JPS643523Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The present invention, as a double-stem type indirect extrusion press, can effectively prevent the blister phenomenon in which air remains inside the container, especially when upsetting a billet charged into the container. , and also relates to a device that allows extrusion to be carried out smoothly.

<Prior art> A press stem and a die stem are placed opposite each other on the extrusion center line with a billet charging container in between, and both end surfaces of the billet (including both solid and hollow types) charged in the container are pressed by both stems. By moving both the press stem and the container together toward the die stem side, the press stem side is pressurized, and a rod or tubular product is extruded through the die of the die stem. This indirect extrusion press belongs to well-known press technology, which need not be exemplified. Now, to explain the outline of the mechanism and operation with reference to Fig. 1, in Fig. 1 I, there is a press platen on the right side of the extrusion center line XX direction, although it is not shown. A press frame (not shown) is provided on the left side of the figure, and the two are connected by tie rods, and one press platen has a die stem 7 as shown in the figure, and the extrusion center line - It is fixedly installed in the X direction. Although not shown on the other press frame, as is well known, there are a main cylinder, main ram, crosshead, etc.
A series of extrusion pressure application mechanisms are installed, and a press stem 6 is installed at the crosshead thereof, as shown in the figure, so as to be movable forward and backward to apply pressure along the extrusion center line XX.
Although not shown, a container holder 2 is provided between the press stem 6 and the die stem 7, and is movable along the extrusion center line XX via a shift cylinder such as a container hydro coupling cylinder. Container 1 is placed and Container 1
A solid or hollow billet 5 is supplied into the die stem 7 by, for example, a mobile billet loader 9 shown in the figure, and the die is not shown in the die stem 7 in FIG. Die 8 and die handling robot 10
Of course, a type in which the die 8 is pre-attached to the tip of the die stem 7 will also have the same effect. Further, a shear cutting device including a shear blade 3 and a shear cylinder 4 is installed at the rear end of the container holder 2 as is known in the art. In such a double-stem type indirect extrusion press, first, the billet 5 is placed in the container 1 via the billet loader 9 on the extrusion center line XX, and then charged by moving the container 1, etc. Billet 5 by 6 die stem 7
Upsetting is carried out from both end faces of the container 1, and the press stem 6 of the container 1 is then moved along with the billet 5 toward the die stem 7 to extrude the upset billet 5 through the die 8 of the die stem 7 into a bar-shaped product or the like. When obtaining a small tubular product, a hollow billet is used as is known, and a mandrel arranged concentrically within the die stem 6 is used.
Alternatively, a piercing mandrel or the like is used, and is often used as an extrusion press for rod or tubular products, but this type of press has the following problems.

<Problems to be solved by the invention> In the conventional double-stem type indirect extrusion press, the billet 5 in the container 1 is upset from both axial end faces of the billet 5 through the pressure of both stems 6 and 7. Therefore, among the air existing between the inner surface of the container 1 and the outer surface of the billet 5, the billet yielding phenomenon starts from both ends of the billet, so that the remaining air, especially in the center, has no place to escape, and the surface of the extruded product is This residual air causes a blister phenomenon, resulting in a deterioration of the surface quality of the product. A taper heating method that increases the temperature of the part of the billet 5 toward the die stem 7 side is generally adopted as a countermeasure against this problem, but it is not effective enough for long billets or billets with a small extrusion ratio. Additionally, equipment for taper heating is also required.

<Means for Solving the Problem> The technical problem of the present invention is to prevent the blister phenomenon that occurs during upset in such a double-stem type indirect extrusion press without using thermal means. The technical means of the present invention taken for this purpose includes a container having a billet charging hole on the extrusion center line, a press stem and a die stem that are opposed to each other on the extrusion center line with the container in between, and the billet charging hole is In an indirect extrusion press, the billet housed in the press stem is upset through both stems, and the container and press stem are moved together to the die stem side, and the billet is extruded while the container is placed over the die stem. A detachable blister prevention lid member is provided on the billet end face accommodated in the billet charging hole and the container end face on the side of the billet end face, and pressurizing force on the press stem side is applied to the billet and the billet through the blister prevention lid member. The point is that it is distributed to containers.

