DE10122184A1 - To shape tooth structures, in a row of teeth, the shaping is by plastic distortion of the tooth material, and the displaced material is taken up by a prepared opening - Google Patents

Abstract

To shape at least a section (8) of at least one tooth (3), in a row of teeth (1), the shaping is by plastic distortion of the tooth material to reduce the shaped section. At least one opening (14) is formed in the teeth structure, with a volume at least equal to the amount of material displaced from the shaped tooth. The displaced material from the shaped tooth is taken up by the opening, so that it is wholly or partially filled by it.

Description

Field of the Invention

The invention relates to a method for forming at least one section at least one tooth of a toothing by means of plastic deformation of Material of the tooth, as well as a tooth made with this method voltage.

Background of the Invention

On gears where the tooth cross-section on individual or all Teeth are reduced in certain areas of these teeth, these re Reduction of the cross-section by cutting or non-cutting through forming generated. Such reductions in the cross-section are machined on the otherwise finished gearing z. B. introduced by milling. At the Processes such as rolling / back rolling or embossing / pressing are used looking. After such operations are then from the tip circle Toothed outgoing pockets / grooves extending radially into the tooth  or flank constrictions on the teeth. This over the tooth wide partial reductions in tooth height or tooth thickness are often referred to as undercuts. Is known for. B. that the tooth flanks of a radially inward-facing toothing on switching must be undercut a synchronized switching unit. Through the Undercuts is the tooth thickness of the tooth at one (several) limited Section (s) of the width of the tooth reduced. This is where the undercut serves as a lock against unwanted axial detachment from the axially one another the shifted teeth of the sliding sleeve and the ge gear wheel hearing clutch teeth.

Shift sleeves are usually located along the central axis of the shift unit can be pushed on switch sleeve supports. They reach along the central axis of the Gear unit aligned and radially inward facing teeth in one Toothing with radially outward teeth of the switch sleeve gers. On individual teeth of these teeth of the gearshift sleeves and / or Shift sleeve carriers are often grooves radially into the teeth from the outside brought. These grooves extend along the width of the tooth on one limited section. Through these grooves, the tooth height is in the affected section (s) reduced. Locked in these grooves z. B. a Rastele ment, which the shift sleeve in a non-shifted neutral position holds the shift sleeve carrier in position and, if necessary, also the shift sleeve against a premature postponement prevents. Through the described grooves or through other undercuts is the cross section of the tooth on one (several) limited section (s) of the width of the tooth reduced. This also come Sections on the teeth in which both the tooth height and the Tooth thickness on one and the same cross-section compared to the basic cross cut of the tooth are reduced.

The cutting reduction of the basic cross section on teeth one otherwise shaped gearing is complex and expensive. Therefore be Undercuts are often produced without cutting. The material of the teeth becomes plas table deformed and physically to create space for, for example  displaced a groove. The material flows to the edges Tooth flanks into the tooth gaps between the teeth or out of the tooth flanks displaced towards the tooth head. There it forms a throw out of the displaced material. The production of such a toothing is by reworking these poses in a rework also costly.

In a few cases, this can cause the tooth to form another functional element remain. One of these cases is in DE 199 32 300 A1 described. The interlocking of a gearshift sleeve indicates some Teeth on their teeth recesses. These recesses are with generated by plastic material displacement. The tooth height in this Ab cut of the tooth is reduced. The displaced material protrudes specifically the tooth gaps delimiting the affected tooth. When postponed the shift sleeve on the shift sleeve carrier forms a lock ge against insertion of an outward tooth of the gearshift sleeve carrier in the tooth gap. The shift sleeve can therefore only be used directionally or be positioned in a position-oriented manner on the shift sleeve carrier.

In practice, however, the aforementioned application is less common than that Applications in which the throw-up of the material for the functioning of the Switching device must be eliminated.

Summary of the invention

The object of the invention is therefore to provide a method for forming an Ab Cut a tooth on a toothing by means of plastic deformation of creating material of the tooth with which the emergence of an annoying Is prevented. Furthermore, it is an object of the invention with an egg nem such process to create gearing that is easy and can be produced inexpensively.  

This object is achieved according to the characterizing part of the claim by a method with the following manufacturing steps:

• 1. Make at least one hole in the toothing.
• 2. Forming the section by means of plastic deformation of material.
• 3. Displacing the material that has flowed out of the section with the deformation than in the hole.

