New pressure switch for excavator
The pressure switch is a simple pressure control device. When the measured pressure reaches the rated value, the pressure switch can send out an alarm or control signal.The working principle of the pressure switch is: when the measured pressure exceeds the rated value, the free end of the elastic element is displaced, and the switching element is pushed directly or after comparison to change the on-off state of the switching element to achieve the purpose of controlling the measured pressure.Pressure switches need different structural designs in different occasions.
At present, pressure switches used on excavators usually include a housing with a cavity and a connector exposed outside the housing. The cavity of the housing is provided with a switch assembly，which includes a switch seat, a top rod, a pressure spring, a moving contact and a static contact, and a contact mounting frame,the connector is fixedly connected with the switch base, the switch base is placed on one side of the corresponding connector in the cavity, the pressure spring is placed on the other side of the corresponding connector of the switch base, the ejector rod is connected with the switch base and is elastically deformed by the pressure spring Drive to achieve axial slip,the contact piece mounting frame is fixed in the cavity of the housing, the static contact piece is fixedly connected to the contact piece mounting frame, the moving contact piece is movably connected to the contact piece mounting frame, and the top rod drives it to close or disconnect with the static contact piece.the pressure shrapnel is directly connected to the mounting frame of the contact piece, and the contact connection is a flat structure. When the measured pressure exceeds the rated value, the free end of the pressure piece is displaced, which may cause the pressure shrapnel and the contact piece mounting frame Loss of the conflicting connection makes the pressure switch insensitive or malfunctioning.
Competing for the defects of the existing pressure switch, developed a new type of pressure switch，The difference is that the contact piece mounting frame of the new pressure switch is provided with a cavity with an opening on the side corresponding to the top rod. The pressure spring piece is in contact with the contact piece mounting frame, and the corresponding contact part of the pressure spring piece constitutes a stepped structure. Plate mounting frame limit coordination，By adopting the above technical solution, the position of the interference connection between the pressure spring and the contact plate mounting frame is changed from the traditional plane interference connection to the stepped interference connection。When the measured pressure exceeds the rated value, the pressure dome will be displaced, which can also ensure that the pressure dome and the contact mounting frame maintain a good contact connection relationship, so that the pressure switch is sensitive and reliable.in addition, the contact piece mounting frame is provided with an outer peripheral flange at one end corresponding to the pressure spring, and the switch base is rolled into a limit part that cooperates with the outer peripheral surface flange to prevent the contact piece mounting frame from moving. The switch base and the contact piece are installed The gap between the frame and the shell is filled with epoxy resin.By adopting the above technical solutions, compared with the cutting and grinding processes, the roll forming process not only has high production efficiency, saves materials, but also has high product strength and stable quality. After the assembly of each component is completed, epoxy resin can be poured into the shell. The switch assembly inside is effectively fixed.