A dual-purpose tooling and processing method for box-shaped products

Abstract

The present invention relates to the field of machining of aerospace products, and discloses a dual-purpose tooling and a machining method for box-shaped products. The tooling of the present invention has high reliability, reasonable design, simple structure, simple operation, low skill level requirements, small fit clearance and high positioning accuracy. It avoids many drawbacks in the use of traditional combined fixtures (fixtures composed of lathe faceplate angle irons), greatly shortens the product clamping and alignment time, reduces labor intensity and personnel costs. It can adapt to the rhythm of rapid testing and iterative production of aerospace products. The tooling has good service performance and long service life, and one set of tooling can be used for mass production. It has a wide range of promotion and high economic value.

Description

Technical Field

[0001] The present invention relates to the field of machining of aerospace products, and in particular to a dual-purpose fixture and a machining method for box-shaped products. Background Art

[0002] When machining some box-shaped products, it is difficult to align the eccentric center of the product using a general fixture on a lathe, and due to the lack of a reference surface, the clamping of the product is also very difficult. The production of such products mostly uses traditional combined fixtures (fixtures composed of a lathe faceplate angle iron), but due to the large cumulative error between standard parts in the combined fixture, the clamping and positioning, adjustment and balancing take a long time, with high production costs, low efficiency, and high requirements for the operator's skill level. Therefore, for the mass production of irregular box-shaped products, there is an urgent need for a machining fixture and method that are convenient for loading and unloading products, efficient in alignment, and high in machining quality. Summary of the Invention

[0003] The technical problem solved by the present invention is: to provide a machining method for box-shaped products, and a fixture with a simple structure and convenient operation corresponding to the method, which can clamp box-shaped products, has strong versatility, can replace traditional combined fixtures, causes no damage to the products, can adapt to the production rhythm of large quantities, and can ensure the geometric tolerances of the products.

[0004] The technical solution adopted by the present invention is: a machining method for box-shaped products, the box-shaped products being of a quadrangular prism box structure and being eccentric parts; having internal threads and intersecting holes, one of the holes passing through both ends of the product and extending out of the box end face to form two cylindrical boss structures, H circles and M circles; and the central axis positions of the two H circles and M circles not being at the center of the square box; the method steps include:

[0005] Design a dual-purpose fixture, the dual-purpose fixture including a clamping end and a positioning and fixing end connected thereto and having two mutually perpendicular mounting planes;

[0006] Define a virtual coordinate system at the center of the interface where the clamping end and the positioning and fixing end intersect, with the X axis coinciding with the central axis of the clamping end, the Y axis perpendicular to one of the mounting planes, and the Z axis satisfying the right-handed Cartesian coordinate system;

[0007] Position the product respectively according to the relationship between the two machining parts of the box-shaped product and the mounting plane, using the six-point positioning principle, while satisfying the relationship that the center line of the part to be machined of the product is coaxial with the rotary center line of the lathe spindle, and machine threaded holes and grooves on the mounting plane;

[0008] Install the multi-functional tooling on the lathe, clamp the product longitudinally, install the box-shaped product on the multi-functional tooling, and embed the cylindrical convex structure H circle of the product into the groove on the installation plane along the X direction. The installation plane is in close contact with the outer circle root end face of the corresponding box-shaped product for positioning the product; use fasteners to pass through the product process hole along the X direction and fix it with the multi-functional tooling, and complete the machining of the eccentric hole F of the box-shaped product along the X direction;

[0009] After machining the product, remove the fasteners along the X direction;

[0010] Clamp the product transversely, embed the cylindrical convex H circle of the product into the groove of an installation plane along the Y direction. The installation plane is in close contact with the outer circle root end face of the corresponding box-shaped product for positioning the product; use fasteners to pass through the product process hole along the Y direction and fix it with the multi-functional tooling, and complete the machining of the eccentric hole G of the box-shaped product along the X direction during machining;

[0011] Remove the fasteners. After machining the product, remove the fasteners along the Y direction.

[0012] Preferably, when the multi-functional tooling is installed on the lathe, it is necessary to align the radial circular runout and end face circular runout of the tooling, and both runout amounts are within the range of 0.03 mm.

