JP2537754Y2 - Gas burner for mold heating - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safe and high-efficiency gas burner for molds developed especially for preheating a mold for a die-cast machine.

[0002]

2. Description of the Related Art As a general preheating method conventionally used for heating a mold, as shown in FIG. 3 , a burner chip 12 is mounted on the upper and lower surfaces to simultaneously heat the upper and lower surfaces of a mold A. This is a method of heating the original mixed gas burner 11 by a direct flame.

[0003] In this type of burner, a plurality of holes are provided.
Insert the inner cylinder with multiple holes into the arranged outer cylinder,
A gutter drying burner with an inlet pipe for blowing fuel etc. into the cylinder
(See Japanese Utility Model Application Laid-Open No. 2-115630) .

[0004]

[Problem to be solved by the present invention] The above-mentioned mixed gas burner has the following problems. That is, since the high temperature flame of the burner directly heats the coating agent on the mold surface, the life of the coating agent is shortened, and the number of times of changing the mold increases.

Since it is not possible to attach a very large burner between the molds, it takes time to raise the temperature. In addition, when heating with a gas burner (not shown) fixed to the mold not only from the inside of the mold but also from the back to shorten the heating time, it is difficult to control the temperature of the mold.

When the temperature is raised to about 500 ° C., which is the preheating temperature of the mold, because of the original mixed gas burner, it is dangerous because the burner often causes a backfire. In addition, it is difficult to provide an automatic ignition device by the electric spark of the burner and a safety device for flame detection.

[0007] In the latter gutter drying burner, holes provided in the outer cylinder are provided.
The size is the same and the emission of combustion gas can be changed
Not evenly heated according to the shape of the mold.
The cylinder is provided with a plurality of holes through which the combustion flame blows out.
The combustion flame blows out from the hole to the outer tube,
Completely burned, the inner tube glows red, the outer tube
The inner tube glows to higher and higher temperatures because there is little heat radiation
To 1100 ° C to 1200 ° C and use heat-resistant cast steel
Temperature. For heating the mold of this application
Its use has a problem in terms of durability .

[0008] This invention , in view of the problems of the prior art ,
Previously mixing gas burner provided single-ended double radiant and out tube, the inner tube without providing the hole, reducing the combustion of the inner tube, the outer
Distribute or change the size of combustion gas discharge holes only above and below the pipe.
The upper and lower dies,
It is an object of the present invention to provide a mold-heating gas burner that can be uniformly heated with high efficiency according to the shape of a mold and can be heated to a predetermined temperature.

[0009]

According to the present invention, in order to achieve the above object, a radiating inner tube 2 is connected to a high-load combustion premix gas burner 1 capable of burning in a tube, and a tip end is provided on the outer periphery of the inner tube 2.
Closing the, and combustion gas which Ru by inverting the combustion gas from the inner pipe 2 a radiant outer tube 3 bored a plurality of combustion gas discharge holes 5 in the vertical
In the scan path 4 that surrounds and exist, the radiant outer tube 3
By changing the distribution or size of the plurality of combustion gas discharge holes 5 provided above and below, the heating of the upper and lower molds can be made substantially uniform.
It was made .

[0010]

In the gas burner for heating a mold according to the present invention, gas and air are separately supplied to a burner head by a premixed gas burner 1, mixed in a flame holder of the burner, ignited by an electric spark, and combustion is started. The flame is held by the inner radiation tube 2 connected to the burner and burned.

The combustion gas burned in the inner tube 2 is inverted into the combustion gas passage 4 at the tip of the inner tube, and the radiant heat of the inner tube 2 and the combustion gas cause the outer tube 3 to glow to generate radiant heat. ejection amount of the combustion gas the distribution or size of a plurality of combustion gas discharge holes 5 of the upper and lower surface facing the mold of the outer pipe by change
Can be increased or decreased in accordance with the shapes of the upper and lower molds and the molds, so that the molds having irregularities in the upper and lower thicknesses can be heated and heated almost uniformly.

[0012]

An embodiment will be described with reference to the drawings. In FIGS. 1 and 2 , reference numeral 1 denotes a high-load combustion premix gas burner capable of in-pipe combustion, to which a single-ended double pipe comprising a radiation inner pipe 2 and a radiation outer pipe 3 is connected.

One end of the radiating inner tube 2 is connected to the premixed gas burner 1 horizontally, and the outer radiating tube 3 is provided with a closing portion 6 at the tip, and is disposed concentrically with the inner tube 2 so that the closing portion 6 at the tip and the inner tube are connected. A combustion gas passage 4 for inverting combustion gas is formed in the outer pipe 3 from the outlet of the inner pipe 2 at a certain distance from the tip of the inner pipe 2, and a plurality of combustion gas discharge holes 5 are formed above and below the outer pipe 3. The distribution or size
And radiate heat up and down from the outer tube 3,
Combustion gas is discharged above and below the combustion gas discharge hole 5. In the embodiment, the combustion gas discharge hole 5 of the outer tube 3 is
Any number between the upper and lower surfaces of the outer tube facing the mold A in the axial direction
It is drilled at a distance. The discharge holes 5 are located on the upper and lower surfaces.
Also in the direction, it is provided at an arbitrary interval facing the mold. What
In the drawing, the gas burner is horizontal and discharge holes are provided above and below the outer tube.
While showing the case of providing, it is not limited thereto
When the burner is vertical, discharge holes are provided on the left and right of the outer tube.
Will be provided. A is a die for a die-cast machine, which is provided with a die-heating gas burner between the dies to heat the inner surface of the die.

