DE8801000U1 - Device for straightening workpieces with impact - Google Patents

Description

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Device for straightening workpieces with impact

Devices for straightening components that are subject to impact are known. Generally speaking, this refers to curved components that are straightened by bending them back to a corresponding degree. To do this, the workpiece is usually placed on two supports and a sufficiently large, radially opposite force is exerted on the workpiece in the area of greatest deflection between the two supports until the corresponding elastic deformation is exceeded and plastic deformation has set in. The result of this straightening operation is then measured and the straightening operation is repeated, if necessary, at the same point or at a different point and possibly with different forces, until the workpiece is sufficiently straight. This type of straightening, however, has the disadvantage that the straightening operation has an unfavorable effect on the internal stress state of the workpiece, which means that the workpiece has lower mechanical strength and/or lower fatigue strength after the straightening operation. It is immediately apparent that, in particular, workpieces that are subjected to dynamic stress must not have their fatigue strength reduced by a straightening operation, because otherwise this would have to be taken into account when dimensioning the workpiece. This in turn would lead to uneconomical dimensions of the workpiece. A satisfactory straightening method that at least avoids the reduction in the fatigue strength of the straightened workpiece is not known. The described state-of-the-art straightening method has particularly negative effects on workpieces that have been subjected to treatment to increase fatigue strength. The described state-of-the-art straightening method generally completely negates the increase in the fatigue strength of the workpiece achieved by the pre-treatment, so that this processing is pointless.

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The innovation is therefore based on the task of proposing a device with which a workpiece can be straightened without reducing the existing durability of the workpiece or the durability achieved through additional processing.

According to the innovation, the problem is solved by a device which has at least one workpiece clamping device arranged on a machine stand. In order to carry out the necessary straightening operation, means must also be present for influencing the compressive residual stresses in a surface layer area of the workpiece, means for generating a relative movement between the workpiece and the means for influencing the compressive residual stresses and further means for detecting the position between the workpiece and the latter means as well as means for controlling the means for influencing the compressive residual stresses and the relative movement between this and the workpiece depending on the data from the means for detecting the position and further data which determine the location and magnitude of the compressive residual stresses to be introduced.
This allows localized residual compressive stresses to be introduced through hardening in the surface layer area of the workpiece, at least to reduce the impact present on the workpiece. Residual compressive stresses in the surface layer area of the workpiece can be introduced in various known ways. An example of this is a more or less deep so-called surface hardening, which can be carried out as case hardening or induction hardening, or even surface layer hardening using a laser beam.

Furthermore, residual compressive stress can be achieved in the surface layer area by nitriding. Another example of introducing residual compressive stress into the workpiece is the well-known deep rolling process.

When introducing residual compressive stresses, care must be taken to ensure that these do not run through the entire structure, but occur in significant quantities only in the edge layer area of the workpiece. The residual compressive stresses that are present or introduced trigger a corresponding deformation of the workpiece. The direction of deformation depends, among other things, on the surface area of the workpiece in which the residual compressive stresses are introduced. The size of the deformation or the guide size of the workpiece depends on how strong these residual compressive stresses are and how deep the residual compressive stresses extend into the edge layer area. In order to achieve the desired guide effect, the residual compressive stresses must be introduced into the workpiece in a locally limited manner. This can be done, for example, by a locally limited induction hardening process or by a locally limited deep rolling process. The local limitation can be any type of local limitation. For example, it is possible to harden workpieces with a rotation axis with a selected hardness, axially limited but within the axial limitation around the entire circumference, to a desired or necessary depth, or to roll them with a selected specific rolling force. In the case of deep rolling, another way of influencing this is the number of overrolls. i

A local limitation of the hardening in the surface layer area for the introduction of residual compressive stresses also occurs if, for example, hardening or deep rolling is not carried out over the entire circumference in the circumferential direction, regardless of the size of the axial extension in which the hardening or deep rolling operation is carried out. However, a circumferential angle range of at least 10° should be treated in order to exert a significant influence on the workpiece.

If workpieces, especially workpieces with a rotation axis, have, for example, cross-sectional transitions at the beginning of which a notch effect occurs, then it is advantageous to carry out the hardening in the surface layer area of the workpiece in order to introduce the pressure residual stresses in this notch area. Typical examples of this are the

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Transitional concave grooves on steering knuckles or crankshafts or camshafts or similar workpieces. In such areas, hardening or deep rolling can be carried out very cheaply. It is also easy to carry out this hardening or deep rolling process to introduce the residual compressive stresses in the area of the concave groove not over the entire circumference of the concave groove, but only over a suitable limited angle range, which, as already explained above, should be at least 10°.

In the case of simple and, for example, rotationally symmetrical workpieces, such as stepped shafts, it can be expected that if residual compressive stresses are introduced in a notch area, e.g. in a transitional fillet, over a limited circumferential angle range in such a way that they occur in the two adjacent workpiece zones, a corresponding deformation reaction of the workpiece occurs in the plane in which the bisector of the circumferential angle range lies, in which the residual compressive stresses were introduced.

In the case of more complex components, such as a crankshaft, the size, shape and position of adjacent elements of the crankshaft, such as the crank web, can also influence the direction of deformation of a deformation movement that was triggered by the introduction of residual compressive stresses. However, such effects can easily be determined empirically, so that it is always possible to introduce the residual compressive stresses or to increase the residual compressive stresses in such a circumferential sector that the adjacent workpiece areas are deformed in the correct way. The original deformation and the deformation caused by straightening should therefore add up vectorially in such a way that the result is at least a small impact on the workpiece.

The described straightening of workpieces with impact by introducing residual compressive stresses into the workpiece at suitable locations to achieve the straightening effect can also be carried out effectively if the workpiece to be straightened has already been pre-strengthened. In such a case, however, it is necessary that such values

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which produce greater residual compressive stresses and/or deeper residual compressive stresses relative to the already existing hardening in the desired areas. This is possible, for example, when using a deep rolling operation to straighten workpieces that have already been deep rolled to increase their fatigue strength, by rolling with a higher specific rolling force than in the previous deep rolling operation, or by rolling with the same specific rolling force but a higher absolute rolling force. If the rolling roll is designed correctly, the higher specific rolling force can prevent the resulting residual compressive stresses from becoming deeper, but can increase the residual compressive stresses that are already present in the surface layer area. This can be achieved, for example, with a deep rolling roll that is smaller in diameter than the deep rolling roll used for the first deep rolling operation. According to the rules of so-called Hertzian pressure, this increases the specific rolling force on the workpiece with the same absolute rolling force. If the reduction in the ^diameter of the rolling roller alone is not sufficient, an increase in the absolute force can also be added.

Conversely, if the diameter of the rolling roll is increased, a lower Hertzian pressure and thus a lower specific rolling force on the workpiece can be achieved. By increasing the absolute rolling force, the specific rolling force that was originally achieved with the smaller roll in the previous deep rolling operation can be achieved again. This means that the compressive residual stresses in the surface layer area are not increased but extend deeper into the surface layer area. In this case, it is irrelevant whether the deepening operation to increase the fatigue strength of the workpiece precedes the straightening operation or is carried out at the same time as the straightening operation. It is only necessary to view the respective measure used to increase the fatigue strength of the workpiece in its specific performance data as the starting point for the necessary variation of these data in order to introduce higher compressive residual stresses in a localized manner.

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If, for example, a deep rolling operation is carried out in the area of the transition groove of a steering knuckle to increase the fatigue strength of the steering knuckle and it is determined that the steering knuckle has a certain amount of runout pointing in a certain direction, it is possible to increase the deep rolling force at the required point during the deep rolling operation by a required amount above the previous deep rolling force. This increase in force is only required in the circumferential direction over part of the circumferential angle and must then be reduced again to the value that was previously used to achieve the desired fatigue strength through the deep rolling operation.

The same applies to hardening the steering knuckle pin mentioned as an example.

The new device is particularly cost-effective in the series production of identical workpieces. If, for example, one looks at the series production of a very specific crankshaft, one can see that the various, successive types of processing used to produce the crankshaft produce a runout in a very specific direction and of a very specific, always identical size. It is then very easy to determine through tests at the start of series production at which points and to what extent compressive stresses must be introduced in order to achieve the desired straightening effect on this crankshaft. Once the data required for this is known, this data can be processed by a corresponding device as a fixed program. The necessary device is then particularly simple in its structure. In such a case, the device can dispense with the appropriate testing equipment and measuring instruments to record the actual condition of the crankshaft and there is also no need for devices to check the respective straightening result. A random sample check is completely sufficient for this purpose.

