DE10354167B3 - Production of a metal locking sleeve for a manual transmission of a motor vehicle comprises cutting to length a tubular blank, increasing or reducing the diameter of the tubular blank along part of its length, and cutting a gate - Google Patents

Abstract

Production of a metal locking sleeve (1) comprises cutting to length a tubular blank from a metal pipe in the form of a pipe section, and increasing or reducing the diameter of the tubular blank along part of its axial length to create a sleeve-shaped basic element with a graduated diameter. The basic element is given its final geometric shape in at least one pressing process. A gate (16) is cut into the basic element to form the locking sleeve. Preferred Features: The gate is cut into the basic element using a laser- or water jet-cutting process.

Description

The The present invention relates to a process for the preparation of a metallic Rastierungshülse with a backdrop, especially for a manual transmission of a Motor vehicle, wherein the Rastierungshülse is part of a switching dome, the connection between the inner circuit of the gearbox and an associated one The gear selector forms, wherein the Rastierungshülse is produced from a starting blank by forming and cutting.

The Rastierungshülse with its backdrop serves within a gearshift to guide the lever, exactly the desired gear appeal. Here, the Rastierungshülse for a soft and exact switching behavior, for a precise zero position of the lever in the selection plane and for a return of the Gear lever from the reverse gear to take care of the zero position. For this reason, relatively high demands placed on the accuracy and durability of Rastierungshülse.

Out the relevant State of the art are several methods for producing a metallic Rastierungshülse known with a backdrop.

A first, from the DE 199 42 562 A1 known method provides that the Rastierungshülse is constructed in several parts and includes a sleeve, a disc and a cup part. The cup part is either made of at least two components and joined together via a parting line or it is made of a strip material, in which all the form elements are first formed and which is then rolled and joined together at the ends.

In a second, from the EP 0 974 777 A2 known method, the Rastierungshülse is made of two individually shaped sheet-half shells. The two prefabricated half-shells are welded together in a dividing plane.

From the DE 195 80 804 C1 It is known to form a Rastierungshülse at least in two parts, wherein a cup part, a bottom and a cylindrical part are joined together by joining methods. This bonding is preferably done by caulking, welding or soldering; the individual parts of the Rastierungshülse are here preferably prepared by extrusion, deep drawing or expansion.

When It is disadvantageous in all known methods that it on the finished Rastierungshülse to form inaccuracies and in particular paragraphs in the contour of the backdrop in the area of the weld comes. Every little paragraph in the scenery leads in the Practice to a disorder, in particular to a hooking movement of the gearshift, which is undesirable. Such inaccuracies of Rastierungshülse require rework or lead to a relatively high proportion of waste products in production.

For the present Invention is therefore the task of a method of the beginning to create said type which avoids the disadvantages set out and that the economical production of Rastierungshülsen with high accuracy and good functional properties Prevention of rework and rejects allowed in production.

• a) aus einem Metallrohr wird ein Ausgangsrohling in Form eines Rohrabschnitts abgelängt;
• b) der rohrförmige Ausgangsrohling wird über einen Teil seiner axialen Länge in seinem Durchmesser aufgeweitet oder eingezogen, wodurch ein hülsenförmiger, im Durchmesser gestufter Grundkörper gebildet wird,
• c) der Grundkörper wird durch wenigstens einen Pressvorgang in seine geometrische Endform gebracht und
• d) in den Grundkörper wird zur Bildung der Rastierungshülse die Kulisse eingeschnitten.

The solution of this object is achieved according to the invention with a method of the type mentioned, which is characterized by the following process steps:

• a) a starting blank in the form of a pipe section is cut from a metal tube;
• b) the tube-shaped starting blank is widened or drawn in its diameter over a part of its axial length, whereby a sleeve-shaped basic body stepped in the diameter is formed,
• c) the base body is brought by at least one pressing operation in its geometric final shape and
• d) in the body, the backdrop is cut to form the Rastierungshülse.

The inventive method has the significant advantage that no more welding connection must be made. This is achieved in that the method carries out the further transformations starting from a tubular starting blank. Since no more welding must be made, a complex operation can be omitted. In addition, so all inaccuracies are avoided, which occur as a result of the weld in the known methods. In particular, it is in principle excluded in the case of the invention that two edges of the component which have to be welded together have an offset from one another, which leads to edges or steps in the contour of the slide. The inventive method can therefore Rastierungshülsen produce with a very high accuracy, which was not achievable with the previously known methods. The Rastierungshülsen, which are produced by the process according to the invention, have very low tolerances, whereby post-processing and Committee be avoided. In addition, the seamless Rastierungshülsen produced by the process according to the invention are particularly stable and durable and can therefore expect a long trouble-free operation. In addition, a particularly accurate and at the same time soft switching of the gears of the associated gearbox is achieved with the Rastierungshülsen produced by the method according to the invention.

The execution the process steps are preferably carried out in the above and in Claim 1 sequence in chronological order; alternative can the steps c) and d) reversed in their temporal order without losing the advantages of the method according to the invention. There is also the possibility when using several pressing operations this partly in time before and partly after cutting to perform the scenery.

