JPH08168816A - Method for preventing falling of fixed dummy block - Google Patents

Abstract

PURPOSE: To prevent failure such as galling due to looseness by providing a cooling path in the interior from an extruding stem to a dummy block and detecting the looseness of the dummy block by decrease of the pressure of water which flows in the cooling path. CONSTITUTION: The dummy block 2 is cooled from its interior by making a stop valve 61 into an opening state before starting upset and starting up a feed pump 62 for cooling water. The cooling water is entered from the rear of the extruding stem 6, runs through the water-supply pipe 58 of a connection rod 57 and is returned to a tank 97 from the drain port 64 through a radial cooling port, drain pipe 59 or the like. When the extrusion of a billet 4 is repeatedly executed, the joined part between a bayonet block 50 and the dummy block 2 is gradually loosened and cooling water leaks from here to the outside. Thus, water pressure detected with a water-pressure detector 98 is decreased and, by comparing it with the value of normal water pressure with a comparator 100, an alarm is given from an alarm device 101 and the generation of failure such as galling is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing a fixed damy block from falling off by detecting looseness of the damy block by means of water pressure in a cooling passage.

[0002]

2. Description of the Related Art Conventionally, an extruding stem having a fixed damy block attached to the tip of the extruding stem pushes a billet inserted into a container toward a die.

[0003]

However, when the fixed damey block is attached to the tip of the extrusion stem by screwing or bayonet connection, the billet loaded in the container is repeatedly extruded. Fixed Damy Rock sometimes loosened.

Due to this looseness, the tip of the fixed damy block (on the side of the pushing action surface) is lowered by its own weight. Therefore, when the billet placed on the billet loader in this state is loaded into the container by advancing the extrusion stem, the tip of the fixed damy block comes into contact with the end surface of the container liner when the looseness is large. There is a problem that if the billet cannot be extruded, or if the looseness is too small, the tip of the fixed damy block may cause galling when advanced with the tip of the fixed damy block in contact with the inner peripheral surface of the container liner. .

The present invention has been made in view of the above problems, and an object thereof is to detect looseness of a fixed damy block in advance.

[0006]

In order to achieve the above object, according to the present invention, there is provided an extruding stem for pushing a billet inserted in a container to a die side and a fixed type damai block provided at a tip portion of the extruding stem. A cooling passage is provided inside the extrusion stem to the Damii block, and looseness of the Damii block is detected by a decrease in water pressure flowing in the cooling passage.

[0007]

In the present invention, since the cooling water is passed through the fixed damey block and the extrusion stem to cool the inside,
After connecting the fixed damy block and the extrusion stem with a bayonet block or screwing them together, cooling water is passed through, but problems such as galling caused by loosening of the fixed damy block may occur on the outlet side. Since the detection is made by detecting the water pressure of the cooling water, the looseness of the fixed damy block can be known early and the malfunction can be prevented.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings.

In FIG. 1, a vacuum deaerator 30 as shown in FIG. 6 is provided on the die 5 side of the container 1 composed of the content liner 1a and the container tire 1b. An outer ring 15 concentric with the container 1 is fixed to the end surface of the container tire 1b on the die 5 side by bolts. In addition, a seal ring 16 is provided on the inner peripheral surface side of the outer ring 15 so as to be able to move forward and backward, but not to be disengaged in a stepwise manner.

A part of the seal ring 16 has a structure having a projecting portion 16a projecting toward the center, and the container 1
When the container 1 is temporarily stopped with a gap of, for example, 2 to 3 mm left between the die 5 and the die 5, the protrusion 16a of the seal ring 16 with respect to the end surface of the die ring 5a on the side of the container 1 causes the spring 17 (in this embodiment, the container 17). Eight springs 17 are elastically mounted at equal intervals between the tire 1b and the seal ring 16) to press and contact (face seal) in the push-out direction so that the clearance becomes zero.

A deaeration hole 18 is provided above the seal ring 16.
There are two (in this embodiment), and from there are connected to a vacuum tank 11 and a vacuum pump 12 via a pipe 9 and an electromagnetic switching valve 10. 13 is a motor, 19 is an outer ring 1
5 is a heat-resistant sealing material that prevents air from entering between the seal ring 16 and the seal ring 16, and 20 is the outer ring 15 and the container tire 1.
Metal hollow ring to prevent air from entering between b, 21
Is a replaceable seal plate that prevents direct abrasion and air intrusion of the protrusion 16a of the seal ring 16 by repeated contact with the die ring 5a. Also, 4 is a billet, 6
Reference numeral 2 denotes an extruding stem, 2 is a fixed damy block which is attached to the tip of the extruding stem 6 and which is in close contact with the inner surface of the container 1 and pushes the rear end surface of the billet 4.

The container 1 is attached to a piston rod 25 of a container cylinder 24 attached to the end platen 23. Reference numeral 28 is a piston, and 29 is a cylinder tube forming a cylinder body. Container cylinder 2
The portion B on the piston head side of No. 4 is composed of a movement stopper block 26, a head block 27 that also serves as a stopper, and the like, and the piston 28 can be rapidly stopped at the maximum distance of the movement range of the movement stopper block 26. . When the piston 28 is temporarily stopped just before the rear end, the container 1 is stopped just before it hits the die 5. Reference numeral 37 is a rear plug, and 14 is a pressure gauge.

A hollow rod 31 having a plurality of communication holes for oil passage arranged in a zigzag pattern in the axial direction is integrally attached to the shaft core on the rear side, which is the head side of the piston 28, by screws or the like. When 28 is retracted, the hollow rod 31 enters into the hole on the front end side of the movement stopper block 26.

On the other hand, the structure on the extrusion stem side is shown in FIGS.
In addition, as shown in FIG. 4, the damai block 2 and the extruding stem 6 are bayonet-coupled via the bayonet block 50, and the damy block 2 and the extruding stem 6 are directly screw-coupled as shown in FIG. There is.

First, the structure in which the damy block 2 and the extruding stem 6 are bayonet-bonded will be described in detail as a representative. In FIG. 4, 1 is a container, 6 is a tubular extrusion stem, and 2 is a fixed damy block fixedly provided on the front surface of the extrusion stem 6 and slidably provided in the container 1. As shown in FIG. 1, the rear end portion of the extrusion stem 6 has a stem holder 53 and a pressure ring 54.
It is fixed to the main crosshead 55 via.

A bayonet block 50 is arranged on the front surface of the extrusion stem 6, and the bayonet block 5 is provided.
In the rear half of 0, the tip of a connection rod 57 having a circular outer diameter cross section is attached by screw attachment.
The rear end portion of the connection rod 57 is a large diameter portion 57a as shown in FIG. 1, and is engaged and fixed with a tapered surface in the hole at the rear end portion of the extrusion stem 6.

The front half of the bayonet block 50 is of a bayonet type as shown in FIG. 3, and three projections 50a are arranged at equal intervals, for example. On the other hand, recesses 56b engageable with the protrusions 50a are provided at equal intervals on the side of the damee boss 56 to be mounted, and at the time of mounting, the protrusions 50a of the bayonet block 50 and the recesses 56b on the side of the damie boss 56 are formed. Engage and insert, approximately 60
By rotating the damee boss 56, the damee boss 5
The 6 can be attached to and removed from the bayonet block 50 reliably and quickly.

A through hole is bored in the connection rod 57 in the axial direction, and a water supply pipe 58,
A drain pipe 59 is provided. The tips of the water supply pipe 58 and the drainage pipe 59 that form the cooling pipe 65 are firmly attached to the holes 57b and 57c of the cooling pipe tip block 65a by welding, and the rear end portion extends into the pressure ring 54. .

