WO2014006315A1

WO2014006315A1 - Stub-axle bracket with hollow portions by core-making

Info

Publication number: WO2014006315A1
Application number: PCT/FR2013/051541
Authority: WO
Inventors: Laurent SOULAT
Original assignee: Renault S.A.S
Priority date: 2012-07-05
Filing date: 2013-07-01
Publication date: 2014-01-09
Also published as: FR2992892B1; FR2992892A1

Abstract

The invention relates to a stub-axle bracket (10) which includes an integral moulded part forming a support element (11) defining a recess (15) for rotatably mounting the hub as well as a plurality of linking elements (12, 13, 14) which are to be attached to various members secured to the vehicle and associated with said linking elements, respectively, in order to ensure the attachment of the stub-axle bracket onto the vehicle. The integral moulded part includes hollow portions (111, 121, 131, 141) formed by core-making in the support element as well as in all of the linking elements. Each of the hollow portions connects to another hollow portion such that all of the hollow portions communicate with one another and define, on the inside of the integral moulded part, a cavity that extends in the support element and in each of the linking elements. The invention also relates to an arrangement and a manufacturing method.

Description

Rocket support with hollow parts by coring

TECHNICAL FIELD OF THE INVENTION The invention relates to a rocket support for the rotational mounting of a hub of a wheel of a motor vehicle, comprising a one-piece molded part (cast iron, steel, aluminum, etc.) constituting on the one hand a support element delimiting a housing intended for the rotational mounting of the hub and on the other hand a plurality of connecting elements intended to be respectively fixed to different integral members of the vehicle and respectively associated with said elements link for securing the rocket carrier to the vehicle.

The invention also relates to an arrangement for a motor vehicle wheel train, in particular a front or rear axle, and a process for the casting of the rocket support.

State of the art Conventionally, to build a wheel train of a motor vehicle, including a nose gear, each wheel of the train is associated with a substantially cylindrical hub, also known as "rocket". The hub is rotatably mounted relative to a rocket or knuckle support via a bearing. The rocket support, currently obtained at least by a foundry operation, comprises for this purpose a support member delimiting a housing for receiving the bearing. For attachment to the rest of the vehicle, the rocket carrier also includes a plurality of link members, including:

a connecting element to a lower suspension arm secured to the vehicle, in particular with the interposition of a ball joint,

and / or a connecting element to a steering rod secured to the vehicle, in particular with the interposition of a ball joint, and / or a connecting element to a damping device and / or spring secured to the vehicle, in particular by a screw connection or a clamping or clamping connection. In the case of a Mac-Pherson or pseudo MacPherson type front or rear axle, the rocket support comprises each of these three connecting elements in addition to the support element, which is generally arranged in the center of the elements. link. It may also comprise fixing elements intended for fixing a braking device, in particular a brake caliper and / or a wheel lock monitoring sensor, a bearing sealing function at the interface with the transmission, disc guard fastener elements and ball joint bellows protector.

It thus raises, in addition to the ease of obtaining, the essential problematic of the weight formed by this set with respect to the respect of the specifications in terms of respect of the mechanical stresses in normal operation and in case of shock.

In an attempt to meet these objectives, the documents EP1894816A2, EP0776814A1 and EP0980814A2 describe solutions where the connecting element of the rocket support to the damping device comprises a hollow portion obtained by coring at the time of the foundry operation.

Object of the invention

The object of the present invention is to provide a rocket support that overcomes the drawbacks listed above, in particular that is easy to obtain, which has a weight content while having a resistance adapted to compliance with a specification of operation. normal and shock conditions.

A first aspect of the invention relates to a rocket support for the rotational mounting of a hub of a wheel of a motor vehicle, comprising a one-piece molded part constituting on the one hand a support element delimiting a housing intended for the rotational mounting of the hub and on the other hand a plurality of connecting elements intended to be respectively fixed to different integral members of the hub; vehicle and respectively associated with said connecting elements for fixing the rocket support on the vehicle. The one-piece molded part comprises hollow parts formed by coring both in the support element and in all the connecting elements, each of the hollow parts opening into another hollow part so that all the hollow parts communicate with each other. and defining within the one-piece molded part a cavity extending in the support member and in each of the connecting members.

The hollow portion formed in the support member may be arranged at the periphery of said housing, in particular in an annular manner generally included in a plane perpendicular to the axis of a bore constituting the housing.

The housing may be configured to allow for force-fitting of an outer cage of a hub-rotating guide bearing.

The plurality of connecting elements may comprise a first connecting element made of material from the support element and intended to be fixed, in particular by a first ball joint connection, to a lower suspension arm integral with the vehicle constituting a integral member of the vehicle and associated with said first connecting element.

The first link member may be configured such that the hollow portion formed in the first link member opens into the hollow portion formed in the support member.

The plurality of connecting elements may comprise a second connecting element made of material from the support element and intended to be fixed, in particular by a second ball joint connection, to a steering rod secured to the vehicle, constituting a member secured to the vehicle and associated with said second connecting element. The second link member may be configured such that the hollow portion formed in the second link member opens into the hollow portion formed in the support member.

The plurality of connecting elements may comprise a third connecting element made of material from the support element and intended to be fixed, in particular by a screw connection or a clamping or clamping connection, to a damping device and / or spring secured to the vehicle, constituting a member integral with the vehicle and associated with said third connecting element.

The third link member may be configured such that the hollow portion formed in the third link member opens into the hollow portion formed in the support member. The one-piece molded part may comprise fixing elements intended for fixing a braking device, in particular a brake caliper and / or a wheel lock monitoring sensor.

A second aspect of the invention relates to an arrangement for a motor vehicle wheel train, in particular a front or rear gear, which comprises such a rocket support, a wheel of the vehicle and a hub integral with the wheel and mounted to rotate at the the housing delimited by the support member of the integrally molded part of the rocket support. The arrangement may include: at least one lower suspension arm fixed, in particular by a first ball joint, to a first connecting element of the one-piece molded part of the rocket support,

and / or a steering rod fixed, in particular by a second ball joint, to a second connecting element of the one-piece molded part of the rocket support,

and / or a damping and / or spring device fixed, in particular by a screw connection or a clamping or clamping connection, to a third connecting element of the one-piece molding of the rocket support, the assembly being configured so that to build a Mac-Pherson or pseudo Mac-Pherson wheelset.

It may comprise a bearing for rotating the hub having an outer cage force-fitted in a bore of the housing and an outer cage force-fitted on the hub.

A third aspect of the invention finally relates to a method of manufacturing by casting a rocket support for the rotational mounting of a hub of a wheel of a motor vehicle, comprising a casting step of an alloy in a mold configured so as to obtain, after cooling of the cast alloy, a one-piece molded part constituting on the one hand a support element intended for the rotational mounting of the hub and on the other hand a plurality of elements linkages intended to be respectively fixed to different integral members of the vehicle and respectively associated with said connecting elements to ensure the attachment of the rocket carrier on the vehicle. The method comprises a step of providing a single core and placing the core in the mold prior to the casting step, the core and its implementation being configured so that at the end of the casting step, the one-piece molded part comprises hollow parts formed by coring resulting from the presence of the core during casting, both in the support member and in all the connecting elements, and that each of the hollow parts opens into another part digs so that all of hollow portions communicate with each other and delimit, within the single-piece molded part, a single cavity corresponding to all or part of the impression left by the casting core and which extends both in the support member and in each of the connecting elements.

The core used may include, for its implementation in the mold:

at least a first scope for positioning the core relative to the mold and arranged at a zone of the core forming, after casting, the hollow portion formed in a connecting element of the one-piece molded part, in particular coming from material from its support member and intended to be fixed, in particular by a ball joint connection, to a lower suspension arm integral with the vehicle,

and at least one second span for positioning the core relative to the mold and arranged at another region of the core forming, after casting, the hollow portion formed in another connecting element of the one-piece molded part, in particular a connecting element made of material from its support member and intended to be fixed, in particular by a screw connection or a clamping or clamping connection, to a damping device and / or spring secured to the vehicle.

Brief description of the drawings

Other advantages and features will emerge more clearly from the following description of particular embodiments of the invention given as non-restrictive examples and shown in the accompanying drawings, in which:

FIG. 1 is a perspective view of an exemplary rocket support according to the invention,

FIG. 2 is a longitudinal-lateral sectional view of the rocket support of FIG. 1;

FIG. 3 is a longitudinal cross-sectional view of the rocket support of FIG. 1; and FIG. 4 is a perspective view of an example of a core enabling the manufacture of the rocket support of FIGS. 1 to 3.

Description of preferred modes of the invention

Figures 1 to 4 relate to an exemplary rocket support 10 according to the invention.

For better clarity, a three-dimensional orthogonal reference frame (X, Y, Z) is locally associated with the rocket support 10. The X, Y, Z directions are respectively called "longitudinal", "lateral", "transverse".