[0013] A multi-functional tooling for box-shaped products. The box-shaped product is a quadrangular prism box structure and is an eccentric part; it has internal threads and intersecting holes. One of the holes runs through both ends of the product and extends out of the box end face, forming two cylindrical boss structures, H circle and M circle; and the central axis positions of the two H circles and M circles are not at the center of the square box. The tooling includes a tooling body; one end of the tooling body is a clamping end for cooperating with the lathe, and the other end is a positioning and fixing end with two mutually perpendicular installation planes. The two installation planes are respectively used as positioning planes for machining the inner holes of different end faces of the product. There are two threaded holes and grooves on both installation planes; the positions of the threaded holes on the two installation planes are used to cooperate with the process holes on the box-shaped product during machining to fix the product; the positions of the grooves on the two installation planes are used to cooperate with the cylindrical convex structure H circle during machining to position the product and ensure that the inner hole to be machined is coaxial with the center line of the clamping end.

[0014] Preferably, the tooling further includes a bushing and fasteners; the bushing is installed in the process hole of the box-shaped product, and the fasteners pass through the bushing and cooperate with the threaded holes on the tooling body to fix the product.

[0015] Preferably, the fastener is a hexagon bolt, and after tightening, the hexagon bolt is perpendicular to the positioning plane.

[0016] Preferably, the bushing is a polytetrafluoroethylene bushing.

[0017] Preferably, the clamping end is of a cylindrical structure.

[0018] Preferably, the cylindrical protrusion is in clearance fit with the groove.

[0019] Preferably, the clearance is 0.01 - 0.03 mm.

[0020] The beneficial effects of the present invention compared with the prior art are as follows:

[0021] 1. The tooling of the present invention has high reliability, accurate product positioning, can achieve rapid loading and unloading, significantly shortening the product alignment time from 15 minutes before to 2 minutes now. After aligning the first product, there is no need to realign the product during mass production; it provides an idea for machining eccentric holes of box-shaped products. Compared with the traditional combined fixture, the maximum rotational speed can be increased from 800 r / min to 3000 r / min, greatly improving production efficiency.

[0022] 2. The operation is simple and requires a low skill level. For traditional combined fixtures, the minimum required skill level is intermediate workers, but now junior workers can use this tooling to process products;

[0023] 3. It reduces labor. One set of tooling can process two inner cavity parts of the product, reducing the usage cost of two sets of combined fixtures and the labor cost input.

[0024] 4. This tooling has strong versatility, a wide application range, and is convenient for loading and unloading. The tooling can be installed on most three-jaw self-centering chucks of lathes, and only two hexagon bolts need to be disassembled and assembled for product disassembly and assembly;

[0025] 5. This tooling has good use performance and a long service life. One set of tooling can be used for the production of at least 5,000 products;

[0026] 6. It creates economic benefits, avoiding the risk of damaging the product during clamping with traditional combined fixtures. The first-pass processing qualification rate of the product has increased from 91% to 98%. Compared with the traditional processing method for every 100 products, the cost is saved by about 2,000 yuan.

[0027] 7. This tooling has a wide promotion range and scalability, and is applicable to box-shaped structure products. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is the structural schematic of the present invention Figure 1 , with the product in the horizontal clamping state. In the figure, (1) is the product, (2) is the tooling, (3) is the bushing, and (4) is the hexagon bolt

[0029] Figure 2 is the structural schematic of the present invention Figure 2 ; the product is in the vertical clamping state.

[0030] Figure 3 is the product of the illustrated example, where (H) is the large outer circle;

[0031] Figure 4 is a schematic cross-sectional view of a horizontal installation, corresponding to Figure 1 where (G) is an eccentric hole;

[0032] Figure 5 is a schematic cross-sectional view of a vertical installation, corresponding to Figure 2 where (F) is an eccentric inner cavity; Specific embodiments

[0033] The present invention will be further described below in conjunction with embodiments.

[0034] The present invention relates to the field of machining of aerospace products and discloses a machining method for box-shaped products. The present invention mainly uses the six-point positioning principle to position the product, and at the same time makes the center line of the part to be machined of the product coaxial with the center line of the rotation of the lathe spindle, so that the product is in the correct position. The fixture is designed according to the distance between the central axis of the part to be machined of the product and the outer surface of the product. The main body of the product of the present invention, such as the overall structure Figure 3 as shown, the main features of the product are that the outer shape is a quadrangular prism box structure, and there are internal threads, intersecting holes, eccentric holes G, F, etc. inside. Generally, the present invention can realize the vertical and horizontal installation of the product to machine the corresponding inner cavities. Realize the reliable clamping of the product and the machining of the position of the eccentric hole of the product. And it is convenient to disassemble the product, and the fixture body can be used for most common lathes. The machining steps are as follows:

[0035] Design a dual-purpose fixture, the dual-purpose fixture includes a clamping end and a positioning and fixing end connected thereto with two mutually perpendicular mounting planes;

