JPH072111Y2 - Extrusion mold equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an extrusion molding die apparatus used for extrusion molding.

(Prior Art) As a conventional technology, there is one described in Japanese Utility Model Laid-Open No. 2-6135.

That is, as shown in FIG. 4, a counter punch 3 is formed in which a die hole 2 is formed in a vertical direction in a die 1, and a plurality of annular support protrusions 3a are vertically formed on the outer periphery at the axial center of the die hole 2. The knockout ring 4 is slidably fitted in the gap between the die hole 2 and the counter punch 3, and the knockout ring 4 is pressed upward by a predetermined force by a biasing mechanism such as a spring or a cylinder. Then, by punching the punch 5 into the die hole 2 from above the die 1, the material 6 fitted to the upper part of the die hole 2 is moved downward by the knockout ring 4 and the gap between the die hole 2 and the counter punch 3 is made. There was an extrusion molding die device that was plastically fluidized in the section.

(Problems to be Solved by the Invention) In the above-mentioned conventional one, the material 6 is held while the counter punch 3 is held concentrically in the die hole 2 by the knockout ring 4.
Since extrusion molding is carried out, a highly accurate molded product can be obtained, and at the same time, the bending of the counter punch 3 can be prevented at the time of molding to prevent the damage. However, in the above-mentioned conventional one, since the knockout ring 4 is pressed upward by a predetermined force by an urging mechanism such as a spring or a cylinder, there is a drawback that the structure becomes complicated and the cost becomes high. That is, the urging mechanism is provided in the machine base of the mold apparatus, and an extruding rod (not shown) for moving the knockout ring 4 upward to separate the product from the die hole 2 after the molding is completed, It must be installed between the knockout ring and the knockout ring. An object of the present invention is to obtain a novel extrusion molding die device which solves the above drawbacks.

(Means for Solving the Problems) The present invention is configured as follows in order to achieve the above object.

That is, a die hole is formed in the vertical direction in the die, a counter punch is erected and fixed at the axial center of the die hole, and a cylindrical knockout ring is provided in the gap between the die hole and the counter punch so that the punch can be moved up and down. A die for extrusion molding in which the material fitted into the upper part of the die hole is driven plastically into the gap between the die hole and the counter punch by driving the material into the die hole from above the die. In the device, a plurality of annular inner peripheral protrusions protruding in the axial direction are formed vertically in the die hole at a predetermined interval, and the vertical length of the knockout ring is shorter than the vertical length of the die hole. The knockout ring is formed with an annular thick portion that projects outward in the radial direction and is in pressure contact with the inner circumferential projection.

(Operation) Since the present invention has the above-described configuration, when the thick part at the bottom of the knockout ring faces the inner peripheral projection of the die hole, the knockout ring is pressed against the inner peripheral projection and is prevented from falling due to its own weight. Blocked, where the knockout ring supports the counterpunch concentrically within the die hole.

Then, the material is fitted into the upper part of the die hole, the punch is driven from above the die toward the die hole, and this material plastically flows in the gap between the die hole and the counter punch, and the lower end thereof is the upper end of the knockout ring. When is pressed downward, the thick portion of the knockout ring separates downward from the inner peripheral projection and falls by its own weight.

When the thick-walled portion reaches the inner peripheral protrusion of the lower stage due to the self-weight drop, the thick-walled portion is pressed against the inner peripheral protrusion of the lower stage to prevent further weight drop, and the knockout ring is countered at this portion. The punch is supported concentrically within the die hole.

When the lower end again pushes the upper end of the knockout ring downward due to the progress of the plastic flow of the material, the knockout ring again falls by its own weight in the same manner as described above, and then the thick wall portion comes into pressure contact with the inner peripheral projection of the lower stage. The counter punch is supported concentrically in the die hole at this portion.

As a result, the knockout ring supports the counter punch concentrically in the die hole while dropping downward gradually as the plastic flow of the material progresses.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. In the drawings, FIG. 1 is a vertical sectional view showing an embodiment of the present invention, and FIGS. 2 and 3 are vertical sectional views showing its operating process.

In FIG. 1, a die 10 has a die hole 12 extending in the vertical direction.

The die hole 12, the upper end is formed into a large diameter material feeding portion 12a, the middle portion is formed into a small diameter forming portion 12b, and the lower portion is formed into a large diameter guide portion 12c, and the upper and lower end portions of the forming portion 12b and Guide part 12c
An annular inner peripheral projection 13a, 13b, 14a, 14b protruding in the axial direction is formed at the upper end portion and the intermediate portion in the vertical direction.

The vertical spacing L1 between the inner peripheral projections 13a and 13b on the molding portion 12b side is L1.
And the inner circumferential protrusions 14a, 14b on the side of the guide portion 12c are formed at equal intervals to the upper and lower intervals L2.

A counter punch 15 is erected at the axial center of the die hole 12, and the lower end of the counter punch 15 is fixed to a pressure plate 11 arranged at the bottom of the die 10.

The counter punch 15 has annular outer peripheral projections 15a, 15b, 15c protruding outward in the radial direction at three positions above and below the outer peripheral portion thereof.

The outer peripheral protrusions 15a to 15c are the inner peripheral protrusions 13a and 13b on the molding portion 12b side, which are the outer peripheral protrusions 15a and 15b in the upper and middle portions.
The lower outer peripheral protrusion 15c is made to correspond to the lowermost inner peripheral protrusion 14b on the guide portion 12c side. A tubular knockout ring 16 is vertically movably fitted in a gap between the molding portion 12b and the guide portion 12c and the counter punch 15. The knockout ring 16 is formed to be slightly longer in the vertical direction than the molding portion 12b, and has annular thick portions 16a, 16b protruding outward in the axial direction and the radial direction at the upper end portion and the lower end portion thereof.

The thick portion 16a at the upper end has a molding portion 1 whose inner peripheral surface and outer peripheral surface
The inner peripheral protrusion 13a (13b) on the 2b side and the outer peripheral protrusion 15a (15b) of the counter punch 15 are formed in such a size that they are in pressure contact with each other, and the thick portion 16b at the lower end has an outer peripheral surface on the guide portion 12c side. Protrusion 14a (1
The inner peripheral surface of the counter punch 15 is pressed to the outer peripheral projection 15c of the counter punch 15, and the inner peripheral surface of the counter punch 15 is pressed to the outer peripheral projection 15c. For example, the material of the inner peripheral projections 14a, 14b and the knockout ring 16 is SKD.
When set to 11 (die steel for cold forging), inner peripheral projections 14a, 14
The tightening margin between b and the thick portion 16b at the lower end of the knockout ring 16 is set to 0.01 mm to 0.03 mm.

Reference numeral 17 denotes a punch that is fitted into the die hole 12 from above the die 10. The cylindrical second punch 17b is fitted to the outer periphery of the cylindrical first punch 17a, and the first punch 17a is inserted from the second punch 17b. Is also projected downward. In addition, in FIG. 1, 1
Reference numeral 8 denotes an extruding rod that pushes the molded product molded in the die hole 12 upward.

Next, the operation mode of the above embodiment will be described. First, as shown in FIG. 1, when the knockout ring 16 is pushed up by the pushing rod 18 and the upper end portion thereof is positioned at the upper end portion of the molding portion 12b, the outer peripheral surface of the thick portion 16a on the upper end side of the knockout ring 16 is formed. And the inner peripheral surface are the inner peripheral protrusion 13a on the upper side of the forming portion 12b and the outer peripheral protrusion 15a on the upper side of the counter punch 15.
Also, the inner peripheral surface of the thick portion 16b on the lower end side is pressed against the inner peripheral protrusion 14a on the upper side of the guide portion 12c. As a result, the knockout ring 16 is prevented from falling due to its own weight and supports the counter punch 15 in the die hole 12 concentrically.

In this state, the cylindrical material 20 is fitted into the upper end portion of the die hole 12, that is, the material feeding portion 12a, and then the punch 17 is lowered and driven into the material feeding portion 12a.
The gap between the 2 and the counter punch 15 will plastically flow.

Then, when the lower end 20b of the plastic flow part 20a of the above 20 reaches the upper end of the knockout ring 16 for the first time in the state of FIG. 1 and presses it downward, the knockout ring 16
The thick portions 16a, 16b are detached downward from the inner peripheral protrusions 13a, 14a and the outer peripheral protrusions 15a, 15b and fall by their own weight as shown in FIG. Circumferential protrusion 13b, 14b
And, the counter punch 15 is held by the outer peripheral projections 15b and 15c so as not to drop further by its own weight, and the counter punch 15 is concentrically supported in the die hole 12 at this portion.

When the lower end 20b reaches the upper end of the knockout ring 16 again by pushing the plastic flow of the material 20 and presses it downward, the thick portions 16a, 16b are the inner peripheral projections 13b, 14b of the lower stage in the same manner as described above. Separated downward from the outer peripheral projections 15b, 15c,
As shown in FIG. 3, the knockout ring 16 again falls by its own weight and is positioned at the lower end of the die hole 12.

Then, in the state shown in FIG. 3, the lower part of the plastic flow portion 20a of the material 20 is fitted between the inner peripheral projection 13b and the outer peripheral projection 15b, and the counter punch 15 is fitted into the die hole 1 by this fitting portion 20c.
It will be supported concentrically within 2.

The number of the inner peripheral projections 13a, 13b, 14a, 14b and the outer peripheral projections 15a to 15c described above and the vertical intervals L1 and L2 between them.
Is appropriately set according to the material of the material 20, the thickness of the molded product, the depth thereof, and the like.

(Effect of the Invention) As is apparent from the above description, according to the present invention, the counter punch is supported concentrically in the die hole while gradually dropping the knockout ring by its own weight as the material is molded. It is possible to omit the conventional mechanism for pressing and urging the knockout ring upward, and the structure is simplified and the cost is reduced. In addition, the counter punch does not significantly protrude from the knockout ring, a highly accurate molded product can be obtained, and the counter punch can be prevented from being damaged.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, FIGS. 2 and 3 are longitudinal sectional views showing its operating process, and FIG. 4 is a longitudinal sectional view showing a conventional example. 10: Die, 11: Pressure plate, 12: Die hole, 12a: Material feeding section, 1
2b: forming part, 12c: guide part, 13a, 13b, 14a, 14b: inner peripheral protrusion, 15: counter punch, 15a, 15b, 15c: outer peripheral protrusion, 16: knockout ring, 16a, 16b: thick part, 17 : Punch, 17a:
1st punch, 17b: 2nd punch, 18: extrusion rod, 20: material, 20a: plastic flow part, 20b: lower end, 20c: fitting part.

Claims (1)

[Scope of utility model registration request] 1. A die hole (12) is formed in a vertical direction in a die (10), and a counter punch (15) is formed at the axial center of the die hole (12).
Upright and fixed, a cylindrical knockout ring (16) is provided in the gap between the die hole (12) and the counter punch (15) so that it can move up and down, and the punch (17) is inserted from above the die (10) into the die hole. The material (20) fitted into the upper part of the die hole (12) by being driven into the (12) moves the knockout ring (16) downward, and the gap between the die hole (12) and the counter punch (15). In the extrusion molding die device that is plastically flown into, a plurality of annular inner peripheral projections (14a, 14b) protruding in the axial direction are formed vertically in the die hole (12) at predetermined intervals, The vertical length of the knockout ring (16) is shorter than the vertical length of the die hole (12), and the inner peripheral projection (14a, 14a, Extrusion forming characterized by forming an annular thick part (16b) that is in pressure contact with 14b) Mold apparatus.