A quick preparation method of conductive module in mine tear sensor

Abstract

The application discloses a kind of quick preparation methods of conductive module in mine tear sensor, and the conductive module structure in the tear sensor is composed of soft glue shell, metal conductive layer and fixing part, and metal conductive layer is fixedly installed on the inner surface of soft glue shell by fixing part;The soft glue shell is formed by rapid forming device using injection molding machine injection molding.The original production process and product structure are changed in the application, the product quality is improved, the false report is eliminated, and the production cycle is short, the site occupation is less, the environmental pollution is small, the energy consumption is less, and the problems existing in vulcanization process and irrigation process are solved.

Description

Technical Field

[0001] This invention relates to a rapid fabrication method for a conductive module in a mine tear sensor, belonging to the field of sensor manufacturing technology. Background Technology

[0002] Mining tear sensors are intrinsically safe and can be used in conjunction with integrated protection devices for mining belt conveyors in hazardous environments containing methane, coal dust, and explosive gases in underground coal mines. They serve as tear protection devices for belt conveyors, but can also be used in non-explosion-proof surface applications with belt conveyors. The tear monitoring works in conjunction with a programmable controller (PLC). When the belt tears, material spills onto the sensor located between the belt segments. When the spilled material reaches a certain weight, the sensor activates, and the PLC, upon receiving the signal, immediately stops the conveyor belt, thus protecting it. These sensors are typically rectangular, covered with a waterproof bag, and equipped with steel wire ropes at both ends for installation. Inside the sensor frame is a mounting plate with circuitry. Several tear-conductive modules are mounted on the mounting plate. These modules contact the circuitry when material falls, providing a signal. However, a certain weight is required for activation to prevent false alarms. Therefore, the tear-conductive modules must possess both strength and flexibility, similar to keyboard keys. Existing tear-resistant conductive module structures consist of a square rubber shell bulging upwards in the center. Conductive rubber strips or sheets are laminated to the inner surface of the bulge within the shell. The manufacturing process primarily employs rubber vulcanization, where conductive rubber strips or sheets of the desired shape are first vulcanized and then placed into a vulcanization mold within the shell for further vulcanization. This structure suffers from several problems. Firstly, after a period of use, both the rubber shell and the conductive rubber blocks deform, leading to false alarms and forced shutdowns, resulting in production losses. Furthermore, this vulcanization process causes significant environmental pollution, has a long molding cycle, and consumes substantial energy. Currently, casting processes are also used. While casting processes address environmental pollution and energy consumption issues, the need for material curing further extends the production cycle and requires more space. Therefore, this technology is not suitable for mass production.

[0003] To address these issues, a search revealed that many existing patents utilize infrared detection sensors. However, in commercially available products, the safety advantages of these sensors are evident due to the hazardous environment of explosive gases such as methane and coal dust in underground coal mines, and their low cost. Consequently, they remain in use. However, existing technologies do not provide a good solution for the manufacturing process of the tear-conductive module. Summary of the Invention

[0004] The purpose of this invention is to solve the problems existing in the current technology and provide a rapid preparation method for the conductive module in a mining tear sensor. This method changes the drawbacks of the original rubber vulcanization process and can be injection molded using an injection molding machine. It has a short production cycle, requires less space, causes less environmental pollution, consumes less energy, and also solves the problems existing in the casting process. It is suitable for mass production.

[0005] To achieve the above objectives, the technical means adopted by the present invention is: a rapid preparation method for a conductive module in a mining tear sensor, wherein the conductive module structure in the tear sensor consists of a soft rubber shell, a metal conductive layer and a fixing component, and the metal conductive layer is fixedly installed on the inner surface of the soft rubber shell by the fixing component; the soft rubber shell is injection molded using an injection molding machine through a rapid prototyping device.

[0006] Furthermore, the soft rubber shell is made of TPR soft rubber material.

[0007] Furthermore, the rapid prototyping device includes an upper mold body and a lower mold body. A shell groove for the soft rubber shell is provided on the opposite surfaces of the upper and lower mold bodies. A positioning ring is provided on the top surface of the upper mold body. A nozzle is provided on the upper mold body in the positioning ring and communicates with the shell groove. The rapid prototyping device is fixed to the injection molding machine by the positioning ring. After the soft rubber particles are melted by the injection molding machine, they are pressed into the mold by the nozzle under high pressure. After the molten soft rubber is formed and cooled by the mold, the upper and lower mold bodies are opened to obtain a set of soft rubber shells.

[0008] Furthermore, the upper mold body includes an upper cover plate and an upper mold plate fixed by bolts, and the lower mold body includes a base plate, a supporting square iron, a support plate and a lower mold plate fixed by bolts in sequence. Guide sleeves and guide posts are provided on the opposite surfaces of the upper mold plate and the lower mold plate for assembling the upper mold body and the lower mold body together. Grooves are provided on the upper mold plate and the lower mold plate to form a number of shell-shaped grooves after assembly.

[0009] The beneficial technical effects of this invention are: by changing the original production process and product structure, the product quality is improved, false alarms are eliminated, and the production cycle is short, the site occupation is small, the environmental pollution is small, the energy consumption is small, and the problems existing in the vulcanization process and the pouring process are solved. Attached Figure Description

[0010] Figure 1 This is a cross-sectional schematic diagram of the rapid prototyping device of the present invention;

[0011] Figure 2 This is a schematic diagram of the external structure of the rapid prototyping device of the present invention.

[0012] In the diagram: 1. Upper cover plate, 2. Upper mold plate, 3. Lower mold plate, 4. Support plate, 5. Support square iron, 6. Base plate, 7. Positioning ring, 8. Nozzle, 9. Fixing screw, 10. Guide sleeve, 11. Guide post. Detailed Implementation

[0013] Example 1

[0014] To address the issues inherent in vulcanization and casting processes while meeting the intrinsic safety requirements of hazardous environments containing methane and coal dust in underground coal mines, our company has developed a rapid fabrication method for the conductive module in a mine-use tear sensor. First, the structure of the conductive module in the tear sensor has been redesigned, consisting of a flexible rubber shell, a metal conductive layer, and a fixing component. The metal conductive layer is fixed to the inner surface of the flexible rubber shell by the fixing component. This structure eliminates the need for the traditional rubber vulcanization process of conductive rubber strips or sheets. The flexible metal sheet is fixed to the inner surface of the shell using nails, adhesives, or other methods. The conductivity of the flexible metal sheet is superior to that of conductive rubber strips or sheets. At this point, the strength and toughness of the shell meet the requirements. Furthermore, because the flexible metal sheet is thin, the overall deformation due to prolonged use is minimal. Therefore, simply designing the shell to minimize deformation is sufficient to resolve the false alarm problem.

[0015] The working principle of existing conductive blocks on the market is basically based on resistive pressure sensors. The output resistance is related to the magnitude of the actuation force; the greater the actuation force, the smaller the output resistance. This leads to the risk of false activation during use. The conductive metal layer of this invention achieves instantaneous conduction upon contact, thus triggering an immediate alarm, unaffected by the magnitude of the actuation force, eliminating the risk of action delay and false activation. Regarding the thickness design of the conductive module's metal layer, tests were conducted at thicknesses ranging from 0.1 to 0.5 mm, all achieving the expected results and exhibiting the characteristic of instantaneous conduction and alarm upon contact, demonstrating stable performance.

[0016] Regarding the production process of the soft rubber shell, in order to shorten the molding cycle, reduce energy consumption, and meet the requirements for strength and toughness, we ultimately adopted TPR soft rubber material and used a rapid prototyping device to perform injection molding. Injection molding reduces the time by about 95% compared to vulcanization molding, and the injection molding process achieves almost zero pollution compared to vulcanization, thus solving environmental protection issues.

[0017] Example 2

[0018] like Figure 1 , 2 As shown, in Example 1, as the rapid prototyping device required for the preparation of the soft rubber shell, we designed an upper mold body and a lower mold body. The shell-shaped groove of the soft rubber shell is set on the opposite surface of the upper mold body and the lower mold body. A positioning ring is set on the top surface of the upper mold body. The nozzle is set on the upper mold body in the positioning ring and connects to the shell groove. The rapid prototyping device is fixed on the injection molding machine by the positioning ring. After the soft rubber particles are melted by the injection molding machine, they are pressed into the mold by the high pressure of the nozzle. After the molten soft rubber is formed and cooled by the mold, the upper and lower mold bodies are opened to obtain a set of soft rubber shells.

[0019] The upper mold body includes an upper cover plate 1 and an upper mold plate 2 fixed by bolts 9. The lower mold body includes a base plate 6, a supporting square iron 5, a support plate 4, and a lower mold plate 3, which are sequentially fixed by bolts 9. Guide sleeves 10 and guide posts 11 are provided on the opposite surfaces of the upper and lower mold plates for assembling the upper and lower mold bodies together. Grooves are provided on the upper and lower mold plates, forming several shell-shaped grooves after assembly. Because the soft rubber shell is injection molded from TPR material, reinforcing ribs are added to the upper side of the soft rubber shell to ensure its overall strength, thereby achieving the expected strength.

[0020] The corresponding product shape is milled between the upper mold plate 2 and the lower mold plate 3. During product production, the upper and lower molds are assembled together using guide pillars 11 and guide sleeves 10. The guide sleeves 10 are installed on the upper mold plate 2, and the positioning ring 7 and nozzle 8 are installed on the upper cover plate 1. The upper cover plate 1 and the upper mold plate 2 are fixed together with fixing screws 9 to form the upper mold body. The lower mold plate 3, support plate 4, support square iron 5, base plate 6, and guide pillars 13 are sequentially fixed together with fixing screws 9 to form the lower mold body. The shape of the soft rubber shell is milled between the upper mold plate 2 and the lower mold plate 3 and assembled together using guide pillars and guide sleeves. The mold is fixed to the injection molding machine using the positioning ring 7. The soft rubber granules are melted in the injection molding machine and then pressed into the mold under high pressure through the nozzle 8. After the molten soft rubber is formed and cooled by the mold, the upper and lower molds are opened to obtain the corresponding soft rubber shell product.

[0021] Because of the small size of the soft rubber shell, multiple soft rubber shell grooves can be set on the upper and lower mold bodies, allowing multiple products to be produced in a single molding process. This change in production process and product structure improves product quality, eliminates false alarms, and shortens the production cycle, reduces space requirements, minimizes environmental pollution, and lowers energy consumption, while also solving problems associated with the vulcanization and casting processes.

Claims

1. A rapid fabrication method for a conductive module in a mine tear sensor, characterized in that: The conductive module structure in the tear sensor consists of a soft rubber shell, a metal conductive layer, and a fixing component. The metal conductive layer is fixedly installed on the inner surface of the soft rubber shell by the fixing component. The soft rubber shell is injection molded using a rapid prototyping device and an injection molding machine; The conductive metal layer is made of flexible metal sheet.

2. The rapid fabrication method of the conductive module in the mine tear sensor according to claim 1, characterized in that: The soft rubber shell is made of TPR soft rubber material.

3. The rapid fabrication method of the conductive module in the mine tear sensor according to claim 1, characterized in that: The rapid prototyping device includes an upper mold body and a lower mold body. Shell grooves for soft rubber shells are provided on the opposite surfaces of the upper and lower mold bodies. A positioning ring is provided on the top surface of the upper mold body. A nozzle is provided on the upper mold body in the positioning ring and connects to the shell groove. The rapid prototyping device is fixed to an injection molding machine by the positioning ring. Soft rubber particles are melted by the injection molding machine and then pressed into the mold by the nozzle under high pressure. After the molten soft rubber is formed and cooled by the mold, the upper and lower mold bodies are opened to obtain a set of soft rubber shells.

4. The rapid fabrication method of the conductive module in the mine tear sensor according to claim 3, characterized in that: The upper mold body includes an upper cover plate and an upper mold plate fixed by bolts. The lower mold body includes a base plate, a supporting square iron, a support plate and a lower mold plate fixed by bolts in sequence. Guide sleeves and guide posts are provided on the opposite surfaces of the upper mold plate and the lower mold plate for assembling the upper mold body and the lower mold body together. Grooves are provided on the upper mold plate and the lower mold plate to form a number of shell-shaped grooves after assembly.

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