JPH06277782A - Method for atomizing lubricant to metallic die at time of hot forging of steel - Google Patents

Abstract

PURPOSE:To enable sticking of a lubricant by lowering the surface temperature of a metallic die in a short time. CONSTITUTION:The method is for atomizing a lubricant to metallic dies C1, C2, D1, D2 at the time of hot forging of steel; a nozzle head 1 is used in which nozzles 1aa-1ad for jetting cooling water and nozzles 1ba-1bd for atomizing the lubricant are integrated or nearly integrated in structure; and when a surface temp. sensor 2 indicates the temp. above the upper limit for sticking the lubricant, cooling water is injected to the surface of the metallic dies C1, C2, D1, D2 from the nozzles 1aa-1ad for jetting cooling water. After the surface temp. of the metallic dies is confirmed to be the optimum temperature for sticking the lubricant by means of a signal from the sensor 2 for detecting surface temp., the jetting of the cooling water from the nozzles 1aa-1ad is immediately stopped, the atomization of the lubricant from the nozzles 1ba-1bd for atomizing the lubricant is commenced, and the absolute minimum quantity of the lubricant is atomized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention has a forging pitch of 1
The mold surface temperature is locally 300 to 400 ° C in 2 seconds or less.
The present invention relates to a method for spraying a lubricant onto a die during high-speed hot die forging of steel that rises rapidly.

[0002]

2. Description of the Related Art When performing hot die forging of steel, a liquid lubricant is generally sprayed and adhered to the die surface for the purpose of formability and releasability. However, the lubricants currently on the market,
In particular, the amount of water-soluble graphite attached varies greatly depending on the temperature of the object to be sprayed, and about 200 ° C. is the optimum temperature.

In the case of hot die forging of steel, the temperature of the raw material is as high as 1000 ° C. and the die surface temperature due to forging locally rises to about 300 to 400 ° C., so that the lubricant is optimally attached. When the temperature exceeds the temperature, the amount of adhesion to the mold decreases and the moldability and mold releasability deteriorate.

Therefore, conventionally, in order to lower the surface temperature of the mold, the spraying time of the lubricant is lengthened to give the lubricant a cooling effect, so that the amount of the lubricant used tends to increase. It was Especially, in the conventional lubricant, since a binder is mixed in the lubricant in order to have adhesion to the mold,
The cooling effect was poorer than that of other coolants, and it took longer than necessary to cool the mold. Further, for the same reason, the lubricant is less likely to evaporate, so that the excess lubricant is likely to accumulate in the engraved portion, resulting in the lack of thickness of the product.

[0005]

However, in recent years, in order to reduce the manufacturing cost of forged products, speeding up of forging press,
There is a tendency to reduce the amount of lubricant used, and it has become necessary to shorten the lubricant spray time. For this reason, the surface temperature of the mold is significantly increased, and it becomes difficult for the lubricant to adhere to the mold, resulting in problems in moldability and mold releasability.

The present invention has been made in view of the above-mentioned problems, and a lubricant spraying method in hot forging of steel which cools the surface temperature of a mold in a short time to allow the lubricant to adhere. Is intended to provide.

[0007]

In order to achieve the above object, a method of spraying a lubricant in hot forging of steel according to the present invention is a method of spraying a lubricant into a die during hot forging of steel. So, using a nozzle head with a structure in which the cooling water injection nozzle and the lubricant spray nozzle are integrated or close to that, after receiving a signal from the surface temperature detection sensor that the upper limit of the adhesion temperature of the lubricant has been exceeded, Cooling water is jetted from the cooling water jet nozzle to the die surface, and after confirming from the signal from the surface temperature detection sensor that the die surface temperature has reached the optimum temperature for the lubricant adhesion, the cooling water jet nozzle immediately cools it. The water spray is stopped, the spray of the lubricant is started from the lubricant spray nozzle, and the minimum necessary amount of the lubricant is sprayed.

In the present invention, the reason why the nozzle head in which the cooling water jet nozzle and the lubricant spray nozzle are integrated or have a structure close to that is used is to enable the cooling and the lubricant adhering effect in a few seconds. . Further, in the present invention, the necessary minimum amount of the lubricant is sprayed because the surface temperature of the mold lowers more than necessary when applied in a large amount, and the lubricant adhered is washed away. This is because, when applied to, the lubricant is likely to accumulate in a portion where the lubricant is likely to accumulate.

[0009]

In the method of the present invention, after the signal from the surface temperature detecting sensor indicates that the upper limit of the lubricant adhesion temperature is exceeded,
Cooling water is jetted from the cooling water jet nozzle to the die surface, and after confirming from the signal from the surface temperature detection sensor that the die surface temperature has reached the optimum temperature for the lubricant adhesion, the cooling water jet nozzle immediately cools it. Since the spraying of water is stopped and the minimum necessary amount of lubricant is sprayed from the lubricant spray nozzle, the lubricant can be satisfactorily applied to the mold surface in a short time.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention will be described below with reference to an embodiment shown in the accompanying drawings. FIG. 1 is an explanatory diagram of a nozzle head used in the method of the present invention and a lubricant spray system thereof, and FIG. 2 is a diagram showing a relationship between a mold surface temperature and a lubricant adhesion amount when a water-soluble graphite lubricant is used, FIG. 3 is a diagram showing a cooling curve of a mold surface by spraying water and a lubricant, and FIG. 4 is a spray pattern 1
FIG. 5 is a diagram showing an example, and FIG. 5 is a diagram showing changes in die surface temperature during forging.

In FIG. 1, reference numeral 1 denotes a nozzle head which is arranged in the middle of an upper die C1 and a lower die C2 for roughing, and an upper die D1 and a lower die D2 for finishing hammering so as to freely come and go. Spray parts 1A1-1A4 and lubricant / air spray part 1
B1 to 1B4 are integrally provided. Then, this nozzle head 1 is inserted in the position shown in FIG. 1 in conjunction with the rise of the upper molds C1 and D1, and first, the cooling water jet parts 1A1 to 1A.
From the multi-hole nozzles 1aa to 1ad provided in No. 4, for example, 0.3
The cooling water is jetted for a second (L in FIG. 4). Before injection of this cooling water, upper mold C1 ・ D1 and lower mold C2 ・ D
It is desirable to perform air injection to remove the scale in the engraved surface of 2 (K in FIG. 4).

Upper mold C1 · D at the time of jetting this cooling water
1 and the surface temperature of the lower molds C2 and D2 are measured by the temperature sensor 2 installed in the press. When the temperature sensor 2 exceeds the upper limit of the lubricant adhesion temperature, the controller 3 causes the cooling water jetting section 1A1 ~ Opening the solenoid valve 4a provided in the cooling water supply pipe to 1A4, the upper mold C1 ・ D1 and the lower mold C2 ・
Spray cooling water on the surface of D2.

The upper mold C1 and D1 and the lower mold C2 and D2
The surface temperature of the
50 ° C.), a signal is output to the controller 3, and based on this signal, the controller 3 causes the solenoid valve 4 to be installed in the cooling water supply pipe to the cooling water injection parts 1A1 to 1A4.
While closing a, lubricant / air spray section 1B
1B1 to 1B4 are operated by opening the solenoid valve 4b provided in the lubricant / air supply pipes, and the lubricant / air spray sections 1B1 to 1B1 are opened.
From the multi-hole nozzles 1ba to 1bd provided in B4, for example, 0.
The lubricant is sprayed for 5 seconds (M in FIG. 4).

After the lubricant is sprayed, the upper molds C1 and D1 are
It is desirable to spray air into the engraved surfaces of the lower molds C2 and D2 to promote the drying of the lubricant (N in FIG. 4). Further, in the present example, water was used as the cooling agent as shown in FIG. 3, when water was used as the cooling agent (I in FIG. 3), when water-cooled lubricant was used for cooling. This is because a cooling effect of 20% more than that of (J in FIG. 3) can be seen.

FIG. 5 shows the results of measuring the surface temperature of the upper mold C1.D1 and the lower mold C2.D2 when the lubricant was sprayed in the spray pattern shown in FIG. It can be seen that the surface temperature is lowered by about 120 ° C. when water cooling is used (P), compared with O). As a result, the adhesion of the lubricant is stable, and the mold adhesion occurrence rate is 80
It was 0% compared to 90%.

[0016]

As described above, by adopting the method of the present invention, the die adhesion can be prevented, the production speed is improved, and the die life is also improved. Further, since the lubricant does not collect in the die-cut surface, the rate of occurrence of wall thinning is reduced. further,
Since the amount of lubricant used is reduced, the lubricant cost is also reduced.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a nozzle head used in the method of the present invention and a lubricant spray system thereof.

FIG. 2 is a diagram showing a relationship between a mold surface temperature and a lubricant adhesion amount when a water-soluble graphite lubricant is used.

FIG. 3 is a view showing a cooling curve of a mold surface by spraying water and a lubricant.

FIG. 4 is a diagram showing an example of a spray pattern.

FIG. 5 is a diagram showing a change in die surface temperature during forging.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Nozzle head 1A1 to 1A4 Cooling water jetting section 1B1 to 1B4 Lubricant / air spraying section 1aa to 1ad Porous nozzle 1ba to 1bd Porous nozzle 2 Temperature sensor 3 Controller 4a and 4b Electromagnetic valve

Claims (1)

[Claims] 1. A method for spraying a lubricant onto a die during hot forging of steel, which comprises using a nozzle head having a structure in which a cooling water jet nozzle and a lubricant spray nozzle are integrated or close to each other, and After receiving a signal from the surface temperature detection sensor that the upper limit of the temperature of the agent adhesion has been exceeded, cooling water is sprayed from the cooling water injection nozzle onto the mold surface, and the mold surface temperature becomes the optimum temperature for lubricant adhesion. Immediately after confirming this with the signal from the surface temperature detection sensor, immediately stop the cooling water injection from the cooling water injection nozzle, start the lubricant spray from the lubricant spray nozzle, and spray the minimum amount of lubricant required. A method of spraying a lubricant onto a die during hot forging of steel, which is characterized by: