DE102019207211B4 - Process for screwing two components together - Google Patents

Abstract

Method for screwing a first component (8) comprising an elastic area to a second component (13) with a defined prestressing force, comprising the following method steps:
- Positioning of the first component (8) to the second component (13) in the installation position,
- Attaching a connecting element (15) to connect the first (8) to the second (15) component,
- connecting the first component (8) to a means (16) for generating a prestressing force,
- connecting the first component (8) to a measuring device (20) for measuring the deformation of the first component (8) under the action of the prestressing force,
- Application of a defined prestressing force to the first component (8),
- Storage of the deformation value determined by the measuring device (20) when the defined prestressing force is reached,
- Applying the connecting element (15) to the second component (13) until full contact is made,
- Release the preload force
- Adjusting the connecting element (15) until the stored deformation value is reached.
- Dismantling the means (16) for applying the preload force and the measuring means (20).

Description

The invention relates to a method for screwing two components together.

In modern assembly technology, the screw connection is still one of the most important types of connection. The variety of screw connections in screw technology has increased significantly compared to the past. Methods for calculating screw connections and newly developed screw processes offer the possibility of significantly reducing the dimensions of the screw connections. The result is smaller and lighter screws and/or nuts, which leads to significant savings in raw materials and weight and greatly reduces the space required for screw connections.

Screw connections also play an important role in the field of projection exposure systems for semiconductor lithography, in particular in EUV projection exposure systems. Due to the typically small amount of space available here and the drastic consequences of the failure of a screw connection, there are increased requirements here.

A bolted connection is a detachable connection that joins two or more parts together in such a way that they behave as one part under all operating forces that occur. Maintaining a sufficient residual preload force (residual clamping force) is of crucial importance for operational safety. If the operating force during operation is so great that it cancels out the preload force, the screw may loosen or break, depending on the operating load, or a seal caused by the preload force may leak. At the same time, the preload force must not exceed the yield points of the components of the screw connection, as this can lead to premature failure of the component. The preload force can be increased by increasing the stress cross-section, by using several or larger screws, by increasing the quality of the screw, which makes it possible to increase the assembly preload force with the same screw dimensions, or by using more precise screwing processes so that the screw can be better utilized , increase. Screwdriving methods used today enable more accurate information or a smaller spread of the resulting preload force to be obtained using the parameters monitored during screwing, such as the torque, the increase in the torque and/or the angle of rotation exceeded. However, the determination of the preload force via the torque is made more difficult by the high scattering of the thread friction and the underhead friction, for example between a nut and a support, which, in addition to the preload force, determine the level of the torque.

Known tightening methods are disclosed, for example, in the training documents from the company IBES Elektronik GmbH, which are published at http://www.ibeselectronic.de/Schulungsschriften_Neutral.pdf. Other generic screwing methods are in the German published specifications DE 10 2010 009 712 A1 , DE 10 2014 214 931 A1 and in the European patent specification EP 0 504 676 B1 described.

The disadvantage of the methods described there is that the tolerable spread of the preload force of the screw connections does not always meet the requirements.

The object of the present invention is to specify a method which solves the disadvantages of the prior art described above.

This object is achieved by a method having the features of the independent claims. The dependent claims relate to advantageous developments and variants of the invention.

• - Positionieren des ersten Bauteils zu dem zweiten Bauteil in Einbaulage,
• - Anbringen eines Verbindungselementes zur Verbindung des ersten mit dem zweiten Bauteil,
• - Verbinden des ersten Bauteils mit einem Mittel zur Erzeugung einer Vorspannkraft,
• - Verbinden des ersten Bauteils mit einem Messmittel zur Messung der Deformation des ersten Bauteils unter Einwirkung der Vorspannkraft,
• - Aufbringen einer definierten Vorspannkraft auf das erste Bauteil,
• - Speicherung des durch das Messmittel bei Erreichen der definierten Vorspannkraft ermittelten Deformationswertes,
• - Anlegen des Verbindungselementes an das zweite Bauteil bis zum vollständigen Kontakt,
• - Lösen der Vorspannkraft
• - Nachstellen des Verbindungselementes, bis der gespeicherte Deformationswert erreicht ist.
• - Demontage des Mittels zur Aufbringung der Vorspannkraft und des Messmittels.

A method according to the invention for screwing a first component to a second component with a defined prestressing force comprises the following method steps:

• - Positioning of the first component to the second component in the installation position,
• - attaching a connecting element to connect the first to the second component,
• - connecting the first component to a means for generating a prestressing force,
• - connecting the first component to a measuring device for measuring the deformation of the first component under the action of the prestressing force,
• - Application of a defined preload force to the first component,
• - Storage of the deformation value determined by the measuring device when the defined prestressing force is reached,
• - Applying the connecting element to the second component until full contact is made,
• - Release the preload force
• - Adjusting the connection element until the stored deformation value is reached.
• - Disassembly of the means for applying the pretensioning force and the measuring equipment.