A preferred development of the method according to the invention proposes that a tubular Starting blank with an axial length that is more than twice as is great like the axial length of the basic body, is inserted, that the section of the starting blank, the. in its diameter is widened or fed in, a middle one Section of the starting blank and that after widening or Pulling in and after or before the pressing process or between two pressing operations of the Starting blank divided transversely to its axial direction in two main body becomes. The advantage of this embodiment of the method is in particular in that in each case two basic bodies produced in one operation can be what is particularly economical and at low production costs leads.

Further is preferably provided that the starting blank widened by hydroforming becomes. In this forming process by applying a hydraulic pressure inside the starting blank this radially outward widened, wherein the starting blank in a him outside surrounding mold is set. It is advantageous here that no solid tools are introduced into the interior of the starting blank have to, but that here a hydraulically acting liquid forms the tool. In order to Is available for On the blank of the starting blank no restrictions as a result of in the Practice relatively small dimensions of the starting blank and the Rastierungshülse, because the hydraulic fluid even at small diameters of the hollow interior of the starting blank can easily be initiated in these.

Around an overuse to avoid the material of the starting blank during its expansion, It is suggested that the starting blank in two successive the following forming steps to the main body is transformed.

In Another embodiment is preferably provided that between the two aforementioned Forming a heat treatment of the Starting blanks takes place. The heat treatment can cause stress be degraded within the starting blank, in the first forming step have arisen. After the heat treatment can then undergo further forming without the risk of overuse of the material. In this way are big changes in diameter of the starting blank possible. For example, the outer diameter of the starting blank after two forming steps by up to 100 greater as the starting diameter of the starting blank.

Around the wished Reduction of mechanical stresses within the starting blank after Safely reaching the first forming step is preferred heat treatment the starting blank a glow.

A alternative development of the method according to the invention proposes that a tubular Starting blank with an axial length that is greater than the axial length of the Body, is used and that the part of the axial length of the starting blank, the is widened or contracted in its diameter, an end portion of the starting blank. In this embodiment of the method In each case a base body is made from a starting blank, which Although less favorable from the economic point of view, but a lighter one Access to the interior of the starting blank allows. Others can do that too Forming process than the above-mentioned Hydroforming process can be used.

A sees preferred development of the method described above suggest that the starting blank be widened or included by spin forming becomes. Even with the forming by flow-forming can be large Umformraten realize economically.

For all embodiments of the method, as described so far, it is further preferably provided that the base body is brought to a defined axial length dimension after the pressing operation by trimming at at least one of its front ends. This ensures that the Rastierungshülse produced by the method receives an exact measure not only in terms of their different diameter ranges but also in terms of their axial length. The trimming is easily possible, as above is given, the base body is preferably made of a starting blank with an oversize in the axial direction. In practice, it is generally sufficient if the starting blank has a length oversize of about 1/10 to 1/3 of the desired axial length of the main body.

A Another development of the method suggests that the pressing process of the basic body is made in a two-part mold. Because of the engagement a two-part mold, this process step is easy and cost-effective held, which contributes to low manufacturing costs for the Rastierungshülse. there Preferably, this pressing also takes place by means of hydroforming, around the main body the desired to give geometric shape.

at Need can be after the pressing process of the basic body a geometry calibration operation done. This operation takes place especially when the pressing process is not yet to the desired exact geometry of the body guided Has.

Finally is still preferred according to the invention provided that the scenery by laser or water jet cutting is cut out. The laser or water jet cutting ensures for one very clean cut, creating a rework of the contour of the Scenery becomes unnecessary. With the mentioned cutting process is achieved a contour of the backdrop, which is very smooth and steady and in particular free of disturbing Stages or heels remain.

in the The following is an exemplary procedure based on a Drawing explained. The figures of the drawing show:

1 a starting blank after a widening of its middle section, in side view,

2 a body formed by pressing and dividing the starting blank in side view, partly in broken-away representation,

3 one by hammering a further contour and by cutting a backdrop in the body 2 formed finished Rastierungshülse, also in side view, partly in broken-away illustration, and

4 the finished Rastierungshülse in a perspective view.

In the process sequence shown by way of example in the drawing figures for producing a Rastierungshülse is used as starting blank 10 one of a metal tube, preferably steel pipe, cut to length pipe section used. This pipe section initially has a diameter which is the diameter of the two end regions 11 of in 1 visible starting blank 10 equivalent. This tubular starting blank 10 is made by a hydroforming process in its middle section 12 widened in diameter. For this purpose, a hydraulic fluid with high pressure in the interior of the starting blank 10 pressed in, whereby the wall of the starting blank 10 against during this forming the starting blank 10 surrounding, not shown here, appropriately designed mold is pressed ge. After this expansion process, the starting blank has 10 in the 1 in side view visible form with a widened middle hollow cylindrical section 12 and two hollow cylindrical end portions remaining in their original form 11 , Each end section 11 is with the middle section 12 each connected via an unnumbered conical transition section.