If the residual compressive stresses are to be introduced by a rolling operation, a power-operated rolling tool with at least one rolling roller must be used as a means of influencing the compressive properties.

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A device for controlling the rolling force must be provided. The necessary rolling process can be carried out by a relative movement between the roller and the workpiece, generated by a rotational movement of the workpiece. Furthermore, path-controlled, movable support means can be provided to generate a further relative movement between the workpiece and the rolling tool according to a predeterminable movement sequence and in predeterminable positions. For individual rolling tools, it may be necessary to bring each existing rolling tool with the rolling roller into an axially correct position and then to bring the rolling tool into contact with the workpiece by a radial movement of at least the rolling roller towards the workpiece. The correct rolling force and the correct rolling force change must then be controlled by controlling the rolling force in order to achieve the desired straightening effect.

Advantageously, a device according to the innovation also has at least one deformation measuring system containing measuring elements for detecting the workpiece impact at predetermined or predeterminable positions, whereby the deformation measuring system is connected to a data evaluation device and this in turn is connected to a machine control system. This allows the condition of the workpiece to be checked directly in the straightening device and the straightening data to be determined and, if necessary, continuously corrected.

In the above-mentioned device, the means for influencing the residual compressive stresses of the workpiece can also be designed as hardening devices for hardening the edge layer area of the workpiece. For example, an induction coil can be used to heat the workpiece. The subsequent cooling to achieve the necessary increase in hardness in the edge layer area of the workpiece can take place in the air or by means of additional cooling devices. This depends on the type of material of the workpiece. The hardening device must be designed in such a way that both the hardness itself and the hardening depth in the edge layer area of the workpiece can be influenced. The technique of hardening in the edge layer area of a workpiece as such is known and it is also

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It is known which parameters must be changed in order to achieve a greater hardness in the edge layer area or a greater or smaller hardening depth in the edge layer area. This must therefore be dealt with separately at this point. Appropriate means for controlling the hardness as such, the hardening depth and also the hardening location should therefore be provided in order to achieve an optimal straightening result on the device according to the invention.

In general, in order to carry out the straightening operation, it is necessary to carry out at least one measurement on the workpiece* in which the location, magnitude and direction of impact are determined. The straightening operation is then carried out depending on the data determined in this way. In the case of crankshafts, the angular range in the circumferential direction of a notch area (transitional fillet) is also determined on the main and/or connecting rod bearings in which the compressive residual stress is to be influenced.

After the first straightening operation, the result of this straightening operation can be determined and then, if necessary, another straightening operation can be carried out with adjusted straightening data. Here, "adjusted straightening data" means that the specific rolling force, the absolute rolling force, the number of over-rolls or the angle of rotation of the direction of action of the rolling force, or the axial position of the location of the action of the rolling force can be changed individually or in combination as required. The same applies if the necessary residual compressive stresses are introduced via a hardening process. The respective sizes of the desired changes can be fixed so that constant change steps always take place. However, it is also possible to make the type and size of a necessary change dependent on the result of the previous straightening operation. For this purpose, an assigned device must have appropriate deformation measuring systems. An assigned computer can then, by learning step by step from the result of a previous straightening operation, determine the parameters of the next straightening operation and feed them to a corresponding machine control system.

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When straightening particularly cylindrical, elongated workpieces, the residual compressive stresses can be introduced by a rolling operation on the surface side facing away from the direction of deflection (i.e. on the inside of the arch). This rolling operation can be carried out as a plunge rolling or as a rolling in a feed process.

The new device can also be used to straighten crankshafts very effectively. It is particularly advantageous if the runout is measured at several points on the crankshaft to be straightened and the straightening operation is started in the area of the greatest runout.

Figures 1 to 5 illustrate the essential principles and the basic structure of a device for carrying out the method in question.

