the pressure piece 11 is designed as a hollow cylinder, whereby other intermediate products can be incorporated into the production process and advantageously allow a reduction of the moved mass for the synchronization process.

Description

Presynchronization system for synchronizers of

Motor vehicle gearboxes

description

The invention relates to a Vorsynchronisierungsssystenn for Vorsynchronisieren a synchronizer ring on a transmission part of a motor vehicle transmission, wherein the Vorsynchronisationssystem a pressurized by a spring pressure piece and the pressure piece is provided for locking in a latching recess of a shift sleeve of the Vorsynchronisationssystems. Furthermore, the invention relates to a motor vehicle change gear with such a Vorsynchronisationssystem.

Background of the invention

Plungers are used in synchronizers, in particular Vorsynchronisationssystemen, used to position the actual, directly involved in the synchronization components defined to each other and hold in position. To avoid drag losses, an axial movement of synchronizer rings in non-connected gears is usually prevented. If a certain gear, however, be switched, conical synchronizer rings must be pushed axially towards each other in a Vorsynchronisationsprozess that their friction surfaces can interact with each other. For this purpose, for example, pressure pieces are used, which can simultaneously cause a locking sleeve centering as locking elements. The sliding sleeve of these clutches is held on the shift sleeve carrier mostly in a neutral parking position by means of the locking element. In this position, three to four arranged on the circumference of the shift sleeve carrier and held on the shift sleeve carrier locking elements are biased against the shift sleeve. For this purpose, the locking elements are based on the switching sleeve carrier and engage in locking recesses on the sliding sleeve. Furthermore, locking elements in the form of pressure pieces are used in designed as a synchronizer clutch clutches.

With the increasing use of power assisted or automated manual transmissions, the use of relatively expensive locking elements is often no longer required. In their execution simpler, but robust and inexpensive to produce locking elements are increasingly in demand.

A locking element in the form of a pressure piece is described in DE 102 25 269 A1. A base body of the locking element made of sheet metal is formed shell-shaped with a transverse to the direction of pressure bottom and walls, wherein the base body is covered by a lid opposite in the pressure direction. The lid is held to the base body in the pressure direction along longitudinally movable movable on the base body, wherein the edge of the lid is slipped over the base body. A bow-like spring element is encapsulated by the main body and the lid and biased against this. The main body is supported on a switching sleeve carrier, wherein the spring element is biased against a seated on the shift sleeve carrier shift sleeve and locked in a detent recess. In a switching movement, the shift sleeve initially takes the pressure piece along in the direction of the gear wheel to be switched along, whereby the known synchronization process is initiated. Greater axial resistance to the locking element in further in the direction of the gear wheel longitudinally moving shift sleeve forces the spring element to spring out of the detent recess on the shift sleeve in the direction of the body. The spring element snaps back into the detent recess when the shift sleeve is returned to the neutral position. A disadvantage of the satisfactory solution in itself is that the locking element, in particular when this is used as a pressure piece, can tilt at obliquely introduced forces. By tilting the lid may cause jamming or entanglement between the shift sleeve carrier and the shift sleeve. Furthermore, it is necessary to further reduce the height of the locking element in order to achieve the highest possible stability of the shift sleeve carrier, and to keep the number of components as small as possible. Another locking element with a needle biased by corrugated springs or a solid cylinder is shown in DE 10 2007 062 464. The locking element is heavy, requires high spring forces and is elaborately constructed.

Object of the invention

The object of the invention is to provide a locking element and a motor vehicle change gear, which is robust and can be produced inexpensively without having to accept functional restrictions.

Background of the invention

This object is achieved in an article of the preamble of claim 1 by the features of the characterizing part of claim 1. Accordingly, the pressure piece in a Vorsynchronisationssystem of the type mentioned partially or completely as a hollow cylinder, in particular as a hollow roller formed. The resulting cavity significantly reduces the weight of the pressure piece and simplifies its production, especially as can be used in the production of intermediate products, such as pipes or standardized forming parts.

Alternatively, the pressure piece is referred to as Vorsynchronisationselement, wherein the cylindrical Vorsynchronisationselement has a roller and the role is partially or completely formed as a hollow cylinder, or the cylindrical Vorsynchronisationselement is partially or completely formed as a hollow cylinder. Again, mass is considerably reduced, and the role or the Vorsynchronisationselement, does not have to be made from the full machined, but can be cold forming formed. Further advantages arise when the roller diameter is reduced axially end and / or the roller is made of sheet steel. The pressure piece is acted upon by a spring with spring force and optionally has further elements. Further, the pressure piece is provided to secure a neutral switching position of the coupling element by a power transmission. Therefore, a wall of designed as a hollow cylinder pressure piece of the switching force to be transmitted is designed to be stable according to avoid plastic deformation of the pressure piece.

The pressure piece is provided for latching in a latching recess of a coupling element, such as the sliding sleeve. This defines a neutral setting position in which no gear is engaged. The pressure piece thus also forms a locking element or has the function of bringing about the locking of the coupling element.

The cavity of the hollow cylinder may be designed such that, structurally, the pressure piece is not subject to any plastic deformation which could prevent a defined engagement during operation. Due to the cavity, the stability of the pressure piece is not guaranteed solely by its material stability, as would be the case with a solid body, but partly also by a shape-related stability.

Advantageously, no components are required, which secure the pressure piece and the spring to each other, especially since both elements radially between a sleeve carrier and the coupling element, such as the shift sleeve, or the like can be held together radially. For this purpose, it is necessary to radially bias the spring by means of the pressure piece relative to the coupling element, so that a partially elastic relaxation of the spring occurs when the pressure piece engages in the latching recess.

Advantageously, the detent recess is integrated in an internal toothing of the coupling element. The internal toothing of the coupling element indirectly establishes torsional strength with the selector shaft via the sleeve carrier. The internal gear is further provided for axial movement in the direction of a synchronization partner, such as an axially adjacent synchronization ring or gear wheel. The spring is advantageously a leaf spring or, in particular, a spring which forms a hollow cylinder segment in the unloaded state, which ideally can be cut at a circumferential location.

Advantageously, the spring has a radial depression, in which the pressure piece is attached radially. Because of such a depression, it is possible to prevent the spring from migrating axially, provided that it is not or at least not completely axially guided or bordered by adjacent components, such as, for example, elements of the sleeve carrier.

In an advantageous embodiment, the pressure piece forms one, two or more cavities. In addition to the weight reduction, the separations of the cavities contribute to the dimensional stability of the hollow cylindrical pressure piece and thus also lead to an overall lower wall thickness of the pressure piece.

Advantageously, the one or the two or more cavities of the pressure piece is / are provided partially or completely with a filling. In this case, a filling may have a plurality of functions, such as ensuring a structural support of the hollow cylindrical shape of the pressure piece and / or an improvement in the rigidity thereof. In addition, it can be prevented that lubricant enters the respective cavity of the pressure piece and thus the total amount of lubricant required is disadvantageously increased. The filling is advantageously made of a low-cost plastic or a metal foam.

In any case, it makes sense to keep the weight of the filling low, so that in total less mass must be moved during a switching operation. Therefore, fillings, such as a metal foam or a plastic filling quite beneficial. In principle, in another advantageous embodiment, the cavity can be formed from a plurality of partial cavities, wherein the partial cavities are interconnected (metal foam) or not. In an advantageous embodiment, the pressure piece is designed as a bush and axially frontally with a bush bottom partially or completely closed. This makes it possible to use other standard components of the automotive industry as a pressure piece without significantly modify them. In addition, the bush bottom has a stabilizing effect and prevents jamming of the pressure piece. Due to the fact that the bush-shaped pressure piece can only be designed to be axially open on one side, it is particularly well suited to receive a filling during production, which is first injected in liquid form into the bush, in order to harden there.

In an advantageous embodiment, the pressure piece, which has the function of a latching element, designed as a circular cylinder. A circular-cylindrical design have, for example, pressure pieces which, as hollow rollers or in particular as hollow pins-in contrast to a cylinder with an elliptical base-have a non-variable inner or outer diameter. Their end faces are preferably radially outwardly rounded. The pressure piece is thus substantially tubular, wherein the wall thickness of the tube is determined by the acting locking forces. In this way, the pressure piece can advantageously be obtained from the intermediate tube, which is commercially available by default, which considerably shortens and simplifies the production of the presynchronization system.

In an advantageous embodiment, the pressure piece on the front side has a reduced diameter. The reduced diameter is smaller than an average diameter over the axial length of the pressure piece or against an average diameter in the axial center of the pressure piece. The reduced diameter at one or both axial ends of the hollow cylindrical pressure piece can lead to increased structural stability, which allows to further reduce the wall thickness of the pressure piece, and thus save material. In an advantageous embodiment, the reduced diameter is an inner diameter or an outer diameter. If the reduced diameter is an inner diameter, it is possible to precisely define an axial stop of the pressure piece. If the outside diameter is a reduced diameter, then the problem of jamming of the pressure piece during engagement or disengagement is significantly alleviated.

