JP7110526B2 - Belt winding device and mesh belt type continuous sintering furnace - Google Patents

Description

The present invention relates to a belt winding device and a mesh belt type continuous sintering furnace.

BACKGROUND ART A sintered body obtained by sintering a molded body obtained by pressure-molding metal powder such as iron powder is used for parts for automobiles, parts for general machines, and the like. Such a sintered body can be produced using a mesh belt type continuous sintering furnace using a mesh belt.

FIG. 6 is a cross-sectional explanatory view of a general mesh belt type continuous sintering furnace (hereinafter also simply referred to as "sintering furnace") 100. As shown in FIG. The sintering furnace 100 includes a furnace main body 101 made of metal and having a dome-shaped cross section, and an endless mesh belt 102 running inside the furnace main body 101 . A workpiece W to be heated is placed on the mesh belt 102 . The furnace body 101 has a degassing zone 103, a sintering zone 104, and a cooling zone 105 in order from the inlet side (left side in FIG. 6) toward the outlet side. The mesh belt 102 is stretched over a drive pulley 106 provided on the inlet side of the furnace body 101 and a driven pulley 107 provided on the outlet side. The drive pulley 106 is driven by a motor (not shown) so that the mesh belt 102 runs in the furnace main body 101 under tensile stress. In the sintering zone 104, the mesh belt 102 exposed to a high temperature of, for example, about 1100-1200.degree. C. is cooled to a temperature of about 100.degree. In FIG. 6, reference numeral 108 denotes conveying rollers arranged on the floor to reduce the resistance of the mesh belt 102 during running, and reference numeral 109 denotes a pit for accommodating the stretched mesh belt 102. is.

The mesh belt 102 is made of stainless steel such as SUS310 or SUS316, which has high hot strength and heat resistance. high temperature creep causes large elongation in a relatively short period of time. For example, a mesh belt with a total length of about 50m may stretch about 1m in two weeks. Therefore, in the sintering furnace 100, the mesh belt 102 is periodically inspected for elongation, and maintenance is performed by cutting and joining the mesh belt 102 each time a predetermined elongation occurs.

The mesh belt 102 is made of metal. For example, the mesh belt 102 with a width of 100 cm is very heavy, about 20 kg/m. be. In addition, since the stretched mesh belt portion housed in the pit 109 needs to be lifted manually, maintenance takes a long time.

The present invention has been made in view of such circumstances, and provides a belt hoisting device and a mesh belt type continuous sintering furnace that can safely and easily perform the work of hoisting a mesh belt in a short period of time. It is intended to

A belt hoisting device according to one aspect of the present invention is a belt hoisting device for hoisting a mesh belt in a mesh belt type continuous sintering furnace,
a driven roller in contact with the inner surface of the mesh belt;
a drive roller having a rotation axis parallel to the rotation axis of the driven roller, sandwiching the mesh belt between itself and the driven roller, and sending out the mesh belt by its rotation;
The drive roller has a ratchet mechanism that allows rotation only in the direction of sending out the mesh belt.

According to the above invention, the mesh belt can be hoisted safely and easily in a short period of time.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of an example of a mesh belt type continuous sintering furnace equipped with a mesh belt that is wound up by a belt winding device of the present invention; 1 is a perspective explanatory view of one embodiment of a belt winding device of the present invention; FIG. It is a figure explaining the relationship between a drive roller and a driven roller. It is explanatory drawing of a guide mechanism. It is a cross-sectional explanatory drawing of the side part of a moving plate. It is an explanatory view of an example of a conventional mesh belt type continuous sintering furnace.

[Description of an embodiment of the present invention]
First, embodiments of the present invention will be listed and described.
A belt hoisting device according to one aspect of the present invention includes:
(1) A belt hoisting device for hoisting the mesh belt in a mesh belt type continuous sintering furnace,
a driven roller in contact with the inner surface of the mesh belt;
a drive roller having a rotation axis parallel to the rotation axis of the driven roller, sandwiching the mesh belt between itself and the driven roller, and sending out the mesh belt by its rotation;
The drive roller has a ratchet mechanism that allows rotation only in the direction of sending out the mesh belt.

In the belt winding device according to this aspect, the mesh belt sandwiched between the driving roller and the driven roller can be sent out by rotating the driving roller. The driving roller can be easily rotated in a short time by using a handle or the like, and the belt winding device according to this aspect has a ratchet mechanism that allows the driving roller to rotate only in the direction in which the mesh belt is sent out. Therefore, the winding operation can be safely performed without causing the drive roller to rotate in the reverse direction due to the weight of the mesh belt that has been wound up.