In Figures 1 and 2, a simple offset shaft is shown as workpiece 1, which can be, for example, part of a steering knuckle, as used in the area of the steered wheels of a motor vehicle. This workpiece 1 has a runout 3 that is to be straightened. To introduce the necessary residual compressive stresses, the deep rolling process is selected. In this case, a rolling roller 25 is pressed into the notch area V, i.e. into the transition groove of the peripheral surface 4. In this case, the rolling roller 25 is loaded with the force F, acting in the direction of the arrow shown in Figure 1. The direction of action of the force F goes through the center of the radius of the transition radius. To introduce the necessary residual compressive stresses, a force F I is applied over the angular range Beta 1, while the smaller force F 2 is applied over the angular range Beta 2. Since the force F 1 is greater than the force F 2, higher compressive residual stresses are introduced into the workpiece in the angle range Beta 1, in which the force F 1 acts, whereby the impact 3 can be reduced and even made zero. The compressive residual stresses are only introduced into the surface layer area 2. The

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Force F 2 acting on the peripheral surface 4 must be large enough to achieve a solid rolling effect with a desired increase in the fatigue strength of the workpiece. However, to achieve the straightening effect, it is then necessary that the force F 1 acting in the angle range Beta 1 is sufficiently larger than the force F 2. With the dimensions of the rolling roller 25 remaining the same, a precisely defined specific rolling force is generated by the rolling roller 25 in the area of the peripheral surface 4 of the workpiece 1 using the forces F 1 and F 2. In order to increase the residual compressive stresses in the edge layer area 2 of the workpiece, this specific rolling force must be increased. This can be done by, for example, giving the rolling roller 25 a smaller diameter (Hertzian surface pressure). With the same force F 1 or F 2, this results in a larger specific rolling force with a correspondingly increased residual compressive stress in the workpiece, without this residual compressive stress extending deeper into the edge layer area 2. However, if the force F 1 or F 2 is increased with the same diameter of the rolling roller 25, this also results in a higher specific rolling force and thus a higher residual compressive stress in the workpiece. This higher residual compressive stress, however, extends deeper into the edge layer area 2.

However, it is also possible to generate a greater depth of this compressive residual stress with the same residual compressive stress. This means that a greater thickness of the edge layer area 2 has corresponding residual compressive stresses. This can be achieved by increasing the diameter of the rolling roller 25 and increasing the force F 1 or F 2 until the originally intended specific rolling force is reached again. This also means that the compressive residual stress in the workpiece reaches the originally intended value, but over a greater depth or thickness of the edge layer area 2.

Instead of the rolling roller 25, a hardening device could also be provided, for example a lifting device that can be used for local heating of the workpiece using a laser beam of appropriate energy. By hardening the edge layer area of the workpiece in the same area in which the rolling roller 25 is working,

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correspondingly increased residual compressive stresses are introduced into the workpiece and thus the desired straightening effect is achieved. The size of the straightening effect can again be influenced by the size of the |.

Hardness as such and/or the penetration depth of the hardness into the U

Boundary layer area 2. f

Both the hardening during a straightening process and the deep rolling operation during a straightening process can be carried out on a workpiece that has already been hardened by a previous hardening or deep rolling operation in the areas in which the higher compressive residual stresses are to be introduced. It is only necessary to increase the corresponding parameters for the subsequent hardening operation or deep rolling operation with which a straightening effect is to be achieved so that higher compressive residual stresses are actually introduced into the workpiece in the desired areas. The angle range Beta 1 over which this has to take place can easily be determined by simple tests.

The same method described so far can of course also be used particularly advantageously when the workpiece 1 is a crankshaft. This is indicated in Figures 3 and U. The shaft end 26 j of the crankshaft 1 is bent in the opposite direction to the shaft journal of the steering knuckle according to Figure 1. This shaft end 26 can also be straightened, for example, by a deep rolling operation. The rolling roller is set in the notch area 4 ¹ , as shown in Figure 3, and rolling is carried out in the angle range Beta 1 with a correspondingly large rolling force F 1. If a deep rolling operation has already been carried out in the entire notch area W of the crankshaft 1, the force FI must be correspondingly greater than the force F 2 used for the deep rolling operation in the angle range Beta 2. However, what was described for Figure 1 also applies here. The rolling operation can also be replaced here by a corresponding hardening operation.

