EP1387917B1 - Internal vibrator for concrete compacting - Google Patents

Description

The invention relates to an internal vibrator for compacting concrete.

Internal vibrators for compacting concrete are known and have been used on construction sites for many years. FIG. 1 shows one from the DE-U-92 17 854.5 known embodiment of an internal vibrator whose structure and operation is explained briefly below:

An internal vibrator 20 comprises a vibrating bottle 21, a protective and service hose 23, an installation unit 24 integrated into the protective and operating hose 23 for accommodating a converter (not shown) and an operating switch 25, a power supply in the form of a power supply cable 26 and a mains plug 27 on.

The vibrating bottle 21 comprises a vibrator housing 21a, an electric motor which is not visible in the drawing, and an imbalance mass (not shown) likewise arranged in the vibrator housing 21a, which can be set in rotation about a longitudinal axis of the vibrator bottle 21. The converter integrated in the installation unit 24 generates the current required to drive the electric motor with higher than mains frequency, which is supplied to the electric motor via the power supply cable 26 integrated in the protective and operating hose 23. The power supply can be controlled by the operation switch 25.

DE-20017054 also shows an internal vibrator with the features of the preamble of claim 1.

Internal vibrators of the type described above become very hot during operation, in particular in the area of the vibrating bottle 21, due to the waste heat of the electric motor integrated therein and also due to bearing friction. This poses no problem if the vibrating bottle 21 is surrounded by liquid concrete in operation, since the heat generated in the vibrating bottle 21 can be released very effectively to the environment due to the high thermal conductivity of the concrete or the water contained in the liquid concrete. If, however, the vibrating bottle 21 is removed from the concrete during operation, the heat generated can no longer be removed quickly enough due to the low thermal conductivity of air. The risk of overheating of the internal vibrator 20 and the electric motor is thus given.

In order to prevent a possible overheating of the electric motor, it is known to integrate an overtemperature protection in the vibrating bottle 21 or in the vibrator housing 21a in the immediate vicinity of the electric motor or in the electric motor. The excess temperature fuse interrupts the power supply of the electric motor when its temperature exceeds a predetermined threshold. Thus, the electric motor is also protected against overheating, which may arise due to a defective mechanism or a defective supply voltage of the electric motor.

Usually, the overtemperature protection is realized in the form of several bimetallic switches. In this case, a separate bimetallic switch is preferably integrated in the winding head of the motor in each conductor of the power supply cable 26, which changes its switching state at a certain temperature and thus interrupts the power supply.

Since, due to production tolerances, the bimetallic switches have slightly different temperature switching points, and in addition inhomogeneous temperature fields can prevail within the vibrating bottle, the bimetallic switches usually change their switching state at different times. However, this leads to the fact that the electric motor is exposed to heavy current loads in the shutdown phase of the bimetal switch. The high current load can also quickly lead to a scaling of the bimetal switch. In the worst case, the scaling can lead to total failure of the bimetal switch and thus the internal vibrator. Another disadvantage is that when the electric motor is switched on again by the bimetal switch after a cooling phase of the electric motor again a strong current load is exposed, as well as the bimetallic switch does not switch at exactly the same time. This can cause the still heated electric motor to reach the temperature threshold very quickly, and be switched off again within a very short time by the bimetallic switches.

The over-temperature protection based on bimetallic switches has the further disadvantage that the bimetallic switches often open or close for a short time due to the strong vibration generated by the electric motor and the unbalance. The associated current loadings of the electric motor can cause wear of the electric motor or destruction thereof lead connected drive electronics.

To produce the vibrator usually the electric motor, the bimetallic switch and the power supply are shed by means of a suitable material to a common unit. The occurring high pressures can lead to failure of the bimetallic switch or to an unwanted displacement of the respective temperature switching points by the mechanical forces.

The object underlying the invention is to provide an internal vibrator for compacting concrete, in which the electric motor is effectively protected against overheating.

According to the invention the object is achieved by an internal vibrator with the features of claim 1. Advantageous embodiments and further developments of the inventive idea are explained in the following description and / or defined in subclaims.

The internal vibrator according to the invention has a vibrator housing into which a rotatable imbalance mass, an electric motor driving the imbalance mass, and a part of a power supply line connected to the electric motor for the power supply of the electric motor are integrated. Furthermore, the internal vibrator has an interposed in the power supply line, electrically controllable breaker for interrupting the power supply of the electric motor and an internal signal generator. It is essential that the breaker and the internal signal generator are integrated in the vibrator housing.

