DE19757160A1 - Safety control block for high pressure cleaning device - Google Patents

Abstract

The safety control block (8) for a high pressure cleaning device detects the displacement of a sliding control piston (1) contained within a cylinder space into each of its end positions using a contactless measuring sensor (4), e.g. a magnetic sensor cooperating with a permanent magnet (5) attached to the control piston end face, or an optical, inductive, or capacitive sensor.

Description

The invention relates to a control security block for High pressure cleaning devices according to the generic term of Claim 1.

Such control safety blocks for the control of High pressure washers serve the pump motor and possibly also the burner device depending controlled by water flow. Is it for example, a so-called cold water high-pressure cleaning devices are only a single-phase or multi-phase Drive motor for the pump available, which corresponds to the Water flow must be controlled. Will the High pressure gun open, then the pump motor be switched on. Conversely, the engine should be stopped as soon as the high pressure gun is switched off.  

In the case of so-called hot water devices, which also have a Having a heater is an additional task made that so-called water deficiency states are recognized. Also in this case the entire device should be switched off become.

The previously mentioned pressure shutdown in cold water devices was done in that in a housing of Control safety block a control piston axially displaceable was arranged under the influence of the high pressure medium was moved against a spring in the piston chamber.

In the presence of high water pressure, the control piston shifted in one direction against the force of the spring, while in the absence of high water pressure, the spring force weighed and relieved the spool in the other Position shifted.

This change in position of the control piston was in the known control safety blocks via a so-called Microswitch detected. The use of such microswitches has the disadvantage, however, that it is labor-intensive to assemble are that the switch attachment and adjustment is relatively expensive. Another disadvantage is that such microswitch against sudden movements of the Control piston are sensitive and can be damaged.

There are even known solutions where the microswitch even as a control contactor for switching off the motor from the three-phase supply is used. With this solution but there is the disadvantage that the microswitch by high motor starting currents - a multiple of normal currents are - can be damaged.

It is also known the motor winding of the pump motor to protect with a so-called thermal fuse. Here is  it is known as a thermal fuse to a bimetal switch use, but which has the disadvantage that it is relatively sluggish responds.

The invention is therefore based on the object Control safety block for high pressure cold water and / or Hot water devices of the type mentioned above to further develop that with much simpler means reliable training of the control safety block is guaranteed.

To achieve the object, the invention is by characterized technical teaching of claim 1.

An essential feature of the invention is that now Use of the control safety block for cold water devices the displacement of the control piston in its two end positions is detected via a contactless sensor. Is the Control safety block still for a hot water device provided is proposed according to the invention, not only the axial displacement of the control piston in the two End positions without contact with appropriate sensors capture, but it is additionally proposed that the Displacement of a non-return piston in its two end positions is also recorded with a non-contact sensor, which last-mentioned non-return piston in the water cycle the high-pressure cleaning device is switched on that at Lack of water from one end position to the other is shifted and this axial shift in turn by a non-contact sensor is detected.

For convenience, in the present invention no longer sharp between a cold water cleaning device and a hot water cleaning device. The two Devices differ only in that both devices in Control safety block the axial displacement of the  Control piston in its two end positions via non-contact Detect transducers and that additionally when using the Control safety block for a hot water device still there is an additional non-return piston, both of which End positions also by a contactless sensor be recorded. It is essentially sufficient, always from talking to a hot water device because a Control safety block for a hot water device both Has sensor arrangements, while a Control safety block for one chiller only one Provides sensor.

It is essential in the present invention that the Signals from both sensors in a single electronics module be summarized and that it is for the attachment of this Electronic module there are different embodiments.

In a first preferred embodiment it is provided that the electronics module immediately as closed unit flanged to the control safety block and that in this electronics module all immediately electronic shutdown devices for the control of the Pump motor and possibly for the control of the Blower motor and the magnetic shut-off valve for the Fuel supply for the hot water burner housed are. This results in a particularly compact and thus also reliable construction, because the whole Electronic module can be potted and integrated Flanged unit directly on the control safety block be.

So it is only necessary when using as Hot water device only a single signal line from that the water shortage assigned sensor in the Introduce electronics module and go from the electronics module then only output lines that directly with the  Switchboard connected for the introduction of the alternating current are.