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The schematic structure of a machine suitable for carrying out the method according to the invention is shown in Figure 5. A machine stand 10 has a workpiece rotation drive 23 with a workpiece clamping device 11. A punch 27 can be provided as a counter-holding device for the workpiece 5 designed as a crankshaft. The angular position of the workpiece rotation drive and thus of the workpiece is monitored by an angle sensor 7k , which forwards its information to a deformation measuring system 22. In the workpiece clamping device 11, it can be ensured that the crankshaft 5 is inserted into the workpiece clamping device 11 in a known angular position.

The deformation measuring system 22 further comprises the measuring points 6 to 9, which are located at predetermined or predeterminable points on the crankshaft 5

-in the embodiment according to Figure 5, these are the main bearings of the I

Crankshaft- the runout of the crankshaft 5 in radial direction j

directed size according to certain. These measuring points derive their j

Information is also passed on to the deformation measuring system 22, which in conjunction with the angle sensor 7k is thereby able to determine the rotational angle of the measured impact.

Furthermore, a rolling tool 12 with a rolling force generating device

tung 13. Such rolling tools with which the transition hollow I

grooves can be rolled on the bearings of crankshafts and the associated rolling force generation device are state of the art, so that there is no need to go into this in more detail here.

The deep rolling force generating unit 13 is mounted on a support means 15 |

and can be moved by this, for example, via a ball screw 16 with associated spindle drive 17 along the workpiece axis 28 f,

The spindle drive 17 has a resolver, |

so that information about the respective position of the support means 15 is available, whereby the support means 15 can be positioned. The deep rolling force generating unit 13 can also be arranged stationary if rolling always takes place at the same axial location of the workpiece. This

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The rolling force generating unit 13 can also be moved in the radial direction to the workpiece axis 28 via a ball screw 18 with a corresponding spindle drive 19. In order to enable the simultaneous axial movement, the spindle drive 19 is arranged on a carriage 29 that can be moved in the direction of the arrow 30. The spindle drive 19 also has a resolver, so that the radial position of the rolling force generating device 13 with the rolling tool 12 is known and can therefore also be positioned.

The data from measuring points 6 to 9 and from the angle sensor 24 are fed to the data evaluation device 20 via the deformation measuring system 22. The data evaluation device 20 continuously receives information about the current position of the rolling force generating device 13 and the support means 15 via line 31. The unspecified rotary resolvers of the spindle drives 17 and 19 supply the corresponding data.

To control the rolling force, the rolling force generating device 13 is connected to a rolling force control device 14. With this rolling force control device 14, the rolling force can also be varied during each individual revolution if required. As the description of Figures 1 to 4 makes clear, this is often necessary.

The data evaluation device 20 also exchanges data with the machine control 21, which, in conjunction with the data evaluation device 20, controls the control of the entire machine both in terms of the positions of the individual components and in terms of speed, number of rolls, deep rolling force and change in deep rolling force as well as the sequence of straightening locations. If a computer is present in the data evaluation device 20, this can also be freely programmable. It is then possible to carry out different pre-programmed straightening sequences or, if the condition of the workpiece in the machine has been recorded or is known, to carry out a straightening operation corresponding to the individual start of the workpiece. The necessary data exchange

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between the data evaluation device with computer, the machine control system and the machine itself, takes place via lines 32 and 33. Lines 31 and 34 only supply data to the data evaluation device 20. The individual connections and connection directions between the devices of the machine itself and the associated peripheral devices are indicated in Figure 5 by the thin arrow lines.

The device according to the invention can certainly consist of several independent units. For example, the deformation measuring system can form such an independent unit, which is followed by an independent straightening unit. This straightening unit can in turn be designed as a hardening machine or as a rolling machine. In addition to the above-mentioned independent units, an independent hardening machine or deep rolling machine can be arranged, for example, with which the desired strength properties of the workpiece are achieved before straightening. However, this should be placed in front of the deformation measuring system, because deformation of the workpiece, triggered by the hardening operation or deep rolling operation, is to be expected.

Figures 1 to 5 illustrate the essential principles and the basic structure of an innovative facility.