The electrically controllable design of the breaker makes it possible to control the breaker by means of electrical interrupt signals in time exactly. Is the breaker - z. B. for controlling different current phases - from several independent interrupt subunits, they can be switched by respective interrupt signals at the exact same time. To this end, the interrupt signals are generated and supplied to the interrupt subunits such that the interrupt subunits are simultaneously applied by the respective interrupt signals. Thus, unwanted two-phase cycles when switching on and off of the electric motor can be avoided.

The breaker preferably has at least one triac, wherein in each conductor or - depending on the application - in a part of the conductor of the power supply a separate interrupt subunit may be interposed in the form of a triac, which is controllable or switchable in each case by a corresponding interrupt signal , The control of the triacs by respective electrical interrupt signals allows switching of the triacs at the exact same time. Of course, other electronic switching elements such as transistors or thyristors can be used instead of the triacs.

The electrically controllable design of the breaker allows, as will become clear later, to use this both as a component of an overtemperature protection as well as for switching on and off of the internal vibrator in general. Thus, it can be dispensed with a known internal vibrators normally provided separately power interruption point for switching on and off the internal vibrator by this invention is replaced by a signal generator connected to the breaker. The switching on and off of the internal vibrator is then carried out by the signal generator by acting on the breaker with an interrupt signal. The power interruption of the power supply of the electric motor thus takes place only at one point, and not, as in known internal vibrators, in two places, namely the conventional on / off switch and the bimetallic switch. This reduces the complexity of the internal vibrator while maintaining the same functionality.

In generalization of the above example can be said: Since in principle any number of signal transmitters can be connected with the electrically controllable breaker, the functional scope of the internal vibrator can be "arbitrarily" expanded with minimal additional technical effort (adding additional signal generators).

Furthermore, electrically controllable breakers, in particular triacs, are mechanically and thermally more stable than bimetallic switches, since they are not subject to any mechanical wear and scaling, and are not influenced in their function during the spraying of the components with one another. This creates an optimized with regard to the manufacturing process and on the cost of internal vibrators whose operation over a long Period is guaranteed.

The interrupt signals controlling the interrupter subunits (hereinafter referred to as interrupters) generated by signalers connected to the interrupter can be divided into internal and external interrupt signals. The internal vibrator has at least one connected to the breaker, integrated in the vibrator housing internal signal generator, wherein a corresponding internal interrupt signal can be generated by each of the internal signal generator, in dependence of the breaker is controlled. Furthermore, in a preferred embodiment, at least one connected to the breaker, mounted outside the Rüttelgehäuses external signal generator is provided, whereby by each of the external signal generator, a corresponding external interrupt signal can be generated, in dependence of the breaker is controlled.

An example of an internal signal generator is the already mentioned above temperature monitoring device for detecting the temperature of the electric motor or in the vibrator. The temperature monitor generates an internal interrupt signal based on the sensed temperature of the electric motor which is applied to the breaker (which may also be considered as a component of the temperature monitor). For this purpose, the temperature monitoring device has at least one preferably in the immediate vicinity of the electric motor winding head mounted temperature sensor. The overtemperature protection based on bimetallic switches is thus replaced by the combination of a temperature sensor with an electrically controllable breaker.

Another example of an internal signal generator is a voltage-dependent switching element connected to the power supply line, by means of which a corresponding internal interruption signal can be generated as a function of the voltage applied to the electric motor. For example, the voltage-dependent switching element is designed such that it registers a failure of the current flow or the supply voltage in one of the conductors and to avoid a high current load of the electric motor (two-phase) the current flow in the other conductors by generating corresponding internal interrupt signals also interrupts. Furthermore, the voltage-dependent switching element can be designed such that it can be switched as a function of a modulated supply voltage signal. Furthermore, it would be possible to design the voltage-dependent switching element in such a way that it interrupts the current flow in the event of overvoltages or adjusts to values which correspond to the nominal values of the internal vibrator.

Another example of an internal and / or external signal generator is a position switch, by the function of the spatial orientation of the Rüttelgehäuses -. B. in horizontal position - a corresponding interruption signal can be generated: If the internal vibrator is placed by the operator on the ground, the internal vibrator switches off automatically.

Further examples of respective internal or external signal transmitters are light sensors, magnetic sensors, bimetallic switches, ball switches, capacitive and inductive sensors, mercury switches, liquid switches, oil switches with light barriers, radio signal transmitters, light signal transmitters or infrared signal transmitters. The signalers may further comprise conductive plastics, reed relays and the like.

