Grinding of hard valves of diesel generators requires an electro-optical grinder. The order of smoothing the valve seat of the smoothing machine is basically the same as the order of reaming. The difference is that the polisher replaces the reamer with a grinding wheel of different angles, and the hand drill motor replaces the hand reamer. Repair the valve seat with a polishing machine, the finish is good, especially suitable for the grinding of high hardness valves, and the effect is better. Therefore, many maintenance units now use electro-optic grinding devices to make light door seats. The operation points of valve seat grinding are as follows:
1. According to the angle of the working face of the valve seat, select the appropriate grinding wheel, and dress the grinding wheel on the grinding wheel dresser according to the requirements of the working face angle.
2. Install the renovated grinding wheel at the end of the polishing machine, then install the guide rod suitable for the inner diameter of the valve guide tube, use the guide rod handle to rotate the guide rod to expand the fixed spring expansion ring, and drop a little oil.
3. When the polishing machine turns on the motor switch grating, the polishing machine should pay attention to the following points:
(1) The motor should be leveled, pressed moderately, and pressed tightly.
(2) The polishing time should not be too long. It should be checked during grinding and used during trial matching.
(3) When the operation is stopped, the motor switch should be turned off first, and after the grinding wheel stops rotating, the grinding wheel should be moved out to observe its contact state.
The air valve seat ring has been reamed and ground for many times. After grinding, its aperture will gradually increase, making the working surface concave. After reaching a certain level, it will affect the inflation efficiency and reduce the spring tension. At the same time, it will also cause the contact surface between the valve and the valve seat. The contradiction of being high and not moving down. If the working surface of the valve seat is 1.5mm lower than the surface of the cylinder block (that is, the valve mechanism device is a lower-mounted machine, for example, the valve seat ring is generally installed on the cylinder block in a gasoline engine), or the valve seat sinking amount that meets the requirements exceeds the allowable value When the valve seat is severely ablated, a new valve seat should be re-installed.
The steps of the diesel generator valve seat fitting method include: pulling out the old seat ring, selecting a new valve seat, and pressing the seat ring into the seat ring. The three aspects are:
1. Open the old seat.
The valve seat ring can be pulled out with a conical spring ring or a claws.
2. Select the new valve seat.
When choosing a new valve seat ring, first trim the seat hole with a flat reamer, and the base should be flat, the out-of-roundness and taper should not exceed 0.015mm, the inner wall should be smooth, and the fit interference between the valve seat ring and the cylinder body is generally 0.07 ~0.17mm to ensure better heat transfer and stability.
3. Press the seat ring into the seat ring.
(1) The method of cold shrinking the seat ring is to place the sealing ring in the cooling box, and release CO2 gas from the gas storage bottle containing compressed CO2, so that the temperature of the sealing ring is lowered to about -70 °C. Or use the refrigerator to shrink the valve seat ring, and then use a sealant mixed with glycerin and yellow dan powder to pad with soft metal to quickly press the seat ring.
(2) The thermal expansion seat ring hole method generally adopts the heating of the seat hole to about 100 ℃, and then uses a sealant mixed with glycerin and Huangdan powder, cushions it with soft metal, and quickly presses it into the seat ring.
After the seat ring is installed, check and correct the raised part of the seat ring so that it is consistent with the top of the cylinder. The axis lines of the seat ring and the air guide tube should be the same, and the deviation should not exceed 0.05mm, and then they are matched with the valve by reaming or polishing.
Guangxi Dingbo Power Equipment Manufacturing Co.,Ltd. is a diesel generator set manufacturer with more than 40 years of production experience. Its main brands include Yuchai generator sets, Cummins generator sets, Volvo generator sets, etc., and 64 sales and service departments nationwide. Users provide one-stop service of design, supply, debugging and maintenance. Welcome contact us by email firstname.lastname@example.org