EP3151987A1

EP3151987A1 - Radial press

Info

Publication number: EP3151987A1
Application number: EP15717807.0A
Authority: EP
Inventors: Hubert POTH; Harald VON WAITZ; Carsten Baumgartner
Original assignee: Uniflex Hydraulik GmbH
Current assignee: Uniflex Hydraulik GmbH
Priority date: 2014-06-06
Filing date: 2015-04-21
Publication date: 2017-04-12
Anticipated expiration: 2035-04-21
Also published as: RU2016145440A3; CN106573288A; EP3151987B1; WO2015185174A1; CN106573288B; US20170080659A1; RU2016145440A; RU2696116C2; DE102014008613A1; US10286620B2

Abstract

The invention relates to a radial press having a frame structure, a pressing tool, a drive unit, and a press control. The pressing tool comprises a plurality of pressing elements (2) which are disposed uniformly concentrically around a press axis and have pressing surfaces (8). During the appropriate activation of the drive unit, the pressing elements can be moved synchronously as required towards or away from the press axis (A). To this end, at least two measured value recorders (12), which are connected for signal transmission purposes to a comparator associated with the press control, are disposed on the pressing tool at positions spaced apart from one another in the direction of the press axis (A). When the comparative value, generated by the comparator, of the measured values provided by the measured value recorders (12) exceeds a tolerance range stored in the press control, an activation of the signal output unit is triggered.

Description

radial press

The present invention relates to a radial press with a frame structure, a pressing tool, a drive unit and a press control, wherein the

Pressing tool comprises a plurality of uniformly concentric about a press axis down herunf arranged, pressing surfaces having pressing bodies, which are under appropriate loading of the drive unit synchronously either in the direction of the press axis or away from this movable.

Radial presses of the type mentioned above are used for various applications, for example for connecting fittings with hose sections in the production of ready-to-install hydraulic hose assemblies. They are known in various construction methods and designs, for example as so-called "yoke presses" (cf., for example, DE 4135465 A1, DE 19912976 A1 and DE 19817882 B4), "hollow-piston press" (cf., for example, DE 10149924 A1) or in other construction (cf. For example, DE 2844475 AI, DE 3611253 AI, DE 10047025 C2 and DE 3331721 AI).

Generic radial presses have proven themselves in practice. When used properly, for example, long-lasting, very high-requirements connections between two components (e.g.

Hose section and connection fitting). Regardless of the present invention has the object to further improve radial presses of the type specified in terms of their handling, and In particular, to the extent that high-quality results are even less dependent than ever on the experience and / or detailed training of the respective operator or, in other words, the risk of producing inferior results is reduced by less experienced or trained operating personnel.

This object is achieved according to the present invention by arranged at a radial press of the generic type on the pressing tool in the direction of the pressing axis spaced positions at least two associated with the press control comparator signal transmitting connected transducers, wherein exceeding a stored in the press control tolerance by the one in the

Comparator generated comparison of the measured values provided by the transducers triggers a signal output unit. The

Radial press according to the invention is thus, in other words, characterized in that at least two transducers are provided on their pressing tool, in a mutually offset in the direction of the press axis arrangement. These two transducers are signal-transmitting connected to the press control, namely with a comparator associated therewith, in which during the execution of the pressing or at least at the end of the provided by the two transducers measured values or possibly measured value curves (continuous or intermittent) are compared.

If the comparison value determined in this case is - depending on the specific design of the sensor For example, in the difference between the measured values provided by the pickups or their relationship to one another, outside a tolerance range stored in the press control, the output of a signal which gives the operator a result deviating from the target range or an unscheduled course of the pressing occurs signaled. In this way, in particular various errors caused by the operator, which can be reflected in an inferior version of the pressure, recognized early and a corrector can be made. This applies in particular to an incorrect positioning of the workpiece within the radial press, ie offset more or less in the direction of the press axis to the ideal position. In this way, the present invention makes use of the insight that even a rather small offset of the workpiece - in the direction of the press axis - relative to its ideal position leads to internal (asymmetric or off-center) force relationships, which cause such a deformation of the radial press deviates from its desired shape deviating result of the pressing, for example, by the workpiece is slightly conical at the end of the pressing instead of cylindrical. Such a situation can not be detected with conventional press controls even in the case of monitoring the press force during the press cycle ¹ ; because the pressing force as such typically moves within the given bandwidth, but is introduced over the axial extent of the workpiece to varying degrees in the latter, because by the said offset caused deformation of the radial press to a - more or less pronounced - skew the

Pressing surfaces relative to the press axis leads.

