FR2801822A1 - Method of crimping control rod for vehicle brake control pedal involves compressing crimping sleeve axially against fixed stops to deform it radially - Google Patents

Abstract

The method of crimping a control rod for a brake control pedal involves radially inwardly deforming a sleeve (4) to capture a projection (5) of a cup (3). It involves longitudinally driving the sleeve along its axis of rotation (ZZ') to deform it radially in a plane transverse against fixed engagement surfaces (8). Claims include a press for forming the crimp

Description

 <U> CRIMPING METHOD, ASSOCIATED CRIMPING DEVICE, AND <U> PUSH </ U> ROD <U> SERENE OBTAINED BY THIS </ U> METHOD.

The present invention relates to a method of crimping its associated crimping device for implementing the method. It also relates to a push rod crimped thanks to the device and the method of the invention.

In several types of mechanical connections, push rods or equivalent parts by their function are used. They are intended to serve as relays between control members such as, for example, a pedal and mechanical devices such as, for example, a braking system.

These push rods or equivalent parts must present for safety reasons a breaking strength which must necessarily remain below a given threshold to break when too much stress.

Thrust rods are advantageously formed in two parts, a rod and a cup, which are assembled together by crimping or welding. However, the assembly processes of the two parts are not entirely satisfactory because they offer too high breaking strength does not allow the piece to break in the desired solicitation range.

To solve this problem, the assembly methods have used a complementary socket intended to trap the rod and the cup together a lateral crimping as, for example, using a wheel. However, the results obtained are not sufficiently reliable and do not allow obtaining sufficient accuracy in the production of the part, in particular because of the undesirable operating play.

Thus, the present invention aims to propose a new crimping process intended to allow the assembly of two mechanical parts accurately and reliably by allowing the repetition of the mechanical characteristics obtained for the part thus assembled, and this, to the using simple, reliable and easy to implement means. It also aims to propose a crimping device for implementing the crimping process of the invention to obtain the assembly of two mechanical parts and in particular assembly of a rod and a cup to form a rod crimped thrust.

According to its main feature, the crimping method is of the type intended to deform radially a sleeve for trapping a projection of a receiving part such as a cup and is characterized that it comprises a main step of soliciting the sleeve in longitudinal displacement along an axis of revolution to obtain its radial deformation in a transverse plane by its cooperation with fixed bearing surfaces relative to the longitudinal movement of the sleeve.

According to a complementary feature of the crimping method of the invention, it is characterized in that it comprises a preliminary step which consists of placing a matrix of a crimping device formed in at least two parts around the projection, and carries the bearing surfaces and an intermediate step which consists in accurately positioning the die to center exactly the longitudinal axis of displacement of the sleeve.

According to another characteristic of the crimping method of the invention, it is characterized in that it comprises a complementary step which consists in simultaneously moving the sleeve and the projection of the receiving part in a common longitudinal movement with respect to the surfaces. support.

It may be noted that the invention also relates to a crimping device for implementing the crimping method, the main characteristic of which is that it comprises a matrix which carries the bearing surfaces formed in at least two moving parts. relative to each other in a transverse plane. According to the preferred embodiment of the crimping device, the matrix is formed of two half-shells mounted with a slight clearance on supports or drawers movable in the transverse plane under the action of mechanical biasing means, said device comprising centering means intended to achieve the alignment between the revolution axis of the socket and the axis of revolution of the matrix.

According to a complementary feature of the crimping device, it comprises centering means for aligning the axis of revolution of the bushing and that of the matrix, these centering means being formed by an outer wall of a bead carrying the bushing and of which the shape of the inner face is identical to that of the outer face of the die to be able to fit exactly around the die and a centering chamfer located on the die or on the outer wall. According to one embodiment of the crimping device, it comprises means of catching the games constituted by a support which is arranged the receiving part, said support being mounted movable in longitudinal translation against elastic return means which urges it in position high.

According to another characteristic of the crimping device of the invention, it comprises a bead for carrying the sleeve to drive it in longitudinal displacement, said bite having the shape of a bell to present a cylindrical peripheral wall intended to block in a transverse plane and hold together half shells that form the matrix during the entire crimping operation.

According to another characteristic of the crimping device of the invention, it is characterized in that it comprises a bead for carrying a rod and a sleeve disposed in abutment on the rod and in that the support is biased in position high so as to allow the radial deformation in a transverse plane of the sleeve between the projection and the support surfaces of the matrix, said support being driven in longitudinal displacement by the cooperation between the rod and the projection. Furthermore, the invention also relates to a push rod set by the crimping method of the invention, it is achieved by crimping a rod on a cup with a socket.

