A tooling for machining the reference surface of a mountain-shaped joint and a deformation-resistant machining method

Abstract

This application provides a machining fixture for the reference surface of a mountain-shaped joint and a method for anti-deformation machining, including: a reference surface machining fixture and a finishing fixture, comprising a reference surface machining fixture base 2, bolts 3, locating pins 4, a notched pressure ring 5, and a pressure plate 6, wherein: the reference surface machining fixture base 2 has an inverted T-shaped structure, and the bolts 3, locating pins 4, notched pressure ring 5, and pressure plate 6 are installed on the reference surface machining fixture base 2. The upper end surface of the reference surface machining fixture base 2 is a horizontal locating surface, used for horizontal positioning of the workpiece; the side surface of the reference surface machining fixture base 2 is a vertical locating surface, used for vertical positioning of the workpiece; the reference surface machining fixture locating pins 4 are installation auxiliary positioning devices, used for auxiliary installation support of the workpiece. The mountain-shaped joint is positioned using the horizontal and vertical locating surfaces and installed on the reference surface machining fixture base 2 by the bolts 3, notched pressure ring 5, and pressure plate 6.

Description

Technical Field

[0001] This invention pertains to machining processes, specifically relating to a tooling for machining the reference surface of a mountain-shaped joint and a method for anti-deformation machining. Background Technology

[0002] like Figure 1 As shown, zigzag joints are widely used in load-bearing components in aviation and aerospace, and are often critical components that directly affect flight safety. These products are characterized by long cantilever lengths, thin walls, and high machining precision. To ensure the performance of zigzag joints, high-strength steel and titanium alloys are mostly used, placing high demands on their machining. With the increasing emphasis on weight reduction in aviation and aerospace products, the wall thickness requirements for zigzag joints are becoming increasingly thinner, leading to decreasing rigidity in the machined parts. Currently, the machining of zigzag joints faces the following problems:

[0003] 1. In order to minimize the deformation of the zigzag joint caused by clamping during the finishing stage, the flatness of the finishing reference surface must be no more than 0.02mm. Since titanium alloy is not suitable for grinding, the reference surface can only be machined by milling. Commonly used clamping methods such as pressure plates and vises will cause large clamping deformation, making it difficult to guarantee the flatness requirements of the finishing reference surface.

[0004] 2. The two outer lugs of the mountain-shaped connector are only about 5mm thick and about 60mm high. The structure is similar to a large tuning fork. During the cutting process, the tool is prone to deflection and resonance. The deflection phenomenon causes the lug size tolerance to fail to meet the design requirements; the resonance phenomenon causes serious damage to the tool, resulting in poor surface roughness of the lugs or even forcing the machine tool to stop processing. Summary of the Invention

[0005] This application provides a datum surface machining fixture and anti-deformation machining method for a mountain-shaped joint, which can solve the problems of trembling during the cutting process and poor surface finish caused by the poor rigidity of the mountain-shaped joint; and solve the problem that the part's form and position tolerances are difficult to meet assembly requirements due to easy deformation during the preparation and clamping of the finishing datum.

[0006] In a first aspect, this application provides a machining fixture for the reference surface of a mountain-shaped joint, comprising: a reference surface machining fixture and a finishing fixture, including a reference surface machining fixture base 2, bolts 3, locating pins 4, a notched pressure ring 5, and a pressure plate 6, wherein:

[0007] The datum surface machining fixture base 2 has an inverted T-shaped structure. Bolts 3, locating pins 4, notched pressure rings 5, and pressure plates 6 are installed on the datum surface machining fixture base 2. The upper surface of the datum surface machining fixture base 2 is a horizontal locating surface, used for horizontal positioning of the workpiece; the side surface of the datum surface machining fixture base 2 is a vertical locating surface, used for vertical positioning of the workpiece; the datum surface machining fixture locating pins 4 are auxiliary positioning devices used for auxiliary installation and support of the workpiece. The mountain-shaped joint is positioned using the horizontal and vertical locating surfaces and is installed on the datum surface machining fixture base 2 using bolts 3, notched pressure rings 5, and pressure plates 6.