<Operation> According to the technical means described above (see FIG. 1 below), as shown in FIG. 1 I, the billet charging hole 1 on the side facing the press stem 6 in the container 1
pristar prevention lid member 11 having a size and shape that can open and close the end face 1a including one end of the opening of b;
As shown in FIG. 1, by arranging the container boulder 2 as a supporting member and movable in and out on the extrusion center line XX from outside the extrusion center line XX as shown in FIG. When the billet 5 charged into the container 1 is upset from both ends by the die stem 7 and the press stem 6, the billet charging toward the press stem 6 of the container 1 is prevented by the blister prevention lid member 11. Hole 1b
It is possible to close the end surface 1a including one end of the opening of the container 1, and at this time, by backing up the press stem 6 to the member 11, the lid member 11, which does not move relative to the container 1, is closed. , a force is applied to the die stem 7 side, and as shown by 5a in FIG. 1 from the die 8 side,
Yield deformation of billet 5 starts from the die side,
This sequentially causes a movement to reach the other end of the billet 5, that is, the lid member 11 side. According to this, the inner surface of the container 1, that is, the billet charging hole 1b surface and the billet 5
The gap existing between the billet 5 and the inside of the container will be filled sequentially from the die 8 side, and the air existing between the inner surface of the container and the billet 5 will flow from the die 8 side to the lid as the yield deformation movement progresses. The residual air is reliably and completely discharged from the lid member 11 side, and yield deformation starts simultaneously from both ends of the billet 5 due to the upsetting of both stems 6 and 7, as in the conventional case. This eliminates the problem of air in the center losing its escape and remaining, resulting in the blister phenomenon.

<Example> Each example that specifically realizes the above-mentioned technical means of the present invention will be described.

In the embodiment shown in Fig. 1, the blister prevention lid member 11 according to the present invention is disposed as a dedicated member independent of any of the press stem 6, die stem 7, and container 1/container holder 2. Figs. 1 to 10 show the various states in the order of press cycle movement. Fig. 1 shows the billet supply state, but the press stem 6 and die stem 7 equipped with a die 8 and container 1, container holder 2 supporting said container 1, shear (cutting) device consisting of shear blade 3 and shear cylinder 4, and container 1, container holder 2, ...
Each of these devices is equipped with the necessary mechanisms for each member of a double stem type indirect extrusion press, as described above in the prior art. In this device, the container holder 2 is used to mount a holder shaft 13 via bearings 12, 12 so that it can rotate about its axis and move forward and backward in the axial direction, and a blister prevention cover member 11 is fixed to the holder shaft 13. This cover member 11 is a disk body formed in two stages, a large diameter portion 11a and a small diameter portion 11b, and the small diameter portion 11b has a diameter dimension that fits appropriately into one end of a billet insertion hole 1b in the end face 1a of the container 1 facing the press stem 6, while the large diameter portion 11a is a diameter dimension that fits into one end of the insertion hole 1b.
The billet 5 is completely engaged with and closed by the end surface 1a surrounding the billet insertion hole 1b, and of course has a larger diameter than the tip of the press stem 6, which has a smaller diameter than the billet insertion hole 1b.
moves forward and loads the billet 5 into the container 1,
At the same time, the container 1 also moves in the direction of the arrow via the container holder 2, and the billet 5
is shown being loaded into the container 1.
Next, as shown in the figure, after the billet 5 is loaded, the blister prevention lid member 11, which is in the retracted position, is set in a position concentric with the extrusion center line X-X by the rotation of the holder shaft 13 in the gap between the press stem 6 and the container 1, which is created by the return movements of the press stem 6 and the container 1. Also, the die 8 is attached to the die stem 7, which is in a fixed position, via the die handling robot 10. Next, as shown in Figure 1, the press stem 6 is advanced toward the die stem 7 as shown by the arrow via a pressing force applying means below the known main cylinder and main ram, although not shown in the figure. At the same time, the blister prevention lid member 11 is moved in the axial direction of the holder shaft 13, and the container 1 is also moved in the same direction, so that the small diameter portion 11b of the lid member 11 is inserted into the billet loading hole 1b.
The press stem 6 backs up the cover member 11 with the large diameter portion 11a engaged with the end face 1a, and the billet 5 is inserted between the die stem 7 and the die 8 side.
According to this upsetting, one end of the container 1 is closed by the lid member 11, which does not move relative to the container 1, and pressure is applied to the other end, the die 8 side, so that the billet 8 begins to yield and deform from the die 8 side as shown in FIG. 5a. As this progresses toward the lid member 11 side, the gap between the container 1 and the billet 5 closes to the die 8 side.
Since the air is gradually filled from the side, any remaining air is reliably expelled to the outside from the lid member 11 side. Following the completion of upsetting, the press stem 6 continues to apply pressure, and the billet 5 is extruded through the die 8 as shown in Fig. 1. Needless to say, the container 1 and the container holder 2 move together with the press stem 6, resulting in indirect extrusion. Reference numeral 14 denotes a rod-shaped extrusion product extruded by the solid billet 5. Next, as shown in Fig. 1, with the completion of extrusion, the press stem 6
The container 1 is then moved backward, and the cover member 11 is moved forward and backward in a straight line via the holder shaft 13 to release the closing of the end face 1a, and then is moved backward and forward in a rotating manner. In the figure, 15 denotes a disc card. Next, as shown in Fig. 1, the container 1 and the container holder 2 are moved forward toward the die stem 7 side via a shift cylinder (not shown) or the like, and the disc card 15 present in the container 1 is exposed on the end face 1a of the container 1, and the shear blade 3 is lowered via the shear cylinder 4, whereby the disc card 15 is cut and removed.
As shown in FIG. 1, the container 1 and the container holder 2 are further advanced toward the die stem 7.
The die 8 positioned in the container 1 is exposed to the outside of the end surface 1a as shown in the figure, and is then held and carried out by the die handling robot 10, completing one cycle. Then, the container 1 and the container holder 2 are returned to their initial positions, and the first cycle is started again.
Which brings us back to the figure.

