JP7357357B2 - induction heating welding equipment - Google Patents

Description

The present invention relates to an induction heating welding device that welds a sheet to a fixing member by induction heating the fixing member covered with the sheet. The fixing member is made of a conductive material and has a heat-welding layer on its surface.

For example, Patent Document 1 discloses an induction coil unit including a heating coil unit having a pressing surface facing the object to be welded, and a power supply control device that supplies current to the heating coil housed in the heating coil unit via a cable. A heat welding device is disclosed. In adhesively fixing a waterproof sheet using this induction heating welding device, the heating coil is excited while the pressing surface of the heating coil unit is brought into contact with the portion of the waterproof sheet that is above the fixing member. The fixing member is heated by induction heating by the heating coil, and the waterproof sheet and the fixing member are welded together.

JP2018-200847A

In a sheet welding operation using an induction heating welding apparatus such as that disclosed in Patent Document 1, an operator moves a power supply control device near a fixed member, and positions a heating coil unit on the fixed member from above the sheet. have to match. Since several fixing members are provided for each square meter of sheet area, installing the sheet on the roof of a large building places a heavy physical and mental burden on the worker. The burden becomes even greater when working under the scorching sun or cold. In order to reduce this burden, a large number of induction heating welding devices and a large number of workers are required. However, when a plurality of induction heating welding devices operate simultaneously, the power consumption increases, but it is difficult to secure such power at a site such as a rooftop.

Therefore, there is a need for an induction heating welding device that can reduce the burden on workers at large sheet laying sites.

The induction heating welding device according to the present invention is a device that welds the sheet to the fixing member by induction heating the fixing member covered with the sheet, and includes a plurality of heating coils for induction heating the fixing member. a coil unit, a power supply unit that supplies heating power to the heating coil, a time division control unit that supplies power from the power supply unit to each of the heating coils of the plurality of heating coil units in a time division manner; A control unit that controls a power supply unit and the time division control section is provided.

In this configuration, since time-divided power supply is performed, the power supply unit can supply heating power to a plurality of heating coils without increasing power consumption. If the operator positions the pressing surface of each heating coil unit on the seat so that it is above the fixed member and starts time-divided power supply to each heating coil, multiple fixed members can be heated substantially at the same time. can do. As a result, the sheet and the fixing member can be welded at multiple locations. This is a great advantage in sheet installation sites, such as rooftops, where it is difficult to secure a power source with sufficient capacity and the area is large.

Even if the heating time by the heating coil is too short or too long, an appropriate welded state cannot be obtained. Therefore, in order to obtain an appropriate welding state, it is necessary to supply electricity so that a current of a preset strength is passed through the heating coil for a preset time. However, even if the same heating power is supplied to the heating coil, the temperature at the fixed member varies depending on the state of the fixed member and the sheet, the environmental temperature, the pressing state of the heating coil unit against the sheet, and the like. This problem can be solved by estimating the temperature state of the fixing member heated by the heating coil from the temperature around the fixing member, and controlling the power supply to obtain an appropriate welding state based on this estimated temperature. It is solvable. Therefore, in one of the preferred embodiments of the present invention, a temperature sensor that detects the temperature around the fixing member heated by the heating coil is provided corresponding to the heating coil, and the control unit: Based on the detection result by the temperature sensor, a heating end timing for each of the heating coils is determined.

When the temperature states of the fixed members heated by the heating coils are different, it is necessary to adjust the amount of heating power supplied for each heating coil. In the present invention, since the supply of heating power is time-division controlled, the amount of heating power supplied to each heating coil can be adjusted by changing the time-division pattern for the heating coils. For example, such adjustment is not a time-sharing pattern in which heating power is supplied to heating coils the same number of times in a fixed time interval, but a pattern in which the number of times heating power is supplied to a specific heating coil is increased or decreased. This becomes possible by adopting a division pattern. Therefore, in one of the preferred embodiments of the present invention, a temperature sensor that detects the temperature around the fixing member heated by the heating coil is provided corresponding to the heating coil, and the control unit is configured to By changing the time division pattern in the time division control section based on the detection result by the temperature sensor, the heating time of each of the heating coils can be adjusted.

Of course, heating power supply control using the two temperature sensors described above, that is, determining the heating end timing based on the detection results by the temperature sensors and changing the time division pattern based on the detection results by the temperature sensors, can be performed simultaneously. May be done.

The heating power required to achieve proper welding varies depending on the environmental temperature differences between regions such as Hokkaido and Okinawa, or even within the same region between winter and summer, or between morning and afternoon. different. Adjustment of heating power due to differences in environmental temperature is common to all heating coils, so it is done by changing the basic power (current intensity and frequency before time-sharing control) in the power supply unit. It is preferable. Such basic power changes are advantageously carried out by manual or automatic selection of preset heating modes. For this reason, one of the preferred embodiments of the present invention is provided with a mode selection switch that selects a heating mode, and the control unit selects the heating mode from the power supply unit based on the selection result of the mode selection switch. Adjust the basic power supplied to the heating coil.

Even if the power supply unit is only placed in one place, it is a cumbersome task for the operator to individually place a plurality of heating coil units on their assigned fixing members. For this reason, one of the preferred embodiments of the present invention is provided with a holding device that connects a plurality of the heating coil units and individually arranges the heating coil units on the fixing member with the sheet in between. ing. The fixing members are generally arranged at equal intervals, so if the holding device holds a plurality of heating coil units in accordance with the arrangement pattern of the fixing members, the arrangement of all the heating coil units can be adjusted. It can be done all at once.

If the holding device fixes a plurality of heating coil units with prescribed dimensions, it is impossible to deal with installation errors of the fixing members. This problem is solved if the position of each heating coil unit in the holding device is adjustable. Therefore, in one of the preferred embodiments of the present invention, the holding device includes a connection frame that connects a plurality of housings that individually house the heating coils at predetermined intervals, and a positional relationship between the connection frame and the housing. Equipped with an adjustment mechanism for fine-tuning. With this configuration, even if an error occurs in the installation position of a specific fixing member, the heating coil unit is adjusted to an appropriate position by the adjustment mechanism.

It is a perspective view showing the relationship between an induction heating welding device, a waterproof sheet, and a fixing member. It is a longitudinal cross-sectional view of a heating coil unit. FIG. 3 is a functional block diagram of a time-division heating control system. It is a time chart figure of time division heating control.

Embodiments of the present invention will be described below based on the drawings. FIG. 1 shows an induction heating welding device IH that welds a sheet such as a waterproof sheet SH covering the fixing member FX to the fixing member FX by induction heating the conductive fixing member FX having a heat-welding layer on the surface. It is shown. FIG. 1 shows a work in which a waterproof sheet SH is welded to a conductive fixing member FX that is fixed to a concrete waterproof base on a rooftop or the like using an anchor or the like. Furthermore, the fixing member FX is a circular conductor, and is made of, for example, a steel plate. A planar hot melt adhesive layer made of a thermoplastic synthetic resin such as polyester resin is formed on the upper surface of the fixing member FX as a heat welding layer for the waterproof sheet SH.

This induction heating welding apparatus IH includes a plurality of (four in FIG. 1, but it may be more or less than four) heating coil units 2 and a heating welding management device 1. The heat welding management device 1 has a function of supplying power to a plurality of induction heat welding devices IH and managing a heat welding operation using the heating coil unit 2. The plurality of heating coil units 2 are connected by the holding device HD at equal intervals so as to match the installation pitch of the fixing member FX, and the plurality of heating coil units 2 are moved at once using the holding device HD. Ru. The heat welding management device 1 and each heating coil unit 2 are connected by a connection cable CA including a power line and a control line. The heating coil unit 2 houses a heating coil 6 that inductively heats the fixing member FX.

The heat welding management device 1 includes a control unit 10, a power supply unit 11, a time division control section 12, a data logger unit 13, an environmental temperature sensor 14, an operation panel 15, a display panel 16, a GNSS unit 17, and the like. The control unit 10 is connected to an environmental temperature sensor 14, an operation panel 15, and a display panel 16, and controls and manages various components.

The power supply unit 11 supplies heating power (basic power) to the heating coil 6 using a commercial power source or a private power generator as an input. The time division control unit 12 time divisions the power sent from the power supply unit 11 and sequentially supplies it to each heating coil 6 of the plurality of heating coil units 2 .

The GNSS unit 17 calculates the position coordinates of the heat welding location using a satellite positioning system. Since the position coordinates thus calculated are the positions of antennas (not shown), only the antennas are provided in each heating coil unit 2. Of course, since the positions of other heating coil units 2 can be estimated from the positions of one or two heating coil units 2, it is not necessary to provide antennas to all heating coil units 2. Furthermore, the antenna may be provided only in the heat welding management device 1.

