JPH0594695U - Mesh belt furnace - Google Patents

Abstract

(57) [Summary] [Purpose] The life of the mesh belt can be extended, thereby improving the operating rate. A mesh belt furnace including a mesh belt 20 for moving articles in the furnace from an inlet 11 to an outlet 12, and a plurality of pulleys for supporting and driving the mesh belt 20 with respect to a furnace body 10. In the drive pulley 4 for driving the mesh belt 20 among the pulleys
0 and 41 are provided on the inlet side and the outlet side of the furnace, and slack portions 20a and 20b are provided on the belt portion on the belt traveling direction side of each drive pulley.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a sintering furnace for powder metallurgy, a heat treatment furnace for quenching or tempering, and in particular, a mesh belt furnace.

[0002]

[Prior art]

 For example, in a mesh belt furnace as a sintering furnace, as shown in the schematic structure of FIG. 3, the main body 10 of the furnace is installed on a pedestal not shown, and the molded body is introduced into the main body 10 of the furnace from an inlet 11 to an outlet. It is equipped with an endless mesh belt 20 which moves in the furnace to 12. The main body 10 includes a preheating unit 13, a sintering unit 14, and a cooling unit 15. Reference numeral 16 is a gas inlet, and reference numeral 17 is a heating element such as SiC. The preheating part 13 is 400 to 600 ° C., and the lubricant and the like added to the green compact is vaporized and dewaxed here. The sintered part 14 is heated to about 800 ° C. for a copper-based material and to about 1100 ° C. for an iron-based material. The cooling unit 15 has a water cooling structure or the like.

The mesh belt 20 is supported and driven by a plurality of pulleys attached to the frame. Of the above pulleys, the pulleys arranged at the lower portions on the inlet / outlet 11, 12 side and the outlet 11 side are the idle pulleys 30, 31, 32, and those arranged at the lower portion on the inlet 11 side are the drive pulleys 40. A tensioner pulley 50 is arranged opposite to the drive pulley 40. The mesh belt 20 forms a belt loop circumscribing the idle pulleys 30, 31, 32 and the drive pulley 40. The mesh belt 20 is pressed against the drive pulley 40 by the tensioner pulley 50, and the drive pulley 40 is rotated by a motor 60 or the like so as to be predetermined. It is driven in the direction of the arrow at the speed of. Further, the belt portion between the tensioner pulley 50 and the idle pulley 30 is provided with a slack portion 20a so that it is not affected by the expansion and contraction of the mesh belt 20. As the mesh belt 20, a wire made of a heat-resistant alloy is formed into a flat coil shape, and the mesh belt 20 is sequentially connected by a force frame. The compact such as green compact is usually placed on the belt at the inlet 11 of the furnace as it is, and in some cases, put in a container, and as the mesh belt 20 moves, the preheating unit 13, the sintering unit 14, the cooling unit, and the like. The part 15 passes through the furnace in order, is sintered during this period, and is taken out at the outlet 12.

[0004]

[Problems to be solved by the device]

 By the way, in the mesh belt 20, tension is always applied to a portion from the idle pulley 30 through the inside of the furnace to the drive pulley 40. This tension is the sum of the frictional resistance between the belt and the hearth, which is based on the weight of the mesh belt 20 and the weight of the compact placed on it, and the transmission loss that occurs in each part. As described above, the mesh belt 20 is subjected to a large tension in part, is exposed to a high temperature of about 800 to 1100 ° C. in the sintering part 14, and is cooled in the cooling part 15 and outside the furnace under severe conditions. It is underneath and is under heavy load. This harsh load causes the mesh belt 20 to expand and contract, so the belt portion between the tensioner pulley 50 and the idle pulley 30 has a slack portion 20a, but the mesh belt 20 is further deformed in the extending direction. , It will be a relatively short life.

Further, in the conventional structure, the mesh belt 20 is subjected to tension, and is repeatedly bent and stretched slightly along the outer diameter of the pulley, for example, the portion of the idle pulley 31, and is repeatedly stretched. Friction easily progresses at the connecting portion of the mesh belt 20, further shortening the life. The replacement of the mesh belt 20 is not limited to the cost of the belt itself, the replacement work takes time, and the operation rate is affected.

In view of the above background, the present invention has an object to provide a mesh belt furnace which can extend the life of the mesh belt and thereby improve the operation rate.

[0007]

In order to achieve the above object, the present invention provides a drive pulley for driving a mesh belt and a tensioner pulley on both an inlet side and an outlet side of a furnace as described in claim 1. The gist is that it is provided on one side and a slack part is provided on the belt part on the belt traveling direction side of each drive pulley. In addition to the above configuration, as described in claim 2, there are provided a plurality of pulleys on the inlet side and the outlet side of the furnace that are inscribed in the curved belt loop of the mesh belt, and the average radius of the belt loop. Is more preferably larger than the radius of the pulley.

[0008]

[Action]

 According to the present invention, when the drive pulley and the tensioner pulley are provided on both the inlet side and the outlet side of the furnace as claimed in claim 1, the drive pulley on the outlet side is mainly responsible for pulling the mesh belt in the furnace, Since the drive pulley on the inlet side takes charge of pulling the mesh belt outside the furnace sent from the drive pulley on the outlet side, the tension applied to the mesh belt is reduced. In addition, the slack part of each belt part stores the elongation of the mesh belt, and if there is a temporary difference in the belt feeding speed due to the drive pulley on the inlet side and the outlet side, these slack parts supplement and absorb it, Do not pull belts between drive pulleys. Further, when a plurality of pulleys are provided on both the inlet side and the outlet side of the furnace as in claim 2 and the arrangement is such that the bending of the belt loop is as large an arc as possible, the bending of the belt loop becomes gentle. Deformation and friction are reduced. As another means of making the bend of the belt loop into a large arc, for example, an idle pulley with a large diameter may be provided, but a large diameter idle pulley is expensive, difficult to handle, and requires a large installation space. On the other hand, if it is composed of multiple pulleys with small diameters, they will be eliminated. Here, the present invention is based on the fact that drive pulleys and tensioner pulleys are provided on the inlet side and the outlet side of the furnace. Is. The plurality of pulleys inscribed in the mesh belt belt loop may be any of an idle pulley, a drive pulley, and a tensioner pulley.

[0009]

【Example】

 An embodiment in which the present invention is applied to a mesh belt sintering furnace will be described below with reference to FIGS. 1 and 2. In the embodiment, the same parts as those in the conventional structure shown in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 1 shows a membrane type main part of a mesh belt sintering furnace which is a first embodiment of the present invention. The mesh belt sintering furnace shown in the figure differs from the conventional one in that the pulley on the outlet 12 side of the furnace is a belt drive unit composed of a drive pulley 41 and a tensioner pulley 51, and is fed from the belt drive unit. That is, the slack portion 20b is provided on the belt portion of the mesh belt 20 that is formed. The drive pulley 41 is rotated through a motor 61 and the like like the drive pulley 40 provided in the lower portion on the inlet 11 side. That is, the drive pulley 40 and the tensioner pulley 50 are provided at the same positions as in the conventional case, and as the belt driving unit on the inlet 11 side, the belt portion at the lower part of the furnace of the mesh belt 20 is exclusively pulled. On the other hand, since the drive pulley 41 and the tensioner pulley 51 are located on the outlet 12 side of the furnace, the drive pulley 41 and the tensioner pulley 51 exclusively pull the belt portion of the mesh belt 20 in the furnace on which articles such as molded bodies are placed.

The slack portion 20b on the drive pulley 41 side stores the expansion of the mesh belt 20 here as well as the slack portion 20a on the drive pulley 40 side. It is supplemented and absorbed in this part together with 20a. With the above configuration, the mesh belt 20 can greatly reduce its deformation, elongation, and friction, maintain stable driving for a long period of time in comparison with the conventional configuration, and have a long life. The positions of the drive pulley 40 and the tensioner pulley 50 or the drive pulley 41 and the tensioner pulley 51 may be reversed.

FIG. 2 shows, in a film form, a main part of a mesh belt sintering furnace which is a second embodiment of the present invention. The mesh belt sintering furnace shown in the figure is different from that of the first embodiment in that a plurality of pulleys inscribed in the belt loops of the curved mesh belt 20 on the inlet 11 side and the outlet 12 side of the furnace are provided. The mesh belt 20 is curved in a large arc shape. The pulleys here use idle pulleys 31, 32 and 33 on the inlet 11 side and one idle pulley 34 and drive pulleys 45 and 46 on the outlet 12 side. 47 and the corresponding tensioner pulleys 55, 56 and 57 are used for both belt drive and belt loop guide. That is, in this embodiment, a plurality of pulleys are provided on both the inlet 11 side and the outlet 12 side of the furnace, and the arrangement is such that the bending of the belt loop is as large an arc as possible. Further, the belt drive unit on the inlet 11 side of the furnace also uses a plurality of drive pulleys 42, 43, 44 and tensioner pres 52, 53, 54, and the mesh belt 20 passing therethrough is pulled straight. There is.

Therefore, in this configuration, the average radius of the belt loops on the inlet 11 side and the outlet 12 side of the furnace is larger than the radius of each pulley, and the deformation and abrasion in the belt loops are further reduced. Wear reduction at the 20 connections is achieved. In this case, the belt wraps around the outer shapes of the drive pulleys 42 to 44 and 45 to 47 having a small diameter, and the belt can be gently bent to form a belt loop having a natural bend, which prevents deformation, elongation and friction of the mesh belt 20. It can be reduced.

Although the mesh belt sintering furnace for powder metallurgy has been described in the above embodiment, the same effect can be obtained by applying the present invention to a similar heat treatment furnace.

[0015]

[Effect of the device]

 As described above, in the mesh belt furnace of the present invention, since the belt driving parts of the mesh belt are provided at two places on the inlet side and the outlet side of the furnace, the deformation, elongation and friction of the mesh belt are reduced. And the life can be extended. In addition to this structure, by forming the curved portion of the belt into a large arc shape as claimed in claim 2, it is possible to greatly reduce friction and the like particularly at the connecting portion of the mesh belt, and to further extend the life. ..

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a main structure of a mesh belt furnace according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a main structure of a mesh belt furnace according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a main part structure of a conventional mesh belt furnace.

[Explanation of symbols]

10- ・ Main body of furnace 11 --- Inlet of furnace 12 --- Outlet of furnace 20-Mesh belts 20a, 20b-Slack portion of belt 30, 31, 32, 33, 34 ... Idle pulleys 40, 41, 42, 43, 44, 45, 46, 47 ...
Drive pulleys 50, 51, 52, 53, 54, 55, 56, 57 ...
Tensioner pulley

Claims (2)

[Scope of utility model registration request] 1. An endless mesh belt that moves an article such as a molded body on a belt and moves in the furnace from an inlet to an outlet with respect to a main body of the furnace, and a plurality of pulleys that support and drive the mesh belt. In the provided mesh belt furnace, among the pulleys, drive pulleys and tensioner pulleys for driving the mesh belt are provided on both the inlet side and the outlet side of the furnace, and the belt pulley on the belt traveling direction side of each drive pulley is loosened. Mesh belt furnace characterized by having parts. 2. A plurality of pulleys on the inlet side and the outlet side of the furnace, which are inscribed in the curved belt loop of the mesh belt, are inscribed, and the average radius of the belt loop is larger than the radius of the pulleys. Item 2. The mesh belt furnace according to Item 1.