In an advantageous embodiment, the pressure piece is made of sheet metal, in particular sheet steel or plastic, in particular a thermoplastic or a thermosetting plastic. In sheet steel, the pressure piece can be easily manufactured as a formed part of sheet steel plates, which neither forging nor a machining is required or can be avoided for the most part. Plastics usually achieve a cost advantage and are also easy and inexpensive to use.

In an advantageous embodiment, the pressure piece on the front side on a radial outboard. The radial outboard may be a fixed board or a flanged board, wherein advantageously both the inner radius and the outer radius are reduced at the front side. It is possible to form flanged shelves on both sides, wherein their shape is executed only after the production of the main body of the pressure piece. Alternatively, one of the two radial outer rims can be a fixed board, which is formed during the production of the main body, for example during a stamping or pressing process.

Advantageously, the radial outboard improves the guiding properties of the thrust piece, which makes it easier for it to move radially in the sleeve carrier and to engage or disengage in the latching recess more easily.

The object is further achieved in the case of the aforementioned vehicle change gearbox in that a pressure element according to the invention is provided as a locking element in the change-speed vehicle transmission. In an advantageous embodiment of the motor vehicle exchange transmission, the transmission part is a gear wheel or a synchronizer ring of the motor vehicle change gear, wherein the synchronizer ring is provided in particular for Vorsynchronisierung a gear wheel. Thus, in a well-established manner, not only one, in particular conical, synchronization ring, but also other synchronization rings or sets thereof can be used for synchronization.

Advantageous developments and preferred embodiments are described and explained in the subclaims and the description of the figures.

Short description of the figures

Show it:

FIG. 1 shows a first pressure piece, which is formed as a hollow roller, in longitudinal section along the center axis, and

FIG. 2 shows a second pressure piece,

FIG. 3 shows a third pressure piece,

FIG. 4 shows a fourth pressure piece, and

FIG. 5 is a longitudinal section of a motor vehicle change gear with a locking device along a switching shaft.

Like reference numerals in different figures indicate the same component or element. Detailed description of the figures

FIG. 1 shows a trained as a hollow roller pressure piece 1 1 for a locking device of a motor vehicle transmission, which has axially frontally designed as a fixed board 12 Radialbord 12 which has a relation to the inner diameter D reduced inner diameter D1 and is also reduced in terms of its outer diameter D3. This reduction leads to a conical section which connects the cylindrical center piece 8 with the fixed board 12 of the pressure piece 1 1. This ensures that when locking or releasing the locking the pressure piece 1 1 does not jam. The same applies mutatis mutandis to the Bördelbord 9, which has been formed after the formation of the cylindrical central portion 8 subsequently axially from a cylindrical end piece by cold forming. The reduced inner diameter D2 is equal to the reduced inner diameter D1, thus essentially a symmetry is produced, which avoids a swapping of different ends in the installation by both sides of the same properties of the pressure pad 1 1 are prepared.

The starting material for the production of the pressure piece 1 1 may be a steel plate with a defined thickness or preferably tube material, which has from the outset a fixed inner diameter D, as it has the cylindrical central part 8 (still). Thus, a variety of manufacturing steps can be saved, which has an advantageous effect on the final price of the product.

FIG. 1, 2, 3 and 4 respectively show differently manufactured plungers which are used in a pre-synchronization system of a motor vehicle transmission, such as that shown in FIG. 1 shown Vorsynchronisationssystem, can be used. The pressure piece of FIG. 2 is made of a solid roller, which is axially provided on both sides with a respective bore, wherein the holes make the roll into a hollow cylinder with two unconnected cavities 27. The partition wall 28 separates the cavities 27 from each other and supports the dimensional stability of the pressure piece.

The pressure piece of FIG. 3 is made of a tube segment, which axially on both sides, radially outwardly has a chamfer to avoid jamming. The wall thickness is due to lack of formunterstützender elements against the pressure piece of FIG. 2 significantly larger.

The pressure piece of FIG. 4 is a sleeve with flange 30 and axially opposite to a final sleeve bottom 29. The single cavity 31 may for example be sprayed with a plastic to achieve high stability with low weight.

FIG. 5 shows the built-in pressure piece 1 1 of FIG. 1 with a spring 15, which is designed as an endless leaf spring, and the pressure piece 1 1 biases against the switching sleeve 10 designed as a coupling element 10. The shift sleeve 10 is in the locked state of the neutral setting position, especially since the pressure piece 1 1 rests in the locking recess 4 and determines the axial position of the shift sleeve 10. The spring 15 acts on the pressure piece 1 1 with a radial force, so that the pressure piece 1 1 remains in the locking recess 4, provided that no switching force is exerted on the shift sleeve 10.

