Prevention of chip damage in the latest train

Prevention of turning chip injury

from the structure and motion characteristics of the lathe, we can see that the unsafe factors of objects in turning mainly come from two aspects: first, the rotation of the workpiece and its clamping devices (chuck, flower plate, chicken heart clamp, center, and other fixtures), especially the rotation of long bar material; The second is the splashing high-temperature chips produced in the chip cutting process. Shavings hurt people, mainly manifested as scratches and burns. Broken chips are very easy to hurt people's eyes

1 common chip shapes

the most common chip shapes are: banded chip, broken chip, C-shaped chip, spiral chip, long and tight chip, spring shaped chip, pagoda shaped chip, etc

2 danger of chips with different shapes

2.1 when cutting plastic metal materials at high speed, banded chips are easy to form if appropriate chip breaking measures are not taken. Banded chips are continuous and often wound on the workpiece or tool, which is not easy to remove. They can not only scratch the surface of the workpiece and damage the tool, but also easily hurt people. Therefore, except in special cases, banded chips should be avoided as far as possible

2.2c chip. When turning general carbon steel and alloy steel workpieces, if the turning tool with chip curling groove is used, it is easy to form C-shaped chips. C-shaped chips will not be entangled on the workpiece or cutter, which is generally not easy to hurt people

2.3 chipping when turning brittle materials such as cast iron and brittle brass, it is easy to form chipping, which will break into fragments or fly out in needle shape, which is very easy to hurt people, and it is easy to cause grinding damage to the surface of machine tool guide rail. Therefore, it is very important to take measures to change the broken chips into spiral chips to ensure the safety of workers

2.4 the cutting process of long spiral curls and long tight curls when these two kinds of chips appear is relatively stable, not easy to wrap around the workpiece and tool, and easy to remove, so it is an ideal chip for turning. However, the range of cutting parameters that produce long and tight curls is narrow and difficult to control

2 focus on solving the problem of materials 5 pagoda shaped chip for automatic lathes, belt shaped chip and spiral chip will wrap around the workpiece or tool, affecting normal cutting, while C-shaped chip may be embedded in the sliding surface of the machine tool and wear the machine tool. Therefore, the most ideal chip on automatic lathes is pagoda shaped chip

different chip shapes have different effects on the safety of operators, and the most detrimental to safe operation are chipped chips and banded chips. We can change the shape of chipped chips and banded chips by selecting appropriate cutting parameters, tool geometric angle and lubrication conditions, so as to reduce the damage of chips to people

3 the reason why chips hurt people

3.1 the operator does not wear appropriate fixtures is the combination of these structures. The structures of these fixtures have their own advantages and disadvantages. Protective clothing and protective appliances (such as wearing too loose clothes, operating with gloves, not wearing goggles, etc.) are not small enough to be caught by chips and twisted into the rotating parts during operation, or chips damage the exposed parts of the operator (such as eyes, etc.)

3.2 bruises, scratches or burns caused by thrown chipping or banded chips

3.3 during the operation of the lathe, injury accidents occur due to the removal of chips by hand

3.4 the lack of regular inspection and maintenance of the lathe led to the "failure" of the chip protection device; Or simply discard the protective device. In this way, chips are easy to hurt people

3.5 the layout lighting of the lathe is insufficient or there are dazzling lights, which is not conducive to the operator to observe the chip condition

3.6 unreasonable layout around the lathe, poor sanitary conditions, improper stacking of chips, hinder the normal activities of operators, resulting in slipping and injury

4 prevention of chip injury

4.1 the operator should take preventive measures. In order to prevent cutting chips from hurting people, the operator should make regular inspection of the lathe, and must abide by the turning safety operation regulations during operation. In order to ensure that the chips in the turning process do not hurt people, the operator should especially do:

(1) wear tight protective clothing, do not open the cuffs, do not open the neckline, and wear protective hats or cut short hair for long hair; Do not operate with gloves. In order to prevent crushing and cutting from hurting eyes, operators should also wear goggles

