JP2021171783A - Push rod and extrusion method - Google Patents

Abstract

To provide a push rod capable of preventing excessive heating and efficiently extruding a billet, and an extrusion method.SOLUTION: One tip fitting 3 is selected from among a plurality of tip fittings 3 different in a diameter in accordance with a diameter of a billet 2 to be extruded. The tip fitting 3 is connected to a tip of a rod-shaped body 4. Subsequently, the tip fitting 3 is fed into an induction heating furnace 6 together with the rod-shaped body 4. Thus, a front end of the tip fitting 3 and a rear end of the billet 2 are brought into contact with each other so that the billet 2 can be extruded from the induction heating furnace 6.SELECTED DRAWING: Figure 1

Description

The present invention relates to a push rod and an extrusion method for extruding a billet inside an induction heating furnace along a transport direction, and more particularly, a push rod and an extrusion method capable of preventing excessive heating and efficiently extruding the billet. It's about the method.

Various configurations of push rods for pushing billets out of an induction heating furnace have been proposed (see, for example, Patent Document 1). Patent Document 1 discloses a configuration of a push rod that is fed by a pinch roller and pushes out a billet inside an induction heating furnace.

Billets of different sizes, such as large-diameter billets with a relatively large diameter and small-diameter billets with a relatively small diameter, were sometimes supplied to the induction heating furnace. If the diameter of the push rod is too small for the billet, the magnetic flux may be concentrated on the edge of the rear end of the billet pushed by the push rod and overheated. There was a problem that the overheated billet could not be used for subsequent processing and had to be discarded.

If the diameter of the push rod is too large for the billet, the pinch roller that feeds the billet cannot ride on the push rod from the billet, and there is a problem that the push rod is not fed by the pinch roller. In this case, the billet could not be pushed out from the inside of the induction heating furnace.

Japanese Patent Application Laid-Open No. 58-107419

The present invention has been made in view of the above problems, and an object of the present invention is to provide a push rod and an extrusion method capable of preventing excessive heating and efficiently pushing out billets.

The push rod for achieving the above object is a push rod that pushes the billet inside the induction heating furnace forward along the transport direction, and is connected to the tip fitting that comes into contact with the billet and behind the tip fitting. It is characterized in that it is provided with a rod-shaped body, and the tip metal fitting is configured to be detachable from the rod-shaped body.

The extrusion method for achieving the above object is an extrusion method in which a billet inside an induction heating furnace is extruded forward along a transport direction, and the billet is to be extruded from a plurality of tip fittings having different diameters. One of the tip fittings is selected according to the diameter, the tip fitting is connected to the tip of the rod-shaped body, and then the tip fitting is sent to the inside of the induction heating furnace together with the rod-shaped body. The billet is extruded from the induction heating furnace by contacting the front end of the tip metal fitting with the rear end of the billet.

According to the present invention, the tip metal fitting can be replaced according to the diameter of the billet. Therefore, it is advantageous to avoid a problem that the diameter of the push rod is too small with respect to the billet and the billet is excessively heated, or the diameter of the push rod is too large and the billet is not extruded.

It is explanatory drawing which illustrates the push rod sent to an induction heating furnace from the side view. It is explanatory drawing which illustrates the AA arrow view of FIG. It is explanatory drawing which illustrates the tip metal fitting with a perspective. It is explanatory drawing which illustrates the tip metal fitting with a perspective. It is explanatory drawing which illustrates the rod-shaped body with a perspective view. It is explanatory drawing which illustrates the conventional example in the case where the diameter of a push rod is smaller than a billet. It is explanatory drawing which illustrates the conventional example in the case where the diameter of a push rod is larger than a billet.

Hereinafter, the push rod and the extrusion method will be described based on the embodiment shown in the figure. In the figure, the transport direction of the billet is indicated by an arrow x, the width direction crossing the transport direction x at a right angle is indicated by an arrow y, and the vertical direction is indicated by an arrow z.

As illustrated in FIG. 1, the push rod 1 includes a tip metal fitting 3 arranged on the front side and in direct contact with the billet 2, and a rod-shaped body 4 connected to the rear side of the tip metal fitting 3. The billet 2 is formed in a cylindrical shape or a prismatic shape, for example. The billet 2 is transported with its axial direction as the transport direction x. In FIG. 1, for the sake of explanation, the direction in which the billet 2 moves is indicated by a white arrow.

