JP2737806B2 - Method of supplying refrigerant to extruded material and die backer in multi-hole hot extrusion - Google Patents

Description

The present invention relates to a method for supplying a refrigerant to an extruded material and a method for performing the method in a multi-hole hot extrusion of aluminum or an alloy thereof or the like. It is about a diver backer suitable for

[Prior Art] A conventional die backer and a method of supplying a refrigerant to an extruded material will be described with reference to FIGS. 3 and 4. FIG.

FIG. 3 is a front view of the die backer, and FIG.
It is sectional drawing which follows the arrow BB of the figure.

The die backer a is used for six-hole hot extrusion, and is in contact with the rear side in the extrusion direction of the die b. The die backer a has six through holes 5 through which the extruded material 6 passes from the center. They are formed equidistantly and equidistant from each other.

At the position near the outer periphery of the die backer a, the rear side a2 in the passing direction of the extruded material 6 indicated by the reference numeral a in FIG.
A lateral flow hole 7 having an outlet 71 at a1 is formed.

On the front side a1, a dispersion groove 8 is provided near the outer periphery so as to communicate with the outlet 71 of the flow hole 7, and the dispersion groove 8 communicates with the dispersion groove 8, respectively.
Further, a surrounding groove 9 surrounding the periphery of each passing hole 5 and a discharge port 91 communicating from each surrounding hole 9 to a peripheral edge of the corresponding passing hole 5 are formed.

A refrigerant (liquid nitrogen) pipe terminal (not shown) is screwed into the inlet 70, and at the time of extrusion, the refrigerant is supplied at a predetermined pressure from the inlet 70 to the outlet 71 through the circulation hole 70, and the refrigerant is dispersed from the outlet 71. Each discharge port 91 passes through the groove 8 and each surrounding groove 9.
, And is sprayed onto the extruded material 6 passing through each passage hole 5.

[Problems to be Solved by the Invention] According to the conventional refrigerant supply method and the die backer, as described above, the refrigerant is first moved from the position near the outer periphery of the rear side a2 of the die backer a to the position closer to the outer periphery of the front side a1. The extruded material 6 is supplied and then blown from the surrounding groove 9 to the extruded material 6 through the dispersion groove 8 in the outer peripheral portion on the front side a1. The refrigerant reaches the passage hole 5 of the extruded material 6 from the outlet 71 of the circulation hole 7. Since the distance (hence the time) required for the passage is significantly different for each of the passage holes 5, the refrigerant is supplied more to the circulation hole 5 closer to the outlet 71 of the circulation hole 7.

Therefore, the extruded material 6 passing through the through hole 5 closest to the outlet 71 is supercooled, and the extruded material 6 passing through the through hole 5 farthest from the outlet 71 is undercooled. At the same time, the lengths of the products extruded at the same time are remarkably irregular, and the insufficiently cooled extruded material that has passed through the passage hole 5 farthest from the outlet 71 has disadvantages such as cracking.

An object of the present invention is to provide a method for supplying a refrigerant to an extruded material in a multi-hole hot extrusion in which a refrigerant is more uniformly dispersed in an extruded material immediately after extrusion, and thus problems such as irregularity in product length and cracks can be prevented. And a diver backer.

[Means for Solving the Problems] A method for supplying a refrigerant to an extruded material according to the present invention includes, in order to achieve the above-mentioned object, a rear surface of a die backer having a plurality of passage holes through which the extruded material passes in the extruded material passing direction. The refrigerant is supplied from a position near the outer periphery of the die backer or an outer peripheral portion of the die backer to a substantially intermediate position between the respective passing holes on the front side of the extruded material passing direction of the die backer, and is distributed and supplied in the direction of the respective passing holes. It is configured as follows.

In order to carry out the above-described refrigerant supply method, it is a die backer having a plurality of passage holes through which the extruded material passes. It is preferable to use a through hole having an outlet at a substantially intermediate position between the through holes on the front side, and a groove formed from the outlet of the through hole to several places on the periphery of the through hole. .

The groove is an enclosing groove formed so as to surround each of the passage holes, a dispersion groove that communicates from the outlet of the flow hole to each of the enclosure grooves, and a discharge port that communicates from each of the enclosure grooves to several locations around the periphery of the through hole. It is preferred to be composed of

According to the method of the present invention, on the front side of the die backer, the refrigerant is dispersed in the direction of the passage hole from a substantially intermediate position between the plurality of passage holes, so that the extruded material passing through each passage hole is more uniformly dispersed. The refrigerant disperses.

Further, according to the die backer according to the present invention, the refrigerant is supplied to a substantially intermediate position between the plurality of passage holes on the front side of the die backer, and thereafter is distributed and supplied to the respective passage holes through the grooves. It is more uniformly dispersed in the extruded material passing through each through hole.

"Example" A preferred example of a refrigerant supply method and a die backer according to the present invention will be described with reference to Figs.

The illustrated die backer a is used for six-hole hot extrusion, and is in contact with the rear side of the die b in the extrusion direction. The die backer a has six through holes 5 through which the extruded material 6 passes. It is formed equidistant from the center and at equal angular intervals.

