Outer Circle Precision Turning Positioning Device and Method for Inclined L-Shaped Cast Pipe Parts

Abstract

The present invention belongs to the technical field of precision turning of inclined L-shaped cast pipe parts, and relates to an outer circle precision turning positioning device and method for inclined L-shaped cast pipe parts, which is applicable to the clamping and positioning in the process of precision turning of the outer circle of complex special-shaped cast parts. The present invention avoids the problems that the alignment is difficult and the center of gravity is unstable during the processing of inclined L-shaped pipe parts, which affect the dimensional and angular accuracy; it can make the clamping more firm, the force is more uniform, and the center of gravity always remains unchanged during high-speed rotation, avoiding the influence of slight rotation or unstable center of gravity of the parts on the dimensional accuracy, and the clamping method is simple and convenient, suitable for mass production of parts, improving the processing accuracy and the processing efficiency of operators.

Description

Technical Field

[0001] The present invention belongs to the technical field of precision turning of inclined L-shaped cast pipe parts, and relates to an outer circle precision turning positioning device and method for inclined L-shaped cast pipe parts, which is applicable to the clamping and positioning in the outer circle precision turning process of complex special-shaped cast parts. Background Art

[0002] In the field of precision turning of inclined L-shaped pipe parts, horizontal lathes and CNC lathes are mainly used for processing. The parts are clamped and positioned by the lathe jaws to ensure the dimensional accuracy of the internal and external features on both sides of the part and the angular relationship between the axes of the corresponding features, as well as the angular relationship between the axes of the two outlets. The structure of the large inclined L-shaped pipe part is shown in Figure 1 .

[0003] For the traditional machining of the outer circle of inclined L-shaped pipe parts, the non-machined outer circle close to the outlet to be machined is clamped by the jaws. When using the jaws to clamp and position the outer circle to be machined, the probe of the dial indicator needs to be pressed on the surface of the outer circle to be machined, and at the same time, the lathe chuck is rotated. During the rotation of the chuck, the pointer fluctuation of the dial indicator is observed, and the position of the jaws is adjusted to control the pointer fluctuation of the dial indicator within 0.05 mm to complete the clamping and positioning of the inclined L-shaped pipe parts.

[0004] During the clamping and positioning process, since the angles of most inclined L-shaped pipe parts are not 90°, there are gaps and small contact areas between the jaws and the clamped outer circle of the part, making it difficult to align the outer circle of the part with the dial indicator. When clamping, the other side of the inclined L-shaped pipe needs to be inserted into the lathe chuck. There is no auxiliary support for the other side inside the chuck. When the axial length of the inclined L-shaped pipe is relatively long, the part inside the chuck is relatively heavy, resulting in inconvenient operation during part alignment.

[0005] Inclined L-shaped pipe parts are generally castings or welded parts. The surface roughness of the outer circle of the casting is relatively poor and there are easy to have protrusions or depressions, which increases the difficulty of aligning the outer circle to be machined of the part. At the same time, it is difficult to ensure the angular relationship between the two outlets of the part, and it is easy to cause defective products.

[0006] Most pipe parts are thin-walled parts, and the materials are generally aluminum alloy or stainless steel. When using traditional jaws for clamping and positioning, it is easy to damage the non-machined outer circle, and at the same time, too large clamping force will cause elliptical deformation or pits on the outer circle surface of the part. Each inclined L-shaped pipe part needs to be aligned again during processing, and the alignment process is relatively difficult, reducing the production efficiency. Summary of the Invention

[0007] The object of the present invention is to invent an external circle precision turning positioning device for inclined L-shaped cast pipe parts. This tooling provides a new clamping method for inclined L-shaped pipe parts. By making a processing fixture for inclined L-shaped pipe parts, a method is provided to quickly align the center and clamp the inclined L-shaped pipe parts during the external circle processing, avoiding the problems that the inclined L-shaped pipe parts are difficult to align and have unstable center of gravity during processing, which affect the dimensional and angular accuracy. It can make the clamping more firm, the force more uniform, and the center of gravity always remain unchanged during high-speed rotation, avoiding the influence of slight rotation or unstable center of gravity of the parts on the dimensional accuracy. Moreover, the clamping method is simple and convenient, suitable for mass processing of parts, improving the processing accuracy and the processing efficiency of operators.

