Method for punching or cutting out ring-shaped, flat components and a clutch or brake equipped therewith.

Abstract

Method for punching or cutting out ring-shaped, flat components (12) from a flat, strip-shaped semi-finished product (2), wherein the components (12) are intended to be stacked on top of each other at a specific installation angle relative to each other, characterized in that the components (12) are punched or cut out of the semi-finished product (2) in different component types (Type 1, Type 2), which differ in their angular position relative to the orientation of the strip-shaped semi-finished product (2), such that in the installation angle, sectors with increased thickness (14) and sectors with reduced thickness (16) of the different component types (Type 1, Type 2) are aligned with each other in such a way that the thickness variations during stacking at least partially compensate for each other.

Description

The invention relates to a method for punching or cutting out ring-shaped, flat components from a flat, strip-shaped semi-finished product according to the preamble of claim 1, wherein the components are designed to be stacked on top of each other at a specific installation angle relative to one another. Such methods are used in the manufacture of clutch plates for multi-plate clutches. Furthermore, the invention relates to a clutch or brake. Multi-plate clutches or brakes are used in vehicle transmissions as friction switching elements for torque transmission. The plates are ring-shaped discs, with outer plates having drive teeth on the outside and inner plates having drive teeth on the inside. In a clutch or brake, outer and inner plates are stacked alternately. The drive teeth of the plates engage with corresponding drive teeth on the two clutch halves, allowing axial movement. In the disengaged state, virtually no torque is transmitted between the inner and outer plates – the clutch or brake is then open. To actuate the clutch or brake, the stack of plates is typically compressed hydraulically with an axial force, thus transmitting a torque whose magnitude depends on the axial force. To achieve uniform contact pressure of the friction plates and consistent torque transmission during slippage, one option would be to manufacture the individual plates with very high precision in terms of their thickness, but this would incur high costs. Typically, the plates are punched from a rolled sheet metal strip – a so-called sheet coil. With the sheet coils used for this purpose, a constant sheet thickness across the width of the coil is not guaranteed, which means that plates punched from the sheet coil typically have a maximum thickness in one sector and a minimum thickness in a sector – usually diametrically opposite. Therefore, in known clutch manufacturing processes, the thickness or thickness distribution around the circumference of the plates is measured before installation. The plates are then mounted in the clutch with a suitable, angularly offset orientation relative to each other.The disadvantage is the time and cost involved in the surveying. German patent DE 10 2013 223 770 A1 discloses a method for manufacturing a clutch plate pack for motor vehicle clutches, in which the plates are marked with their angular position relative to the sheet metal coil during the stamping process. The plates are then installed in a clutch pack with different marking orientations, so that variations in the sheet metal coil thickness, which would cause the plates to systematically exhibit a maximum thickness in one angular sector and a minimum thickness in another, are compensated for in the clutch pack. This method eliminates the need for measurement; however, a prerequisite for its implementation is that the plates can be installed at different angular positions. This, in turn, means that the plate design also allows for installation errors. The other documents DE 17 21 489 U and DE 34 25 346 A1 also disclose manufacturing processes for lamellae for motor vehicle clutches. The present invention is based on the objective of providing an alternative manufacturing process for lamellae. This objective is achieved by the method according to claim 1. The objective is also achieved by a clutch or brake according to the features of claim 14. Advantageous further developments of the method and embodiments of the clutch lamellae are given by the dependent claims. In the inventive method, components of various types are punched or cut out of the semi-finished product, differing in their angular position relative to the orientation of the strip-shaped semi-finished product. When the components are stacked and mounted, sectors of the different component types with increased and decreased thickness are aligned with each other in the stack's installation angle such that the thickness variations during stacking at least partially compensate for each other. The components can be formed from the semi-finished product by punching in a stamping press or by a cutting process such as laser or waterjet cutting. In the stamping process, the various component types can be stamped out of the strip-shaped semi-finished product one after the other, whereby the angular position of the stamping tool or the orientation of the strip-shaped semi-finished product is changed between the stamping operations. Either the stamping tool is rotated by a specific angle or the semi-finished product is rotated. Advantageously, two or more