Advantageously, the spring 15 and the pressure piece 1 1 can be held radially between the sliding sleeve 10 and the sleeve carrier 16 in position. In particular, it is not necessary to attach the pressure piece 1 1 to the spring 15 by means of a fastening element. The shift sleeve 10 is in a known manner with a transmission part, namely either the first synchronizer ring 13 or the second synchronizer ring 14, coupled via the shift teeth 20 and 19 gearing so that a Vorsynchronisierung with respect to the gear wheel 18 and the gear 17 is brought about. Advantageously, the detent recess 4 extends in the circumferential direction and thus forms a catch possibility for a plurality of possible further pressure pieces 1 1 on the outer circumference of the sleeve carrier 16, each biased with a further spring 15. A minimum number of pressure pieces 1 1 is certainly useful for a uniform locking, where depending on the application two, three or even four pressure pieces 1 1 can be used.

Advantageously, the locking recess 4 is integrated into the internal toothing 23 of the sliding sleeve 10, so that the locking recess 4 can be produced by a cutting turning operation, instead of individual depressions for circumferentially, preferably equidistantly, arranged pressure pieces 1 1 form.

The installation of the pressure piece 1 1, including the spring 15, is extremely simple, especially since the spring 15 and the pressure piece 1 1 only need to be correctly arranged and no whole assembly must be pre-installed.

In summary, the invention relates to a pressure piece 1 1 for synchronization devices of automotive exchanges. It is desirable to modify the structure of previously known plungers in favor of a simpler and less expensive manufacturing process without degrading the functional properties of the pressure piece. For this purpose, it is proposed to form the pressure piece 1 1 as a hollow cylinder, whereby other intermediates can be incorporated into the manufacturing process and advantageously a reduction of the moving mass for synchronization is made possible. LIST OF REFERENCE NUMBERS

gearing

shift shaft

latching depression

bending area

cavity

mid-axis

Cylindrical centerpiece

Cold-formed flange

shift sleeve

Pressure piece

Fixed board / Radial board

First synchronizer ring / transmission part

Second synchronizer ring / transmission part

feather

sleeve carrier

First gear / transmission part

Second gear / transmission part

locking teeth

shift gearing

internal gearing

Conical frictional contact

chamfer

Only cavity

Half a cavity

partition wall

bush base

flange rim

Only cavity

Claims

claims

1 . Presynchronization system for presynchronizing a synchronizer ring (14) on a transmission part (13, 14, 17, 18) of a motor vehicle change gear, wherein the Vorsynchronisationssystem a by means of a spring (15) acted upon, cylindrical pressure piece (1 1) and the cylindrical pressure piece (1 1) for latching in a latching recess (4) of a coupling element (10) of the Vorsynchronisationssystems is provided, characterized in that the pressure piece (1 1) partially or completely as a hollow cylinder, in particular as a hollow roller, is formed.

2. Vorsynchronisationssystem according to claim 1, characterized in that the pressure piece (1 1) one, two or more cavities (6, 26, 27, 31) is formed.

3. Vorsynchronisationssystem according to claim 2, characterized in that at least one, the two or more cavities (6, 26, 27, 31) of the pressure piece (1 1) is provided partially or completely with a filling / are.

4. Vorsynchronisationssystem according to any one of the preceding claims, characterized in that the pressure piece (1 1) is designed as a sleeve and axially frontally with a bush bottom (29) is partially or completely closed.

5. Vorsynchronisationssystem according to any one of the preceding claims, characterized in that the pressure piece (1 1) frontally a reduced diameter (D1, D2, D3).

6. Vorsynchronisationssystem according to claim 5, characterized in that the reduced diameter (D1, D2, D3) is an inner diameter (D1, D2) or an outer diameter (D3).

7. Vorsynchronisationssystenn according to any one of the preceding claims, characterized in that the pressure piece (1 1) of sheet metal, in particular sheet steel, or of plastic, in particular a thermoplastic or a thermosetting plastic is formed.

8. Vorsynchronisationssystem according to any one of the preceding claims, characterized in that the pressure piece (1 1) frontally a Radialaußenbord (9, 12).

9. Vorsynchronisationssystem according to claim 8, characterized in that the radial outboard (9, 12) is a fixed board (12) or a Bördelbord (9.30).

10. Motor vehicle change gear with a Vorsynchronisationssystem according to one of the preceding claims.