EP3828368A1 - Method for fabrication of a vehicle lock - Google Patents

Abstract

The invention relates to a method for producing a motor vehicle locking device, in particular a motor vehicle lock, with at least one metallic base element (1) and a closing element (2, 3, 4). According to the invention, the base element (1) and / or the closing element (2, 3, 4) is subsequently reinforced at least locally after its shaping process.

Description

The invention relates to a method for producing a motor vehicle locking device, in particular a motor vehicle lock, with at least one metallic base element and a locking element.

The motor vehicle locking device mentioned above is generally a motor vehicle lock, i.e. a motor vehicle door lock, a motor vehicle tailgate lock, a motor vehicle front hood lock, a motor vehicle fuel filler flap lock, etc. Basically, however, this also includes a backrest lock in connection with a motor vehicle seat , a lock for a motor vehicle flap, etc. The term motor vehicle locking device is therefore to be interpreted broadly in the present case.

Motor vehicle door locks in particular are exposed to considerable attacking forces in the event of an accident or crash situations. These must generally be picked up by the motor vehicle locking device or the motor vehicle door lock in the example case and introduced into the motor vehicle body in order to prevent unintentional opening of an associated motor vehicle door in such a case. For this reason, safety-relevant components such as, in particular, the metallic base element and also the at least one metallic closing element are solid and often made of steel. Because tearing forces equivalent of up to three and a half tons and more must be absorbed at this point.

For this reason, in such a motor vehicle door lock, the lock case or a lock plate are typically used as the base element, as are a rotary latch and at least one pawl as the closing elements made of solid steel. In addition, additional components are often used to improve power transmission.

So is by the generic DE 10 2009 029 025 A1 a lock with a lock case is known in which a locking mechanism made up of a rotary latch and pawl additionally comprises at least one means for transmitting power to the lock case. The means in question is a bolt made of plastic or steel, which also controls a rotary latch query. The bolt represents a stop for the rotary latch, which limits the rotary movement of the rotary latch starting from an open position beyond the main detent position. As a result, the known motor vehicle lock should also be able to withstand sudden shock loads reliably.

The state of the art offers room for improvement. So the bolt additionally provided in the generic state of the art must be manufactured and installed. In addition, such additional elements pose the risk that the safe functioning of the motor vehicle locking device is impaired in extreme situations. In addition, the load on such motor vehicle locking devices is currently increasing. This can essentially be traced back to two aspects. First of all, the weight of automobiles has been increasing for years. In addition, the achievable speeds also increase, so that on the whole one can expect increased forces acting on the motor vehicle locking device, especially in the event of a crash. The invention aims to provide a remedy here overall.

The invention is based on the technical problem of further developing such a method for producing a motor vehicle locking device in such a way that the loads that can be absorbed can be increased in a simple manner without deformations which are problematic in terms of security.
To solve this technical problem, a generic method for producing a motor vehicle locking device is within the scope of Invention characterized in that the base element and / or the closing element is subsequently reinforced at least locally after its shaping process.

According to the invention, the base element or the closing element is reinforced after its shaping process. That is, first of all, the base element or the closing element is usually punched out of, for example, a metal plate or steel plate, if necessary reshaped and deep-drawn, before it is equipped with the at least local reinforcement according to the invention. In other words, the additional local reinforcement provided according to the invention does not change anything (any more) in the basic shape of the base element or closing element. This has the twofold advantage that at this point conventional and proven shaping processes such as the previously mentioned cutting, punching, deep drawing, forming, etc. can be used and this process is retained. This makes it possible to dispense with a large-area reinforcement, which under certain circumstances is weakened by a subsequent deformation process or may not allow deformation at all. Rather, the invention provides only local amplification. In principle, of course, a reinforcement covering the entire surface of the respective element can also be carried out after the shaping process.