Preferably, an integrated logic circuit is provided, which is connected to the breaker and with respective internal and / or external signal generators, wherein the integrated logic circuit in response to several supplied thereto, generated by the internal or external signal generator interrupt signals a common interrupt signal (or more " common "interrupt signals when using multiple interrupt signal subunits) can be generated, by which the interrupt is controllable. With the help of the integrated logic circuit can be evaluated a variety of different interrupt signals, whereby a simultaneous operation of a variety of different signal generator is possible in a simple manner.

The internal vibrator according to the invention preferably has the already described, in Fig. 1 shown construction. Accordingly, a protective tube is provided, at one end of the Rüttelgehäuse or the Rüttelflasche and at the other end is connected via a coupling piece another, leading to a power plug part of the power supply line. The coupling piece can be a mounting unit for receiving a frequency converter and / or have a switch for switching the electric motor in Rüttelgehäuse.

The integrated logic circuit can be provided at any point in or on the internal vibrator. The integrated logic circuit is preferably integrated in the vibrator housing or in the vibrator bottle itself, in the power plug or in the installation unit. The integrated logic circuit can be designed, for example, together with the breaker and / or at least part of the internal signal generator as a single component.

As already mentioned, an external signal generator can be a user-operable signal generator (for example a pushbutton or switch), by means of whose corresponding external interruption signal the internal vibrator can be switched on and off. The signal transmitter is in this case preferably provided away from the vibrator bottle, that is, for example, attached to the end of the protective tube or configured as a separate remote control, by means of which the internal vibrator can be controlled via a receptor element attached to the internal vibrator.

The external interrupt signal generated by the external signal generator can be transmitted to the breaker or to the integrated logic circuit either by a signal line preferably extending in the protective tube, such as an optical waveguide, or by radio or infrared light, wherein in the case of a radio or infrared transmission at the breaker or in the integrated logic circuit, a corresponding receptor element for receiving the interrupt signal is provided.

Fig. 1

eine Ausführungsform eines Innenrüttlers gemäß dem Stand der Technik;

Fig. 2

eine schematische Schaltskizze zur Verdeutlichung des Zu- sammenwirkens eines Unterbrechers mit den internen und/ oder externen Signalgebern in einer ersten Ausführungsform der Erfindung;

Fig. 3

eine schematische Schaltskizze zur Verdeutlichung des Zu- sammenwirkens des Unterbrechers mit den internen/exter- nen Signalgebern eines erfindungsgemäßen Innenrüttlers in einer zweiten Ausführungsform;

Fig. 4

eine schematische Schaltskizze eines erfindungsgemäßen In- nenrüttlers in einer dritten Ausführungsform der Erfindung;

Fig. 5

eine schematische Schaltskizze eines erfindungsgemäßen In- nenrüttlers in einer vierten Ausführungsform;

Fig. 6

eine schematische Schaltskizze eines erfindungsgemäßen In- nenrüttlers in einer fünften Ausführungsform;

Fig. 7

eine schematische Schaltskizze eines erfindungsgemäßen In- nenrüttlers in einer sechsten Ausführungsform;

Fig. 8

eine Aufbauskizze eines Elektromotorkopfs im Zusammen- hang mit der in Fig. 2 gezeigten Ausführungsform des Innen- rüttlers in Querschnittdarstellung.

These and other features and advantages of the invention will be explained in more detail below with reference to the drawings in exemplary embodiment. Show it:

Fig. 1

an embodiment of an internal vibrator according to the prior art;

Fig. 2

a schematic circuit diagram to illustrate the interaction of a breaker with the internal and / or external signal generators in a first embodiment of the invention;

Fig. 3

a schematic circuit diagram to illustrate the interaction of the interrupter with the internal / external signal generators of an internal vibrator according to the invention in a second embodiment;

Fig. 4

a schematic circuit diagram of an internal vibrator according to the invention in a third embodiment of the invention;

Fig. 5

a schematic circuit diagram of an internal vibrator according to the invention in a fourth embodiment;

Fig. 6

a schematic circuit diagram of an internal vibrator according to the invention in a fifth embodiment;

Fig. 7

a schematic circuit diagram of an internal vibrator according to the invention in a sixth embodiment;

Fig. 8

a construction sketch of an electric motor head in connection with the in Fig. 2 shown embodiment of the internal vibrator in cross-sectional view.

