JP2008068488A - Heat caulking apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat caulking apparatus with good workability and high reliability. <P>SOLUTION: The heat caulking apparatus performs heat caulking of a molded article using a thermoplastic resin with a boss integrally molded by supplying an electric current to a heater chip connected to the secondary side of a transformer and a body to be connected with a fitting hole to be fitted to the boss. The heat caulking apparatus in which the boss is pressed by the heater chip and after heating/molding, a cooling means for the boss exists, comprises a temperature detecting means arranged on the heater chip and for detecting the temperature of the boss after molding, a comparing means for comparing the temperature of the boss after molding detected by this temperature-detecting means with a preset solidification temperature inherent to the thermoplastic resin, and an informing means for informing that the temperature of the boss after molding reaches the solidification temperature when this is detected by the comparing means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention has a molded article using a thermoplastic resin having a boss integrally formed by supplying current to a heater chip connected to the secondary side of the transformer, and a fitting hole for fitting with the boss. In particular, the present invention relates to a cooling control technique by detecting the temperature of a boss after molding.

2. Description of the Related Art Conventionally, a heat caulking device for fixing a part made of a heat deformable material such as a thermoplastic resin to another part by heat caulking is known.
As a fixing method using a heat caulking device, after positioning a welding boss projecting from one side of a thermoplastic resin component in a mounting hole of another component such as a metal, the welding boss is inserted into the mounting hole and then inserted. The tip is protruded to the other side, and a crimping pin (having a function equivalent to a heater chip) that has been heated to a predetermined temperature (a temperature at which the welding boss is thermally deformed) in advance is pressed against the tip. The tip is fixed by being thermally deformed to a diameter larger than the diameter of the mounting hole.
Then, the caulking pin is separated from the tip of the welding boss after the caulking pin is cooled and lowered below a predetermined temperature (for example, Patent Document 1).
Japanese Patent Laid-Open No. 4-191034

In this cooling method, whether or not the temperature has become a predetermined temperature or less is determined by an operator by looking at a thermometer, or the thermoplastic resin used is solidified after a lapse of a certain time after the heating of the caulking pin is completed. I was watching. Such a method in which an operator makes a judgment by looking at a thermometer is not only complicated because the operator has to read an indication value of the thermometer, and there is a possibility of misreading, which causes a problem in workability. On the other hand, in the method that is considered to have solidified after a certain period of time, the thermoplastic resin may not be completely solidified. In this case, the thermoplastic resin may cause stringing on the caulking pin, or the thermoplastic resin may solidify. There was a problem in the quality of heat caulking because the caulking pin and the welding boss were fixed too much.
The present invention has been made to solve the above-described problems, and has an object to provide a heat staking device with good workability and high quality of heat staking by enabling a predetermined temperature to be reliably detected. And

The heat caulking device according to the present invention is fitted with a molded product using a thermoplastic resin having a boss integrally formed by supplying current to a heater chip connected to the secondary side of the transformer, and the boss. A heat staking device for heat staking a bonded body having a fitting hole, wherein the boss is pressed by the heater chip, and after heating and molding, the boss is provided with a cooling means for the boss. Temperature detecting means for detecting the temperature of the boss after molding provided, and means for comparing the temperature of the boss after molding detected by the temperature detecting means with a preset solidification temperature of the thermoplastic resin. And a notifying means for notifying that when the comparison means detects that the temperature of the boss after molding has reached the solidification temperature.

The heat staking device according to the present invention is characterized in that the cooling to the boss after molding is stopped based on the detection result, and the pressing to the boss by the heater chip is released. It is characterized by.

