In-depth Analysis and Optimization of Machining Location Datum and Fixtures in Machining Centers
Abstract: This paper elaborates in detail on the requirements and principles of the machining location datum in machining centers, as well as relevant knowledge about fixtures, including the basic requirements, common types, and selection principles of fixtures. It thoroughly explores the importance and interrelationships of these factors in the machining process of machining centers, aiming to provide comprehensive and in-depth theoretical basis and practical guidance for professionals and relevant practitioners in the field of mechanical machining, so as to achieve the optimization and improvement of machining accuracy, efficiency, and quality.
I. Introduction
Machining centers, as a kind of high-precision and high-efficiency automated machining equipment, occupy an extremely important position in the modern mechanical manufacturing industry. The machining process involves numerous complex links, and the selection of the machining location datum and the determination of fixtures are among the key elements. A reasonable location datum can ensure the accurate position of the workpiece during the machining process, providing an exact starting point for subsequent cutting operations; an appropriate fixture can stably hold the workpiece, ensuring the smooth progress of the machining process and, to a certain extent, affecting the machining accuracy and production efficiency. Therefore, in-depth research on the machining location datum and fixtures in machining centers is of great theoretical and practical significance.
Machining centers, as a kind of high-precision and high-efficiency automated machining equipment, occupy an extremely important position in the modern mechanical manufacturing industry. The machining process involves numerous complex links, and the selection of the machining location datum and the determination of fixtures are among the key elements. A reasonable location datum can ensure the accurate position of the workpiece during the machining process, providing an exact starting point for subsequent cutting operations; an appropriate fixture can stably hold the workpiece, ensuring the smooth progress of the machining process and, to a certain extent, affecting the machining accuracy and production efficiency. Therefore, in-depth research on the machining location datum and fixtures in machining centers is of great theoretical and practical significance.
II. Requirements and Principles for Selecting Datum in Machining Centers
(A) Three Basic Requirements for Selecting Datum
1. Accurate Location and Convenient, Reliable Fixturing
Accurate location is the primary condition for ensuring machining accuracy. The datum surface should have sufficient accuracy and stability to accurately determine the position of the workpiece in the coordinate system of the machining center. For example, when milling a plane, if there is a large flatness error on the location datum surface, it will cause a deviation between the machined plane and the design requirements.
Convenient and reliable fixturing is related to the efficiency and safety of machining. The way of fixturing the fixture and the workpiece should be simple and easy to operate, enabling the workpiece to be quickly installed on the worktable of the machining center and ensuring that the workpiece will not shift or become loose during the machining process. For example, by applying an appropriate clamping force and selecting appropriate clamping points, deformation of the workpiece due to excessive clamping force can be avoided, and movement of the workpiece during machining due to insufficient clamping force can also be prevented.
Accurate location is the primary condition for ensuring machining accuracy. The datum surface should have sufficient accuracy and stability to accurately determine the position of the workpiece in the coordinate system of the machining center. For example, when milling a plane, if there is a large flatness error on the location datum surface, it will cause a deviation between the machined plane and the design requirements.
Convenient and reliable fixturing is related to the efficiency and safety of machining. The way of fixturing the fixture and the workpiece should be simple and easy to operate, enabling the workpiece to be quickly installed on the worktable of the machining center and ensuring that the workpiece will not shift or become loose during the machining process. For example, by applying an appropriate clamping force and selecting appropriate clamping points, deformation of the workpiece due to excessive clamping force can be avoided, and movement of the workpiece during machining due to insufficient clamping force can also be prevented.
2. Simple Dimension Calculation
When calculating the dimensions of various machining parts based on a certain datum, the calculation process should be made as simple as possible. This can reduce calculation errors during programming and machining, thereby improving machining efficiency. For example, when machining a part with multiple hole systems, if the selected datum can make the calculation of the coordinate dimensions of each hole straightforward, it can reduce the complex calculations in numerical control programming and lower the probability of errors.
