EP2994254B1 - Method and device for rolling threads with rolling rolls - Google Patents

Description

The invention relates to a method and an apparatus for thread rolling with rolling rolls according to the preamble of claim 1 and (see, for example DE 10 13 613 B ).

A device is, for example, with the subject of DE 10 2008 027 964 A1 known. In the rolling machine shown there, workpieces are rolled in the hot forming process, because the oppositely arranged rollers form a gap between them, in which the workpiece to be formed is provided at its outer periphery with a thread or a thread-like profile.

Disadvantage of said arrangement, however, is that the two forming rollers are mounted centrally rotatable, and do not perform a wobble during the rolling process.

At the subject of DE 10 2008 027 964 A1 Bar stock is moved in the longitudinal direction of the bar product by being conveyed between the nip of the opposing and counter-driven rolling rolls. Therefore arise in this document is not the problems that arise in the piecemeal introduction of rolling stock in the nip, namely those which occur when the rolling stock only briefly dwells in the nip to attach a profile thread on the outer circumference of the rolling stock and then the piecewise supplied rolling again from the Rolling gap is led out. The cited document does not deal with this problem of synchronized feed and discharge.

The BE 495 407 A shows an apparatus for feeding blanks to a rolling roll. In this case, a blank is introduced into a recess of a transport drum, which conveys by rotation of the blank in the working area of the rolling roller. The rotation is controlled by a locking device, which releases the transport drum depending on the control or upon reaching fixed to the rolling position. Disadvantage of the above arrangement, however, is that the two forming rollers are rotatably mounted centrally, and perform no wobble during the rolling process.

The DE 939 628 C shows a device for rolling and feeding of workpieces in tool rolls having machine tools, wherein one of the tool rolls stationary and the other tool roll via a slide linearly on the first roller and can be removed. Depending on the position of the carriage, the first tool roll is fixed during the rolling process via a locking lever and released after completion of the process. A disadvantage of this device are the high forces on the locking lever, which makes the device susceptible to wear.

The DE 10 13 613 B shows a method for thread rolling of workpieces on the basis of opposite and co-driven rollers in the forming process, with a forming between the rolling rolls nip in which the workpiece to be formed is provided at its outer periphery by forming a roll-side threaded thread with a thread, wherein in a first Process step at least one rolling roller performs a lifting movement with a carriage to open the nip, and wherein in a second process step in this open nip, the rolling stock to be formed is conveyed. In a third method step, the roll gap is narrowed, so that the rolling thread of the opposite rolling rolls reshapes the outer circumference of the rolling stock, and in the next step, the roll gap is opened again and the finished rolled rolled material is removed from the roll gap.

A disadvantage of this document is that the linear lifting movement of the carriage is caused by an eccentric disc, which converts a rotational rotary motion into a translational longitudinal movement. Thus, the production capacity is limited, since no high speeds for the supply and Wegstellung this rolling roll, due to the hydraulic drive, can be implemented.

Accordingly, the invention has the object, a method and an apparatus for thread rolling with rolling rolls for piece-by-piece rolling develop so that controlled at high production capacity piecewise rolling, rolled and controlled can be removed.

To achieve the object, the invention is characterized by a method according to the technical teaching of claim 1 and an apparatus having the features of claim 3.

Important in the invention is that in a first process step, at least one rolling roller performs a lifting movement to open the nip, and that in a second process step in this open nip the reshaped rolling is conveyed in that narrows in a third process step, the nip , so that the rolling thread on the opposite rolling rolls reshaping abuts the outer circumference of the rolling stock, and that in the next step, the roll gap opens again and the finished rolled stock is removed from the roll gap.

Important in the invention is therefore a synchronized supply by a feeder, which is formed in the present case as a parts basket, which performs an opposite or same direction of rotation to a roll and this ensures that always synchronized a rolling stock as a cut piece, for example in Shape of a screw is introduced into the now extended nip, that then the opposite roller performs a Exzenterhub that narrows the nip for the purpose of forming, and in this case the rolling is formed on the outer circumference, and that designed after narrowing of the nip of the Exzenterhub so is that the roll gap widens again and thus the finished rolled stock can be removed from the roll gap again.

The device used for this purpose is thus characterized in that the one roller is mounted centrally and is driven in rotation, and coaxially on the axis of rotation a feeder is arranged with a parts basket, which synchronized in the piece gap rolling stock leads into the nip and discharges from there again.

In a preferred first embodiment, it is provided that the supply device is driven opposite to the direction of rotation of the central rolling roller and is synchronized with the rotation of this rolling roller.