The rocket support 10 is intended for the rotational mounting of a hub (not shown) of a wheel of a motor vehicle, also called a "rocket". The manufacture of the rocket support comprises a foundry operation, possibly followed by one or more machining operation (s) and / or one or more heat treatment operation (s).

The foundry operation comprises a step of casting an alloy (cast iron, steel, aluminum, metal, etc.) in a mold configured so as to obtain, after cooling of the cast iron, a constitutive monobloc molded part:

on the one hand a support element 1 1 intended for the rotational mounting of the hub,

and on the other hand a plurality of connecting elements 12, 13, 14 intended to be fastened respectively to different members (not shown) integral with the vehicle and respectively associated with said connecting elements 12, 13, 14 to ensure the fixing the rocket support 10 on the vehicle. In other words, the rocket support 10 comprises, at the end of the foundry operation, a one-piece molded part constituting on the one hand a support member 1 1 delimiting a housing 15 for the rotational mounting of the hub and on the other hand a plurality of connecting elements 12, 13, 14 intended to be fixed respectively to the various members associated with the connecting elements.

According to an essential characteristic, the one-piece molded part comprises hollow parts formed by coring in both the support element 11 and in all the connecting elements 12, 13, 14, each of the hollow parts opening into another hollow part. so that all the hollow portions communicate with each other and delimit inside the one-piece molded part a cavity extending in the support member 1 1 and in each of the connecting elements 12, 13, 14.

The housing 15, which is intended to receive a bearing guide (not shown) in rotation of the hub, may adopt a generally bore, for example generally cylindrical bore optionally comprising radial grooves and / or shoulders. The axis D of the bore constituting the housing 15 is oriented in the longitudinal direction X. In particular in the case of a so-called "first generation" assembly, the housing 15 is configured so as to allow a press fitting. an outer race of the hub-turning guide bearing.

The hollow portion 1 1 1 formed in the support member 1 1 is arranged at the periphery of the housing 15, in particular in an annular manner generally included in a plane perpendicular to the axis D. This facilitates a particular but not mandatory organization in which the hollow portion of each of the connecting elements 12, 13, 14 opens into the hollow portion 1 January 1 of the support member 1 1, so as to form a generally octopus shaped cavity or spider centered on the hollow portion 1 1 1.

The plurality of connecting elements 12, 13, 14 comprises in particular in the case of a Mac-Pherson or pseudo Mac-Pherson assembly:

a first connecting element 12 coming from material from the support element 1 1 and intended to be fixed, in particular by a first ball joint, to a lower suspension arm (not shown) integral with the vehicle, constituting an integral member of the vehicle and associated with the first connecting element 12,

and / or a second connecting element 13 made of material from the support member 11 and intended to be fixed, in particular by a second ball joint, to a steering rod (not shown) integral with the vehicle, constituting a integral member of the vehicle and associated with the second connecting element 13,

and / or a third connecting element 14 made of material from the support element January 1 and intended to be fixed, in particular by a screw connection or a connection by clamping or clamping, to a damping device and / or spring secured to vehicle (not shown) constituting an integral member of the vehicle and associated with the third connecting member 14. According to the above, the first, second and third connecting elements 12, 13, 14 each comprise a hollow portion obtained by coring, respectively marked 121, 131, 141. Each of the hollow portions 11, 121, 131, 141 is configured to open into at least one of the other hollow portions.

As noted above, an advantageous provision is to provide that:

the first connecting element 12 is configured so that the hollow portion 121 formed in the first connecting element 12 opens into the hollow part 11 formed in the support element January 1,

the second connecting element 13 is configured so that the hollow portion 131 formed in the second connecting element 13 opens into the hollow part 11 formed in the support element January 1,

the third connecting element 14 is configured so that the hollow portion 141 formed in the third connecting element 14 opens into the hollow portion 1 1 1 formed in the support member January 1. The one-piece molded part also comprises fastening elements 16 for fastening a braking device (not shown), in particular a brake caliper and / or a wheel lock monitoring sensor. Such a rocket support 10 makes it possible to constitute an arrangement for a motor vehicle wheel train, notably a front or rear gear, advantageously of the Mac-Pherson or pseudo Mac-Pherson type. The arrangement also comprises a wheel of the vehicle and a hub integral with the wheel and rotatably mounted at the housing 15 delimited by the support member 1 1 of the monoblock alloy piece of the rocket support 10.

The arrangement may also include:

at least one lower suspension arm fixed, in particular by a first ball joint, to the first connecting element 12,

and / or a steering rod fixed, in particular by a second ball joint, to the second connecting element 13,

and / or a damping and / or spring device fixed, in particular by a screw connection or a clamping or clamping connection, to the third connecting element 14,

the assembly being configured so as to constitute a type of wheel train

Mac-Pherson or pseudo Mac-Pherson.