The data logger unit 13 stores data on the heat welding work performed there (environmental temperature, work date and time, heating intensity, heating time, positional deviation of heat welding, temperature of the heating target location, etc.) along with the positional coordinates of the heat welding work location. Record. The environmental temperature sensor 14 detects the temperature of the surrounding area where the heat welding management device 1 is placed. On the operation panel 15, a group of various operation switches (including not only switches but also buttons, levers, etc.) 15a and various notification lamps 15b are arranged. The display panel 16 is a liquid crystal display for visually informing the operator of information.

In this embodiment, the fixing members FX are provided at a large number of fixing locations at a predetermined arrangement pitch. The holding device HD has a connecting frame 80 that is a long frame. Each heating coil unit 2 is mounted on the connection frame 80 via mounting brackets 81 at predetermined intervals that match the arrangement pitch of the fixing members FX. The worker carries the heating coil units 2 using the connection frame 80 and places all the heating coil units 2 on the fixing member FX with the waterproof sheet SH in between. The heating coil unit 2 presses down the upper surface of the fixing member FX with the waterproof sheet SH interposed therebetween due to the weight of the holding device HD. In this state, the heating coil 6 is excited to heat the fixing member FX, and the waterproof sheet SH is welded to the fixing member FX.

As shown in FIG. 2, the heating coil unit 2 includes a heating coil 6, a coil drive section 61, a positional deviation detection coil 63, and a housing 20. The housing 20 includes a cylindrical body part 21, an upper end part 22 connected to the upper end of the body part 21, and a lower end part 23 connected to the lower end of the body part 21. A connection cable CA is connected to the side wall of the body section 21.

The heating coil 6 is a thin, flat coil wound, and is housed in the bottom recess 23a of the lower end portion 23. Four misalignment detection coils 63 are arranged below the heating coil 6 and are distributed at a circumferential angle of 90 degrees.Furthermore, on the lower surface of the misalignment detection coil 63, there is a silicone film that functions as a pressing surface for the heating coil unit 2. A rubber pressure pad 24 is arranged.

The coil drive unit 61 causes current to flow through the heating coil 6 at a predetermined timing. The positional deviation calculation unit 62 uses detection signals from the four positional deviation detection coils 63 to determine whether the center of the heating coil unit 2 and the center of the fixed member FX match, that is, the fixed member FX of the heating coil 6. Calculate the degree of deviation with respect to . The determination result (positional deviation direction) by the positional deviation calculation unit 62 is sent to the control unit 10 of the heat welding management apparatus 1 via the connection cable CA. The control unit 10 displays the received determination result on the display panel 16. Furthermore, the determination result by the positional deviation calculating section 62 can be displayed through a display device (not shown) provided in the heating coil unit 2.

As shown in FIG. 2, the upper end 22 of the housing 20 is provided with a mounting bracket 81 for attaching the heating coil unit 2 to the connection frame 80. This mounting bracket 81 incorporates an adjustment mechanism that finely adjusts the horizontal positional relationship between the connection frame 80 and the housing 20, and a biasing mechanism that biases the housing 20 downward. The adjustment mechanism includes a feed screw mechanism and the like, and the biasing mechanism includes a spring-loaded slide mechanism and the like. The adjustment mechanism is manually adjusted using an adjustment screw or the like. Of course, the adjustment mechanism may be configured to be automatically adjusted by driving an actuator or the like based on the direction and amount of positional deviation calculated by the positional deviation calculating section 62.

Furthermore, this heating coil unit 2 includes a non-contact type temperature sensor 7 (for example, infrared type) that detects the surface temperature of the waterproof sheet SH, and a temperature sensor 7 that calculates the surface temperature based on the detection signal of this temperature sensor 7. A measuring circuit 70 is also provided. The temperature sensor 7 and the temperature measurement circuit 70 need to be placed as far away from the heating coil 6 as possible so as to avoid signal interference due to the excitation of the heating coil 6 as much as possible. Therefore, the infrared passage path formed between the temperature sensor 7 and the waterproof sheet SH becomes long. In order to ensure this infrared passage, a first through hole 23b is provided in the lower end portion 23 of the housing 20, and a second through hole 23c is provided in the press pad 24. Furthermore, the heating coil 6 is divided into an inner coil part and an outer coil part, and the interval between the outermost winding of the inner coil part and the innermost winding of the outer coil part is widened, so that the inner coil A gap is formed between the outer coil section and the outer coil section. With this structure, an infrared passage of the temperature sensor 7 is created by the first through hole 23b, the gap between the heating coil 6, and the second through hole 23c. The surface temperature data measured by the temperature measurement circuit 70 is sent to the control unit 10 of the heat welding management device 1 via the connection cable CA.