In the Fig. 1 shown, known embodiment of an internal vibrator has already been described and will therefore not be explained in more detail at this point. In the embodiments described below, corresponding components are identified by the same reference numerals.

Fig. 2 shows a schematic circuit diagram 1 with an electric motor 2, a first triac 3, a second triac 4, a first conductor 5, a second conductor 6, a third conductor 7, an integrated Logic circuit 8 and a temperature sensor 9. All within the range indicated by reference numeral 15 components are considered to be integrated into the jar 21, all out-of-range components 15 are mounted outside of the vibrating bottle 21 to the internal vibrator or completely separate provided.

The three-phase current supplied to the electric motor 2 by means of the first, second and third current conductors 5 to 7 can be interrupted by the first triac 3 interposed in the first current conductor 5 and the second triac 4 interposed in the third current conductor 7. For this purpose, "integrated" interrupt signals in the form of a first interrupt signal for acting on the first triac 3 and a second interrupt signal for acting on the second triac 4 are generated by the integrated logic circuit 8 and supplied to the first 3 and second triac 4. The first triac 3 and the second triac 4 together represent a breaker 10.

Instead of triacs 3, 4, other electrically controllable breaker may be used.

As an internal signal transmitter, the temperature sensor 9 is provided here, which measures the temperature in or on the electric motor 2 and, when a certain temperature threshold value is exceeded, supplies a corresponding interrupt signal to the integrated logic circuit 8, which generates the common interrupt signals as a function thereof. Alternatively, the temperature sensor 9 of the integrated logic circuit 8 permanently supplies a temperature signal, which is evaluated by the integrated logic circuit 8.

In the Fig. 3 The embodiment shown differs from that in FIG Fig. 2 shown embodiment only by the addition of an additional first external signal generator 11 which is connected to the integrated logic circuit 8, and this a corresponding interrupt signal upon actuation of the first external signal generator 11 supplies. The first external signal generator 11 is connected to the integrated logic circuit 8 via a signal line 12 which can be realized for example on the basis of a copper or glass fiber cable or a radio transmission. About the first External signal generator 11, the breaker 10 can be controlled independently of the temperature sensor 9. The external signal generator 11 is preferably configured as an on-off switch of the internal vibrator.

In the Fig. 4 The embodiment shown differs from that in FIG Fig. 2 shown embodiment by the additional use of a second external signal generator 13, which is realized here in the form of a position switch. The second external signal generator 13 is connected via a corresponding signal line 12 b to the integrated logic circuit 8 to a given spatial, z. B. horizontal orientation of the internal vibrator 20 to send a corresponding interrupt signal to the internal logic circuit 8, in response to which the integrated logic circuit the breaker 10 and the first triac 3 and the second triac 4 applied to the common interrupt signals.

In the Fig. 5 embodiment shown represents a combination of in Fig. 3 and 4 Both the first external signal transmitter 11 and the second external signal transmitter 13 are present. Thus, the breaker 10 is controlled both by the user himself by means of the first external signal generator 11, as well as by the temperature sensor 9 and the second external signal generator 13, which is preferably realized as a position switch.

In the Fig. 6 The embodiment shown differs from that in FIG Fig. 4 shown embodiment only in that the second external signal generator 13 (position switch) is designed here as an internal signal generator, that is integrated in the vibrator housing 21a.

In the Fig. 7 The embodiment shown differs from that in FIG Fig. 5 shown embodiment in that the second external signal generator 13 (position switch) here as in the embodiment according to Fig. 6 designed as an internal signal generator.

In Fig. 8 It can be seen how the temperature sensors 9, the integrated logic circuit 8, the breaker 10 consisting of the first triac 3 and the second triac 4 can be configured as a common component. These are all components on a common circuit board 14 mounted.

Although in the embodiments described above one or more temperature sensors are always described as internal signal generators, other embodiments of the invention also provide other types of internal signalers (e.g., position switches, tachometers, etc.).

Claims (15)

1. Internal vibrator (20) for compacting concrete, having a vibrator housing (21 a) into which there are integrated:

   - a rotatable unbalanced mass,

   - an electric motor (2) driving the unbalanced mass, and

   - part of a power supply (5, 6, 7, 26), connected to the electric motor (2), for supplying current to the electric motor (2), and having

   - an electrically controllable interrupter (3, 4, 10) interconnected in the power supply (5, 6, 7, 26) for interrupting the supply of current to the electric motor (2), characterised in that the interrupter (3, 4, 10) is integrated into the vibrator housing (21 a), and in that the internal vibrator (20) comprises at least one internal signal generator (9, 13) which is connected to the interrupter (3, 4, 10) and is integrated into the vibrator housing (21a), wherein a corresponding internal interruption signal can be produced by each of the internal signal generators (9, 13) and the interrupter (3, 4, 10) can be controlled in dependence upon the internal interruption signal.
2. Internal vibrator (20) as claimed in Claim 1, characterised in that the interrupter (3, 4, 10) comprises at least one triac (3, 4).
3. Internal vibrator (20) as claimed in any one of the preceding Claims, characterised by at least one external signal generator (11, 13) which is connected to the interrupter (3, 4, 10) and is mounted external to the vibrator housing, wherein a corresponding external interruption signal can be produced by each of the external signal generators (11, 13) and the interrupter (3, 4, 10) can be controlled in dependence upon the external interruption signal.
4. Internal vibrator (20) as claimed in any one of the preceding Claims, characterised in that the internal signal generator is a temperature monitoring device (9), connected to the interrupter (3, 4, 10), for detecting a temperature in the vibrator housing (21a), and in that the interrupter (3, 4, 10) can be controlled in dependence upon an internal interruption signal which can be produced by the temperature monitoring device (9) and is based on the detected temperature.
5. Internal vibrator (20) as claimed in any one of Claims 1 to 3, characterised in that the internal signal generator is a voltage-dependent switching element which is connected to the interrupter (3, 4, 10) and the power supply (5, 6, 7, 26), and in that a corresponding internal interruption signal can be produced in dependence upon the voltage applied to the electric motor (2).
6. Internal vibrator (20) as claimed in any one of the preceding Claims, characterised in that the internal and/or external signal generator is a position switch (13) by means of which a corresponding interruption signal can be produced in dependence upon the spatial orientation of the vibrator housing (21a).
7. Internal vibrator (20) as claimed in any one of the preceding Claims, characterised in that respective internal signal generators (9, 13) and/or respective external signal generators (11) comprise light sensors, magnetic sensors, bimetallic switches, ball switches, capacitive and inductive sensors, mercury switches, liquid switches, oil switches having photoelectric relays, radio signal generators, light signal generators or infrared signal generators.
8. Internal vibrator (20) as claimed in any one of the preceding Claims, characterised by an integrated logic circuit (8) which is connected to the interrupter (3, 4, 10) and to respective internal signal generators (9, 13) and/or to respective external signal generators (11), wherein a common interruption signal can be produced by the integrated logic circuit (8) in dependence upon several interruption signals which are supplied thereto and are produced by the internal and/or external signal generators (11) and the interrupter (3, 4, 10) can be controlled by means of the common interruption signal.
9. Internal vibrator (20) as claimed in Claim 8, characterised in that the external interruption signal can be transmitted from the external signal generator (11) to the interrupter (3, 4, 10) or to the integrated logic circuit (8) via radio, infrared light, cable or fibre optic cable and if necessary via a receptor element provided on the interrupter (3, 4, 10).
10. Internal vibrator (20) as claimed in any one of the preceding Claims, characterised by a protective tube (23), on one end thereof the vibrator housing (21 a) is mounted and the other end thereof is connected, via a coupling piece, to another part of the power supply (26) leading to a mains plug (27).
11. Internal vibrator as claimed in Claim 10, characterised in that the coupling piece is a mounting unit (24) for accommodating a frequency converter.
12. Internal vibrator (20) as claimed in Claim 10 or 11, characterised in that the external signal generator is a signal generator (11) which can be operated by a user and by means of which a corresponding external interruption signal can be produced and thus the internal vibrator (20) can be switched on and off, wherein the external signal generator (11) is provided at a remote location from the vibrator housing (21), in particular on the protective tube (23) of the internal vibrator (20), in the mounting unit (24) or as a separate remote control unit.
13. Internal vibrator (20) as claimed in any one of the preceding Claims, characterised in that the integrated logic circuit (8) is integrated into the vibrator housing (21a).
14. Internal vibrator (20) as claimed in any one of Claims 10 to 12, characterised in that the integrated logic circuit (8) is integrated into the mains plug (27).
15. Internal vibrator (20) as claimed in any one of Claims 10 to 12, characterised in that the interrupter (3, 4, 10) and/or the integrated logic circuit (8) is integrated into the mounting unit (24).

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