RF generator for the press. HDTV press for the production of curved glued products OBEL P. Brief technical characteristics

When it comes to solid wood furniture, we are talking about a hot wood press. This type of press has proven itself and, depending on requirements, can be completed in a variety of ways.

The system includes:
- high frequency current generator
- press
- hydro station
- Remote Control.

System Features:
- Use of high-frequency heating of the dielectric medium
- Automatic PLC control
- Loading and unloading tables
- Exposure time of one shield with a size of 2440 * 1200 mm, 1-3 minutes
- Possibility of gluing a board 12 meters long by successive heating

How the press works:
1. The blanks smeared with glue are placed on the feeding table.
2. At the push of a button, the automatic feed pusher feeds the blanks into the press.
3. Vertical pressure on the workpieces is created by vertically located hydraulic cylinders, which are switched on automatically, after which the workpieces are compressed by side pressure hydraulic cylinders and glued (the workpieces) into a solid shield.
4. HDTV heating is turned on, the glue is heated (the heating time is set by the staff) during heating, the workpieces are compressed from the top and side by means of hydraulic cylinders.
5. After heating, the pressure of the hydraulic cylinders is automatically turned off, the press opens, and the finished shield comes out of the press.

Brief specifications

Technical characteristics of the press

Technical characteristics of the high frequency current generator 30 kW

Power	AC 38V, 50Hz, 3 phase
Input power	40 kVA
Output power	30 kW
Frequency	6.78 MHz
Electric lamp	FU924FA
Heating voltage	AC 7.5
Switching mode	variable capacitor
Cooling type	Air
Setting mode	Variable Capacity
Type of protection	Two-stage filament heating, overheating warning, electric fan protection, door switch protection
output mode	One way exit

http://mwm.com.ua/catalog/pr_129

See also:

Press with high-frequency heating for the production of glued panels

6. 2 Making a furniture board. 1 Materials for the manufacture of furniture panels. The sequence of technological operations, the equipment used

High frequency currents (HF) have mass useful properties. The main one is the ability to pass over the surface of the conductor without affecting its core. Due to this feature, the surface of the conductor, through which high-frequency currents pass, heats up quickly and to high temperatures.

Moreover, the higher the frequency of the currents, the faster and stronger the conductor heats up.

1 Application of HDTV in industry

High frequency currents are currents in which the number of oscillations in one second reaches one million. The voltage in HDTV machines can be from one thousand to several hundred thousand volts.

HDTV devices are widely used in industry.

• With the help of HDTV in induction furnaces, any metal is melted. The convenience of this method is that it can be applied in a complete vacuum. This avoids oxidation and contamination of metals;
• using high-frequency currents, metal is hardened. The peculiarity of such hardening is that only the shell of the product is hardened, inner part remains plastic. This protects the metal from brittleness;
• with the help of HDTV devices, some parts are welded in the automotive industry .;
• in medicine, high-frequency currents are used to treat skin diseases, by improving blood circulation in the capillaries, joints, spine, warming up internal organs;

The latest invention based on high-frequency currents was the welding machine stretch ceilings from PVC. We will consider this device in more detail.

1.1 HDTV devices for PVC stretch ceilings

Stretch ceilings today rightfully occupy one of the first places in interior decoration Houses. They have high aesthetic qualities, are mounted quite quickly, and allow you to hide ceiling communications. In addition, patterns, drawings and even your own photographs can be applied to stretch fabrics.

With the help of coloring and shaping of canvases, designers solve the issues of visual increase in space, artificial spot lighting of rooms and much more.

The only problem is that the width of a roll of PVC sheets for stretch ceilings does not exceed 3 meters. And if fabric sheets are connected by weaving, then it is impossible to create a seam on PVC in this way.

The seam on stretch ceilings made of fabric or PVC should be:

• durable. The canvas on the ceiling has a fairly high coefficient of tension. Therefore, the seam on the fabric or PVC must be so strong that it does not break or stretch either during installation or over time;
• inconspicuous. The beauty of stretch ceilings lies precisely in the fact that they look like a single sheet of beautiful fabric. Any bends or will significantly reduce the aesthetics of the interior.

It is these two tasks that can be perfectly solved with the help of an HDTV device for stretch ceilings.

1.2 Device

HDTV machines consist of the following mechanisms:

1. Arc suppression mechanism. In the event of sparks or, as a result, an electric arc, the welded fabric may burn out. In addition, there is a possibility of failure of the welded electrode itself. Therefore, the machine is equipped with an automatic regulator that reduces the power of the generator in case of danger of sparks.
2. Interference suppression mechanism. Since high-frequency currents create their own high magnetic field, but are sensitive to other magnetic fields, the machine is equipped with a screen that creates a kind of protective dome over a single HD device.
3. The safety device protects the machine from power surges.
4. Welding device. This mechanism connects PVC sheets by means of dielectric heating.
5. Drive mechanism. Most machines are equipped with two types of drives: foot and pneumatic. The pneumatic drive is more accurate and safer, as it allows you to save the machine and the web from pinching and other errors of the maintenance personnel.
6. In addition, each machine provides for the presence of an inverter, which, in fact, generates high-frequency currents.

All these mechanisms are installed on a frame, which is a table. Such the bed allows you to conveniently lay the fabric for welding and avoid bends or twists.

1.3 How it works

The principle of operation of HDTV machines for stretch ceilings is based on the dielectric heating of two canvases that are in contact with each other. In the welding process, in some cases, filler materials can be used.

Such devices allow soldering:

• fast;
• evenly;
• reliable;
• warming up only specific points.

