DE102021126038A1 - Method and computer program product for manufacturing a tolerance ring of a steering bearing using an additive manufacturing process - Google Patents

Abstract

Method for producing a tolerance ring (1) of a steering bearing (2) using an additive manufacturing process in which, based on the principle of extrusion, according to a digital computer model, depending on the component, different materials are printed in layers by several print heads (I, II, III) along defined paths in three Dimensions are applied and solidified in the following successive or simultaneous steps: - Generating the basic geometric structure of the tolerance ring (1) with a print head (I) that dispenses a first material, - Generating the geometric structure of at least part of a sealing profile on the tolerance ring (1) with a print head (II) applying a second material,- generating the geometric structure of a damping element from the first material by means of the first print head (I) or a print head (III) applying a third material.

Description

field of invention

The invention relates to a method for producing a tolerance ring of a steering bearing, and to a computer program product that implements this method in terms of software.

Background of the Invention

Tolerance rings are used between a shaft and a ring-shaped element arranged on the shaft, for example to compensate for distances between the shaft and the ring-shaped element, to compensate for production-related inaccuracies and functional forces, such as in particular displacement forces between the shaft and the ring-shaped element, within a desired range and to compensate for deviations in position and shape of the surrounding construction. A preferred area of application is, for example, the mounting of steering shafts in the steering housing.

The DE 10 2012 221 301 A1 describes a tolerance ring which is used in bearings for steering shafts. The tolerance ring has a continuous slot in the axial direction, with a web being provided in the region of the slot.

From the DE 199 22 914 A1 a tolerance ring is known which has a radial flange. Furthermore, the tolerance ring has retaining tongues formed uniformly around its circumference by recesses spaced apart from one another. The retaining tongues are elastic. A bearing inner ring of a roller bearing can be arranged on a lateral surface of the tolerance ring.

The DE 41 14 643 A1 discloses a rolling bearing for steering columns, which is pushed onto a steering column. The roller bearing is also equipped with a tolerance ring, which has a number of elastic projections that protrude radially inward into the area of the bore of the tolerance ring. These elastic projections can snap into recesses in the steering shaft and can be supported on corresponding support surfaces on the steering shaft.

When the tolerance ring is produced by injection molding, the geometric design is limited because it can be removed from the injection mold. This means that the contours of the components cannot be designed arbitrarily. Usually, geometric undercuts in components of the type of interest here may only be a few tenths of a millimeter in size. In the case of snap-on connections, it is difficult to achieve sufficiently high dismantling forces that would prevent the components connected to one another from automatically coming loose. In addition, when the plastic cools down in the injection molding tool, there is material shrinkage, which must be taken into account when designing the component tool.

Summary

It is the object of the present invention to create a method for producing a tolerance ring which enables efficient production with a minimum number of production steps with high dimensional stability.

The object is achieved with regard to a production method according to claim 1. Claim 4 is directed to a steering bearing produced thereby. Advantageous developments of the invention are reflected in the dependent and dependent claims.

• - Erzeugen der geometrischen Grundstruktur des Toleranzrings (1) mit einem ein erstes Material ausbringenden Druckkopf (I),
• - Erzeugen der geometrischen Struktur zumindest eines Teils eines Dichtungsprofils am Toleranzring mit einem ein zweites Material ausbringenden Druckkopf (II),
• - Erzeugen der geometrischen Struktur eines Dämpfungselementes aus dem ersten Material mittels des ersten Druckkopfes (I) oder einem ein dritten Material ausbringenden Druckkopf (III).

The invention includes the procedural teaching that for the production of a tolerance ring of a steering bearing by an additive manufacturing process, in which based on the extrusion principle according to a digital computer model, depending on the component, different materials are printed in layers by several print heads (I, II, III) along defined paths be applied and solidified in three dimensions in the following sequential or simultaneous steps:

• - Generating the basic geometric structure of the tolerance ring (1) with a print head (I) dispensing a first material,
• - Generating the geometric structure of at least part of a sealing profile on the tolerance ring with a print head (II) dispensing a second material,
• - Generating the geometric structure of a damping element from the first material by means of the first print head (I) or a print head (III) dispensing a third material.

The advantage of the invention lies in particular in the fact that by utilizing an additive manufacturing process, for example by so-called 3D printing, a component consisting of several components, here the tolerance ring, can be produced in just one process step. The otherwise customary individual assembly steps for assembling the components are no longer necessary. In addition, there is no effort with regard to the individual part tools that would otherwise be required. Since the additive manufacturing process is not subject to any restrictions with regard to undercuts and channel courses, a connection can be created that withstands high disassembly forces.

In the additive manufacturing process, the volume and structure of the components are built up layer by layer according to the digital computer model, which is the result of a CAD design. The building material required for the shaping can have a solid or liquid initial state and preferably consists of a plastic. In the case of solid materials, additive manufacturing is implemented by applying the material in layers to a carrier base in an appropriately preconditioned state and solidifying it. The connection can be made by gluing, baking or fusing. The strength of the connection between the individual layers can be controlled via the relative movement speed of the print head to the support base. The solution according to the invention makes use of this effect in order to apply a structural layer between the material of the individual components that is not materially bonded to the previous layer in order to generate the relative mobility. For this purpose, it is also conceivable to create a soluble intermediate layer between the said components, which is removed again after the additive manufacturing process, for example by washing out or the like. In the additive manufacturing process based on the extrusion principle, the component is usually built on a movable carrier base. The at least one print head for applying the material is a heated extruder, which melts the material supplied in the form of a substrate, rods or granules and applies it layer by layer in accordance with the computer model. Depending on the structure of the device, the at least one print head or both can also be moved relative to one another instead of the carrier base.