[0008] The finishing fixture includes a finishing fixture base 7 and bolts 8. The upper surface of the finishing fixture base 7 is a horizontal positioning surface, which is used to mate with the finishing reference surface. The finishing fixture bolts 8 are used to fix and tighten the triangular joint onto the finishing fixture base 7.

[0009] Specifically, the datum surface machining fixture base 2 has an inverted T-shaped structure. The upper surface is a horizontal positioning surface, with a parallelism requirement of less than 0.02mm with the bottom plane. The side surface is a vertical positioning surface, with a perpendicularity requirement of less than 0.02mm with the bottom plane.

[0010] Specifically, the reference surface machining fixture bolt 3 is an M12 socket head cap bolt, totaling 3 bolts, used to secure the mountain-shaped joint to the reference surface machining fixture base 2.

[0011] Specifically, the outer diameter of the locating pin 4 of the reference surface machining tool is 0.1 to 0.2 mm smaller than the diameter of the middle lug hole of the mountain-shaped connector, the height is 8 mm, it has a 1×45 chamfer, and the center is an M12 internal thread. It is an auxiliary positioning device for installation and is used to assist in the installation and support of the workpiece.

[0012] Specifically, the outer diameter of the notched pressure ring 5 of the reference surface machining tool is 20mm larger than the diameter of the mountain-shaped joint hole, and it has a 12mm notch for applying clamping force to the mountain-shaped joint.

[0013] Specifically, the reference surface machining tooling plate 6 is L-shaped, and its height is slightly higher than the thickness of the middle lug of the mountain-shaped joint.

[0014] Specifically, the base plate of the precision-machined tooling base 7 has 6 Φ12 through holes evenly distributed for connection with the CNC machine tool worktable. The parallelism between the upper end surface and the bottom plane is required to be within 0.02mm. The length and width dimensions are consistent with the dimensions of the mountain-shaped connector base plate, and there are 4 M12 threaded holes distributed at the four corners.

[0015] Specifically, the finishing tooling bolts 8 are M12 bolts, a total of 4, used to deposit the mountain-shaped joint onto the finishing tooling base 7.

[0016] Secondly, this application provides a method for anti-deformation processing of a mountain-shaped joint, including:

[0017] Step 1: Clamp the hexagonal blank of the mountain-shaped connector with a general-purpose vise and perform rough machining on a CNC machining center. Reserve a total of 4 reinforcing ribs 1 on the sides of the two outer lugs of the mountain-shaped connector.

[0018] Step 2: After rough machining, the parts are heat-treated according to the design requirements.

[0019] Step 3: Install the part on the datum surface machining fixture base 2, use the locating pin 4 for auxiliary positioning, use bolt 3 and notched pressure ring 5 to press the middle lug of the mountain-shaped connector, and machine the datum surface on the CNC machining center to ensure that the flatness of the machined datum surface is within 0.02mm;

[0020] Step 4: Install the mountain-shaped connector on the precision machining fixture base 7. Use a 0.02mm feeler gauge to check the contact between the precision machining reference surface and the upper plane of the precision machining fixture base to ensure a complete fit. Tighten the part with bolts 8 and complete the precision machining of the mountain-shaped connector on a CNC machining center.

[0021] Step 5: After processing, inspect as required.

[0022] Specifically, the reinforcing ribs 1 on the two outer lugs of the mountain-shaped connector are reserved using the blank allowance of the outer lugs of the mountain-shaped connector. The length is determined according to the height of the part, the width is 2mm, and the height is determined according to the blank allowance. They are used to strengthen the rigidity of the outer lugs of the mountain-shaped connector.

[0023] In summary, this invention provides a tooling for machining the reference surface of a mountain-shaped connector and a method for anti-deformation machining. The tooling for machining the reference surface has a simple structure, low manufacturing cost, and simple and reliable operation, enabling stress-free clamping during the machining process of the reference surface. This method has strong applicability and is particularly suitable for machining mountain-shaped and tuning fork-type structural parts. It can effectively enhance the rigidity of such parts, prevent deformation of the lugs, and ensure the stability of the machining quality of the parts. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a mountain-shaped connector;

[0025] Figure 2 This invention provides a reinforcing rib to enhance the rigidity of the outer lug of a mountain-shaped connector;

[0026] Figure 3 A schematic diagram of a reference surface machining fixture for a mountain-shaped joint provided by the present invention;