The end of the water supply pipe 58 has a pressure ring 5
It is connected to a cooling water supply pump 62 via a passage 60 by a pipe in 4, a switching valve 61, and a pipe 90. The end of the drainage pipe 59 is connected to the drainage port 64 through a pipe passage 63 in the pressure ring 54. A small gap is provided between the inner peripheral surface of the extrusion stem 6 and the outer peripheral surface of the connection rod 57 in order to keep the core of the connection rod 57 in a flexible state. In addition, the inner peripheral surface of the connection rod 57 and the water supply pipe 5
8. A slight gap is provided between the drain pipe 59 and the outer peripheral surface of the drain pipe 59 so that the connection rod 57 is not directly cooled. Further, a slight gap is provided between the inner peripheral surface of the connection rod 57 and the cooling pipe tip block 65a in order to hold the core in a flexible state.

In this case, since the connection rod 57 is provided with a through hole to pass the water supply pipe 58 and the drainage pipe 59, the connection rod 57 is not directly cooled, and therefore the temperature difference between the extruding stem 6 and the connection rod 57. And the flexibility of the core of the dami block 2 is not impaired. The hole 57b in the cooling pipe tip block 65a is provided so as to penetrate therethrough, but the front end portion of the hole 57c communicates with the opening 66 in the outer peripheral direction via the cooling pipe 65.

Reference numeral 98 is a water pressure detector for detecting the cooling water pressure after circulating and cooling the inside of the extrusion stem 6 and the Damii block 2, 99 is a converter for converting the pressure detected by the water pressure detector into an electric signal, and 100 is set. A comparator for comparing the detected value with the detected value, and 101 an alarm device, respectively.

In the front half of the dami boss 56, a small cylindrical protrusion 70a provided in the center of the core block 70 is inserted into the center through hole 56a of the dami boss 56, and the connection is made from the rear end side of the dami boss 56. The core block 7 is formed by screwing the bolt 69 into the threaded portion of the small cylindrical protrusion 70a and tightening the connection bolt 69.
The 0 is strongly contacted with the dami boss 56.

A cylindrical outer ring 71 is fixed to the outer periphery of the front side of the dami boss 56. Further, between the rear end surface of the core block 70 and the front end surface of the dami boss 56,
The tip of the outer ring 71 and the outer surface 8 of the core block 70
5 is provided with a gap corresponding to a step, and when the core block 70 is pushed backward during extrusion, the core block 70
The rear end face of the rear end contacts the front end face of the dami boss 56. The outer ring 71 is expanded and hits the inner surface of the container, and the billet 4 is pushed out by the extrusion stem 6 of the damy block 2.
It is designed to prevent it from flowing to the side.

The core block 70, the dami boss 56 having the outer ring 71, and the like constitute the dami block 2 integrally. Therefore, the outer peripheral surface of the outer ring 71 on the front end side is sized to substantially contact the outer peripheral surface of the container 1. Further, the outer peripheral portion of the front end of the core block 70 is formed into a tapered surface portion 70b which is widened to the front side, so that the outer peripheral portion of the outer ring 71 can be closely adhered to the tapered surface portion.

A passage 72 for passing the cooling water supplied from the water supply pipe 58 is provided in the central axis portion of the core block 70 and the protrusion 70a, and the tip end of the passage 72 is the outer surface of the core block 70. It is extended to around 85.

As shown in FIG. 4, a plurality of radial cooling holes 74 (eight in this embodiment) extending radially from the tip of the passage 72 to the outer ring 71 are provided.

A passage 75 is provided in the axial direction in the vicinity of the outer periphery from the outer peripheral end of the radial cooling hole 74 to the core block 70 from the dami boss 56, and the opening 6 of the cooling pipe 65 is provided.
6. Here, reference numerals 79, 80, 81, 8
2 is a plug, and 86, 87, 88 are heat resistant O-rings, respectively.

Next, the operation of the device will be described.

First, pressure oil is supplied to the rod side of the container cylinder 24, the piston 28 is moved leftward, and the container 1 separated from the die 5 is advanced. This time,
While the distal end of the hollow rod 31 attached to the piston 28 moves to the distal end of the stopper block 26, the retreating speed of the piston 28 is relatively high. Eventually,
The hollow rod 31 begins to enter the hole of the stopper block 26, and the piston 28 decelerates.