[0036] Respectively, according to the relationship between the two machining parts of the box-shaped product and the mounting plane, use the six-point positioning principle to position the product, and at the same time satisfy the relationship that the center line of the part to be machined of the product is coaxial with the center line of the rotation of the lathe spindle, and machine threaded holes and grooves on the mounting plane;

[0037] As Figure 1 , 2 shown, the product 1 can be horizontally installed on the fixture 2 or vertically installed on the fixture 2. When the product is horizontally installed on the fixture 2, as shown in the cross-sectional view Figure 4 shown, for clearer description, a virtual coordinate system is established at the center of the fixture. The X-axis coincides with the central axis of the clamping end, the Y-axis is perpendicular to one of the mounting planes, and the Z-axis satisfies the right-handed Cartesian coordinate system; as shown in the appendix Figure 4 , 5 . Horizontally installing the product is mainly used for machining the left inner hole G of the product, as Figure 4, at this time, the center line of the left inner hole of the product is coaxial with the center line of the right cylindrical surface of the tooling, that is, the center line of the left inner hole of the product and the center line of the right cylindrical surface of the tooling are both located on the X-axis. At this time, the large outer circle H of the product in the negative Y direction is nested in the tooling and has a clearance fit with the tooling. The lower end face of the product parallel to the X-axis direction is closely attached to the tooling, which is used to position the product so that the lower end face of the product is in the correct position. Then, two hexagon bolts 4 are used to pass through the product along the negative Y-axis direction and cooperate with the internal threaded holes on the tooling to be fastened, restricting the rotation of the product along the Y-axis direction and the displacement in the Z direction. The product is accurately positioned on the tooling. After processing the product, the fasteners are disassembled along the Y direction.

[0038] As Figure 2 , as shown, when the product is longitudinally installed on the tooling 2 as shown in the sectional schematic diagram Figure 5 shown, the longitudinal installation of the product is mainly used to machine the left inner threaded hole F coaxial with the X direction of the product. At this time, the center line of the left inner threaded hole of the product is coaxial with the center line of the right cylindrical surface of the tooling, that is, the center line of the left inner threaded hole of the product and the center line of the right cylindrical surface of the tooling are both located on the X-axis. At this time, the large outer circle H of the product in the negative X-axis direction is nested in the tooling and has a clearance fit with the inner hole on the tooling. The right end face of the product parallel to the Y-axis direction is closely attached to the tooling, which is used to position the end face of the product so that the right end face of the product is in the correct position. Then, two hexagon bolts 4 are used to pass through the product along the positive X-axis direction and cooperate with the tooling to be fastened, restricting the rotation of the product along the X-axis direction and the displacement in the Y direction. The product is accurately positioned on the tooling. After processing the product, the fasteners are disassembled along the X direction.

[0039] The present invention provides a dual-purpose tooling applicable to the above processing method, including a tooling body 2, a polytetrafluoroethylene bushing 3 hereinafter referred to as a bushing, and hexagon bolts 4. The hexagon bolts 4 can pass through the bushing 3 and two inner holes of the product 1 and cooperate with the tooling body 2.

[0040] One end of the tooling body 2 is a clamping end for cooperating with a lathe, and the other end is a positioning and fixing end with two mutually perpendicular mounting planes. The two mounting planes are respectively used as positioning planes when machining the inner holes of different end faces of the product. Threaded holes and grooves are provided on both mounting planes; the positions of the threaded holes on the two mounting planes are used to cooperate with the process holes on the box-shaped product during machining to fix the product; the positions of the grooves on the two mounting planes are used to cooperate with the cylindrical convex structure during machining to position the product and ensure that the center line of the inner hole to be machined is coaxial with the clamping end.

[0041] The right cylindrical surface part (clamping end) of the tooling body 2 is used to be clamped in the three-jaw chuck of the lathe, and the center line of the right cylindrical surface of the tooling is coaxial with the lathe spindle. When two hexagon bolts 4 are used to fasten the product, the center lines of the outer circle parts of the hexagon bolts 4 are perpendicular to the product positioning surface. When two hexagon bolts 4 are used to fasten the product, they both need to pass through the polytetrafluoroethylene bushing 3, and the function of the bushing 3 is to protect the product from being damaged by the bolts.