In another embodiment, however, it may be provided that the supply device rotates in the same direction of rotation as comparatively the centrally mounted roller, so that the two embodiments are both encompassed by the inventive concept.

It is essential to the invention that the rolling roller opposite the centrally rotating rolling roller performs an eccentric stroke with its outer circumference in the direction of the outer circumference of the centrally rotating rolling roller.

With this Exzenterhub a cyclic opening and closing of the roll gap is achieved, and when the roll gap is closed, the transformation of the rolling stock takes place, whereas when the roll gap is open, the rolling stock is either added or removed.

As a piecewise isolated rolling stock in this case all rotationally symmetrical metal parts must be reshaped, such as screws, rods, which is cut to a certain length, plastic parts, plastic-metal composite parts, wood or the like workpieces. Thus, it does not essentially depend on the choice of material of the rolling stock to be formed, but only on the fact that it is conveyed cyclically into the roll gap, wherein the roll gap is widened during the delivery, and that with closed roll gap on the outer circumference with a suitable thread or a suitable profile forming is provided, and that after conversion of this rolling stock, it can be discharged again with open nip.

In the case of the formation of the rolling stock as a screw blank it is processed between two rotating, profiled rolling rolls.

The first profiled cylindrical rolling roll rotates about its own axis and will be referred to as rolling roll A in the text below.

The second cylindrically profiled roller also rotates about its own axis and will be referred to as rolling roller B in the text below. However, it describes due to an eccentric receiving sleeve an eccentric track on the outer circumference.

The working stroke of the eccentric roller B thus takes place through an axial offset to the drive shaft.

The size of the axial offset depends on the thread pitch to be produced (single roll depth).

A larger thread pitch requires a larger axial offset.

As an example, it can be stated that if a thread
M6 x 1 = chopper depth 0.613 mm according to DIN13-1,
M8 x 1.25 = rolling depth 0.767 mm according to DIN13-1.

About the rolling roller A, a workpiece-receiving cage is arranged, which is referred to in the following text as a parts basket. This parts basket is driven by a step gear. The parts basket feeds the blanks into the forming process in individual timed steps and transports the finished screws out of the forming process.

1. 1. Leerhub:
   Im ersten Arbeitsschritt, in dem der Rohling zwischen den beiden Walzrollen A und B positioniert worden ist, bewegt sich im Leerhub die rotierende Walzrolle B auf die ebenfalls rotierende Walzrolle A zu.
2. 2. Walzweg:
   Sobald der Rohling von beiden Walzrollen berührt worden ist, beginnt der zweite Arbeitsschritt, der Walzweg. Die rotierende Walzrolle B bewegt sich weiter auf die rotierende Walzrolle A zu. Der Gewindeumformprozess dauert solange an, bis kein Material mehr umgeformt wird.
3. 3. Beladeweg:
   Im dritten Arbeitsschritt, am Rückweg des exzentrischen Hubes der Walzrolle B, wird das Werkstück freigegeben. Während des Beladeweges dreht sich der Teilekorb und befördert die gewalzte Schraube aus der Walzposition heraus und führt gleichzeitig einen neuen Rohling in die Walzposition hinein.

In general, the rolling operation can be described as follows in one complete revolution of the two rolling rolls A, B.

1. 1st idle stroke:
   In the first step, in which the blank has been positioned between the two rolling rolls A and B, the rotating rolling roll B moves toward the likewise rotating rolling roll A in the idle stroke.
2. 2nd rolling path:
   Once the blank has been touched by both rollers, the second step, the rolling path, begins. The rotating rolling roll B continues to move toward the rotating rolling roll A. The thread forming process continues until no material is reshaped.
3. 3. Loading path:
   In the third step, on the way back of the eccentric stroke of the roller B, the workpiece is released. During the loading path, the parts basket rotates and conveys the rolled screw out of the rolling position while introducing a new blank into the rolling position.

After performing a tool rotation of 360 degrees, a new work process begins.

In the following the invention will be explained in more detail with reference to drawings showing only one embodiment. Here are from the drawings and their description further features essential to the invention and advantages of the invention.