Before the basic geometric structure of the tolerance ring is produced, at least one spring element is preferably arranged on the carrier base, which is then at least partially surrounded by the material to be applied.

The individual components of the additively manufactured tolerance ring preferably consist of a polyoxymethylene material (POM), a polyethylene material (PE) or a polyamide material (PA). The components, such as seals, snap hooks, spring elements, etc., can also consist of different materials mentioned. In particular, the polyamide (PA66-GF) or similar can be used for the base body of the tolerance ring.

For additive manufacturing, preferably in the course of 3D printing, the manufacturing method can be embodied by a program code that maps the individual steps in the form of a computer program product, which is implemented in the digital computer model of the tolerance ring to be manufactured. The digital computer model provides the three-dimensional shape data required for production. These can be carried out, for example, on the control unit of a 3D printer in order to produce the tolerance ring that is the subject of the invention. In addition, it is of course also conceivable that corresponding digital computer models can also be made available without data carriers.

character list

• 1 einen erfindungsgemäßen Toleranzring eines Lenkungslagers gemäß einer ersten Ausführungsform,
• 2 einen erfindungsgemäßen Toleranzring eines Lenkungslagers gemäß einer zweiten Ausführungsform,
• 3 einen erfindungsgemäßen Toleranzring eines Lenkungslagers gemäß einer dritten Ausführungsform,
• 4 einen erfindungsgemäßen Toleranzring eines Lenkungslagers g gemäß einer vierten Ausführungsform,
• 5 einen erfindungsgemäßen Toleranzring eines Lenkungslagers gemäß einer fünften Ausführungsform, und
• 6 einen erfindungsgemäßen Toleranzring eines Lenkungslagers gemäß einer sechsten Ausführungsform.

Six exemplary embodiments of the invention are presented below with reference to six figures. Show it:

• 1 a tolerance ring according to the invention of a steering bearing according to a first embodiment,
• 2 a tolerance ring according to the invention of a steering bearing according to a second embodiment,
• 3 a tolerance ring according to the invention of a steering bearing according to a third embodiment,
• 4 a tolerance ring according to the invention of a steering bearing g according to a fourth embodiment,
• 5 a tolerance ring according to the invention of a steering bearing according to a fifth embodiment, and
• 6 a tolerance ring according to the invention of a steering bearing according to a sixth embodiment.

Detailed description of the drawing

1 until 6 show different embodiments of the tolerance ring 1 according to the invention of a steering bearing 2. In the following, first the similarities are described and then the differences are discussed in detail. shows a tolerance ring 1 made of plastic. The steering bearing 2 shown is designed as a ball bearing 3 in which bearing balls 4 roll around the bearing axis 5 on an outer raceway 5 and an inner raceway 6 . The inner track 6 is formed by an inner ring 7 which is provided on the outer circumference of the tolerance ring 1 .

The tolerance ring 1 has a first section 8 and a second section 9 . In the area of the first section 8 , the tolerance ring 1 has a circumferential radial flange 10 .

The second section 9 has elastic elements 11 . The elastic elements 11 are formed by retaining tongues 12, which are subdivided by recesses spaced evenly around the circumference. The retaining tongues 12 are designed in such a way that they can spring radially inwards and outwards.

How out 1 As can be seen, it is possible to produce parts of the first section 8 and the second section 9 from a first material and the radial flange 10 from a second material by means of the additive manufacturing process.

The 2 until 6 primarily show variants of the production of the retaining tongues of the second section 9 and of spring elements 13 by means of the additive manufacturing process.

reference list

1

tolerance ring

2

steering bearing

3

ball-bearing

4

bearing balls

5

outer track

6

inner race

7

inner ring

8th

first section

9

second part

10

radial flange

11

elastic elements

12

retaining tabs

13

spring element

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102012221301 A1 [0003]
• DE 19922914 A1 [0004]
• DE 4114643 A1 [0005]

Claims (7)

Method for producing a tolerance ring (1) of a steering bearing (2) using an additive manufacturing process in which, based on the principle of extrusion, according to a digital computer model, depending on the component, different materials are printed in layers by several print heads (I, II, III) along defined paths in three Dimensions are applied and solidified in the following sequential or simultaneous steps: - Generating the basic geometric structure of the tolerance ring (1) with a print head (I) dispensing a first material, - Generating the geometric structure of at least part of a sealing profile on the tolerance ring (1) with a print head (II) dispensing a second material, - Generating the geometric structure of a damping element from the first material by means of the first print head (I) or a print head (III) dispensing a third material. procedure after claim 1 , whereby the print heads (I,II,III), designed as heated extruders, are moved in layer-by-layer production of the geometric structures of the components relative to a carrier base receiving the tolerance ring (1) to be produced, with the fusing and cooling of the material applied thereby being controlled via the process speed becomes. Method according to one of the preceding claims, wherein before the basic geometric structure of the tolerance ring (1) is produced, at least one spring element (13) is arranged on the carrier base, which is then at least partially surrounded by the material to be applied. Steering bearing with a tolerance ring (1) for bridging a radial distance between a roller bearing and a steering shaft, characterized in that at least the component tolerance ring (1) as component sections of an additive according to one of Claims 1 until 3 ready-made component are formed. steering bearing after claim 4 , wherein the tolerance ring (1) consists of a 3D-printable plastic material that is selected from a group of materials comprising: polyoxymethylene material (POM), polyethylene material (PE), polyamide material (PA). Computer program product with program code means for carrying out the method according to one of Claims 1 until 3 when the computer program product designed as a digital computer model runs on a control unit of an additive manufacturing device in order to manufacture the tolerance ring (1). Computer-readable data carrier on which the computer program product claim 6 is saved.

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