[0042] The tooling of the present invention has high reliability, reasonable design, simple structure, simple operation, low skill level requirements, small clearance and high positioning accuracy. It avoids many disadvantages in the use of traditional combined fixtures (fixtures composed of lathe faceplate angle irons), greatly shortens the product clamping and alignment time, realizes the convenient processing of eccentric inner cavities, reduces labor intensity and personnel costs. It can adapt to the rhythm of rapid testing and iterative production of aerospace products. The tooling has good performance and long service life, and one set of tooling can be used for mass production. It has a wide range of promotion and high economic value.

[0043] Although the present invention has been disclosed above with preferred embodiments, it is not used to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A processing method for a box-shaped product, the box-shaped product being a quadrangular prism box structure and being an eccentric part; it has internal threads and intersecting holes, and one of the holes penetrates both ends of the product and extends out of the box end face, forming two cylindrical boss structures, H circle and M circle; and the central axis positions of the two H circles and M circles are not at the center of the square box; characterized in that Including: Design a dual-purpose tooling. The dual-purpose tooling includes a clamping end and a positioning and fixing end connected thereto, which has two mutually perpendicular mounting planes. Define a virtual coordinate system at the center of the interface where the clamping end and the positioning and fixing end intersect. The X-axis coincides with the central axis of the clamping end, the Y-axis is perpendicular to one of the mounting planes, and the Z-axis satisfies the right-hand Cartesian coordinate system. According to the relationship between the two machining parts of the box-type product and the mounting plane respectively, position the product using the six-point positioning principle, and at the same time satisfy the relationship that the center line of the part to be machined of the product is coaxial with the rotation center line of the lathe spindle. Machine threaded holes and grooves on the mounting plane. Install the dual-purpose tooling on the lathe and longitudinally clamp the product. Install the box-type product on the dual-purpose tooling. The product inserts the cylindrical convex structure H circle along the X direction into the groove on the mounting plane. The mounting plane is closely attached to the outer circle root end face of the corresponding box-type product for positioning the product. Use fasteners to pass through the product process hole along the X direction and fix it with the dual-purpose tooling, and complete the machining of the eccentric hole F of the box-type product along the X direction. After machining the product, remove the fasteners along the X direction. Transversely clamp the product. Insert the cylindrical convex H circle of the product into the groove of one mounting plane along the Y direction. The mounting plane is closely attached to the outer circle root end face of the corresponding box-type product for positioning the product. Use fasteners to pass through the product process hole along the Y direction and fix it with the dual-purpose tooling. During machining, complete the machining of the eccentric hole G of the box-type product along the X direction. Remove the fasteners. After machining the product, remove the fasteners along the Y direction.

2. The processing method according to claim 1, characterized in that: When the dual-purpose tooling is installed on the lathe, it is necessary to align the radial circular runout and the end face circular runout of the tooling. Both runout amounts are within the range of 0.03 mm.

3. A dual-purpose tooling for box-shaped products. The box-shaped product has a quadrangular prism box structure and is an eccentric part. It has internal threads and intersecting holes. One of the holes penetrates both ends of the product and extends out of the box end face, forming two cylindrical boss structures, H circle and M circle. Moreover, the central axis positions of the two H circles and M circles are not at the center of the square box. It is characterized in that The tooling includes a tooling body. One end of the tooling body is a clamping end that cooperates with the lathe, and the other end is a positioning and fixing end with two mutually perpendicular mounting planes. The two mounting planes are respectively used as positioning planes when machining the inner holes of different end faces of the product. Two threaded holes and grooves are provided on both mounting planes. The positions of the threaded holes on the two mounting planes are used to cooperate with the process holes on the box-type product during machining to fix the product. The positions of the grooves on the two mounting planes are used to cooperate with the cylindrical convex structure H circle during machining to realize product positioning and satisfy that the inner hole to be machined is coaxial with the center line of the clamping end.

4. The dual-purpose tooling according to claim 3, characterized in that: It also includes a bushing and fasteners. The bushing is installed in the process hole of the box-type product, and the fasteners pass through the bushing and cooperate with the threaded holes on the tooling body to fix the product.

5. The dual-purpose tooling according to claim 4, wherein: The fastener is a hexagon bolt. After fastening, the hexagon bolt is perpendicular to the positioning plane.

6. The dual-purpose tooling according to claim 4, wherein: The bushing is a polytetrafluoroethylene bushing.

7. The dual-purpose tooling according to claim 3, characterized in that: The clamping end is a cylindrical structure.

8. The dual-purpose tooling according to claim 3, characterized in that: The cylindrical convex and the groove are in clearance fit.

9. The dual-purpose tooling according to claim 8, wherein: The clearance is 0.01 - 0.03 mm.

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