FIG. 2 Embodiment In the embodiment shown in FIG. 2, the blister prevention lid member 11 according to the present invention is formed using a part of the shear device installed in the container holder 2.
FIGS. 2 to 3 show each state in the order of the press cycle movement. In FIG. 6
One surface that slides along the end surface 1a toward the end surface 1a is a blister-preventing lid surface 11A that is a flat surface that is slidably joined to the end surface 1a. That is, FIG. 2 shows the billet 5 being loaded into the container 1, which is the same as the embodiment shown in FIG. Next, FIG. 2 shows the set state of the blister prevention lid surface 11A,
By lowering the shear blade 3 via the shear cylinder 4, the end surface 1a of the container 1 including the billet charging hole 1b is closed by the lid surface 11A. Then, as shown in Figure 2,
It is clear that by backing up the press stem 6 to the opposite side of the shear blade 3 and moving the stem 6 container 1, the same upset action and effect as in the embodiment of FIG. 1 can be obtained. FIG. 2 shows the extrusion state following the completion of upsetting, and it goes without saying that the lid surface 11A and the shear blade 3 move without moving relative to the container 1.

When the extrusion is thus completed, as shown in FIG. 2, the press stem 6 is first retracted, and the shear blade 3 is once raised with the disk card 15 and die 8 positioned in the billet charging hole 1b. Open the end face 1a, move the container 1 container holder 2 to the die stem 7 side, expose the disc card 15 on the end face 1a, lower the raised shear blade 3, and cut the disc card 15 as shown. As shown in FIG. One cycle is completed by gripping the .

FIG. 3 Embodiment The embodiment shown in FIG. 3 is an example in which the present invention was implemented in a double-acting press type as an indirect extrusion press. Through a mandrel holder that is movably held by a cylinder provided inside the press stem 6, the mandrel is used both concentrically with the press stem 6 and can move forward and backward independently. It is possible to provide the invented blister-preventing lid member 11 on the mandrel side. Figure 3~
shows each state in order of press cycle movement, and in Fig. 3, 16 is a mandrel;
Although not shown since it is well known, the mandrel 16
is connected to a cylinder provided in the main ram of the main cylinder that holds the press stem 6 through the crosshead so that it can move forward and backward, and passes through the crosshead and the press stem 6 so that it can move along with and independently of the stem 6. A blister-preventing lid member 11B is attached to the front end of this mandrel 16 and has a diameter that fits appropriately into the billet charging hole 1b of the container 1. The lid member 11B is larger than the press stem 6. The press stem 6 has a large diameter and is provided so that the press stem 6 is backed up with respect to the lid member 11B via a shear blade 3 in a shear device provided on the container holder 2, as will be described later. For this purpose, a notch 3a for passing the mandrel 16 is formed in the shear blade 3 as shown in the figure, and the shape of the notch 3a is shown in FIG.

