KR20100016321A - Friction member for a clutch friction disk - Google Patents

Abstract

The invention relates to a friction member for a disk of a dry clutch, including a friction fitting (3) glued to an intermediate part (6) in which holes are formed after gluing said fitting and said intermediate part for allowing attachment with rivets (7), and include a first portion with a thickness ein the fitting (3) and a constant diameter d, and a second portion with a thickness e+ eand a diameter smaller than d, in order to define a spot facing surface (31) on which bears the end of a rivet (7) after assembly, wherein the thickness eof the fitting in the second portion of the holes represents between 2 and 15% of the total thickness e+ eof friction fitting (3). The invention also relates to an associated method.

Description

Friction member for clutch friction disk {FRICTION MEMBER FOR A CLUTCH FRICTION DISK}

The invention relates in particular to a friction member for a dry clutch friction disk for a vehicle.

Clutch friction discs are generally mounted on a shaft called a driven shaft, and the pressure plate and reaction plate of the clutch that are forced to rotate with the shaft known as the driving shaft. It is intended to be inserted between). When the clutch is engaged, the pressure plate clamps the friction disk against the rebound plate.

The present invention can be applied to any type of friction disk, but is particularly useful for clutch friction disks known as progressive clutch friction disks.

As shown, for example, in FIGS. 7 and 8 of French Patent No. 1 304 067, the progressive clutch friction disk comprises a substantially flat ring-shaped metal support, commonly referred to as a "progressive disk". The outer circumference of the progressive disc is branched to form a blade that is integrally formed with or attached to the ring.

These blades are alternately bent to form portions that are offset on both sides of the mean plane and are suitable for elastic deformation under the influence of clamping forces.

Ring-shaped friction facings are attached to both sides of the support, which are secured to a portion of the offset portion by any suitable means.

The blade is elastically deformed while clamping the offset portions proximate to each other.

This results in progressive clamping of the friction disk and thus progressive transmission of the rotational torque during clutch engagement operation, whereby vibrations are significantly reduced.

The blade includes cut-outs and holes to increase elasticity.

In operation, the friction facing is heated by considerable heat, which tends to weaken the surface hardness.

Due to the influence of the clamping force acting on the facing, it is frequently experienced such as insertion of the blade into the facing, which leads to a loss of elasticity and thus a loss of progressivity.

To avoid this drawback, it has been proposed to arrange intermediate parts, in particular steel strips or foils, bonded to each facing between the facing and the blade.

Such a device, which can be seen in FIGS. 7 and 8 of French Patent No. 1 304 067, mentioned above, proves satisfactory.

In order to produce this kind of friction discs by techniques known in the art, the friction facings and intermediate portions which are glued together as a result are perforated separately.

Facing adhered to the middle portion is usually attached to the progressive disc by rivets. In a manner known in the art, the rivet is smaller than the diameter of the two ends, the head portion which is undeformed or slightly deformed during assembly and the diameter whose diameter increases when compressed during assembly, and the end of the rivet after assembly. It has a body of diameter. The diameters of the ends of the rivets are generally substantially the same after assembly. After assembly, the end of the rivet needs to be supported on the material portion of each part to be assembled.

Two methods are used to assemble the facing adhered to the middle portion of the progressive disk described in detail herein using the reference from FIG. 3A, in which the facing 3 is the middle portion 6. Adheres to

The facing 3 comprises a hole having a wide diameter portion 32 of a constant diameter d ₁ and a thickness e ₁ large enough for the rivet end to pass after assembly and is assembled without allowing passage of the rivet end. And a narrow portion 33 of diameter d ₂ and thickness e ₂ to allow movement of the rivet body later. At the bottom of the wide part 32 is a spot facing surface 31 on which the rivet end can be supported after assembly. The spot facing surface 31 has a shape complementary to the selected shape of the rivet end after assembly and may be planar or conical. The intermediate part 6 of thickness e ₃ comprises a hole 61 of diameter d ₃ (not shown) which allows movement of the rivet body after assembly without allowing passage of the rivet end, and the attachment It is arranged to face a hole in the facing before.