In this state, the piston 28 continues to retract,
The tip surface portion of the piston 28 contacts the tip portion of the stopper block 26. At this time, the piston 28 completes stopping at an intermediate position due to the action of the stopper block 26. Then, due to the action of the stopper block 26, the accuracy of the stop position in the middle of the stroke is sufficiently ensured. At this time, the protrusion 16a of the seal ring 16 contacts the die ring 5a, and the gap 7 between the container 1 and the die 5 is, for example, 2 to 3 mm. The state at this time is shown in FIG.

When this operation is completed, the billet 4
When a billet loader (not shown) in a state where the bill is placed is lifted and the extrusion stem 6 is moved forward, the billet 4 is pushed into the container 1 and the billet 4 comes into contact with the end surface of the die 5 side, as shown in FIG. Like Further, the extrusion stem 6 advances to start upset.

However, before starting the upset, the solenoid valve 96 is excited and the on-off valve 61 is opened, and the cooling water supply pump 62 is activated to start the radial cooling holes 74.
Cooling water is introduced to cool the damii block 2 from the inside. At this time, the cooling water enters from the rear of the extrusion stem 6, passes through the water supply pipe 58 in the connection rod 57 in the extrusion stem 6, the passage 72, the radial cooling holes 74,
The cooling water discharged from the drainage port 64 through the drainage pipe 59 from the passage 75 and the opening 66 is discharged to the tank 97 through the pipe 92.

At this time, the water pressure detected by the water pressure detector 98 is usually 0.8 to 0.9 kg / cm ^2, which is a substantially constant value. However, as shown in FIG. 2, when the billet 4 loaded in the container 1 starts to be extruded, the damy block 2
Is attached at a predetermined position with its axis aligned with the tip of the extruding stem 6, but when the billet 4 is repeatedly extruded many times, the joint between the bayonet block 50 and the damii block 2 gradually loosens, Due to the weight of the damy block 2, it is lowered to the state shown by the chain line in FIG.

Under normal conditions, the gap between the outer peripheral portion (D1) of the damy block 2 and the container liner 1a (inner diameter D2) is only D2-D1≈1 mm. When the weight is lowered, if the looseness between the bayonet block 50 and the damee block 2 is great, the tip of the damie block 2 may come into contact with the end surface of the container liner 1a.

On the contrary, when the billet 4 loaded in the container 1 in which the looseness between the bayonet block 50 and the damie block 2 is small is extruded by the forward movement of the extruding stem 6, the tip of the damie block 2 is moved to the container liner 1a.
The extruding stem 6 is moved forward in the state of being in contact with, which causes galling.

Further, as shown in FIG. 2, due to the looseness between the bayonet block 50 and the damie block 2, the cooling water passing through the passage 75 is removed from the heat resistant O-ring 88 to the joint surface between the bayonet block 50 and the damie block 2. It will be leaked to the outside through.

As described above, with the leakage of the cooling water due to the looseness between the bayonet block 50 and the dami block 2,
The value of the water pressure detected by the water pressure detector 98 provided on the pipe 92 connected to the drainage port 64 becomes low, and the comparator 10
At 0, such normal water pressure value is 0.8 to 0.9 kg / cm.
² and water pressure decreased due to leakage 0.6-0.7 kg / c
An alarm is issued from the alarm device 101 by comparison with m ² . From this alarm, Bayonet Block 5
The leak of cooling water due to the looseness between 0 and Damii block 2 is known. The alarm informs the leakage of the cooling water, demagnetizes the solenoid valve 96, and stops the forward / backward movement of the extrusion stem 6.

