SK288361B6 - Friction member for a clutch friction disk - Google Patents

Abstract

The friction member of the disc of a dry clutch including a friction fitting (3) glued to on insert (6), in which holes are formed after gluing said fitting and said insert to allow attachment with rivets, and including a first portion having a thickness e1 in fiting (3) and with a constant diameter d1 and a second portion with a thickness e2 + e3 and a diameter smaller than d1, in order to define a spot facing surface depressions (31) on which bears the end of a rivet after assembly, wherein the thickness e2 of fitting in the second portion of the holes represented the range from 2 to 15% of the total thickness e1+e2 said fitting (3). The invention also relates to the production of the friction element of the friction disc clutch.

Description

Technical field

The present invention relates to a friction disc friction disc of a dry clutch, in particular for a motor vehicle. Typically, the clutch friction disk is designed to be mounted on a so-called driven shaft, being inserted between the reaction disc and the clutch pressure plate, which is fixedly rotatably coupled to the so-called drive shaft. During the clamping process, said pressure disc presses the friction disc against said reaction disc.

BACKGROUND OF THE INVENTION

The present invention, although applicable to any type of friction disc, is specifically directed to the clutch friction disc, which is called progressive.

The progressive clutch friction disk, such as shown in Figures 7 and 8 of FR 1 304 067, comprises a metal carrier in the form of a substantially flat rim, commonly referred to as a progressive disk, the outer periphery of which is divided to form blades that are firmly attached to or mounted on said rim.

These vanes are alternately bent to include displaced parts, from one side to the other of the median plane, which may be elastically deformed under the influence of a thrust force.

The friction lining in the form of a wreath is mounted on each side of said support and is fixed by any suitable means to some of said displaced parts.

During the pressing, the blades are elastically deformed, with the displaced parts approaching each other.

This results in a progressive effect when the friction disk is compressed and subsequently the torque torque is transmitted during the switching operation, which makes it possible to greatly reduce shocks.

Said blades create cuts and openings to increase their flexibility.

During operation, the friction linings are subjected to considerable heating which is able to reduce their surface hardness.

Under the effect of the pressure applied to the linings, these linings are often the subject of a phenomenon which is comparable to the coating on said vanes in the linings, causing loss of elasticity and consequently of progressivity.

In order to overcome this disadvantage, it has been proposed to insert an insert, in particular a steel strip, which is adhered to each lining between the lining and said blades.

Such an arrangement, as seen in Figures 7 and 8 of the aforementioned French patent 1 304 067, is satisfactory.

In order to produce such a friction disc according to the state of the art, the friction lining and the liner are drilled separately, which are then joined by gluing.

In a conventional manner, linings glued to the inserts are mounted on the progressive disc by means of rivets. The rivets generally comprise two ends, usually a non-deformed or little deformed head during assembly, and one end whose diameter increases during assembly by deformation, and a body with a diameter smaller than the diameter of the rivet ends after assembly. Generally, the diameters of each end of the rivets after assembly are substantially equal to each other. It is desirable that the ends of the rivets rest upon assembly of a portion of the material of each of the assembled pieces.

Two methods of assembly are used to join the adhesive lining to the progressive disc insert, which are described in detail with reference to Figures 3a, where the lining 3 is glued to the insert 6.

The lining 3 comprises a hole with a wide portion 32 with a constant diameter d1 and a thickness el that is large enough to release the end of the yarn after assembly and may comprise a narrower portion 33 with a diameter d2 and a thickness e2 to allow movement of the yarn body without so that the end of the thread can pass through after assembly. At the bottom of the widest part 32 there is a recess area 31 on which the end of the thread can be supported after assembly. The recess surface 31 has a complementary shape with the end of the thread after the selected assembly and can be flat or conical. The liner 6 with a thickness e3 comprises an opening 61 with a diameter d3 (not shown) which allows the yarn body to move without being able to pass the end of the yarn after assembly and is positioned before gluing against the lining opening.

According to a first known assembly method, the recess surface 31 is formed in the lining thickness. The inventors have found that in order to be able to drill the lining in this way without destroying it, it is desirable to maintain a considerably large thickness of the material e2. It is estimated that it is necessary to maintain a thickness e2 which is at least 20% of the total thickness (e1 + e2) of the lining. This thickness e2 is defined between the portion of the recess area furthest away from the lining area to be connected to the liner and this lining area. For example, conventional linings intended for passenger car applications have a thickness of 3 mm and a distance e2 of 0.9 mm, and conventional linings intended for industrial car applications, especially heavy duty, have a thickness of 4.5 mm and a distance e2 of 1.3 mm, even 1.45 mm, and even 1.6 mm. This minimum thickness e2, although advantageous in terms of drilling quality, limits the thickness of the lining material that may be worn during the life of the friction disk. Namely, the depth of wear is limited by the position of the end of the thread after mounting, which must not come into contact with the fastening disc, as there is a risk of very great damage. The drilled lining is then glued to an insert 6 having previously drilled holes of diameter d3, the axis of which substantially coincides with the axis of the holes drilled into the lining.