In a first assembly method known in the art, the spot facing surface 31 is formed within the thickness of the facing. The inventor has found that a material of considerable thickness (e ₂ ) must be maintained in order to perforate the facing in this manner without damaging the facing. It is assumed that it is necessary to maintain a thickness e ₂ of at least 20% of the total thickness e ₁ + e ₂ of the facing. This thickness e ₂ is the distance between the portion of the spot facing face that is farthest away from the surface of the facing to be assembled with the intermediate portion and its surface of the facing. For example, a typical facing for use in a private vehicle has a thickness of 3 mm and a gap of 0.9 mm (e ₂ ), especially for facing industrial vehicles such as heavy transport vehicles. , 1.3 mm or even 1.45 mm or 1.6 mm apart (e ₂ ). This minimum thickness e ₂ , despite being advantageous in terms of piercing quality, limits the thickness of the facing material that may wear out during the service life of the friction disc. The depth of wear is limited by the position of the rivet end after assembly, since the rivet end must not contact the clutch plate, assuming the risk of very serious damage. The facing punched in this way is then bonded to the predrilled intermediate portion 6 with holes of diameter d ₃ , the axis of the intermediate portion substantially coinciding with the axis of the drilled hole in the facing.

In a second assembly method known in the art, holes of constant diameter d ₁ are drilled through the entire thickness of the facing, the facings are then pre-drilled intermediate part 6 with holes of diameter d ₃ . ), The axis of the intermediate portion substantially coincides with the axis of the perforated hole in the facing. In this embodiment, the rivet end after assembly is only supported on the middle part, and the facing does not contribute to the connection strength to the friction disk. This generally causes weakening of such connections compared to previous solutions and is particularly sensitive during rivet shaking tests to ensure centrifugal strength.

It is an object of the present invention to solve the above drawbacks and to propose a solution which harmonizes that the facing may wear as much as possible and at the same time contribute to the connection to the friction disk.

This object is a friction member of a dry clutch disc, comprising a friction facing 3 bonded to an intermediate portion, wherein a hole is formed to allow fixing by rivets after the facing and the intermediate portion are bonded to each other, and the hole is The first portion of the thickness e ₁ and the constant diameter d ₁ and the thickness e ₂ + e ₃ and the diameter of the first portion in the facing, such that the end face of the rivet constitutes a spot facing surface which is supported after assembly. and a second portion of diameter d ₂ smaller than (d ₁ ), wherein the thickness e ₂ of the friction facing in the second portion of the hole is from 2% of the total thickness e ₁ + e ₂ of the facing. Achieved by a friction member in the 15% range.

Due to this shape, the facing of the present invention can be worn more than in methods known in the art in which the facing contributes to the connection to the friction disk. The diameter of the hole in the second part of the thickness (e ₂ + e ₃ ) is constant and may be equal to the diameter d ₂ of the hole opening to the side of the intermediate portion opposite the face bonded to the facing. In this case, the spot facing surface is flat and parallel to the friction surface of the facing (surface delegation opposite the face of the facing bonded to the intermediate portion) to accommodate the rivet end with the flat bearing surface after assembly. The diameter of the aperture in the second portion of the thickness (e ₂ + e ₃₎ may be reduced to d ₂ corresponding to the diameter of a hole opened in the middle portion side opposite to the bonded surface in the pace from d _1. This kind of shape accommodates the rivet end with the conical bearing face after assembly due to the conical spot facing face.

The facing preferably consists of a continuous filament infused with one or more resin containing charges. It is preferable that a filament is glass fiber, organic fiber, and metal fiber. They are advantageously lobed.

In one embodiment of the friction member according to the invention, the intermediate part is a metal plate.

In the case of a conical spot facing face, the angle α of the cone with respect to the face parallel to the friction face of the facing may be between 3 ° and 30 °.

In the case of a conical spot facing face, it may be entirely in facing or only partially in facing.

It should be noted that the tolerance for the angle of the spot facing is generally on the order of ± 3 °.

The invention also relates to a dry clutch friction disk comprising a progressive disk and at least one said friction member.

Progressive discs may include progressive areas. These may include blades that are elastically deformable in the axial direction.

The present invention also relates to a method for manufacturing a friction member of a dry clutch friction disk comprising a friction facing and an intermediate portion, the method comprising the steps of adhering the friction facing to the intermediate portion and forming the fixing hole for the rivet. And machining said hole, said hole having, after assembly, a first portion and thickness e of thickness e ₁ and constant diameter d _{1 in the} facing such that the end face of the rivet constitutes a spot facing surface. ₂ + e ₃ ) and a second portion of diameter d ₂ smaller than the diameter d ₁ of the first portion, wherein the thickness e ₂ of the friction facing in the second portion of the hole is the total thickness of the facing. it is in the range 2% to 15% of (e ₁ + e ₂ ).

Machining is preferably done using a cutting tool, but indentation or corrosion techniques may be considered, for example. The cutting tool allows for example drilling or milling techniques or other suitable techniques.

In one embodiment of the method of the invention, a spot facing cutting tool is used to machine the friction facing and the intermediate part when they are glued to each other, which cuts the material in the facing and the intermediate part and adheres to the facing. And a first portion for forming a hole of diameter d _{2 that} is open to the outer surface of the intermediate portion opposite the curved surface, the cutting tool further comprising: at least for removing material in the facing and forming a spot facing surface. A second portion of diameter d ₁ .

The second portion of the diameter d ₁ of the spot facing cutting tool may have an edge perpendicular to the axis of the cutting tool to form a flat spot facing surface.

The second portion of the diameter d ₁ of the spot facing cutting tool may have an edge that is inclined with respect to the axis of the cutting tool to form a conical spot facing surface.

The spot facing cutting tool can be for example a spot facing drill or a spot facing milling tool.

The present invention also relates to a method of manufacturing a friction disk comprising the step of manufacturing the friction member and securing the friction member to the progressive disk by riveting.

1 is a view of a friction disk,

2 is a cross-sectional view taken along line A-A of FIG. 1 of the assembled component of the friction disk of the present invention;

3A to 3C are cross-sectional views of a part of three modifications of the friction member of the present invention;

4 is a cross-sectional view taken along line B-B of FIG. 1 of the assembled component of the friction disk of the present invention.

The invention is now described in detail with reference to the non-limiting examples shown in the accompanying drawings.

For clarity, the dimensions of the various elements shown in these figures are not proportional to the actual dimensions. In all drawings, the same reference numerals correspond to the same elements.

In the context of the present invention, the terms "axial", "axially", "radial" and "radially" refer to the axis of rotation of the friction disk. As defined, "axial" means a direction parallel to this axis of rotation, and "radial" means a direction passing through the axis perpendicular to that axis.

1 shows a front view of a friction disk 1 comprising a hub 5 suitable for fastening to a driven shaft, a friction facing 3 and a progressive disk 2 shown in dashed lines. Elastic means, in particular springs 4, are arranged for damping and / or filtering the vibrations transmitted from the drive shaft to the driven shaft.

FIG. 2 is a cross-sectional view of the friction disk of the present invention taken along the line A-A of FIG. 1 showing the components after assembly. On each side of the progressive disc 2 there is an intermediate portion 6 between the progressive disc and the facing 3. The facing has a portion 32 wide enough to receive the rivet end 7 after assembly and a narrow portion 33 that allows movement of the rivet end after assembly without allowing passage of the rivet end. At the bottom of the wide part 32 is a spot facing surface 31 on which the rivet end can bear after assembly. In addition, the part of the intermediate part 6 intended to contact the area of the hole 33 in the facing comprises a hole 61 of the same diameter, and the progressive disc 2 likewise comprises a hole 21. The intermediate part 6 and the facing 3 on the opposite side of the progressive disc comprise holes 62 and holes 34, respectively, suitable for allowing the rivet end to pass after assembly. The rivet 7 is crimped to fasten the facing and progressive discs pre-adhered to the middle part, the head of the rivet being at the side in contact with the spot facing face 31, for example, and the other end of the rivet Squeezed onto the progressive disc, the rivet body drills holes 33, holes 61 and holes 21.

After assembly, there is a gap e between the two intermediate portions due to the presence of a progressive area in the progressive disc, in particular in the form of an axially elastically deformable blade. Such blades are shown in dashed lines in FIG. 1 and in cross-section in FIGS. 2 and 3.

Here, the blade is attached to a plate which has been cut in advance and formed to form the progressive disc 2.

3A-3C show enlarged cross-sectional views taken along the line A-A of FIG. 1 for a portion of the friction member to show the different hole shapes of the present invention that enable fastening by rivets.

3A shows the case where the facing comprises a flat spot facing surface. The fixing holes by the rivets have a first portion of the thickness e ₁ and a constant diameter d ₁ in the facing, and a diameter d smaller than the thickness e ₂ + e ₃ and the diameter d ₁ of the first portion. ₂ ) the thickness e ₂ is the thickness of the second part in the facing face and the thickness e ₃ is the thickness of the intermediate part 6.

3B and 3C show two embodiments in which the facing comprises a conical spot facing face that is inclined at an angle with respect to the face parallel to the friction face of the face.

The fixing holes by the rivets have a _first portion of thickness e ₁ and a constant diameter d ₁ in the facing and a second portion of diameter e ₂ + e ₃ and a diameter decreasing from d ₁ to d ₂ . A diameter d ₂ corresponds to the diameter of the hole opening to the face of the intermediate part 6 opposite the face bonded to the facing 3.

In the embodiment shown in FIG. 3B, the spot facing face 31 lies entirely within the facing 3. The second part of the thickness e ₂ + e ₃ of the fixing hole in the friction member is the thickness e ₂₁ and the portion in the facing of the diameter decreasing from d ₁ to d ₂ , the thickness e ₂₂ and the constant diameter ( d ₂ ) and the portion in the facing and the portion in the middle of the thickness e ₃ and the constant diameter d ₂ . The thickness (e ₂₎ of pacing in the second part of the fixing holes is the sum of the thickness (e ₂₁₎ to the thickness (e _22).

In the embodiment shown in FIG. 3C, the spot facing surface 31 is partly in the facing 3 and partly in the intermediate part 6. The second portion of the thickness e ₂ + e ₃ of the fixing hole in the friction member is from the thickness e ₂ and the portion in the facing of the diameter decreasing from d ₁ to d ₁₂ , and from the thickness e ₃₁ and d ₁₂ . a portion in the middle portion of the diameter decreasing to d ₂ and a portion in the middle portion of the thickness e ₃₂ and a constant diameter d ₂ . The thickness e ₃ of the intermediate portion 6 is the sum of the thickness e ₃₁ and the thickness e ₃₂ .

4 is a cross-sectional view taken along line B-B of FIG. 1 of the same friction disk as shown in FIG. The progressive disc 2 comprises two blades, the first part of which is in sliding contact with the first intermediate part 6, the second part being fixed to the second intermediate part 6, It is clear that the three parts are fixed to the first intermediate part 6 and the fourth part is in sliding contact with the second intermediate part 6. The result of this is that, in FIG. 4, the area of the progressive disc has a wave shape that describes the progressive action of the friction disc.

The examples set forth in Table 1 below represent a non-limiting embodiment of the invention as compared to the prior art embodiments.

TABLE 1

Flat spot facing surface Conical Spot Facing Faces Thickness (mm) Example 1 Example 2 Example 3 Example 4 Example 5 e ₁ + e ₂ 3 3 3 3 3 e ₁ 2.1 2.6 2.1 2.6 2.8 e ₂ e ₂₁ e ₂₂ 0.9 0 0.9 0.4 0 0.4 0.9 0.7 0.2 0.4 0.3 0.1 0.2 0.2 0 e ₃ e ₃₁ e ₃₂ 0.3 0 0.3 0.2 0 0.2 0.3 0 0.3 0.2 0 0.2 0.2 0.1 0.1 e ₂ / (e ₁ + e ₂ ) 30% 13% 30% 13% 7%

Examples 1 and 3 are examples for comparison, in which the facing is pre-punched and then also assembled in the pre-punched intermediate part. For example 1 the spot facing surface is flat while for example 3 it is conical. Of pacing in the second part of the clamping hole in the thickness (e ₂₎ is 30% of the total thickness of the facing.

Examples 2, 4 and 5 are examples of the invention wherein the facing is adhered to the intermediate portion prior to drilling. For example 2 the spot facing surface is flat while for example 4 and 5 it is conical. The conical spot facing face of Example 4 lies entirely within the facing, while the spot facing face of Example 5 lies partially in the pacing and partially in the middle.

The test was conducted after the assembly of the pressure plates after assembly by means of riveted ends, while the embodiments of Examples 2, 4 and 5 provided the same level of centrifugal force strength as the embodiments of Examples 1 and 3, while at the same time securing the friction member to the progressive disc. Revealed that the facings would wear more before the risk of damage.

The invention is not limited to these types of examples and should be construed in a non-limiting manner including any equivalent examples.

Claims (15)

In the friction member of a dry clutch disc, A friction facing (3) bonded to the intermediate portion (6), After the friction facing and the intermediate portion are bonded to each other, a hole is formed to allow fixing by the rivets 7, The hole is provided with a first portion of a thickness e ₁ and a constant diameter d _{1 in} the friction facing 3 so as to constitute a spot facing surface 31 on which the end of the rivet 7 is supported after assembly, A thickness of the friction facing 3 in the second portion of the hole, the second portion having a thickness e ₂ + e ₃ and a diameter d ₂ smaller than the diameter d ₁ of the first portion. (e ₂ ) is in the range of 2% to 15% of the total thickness (e ₁ + e ₂ ) of the friction facing Friction member. The method of claim 1, The intermediate part 6 is characterized in that the metal plate Friction member. The method according to claim 1 or 2, The spot facing surface 31 is characterized in that it is flat and parallel to the friction surface of the friction facing. Friction member. The method according to claim 1 or 2, Said spot facing surface 31 is conical Friction member. The method of claim 4, wherein The angle (α) between the surface parallel to the friction surface of the friction facing and the cone is characterized in that 3 ° to 30 ° Friction member. The method according to claim 4 or 5, The spot facing surface 31 is characterized in that it is in the friction facing 3. Friction member. The method according to claim 4 or 5, The spot facing face 31 is characterized in that part is in the friction facing 3 and part is in the intermediate part 6. Friction member. In a dry clutch friction disk, Progressive disk (2), Claims 1 to 7 comprising at least one friction member according to claim Dry clutch friction disc. The method of claim 8, The progressive disc comprises an area of progressivity. Dry clutch friction disc. The method of claim 9, The progressive region comprises a blade configured to elastically deform in the axial direction Dry clutch friction disc. In a method of manufacturing a friction member of a dry clutch friction disk comprising a friction facing (3) and an intermediate portion (6), Adhering the friction facing 3 to the intermediate portion 6; Machining the assembly of the friction facing 3 and the intermediate part 6 adhered to each other to form a fixing hole for the rivet 7, The hole is provided with a first portion of thickness e ₁ and of constant diameter d ₁ , thickness e ₂ + e ₃ , and so as to constitute a spot facing surface on which the end of the rivet is supported after assembly. And a second portion of diameter d ₂ smaller than the diameter d ₁ of the first portion, wherein the thickness e ₂ of the friction facing in the second portion of the hole is equal to the total thickness of the friction facing ( e ₁ + e ₂ ), characterized in that in the range of 2% to 15% Friction member manufacturing method. The method of claim 11, A spot spot cutting tool is used to machine the friction facing 3 and the intermediate part 6 when they are bonded together, The cutting tool has a diameter d ₂ that removes material in the friction facing 3 and the intermediate portion 6 and opens to the outer surface of the intermediate portion 6 opposite the face bonded to the friction facing. A first portion for forming a hole, The cutting tool further comprises a second portion of diameter d ₁ for removing at least material in the friction facing 3 and forming a spot facing surface 31. Friction member manufacturing method. The method of claim 12, Characterized in that the second portion of the diameter d ₁ of the spot facing cutting tool has an edge perpendicular to the axis of the spot facing cutting tool to form a flat spot facing surface 31. Friction member manufacturing method. The method of claim 12, Characterized in that the second portion of the diameter d ₁ of the spot facing cutting tool has an edge which is inclined with respect to the axis of the spot facing cutting tool to form a conical spot facing surface 31. Friction member manufacturing method. Manufacturing a friction member according to any one of claims 1 to 10, Securing the friction member to the progressive disc by riveting; Friction Disc Manufacturing Method

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