WO2007032125A1

WO2007032125A1 - Feeder head heating device

Info

Publication number: WO2007032125A1
Application number: PCT/JP2006/310355
Authority: WO
Inventors: Tamio Okada; Tadao Sasaki; Hideaki Ohashi; Shinji Origuchi
Original assignee: Nippon Crucible Co., Ltd.
Priority date: 2005-09-14
Filing date: 2006-05-24
Publication date: 2007-03-22
Also published as: JP4698353B2; JP2007075854A

Abstract

A feeder head heating device capable of efficiently heating a feeder head. The feeder head heating device (1) has an electrically conductive sleeve (2) and a pair of electrodes (21, 22) attached to one end and the other end, respectively, of the sleeve (2). A feeder head (a) received in the sleeve (2) is heated by applying a voltage between the pair of electrodes (21, 22) to supply electricity to the sleeve (2).

Description

Specification

Hot water heater

Technical field

[0001] The present invention relates to a feeder heating apparatus that heats a feeder when forging a metal product.

Background art

[0002] In the process of forging a metal product such as iron, copper, and aluminum, the volume of the metal shrinks when the molten metal filled in the mold solidifies, and there is a void called a shrinkage nest in the forged product. appear. In order to prevent this shrinkage from occurring, it is necessary to replenish the hot metal in the mold while the product is manufactured. Therefore, the hot water must be heated and kept at a temperature that does not cause the metal to solidify during the forging process!

[0003] As a method for heating and keeping the hot water, a hot water keeping method described in Patent Document 1 is known. As shown in FIG. 3, this hot water insulation method is configured by arranging an electric resistance heating element 58 around a hot water portion 55 connected to the upper portion of the vertical gap 52 and a metal terminal provided on the outer peripheral surface thereof. In this method, the heating element 58 is energized through 59 to use the generated Joule heat to uniformly heat and maintain the hot water. Then, the hot water heated by the hot water supply section 55 can be supplied to the vertical cavity 52 through the supply port 53.

Patent Document 1: Japanese Patent Laid-Open No. 56-71556

Disclosure of the invention

Problems to be solved by the invention

[0004] However, according to such a hot water insulation method, the entire hot water supply section 55 is heated in order to heat the hot water in the vicinity of the supply port 53 that particularly requires heating. , It required excessive power.

[0005] The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a feeder heating apparatus capable of efficiently heating a feeder.

Means for solving the problem

[0006] The object of the present invention includes a conductive sleeve and a pair of electrodes attached to one end side and the other end side of the sleeve, respectively, and applies a voltage between the pair of electrodes. This is accomplished by a feeder heating device that heats the feeder contained in the sleeve by energizing the sleeve.

[0007] In this feeder heating device, the sleeve includes a high resistance portion and a low resistance portion arranged along the axial direction, and the high resistance portion has a unit length in the axial direction relative to the low resistance portion. The electrical resistance is great!

[0008] Further, it is preferable that the high resistance portion is thinner than the low resistance portion.

[0009] Alternatively, the high resistance portion has a larger electrical resistivity value than the low resistance portion!好 It is preferred to be made of material.

[0010] In each of the above hot-water feeder heating devices, it is preferable that the entire inner peripheral surface of the sleeve is a tapered surface.

[0011] Further, the sleeve has a pair of attachment portions protruding outward from the outer peripheral surfaces of both end portions, and the pair of electrodes are respectively connected to the attachment portions via conductive heat insulating materials. Attached to, prefers to be.

The invention's effect

[0012] According to the feeder heating apparatus of the present invention, the feeder can be efficiently heated.

Brief Description of Drawings

FIG. 1 is a side sectional view of a feeder heating apparatus according to an embodiment of the present invention.

FIG. 2 is a top view of the feeder heating device.

FIG. 3 is a side sectional view of a conventional hot water heater.

Explanation of symbols

a feeder

E Power supply

1 Hot water heater

2 sleeve

4 High resistance section

5 Low resistance part

7 Upper mounting part

8 Lower mounting part 21 Upper electrode

22 Lower electrode

31 Thermal insulation sheet

32 Conductive insulation

40 vertical

43 Vertical gap

44 Spacer

45 Fixed tie rod

BEST MODE FOR CARRYING OUT THE INVENTION

[0015] Hereinafter, actual forms of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a side cross-sectional view of a hot water heater 1 according to an embodiment of the present invention, and FIG. 2 is a top view of the hot water heater 1.

[0016] As shown in Fig. 1, the feeder heating device 1 includes a sleeve 2, an upper electrode 21 attached to the upper portion of the sleeve 2, and a lower electrode 22 attached to the lower portion. It is installed on top of the vertical 40.

[0017] The sleeve 2 is formed of a conductive material that generates heat when energized. For example, a metal having a relatively high melting point with respect to a refractory material including a carbon, a black ship, silicon carbide, or a metal tapping metal. Can be used. The sleeve 2 includes a high resistance portion 4 and a low resistance portion 5 arranged along the axial direction. An upper mounting portion 7 and a lower mounting portion 8 that protrude outward from the outer peripheral surface are respectively provided at the upper end portion and the lower end portion of the sleeve 2. In addition, the sleeve 2 has a heat insulating sheet 31 wound around the outer peripheral surface thereof, and a hot water a that is a molten metal force is accommodated therein.

