DE202013005237U1 - Follow-up control for a blasting hose - Google Patents

Abstract

Apparatus (10) for controlling the wake of a blasting medium medium driven by compressed air, comprising: a pneumatic connection (11) for supplying the device (10) with compressed air, a blasting hose (25) connected to the pneumatic connection (11), one at the free one At the end (31) of the blasting hose (25) arranged blasting nozzle 30, one, a blasting medium vorratsenden pressure jet container (27) which is connected to the blasting hose (25) via a metering valve (29), a pressure reducer (26), the compressed air from the Pneumatic connection (11) reduced to a working pressure, at least one control valve (23, 24) for releasing the compressed air to the blast hose (25), arranged at the free end of the hose remote control (18) for controlling and regulating the pneumatic Connection (11) provided compressed air is used, as well as one with the remote control (18) connected electrical circuit unit (17) for controlling the D back control air control valve (23, 24), characterized in that the remote control (18) is controlled electro-pneumatically and the control and regulation of the inflow of the compressed air via the pneumatic means (14, 19, 20, 22) made available compressed air itself ,

Description

The present invention relates to a device for controlling the wake of a blasting medium medium driven by compressed air, a pneumatic connection for supplying the device with compressed air, a blasting hose connected to the pneumatic connection, a blasting nozzle arranged at the free end of the hose, a pressure blasting container storing a blasting material medium connected to the blast hose via a metering valve, a pressure reducer which reduces the compressed air from the pneumatic port to a working pressure, at least one control valve for releasing the compressed air to the blast hose, a remote control located at the free end of the hose for driving and regulating the compressed air provided by the pneumatic connection, as well as an electrical circuit unit connected to the remote control for controlling the control valve controlling the compressed air.

Furthermore, the invention relates to a method for generating an electrical signal for closing or opening the supply of a blast hose with compressed air.

Such devices can be summarized, for example, under the collective term sandblast blower. This is understood as the surface treatment of a material or workpiece by the action of, for example, sand as an abrasive against rust, dirt, paint, scale and other impurities. Here, a strong compressed air jet is generated by means of a compressor, which entrains and accelerates the blasting medium, such as sand, blast furnace slag, glass granules, corundum, steel, plastic granules, nut shells or soda - with different degrees of fineness - from a storage container. The blasting medium then hits, together with the air jet at high speed, for example, on the surface to be treated of a workpiece. Due to the mostly abrasive effect of the blasting medium unwanted components of the surface, such as rust or paint, detached and carried away.

Such devices are very effective depending on the size and design and can not be safely operated by the operator without special protective equipment.

Because it has been shown that such devices, due to the system, react relatively slowly to control commands. In other words, when the compressed air supply is closed or shut off, the blasting material medium still exits the blasting nozzle connected to the blasting hose.

In an emergency situation, this can lead to a considerable risk of injury to the operating personnel. It is thus desirable to avoid accidents, to obtain the best possible control of the timing, duration and amount of the emerging from the nozzle blasting medium.

The publication DE 295 08 405 U1 proposes a Schnellabschaltvorrichtung for a device for blasting workpieces, structures u. Like. By means of a loaded with a granular abrasive agent carrier air flow before.

From the publication DE 296 05 704 U1 is a Schnellabschaltvorrichtung for a sandblaster, which includes a blast hose and a parallel extending vent hose, known. In this case, the cross section of the blasting hose can be compressed by means of a crimping device associated therewith until its complete closure.

The DE 36 17 035 A1 discloses a mechanical dead man switch for sandblasting, with additional pneumatically-mechanically controlled safety device.

The aforementioned solutions have proven to some extent, but have the disadvantage that they can not significantly shorten the follow-up time in which the jet medium still exits the jet nozzle. Furthermore, it has been found that such devices do not prevent the occurrence of uncontrollable recoil in the blasting hose.

For this purpose, a device for Strahlgutblasen has been proposed with an emergency shutdown. The quick shutdown is equipped with a so-called deadman switch, which is located at the end of the blasting hose. When the dead man switch is actuated, the flow of the blasting medium medium takes place and when the dead man switch is released, the pressure in the hose is reduced until no blasting medium escapes from the hose or the blasting hose nozzle. Such an emergency shutdown can significantly reduce the overrun time.

The shutdown is controlled by an electric dead man's switch, which is located at the end of the blasting hose. However, such devices have the disadvantage that the electrical installation of the deadman switch leads to downtime in the blasting plant, since the electrical installation is fixed by means of cable ties, tape or rubber rings on the blasting hose and together with the hose on the ground, for example, a grate o. Like. Be drawn.