The hole is made in the toothing, for example, by punching, the individual teeth of the toothing essentially manufacture theirs Have basic cross-section. The undercut (s), for example slanted tooth flanks or locking grooves for locking locking elements but also undercut-free molding on teeth is possible with plasti shear deformation of material shaped by molding tools. undercut free formations arise, for example, when calibrating the basic contour of the tooth and the formation of bevels on roof gears. The shape tools are formed by stamps or dies. That displaced Material or displaced material from calibrations, for example the Overall shape of the tooth, does not interfere with the contours of the finished Tooth because the material is displaced into the hole. The free volume one or more of those in the flow zone of the plastically deforming Holes lying in the material provide a space in which the repressed Ma can dodge material. The flowing material is targeted by the Contour of the stamp and / or a die or by the interaction both molding tools steered into the hole (s). The material gives way also due to lower forming resistances in the holes, since the Structure of the toothing in the perforated area is weakened. From the for the grooves or undercuts exposed material is displaced not as a nuisance. Cutting or other rework is therefore not applicable. An additional advantage with the introduction of holes results itself through the decrease in the resistance of the relatively massive structures a toothing against plastic deformation if there are holes in this structure are introduced. The material structure can be made by means of targeted holes  "Loosened up" around the forming process due to reduced forming forces facilitate.

The holes are preferably in the toothing by punching before or after the shaping of the basic shape of the teeth or in the process of shaping integ introduced. The number of holes per section and / or tooth and their The shape can be freely selected according to the requirements. They are circular designed holes can be used as well as elongated holes.

The invention is preferred for forming teeth on teeth seen on a ring, an annular element or on a hollow body or formed on an annular portion of a hollow body are. The toothing is directed inwards or outwards or on the face formed on a disc-shaped body. A variant of a gear tion with at least one tooth machined according to the invention is on one Ring formed in its initial state as a with a profile of Toothed sheet metal strip is present. The bent En those of the circularly bent sheet metal strip with the tooth profile are one against the other the attached. The undercut in one or more teeth is with the Process either on the stretched sheet metal strip or in the annular toothing introduced.

An embodiment of the method according to the invention provides for molding a section with a reduced tooth height that the material at Forming the section flows freely to at least one flank of the tooth. to finally the material is connected to at least one by means of a molding tool displaced hole on the tooth flank side. The molding tool covers at least the section and has the nega on the section tive shape of the finished tooth with the reduced cross-section. As a form tools are preferred punches or dies, also interacting, used. A recess, the depth of the tooth height at an Ab cut of the tooth is reduced, for example by means of a stamp in egg generated in the first process step. The stamp moves onto the head of the tooth  and displaces material in the area of the section. The stamp creates a recess with the same or along the section varying depth. The recess is made in the tooth so that flan No material remains on the opposite side of the cleared space on the tooth. The material that is displaced when the section is formed follows this procedure step freely into the tooth gap defining the tooth. In the subsequent process step, displacing the material into the hole, will be the single tooth or all the teeth involved in the gearing pressed together, for example, in a die or with a stamp loaded. Due to the inner contour of the die or the contour of the stamp the negative contour of the finished tooth at least in the area of the deformed Reproduced section. The matrix is after displacing the open thrown into the hole with the material of the finished tooth molded on it Section completely filled out.

It is further developed for the aforementioned method steps in the toothing at least one hole on each side of the affected tooth introduced. The material flows freely in proportion to both when the section is formed Flanks and forms a face there. Displace the die or stamp the material then partially into the holes. Another shape tion with regard to the aforementioned configurations provides that the Ma material during shaping minus a portion remaining on the tooth Flanks is displaced. This share is then together with the Thrown up with a matrix or a stamp in at least one of the holes repressed. The depth of the recess or groove is, for example, one Form stamp when forming the recess is not initially complete formed. There is so much material on the tooth that the recess 1/10 to 6/10 millimeters, but preferably 0.2 mm in depth were missing. This after the first molding of the section is remaining portion of the material in a subsequent process step together with the throw in the or ousted the holes.  