The heat staking device according to the present invention includes a molded product using a thermoplastic resin having a boss integrally formed by supplying current to a heater chip connected to the secondary side of the transformer, and the boss and the fitting. A heat caulking device for caulking a to-be-coupled body having a mating fitting hole, wherein the boss is pressed by the heater chip, and after heating and forming, a heat caulking device having a cooling means for the boss. A synchronization signal generator that detects a zero-cross point from the current and generates a synchronization signal based on the zero-cross point, and a current supplied to the primary side of the transformer by increasing or decreasing the input AC current based on the gate signal A phase control unit to control, an amplifying unit for detecting a voltage corresponding to the temperature of the heater chip with a thermocouple attached to the heater chip, and amplifying the voltage at a predetermined amplification degree; A parameter setting unit for setting parameters including temperature, pressing force and time to the boss through the heater chip, a solidification temperature specific to the thermoplastic resin, and cooling conditions after molding the boss, and from the parameter setting unit Calculating a target voltage based on temperature information based on the same correspondence relationship between the temperature and the voltage in the amplifying unit; calculating a difference between the detected voltage from the amplifying unit and the target voltage; separately provided heat caulking When a heat caulking start signal is received by the starting means, the heater chip is lowered toward the boss, and when it is detected that the heater chip is in contact with the boss, the boss is pressed with a set pressing force. However, the phase control amount is calculated according to the difference based on the synchronization signal from the synchronization signal generation unit, and the gate is based on the phase control amount. The current flowing through the heater chip is controlled by the gate signal; the current to the heater chip is stopped after a set time, and the boss after molding is cooled under the set cooling conditions. Comparing the detected voltage from the amplifying unit with the corresponding solidification temperature of the set thermoplastic resin and detecting that the detected temperature is lower than or equal to the solidification temperature; A controller that stops cooling the boss after molding and releases the pressing force of the heater chip on the boss after molding. The thermal staking device is characterized in that the calculation of the phase control amount is executed by PID control.

According to the present invention, when the solidification temperature specific to the thermoplastic resin to be heat squeezed is set as a parameter in the heat staking device, the temperature of the boss after molding is measured, and when this temperature reaches the set solidification temperature Therefore, the operator can surely know that the boss after molding has solidified. Therefore, cooling can be stopped by this notification,
In addition, since the heater chips can be separated, a heat caulking device with good workability and high heat caulking quality can be provided.

Next, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a heat caulking apparatus showing the best mode for carrying out the present invention, FIG. 2 is a schematic block diagram of the heat caulking apparatus, and FIG. 3 is a schematic operation flowchart of the heat caulking apparatus. These are figures which show the temperature profile at the time of operation | movement of this heat crimping apparatus.

In FIG. 1, reference numeral 21 denotes a welding power source that supplies a current for heat caulking, 22 denotes a welding transformer that receives a current from the welding power source 21 and steps down to convert it into a large current, and 23 denotes a welding power source from the welding transformer 22. This is a welding head that causes an electric current to flow through a heater chip 23a (corresponding to a heat-caulking pin of a conventional example) disposed at the tip of the object to heat-cause an object. Note that the welding transformer 22 has a built-in blower for cooling the object after heat caulking. And heater chip 23
A is provided with a thermocouple 23aa and a cooling port (not shown) for the heat-caulked object after molding by heat caulking as a temperature detector for the object to be heat-caulked. The welding head 23 is provided with a welding start operation unit 23b and a cooling stop operation unit 23c.

Reference numeral 24 denotes a power line for supplying current from the welding power source 21 to the welding transformer 22, a ventilation hose for cooling air from the blower, a signal line from the thermocouple 23aa, a welding start operation unit 23b, and a cooling stop operation unit 23c. 25 is a power line for supplying current from the welding transformer 22 to the welding head 23, a ventilation hose for cooling air from the blower, and a thermocouple 23a.
A signal line from a, a signal line from the welding start operation unit 23b and the cooling stop operation unit 23c.

In FIG. 2, reference numeral 1 denotes a transformer 1 by increasing or decreasing the input AC current based on the gate signal.
Phase control unit for controlling the current supplied to the next side, 2 (22 in FIG. 1) is a welding transformer for converting the input AC current into a low voltage and a large current, 3 (23a in FIG. 1) is heated and pressed Thus, a heater chip that heats the object to heat, 4 (23aa in FIG. 1) is a thermocouple that detects a voltage corresponding to the temperature of the heater chip 3, and 5 is an output voltage of the thermocouple 4 with a predetermined amplification degree. The amplifying unit mainly includes a differential amplifier to be amplified.

Also, 6 is a parameter setting unit for setting a temperature and time as parameters for setting a temperature profile as an input means provided separately, and a solidification temperature unique to the thermoplastic resin to be heat caulked, and 7 is a parameter. In response to the temperature and time from the setting unit 6, a target temperature profile generation unit that generates a target temperature profile defined as a target voltage by the same correspondence as the correspondence between the temperature and voltage in the amplification unit 5, and 8 from the amplification unit 5 Receiving the detected voltage amplified according to the temperature of the heater chip 3 and the amplified target voltage from the target temperature profile generator 7 and calculating the difference and using the manipulated variable for generating the phase control signal Is a PID control unit that calculates and outputs.