However, it is preferred to work only with local reinforcements in order to keep the associated costs low and also to actually only reinforce the element in question locally where such reinforcement is required, as will be explained in more detail below in the description. The local reinforcement of the element can preferably take place intrinsically and / or extrinsically. An intrinsic reinforcement of the element is to be understood as one in which the internal properties of the metal element in question are at least locally influenced by the reinforcement process in such a way that subsequent reinforcement is observed.

The invention generally understands this to mean increasing the tensile strength (R _m, measured in N / mm ² ) of the element in question and / or its hardness (Vickers hardness). Both of the aforementioned physical properties can be intrinsically changed or increased in that the microstructure inside the metal undergoes a change.

In most cases, the procedure (with the intrinsic reinforcement of the element) is such that the respective element undergoes a combined heat treatment, which is made up of the individual steps of "hardening", "quenching" and, if necessary, "tempering". During hardening, the element in question is quickly heated up with a temperature gradient above 4K / min above the so-called austenitizing temperature. The element in question is then quenched, i.e. subjected to rapid cooling in the heated state. This is done using deterrents such as water, oil or air. Thereby gradients of deterrence in the range of more than 100 K / sec. set, so that the result is usually a hard structure of martensite, bainite or a mixture subsequently.

At this point you can also temper the element in which the associated workpiece is tempered after quenching at approx. 100 ° C or even more, i.e. a heat treatment at temperatures below the so-called transformation point (approx. 700 ° for steel approx C) is subjected. This allows internal stresses in the structure to be reduced. Usually, so-called tempering temperatures between 200 ° C and 500 ° C to 600 ° C are used, taking into account a tempering time between minutes and one or more hours.

In other words, the respective element and / or the reinforcement part is subjected in this context to a combined hardening and, if necessary, subsequent tempering process. This is generally done through a Compensation in which the element in question is subjected to the previously mentioned process steps "hardening", "quenching" and, if necessary, "tempering" with the parameters given above. Suitable materials for such an intrinsic treatment of the element in question are, for example, heat-treatable steels, that is, steels that are suitable for heat-treatment, as specified in detail by the DIN standard DIN EN 10083. In principle, heat-treatable non-ferrous metals or non-ferrous alloys such as titanium alloys can also be used as materials at this point.

In this context, it has also been found to be particularly preferred if the respective element and / or the reinforcement part is tempered to such an extent that its tensile strength (R _m ) and / or Vickers hardness (HV) increases to at least twice compared to the non-tempered state. In order to realize and implement this in detail, comparative tests are generally carried out by examining the respective element in the non-tempered state after its shaping process, for example with regard to the achievable tensile strength, and comparing it with the state after the tempering. In this respect, reference is made to DIN EN 10083, which was previously referred to.

As an alternative or in addition to the intrinsic local reinforcement of the element in question described in detail above, an extrinsic local reinforcement is also possible. In this case, the respective element is equipped with at least one reinforcement part welded on or welded on. Typically, the reinforcement part can be a reinforcement disk, which is mostly placed in the area of a recess.
Conventional welding methods can be used to achieve the local intrinsic reinforcement or to weld the additional reinforcement part on or on. Such methods have proven to be particularly favorable here, which ensure a local application of heat. For example, the respective element can be induction and / or laser beam and / or be flame hardened. The additional attachment of the reinforcement part can also be realized and implemented in this way by an induction and / or laser beam and / or flame application.

The subject matter of the invention is also a motor vehicle locking device, preferably produced according to the method described above, which, after its shaping process, has at least local reinforcement of the base element or locking element. The procedure here can typically be such that the base element is reinforced in the area of its axle mounting for the closing element. The invention is based on the knowledge that in the area of such an axle mounting, especially in the event of a crash, the greatest forces are transmitted from the closing element to the base element, so that the area of the axle mounting has to be particularly reinforced.

As a result, a method for producing a motor vehicle locking device and an associated motor vehicle locking device are described and made available, which have an at least local reinforcement of the relevant base element or locking element as their object. In this way, the motor vehicle locking device is made capable of withstanding the highest loads, especially in the event of a crash. All of this succeeds without the upstream shaping process of the base element or closing element having to undergo a fundamental change. Rather, the at least local reinforcement takes place subsequently.

In general, the element concerned is tempered, with a tensile strength that is at least twice as high as that observed in the non-tempered state. In addition, the achievable hardness of the element (Vickers hardness) can be increased significantly, with values for the Vickers hardness of generally more than 300 HV being observed at this point after the tempering process. The increased tensile strength and hardness Compared to the non-remunerated state, on the one hand, the relevant elements can be used with unchanged dimensions in a motor vehicle lock, so that the motor vehicle lock can better withstand higher loads overall, or dimensions, in particular thicknesses, of the elements can be reduced so that a Weight reduction of the elements is achieved while maintaining or further increasing the resistance of the motor vehicle lock to loads.

In addition to the possibility of using an additionally welded-on or welded-on reinforcement part and in this way to ensure the desired mechanical reinforcement of the element in question, the invention particularly relies on local reinforcement by intrinsic treatment of the element in question. This is usually achieved through heat treatment and, in particular, a tempering treatment. The heat treatment typically uses non-contact methods for applying heat. Induction treatment, laser treatment or flame treatment have proven to be beneficial here.

In the course of an induction treatment, the element in question (base element or closing element) can, in the simplest case, be acted upon by an alternating current-operated coil, which causes eddy currents in the element in question by induction and thus a local heat treatment. Alternatively or additionally, laser beam treatment can also be used. In general, lasers that emit in the infrared (IR) are used here, such as CO ₂ lasers, Nd: YAG lasers or the like. In principle, the element in question can also be flame-hardened by directing a flame onto the element locally. The quenching that usually takes place afterwards is carried out with water, oil or air. This can then be followed by a starting process, as has already been described above.

As a result of this intrinsic local treatment of the element, its metal structure is changed, with a view to increased tensile strength and increased hardness. All of this succeeds in a strikingly simple manner, taking into account reduced costs compared to the state of the art. This is where the main advantages can be seen.

Fig. 1

eine erfindungsgemäße Kraftfahrzeug-Schließeinrichtung in Gestalt eines Kraftfahrzeug-Schlosses mit den hieran angreifenden Kräften im Crashfall und

Fig.

2 den Gegenstand nach der Fig. 1 auszugsweise im Bereich eines Basiselementes bzw. einer Schlossplatte mit den hier zu erwartenden Verformungen, die durch die erfindungsgemäß durchgeführte Verstärkung verhindert werden.

The invention is explained in more detail below with the aid of a drawing showing only one exemplary embodiment; show it:

Fig. 1

a motor vehicle locking device according to the invention in the form of a motor vehicle lock with the forces acting on it in the event of a crash and

Fig.

2 the subject after the Fig. 1 excerpts in the area of a base element or a lock plate with the deformations to be expected here, which are prevented by the reinforcement carried out according to the invention.

A motor vehicle locking device is shown in the figures. The motor vehicle locking device is not restrictively a motor vehicle lock which is equipped with at least one metallic base element 1 and one metallic locking element 2, 3, 4. In the context of the exemplary embodiment, the base element 1 is a plate-shaped lock plate or a lock case 1. In contrast, the locking elements 2, 3, 4 are designed as a rotary latch 2 on the one hand and two pawls 3, 4 on the other.

The two pawls 3, 4 are, on the one hand, a comfort pawl 3 and, on the other hand, a blocking pawl 4 securing the comfort pawl 3 Fig. 1 The illustrated two-ratchet locking mechanism can of course also be used with a single locking mechanism with only one locking pawl 3, 4 come, but this is not shown. In any case, one recognizes in the Fig. 1 a force F (F-action) acting on a lock holder 5, in particular in the event of a crash, which as a reaction results in the rotary latch 2 on the one hand and the comfort pawl 3 on the other hand acting on the F-reaction reaction forces as outlined.