When calculating the dimensions of various machining parts based on a certain datum, the calculation process should be made as simple as possible. This can reduce calculation errors during programming and machining, thereby improving machining efficiency. For example, when machining a part with multiple hole systems, if the selected datum can make the calculation of the coordinate dimensions of each hole straightforward, it can reduce the complex calculations in numerical control programming and lower the probability of errors.
3. Ensuring Machining Accuracy
Machining accuracy is an important indicator for measuring machining quality, including dimensional accuracy, shape accuracy, and positional accuracy. The selection of the datum should be able to effectively control machining errors so that the machined workpiece meets the requirements of the design drawing. For example, when turning shaft-like parts, selecting the center line of the shaft as the location datum can better ensure the cylindricity of the shaft and the coaxiality between different shaft sections.
Machining accuracy is an important indicator for measuring machining quality, including dimensional accuracy, shape accuracy, and positional accuracy. The selection of the datum should be able to effectively control machining errors so that the machined workpiece meets the requirements of the design drawing. For example, when turning shaft-like parts, selecting the center line of the shaft as the location datum can better ensure the cylindricity of the shaft and the coaxiality between different shaft sections.
(B) Six Principles for Selecting Location Datum
1. Try to Select the Design Datum as the Location Datum
The design datum is the starting point for determining other dimensions and shapes when designing a part. Selecting the design datum as the location datum can directly ensure the accuracy requirements of the design dimensions and reduce the datum misalignment error. For example, when machining a box-shaped part, if the design datum is the bottom surface and two side surfaces of the box, then using these surfaces as the location datum during the machining process can conveniently ensure that the positional accuracy between the hole systems in the box is consistent with the design requirements.
The design datum is the starting point for determining other dimensions and shapes when designing a part. Selecting the design datum as the location datum can directly ensure the accuracy requirements of the design dimensions and reduce the datum misalignment error. For example, when machining a box-shaped part, if the design datum is the bottom surface and two side surfaces of the box, then using these surfaces as the location datum during the machining process can conveniently ensure that the positional accuracy between the hole systems in the box is consistent with the design requirements.
2. When the Location Datum and the Design Datum Cannot Be Unified, the Location Error Should Be Strictly Controlled to Ensure Machining Accuracy
When it is impossible to adopt the design datum as the location datum due to the structure of the workpiece or the machining process, etc., it is necessary to accurately analyze and control the location error. The location error includes the datum misalignment error and the datum displacement error. For example, when machining a part with a complex shape, it may be necessary to first machine an auxiliary datum surface. At this time, it is necessary to control the location error within the allowable range through reasonable fixture design and location methods to ensure machining accuracy. Methods such as improving the accuracy of location elements and optimizing the location layout can be used to reduce the location error.
When it is impossible to adopt the design datum as the location datum due to the structure of the workpiece or the machining process, etc., it is necessary to accurately analyze and control the location error. The location error includes the datum misalignment error and the datum displacement error. For example, when machining a part with a complex shape, it may be necessary to first machine an auxiliary datum surface. At this time, it is necessary to control the location error within the allowable range through reasonable fixture design and location methods to ensure machining accuracy. Methods such as improving the accuracy of location elements and optimizing the location layout can be used to reduce the location error.
3. When the Workpiece Needs to Be Fixtured and Machined More Than Twice, the Selected Datum Should Be Able to Complete the Machining of All Key Accuracy Parts in One Fixturing and Location
For workpieces that need to be fixtured multiple times, if the datum for each fixturing is inconsistent, cumulative errors will be introduced, affecting the overall accuracy of the workpiece. Therefore, a suitable datum should be selected to complete the machining of all key accuracy parts as much as possible in one fixturing. For example, when machining a part with multiple side surfaces and hole systems, a major plane and two holes can be used as the datum for one fixturing to complete the machining of most of the key holes and planes, and then the machining of other secondary parts can be carried out, which can reduce the accuracy loss caused by multiple fixturings.
For workpieces that need to be fixtured multiple times, if the datum for each fixturing is inconsistent, cumulative errors will be introduced, affecting the overall accuracy of the workpiece. Therefore, a suitable datum should be selected to complete the machining of all key accuracy parts as much as possible in one fixturing. For example, when machining a part with multiple side surfaces and hole systems, a major plane and two holes can be used as the datum for one fixturing to complete the machining of most of the key holes and planes, and then the machining of other secondary parts can be carried out, which can reduce the accuracy loss caused by multiple fixturings.