This also makes it easy Interchangeability of the entire electronics module and in the rest are all parts - due to the plastic potting - optimal against penetration of moisture and dirt protected. In another embodiment of the present Invention it is provided that only on Control safety block a holder for attaching the Sensor for detecting the axial displacement of the Control piston is arranged and that accordingly the associated Electronics module in the switch box of the device - removed from the Rules security block - is arranged.

In this case, too, there is a particularly favorable one Structure, because the entire electronics module can also be used as encapsulated, self-contained structure in the Control box of the device can be integrated, which only There is a need for a maximum of two signal lines this Electronic module feed. The one signal line comes from the magnetic sensor for pressure monitoring (monitoring the Movement of the end positions of the control piston) and the other Signal line comes from the flow monitoring (at the Use of hot water devices).

The present invention also proposes several options for the control of the engine shutdown by the above non-contact sensor.

In a first preferred embodiment it is provided that the engine shutdown via a electromechanical contactor, and that the contactor driving coil controlled by the sensor arrangement becomes. It is therefore an indirect one  Shutdown of the pump motor via the electronic device in connection with the electromechanical contactor.

In a second embodiment of the invention it is provided that instead of an electromechanical contactor directly shutdown via semiconductor switches (in particular preferably triacs and diacs), so that the possibility is that the previously described, non-contact Sensor arrangement directly on the control input of the Semiconductor switch acts, so that direct control this semiconductor switch for the purpose of switching off the pump motor given is.

It goes without saying in all applications that the present invention does not only apply to three-phase Three-phase motors refers, but also to two-phase AC motors, which in the latter case only one phase disappears.

In a third embodiment of the present invention it is contemplated that in addition to the aforementioned two variants of switching off the pump motor (with indirect control of the contactor or with direct Control via semiconductor switch) assigned further semiconductor switches the blower motor for the burner and possibly also the solenoid valve can be controlled for the fuel supply to the burner.

All embodiments have the advantage in common, moreover, that also the temperature monitoring in winding of the motor is included in the electronics module, so that this line also leads into the electronics module and there accordingly for a shutdown of the high pressure valve ensures if the winding overheats.  

It is preferred here as thermal monitoring for the Motor winding to use fast temperature sensors; it these are either PTC resistors or NTC resistors that are particularly fast Have temperature behavior, so that even short-term Temperature increases in the motor winding, which also lead to Destruction of the motor winding can be recognized and reliably lead to engine shutdown.

When using such resistors there is namely Advantage that no current monitoring of the winding of the motor more takes place, but an actual monitoring of Winding temperature, which is much more sensitive than comparatively the previously known current monitoring in the winding.

The subject matter of the present invention provides not just from the subject of each Claims, but also from the combination of individual claims among themselves.

All in the documentation, including the summary, Disclosed information and features, in particular those in the Drawings illustrated spatial training are considered essential to the invention, insofar as they are used individually or in Combination are new compared to the prior art.

In the following the invention based on several Drawings illustrating execution paths explained in more detail. Here go from the drawings and their description further features and advantages essential to the invention Invention.

Show it:

FIG. 1 shows schematically in a first embodiment, a section through a safety control block;

Fig. 2 shows a variant compared to Fig. 1;

Figure 3 shows a first embodiment for the formation of an electronic module according to the invention in a three-phase AC motor with contactor.

FIG. 4 shows a variant modified from FIG. 3 in a three-phase three-phase motor without contactor;

Fig. 5 shows a variant compared to Figs. 3 and 4 in a three-phase AC motor without contactor in the design of a hot water device.

In Figs. 1 and 2, a safety control block 8 is schematically shown, being provided in the regulating safety block 8 according to FIGS. 1 and 2, the same parts with the same reference numerals.

At an upper inlet 12 , the high-pressure medium is fed in the direction of arrow 11 into the control safety block 8 and flows there in two opposite directions.

On the right side - on the other side of the inlet 12 - in a piston chamber 13, a control piston 1 is arranged displaceably against the spring force of a spring 15, wherein a permanent magnet 5 is disposed at a front end side of said control piston. 1 As soon as a high-pressure medium is present at the inlet 12 , the control piston 1 is displaced to the right against the force of the spring 15 , as a result of which the permanent magnet 5 enters the region of a recess 16 in a holding plate 2 on the control safety block 8 .

An electronics module 3 , in which a magnetic sensor 4 is arranged, is fixedly flanged to the holding plate 2 . This magnetic sensor 4 is preferably designed as a Hall sensor and is flush with the permanent magnet 5 .

When the control piston 1 is shifted to the right, the magnetic field of the permanent magnet 5 thus acts on the magnetic sensor 4 and a corresponding signal is generated in the magnetic sensor 4 , which will be explained later using the circuits.

If the control safety block is only intended for a cold water device, then this arrangement of the control piston 1 is sufficient.

However, if the control safety block is additionally provided for monitoring a hot water device, then a further check valve 6 is also arranged in the control safety block 8 , which is designed to be axially displaceable against the force of a spring 42 in a further piston chamber 43 .

The back check piston 6 flows around the high-pressure medium and applied as soon as the high pressure in the piston chamber 43, the check piston 6 in its position 6 the partial section in Fig. 1 'according shifted. The high-pressure medium then emerges from the outlet 10 in the direction of arrow 9 .

If there is a lack of water, the high-pressure medium is accordingly missing in the piston chamber 43 and the check piston 6 is moved into its right-hand displacement position under the force of the spring 42 .

To detect the displacement position of the check piston 6 , a magnetic sensor 7 is arranged in the wall of the control safety block 8 , which is preferably cast in there and which is introduced into the electronics module 3 via a signal line 17 .

In a similar manner, a permanent magnet 5 is arranged on the front face of the check piston 6 . In an alternative embodiment, however, the entire check piston 6 could also be designed as a permanent magnet.

It is important that, in the embodiment according to FIG. 1, all switching parts are also arranged in the electronic module 3 , as is shown, for example, in FIGS. 4 and 5. This means that the semiconductor circuits for the direct shutdown of the motor of the high-pressure cleaner are also arranged in the electronics module 3 .

In addition, there is also the shutdown for the Integrated winding temperature monitoring and others Switching elements more.

In the alternative embodiment according to FIG. 2, the same explanations apply as for the control safety block according to FIG. 1.

In contrast to the exemplary embodiment according to FIG. 1, it is shown there that only one holder 18 is flanged in the control safety block, which holds the magnetic sensor 4 for pressure monitoring.

This signal lines 17 , 17 'of both sensors (if it is a hot water device) are thus introduced into an electronic module, which are installed to the switch box 19 of the device.

It is essential that when the electronics module 3 is installed in the switch box 19 of the device, there is still the possibility of installing further electronic elements in this electronics module. This includes e.g. B. a burner temperature monitoring in the case of training as a hot water device or a thermostat for setting the water temperature of this hot water device.

In all cases, there is accordingly the advantage that in one electronic module all electronic Circuit elements can be integrated and thus potted are that they are moisture, vibration and are housed protected from dirt.

An indirect control of a contactor 22 is now shown in FIG. 3 as the first embodiment variant. The contactor 22 switches off the motor 20 from the three-phase network, a coil 23 being used to trigger the contactor. The coil 23 is in turn controlled by the electronics module 24 in that a semiconductor switch 25 is only shown schematically. The two magnetic sensors 4 , 4 ′ act on the control input of this semiconductor switch 25 , provided that it is a hot water device. In contrast, the permanent magnets 5 , 5 are arranged, each of which is assigned to the pressure control 26 (= control piston 1 ) or the flow control 27 (= check piston 6 ).

In all applications, there is of course also a manually operated control switch 28 in order to be able to switch the motor 20 on and off.

In addition, FIG. 3 shows that a temperature sensor 21 is provided for winding monitoring and is introduced into the electronics module 24 via the line 32 .

FIG. 4 shows, in comparison to FIG. 3, a direct shutdown of the motor 20 via assigned semiconductor switches 30 , 31 , the control inputs of these semiconductor switches in turn being connected to the magnetic sensors 4 , 4 ′ for the pressure and temperature control 26 , 27 via assigned signal lines are.

It is also shown that the temperature sensor 21 for winding monitoring is also introduced into this electronics module 29 .

FIG. 5 shows, in comparison to FIGS. 3 and 4, substantially the same embodiment, but for simplicity, only a two-phase electric motor 20 is shown, in which it is sufficient to turn off with a single semiconductor switch 41 one phase. Here, too, it is shown that the electronic module 33 used in turn processes the signals from the magnetic sensors 4 , 4 'for the pressure and flow control 26 , 27 , and it is also shown that a further semiconductor switch 34 is present, which is connected via the lines 35 , 36 first switches on a blower motor 37 and then switches on the solenoid valve 39 for the fuel supply to the burner via a delay element 40 (about 4 seconds later) via the coil 38 .