As shown in FIG. 2, a cylindrical skirt body 26 that functions as a downward guide for the waterproof sheet SH of the housing 20 is fitted into the lower end portion 23 of the housing 20. The cylindrical skirt body 26 is vertically slidable and biased downward by a spring.

FIG. 3 shows a functional block diagram of a control system used to time-divisionally excite the plurality of heating coils 6. Each heating coil 6 is connected to a power line from a power supply unit 11 via a coil drive section 61. The coil drive unit 61 functions as an inverter circuit and includes a switching element 611 and a resonant capacitor 612. The switching element 611 is a power MOSFET, IGBT, or the like, and a diode 613 is connected thereto.

The time division control unit 12 switches the heating power supplied to each heating coil 6 via the coil drive unit 61 in time series. The time division control unit 12 has a gate driver 12a assigned to each heating coil 6, and each gate driver 12a sends a gate pulse signal to the switching element 611 of each coil drive unit 61. This gate pulse signal is generated based on a control signal from the control unit 10.

The power source of the heating power supplied to the heating coil 6 is supplied from the power supply unit 11. This power supply unit 11 has a rectifier circuit 11a and a voltage control circuit 11b. Electric power supplied from a commercial power source to the power supply unit 11 is rectified by a rectifier circuit 11a, and voltage-controlled by a voltage control circuit 11b. The output voltage by the voltage control circuit 11b can be controlled by the control unit 10.

FIG. 4 shows an example of a time-division time chart in induction heating welding using three heating coil units 2 (denoted as coil A, coil B, and coil C in FIG. 4). In this embodiment, as the basic power (current intensity and frequency before time-sharing control) from the power supply unit 11, two heating modes differing in current intensity and/or frequency, namely mode A output power and mode B output power is available. Selection of these heating modes is performed by a manually operated mode selection switch (included in the operation switch group 15a). The mode A output power shown in FIG. 4 indicates the output power output from the power supply unit 11 when heating mode A is selected by the mode selection switch. Mode B output power indicates the output power output from the power supply unit 11 when heating mode B is selected by the mode selection switch. That is, output power with different voltages and frequencies is output from the power supply unit 11 based on the selection result by the mode selection switch.

The selection of the heating mode is based on the temperature information input through the operation panel 15 based on the thickness of the waterproof sheet SH, the environmental temperature detected by the environmental temperature sensor 14, and the position information and date and time information calculated by the GNSS unit 17. It is also possible to perform this automatically based on (temperature information specified by region or season).

Time division pattern A and time division pattern B in FIG. 4 are examples of time division patterns that are automatically selected by the control unit 10 or by a time division pattern selection switch (included in the operation switch group 15a). ing. The time division pattern A and the time division pattern B have different gate pulse widths (time widths indicated by W1 and W2 in FIG. 4). Here, in both time division pattern A and time division pattern B, the gate pulse given to coil A, coil B, and coil C is common, so if the time division pattern is the same, coil A , coil B, and coil C are each excited with the same time width. Of course, it is also possible to select a time division pattern in which the width of the gate pulse differs for each heating coil 6. In the time division pattern shown in FIG. 4, gate pulses are given equally to coil A, coil B, and coil C in the order ABC, ABC, etc. . Alternatively, a configuration may be adopted in which gate pulses are applied to each coil in an unequal order such as different permutation combinations, for example, A-B-A-C-A-B-A-C... .

The time division pattern in the time division control unit 12 can be changed, that is, the heating time of each heating coil 6 can be adjusted based on the detection result by the temperature sensor 7.

As shown in the example of FIG. 4, when gate pulses are applied to the switching elements 611 of each heating coil 6 without duplication, the output power output from the power supply unit 11 increases as the number of heating coils 6 increases. is also constant. Even if induction heating welding is performed using the holding device HD that incorporates multiple heating coil units 2, the amount of electricity used per hour is limited, and it can be used even on sites such as rooftops where power supply is limited. , can be used with confidence.

In this embodiment, the supply of heating power to each heating coil 6 is stopped based on the surface temperature data of the waterproof sheet SH measured by the temperature measurement circuit 70, that is, the measurement result of the temperature sensor 7. That is, the timing at which heating of the heating coil 6 ends is determined by the control unit 10 based on the surface temperature data sent from the temperature measurement circuit 70. For example, control is possible such that the supply of heating power to the heating coil 6 is stopped after a predetermined time has elapsed after the surface temperature reached a predetermined value.