4. The Selected Datum Should Ensure the Completion of as Many Machining Contents as Possible
This can reduce the number of fixturings and improve machining efficiency. For example, when machining a rotating body part, selecting its outer cylindrical surface as the location datum can complete various machining operations such as outer circle turning, thread machining, and keyway milling in one fixturing, avoiding the time waste and accuracy reduction caused by multiple fixturings.
This can reduce the number of fixturings and improve machining efficiency. For example, when machining a rotating body part, selecting its outer cylindrical surface as the location datum can complete various machining operations such as outer circle turning, thread machining, and keyway milling in one fixturing, avoiding the time waste and accuracy reduction caused by multiple fixturings.
5. When Machining in Batches, the Location Datum of the Part Should Be as Consistent as Possible with the Tool Setting Datum for Establishing the Workpiece Coordinate System
In batch production, the establishment of the workpiece coordinate system is crucial for ensuring machining consistency. If the location datum is consistent with the tool setting datum, programming and tool setting operations can be simplified, and errors caused by datum conversion can be reduced. For example, when machining a batch of identical plate-like parts, the lower left corner of the part can be located at a fixed position on the worktable of the machine tool, and this point can be used as the tool setting datum to establish the workpiece coordinate system. In this way, when machining each part, only the same program and tool setting parameters need to be followed, improving the production efficiency and the stability of machining accuracy.
In batch production, the establishment of the workpiece coordinate system is crucial for ensuring machining consistency. If the location datum is consistent with the tool setting datum, programming and tool setting operations can be simplified, and errors caused by datum conversion can be reduced. For example, when machining a batch of identical plate-like parts, the lower left corner of the part can be located at a fixed position on the worktable of the machine tool, and this point can be used as the tool setting datum to establish the workpiece coordinate system. In this way, when machining each part, only the same program and tool setting parameters need to be followed, improving the production efficiency and the stability of machining accuracy.
6. When Multiple Fixturings Are Required, the Datum Should Be Consistent Before and After
Whether it is rough machining or finish machining, using a consistent datum during multiple fixturings can ensure the positional accuracy relationship between different machining stages. For example, when machining a large mold part, from rough machining to finish machining, always using the parting surface and locating holes of the mold as the datum can make the allowances between different machining operations uniform, avoiding the influence on the accuracy and surface quality of the mold caused by uneven machining allowances due to datum changes.
Whether it is rough machining or finish machining, using a consistent datum during multiple fixturings can ensure the positional accuracy relationship between different machining stages. For example, when machining a large mold part, from rough machining to finish machining, always using the parting surface and locating holes of the mold as the datum can make the allowances between different machining operations uniform, avoiding the influence on the accuracy and surface quality of the mold caused by uneven machining allowances due to datum changes.
III. Determination of Fixtures in Machining Centers
(A) Basic Requirements for Fixtures
1. The Clamping Mechanism Should Not Affect the Feed, and the Machining Area Should Be Open
When designing the clamping mechanism of a fixture, it should avoid interfering with the feed path of the cutting tool. For example, when milling with a vertical machining center, the clamping bolts, pressure plates, etc. of the fixture should not block the movement track of the milling cutter. At the same time, the machining area should be made as open as possible so that the cutting tool can smoothly approach the workpiece for cutting operations. For some workpieces with complex internal structures, such as parts with deep cavities or small holes, the design of the fixture should ensure that the cutting tool can reach the machining area, avoiding the situation where machining cannot be carried out due to the fixture blocking.
When designing the clamping mechanism of a fixture, it should avoid interfering with the feed path of the cutting tool. For example, when milling with a vertical machining center, the clamping bolts, pressure plates, etc. of the fixture should not block the movement track of the milling cutter. At the same time, the machining area should be made as open as possible so that the cutting tool can smoothly approach the workpiece for cutting operations. For some workpieces with complex internal structures, such as parts with deep cavities or small holes, the design of the fixture should ensure that the cutting tool can reach the machining area, avoiding the situation where machining cannot be carried out due to the fixture blocking.
2. The Fixture Should Be Able to Achieve Oriented Installation on the Machine Tool
The fixture should be able to accurately position and install on the worktable of the machining center to ensure the correct position of the workpiece relative to the coordinate axes of the machine tool. Usually, location keys, location pins and other location elements are used to cooperate with the T-shaped grooves or location holes on the worktable of the machine tool to achieve the oriented installation of the fixture. For example, when machining box-shaped parts with a horizontal machining center, the location key at the bottom of the fixture is used to cooperate with the T-shaped grooves on the worktable of the machine tool to determine the position of the fixture in the X-axis direction, and then other location elements are used to determine the positions in the Y-axis and Z-axis directions, thereby ensuring the correct installation of the workpiece on the machine tool.
The fixture should be able to accurately position and install on the worktable of the machining center to ensure the correct position of the workpiece relative to the coordinate axes of the machine tool. Usually, location keys, location pins and other location elements are used to cooperate with the T-shaped grooves or location holes on the worktable of the machine tool to achieve the oriented installation of the fixture. For example, when machining box-shaped parts with a horizontal machining center, the location key at the bottom of the fixture is used to cooperate with the T-shaped grooves on the worktable of the machine tool to determine the position of the fixture in the X-axis direction, and then other location elements are used to determine the positions in the Y-axis and Z-axis directions, thereby ensuring the correct installation of the workpiece on the machine tool.
3. The Rigidity and Stability of the Fixture Should Be Good
During the machining process, the fixture has to bear the actions of cutting forces, clamping forces and other forces. If the rigidity of the fixture is insufficient, it will deform under the action of these forces, resulting in a decrease in the machining accuracy of the workpiece. For example, when performing high-speed milling operations, the cutting force is relatively large. If the rigidity of the fixture is not enough, the workpiece will vibrate during the machining process, affecting the surface quality and dimensional accuracy of the machining. Therefore, the fixture should be made of materials with sufficient strength and stiffness, and its structure should be reasonably designed, such as adding stiffeners and adopting thick-wall structures, to improve its rigidity and stability.
During the machining process, the fixture has to bear the actions of cutting forces, clamping forces and other forces. If the rigidity of the fixture is insufficient, it will deform under the action of these forces, resulting in a decrease in the machining accuracy of the workpiece. For example, when performing high-speed milling operations, the cutting force is relatively large. If the rigidity of the fixture is not enough, the workpiece will vibrate during the machining process, affecting the surface quality and dimensional accuracy of the machining. Therefore, the fixture should be made of materials with sufficient strength and stiffness, and its structure should be reasonably designed, such as adding stiffeners and adopting thick-wall structures, to improve its rigidity and stability.
(B) Common Types of Fixtures
1. General Fixtures
General fixtures have wide applicability, such as vices, dividing heads, and chucks. Vices can be used to hold various small parts with regular shapes, such as cuboids and cylinders, and are often used in milling, drilling and other machining operations. Dividing heads can be used to perform indexing machining on workpieces. For example, when machining parts with equi-circumferential features, the dividing head can accurately control the rotation angle of the workpiece to achieve multi-station machining. Chucks are mainly used to hold rotating body parts. For example, in turning operations, three-jaw chucks can quickly clamp shaft-like parts and can automatically center, which is convenient for machining.
General fixtures have wide applicability, such as vices, dividing heads, and chucks. Vices can be used to hold various small parts with regular shapes, such as cuboids and cylinders, and are often used in milling, drilling and other machining operations. Dividing heads can be used to perform indexing machining on workpieces. For example, when machining parts with equi-circumferential features, the dividing head can accurately control the rotation angle of the workpiece to achieve multi-station machining. Chucks are mainly used to hold rotating body parts. For example, in turning operations, three-jaw chucks can quickly clamp shaft-like parts and can automatically center, which is convenient for machining.
2. Modular Fixtures
Modular fixtures are composed of a set of standardized and standardized general elements. These elements can be flexibly combined according to different workpiece shapes and machining requirements to quickly build a fixture suitable for a specific machining task. For example, when machining a part with an irregular shape, appropriate base plates, supporting members, location members, clamping members, etc. can be selected from the modular fixture element library and assembled into a fixture according to a certain layout. The advantages of modular fixtures are high flexibility and reusability, which can reduce the manufacturing cost and production cycle of fixtures, and are especially suitable for new product trials and small batch production.
Modular fixtures are composed of a set of standardized and standardized general elements. These elements can be flexibly combined according to different workpiece shapes and machining requirements to quickly build a fixture suitable for a specific machining task. For example, when machining a part with an irregular shape, appropriate base plates, supporting members, location members, clamping members, etc. can be selected from the modular fixture element library and assembled into a fixture according to a certain layout. The advantages of modular fixtures are high flexibility and reusability, which can reduce the manufacturing cost and production cycle of fixtures, and are especially suitable for new product trials and small batch production.
3. Special Fixtures
Special fixtures are designed and manufactured specifically for one or several similar machining tasks. They can be customized according to the specific shape, size and machining process requirements of the workpiece to maximize the guarantee of machining accuracy and efficiency. For example, in the machining of automobile engine blocks, due to the complex structure and high accuracy requirements of the blocks, special fixtures are usually designed to ensure the machining accuracy of various cylinder holes, planes and other parts. The disadvantages of special fixtures are high manufacturing cost and long design cycle, and they are generally suitable for large batch production.
Special fixtures are designed and manufactured specifically for one or several similar machining tasks. They can be customized according to the specific shape, size and machining process requirements of the workpiece to maximize the guarantee of machining accuracy and efficiency. For example, in the machining of automobile engine blocks, due to the complex structure and high accuracy requirements of the blocks, special fixtures are usually designed to ensure the machining accuracy of various cylinder holes, planes and other parts. The disadvantages of special fixtures are high manufacturing cost and long design cycle, and they are generally suitable for large batch production.
4. Adjustable Fixtures
Adjustable fixtures are a combination of modular fixtures and special fixtures. They not only have the flexibility of modular fixtures but also can ensure machining accuracy to a certain extent. Adjustable fixtures can adapt to the machining of different-sized or similarly-shaped workpieces by adjusting the positions of some elements or replacing certain parts. For example, when machining a series of shaft-like parts with different diameters, an adjustable fixture can be used. By adjusting the position and size of the clamping device, different-diameter shafts can be held, improving the universality and utilization rate of the fixture.
Adjustable fixtures are a combination of modular fixtures and special fixtures. They not only have the flexibility of modular fixtures but also can ensure machining accuracy to a certain extent. Adjustable fixtures can adapt to the machining of different-sized or similarly-shaped workpieces by adjusting the positions of some elements or replacing certain parts. For example, when machining a series of shaft-like parts with different diameters, an adjustable fixture can be used. By adjusting the position and size of the clamping device, different-diameter shafts can be held, improving the universality and utilization rate of the fixture.
5. Multi-station Fixtures
Multi-station fixtures can simultaneously hold multiple workpieces for machining. This type of fixture can complete the same or different machining operations on multiple workpieces in one fixturing and machining cycle, greatly improving machining efficiency. For example, when machining the drilling and tapping operations of small parts, a multi-station fixture can simultaneously hold multiple parts. In one working cycle, the drilling and tapping operations of each part are completed in turn, reducing the idle time of the machine tool and improving production efficiency.
Multi-station fixtures can simultaneously hold multiple workpieces for machining. This type of fixture can complete the same or different machining operations on multiple workpieces in one fixturing and machining cycle, greatly improving machining efficiency. For example, when machining the drilling and tapping operations of small parts, a multi-station fixture can simultaneously hold multiple parts. In one working cycle, the drilling and tapping operations of each part are completed in turn, reducing the idle time of the machine tool and improving production efficiency.
