Method for producing motor vehicle locks with a twisted locking part edge

Abstract

In order to minimize the sliding friction between the locking parts that is, between the pawl and the rotary latch of a motor vehicle lock, it is advantageous if, during the production process, the different latch surfaces of both locking parts are provided with a stamping contour having straight grooves and with a stamping contour characterized in that the provided grooves are oblique. Said oblique grooves of the latch surface on the pawl are placed in the position indicated in figure such that the entire pawl is twisted about the longitudinal axis thereof. Also, at least two overlapping points are provided between the straight grooves and the oblique grooves such that both of the locking parts come into mutual contact reducing the friction.

Claims

1. Method for producing a first locking part of a motor vehicle door lock, namely, a catch and a second locking part of the motor vehicle door lock, namely, a pawl, wherein: the catch and the pawl are stamped, said stamping generates a stamped contour that includes grooves extending across a thickness of both the catch and the pawl along an axis; after said stamping, one of the locking parts is deformed by twisting by a specified angle in an area which is engaged by a stamping contour of the other locking part such that the grooves on the twisted locking part in the area are not aligned with either the axis or the grooves on the other locking part that engage the area; and the catch and the pawl are coated except for latching surfaces.

2. Method according to claim 1, wherein the grooves in the stamped contour of the catch and the pawl include straight grooves, the pawl is twisted by a specified first angle, so that the twisted grooves of the pawl are oblique relative to the straight grooves in the catch.

3. Method according to claim 2, wherein the catch is twisted by a second angle, resulting in at least two overlapping points of straight and oblique grooves.

4. Method according to claim 2, wherein the first angle of twisting is set to 5-15 depending on the thickness of the pawl and the distance of the grooves.

5. Method according to claim 1, wherein the catch and pawl are twisted to such an extent that the grooves of the other facing latching surface of the catch and the pawl contain respective overlapping points or contact points.

6. Motor vehicle door latch with a first locking part, namely, a catch and a second locking part, namely, a pawl locking the catch when the motor vehicle door is closed, wherein both the catch and the pawl contain corresponding ratchet surfaces on vertical edges created during stamping, the ratchet surfaces including straight grooves extending along an axis and a coating except for on the ratchet surfaces, one of the locking parts is deformed by twisting the one locking part after stamping so that the ratchet surface on the one locking part includes a stamping contour whose straight grooves are obliquely arranged in relation to both the axis and the straight grooves of the other locking part as a result of twisting of the one locking part.

7. Motor vehicle door latch according to claim 6, wherein the oblique grooves are formed on the twisted part of the pawl.

8. Motor vehicle door latch according to claim 6, wherein both the catch and the pawl are twisted in opposite directions by a respective smaller angle.

9. Motor vehicle door latch according to claim 6, wherein the catch is twisted in the area opposite to the pawl creating respective overlapping points on the ratchet surfaces.

10. Motor vehicle door latch according to claim 6, wherein the pawl or the catch is twisted around its longitudinal axis.

11. Method according to claim 3, wherein the angle of twisting is set to 5-15 depending on the thickness of the pawl and the distance of the grooves.

12. Method according to claim 2, wherein the catch and pawl are twisted to such an extent that the grooves of the other facing latching surface of the catch and the pawl contain respective overlapping points or contact points.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a top view of a motor vehicle door latch in a closed state,

(2) FIG. 2 shows an enlargement of the edge profile of a catch in the area of its ratchet surface,

(3) FIG. 3 shows an enlargement of the ratchet surface of the pawl in the twisted state and

(4) FIG. 4 a perspective view of the catch with the particular edge formation.

DETAILED DESCRIPTION OF THE DRAWINGS

(5) FIG. 1 shows a top view of a motor vehicle door latch 1, in which the catch 2 moving around axis 3 contains the hanger arm 9 of the latch bracket 7. This shows the closing state of a respective motor vehicle door latch 1; the catch 2 is secured by pawl 5 pivotable around pawl axis 6, i.e. the motor vehicle door latch 1 can only be opened again once the pawl 5 has been pivoted away, which can be achieved by actuation of the handle of the motor vehicle doornot shown in the drawing. By means of the seat 4, the hanger arm 9 is moved into the lowest point 27 on the catch 2 thus ensuring the closed condition of also the vehicle doornot shown, with the locking parts 30, 31, i.e. the pawl 5 and the catch 2 being part of the motor vehicle door, whilst the latch bracket 7 with the hanger arms 9 is secured to the car body of the motor vehicle.