In Figures 1 and 2, a simple offset shaft is shown as workpiece 1, which can be part of a steering knuckle, for example, as used in the area of the steered wheels of a motor vehicle. This workpiece 1 has a runout 3 that is to be straightened. The deep rolling process is selected to introduce the necessary residual compressive stresses. Here, a rolling roller 25 is pressed into the notch area 4', i.e. into the transition concave groove of the peripheral surface 4. The rolling roller 25 is loaded with the force F, acting in the direction of the arrow shown in Figure 1. The direction of action of the force F goes through the radius center of the transition radius.
To introduce the necessary residual compressive stresses, a force F 1 is applied over the angle range Beta 1, while the smaller force F 2 is applied over the angle range Beta 2. Since the

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F 1 is greater than the force F 2, higher compressive stresses are introduced into the workpiece in the angular range Beta 1 in which the force F 1 acts, whereby the impact 3 can be reduced and also made zero. The compressive stresses are only introduced into the edge layer area 2. The force F 2 acting on the peripheral surface 4 can also be so great that a deep rolling effect with a desired increase in the fatigue strength of the workpiece is achieved. In order to carry out the straightening effect, however, it is then necessary that the force F 1 acting in the angular range Beta 1 is sufficiently greater than the force F 2. With the dimensions of the rolling roller 25 remaining the same, a very specific rolling force is generated by the rolling roller 25 in the area of the peripheral surface k of the workpiece 1 with the forces F 1 and F 2. In order to increase the compressive stresses in the edge layer area 2 of the workpiece, this specific rolling force must be increased. This can be done by, for example, giving the rolling roller 25 a smaller diameter (Hertzian surface pressure). With the same force F 1 or F 2 , this results in a larger specific rolling force with a correspondingly increased &igr;

Residual compressive stress in the workpiece, without this residual compressive stress

deeper into the boundary layer area 2. However, if I

the same diameter of the roller 25, the force F 1 or F 2 f

increased, this also results in a higher specific rolling force and |

thus a higher residual compressive stress in the workpiece. This higher |

However, residual compressive stress extends deeper into the surface layer region 2 |

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depth of this compressive residual stress. This means that a \

greater thickness of the boundary layer area 2 corresponding pressure properties f

This can be achieved by increasing the diameter of the rolling roller 25 and increasing the force F 1 or F 2 until the originally intended specific rolling force is reached again. This also causes the residual compressive stress in the workpiece to reach the originally intended value, but over a greater depth or thickness of the surface layer area 2.

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Instead of the rolling roller 25, a hardening device could also be provided, for example a hardening device that uses a laser beam of appropriate energy to locally heat the workpiece. By hardening the edge layer area of the workpiece in the same area in which the rolling roller 25 is working, correspondingly increased residual compressive stresses are also introduced into the workpiece and the desired straightening effect is thus achieved. The size of the straightening effect can again be influenced by the size of the hardness as such and/or by the depth of penetration of the hardness into the edge layer area 2.

Both the hardening when carrying out a straightening process and the deep rolling operation when carrying out a straightening process can be carried out on a workpiece that has already been hardened in the areas in which the higher compressive residual stresses are to be introduced by a previous hardening or deep rolling operation. It is only necessary to increase the corresponding parameters for the subsequent hardening operation or deep rolling operation, with which a straightening effect is to be achieved, so that higher compressive residual stresses are actually introduced into the workpiece in the desired areas* The angle range Beta 1 over which this is to take place can easily be determined by simple tests.

The same method described so far can of course also be used particularly advantageously when the workpiece 1 is a crankshaft. This is indicated in Figures 3 and 4. The shaft end 26 of the crankshaft 1 is bent in the opposite direction to the shaft journal of the steering knuckle according to Figure 1. This shaft end 26 can also be straightened, for example, by a deep rolling operation. The rolling roller is set in the notch area V , as shown in Figure 3, and rolling is carried out in the angle range Beta 1 with a correspondingly large rolling force F 1. If a deep rolling operation has already been carried out in the entire notch area 4' of the crankshaft 1, the force FI must be correspondingly greater than the

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for the deep rolling operation in the angle range Beta 2 used force F 2. E!> However, what is described for Figure 1 also applies here. The rolling operation can also be replaced here by a corresponding hardening operation.

The schematic structure of a machine suitable for carrying out the method according to the invention is shown in Figure 5. A machine stand 10 has a workpiece rotation drive 23 with a workpiece clamping device 11. A punch 27 can be provided as a counter-holding device for the workpiece 5 designed as a crankshaft. The angular position of the workpiece rotation drive and thus of the workpiece is monitored by an angle sensor 2k , which forwards its information to a deformation measuring system 22. In the workpiece clamping device 11, it can be ensured that the crankshaft 5 is inserted into the workpiece clamping device 11 in a known angular position.