FIG. 3 shows the state in which the billet 5 is loaded into the container 1. As shown in the figure, the billet 5 carried in via the billet loader 9 on the extrusion center line XX is moved in the direction of the arrow by the container 1. The press stem 6 is inserted at the same time as the press stem 6 is pushed in. At this time, the cover member 11B at the front end of the mandrel 16 accompanying the press stem 6 is located at the front end of the stem 6 and is in a supported state with the billet 5. Next, as shown in FIG. 3, charging of the billet 5 is completed by the independent advancement of the mandrel 16, and the lid member 11B is stopped at one end position of the charging hole 1b, and at the same time, the shear blade 3 of the shear device is stopped. The shear cylinder 4 lowers the shear blade 3 through the notch 3a, and the container 1 including the entire surface of the lid member 11B whose one side 3b is located at one end of the charging hole 3b.
The lid member 1 is lowered to close the end surface 1a of the lid member 1.
Complete setting of 1B. From this state, as shown in FIG. 3, the press stem 6 is moved forward in the direction of the arrow to back up the lid member 11B via the shear blade 3, and the container 1 and the container holder 2 are moved together. The billet 5 is upset by advancing the die 8 toward the attached die stem 7, and the upset action and its effects in this case are exactly the same as those explained in the embodiments of FIGS. 1 and 2. can get.

From the end of this upset, extrusion of the billet 5 through the die 8 of the die stem 7 is continuously obtained through the continued movement of the press stem 6, and FIG. 3 shows the progress of the extrusion.
Thus, when extrusion is completed, the disk card 15 and the die 8 are located within one end of the billet charging hole 1b of the container 1 on the press stem 6 side, and the shear blade 3 is first moved upward and retracted, and then the press stem 6
With the retreat of the mandrel 16, the mandrel 16 is retreated together with the lid member 11B, and the mandrel 16 is also retreated independently, and as shown in FIG. 3, the container 1 container holder 2 is advanced toward the die stem 7,
The disk card 15 in the charging hole 1b is exposed on the end surface 1a of the container 1, and the shear blade 3, which has been raised, is lowered to remove the disk card 1.
5 is cut and removed, and then as shown in FIG.
The shear blade 3 is raised, the container 1 container holder 2 is further advanced toward the die stem 7 side, the remaining die 8 is made to protrude outside the end surface 1a of the container 1, and is gripped by the die handling robot 10.
It completes the cycle.

Embodiment in FIG. 4 The embodiments in FIGS. 1, 2, and 3 are all examples in which a bar-shaped product 14 is obtained using a solid billet 5. The example shown in Fig. 5 shows an example in which the present invention is applied to an indirect extrusion press for producing tubular products using a hollow billet, and Figs. 4 to 4 show each state in the order of the press cycle movement. However, in FIG. 4, the same reference numerals as those in the embodiments in FIGS. 1, 2, and 3 indicate the same parts, and only the differences will be explained. A mandrel 17 that runs concentrically through the press stem 6 in correspondence with the hollow billet 5A.
A core head 17a is formed at the tip thereof to correspond to the die hole of the die 8 in the die stem 7 and to determine the extrusion gap of the tubular product. This mandrel 17 is moved forward and backward by a mandrel holder 18 that is moved forward and backward by a cylinder provided in the main ram of the main cylinder that supports the press stem 6 via a crosshead.
It is held by the press stem 6 and can move forward and backward independently and together with the press stem 6. In this embodiment, as in the embodiment shown in FIG.
However, the lid member 11 has a structure in which a passage hole 11C for the mandrel 17 is bored in the center of the lid member 11.
Use D. FIG. 4 shows the state in which the billet 5A is charged into the container 1. The hollow billet 5A is charged into the container 1 by the same operation as in FIG. FIG. 4 shows a state in which the blister prevention lid member 11D in the retracted position is pivoted and set on the extrusion center line XX, and is similar to FIG. 1. FIG. 4 shows the closed state of the lid member 11D, in which the press stem 6 and the mandrel 17 move forward together, causing the lid member 11D to move forward.
The small diameter portion 11b of the billet D fits into one end of the billet charging hole 1b, the large diameter portion 11a engages and closes the end surface 1a surrounding the charging hole 1b of the container 1, and the mandrel 17 advance independently. Thus, under the backup of the lid member 11D of the press stem 6, the press stem 6 container 1 container holder 2 is moved to the side of the die stem 7 equipped with the die 8 to perform upsetting, and the upsetting action and effects are as shown in FIG. Obtained in the same manner as in the example. FIG. 4 shows the extrusion state that is carried out subsequent to the above-mentioned upset, and the billet 5A is moved through the die by stopping the mandrel 17 at a fixed position by moving the press stem 6 container 1 container holder 2 forward with respect to the die stem 7. 8 and core head 17a to form a tubular product 14A as shown.
Similarly, the lid member 11D does not move relative to the container 1. When the extrusion is thus completed, as shown in FIG. 4, the press stem 6 and the mandrel 17 are first retracted, and then the lid member 11D is pivoted and retracted, and 15 indicates a disc card. Next, as shown in FIG. 4, the container 1 container holder 2
to the die stem 7 side, and that die card 1
5 is exposed on the end surface 1a of the container 1, the shear blade 3 is lowered to cut and remove the disk card 15, and then, as shown in FIG. The process of advancing toward the die stem 7 side, protruding the die 8 out of the container 1, and having the die handling robot 10 grip the die is shown in FIG.
This is exactly the same as above, and one press cycle is thus completed.

Embodiment in FIG. 5 The embodiment shown in FIG. 5 is similar to the embodiment in FIG. As in the example, it was formed using a part of the shear device installed in the container holder 2. Figures 5 to 5 show each state in the order of press cycle movement. One surface of the shear blade 3 in the shear device installed in the holder 2 that slides along the end surface 1a of the container 1 is a blister prevention lid surface 11E consisting of a flat surface that is slidably joined to the end surface 1a, and the shear blade 3 has a passage hole 3C for the mandrel 17 at a position corresponding to the mandrel 17 on the press stem 6 side when descending. The press cycle in this embodiment is almost the same as that in the embodiment shown in Fig. 4, and Fig. 5 shows the state in which the hollow billet 5A is charged into the container 1. can be accessed. Next, when closing the blister prevention lid surface 11E against the end surface 1a of the container 1 using the shear blade 3 shown in FIG. 5, after retracting the press stem 6 mandrel 17 as shown in the figure, the shear blade 3 is is lowered through the shear cylinder 4 to position the mandrel passing hole 3C concentrically with the extrusion center line XX, so that the lid surface 11E is aligned with the billet charging hole 1.
The end face 1a including b is closed. Therefore, as shown in FIG. 5, the press stem 6 mandrel 17 is advanced toward the container 1 side, the press stem 6 is brought into contact with the shear blade 3, and backed up, and the mandrel 17 is released independently through the passage hole 3C. and advance the core head 17a to a position corresponding to the die 8 of the die stem 7,
The hollow billet 5A is upset, and the functions and effects of the upset are exactly the same as those of the previous embodiments. After the upsetting is completed, the billet 5A in the container 1 is transformed into a tubular product 14A through the mandrel 17 and the die 8, which are stopped at a fixed position, by the subsequent advancement of the press stem 6 container 1 container holder 2 toward the die stem 7. Extrusion proceeds as shown in Figure 5. In this way, after the extrusion is completed, the disk card 15 die 8 becomes the container 1.
First, as shown in FIG.
The mandrel 17 is moved back, the shear blade 3 having the lid surface 11E is temporarily raised and retracted, and the container 1 and the container holder 2 are advanced toward the die stem 7 to expose the disk card 15 onto the end surface 1a, and the shear blade is raised. Discard cutting by the descent of 3 is obtained, and as shown in FIG.
A series of press cycles in which the shear blade 3 rises again, the container 1 container holder 2 advances again toward the die stem 7 side, the die 8 thereby protrudes outside the end surface 1a, and the die 8 is gripped by the die handling robot 10 are performed in the same manner. It will be completed.

