JPH09201669A - Electric soldering iron - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electric soldering iron without cutting of a sensor wire and detaching of a coating material on the sensor wire by coating temp. sensitive part of the temp. sensor with a protecting tube and fixing a part incorporating the temp. sensitive part to the outer periphery of the iron tip. SOLUTION: The temp. sensor 12 is fixed to the outer periphery of the tip part 10a of the iron tip 10 in the condition of once covering with the protecting tube 15, i.e., in the condition of uniting the sensor itself. At the time of transporting, etc., the temp. sensor 12, it can, therefor, be prevented that the sensor wire 14 is cut and further, the coating material on the sensor wire 14 is detached. Moreover, since the part of the protecting tube 15 incorporating the temp. sensitive part of the temp. sensor 12 is formed as flat state and fixed to the iron tip, the fixed contacting area between the protecting tube 15 and the outer periphery of the iron tip can be widened and the firm fixing can be obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric soldering iron having a temperature sensor for detecting the temperature of a tip.

[0002]

2. Description of the Related Art The following technique is disclosed in Japanese Patent Laid-Open No. 7-40037 as an electric soldering iron having a temperature sensor at its tip. That is, as shown in FIG. 5, the joining portion 2A of the thermocouple 2 is welded from the outside in the vicinity of the tip of the tip 1, and the sensor wire 2B is extended to the rear of the tip end of the tip 1 to form the sensor plug. Is connected to the temperature control unit via. The temperature control unit controls the amount of electricity supplied to the heater 3 inserted into the tip 1 in accordance with the temperature of the tip 1 detected by the thermocouple 2 to control the temperature of the tip 1. It keeps it constant. With such an electric soldering iron,
Compared to the one in which a temperature sensor is provided inside the tip 1 as in the past, the tip 1 that contacts an object to be heated such as an electric component
Since the temperature of the tip of the can be directly detected, it can be accurately detected with good responsiveness. Therefore, there is an advantage that the temperature of the tip 1 can be controlled with high accuracy.

[0003]

The electric soldering iron described above has the following problems. That is, in manufacturing, since the joint portion 2A of the thermocouple 2 is welded directly to the outer peripheral surface of the tip 1, the joint portion 2A of the thermocouple 2 is very small and the sensor wire 2B may be thin and easily cut. However, care must be taken not to damage or break them, and the work of fixing the joint portion 2A of the thermocouple 2 to the outer circumference of the tip 1 is very troublesome. Further, even after production, the sensor wire 2B is arranged outside the tip 1 in a state of being exposed, so that, for example, during soldering work, the sensor wire 2B or the joint portion 2A is hit by an electric component or the like. Two
There is a possibility that B may be broken, the covering material of the sensor wire 2B may be peeled off, and further, the fixing of the joint portion 2A may be released.
It is also considered that a metal wire is arranged on the sensor wire 2B to protect the sensor wire 2B. However, even if such a means is adopted, it is possible to avoid hitting the sensor wire 2B with an electric component or the like. However, when the metal wire is fixed, a new problem arises that the joint portion 2A of the sensor wire 2B is peeled off.

The present invention has been made in view of the above circumstances, and the work of fixing the temperature sensor to the outer circumference of the iron tip can be easily performed, and further, the sensor wire may be broken or the sensor may be damaged during soldering work. It is an object of the present invention to provide an electric soldering iron in which there is no fear that the covering material of the wire will be peeled off and the sticking of the temperature sensing part will be released.

[0005]

In order to achieve the above object, in the invention according to claim 1, at least the temperature sensing portion of the temperature sensor is covered with a protective pipe, and the temperature sensing portion of the temperature sensor of the protective pipe is covered. It is characterized in that the part storing the is fixed to the outer circumference of the tip. According to a second aspect of the present invention, the portion of the protective pipe in which the temperature sensor of the temperature sensor is housed is made flat, and the flat portion is fixed to the outer periphery of the tip. The invention according to claim 3 is characterized in that the temperature sensor is a thermocouple. The invention according to claim 4 is characterized in that the protection pipe is made of stainless steel. In the invention according to claim 5, between the protection pipe and the sensor wire and between the sensor wires,
Each is characterized by having an insulating material interposed. According to a sixth aspect of the invention, the flat portion of the protective pipe is fixed to the outer circumference of the tip by spot welding. In the invention according to claim 7, a groove along the axial direction of the tip is provided on the base end side of the tip where the protection pipe is fixed, and the protection pipe is fitted into the groove. Characterize.

According to the present invention, the sensor itself is unitized by covering the temperature sensitive portion of the temperature sensor with the protective pipe. Therefore, when the temperature sensor is carried, the temperature sensor is attached to the outer circumference of the tip. It is possible to prevent the temperature sensitive part from being damaged, the sensor wire from being broken, and the coating material of the sensor wire from being peeled off when it is fixed to the temperature sensor, and the workability when fixing the temperature sensor is improved. To do. In addition, since the sensor wire and the like are covered with the protective pipe even after being fixed, the temperature sensing portion of the temperature sensor and the sensor wire can be sufficiently protected.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of an iron tip of an electric soldering iron, and FIG. 2 is an exploded perspective view of the iron tip. As shown in the figure, the electric soldering iron is provided with a tip 10 at its tip, and this tip 10 has a tip 10a formed in a substantially conical shape and a base 10b having a cylindrical shape. Is formed in. A heater 11 is inserted inside the base portion 10b of the tip 10. Also, the base 1 of the tip 10
The outside of 0b is covered with a heater cover as needed.

A temperature sensing portion 13 of the temperature sensor 12 and a sensor wire 14 extending from the temperature sensing portion 13 are fixed to the outer periphery of the tip portion 10a of the tip 10 in a form covered with a protective pipe 15. That is, the joint portion (temperature sensing portion) of the thermocouple and the sensor wire 14 extending from the joint portion of the temperature sensor 12 are
As shown in FIG. 4, the temperature sensing portion 13 is accommodated in the protection pipe 15 having a substantially elliptical cross section and made of stainless steel. After being inserted, the temperature sensitive portion 13 is flattened by being crushed within a range where it is not damaged. Then, the flat portion 15a is fixed to the outer peripheral portion of the tip portion 10a of the tip 10 by spot welding or the like. The protective pipe 15 is set so that its thermal capacity is as small as possible, that is, its diameter is small and its wall thickness is thin so that it can be detected accurately and responsively by the temperature sensor 12.

Here, the protective pipe 15 and the sensor wire 1
An insulating material 16 made of glass fiber or the like having heat resistance is interposed between the sensor wire 14 and the sensor wires 14, 14. As is well known, the outer circumference of the sensor wire 14 is covered with an insulating film, and the outer side of the base side of the sensor wire 14 is further covered with an insulating sheet 17. The tip of the sensor wire 13 is connected to the temperature controller. The power supply line of the heater 11 is also connected to the temperature control unit, and based on the temperature of the tip portion 10a of the tip 10 detected by the temperature sensor 12, the tip portion 10a of the tip 10 is adjusted by the user. The energization amount to the heater 11 is controlled so that the set temperature is set.

Further, from the step portion 10c which is a boundary portion between the tip portion 10a of the tip 10 and the base portion 10b to the base portion 10b.
A groove 18 is provided along the axial direction of the tip 10, and a protective pipe 15 for accommodating the temperature sensor 11 is fitted and fixed in the groove 18.

Next, the operation of the electric soldering iron having the above structure will be described. When performing a soldering operation using an electric soldering iron, the tip portion 10a of the iron tip 10 is heated by the heater 11 while being cooled by being brought into contact with solder or an electric component to be soldered. However, the temperature of the tip 10a of the tip 10 at this time is
It is directly detected by the temperature sensor 12 mounted via. A protective pipe 15 is interposed between the tip 10 and the temperature sensor 12. However, since the protective pipe 15 has a very small heat capacity, it is necessary to measure the temperature of the outer circumference of the tip 10a of the tip 10. Decrease in accuracy does not matter. In this way, the temperature of the tip portion 10a of the tip 10 can be detected without a time delay, and the information can be transmitted to the temperature control unit to immediately adjust the temperature. Therefore, the temperature of the tip 20, especially the tip 1
The temperature of the tip portion 10a of 0 can be accurately adjusted in real time, and the precise soldering temperature required for soldering of precision electrical components can be accurately adjusted.

Further, the temperature sensor 12 is not directly fixed to the outer periphery of the iron tip 10, but the temperature sensor 12 is once covered with the protective pipe 15, that is, the sensor itself is unitized. The tip 10a of the tip 10 is fixed to the outer periphery of the tip 10, and therefore, when carrying the temperature sensor 12, the temperature sensor 12 is also attached to the tip 1 of the tip 10.
When it is fixed to the outer periphery of 0a, the temperature sensing portion 13 is damaged, the sensor wire 14 is broken, and further, the sensor wire 1
It is possible to prevent the covering material of No. 4 from coming off. After that, the temperature sensor 12 that is actually unitized is attached to the tip 1
Even when it is fixed to the tip portion 10a of No. 0, the fixing target is much larger than that in the case of only the joint portion of the thermocouple as shown in the conventional example, and moreover, the protection pipe 15
Since the flat portion 15a is formed by crushing the tip of the tip and the contact area with the tip 10 is wide, the actual fixing work by spot welding can be easily performed. in addition,
Even after being fixed, the sensor wire 14 and the like are protected by the protective pipe 15.
Since the temperature sensor 12 and the sensor wire 14 of the temperature sensor 12 can be sufficiently protected by being covered with, the sensor wire 14 and the temperature sensor 13 can be protected from electric parts at the time of actual soldering work. It is possible to prevent the sensor wire 14 from breaking, the coating material of the sensor wire 14 coming off, and the temperature-sensitive portion 13 from being damaged.

In the above embodiment,
Although the protective pipe 15 covers not only the joint portion of the thermocouple but also the sensor wire 14 extending rearward from the joint portion, it is not always necessary to cover the sensor wire 14, and it is sufficient to cover only the joint portion of the thermocouple. In the above embodiment, the tip 1
Although a thermocouple is used to detect the temperature of the zero tip portion 10a, the temperature is not limited to this, and another temperature sensor such as a resistance thermometer may be used. Further, as shown in FIG. 4, a groove 19 provided in the step portion 10c of the iron tip 10 is formed so as to reach the tip of the base portion of the iron tip.
Further, not only the protective pipe but also the sensor wire extending from the protective pipe to the base side may be fitted. Further, in the above-described embodiment, the protection pipe 15 is fixed to the outer circumference of the tip 10 by spot welding, but the embodiment is not limited to this, and other brazing, beam welding, laser welding, or the like. Fixing means may be used.

[0014]

As described above, the present invention has the following excellent effects. According to the first aspect of the present invention, the temperature sensing portion of the temperature sensor is covered with the protective pipe to unitize the sensor itself. Therefore, when the temperature sensor is carried, the temperature sensor can be attached to the tip of the temperature sensor. It is possible to prevent breakage of the sensor wire and peeling off of the coating material of the sensor wire when fixing to the outer periphery, and further, workability at the time of fixing can be improved. In addition, since the sensor wire and the like are covered with the protective pipe even after being fixed, the temperature-sensitive part of the sensor and the sensor wire can be sufficiently protected. According to the second aspect of the invention, since the portion of the protective pipe in which the temperature sensing portion of the temperature sensor is housed has a flat shape and is fixed to the outer periphery of the tip, the fixed contact area between the protective pipe and the outer periphery of the tip is Can be widely adopted, and strong fixation can be realized. According to the invention described in claim 3, since the temperature sensor is constituted by a thermocouple, and the thermocouple is simple in construction and inexpensive, it is possible to detect with relatively high precision, and therefore, the high precision of the tip is provided. The temperature control can be performed. According to the invention of claim 4, since the protective pipe is made of stainless steel, it is possible to prevent the temperature sensor from being corroded, and it is excellent in durability. According to the invention of claim 5, since the insulating material is interposed between the protective pipe and the sensor wire and between the sensor wires,
Even if the insulating coating of the sensor wire is peeled off or is easily peeled off, it is possible to prevent the middle part of the sensor wire from electrically contacting another sensor wire or the protective pipe and lowering the temperature detection accuracy. . According to the sixth aspect of the invention, the flat portion of the protective pipe is fixed to the outer periphery of the tip by spot welding, so that strong fixing can be performed while being simple. According to the invention described in claim 7, since the protection pipe is fitted in the groove formed on the outer circumference of the iron tip, the protection pipe is protected by hitting the protection pipe against the object or the like during the soldering work. The pipe moves unnecessarily and the temperature sensitive part is damaged,
It is possible to prevent the sensor wire from breaking.

[Brief description of drawings]

FIG. 1 is a half sectional view of a tip portion of an electric soldering iron showing an embodiment of the present invention.

FIG. 2 is an exploded perspective view of a tip portion of the electric soldering iron.

FIG. 3 is a cross-sectional view showing a state in which a temperature sensor is housed in a protection pipe.

FIG. 4 is a perspective view of a tip showing another embodiment of the present invention.

FIG. 5 is a half sectional view showing a conventional example of an electric soldering iron.

[Explanation of symbols]

 10 Tip 10a Tip part 10b Base part 10c Step part 11 Heater 12 Temperature sensor 13 Temperature sensing part 14 Sensor wire 15 Protective pipe 16 Insulation material 17 Insulation sheet 18 Groove

Claims (7)

[Claims] 1. A tip (10) covering at least the temperature sensing part (13) of a temperature sensor (12) with a protection pipe (15), and the part of the protection pipe accommodating the temperature sensing part of the temperature sensor. An electric soldering iron characterized by being fixed to the outer circumference of. 2. The electric soldering iron according to claim 1, wherein a portion of the protective pipe in which the temperature sensing portion of the temperature sensor is housed is flat, and the flat portion (15a) is provided on the outer circumference of the tip. An electric soldering iron characterized by being fixed. 3. The electric soldering iron according to claim 2, wherein the temperature sensor is a thermocouple. 4. The electric soldering iron according to claim 2, wherein the protection pipe is made of stainless steel. 5. The electric soldering iron according to claim 2, wherein an insulating material (16) is interposed between the protective pipe and the sensor wire and between the sensor wires. An electric soldering iron that is characterized by: 6. The electric soldering iron according to any one of claims 2 to 5, wherein the flat portion (15a) of the protection pipe is fixed to the outer periphery of the tip by spot welding. Electric soldering iron to do. 7. The electric soldering iron according to any one of claims 1 to 6, wherein a groove (17) extending along the axial direction of the iron tip is provided on the base end side of the iron tip to which the protection pipe is fixed. ) Is provided, and the protection pipe is fitted in this groove.