These mentioned circuit parts can also all be integrated in the electronics module 33 shown there and are therefore protected against moisture, dirt and vibration.

Overall, the new electronic module according to Invention a much simpler and more reliable Structure shown, because it is now possible for the first time the displacement of the control piston for the Pressure control and flow control to capture what is associated with considerably less effort, works more reliably and, moreover, more cost-effectively is.  

Assembly is also much easier because corresponding adjustment work avoided with microswitches and wear of these non-contact sensors is not given.

When designing the flow control 27 , it is not necessary for the solution to be able to detect the displacement position of a non-return piston 6 by means of a non-contact measuring transducer. Instead of a check piston 6 , other movable elements, such as. B. a float can be used, the end positions are also detected without contact via the magnetic sensors described.

Reference list

1

Control piston

2nd

Retaining plate

3rd

Electronics module

4th

Magnetic sensor

4th

'

5

Permanent magnet

5

,

6

Non-return piston

6

'

7

Magnetic sensor

8th

Control security block

9

Arrow direction

10th

Outlet

11

Arrow direction

12th

Inlet

13

Piston chamber

14

Arrow direction

15

feather

16

Recess

17th

Signal line

17th

'

18th

holder

19th

Switch box

20th

engine

21

Temperature sensor

22

Motor contactor

23

Kitchen sink

24th

Electronics module

25th

Semiconductor switch

26

Pressure control

27

Flow control

28

Control switch

29

Electronics module

30th

Semiconductor switch

31

Semiconductor switch

32

management

33

Electronics module

34

Semiconductor switch

35

management

36

management

37

Blower motor

38

Kitchen sink

39

Solenoid valve (oil supply)

40

Delay element

41

Semiconductor switch

42

feather

43

Piston chamber

Claims (15)

1. Control safety block for high-pressure cleaning devices, with an inlet and an outlet for a high-pressure medium, which acts on a control piston arranged displaceably in a piston chamber, characterized in that the displacement of the control piston ( 1 ) in its two end positions is detected by a contactless measuring sensor ( 4 ) becomes. 2. Control safety block according to claim 1, characterized in that the sensor ( 4 ) is a magnetic sensor. 3. Control safety block according to claims 1 and 2, characterized in that a permanent magnet ( 5 ) is arranged on the end face of the control piston ( 1 ), which cooperates with the magnetic sensor. 4. Control safety block according to one of claims 1-3, characterized in that the sensor ( 4 ) is designed as an optical, inductive or capacitive sensor. 5. Control safety block according to one of claims 1-4, characterized in that a non-return piston ( 6 ) is provided which is switched on in the flow of the control safety block in such a way that when there is a lack of water from one end position (working position) to the other end position (rest position) ) is displaced, and this axial displacement is detected by a further contactless measuring sensor ( 7 ). 6. Control safety block according to one of claims 1-5, characterized in that the signals of both sensors are fed to a single electronics module ( 3 ) and processed in this. 7. Control safety block according to one of claims 1-6, characterized in that the entire electronic module ( 3 ) is potted. 8. Safety control block according to one of claims 1-7, characterized in that in the electronics module ( 3 ) all electronic switching devices for operating the high-pressure cleaner are housed directly. 9. control safety block according to one of claims 1-8, characterized in that the electronic module ( 3 ) is flanged directly as a closed unit on the control safety block. 10. Control safety block according to one of claims 1-8, characterized in that a holder ( 18 ) for attaching the sensor is attached to the control safety block. 11. Control safety block according to one of claims 1-8 and 10, characterized in that the associated electronics module ( 24 ) in the switch box ( 19 ) of the device - is arranged away from the control safety block. 12. Control safety block according to one of claims 1-11, characterized in that the activation of the engine shutdown is carried out by the contactless sensor ( 4 ). 13. Control safety block according to one of claims 1-12, characterized in that the motor is switched off by an electromechanical contactor ( 22 ) 14. rule safety block according to any one of claims 1-12, characterized in that the engine cut-off is carried out by semiconductor switches (30/31). 15. rule safety block according to any one of claims 1-14, characterized in that the fan motor (37) are driven for the burner and, optionally, also the solenoid valve (39) for the fuel supply of the burner via associated further semiconductor switch (34/41).