When rubber injection molding machine in production, use good mobility plastic nozzle prone plastic salivation, drooling is not only a waste of such material will also affect the quality of products, even interrupting production. To solve the problem of plastic salivation, existing common solution is to use the first three self-locking spring nozzle; the second is the use of a hydraulic control device to control the nozzle switch; the third is to reduce the nozzle aperture . For the first solution, since the spring lock nozzle has the advantage of cheap and widely used, but due to the large pressure loss, when converting liquidity fair or poor materials to replace the nozzle, while the spring at high temperatures prone to failure, it is generally a year and would replace a nozzle, and the current domestic spring up on the performance is not to IJ, often imported, high maintenance costs. For the second solution, using the hydraulic control device to control the nozzle switch is better, but the cost is too high and must install the appropriate software to control the rubber injection molding machine and therefore not widely used. For the third solution, reducing the nozzle aperture prone to gag, but rubber injection molding machine is difficult to completely prevent salivation, different injection materials still need to replace the corresponding nozzle.