When the radial press according to the invention is used, in the case of such positioning of the workpiece within the radial press, deviating from the ideal position, the ratio of the measured values provided by the two transducers shifts out of the tolerance range stored in the press control. This is signaled to the operator, possibly with simultaneous automatic termination of the pressing process. If such a detection takes place not only or not at the end of the pressing process, but rather (continuously or at least intermittently) over the pressing process, the latter can be broken off so early that a correction of the pressure is possible, ie reject does not arise , First and foremost, in the practice of the present invention, gross operating errors or significant disturbances can be detected immediately, for example the presence of foreign bodies in the region of the workpiece, the processing of defective (eg broken) workpieces or the like, with a workpiece fracture occurring during the pressing process, for example in a distinct manner Discontinuity of the readings provided by the transducers. The detection of incorrect operations is also in terms of the life of the radial press of great advantage, for example, by the pressing process is stopped immediately, if there is an indication by a corresponding reference value that one with a The connection fitting to be connected to the hose has been inserted into the radial press up to the union nut or there is a foreign object in the tool.

Even if less experienced or less trained personnel are used to operate the radial press, in the case of the use of a

Radial press according to the invention the risk of producing inferior workpieces by the radial pressure far less than in the case of the use of known generic radial presses according to the prior art.

The measured values provided by the measuring sensors can also be used in a preferred manner for an individual workpiece-related modification of the press profile stored in the press control. In this sense, for example, it is possible to modify the pressing speed as a function of the measured values of the measuring importers and in this way to optimize them specifically with regard to the individual workpiece to be pressed. Tolerances within the tolerance with respect to the dimensions and / or the material of the workpiece can thus be taken into account when carrying out the individual pressing.

Furthermore, when using the radial press according to the invention by way of a comparison of the forces causing the deformation of the workpiece, for which - in a suitable design the transducers - the measured values provided by the transducers are an indicator, and the energy consumption of the radial press one Efficiency analysis possible. Again, this is a measure that allows an optimization of the pressing process - in terms of its energy efficiency.

Another positive effect of the present invention is the possibility of producing material (with equal performance) in the manufacture of the workpiece

save. Because by optimizing the forming of the workpiece in the radial press according to the invention (see above), the workpiece needs to have fewer safety margins than this - for example to ensure a secure and reliable connection of a connection fitting with a piece of tubing - when machining corresponding workpieces on conventional radial presses is required.

However, the positive effects of the present invention are not limited solely to the quality of the pressed workpiece. Rather, the monitoring and analysis or evaluation of the measured values provided by the transducers allows conclusions to be drawn about the state of the radial press, for example the wear of wearing parts. This makes it possible to match the maintenance intervals and the replacement of wearing parts better to the individual needs of the individual machine. A precautionary early replacement of wearing parts is not required in this case, which is a significant economic aspect. At the same time, security can also be increased; because by monitoring and analyzing or

Evaluation of the data provided by the transducers In addition to the resulting anomalies of the measured values, measured values can also be used to immediately detect any damage (eg fractures on pressing bodies or other parts of the pressing tool) that could possibly result in consequential damage even if the operating personnel is endangered. The same applies to the detection of fatigue of machine components as well as conceivable manipulations of the radial press. For the purpose of optimizing the processes and the quality assurance, the measured values determined are preferably stored over a longer period, archived (possibly compressed) and evaluated, with a transmission (online or on data carrier) to the machine manufacturer - for a statistical, on several radial presses related evaluation - comes into consideration.

Furthermore, in the case of a suitable design of the at least two transducers, the measured values provided by them can be used for a substantially more accurate determination of the pressing force compared with the

Presence of only one press force sensor.

