DE102015012133A1 - Device for detecting the collision of machine parts - Google Patents

Abstract

Device for detecting the collision of machine parts of a forming machine and / or of a mold mounted thereon with a sensor (2) and an output device (3) connected to the sensor (2), wherein by means of the sensor (2) structure-borne noise, which by the meeting at least arises two machine parts, is measurable and measuring signals (SG) of the sensor (2) of the output device (3) can be fed.

Description

The present invention relates to a device for detecting the collision of machine parts of a forming machine and / or a mold mounted thereon according to the features of the preamble of claim 1 and a method for detecting the meeting of machine parts of a forming machine and / or a mold mounted thereon. This may be an unintentional collision of machine parts as a result of an alignment error.

Forming machines can include injection molding machines, transfer molding presses and the like. For the purposes of this invention, the forming machine may also be assigned peripheral devices such as handling robots.

For example, in the case of injection molding machines, two mold halves are mounted on clamping plates of the clamping unit before the start of production. It is important that the molds are aligned exactly with each other. If this is not the case, wear occurs, for example on guide pins in the region of a column, on flat guides or dipping edges of the molds. On the other hand, this can even affect the quality of the molded part.

In any case, increased wear causes molds to have a shorter life, which of course increases overall production costs.

Similar problems occur in all molding machines.

For the protection of forming machines and tools, some considerations have already been made in the prior art.

For example, in the EP 0 158 031 A1 The applicant is proposed to mount an acceleration sensor on the movable platen. If a deviation of the acceleration then occurs when the closing unit closes before touching the two tool halves, the closing unit can interrupt the movement. Damage to the mold, for example, by incorrectly demolded moldings, can be prevented.

It is also known to investigate the frequency spectrum of the vibrations occurring in the forming machine. Changes in the frequency spectrum over the production period suggest material fatigue ("condition monitoring"). This principle is for example in the US 2008/111264 A1 disclosed.

The object of the invention is to provide an apparatus and a method with which alignment errors of machine parts of a forming machine can be reliably detected.

This object is achieved with regard to the device having the features of claim 1 and with regard to the method having the features of claim 9.

A core aspect of the invention consists in the measurement of structure-borne noise, which results from the meeting of at least two machine parts, by means of a sensor. It has been recognized by the inventors that the sensing signals of such a sensor can be used to infer the presence or absence of alignment errors.

• – Während des laufenden Betriebs auftretende Ausrichtungsfehler an der Formgebungsmaschine (Fundamentnachgiebigkeit, Maschinenschuhbruch usw.)
• – Während der Produktion auftretende Ausrichtungsfehler der Werkzeughälften, beispielsweise durch Wärmedehnung (Fehlfunktion von Kühlungen), Wandern von Werkzeughälften oder Verschmutzung; dies umfasst beispielsweise auch Mittelplatten und dergleichen
• – Ausrichtungsfehler von Schiebetischen und Drehtischen sowohl vor als auch während der Produktion
• – Überwachung des Verschleißes von Führungselementen
• – Überwachung der richtigen Parametereinstellung bei der Inbetriebnahme

The invention can be used not only in the case described above, the alignment of mold halves of clamping units. Further examples of possible applications are:

• - Alignment errors on the forming machine occurring during operation (foundation compliance, machine shoe break, etc.)
• - Alignment errors of the tool halves occurring during production, for example due to thermal expansion (malfunction of cooling), migration of mold halves or contamination; this includes, for example, center plates and the like
• - misalignment of sliding tables and turntables both before and during production
• - Monitoring the wear of guide elements
• - Monitoring the correct parameter setting during commissioning

Another advantage of the invention is that it can be retrofitted at any time to existing molding machines.

Moreover, the invention can not be used only for detection of registration errors. It is also possible through them to monitor deliberate collision of machine parts. An example would be the monitoring of a backstop of a plasticizing screw. If a locking ring of the backstop or a differently shaped valve body on the valve seat, this can be detected by means of the invention.

Further advantageous embodiments of the invention are defined in the dependent claims.

The evaluation of the measuring signals of the sensor can be carried out by an operator after the structure-borne noise measured by the sensor has been visually displayed by means of the output device for the operator.

