Tunnel reduction furnace for improving reduction consistency of piezoresistor electrode
By setting up multiple heating rods in different temperature zones in the tunnel reduction furnace, the hot air flows from the middle to both sides is solved, and the temperature inhomogeneity problem in the tunnel reduction furnace is improved and the reduction consistency of the varistor electrode is improved.
Patent Information
- Application Number
- CN202422467013.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-12
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2034-10-12
AI Technical Summary
There is temperature inhomogeneity in the furnace of existing tunnel reduction furnaces, which leads to inconsistent reduction of varistor electrodes, affecting the upper and lower lamination ratio of the product.
A tunnel reduction furnace is designed. By setting a plurality of heat rods arranged in sequence in the upper and lower heat rods, each heat rod is equipped with a zone of different temperatures, and the heating temperature on the left and right sides is higher than the intermediate zone. , causing hot air to flow from the middle to both sides, making the high-temperature area in the middle of the furnace evenly heat.
The temperature and atmosphere consistency of the varistor dielectric sheet is achieved, the uniformity of the upper and lower lamination ratios of the reduced product is improved, and the reduction consistency of the electrode is improved.
Smart Images
Figure CN222187756U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a tunnel reduction furnace, in particular to a tunnel reduction furnace for improving the reduction consistency of varistor electrodes. Background Art
[0002] When making a varistor, it is necessary to perform an electrode sintering process on the varistor dielectric sheet with electrode paste (such as silver electrode paste or copper electrode paste) printed on both sides to form an electrode. When sintering the electrode, it is necessary to first put the varistor dielectric sheet printed with electrode paste into a reduction carrier, and then place the reduction carrier on a conveying mechanism. The conveying mechanism moves the reduction carrier and the varistor dielectric sheet therein to the furnace of the tunnel reduction furnace and gradually conveys it backwards to perform the electrode sintering process so that the electrode paste forms an electrode.
[0003] At present, the furnace of the tunnel reduction furnace is equipped with an upper heating element and a lower heating element, and the conveying mechanism crosses between the upper heating element and the lower heating element. When working, the upper heating element and the lower heating element generate heat, releasing hot air to circulate in the entire furnace, so that there is a temperature range inside the furnace, the middle of the furnace is a high temperature zone, and the front and rear of the furnace are low temperature zones. However, the upper and lower heating elements are easily heated unevenly, making the temperature of the upper position of the conveying mechanism in the high temperature zone as high as 20°C higher than the temperature of the lower position, resulting in a temperature deviation between the upper and lower positions of the conveying mechanism, resulting in a large deviation in the pressure ratio between the upper and lower layers of the restored product, affecting the consistency of the reduction of the varistor electrode. Utility Model Content
[0004] The problem to be solved by the utility model is to provide a tunnel reduction furnace for improving the reduction consistency of varistor electrodes. The tunnel reduction furnace can make the high temperature zone in the middle of the furnace heat evenly and improve the reduction consistency of the varistor electrodes.
[0005] In order to solve the above technical problems, the technical solutions adopted by the utility model are as follows:
[0006] A tunnel reduction furnace for improving the reduction consistency of varistor electrodes comprises a tunnel furnace and a conveying mechanism, wherein an entrance is arranged at the front end of the tunnel furnace and an exit is arranged at the rear end, the conveying mechanism enters the tunnel furnace from the entrance and passes through the tunnel furnace from the exit, an upper heating element and a lower heating element are arranged in the tunnel furnace, the upper heating element is located above the conveying mechanism, and the lower heating element is located below the conveying mechanism; the characteristic is that: the upper heating element comprises a plurality of upper heating rods arranged in sequence from front to back, each upper heating rod is arranged above the conveying mechanism in a left-right direction, the upper heating rod is provided with an upper left heating zone, an upper middle heating zone and an upper right heating zone in sequence from left to right, and the heating temperatures of the upper left heating zone and the upper right heating zone are both greater than the heating temperature of the upper middle heating zone; the lower heating element comprises a plurality of lower heating rods arranged in sequence from front to back, each lower heating rod is arranged below the conveying mechanism in a left-right direction, the lower heating rod is provided with a lower left heating zone, a lower middle heating zone and a lower right heating zone in sequence from left to right, and the heating temperatures of the lower left heating zone and the lower right heating zone are both greater than the heating temperature of the lower middle heating zone.
[0007] The definition of the front and back mentioned above is: along the conveying direction of the above-mentioned conveying mechanism, the one that arrives first is the front and the one that arrives slowly is the back.
[0008] During operation, each upper heating rod and lower heating rod generates heat. Since the heating temperatures of the upper left heating zone and the upper right heating zone are both greater than the heating temperatures of the middle upper heating zone, and the heating temperatures of the lower left heating zone and the lower right heating zone are both greater than the heating temperatures of the middle lower heating zone, the heat emitted from the left and right ends of the upper heating rod and the lower heating rod is higher than the heat emitted from the middle part. Since the air expands at a high temperature position, the volume increases and the pressure decreases, and thus the air pressure at the low temperature in the middle of the upper heating rod and the lower heating rod is relatively large. Therefore, the hot air will flow from the middle position of the upper heating rod and the lower heating rod to the left and right sides, so that the high temperature zone in the middle of the furnace heats evenly, and the hot air can wrap around the varistor dielectric sheet in the reduction carrier on the conveying mechanism, so that the temperature atmosphere of the varistor dielectric sheet remains consistent, and the pressure ratio of the restored upper layer and the lower layer of the product is consistent, thereby improving the consistency of the varistor dielectric sheet after reduction.
[0009] The above-mentioned conveying mechanism can use a plurality of conveying rollers arranged in sequence, which belongs to the prior art and will not be described in detail here.
[0010] In the preferred embodiment, the winding spacing of the heating wires in the upper left heating zone and the upper right heating zone is smaller than the winding spacing of the heating wires in the upper middle heating zone. The winding spacing of the heating wires refers to the tightness of the winding of the heating wires. Through this arrangement, the winding spacing of the heating wires in the upper left heating zone and the upper right heating zone is small, so that the heating wires in the upper left heating zone and the upper right heating zone are wound more densely; the winding spacing of the heating wires in the upper middle heating zone is large, so that the heating wires in the upper middle heating zone are wound more sparsely, which in turn causes the heat emitted by the more dense heating wires on the left and right ends to be higher than the heat emitted by the more sparse heating wires in the middle.
[0011] In the preferred embodiment, the winding pitch of the heating wires in the lower left heating zone and the lower right heating zone is smaller than the winding pitch of the heating wires in the lower middle heating zone. With this arrangement, the winding pitch of the heating wires in the lower left heating zone and the lower right heating zone is small, so that the heating wires in the lower left heating zone and the lower right heating zone are wound more densely; the winding pitch of the heating wires in the lower middle heating zone is large, so that the heating wires in the lower middle heating zone are wound more sparsely, which in turn causes the heat emitted by the more dense heating wires at the left and right ends to be higher than the heat emitted by the more sparse middle heating wire.
[0012] Compared with the prior art, the utility model has the following advantages:
[0013] The utility model can make the temperature atmosphere of the varistor dielectric sheet consistent, and the pressure ratio of the restored upper layer and the lower layer of the product is consistent, thereby improving the consistency of the varistor dielectric sheet after restoration. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is a structural schematic diagram of an embodiment of the utility model;
[0015] Figure 2 yes Figure 1 Left view of;
[0016] Figure 3 It is a structural schematic diagram of an upper heating rod and a lower heating rod in an embodiment of the utility model. DETAILED DESCRIPTION
[0017] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0018] like Figure 1-3As shown, the tunnel reduction furnace for improving the reduction consistency of the varistor electrode in this embodiment includes a tunnel furnace 1 and a conveying mechanism 2. The front end of the tunnel furnace 1 is provided with an entrance 11, and the rear end is provided with an exit 12. The conveying mechanism 2 enters the tunnel furnace 1 from the entrance 11 and passes through the tunnel furnace 1 from the exit 12. An upper heating element 3 and a lower heating element 4 are arranged in the tunnel furnace 1. The upper heating element 3 is located above the conveying mechanism 2, and the lower heating element 4 is located below the conveying mechanism 2; the upper heating element 3 includes a plurality of upper heating rods 31 arranged in sequence from front to back, each upper heating rod 31 is arranged above the conveying mechanism 2 in a left-right direction, and the upper heating element 3 is arranged above the conveying mechanism 2. The rod 31 is provided with an upper left heating zone 311, an upper middle heating zone 312 and an upper right heating zone 313 from left to right, and the heating temperatures of the upper left heating zone 311 and the upper right heating zone 313 are both greater than the heating temperature of the upper middle heating zone 312; the lower heating element 4 includes a plurality of lower heating rods 41 arranged from front to back, each lower heating rod 41 is arranged in a left-right direction below the conveying mechanism 2, and the lower heating rods 41 are provided with a lower left heating zone 411, a lower middle heating zone 412 and a lower right heating zone 413 from left to right, and the heating temperatures of the lower left heating zone 411 and the lower right heating zone 413 are both greater than the heating temperature of the lower middle heating zone 412.
[0019] The definition of the front and back mentioned above is: along the conveying direction of the above-mentioned conveying mechanism 2, the one that arrives first is the front, and the one that arrives slowly is the back.
[0020] During operation, each upper heating rod 31 and lower heating rod 41 generates heat. Since the heating temperatures of the upper left heating zone 311 and the upper right heating zone 313 are both greater than the heating temperatures of the middle upper heating zone 312, and the heating temperatures of the lower left heating zone 411 and the lower right heating zone 413 are both greater than the heating temperatures of the middle lower heating zone 412, the heat emitted from the left and right ends of the upper heating rod 31 and the lower heating rod 41 is higher than the heat emitted from the middle part. Since the air expands at a high temperature position, the volume increases and the pressure decreases, and thus the air pressure at the middle low temperature of the upper heating rod 31 and the lower heating rod 41 is relatively large. Therefore, the hot air will flow from the middle position of the upper heating rod 31 and the lower heating rod 41 to the left and right sides, so that the high temperature zone in the middle of the furnace is heated evenly, and the hot air can wrap the varistor dielectric sheet in the reduction carrier 5 on the conveying mechanism 2, so that the temperature atmosphere of the varistor dielectric sheet remains consistent, and the pressure ratio of the restored upper layer and the lower layer of the product is consistent, thereby improving the consistency of the varistor dielectric sheet after reduction.
[0021] The above-mentioned conveying mechanism 2 can use a plurality of conveying rollers arranged in sequence, which belongs to the prior art and will not be described in detail here.
[0022] The winding pitch of the heating wires in the upper left heating zone 311 and the upper right heating zone 313 is smaller than the winding pitch of the heating wires in the upper middle heating zone 312. With this arrangement, the winding pitch of the heating wires in the upper left heating zone 311 and the upper right heating zone 313 is small, so that the heating wires in the upper left heating zone 311 and the upper right heating zone 313 are wound more densely; the winding pitch of the heating wires in the upper middle heating zone 312 is large, so that the heating wires in the upper middle heating zone 312 are wound more sparsely, which in turn causes the heat emitted by the more dense left and right end heating wires to be higher than the heat emitted by the more sparse middle heating wires.
[0023] The winding pitch of the heating wires in the lower left heating zone 411 and the lower right heating zone 413 is smaller than the winding pitch of the heating wires in the lower middle heating zone 412. With this arrangement, the winding pitch of the heating wires in the lower left heating zone 411 and the lower right heating zone 413 is small, so that the heating wires in the lower left heating zone 411 and the lower right heating zone 413 are wound more densely; the winding pitch of the heating wires in the lower middle heating zone 412 is large, so that the heating wires in the lower middle heating zone 412 are wound more sparsely, which in turn causes the heat emitted by the denser left and right heating wires to be higher than the heat emitted by the sparser middle heating wire.
[0024] In addition, it should be noted that the names of the various parts of the specific embodiments described in this specification may be different, and any equivalent or simple changes made based on the structure, features and principles described in the utility model patent concept are included in the protection scope of the utility model patent. The structure, features and principles described in the utility model patent can also be applied to the electrode sintering process of thermistors and ceramic capacitors. Technicians in the technical field of the utility model can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the utility model or exceed the scope defined by the claims, they should all fall within the protection scope of the utility model.
Claims
1. A tunnel reduction furnace for improving the reduction consistency of varistor electrodes, comprising a tunnel furnace and a conveying mechanism, wherein the tunnel furnace is provided with an entrance at the front end and an exit at the rear end, the conveying mechanism enters the tunnel furnace from the entrance and exits the tunnel furnace from the exit, and an upper heating element and a lower heating element are provided in the tunnel furnace, the upper heating element being located above the conveying mechanism and the lower heating element being located below the conveying mechanism; and characterized in that: The upper heating element includes a plurality of upper heating rods arranged in sequence from front to back, each upper heating rod is arranged in a left-right direction above the conveying mechanism, and the upper heating rods are provided with an upper left heating zone, an upper middle heating zone and an upper right heating zone from left to right, and the heating temperatures of the upper left heating zone and the upper right heating zone are both greater than the heating temperature of the upper middle heating zone; the lower heating element includes a plurality of lower heating rods arranged in sequence from front to back, each lower heating rod is arranged in a left-right direction below the conveying mechanism, and the lower heating rods are provided with a lower left heating zone, a lower middle heating zone and a lower right heating zone from left to right, and the heating temperatures of the lower left heating zone and the lower right heating zone are both greater than the heating temperature of the lower middle heating zone.
2. The tunnel reduction furnace for improving the reduction consistency of varistor electrodes according to claim 1, characterized in that: The winding pitch of the heating wires in the upper left heating zone and the upper right heating zone are both smaller than the winding pitch of the heating wires in the upper middle heating zone.
3. The tunnel reduction furnace for improving the reduction consistency of varistor electrodes according to claim 1, characterized in that: The winding pitch of the heating wires in the lower left heating zone and the lower right heating zone are both smaller than the winding pitch of the heating wires in the lower middle heating zone.