Especially meaningful findings about the state of the radial press and of the pressed workpiece arise when the measured values provided by the transducers are set in relation to process parameters characteristic of the pressing process, such as the pressure in a hydraulic cylinder associated with the drive unit, the time within a pressing cycle 'and / or the path of the drive for the pressing tool. By comparing the determined values with the setpoint Values that are characteristic of the pressing process to be performed not only detect irregular operating conditions such as the pressing of a wrong workpiece, the use of a wrong pressing tool, the absence of individual compacts or the like. Evaluations are also useful in regular press runs, for example, by determining the ideal duration of press holding at the end of the press, depending on how the readings provided by the transducers change over time. Thus, in the interests of high efficiency, ie the shortest possible cycle times, in conventional radial presses, as a precaution, long measured holding times can be shortened. In this sense, the

Radial press be opened as soon as the change in the measured values over time (measured value gradient) falls below a certain value.

The course of the measured values when opening the radial press, on the other hand, provides immediate information on the return spring of the workpiece. Thus, it can already be determined at an early stage, ie when the radial press is not yet fully open, that a certain repressing is still required, so that the (spring-loaded) workpiece complies with its specified dimension after opening the radial press. Comparable conclusions on the subsequent springback of the workpiece can be drawn from those measured values which determine the at least two transducers when the desired dimension of the workpiece is reached for the first time, so that the degree of a required overpressing can already be determined taking into account these measured values. It has already been indicated above that, in addition to the (in particular optical and / or acoustic) signal output unit, by means of which the operator is made aware of the unscheduled course of the pressing, it may be provided that - by appropriate influence on the drive unit - the pressing process automatically interrupted or aborted. It is advantageous if the signal output unit has a comparison value display and / or a correction value display, which allows the operator to determine the extent of a possible incorrect positioning of the workpiece or the correction required accordingly. In the press control itself, the value for a positional correction of the workpiece can be calculated from the deviation of the comparison value of the two measured values provided by the transducers from the ideal value stored in the press control for the relevant pressing process, and, for example, a stop for the workpiece accordingly shifted. The same applies to the visual display of a corrected position of the workpiece, for example by means of a laser marking.

According to another preferred embodiment of the invention, it is provided that three transducers arranged at a distance from one another in the direction of the press axis are provided. The third transducer may in particular provide a reference value, for which purpose it ideally more or less centrally between the other two transducers or in the - on the press Axially perpendicular - symmetry plane of the radial press is arranged. The simultaneous consideration of the signals of all three transducers provides additional information from which in particular workpiece-specific anomalies (eg punctual damage to the workpiece) can be concluded.

The present invention can be realized with excellent results even in such widely used radial presses whose compacts are constructed in several parts, in particular by - two-piece structure - each radially outside a base jaw and radially inside a removable jaw or - built in three parts - a base jaw, a Include intermediate jaw and a removable, the pressing surface having pressing jaw. Particularly meaningful results result in this case when the transducers are arranged on at least one pressing jaw, and preferably in the region of the two opposite in the direction of the pressing axis opposite ends. Under structural and other practical aspects, however, the arrangement of at least two sensors on at least one base jaw is particularly favorable. Although the signal strength of the signal provided by the respective transducer is typically lower in this arrangement of the transducer than in the case of the arrangement of the transducers on the pressing jaw directly adjacent to the workpiece, which would rather speak for the arrangement of the transducers on the latter; However, the signal is still sufficient when properly designed the arranged on a base jaw transducer strong that a reliable evaluation in the sense of the present invention can be done. And the disadvantage of a lower signal strength is more than offset by pronounced advantages in terms of the reproducibility of the measurement results and also the handling of the radial press during operation. Among the latter aspect is that in the arrangement of the transducers on at least one base jaw the pressing jaw change, as it is required for conversion of the radial press from one pressing task to another, is not hindered. Also arise in the arrangement of the transducers on at least one base jaw in terms of cost

significant benefits; because in this case, reliable and cost-effective transducers with a wired signal transmission can be used, and it is not the equipment of all prepared for the different pressing tasks set of press jaws with transducers required. is

In contrast, in individual cases it is desirable from a special point of view to arrange the transducers on the pressing jaws, the latter are particularly preferably prepared for wireless signal transmission in order to avoid the expense otherwise associated with the connection of the transducers to the press control during each conversion of the radial press.

In such radial presses (typically "yoke presses"), in which one of the base jaws - is arranged in a fixed position relative to the frame structure, at least two transducers are preferably arranged at least on that stationary base jaw. This proves to be look at the simplest possible structure of the radial press according to the invention with simultaneous high reliability as particularly favorable. In that regard, as far as the signal quality is concerned, it is particularly important to ensure that there are no disturbing influences, as is the case in the case of non-stationary, ie, base surfaces that are slidably supported on control surfaces.