Alternatively or additionally, the output device may be designed to decide on the basis of the measured structure-borne noise whether an alignment error exists and, if so, to transmit a warning for the presence of an alignment error to a machine control of the forming machine. The latter embodiment thus represents an automatic detection of alignment errors.

Likewise, an actuator for influencing the alignment of machine parts of the shaping machine and / or of tool parts mounted thereon, and a control or regulating device connected to the actuator and the output device is provided, by means of which the actuator can be controlled or regulated as a function of the measuring signals. In particular, the actuator can be controlled or controlled such that a limit value for a deviation from a nominal body sound value or a nominal body profile is not exceeded. Wear and other negative effects of alignment errors and the like can thus be better counteracted.

In addition, this realizes an automatic correction of an alignment error, which otherwise would have to be done manually. A corresponding actuator can be designed electrically, mechanically, thermally, hydraulically, pneumatically or similarly.

In response to an alignment error warning, a lubrication cycle may also be initiated (automatically).

Preferably, it may be provided that a characteristic of a variable characteristic of structure-borne noise is measured by means of the sensor. For example, a premature impact of machine parts or mold parts, which is caused by alignment errors can be particularly easily detected by the course. Suitable characteristic quantities may be an amplitude, a vibration speed or the like.

For monitoring purposes, however, it may also be provided to record only individual measuring points - for example, shortly before the planned impact of the machine parts or mold parts. Thus, a reliable monitoring can also be carried out with relatively little effort.

Particularly preferably, it can be provided that the sensor can be fastened to the component of the shaping machine. The structure-borne noise occurring in the forming machine or in the mold can be measured particularly easily in this way. Incidentally, it is not necessary for the sensor to be fastened to precisely that machine part whose orientation is to be checked or monitored. It is only important that the corresponding structure-borne noise is transmitted to the sensor. It is therefore readily possible to measure the orientation of the mold halves, for example, by attached to the platen sensors.

This even goes so far that the structure-borne sound, which is transmitted into the air, can also be used for this purpose.

Particularly preferably, it can also be provided that the sensor can be detachably fastened to the component of the shaping machine or the tool. If, for example, no monitoring is to take place, but only the alignment of machine parts or mold halves is to be facilitated, a device according to the invention can be sufficient to serve a plurality of shaping machines. Particularly easy detachable attachment can be achieved by doing so by means of a magnet. The device according to the invention may preferably be attachable to a movable platen and / or a fixed platen and / or a machine frame and / or a Auswerfplatte.

Of course, in addition to the magnetic detachable attachment, a screw or the like can be used.

It is particularly preferred that the sensor is a vibration sensor (for example, after DIN 18010816 ). These sensors are particularly well suited to measure corresponding structure-borne noise. With appropriate data evaluation, for example, they output an effective vibration velocity or a vibration amplitude (or the course of the same) as a measurement signal.

However, it is also possible to use other sensors. As an example, sensors are called, which rely on the piezoelectric effect. Since the corresponding structure-borne sound in many cases even transmits to the surrounding air and In order to become acoustic sound, acoustic sensors can also be used.

The transmission of the measurement signals to the output device can be cable-supported or by radio. In the latter case, various known standards for the transmission of data by means of electromagnetic waves can be used. Examples would be different wireless standards or wireless LAN standards. But near-field communication standards (NFC) such as Bluetooth are conceivable. The same applies to the connection between the output device and the machine control.

In addition, the dispenser may be integrated with the machine control of the molding machine. Furthermore, laptops, mobile phones and the like can also be used as the output device.

Protection is also desired for a closing unit of a molding machine or a molding machine with a device according to the invention, wherein the sensor is preferably attached to a component of the closing unit of the molding machine.

The output device may be configured to compare a measurement signal of the sensor with a reference region and to transmit a warning of the presence of an alignment error to a machine control of the shaping machine if the measurement signal of the sensor leaves the reference region. An automatic detection of alignment errors can be solved particularly easily in this way.

The range in this case may be given by upper or lower limits for the measuring signal of the sensor. Of course, it is also possible to use both an upper and a lower limit, so that the range is formed by the values between the two limits.

Further advantages and details of the invention are apparent from the figures and the associated description of the figures. Show

1 schematically a device according to the invention used in a closing unit,

2 and 3 two courses of structure-borne sound signals to illustrate the detection of alignment errors and

4 a diagram for the evaluation of measurement signals of an acceleration sensor.

1 shows first a closing unit 10 a molding machine 1 with a machine frame 7 , a movable platen 5 , a fixed platen 6 and schematically an ejector plate 8th , Various positions of the sensor 2 are shown. Not all possible positions of the sensor 2 are provided with reference numerals, which serves for clarity. It is understood that for the invention, only one sensor 2 necessary is. Of course, several, for example, to increase the accuracy or to check different orientations can be used.

The sensor 2 is with the device according to the invention 1 connected. It is only the connection with one of the displayed positions of the sensor 2 shown. It goes without saying that all the sensors used 2 with the output device 3 to connect.

The sensors 2 are in this embodiment by means of magnets 4 attached to the machine parts or mold parts.

The sensor 2 is formed in this case as a vibration sensor.

The sensor 2 records the course of an effective vibration speed and gives the measured values to the output device 3 further. The output device 3 visualizes the course of the measured values on the one hand. This is in the 2 and 3 shown.

On the other hand, the output device 3 automatically check if there is an alignment error. If this is the case, it can itself issue a warning to an operator or the warning to the machine control 9 with which it is connected for this purpose.

The machine control 9 can also issue the alert to an operator or use the alert to automatically take action against the alignment errors. In the simplest case, this can be the shutdown of certain movements of the molding machine 1 be.

For the operation of the automatic detection is on the description of the 2 and 3 directed.

Particularly in the case that the device according to the invention is to serve for monitoring, it can be provided that the output device 3 in the machine control 9 is integrated.

By the way, it is also possible to use the sensor 2 in the vicinity of a backstop of a plasticizing screw. By detecting the meeting of the valve body of the backstop on the valve seat, the function of the backstop can be monitored. Likewise, a device according to the invention can be used in a handling robot to monitor its movement scheme.

In the 2 and 3 two examples of measurement signals S are shown. Shown is their respective time course. Furthermore, the form FW is located. This is the distance of the molds from each other. If this value drops to 0, the mold halves lie against each other at the parting line.

As can be clearly seen, is close to the complete juxtaposition of the mold halves in 2 to detect a significant increase of the measurement signal SG (circled). The operator can thus recognize that there is an alignment error here. After correcting the alignment, the measurement signal SG is considerably flatter ( 3 ). The operator can thus see that the correction has shown the desired effect and the alignment error between the mold halves has been corrected.

It should be noted that in this example the sensor 2 was not attached to the mold halves, but attached to a platen.

After these measurement data are available, the output device can 3 be adjusted so that at a certain time shortly before the complete closure of the mold, a maximum value of the measurement signal SG must be maintained. This maximum value can be from the 2 and 3 be determined. If the measuring signal SG exceeds the maximum value during operation, an alarm signal can be output or, as described above, the switching off of the closing movement can be initiated. An automatic monitoring can thus be realized in this way.

This method of setting up and monitoring mold alignment can be transferred to a variety of machine parts of the molding machine or mold.

4 shows a diagram for data evaluation in the event that the sensor 4 having an acceleration sensor. The curve 11 shows that of the sensor 4 output data - ie the acceleration, which is the component of the molding machine 1 , learns. Between the zeros becomes the amount of the curve 11 integrated, reflecting the hatched areas 12 is indicated. The value of the integral becomes per vibration as the average or effective vibration velocity 13 shown. In this way, the measurement signal SG from the 2 and 3 come about. It should be noted that the step-like structure, which determines the speed of vibration 13 has, in the 2 and 3 can not be seen, since the steps relative to the in the 2 and 3 period are very short. Thus, a measurement signal SG for the invention can be generated in a particularly simple manner.

This calculation can be performed for all axes of the acceleration sensor (for example, three). For the measuring signal SG the 2 and 3 For example, a maximum, an average or a median of the speeds of the axes can be used.

