Chapter 4 Fill in the blanks by metal cutting

Fill in the blanks

1, lathes can be roughly divided into horizontal lathes, vertical lathes, turret lathes, copying lathes, multi-tool lathes, automatic lathes, etc.

2. The lathe consists of spindle box, feed box, slide box, tool rest, endnote and lathe bed.

3. The carriage includes four parts: saddle, middle skateboard, turntable and small skateboard.

4. The lead screw is mainly used for turning threads.

5. Compared with horizontal lathe, turret lathe has no tailstock and screw.

6. All kinds of parts processed on the lathe have a common feature-having a revolving surface.

7. The turning accuracy is generally between 1t 12 and 1t7.

8. There are always chuck, panel, top, center frame, heel holder and other accessories on the lathe.

9. There are two kinds of chucks: three-jaw self-centering chuck and four-jaw single-acting chuck.

10, milling machine types are vertical milling machine, horizontal milling machine, copying milling machine, tool milling machine and gantry milling machine.

Models 1 1 and X6 132 represent horizontal universal lifting table milling machines with a workbench width of 320mm.

12. The gantry milling machine is mainly used for milling planes, inclined planes and grooves of large and medium-sized workpieces.

13, the accessories of milling machine mainly include flat vice, turntable, Universal dividing head, vertical milling head, etc.

14, the main types of drilling machines are table drilling machine, vertical drilling machine, radial drilling machine and center hole drilling machine.

15, vertical drilling machine processing aperture is generally less than 50 mm ..

16, the outer column, rocker arm and spindle of the radial drilling machine have locking mechanisms.

17. Boring machines include horizontal boring machines, coordinate boring machines, fine boring machines, floor boring machines, vertical boring machines and deep hole boring machines.

18, grinder types: general grinder, precision grinder and special grinder.

19. Ordinary grinders include cylindrical grinder, surface grinder, internal grinder and tool grinder.

20. The feeding movement of the internal grinding tool is realized by the movement of the grinding wheel rack or workbench.

2 1, grinding has not only cutting function, but also scoring and polishing function.

22. Planers include shapers, gantry planers, cantilever planers and slotting machines.

23. The shaper consists of a lathe bed, a ram, a tool rest and a workbench.

24. Planer (or workpiece) is mainly reciprocating linear motion, and the intermittent motion of workpiece (or planer) is feed motion.

25. The technological characteristics of planing are low processing cost, intermittent cutting, large instantaneous inertia, large return time loss and low efficiency.

26. The planing accuracy is IT 10~IT7.

The fifth chapter answers

Fill in the blanks

1, positioning and clamping is called installation.

2. Machine tool fixture can be divided into general fixture, special fixture, adjustable fixture, combined fixture and automatic line fixture according to its general characteristics.

3. The machine tool fixture consists of positioning elements and positioning devices, clamping devices, clamping bodies, tool setting elements and guiding elements, and other elements and devices.

4. Positioning elements include support nails, support plates, V-shaped blocks and positioning pins.

5. The clamping device includes a clamping element, a booster transmission device and a power device.

6. The uncertainty of workpiece position is called degree of freedom.

7. Six reasonably distributed support points define six degrees of freedom of the workpiece, which is the six-point positioning principle.

8. The three degrees of freedom of workpiece limitation are called the main positioning datum.

9. The limit of two degrees of freedom of the workpiece is called the guiding positioning datum.

10, the workpiece is limited by a degree of freedom, which is called positioning datum.

1 1. Positioning with limited degrees of freedom is called incomplete positioning.

12, and the number of degrees of freedom that cannot be limited is called underpositioning.

13, the same degree of freedom is repeatedly restricted, which is called over-positioning.

14. According to the relationship between finite degrees of freedom and machining requirements, degrees of freedom can be divided into related degrees of freedom and unrelated degrees of freedom.

15, the choice of positioning mode and positioning element depends on the processing requirements of the workpiece, the positioning datum of the workpiece and the action of external force.

16, the common positioning elements of rough datum are fixed support nails and adjustable support nails.

17. There are three types of fixed support nails: flat head, ball head and tooth shape.

18, the common positioning elements for precision datum positioning are flat-headed support nails and support plates.

19, floating bearings are often used to locate rough datum, discontinuous surface and step surface.

20. Positioning pins can be divided into fixed type and replaceable type.

2 1. Most fixed locating pins are directly pressed into the clamp body through interference fit.

22. The outer cylindrical surface of the workpiece can be used as a positioning datum, and positioning elements such as V-shaped blocks, semi-circular sleeves and positioning sleeves can be used.

23.v-block can be divided into movable type and fixed type.