[0027] Figure 4 A schematic diagram of the reference surface machining and clamping provided for the invention;

[0028] Figure 5 A schematic diagram of a precision machining fixture for a mountain-shaped connector provided by the present invention;

[0029] Figure 6 A schematic diagram of the finishing clamping method provided for the invention;

[0030] Among them: 1-reinforcing rib, 2-reference surface machining fixture base, 3-bolt, 4-locating pin, 5-notched pressure ring, 6-pressure plate, 7-precision machining fixture base, 8-bolt. Detailed Implementation

[0031] The principle of this application is to utilize the machining allowance of the U-shaped connector blank. During the rough machining stage, four reinforcing ribs with a width of 2mm are reserved on the two outer lugs of the U-shaped connector to enhance the rigidity of the two outer lugs and reduce vibration during the entire machining process. In the datum surface machining stage before finish machining, a datum surface machining fixture is designed. This fixture ensures that the clamping force is applied only to the middle lug of the U-shaped connector, ensuring that the two outer lugs are suspended, avoiding part deformation caused by clamping stress, and guaranteeing that the flatness of the finish machining datum surface is controlled within 0.02mm. During the finishing stage, a set of reference surface machining fixtures is designed. The mountain-shaped connector is installed on the finishing fixture to ensure that the finishing reference surface and the upper end surface of the finishing fixture fit tightly in a stress-free state. While retaining the four reinforcing ribs, the remaining feature surfaces of the mountain-shaped connector are machined. Finally, the reinforcing ribs are removed to ensure that the rigidity of the part is strengthened throughout the finishing process. At the same time, it avoids the deformation of the part caused by clamping stress and solves the problem of the "opening" or "closing" of the two outer lugs of the mountain-shaped connector.

[0032] The hexagonal blank of the mountain-shaped connector is held in a universal vise and rough-machined on a CNC machining center. Four reinforcing ribs 1 are reserved on the sides of the two outer lugs of the mountain-shaped connector. After rough machining, the part is heat-treated according to the design requirements. After heat treatment, the part is installed on the datum surface machining fixture base 2, with locating pins 4 for auxiliary positioning, and bolts 3 and notched pressure rings 5 ​​to press the middle lug of the mountain-shaped connector. The datum surface is machined on the CNC machining center to ensure that the flatness of the datum surface is within 0.02mm. The mountain-shaped connector is installed on the finishing fixture base 7, and a 0.02mm feeler gauge is used to check the contact between the finishing datum surface and the upper plane of the finishing fixture base to ensure complete contact. The part is pressed with bolts 8, and the finishing of the mountain-shaped connector is completed on the CNC machining center.

[0033] Example 1

[0034] like Figure 3 , Figure 5As shown, this application provides a machining fixture for the reference surface of a mountain-shaped joint, including: a reference surface machining fixture and a finishing fixture, wherein:

[0035] The datum surface machining fixture includes a datum surface machining fixture base 2, bolts 3, locating pins 4, notched pressure rings 5, and pressure plates 6. The datum surface machining fixture base 2 has an inverted T-shaped structure. Bolts 3, locating pins 4, notched pressure rings 5, and pressure plates 6 are installed on the datum surface machining fixture base 2. The upper end surface of the datum surface machining fixture base 2 is a horizontal locating surface, used for horizontal positioning of the workpiece; the side surface of the datum surface machining fixture base 2 is a vertical locating surface, used for vertical positioning of the workpiece; the datum surface machining fixture locating pins 4 are auxiliary positioning devices used for auxiliary installation and support of the workpiece. The mountain-shaped joint is positioned using the horizontal and vertical locating surfaces and is installed on the datum surface machining fixture base 2 using bolts 3, notched pressure rings 5, and pressure plates 6.

[0036] The finishing fixture includes a finishing fixture base 7 and bolts 8. The upper surface of the finishing fixture base 7 is a horizontal positioning surface, which is used to mate with the finishing reference surface. The finishing fixture bolts 8 are used to fix and tighten the triangular joint onto the finishing fixture base 7.

[0037] like Figure 1 As shown, this application is used in a mountain-shaped connector.