If the damee block 2 is attached to the tip of the extruding stem 6 in a normal state and the upsetting is performed while the inside of the damee block 2 is cooled, the degree of friction with the front end face of the damee block 2 increases. Billet 4
The rear end of the billet 4 is prevented from being caught inside the outer skin, and the air is also prevented from being simultaneously entrained inside the billet 4 due to the catching. Sealing is done. In this way, the air that causes blisters is prevented by cooling the damii block 2 to prevent the trailing end skin of the billet 4 and the air from being entrained inside and degassing the surface of the billet 4 on the front die 5 side. Can be fully removed.

In particular, in this embodiment, various experiments were carried out, and if the front end face of the damii block 2 was 250 ° C. or lower, the billet 4
The fluidity on the rear end side is deteriorated, and the billet 4 is prevented from being caught in the outer skin of the rear end portion, and the formation of blisters in the extruded product profile can be prevented.

During the upset, the extrusion stem 6 continues advancing without a break, the billet 4 is crushed, and when the end surface of the billet 4 on the die 5 side begins to deform, the container 1 is advanced to the die 5 side and the container 1 The gap 7 of the die 5 becomes zero. The reduction of the gap 7 is performed by the backward movement of the movement stopper block 26.

Further, in this embodiment, as shown in FIG. 7, the damee block 2 and the extrusion stem 6 may be directly screwed together by the screw portion 33 to be coupled, and in this case as well, the billet loaded in the container 1 When the pushing operation of No. 4 is repeated, the screw portion is loosened, the tip of the damii block 2 is lowered by its own weight, and the same leakage of cooling water as in the case of bayonet connection occurs.

In this case as well, as described above, the pressure drop due to the leakage of the cooling water discharged from the drain port 64 is detected by the water pressure detector 98, and the forward / backward movement of the extrusion stem 6 is also stopped.

[0043]

The extruding stem for pushing the billet inserted into the container toward the die side and the fixed damy block provided at the tip of the extruding stem, wherein a cooling passage is provided inside the extruding stem to the damy block, By performing the loosening of the damy block by detecting the decrease in the water pressure flowing in the cooling passage, it becomes possible to reliably detect the looseness of the fixed damy block, and the shaving caused by the looseness of the fixed damy block. It becomes possible to completely and easily prevent the occurrence of such problems.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of an apparatus for carrying out the method of the present invention.

FIG. 2 is a conceptual diagram showing a water leak state between a fixed damy block and a bayonet block.

FIG. 3 is a perspective view of a bayonet block.

FIG. 4 is an enlarged view of the extrusion stem side of FIG.

5 is a front view seen from AA of FIG. 4. FIG.

FIG. 6 is an enlarged cross-sectional view of a main part of a suction unit that sucks air through a minute gap between a die and a container.

FIG. 7 is a conceptual diagram showing a state of water leakage between the fixed damy block and the extrusion stem.

[Explanation of symbols] 1 container 2 damy block 3 die ring seal 4 billet 5 die 6 extrusion stem 7 gap 8 degassing hole 12 vacuum pump 15 outer ring 16 seal ring 16a protrusion 17 spring 18 degassing hole 23 end platen 24 container cylinder 25 Piston Rod 26 Stopper Block 27 Head Block 28 Piston 31 Hollow Rod 50 Bayonet Block 50a Projection 56 Damii Boss 57 Connection Rod 58 Water Supply Pipe 59 Drain Pipe 62 Cooling Water Supply Pump 63 Passage 64 Drain Port 65 Cooling Pipe 65a Cooling Pipe Tip Block 69 Connection Bolt 70 Core Block 70a Projection 70b Tapered Surface 71 Outer Ring 72, 75 Passage 74 Radial Cooling Hole 85 Outer Surface (Extrusion Action Surface) 90, 92 Piping 9 Solenoid valve 98 pressure detector 100 comparator 101 alarm

Claims (1)

[Claims] 1. An extruding stem for pushing a billet inserted into a container to a die side, and a fixed damy block provided at a tip portion of the extruding stem, wherein a cooling passage is provided inside the extruding stem to the damy block. A method for preventing falling out of a fixed damy block, wherein looseness of the damy block is detected by a decrease in water pressure flowing through the cooling passage.