JPS59114782A - Member induction heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to electric heating devices, particularly devices for induction heating of items.

The invention may be used for induction heating of a wide range of parts with welds, for example using power supplied from several power sources.

Devices for regulating induction heating for surface hardening of parts are known in this field (USSR No. 168317 Inventor's Certificate).

See Classification C21D142) 0 The above device includes an automatically programmed temperature regulator inserted into a generator-like excitation circuit and uses temperature feedback. The device is used to adjust the hardening process. Its principle elements are an operating coil connected to a regulated high-frequency power source, a temperature and degree sensing element for detecting the temperature at a selected point with the heated member, and a setting element connected to a comparison unit of the regulator. , the output of the comparison unit is connected to a regulated high frequency power supply (generator) via an amplifier and an actuator.

Equipment for regulating the induction heating process is also known in the art (
USSR No. 541155 Inventor Certificate/Classification G05D23/2
(see 7). The above device includes a temperature sensing element connected to the first power of the automatic regulator and whose output is used as a high frequency power supply and coupled to the exciter of the control generator. The O output connected to an oscillator circuit consisting of a converter is connected to the second power of the automatic regulator through a converter. Consisting of a tuning element and an integrator, these are arranged in parallel, however,
If a certain heating effect is required, the working coils of said devices are arranged in close proximity to each other, in the processing of large parts (e.g. to heat several areas of a large part). The magnetic fluxes associated with the working coils interact, a drawback which essentially limits the field of use of the known device. When conditions change in a heated region, a corresponding change occurs in an adjacent region, and vice versa. This is generally a limiting factor. Furthermore, continuous oscillation is established in the power circuit of the device, operating the overvoltage protection circuit.

Other studies are on induction heating devices for tempering welding (see the well-known Ell) hiae booklet published in Belgium). the temperature sensing element connected to the thyristor exciter of the alternator. Two working coils with balanced capacitances whose capacitances are set before excitation is applied are connected to the output of the transformer.

The device includes a temperature regulator for each working coil.

An electrical mode transducer is connected to the input of each regulator to determine the temperature to be maintained by the regulator. Contains the equipment to be configured. Known device■
The disadvantage lies in the inability to provide uniform heating of the entire heating area of a given part, especially during partial heat treatment of large asymmetrical parts. The disadvantage of the above is that when the working coils are placed close to each other in the same member, the desired heating turn cannot be obtained in the working area of the opening working coil due to interference of the above device. This interference is intensified by the disturbance acting on each working coil, thereby establishing self-sustaining oscillation in the thermal mode control system.

The different glare of the pivot motor of the device power supply is a cause of self-sustaining oscillation of the ffjlj control system due to disturbances, which reduces the efficiency of the entire device. SUMMARY OF THE INVENTION An object of the present invention is to provide a component induction heating device that maintains a uniform nine-channel heat in all areas undergoing heat treatment.

Another object of the invention is to ensure partial heat treatment of large asymmetrical parts.

Another object of the invention is to increase the efficiency of the power supply used in the device.

Yet another object of the invention is to improve the heat treatment of welded joints of large parts.

Electrical mode, comprising at least two working coils, connected to independent power sources, each with a balanced capacity, one power connected to an individual input of a temperature regulator connected to a corresponding temperature sensing element In cooperation with the power supply, the temperature regulator consists of a unit for setting the ratio between the electric current transducer and the power of each power source according to the invention, and the first manual power of the unit (or through the corresponding signal converter) connected to the electric quadrature transducer of the power source, the other input being common to all working coils of the device and connected to the output of a temperature regulator having a device for setting the temperature maintained throughout the heated area of the component; and in which the output of the power regulator is coupled to a corresponding power source of a working coil.

Preferably, the power ratio regulator includes a power ratio setting circuit and a comparator circuit, each of which connects one input to a corresponding electric quadrature transducer and the other input to a corresponding output of a temperature sensor. Connected.

The invention will be described in detail on the basis of specific embodiments thereof and in conjunction with the accompanying drawings, in which: FIG.

The component induction heating device forming the essence of the invention comprises at least two single-acting coils and is designed for the partial heat treatment of highly asymmetrical components 1 (FIG. 1), for example with welds 2. Depending on the radius, wall thickness and shape of the member 1 to be heated, the device comprises three working coils 3, 4.5 (FIG. 1) or two working coils 3, 4 (FIG. 2).

According to the invention, the device comprises a power supply 6°7.8 (FIG. 1) for each working coil 3-5 with a balancing capacitance 9, 10.11 and a commutator, and a temperature sensing element 13, 14.

15 and electric mode transducer 16.17.

18, for example a current transducer connected to the input 19.20 of the temperature regulator 21.

Furthermore, according to the invention, the device includes an electric quadrature transducer for each power source 6, 8, a unit 25 for adjusting the ratio between the power sources,
It comprises an input 26 of said unit connected to said transducers 22-24 via a corresponding signal converter 27. The input 28 of the regulator 2-5 is connected to all working coils 3-3 of the device.
It is connected to the exit of the temperature regulator 21 that is common to the The output of the regulator 25 is connected to the power supplies 6-8 of the working coils 3-5. A temperature regulator designed according to known methods is the only device for setting the temperature maintained in the heating area of the section 1.
It is only a cylinder.