In the context of the present invention, transducers of different designs can be used to detect the load states leading to unscheduled results discussed above. Particularly favorable results can be achieved with comparatively low cost with transducers, which are designed as Verformungsaufnehmer. In particular, strain gauges should be mentioned here as particularly preferred embodiments. Excellent evaluable signals provide full-bridge strain gauges, which can be attached in particular to the end faces of the compacts (in particular the base jaws). Instead of indirectly determining the stress states via the deformation caused thereby, as detected by strain transducers such as strain gauges, however, the stress conditions (for example in the at least one base jaw) can also be detected directly and directly using corresponding transducers.

The sampling rates of the transducers depend on the workpiece to be pressed. While for typical applications (eg pressing a connection fitting with a hydraulic hose) sampling rates preferably in the range between 5ms and 10ms (corresponding to a frequency between 100Hz and 200Hz), are for sensitive applications of the radial press according to the invention (eg when pressing or ceramic components such as insulators) sampling rates preferably lower, eg in the range between 1ms and 10ms (corresponding to a frequency between 100Hz and 1kHz) or even lower.

The tolerance range stored in the press control and used in the evaluation of the measured values provided by the transducers is particularly preferably adjustable by means of an input unit. This takes into account the fact that, for different pressing tasks, different relationships of the measured values provided by the individual measuring sensors relative to one another can prove to be ideal, favorable or tolerable. In particular, the relationship that ideally holds the measurements provided by the transducers depends on which is the ideal position of the workpiece within the crimping tool.

Alternatively or additionally, the press control may in particular also include an adaptation circuit for the tolerance range, which serves as the input signal

geometric position of the pressing surfaces relative to the position of the transducer taken into account. In this development of the present invention, it is considered that (in the case of multi-part compacts), the axial length of the pressing jaws - in particular those for small workpiece diameters. This is often substantially less than the axial length of the base jaws, on which ideally the transducers are attached at the end (see above). The pressing jaws are typically not centered on the

Base jaws positioned, but rather such that press jaws and base jaws on the side facing the operator flush. This in turn leads to the fact that the pressing surfaces are typically offset relative to the center of the base jaws. The larger the offset, the more pronounced

With an ideal course of the pressure, the measured values provided by the transducers differ.

It was possible to determine that very good results (in particular in terms of high reproducibility) can already be achieved in the case of the use of two transducers assigned to a particular compact. However, this does not exclude, in the interests of redundancy or the possibility of additional plausibility checks distributed over the circumference (in particular on multiple compacts) to provide transducer assemblies each having at least two transducers, wherein in the press control averaging on the one hand the measured values of those transducers, on the Operator-facing side of the radial press are arranged, and on the other hand, the measured values of those transducers, which are arranged on the side facing away from the operator of the radial press, can take place. Within the comparator, a comparison of the one and the other average takes place with one another, in order to determine a possible unplanned load situation in the sense of the explanations set out above.

The radial press according to the invention can furthermore, according to yet another preferred development, have a temperature sensor whose signal is fed to the machine control. As a result, temperature-related influences, such as the depending on the operating temperature lubricity of

Lubricants, take into account and compensate. In this sense, in the machine control, preferably for each predetermined pressing operation, a plurality of temperature-dependent characteristic maps concerning the ideal comparison value of the measured values and the permissible tolerance are stored. In this way, even better workpiece qualities can be achieved.

In the following, the present invention will be explained in more detail with reference to a preferred embodiment illustrated in the drawing, which is based on a construction of the radial press designed as a yoke press substantially corresponding to DE 4135465 A1 (referred to in this respect). It shows

Fig. 1 in a fragmentary plan view of the operator facing end face of the pressing tool of the radial press with inventive equipment and

2 shows a detail of a perspective view of the operator facing away from the end face of the pressing tool of the radial press. The radial press underlying the present embodiment largely corresponds to that in the DE

4135465 AI described and explained construction, as it is also widely used in practice. To avoid repetition, reference is therefore made in full to the cited publication.