The deformation measuring system 22 also has the measuring points 6 to 9, which determine the runout of the crankshaft 5 in terms of its size in the radial direction at predetermined or predeterminable points on the crankshaft 5 - in the embodiment according to Figure 5, these are the main bearings of the crankshaft. These measuring points also pass their information on to the deformation measuring system 22, which is thereby able, in conjunction with the angle sensor 2k , to also determine the angular position of the measured runout.

Furthermore, a rolling tool 12 is connected to a rolling force generating device 13. Such rolling tools with which the transition fillets on the bearings of crankshafts can be rolled and the associated rolling force generating device are state of the art, so that no further details are required here.

The deep rolling force generating unit 13 is arranged on a support means 15 and can be moved by this, for example, via a ball screw 16 with associated spindle drive 17 along the workpiece axis 28. The spindle drive 17 has a resolver,

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so that information about the respective position of the support means 15 is available, whereby the support means 15 can be positioned. The deep rolling force generating unit 13 can also be arranged stationary if rolling always takes place at the same axial point on the workpiece. This is also possible with a multiple arrangement of such units.

The rolling force generation unit 13 is also connected to the

Workpiece axis 28 can be moved in a radial direction. In order to enable the simultaneous axial movement, the spindle drive 19 is arranged on a chute 29 that can be moved in the direction of the arrow 30. The spindle drive 19 also has a resolver so that the radial position of the rolling force generating device 13 with the rolling tool 12 is known and can therefore also be positioned.

The data from measuring points 6 to 9 and from the angle sensor 2k are fed to the data evaluation device 20 via the calibration measuring system 22. The data evaluation device 20 continuously receives information about the current position of the rolling force generating device 13 and the support means 15 via the line 31. The unspecified resolvers of the spindle drives 17 and 19 supply the corresponding data.

To control the rolling force, the rolling force generating device I^ is connected to a rolling force control device \k. With this rolling force control device 14, the rolling force can also be varied during each individual revolution if required. As the description of the figures &igr; to h makes clear, this is also often necessary.

The data evaluation device 20 also exchanges data with the machine control 21, which, in conjunction with the data evaluation device 20, controls the entire machine both with regard to the positions of the individual components and with regard to the speed, number of rolls, deep rolling force and change in deep rolling force as well as the sequence of the rows. If a computer is present in the data evaluation device 20, this can also be freely programmable. It is then possible

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to carry out different pre-programmed alignment procedures or if the condition of the workpiece in the machine has been recorded or is known, a procedure corresponding to the individual condition of the workpiece- |

de directing operation. The necessary data exchange I

between the data evaluation device with computer, the machine control |

and the machine itself takes place via the lines 32 and 33. The lines 31 and 32 only supply data to the data evaluation device 20. The individual connections and connection directions between the devices of the machine itself and the associated peripheral devices are indicated in Figure 5 by the thin arrow lines.

The device according to the invention can consist of several independent units. For example, the deformation measuring \

system form such an independent unit which has an independent |

Straightening unit is arranged downstream. This straightening unit can in turn be designed as a hardening machine or as a rolling machine. In addition to the independent units mentioned, an independent hardening machine or deep rolling machine can be arranged, for example, with which the desired strength properties of the workpiece can be achieved before straightening. However, this should be placed upstream of the deformation measuring system, because deformation of the workpiece, triggered by the hardening operation or deep rolling operation, is to be expected.

List of reference symbols used

1 workpiece 2 Boundary layer area 3 hit t l'miangsfläche V Notch area 5 crankshaft 6 Measuring point 7 Measuring point 8th Measuring point 9 Measuring point 10 Machine stand 11 Workpiece clamping device 12 Rolling tool 13 Rolling force generation device \t Rolling force control device 15 Carrying means 16 spindle 17 Spindle drive with resolver 18 spindle 19 Spindle drive with resolver 20 Data evaluation device 21 Machine control 22 Deformation measuring system 23 Workpiece rotation drive 24 Angle sensor

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26 Shaft end

27 center punch

28 Workpiece axis

29 sledges

30 Arrow

31 Line

32 lines

33 lines

34 lines

Claims (1)

