JPH0788640A - Electric iron - Google Patents

Abstract

PURPOSE:To improve the efficiency and reduce the electric power consumption of an electric heater by disposing a clamping spring consisting of an elastic material between an iron tip member and a stationary pipe and increasing the contact area of the iron tip member and the electric heater by the pressing force of this spring. CONSTITUTION:The small-diameter part in a step part 22 of the stationary pipe 19 rides on the large-diameter part in a step part of the clamping spring 15 and applies the force to decrease the diameter thereof on this part, thereby deforming the clamping spring 15. The force is acted by this deformation on the load bearing part of the outside diameter larger than in the other parts on the root side of the iron tip member 9. Since a slit groove to expand or contract the diameter is formed in this part, entire part of the inside surface of the iron tip member 9 comes into contact with the electric heater 1. The step part 12 of the iron tip member 9 fitting to the electric heater 1 and the stationary side 24 of a fastening device fixed to a flange 5 at the root of the electric heater 1 are sealed by the stationary pipe 19 and a moving side of the fastening device, by which the dislodgment of the iron tip is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric iron applicable to a soldering iron, a hair iron, a branding iron, and the like.

[0002]

2. Description of the Related Art The present inventor has proposed an electric iron according to Japanese Patent Application No. 1-92037 (Japanese Patent Laid-Open No. 3-55223). As shown in FIG. 7, in order to strongly press the iron tip member 52 against the rod-shaped ceramic heater 51, a first taper portion 53 is provided at the base of the iron tip member 52, and a fixed pipe covering the first taper portion 53 is provided. 54 is also provided with a second taper portion at a position corresponding to the first taper portion 53 in the assembled state, and the flange 5 at the base of the heater 51 is provided.
6, the male screw of the member 55 fixed to 6 and the fixed pipe 54
By screwing a fastening member 58 having a female screw that engages with the root-side end of the tip end portion 53, the tip end member 53 is strongly pressed against the first taper portion 53 and the second taper portion. It is a structure that is pressed against.

However, according to this conventional example, the thermal expansion and cooling are repeated by turning on and off the power source of the electric iron during the use over a long period of time, and the surface of the tip member is oxidized. Due to deterioration, etc., the tightened state of the male and female screws may become loose.In addition, the tightening part gradually loosens due to repeated impacts of the user strongly hitting the soldering iron on the iron holder, and finally the iron The tip member 52, the fixed pipe 54, and the fastening member 58 may fall off the heater 51.

[0004]

SUMMARY OF THE INVENTION Therefore, the present invention is arranged to repeatedly expand and contract between a few hundred degrees Celsius when the power is turned on and room temperature when not in use, and to throw an electric iron on a receiver. Despite repeated impacts, the iron tip member always adheres strongly to the electric heater, and the heat conduction between them is good, and moreover, it is discharged from the fixed pipe covering the outside of the electric iron to the outside. Heat loss is small, nevertheless, even when the soldering iron, which is the most severe condition, is left standing on the receiving tool for a long time, the temperature of the tip is not conducted to the handle and the electric circuit in the handle, The problem to be solved is to provide an improved electric iron that protects electronic circuits from thermal destruction.

[0005]

An electric iron according to the present invention comprises a rod-shaped electric heater having a first flange at a base thereof,
A tubular handle provided behind the first flange, a fastening device including a fixed side fixed to the front side of the first flange and a movable side that is screwed to the fixed side, and a small number of the electric heater. Both of them are fitted to the front half, and a first step is formed between the support part on the root side and the tip part, and a load receiving part having an outer diameter larger than that of the root side and a slit groove for expanding and contracting the diameter. Which is a member covering the base side of the iron tip member and the rear half of the electric heater, and is made of an elastic material having a cylindrical shape as a whole, and has a shaft at the center except both ends. A holding spring having a directional slit formed therein, and a second step portion formed behind the contact point with the load receiving portion, and a member covering the holding spring, the first step being at the tip. And a rear end connected to the movable side of the fastening device. In the assembled state the press the said clamping spring to the rear than the second step portion in the radial direction 3
It is characterized by having a fixed pipe in which a step is formed.