The extruded material 6 indicated by reference numeral a in FIG.
At the position near the outer periphery of the rear side a2
10, and a flow hole 1 having an outlet 11 on the front side a1 is formed. The circulation holes 1 are formed with holes 12 and 13 from the position near the outer periphery of the rear side a2 of the die backer a and from the approximate center position of the front side a1, respectively.
A vertical hole 14 is opened in the center direction so as to communicate the inner parts of the two and 13 with each other, and a padding 15 is formed by filling the outer peripheral end of the vertical hole 14.

At the front side a1 of the die backer a, the outlet of the circulation hole 1 is provided.
Dispersion grooves 2 are formed radially from 11 toward each through hole 5, and each dispersion groove 5 communicates with an enclosing groove 3 formed so as to surround the corresponding through hole 5. 3
Are connected to the corresponding through-hole 5 by four equally-spaced discharge ports 4 communicating with the periphery of the corresponding through-hole 5.

Screw the end of a pipe (not shown) of a refrigerant (liquid nitrogen) into the inlet 10 of the circulation hole 1 and use an aluminum alloy (2014) billet to set the extrusion ram speed (not shown) to about 150 mm / min by hot extrusion. While extruding a round bar having a cross-sectional diameter of 24 mm, through the circulation hole 1 from the refrigerant pipe,
Liquid nitrogen of -190 to 195 ° C was continuously supplied at about 23 kg per hour and sprayed on each extruded material 6 to produce an extruded product having an average length of 30 m.

 No crack occurred in the extruded product.

Using the conventional die backer described with reference to FIGS. 3 and 4, a round bar having the same size and shape is manufactured in the same manner as in the above-described embodiment, and the extruded product by the refrigerant supply method of the above-described embodiment and the conventional product are used. Table 1 shows the comparison of the product length irregularity between the extruded product and the extruded product according to the refrigerant supply method.

In Table 1, "uneven product length" means "longest product length-shortest product length / average product length".

As described above, the extruded product cooled by the refrigerant supply method of the above embodiment has much less irregularity in product length than the extruded product cooled by the conventional refrigerant supply method, and also prevents product cracking.

In the die backer of the above embodiment, the inlet 10 of the coolant circulation hole 1 is formed at a position near the outer periphery of the rear side a2, but if there is no problem in the arrangement relationship with the support member and other members (not shown) of the die backer a, This portion can be used as a refrigerant inlet except for the padding 15 without forming the side hole 12 at a position close to the outer periphery.

The grooves 2 and 3 do not necessarily need to be formed as shown in the drawing as long as the coolant is uniformly dispersed in the respective passage holes 5.

In the above embodiment, liquid nitrogen is used as the refrigerant. However, the present invention can be practiced using other refrigerants.

The present invention is not limited to only the above embodiments,
The present invention includes a case where another element is appropriately added or changed within the scope of the claims.

[Effect of the Invention] According to the refrigerant supply method and the die backer according to the present invention, the refrigerant is more uniformly dispersed in each extruded material, so that the cooling of each extruded material is uniform, and as a result, the product length is extremely uneven. There is little product cracking during cooling, and hot pressing can be performed with good yield.

[Brief description of the drawings]

FIG. 1 is a front view of a die backer according to the present invention, FIG. 2 is a sectional view taken along the arrow AA of FIG. 1, FIG. 3 is a front view of a conventional die backer, and FIG. It is sectional drawing in alignment with the arrow BB of FIG. Description of the main symbols in the figure a is a die backer, a1 is the front side of the extruded material passing direction, a2 is the rear side of the extruded material passing direction, b is a die, 1 is a flow hole, 10 is an inlet, 11 is an outlet, and 2, 3 are 2 is a distribution groove, 3 is an encircling groove, 4 is a discharge port, 5 is a passage hole, and 6 is an extruded material.

Claims (3)

(57) [Claims] 1. A die backer having a plurality of through holes through which an extruded material passes is located at a position near the outer periphery of a rear surface of the die backer in a direction in which the extruded material passes or an outer peripheral portion of the die backer. A method for supplying a refrigerant to an extruded material in a multi-hole hot extrusion, comprising supplying a refrigerant to a substantially intermediate position between the through holes and supplying the refrigerant in a direction toward each of the through holes. 2. A die backer having a plurality of through-holes through which an extruded material passes, wherein said through-hole is located at an outer peripheral portion or a position near an outer periphery on a rear surface side in a passing direction of the extruded material. 3. A die backer in a multi-hole hot extrusion, wherein a flow hole having an outlet at a substantially middle position of the hole is formed, and a groove is formed from the outlet of the flow hole to several places on the periphery of each of the through holes. 3. The groove is formed so as to surround each of the passage holes, a dispersion groove extending from the outlet of the flow hole to each of the passage grooves, and a number of peripheral edges of the passage hole from each of the passage grooves. 3. The die backer according to claim 2, wherein the die backer comprises a discharge port communicating with a location.