INVENTION DESCRIPTION

1. FIELD OF APPLICATION

The invention relates to production of spiral wound plastic pipes where automatic monitoring of the working temperature and controlling the production process is required, aimed to decreasing the waste.

In the International Patent Classification, it is classified as field G - Physics, class D01 - Measuring, subclass G01K - Measuring temperature; also class G05 - Controlling, Regulating, subclass G05F - Systems for regulating electric variables; and class G08 - Signalling, subclass G08B - Alarm systems.

2. TECHNICAL PROBLEM

Production of monolithic, pressurised or non-pressurised, spiral wound plastic pipes requires continuous monitoring of working temperature of the hollow tool that in the course of production rotates in the machine and is heated from outside. As the tool rotates, it is applied the materials of which the pipes are being produced: polyethylene, polypropylene and other plastic materials. Pipes are produced of different diameters, wall thickness and lengths. When the tool is heated to the predetermined temperature, the plastic material adheres evenly to the outer wall of the tool, without adhesives. This is important since the pipe inner side is to be smooth to enable its easy removing from the tool. If the temperature is not set correctly, at that part of the tool occurs hard connection between the plastic pipe and the outer side of the tool. Such pipes are hard to remove, hard to finish and often become waste. In the process of cooling of the tool and the plastic pipe it is important that the tool and pipe temperature is the same with all pipes of the same nominal diameter, that is, that at the moment of removing the pipe from the tool the temperature of tools of the same nominal diameter is the same. This guarantees the connecting dimensions of the finished inner ("male") end and the unfinished outer ("female") ends in all pipes of the same nominal diameter to be the same, which again provides impermeable connections when pipes are connected into a pipeline.

The technical problem being solved by this invention relates to automatic monitoring the tool working temperature and controlling the pipe production and finishing process, free of any subjective influence from the machine operator, thus enabling high quality and economic production, generating no unnecessary waste.

3. STATE OF THE ART

Spiral wound plastic pipe is produced by a machine that rotates a hollow metal tool. During the production, the tool is heated from outside. Around the heated tool, hot plastic is spirally wound in one or several layers, mutually unified to make the designed spiral wound pipe. The process is run continuously along the entire length of the tool. The continuous production requires heating of the tool. The tools is heated from the outside, normally by gas heaters. Presently, the tool outside working temperature is monitored by workers by common or laser reading instruments as the machine rotates the tool. Such temperature monitoring is not precise enough and always results in departures. For this reason, the product quality depends on the operator's personal discretion and experience. Once the plastic pipe is produced, the tool with the pipe on it is moved to the finishing machine, whereas a new tool for a new pipe is mounted on the production machine. The process of producing the new pipe runs simultaneously with finishing and cooling of the previous pipe on the finishing machine. Finishing relates to the pipe male end, that is, the end that is to enter the female end of the next pipe when these are connected. The male end finishing is to be started and completed at the same temperature in order to make connecting dimensions of pipes produced on any machine of the same nominal diameter identical. Following finishing the male end and cooling the tool, the mechanism for decreasing the tool outer diameter is activated, so that the finished pipe is easily removed from the tool.

4. ESSENCE OF THE INVENTION

The essence of the invention is the system for automatic monitoring and controlling the process of production and finishing of spiral wound plastic pipes. The system comprises the tool working temperature measuring unit, fitted on the tool, and the unit warning about the measured temperatures deviating from the preset ones, located separate from the tool and warning about the deviations by light and sound alarms. The working temperature measuring unit is mounted at every tool. The unit warning about the measured temperatures deviating from the preset ones simultaneously monitors and warns about deviations in the pipe production and the pipe finishing machines. Once the male pipe end is finished and the pipe is cooled down, the system simultaneously instructs the finishing machine to stop the tool rotations and activates the tool diameter decreasing mechanism, aimed to easier removing the pipe from the tool. The warning unit may simultaneously monitor pipe production and finishing processes on several production lines.

5. BRIEF ILLUSTRATION DESCRIPTIONS

Figure 1 shows the tool with the tool working temperature measuring unit - perspective view.

Figure 2 shows enlarged entry into the tool where, on the tool diameter decreasing mechanism, fitted is housing containing measuring the modules and wireless communication module - front view.

Figure 3 shows a partial cross section of the tool - side view.

Figure 4 shows the tool - front view.

Figure 5 shows the tool - back view.

Figure 6 shows a partial cross section of the tool with plastic pipe on it - side view.

Figure 7 shows the tool with plastic pipe on it - front view.

Figure 8 shows the tool with plastic pipe on it - back view.

Figure 9 shows diagram of the monitoring system comprising the tool working temperature measuring unit and the unit warning about the measured temperatures deviating from the preset ones - for one tool.

Figure 10 shows diagram of the monitoring unit comprising the tool working temperature measuring unit at the production machine and the monitoring unit comprising the tool working temperature measuring unit at the finishing machine, rotating simultaneously, and the unit warning about the measured temperatures deviating from the preset ones, simultaneously on both machines. Figure 11 shows a possible appearance of the computer monitor panel, showing the preset and the measured tool working temperatures by the measuring zones, simultaneously at the plastic pipe production and finishing machines.

6. DETAILED DESCRIPTION OF INVENTION EMBODIMENT AND FUNCTIONING

In this invention description, for easier following up and understanding, certain long expressions made of large numbers of words are substituted by the following shorter expressions:

- "monolith spiral wound pressurised and non-pressurised plastic pipe" is substituted by "plastic pipe",

- "hollow round metal tool" is substituted by "tool",

- "tool working temperature measuring unit" is substituted by "measuring unit",

- "unit warning about the measured temperatures deviating from the preset ones" is substituted by "warning unit", and

- "system operating computer programme" is substituted by "computer programme".

Plastic pipes may be produced simultaneously on one or more production lines. Each line consists of a plastic pipe production machine and a machine that finishes and removes the pipe from the tool. Once the procedure on the plastic pipe production machine is complete, the tool with the pipe is moved to the plastic pipe finishing machine of the same production line. On each tool is fitted the measuring unit. Several tools may be linked to the same warning unit at the same time. Here is described in detail the process of production and finishing of plastic pipes at one production line, whereas, as a possibility, on the computer monitor is shown panel with two tools at two production line, their measured and preset temperature data being displayed simultaneously.

On the tool are produced plastic pipes of various lengths and diameters.

Plastic pipes are produced by winding of a plastic band and a plastic profile around the tool outer surface. The tool outer surface determines the inner dimension of the pipe with its female end. Safe and quality plastic pipe production by this technology requires automatic and continuous measuring and regulation of the tool preset temperature, free of the machine operator's personal influence. After the production, the tool with the plastic pipe on it is removed from the production machine and moved to the finishing machine, where its male end is finished manually and the tool is cooled for its easier removal from the tool.

At the same time, on the plastic pipe production tool a new tool is mounted. Thus, the production and the finishing cycles are continuously repeated.

The described procedure guarantees that measures of the plastic pipe male and female ends, produced on both tools, are identical, that is, there are no deviations in measures of the finished male ends and the not manually finished female ends.

The tool temperature is essential in producing of plastic pipes. When the tool is heated up exactly to the preset temperature, the plastic pipe inner surface presses against the tool outer surface. In this case, the pipe is easily removed from the tool. If the plastic pipe inner surface is not smooth, such pipe cannot be used without additional finishing. Such finishing includes repairs of the pipe inner surface, impossible with smaller profiles since the worker cannot enter the pipe. If a pipe cannot be finished, it becomes waste. Such plastic pipe is recycled, which means large loss of time and material, especially with heavy plastic pipes.

TOOL A

The plastic pipe production tool A comprises body 1 and mechanism 3. On the body is made a protruding ring 2 that shapes the pipe female end. The mechanism 3 is fitted in the tool. The mechanism is to decrease the tool outer diameter, and is activated when the plastic pipe finishing and cooling are completed, in order to facilitate removing the pipe from the tool.

THE MONITORING AND CONTROLLING SYSTEM includes:

- measuring unit C, and

- warning unit D.

Measuring unit C

The measuring unit C, Figure 9, comprises: working temperature sensors 4, electric wiring 5, connectors 6, analogue measuring module 7, digital measuring module 8, wireless communication module 9, battery 10, battery recharger 11, and unit housing 12. The measuring unit C makes an integral part of the tool A.

The measuring unit C is provided with one or more working temperature sensors 4. In the described example, the tool is provided with seven sensors. The sensors are distributed by previously determined zones and are fitted to the inner wall of the tool A. The number of sensors in a given tool depends on its length and inner diameter. The sensor measuring field is up to 300°C, and the working field up to 150°C. Each sensor is connected by thermo-electric cables to the connectors 6 in the housing 12.

The analogue module 7, the digital module 8 and the wireless communication module 9 are placed in the common housing 12. The housing 12 is fitted to the diameter decreasing mechanism 3 with which it rotates in the course of the pipe production. To the housing are also connected connectors 6 for electric cables 5 to sensors 4. The housing is fitted at the tool in a way that enables its removal and use on another tool provided with its working temperature sensors.

The wireless communication module emits radio signals containing the temperatures measured by the sensors 4 on the tool A, which signals are received by the wireless communication module 13, fitted in the warning unit D. The unit D is physically separate from the tool A.

Figures 3, 4 and 5 show the tool A, in partial cross section, and the fitted measuring unit C.

Warning unit D

The warning unit D, Figures 9 and 11, comprises: wireless module 13, wired communication module 14, unit housing 15, computer 16 with monitor 17. The monitor, in the form of the panel 18, shows simultaneously the measured and preset working temperature data, separately for the plastic pipe production and the finishing machines. On the panel are also sound alarm 19 and light alarm 20, separate for each tool.

The warning unit D is physically separate from the tool A.

A single warning unit D, Figure 11, enables simultaneous monitoring and controlling of temperatures of tools currently at both the production machine and the finishing machine, the tools being provided with the measuring units C. In that case the monitor screen shows preset and measured temperatures with light and sound alarms, separately for the tool at the production machine and the tool at the finishing machine. The warning unit D has the communication module 13 that receives electromagnetic signals containing the measured temperature values of the tool A, emitted by the wireless communication module 9 in the unit C. To the wireless communication module 13 is connected the wired communication module 14 that sends the measured temperature data by wire to the computer 16. Both communication modules, 13 and 14, are situated in the common housing 15, placed next to the computer 16. The computer monitor 17, Figure 11 , shows, in the form of a panel, the preset and measured working temperature values by measuring zones in the tool A. The computer is provided with the sound alarm 19 and the light alarm 20, activated if the measured temperatures deviate from those preset for that part of the tool. In that case, the operator of the production or finishing machine, as the case may be, intervenes and corrects the tool temperature in order to avoid sticking of the plastic pipe to the tool outer surface, that would require additional finishing or rejecting the pipe into waste.

Figure 11 shows, as an example only, appearance of the monitor 17 with the panel 18, and the sound alarm 19 and the light alarm 20 symbols, indicating any difference between the preset and the measured temperatures, for tools in all production lines simultaneously.

The person monitoring the tool rotating machine monitors and compares the temperatures displayed on the monitor. If the differences are significant, he corrects the tool heating temperature. In cases of significant temperature deviations, the sound and the light alarms are activated automatically, and the operator is to intervene and eliminate the cause of the problem, to establish once again the normal status as required for a quality production.

Figures 6, 7 and 8 show a partial cross section of the tool A with the plastic pipe 21, and its female end 22 and male end 23. When two plastic pipes are being mutually connected, the male end of one pipe enters the female end of the other. At building of a pipeline, the mutually connected male and female ends are mutually welded by a special electric welding procedure.

The entire operating system is controlled by the computer programme installed in the computer 16.

The computer programme enables simultaneous visual displaying at the monitor 17, in the form of the panel 18, numerically and in colours, the preset and measured working temperatures of the tool A, in one production line during plastic pipe production and finishing, and at the same time at the tool B, in the second production line during plastic pipe production and finishing. In case of temperature deviation, activated are both the sound and the light alarms, separately for each tool at each line. The computer programme enables loading and recording of the preset temperatures for each sensor and tool separately. It also enables automatic sending of operating commands when the tool and the pipe working temperature reaches the value preset for finishing the pipe male end.

BRIEF DESCRIPTION OF REFERRAL MARKS USED IN DESCRIPTIONS AND ILLUSTRATIONS

A - tool for producing of plastic pipes at the first production line

1 - tool body

2 - ring shaping the pipe female end

3 - mechanism decreasing the tool diameter to enable removing of pipe from the tool B - tool for producing of plastic pipes at the second production line

C - unit measuring the tool working temperature during production and finishing of plastic pipes

4 - tool working temperature sensors

5 - electric cables connecting the sensors and the analogue measuring module

6 - connectors

7 - analogue measuring module

8 - digital measuring module

9 - wireless communication module

10 - battery

11 - battery recharger

12 - housings containing parts of the tool working temperature measuring unit

D - unit warning about departures of measured from preset tool temperatures

13 - wireless communication module receiving signals from the unit D

14 - wired communication module transmitting signals to the computer

15 - housing containing the wireless and the wired communication modules 13 and 14

16 - computer

17 - monitor

18 - an example of the monitor appearance showing working temperature measured on and preset for the tools on the production machine and the finishing machine

19 - sound alarm symbol 20 - light alarm symbol

21 - plastic pipe

22 - pipe female end, the widened end that receives other pipe male end when being mutually connected

23 - pipe male end, the finished pipe end that enters other pipe female end when being mutually connected

7. INVENTION APPLICATION

The invention application is evident from its very description.

Experts will find obvious the possibility of making certain modifications and alterations in the system for monitoring and controlling of temperature of tools for production and finishing of monolith plastic spiral wound pipes, according to this invention, without leaving the scope and spirit of the invention.