[0006]

FIG. 3 shows a thermal equivalent circuit diagram in which the thermal phenomenon of the present invention is modeled on an electric circuit. The heat source is represented by a current source, the heat transfer path is represented by an electric resistance, and the heat capacity is represented by an electrostatic capacity.
The meanings of the symbols attached to the figures are listed below.

T _H : heater temperature T _t : iron tip temperature T _a : ambient temperature T _G : handle temperature P _h : heater power loss R _O : thermal resistance between heater and tip _Ra : Thermal resistance between tip and outside air _RL : Thermal resistance between heated object and outside air R _og : Thermal resistance between heater and handle R _ag : Thermal resistance between handle and outside air C _a : Trowel previous capacity C _L: the object to be heated in the heat capacity S _W: contact tip and the object to be heated, the switch generally representative of the non-contact, in the heater for heating the soldering tip by the electric heater, to control the energization of the heater If the tip temperature T _t
It is preferable to control so that the deviation between the target value and the target value is as small as possible.

Considering the path through which the heat generated by the heater is conducted to the tip by the above circuit diagram, in the thermal steady state, T _H = P _h R _O + P _h R _a + T _a (1) ) However, since R _og >> R _O , the heat escaping from the tip to the outside air through the handle is ignored.

Since T _t = P _h · R _a + T _a (2), both formulas (1) and (2) yield (T _t −T _a ) / (T _H −T _a ) = (P _h・ R _a ) / (P _h · R _o + R _h · R _a ) = R _a / (R _o + R _a ) ... (3) As is apparent from this equation, the tip temperature T _t is the heater temperature. lower than T _H. Furthermore, the tip becomes the switch SW is turned touches the object to be heated, but heat is to transiently heat capacity C _L is deprived, then the steady state when the thermal resistance R _a
Since the circuit of thermal resistance R _L is in parallel contact with the circuit of No. 3, heat dissipation to the outside air increases, and the tip temperature T _t further decreases.

[0010] That is, the tip is at the SW-OFF not in contact with the object to be heated, tip temperature T _t is _{T t} = T _H × _{[R a / (R O + R} a) ] ‥‥ ( 4) tip is tip temperature T _t at SW-oN in contact with the object to be heated is _{T t} ≒ T _H × _{[R L / (R O + R} L) ] ‥‥ (5) . As is clear from the equations (4) and (5), the thermal resistance _Ra is large in order to prevent heat radiation to the outside air, and the tip temperature T _t
In order to reduce the difference between the heater temperature T _H and the heater temperature T _H , it is preferable that the thermal resistance R _O be small.

FIG. 4 (A) shows a state of each member when the pressing member is in a natural state in which no pressing force acts in the positional relation of the assembled state, and FIG. 4 (B) shows the state between the members in the assembled state. The force relationship of is schematically shown.

The force of the small diameter portion of the third step portion 22 of the fixed pipe 19 to rise to the large diameter portion of the second step portion 17 of the holding spring 15 to reduce the diameter of the second step portion 17. F _{1 is applied} to the holding spring 15, so that the holding spring 15 is deformed in the direction of decreasing its diameter. Due to this deformation, a force F ₂ acts on the load receiving portion 13 of the tip member 9, and the tip member 9 is formed with a slit groove 14 that expands and contracts in diameter, so that the entire inner surface of the tip member is formed. Contacts the electric heater 1.

Further, the first step portion 12 of the tip member 9 fitted to the electric heater 1 and the flange 5 at the base of the electric heater 1 are provided.
The fixed side 24 of the fastening device fixed to the fixed pipe 1
9 and the movable side 25 of the fastening device are engaged to prevent the tip from falling off.

[0014]

1 shows an exploded perspective view of an embodiment of the present invention, and FIG. 2 shows a longitudinal sectional view of the assembled state.