Another embodiment of the invention provides for the formation of an Ab cut with a reduced tooth height that a molding tool Tooth when molding the section covers at least the section where at the inner contour of the mold on the section through the negative shape of the tooth in its basic cross-section, i.e. without the reduced cross cut, is described. It is also envisaged that the section by means of at least one further molding tool is formed, the further Molding tool when molding the material into itself from the top of the circle Toothed outgoing and radially inwardly extending into the tooth Hole displaced. A molding tool, for example a die, sits on the tooth to be machined. The die points at least in the section where the basic cross section of the tooth is to be reduced, the negative form of the tooth in its basic cross section. The matrix is through the Basic cross-section of the tooth completely filled. The tooth is on this Date not yet finished, since he reduced the section or sections Cross section not yet available. A stamp inserted into the die forms the section. At the same time, the material for the franking is flowing displaced into the holes by the interaction of stamp and die. After this processing step, the die is no longer on the section completely filled in by the material of the finished tooth. The share of to form the section of displaced material is poured into the hole chen. The tooth now shows the reduced one on the machined section Cross section on. The hole or holes in the tooth and are preferred arranged on the section. The flowing material has only short distances put back to fill the hole. That or the holes are again preferably starting from the tip circle of the toothing in the depth of the tooth nes continuously introduced in the direction of the tooth base.

The invention also provides a product produced by the method according to the invention. The product is geared with the following features:

• The teeth have at least one or more teeth, the cross section of at least a limited portion is reduced by shapes.
• - The section is made from plastic material Tooth shaped, the tooth thickness and / or preferably the Tooth height by moving material from the tooth to the Section is reduced.
• - The toothing has at least one hole in the flow area of the moved material.
• - The hole is at least partially filled with material, whereby at least some sections of the wall of the hole inwards the hole has collapsed and the free cross section of the hole thus constricted or ver by the displaced material is closed.

Preferred configurations then also provide that at least one tooth gap adjoining the tooth on the flank side has the hole or that the hole is formed in the tooth. If the hole in the tooth is out the hole is preferably formed on the machined section, again preferably the hole at least over the section the entire reduced tooth height extends through the tooth.

Finally, it is provided that the toothing on a gearshift sleeve synchronized switching unit of a change gear is formed. A such teeth provided with the features of the invention can for example, but also be formed on a shift sleeve carrier.

Brief description of the drawings

The invention is described below using several exemplary embodiments explained in more detail. Show it

Fig. 1 shows an embodiment of a detail of a processed with the inventive method toothing,

Fig. 2 is a longitudinal section through the gearing of FIG. 1 along the line II-II,

Fig. 3 shows the cross-section of the tooth of FIG. 1 taken along the line III-III,

Fig. 4 shows the detail Z from FIG. 3 in an enlarged representation,

Fig. 5 shows the section of the toothing with its the basic cross section having teeth in Fig. 1 before Bear processing with the inventive method,

Fig. 6 shows a cross section through the tooth of FIG. 5 ent long line VI-VI,

Fig. 7 shows the detail of the tooth of FIG. 1 with a tooth comprising a molded portion,

Fig. 8 is a cross-section of the cutout of the toothing, ge cut along the line VIII-VIII of Fig. 7,

Fig. 9 shows the cross section of the detail of the gearing according to FIG. 1, after the displacement of the material in holes

Fig. 10 shows a further embodiment of the method to the invention OF INVENTION machined portion of a tooth system,

Fig. 11 is a longitudinal section through the gearing of FIG. 10 along line XI-XI,

Fig. 12 shows the cross-section of a finished tooth of the tooth of FIG. 10 taken along line XII-XII after processing with the inventive method,

Fig. 13 shows the cross section of the tooth of Fig. 12 before its Bear processing with the inventive method and

Fig. 14 shows the cross section of the tooth of FIG. 12 during processing with the method.

Detailed description of the drawings

Figs. 1 to 3 show a section of a tooth 1 invention produced by a method according to. The toothing 1 is provided with teeth 2 and teeth 3 . The teeth 2 and 3 have at their longitudinal En 2 a or 3 a roof slopes 4 of a roof toothing. The teeth 3 , of which only one is illustrated, are provided with a locking groove 5 for a handle of a locking element, not shown, of a Synchronisierein unit. As can be seen from Fig. 3, the toothing 1 is formed on a sliding sleeve of the synchronizing unit. Rings 6 sit on the outer jacket of the ring-shaped toothing 1 . The rings 6 and the outer jacket of the toothing 1 limit an annular groove 7 for engaging egg ner shift fork, not shown.