• Figur 1: Draufsicht auf die Vorrichtung zum Gewindewalzen mit zwei Walzrollen
• Figur 2: Schnitt durch die Vorrichtung nach Figur 1 als Mittenlängsschnitt
• Figur 3: das Diagramm eines Arbeitszyklus in Form einer Hubkurve
• Figur 4: der Hub der Walzrolle über einen Weg von 1 mm bei einer vollen Umdrehung

Show it:

• FIG. 1 : Top view of the device for thread rolling with two rollers
• FIG. 2 : Cut through the device after FIG. 1 as middle longitudinal section
• FIG. 3 : the diagram of a work cycle in the form of a lift curve
• FIG. 4 : the stroke of the rolling roller over a distance of 1 mm in one full turn

The roll mill machine 1 according to the invention consists according to FIG. 1 from two co-rotating with each other driven rollers 3, 13, wherein the left roller B is designed as eccentrically driven roller.

On a machine frame 2, said rolling roller 3 is rotatably driven in a rotary bearing 4 in a rotation axis 44, because a central rolling shaft 5 is provided, which is coupled at its outer periphery via a sliding block 7 with an eccentric sleeve 8, which during the rotation of the rolling roller in the direction of arrow 6 for a lifting movement in the direction of arrow 28 (wobble) ensures.

In this way, in a full revolution of the roller 3, which is in the space between the outer periphery of the roller 3 and the outer periphery of the opposite, centrally driven and rotating roller 13, a roll gap 43 (see FIG. 2 ), which opens and closes cyclically.

The line 9 in this case denotes the gear center in the drive gear and thus from the central axis of rotation 44, while the line 10 describes the highest point of Exzenterverstellung the eccentric sleeve 8.

In this way, an eccentric stroke 36 (see FIG. 2 ) with respect to the central axis of rotation 44 can be achieved. This Exzenterhub 36 serves the one-time adjustment of the size of the roll gap and does not change over the rotation angle of the roller 3. It is set once and determines the basic width of the nip 43.

As an adjustment of this Exzenterhubes serve the auxiliary points 11, 12 and 14, in their overall position, the whale shaft 5 can be rotated to adjust the required Exzenterhub 36 once and then set.

However, for the cyclic opening and closing of the nip 43, the smaller Exzenterhub 64 serves (see FIG. 2 ), which results from the eccentric mounting of the eccentric sleeve 8.

The Exzenterhub 36 indicated therein is used to adapt to the diameter of larger or smaller rolling stock 26 by means of the auxiliary points 11, 12 and 14, while the smaller Exzenterhub 64 (see FIG. 2 ) causes an adjustment or a rotation of the eccentric sleeve 8 and is provided for the cyclic opening and closing of the nip 43.

The right-hand rolling roller 13 has a roller shaft 15, which is mounted centrally in a rotation axis 45 and rotates, for example, in the direction of arrow 16. The outer periphery is provided with a rolling thread 27. The rolling thread on the roller 3 is indicated at 17.

After the rolling roller 13 is mounted centrally, only a round sleeve 18 is present, which is connected to a sliding block 7 with the roller shaft 15.

In FIG. 1 is still shown with respect to the sliding block 7 on the roller 3, that this nut connects the eccentric sleeve 8 with the roller shaft 5.

For cyclical feeding of rolling stock, a supply device is provided, which consists essentially of a feed channel 22 and a discharge channel 32.

The rolling stock 26 is fed via the feed channel in the direction of arrow 23 and then passes outwardly open receptacles 21 of a parts basket 19, which is driven separately from the rotation of the roller shaft 15, in the opposite direction in the direction of arrow 24 in comparison to the drive direction of the roller 13 in Arrow direction 16.

The rolling stock 26 is thus introduced in pieces in each case an open receptacle 21, wherein the rolling stock 26 rests on an annular flange 20 of the parts basket 19 and is supplied to the nip 43 in the direction of arrow 24. Likewise, the rolling stock 26 can be hung hanging on the head of the top of the flange 19 of the basket.

After rolling has been completed, the rolling stock is conveyed out of the now open roll gap 43 and leaves the discharge channel 32 in the direction of the arrow 25.

The rolling stock 26 is protected in the receptacles 21 against falling out by a guard rail 29.

In FIG. 2 are the further details of the structural design of the rolling mill 1 according to the invention shown.

It can be seen that the eccentric sleeve 8 is arranged on the upper side of the left rolling roller 3, which is connected via the sliding block 7 with the inner roller shaft 5, so that the entire eccentric sleeve for a displacement of the

Roller 3 provides in the direction of arrow 28 and so performs the required Exzenterhub 64.

To fix the rotational position of the eccentric sleeve 8, a pressure washer 30 is used, which is pressed by means of screws 33 on the upper side of the roller 3, wherein the eccentric sleeve 8 remains free.

In this case, a pressure ring 31 is used, which is penetrated by the screws 33 and which is screwed onto an associated external thread 34 of the rolling shaft 5.