As a result, the insulation of the electrical installation is constantly subject to increased mechanical stress. This leads sooner or later to damage to the electrical wiring. In particular, the cable cores themselves are affected by this, which ultimately leads to a cable break. The tearing of the wire insulation and / or the breaking of the cable leads to faulty circuits, for example in the form of uncontrollable recoil in the jet hose and thus to a risk to the operating personnel or to a total failure of the emergency shutdown. The frequently occurring defects lead to a severely restricted production process, which in turn involves additional costs due to repair measures.

It is therefore an object of the present invention to provide a device for controlling the wake in a blasting hose, which is safe and durable, while avoiding caused by malfunction downtime.

This object is achieved by the features specified in claim 1, in particular in that the remote control is controlled electro-pneumatically and the control and regulation of the inflow of compressed air via the compressed air provided by the pneumatic means itself is made. The pneumatic means may for example be a compressor.

In a particularly preferred embodiment of the device according to the invention the remote control is associated with a control hose which is connected to the pneumatic medium via a pressure reducer and so can provide a pneumatic control pressure of the remote control available.

In a further particularly preferred embodiment of the device according to the invention the normally open contact of the remote control is designed as a closing switch, which is guided in the operation of the control pressure from the control tube via a connecting means in the remote control to a flow sensor. In another embodiment, the normally open contact of the remote control can be designed as an opener (open switch).

According to a particularly preferred embodiment of the device according to the invention, it is provided to connect the flow sensor with at least one delayed-time relay, wherein the time relay is associated with the electrical circuit unit.

In a further embodiment of the device according to the invention, the flow sensor controls the time relay on actuation of the remote control, wherein the time relay generates a delayed start signal, which is forwarded to the circuit unit, from where the control valves for compressed air delivery in the blasting hose in response to the switch position of the remote control and the flow rate of compressed air registered by the flow sensor can be switched on or off.

A further object of the present invention is to provide a method for generating an electrical signal for closing or opening the tracking control of the blasting hose for compressed air containing blasting material medium.

• – Einschalten der elektrischen Einheit,
• – Betätigen der pneumatischen Fernbedienung, so dass druckgeminderte Druckluft aus dem pneumatischen Anschluss durch den Steuerschlauch freigegeben wird,
• – Messen der Durchflussmenge an Druckluft in dem Steuerschlauch durch Durchflusssensor,
• – bei einem festgestellten Durchflussvolumen durch den Durchflusssensor Erzeugen und Weiterleiten eines elektrischen Signals an ein anzugsverzögertes Zeitrelais,
• – nachdem das Zeitrelais auf den Steuerungsbefehl zeitverzögert angesprungen ist, erzeugen eines elektrischen Ausgabesignals, das an die Fernbedienung weitergeleitet wird und diese sodann ausgelöst,
• – Weiterleiten des Signals an die Steuerventile zur Freigabe der Druckluft für den Strahlschlauch und ggf. Ansteuerung des Strahlmitteldosierventils für das Zuführen des Strahlgutmediums in den Strahlschlauch.

This object is achieved by the steps according to claim 6, in particular by:

• - switching on the electrical unit,
• - Actuation of the pneumatic remote control so that pressure-reduced compressed air is released from the pneumatic connection through the control hose,
• Measuring the flow rate of compressed air in the control tube by flow sensor,
• At a detected flow volume through the flow sensor, generating and relaying an electrical signal to a time delayed relay,
• - After the timer has jumped on the control command delayed, generate an electrical output signal, which is forwarded to the remote control and then triggered,
• - Forwarding the signal to the control valves to release the compressed air for the jet hose and, if necessary, control of the Strahlmitteldosierventils for supplying the Strahlgutmediums in the jet hose.

A further object of the present invention is to provide a free-jet house for surface cleaning of workpieces by means of a jet of compressed air mixed with a blasting material medium with a device for electropneumatic control of the wake in the blasting hose. This object is achieved according to claim 7.

The invention will be explained in more detail below with reference to an exemplary embodiment with reference to the accompanying drawings. It shows the only figure:

1 a schematic representation of an embodiment of the inventive device for electropneumatic control of the wake of a Strahlgutmediums in a blasting hose.

As the 1 shows, the device comprises 10 for controlling the wake of a jet medium (not shown) driven by compressed air, a pneumatic connection 11 to supply the device 10 with compressed air.

The pneumatic connection 11 can with a pressure line 12 be actively connected. The pressure line 12 can consist of a flexible pressure-resistant hose. Furthermore, the pressure line 12 a branch 13 on. From the branch 13 becomes a control line 14 and a work management 15 diverted.

By pressing a switch 16 on a control panel is the electrical control 17 switched on. The device 10 is thereby supplied with power, which is forwarded to systemically relevant consumers.

The control line 14 is with a remote control 18 connected. The remote control is designed as a deadman switch.