In the round rod-shaped ceramic heater 1, a heating element is embedded in the tip portion thereof, and a lead wire is led out from the rear end. At the base of this ceramic heater, the first flange 5
Are integrally joined by brazing. This flange 5
Is made of a material having good thermal conductivity and relatively small bending stress, such as nickel or its alloy. The outer periphery of the flange 5 has, for example, three through-holes 6 ... 6 and has no opening, so as to block the space around the outside of the ceramic heater in the front-rear direction.

The handle 7 is made of a heat-defective conductor such as plastic or wood, and has a flange portion 8 formed at its tip.
3 corresponding to the above-mentioned through hole on the end face of the flange portion 8
Each seat is integrally formed, and a female screw is engraved on the seat. The handle 7 is hollow at the center, has the temperature control electronic circuit 4 built-in, and a power cord for connecting to a commercial AC power source is led out from the rear end of the handle 7.

The tip member 9 is a circular hole 1 which is fitted in at least the front half of the electric heater 3 of the ceramic heater 1.
0 is drilled in the rear end surface, and a first step portion 12 is formed between the tip 11 of the tip and the root side so that a locking portion 21 at the tip of the fixed pipe 19 described later hangs. A load receiving portion 13 having an outer diameter larger than the others is formed. Further, a cut groove 14 for enlarging and expanding the outer diameter and the inner diameter on the root side is engraved in the portion where the circular hole 10 is drilled.

The holding spring 15 is made of an elastic material having a cylindrical shape as a whole, for example, a phosphor bronze plate, a second flange 16 is integrally formed at a rear end thereof, and a diameter of a rear half portion is formed at a predetermined position in a central portion rather than a front half portion. The second step portion 17 is formed in the direction of increasing the width, and a plurality of axial slits 18 ... 18 are formed on the entire central portion excluding the front and rear ends to facilitate bending in the radial direction. The length of the holding spring 15 is substantially equal to the length of the ceramic heater 1, and the diameter in the natural state is such that the front half portion loosely fits into the load receiving portion 13 of the tip member 9, and the rear half portion has a fixed pipe 19 described later. Is larger than the inner diameter of the first half and smaller than the inner diameter of the second half. The width of the slit 18 may be different between the front half and the rear half to freely design the spring constant ratio, and the slit 18a may be provided only in the rear half.

The fixed pipe 19 is a member for pressing the iron tip member 9 against the ceramic heater 1 and fixing the iron tip member 9 by interposing a holding spring 15 around the outer circumference of the iron tip member 9. A flange that is rotatably connected to the movable-side member 25 of the fastening device is formed on the rear end surface thereof, and a locking portion 21 that narrows the diameter inward is formed on the front end surface, and is located at a predetermined position in the axial direction. The third step portion 22 is formed so that the diameter of the latter half portion is larger than that of the first half portion.

The fastening device 23 comprises a fixed side member 24 and a movable side member 25. A male screw 26 engraved on the outer diameter of the tip of the fixed side member 24 and an inner diameter of the movable side member 25 are screwed to the fastening device 23. Are engaged. The fixed-side member 24 includes a cylindrical portion 20 that penetrates the rear end portion of the holding spring 15 and a flange portion 28 formed on the rear end surface.
8 is provided with, for example, three screw holes for sandwiching the first flange 5 of the heater 1 and the second flange 16 of the sandwiching spring 15 on the front end surface of the handle 7, and screws 29 ... 2
It is fixed to the handle 7 by 9. The movable member 25 is a nut-like member having a hexagonal outer diameter, and is rotatably connected to the rear end surface of the fixed pipe 19.

When assembling this embodiment, after the electronic circuit and the power cord are connected to the ceramic heater 1, these are inserted into the handle 7 and the clamping spring 1 is placed thereon.
5 is covered, and the first flange 5 and the second flange 16 are sandwiched and fixed by the flange portion of the fixed side member 24 of the fastening device. Next, the tip member 9 is inserted between the heater 1 and the holding spring 15. Finally, the fixed pipe 19 is inserted onto the clamping spring 15, and the movable member 25 of the fastening device is tightened,
The tip member 9 is pressed against the ceramic heater 1.