The billet 2 is sent to the induction heating furnace 6 by, for example, a pair of pinch rollers 5 arranged one above the other. The upper pinch roller 5 may be installed in a cylinder mechanism 7 that expands and contracts in the vertical direction z. The pinch roller 5 is rotated by the power of a drive motor or the like (not shown) to convey the billet 2 to the right side of FIG. The billet 2 pushed out by the pinch roller 5 on the front side (right side in FIG. 1) in the transport direction x pushes the billet 2 further forward. A plurality of billets 2 are continuously sent to the induction heating furnace 6 along the transport direction x. In FIG. 1, the billet 2 inside the induction heating furnace 6 is shown by a broken line for explanation.

When the heating work by the induction heating furnace 6 is completed, the push rod 1 pushes out the rearmost billet 2 from the inside of the induction heating furnace 6. The tip fitting 3 and the rod-shaped body 4 constituting the push rod 1 are sent out to the front side in the transport direction x by the pinch roller 5. The tip metal fitting 3 and the rod-shaped body 4 are formed in a substantially cylindrical shape with the transport direction x of the billet 2 as the axial direction. The tip metal fitting 3 is connected to the rod-shaped body 4 via the connecting portion 8.

As illustrated in FIG. 2, the push rod 1 is supported from below by a skid rail 9 composed of a pair of frame-shaped members arranged at intervals in the width direction y. The path through which the push rod 1 and the billet 2 are conveyed is not limited to the one composed of the skid rail 9. The push rod 1 and the billet 2 may be supported from below in a state of being movable in the transport direction x, and may be composed of, for example, a U-shaped member or a conveyor that expands upward.

As illustrated in FIG. 3, a pressing surface 10 that comes into contact with the billet 2 and presses the billet 2 is formed at the front end of the tip metal fitting 3. A connecting portion 8a is formed at the rear end of the tip metal fitting 3, and the diameter of the connecting portion 8a is set to be equivalent to the diameter of the rod-shaped body 4. The connecting portion 8a formed at the rear end of the tip metal fitting 3 is connected to the connecting portion 8b formed at the front end of the rod-shaped body 4.

A tapered portion 11 is formed on the tip metal fitting 3 from the pressing surface 10 on the front side in the transport direction x toward the connecting portion 8a on the rear side. The tip metal fitting 3 has a pressing surface 10 having a diameter larger than that of the rod-shaped body 4. Therefore, the upper surface of the tapered portion 11 is formed so as to be inclined downward from the pressing surface 10 on the front side toward the connecting portion 8a on the rear side. The lower surface of the tapered portion 11 is formed in a straight line parallel to the transport direction x.

The tip metal fitting 3 is formed in a solid truncated cone shape. The tip metal fitting 3 may be formed hollow. Further, when the billet 2 has a prismatic shape, the tip metal fitting 3 can be formed in a pyramidal trapezoidal shape corresponding to the billet 2. In the present specification, the diameter of the push rod 1 or the billet 2 means the thickness of the push rod 1 or the like in a cross section orthogonal to the transport direction x. Specifically, the diameter means the diameter when the push rod 1 or the like has a substantially cylindrical shape, and means the size in the width direction y and the vertical direction z when the push rod 1 or the like has a substantially prismatic shape.

As illustrated in FIG. 4, when the pressing surface 10 has a smaller diameter than the rod-shaped body 4, the upper surface of the tapered portion 11 is inclined upward from the pressing surface 10 on the front side toward the connecting portion 8a on the rear side. Is formed in. Also in this embodiment, the lower surface of the tapered portion 11 is formed horizontally. The lower surface of the tapered portion 11 is formed in a straight line parallel to the transport direction x.

It is desirable that the connecting portion 8 has a configuration in which the tip metal fitting 3 is restrained from tilting in the vertical direction z with respect to the rod-shaped body 4. In this embodiment, the connecting portion 8a has a gap portion 12 extending in the width direction y. Further, a bolt hole 13a that penetrates the gap portion 12 in the vertical direction z is formed in the connecting portion 8a. The gap portion 12 has a configuration in which the connecting portion 8b of the rod-shaped body 4 is inserted. The bolt inserted into the bolt hole 13a penetrates and fixes the connecting portion 8b of the rod-shaped body 4. It is desirable that the bolt and the upper surface of the rod-shaped body 4 are flush with each other. It is advantageous to avoid the concentration of magnetic flux and the overheating state.