According to a second known assembly method, a constant diameter hole d1 is drilled over the entire thickness of the lining, which is then glued to an insert 6 having previously drilled holes with a diameter d3 (not shown) whose axis substantially coincides with the axis of the holes drilled into the lining. In this embodiment, the end of the thread is only held on the insert after assembly and the lining does not contribute to the strength of the connection to the friction disc. This usually results in a weakening of this connection compared to the previous solution, particularly noticeable during the rivet shaking tests in order to ensure the holding at the centrifugal forces.

It is an object of the present invention to overcome the aforementioned disadvantages and to propose a solution which makes it possible to harmonize as much wear as possible of the lining and to allow the lining to participate in the connection with the friction disc.

SUMMARY OF THE INVENTION

This object is achieved by a friction member of a dry clutch disc comprising a friction lining adhered to an insert, wherein the apertures are formed after gluing said lining and said insert to allow fastening by threads comprising a first portion having a thickness el in the lining and a constant diameter d1; a second portion of thickness e2 + e3 having a diameter of less than dl to form a recess area to support one end of the thread after assembly, wherein the thickness e2 of the lining in the other portion of the holes ranges from 2 to 15% of the total friction lining .

Thanks to this arrangement, the lining can be more worn than in the known solutions in which the lining participates in the connection with the friction disc. The diameter of the opening in the second part with a thickness e2 + e3 may be constant and equal to the diameter d2 of the opening that opens on the surface of the insert which is opposite to the surface glued to the lining. In this case, the recess surface is flat and parallel to the friction surface of the lining (located on the opposite side of the lining surface glued to the liner) to receive the ends of the rivets after assembly with the flat support surfaces. The diameter of the opening in the second part with a thickness e2 + e3 can also be reduced from d1 to d2, which corresponds to the diameter of the opening that opens on the surface of the insert opposite the surface glued to the lining. Such an arrangement makes it possible to receive the ends of the rivets after assembly with conical support surfaces due to the conical recess surface.

The lining is ideally formed by continuous fibers impregnated with one or more resins containing the filler. Ideally, the fibers comprise glass wool fibers, organic fibers, metal fibers. The fibers may preferably be with protrusions.

According to one embodiment of the friction member according to the invention, the insert is a metal sheet.

In the case of conical recess faces, the angle and cone with a surface parallel to the friction surface of the lining may be in the range of 3 ° to 30 °.

In the case of conical recess surfaces, these surfaces may be located either wholly or only partially in the lining.

Usually, the angles of the countersink surfaces are plus, minus 3 degrees.

The present invention also aims at a dry clutch friction disc comprising a progressive disc and at least one said friction member.

The progressive disc may contain sequence zones. These may comprise blades capable of elastic axial deformation.

The present invention also relates to a method of manufacturing a friction disc friction disc member of a dry clutch comprising a friction lining and an insert, wherein:

the friction lining is glued to the liner, the previously glued assembly is machined to form rivet fastening holes, wherein the openings comprise a first part having a thickness el in a constant diameter d1 and a second part having a thickness e2 + e3 and a diameter d2 which is less than d1 to form a recess area to support the end of the thread after assembly, wherein the thickness of the lining e2 in the second portion of the holes is in the range between 2 to 15 percent of the total thickness of the friction lining e + e2.

Preferably, the processing is done with a cutting tool, but it is also possible to use, for example, excavation or erosion techniques. The use of a cutting tool allows, for example, the use of drilling, milling or any other suitable technique.

According to one embodiment of the method of the present invention, a cutting indentation tool is used to treat a friction lining adhered to the insert, said cutting tool comprising a first portion to remove material in the lining and in the insert and form an opening opening with diameter d2 on the outer surface opposite to the surface glued to the liner, inserts, and this cutting tool also includes a second portion having a diameter d1 to remove material at least in the liner and to form a recess area.

The second diameter portion d1 of the recess cutting tool may comprise an edge perpendicular to the axis of the cutting tool to form a flat recess surface.

The second diameter portion d1 of the recess cutting tool may include an edge inclined with respect to the cutting tool axis to form a conical recess surface.

The countersink cutting tool may be, for example, a countersink drill or a countersink cutter.

