JP2001121258A - Brazing furnace for making chain ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformize the heating temperature of a gold or a gold alloy-made chain ring butting part and to electrically realize the high temperature for heating-brazing a platinum or a platinum alloy-made chain ring butting part in high accuracy. SOLUTION: This apparatus disposes a transportating device for continuously or intermittently shifting partially in the vertical direction of a long chain to be heated having powdery brazing filler metal for joining near the butting position of the noble metal-made chain ring, a tunnel type preheating furnace provided with a resistance heating exothermic body disposing a temperature detector for controlling the temperature of a preheating tube and inside of this tube where the chain to be heated passes, a tunnel type heating furnace provided with a resistance heating exothermic body disposing a temperature detector for controlling the temperature of a furnace core tube and inside of the furnace core tube where the chain to be heated passes in succession to the preheating furnace, a gas introducing member for introducing the atmospheric gas into the furnace core tube continuously penetrated from the preheating furnace to the outlet of the heating furnace, and a rapid cooling device arranged corresponding to the shifting path in the transporting device and holding the coolant for rapidly cooling the chain heated in the heating furnace in succession to the heating furnace.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brazing furnace for a noble metal chain ring for forming accessories such as necklaces and bracelets of various noble metals.

[0002]

2. Description of the Related Art Recently, various methods of brazing a butt portion to a noble metal chain ring forming jewelry such as a necklace or a bracelet are selected according to the material and size of the chain ring. In general, a chain made of gold or a gold alloy is often brazed in a conveyor furnace having a metal belt conveyance section and capable of setting a reducing atmosphere. On the other hand, a chain made of platinum or a platinum alloy is heated and brazed by a gas burner.

[0003]

However, when the butting portion is brazed by using the above-described method, first, a conveyor furnace having a metal belt conveyor and having a reducing atmosphere has a maximum working temperature. Because it is about 1100 ° C,
In the conveyor furnace, insufficient heating temperature occurs at a chain ring abutting portion made of platinum or a platinum alloy, resulting in insufficient winding. In addition, the chain ring butting portion made of gold or gold alloy is placed on a metal belt. However, a difference in heat capacity is generated depending on the size of the chain ring, which appears as a surface temperature difference. As a result, uneven heating causes temperature unevenness, so that the wax does not flow uniformly. The heating and brazing operation of the precious metal chain ring butt with the gas burner can be easily obtained up to a relatively high temperature, but it is difficult to measure the heating temperature during the operation. It has a drawback that it is difficult to improve the process yield because of relying on the visual experience of the operator. In view of the above problems, the present invention aims to make the heating temperature of the noble metal chain ring abutting portion uniform and to realize the high temperature required for heating and brazing the platinum and platinum alloy chain ring abutting portion. An object of the present invention is to provide a brazing furnace for a chain ring.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a brazing furnace for a chain ring according to the present invention comprises a long heated chain having a powdered brazing joint in the vicinity of abutment of a noble metal chain ring. And a conveying device for transferring, in part or in a vertical direction, continuously or intermittently, a preheating pipe provided in correspondence with a vertical transfer path of the conveying apparatus, and a preheating pipe through which the heated chain passes, and a pipe in the pipe. A tunnel-shaped preheating furnace including a resistance heating element provided with a temperature detector for performing temperature control, a furnace core tube through which a heated chain passes at a stage subsequent to the preheating furnace, and temperature control in the furnace core tube , A tunnel-shaped heating furnace comprising a resistance heating element provided with a temperature detector for detecting the temperature, a space provided inside the tunnel-shaped preheating furnace and the heating furnace, and further surrounded by the resistance heating element. Continuously from the vicinity of the preheating furnace inlet to the heating furnace outlet. A gas introduction member for introducing an atmospheric gas into the furnace core tube, and a cooling medium provided corresponding to a transfer path of the transfer device following the heating furnace, for rapidly cooling a heated chain heated by the heating furnace. Which has a quenching device containing the.

[0005]

The present invention has the above-mentioned structure, and its operation is as follows. The chain to be heated is sandwiched between the feed roller and the holding roller, passes through the tunnel-shaped preheating furnace continuously or intermittently in the longitudinal direction, and moves in parallel to the tunnel-shaped heating furnace outlet. The heated chain is located on the center line of the annular resistance heating element heated to the joining powder brazing temperature through the space surrounded by the resistance heating element heated to the preheating temperature. Atmospheric gas controlled at a constant flow rate flows from an external gas supply source through a flow meter into the furnace core tube that continues until the furnace, and after passing through the heating furnace, the high-temperature heated chain that moves from the furnace outlet is underwater. It is quenched. As a result, the heating temperature of the chain linking butting portion is made uniform, and it is possible to prevent poor finishing of the chain making ring due to uneven temperature distribution and instability of the metal structure of the butting brazing portion.