(2) In the belt winding device of (1) above, the drive roller is moved toward and away from the driven roller while maintaining parallelism of the rotation axis of the drive roller with respect to the rotation axis of the driven roller. It is desirable to have a guide mechanism to guide the direction. In this case, by using a guide mechanism, it is possible to easily obtain a state in which the drive roller is in contact with the mesh belt (the mesh belt can be wound up by rotating the drive roller in this state) and a state in which the mesh belt is separated from the mesh belt. state.

(3) A mesh belt type continuous sintering furnace according to another aspect of the present invention comprises the belt hoisting device of (1) or (2) above.

[Details of the embodiment of the present invention]
The belt hoisting device and the mesh belt type continuous sintering furnace of the present invention will be described in detail below. The present invention is not limited to these examples, but is indicated by the scope of the claims, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.
FIG. 1 is an explanatory diagram of an example of a mesh belt type continuous sintering furnace equipped with a mesh belt that is wound up by the belt winding device of the present invention, and FIG. 2 is a belt winding device according to one embodiment of the present invention. is a perspective explanatory view of the.

The sintering furnace 1 includes a furnace main body 2 made of metal or the like and formed of a muffle having a dome-shaped cross section, and an endless mesh belt 3 running inside the furnace main body 2 . The mesh belt 3 is made of stainless steel such as SUS310 or SUS316, which has high hot strength and heat resistance. On the mesh belt 3, a work W made of a compact obtained by pressure-molding metal powder such as iron powder is placed.

The furnace body 2 has a degassing zone 4, a sintering zone 5, and a cooling zone 6 in order from the inlet side (left side in FIG. 1) toward the outlet side. The mesh belt 3 is stretched over a driving pulley 7 provided on the inlet side of the furnace body 2 and a driven pulley 8 provided on the outlet side. The drive pulley 7 is driven by a motor (not shown) provided in the vicinity of the drive pulley 7, so that the mesh belt 3 runs inside the furnace main body 2 under tensile stress.

In the degassing zone 4, the work W is heated to about 650 to 750° C., for example, by heating means such as a gas burner or an electric heater. While the workpiece W is passing through the degassing zone 4, waxy lubricant components such as zinc stearate and metallic soap used in pressure molding the metal powder are thermally decomposed and removed.

The workpiece W that has passed through the degassing zone 4 is heated to a predetermined sintering temperature (for example, about 1100 to 1200° C.) in the subsequent sintering zone 5 . Heating can be performed using a heating element such as nichrome or kanthal provided in the sintering zone 5 . At the time of sintering, atmosphere gas such as nitrogen gas or modified gas is introduced into the sintering zone 5 .

The workpiece W that has passed through the sintering zone 5 is cooled to, for example, about 900 to 100° C. in the subsequent cooling zone 6 by cooling means such as a water jacket (not shown) provided in the furnace body 2 . The work W that has passed through the cooling zone 6 and has undergone the sintering process is discharged from the discharge port 9 of the furnace main body 2 and collected for transfer to the subsequent process.

A plurality of conveying rollers 10 are laid on the floor surface below the furnace main body 2, and the mesh belt 3 exiting the discharge port 9 of the furnace main body 2 and passing through the driven pulley 8 is conveyed by these conveying rollers. It runs over 10 and returns to the drive pulley 7 .

A pit 11 is provided on the floor in front of the entrance of the furnace body 2 . This pit 11 is a space for accommodating the mesh belt 3 stretched by high temperature creep. The mesh belt 3 immediately after being replaced is in the state indicated by the chain double-dashed line in FIG. When this sagging becomes severe and the mesh belt 3 reaches the bottom surface 11a of the pit 11, the mesh belt 3 is deformed and cannot run normally. need to do After passing through the driving pulley 8, the mesh belt 3 is guided by a plurality of guide rollers 12 and introduced into the furnace through an inlet 13. As shown in FIG.

The sintering furnace 1 includes a belt hoisting device 20 according to the present embodiment for hoisting the mesh belt 3. The belt hoisting device 20 is attached to the furnace body 2 as shown in FIG. It is provided slightly upstream of the entrance 13 and above the pit 11 . The belt winding device 20 includes a driven roller 21 , a drive roller 22 , a ratchet mechanism 23 and a guide mechanism 24 .

The driven roller 21 is in contact with the inner surface 3a of the mesh belt 3, as shown in FIG. In this embodiment, one of the guide rollers 12 also functions as the driven roller 21 .

The driving roller 22 has a rotating shaft 22 a parallel to the rotating shaft of the driven roller 21 , sandwiches the mesh belt 3 between itself and the driven roller 21 , and pulls the mesh belt 3 out of the pit 11 by its rotation. It is delivered to the furnace main body 2 side. One end side of the rotating shaft 22 a of the drive roller 22 is connected to the ratchet mechanism 23 . The driving roller 22 has a configuration in which a rotating shaft 22a made of metal such as iron is covered with rubber (NBR).

The ratchet mechanism 23 is arranged above a metal base 25 provided on the inlet 12 side of the furnace body 2 . The ratchet mechanism 23 is not fixed to the pedestal 25 and is separated from the upper surface 25 a of the pedestal 25 so as to move together with the drive roller 22 . The lower base 50a of the mounting plate 50 of the ratchet mechanism 23 is in contact with the lower surface of the holding plate 51 fixed to the upper surface 25a of the pedestal 25 while being separated from the upper surface 25a of the pedestal 25, or arranged to be slightly separated from the lower surface. is set. The ratchet mechanism 23 allows the driving roller 22 to rotate only in the direction D (see FIG. 3) in which the mesh belt 3 is sent out. Even so, the rotation of the driving roller 22 is locked by the ratchet mechanism 23, so that such sliding down is prevented. Therefore, the hoisting work can be safely performed. As the ratchet mechanism 23, one having a known configuration can be used.

A handle 26 is attached to the rotating shaft 22a of the driving roller 22 passing through the ratchet mechanism 23 for rotating the rotating shaft 22a. By rotating the handle 26, the drive roller 22 is rotated, and the mesh belt 3 sandwiched between the drive roller 21 and the driven roller 21 can be wound up or sent out.

In this embodiment, guide mechanisms 24 are provided at both ends of the drive roller 22 . The guide mechanism 24 serves to guide the movement of the driving roller 22 toward and away from the driven roller while maintaining the parallelism of the driving roller 22 with respect to the rotational axis of the driven roller 21. . As shown in FIG. 4, the guide mechanism 24 is fixed by bolts 29 to a support 28 mounted on a pedestal 25, and includes a block 30, a threaded portion 31, a handle portion 32, and a moving plate. 33 and a guide plate 34 .

The block body 30 has a screw hole 35 formed near the center in the longitudinal direction. The threaded portion 31 is screwed into the threaded hole 35 . A handle portion 32 for turning the threaded portion 31 is attached to one end of the threaded portion 31 . A short cylindrical contact member 36 is fixed to the other end of the threaded portion 31 .

The guide plate 34 is fixed with bolts 29 to a support 28 mounted on the pedestal 25 . The guide plate 34 has an upper guide 37 , a lower guide 38 and a central plate 39 . The upper guide 37 is provided on the upper edge of the central plate 39 and the lower guide 38 is provided on the lower edge of the central plate 39 . Both the upper guide 37 and the lower guide 38 are L-shaped members in cross section. is provided on the central plate 39 so as to form a .

The central plate 39 has a rectangular shape and has a rectangular opening 40 along its longitudinal direction. The opening 40 has a size that allows at least the rotation shaft 22a of the drive roller 22 to pass therethrough.

The moving plate 33 consists of a pair of rectangular plates, and has a hole 41 large enough for the rotating shaft 22a of the drive roller 22 to pass through. A first bent portion 42 is formed at the upper edge of each plate, and a second bent portion 43 bent in the same direction as the first bent portion 42 is formed at the lower edge. A pair of plates are fixed to each other such that the bent portions form a groove. The wall 37a of the upper guide 37 is sandwiched with a gap between the grooves formed by the two first bent portions 42, and the wall 38a of the lower guide 38 with a gap between the two second bent portions 43. sandwiched. Therefore, the moving plate 33 can move along the longitudinal direction of the upper guide 37 and the lower guide 38 while being guided by both the guides.

As shown in FIGS. 4 and 5, a receiving portion 44 having a semicircular cross-section is formed near the center in the vertical direction of the side portion of each of the pair of plates constituting the moving plate 33 on the side of the handle portion 32. The threaded portion 31 is inserted through the short cylindrical portion formed by both receiving portions 44 .

A contact member 36 at the tip of the threaded portion 31 is fixed to the threaded portion 31 and rotates as the threaded portion 31 rotates. The abutment body 36 is located in an opening 45 formed in a portion of the moving plate 33 near the handle portion 32 . Since the threaded portion 31 is screwed into a threaded hole 35 formed in the block body 30 , when the handle portion 32 is operated to rotate the threaded portion 31 , the abutment body 36 is engaged with the threaded portion 31 together with the threaded portion 31 . Move back and forth along the axial direction. When the threaded portion 31 is moved forward, the abutment body 36 at the tip of the threaded portion 31 eventually contacts the edge of the opening 45 of the moving plate 33 . When the threaded portion 31 is further moved forward, the drive roller 22 is pushed by the abutment member 36 and moves toward the driven roller 21 , sandwiching the mesh belt 3 between itself and the driven roller 21 . After that, the mesh belt 3 can be firmly sandwiched between the drive roller 22 and the driven roller 21 by rotating the handle portion 32 against the load. By turning the handle 26 in this state, the mesh belt 3 can be easily rolled up. The guide mechanism 24 in the present embodiment, in the state where the mesh belt 3 is sandwiched between the driving roller 22 and the driven roller 21 as described above, moves the mesh belt 3 by its own weight in the direction opposite to the direction in which the mesh belt 3 is sent out by the driving roller 22. Frictional force can be generated between the drive roller 22 and the mesh belt 3 to such an extent that the mesh belt 3 does not slide down.

Before turning the handle 26, it is necessary to cut the mesh belt 3 at a location downstream of the drive roller 22 (on the inlet 12 side of the furnace body 2). The handle portion 32 can be operated by two workers, or one worker can alternately operate both handle portions 32 to move the drive roller 22 .

When the winding of the mesh belt 3 of a predetermined length is completed, the wound mesh belt part is cut and removed, and the remaining mesh belt end is joined to the cut mesh belt end before winding. In addition, the drive roller 22 moved toward the driven roller 21 is moved away from the driven roller 21 . At this time, since the abutting body 36 at the tip of the threaded portion 31 abuts against the short cylindrical body formed by both the receiving portions 44 when retracting, further operation of the handle 26 causes the movement that had moved toward the driven roller 21 side. Drive roller 22 can be separated from driven roller 21 together with plate 33 . This completes the maintenance of the mesh belt.

[Other Modifications]
The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims.
For example, in the above-described embodiment, the work placed on the mesh belt and sintered in the sintering furnace is a compact obtained by pressure-molding metal powder such as iron powder. Other materials can be sintered.
Further, in the above-described embodiment, the drive roller is arranged outside the mesh belt and the driven roller is arranged inside the mesh belt, but the arrangement of the rollers may be reversed. That is, the drive roller can be arranged inside the mesh belt, and the driven roller can be arranged outside the mesh belt.

1: Sintering furnace 2: Furnace body 3: Mesh belt 4: Degassing zone 5: Sintering zone 6: Cooling zone 7: Drive pulley 8: Driven pulley 9: Discharge port 10: Conveying roller 11: Pit 11a: Bottom 12: Entrance 13: Stage 20: Belt winding device 21: Driven roller 22: Driving roller 22a: Rotating shaft 23: Ratchet mechanism 24: Guide mechanism 25: Base 26: Handle 28: Support column 29: Bolt 30: Block body 31 : Threaded portion 32 : Handle portion 33 : Moving plate 34 : Guide plate 35 : Screw hole 36 : Contact body 37 : Upper guide 38 : Lower guide 39 : Center plate 40 : Opening 41 : Hole 42 : First bent portion 43 : Second bent portion 44: Receiving portion 45: Opening 50: Mounting plate 50a: Base portion 51: Holding plate 100: Continuous sintering furnace 101: Furnace body 102: Mesh belt 103: Degassing zone 104: Sintering zone 105: Cooling zone 106: Drive pulley 107: Driven pulley W: Work

Claims (3)

A belt hoisting device for hoisting up a mesh belt that hangs down after running a drive pulley of a mesh belt type continuous sintering furnace,
a driven roller in contact with the inner surface of the mesh belt;
a driving roller having a rotating shaft parallel to the rotating shaft of the driven roller, sandwiching the mesh belt between itself and the driven roller, and feeding the mesh belt upward by its rotation;
The belt hoisting device, wherein the drive roller has a ratchet mechanism that allows rotation only in a direction in which the mesh belt is sent out. A guide mechanism that guides the movement of the drive roller in directions toward and away from the driven roller while maintaining parallelism of the rotation axis of the drive roller with respect to the rotation axis of the driven roller. Item 1. The belt hoisting device according to item 1. A mesh belt type continuous sintering furnace comprising the belt winding device according to claim 1 or claim 2.

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