The first component includes an elastic area. This is deflected by the preload force, which leads to a deformation of the first component. The elastic area can be designed in such a way that the first component can be loaded with the defined prestressing force and the loads of the operating force without reaching the yield point, ie without the risk of failure, with a minimal size. This is particularly advantageous in a projection exposure system with the typically only small amount of space available.

In addition, the connecting element can be designed as a nut. In addition to the elastic area, the first component includes an external thread onto which the nut can be screwed and screwed against the second component. The nut thus connects the first component to the second component.

Furthermore, the measuring means can be designed as a length measuring system, such as a tactile dial gauge or a confocal sensor. The probe of the dial gauge or the measuring beam of the confocal sensor can be placed on the surface of the first component, which is connected to the means for generating a defined preload force, so that the probe or the measuring beam can be used to measure the deformation of the first component caused by the preload force . Once the defined preload force has been reached, the value can be read off the tactile dial gauge or, in the case of an electronic dial gauge or the confocal sensor, saved. Alternatively, the dial indicator or the confocal sensor can be zeroed in this position. After releasing the preload force, the deformation value can decrease slightly due to settling effects at the contact point between the nut and the second component. The nut can now be tightened until the display of the measuring device has reached the deformation value stored with the applied preload force or the zero position. As a result, the prestressing force can advantageously be set very precisely without running the risk of overloading the first component. The prestressing force can be set in the range of less than 3%, in particular in the range of less than 1.5% of the defined prestressing force.

In addition, the means for generating a force can include a load cell. The defined preload force for preloading the first component can be easily read from the load cell; in conjunction with a controller and an electronic load cell, the force can also be automatically adjusted to the defined preload force.

Furthermore, a torque for applying the connecting element designed as a screw to the second component can be in a range of 0.1 Nm and 2 Nm. This can ensure contact between the nut and the second component without increasing the preload force. In addition to the torque, the reduction in the force measured at the load cell can be used as an additional decision parameter for contact between the nut and the second component. Furthermore, the length measurement can be used to check the contact between the nut and the second component. For example, when the nut is put on, the length measurement is observed, with the nut being in contact during the first movement of the length measurement.

In particular, the angle for adjusting the first component to the stored deformation value of the measuring device after releasing the prestressing force can be in the range between 0 and 30 degrees. The nut only has to be tightened by a maximum of 30° in order to deform the first component in such a way that the stored deformation value is reached again. This has the advantage that when the nut is tightened, there is only minimal friction between the nut and the second component, and the formation of particles can thus advantageously be reduced to a minimum. Alternatively, in the case of less critical components, the value for the preload force can be selected higher than necessary, so that the settling effects to be expected can be compensated. As a result, there is almost no need to retighten the nut after the nut has been put on and the preload force has been released.

In a variant of the invention, a seal can be arranged between the first component and the second component. The pre-tensioning force ensures that the seal retains its sealing effect and position under all stresses on the first component that occur during operation due to temperature, pressure differences, vibrations or shocks.

• 1 eine Vorrichtung zur Ausführung des erfindungsgemäßen Verfahrens, und
• 2 ein Flussdiagramm zu einem erfindungsgemäßen Verfahren.

Exemplary embodiments and variants of the invention are explained in more detail below with reference to the drawing. Show it

• 1 a device for carrying out the method according to the invention, and
• 2 a flowchart for a method according to the invention.

1 shows a device 1 for screwing a first component 8 to a second component 13 with a defined prestressing force. The device 1 comprises a receptacle 2 with a recess 3 which has an opening 4 at the lower end and a support 5 for receiving the second component 13 has been formed. The second component 13 is connected to the receptacle 2 by a clamping element 6 which is screwed to the top of the receptacle 2 with a screw 7 . The first component 8 is mounted in a passage 14 in the second component 13 and rests with a flange 11 on the underside of the second component 13 . A seal 12 is arranged between the first component 8 and the second component 13 .