When operating the remote control 18 Approximately 40 to 60 liters of compressed air flow per minute through the control line 14 , which is formed in this embodiment as a flexible and durable pressure hose, to a flow sensor 19 , As the pressure of the compressed air from the pneumatic connection 11 Too high, this is before it is fed into the control line by a pressure reducer 20 down regulated. The control pressure in the control line is monitored 14 through a pressure gauge 21 , It is conceivable that the pressure gauge 21 independently adjusts the control pressure to a desired pressure level.

Once the flow sensor 19 the flow of compressed air registered in the control line is via the flow sensor 19 a delayed-action time relay 22 that, as well as the flow sensor 19 the electrical control 17 can be assigned, controlled.

The time relay 22 forms, after a predeterminable time interval for the release of the compressed air in the working line 15 , a control signal K. The control signal K is to control valves 23 . 24 forwarded, then the compressed air to the blasting hose 25 hand off. Again, it is envisaged that the compressed air demand-oriented via one of the working line 15 associated pressure reducer 26 monitored and controlled. The time interval may include a period of 2 to 4, ideally 3 seconds, before the control signal K is output.

That in a storage container 27 stocked blasting medium is via a further pneumatic connection 28 pressurized with compressed air. The blasting medium is released by the control signal K via a Strahlmitteldosierventil 29 to the blast hose 25 issued. The blasting hose 25 is a nozzle 30 assigned, via which the blasting medium can be selectively delivered to a workpiece to be machined (not shown).

The remote control 18 , or the deadman switch is in this embodiment, at the free end 31 the blasting hose 25 assigned. The remote control 18 is pneumatically controlled in this embodiment, wherein the normally open contact is designed as a closer. Will the remote control 18 let go, that is, the normally closed contact is closed, registers the flow sensor 19 no flow of compressed air in the control line 14 , This is from the electrical control unit 17 registered and the control signal K is not sent to the control valves 23 . 24 delivered, which then close. The blasting process is stopped immediately and without delay.

LIST OF REFERENCE NUMBERS

10

contraption

11

pneumatic connection

12

pressure line

13

junction

14

control line

15

working line

16

switch

17

electrical control

18

remote control

19

Flow Sensor

20

pressure reducer

21

pressure monitor

22

relay

23

control valve

24

control valve

25

ray tube

26

pressure reducer

27

reservoir

28

pneumatic connection

29

Strahlmitteldosierventil

30

jet

31

free end

K

control signal

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

• DE 29508405 U1 [0007]
• DE 29605704 U1 [0008]
• DE 3617035 A1 [0009]

Claims (6)

Contraption ( 10 ) for controlling the wake of a blasting media medium driven by compressed air, comprising: a pneumatic connection ( 11 ) for the supply of the device ( 10 ) with compressed air, one with the pneumatic connection ( 11 ) connected blasting hose ( 25 ), one at the free end ( 31 ) of the blasting hose ( 25 ) arranged jet nozzle 30 , a pressure jet container storing a blasting medium ( 27 ), with the blasting hose ( 25 ) via a metering valve ( 29 ), a pressure reducer ( 26 ), which removes the compressed air from the pneumatic connection ( 11 ) reduced to a working pressure, at least one control valve ( 23 . 24 ) for releasing the compressed air to the blasting hose ( 25 ), a remote control located at the free end of the hose ( 18 ), which are used to control and regulate the pneumatic connection ( 11 ) and one with the remote control ( 18 ) connected electrical circuit unit ( 17 ) for controlling the compressed air regulating control valve ( 23 . 24 ), characterized in that the remote control ( 18 ) is controlled electro-pneumatically and the control and regulation of the inflow of compressed air by the pneumatic means ( 14 . 19 . 20 . 22 ) made available compressed air itself. Device according to claim 1, characterized in that the remote control ( 18 ) a control hose ( 14 ) associated with the pneumatic medium via a pressure reducer ( 20 ) and so a pneumatic control pressure of the remote control ( 18 ). Device according to claim 2, characterized in that the working contact of the remote control ( 18 ) is designed as a closing switch and upon actuation of the closing switch, the control pressure from the control tube ( 14 ) via a connection means in the remote control to a flow sensor ( 19 ) is conductive. Apparatus according to claim 3, characterized in that the flow sensor ( 19 ) with at least one delayed on-time relay ( 22 ), and the electrical circuit unit ( 17 ) assigned. Apparatus according to claim 4, characterized in that the flow sensor ( 19 ) when operating the remote control ( 18 ) the time relay ( 22 ), the time relay ( 22 ) generates a time-delayed start signal which is sent to the circuit unit ( 17 ), from where the control valves ( 23 . 24 ) for the compressed air delivery into the blasting hose ( 25 ) depending on the switch position of the remote control ( 18 ) and the flow sensor ( 19 ) registered flow rate of compressed air to be opened or closed. Freistrahlhaus for surface cleaning of workpieces by means of a, mixed with a Strahlgutmedium compressed air jet with a device for electropneumatic control of the wake in the blasting hose ( 25 ) according to claims 1 to 5.

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