The rolling shaft 5 is still rotatably supported by spaced-apart roller bearings 37, and provided for the output width of the nip 43 eccentric adjustment with the eccentric axis 38 and the Exzenterhub 36 is not shown in detail. It is a conventional eccentric adjustment of the rolling shaft 5 to the Exzenterhub 36, which is set once and then fixed.

The bottom of the roller 3 is located on a shim 35, which is designed to be interchangeable and by means of which the thread height of the rolling stock 26 is precisely adjustable.

The shim 35 allows for a displacement of the roller 3 in the axial direction. It is therefore a height adjustment game.

For the right roller 13 is according to FIG. 2 to recognize that the local whale shaft 15 is mounted in a central axis of rotation 45, and also via the sliding block 7, the centric round sleeve 18 is coupled to the outer periphery of the roller shaft 15.

With a step gear 46, a gear 48 is intermittently and stepwise driven so that it is rotatably coupled via an intermediate flange 49 with the annular flange 20 of the feeder (parts basket 19).

In this way, a stepwise intermittent drive rotational movement is achieved for the annular flange 20, on which the rolling stock 26 to be supplied is introduced into the nip 43.

On the annular flange 20 of the parts basket 19 is arranged, in the receptacles 21, the reshaped screws or the rolling stock 26 are arranged.

In FIG. 2 only the tooth engagement 47 between the indexable gear 46 and the gear 48 is shown schematically.

In FIG. 2 is still on the left side of the eccentric adjustment with respect to the Exzenterhubes 36 shown. This is done according to FIG. 2 in that a centric bearing flange 39 is present, which forms an inner eccentric circumference, wherein on the inner circumference still an exemption 40 with respect to the outer circumference of the roller shaft 5 is arranged.

Was the correct Exzenterhub 36 found, then the rotational position of the bearing flange 39 is set via a clamping sleeve 42 which cooperates with a clamping ring 41.

FIG. 3 now shows a working cycle of a lifting cam 53 of the roller 3, wherein the abscissa of the rotation angle of the roller and the ordinate of the stroke of the roller is applied. It can therefore move between a stroke of 0 to 0.5 mm, for example.

At position 59, rotation begins in the direction of arrow 54 and is an idle stroke 60 that ends at position 55.

After exceeding the position 55, the top dead center is reached, wherein between the position 55 and 56, an idle stroke 60 takes place.

From the position 56, the actual rolling path 57 of the rolling roller 3, which takes place beyond the bottom dead center up to the position 51 with the indicated rotation angle of, for example, 270 degrees.

From position 51, a loading path 58 is then carried out, in which the roll gap 43 is opened and the rolling stock 26 is introduced into the opened roll gap. Upon further rotation is then completed at position 52 of the loading path and there is a new process, with the position 55 and 56 back in FIG. 3 starts.

According to FIG. 4 Thus, the stroke of the roller can be changed by 1 mm at a revolution of, for example, 360 degrees. This is only an exemplary dimension and is not intended to limit the invention in any way.

It is shown that there is either a forward stroke 21 for closing the roll gap or also a backward stroke 62 for opening the roll gap, and that overall the eccentric lift curve 63 in FIG FIG. 4 is specified via the angle of rotation and the stroke.

From the present invention there is the advantage that with a very high production capacity precise forming work on the deformable rolling stock 26 can be made. Such a machine has a production capacity of, for example, 400 pieces per minute, wherein the feeding movement of the parts basket 19 with the annular flange 20 exactly with the Exzenterhubkurve 63 in FIG. 4 must be synchronized to ensure that when the nip is opened, a part is introduced, then reshaped and can be removed after forming with the nip open again.

drawing Legend

1

Roll rolling machine

2

machine frame

3

Rolling roller B (left eccentric)

4

pivot bearing

5

roller shaft

6

arrow

7

sliding block

8th

eccentric

9

Line (gear center)

10

Line (highest point)

11

auxiliary point

12

auxiliary point

13

Rolling roller A (right)

14

auxiliary point

15

Whale wave (right)

16

arrow

17

Rolling thread (left)

18

Round sleeve (right)

19

parts Bin

20

annular flange

21

Intake (for rolling stock)

22

feed

23

arrow

24

Arrow direction (parts basket)

25

arrow

26

rolling

27

Rolling thread (right)

28

wobble

29

barrier

30

pressure disc

31

pressure ring

32

discharge channel

33

screw

34

thread

35

shim

36

eccentric stroke

37

roller bearing

38

eccentric

39

Lagerflansch

40

exemption

41

clamping ring

42

collet

43

nip

44

Rotation axis (from 4)