The positional relationship between the members in this assembled state is shown in FIG. 4 (A). The step 22 of the fixed pipe 19 and the step 1 of the holding spring 15 are arranged in this order from the handle 7 toward the tip.
7, the load receiving portion 13 of the iron tip member 9, the front end surface of the sandwiching spring 15, the locking points of the step portion 12 of the iron tip member 9 and the front end locking portion 21 of the fixed pipe 19 are aligned in the axial direction. There is. As a result, the radial tightening force and the axial tightening force as described in the section <Operation> shown in FIG. 4 (B) act.

Clamping spring 1 for obtaining such a force relationship
The shapes of 5 and the fixed pipe 19 can also be implemented by the following modified examples. FIG. 5 shows the holding spring 1
A ring-shaped convex portion 30 having an increased outer diameter is formed on 5A. In this case, the front side 31 of the convex portion 30 functions as the second step. In the structure shown in FIG. 6, the fixed pipe 19A is formed with a ring-shaped convex portion 32 whose inner diameter is reduced (a concave portion appears on the outer diameter when a pipe having a uniform wall thickness is processed).
In this case, the rear side 33 of the protrusion 32 functions as the third step.

[0024]

According to the present invention, the sandwiching spring 15 made of an elastic material is provided between the tip member 9 and the fixed pipe 19.
The third step 22 of the fixed pipe 19 is the second step of the holding spring 15.
Since the supporting spring of the iron tip member 9 presses the outer peripheral surface of the electric heater 1 from the radial direction by being lifted up to the step portion 17 of the electric heater 1, the contact area between the iron tip member 9 and the electric heater 1 is increased. and There is always kept large, kept small thermal resistance R _O therebetween, thus, may be slightly higher heater temperature T _H to the required tip temperature T _t. As a result, less heat energy escapes to the outside, efficiency is improved, and power consumption of the heater is reduced.

Further, according to the present invention, since the clamping spring 15 is in line contact with the tip member 9 and the ring-shaped convex portion of the load receiving portion 13, the thermal resistance between them is large and the temperature of the clamping spring 15 is high. Can be kept low. Moreover, since the transverse cross section of the entire holding spring 15 is circular and the transverse cross section of each spring member divided by the slit 18 is arcuate, a large spring constant can be obtained even with a thin material. The diameter of the fixed pipe 19 can be reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the assembled state of the embodiment.

FIG. 3 is a thermal equivalent circuit diagram showing a thermal phenomenon of the present invention.

FIG. 4 is an explanatory view of the operation of the above embodiment.

FIG. 5 is a diagram showing a modified example of the holding spring of the present invention.

FIG. 6 is a view showing a modified example of the fixed pipe of the present invention.

FIG. 7 is a vertical sectional view showing a conventional example.

[Explanation of symbols]

 1 ... Electric heater 5 ... 1st flange 7 ... Handle 9 ... Iron tip member 12 ... 1st step part 13 ... Load receiving part 14・ ・ ・ Clit groove 15 ・ ・ ・ Clamping spring 16 ・ ・ ・ ・ Second flange 17 ・ ・ ・ ・ Second step 18 ・ ・ ・ ・ ・ ・ Slit 19 ・ ・ ・ ・ ・ ・ Fixed pipe 21 ・ ・ ・Locking part 22 ... 3rd step 24 ... Fixed side of fastening device 25 ... Movable side of fastening device

Claims (1)

[Claims] 1. A rod-shaped electric heater having a first flange at its base, a cylindrical handle provided at the rear of the first flange, and a fixing member fixed at the front of the first flange. Side and a fixed side of the movable side that is screwed to the fixed side, and fits at least the front half of the electric heater, and expands and contracts the load receiving portion having an outer diameter larger than the other on the root side. An iron tip member having a slit groove, a member covering the root side of the iron tip member and the latter half of the electric heater, and is made of a cylindrical elastic material as a whole,
A holding spring having an axial slit formed in a central portion excluding both end portions and a second step portion formed behind a contact point with the load receiving portion, and a member covering the holding spring. An electric machine having a fixed pipe, the rear end of which is connected to the movable side of the fastening device, and a third step portion for pressing the holding spring in the radial direction is formed behind the second step portion in the assembled state. Trowel.