6results about How to "Reduce negative pressure" patented technology

This invention relates to the field of automotive parts technology, and provides a dual-valve controlled PRV valve, comprising: a valve seat having an intake chamber and an exhaust chamber therein, the intersection of which forms a cavity with one end communicating with the outside air; a piston movably inserted into the cavity, with an exhaust hole penetrating the first and second parts at the center of the piston; a diaphragm movably connected to the upper end of the piston; a spring sleeved on the outer wall of the piston, with the end of the spring abutting against the diaphragm on the moving side; and a seal disposed within the cavity. Compared with the prior art, the advantage of this invention is that by providing a seal within the valve seat that seals the piston and the cavity, when the negative pressure in the cavity is high, the seal and the diaphragm together achieve a seal on the intake and exhaust chambers. Under the same operating conditions, this makes it easier to achieve the sealing function, preventing excessively low crankcase negative pressure and ensuring normal engine starting.

The utility model discloses a suction-sweeping type sweeper suction nozzle, which belongs to the technical field of sweeper suction nozzles, and comprises two suction nozzle shells, a connecting frame, a suction mechanism, a separation mechanism, a suction mechanism and a suction mechanism, the connecting frame is arranged between the two suction nozzle shells and is used for connecting the two suction nozzle shells, the suction mechanism is arranged on the suction nozzle shells and is used for sweeping leaves and dust, and the separation mechanism is arranged in the suction nozzle shells and is used for assisting the suction mechanism in sweeping. The gathering mechanism is arranged on the suction nozzle shell and used for gathering garbage, and the mounting mechanism is arranged on the top side of the suction nozzle shell and used for mounting the suction nozzle shell on the sweeping vehicle. According to the utility model, the contained garbage is sucked into the garbage truck through the negative pressure environment by utilizing the negative pressure pipe and the negative pressure chamber, meanwhile, the airflow generated when the garbage truck generates negative pressure is injected into the air blowing pipe and the inclined nozzle, and the inclined nozzle blows air to the ground within an angle range of 30-40 degrees, so that the condition that leaves are attached to the ground can be disturbed, and the effect of preventing the leaves from being attached to the ground is achieved. And the purpose of enhancing the equipment cleaning effect is achieved.

This invention discloses a control method, system, equipment, and medium for a nitrogen-sealed split-range regulating valve in a storage tank, relating to the field of petrochemical production technology. The invention includes obtaining the design pressure value P of the nitrogen-sealed storage tank. S The invention monitors the real-time pressure P inside the nitrogen-sealed storage tank. When material increases in the tank, it automatically releases nitrogen gas from the top; when material is released, it automatically replenishes nitrogen gas from the top. Specifically, based on the monitored real-time pressure inside the nitrogen-sealed storage tank, logic control is used to control the opening degree of the nitrogen regulating valve and the vent regulating valve. This invention enables the pressure of the nitrogen-sealed storage tank to be controlled within a certain range, rather than a fixed value, reducing the frequent operation of the nitrogen valve and vent valve in each segmented control valve. It also allows for quantitative control of the valve opening, reducing nitrogen and material consumption and improving safety.

The application discloses a conveying device and a surface defect detection device, and belongs to the technical field of printed circuit manufacturing equipment. In the conveying device, a first negative pressure body, a positive pressure body and a second negative pressure body are arranged along the conveying direction from the first conveying mechanism to the second conveying mechanism. The first negative pressure body provides negative pressure suction force to the first air holes on the first conveying belt to flatten the passing flexible sheet material. The second negative pressure body provides negative pressure suction force to the second air holes on the second conveying belt to transition the flexible sheet material from the first conveying belt to the second conveying belt and flatten the passing second flexible sheet material. The positive pressure body provides positive pressure blowing force to the first air holes to pre-lift the flexible sheet material. In one aspect, the flexible sheet material is more conveniently adsorbed on the second conveying belt, and the required negative pressure of the second negative pressure body is reduced. In another aspect, the bending angle of the flexible sheet material during the transition from the first conveying belt to the second conveying belt is reduced, and the phenomenon of creases on the flexible sheet material due to the excessively large bending angle is avoided.

The utility model discloses a breast suction shield and a breast pump, and relates to the technical field of mother and baby products, the breast suction shield comprises a breast suction piece and a fitting piece; a milk sucking channel with two through ends is formed in the milk sucking piece; the attaching part is connected to one end of the milk sucking part, an attaching channel communicated with the milk sucking channel is formed in the attaching part, and the attaching channel gradually shrinks in the direction close to the milk sucking part; wherein a partial pressure channel is formed in the inner wall of the attaching piece, the partial pressure channel is located at the end, close to the breast suction piece, of the attaching piece, and when the attaching piece is attached to the breast, the partial pressure channel is communicated with the breast suction channel. According to the breast suction protective cover, the pressure dividing channel is arranged at the position close to the joint of the attaching piece and the breast suction piece, the negative pressure intensity borne by the mammary areola is reduced, the problem that a circle of red marks are formed at the mammary areola after an existing adsorption protective cover is used for sucking milk is solved, and the use experience feeling of a user is improved.

This utility model discloses a negative pressure prevention device for loading and unloading operations, relating to the field of sulfuric acid pipeline transportation. It includes a pressure-reducing pipe and a first pipeline. A pressure-reducing box is installed at the top of the pressure-reducing pipe, and a connecting box is connected to the top of the pressure-reducing box. A vent pipe is fixed to the end of the connecting box, and a connecting pipe is connected to one side of the pressure-reducing box. A rim is provided on the outer wall of the seal. When the electric valve is closed, the negative pressure inside the first pipeline attracts the seal, causing it to wrap around the top of the pressure-reducing pipe. The negative pressure also draws the rim on the seal inward, creating a gap between the seal and the pressure-reducing box. External gas enters the pressure-reducing box through the vent pipe and flows into the first pipeline through the connecting pipe, thereby filling the negative pressure area inside the first pipeline near the connecting pipe end, reducing the negative pressure and thus protecting the electric valve.