45

Rotation axis (from 13)

46

step gear

47

meshing

48

gear

49

Wafer

50

51

Position (loading path)

52

position

53

stroke curve

54

arrow

55

position

56

position

57

Walzweg

58

Beladeweg

59

position

60

idle stroke

61

Hub (forward)

62

Hub (backward)

63

Exzenterhubkurve

64

eccentric stroke

Claims (8)

1. Method for thread rolling of workpieces (26) using opposing rolling rolls (3, 13) driven in the same direction in a reshaping process, wherein a rolling roll (13) is mounted centrally and driven in rotational manner, with a roll gap (43) being formed between the rolling rolls (3, 13) and in which the workpiece (26) to be reshaped is provided with a thread or a thread-like profile on its outer circumference by reshaping using a roll-side rolling thread (17, 27), wherein in a first method step, at least one rolling roll (3) executes a lifting movement in order to open the roll gap (43), wherein in a second method step, the rolled stock (26) to be reshaped is conveyed into this opened roll gap (43), wherein in a third method step, the roll gap (43) is narrowed so that the rolling thread (17, 27) of the rolling rolls (3, 13) opposite one another rests in reshaping manner on the outer circumference of the rolled stock (26), and wherein in the next method step, the roll gap (43) is opened again and the finally rolled, rolled stock (26) is conveyed away from the roll gap (43), characterised in that the rolling roll (3) opposite the centrally rotating rolling roll (13) executes eccentric lifting (64) with its outer circumference in the direction of the outer circumference of the centrally rotating rolling roll (13), whereby cyclic opening and closing of the roll gap is achieved.
2. Method according to claim 1, characterised in that the rolled stock (26) is supplied in synchronised manner in individual cycled steps to the roll gap (43) via a supply device driven by a stepping gear (46) and is carried away after the reshaping process.
3. Device for thread rolling of workpieces (26) using opposing rolling rolls (3, 13) driven in the same direction in a reshaping process, with a roll gap (43) being formed between the rolling rolls (3, 13) and in which the workpiece (26) to be reshaped is provided with a thread or a thread-like profile on its outer circumference by reshaping using a roll-side rolling thread (17, 27), wherein a rolling roll (13) is mounted centrally and driven in rotational manner, and coaxially on the rotational axis (45) is arranged a supply device with a parts cage (19) which is suitable for guiding the rolled stock in synchronised manner into the roll gap (43) and for carrying it away from there again, characterised in that the rolling roll (3) opposite the centrally rotating rolling roll (13) is driven to be rotatable via a central roll shaft (5) which is coupled to an eccentrically mounted eccentric sleeve (8) to be resistant to rotation on its outer circumference so that for cyclic opening and closing of the roll gap (43), the rolling roll (3) opposite the centrally rotating rolling roll (13) for carrying out rolling reshaping, executes first eccentric lifting (64) with its outer circumference in the direction of the outer circumference of the centrally rotating rolling roll (13).
4. Device according to claim 3, characterised in that the rolling roll (3) opposite the centrally rotating rolling roll (13) is driven in rotational manner by a central roll shaft (5) in a pivot bearing (4) in a rotational axis (44) and an eccentric adjustment provided for the starting width of the roll gap (43) is provided with an eccentric axis (38) for second eccentric lifting (36).
5. Device according to one of claims 3 to 4, characterised in that the supply device is formed as a parts cage (19) which is arranged coaxially on the rotational axis of the centrally rotating roll (13) and is driven counter to the direction of rotation of the centrally rotating rolling roll (13) and is synchronised with the rolling roll (13).
6. Device according to one of claims 3 to 4, characterised in that the parts cage (19) is arranged coaxially on the rotational axis of the centrally rotating roll (13) and is driven in the same direction of rotation as the centrally rotating rolling roll (13) and is synchronised with the rolling roll (13).
7. Device according to one of claims 3 to 6, characterised in that the rolled stock (26) can be supplied piece by piece into an outwardly opened receiver (21) of the parts cage (19) cyclically via a supply channel (22) and the rolled stock (26) stands up on an annular flange (20) of the parts cage (19) and can be supplied to the roll gap (43).
8. Device according to one of claims 3 to 7, characterised in that the rolled stock (26) can be supplied piece by piece into an outwardly opened receiver (21) of the parts cage (19) cyclically via a supply channel (22) and the rolled stock (26) is suspended in the upper region of the parts cage (19) and can be supplied to the roll gap (43).

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