[0006]

Next, an embodiment of the present invention will be described with reference to FIG. The heated chain 1 wound around the supply reel 13 is pulled out while being sandwiched between the continuously rotating feed roller 2 and the pressing roller 3, transported downward, and guided into the furnace core tube 4 in the vertical direction. Atmosphere gas whose gas flow rate has been previously adjusted by a flow meter (not shown) is introduced into the furnace core tube 4 through an introduction pipe 7 serving as a gas introduction member, if necessary. The temperature of the inside of the preheating furnace is measured by the temperature detector 11 installed near the resistance heating element 5 and the PDI control of the resistance heating element 5 is performed according to the material, shape, size, etc. of the chain 1 to be heated. The temperature of the heating furnace at the subsequent stage is adjusted to a predetermined temperature. The temperature of the heating furnace at the subsequent stage is measured by a temperature detector 12 installed near the resistance heating element 6, and the resistance heating element 6 is PDI-controlled to make the material and the shape of the chain 1 to be heated.・ Adjusted to a predetermined temperature according to the dimensions. The furnace core tube 4 and the resistance heating elements 5 and 6
A preheating furnace and a heating furnace are constituted by the temperature detectors 11 and 12. The heated chain 1 that has been heated and brazed while passing through the furnace core tube 4 is guided to a cooling tank 8 that stores cooling water as a quenching device, and is subjected to an underwater quenching process. The pulling roller 9 and the pressing roller 3 which constitute a transport device together with the feed roller 2 and the pressing roller 3 are preset so that the pulling roller 9 rotates synchronously with the feed roller 2. To be heated 1 which has been subjected to quenching treatment in water
Is raised. This series of processing operations is continuously performed, and a pair of position detectors 10 and 10 are provided at positions vertically sandwiching a transfer path between the supply reel 13 and the feed roller 2.
The feeding speed of the supply reel 13 is adjusted in accordance with the detection signal of 10. That is, when the upper position detector 10 detects the chain 1 to be heated, the feeding speed of the supply reel 13 is increased, while when the position detector 10 below detects the chain 1 to be heated, the feeding speed of the supply reel 13 is increased. Slow down.

[0007]

As described above, according to the present invention, the brazing temperature is controlled while flowing the atmosphere gas in the brazing portion of the noble metal chain ring so that the heat applied to the brazing portion of the chain ring is uniform. As a result, the following effects can be obtained as compared with the conventional method. (1) For the chain ring butted part made of platinum or platinum alloy,
Conventionally, the step of heating and brazing by a skilled worker with a gas burner becomes possible even for an unskilled person, which helps to reduce labor shortage and reduces manufacturing costs. (2) A brazing area of 90% or more is ensured, and the joining portion of the chain-making ring does not protrude to the outer peripheral portion in a protruding manner, and a gap not joined to a portion corresponding to the front side of the chain-making ring butted portion on the back side. There is no leaving. (3) The heat capacity inside the heating furnace main body is large, and the radiant heat generated during brazing is reflected to the region where the chain to be heated passes, so that the atmosphere temperature in the furnace can be stabilized, and compared with the conventional case. In addition, the temperature reproducibility between chains to be heated is increased. (4) The rate of defective brazing is reduced, and the yield is improved. (5) Compared to the conventional conveyor furnace where the conveyor belt moves in the heating furnace and repeats overheating and cooling, only the non-heating chain moves in the heating furnace, so the power consumption required for the electric furnace is about one-fifth. To save money. (6) Compared with the conventional conveyor furnace, the direction of movement of the chain to be heated during the process is limited to the direction of gravity, so that the installation floor area of the apparatus can be reduced to about 1/5.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a schematic structure of a brazing furnace for a chain ring in one embodiment of the present invention.

FIG. 2 is a perspective view of various chain rings used in Examples.

FIG. 3 is a cross-sectional view showing a schematic structure of a conveyor furnace as an example of a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chain-making (ring) 2 Feed roller 3 Holding roller 4 Furnace core tube 5 Resistance heating element (Preheating furnace) 6 Resistance heating element (Heating furnace) 7 Introductory pipe 8 Cooling tank 9 Pulling roller 10 Position detector 11 Temperature detection Vessel (preheating furnace) 12 Temperature detector (heating furnace) 13 Supply reel

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) F27D 7/02 F27D 7/02 Z

Claims (4)

[Claims] 1. A conveying device for continuously or intermittently transferring a long heated chain having a powdered solder for joining in the vicinity of abutment of a noble metal chain ring, and partly in a vertical direction. A tunnel-shaped heating furnace provided corresponding to the vertical transfer path and comprising a furnace core tube through which the heated chain passes and a temperature detector for controlling the temperature in the furnace core tube. A brazing furnace for a chain ring, comprising: a heating furnace according to (1). 2. A method for continuously or intermittently brazing a long heated chain having a powdered brazing filler metal in the vicinity of abutment of a noble metal chain ring, the method comprising: A tunnel provided with a preheating tube through which the chain to be heated passes and a resistance heating element provided with a temperature detector for controlling the temperature in the tube; A brazing furnace for a chain-making ring, wherein a brazing furnace is provided, and a long heating chain is preheated and then brazed. 3. A method for continuously or intermittently brazing a long heated chain having a powdered brazing filler metal in the vicinity of abutment of a precious metal chain ring. A gas introduction member for introducing an atmospheric gas into a furnace core tube continuous from the vicinity of the entrance of the preheating furnace to the exit of the heating furnace is provided in a space surrounded by the resistance heating element, and a long heated chain is provided. A brazing furnace for chain-making rings, wherein the brazing furnace is heated in an atmosphere in which an atmosphere gas flows. 4. A method for continuously or intermittently brazing a long chain to be heated having a powdered brazing filler metal in the vicinity of abutment of a noble metal chain ring. A brazing furnace for a chain making ring, comprising a quenching device provided corresponding to a transfer path and containing a cooling medium for quenching a chain to be heated heated by the heating furnace.