[0040] Example 1
[0041] Combine figure 2 , image 3 with Figure 4 , The traditional fire extinguisher valve mainly includes the riser seat 1, the spring 2, the valve body 3, the mandrel assembly 4, the pressure handle 51 and the handle 52. The valve body 3 is in a closed connection with the fire extinguisher storage bottle through the standpipe seat 1, and is provided with a side channel 31, an upper channel 32 and a lower channel 33. The valve body 3 is provided with a mandrel assembly 4, the lower part of the mandrel assembly 4 is provided with a spring 2, and the upper part is pressed against the pressing handle 51. The mandrel assembly 4 blocks the upper channel 32 and the lower channel 33 of the valve body 3 for To realize the sealed filling of the fire extinguishing agent, the pressing handle 51 and the handle 52 are connected by a rivet 53. A safety pin 62 is also provided between the pressing handle 51 and the handle 52. The safety pin 62 is connected to the handle through a rubber chain 61 52 connected. When extinguishing the fire, the firefighter pulls out the safety pin 62 and presses the pressing handle 51, so that the ejector rod assembly 4 is pressed down, and the extinguishing agent is sprayed from the side channel 31.
[0042] It can be said that the mandrel assembly 4 and the valve body 3 are the core components to ensure the performance of the fire extinguisher valve, but the mandrel assembly 4 of the traditional structure is like figure 1 As shown, the ejector pin 42, the cap 45, and the insert 43 are all made of metal materials such as copper or aluminum. The production cost is high, and the corrosiveness of the fire extinguishing agent filled in the fire extinguisher storage bottle to metal cannot be ignored. .
[0043] To this end, this embodiment provides a fire extinguisher valve plastic ejector rod, which has a structure such as Figure 5 As shown, it is integrally formed by injection molding of nylon composite material. One end of the top rod 42 is provided with a sealing ring groove 421, a rubber O-ring 41 is sleeved in the sealing ring groove 421, and the other end of the top rod 42 is provided with a cap head 423 A sealing gasket groove 422 is opened on the side of the cap head 423 close to the sealing ring groove 421, and the sealing gasket 44 is sleeved in the sealing gasket groove 422. Compared with the traditional structure, in this embodiment, the original ejector pin 42 and the cap head 45 are integrally molded by injection molding of nylon composite material, and the insert 43 is also omitted. On the one hand, the structure is simpler and the assembly time is greatly shortened; on the other hand, the injection molding process of the ejector pin is also more labor-saving compared to the processing technology of metal parts, and the purchase cost of nylon materials is much lower than that of metal materials and the manufacturing of plastic ejector pins. The cost is significantly reduced, which increases the market competitiveness of fire extinguisher manufacturers.
[0044] It is worth noting that the injection molding of the ejector rod and the valve body can not be simply manufactured by using the traditional injection molding process. To meet the special environment and use requirements of the fire extinguisher valve, the plastic ejector rod and the valve body must be creeping under the action of permanent pressure. The change is small, and it meets the requirements of corrosion resistance, high pressure resistance, high and low temperature resistance. In addition, the ejector rod and valve body are a small product, and they need to cooperate with other structures to achieve the encapsulation of the fire extinguishing agent. The dimensional accuracy of the valve body is also very high. However, the traditional injection molding process cannot meet the above requirements well.
[0045] Based on this, first this embodiment provides a new material formula, including the following components:
[0046]
[0047] The glass fiber length of the long glass fiber is 18 mm.
[0048] The material formula used in this embodiment can form a uniformly dispersed fiber phase structure in the nylon 66 matrix, with good fluidity and thermal stability in the molten state, thereby significantly improving the mechanical properties of the nylon composite material. The plastic ejector rod and valve body have good dimensional stability, good surface gloss, and can effectively increase the rigidity and toughness of the valve ejector rod and valve body.
[0049] Secondly, this embodiment provides a method for preparing a fire extinguisher valve plastic ejector rod and valve body, and the steps are:
[0050] Step 1. Mix 40 parts of nylon 66 slices, 25 parts of long glass fiber, 2 parts of silicon carbide, 0.5 parts of talc powder and 1 part of mica powder under stirring conditions;
[0051] Step 2. Ejector injection: Put the mixed raw materials into the feeding port of the injection molding machine, and then quickly inject it into the ejector cavity at high pressure by the thrust of the screw after melting; the screw speed of the injection molding machine is 100rpm; the screw length of the injection molding machine The diameter ratio is 18. The temperature of the feeding section of the injection molding machine is controlled at 300°C; the temperature of the feeding section is controlled at 285°C; the temperature of the injection section is controlled at 285°C; the nozzle temperature is controlled at 280°C; the mold temperature is controlled at 90°C. The injection molding machine is divided into three sections to complete the injection. The injection parameters are: the injection speed of the first injection section is 60mm/s, and the injection pressure is 85kg/cm. 2 , The injection time is 9s, the injection speed of the second injection section is 35mm/s, and the injection pressure is 80kg/cm 2 , The injection time is 6s, the injection speed of the third injection section is 20mm/s, and the injection pressure is 45kg/cm 2 , The injection time is 9s, after the third injection section, keep the pressure for 15s. After cooling and solidification, open the mold, and immerse the first product of the ejector pin in water at 15°C for 2 minutes to shape the surface to keep the surface flat.
[0052] Valve body injection molding: Put the mixed raw materials into the feeding port of the injection molding machine, and quickly inject them into the cavity of the valve body at high pressure by the thrust of the screw after melting. The screw speed of the injection molding machine is 100 rpm; the screw length to diameter ratio of the injection molding machine is 18. The temperature of the feeding section of the injection molding machine is controlled at 300°C; the temperature of the feeding section is controlled at 285°C; the temperature of the injection section is controlled at 285°C; the nozzle temperature is controlled at 280°C; the mold temperature is controlled at 90°C. The injection molding machine is divided into two sections to complete the injection. The injection parameters are: the injection speed of the first injection section is 55mm/s, and the injection pressure is 75kg/cm. 2 , The injection time is 6s, the injection speed of the second injection section is 25mm/s, and the injection pressure is 40kg/cm 2 , The injection time is 15s, after the second injection section, keep the pressure for 15s. After cooling and solidification, the mold is opened to prepare the initial valve body, and the initial valve body is immersed in water at 20°C for 2 minutes.
[0053] Step 3. After the molded ejector rod and valve body products are inspected, they are put into the equipment for high-temperature cooking for 3 hours, and the final product is obtained.
[0054] Step 4. Assemble the components of the fire extinguisher valve into one.
[0055] This embodiment is based on the material formula used, and by controlling the injection molding process parameters, the problem of poor fluidity caused by the addition of long glass fibers is overcome, and the shearing effect of the long glass fibers is reduced when the long glass fibers enter the mold cavity. Not easy to break. It is especially important that this embodiment overcomes the problem of flashing in small products by controlling the injection speed and pressure (this is very important). The produced ejector rod and valve body have high dimensional accuracy, which can fully meet the requirements. The internal environment of the fire extinguisher valve puts forward the requirements of corrosion resistance, high pressure resistance, high and low temperature resistance, and the use of the fire extinguisher valve is ideal, which is convenient for popularization and application.
