JPS585961B2 - Reduction sintering cake lowering device for vertical reduction annealing furnace - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a reduction cake descending device for a vertical reduction annealing furnace, particularly for producing low-oxygen iron-based metal powder for powder metallurgy.
The present invention relates to a device for lowering at a predetermined speed a powder raw material that has been reduced and sintered through a preheating furnace and an induction heating furnace of a vertical reduction annealing furnace.

As shown in Fig. 1, the vertical reduction annealing furnace includes a device 1 for quantitatively cutting out the powder raw material, and receives the powder raw material from the quantitative cutting device 1, and partially reduces and slightly sinters the powder raw material. It consists of a preheating furnace 2 for carrying out the process, an induction heating furnace 3 for finishing reduction of the raw material passed through the preheating furnace 2, and a descending cutting device 4 for reducing and sintering the powdered raw material, that is, the reduction sintered cake. This is a reduction annealing furnace for producing metal powder for sintered machine parts or powder forged parts with high strength and high toughness.

In this reduction annealing furnace, firstly, the powder material is quantitatively cut out by the device 1.
is introduced into the hopper 5, and a predetermined amount of powdered raw material is intermittently cut out into the preheating tube γ under a vacuum atmosphere via the raw material cutting feeder 6.

In the preheating furnace 2, the raw material supplied into the preheating tube γ is supported in the preheating tube 7 with the aid of the sintered cake support rod 8, and is sintered while being gradually moved downward.

The powder raw material, which is gradually sintered into columnar lumps while descending inside the preheating tube 7, passes through the preheating tube 7 and then enters the induction heating furnace 3, which is also in a vacuum atmosphere, where it is strongly sintered. It undergoes deoxidation and decarburization reactions, undergoes final reduction, and is sent out as a columnar, relatively strong sintered cake.

This sintered cake then reaches the pinch rolls 9 and cutting device 10 of the descending cutting device 4 and is cut into a predetermined length.
The product is then taken out of the furnace as a sintered cake.

In short, the vertical reduction annealing furnace produces the required metal powder by causing a reduction reaction using the internal carbon under a reduced pressure or vacuum heating atmosphere of the powder raw material.

The purpose of the invention is that in such a vertical reduction annealing furnace,
The reduced sintered cake that has passed through the induction heating furnace is made to descend at a constant speed so that it does not fall suddenly due to its own weight, and regardless of the diameter of the reduced sintered cake, its axis is It is an object of the present invention to provide a lowering device that advantageously prevents bending or bending of the cake by lowering the cake while maintaining the cake in a constant position.

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

FIG. 2 is a front view showing an embodiment of the present invention.

The pinch roll 9 disposed below the induction heating furnace 3 in the path of the reduced sintered cake in the vacuum housing 11 includes a pair of pinch roll members 12 and 13 facing each other, and each of these pinch roll members 12 and 13 are horizontally moved by the cooperation of a rond 16, 17 connected to the rear of arm members 14, 15, each having a U-shaped horizontal cross section, and a cylinder 18, 19 serving as a forward/backward drive means. will be advanced and retreated.

Further, the cutting device 10 disposed below the pinch roll 9 is equipped with a cutter blade 20 whose cutting edge has changed in inclination, and like the pinch roll member, this cutter 20 also cooperates with a rod 21 and a cylinder 22 connected to its rear part. It moves horizontally under the action.

Since each of the pinch roll members 12 and 13 has almost the same structure, only one pinch roll member 13 will be described here for ease of understanding.

First, as shown in FIG. 3, the i-type sintered cake has an arcuate constriction of approximately the same diameter between the fixed plates 23 attached at right angles to the housing 11.
The horizontal shafts 13c and 13a to which these rolls are fixed are passed through the fixed plate 23 and are supported by the arm member 15.

Next, in order to move the arm member 15 back and forth in the horizontal direction with respect to the fixed plate 23, the arm member 15 is supported on the outside of the plate 23 by the guide member 24, and the fixed plate 23 moves horizontally corresponding to the above momentum. Elongated holes (not shown) are provided to allow relative movement of the horizontal shafts 13c, 13d with respect to the plate.

In addition, an annular tooth-shaped portion 13es13f is provided at least at the constriction of each of the drum-shaped rolls 13a, 13b, and each tooth of the tooth-shaped portion is sintered to prevent the cylindrical reduction sintered cake from dropping rapidly due to its mouth weight. Let them bite into the cake.