The locking groove 5 is introduced into a section 8 that extends along the width of the tooth 3 by machining with a method according to the invention. For this purpose, section 8 is processed by forming. The locking groove 5 is formed from the section 8 of the tooth 3 by plastic displacement of material 13 ( FIG. 4). Compared to the basic cross section 9 of the teeth 2 and 3 , the cross section 10 on the tooth 3 is reduced. The depth 12 ( FIG. 3) of the locking groove 5 starting from the tip circle 11 varies in this example over the length of the section 8 .

The material 13 is partially displaced into both sides of the tooth 3 by means of punched elongated holes 14 . The elongated holes 14 extend from the Bo of the tooth gaps 15 and 16 starting through the wall of the toothing 1 to the outside.

FIG. 4 shows a not to scale and enlarged representation of the detail Z of one of the elongated holes 14 shown in FIG. 3. The walls of the elongated hole 14 have collapsed due to the mass of the material 13 which is plastically displaced into the hole 14 . The slot 14 is almost completely filled out and closed by the material 13 .

. In Fig. 5 and Fig 6, the tooth 1 after processing by the first process step, - punching - prepared according to the method according to the invention. The tooth 3 , like the teeth 2, has the basic cross section 9 without the reduced cross section. The elongated holes 14 are made on both sides of the tooth 3 in the base of the tooth gaps 15 and 16 . The provided by the Langlö cher 14 free volume is greater than the largest possible volume of the material 13 displaced for forming the locking groove 5 (according to FIG. 4).

Figs. 7 and 8 show the tooth 1 after processing by the method step - forms the portion -. In this process step, a stamp (not shown) is placed on the head of tooth 3 on tip circle 11 and material is moved by means of the stamp. In the associated plastic deformation of the tooth tip at section 8 , part of the material to be displaced flows proportionately on both sides over the flanges of tooth 3 and remains there as a throw-up 17 . A portion 18 of the material to be displaced to form the locking groove 5 remains undeformed on the tooth 3 .

In FIG. 9, the end position of another punch 19 after the completion of the process step is - displacing the material in the holes - illustrated. The stamp 19 has the negative shape of the tooth 13 and its adjacent areas. The material 13 , which is composed of the material portions of the throws 17 and the portion 18 , has been displaced into the holes 14 and partially closes the holes 14 , as is shown by way of example in FIG. 4. The tooth 3 is provided with the finished locking groove 5 .

The Figs. 10 and 11 show a further embodiment of a section from a tooth. The toothing 20 has teeth 21 and 22 which are undercut on their flanks and beveled at their ends. The teeth 22 , only one of which is illustrated, are also each provided with a locking recess 23 . The locking recess 23 is formed on a section 24 which extends along the tooth width. With the Rastver recess 23 , the cross section of the tooth 22 on the portion 24 is reduced, as can be seen from FIGS. 11 and 12.

The locking recess 23 was generated by machining steps of the method according to the invention. In a first step - punching - a hole 25 was made in tooth 22 . As can be seen from FIG. 13, the hole 25 is introduced into the tooth 22 from the head of the tooth 22 , the tooth 22 still having its basic cross section over the entire tooth width.

In the next step of the method - forming the section - a die 26 , encompassing the tooth 22 , and a stamp 27 are placed on the head of the tooth 22 . The stamp 27 forms the locking recess 23 on the section 24 ( FIG. 14). The material 28 displaced plastically for this purpose escapes into the hole 25 . The walls of the hole 25 thereby partially fall inwards. The hole 25 is at least partially filled by the material 28 . In this example, the procedural steps - forms of the section - and - displacement of the material - run seamlessly within one processing step. As can be seen from FIG. 11, the cross section of the locking recess 23 varies along the section 24 . It can also be seen that the toothing 20 is formed on a sliding sleeve of a synchronizing unit. Rings 29 sit on the outer jacket of the ring-shaped toothing 20 . The rings 29 and the outer casing of the toothing 20 limit an annular groove 30 for the engagement of a shift fork, not shown.