FIG. 2 now shows a more detailed embodiment of the device with an operating coil 3.4. Here, power ratio regulator 2
5 is composed of comparison elements 30, 31, corresponding electroquadratic transducers 22, 23, and inputs of each element connected to the output of temperature regulator 21. The outputs of the comparison elements 30, 31 are connected to the power supply 6°7, and the elements 30, 31, like the operating coil 34, are connected to each other via a common control line 33 and a power ratio setting circuit cooperating with the variable resistor 32. There is.

The device forming the essence of the invention operates as follows.

The computing unit operates the device 2 in order to obtain the desired state when heating the member 1.
9 is driven, and the control line 3°3 of the resistor 32 is set at a position where the power ratio of each operating coil 3, 4 is optimized. The distribution of the axial temperature T over a given time length L must conform to the distribution as shown in FIG.

After the device has been activated, the temperature regulator 21 controls the regulated power supplies 6, 7 of the working coil 3.4 via the regulator 25. The component 1 is now heated in a predetermined manner.

Temperature deviations in the heating region are detected by temperature detection elements 13.14 which provide signals corresponding to the two-power input 19 of the temperature regulator 21.
detected by. The temperature regulator 21 compares the current temperature value with a set value based on the signal received from the setting device 29 . If the temperature setting signal is greater or less than the current temperature at which the component 1 is heated, the temperature regulator 21 generates an output control voltage for the corresponding 1B source 6,7. Said control device influences the power supply i via the regulator 25. Adjuster 2
5 redistributes the output control voltage of the temperature regulator 21 through the resistor 32 according to the power ratio set by the comparator 30, 31 and the lead wire 33.

In this way, a predetermined temperature T (FIG. 3) is maintained in each heating zone. The feature of such control is that it eliminates the following disadvantages of prior art induction heating devices for parts and also ensures a uniform temperature range over the entire heating area of the part. Moreover, complex temperature range patterns can be obtained by setting different power ratios for each working coil using control lines 33 of resistors 32.

Transducers 16 , 17 which detect the electrical parameters of the working coils 3 , 4 supply commands to the inputs of the temperature regulator 21 and dictate the currents of the working coils 3 , 4 . If the permissible current value is exceeded, the transducer provides a command to disconnect the working coil from the power supply 6,7.

When various disturbances act on the working coil 3, for example, the electroquadratic transducer 22 detects the disturbance and the transducer 27
A command is given to the regulator 25 via. This command is input 2
6 to the comparison element 30 and from there the resistor 3
2 and proportionally affects the second comparison element 31 through 2. As a result, the rA condenser 25 output generates a control voltage that affects the power supplies 6, 7, thereby eliminating disturbances.゛The above disturbance occurs between operating coil 3 and operating coil 4 (in the latter case,
(depending on the position of the control line 33 of the resistor 32). Such a method of removing existing disturbances is
This makes it possible to eliminate self-sustaining oscillations in the heating process control of the member 1.

The present invention has the advantage of allowing a method to automatically adjust the induction heating mode according to the outputs of frequency converters with different characteristics, thereby increasing efficiency. Furthermore, the general feature is the elimination of self-sustaining oscillations associated with heat treatment and various disturbances, which ensures a more uniform heating of the corresponding areas of the component undergoing heat treatment, thereby improving the automatic control of the heating process. There is an O

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an apparatus for induction heating of a bullet according to the invention FIG. 2 is a block diagram of an apparatus including two working coils FIG. 3 is a diagram showing the heating temperature along the length of a bullet according to the invention Show change. 1... Member, 2... Welded part, 3, 4.5...
Operating coil, 6,7.8...-Power supply, 9,10.1
1... Balance capacity, 12... Commutator, 13, 14
．． 15... Temperature detection element, 16, 17, 18...
Electric mode transducer, 19.20... Regulator input, 21... Temperature regulator, 22.23,
24...Electric force transducer, 25...Power ratio regulator, 26...Input of unit 25, 27...
Signal converter, 28... input of unit 25, 29.
...Temperature setting device, 30.31...Comparison element, 32.
... Variable resistor, 33... Control line of resistor 32, 34.
...Operating coil. Patent applicant agent Patent attorney Fumi Sato (and 1 other person) EEE, 7 EEE, , 5 E2

Claims (1)

[Claims] 1. At least two operating coils (3 to 5);
Each of these has a balanced capacitance (9-11), is connected to an independent power supply (6-8), and is connected to an electrical mode transducer (
16 to 18), and one person is connected to the individual inputs of the temperature regulator (21) connected to the corresponding temperature detection element (13 to 15).
A unit (25) for setting the ratio between the electric quadrature transducer (25) of ~8) and the power supply, and the first human power (26) of the unit is connected via a corresponding signal converter (27). Power supply (6 to 8) electric quadrature transducer (22 to 8)
24), whose individual input (28) is common to all the coils (3-5) of the device, and which has a device (29) for maintaining the heating area of the component at a set temperature. (2
1) and characterized in that the output of the power ratio regulator (25) is coupled to the corresponding power source (6-8) of the working coil (3-5). 2. In the device number recited in the first claim, the power ratio F, 11 rectifier (25) includes a power ratio setting circuit and comparison elements (30, 31), each of which has a corresponding one of which is connected via one input to the electric quadrature transducer (22, 23), the other input is connected to the corresponding output of the temperature regulator (21), and the said element (ao, 31)
) are interconnected via a power ratio setting circuit cooperating with a variable resistor (32) having a common control shaft (33).