The soldering process is carried out by means of two electrodes, through which the dielectric current passes.

Soldering can be done in three ways:

• butt;
• overlap;
• T-stitch.

HDTV machine tools made in China for PVC industry used not only for soldering stretch ceilings. They are used to make:

• airbags for cars;
• children's inflatable balls and circles;
• beach slides and attractions, such as "banana";
• beach bags and mattresses, and other PVC products.

1.4 How does the HDTV machine work? (video)

2 Do-it-yourself HDTV machine

Making a full-fledged HDTV device for soldering stretch ceilings and other PVC sheets with your own hands is quite problematic, if not impossible.

Indeed, for its manufacture, it will be necessary not only to decide how to receive high-frequency currents, but also to manufacture or purchase mechanisms for arc suppression, interference suppression, install a press, a drive, and much more.

As for the simplest inverter operating on the basis of Foucault currents for melting and hardening metal rods, it can be made from a conventional welding inverter.

Welding is generally a fairly versatile device. With its help, the production and processes of welding and cutting of metal are carried out, pyrolysis processes are carried out and, as it turns out, high-frequency currents are obtained for the rapid melting of metals and more.

In the process of making the device with your own hands, in addition to the welding inverter itself, you will also need a water cooling mechanism and a coil, which is best made from a copper tube with a cross section of 10 mm. It is this coil that will act as an inductor, or a circuit with induction (high-frequency) currents.

2.1 Manufacturing process

1. Inside the welding inverter, you need to conduct a cooling system. It can be water or freon cooling, powerful coolers or heat sinks.
2. From a copper tube with a cross section of 10 mm and a length of 1 meter, we twist a spiral - an inductor (according to appearance it resembles a boiler). Both ends of the tube, 10-15 cm long, should be curved in one direction and be at the same level.
3. We clamp both ends of the inductor into the grooves of the welding inverter for welding cables.

With the help of such an induction device, made by hand from a welding inverter, it is possible to melt metal rods with a diameter of up to 10 mm for 20-30 seconds. After this time, the metal will turn red and will be ready for both forging and hardening of the upper layers.

The more turns the inductor has, the higher the frequency of the induction currents.

2.2 How to use the machine?

Using a do-it-yourself HDTV machine is quite simple.

1. We turn on the cooling system of the inverter.
2. Turn on the inverter itself.
3. Let's put the metal rod we need inside the inductor so that it does not touch the walls of the coil itself.
4. We wait 20-30 seconds until the metal turns red, and start working with it.

2.3 Homemade HDTV devices in everyday life

Quite simply and cheaply, you can make a home-made heating system or water heater. based on induction currents. To do this, it is enough to wrap the inductor around the pipe (the optimal number of turns is 90) and turn it on.

In this case, it is important to ensure that the inverter is not turned on if there is no liquid in the system or it is not circulating. Such an oversight can lead to the melting of the pipeline system itself.

Specifications

• The bottom plate is 600 mm above the floor, rigidly fixed to the press frame.
• Dimensions working area 2500x1200 mm
• Press opening 1500 mm
• Stroke of main hydraulic cylinders 1200 mm
• Two main top hydraulic cylinders 2x 80 tons each
• Max. Hydraulic system pressure 250 bar
• Pressure readings Manometer on the control panel of the press
• Closing speed of plates 1000 mm in 30 sec
• Low squeezing speed 10 mmv s
• Press opening speed 1000 mm in 30 sec
• Two side hydraulic cylinders 40 tons each
• Side cylinder closing and opening speed 1000 mm in 30 sec

To install the device for lateral compression (pressure) in height (5 positions) there is a series of holes on the racks of the press frame, located at a distance of 100 mm from each other.
The device for lateral pressure is fixed with the help of special fingers.
Stopping the upper plate in the upper position - with the help of a limit microswitch. (position adjustable)
Switching the high speed of closing the press to a low one - limit microswitch (adjustable position).

The press control unit is mounted on the press bed.
This control unit contains the following components:
2 buttons to turn high pressure on and off
When the top plate starts to move at low speed, the operator presses the "Start" button and the pressing cycle ends automatically.
Timer setting the time during which the press must be closed
Emergency stop block.

Obel- PHDTVGeneratorTypeOPA40 L

RF power - 40 kW
. Air cooling
. Frequency 13.56 MHz for industrial use
. Output type - Symmetrical
. Noise protection All devices capable of emitting microwaves are placed in the upper part of the generator and shielded with special protection.

Generator control unit

PLC control - Siemens PLC
. Fully automatic HF-Power control
. Ability to have several heating modes for parts of various shapes for complex parts.

Safety

In accordance with EU requirements. Ensuring safety - a fence around the press and the generator at a distance of 1000 mm. From the loading side, the fence is lighter and opens for feeding blanks.

Some BenefitsObel- PHF

Obel-P Generator and press manufactured by the Obel-P group in Denmark

• Over 60 years of experience in the production of generators and presses
• No RF interference from generator or press (interference with radio waves)
• Fixed frequency 13.56 MHz
• Symmetrical output for efficient RF energy distribution over the entire workpiece area.
• Fully automatic control of the RF generator (Siemens PLC)
• Automatic HF-Poser compensates for fluctuations in power consumption and maintains its maximum value during the entire exposure (drying) process
• Computer control for RF generator
• Ability to use multiple control programs for very heavy and difficult workpieces.
• Powerful press bed.
• High quality hydraulics, power pack and cylinders from Danish and German suppliers.
• Omron type microswitches