The concept of systematic error for thermal deformation control measure of cutting machine
(1) Reduce heat and insulation. In order to reduce the heating of the process system, it is possible to separate the heat source from the main machine. Such as motor, gearbox, lead screw pair, oil tank, etc. should be placed on the outside of the machine as far as possible. For a heat source that can be separated, such as the main bearing, screw pair, gear pair, friction clutch, and other parts and components, the structure and lubrication side should be improved to improve the friction characteristics, reduce heat.
Cutting machine to reduce the thermal deformation of an important link. Therefore, make the machine tools, usually adopt static pressure bearing, bearing, low temperature dynamic pressure bearing and air meter with low degree of lubricating oil drum, the bearing temperature control easier * jorge source can't separate from the machine tool, can be in these hot bonding surface of large parts and machine tool installed insulation (heat source heat dissipation is not good, appropriate USES the cooling measures), prevent quantity of heat conduction.
(2) The heat of the cutting machine, thus controlling the temperature rise and thermal deformation of the machine tool. Such as CNC machine tools and processing towel center machine tools, the general use of freezers to run
The forced cooling of lubricating oil greatly reduces the heating and deformation of spindle box components.
(3) To accelerate the temperature rise and maintain the thermal balance. The rule of internal thermal deformation shows that the thermal deformation becomes constant after the cutting machine reaches the thermal balance during the preheating stage of the machine tool, and then the machining accuracy can be guaranteed. This can shorten the preheating period of the machine, improve productivity and ensure machining accuracy.
The machining errors of various single factors can be divided into systematic errors and accidental errors according to their properties.
1. System error of cutting machine
When hydraulic cutting machine processing a batch of parts, the size does not change is a regular change of the error known as the system error monitoring. The front streamline is a constant systematic error, while the latter is a systematic error that varies regularly (variable system error). For example, with a reamer with a diameter smaller than the specified size of o.02, the diameter of all the reamed holes is smaller than the specified size of o.02, and this error is often caused by systematic errors. For example, when turning axle, due to tool wear, the white diameter of the turning axle is larger than that of the other. The increase of the vertical diameter of the axle is regular, so the error caused by tool wear belongs to the systematic error of regular change (variational systematic error). The thermal deformation of The Ru-Ding system is also a variable value system error.
2. The cutting machine is accidentally wrong
In the addition of a batch of parts, the magnitude and direction of such errors vary irregularly, sometimes large, sometimes small, sometimes positive, sometimes negative. This type of error is called accidental hardening. For example, when a four-column cutting machine processes the holes of a batch of parts with a single reamer, under the same conditions, a batch of holes with the same diameter still have to be small, which may be caused by the uneven hardness of the blank, the difference of AJJl 'margin, the deformation caused by the redistribution of internal stress and other factors. All these factors are subject to variation. Although the causes of the accidental error are various and the action of the cutting machine is very complicated, the law of the accidental error can be found and controlled by using the mathematical statistical force method.