The connecting portion 8 can prevent the tip metal fitting 3 from tilting with respect to the rod-shaped body 4 about the width direction y as a central axis. It is advantageous to maintain good contact between the rear end surface of the billet 2 and the pressing surface 10 of the tip fitting 3. When the tip metal fitting 3 is tilted in the vertical direction z and the pressing surface 10 is tilted upward or downward, the contact state with the billet 2 is deteriorated. As a result, there is a problem that the force with which the push rod 1 pushes the billet 2 becomes small. In addition, there is a problem that the magnetic flux is concentrated on a part of the rear end surface of the billet 2 and the billet 2 is overheated.

It is desirable that the connecting portion 8 restrains the tilt of the tip metal fitting 3 in the left-right direction. The connecting portion 8 can prevent the tip metal fitting 3 from tilting with respect to the rod-shaped body 4 with the vertical direction z as the central axis. A good contact state between the billet 2 and the tip metal fitting 3 can be maintained. It is advantageous for improving the transport efficiency of the billet 2. Further, it is more desirable that the connecting portion 8 prevents the tip metal fitting 3 from tilting about the vertical direction z as the central axis and the above-mentioned tilting about the width direction y as the central axis.

As illustrated in FIG. 5, the rod-shaped body 4 has an upper surface 4a and a lower surface 4b curved in an arc shape, and a wall portion 4c connecting the upper surface 4a and the lower surface 4b. The wall portion 4c is composed of a plate-shaped member extending in the transport direction x and the vertical direction z.

In this embodiment, the connecting portion 8b is composed of plate-shaped members extending in the width direction y and the transport direction x. The connecting portion 8b is erected horizontally from the wall portion 4c. A bolt hole 13b penetrating in the vertical direction z is formed in the connecting portion 8b formed of the plate-shaped member. The connecting portion 8b made of a plate-shaped member is inserted into the gap portion 12 illustrated in FIG. 4 and fixed with bolts penetrating the bolt holes 13a and 13b.

It is desirable that the length of the connecting portion 8b in the vertical direction z is the same as or slightly smaller than the length of the gap portion 12 in the vertical direction z. It is advantageous to prevent the tip metal fitting 3 from tilting about the width direction y as the central axis. It is desirable that the length of the connecting portion 8b in the transport direction x is the same as or slightly smaller than the length of the gap portion 12 in the transport direction x. It is advantageous to prevent the tip metal fitting 3 from tilting about the vertical direction z as the central axis.

The configuration of the connecting portion 8 is not limited to the above. The structure may be such that the tip metal fitting 3 and the rod-shaped body 4 are connected at least in a state where they are not separated.

The method of extruding the billet 2 using the push rod 1 will be described below. When heating the billets 2, a plurality of billets 2 are continuously supplied to the induction heating furnace 6 by the pinch rollers 5. For example, when the heating work by the induction heating furnace 6 is completed at the end of work, the billet 2 is pushed out from the inside of the induction heating furnace 6 by the push rod 1.

A tip fitting 3 having an appropriate size is selected from a plurality of tip fittings 3 prepared in advance according to the diameter of the billet 2 heated in the induction heating furnace 6. The tip fitting 3 having an appropriate size is a tip fitting 3 having a diameter substantially equal to the diameter of the billet 2. Desirably, a tip fitting 3 having a diameter equal to the diameter of the billet 2 is selected. When there is no tip fitting 3 having a diameter equal to that of the billet 2, it is desirable to select a tip fitting 3 having a diameter larger than the diameter of the billet 2. Further, it is desirable to select the tip metal fitting 3 having the smallest diameter within a range not smaller than the diameter of the billet 2.

The selected tip metal fitting 3 is fixed to the tip of the rod-shaped body 4 with a bolt or the like to form the push rod 1. The push rod 1 is sent to the induction heating furnace 6 from behind the last billet 2. The push rod 1 is sent to the inside of the induction heating furnace 6 by the pinch roller 5. By contacting and pushing the pressing surface 10 of the tip metal fitting 3, the rearmost billet 2 is discharged from the induction heating furnace 6. Since the last billet 2 is appropriately heated, it is processed into parts or the like in a subsequent process. After the last billet 2 is discharged, the induction heating furnace 6 stops heating. Further, the rotation of the pinch roller 5 is stopped. The push rod 1 is retracted and returned to its original position.

When each push rod 1 is used, a tip metal fitting 3 having an appropriate diameter is selected according to the diameter of the billet 2 and replaced with the rod-shaped body 4. Therefore, excessive heating of the billet 2 can be prevented, and the last billet 2 can be efficiently pushed out from the induction heating furnace 6.