Although the combustion gas and the like are released from the radiation outer tube 3 , the heat rises, so that when the same amount of discharge occurs , the temperature of the upper mold A is slightly higher than that of the lower mold. Whether the distribution of the gas discharge holes 5 is slightly larger in the lower part than in the upper part
(See FIG. 1) Alternatively, it is preferable that the diameter of the lower portion is slightly larger than that of the upper portion so that the emission of the combustion gas downward is slightly increased so that the heating of the upper and lower molds A is substantially uniform.
If the mold has an uneven surface, the size of the combustion gas discharge hole 5 is changed according to the distance from the mold so that uniform heating can be performed. The distance between the concave surface B and the convex surface C of the mold A is away from the burner.
Because it is different, farther is more heat than closer to heat evenly
Because of the required volume, the distant discharge hole 5b has a large diameter,
The other discharge hole 5c has a small diameter (see FIG. 2) .

In the premixed gas burner 1, gas and air are separately supplied to a burner head, mixed in a flame holder of the burner, ignited by an automatic ignition spark plug (not shown), and burned. Further, the burner 1 is provided with a flame detection hole (not shown) at the base of the flame stabilizer so that the flame can be detected by ultravision or the like.

[0016] With the above-described structure, combustion is started by mixing in the flame holder of the premixed gas burner 1, and gas and air are mixed slowly in the radiant inner tube 2 to suppress combustion. so as to most often burned in the combustion gas passage 4 in the outer tube 3 to expand the pipe diameter is inverted at the tip, a plurality of combustion of the outer tube
The metal is completely burned and glows red before being discharged from the gas discharge holes, and the upper and lower gold are combined by utilizing the radiant heat of the outer tube 3 and the convective heating by the high-temperature combustion gas ejected from the combustion gas discharge holes 5 of the outer tube 3. The inner surface of the mold A , for example, the uneven surface is uniformly heated and heated to a desired temperature, for example, 500 ° C.

[0017]

According to claim 1 of the present invention, the radiation inner tube is
Keep the outer tube glowing as little as possible ,
Distribution or large size of combustion gas discharge holes provided on the upper and lower surfaces
Since the size has been changed, it is compatible with upper and lower molds and mold shapes
To change the amount of combustion gas emitted from the discharge holes.
The upper and lower molds, the uneven surface of the molds are efficient and uniform
Can be heated. And since there is no hole in the inner tube, the inner tube
At the end of the inner tube to increase combustion
Combustion in the combustion gas passage inside the outer tube
Completely burn until exhausted from multiple holes, heat is transferred to the mold
Heat is dissipated toward the
Radiated heat from the outer tube and blows out from the combustion gas discharge hole of the outer tube
The mold can be heated evenly by the high temperature combustion gas. Since the indirect heating method using radiant heat and combustion gas, the flame of the burner does not hit the inner surface of the mold directly.
The degree of damage to the coating agent on the mold surface is small,
Therefore, the life of the coating agent is prolonged, and the number of times of changing the mold can be reduced.

Further, since the heating is performed by the radiant heat of the outer tube and the convection heating of the combustion gas from the discharge hole, the mold can be efficiently heated without increasing the input of the burner, and the heating speed of the mold is reduced. Not even. Therefore, heating from the back of the mold can be eliminated, and the apparatus can be simplified by reducing the number of heating points, and the temperature control can be simplified. Since the flame holding part and the heating part are separated, backfire can be completely prevented and it is safe.

[Brief description of the drawings]

FIG. 1 shows a portion of a discharge hole of a gas burner for heating a mold according to the present invention.
It is the longitudinal section which changed cloth .

FIG. 2 is a longitudinal sectional view in which the size of a discharge hole is changed.

FIG. 3 is a side view showing a conventional original mixed gas burner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Premixed gas burner 2 Radiation inner tube 3 Radiation outer tube 4 Combustion gas passage 5 Combustion gas discharge hole

Claims (1)

(57) [Scope of request for utility model registration] A radiant inner pipe (2) is connected to a high-load combustion premix gas burner (1) capable of burning in a pipe, and the inner pipe (2) is connected to the radiant inner pipe (2).
Periphery to closing the tip, and resides a plurality of combustion gas discharge holes (5) combustion gas passage for reversing the combustion gas from the inner tube of the radiant outer tube (3) provided with (2) up and down (4) of It was surrounded Te
A plurality of radiation tubes provided above and below the radiation outer tube (3) .
It changed the distribution or size of the combustion gas discharge hole (5)
A gas burner for heating a mold.