(2) when the lathe is running, it is forbidden to remove or install the guard board or other chip protective devices; Do not remove the chips by hand, but use the special tools of hook and brush to remove the chips

(3) before starting the lathe, carefully check whether the chip protection device is safe, and the competitiveness of the market will be further improved and reliable. Whether it needs to be repaired or reconfigured, otherwise it is not allowed to operate

(4) when compressed air must be used to remove chips, or when chips splash seriously, in order not to endanger other operators around, baffles should be installed around the lathe to isolate the operation area. The pressure of compressed air should be as low as possible, and compressed air should not be used to blow clothes or hair chips, so as not to cause damage to ears and eyes

4.2 measures to be considered in installing and arranging the lathe

prevention of chip damage. The layout of the lathe should be convenient for processing observation and avoid the damage of chips to people, so the following factors should be considered:

(1) the layout of the lathe should ensure that chips are not thrown out to hurt people. The second arrangement in the table shall be adopted

(2) the orientation of the lathe position should be conducive to daylighting, and the operator should not be exposed to direct sunlight, so as to avoid dazzle. Although the layout in Figure 1 (a) is conducive to daylighting, the operators are exposed to direct sunlight, which is not conducive to safe production. Therefore, the layout in Figure 1 (b) should be adopted

(3) there should be a proper distance between machine tools and between machine tools and walls to ensure that workers are not disturbed by chips during safe operation and walking. The spacing is determined by the size of the machine tool and the working conditions of the machine tool

(4) the stacking of cuttings shall be convenient for cleaning and shall not interfere with the work of the operator and adjacent machine tools. No chips shall be stacked on the passages in the workshop to avoid injury to pedestrians or accidents caused by inconvenient traffic

4.3 take chip breaking measures

when cutting high-speed alloy steel and nonferrous metals with high strength and high toughness, chip breaking often becomes a key problem affecting normal safety production. Corresponding chip breaking (rolling) measures must be taken to make the belt shaped chips that are easy to hurt people become other forms of chips that are not easy to hurt people. Banded chips often have sharp edges, which are most likely to damage the exposed parts of workers. At the same time, they will also wrap around the workpiece, turning tool, handle and other parts. When workers remove them, it is easy to cut their hands or heels. In order to eliminate the above hazards, the method of chip breaking is usually adopted, that is, the banded chip is broken into granular, semi annular, spiral, etc. The chip breaking measures are:

(1) grind the chip breaking groove or step on the turning tool

(2) chip breaker is used

(3) adopt mechanical clamping without regrinding cemented carbide blades

generally speaking, as long as measures are taken to increase the plastic deformation of cutting area and chips, it is conducive to chip breaking. However, when cutting, we can't consider the problem from chip breaking alone. For example, small rake angle and low cutting speed are conducive to chip breaking, but the cutting is laborious and the cutting efficiency is low. Therefore, increasing chip deformation to promote chip breaking can only be used as an auxiliary means of chip breaking. Therefore, from the perspective of ensuring high-efficiency cutting and conducive to chip breaking, a reasonable chip breaking (curling) groove (table) should be grinded in front of the tool or a chip breaking (curling) device should be used

4.4 measures to prevent chippings from damaging

(1) in order to prevent chippings from damaging the operator's eyes, face, hands and other parts, the operator should wear protective glasses and cover the workpiece with a protective cover (baffle). The glass of the protective cover (baffle) cannot be ordinary glass, because it is easy to be broken by accidental strike, and the fragments are enough to hurt people, so toughened glass or transparent plastic should be used. The display resolution of hexagonal lathe for cutting brittle metal or comprehensive processing: 0.01 n, and comprehensive protective cover is required

(2) wash the chips with air flow or emulsion and change the direction of chip injection. Use a conical nozzle to spray compressed air with 3 ~ 4 atmospheric pressures into the cutting area to blow the chips in a safe direction. This method is mainly used in turning and low-speed turning of precision parts such as clocks and watches, and has a good effect on changing the direction of slight debris. However, it is easy to dirty the working area when washing with emulsified oil

(3) change chipped chips into chips of other shapes