The surface temperature data measured by the temperature measurement circuit 70 can also be used to change the time division pattern in the time division control unit 12. For example, if it is determined based on the surface temperature data that heating by a particular heating coil 6 is insufficient, the width of the gate pulse applied to the switching element 611 of the heating coil 6 may be increased, or the width of the gate pulse may be increased. A time division pattern is generated that repeats more times than others.

When the induction heating welding work is completed, work data consisting of the excitation time of each heating coil 6, measurement result data of the temperature measurement circuit 70, measurement value of the environmental temperature sensor 14, positioning data from the GNSS unit 17, etc. is stored in the data logger unit 13. sent to. The data logger unit 13 records the received work data in a memory in a predetermined format for each induction heating welding point.

[Another embodiment]
(1) In the embodiment described above, the sheet welded to the fixing member FX is the waterproof sheet SH, but other sheets may be used.

(2) In the embodiment described above, a plurality of heating coil units 2 are assembled and held in the holding device HD, and all the heating coil units 2 are simultaneously transported to the next induction heating welding point. Alternatively, each heating coil unit 2 may be connected only to the connection cable CA and individually transported to the next induction heating welding point.

(3) In the embodiment described above, among the functional blocks shown in FIG. Although these functional blocks were housed in the heating coil unit 2, these functional blocks can be arbitrarily combined and housed.

(4) As described above, the adjustment mechanism that finely adjusts the horizontal positional relationship between the connecting frame 80 and the housing 20 is operated manually based on the positional deviation direction and positional deviation amount calculated by the positional deviation calculation unit 62. or operated automatically. However, the direction and amount of positional deviation may be determined visually, and the adjustment mechanism may be manually operated based on the determination result.

Note that the configurations disclosed in the above embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in other embodiments as long as there is no contradiction, and The embodiments disclosed in this specification are illustrative, and the embodiments of the present invention are not limited thereto, and can be modified as appropriate without departing from the purpose of the present invention.

INDUSTRIAL APPLICATION This invention is applicable to the induction heating welding apparatus which welds the welding object by induction heating the welding object.

1: Heat welding management device 2: Heating coil unit 6: Heating coil 7: Temperature sensor 10: Control unit 11: Power supply unit 11a: Rectifier circuit 11b: Voltage control circuit 12: Time division control unit 12a: Gate driver 15a: Operation switch Group (mode selection switch)
61: Coil drive unit 70: Temperature measurement circuit 80: Connection frame 81: Mounting bracket 611: Switching element 612: Resonant capacitor 613: Capacitor CA: Connection cable FX: Fixing member HD: Holding device IH: Induction heating welding device

Claims (6)

An induction heating welding device that welds the sheet to the fixing member by induction heating the fixing member covered with the sheet,
a plurality of heating coil units having heating coils that inductively heat the plurality of fixing members;
a power supply unit that supplies heating power to the heating coil;
a time-sharing control unit that supplies power from the power supply unit to each of the heating coils of the plurality of heating coil units in a time-sharing manner;
a control unit that controls the power supply unit and the time division control section;
An induction heating welding device equipped with. A temperature sensor for detecting the temperature around the fixed member heated by the heating coil is provided corresponding to the heating coil, and the control unit controls the temperature of each of the heating coils based on the detection result by the temperature sensor. The induction heating welding apparatus according to claim 1, wherein the heating end timing is determined. A temperature sensor that detects the temperature around the fixed member heated by the heating coil is provided corresponding to the heating coil, and the control unit controls the time division control unit based on the detection result by the temperature sensor. The induction heating welding apparatus according to claim 1 or 2, wherein the heating time of each of the heating coils is adjusted by changing a time division pattern. 4. A mode selection switch for selecting a heating mode is provided, and the control unit adjusts the power supplied from the power supply unit to the heating coil based on the selection result of the mode selection switch. The induction heating welding device according to any one of the above. 5. The heating coil unit according to claim 1, further comprising a holding device that connects a plurality of the heating coil units and individually arranges the heating coil units on the fixing member with the sheet in between. Induction heating welding equipment. According to claim 5, the holding device includes a connecting frame that connects a plurality of housings that individually house the heating coils at predetermined intervals, and an adjustment mechanism that finely adjusts the positional relationship between the connecting frame and the housing. The induction heating welding device described.

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