This starting blank 10 out 1 is formed in a further process step in a press, which is preferably in two parts, in its geometry. This pressing process is preferably carried out also in the hydroforming process. This gives in particular the section 12 with the larger diameter required for the function geometric contours of its wall.

In a further method step, the starting blank 10 along a plane perpendicular to the axial plane 13 , in the 1 is drawn, divided into two equal body.

One of the two basic bodies produced in this way 14 show the 2 in side view. In 2 is the viewer facing side of the wall of the section 12 With the larger diameter broken away, so that the view here in the interior of the main body 14 falls. In this section 12 are the previously generated contours 15 and 15 ' visible, noticeable.

If necessary, the main body 14 at one or both ends 17 . 17 ' circumcised. By trimming one or both ends 17 . 17 ' receives this body 14 in the axial direction a precisely defined length. Down in 2 lies the section 11 of the base body 14 with the smaller diameter and above it follows the section after a transitional section 12 of the basic body 14 with the larger diameter.

In the 3 illustrated finished Rastierungshülse 1 arises from the basic body 14 according to 2 through two further processing steps. In egg nem further forming process is a third contour 15 '' in the section 12 molded, preferably hammered. This contour 15 '' is the so-called "M" contour of Rastierungshülse 1 , which must be made as accurate as possible for a good function of the gearshift.

Next will, like 3 shows, in a final processing step in the body a backdrop 16 cut. The scenery 16 is preferably generated by laser or water jet cutting. As a result, a smooth and steady contour of the backdrop 16 the Rastierungshülse 1 achieved without further finishing.

4 finally shows the finished Rastierungshülse 1 in perspective view. Down in 4 lies the section 11 with the smaller diameter and with the down facing front side 17 ' , this section 11 serves to connect the Rastierungshülse 1 with a shift shaft, not shown here as part of the gearshift, in particular a motor vehicle.

At the top, the section closes 12 with the larger diameter. In this section 12 are the different contours 15 . 15 ' . 15 '' responsible for the function of the Rastierungshülse 1 needed, visible. At the viewer now facing side of the Rastierungshülse 1 is the backdrop 16 , which is here designed for a five-speed gearbox with reverse gear. At the scenery 16 opposite side of the section 12 with the larger diameter is still a round opening 16 ' , which also for the function of Rastierungshülse 1 is needed and which is preferably also made by laser or water jet cutting.

As the procedure explained above shows, the production of the Rastierungshülse 1 absolutely free of welding seams possible.

Claims (12)

Method for producing a metallic detent sleeve ( 1 ) with a backdrop ( 16 ), in particular for a manual transmission of a motor vehicle, wherein the Rastierungshülse ( 1 ) Is part of a switching dome, which forms the connection between the inner circuit of the gearbox and an associated Gangwählhebel, wherein the Rastierungshülse ( 1 ) from a starting blank ( 10 ) is produced by forming and cutting, characterized by the following method steps: a) from a metal tube is a starting blank ( 10 ) cut to length in the form of a pipe section, b) the tubular starting blank ( 10 ) is widened or retracted over part of its axial length in its diameter, whereby a sleeve-shaped, stepped in diameter body ( 14 ), c) the basic body ( 14 ) is brought into its geometric final shape by at least one pressing operation and d) in the basic body ( 14 ) is used to form the Rastierungshülse ( 1 ) the scenery ( 16 ). Method according to claim 1, characterized in that a tubular starting blank ( 10 ) having an axial length which is more than twice the axial length of the main body ( 14 ), that section ( 12 ) of the starting blank ( 10 ), which is widened or contracted in its diameter, a middle section of the exit blank ( 10 ) and that after the expansion or retraction and after or before the pressing operation or between two pressing operations, the starting blank ( 10 ) transversely to its axial direction into two basic bodies ( 14 ), is shared. Method according to claim 1 or 2, characterized in that the starting blank ( 10 ) is widened by hydroforming. Method according to claim 3, characterized in that the starting blank ( 10 ) in two successive forming steps to the main body ( 14 ) is transformed. A method according to claim 4, characterized in that between the two forming steps, a heat treatment of the starting blank ( 10 ) he follows. A method according to claim 5, characterized in that the heat treatment of the starting blank ( 10 ) is a glow. Method according to claim 1, characterized in that a tubular starting blank ( 10 ) having an axial length which is greater than the axial length of the main body ( 14 ), and that the part of the axial length of the starting blank ( 10 ) which is expanded or contracted in its diameter, an end portion of the starting blank ( 10 ). Method according to claim 7, characterized in that the starting blank ( 10 ) is expanded or retracted by spin forming. Method according to one of the preceding claims, characterized in that the basic body ( 14 ) after the pressing process by trimming on at least one of its front ends ( 17 . 17 ' ) is brought to a defined axial length dimension. Method according to one of the preceding Claims, characterized in that the pressing process of the basic body ( 14 ) is made in a two-part mold. A method according to claim 10, characterized in that after the pressing operation of the base body ( 14 ) a geometry calibration operation is performed. Method according to one of the preceding claims, characterized in that the scenery ( 16 ) is cut out by laser or water jet cutting.