stamping tools can also be arranged one behind the other with respect to the conveying direction of the semi-finished product, and rotated accordingly relative to each other. The different component types can then be stamped out simultaneously or sequentially. A simple way to distinguish between component types during later use is created by marking the components with a label and / or shape that indicates their orientation relative to the strip-shaped semi-finished product. When clutch plates are manufactured using the inventive method, an irregular drive toothing ensures that the clutch plates can be installed in the clutch not in any arbitrary position, but only in certain angular positions. Advantageously, each type of friction plate is provided with a specific tooth in the drive teeth, allowing the different plate types to be distinguished from one another. Such a tooth also enables automatic camera monitoring of the correct insertion position during clutch assembly. According to a further embodiment, the irregular drive teeth are axially symmetrical with respect to an axis of symmetry lying in the plane of the lamellae, except for any missing tooth that may be present. In this embodiment, a first and a second type of lamellae are stamped from the same sheet metal coil, with the second type being stamped from the coil rotated 180° relative to the first. The lamellae produced in this way can then only be inserted into the coupling in two positions. If the front and back of the lamellae are identical, the lamellae can also be reversed, resulting in four insertion positions. If the lamellae are punched out of the sheet metal coil in such a way that the axis of symmetry is skewed relative to the coil's orientation, the thicker sectors will be positioned at different angles in each possible insertion position. If the angle between the axis of symmetry and the coil's discharge or conveying direction is 45°, the thicker sectors will be evenly distributed by 90° in each of the four possible insertion positions (with turning). According to an alternative version of the method, the drive teeth are designed in such a way that each type of lamellar can only be installed in the coupling in a single angular position, thus structurally preventing an incorrect insertion position. To achieve a uniform thickness distribution within the lamella stack, in the simplest case exactly two lamella types are punched out, rotated 180° relative to each other. The two lamella types produced in this way are then stacked alternately in the coupling. An even more uniform thickness distribution in the coupling can be achieved by ensuring that the number of different lamella types corresponds to the number of inner and outer lamellae in a coupling package, whereby the lamella types are punched out with a uniform twist relative to each other, and the number of drive teeth corresponds to a multiple of the number of lamella types. In a clutch or brake with multiple clutch plates manufactured according to the inventive method and installed in the clutch or brake rotated relative to each other with respect to the orientation of the sheet metal coil, existing thickness maxima and minima are uniformly distributed in the circumferential direction in the desired manner. The invention is explained in more detail with reference to the accompanying figures. Figure 1 shows a coupling plate before and after punching from a strip sheet according to the prior art, Figure 2 shows a side view of a stack of plates according to the prior art, and Figure 3 shows two plate types before punching from a sheet coil and in an installed angle position. In Fig. 1, 2 denotes a strip of sheet metal that has been unwound from a coil and is aligned relative to the stamping press in the conveying direction indicated by arrow 4. Due to the rolling process during the production of the strip metal, it has one side with increased thickness 6 and one side with reduced thickness 8. The coupling plate 12 is stamped out of the strip metal according to contour 10. The stamped coupling plate thus has a sector with increased thickness 14 and a sector with reduced thickness. Fig. 2 shows a stack of lamellae in which the lamellae are stacked alternately rotated by 180° relative to each other, so that the thickness variations of the individual lamellae in the stack of lamellae are balanced out. Figure 3 shows how contours 10a and 10b are punched out of the strip sheet 2. Contour 10a corresponds to a first lamella type “Type 1”, and contour 10b to a second lamella type “Type 2”. Contours 10a and 10b are congruent and have an irregular drive toothing that allows for only one insertion position in the coupling. Contour 10b is rotated 180° relative to contour 10a, so that the sectors with increased and decreased thickness are diametrically opposed. If the lamella types “Type 1” and “Type 2” are now stacked alternately on top of each other in the lamella pack in the insertion position defined by the drive toothing, the desired thickness compensation in the stack is achieved, as shown in Figure 2, without any further measures, in particular without the need to measure the lamellae or install them in different angular positions. Reference sign 2 Strip sheet from sheet coil 4 Conveying direction 6 Side with increased thickness 8 Side with reduced thickness 10 Contour 12 Lamella 14 Sector with increased thickness 16 Sector with reduced thickness Type 1 Lamella type 1 Type 2 Lamella type 2