6 to 9 show the sixth to ninth embodiments of the present invention.

That is, while the fourth embodiment shown in FIG. 4 was an example of arresting extrusion of a hollow billet using a stationary mandrel, the sixth embodiment shown in FIGS. This is an example of extrusion, and parts common to FIG. 4 are indicated by common symbols.

Also. The seventh embodiment shown in FIGS. 7 to 7 corresponds to the fifth embodiment shown in FIG.
In the example of flow extrusion in A, parts common to those in FIG. 5 are designated by common reference numerals.

The eighth embodiment shown in FIGS. 8 to 8 is an example of extrusion using a hollow billet 5A using a stationary mandrel. The fourth embodiment shown in FIG. Since this is common to FIG. 4, common parts are indicated by common reference numerals.

The ninth embodiment shown in FIGS. 9 to 9 differs from the fifth embodiment explained in FIG. 5 in that a stationary mandrel is used and the hollow billet 5A is cast and extruded, and other points are common to the fifth embodiment. ,
Common parts are therefore indicated by common symbols.

In each of the eighth and ninth embodiments, the mandrel is a chip mandrel, but it may be a straight mandrel.

10 to 21 are examples in which a dummy block (push plate) is used as part or all of the blister prevention lid member 11, and the basic configuration is as shown in FIGS. 1 to 21 described above. This embodiment is the same as each embodiment shown in FIG. 9, so common parts are indicated by common reference numerals, and the basic outline thereof will be explained.

FIG. 10 Embodiment A blister prevention lid member 11 having a larger diameter than the billet charging hole 1b is provided on the container holder 2 of the container 1 so as to be rotatable and movable in the axial direction. The plate 111 is provided so as to be openable and closable via the billet loader 9, etc., and as shown in FIG.
When the press board 111 closes the billet charging hole 1b and upsets the billet charging hole 1b, the remaining air that fills the gap between the container 1 and the billet 5 from the die 8 side is reliably drained from the lid member 11 side. They will be excluded from the outside world.

FIG. 11 Embodiment This example differs from FIG. 10 in that the shear blade 3 is used as a part of the blister prevention lid member 11, and the billet charging hole 1b is closed with the push plate 111, and the blade 3 is used to close the container end face 1a. In this embodiment, as shown in FIG. 11, the gap between the container 1 and the billet 5 is successively filled from the die 8 side, and the remaining air is reliably discharged to the outside from the lid member 11.

12 to 17 show the case of pipe extrusion, and FIG. 12 shows a container holder 2 with a hole-equipped blister prevention lid member 11 that is rotatably and axially movable, and a press plate 111. The end face 1a and the billet charging hole 1b can be freely closed, and the pipe material is shown in arrest extrusion using a chip mandrel 17.

13 is different from the one shown in FIG. 12 in that a hole is formed in the shear slide 3 and used as a part of the blister prevention lid member 11.

Figure 14 shows the mandrel 17 in Figure 12.
FIG. 15 is an example in which the mandrel 17 in FIG. 13 was flow-extruded using a straight mandrel.

16 is an example of arrest extrusion using the straight mandrel 17 in FIG. 12, and FIG. 17 is an example of arrest extrusion using the straight mandrel 17 in the example of FIG. 13.

18 to 21, the press plate 111 is used as a part of the blister prevention lid member, and the large diameter portion provided at the tip of the press stem 6 is brought into contact with the container end surface 1a to form the blister prevention lid member 11. First, FIG. 18 shows an example in which a lid member 11 is integrally formed at the tip of the press stem 6,
FIG. 19 shows an example in which the lid member 11 is screwed to a sleeve 6A that is inserted into the stem 6 and attached with a nut 6B, and FIG. This is an example of forming the 21st
The figure shows an example of FIG. 20 in which the lid member 11 is attached to the sleeve 6A to have a split structure.