24. Special positioning methods include inner and outer conical surface positioning workpiece, V-shaped guide surface positioning workpiece, dovetail guide surface positioning workpiece and toothed surface positioning workpiece.

25. The clamping device consists of power source, intermediate transmission mechanism and clamping element.

26. The intermediate transmission mechanism and the clamping element are collectively referred to as the clamping mechanism.

27. The commonly used clamping mechanisms are wedge clamping mechanism, eccentric clamping mechanism, screw clamping mechanism and hinge clamping mechanism.

28. There are generally two kinds of eccentric members: circular eccentricity and curve eccentricity.

29. Circular eccentric eccentric components are generally used in situations with small cutting force, small vibration and no centrifugal force.

30. The main disadvantages of single screw clamping mechanism are slow clamping action and time-consuming workpiece loading and unloading.

3 1. The typical structures of common spiral platen mechanisms are moving platen and turntable.

Second, the concept problem.

1, a, when cutting the workpiece on the machine tool, in order to ensure the machining accuracy, it is necessary to make the workpiece occupy the correct position relative to the machine tool and the tool. This process is called positioning.

2, a, in order to maintain the correct position stability in the process of machining, the clamping force applied to the workpiece.

3. Answer: According to the processing requirements of a certain process of the workpiece, it is a special fixture assembled from a set of standard parts manufactured in advance.

4. A: Uncertainty of workpiece position.

5. Answer: Use six reasonably distributed support points to limit the six degrees of freedom of the workpiece.

6. Answer and refer to the cleaned surface of casting and forging blank.

7. Answer: The plane of the workpiece after cutting.

8. Answer: In the process of workpiece positioning, the position of the support can automatically adapt to the position of the workpiece positioning benchmark.

9. Answer: The fixture does not limit the support of the degree of freedom of the workpiece.

10. Answer and clamp the workpiece manually.

1 1, answer, replace manual clamping with pneumatic, hydraulic and electric devices.

12. There should be a mediation mechanism between the power source and the clamping element.

13, a, intermediate force transmission mechanism and clamping element.

14. Answer: The wedge is used as the clamping mechanism of the force transmission element or clamping element.

15, the answer refers to the clamping mechanism that directly or indirectly clamps the workpiece with eccentric elements.

16, the answer refers to the clamping mechanism that directly clamps the workpiece with spiral elements or combines with other elements.

17, the answer is that it refers to the clamping mechanism with the hinged connecting rod as the intermediate force transmission element.

Third, short answer questions

1, answer, positioning means that when cutting a workpiece on a machine tool, in order to ensure the machining accuracy, the workpiece must occupy the correct position relative to the machine tool and tool. Clamping means that a certain clamping force must be applied to the workpiece in order to keep the correct position stable during machining. Positioning limits the degree of freedom of the workpiece, and positioning does not necessarily clamp.

2. Answering and fixing the supporting nails used for positioning larger workpieces in coarse datum positioning; Adjustable support nails are used for workpieces with low blank quality, and are positioned with coarse datum planes; Replaceable support nails are mainly used for mass production; Using flat-headed support nails under the condition of small workpiece contact surface allows over-positioning, which improves the installation rigidity and stability; When the pallet is used for horizontal arrangement, the positioning of small and medium-sized parts can be directly based on the relevant plane on the fixture body, and sometimes the pallet with non-standard structure can be used for positioning.

3. Answer, power source, intermediate transmission mechanism and clamping element.

4, answer, clamping should be reliable and appropriate, clamping device should be safe, convenient and labor-saving, fixture structure should be as simple as possible, the degree of automation should be adapted to batch and production conditions, and has good self-locking performance.

5. Answer: The direction of clamping force should be followed: it is helpful for accurate and stable positioning, reducing clamping force and making the workpiece rigid. The action points of clamping force should follow: the number of action points should be appropriate, the action points should fall within the range of positioning support points, the action points should be selected in the parts with good rigidity of the workpiece, and the action points should be as close as possible to the machining surface.

6. Answer: The inclined wedge clamping mechanism refers to the clamping mechanism that takes the inclined wedge as a force transmission element or a clamping element and clamps the workpiece by using the pressure generated by its inclined plane movement. This mechanism has the advantages of small clamping force, short stroke and time-consuming operation, and is rarely used in actual production. The circular eccentric clamping mechanism has the advantages of simple structure, easy manufacture, convenient operation and wide application, but the clamping force and stroke are small and the self-locking performance is poor. Generally used in situations with small cutting force, small vibration and no centrifugal force. The invention has the characteristics of simple structure, large stroke, large force augmentation and good self-locking. Many components have been standardized and are very suitable for manual clamping. The main disadvantages of single screw clamping mechanism are slow clamping action and time-consuming workpiece loading and unloading.