Reference numeral 9 indicates a zero cross point from the input AC current, and generates a synchronization signal with the zero cross point as a reference. Reference numeral 10 indicates a synchronization signal from the synchronization signal generation unit 9 and an operation from the PID control unit 8. This is a phase control signal generation unit that receives the amount and generates a gate signal based on this operation amount with reference to the synchronization signal from the synchronization signal generation unit 9 as a phase control signal.

Reference numeral 12 denotes a detected voltage amplified according to the temperature of the heater chip 3 from the amplifying unit 5, a temperature rise time t 1 from the target temperature profile generating unit 7, a holding time t 2, and a resin coagulation from the parameter setting unit 6. Upon receiving the temperature, the target voltage is obtained by the same correspondence as the correspondence between the temperature and the voltage in the amplifying unit 5, and the detected voltage is compared with the target voltage after the temperature rise time t1 and the holding time t2, and the heat caulking target object is compared. A comparison unit for detecting that the temperature has reached a set solidification temperature; 13 is a notification unit for receiving solidification temperature arrival detection from the comparison unit 12 and informing the solidification of the thermoplastic resin by a buzzer sound; Cooling composed of a blower or the like that starts sending cooling air to the heat caulking object after elapse of the rising temperature t1 and the holding time, and stops sending cooling air by a cooling stop signal after confirming the notification. It is.
The start signal is a signal for starting the heat caulking operation and is generated when the welding start operation unit 23b is operated. The cooling stop signal is a signal for stopping the blower and stopping the cooling, and the cooling stop operation unit. It is generated when 23c is operated.

Next, the operation of such a heat caulking device will be described. At this time, the schematic operation flowchart shown in FIG. 3 and the temperature profile diagram during operation of the heat caulking device shown in FIG.

[Operation before heat staking operation]
Since the start signal is generated by the operation of the welding start operation unit 23b and the heat caulking is started, the gate signal output from the phase control signal generation unit 10 is turned off in all periods. Since the phase control unit 1 is not turned on, an alternating current does not flow on the primary side of the transformer 2 even if the input alternating current power source is connected to the heat caulking device. Therefore, since no alternating current is generated on the secondary side of the transformer 2, no current flows to the heater chip 3, so that the heater chip 3 does not generate heat.

[Parameter settings]
Before starting the heat caulking operation, the parameter setting unit 6 sets the next parameter according to the heat caulking object (S101 in FIG. 2).
There are two temperature parameters: a heat caulking temperature T2 where the temperature of the heater chip 3 is determined according to the heat caulking object and a solidification temperature T3 which is determined according to the heat caulking object, and a time parameter is the heat caulking temperature T2. Holding time t2 and the temperature rise time t1 from the heat caulking operation start temperature T1 to the heat caulking temperature T2, and the cooling parameter is the pressure of the cooling air.

Here, the heat caulking operation start temperature T1 is the temperature in the room where the heat caulking device is installed before the start of using the heat caulking device, and when the heat caulking operation is continuously performed, cooling is performed after the previous heat caulking operation. This is the temperature after Accordingly, in either case, the temperature T1 is detected by the thermocouple 4 and is not set by the parameter setting unit 6.

Based on these parameters, the target temperature profile generation unit 7 generates a target temperature profile. That is, from the start of the heat caulking operation until the heat caulking temperature T2 is reached, the temperature is increased linearly with the result obtained by dividing the temperature difference between the heat caulking operation start temperature T1 and the heat caulking temperature T2 by the temperature rise time t1. After reaching the heat caulking temperature T2, this temperature is held for the holding time t2 (shown by a solid line in FIG. 4). This temperature profile data is stored in the PID control unit 8
As described above, the thermocouple 4 is configured with a voltage for comparison with the voltage detected according to the temperature of the heater chip 3.

[Heat staking action]
Next, the operation of the heat caulking device when the heat caulking operation is actually performed will be described.
The worker first turns on the entire heat caulking device and sets various parameters according to the object (S101 in FIG. 2).
Then, the welding head 23 is moved by holding it, and the welding head 23 is aligned so that the heater chip 23a is aligned with a boss (not shown) that is a heat-caulking portion of the object to be heat-caulked. 2 S102). Then, the operator senses that the welding head 23 has reached the boss (S103 in FIG. 2).

After detecting the arrival at the boss, the operator operates a welding start operating portion 23b provided on the welding head 23 to generate a start signal (S104 in FIG. 2). The start signal is input to the target temperature profile generation unit 7 and the phase control signal generation unit 10 to start the heat caulking operation.

Upon receiving this start signal, the target temperature profile generation unit 7 sends voltage data as the target temperature profile generated previously to the PID control unit 8 every time (shown by a solid line in FIG. 4). On the other hand, the phase control signal generation unit 10 receives the start signal, generates and outputs a gate signal that is a phase control amount of the phase control unit 1. This gate signal is sent to the phase controller 1 until the holding time t2 elapses from the start of the heat caulking operation through the temperature rise time t1.

This state will be described in more detail. The target voltage as the target temperature from the target temperature profile generation unit 7 and the detection voltage corresponding to the temperature of the heater chip 3 from the amplification unit 5 are both sent to the PID control unit 8. These voltage values are compared by the PID control unit 8 to obtain a difference amount, and an operation amount for generating a phase control signal corresponding to the difference amount is calculated. This manipulated variable is sent to the phase control signal generator 10. In addition to the manipulated variable, the phase control signal generation unit 10 receives a synchronization signal from the synchronization signal generation unit 9.

The phase control signal generator 10 generates a gate signal based on the synchronization signal and the operation amount.
The phase control unit 1 is controlled by this gate signal. This gate signal has a longer ON period of the phase control unit 1 when the pulse width is large (when the difference amount is large) according to the operation amount. Therefore, the control of the phase control unit 1 by this gate signal causes the welding transformer 2 to
Since the input alternating current flowing to the primary side is limited, the current induced on the secondary side of the welding transformer 2 is also limited after all.

When the phase control unit 1 receives this gate signal, the difference between the heat caulking operation start temperature T1 and the heat caulking temperature T2 is large at first. 2 also flows for a relatively long time on the primary side. Then, an alternating current is induced on the secondary side of the welding transformer 2 by the alternating current on the primary side of the welding transformer 2, so that an alternating current flows through the heater chip 3 for a relatively long period. The heater chip 3 generates heat by this alternating current, and the heat staking operation is started by heating the boss (S105 in FIG. 2).

The temperature of the boss, which is a heat caulking object, is always detected as a voltage corresponding to the temperature by a thermocouple 4 attached to the heater chip 3, and this detected voltage is predetermined by an amplifying unit 5 composed mainly of a differential amplifier. And sent to the PID control unit 8. Then, the operation amount is obtained by the PID control unit 8 as described above, and this operation amount is sent to the phase control signal generation unit 10, where a gate signal is generated based on this operation amount.

Such control is repeatedly executed until the holding time t2 of the heat caulking temperature T2 elapses after the temperature rise time t1, the temperature of the heater chip 23a is set by the parameter setting unit 6,
The target temperature profile generated by the target temperature profile generation unit 7 is realized. While the heater chip 3 is energized, the worker continues to press the boss with an appropriate force by the welding head 23 while heating the boss.
As a result, a boss is formed (S106 in FIG. 2).

[Cooling operation]
Finally, the cooling operation will be described.
As described above, the boss is formed. Then, in order to cool the boss after molding, energization to the heater chip 3 is stopped, and at the same time, the cooling unit 14 is driven to start cooling the boss after molding (S107 in FIG. 2).

At this time, the comparison unit 12 receives the amplified detection voltage and the resin solidification temperature T3 from the parameter setting unit 6 which are detected according to the temperature of the heater chip 23a from the amplification unit 5, and the amplification unit 5
The target voltage is obtained by the same correspondence as the correspondence between the temperature and the voltage in, and the comparison between the detected voltage and the target voltage is started. After the start of comparison, after a certain period of time has elapsed in the material and outer shape of the object, the temperature of the boss after molding reaches the set resin solidification temperature T3, so this state can be detected (S108 in FIG. 2).