[0038] Specifically, the datum surface machining fixture base 2 has an inverted T-shaped structure. The upper surface is a horizontal positioning surface, with a parallelism requirement of less than 0.02mm with the bottom plane. The side surface is a vertical positioning surface, with a perpendicularity requirement of less than 0.02mm with the bottom plane.

[0039] Specifically, the reference surface machining fixture bolt 3 is an M12 socket head cap bolt, totaling 3 bolts, used to secure the mountain-shaped joint to the reference surface machining fixture base 2.

[0040] Specifically, the outer diameter of the locating pin 4 of the reference surface machining tool is 0.1 to 0.2 mm smaller than the diameter of the middle lug hole of the mountain-shaped connector, the height is 8 mm, it has a 1×45 chamfer, and the center is an M12 internal thread. It is an auxiliary positioning device for installation and is used to assist in the installation and support of the workpiece.

[0041] Specifically, the outer diameter of the notched pressure ring 5 of the reference surface machining tool is 20mm larger than the diameter of the mountain-shaped joint hole, and it has a 12mm notch for applying clamping force to the mountain-shaped joint.

[0042] Specifically, the reference surface machining tooling plate 6 is L-shaped, and its height is slightly higher than the thickness of the middle lug of the mountain-shaped joint.

[0043] Specifically, the base plate of the precision-machined tooling base 7 has 6 Φ12 through holes evenly distributed for connection with the CNC machine tool worktable. The parallelism between the upper end surface and the bottom plane is required to be within 0.02mm. The length and width dimensions are consistent with the dimensions of the mountain-shaped connector base plate, and there are 4 M12 threaded holes distributed at the four corners.

[0044] Specifically, the finishing tooling bolts 8 are M12 bolts, a total of 4, used to deposit the mountain-shaped joint onto the finishing tooling base 7.

[0045] Example 2

[0046] like Figure 2 , Figure 4 , Figure 6 As shown, this application provides a deformation-resistant processing method for a mountain-shaped joint, comprising:

[0047] Step 1: Clamp the hexagonal blank of the mountain-shaped connector with a general-purpose vise and perform rough machining on a CNC machining center. Reserve a total of 4 reinforcing ribs 1 on the sides of the two outer lugs of the mountain-shaped connector.

[0048] Step 2: After rough machining, the parts are heat-treated according to the design requirements.

[0049] Step 3: Install the part on the datum surface machining fixture base 2, use the locating pin 4 for auxiliary positioning, use bolt 3 and notched pressure ring 5 to press the middle lug of the mountain-shaped connector, and machine the datum surface on the CNC machining center to ensure that the flatness of the machined datum surface is within 0.02mm;

[0050] Step 4: Install the mountain-shaped connector on the precision machining fixture base 7. Use a 0.02mm feeler gauge to check the contact between the precision machining reference surface and the upper plane of the precision machining fixture base to ensure a complete fit. Tighten the part with bolts 8 and complete the precision machining of the mountain-shaped connector on a CNC machining center.

[0051] Step 5: After processing, inspect as required.

[0052] Specifically, the reinforcing ribs 1 on the two outer lugs of the mountain-shaped connector are reserved using the blank allowance of the outer lugs of the mountain-shaped connector. The length is determined according to the height of the part, the width is 2mm, and the height is determined according to the blank allowance. They are used to strengthen the rigidity of the outer lugs of the mountain-shaped connector.

[0053] In summary, this invention provides a tooling for machining the reference surface of a mountain-shaped connector and a method for anti-deformation machining. The tooling for machining the reference surface has a simple structure, low manufacturing cost, and simple and reliable operation, enabling stress-free clamping during the machining process of the reference surface. This method has strong applicability and is particularly suitable for machining mountain-shaped and tuning fork-type structural parts. It can effectively enhance the rigidity of such parts, prevent deformation of the lugs, and ensure the stability of the machining quality of the parts.