In each of the above-mentioned embodiments, as described repeatedly, one end of the container 1 on the side opposite to the die stem is closed by a lid member or a lid surface that does not move relative to the container, and the press stem 6 By applying force to the die side under the back-up of the container, the billets 5, 5A enclosed in the container undergo yield deformation from the die side and become filled, and as this movement progresses sequentially toward the side opposite to the die stem, the inner surface of the container This makes it possible to reliably and easily expel the air present between the billet and the billet without leaving any remaining on one end side, and to discharge the air to the outside.

Here, the reason why the deformation of the billet 5 begins in advance near the die 8 of the die stem 7 and the air between the inner circumferential surface of the container and the outer circumferential surface of the billet is sequentially discharged rearward will be explained just in case.

In FIG. 22, the press stem 6 side is engaged with the billet end surface 5A, and the container end surface 1
The press stem 6 has a blister prevention lid member 11 engaged with the billet 5.
and pressurize container 1 with pressurizing force F.

The pressurizing force F on the press stem side is distributed to the billet 5 and the container 1, and becomes F=F _A + F _B.

Therefore, the force per unit area that the end face of the billet on the press stem side receives is P _A =F _A /A (A is the cross-sectional area of the billet).

F _B is the force generated by the frictional force between the billet and the container.

The force per unit area acting on the billet end face on the die 8 side is P ₀ =F/A.

Therefore, P ₀ > P _A , the pressure on the billet end face on the die side becomes greater than the pressure on the billet end face on the press stem side, and the billet 5 is pressed against the die side 8.
Start transformation from . This is because the billet 5 is heated to a high temperature and easily undergoes plastic deformation, and a slight stress difference causes deformation from one side, that is, from the die 8 side, causing air to flow between the inner peripheral surface of the container and the outer peripheral surface of the billet. are sequentially discharged to the rear, and this phenomenon occurs throughout the entire process during upsetting and extrusion.

<Effects of the invention> According to the invention, in a double-stem type indirect extrusion press, the blister phenomenon can be prevented without requiring any special heat processing treatment for the billet during billet upsetting by the press stem and die stem. It is possible to reliably prevent this, and as a result, extruded products with no loss of surface quality can be easily produced. In this case, if the blister-preventing lid member is installed completely separately from the press stem 6, charging the billets 5 to 5A into the container 1 is extremely easy, and there is no possibility of generating blisters. Even if a jam occurs, it can be easily removed by the press stem 6, and the necessary structure is extremely simple and can be easily incorporated into a conventional indirect extrusion press mechanism. This makes it possible to easily supply billets in a double stem type, facilitate the removal of jammed billets, and improve response to changes in billet length before and after piercing inside a container during pipe extrusion, without sacrificing its features. This is highly effective in preventing the problem of blisters occurring during upset.

[Brief explanation of the drawing]

Figures 1, 2, and 3 are side sectional views of important parts showing the press cycle movement of each embodiment of the indirect extrusion press according to the present invention for obtaining bar-shaped products, and Figures 4 to 2 are
Each figure in FIG. 1 is a sectional side view of a main part showing the press cycle movement of each embodiment of the indirect extrusion press according to the present invention for obtaining a tubular product, and FIG. 22 is an explanatory view showing air bleeding according to the present invention. 1...container, 2...container holder, 3...
...Shear blade, 4...Shear cylinder, 5...
...Billet, 5a...Hollow billet, 6...Press stem, 7...Die stem, 8...Die, 1
1, 11B, 11D...Blister prevention lid member, 1
1A, 11E...Blister prevention lid surface, 14...Bar-shaped product, 14A...Tubular product, 16, 17, 19
...Mandrel.

Claims (1)

[Claims for Utility Model Registration] A billet comprising a container having a billet charging hole on the extrusion center line, a press stem and a die stem opposed to each other on the extrusion center line with the container in between, and a billet inserted in the billet charging hole. In an indirect extrusion press, the billet is extruded while the container and the press stem are moved together to the die stem side, and the container is placed over the die stem.A billet charging hole is formed on the press stem side of the container. A detachable blister prevention lid member is provided on the end face of the billet housed in the press stem and the container end face on the side of the billet end face, respectively, so that the pressing force on the press stem side is distributed between the billet and the container via the blister prevention lid member. An indirect extrusion press characterized by: