1. What types of coordinate boring machines can be classified according to structural features? Brief description of its processing content and accuracy range.
A: The coordinate boring machine can be divided into vertical and horizontal types according to the structural features of the frame. Vertical coordinate boring machine is divided into single column type and double column type; horizontal type coordinate boring machine is divided into vertical bed type and horizontal bed type.
The coordinate boring machine is mainly used to bore high-precision holes and holes with precise coordinates. High-precision milling can be performed. It is also used to draw lines and reticle on templates and precision parts, and to measure precision parts.
Coordinated boring machine hole machining coordinates positioning accuracy of 0.004 ~ 0.01mm, surface roughness of the processing surface is less than Ra0.8μm.
2. What are the common positioning system devices for coordinate boring machines? What are the basic components of these devices?
A: The common positioning systems for coordinate boring machines include mechanical, optical, electromagnetic, photoelectric, and laser types.
The various devices of the positioning system generally consist of the following components:
(1) Test reference element.
(2) Photoelectric signal transmission device.
(3) Reading device.
3, precision line ruler and screen reader positioning principle and characteristics
A: The positioning principle of the precision line ruler and screen reader is: the precision line ruler is fixed on the workbench and serves as the length reference for the sliding plate and the table to move, through a series of optical system devices, the line of the ruler line The inter-grain distance is enlarged and imaged on the screen. When the table is moved, the engraved line on the enlarging line scale is also moved in the screen so that the reticle in the screen can be accurately measured. The distance the station moves.
The main features of the screen reader positioning is high positioning accuracy, and the positioning system is non-contact, it will not be affected by mechanical wear, and can maintain high positioning accuracy for a long time.
4. Briefly describe the positioning principle of the induction synchronizer positioning system
A: The induction synchronizer uses the principle of electromagnetic induction. That is, when the relative positions of two conductors change, their induced electromotive force changes. The scale in the inductive synchronizer positioning device is fixed on the bed, and the slide rule is fixed on the table or the slide plate. The coils on the scale are connected in a row. The coils of the slider are divided into two sections at the center and are offset by 1/4 pitch. When moving a table or a skateboard, there will be a varying induced electromotive force on the scale. Through the electronic detection device, the magnetic signal is converted into an electrical signal, and a series of electronic technology processing such as amplification, shaping, and counting is performed on the changed electrical signal, and then it can be converted into a positioning coordinate value and displayed on the digital display device.
5. Describe the process features of boring holes on a coordinate boring machine. What effect do these process features have on the selection of the main geometric parameters of the file?
A: Coordinated boring machine processing is mainly based on boring precision holes. The dimensional precision, geometric shape accuracy and position accuracy of the holes are all required to be high, and the surface roughness of the machined surface is also required to be fine. Therefore, the machining allowance and the depth of each cutting are smaller and the number of feeds is greater. Due to the above process features, the rake angle and the relief angle of the boring tool should be appropriately increased. The main declination angle should be 90°, the declination angle should be 4°~8°, and the trimming edge should be worn out; the tip radius should be properly repaired. arc. The blade angle is generally positive.
What are the special tools for coordinate boring machines? What is its main function?
A: The special tools for coordinate boring machines can be divided into three categories according to their functions.
(1) As a positioning and alignment tool, it includes a dial gauge centering device, a spindle positioner, a ball centering rod, an optical positioner, a positioning tip, and a spring center punch.
(2) Tool for clamping tool It includes universal boring tool holder, adjustable boring bar, drill chuck, spring chuck and other clamping tools.
(3) Scribing tool It includes a scribing tip and a planer, a scribing knife, and a holding tool.
7. How to use an optical positioner?
Answer: After the optical positioner is installed, the angle iron is placed on the datum plane, and the two sides of the angle iron should be closely combined with the datum plane on the workpiece. Adjust the position of the table so that the reference reticle in the alignment angle coincides with the reticle in the optical positioner, and then adjust the position of the reticle on the screen reader so that the image enters a double reticle. With the combination of the coarse scale and light screen readings, the workpiece can be adjusted to the machining position with precise dimensions from the reference, according to the pattern requirements.
8. When processing parts on a coordinate boring machine, in order to reduce the processing error caused by thermal deformation of the process system, what should be noted?
Answer: The following points should be noted:
(1) The working environment of the coordinate boring machine should have a constant temperature and the temperature should be controlled within 20±1°C.
(2) The workpiece to be machined shall be placed in a constant temperature room in advance before processing. The time shall not be less than 8 hours to ensure that there is no temperature difference between the workpiece and the machine tool.
(3) Before the machine tool is working, it should be idle running, and it should be processed after reaching or approaching thermal equilibrium. During the non-cutting time, the machine tool is still idle to maintain the thermal balance of the machine.
(4) Roughing, semi-finishing and finishing processes should be strictly separated, and the time interval between each process should not be less than 8 h.
(5) Strictly control the amount of cutting, the depth of cut is generally not more than 0.5~1mm, and the amount of feed does not exceed 0.05~0.07mm/r.
(6) The crowds around the machine are not allowed to look around. The machine lighting arrangement should be reasonable so as not to affect the machine's ambient temperature.
9. Accuracy ranges that can be achieved in the milling process of precision planes on the coordinate key bed, and matters needing attention when milling
A: The plane after precision milling on the coordinate boring machine, the surface roughness value can be less than Ra0.8μm, the flatness error is between 0.004~0.012mm, and the position accuracy can reach 0.01mm.
Milling should pay attention to the following points:
(1) Milling allowance can not be too large, generally 1~3mm.
(2) The cutter must be sharp and the clamps should be secure. The contact area between the cutter shaft and the taper hole mating surface of the boring machine spindle should not be less than 80%.
(3) When milling, the main shaft sleeve and the main shaft box must be locked, which does not allow a slight amount of displacement during the milling process.
(4) The workpiece clamping should be reasonable so as not to cause large clamping deformation.
(5) The use of a precision screw as the coordinate boring machine for the positioning measurement system should not be used for milling to avoid excessive uneven wear of the screw.
10. What are the main factors affecting the accuracy of the hole pitch in the machining of the coordinate boring machine? What can be done to solve it?
A: There are the following main factors and solutions
(1) Positioning error is too large. The solution is to reasonably select the positioning method and improve the accuracy of the workpiece positioning reference plane and the fixture positioning element.
(2) The accuracy of the precision screw positioning device is low, and the correction plate wears or shifts. The solution is to improve the positioning accuracy, correct the correction plate again, and add the positioning pins so that they do not shift.
(3) The shift of the front and rear lens groups of the optical positioning system affects the magnification of the machine's optical system. The solution is to readjust the focal length of the objective lens and adjust the magnification.
(4) The geometric accuracy of the machine tool does not meet the requirements, and the straightness error of the guide rail exceeds the accuracy index of the machine tool. The solution is to repair the machine and recalibrate the straightness of the guide.
(5) The machine rigidity is poor. The solution is to place the workpiece in the middle of the workbench as much as possible. The cutter bar and spindle should not be extended too long and the cutting amount should be reasonably selected.
(6) Thermal deformation of the process system. The solution is to take a constant temperature and strictly control the temperature difference. The machine must be idle before processing, and it will be processed after reaching thermal equilibrium.
A: The coordinate boring machine can be divided into vertical and horizontal types according to the structural features of the frame. Vertical coordinate boring machine is divided into single column type and double column type; horizontal type coordinate boring machine is divided into vertical bed type and horizontal bed type.
The coordinate boring machine is mainly used to bore high-precision holes and holes with precise coordinates. High-precision milling can be performed. It is also used to draw lines and reticle on templates and precision parts, and to measure precision parts.
Coordinated boring machine hole machining coordinates positioning accuracy of 0.004 ~ 0.01mm, surface roughness of the processing surface is less than Ra0.8μm.
2. What are the common positioning system devices for coordinate boring machines? What are the basic components of these devices?
A: The common positioning systems for coordinate boring machines include mechanical, optical, electromagnetic, photoelectric, and laser types.
The various devices of the positioning system generally consist of the following components:
(1) Test reference element.
(2) Photoelectric signal transmission device.
(3) Reading device.
3, precision line ruler and screen reader positioning principle and characteristics
A: The positioning principle of the precision line ruler and screen reader is: the precision line ruler is fixed on the workbench and serves as the length reference for the sliding plate and the table to move, through a series of optical system devices, the line of the ruler line The inter-grain distance is enlarged and imaged on the screen. When the table is moved, the engraved line on the enlarging line scale is also moved in the screen so that the reticle in the screen can be accurately measured. The distance the station moves.
The main features of the screen reader positioning is high positioning accuracy, and the positioning system is non-contact, it will not be affected by mechanical wear, and can maintain high positioning accuracy for a long time.
4. Briefly describe the positioning principle of the induction synchronizer positioning system
A: The induction synchronizer uses the principle of electromagnetic induction. That is, when the relative positions of two conductors change, their induced electromotive force changes. The scale in the inductive synchronizer positioning device is fixed on the bed, and the slide rule is fixed on the table or the slide plate. The coils on the scale are connected in a row. The coils of the slider are divided into two sections at the center and are offset by 1/4 pitch. When moving a table or a skateboard, there will be a varying induced electromotive force on the scale. Through the electronic detection device, the magnetic signal is converted into an electrical signal, and a series of electronic technology processing such as amplification, shaping, and counting is performed on the changed electrical signal, and then it can be converted into a positioning coordinate value and displayed on the digital display device.
5. Describe the process features of boring holes on a coordinate boring machine. What effect do these process features have on the selection of the main geometric parameters of the file?