At this time, the comparison unit 12 generates a solidification temperature arrival signal and sends it to the notification unit 13.
3 sounds a buzzer or the like to inform the operator that the molded boss has reached the solidification temperature (S109 in FIG. 2). Upon receiving this notification, the operator operates the cooling stop operation unit 23 c attached to the welding head 23 to generate a cooling stop signal and sends it to the welding power source 21. This cooling stop signal is sent to the cooling unit 14, the blower of the cooling unit 14 is stopped, the blowing of cooling air is stopped, and the cooling of the boss after molding is finished (S110 in FIG. 2). Then, after sensing that the cooling air has stopped, the operator raises the welding head 23 from the molded boss and separates it (S111 in FIG. 2).
As described above, a series of heat caulking operations is completed.

In the present embodiment, the operator performs the heat caulking by holding the welding head in his / her hand, but automating the vertical movement of the welding head and the start / stop of cooling without changing the gist of the present invention. It is possible to respond. In this case, the welding head may be provided with a vertical movement mechanism such as an air cylinder or a motor, an electromagnetic valve for controlling the cooling operation, and the like, and these controls are preferably formed as one control block.

1 is a schematic configuration diagram of a heat caulking device showing the best mode for carrying out the present invention. 1 is a schematic block diagram of the heat caulking device of FIG. FIG. 1 is a schematic operation flowchart of the heat caulking device of FIG. The figure which shows the temperature profile at the time of operation | movement of the heat crimping apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Phase control part 2 Transformer 3 Heater chip 4 Thermocouple 5 Amplification part 6 Parameter setting part 7 Target temperature profile generation part 8 PID control part 9 Synchronization signal generation part 10 Phase control signal generation part 12 Comparison part 13 Notification part 14 Cooling part 21 Welding power source 22 Welding transformer 23 Welding head 23a Heater chip 23b Welding start operation unit 23c Cooling stop operation unit

Claims (5)

A molded article using a thermoplastic resin having a boss integrally formed by supplying a current to a heater chip connected to the secondary side of the transformer, and a joined body having a fitting hole to be fitted to the boss; In the heat staking apparatus that heats and squeezes the boss, presses the boss by the heater chip, and has a cooling means for the boss after heating and molding,
Temperature detecting means for detecting the temperature of the molded boss disposed on the heater chip;
A means for comparing the temperature of the boss after molding detected by the temperature detecting means with a preset solidification temperature of the thermoplastic resin;
A heat caulking device comprising: an informing means for informing that when the comparison means detects that the temperature of the boss after molding has reached the solidification temperature. The heat caulking device according to claim 1, wherein cooling to the boss after the molding is stopped based on the detection result. The heat caulking device according to claim 1, wherein the pressing of the boss by the heater chip is released based on the detection result. A molded article using a thermoplastic resin having a boss integrally formed by supplying a current to a heater chip connected to the secondary side of the transformer, and a joined body having a fitting hole to be fitted to the boss; In the heat staking apparatus that heats and squeezes the boss, presses the boss by the heater chip, and has a cooling means for the boss after heating and molding,
A synchronization signal generator that detects a zero-cross point from the input AC current and generates a synchronization signal based on the zero-cross point;
A phase control unit for controlling the current supplied to the primary side of the transformer by increasing or decreasing the input AC current based on the gate signal;
An amplifying unit that detects a voltage corresponding to the temperature of the heater chip with a thermocouple attached to the heater chip, and amplifies the voltage at a predetermined amplification degree;
A target temperature profile generation unit that receives a temperature and time from an input unit provided separately, and generates a target temperature profile that is defined as a target voltage by the same correspondence relationship between the temperature and the voltage in the amplification unit;
The difference between the detection voltage from the amplification unit and the target voltage from the target temperature profile generation unit is calculated, the phase control amount is calculated according to the difference, and the synchronization signal from the synchronization signal generation unit is calculated as a phase control signal. A phase control signal generator that generates a gate signal based on this phase control amount with reference to
In response to the solidification temperature specific to the thermoplastic resin from the input means, a target voltage is calculated according to the same correspondence relationship between the temperature and the voltage in the amplification unit, and compared with the detection voltage from the amplification unit, A comparison unit for detecting that the temperature of the heater chip has reached the solidification temperature;
A notification unit for reporting a detection result from the comparison unit;
The heater chip starts cooling after completing the operation corresponding to the target temperature profile,
The heat staking apparatus according to claim 1, further comprising: a cooling unit that stops cooling when a cooling stop signal is input in response to a notification from the notification unit. 5. The thermal staking apparatus according to claim 4, wherein the phase control amount is calculated by PID control.

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