(6) The locking parts 30, 31 of the locking mechanism 8 are produced from sheet metal in preferably multiple stamping operations and at the ratchet surfaces 12, 13 not covered by the coating 10, the surface of both locking parts 30, 31 is initially characterized by a stamping contour 14. In the area of the ratchet surface 13 this surface structure has, however been changed as the grooves 18, 19 forming the stamping contour 11 are oblique as a result of the twisting of the component and, in particular pawl 5, and are shown as oblique grooves 18, 19 in FIG. 3. This stamping contour 11 produces a considerably better sliding friction between the locking parts 30, 31, i.e. the pawl 5 on the catch 2, so that the unwanted noises can no longer be generated.

(7) It is not particularly highlighted in the figure that the edges 15, 16 of the catch 2 and pawl 5 contain a plastic coating 10. The edges 15, 16 are thus covered by such a coating, whilst only in the area of the ratchet surfaces 12, 13 and also on the contact surface 20 this coating is not applied, allowing the special surface structure, as shown in the below figures, to become effective. The surface structure ensures that the noise and sliding friction are reduced to a minimum, with both cooperating.

(8) FIG. 2 shows the area of the ratchet surface 12 on the catch 2 that has to correspond with the ratchet surface 13 on the pawl 5 during opening and closing of the motor vehicle door latch 1. This means that during opening and closing of the motor vehicle door latch 1, the two locking parts 30, 31 rub against each other in the area of the ratchet surfaces 12, 13 or even on top of each other at the edges 15, 16, which can, in particular in case of the straight grooves 17, shown in FIG. 2, cause problems, when the ratchet surface 13 on the pawl 5 is the same, i.e. contains straight grooves. As apparent from a comparison between FIGS. 2 and 3 this has, however, been avoided by the latching contour of the ratchet surface 13 being oblique, as a result of the entire component, i.e. the pawl 5 being twisted by a certain angle.

(9) FIG. 3 shows that the end state has not been reached as yet, i.e. the pawl 5 has to be twisted further in order to ensure that at least two overlapping points 25 have to be provided. The, in this case, oblique grooves 18, 19, in particular in the area of the main ratchet position 22, reduce the sliding friction and the produced friction noise, as the oblique grooves 18, 19, as apparent from FIG. 3, only contain a few overlapping points 25. Here, too, it can be assumed that the oblique arrangement caused by the twisting of the pawl 5 around its longitudinal axis 38 is around 5-15, in order to achieve the desired two overlapping points in each case. It is important that said overlapping points 25 are provided in order not to adversely affect the movement of the pawl 5 on the catch 2, so that the movement is even, thus reducing the sliding friction and the noise to such an extent that they are no longer causing a problem. Numeral 36 refers to the twisted part of the pawl 5, although generally, due to the overall design of the pawl 5, it has been found to be advantageous for the entire component to be twisted in such a way that the ratchet surface 13 contains the oblique grooves 18, 19.

(10) A comparison of FIG. 2 and FIG. 3 shows that when the ratchet surface 12 meets the ratchet surface 13, i.e. the facing area 37, the grooves 17, 18 and 19 can no longer engage.

(11) FIG. 4 shows a perspective view of the catch 2 that can be pivoted around axis 3not shown in the drawing. When pivoting the catch 2, the hanger arm 9, not shown in FIG. 4, is inserted in the seat 4 or released therefrom, so that the motor vehicle door can then be opened or evenly closed and is then locked in the closed position by the pawl 5. FIG. 4 shows that the stamping of the catch 2 produces a clearly visible edge 15 whose surface, as explained above, is characterized by the stamping contour 14 on the ratchet surface 12. This stamping contour 14 is only indicated in FIG. 4. The ratchet surface 12 indicates the main ratchet position 22, i.e. the position in which the pawl 5 prevents the catch 2 for pivoting back in the closed position. In this case, the ratchet surface 13 of the pawl 5 rests, as already explained, on the latching surface 12 of the catch 2 and both parts can move on top of each other with less friction, without unwanted noises being generated, as the straight grooves 17 of the catch 2 and the oblique grooves 18, 19 of the pawl 5 cannot engage or latch with each other.

(12) It is apparent that at the lowest point 27 of the seat 4 it contains a surface deviating from the other surface of the edge 15, which is, in particular, achieved by the fact that this area is not covered by a coating 10 and that a separate part has been inserted at this point to positively affect the sliding effect of the catch 2 at the hanger arm 9.

(13) All aforementioned characteristics, including those only shown in the drawings, are separately or in combination essential parts of the invention.