If the weight of the sintered cake cannot be supported sufficiently by providing the toothed portions in the constricted portions, it is also possible to provide four toothed portions over the entire circumference of the arcuate outer peripheral surface of each roll.

In order to advantageously lower the sintered cake by preventing the sintered cake from bending due to straight lowering of the reduced sintered cake by the pinch rolls 9 and the operation of the cutting device 10,
The axes of the horizontal shafts 13c and 13d are arranged in the same horizontal plane as the axes of the horizontal shafts 12c and 12d of the other pinch roll member 12, respectively.

Note that when the cutting device 10 operates, a large impact is applied by the drum-shaped roll 12b below the pinch roll member 12, so in order to increase the durability of the pinch roll 9, the horizontal shaft 12d is It is preferable to make it thicker and rub it more firmly.

Further, due to the operation of the cutting device, a force is applied in the direction of separating the fixing plate 23 and the fixing plate 25 of the other pinch roll member 12, so that both fixing plates 23.2
5 are preferably connected by reinforcing rods 26 and 27.

28 and 29 in Figure 3 are horizontal axes 13C and 13, respectively.
d, and 30 is a guide member that supports the cutter blade 20 between the fixed plates 23 and allows it to move forward and backward in the horizontal direction.

The pinch roll member 13 configured in this manner is connected to a transmission 34 via rotating shafts 33, 33' having two universal joins 31, 31', 32, 32', and this transmission 34 is further connected to a drive motor 35. Connect this.

At the time of this connection, in order to rotate each drum-shaped roll 13a, 13b at the same speed, here, the rotating shaft 33
．． A gear (not shown) provided at the tip of 33' is meshed with a gear of a transmission, and a rotating shaft 36, 36 for the other pinch roll member 12 is connected to the flat drum-shaped rolls 12a, 12b.
A gear (not shown) provided at the end of the gear meshes with a gear of the same transmission to drive the gear.

In addition, at least one pair of worms and worm wheels are arranged inside the transmission 34, and the drum-shaped rolls 13a and 13b are
Even if the reduced sintered cake is subjected to torque due to its own weight, the rolls 13a and 13b are rubbed so that they can resist the torque and reliably support the sintered cake.

The operation of the inventive device will be explained below.

First, the powdered raw material descends through the preheating tube 7 while being supported by the sintered cake support rod 8, and is then deoxidized and decarburized in the induction heating furnace 3 to become a relatively strong columnar reduction sintered cake. The descent of the sintered cake is controlled by only the support rod 8 until it reaches a certain lowering position, but when the tip of the sintered cake reaches the pinch roll 9 of the lowering cutting device 4, the sintered cake is cut by the uninvented device. It is clamped with a yoke for support, and then forced to descend at a constant speed.

Here, when the lower end of the sintered cake reaches the pinch roll 9, the descent of the sintered cake support rod 8 is stopped for a certain period of time, and during this time each cylinder 18 of the pinch roll members 12, 13
, 19 are supplied with equal pressure and simultaneous working fluid through a synchronized cylinder (not shown).

For this reason, the pinch roll members 12 and 13 move forward by the same distance and apply a force commensurate with the pressure in each cylinder 18 and 19 to remove the reduced sintered cake from the drum-shaped rolls 12a and 13a.
And between 12b and 13b, clamp the line while keeping it straight.

From this clamp, each tooth profile 12e, 12f, 13e,
As mentioned above, the teeth of 13f bite into the sintered cake, and since the worm and worm wheel in the transmission 34 prevent the downward rotation of the drum-shaped rolls 12a, 12b, 13a, and 13b, the sintered cake is cut into the pinch roll. 9, it is reliably supported in a fixed position.

After the pinch rolls 9 have clamped the sintered cake in this way, the cake support rod 8 deposits the cake onto the pinch rolls 9 and rapidly descends into the hangar 37. Based on this rapid descent, the shooter 38 is placed above the hangar. It advances to the position of the downward path of the sintered cake on the plate and waits for the sintered cake to be cut off.

Note that this shooter 38 is also similar to the rod 3 shown in the figure.
9 and cylinder 40, it moves horizontally.

Next, in response to the advance of the shooter 38, the cutting device 10
is activated, and the cutter blade 20 makes the first cut at the lower end of the sintered cake.

The cut sintered cake, which is integrated with the spacer and steel wool placed on the upper end of the sintered cake support rod, rolls on the surface of the chute 38 and the guide member 41, enters the packet 42, and enters the elevator. As a result of the operation of the tube 43, the rails 44 and 45C are guided and raised, and are taken out of the housing 11 by being rolled out of the packet 42 at the upper end position of the rail.

After that, the drive motor 35 is operated to move each drum-shaped mouth ring 1.
2a, 12b, 13a, and 13b are each rotated at a constant circumferential speed, and the sintered cake is forcibly lowered at a predetermined speed.

In addition, in this device, each pinch roll member 12, 13 is connected to a universal joint 31.31', 32.3, respectively.
2' and 46, 46', and 47.47', the rotational force of the drive motor 35 is always constant regardless of the diameter of the sintered cake. Transmitted by mouth.

In addition, the optimal descending speed of the sintered cake will of course change depending on the reduction conditions in the preheating furnace 2 and the induction heating furnace 3, etc., but if it becomes necessary to change the rotation speed of the hourglass roll, It is also possible to change the combination of speed change gears in the transmission 34, or to use an electric motor with a continuously variable transmission as the drive motor 35.

In such constant speed forced descent of the reduced sintered cake, each pair of hourglass-shaped rolls 12a, 12b and 13a, 13b are aligned on a perpendicular line, and rolls 12a and 1
Since the axes of 3a and 12b and 13b each lie in the same plane, this also ensures that the sintered cake is lowered and touched without bending.

In addition, even when the sintered cake steadily descends due to the operation of the pinch rolls 9, the diameter of the sintered cake changes somewhat due to slight changes in the reduction conditions and other conditions. When the diameter of the cake becomes thinner, the pinch roll members 12 and 13 are replaced by the cylinders 18 and 19.
Since the inner pressure of the pinch rolls 9 moves the sintered cake forward by the same amount, the state in which the sintered cake is crushed by the pinch rolls 9 does not substantially change, and there is no risk that the sintered cake will suddenly fall due to its own weight.

When the sintered cake falls a predetermined amount below the pinch rolls 9, the cutter blade 20 is advanced by the cylinder 22, and the product sintered cake cut to a predetermined length falls onto the shooter 38.

The subsequent movement of the product sintered cake is as described above.

In FIG. 2, 51 is a lid member that prevents the sintered cake from falling onto the bottom wall of the housing when the packet 42 unexpectedly falls into the guide member 41 while the packet 42 is rising. The lid member 51 is pressed by the cylinder 48 so as to permanently close the outlet of the guide member 41.

Further, 49 and 50 are receiving rods which are integrally formed with the striker and lid member 51 fixed to the packet 42, respectively, and when the packet 42 is at its lower limit position, the strike force -49 engages with the receiving rod 50 and the cylinder 48 The lid member 51 is opened against the internal pressure of the sintered cake to enable transfer of the product sintered cake into the packet 42.

In addition, when cutting the sintered cake with the cutter blade 20, the two drum-shaped rolls arranged on the perpendicular line disperse the force acting on the sintered cake to each roll, so that the force applied to the sintered cake is localized to the sintered cake. This prevents the sintered cake from becoming undesirably bent.

Therefore, according to the invention, it is possible to reliably lower a sintered cake having an extremely large weight at a predetermined speed, and the axis of the sintered cake can always be vertically moved, regardless of the diameter of the sintered cake. The sintered cake can be maintained in a straight position and lowered straight, and the sintered cake can be prevented from being bent or broken by preventing a concentrated load on the sintered cake due to the operation of the cutting device.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing a vertical reduction annealing furnace, Fig. 2 is a front view showing an uninvented embodiment together with attached equipment, Fig. 3 is a sectional view taken along line I-1 in Fig. 2; FIG. 4 is a plan view diagrammatically showing an embodiment of the invention in relation to a drive device. 12.13...Pinch roll member, 12a, 12b,
13a, 13b.・・Trumpet-shaped roll, 12e, 12f, 13e, 13f・・
・Tooth profile portion, 18.19... Cylinder (advancing/retracting drive means), 31, 31', 32, 32', 46, 46', 47
, 47'... Universal joint, 35... Drive motor (rotary drive device).

Claims (1)

[Claims] 1 A pair of pinch roll members having two hourglass-shaped rolls that are vertically spaced apart on a perpendicular line and rotatable around a horizontal axis are arranged oppositely, and the axes of the corresponding upper and lower hourglass-shaped rolls are aligned with each other. Tomoko, each located on the same plane,
A toothed portion is provided on the surface of each of the drum-shaped rolls, and each of the pinch roll members is connected to an advance/retreat driving means, and each of the pinch roll members is connected to a rotational drive device via a universal joint. A reduction sintered cake lowering device for a vertical reduction annealing furnace.