PATENT ATTORNEY MANFRED LIERM&NN. : \ ': - I--II--I &bull;&igr;.... .· ... Telslpft(t)^4*21)1 74 46+ 174 EUROPEAN PATENT ATTORNEY AUTHORIZED REPRESENTATIVE AT THE EUROPEAN PATENT OFFICE Telegramme Lierpaten. Du&trade; ^- ,^ &ldquor; Fax (O 24 21) 178 Duren - Josef-Schregel-Straße 19 Postal check Cologne 3057 15-500 (bank code 370 100 50) Patent Attorney M. Liermann Josef-Schregel-Straße 19 D-5160 Düren Deutsche Bank AG Duian 811 0959 Registered letter Deutsche Bank AG Erkelenz 774 0400 ÄiTdü (bank code 310 700 01) German Patent Office Zweibrückenstrasse 12 8000 Munich 2 your signs your message My Signs (40«)/Ln D üren January 20, 1988 Utility model application Applicant: company Wilhelm Hegenscheidt GmbH Erkelenz Title Device for straightening workpieces with impact Protection claims 1. Device for straightening workpieces (1,5) exhibiting impact, at least containing a workpiece clamping device (11) arranged on a machine stand (10), characterized by means (12,13,14) for influencing the compressive residual stresses in a surface layer region (2) of the workpiece (5), means (13,15-19) for generating a relative movement between the workpiece (5) and the means (12,14) for influencing the compressive residual stress, means (17,19,20) for positioning between the workpiece (5) and the means (12,H) mentioned above and means (21) for controlling the means (12,14) for influencing the compressive residual stresses and the relative movement between this and the Workpiece (5) depending on the data from the means (17,19,20) for position detection and other data that determine the location and Determine the magnitude of the residual compressive stresses to be introduced. 2. Device according to claim 1, characterized by at least one
power-operated (13) rolling tool (12) with at least one &igr; rolling roller (25), and a device (14) for controlling the rolling force. 3. Equipment at least in accordance with standard 2, characterised by movable support means (15) for generating a relative movement between the workpiece (5) and the rolling tool (12) according to a predeterminable movement sequence and in predeterminable positions. 4. Device at least according to claim 2, characterized by at least one deformation measuring system (22) containing measuring elements for detecting at least the direction of impact of the workpiece impact (3) at predetermined and/or predeterminable positions, the deformation measuring system (22) being connected to a data evaluation device (20) and this in turn being connected to a machine control system (21)· 5. Device according to at least one of claims 1 to 4, characterized by a workpiece rotation drive (23) connected to an angle sensor (24), the angle sensor (24) in turn being connected to the deformation measuring system (22). 6. Device at least according to claim 5, characterized by at least one angle sensor for influencing the means for influencing the residual compressive stresses. ■ I tt Il i te Ii i t · Il ' I Facility according to ,· - 3 - I' »4 · «r *
Ll ti marked» «st« at least one ·· » ■
« » I » &igr; « ■ &bull;t that the load-bearing means · · * I * · ·· 6, thereby j 7. force- I of claims 1 until (15) at least a rolling tool (12)» 8i Device according to at least one of claims 1 to 7» characterized in that support means (15) are provided both for a radial movement and for an axial movement relative to the workpiece (5)« 9. Device according to at least one of claims 1 to 8, characterized in that a programmable computer connected to the machine control (21) is provided for processing a straightening program for the workpiece (5) and for correspondingly influencing the machine devices executing the program. 10. Device at least according to claim 1, characterized in that the means for influencing the residual compressive stress are designed as an induction hardening device. Jl. Device at least according to claim 1, characterized in that the means for influencing the residual compressive stress are designed as a laser beam hardening device. 12. Device according to at least claim 10, characterized in that means are provided for controlling at least one of the following parameters, namely the hardness as such, the hardening depth and the hardening location, ^a 13. Device according to at least one of claims 1 to 12, characterized in that the device comprises at least the independent Units deformation measuring system and device for straightening i having. J 4, Device at least according to claim 13, characterized in that at least the independent units, displacement measuring system and device for straightening are or can be connected to one another via data exchange means. 15. Device according to at least one of claims 13 and 14, characterized in that an independent fixed rolling device or hardening device is provided.