The arrangement may finally comprise the rotation guide bearing of the hub. This may comprise an outer cage force-fitted in the bore of the housing 15 and an outer cage force-fitted on the hub in the case of the so-called "first generation" assembly. The fact remains that the concept of the invention is not exclusive of any other rolling assembly. In particular, it is possible to provide mounting of the bearing by screwing on the rocket support 10 in the case of a so-called "second generation" assembly or mounting of the bearing by screwing on the rocket support 10 of a formed assembly previously by assembly between the hub and the bearing in the case of a so-called "third generation" assembly. It follows from the foregoing that the method of manufacturing the rocket support 10 comprises, prior to the casting step, a step of providing a single core 200 (refer to FIG. 4) and of setting up the core 200 in the mold, the core 200 and its implementation being configured so that at the end of the casting step, the one-piece molded part comprises the hollow portions 1 1 1, 121, 131, 141 formed by coring resulting from the presence of the core 200 during casting, both in the support member 1 1 and in all the connecting elements 12, 13, 14. Each of the hollow portions 1 1 1, 121, 131, 141 opens in another hollow part so that all the hollow portions 1 1 1, 121, 131, 141 communicate with each other and delimit inside the single-piece molded part a single cavity corresponding to all or part of the impression left by the core 200 to the casting and which extends both in the support element 1 1 and in each of the connecting elements 12, 13, 14.

In FIG. 4, the core 200 comprises:

a first zone 201 intended to form the hollow part 1 1 1 by coring effect in the support element January 1,

a second zone 202 intended to form the hollow part 121 by coring effect in the first connecting element 12,

a third zone 203 intended to form the hollow portion 131 by coring effect in the second connecting element 13,

and a fourth zone 204 for forming the hollow portion 141 by coring effect in the third connecting element 14.

The core 200 used finally comprises, for its implementation in the mold: at least a first surface 205 for positioning the core 200 relative to the mold and arranged at the zone 202 of the core 200 forming, at the end of the casting the hollow part 121 formed in the first connecting element 12,

and at least one second span 206 for positioning the core 200 relative to the mold and arranged at another zone 203, 204 of the core 200 forming, after casting, the hollow portion 131, 141 formed in the second connecting element 13 and / or the third connecting element 14. For example, two such spans 206 are arranged, in the particular variant illustrated, on both sides of the zone 204 in the transverse direction Z.

The staves 205, 206 and their positions ensure good positioning and good stability of the core 200 in the mold and the removal of the core sand after stalling. The footprints 17 left by the bearing surfaces 206 at the third connecting element 14 and the impression left by the bearing surface 205 are naturally obstructed during the assembly of the ball joint used for the connection to the lower suspension arm and during the assembly of the clevis of the damping device. This gives a sufficient seal to overcome external elements such as chippings in operation.

In addition to these manufacturing facilities, the multiplication of the hollow bearings 1 1 1, 121, 131, 141 allows a considerable weight gain of the rocket support 10, for example of the order of 12% on cast iron casting compared to solutions of the prior art. The general organization allows a good resistance in operation and a good resistance to shocks.

Claims

1. Rocket support (10) for the rotational mounting of a hub of a wheel of a motor vehicle, comprising a one-piece molded part constituting on the one hand a support element (1 1) delimiting a housing (15). ) for the rotational mounting of the hub and secondly of a plurality of connecting elements (12, 13, 14) intended to be respectively fixed to different integral members of the vehicle and respectively associated with said connecting elements to ensure the fixing the rocket support to the vehicle, characterized in that the one-piece molded part comprises hollow parts (1 1 1, 121, 131, 141) formed by coring both in the support element and in all the elements of connection, each of the hollow portions opening into another hollow portion so that all the hollow portions communicate with each other and delimit inside the one-piece molded part a cavity extending in the element d e support and in each of the connecting elements.

2. rocket support according to claim 1, characterized in that the hollow portion (1 1 1) formed in the support member (1 1) is arranged at the periphery of said housing (15), in particular ring-shaped generally included in a plane perpendicular to the axis (D) of a bore constituting the housing.

3. rocket support according to one of claims 1 and 2, characterized in that the housing is configured to allow a force fitting of an outer cage of a hub rotation bearing bearing.

Rocket support according to one of claims 1 to 3, characterized in that the plurality of connecting elements comprises a first connecting element

(12) made of material from the support member (1 1) and intended to be fixed, in particular by a first ball joint, to a lower suspension arm integral with the vehicle, constituting a member secured to the vehicle and associated with said first link element.