A: Coordinated boring machine processing is mainly based on boring precision holes. The dimensional precision, geometric shape accuracy and position accuracy of the holes are all required to be high, and the surface roughness of the machined surface is also required to be fine. Therefore, the machining allowance and the depth of each cutting are smaller and the number of feeds is greater. Due to the above process features, the rake angle and the relief angle of the boring tool should be appropriately increased. The main declination angle should be 90°, the declination angle should be 4°~8°, and the trimming edge should be worn out; the tip radius should be properly repaired. arc. The blade angle is generally positive.
What are the special tools for coordinate boring machines? What is its main function?
A: The special tools for coordinate boring machines can be divided into three categories according to their functions.
(1) As a positioning and alignment tool, it includes a dial gauge centering device, a spindle positioner, a ball centering rod, an optical positioner, a positioning tip, and a spring center punch.
(2) Tool for clamping tool It includes universal boring tool holder, adjustable boring bar, drill chuck, spring chuck and other clamping tools.
(3) Scribing tool It includes a scribing tip and a planer, a scribing knife, and a holding tool.
7. How to use an optical positioner?
Answer: After the optical positioner is installed, the angle iron is placed on the datum plane, and the two sides of the angle iron should be closely combined with the datum plane on the workpiece. Adjust the position of the table so that the reference reticle in the alignment angle coincides with the reticle in the optical positioner, and then adjust the position of the reticle on the screen reader so that the image enters a double reticle. With the combination of the coarse scale and light screen readings, the workpiece can be adjusted to the machining position with precise dimensions from the reference, according to the pattern requirements.
8. When processing parts on a coordinate boring machine, in order to reduce the processing error caused by thermal deformation of the process system, what should be noted?
Answer: The following points should be noted:
(1) The working environment of the coordinate boring machine should have a constant temperature and the temperature should be controlled within 20±1°C.
(2) The workpiece to be machined shall be placed in a constant temperature room in advance before processing. The time shall not be less than 8 hours to ensure that there is no temperature difference between the workpiece and the machine tool.
(3) Before the machine tool is working, it should be idle running, and it should be processed after reaching or approaching thermal equilibrium. During the non-cutting time, the machine tool is still idle to maintain the thermal balance of the machine.
(4) Roughing, semi-finishing and finishing processes should be strictly separated, and the time interval between each process should not be less than 8 h.
(5) Strictly control the amount of cutting, the depth of cut is generally not more than 0.5~1mm, and the amount of feed does not exceed 0.05~0.07mm/r.
(6) The crowds around the machine are not allowed to look around. The machine lighting arrangement should be reasonable so as not to affect the machine's ambient temperature.
9. Accuracy ranges that can be achieved in the milling process of precision planes on the coordinate key bed, and matters needing attention when milling
A: The plane after precision milling on the coordinate boring machine, the surface roughness value can be less than Ra0.8μm, the flatness error is between 0.004~0.012mm, and the position accuracy can reach 0.01mm.
Milling should pay attention to the following points:
(1) Milling allowance can not be too large, generally 1~3mm.
(2) The cutter must be sharp and the clamps should be secure. The contact area between the cutter shaft and the taper hole mating surface of the boring machine spindle should not be less than 80%.
(3) When milling, the main shaft sleeve and the main shaft box must be locked, which does not allow a slight amount of displacement during the milling process.
(4) The workpiece clamping should be reasonable so as not to cause large clamping deformation.
(5) The use of a precision screw as the coordinate boring machine for the positioning measurement system should not be used for milling to avoid excessive uneven wear of the screw.
10. What are the main factors affecting the accuracy of the hole pitch in the machining of the coordinate boring machine? What can be done to solve it?
A: There are the following main factors and solutions
(1) Positioning error is too large. The solution is to reasonably select the positioning method and improve the accuracy of the workpiece positioning reference plane and the fixture positioning element.
(2) The accuracy of the precision screw positioning device is low, and the correction plate wears or shifts. The solution is to improve the positioning accuracy, correct the correction plate again, and add the positioning pins so that they do not shift.
(3) The shift of the front and rear lens groups of the optical positioning system affects the magnification of the machine's optical system. The solution is to readjust the focal length of the objective lens and adjust the magnification.
(4) The geometric accuracy of the machine tool does not meet the requirements, and the straightness error of the guide rail exceeds the accuracy index of the machine tool. The solution is to repair the machine and recalibrate the straightness of the guide.
(5) The machine rigidity is poor. The solution is to place the workpiece in the middle of the workbench as much as possible. The cutter bar and spindle should not be extended too long and the cutting amount should be reasonably selected.
(6) Thermal deformation of the process system. The solution is to take a constant temperature and strictly control the temperature difference. The machine must be idle before processing, and it will be processed after reaching thermal equilibrium.
The conical twin screw is different from the parallel twin screw in appearance. Its two ends have different diameters. The diameter of the feeding section is large, while the diameter of the homogenization section is small, and the middle is gradually transitioned. The conical twin-screw is a meshing type, and most of them are counter-rotating.
Conical Twin Screw Barrel,Barrel Screw Extruder,Extruder Screws And Barrels,Injection Screw And Barrel
Zhejiang Jinteng Machinery Manufacture Co., Ltd. , https://www.jintengmachine.com