Other features and advantages of the invention will become apparent from the description which follows with reference to the accompanying drawings are given by way of non-limiting examples.

Figures 1 to 10 illustrate the crimping process of the invention and the constituent members of the crimping device associated, they also represent a push rod set by the process.

Figures 1 to 6 illustrate the method of crimping the intervention applied to the crimping of a push rod.

Figure 1 illustrates in longitudinal section the crimping device in the initial position.

Figure 2 illustrates in longitudinal section the establishment of the matrix.

Figure 3 shows in longitudinal section the descent of the press and the centering of the matrix.

Figure 4 shows in longitudinal section the beginning of crimping by the deformation of the sleeve.

Figure 5 illustrates in longitudinal section the play catching at the end of the main step of crimping.

Figure 6 shows in longitudinal section the opening of the matrix and the rise of the press.

FIGS. 7a, 7b, 7c and 7d illustrate in detail detail crimping parts respectively according to FIGS. 2, 3, 4 and 5.

Figure 8 illustrates a crimped push rod.

Figure 9 illustrates a top view of the two parts forming the matrix. Figure 10 illustrates in perspective the holding and centering bell.

According to the invention, the crimping method is intended to allow the crimping of a rod (2) with a cup (3) - by means of a sleeve (4) intended to imprison together a projection (5) of the cup and a stop (6) of the rod. To do this, the bushing comprises an annular abutment surface (4a) intended to bear against the stop (6) rod. It is then deformed radially to trap the projection (5) which is advantageously frustoconical in abutment against the abutment (6) of the rod (2) by eliminating the radial transverse and longitudinal play between the two parts (2, 3).

The assembly of the rod (2) on the cup (3) allows obtaining the push rod (77) as shown in FIG 8. It is obvious that the sleeve (4) and the rod (2) could be made of the same piece to form a single subassembly to be crimped directly on projection (5) on the upper face of the cup (3), for example. Similarly, the crimping method and its associated device could serve to crimp similar mechanical assemblies other than thrust rods, such as piston bodies and their rods, for example, without departing from the protective field of the invention.

The crimping method of the invention is of the type intended to deform radially a bushing (4) or the like to trap a projection (5) of a receiving part (3) or cup. It comprises a main step which consists in urging the sleeve (4) in displacement along a longitudinal axis (ZZ ') to obtain radial deformation in a transverse plane thanks to its cooperation with bearing surfaces (8) of a device crimping (1). According to crimping device (1) illustrated, the bearing surfaces (8) are arranged in a fixed manner with respect to the longitudinal movement of the sleeve (1); however, it is possible that these could also have a longitudinal displacement different from that of the sleeve (4) to create a relative longitudinal translation movement between them.

crimping method of the invention comprises a preliminary step which consists in positioning around the projection (5) of the receiving part a matrix (9) of a crimping device (1) which carries the bearing surfaces (8) . It also comprises an intermediate centering step intended to precisely position the bearing surfaces (8) in the transverse plane relative to the longitudinal axis (ZZ ') according to which moves the sleeve (4).

Once the matrix (9) and its support surfaces (8) are positioned and centered with respect to the longitudinal axis (ZZ ') during the preliminary and intermediate steps illustrated in FIGS. 2 and 3, the sleeve is set in motion during the main crimping step illustrated in FIG. 4, to come to deform radially in contact with the bearing surfaces (8) in order to trap the projection (5) as shown in FIGS. 7c and according to the invention, the crimping method also comprises a complementary step illustrated in FIG. 5, which consists in moving the receiving piece (3) and its protrusion (5) in a common longitudinal displacement with the sleeve (4) with respect to the matrix (9) in order to make up for the longitudinal clearances and existing transversals. It can be noted that this common displacement is generated by the stop (6) of the rod (2) which abuts against the projection (5) to drive the part (3) in this displacement. Next, the final step of the process, illustrated in FIG. 6, is to move the die (9) to allow removal of the thus assembled piece. According to the illustrated embodiment of the crimping device (1) and the assembled push rod. (7), the projection (5) of the receiving cup and the bearing surfaces (8) of the matrix (9) have a profile of similar shape and of substantially equal size, the bearing surfaces (8) having, however, slightly higher dimensions to allow the passage of the cylindrical wall forming the sleeve (4) between the walls of the projection (5) and the bearing surfaces (8). The shape of the projection (5) and therefore of the bearing surfaces (8) is advantageously conical (5a, 8a) at their base and is extended by a cylindrical portion (5b, 8b) at their upper end.

According to the preferred embodiment of the crimping device (1), the matrix (9), comprising the bearing surfaces (8), is formed in at least two parts (9a, 9b) movable together so as to allow its placing transversely around the projection (5) of the cup (3) during the preliminary step illustrated in FIG. 2. The matrix (9) is thus advantageously formed of two half-shells mounted movable in lateral translation in the transverse plane under the action of mechanical biasing means such as pneumatic or hydraulic cylinders (10). These half-shells (9a, 9b) have an external semicylindrical shape and an internal bore forming the bearing surfaces (8) whose configuration is a function of the shape and dimensions of the projection (5) on which the crimping takes place . In the illustrated embodiment, the internal bore of the half shells (9a, 9b) has a conical portion (8a) whose generator forms an angle with the longitudinal axis of displacement (ZZ ') of the sleeve (4) when the matrix (9) is positioned.

According to the preferred embodiment of the crimping device, the latter comprises centering means (MC) intended to achieve alignment between the longitudinal axis (ZZ ') of the sleeve (4) and the axis of revolution of the the matrix (9). To do, the sleeve (4) and the rod (2) which carries it are arranged in a bead (11) movable longitudinally along the axis (ZZ ') under the action of a press relative to the frame (12) on which are mounted transversely movable half shells (9a, 9b). This bead (11) comprises a peripheral cylindrical wall (13) intended to cooperate with the outer face (15) of the half-shells (9a, 9b) to exactly match the axis of revolution (ZZ ') of the socket and bent (4, 11) with the axis of revolution of the die (9).

Thus, when the bite (1 is moved longitudinally under the action of a force or impact press, for example, the outer wall (13) is positioned around the die (9), thanks to the half shells (9a, 9b) which are advantageously mounted very slightly floating on their supports (14) actuated by the jacks (10) Note that the half shells (9a, 9b) have a ramp or a centering chamfer (15a) to the upper end of their outer face (15) to allow the wall (13) to move transversely the two half-shells (9a, 9b) to perfectly center the matrix (9), this being done in particular through the play of half shells on their supports 4). The centering means (MC), whose operation is illustrated in FIGS. 3 and 7b, are thus formed by the cylindrical outer wall (1) which gives the bead (11) a bell shape, as shown in the figure and by the outer centering chamfer (15a) of the matrix (9) and its design in half shells, which allows the matrix, thanks to mounting clearance, to fit perfectly into the bell during the main stage and the complementary step of the process .

It is important to note that the half-shells (9a, 9b) and the bell (11, 13) are accurately adjusted so that, during the crimping steps, the die (9) is perfectly closed and is shaped like a piece unique to prevent the flow of material between the half-shells. It goes without saying that the centering bevel of the half-shells could be located on the bell without departing from the protective field of the invention.

According to the preferred embodiment, the crimping device (1) comprises holding means intended to compensate for the forces that occur on the half-shells during crimping to prevent the spacing of the half-shells. These means are advantageously made by the bell (11, 13) whose outer wall (13) holds the assembled matrix during all the crimping steps. It goes without saying that the centering means that make it possible to align the sleeve and the matrix as well as the aforementioned holding means could not be obtained by the same part, namely, the bell, as in the embodiment of the device of crimping described, but be obtained by different independent constituent bodies, without departing from the scope of the invention. One could thus imagine that it is the bite carrying the bushing which is aligned with a fixed matrix in the transverse plane and whose elements constituting it would be held by lateral jacks to compensate for the effort which tends to disassemble the matrix .

According to another characteristic of the crimping device (1) of the invention and as shown in FIGS. 5 and 7d, the latter comprises means for catching the clearances (MR) intended to eliminate any longitudinal axial play and / or any radial play. transverse between the rod (2) and the cup (3). These game recovery means (MR) are constituted by the support (16) of the receiving part (3) and by positioning and displacement means (MD) of said support.

To do this, the support (16) is mounted on the frame (12) so as to be able to move in translation along the axis of revolution (Z Z ') between an upper position illustrated in FIGS. 1, 2 and 3 and a low position not shown. Resilient biasing means such as a spring (17) continuously bias the support (16) towards its upward position; in this high position, the projection (5) of the cup (3) disposed on the support (16), has a sufficient space between its outer wall and the support walls (8) of the matrix (9) to allow the passage of the wall of the sleeve (4) which deforms, said space being greater than the thickness of the sleeve (4).

According to the preferred embodiment of the crimping device, when the rod (2) disposed in the bead (11) bears against the upper face (5c) of the projection (5) and the sleeve (4) is partially deformed to slide between the projection and the bearing walls (8), the rod (2) drives the cup (3) and protruding (5) in longitudinal displacement against the elastic return means (17) which solicit the support (16) which carries them. This common movement of the rod (2), the cup (3) and the sleeve (4) allows the deformation of the sleeve (4) until the projection (5) abuts against the wall of the socket (4), itself abuts on the conical bearing surface (8a) of the matrix (9) as shown in Figure 7d, thus removing all the gaps between the crimped parts.

note that if the centering of the matrix (9) provided by the bell (11, 13) and the floating assembly of the half-shells (9a, 9b) through a connection by screw shouldered on the supports (14) drawers that are actuated by the lateral cylinders, the alignment between the axis of the support (16) and the cup (3) and the axis of displacement (ZZ ') of the rod (2) and the sleeve (4) is obtained thanks to conventional control means in a manner known per se.

It may also be noted that the invention relates to push rods (7) obtained by the crimping method described. These rods are advantageously made in three parts, the rod (2), the crimping sleeve (4) and the cup (3), the said (2, 3) being crimped - the sleeve so as to remove the longitudinal clearance and the transverse clearance between them, only the pivoting around the axis of revolution (ZZ ') constituting a degree of freedom of the rod relative to the cup. These push rods are advantageously intended to be used in. braking systems of motor vehicles.

Of course, the invention is not limited to the embodiments described and shown by way of examples, but it also includes all the technical equivalents and their combinations.

Claims (1)

<U> CLAIMING </ U> Crimping method of the type intended to deform radially sleeve (4) for trapping a projection (5) of a receiving part (3) such as a cup characterized in that it comprises a main step which consists in urging the sleeve (4) in longitudinal displacement along its axis of revolution (ZZ ') to obtain its radial deformation in a transverse plane by its cooperation with bearing surfaces (8) fixed relative to longitudinal movement of the sleeve (4). 2. Crimping method according to claim 1. characterized in that it comprises a preliminary step of placing around the projection (5) a matrix (9) of a crimping device (1) formed at least two parts (9a, 9b) and which carries the bearing surfaces (8) and an intermediate step which consists in precisely positioning the die to center it exactly on the longitudinal axis (ZZ ') of displacement of the sleeve (4). ). Crimping method according to any one of the preceding claims characterized in that it comprises a complementary step which consists in simultaneously moving the sleeve (4) and the projection (5) of the piece (3) in a common longitudinal movement relative to to the bearing surfaces (8). 4. crimping device (1) for implementing a crimping method according to any preceding claim characterized in that it comprises a matrix (9) which carries the bearing surfaces (8) formed in at least two portions (9a, 9b) movable relative to each other in a transverse plane. 5. crimping device (1) according to claim 4 characterized in that the matrix is formed of two half-shells (9a, 9b) mounted with a slight clearance on supports or drawers (14) movable in the transverse plane under the action of mechanical biasing means (10) in that it comprises centering means (MC) intended to achieve alignment between the axis of revolution (ZZ ') of the sleeve (4) and the axis of revolution of the matrix (9). 6. crimping device (1) according to any claim 4 or 5 characterized in that it comprises centering means (MC) for aligning the axis of revolution of the sleeve (4) and that of the die (9), these centering means being formed by an outer wall (13) of a bead (11) which carries the sleeve (4) and whose shape of the inner face is identical to that of the outer face (15). the die (9) to fit exactly around the die (9) and a centering chamfer (15a) located on the die (9) or on the outer wall (13). Crimping device (1) according to any one of claims 4 to 6, characterized in that it comprises means of catching the games (MR) constituted by a support (16) on which is disposed the receiving part (3), said support being mounted movable in longitudinal translation against resilient biasing means (17) which bias it in the high position. Crimping device (1) according to any one of claims 4 to 7 characterized in that it comprises a bead (11) for carrying the sleeve (4) to drive it in longitudinal displacement, said bit having the form of a bell for presenting a cylindrical peripheral wall (13) for locking in a transverse plane and holding together the half-shells (9a, 9b) which form the matrix (9) during the whole crimping operation. Crimping device (1) according to claim 7 characterized in that it comprises a bead (11) intended to carry a rod (2) and a bush disposed in abutment on the rod and in that the support (16) is biased in the up position to allow radial deformation in a transverse plane of the bushing (4) between the projection (5) and the bearing surfaces (8) of the die (9), said support (16) being driven in longitudinal displacement by the cooperation between the rod (2) and the projection (5). 10. Push rod (7) crimped by a crimping method according to any one of claims 1 to 3 characterized in that it is performed by crimping a rod (2) on a cup (3) using a socket (4).