Rocket support according to claim 4, characterized in that the first connecting element is configured so that the hollow part (121) formed in the first connecting element opens into the hollow part (1 1 1) formed in the support member (1 1).

Rocket support according to one of claims 1 to 5, characterized in that the plurality of connecting elements comprises a second connecting element

(13) from material from the support member (1 1) and intended to be fixed, in particular by a second ball joint, to a steering rod integral with the vehicle, constituting a member secured to the vehicle and associated with said second connecting element.

Rocket support according to claim 6, characterized in that the second connecting element is configured so that the hollow part (131) formed in the second connecting element opens into the hollow part (1 1 1) formed in the support member (1 1).

Rocket support according to one of claims 1 to 7, characterized in that the plurality of connecting elements comprises a third connecting element

(14) made of material from the support element (1 1) and intended to be fixed, in particular by a screw connection or a connection fitting by clamping or clamping, to a damping device and / or spring secured to the vehicle, constituting a an integral member of the vehicle and associated with said third connecting element.

Rocket holder according to Claim 8, characterized in that the third connecting element is configured such that the hollow part (141) formed in the third connecting element opens into the hollow part (11 1) formed in the support member (1 1).

Rocket support according to one of claims 1 to 9, characterized in that the one-piece molded part comprises fastening elements (16) for fixing a braking device, in particular a brake caliper and / or a wheel lock monitoring sensor.

1 1. Arrangement for a motor vehicle wheel train, in particular a front or rear axle, characterized in that it comprises a rocket support (10) according to any one of claims 1 to 10, a wheel of the vehicle and a hub integral with the wheel and rotatably mounted at the housing (15) defined by the support member of the integrally molded part of the rocket support.

12. Arrangement according to claim 1 1, characterized in that it comprises: at least one lower suspension arm fixed, in particular by a first ball joint, to a first connecting element (12) of the one-piece molded part of the support of rocket (10),

and / or a steering rod fixed, in particular by a second ball joint, to a second connecting element (13) of the one-piece molded part of the rocket support (10),

and / or a damping and / or spring device fixed, in particular by a screw connection or a clamping or clamping connection, to a third connecting element (14) of the one-piece molding of the rocket support (10),

the assembly being configured so as to constitute a Mac-Pherson or pseudo Mac-Pherson wheelset.

13. Arrangement according to one of claims 1 1 and 12, characterized in that it comprises a bearing for rotating the hub having an outer cage force-fitted in a bore of the housing (15) and an outer cage fitted to force on the hub.

14. A method of manufacturing by casting a rocket support (10) for the rotational mounting of a hub of a wheel of a motor vehicle, comprising a step of casting an alloy in a mold configured so to obtain, after cooling of the cast alloy, a one-piece molded part constituting on the one hand a support element (1 1) intended for the rotational mounting of the hub and on the other hand a plurality of elements of link (12, 13, 14) intended to be fixed respectively to various members integral with the vehicle and respectively associated with said connecting elements to ensure the attachment of the rocket support (10) to the vehicle, characterized in that it comprises a step of providing a single core (200) and placing the core in the mold prior to the casting step, the core and its implementation being configured so that at the end of the step casting, the one-piece molded part comp makes hollow portions (11, 121, 131, 141) formed by coring resulting from the presence of the core (200) during casting, both in the support member (1 1) and in all the elements of link (12, 13, 14), and that each of the hollow portions opens into another hollow portion so that all the hollow portions communicate with each other and delimit inside the single-piece molded part a single cavity corresponding to all or part of the impression left by the casting core (200) and which extends into both the support member (1 1) and each of the connecting members (12, 13, 14).

15. The method of claim 14, characterized in that the core used comprises, for its implementation in the mold:

at least a first bearing surface (205) for positioning the core (200) relative to the mold and arranged at a zone (202) of the core forming, at the end of the casting, the hollow portion (121) formed in a connecting element (12) of the one-piece molded part, in particular material coming from its support member (1 1) and intended to be fixed, in particular by a ball joint connection, to a lower suspension arm integral with the vehicle,

and at least one second span (206) for positioning the core (200) relative to the mold and arranged at another zone (203, 204) of the core forming, at the end of the casting, the hollow part (131, 141) formed in another connecting element (13, 14) of the one-piece molded part, in particular a connecting element (14) coming from its material since its support element (1 1) and intended to be fixed, in particular by a screw connection or a connection fitting by clamping or clamping, to a damping device and / or spring secured to the vehicle.