6. Group Fixtures
Group fixtures are specifically used to hold workpieces with similar shapes, similar sizes and the same or similar location, clamping and machining methods. They are based on the principle of group technology, grouping workpieces with similar characteristics into one group, designing a general fixture structure, and adapting to the machining of different workpieces in the group by adjusting or replacing some elements. For example, when machining a series of different-specification gear blanks, the group fixture can adjust the location and clamping elements according to the changes in the aperture, outer diameter, etc. of the gear blanks to achieve the holding and machining of different gear blanks, improving the adaptability and production efficiency of the fixture.
Group fixtures are specifically used to hold workpieces with similar shapes, similar sizes and the same or similar location, clamping and machining methods. They are based on the principle of group technology, grouping workpieces with similar characteristics into one group, designing a general fixture structure, and adapting to the machining of different workpieces in the group by adjusting or replacing some elements. For example, when machining a series of different-specification gear blanks, the group fixture can adjust the location and clamping elements according to the changes in the aperture, outer diameter, etc. of the gear blanks to achieve the holding and machining of different gear blanks, improving the adaptability and production efficiency of the fixture.
(C) Selection Principles of Fixtures in Machining Centers
1. Under the Premise of Ensuring Machining Accuracy and Production Efficiency, General Fixtures Should Be Preferred
General fixtures should be preferred due to their wide applicability and low cost when the machining accuracy and production efficiency can be satisfied. For example, for some simple single-piece or small batch machining tasks, using general fixtures such as vices can quickly complete the fixturing and machining of the workpiece without the need to design and manufacture complex fixtures.
General fixtures should be preferred due to their wide applicability and low cost when the machining accuracy and production efficiency can be satisfied. For example, for some simple single-piece or small batch machining tasks, using general fixtures such as vices can quickly complete the fixturing and machining of the workpiece without the need to design and manufacture complex fixtures.
2. When Machining in Batches, Simple Special Fixtures Can Be Considered
When machining in batches, in order to improve machining efficiency and ensure the consistency of machining accuracy, simple special fixtures can be considered. Although these fixtures are special, their structures are relatively simple and the manufacturing cost will not be too high. For example, when machining a specific-shaped part in batches, a special positioning plate and clamping device can be designed to quickly and accurately hold the workpiece, improving production efficiency and ensuring machining accuracy.
When machining in batches, in order to improve machining efficiency and ensure the consistency of machining accuracy, simple special fixtures can be considered. Although these fixtures are special, their structures are relatively simple and the manufacturing cost will not be too high. For example, when machining a specific-shaped part in batches, a special positioning plate and clamping device can be designed to quickly and accurately hold the workpiece, improving production efficiency and ensuring machining accuracy.
3. When Machining in Large Batches, Multi-station Fixtures and High-efficiency Pneumatic, Hydraulic and Other Special Fixtures Can Be Considered
In large batch production, production efficiency is a key factor. Multi-station fixtures can simultaneously process multiple workpieces, significantly improving production efficiency. Pneumatic, hydraulic and other special fixtures can provide stable and relatively large clamping forces, ensuring the stability of the workpiece during the machining process, and the clamping and loosening actions are rapid, further improving production efficiency. For example, on the large batch production lines of automobile parts, multi-station fixtures and hydraulic fixtures are often used to improve production efficiency and machining quality.
In large batch production, production efficiency is a key factor. Multi-station fixtures can simultaneously process multiple workpieces, significantly improving production efficiency. Pneumatic, hydraulic and other special fixtures can provide stable and relatively large clamping forces, ensuring the stability of the workpiece during the machining process, and the clamping and loosening actions are rapid, further improving production efficiency. For example, on the large batch production lines of automobile parts, multi-station fixtures and hydraulic fixtures are often used to improve production efficiency and machining quality.
4. When Adopting Group Technology, Group Fixtures Should Be Used
When adopting group technology to machine workpieces with similar shapes and sizes, group fixtures can fully exert their advantages, reducing the types of fixtures and the design and manufacturing workload. By reasonably adjusting the group fixtures, they can adapt to the machining requirements of different workpieces, improving the flexibility and efficiency of production. For example, in mechanical manufacturing enterprises, when machining the same type but different-specification shaft-like parts, using group fixtures can reduce production costs and improve the convenience of production management.
When adopting group technology to machine workpieces with similar shapes and sizes, group fixtures can fully exert their advantages, reducing the types of fixtures and the design and manufacturing workload. By reasonably adjusting the group fixtures, they can adapt to the machining requirements of different workpieces, improving the flexibility and efficiency of production. For example, in mechanical manufacturing enterprises, when machining the same type but different-specification shaft-like parts, using group fixtures can reduce production costs and improve the convenience of production management.
(D) Optimal Fixturing Position of the Workpiece on the Machine Tool Worktable
The fixturing position of the workpiece should ensure that it is within the machining travel range of each axis of the machine tool, avoiding the situation where the cutting tool cannot reach the machining area or collides with machine tool components due to improper fixturing position. At the same time, the length of the cutting tool should be made as short as possible to improve the machining rigidity of the cutting tool. For example, when machining a large flat plate-like part, if the workpiece is fixtured at the edge of the machine tool worktable, the cutting tool may extend too long when machining some parts, reducing the rigidity of the cutting tool, easily causing vibration and deformation, and affecting the machining accuracy and surface quality. Therefore, according to the shape, size and machining process requirements of the workpiece, the fixturing position should be reasonably selected so that the cutting tool can be in the best working state during the machining process, improving the machining quality and efficiency.
The fixturing position of the workpiece should ensure that it is within the machining travel range of each axis of the machine tool, avoiding the situation where the cutting tool cannot reach the machining area or collides with machine tool components due to improper fixturing position. At the same time, the length of the cutting tool should be made as short as possible to improve the machining rigidity of the cutting tool. For example, when machining a large flat plate-like part, if the workpiece is fixtured at the edge of the machine tool worktable, the cutting tool may extend too long when machining some parts, reducing the rigidity of the cutting tool, easily causing vibration and deformation, and affecting the machining accuracy and surface quality. Therefore, according to the shape, size and machining process requirements of the workpiece, the fixturing position should be reasonably selected so that the cutting tool can be in the best working state during the machining process, improving the machining quality and efficiency.
IV. Conclusion
The reasonable selection of the machining location datum and the correct determination of fixtures in machining centers are key links for ensuring machining accuracy and improving production efficiency. In the actual machining process, it is necessary to thoroughly understand and follow the requirements and principles of the location datum, select appropriate fixture types according to the characteristics and machining requirements of the workpiece, and determine the optimal fixture scheme according to the selection principles of fixtures. At the same time, attention should be paid to optimizing the fixturing position of the workpiece on the machine tool worktable to fully utilize the high-precision and high-efficiency advantages of the machining center, achieving high-quality, low-cost and high-flexibility production in mechanical machining, meeting the increasingly diverse requirements of the modern manufacturing industry, and promoting the continuous development and progress of mechanical machining technology.
The reasonable selection of the machining location datum and the correct determination of fixtures in machining centers are key links for ensuring machining accuracy and improving production efficiency. In the actual machining process, it is necessary to thoroughly understand and follow the requirements and principles of the location datum, select appropriate fixture types according to the characteristics and machining requirements of the workpiece, and determine the optimal fixture scheme according to the selection principles of fixtures. At the same time, attention should be paid to optimizing the fixturing position of the workpiece on the machine tool worktable to fully utilize the high-precision and high-efficiency advantages of the machining center, achieving high-quality, low-cost and high-flexibility production in mechanical machining, meeting the increasingly diverse requirements of the modern manufacturing industry, and promoting the continuous development and progress of mechanical machining technology.
Through comprehensive research and optimized application of the machining location datum and fixtures in machining centers, the competitiveness of mechanical manufacturing enterprises can be effectively improved. Under the premise of ensuring product quality, production efficiency can be improved, production costs can be reduced, and greater economic and social benefits can be created for enterprises. In the future field of mechanical machining, with the continuous emergence of new technologies and new materials, the machining location datum and fixtures in machining centers will also continue to innovate and develop to adapt to more complex and high-precision machining requirements.