The tip metal fitting 3 is selected to have a size equal to or larger than the diameter of the billet 2. It is desirable that the tip metal fitting 3 is not selected to have a diameter smaller than that of the billet 2. According to this configuration, all the magnetic flux passing through the billet 2 moves to the tip metal fitting 3.

As illustrated in FIG. 6, when the diameter of the push rod 1X is smaller than that of the billet 2, the magnetic flux is concentrated in the region P which is the upper end behind the billet 2 inside the induction heating furnace 6, and this portion is excessively heated. Will be done. In FIG. 6, for the sake of explanation, the region P where the magnetic flux is concentrated is surrounded by a broken line. If the tip metal fitting 3 has a slightly smaller diameter than the billet 2, the rear upper end of the billet 2 may not be heated so much, which may be acceptable.

As the tip metal fitting 3, the one having the smallest diameter is selected as long as the diameter is not smaller than the diameter of the billet 2. It is desirable to make the difference in diameter between the billet 2 and the tip metal fitting 3 as small as possible.

Even when the tip metal fitting 3 is tilted and the pressing surface 10 and the billet 2 are not in proper contact with each other, the magnetic flux may be concentrated on a predetermined region of the rear end surface of the billet 2 and this portion may be excessively heated. It is desirable that the tip metal fitting 3 has an appropriate diameter with respect to the billet 2 and is in a state of being in proper contact with the billet 2.

As illustrated in FIG. 7, if the push rod 1X has a larger diameter than the billet 2, the pinch roller 5 may not be able to ride on the push rod 1X from the billet 2. In this case, the transportation of the billet 2 is stopped. Even if the pinch roller 5 rides on the push rod 1X, it takes longer than usual, and the transport efficiency of the billet 2 may decrease. In the induction heating furnace 6, there is a problem that the time for the billet 2 to pass is increased and the billet 2 is heated to a state where the temperature becomes higher than a predetermined value.

The smaller the difference in diameter between the billet 2 and the tip metal fitting 3, the more smoothly the pinch roller 5 can ride on the tip metal fitting 3 and push out the push rod 1. The transport efficiency of the billet 2 is hardly reduced. Since the time through which the billet 2 passes in the induction heating furnace 6 hardly increases, the billet 2 can be heated to an appropriate temperature.

1 Push rod 2 Billet 3 Tip bracket 4 Rod-shaped body 4a Top surface 4b Bottom surface 4c Wall part 5 Pinch roller 6 Induction heating furnace 7 Cylinder mechanism 8 Connecting part 8a (tip fitting side) Connecting part 8b (rod-shaped body side) connecting part 9 Skid Rail 10 Pressing surface 11 Tapered part 12 Gap part 13a Bolt hole 13b Bolt hole x Transport direction y Width direction z Vertical direction P area

Claims (6)

In the push rod that pushes the billet inside the induction heating furnace forward along the transport direction,
A push rod comprising a tip metal fitting that comes into contact with the billet and a rod-shaped body that is connected to the rear of the tip metal fitting, and the tip metal fitting is configured to be detachable from the rod-shaped body. .. The push rod according to claim 1, further comprising the plurality of tip fittings having different diameters. The push rod according to claim 1 or 2, wherein a tapered portion is formed on the tip metal fitting so that the diameter of the tip metal fitting becomes equal to the diameter of the rod-shaped body from the front side to the rear side in the transport direction. .. A claim that the connecting portion has a connecting portion for connecting the tip metal fitting and the rod-shaped body, and the tip metal fitting is connected to the rod-shaped body in a state in which tilting in the vertical direction is restrained. Item 2. The push rod according to any one of Items 1 to 3. In the extrusion method that pushes the billet inside the induction heating furnace forward along the transport direction,
One of the tip fittings is selected according to the diameter of the billet to be extruded from a plurality of tip fittings having different diameters, and the tip fitting is connected to the tip of the rod-shaped body.
After that, the tip metal fitting is sent to the inside of the induction heating furnace together with the rod-shaped body, so that the front end of the tip metal fitting and the rear end of the billet come into contact with each other, and the billet is extruded from the induction heating furnace. An extrusion method characterized by. The extrusion method according to claim 5, wherein the tip fitting having a diameter equal to or larger than the diameter of the billet inside the induction heating furnace and having the smallest diameter is selected.

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