The present invention also aims at a method of manufacturing a friction disc, comprising the step of providing said friction member, followed by the step of attaching said friction member to the progressive disc by rivets.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is further described in detail by way of non-limiting examples, with the following figures:

Figure 1: schematic drawing of the friction disc,

Figure 2: A-A schematic cross-sectional view of assembled friction disc components according to the present invention;

Figure 3a-c: a schematic cross-sectional view of a friction member portion according to three variations of the present invention; Figure 4: a schematic sectional view according to B-B of the assembled friction disk components according to the invention.

For the sake of clarity, the dimensions of the individual elements shown in these figures are not proportional to their actual dimensions. In all figures, the identical numbering corresponds to identical elements.

Within the scope of the present invention, the terms axial, axial and radial, radial are defined with respect to the rotational axis of the friction disk. Axial extends parallel to this axis of rotation and radial extends perpendicular to this axis and passes through this axis.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows a schematic front view of a friction disk 1 comprising a hub 5 which can be fixedly connected to a driven shaft, a friction lining 3 and a dotted line showing a progressive disk 2. The resilient means, in particular the springs 4, are arranged to allow damping and / or filtering the vibration of the drive shaft to the driven shaft.

Figure 2 is a cross-sectional view, according to A-A of Figure 1, of a friction disc according to the present invention, where the components are shown in an assembly after assembly. The liner 6 is disposed on each side of the progressive disc 2, between said progressive disc and the liner 3. The liner comprises milled holes with a portion 32 that is wide enough to accommodate the end of the yarn after assembly 7, and a narrower portion 33 to allow movement of the yarn body. without passing the end of the thread after assembly. At the bottom of the widest part 32 there is a recess area 31 on which the end of the thread can be supported after assembly. The portion of the insert 6 to be in contact with the region of the lining opening 33 also includes an opening 61 of equal diameter, as well as a progressive disc 2 containing the opening 21. The insert 6 and the lining 3 located on the other side of the progressive disc 2 holes 62 and 34, which are capable of passing the end of the thread after assembly. A thread 7 is mounted to firmly bond the lining previously glued to the insert and the progressive disc by, for example, placing the thread head on one side with the contact surface of the recess 31 and pushing the other end of the thread on the progressive disc, the thread passes through the holes 33, 61, 21.

After assembly, the distance e between the two inserts is caused by the presence of succession zones in the progressive disc, in particular in the form of axially resiliently deformable vanes. Such vanes are shown by the dotted line in figure 1 and are shown in section in figures 2 and 3.

In this case, the vanes are mounted on a sheet that has been first cut and formed to form a progressive disc 2.

Figures 3 a-c are an enlarged cross-sectional view of a portion of the friction member of A-A to illustrate individual shapes of apertures according to the present invention which allow thread fastening.

Figure 3a illustrates a case where the lining comprises a flat recess area. The hole that allows thread fastening comprises a first portion of thickness l1 in a constant diameter d1 and a second portion of thickness e2 + e3 with a constant diameter d2 that is less than dl, and wherein e2 is the thickness of the second portion of the lining and e3 is the thickness of the insert 6.

Figures 3b and c illustrate two embodiments wherein the lining comprises a conical recess surface that is at an angle and with a surface parallel to the friction surface of the lining.

The hole that allows the thread to be fastened comprises a first portion of thickness el in a constant diameter lining l1 and a second portion of thickness e2 + e3 of decreasing diameter from d1 to d2 corresponding to the diameter of the opening opening on the surface of the insert 6 opposite to surface glued to the lining 3.

In the embodiment shown in Figure 3b, the recess area 31 is entirely within the liner 3. The second friction member thickness e2 + e3 extends partially in the e21 thickness liner with decreasing diameter from d1 to d2, and partly in the liner with a constant diameter d2 thickness e22 and partially in a constant diameter d2 insert e3. The lining thickness e2 in the second opening portion is e2 = e21 + e22.

In the embodiment shown in Figure 3c, the recess area 31 is located partly in the lining 3 and partly in the insert 6. The second friction member thickness e2 + e3 extends partially in the lining thickness e2 with decreasing diameter from d1 to d1 and partly in a liner of thickness e31 with decreasing diameter from d12 to d2 and partly in a liner of thickness e32 with constant diameter d2. The thickness of the insert 6 is equal to e3 = e31 + e32.

Figure 4 is a schematic sectional view according to BB of Figure 1 of the same friction disc shown in Figure 2. It can be seen that the progressive disc 2 comprises vanes, one part in sliding contact with the first insert 6, the other part fixed to the other. and the fourth portion is in sliding contact with the second insert 6. Accordingly, in this view, a wavy shape of this region of the progressive disc is obtained, which makes it possible to ensure the friction disc sequence.

The following examples, presented in Table 1, are non-exhaustive embodiments of the present invention as compared to known embodiments.

area recess flat conical thickness (Mm) EX 1 EX 2 EX 3 EX 4 EX 5 el + e2 3 3 3 3 3 el 2.1 2.6 2.1 2.6 2.6 e2 0.9 0.4 0.9 0.4 0.2 e21 0 0 0.7 0.3 0.2 e22 0.9 0.4 0.2 0.1 0 e3 0.3 0.2 0.3 0.2 0.2 e31 0 0 0 0 0.1 e32 0.3 0.2 0.3 0.2 0.1 e2 / (el + e2) 30% 13% 30% 13% 7%

Table 1

Examples EX1 and EX3 are comparative examples where the linings are first drilled and then mounted on a liner that has been drilled first. In the case of EX1, the countersink area is flat, and according to EX3, it is conical. It can be seen that the lining thickness e2 in the second portion of the openings is of the order of 30% of the total lining thickness.

Examples EX2, EX4 and EX5 are examples of the present invention where the linings are glued to the insert before drilling. In the case of EX2, the countersink area is flat, while in the case of EX4 and EX5 it is conical. The conical surface of the recess at EX4 is entirely in the lining, while the surface at EX5 is partially in the lining and partly in the liner.

The tests made it possible to show that the embodiments corresponding to EX2, EX4, EX5 provided resistance at the order of magnitude of the same centrifugal force that corresponded to EX1 and EX3, while allowing greater wear of the lining before there was a risk of damaging the pressure plate at the ends of the rivets after assembly. attaching the friction member to the progressive disc.

The present invention is not limited to these types of embodiments and is to be interpreted in a non-limiting manner, including each equivalent embodiment.

PATENT CLAIMS

Claims (15)

A dry clutch disc friction member, characterized in that it comprises a friction lining (3) adhered to a liner (6), wherein there are holes for fastening threads (7), and which comprises a first part having a thickness el in the lining (3) and a constant diameter d1 and a second part having a thickness of e2 + e3 and having a diameter of less than d1 to form a recess area (31) to support one end of the thread (7) after assembly, wherein the thickness e2 of the lining in the other part is the total thickness of the friction lining e + e2 (3). Friction member according to the preceding claim, characterized in that the insert (6) is a metal sheet. Friction member according to any one of the preceding claims, characterized in that the recess surface (31) is flat and parallel to the friction surface of the lining. Friction member according to one of Claims 1 or 2, characterized in that the recess surface (31) is conical. Friction member according to claim 4, characterized in that the angle α of the cone with the surface parallel to the friction surface of the lining can be between 3 ° and 30 °. Friction member according to one of claims 4 or 5, characterized in that the recess surface (31) is located in the friction lining (3). Friction member according to one of claims 4 or 5, characterized in that the recess surface (31) is located partly in the friction lining (3) and partly in the insert (6). A dry clutch friction disc comprising a progressive disc (2) and at least one friction member according to any one of claims 1 to 7. Clutch friction disc according to the preceding claim, characterized in that the progressive disc (2) comprises succession zones. Clutch friction disc according to the preceding claim, characterized in that the succession zones comprise vanes capable of axial elastic deformation. Method for producing a friction disc friction disc member of a dry clutch comprising a friction lining (3) and an insert (6), characterized in that the friction lining (3) is glued to the insert (6), the glued assembly (3 + 6) is machined to form rivet fastening holes (7), wherein the holes comprise a first portion having a thickness el in the lining (3) with a constant diameter d1 and a second portion having a thickness e2 + e3 and a diameter d2 that is less than dl so to form a recess surface (31) to support one end of the thread (7) after assembly, wherein the thickness of the lining e2 in the second portion of the holes is between 2 and 15 percent of the total thickness of the friction lining e + e2 (3). Method for producing a friction member according to the preceding claim, characterized in that a cutting recess tool is used for machining the friction lining (3) glued to the insert (6), said cutting tool comprising a first material removal part in the lining (3) and in the insert (6) and forming a hole opening with a diameter d2 on the outer surface opposite to the glued surface on the liner, the insert (6) and the cutting tool also includes a second diameter portion d1 to remove material at least in the liner (3) and forming a recess surface (31). Method for producing a friction member according to the preceding claim, characterized in that the second diameter portion d1 of the cutting recess tool comprises an edge perpendicular to the axis of the cutting recess tool to form a flat recess surface (31). The method of manufacturing a friction member according to claim 12, wherein the second portion of the diameter d1 of the cutting recess tool comprises an edge inclined with respect to the axis of the cutting recess tool to form a conical recess surface (31). A method for producing a friction disc, comprising the step of providing a friction member according to any one of claims 1 to 10, followed by the step of attaching said friction member to the progressive disc (2) by rivets. 2 drawings