Claims

1. A tooling for machining the reference surface of a mountain-shaped joint, characterized in that, include: The datum surface machining fixture and the finishing fixture, wherein: The datum surface machining fixture includes a datum surface machining fixture base (2), bolts (3), locating pins (4), notched pressure rings (5), and pressure plates (6). The datum surface machining fixture base (2) is an inverted T-shaped structure. The bolts (3), locating pins (4), notched pressure rings (5), and pressure plates (6) are installed on the datum surface machining fixture base (2). The upper end face of the datum surface machining fixture base (2) is a horizontal locating surface, used for horizontal positioning of the workpiece. The side face of the datum surface machining fixture base (2) is a vertical locating surface, used for vertical positioning of the workpiece. The locating pins (4) of the datum surface machining fixture are auxiliary positioning devices used for auxiliary installation support of the workpiece. The mountain-shaped joint is positioned using the horizontal and vertical locating surfaces and installed on the datum surface machining fixture base (2) using bolts (3), notched pressure rings (5), and pressure plates (6). The finishing fixture includes a finishing fixture base (7) and a finishing fixture bolt (8); the upper end face of the finishing fixture base (7) is a horizontal positioning surface, which is used to cooperate with the finishing reference surface, and the finishing fixture bolt (8) is used to fix and press the mountain-shaped joint on the finishing fixture base (7).

2. The reference surface machining fixture according to claim 1, characterized in that, The base of the datum surface machining fixture (2) is an inverted T-shaped structure. The upper end is a horizontal positioning surface, and the parallelism with the bottom plane is required to be within 0.02mm. The side is a vertical positioning surface, and the perpendicularity with the bottom plane is required to be within 0.02mm.

3. The reference surface machining fixture according to claim 1, characterized in that, Bolt (3) is an M12 socket head cap screw.

4. The reference surface machining fixture according to claim 1, characterized in that, The outer diameter of the positioning pin (4) is 0.1~0.2mm smaller than the diameter of the middle lug of the mountain-shaped connector, the height is 8mm, it has a 1×45 chamfer, and the center is an M12 internal thread.

5. The reference surface machining fixture according to claim 1, characterized in that, The outer diameter of the notched pressure ring (5) is 20mm larger than the diameter of the mountain-shaped connector hole, and it has a 12mm notch.

6. The reference surface machining fixture according to claim 1, characterized in that, The pressure plate (6) is L-shaped, and its height is higher than the thickness of the middle lug of the mountain-shaped connector.

7. The reference surface machining fixture according to claim 1, characterized in that, The precision-machined tooling base (7) has N Φ12 through holes evenly distributed on the base plate for connecting with the CNC machine tool worktable. The upper end face is a horizontal positioning surface and the parallelism between it and the bottom plane is required to be within 0.02mm. The length and width dimensions are consistent with the dimensions of the mountain-shaped connector base plate. There are 4 M12 threaded holes distributed at the four corners.

8. The reference surface machining fixture according to claim 1, characterized in that, The finishing tooling bolts (8) are M12 bolts, a total of 4.

9. A method for anti-deformation machining of a mountain-shaped joint, comprising using the reference surface machining fixture of the mountain-shaped joint as described in claim 1, characterized in that, include: Step 1: Use a general vise to clamp the hexagonal blank of the mountain-shaped connector and perform rough machining on a CNC machining center. Four reinforcing ribs are reserved on the sides of the two outer lugs of the mountain-shaped connector (1). Step 2: Then, perform heat treatment on the rough-machined mountain-shaped joint; Step 3: Install the mountain-shaped connector on the base (2) of the reference surface machining fixture, use the positioning pin (4) for auxiliary positioning, use bolts (3) and notched pressure ring (5) to press the middle ear of the mountain-shaped connector, and machine the reference surface on the CNC machining center to ensure that the flatness of the machined reference surface is within 0.02mm; Step 4: Install the mountain-shaped connector on the precision machining fixture base (7), use a 0.02mm feeler gauge to check the contact between the precision machining reference surface and the upper plane of the precision machining fixture base to ensure complete contact, tighten the part with the precision machining fixture bolts (8), and complete the precision machining of the mountain-shaped connector on the CNC machining center; Step 5: Inspect the mountain-shaped joint after processing.

10. The anti-deformation processing method according to claim 9, characterized in that, The reinforcing rib (1) is left on the allowance of the outer ear piece of the mountain-shaped connector. The length is determined according to the height of the part, the width is 2mm, and the height is determined according to the blank allowance. It is used to strengthen the rigidity of the outer ear piece of the mountain-shaped connector.

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