Claims

Method for punching or cutting out ring-shaped, flat components (12) from a flat, strip-shaped semi-finished product (2), wherein the components (12) are intended to be stacked on top of each other at a specific installation angle relative to each other, characterized in that the components (12) are punched or cut out of the semi-finished product (2) in different component types (Type 1, Type 2), which differ in their angular position relative to the orientation of the strip-shaped semi-finished product (2), such that in the installation angle, sectors with increased thickness (14) and sectors with reduced thickness (16) of the different component types (Type 1, Type 2) are aligned with each other in such a way that the thickness variations during stacking at least partially compensate for each other. Method according to claim 1, characterized in that the different component types (Type1, Type2) are punched out successively from the strip-shaped semi-finished product (2) and that between the punching operations an angular position of the punching tool or an orientation of the strip-shaped semi-finished product (2) is changed. Method according to claim 1, characterized in that the different component types (Type1, Type2) are punched out from the strip-shaped semi-finished product (2) by several punching dies, wherein the punching dies are arranged one behind the other with respect to an orientation of the strip-shaped semi-finished product (2) corresponding to a conveying direction (4). Method according to one of claims 1 to 3, characterized in that the components (12) are provided with a marking and / or shape which indicates the angular position relative to the orientation of the strip-shaped semi-finished product (2) and thus the component type (Type 1, Type 2). Method according to one of claims 1 to 4, characterized in that the components (12) are coupling plates (12) for a coupling which have a drive toothing, wherein different plate types (Type1, Type2) are punched or cut out from a sheet metal coil. Method according to claim 5, characterized in that the coupling plates (12) are provided with an irregular drive toothing during stamping, which causes the coupling plates (12) to not be able to be installed in the coupling in every angular position. Method according to claim 5 or 6, characterized in that each lamella type is provided at a specific location with a missing tooth in the drive toothing, by virtue of which the different lamella types (Type 1, Type 2) can be distinguished from one another. Method according to claim 6 or 7, characterized in that the lamellae are provided with an irregular drive toothing which is axially symmetric with respect to an axis of symmetry lying in the plane of the lamellae and that a first and a second lamella type are punched out from the same sheet metal coil, wherein the second lamella type (Type 2) is punched out of the sheet metal coil rotated by 180° relative to the first lamella type (Type 1). Method according to claim 8, characterized in that the orientation of the axis of symmetry is inclined relative to the orientation of the sheet coil. Method according to claim 9, characterized in that the orientation of the axis of symmetry is at an angle of 45° to the orientation of the sheet coil. Method according to claim 7, characterized in that the drive toothing is designed such that each lamellar type (Type 1, Type 2) can only be installed in the coupling in a single angular position. Method according to claim 10, characterized in that exactly two lamella types (Type1, Type2) are punched out rotated by 180° relative to each other. Method according to claim 10, characterized in that the number of different lamella types (Type1, Type2) corresponds to the number of inner or outer lamellae in a coupling package, wherein the lamella types (Type1, Type2) are punched out with a uniform twist relative to each other, wherein the number of drive teeth corresponds to a multiple of the number of lamella types (Type1, Type2). Clutch or brake with several clutch plates (12) manufactured according to a method according to one of claims 5 to 13 and installed in the clutch or brake rotated relative to each other with respect to the orientation of the sheet metal coil such that existing thickness maxima and minima are evenly distributed in the circumferential direction.

Images