JP2564091B2 - Die for extrusion of hollow material - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die for extruding a hollow material made of metal such as aluminum.

[0002]

2. Description of the Related Art For extruding a hollow member made of aluminum, for example, a male-male die for combining a male mold for molding the hollow portion of the hollow member and a female mold for molding the outer peripheral portion of the hollow member is used. However, as the extrusion is repeated, the bearing portion of the die wears and the die must be replaced.

In order to carry out this die exchange in a cost-effective manner, it is conceivable to adopt the following division structure especially for the male die. That is, in the male mold, the hollow part molding core that has been integrally held in the bridge part so far is separated from the male mold to form an independent separate member, and instead in the bridge part, the core holding part is integrally formed with the core part. The core-dividing structure is adopted in which the core is held, and the core which is the independent member is held in the core holding portion. According to such a core split structure, if wear of the male bearing part or the like causes die replacement, it is only necessary to replace the core provided with the male bearing part. Other male components can be reused as they are, and the cost associated with die replacement can be reduced.

[0004]

However, in the case of adopting the core split structure as described above, there is a problem with what structure is used to hold the core in the retaining state.

That is, first and foremost, it is necessary to have a structure capable of forming a firm and stable holding state so that the core does not come off during extrusion.

Next, it is necessary to have a structure that enables the core mounting work to be performed efficiently without any trouble.

Further, it is necessary that such a holding structure is a structure that can be easily and cost-effectively manufactured in terms of die manufacture.

The present invention is based on the above demands.
In a die with a split structure in which the cores are separated and independent, the cores can be held in a firm and stable holding state so that the cores do not fall out during extrusion, and the core mounting work (EN) Provided is a die for hollow material extrusion having a structure which can be efficiently carried out without any trouble, and in addition, such a holding structure can be easily and cost-effectively realized in terms of die manufacturing. The purpose is to

[0009]

For the above-mentioned purpose, the first
The invention of, a core having a bearing part for molding the hollow part of the hollow member, and a core holding part having a core holding hole that is held in the bridge part and is opened forward in the extrusion direction,
And a front end portion of the core holding portion in the push-out direction is projected forward of the bridge portion in the push-out direction, and a front end portion of the core holding portion is formed into a tubular protrusion, By forming the slits oriented in the direction, the tubular protrusion can be deformed inward in the radial direction, and is fitted to the inner surface of the tubular protrusion and the core holding hole. The inner surface of the cylindrical projection and the outer peripheral surface of the core that are opposed to each other are provided with retaining engagement portions due to unevenness, respectively, and are formed from an extruded material that acts on the outer peripheral surface of the cylindrical projection during extrusion. The hollow member is designed to be deformed inward in the radial direction by pressure so that the retaining engagement portions are engaged with each other to prevent the core from coming off in the pushing direction. The main point is the extrusion die.

According to a second aspect of the present invention, in the first aspect of the present invention, the retaining engagement portion provided on the outer peripheral surface of the core is an annular groove, and the retaining engagement provided on the inner surface of the cylindrical protruding portion. A hollow member extrusion die comprising an annular projection formed on the inner peripheral edge of the tip of the tubular protrusion by forming an annular groove of a predetermined width on the inner surface of the tubular protrusion. Use as a summary.

[0011]

In the first aspect of the present invention, the core is prevented from coming off during extrusion as follows. That is, if the core is fitted to the holding hole of the core holding portion and used for extrusion,
The tubular projecting portion receives pressure from the extruded material, and by the action of the slit, the tubular projecting portion is deformed inward, whereby the engaging portion on the tubular projecting portion side is engaged with the core side engaging portion. Is engaged with. By the engagement action of the retaining engagement portions, the core is reliably prevented from coming off in the front in the extrusion direction.

Moreover, the core mounting operation is performed simply by fitting the core into the holding hole of the core holding portion, and if this is used for extrusion, the pressure from the extruded material during extrusion is used. The tubular protrusion is deformed so that the engaging portions are engaged with each other to automatically form a state in which the core is not pulled out. Therefore, the work of assembling the core can be efficiently performed.

