Inspection of pressure opening device of suction valve
Check the state of the opening device of the suction valve of air compressor is carried out on the special support ring, and the support 1 itself is placed on the workbench.
The suction valve 2 is installed in the recess of the support ring in the form of assembly, while the cover 3 and the pressure opening device 4 are installed on the suction valve.
Then press the small plug 5 up and down, and check whether the fork rod 6 and the valve plate 7 contact at the same time. If the contact between the fork bar and the valve plate does not occur at the same time, the end of the long fork bar should be filed.
When the full stroke of the small piston 5, the valve plate 7 should be pressed away from the contact belt of the valve seat; if not, then the fork rod should be replaced with a longer one or its end should be extended.
When the small piston 5 is no longer pressed, the fork rod of the pressing device shall immediately return to the original position under the action of the spring 8, that is, it will no longer contact with the cylinder.
If not, then spring 8 must be broken or too soft. So it has to be replaced. For the correctly adjusted press opening device, when the small piston 5 is not pressed down, the clearance between the fork rod and the valve plate shall be within the range of 5-5.5 mm.
The grinding quality of the cylinder socket on the small piston 5 and the cover 4 is checked by injecting kerosene into the upper space of the small piston 5. The injected kerosene shall not pass through the space between the small piston 5 and the cylinder socket of head 4 within 5 minutes, otherwise, the small piston or its piston ring shall be replaced.
In this case, the quality of scraping can be inspected on the painted plate until 12-16 spots appear on the scraped surface every 1cm.
After scraping, the valve plate shall be grinded against the sealing belt of the valve seat. If the injected medium oil does not penetrate through the contact surface within 5 minutes, it can be considered as qualified for grinding.
In addition to using grinding powder and grinding paste, the grinding of valve disc relative to valve seat can also use glass that has been pounded and screened. In this case, the valve seat shall be coated with oil and a thin layer of glass powder shall be spread before grinding.
When grinding, grind both sides of the valve plate in turn. Grind until no more light appears.
When the entire circumference has a matte surface, the grinding is finished.
In addition, the lines engraved on the valve plate by the white seal shall be evenly transmitted to the valve seat under the condition of valve plate rotation.
After the unloading inspection, use kerosene or compressed air in the air box to check the tightness of the grinding surface.