The first component 8 is secured against falling out of the second component 13 with a nut 15 which is screwed onto an external thread 23 in the upper region of the first component 8 . The first component 8 also includes an internal thread 24 on the upper side for connecting the adapter 19 of a means 16 for generating a force. This can be designed, for example, as a tractor or just as a simple spindle. The means 16 is attached to a connection 17 which in turn is connected to the receptacle 2 of the device 1 . A load cell 18 is arranged between the means 16 for generating a force and the adapter 19 . This measures the prestressing force generated by means 16 and acting on the first component in the direction of the arrow. The first component 8 is deformed by the prestressing force predominantly in the direction of the force. The deformation is mainly brought about in an elastic region 9 of the first component 8, which is designed in such a way that the first component can be loaded with a defined prestressing force at a minimum size without exceeding the yield point of the material used. A probe 22 of a dial gauge 20 is arranged on the upper side of the first component 8 and detects a deformation value of the first component 8 under the effect of the prestress. The dial gauge 20 is directly connected to the component 13 via an arm 21, whereby only the movement of the first component 8 to the second component 13 is measured and the rigidity of the receptacle 2 is not included in the measuring section of the dial gauge 20, which means that the measurement error can be reduced to a minimum. In arrangements with less installation space for fastening the arm 21 on the second component 13, the dial indicator 20 can also be connected to the receptacle 2 with an arm 21' (shown in broken lines). As soon as the defined prestressing force is reached, the measured deformation value is stored or the dial gauge 20 is zeroed. The nut 15 is then applied from the first position shown in phantom to full contact with the top of the second component 13 . The prestressing force is released, which leads to a reduction in the deformation of the first component due to the settling effects between nut 15 and the upper side of the second component. The nut 15 is now tightened further until the dial gauge 20 has reached the stored deformation value or the zero position again, ie the first component is deformed with the same deformation value as when the prestressing force was applied.

2 describes a possible method with which the first component 8 can be connected to the second component 13 with a defined prestressing force.

In a first method step 30, the first component 8 is positioned relative to the second component 13 in the installation position.

In a second method step 31, a connecting element 15 for connecting the first 8 to the second component 13 is attached.

In a third method step 32, the first component 8 is connected to a means 16 for generating a prestressing force.

In a fourth method step 33, the first component 8 is connected to a measuring device 20 for measuring the deformation of the first component 8 under the action of the prestressing force.

In a fifth method step 34, a defined prestressing force is applied to the first component 8.

In a sixth method step 35, the deformation value determined by the measuring device 20 when the defined prestressing force is reached is stored.

In a seventh method step 36, the connecting element 15 is applied to the second component 13 until full contact is made.

In an eighth method step 37, the prestressing force is released.

In a ninth method step 38, the connecting element 15 is readjusted until the stored deformation value is reached.

In a tenth method step 39, the means 16 for applying the prestressing force and the measuring means 20 are dismantled.

Reference List

1

contraption

2

recording

3

recess

4

opening

5

edition

6

clamping element

7

screw

8th

first component

9

elastic area

10

inner thread

11

flange

12

poetry

13

second component

14

execution

15

mother

16

Means of generating a force

17

connection

18

load cell

19

adapter

20

dial gauge

21, 21'

poor

22

probe

23

external thread

24

inner thread

30

Process step 1

31

Process step 2

32

Process step 3

33

Process step 4

34

Process step 5

35

Process step 6

36

Process step 7

37

Process step 8

38

Process step 9

39

Process step 10

Claims (7)

Method for screwing a first component (8) comprising an elastic area to a second component (13) with a defined prestressing force, comprising the following method steps: - Positioning of the first component (8) to the second component (13) in the installation position, - Attaching a connecting element (15) to connect the first (8) to the second (15) component, - connecting the first component (8) to a means (16) for generating a prestressing force, - connecting the first component (8) to a measuring device (20) for measuring the deformation of the first component (8) under the action of the prestressing force, - Application of a defined prestressing force to the first component (8), - Storage of the deformation value determined by the measuring device (20) when the defined prestressing force is reached, - Applying the connecting element (15) to the second component (13) until full contact is made, - Release the preload force - Adjusting the connecting element (15) until the stored deformation value is reached. - Dismantling the means (16) for applying the preload force and the measuring means (20). procedure after claim 1 , characterized in that the connecting element (15) is designed as a nut. Method according to one of the preceding claims, characterized in that the measuring means (20) is designed as a length measuring system (20). Method according to one of the preceding claims, characterized in that the means (16) for generating a force comprises a load cell (18). Method according to one of the preceding claims, characterized in that a torque for applying the connecting element (15) designed as a nut (15) to the second component (13) is in a range from 0.1 Nm to 2 Nm. procedure after claim 5 , characterized in that the angle for adjusting the first component (8) to the stored deformation value of the measuring means (20) after releasing the prestressing force is in the range between 0 and 30 degrees. Method according to one of the preceding claims, characterized in that a seal is arranged between the first component (8) and the second component (8).

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