In addition, in terms of the die manufacturing, it is only necessary to process the slits on the peripheral wall of the cylindrical protruding portion and the engaging portions on the inner peripheral portion of the cylindrical protruding portion and the core, so that the die can be easily manufactured. To be done.

In the second aspect of the invention, the retaining engagement portion provided on the outer peripheral surface of the core is formed of an annular groove, so that the retaining engagement portion on the core can be easily processed. be able to. That is, the core has the character of a consumable part,
Therefore, it is required that the manufacturing can be performed with high productivity and cost advantage. However, it is only necessary to process the groove on the outer peripheral surface of the core, which is required in terms of productivity and cost. Can be answered.

Moreover, the retaining engagement portion provided on the inner surface of the tubular projection portion has the annular groove of a predetermined width formed on the inner surface of the tubular projection portion, whereby the tip end portion of the tubular projection portion is formed. Since it is composed of the annular projection formed on the inner peripheral edge portion of this, the annular projection is also formed by processing the annular groove, and the formation of the annular projection is easily performed in processing.

[0016]

Embodiments of the present invention will be described below.

The die of this embodiment is constructed as a die for extruding a plurality of hollow materials at the same time. The object to be extruded is a circular pipe material made of aluminum. In addition, the die may be configured as a normal single-push type instead of a multiple-push type. The object of extrusion is not limited to the circular pipe material, but may be various other cross-sectional shapes or various metal hollow materials.

1 to 8 show a die according to an embodiment. In the die of this embodiment, (1) is a holder mold member, (2) is a flow control mold member, (3) is a backer, (4) and (4) are male molds, and (5) and (5) are It is a small female type.

In the male mold (4), (7) is a core,
(8) is a male holder.

The core (7) is made of a hard material such as cemented carbide or ceramics, and as shown in FIG. An annular step (9) facing the inner side of the annular step (9) is sandwiched between the annular step (9) and the front side in the extrusion direction having a large diameter. It is formed in the fitting portion (11) having a small diameter. And, on the outer peripheral surface of the molding convex portion (10),
A bearing portion (12) for forming a hollow portion of the hollow material is provided. An annular engaging recess (13) is formed on the outer peripheral surface of the small-diameter fitting portion (11) at a position adjacent to the annular step (9). In addition, a through hole (14) is formed in the core of the core (7).

The male holder (8) is made of steel material such as die steel, and as shown in FIG. 3 etc., a circular annular base portion (15) and a core holding portion (16). And the bridge part (17) ...

The bridge portions (17) ... Are the annular base portions (1
It is provided so as to protrude rearward of the extrusion direction from 5), and has a cross shape and is extended to the annular base portion (15). And
The core holding part (1
6) is held. In this holding state, the tip end portion of the core holding portion (16) is located posterior to the annular base portion (15) in the pushing direction as shown in FIGS. 2 to 4, and the bridge portion (17). It is in a state of being projected more forward than.

As shown in FIG. 2, the core holding portion (16) has a through hole (19) in its shaft core portion, and the center of the through hole (19) has a through-hole in the extrusion direction. An annular step (20) facing the front is provided, and the front side in the extrusion direction is sandwiched by the annular step (20) to form a core-holding hole (21) having a large diameter. The fitting part (11) of the core (7) is fitted into the (21) in a conforming state.

The annular step (20) is used for positioning the core (7) in the core holding hole (21), and the rear end surface of the core (7) is attached to the annular step (20). The bearing portion (12) of the core (7) is positioned at a predetermined position near the rear end face of the annular base portion (15) in the pushing direction by contacting the.

Further, due to the holding hole portion (21) formed in the core holding portion (16), the tip end portion of the core holding portion (16) projects forward from the bridge portion (17). It is formed on the cylindrical protrusion (22).

As shown in FIG.
As shown in FIG. 5, an annular groove (23) having a predetermined width is formed, and by the formation of the annular groove (23), an annular engagement is formed on the inner peripheral portion at the distal end of the cylindrical projection (22). A projection (24) is formed.

Then, on the peripheral wall of the cylindrical protrusion (22),
A plurality of slits (25) extending from the tip toward the rear in the extrusion direction, for example, four slits are formed at equal intervals in the circumferential direction, and the extrusion material received on the outer peripheral surface of the cylindrical protrusion (22) during extrusion. The distal end portion of the cylindrical protrusion (22) is deformed inward by the pressure from, and the annular engaging protrusion (24) is displaced inward.

The tip end surface (26) of the cylindrical protrusion (22) is
As shown in FIG. 5, when the core (7) is assembled, the core (7) is opposed to the annular step (9) of the core (7) in a state close to the annular step (9). When the cylindrical projection (22) is deformed, the distal end surface (26) may catch the annular step (9) of the core (7). The surface (26) is formed to be inclined at a slight angle rearward in the extrusion direction toward the outside in the radial direction.

Further, as shown in FIG. 2 and FIG. 8, a tool such as a punch is inserted in the through hole (19) of the core holding part (16) across the annular step (20) in the extrusion direction. The hole (27) for inserting a tool, the diameter of which is designed to be larger than the diameter of the through hole (14) of the core (7).
With the core fitted into the hole (21) for holding the core, the inner peripheral edge of the rear end face of the core (7) faces the punch hole (27) with a small diameter. This surface (28) is
It is designed to be a hitting surface of a tool (29) such as a punch.

The small female die (5) is made of a hard material such as cemented carbide or ceramics, and has a short columnar shape as shown in FIGS. The height is the same as that of the annular base portion (15) of the male holder (8), and is formed to have an outer peripheral size that fits in the annular base portion (15) in a fitted state. . A forming hole bearing portion (30) for forming the outer peripheral portion of the hollow member is formed at the rear end face of the small female die (5) at the rear end face position in the extrusion direction, and the forming hole bearing portion (30) is formed. A relief hole (31) is formed in communication with 30).

Incidentally, (35) is a lid, which is inserted and arranged from the rear into the tool insertion hole (27) of the core holding part (16) of the male holder (8) during extrusion, and during extrusion To prevent intrusion into the through hole (19) of the core holding part (16).

The holding die member (1) holds two sets of male and female dies, and is made of a steel material such as die steel into a large disc shape, as shown in FIGS. 1, 2 and 6 (b). As shown, two corresponding circular hold holes (32, 32) are provided adjacent to each other in a penetrating state. This hold hole (3
An annular step (33) facing forward in the extrusion direction is formed at the axially intermediate portion of (2), and the annular base portion (15) of the male holder (4) disposed in the holding hole (32). The peripheral edge of the rear end face in the extrusion direction is brought into contact with the annular step (33) so that a seal for preventing material leakage is formed therebetween. In this hold state, the male holder (8)
The front end surface of the annular base portion (7) is substantially flush with the front end surface in the extrusion direction of the holding mold member (1), while the bridge portion (17) of the male type holder (8) is formed. Are projected from the holding mold member (1) backward in the extrusion direction. An annular convex step (34) for fitting the flow control mold member (2) in a centered state is provided on the peripheral edge of the rear surface of the hold mold member (1).
Are formed.

The flow control mold member (2) is a large disk-shaped mold member made of a steel material such as die steel, and regulates the flow of the extruded material from the container or the like. And
As shown in FIG. 6 (a), four on each side, a total of 8
Two independent material flow holes (37) ... bridge part (36)
The bridge portions (36) are arranged so as to correspond to the bridge portions (17) of the male holder (8). Then, on the front surface in the extrusion direction of the mold member (2) for flow control, the accommodating recesses (38) (38) corresponding to the positions of the male mold holders (8) (8).
And a bridge of the male holder (8) in each of the receiving recesses (38) (38) in a state where the flow control mold member (2) is combined with the rear part of the hold mold member (1). Department (1
7) is accommodated in a state of non-contact with the flow control mold member (2) with a predetermined gap.

An annular fitting concave step portion (39) is provided along the entire circumference of the front peripheral portion of the flow control mold member (2).
Is provided, and the convex step (34) of the holding mold member (1) is provided.
And the two mold members (1) and (2) are assembled in a centered state.

The backer (3) is made of a steel material such as die steel, and the relief hole (40) smaller than the outer peripheral size of the small female die (5) (5) is the same as the molding gap (44). In a state of being provided in a core state and assembled to the front side of the holding die member (1) in the extrusion direction, the male die holder (8) and the small female are allowed while allowing the hollow material to move forward during extrusion. It functions to support the mold (5) from the front side. As shown in FIG. 1, FIG. 2 and FIG. 7, around the relief holes (40) (40), the knock pins (41) of the male holders (8) (8) are coaxial. Knock pin hole (42)
Are formed, and the annular base portion (1) of the male holder (8) is formed.
5) is connected to the backer (3) by the knock pin (43) in a positioning state.

The die is constructed by combining the above-mentioned die constituent members as follows. That is, the fitting part (11) of the core (7) is fitted into the holding hole (21) of the core holding part (16) of the male holder (8) from the front side in the pushing direction. The rear end face of the core (7) is in contact with the annular step (20). The small female mold (5) is fitted into the annular base part (15) of the male mold holder (8) with the molding hole bearing part (30) positioned on the rear side in the extrusion direction. Have been. Then, by shrink fitting, the core (7)
And the small female mold (5) are integrated with the male mold holder (8). As a result, the forming hole bearing portion (30) of the small female mold (5) is positioned at the rear end face of the annular base portion (15) in the pushing direction, and the bearing portion (12) of the core (7) is formed in the forming hole. A molding gap (44) is formed in the bearing part (30) and formed between the core bearing part (12) and the molding hole bearing part (30) at the rear end face of the annular base part (15) in the extrusion direction. Is done. And this is assembled again, and these are the holding holes (32) of the mold member (1) for the holder.
(32), and the holder mold member (1) is
It is combined with a flow control mold member (2) and a backer (3).

For extrusion, the die thus assembled and set is set, for example, on the front side of the extruder container, the extruder is operated, and the extrusion pressure is applied to the aluminum billet in the container by the stem. By doing.
During this extrusion, the extruded material is divided at the bridge portion (17), and then passes through the bridge portion (17) and is joined and pressed together. ), And then flows through the forming gap (44) to be extruded forward as a circular pipe material.

At the time of this extrusion, the cylindrical protruding portion (22) is shown in FIG.
Under pressure from this extruded material, as shown in
Due to the action of the slits (25), the engagement projections (24) are displaced inward in the radial direction, project into the engagement recesses (13) of the core (7), and the engagement state is formed. The core (7) is retained in the core holder (16) of the male holder (8) in a retaining state.

The core (7) bearing (1
If the die is worn due to 2) and the die needs to be replaced, replace the core (7). That is, the mold member for the holder (1)
The male holder (8) is removed from the male holder (8), and the cover (35) is removed from the male holder (8).
As shown in, a tool (29) such as a punch is inserted into the tool insertion hole (27) of the male holder (8) from the rear, and the tip of the tool (29) is inserted into the core ( 7) Hit the striking surface (28) of the rear end face and insert the core (7) through the tool (29).
Hit the rear end face. Thereby, the core (7) is taken out forward.

As described above, in the die of the above embodiment, the retaining structure by the pressing / engaging action as described above is used as the retaining mechanism for the core, and the outer peripheral surface of the cylindrical protrusion (22) is Is deformed inward by being pressed by the extruded material, the engaging projection (24) is fitted into the engaging recess (13) on the core (7) side, and the core (7) is being extruded. Since it is held in the retaining state, it is possible to reliably prevent the core (7) from coming off during extrusion.

Moreover, by adopting such a core retaining structure, it is only necessary to fit the core (7) into the holding hole (21) of the core holding portion (16) of the male holder (8). Then, if this is used for extrusion, the core retention state is automatically formed by the pressure from the extrusion material, and the male holder (8)
The work of assembling the core (7) can be easily and easily performed.

Moreover, by adopting such a core removal preventing structure, the processing for that is the processing of the slits (25) ... In the peripheral wall of the tubular projecting portion (22) and the processing of the tubular projecting portion (22). It is only necessary to process the inner peripheral portion and the engaging portions (13) and (24) to the core (7), which is easy to manufacture and advantageous in terms of cost. can do.

In particular, the annular engaging projection (24) is formed on the tubular projection (22) by processing the annular groove (23) on the inner peripheral portion of the tubular projection (22). Therefore, the annular engaging convex portion (24) can be easily formed.

Moreover, since the engaging portions (13) and (24) formed in a ring shape are engaged with each other to prevent disengagement, it is necessary to form a firm and stable disengagement prevention state. You can

Further, in the die of the above embodiment, since the small female die (5) is fitted and incorporated in the annular base portion (15) of the male holder (8), the core (7) )
The fitting position for centering between the female and the small female molding hole (30) is the inner peripheral surface position of the annular base portion (15) of the male holder (8), and the centering fitting position is formed. The core (7) and the forming hole (30) are aligned even when the die is bent due to the extrusion pressure acting from the rear of the die during extrusion, because it is close to the position of the gap (44). It is possible to extrude a hollow material having a high degree of dimensional accuracy with less uneven thickness and less uneven thickness.

Particularly, in the case where the molding gap (44) is provided in an eccentric state as in the case of the plural-piece simultaneous extrusion type as described above, the core (7) and the molding hole (30) due to the bending of the die are formed. ), It is possible to effectively suppress the deviation of the alignment state with
It is possible to extrude a hollow material having high dimensional accuracy without uneven thickness with high productivity.

Further, a small female die (5) is adopted as a female die, and this is incorporated in the annular base portion (15) of the male die holder (8) so that the molding gap (44) is formed in the annular base. Since the rear end face position of the part (15) in the extrusion direction or a position in the vicinity thereof is set, the contact area with the extruded material is reduced as compared with the conventional porthole die described above, and the friction between the extruded material and the die is reduced. The force is reduced, and the effect that the extrusion can be performed at a lower extrusion pressure than before is also exhibited.

Moreover, in the male holder (8) integrally including the annular base portion (15), the bridge portion (17) and the core holding portion (16), the core (16) is attached to the core ( 7)
Is fitted, and the small female type (5) is fitted into the annular base portion (15) of the male type holder (8), that is,
Since the integrated product (9) is provided with the fitting holding portions (21) (15a) for the core (7) and the small female die (5), the fitting holding portions (21) The core (7) and the small female die (5) are fitted to the respective holding portions (21) and (15a) so that the core (7) can be processed and formed with high alignment accuracy. By doing this, the core (7) and small female mold (5)
Is fitted to the male holder (8) with high alignment accuracy,
It is possible to extrude a hollow material with high dimensional accuracy without uneven thickness.

In addition, the core (7) and the small female die (5) are respectively the fitting holding portions (21) (15a) of the male die holder (8).
Since the male holder (8) is integrated with the male holder (8) by shrink fitting in the parentheses), the core (7) and the small female type (5) are combined with the male type holder (8) with high alignment accuracy. The alignment accuracy between the child (7) and the molding hole (30) can be improved, and a hollow material with little unevenness and high dimensional accuracy can be extruded.

Further, a through hole (19) directed in the extrusion direction is formed in the core holding portion (16), and an annular intermediate step (20) facing the extrusion direction forward is provided in the through hole (19). Being
The first half in the extrusion direction is formed in the core holding hole (21), and the second half in the extrusion direction is formed in the small diameter hole (27) with the annular step (20) interposed therebetween. In the state where the rear end surface of the core (7) is in contact with the annular step (20), a part of the rear end surface of the core (7) faces the inside of the small-diameter hole portion (27) as a punching surface (28). When the core is assembled, the rear end face of the core (7) is brought into contact with the annular step (20) so that the core (7)
When the core (7) is taken out, the cover (35) is taken out, a tool (29) such as a punch is inserted from behind, and the tool (29) is hit, etc. The core (7) can be easily taken out, and the core taking-out operation can be efficiently performed.

[0051]

According to the above, the extrusion die of the first invention is a die provided with a male die having a divided structure having a core for molding the hollow portion of a hollow member as an independent component, and the core is removed. As the retaining structure, the engaging portion on the core side and the engaging portion on the cylindrical protruding portion side are engaged by deforming the cylindrical protruding portion inward by pressing the extruded material during extrusion. Since the structure is adopted, the core can be held in a firm and stable holding state so that the core does not come off during extrusion.

Moreover, the core mounting operation is performed simply by fitting the core into the holding hole of the core holding portion, and if this is used for extrusion, the pressure from the extruded material during extrusion is used. The cylindrical protruding portion is deformed and the engaging portions are brought into the engaged state to automatically form the state where the core is prevented from being pulled out. Therefore, the core mounting work can be efficiently performed without trouble. You can

In addition, in terms of manufacturing the die, it is only necessary to process the slits on the peripheral wall of the cylindrical protruding portion and the engaging portions on the inner peripheral portion of the cylindrical protruding portion and the core, so that the die can be easily manufactured. In addition, it can be carried out advantageously in terms of cost.

Further, in the extrusion die according to the second aspect of the present invention, since the retaining engagement portion provided on the outer peripheral surface of the core is formed of an annular groove, it is possible to process the retaining engagement portion on the core. Is
It is only necessary to form the annular groove, and it is possible to easily form the engaging portion on the core side. In particular, in a core having the character of a consumable component, such ease of processing can exhibit advantages in terms of productivity, cost, and the like.

Moreover, the retaining engagement portion provided on the inner surface of the cylindrical protrusion has an annular groove of a predetermined width formed on the inner surface of the cylindrical protrusion, so that the tip end portion of the cylindrical protrusion is formed. Since it consists of an annular protrusion formed on the inner peripheral edge of
The annular protrusion can also be formed by processing the annular groove, and the engagement portion on the cylindrical protrusion side can be easily formed.

Further, as described above, since the groove and the protrusion formed in the annular shape are engaged with each other to prevent the core from coming off, a firm and stable state of preventing the core from coming out is realized. be able to.

[Brief description of drawings]

FIG. 1 is an overall sectional view of an extrusion die according to a first embodiment.

FIG. 2 is an enlarged sectional view of a main part of the die.

FIG. 3 is a perspective view showing a male holder, a core, a small female mold and the like in a separated state.

FIG. 4 is a perspective view showing the core in a separated state from the cylindrical protruding portion of the male holder.

FIG. 5 is an enlarged cross-sectional view showing an engagement operation between a core and a cylindrical protrusion.

FIG. 6 (a) shows a flow control mold member,
FIG. 1 is a view taken along the line II of FIG. 1, and FIG. 2B is a view showing the mold member for the holder, and is a view taken along the line II-II of FIG. 1.

FIG. 7 is a view showing a backer, taken along the line III-III in FIG. 1;
FIG.

FIG. 8 is a cross-sectional view illustrating a method of removing a core.

[Explanation of symbols]

 7 ... Core 13 ... Annular engagement concave part 16 ... Core holding part 17 ... Bridge part 21 ... Holding hole 22 ... Cylindrical protrusion 24 ... Annular engagement convex part 25 ... Slit

Claims (2)

(57) [Claims] 1. A core having a bearing part for molding a hollow part of a hollow material, and a core holding part having a core holding hole which is held by a bridge part and opens forward in the extrusion direction. And a front end portion of the core holding portion in the pushing direction is projected forward of the bridging direction with respect to the bridge portion, and a front end portion of the core holding portion is formed into a tubular projecting portion. Is formed so that the tubular projection can be deformed inward in the radial direction, and is fitted to the inner surface of the tubular projection and the core holding hole. To the inner surface of the cylindrical protruding portion and the outer peripheral surface of the core facing each other,
A retaining engagement part due to unevenness is provided, and the cylindrical protrusion is deformed inward in the radial direction by the pressure from the extruded material that acts on the outer peripheral surface of the cylindrical protrusion during extrusion, preventing retention A die for extruding a hollow material, in which the engaging portions are engaged with each other to prevent the core from coming off in the extruding direction. 2. The retaining engagement portion provided on the outer peripheral surface of the core is an annular groove, and the retaining engagement portion provided on the inner surface of the cylindrical protruding portion is provided on the inner surface of the cylindrical protruding portion. The hollow material extruding die according to claim 1, comprising an annular projection formed on an inner peripheral edge portion of a distal end portion of the cylindrical protrusion by forming an annular groove having a predetermined width.