These reaction forces F-reaction lead to the fact that in the example the lock plate 1 in the area of a Fig. 2 indicated recess 6 of the lock plate 1 for receiving the associated joint pin bearing on the one hand the rotary latch 2 and on the other hand the comfort pawl 3, indicated deformations can be observed here. In order to keep these deformations as small as possible or to reinforce the lock plate 1 in this area in the example, the invention proposes various basic procedures.

Thus, the recess 6 in a variant with a welded or welded and in the Fig. 2 only indicated reinforcement part 7 are equipped. This reinforcement part 7 is a reinforcement disk 7 placed in the area of the recess 6. The reinforcement part or reinforcement disk 7 can be welded onto or to the lock plate 1, for example, by laser beam or in some other way.
Alternatively or additionally, the element in question, ie in the example the base element or the lock plate 1, can also be intrinsically reinforced, as was explained in detail in the introduction to the description. In the example, the lock plate 1 is remunerated locally, specifically in the area of the recess 6. For this purpose, in the area of the recess 6, in the example, a laser beam is focused on the area around the recess 6 and is informed of the one used at this point to manufacture the lock case 1 Quenched and tempered steel a remuneration. For this purpose, the area of the recess 6 is first heated, as has already been described in the introduction. Subsequently there is a deterrent in this area and the lock case 1 is finally left on if necessary.

As a consequence of this, the base element 1 or lock case 1 in question can have a tensile strength and / or Vickers hardness in the area of the recess 6 which clearly exceed comparable values in the non-tempered state, as already described in the introduction.

List of reference symbols

• Basic element 1
• Lock plate 1
• Lock case 1
• Rotary latch 2
• Comfort latch 3
• Pawl 3, 4
• Locking pawl 4
• Closing element 2, 3, 4
• Lock holder 5
• Recess 6
• Reinforcement part 7
• Reinforcement washer 7

Claims (10)

Method for producing a motor vehicle locking device, in particular a motor vehicle lock, with at least one metallic base element (1) and one locking element (2, 3, 4),
characterized in that
the base element (1) and / or the closing element (2, 3, 4) is subsequently reinforced at least locally after its shaping process. Method according to Claim 1, characterized in that the local reinforcement of the element (1; 2, 3, 4) takes place intrinsically and / or extrinsically. Method according to Claim 2, characterized in that the respective element (1; 2, 3, 4) is equipped with at least one reinforcement part (7) welded on or welded on. Method according to Claim 3, characterized in that the reinforcement part (7) is designed as a reinforcement disc (7) placed in the region of a recess (6). Method according to one of Claims 2 to 4, characterized in that the respective element (1; 2, 3, 4) is induction and / or laser beam and / or flame hardened. Method according to one of Claims 1 to 5, characterized in that the respective element (1; 2, 3, 4) and / or the reinforcement part (7) is made from a heat-treatable steel and / or a heat-treatable non-ferrous alloy such as titanium. Method according to one of Claims 1 to 6, characterized in that the respective element (1; 2, 3, 4) and / or the reinforcement part (7) is subjected to a combined hardening and subsequent tempering process. Method according to one of Claims 1 to 7, characterized in that the respective element (1; 2, 3, 4) and / or the reinforcement part (7) is tempered to such an extent that its tensile strength (R _m ) and / or Vickers hardness (HV ) increases to at least two times compared to the unrefined condition. Motor vehicle locking device, preferably produced by a method according to one of Claims 1 to 8, in particular motor vehicle lock, with at least one metallic base element (1) and one locking element (2, 3, 4),
characterized in that
the base element (1) and / or the closing element (2, 3, 4) is subsequently reinforced at least locally after a shaping process. Device according to Claim 9, characterized in that the base element (1) is reinforced in the area of its axle mounting for the closing element (2, 3, 4).

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