reference numeral

1

gearing

2

tooth

2

a end

3

tooth

3

a end

4

sloping roof

5

locking notch

6

ring

7

ring groove

8th

section

9

Basic cross section

10

cross-section

11

tip circle

12

depth

13

material

14

Long hole

15

gap

16

gap

17

recast

18

proportion of

19

stamp

20

gearing

21

tooth

22

tooth

23

latching depression

24

section

25

hole

26

die

27

stamp

28

material

29

ring

30

ring groove

Claims (12)

1. A method for shaping at least one section ( 8 , 24 ) of at least one tooth ( 3 , 22 ) of a toothing ( 1 , 20 ) by means of plastic molding of material of the tooth ( 3 , 22 ), the cross section of the tooth ( 3 , 22 ) on the section ( 8 , 24 ) after molding, characterized by the following steps:

• - Introducing at least one hole ( 14 , 25 ) into the toothing ( 1 , 20 ), the volume claimed by the hole ( 14 , 25 ) at least the volume of the material to be displaced from the tooth ( 3 , 22 ) ( 13 , 28 ) and wherein the hole ( 14 , 25 ) can be reached through the material ( 13 , 28 ) displaced during molding,
• - shapes of the section ( 8 , 24 ),
• - Displacing the material ( 13 , 28 ) in the hole ( 14 , 25 ).

2. The method according to claim 1, for forming a section ( 8 ) with a reduced tooth height, characterized in that the material is freely moved to at least one flank of the tooth ( 3 ) during the molding of the section ( 8 ) and then the Material is displaced by means of at least one molding tool in at least one hole ( 14 ) arranged on the tooth ( 3 ) on the flank side, the molding tool covering at least the section ( 8 ) and the molding tool on the section ( 8 ) due to the negative shape of the finished tooth nes ( 3 ) with the reduced cross-section is described. 3. The method according to claim 2, characterized in that for each flank of the tooth ( 3 ) in a tooth gap ( 15 , 16 ) in each case at least one hole ( 14 ) is made and that the material ( 13 ) is freely shifted proportionally to both flanks and is then partially displaced by the molding tool into the holes ( 14 ). 4. The method according to claim 2, characterized in that the mate rial during molding minus a tooth ( 3 ) remaining portion ( 18 ) is shifted to the flanks and the portion ( 18 ) then with the molding tool in at least one of the holes ( 14 ) is displaced. 5. The method according to claim 4, characterized in that the portion ( 18 ) is formed by material from 0.1 to 0.6 mm of the tooth height. 6. The method according to claim 1 for forming a section ( 24 ) with a reduced tooth height, characterized in that at least one molding tool covers the tooth ( 22 ) from outside when forming the section ( 24 ) at least on the section ( 24 ), wherein the inner contour of the molding tool on the section ( 24 ) is described by the negative shape of the basic cross section of the tooth ( 22 ) without the reduced cross section and that the section ( 24 ) is formed by means of at least one stamp ( 27 ), the stamp ( 27 ) during molding, the material is displaced into a hole ( 25 ) extending from the tip circle of the toothing ( 20 ) and extending radially inward into the tooth ( 22 ). 7. gearing ( 1 , 20 ) with at least one tooth ( 3 , 22 ) which has at least at least one section ( 8 , 24 ) a reduced cross-section, where the reduced cross-section is made in a method according to claim 1 ago, thereby characterized in that the toothing ( 1 , 20 ) we at least one hole ( 14 , 25 ), wherein the hole ( 14 , 25 ) is at least partially filled by the displaced material ( 13 , 28 ). 8. A toothing according to claim 7, characterized in that at least one tooth gap ( 15 , 16 ) adjoining the tooth ( 3 ) on the flank side has the hole ( 14 ). 9. Toothing according to claim 7, characterized in that the hole ( 25 ) is formed in the tooth ( 22 ). 10. Toothing according to claim 7, characterized in that the hole ( 25 ) is formed in the tooth ( 22 ) and on the section ( 24 ). 11. Tooth according to claim 7, for a tooth ( 22 ) with a reduced tooth height on the section ( 24 ), characterized in that the hole ( 25 ) on the section ( 24 ) at least over the entire reduced tooth height through the tooth ( 22 ) extends. 12. A toothing according to claim 7, characterized in that the toothing ( 20 ) is formed on a shift sleeve of a synchronized switching unit of a change gear.