Instead of calculating the vibration speed 13 For example, a vibration amplitude of the vibrations of the curve 11 be extracted.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0158031 A1 [0007]
• US 2008/111264 A1 [0008]

Cited non-patent literature

• DIN 18010816 [0027]

Claims (17)

Device for detecting the meeting of machine parts of a forming machine and / or a mold mounted thereon with a sensor ( 2 ) and one with the sensor ( 2 ) output device ( 3 ), characterized in that by means of the sensor ( 2 ) Structure-borne noise, which results from the meeting of at least two machine parts, is measurable and measuring signals (SG) of the sensor ( 2 ) of the output device ( 3 ) can be supplied. Apparatus according to claim 1, characterized in that the sensor ( 2 ) measured structure-borne noise by means of the output device ( 3 ) is visually displayed to an operator. Apparatus according to claim 1 or 2, characterized in that the output device ( 3 ) is adapted to decide on the basis of the measured structure-borne sound whether an alignment error is present, and, if so, a warning about the presence of an alignment error to a machine control ( 9 ) of the forming machine. Device according to one of claims 1 to 3, characterized in that an actuator for influencing the alignment of machine parts of the forming machine and / or tool parts mounted thereon and provided with the actuator and the output device control or regulating device is provided, by means of which the actuator in dependence of the measuring signals (SG) is controllable or controllable. Device according to one of claims 1 to 4, characterized in that the sensor ( 2 ) is designed to measure a course of a characteristic of the structure-borne sound size. Device according to one of claims 1 to 5, characterized in that the sensor ( 2 ) on a component ( 5 . 6 . 7 . 8th ) of the forming machine ( 1 ) is attachable. Device according to claim 6, characterized in that the sensor ( 2 ) releasably - in particular by means of a magnet - is attachable to the component of the molding machine. Apparatus according to claim 6 or 7, characterized in that the component ( 5 . 6 . 7 . 8th ) on which the sensor ( 2 ), a movable mold clamping plate ( 5 ) and / or a fixed platen ( 6 ) and / or a machine frame ( 7 ) and / or an ejector plate ( 8th ) and / or components of an injection unit and / or a handling robot. Device according to one of claims 1 to 8, characterized in that the sensor ( 2 ) is a vibration sensor. Device according to one of claims 1 to 9, characterized in that the output device ( 3 ) is adapted to a measurement signal (SG) of the sensor ( 2 ) and a warning indication of the presence of an alignment error to a machine control ( 4 ) of the forming machine ( 1 ), if the measurement signal (SG) of the sensor ( 2 ) leaves the reference area. Device according to one of claims 1 to 10, characterized in that the measuring signals are cable-supported or by radio to the output device ( 3 ) are transferable. Closing unit of a forming machine or forming machine with a device according to one of claims 1 to 11, wherein the sensor ( 2 ) preferably on a component ( 5 . 6 . 7 . 8th ) of the clamping unit ( 10 ) or the forming machine ( 1 ) is attached. Method for detecting the meeting of machine parts of a shaping machine and / or of a molding tool mounted thereon, structure-borne noise, which results from the meeting of at least two components, by means of a sensor ( 2 ) is measured and fed to an output device. A method according to claim 13, characterized in that the sensor ( 2 ) measured structure-borne noise by means of a with the sensor ( 2 ) output device ( 3 ) is displayed visually. A method according to claim 13 or 14, characterized in that from the output device ( 3 ) is determined on the basis of the measured structure-borne sound, if there is an alignment error, and, if so, a warning of the presence of an alignment error to a machine control ( 9 ) of the forming machine ( 1 ) is transmitted. Method according to one of claims 13 to 15, characterized in that the alignment of machine parts of the forming machine and / or tool parts mounted thereon is influenced by means of an actuator, wherein the actuator is controlled or regulated as a function of the measuring signals (SG). Method according to one of claims 13 to 16, characterized in that sensor data ( 11 ) an acceleration sensor for a the structure-borne noise characteristic vibration velocity ( 13 ) and / or a characteristic for the structure-borne noise oscillation amplitude is calculated.

Images