The high resistance portion 4 is configured so that the thickness is thinner than that of the low resistance portion 5 and the electric resistance value is larger than that of the low resistance portion 5. Here, the electric resistance value is an electric resistance per unit length in the axial direction of the sleeve 2. In this embodiment, when the same material is used, it is preferable that the low resistance part 5 is 1.1 to 5.0 times the high resistance part 4. In this embodiment, the low resistance part 5 is 20 mm. The high resistance part 4 is set to 10 mm.

The upper electrode 21 and the lower electrode 22 are formed in a ring shape as shown in FIG. It is attached to the part attaching part 7 and the lower attaching part 8, respectively. A conductive heat insulating material 32 is interposed between the upper electrode 21 and the lower electrode 22 and the upper mounting portion 7 and the lower mounting portion 8. In the present embodiment, the conductive heat insulating material 32 is preferably made of a material having excellent conductivity, heat insulating properties and adhesion, and an expanded graphite sheet is used. As the conductive heat insulating material 32, carbon fiber paper, carbon fiber felt, or the like may be used. A spacer 44 is installed between the lower electrode 22 and the sleeve 2 and the saddle 40. The spacer 44 is preferably formed of an insulator. In addition, overhangs 21b and 22b and a plurality of frames 46 and 47 that project outward in the radial direction are provided on the periphery of the upper electrode 21 and the lower electrode 22, and the overhangs 21b and 22b It is connected to the conductive plates 21a and 22a.

The frames 46 and 47 are fixed by a fixed tie rod 45. The lower part of the fixed tie rod 45 is fixed to the spacer 44, and the upper part is screwed with a fixing nut 49. As a result, the upper electrode 21 and the lower electrode 22 are fixed to the sleeve 2. As the fixed tie rod 45, a known one that assembles a frame or a plurality of parts by screwing can be used, and it is preferable that the fixed tie rod 45 is made of an insulator. An insulating plate 48 is interposed between the fixing nut 49 and the frame 46.

The conductive plates 21 a and 22 a are connected to a power supply device E such as a thyristor rectifier, and are configured such that a voltage can be applied between the upper electrode 21 and the lower electrode 22.

The saddle mold 40 is, for example, a sand mold or a mold, and a saddle-shaped gap 43 is formed therein, and the saddle-shaped gap 43 communicates with the inside of the sleeve 2. In addition, a sprue 41 for injecting a molten metal and a sprue 42 for connecting the sprue 41 and the scissors-shaped gap 43 are formed in the vertical mold 40.

[0023] Next, a method of heating the feeder a using the feeder heating device 1 configured as described above will be described.

[0024] First, the hot water heater 1 is erected on the upper portion of the saddle mold 40 so that the saddle cavity 43 and the inside of the sleeve 2 communicate with each other. The location where the hot water heater 1 is installed is preferably determined in consideration of the portion where shrinkage cavities of the forged product occur.

Next, power supply device E is turned on, and a voltage is applied between upper electrode 21 and lower electrode 22. The As a result, the sleeve 2 generates heat due to current flowing in the axial direction.

Thereafter, molten metal is poured from the gate 41. At this time, the amount of molten metal is set to be larger than the volume of the vertical cavity 43. The injected molten metal passes through the runner 42 from the sprue 41 and fills the vertical cavity 43. Further, a part of the molten metal overflows from the saddle-shaped gap 43 and is filled in the sleeve 2. Thus, the hot water a is accommodated in the sleeve 2 and is heated by the heat generation of the sleeve 2. On the other hand, the molten metal in the vertical cavity 43 is solidified over time to produce a metal product. In this process, since the feeder a is heated by the sleeve 2, it maintains a molten state without solidifying. At this time, the high resistance portion 4 of the sleeve 2 has a higher electrical resistance value than the low resistance portion 5, and therefore has a higher temperature than the low resistance portion 5. Fever is suppressed. In this way, the high resistance part 4 with which the feeder a mainly comes into contact becomes high in temperature, and the heat generation of the low resistance part 5 is suppressed, so that the feeder a can be efficiently heated.

[0027] After the molten metal solidifies, the power supply E is turned off to stop energization of the sleeve 2. As a result, the sleeve 2 does not generate heat, and the feeder a contained therein is solidified. After that, remove the mold 40 from the manufactured product, and remove the feeder heating device 1 from the feeder a. Finally, the hot water a is separated from the manufactured product. This completes the product.

In the present embodiment, since the conductive heat insulating material 32 is interposed between the upper electrode 21 and the lower electrode 22, and the upper mounting portion 7 and the lower mounting portion 8, the heat generated in the sleeve 2 is generated by the upper electrode. It is possible to prevent heat dissipation through the 2 1 and the lower electrode 22. Further, since the heat insulating sheet 31 is spread on the outside of the sleeve 2, heat radiation from the sleeve 2 can be prevented. In addition, since the spacer 44 is installed, the installation surface of the hot water heater 1 becomes flat and can be installed stably. Further, when the spacer 44 is an insulator, the conduction between the lower electrode 22 and the saddle 40 can be cut off. Further, the temperature of the sleeve 2 can be easily controlled by adjusting the voltage of the power supply device E. Furthermore, by measuring the electrical resistance value of the sleeve 2, it is possible to detect an abnormality and determine the replacement time.

[0029] While one embodiment of the present invention has been described in detail above, a specific aspect of the present invention is not limited to the above embodiment. For example, the configuration of the sleeve 2 is not particularly limited as long as the electrical resistance value of the high resistance portion 4 is larger than the electrical resistance value of the low resistance portion 5. It may be configured such that the electrical specific resistance value is higher than that of the material of the low resistance portion 5. In this case, it is preferable that the electrical specific resistance value of the high resistance portion 4 is 10 X 10 ^{_3 to} 500 Χ 10 ^_3 Ω • cm in order to increase the heat generation efficiency. 50 X 10 ^_3 to 200 Χ 10 ^_3 Ω More preferably, it is' cm. Further, the ratio of the electrical resistivity value of the low resistance portion 5 to the electrical resistivity value of the high resistance portion 4 is preferably 0.001-0. Is more preferable.

[0030] Further, in the present embodiment, the joint portion between the high resistance portion 4 and the low resistance portion 5 has a stepped shape, but may have a shape in which the thickness continuously changes. .

[0031] The entire inner peripheral surface of the sleeve 2 may be a tapered surface. As a result, the sleeve 2 can be easily removed from the feeder a after the product is manufactured.

In the present embodiment, the high resistance portion 4 is arranged on one side in the axial direction of the sleeve 2 and the low resistance portion 5 is arranged on the other side, but the arrangement position can be set as appropriate. . For example, the central portion of the sleeve 2 can be the high resistance portion 4, and the upper and lower portions can be the low resistance portion 5. As a result, the upper electrode 21 and the lower electrode 22 can be attached to the low-resistance portion 5 where heat generation is suppressed, so that the upper electrode 21 and the lower electrode 22 can be prevented from being damaged by heat. it can.

[0033] Further, the inner diameter of the sleeve 2 may be smaller in the vicinity of the saddle-shaped gap portion 43 than the inner diameter of other portions. As a result, the connecting portion between the forged product and the hot water a becomes narrow, so that the hot water a can be easily separated from the product and the yield can be improved.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the present embodiment.

[0035] A voltage was applied to the feeder heating device 1 to conduct current heating. In the example, the thickness of the sleeve 2 is changed, and the electric resistance value is changed. In the comparative example shown as the prior art, the thickness of the sleeve 2 is constant and the electrical resistance value does not change.

[0036] The inner diameter, length, and electrical resistivity of the sleeve 2 were 160 mm, 500 mm, and 15 X 10 ^_3 Ω 'cm in both the examples and the comparative examples. The thicknesses of the high resistance portion 4 and the low resistance portion 5 in the sleeve 2 were set as shown in Table 1, respectively. In addition, the length of the high resistance portion 4 in the example was set to 200 mm. In Example and Comparative Example, 20V is applied to Sleeve 2. The voltage was applied for 5 minutes.

[table 1]

As a result, as is apparent from Table 1, in the comparative example in which the electric resistance value is not changed, the temperature of the sleeve 2 does not rise, and therefore the feeder a cannot be heated, but the electric resistance value is changed. In the example, since the high resistance portion 4 of the sleeve 2 can be heated to a high temperature, the feeder a can be heated. In addition, since the high resistance part 4 with which the feeder a mainly contacts is heated, the heat generation of the low resistance part 5 is suppressed, so that the feeder a can be efficiently heated.

Claims

The scope of the claims

[1] a conductive sleeve;

A pair of electrodes attached to one end side and the other end side of the sleeve, respectively, and applying a voltage between the pair of electrodes to energize the sleeve, thereby allowing the feeder to be accommodated in the sleeve. Hot water heating device to heat the.

[2] The sleeve includes a high resistance portion and a low resistance portion arranged along the axial direction,

The feeder apparatus according to claim 1, wherein the high resistance portion has a larger electrical resistance per unit length in the axial direction than the low resistance portion.

[3] The hot water heater according to claim 2, wherein the high resistance portion is thinner than the low resistance portion.

[4] The electrical resistance value of the high resistance part is larger than that of the low resistance part! 3. The hot water heating apparatus according to claim 2, wherein the hot water heating apparatus is formed of a firewood material.

5. The feeder apparatus according to any one of claims 1 to 4, wherein the sleeve has an entire inner peripheral surface tapered.

[6] The sleeve has a pair of attachment portions projecting outward from the outer peripheral surfaces of both end portions, and the pair of electrodes are respectively attached to the attachment portions via conductive heat insulating materials. The hot water heater according to any one of claims 1 to 5, which is attached.