Visible in the detail of the front view of the pressing tool shown in Fig. 1, the (fixed) lower yoke 1, five compacts 2, arranged between the press bodies springs 3, the two inserted into the lower yoke 1 sliding plates 4 and the "45th Other than this is illustrated in DE 4135465 AI, touched according to Fig. 1, the lower, stationary to the lower yoke 1 arranged compact 2.1 does not directly the lower yoke, but is based exclusively on the sliding plates 4 from. Furthermore, FIGS. 1 and 2 illustrate the three-part construction of the compacts 2 each consisting of a base jaw 6, an intermediate jaw 7 removably attached thereto, and a jaw 9 removably attached to the latter and having the pressing surface 8, as is typical with the use of compacts large radial extent for pressing tasks with comparatively small diameter. If the radial press is converted to the machining of workpieces with a comparatively large diameter, so. come pressing jaws 9 are used, which are mounted directly on the base jaws 6, so that in this case the pressed body. 2

are two-piece. Fig. 2 branches a typical situation of the individual parts of three-part compacts 2 to each other, as far as the axial extent. Namely, the intermediate jaw 7 is significantly shorter than the base jaw 6, and the pressing jaw 9 is in turn significantly shorter than the intermediate jaw 7. Thus, in a typical application, for example 70mm long pressing jaws on 118mm long base jaws are used, wherein the pressing jaws 9, the Intermediate jaws 7 and the base jaws 6 on the side facing the operator (Fig. 1) close almost flush.

At the bottom, stationary compact 2.1, namely its base jaw 6.1 end of the two opposite end faces 10 and 11 transducers 12 in the form of full-bridge strain gauges 13 and 14 are attached. These are signal-transmitting via signal cable 15 with the press control, namely connected to one of these associated comparator.

Claims

claims

Radial press with a frame structure, one

Press tool, a drive unit and a

Press control, wherein the pressing tool a

Plurality of evenly concentric around one

Press axle arranged around, pressing surfaces (8) having pressing bodies (2), which are under appropriate loading of the drive unit synchronously either in the direction of the press axis (A) or away from this movable, characterized in that on the pressing tool in the direction of the press axis (A) spaced apart positions at least two with one of

Press control associated comparator

Signal transmitters connected to the sensor (12) are arranged, wherein exceeding a stored in the press control tolerance range by the comparison value generated in the comparison of the measured value provided by the transducers (12) measured values a

Signal output unit triggers.

Radial press according to claim 1, characterized

in that, when the tolerance range is exceeded by the comparison value of the signals provided by the transducers (12), the press control automatically switches to the

Drive unit acts.

Radial press according to claim 1 or claim 2, characterized in that three in the direction of Press axis (A) spaced from each other arranged transducer (12) are provided.

4. Radial press according to one of claims 1 to 3,

characterized in that the pressing bodies (2) each base jaws (6) and removable, the

Pressing surfaces (8) having pressing jaws (9)

include.

5. Radial press according to claim 4, characterized

characterized in that between the base jaws (6) and the pressing jaws (9) each removable

Intermediate jaws (7) are arranged.

6. Radial press according to claim 4 or claim 5,

characterized in that on at least one base jaw (6) in the region of its two opposite in the direction of the press axis (A) opposite ends transducers (12) are arranged.

7. Radial press according to claim 6, characterized

characterized in that the transducers (12) on the end faces (10, 11) of at least one

Base jaw (6) are arranged.

8. Radial press according to one of claims 4 to 7,

characterized in that the transducers (12) on a stationary base jaw (6.1) are arranged.

9. Radial press according to claim 4 or claim 5,

characterized in that on at least one pressing jaw (9) in the region of their two in the direction the press axis (A) opposite ends are arranged transducers (12) which communicate with the press control wireless signal transmitting.

10. Radial press according to one of claims 1 to 9,

characterized in that the transducers (12) are designed as deformation transducers, in particular as full-bridge strain gauges (13).

11. Radial press according to one of claims 1 to 10,

characterized in that the

Signal output unit comprises a comparison value display.

12. Radial press according to one of claims 1 to 11,

characterized in that the tolerance range is adjustable by means of an input unit.

13. Radial press according to one of claims 1 to 12,

characterized in that the press control comprises an adaptation circuit for the tolerance range, which takes into account as an input signal the geometric position of the pressing surfaces (8) relative to the position of the transducers (12).

14. Radial press according to one of claims 1 to 13,

characterized in that it is arranged several distributed around the press axis (A)

Transducer assemblies each having at least two transducers (12), wherein in the

Press control averaging occurs.