DE102016214918A1 - Method for producing a spindle nut of a ball screw - Google Patents

Abstract

The invention relates to a method for producing a spindle nut (1) of a ball screw (2), wherein the spindle nut (1) is made from a base body (3) into which a threaded bore (4) extending in the direction of a longitudinal axis (L) is incorporated or will. In order to economically achieve a precise geometry of the spindle nut, the invention provides that the base body (3) over its extension in the direction of the longitudinal axis (L) has a continuous outer contour, wherein in a cutting machine tool in a first radially outer region of the Outer contour, a first recess (5) is incorporated, which forms an undercut in the direction of the longitudinal axis (L).

Description

Field of the invention

The invention relates to a method for producing a spindle nut of a ball screw, wherein the spindle nut is made of a base body, in which a running in the direction of a longitudinal axis threaded hole is incorporated or is.

Generic ball screws are well known in the art; is exemplary on the DE 103 46 079 A1 pointed. The ball screw comprises a spindle nut with a base body and a threaded spindle, wherein between the spindle nut and the threaded spindle at least one ball chain formed from balls rolls each along an endless ball channel. The ball channel is formed in sections in a radially outer region of the spindle nut by a deflection.

The preparation of the spindle nut of the ball screw can be done in various ways. For this purpose, a rod material or a tube material can be used as the starting material. Also known is the use of forging blanks or cold extrusion blanks, from which then the mother is made. Likewise, welded assemblies are known.

It is an aspect of an economical production that the required functional surfaces can be manufactured precisely and yet inexpensively. Furthermore, care must be taken to ensure economic use of the raw material used.

Object of the invention

The present invention has the object, the above-mentioned method for producing a spindle nut of a ball screw drive train so that it is possible to produce all the required functional surfaces of the spindle nut in an economical manner, while ensuring an economic use of the starting material. Thus, a precise geometry of the spindle nut is to be achieved in an economical manner.

Summary of the invention

The solution of this problem by the invention is characterized in that the main body of the spindle nut has a continuous outer contour over its extension in the direction of the longitudinal axis, wherein in a cutting machine tool in a first radially outer region of the outer contour, a first recess is incorporated, in the direction the longitudinal axis forms an undercut.

Advantageously, it is provided that in the same machine tool - without changing the clamping of the main body in the machine tool - in a second radially outer region of the outer contour, a second recess is incorporated, which forms an undercut in the direction of the longitudinal axis.

The two recesses are preferably incorporated on opposite sides of the body.

In the direction of the longitudinal axis in front of and behind the first recess, a third recess and a fourth recess can be incorporated.

At least one of said recesses (preferably all recesses) is preferably carried out as a cut.

The first recess is preferably designed such that a fork-like configuration results in the first radially outer region of the outer contour. The fork-like configuration is preferably designed to engage a further component, in particular a shift fork.

The second recess is preferably designed so that there is a groove-like recess in the second radially outer region of the outer contour. The groove-like recess is preferably designed for engagement of a further component, in particular a bolt for preventing rotation.

The body is preferably made from a portion of a profile which is an extruded profile or a drawn profile made by an extrusion or drawing process.

The threaded bore is formed as a raceway for balls.

In the body preferably radially extending apertures are incorporated for receiving deflecting sections for balls.

One aspect of the present concept is therefore the economic production of a forked claw or a rotation lock on or in the spindle nut. Advantageously, a high precision of the functional surfaces can be achieved by the proposed approach, at the same time in particular by processing a multi-spindle machine economic production is ensured.

If the base body is produced from an extruded profile or from a drawn profile, there is the advantage that there is a material-saving design, which offers corresponding cost advantages. Of said profile is then cut only for the purpose of production of the spindle nut required for the body portion.

When using a profile rod as the starting material for the spindle nut thus targeted material can thus be provided only where it is really needed. Thus, a much lower material removal or a smaller Zerspanvolumen is required, as it would be the case if the spindle nut would be made from a standard part. On the other hand, the costs are lower than if specific blanks for the spindle nut had to be produced.

In contrast to the use of blanks, there is still the advantage that not individual blanks must be handled.

In the manufacture of the material for the spindle nut, it is also advantageous that a tool for producing a corresponding profile is much less expensive than that for the production of the blanks by forging or extrusion.

Profile rods as a starting product for the spindle nut are relatively easy to manufacture with a desired cross-section, and this is also possible with high precision.

In particular, for the preferred use here of the ball screw in circuits of gear change transmissions so corresponding configurations can be provided on the spindle nut, which serve to cooperate with other components and ensure the desired functionality.

On the one hand, here an exemption (recess, cutout) is called, which is arranged on one side of the spindle nut in the radially outer region and which can be used as a claw for the operation of a shift fork.

Accordingly, on a further radially outer side of the spindle nut, in particular in the claw opposite region, through a recess (cutout) be introduced a groove into which a guide pin engages, so that a good guidance of the spindle nut upon displacement in the direction of the longitudinal axis Threaded spindle and a rotation is given.

The said recesses are preferably manufactured (milled) in one clamping, whereby a high precision between said functional surfaces (claw and guide groove) can be produced.

Brief description of the figures

In the figures, an embodiment of the invention is shown. Show it:

1 in perspective view a ball screw,

2 in a perspective view of the spindle nut of the ball screw according to 1 .

3 in perspective view of the spindle nut according to 2 , which is shown rotated about its longitudinal axis, and

4a in a perspective view of the spindle nut shown cut, wherein a deflection element for balls is mounted by means of a tool.

Detailed description of the figures

In 1 is a ball screw 2 shown, consisting of a spindle nut 1 and a threaded spindle 11 consists. The direction of the longitudinal axis of the threaded spindle 11 or the spindle nut 1 is denoted by L.

The spindle nut 1 includes a main body 3 consisting of a drawn profile having the shape which results in a section perpendicular to the longitudinal axis L. Between the spindle nut 1 and the threaded spindle 11 There are a plurality of ball chains formed from balls, which roll each along an endless ball channel. Each ball channel is partially in a radially outer region of the spindle nut by a deflection 9 respectively. 10 educated. Accordingly, the main body 3 a threaded hole 4 on, which forms the track for the - not shown - balls. The number of deflection sections 9 . 10 is generally open and depends on the respective concept or application of the ball screw.

It is essential, and this is going on 2 Reference is made to the basic body 3 - Before it is machined in a machine tool (not shown) - over its extension in the direction of the longitudinal axis L has a continuous outer contour, ie the profile which results in a section perpendicular to the longitudinal axis L. In the machine tool then by a milling process, a first recess 5 in a first radially outer region of the outer contour incorporated. This creates an area with an undercut in the direction of the longitudinal axis L.

The recess 5 serves to form a claw, which can cooperate with a (not shown) shift fork.

Before or after then become a third and a fourth recess 7 and 8th milled, causing the in 2 illustrated fork-shaped structure in said first radially outer region of the outer contour of the base body 3 results. For the production of the first, the third and the fourth recess 5 . 7 and 8th An end mill is preferably used. It should be noted that the recesses 7 and 8th are by no means compulsory and offer themselves in particular if there could be a collision in the construction space without them.

In the machine tool is then - without the clamping of the body 3 to change - the basic body 3 rotated about the longitudinal axis L (for example, by 180 °), whereby in a second radially outer region, a second recess 6 is made as in 3 you can see. For the production of the second recess 6 Preferably a finger milling cutter is used.

The recess 6 is intended as anti-rotation. In this groove-shaped recess can engage a (not shown) pin, which then the main body 3 and thus the spindle nut 1 leads in the direction of the longitudinal axis L and the other a rotation of the spindle nut 1 around the longitudinal axis L prevented. The length of the recess 6 then defines the maximum displacement of the spindle nut 1 and thus represents an axial end stop in both directions.

The threaded hole 4 is at a time in the body 3 introduced before, during or after the introduction of the recesses 5 . 6 . 7 . 8th can lie.

In lateral areas of the body 3 be recesses for receiving the deflection sections 9 and 10 incorporated. In 4 is illustrated as the deflection sections 9 respectively. 10 by means of a tool 12 from inside the tapped hole 4 be inserted from the provided recesses. The assumption that this procedure is possible depends on the respective geometric circumstances, in which case a relevant size of the sphere pitch circle is.

By the procedure described can be achieved that in a single clamping of the body 3 in a machine tool (milling machine), which is preferably designed as a multi-spindle machine, both the fork-shaped structure in a radially outer region of the base body and the groove-like structure in the other radially outer region of the body are made, whereby the precision of these functional surfaces without large production engineering effort can be kept at a high level.

By using the drawn profile strand as the starting material for the main body 3 an optimal material distribution is achieved and the required machining volume is minimized.

The ball screw described is used for example as an actuator in a change-speed gearbox. This linear adjustment movements can be accomplished in the transmission.

LIST OF REFERENCE NUMBERS

1

 spindle nut

2

 Ball Screw

3

 body

4

 threaded hole

5

 first recess

6

 second recess

7

 third recess

8th

 fourth recess

9

 deflecting

10

 deflecting

11

 screw

12

 Tool

L

 Direction of the longitudinal axis

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 10346079 A1 [0002]

Claims (10)

Method for producing a spindle nut ( 1 ) of a ball screw ( 2 ), wherein the spindle nut ( 1 ) from a basic body ( 3 ), in which a in the direction of a longitudinal axis (L) extending threaded bore ( 4 ) is or is incorporated, characterized in that the basic body ( 3 ) has a continuous outer contour over its extent in the direction of the longitudinal axis (L), wherein in a cutting machine tool, in a first radially outer region of the outer contour, a first recess ( 5 ) is incorporated, which forms an undercut in the direction of the longitudinal axis (L). A method according to claim 1, characterized in that in the same machine tool without the clamping of the base body ( 3 ) to change in a second radially outer region of the outer contour of a second recess ( 6 ) is incorporated, which forms an undercut in the direction of the longitudinal axis (L). Method according to claim 2, characterized in that the two recesses ( 5 . 6 ) on opposite sides of the body ( 3 ) are incorporated. Method according to one of claims 1 to 4, characterized in that in the direction of the longitudinal axis (L) in front of and behind the first recess ( 5 ) a third recess ( 7 ) and a fourth recess ( 8th ) are incorporated. Method according to one of claims 1 to 4, characterized in that at least one of the recesses ( 5 . 6 . 7 . 8th ) are executed as a milling. Method according to one of claims 1 to 5, characterized in that the first recess ( 5 ) is designed so that a fork-like configuration results in the first radially outer region of the outer contour, wherein the fork-like configuration is preferably designed for engagement of a further component, in particular a shift fork. Method according to one of claims 2 to 6, characterized in that the second recess ( 6 ) is designed so that there is a groove-like recess in the second radially outer region of the outer contour, wherein the groove-like recess is preferably designed for engagement of a further component, in particular a bolt for preventing rotation. Method according to one of claims 1 to 7, characterized in that the basic body ( 3 ) is made from a section of a profile that is an extruded profile or a drawn profile made by an extrusion or drawing process. Method according to one of claims 1 to 8, characterized in that the threaded bore ( 4 ) is formed as a raceway for balls. Method according to one of claims 1 to 9, characterized in that in the main body ( 3 ) radially extending apertures for receiving deflecting sections ( 9 . 10 ) are incorporated for balls.

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