[0008] The technical solution of the present invention:

[0009] The external circle precision turning positioning device for inclined L-shaped cast pipe parts includes a connecting plate 1, a base plate 2, side plates 3, counterweight blocks 4, positioning blocks 5, mandrels 6, nuts 7, positioning pin shafts 8, hexagon socket head cap screws 9, portal-shaped limit frames 10, pressing plates 11, V-shaped positioning blocks 12, arc-shaped positioning blocks 13, cylindrical pins 14, hexagon thin nuts 15 and bolts 16.

[0010] The said connecting plate 1 is vertically arranged, the outer end surface thereof is a stepped external circle surface, the small external circle surface is used to connect the machine tool, the large external circle surface is used for aligning the positioning device, and its inner end surface is a horizontal plane; the said base plate 2 is horizontally arranged, and one end thereof is welded to the inner end surface of the connecting plate 1; there are two side plates 3, which are vertically arranged on both sides of the base plate 2 and are welded to the side edges of the base plate 2 and the inner end surface of the connecting plate 1 respectively; there are multiple counterweight blocks 4, which are arc-shaped blocks and are installed at equal intervals on the tops of the two side plates 3, and both ends of the counterweight blocks 4 are respectively connected to the two side plates 3 through hexagon socket head cap screws 9.

[0011] The said positioning block 5 is installed on the base plate 2 near one end of the connecting plate 1 through a hexagon thin nut 15 and a bolt 16. The surface of the positioning block 5 is an inclined surface. The positioning block 5 is provided with a positioning pin shaft 8 and a mandrel 6. The flange end of the inclined L-shaped cast pipe part is buckled on the positioning block 5. The inclined surface of the positioning block 5, the positioning pin shaft 8 and the mandrel 6 jointly act to automatically position the center of the inclined L-shaped cast pipe part. The top end of the mandrel 6 passes through the corresponding opening at the top end of the inclined L-shaped cast pipe part, and then is locked through a nut 7 to realize the positioning of the flange end of the inclined L-shaped cast pipe part and restrict the axial and radial movement of the part.

[0012] The described U-shaped limit frame 10 is composed of two L-shaped plates arranged opposite to each other, and is installed at one end of the base plate 2 away from the connecting disc 1. The U-shaped limit frame 10 has an upward opening; the V-shaped positioning block 12 is installed on the base plate 2 through a hexagonal thin nut 15 and a bolt 16, and is located in the middle gap of the U-shaped limit frame 10. The end to be processed of the inclined L-shaped cast pipe part is located inside the U-shaped limit frame 10, and the height of the part is adjusted through the V-shaped positioning block 12; the pressing plate 11 is installed at the top opening of the U-shaped limit frame 10 through a cylindrical pin 14 and a nut 7, and together with the U-shaped limit frame 10 forms a square structure. The arc-shaped positioning block 13 is installed on the lower surface of the pressing plate 11, and the arc-shaped positioning block 13 is matched with the profile of the inclined L-shaped cast pipe part. The pressing plate 11 presses the inclined L-shaped cast pipe part tightly inside the U-shaped limit frame 10.

[0013] Advantages of the present invention:

[0014] (1) The present invention adopts the clamping idea of one plane and two holes positioning and V-shaped auxiliary support, effectively avoiding problems such as difficult alignment before part processing and slight rotation easily caused by the non-circular surface of the three-jaw clamping; using positioning blocks and positioning pin shafts with fixed angles to fix the angular relationship of the two sides of the inclined L-shaped pipe part, eliminating the need to align the cylindrical surface to be processed, shortening the production preparation time, and improving the production efficiency.

[0015] (2) Using the device and method of the present invention for clamping can ensure the angular relationship of the two sides of the part. Since the positioning device is modularly assembled, only a special inclined surface positioning block with a certain angle needs to be made to ensure the angular relationship of the two sides of the part; by adding weights to the positioning device, it is ensured that the positioning device and the part as a whole are on the central axis of the machine tool during high-speed rotation; ensuring the stability during the cutting process and prolonging the service life of the cutting tool.

[0016] (3) Using the device and method of the present invention, precise positioning and rapid alignment of the inclined L-shaped pipe part can be achieved. Compared with the conventional clamping and positioning method for inclined L-shaped pipe parts, the present invention ensures the angular relationship of the two sides of the inclined L-shaped pipe part through a support inclined surface with a fixed angle, and at the same time, tightens through a mandrel and a nut to limit the axial freedom of the part. At the same time, the radial freedom of the part is limited through the positioning block, bolt, and nut on the base plate, realizing the function of rapid clamping and positioning of the inclined L-shaped pipe part. Description of the drawings

[0017] Figure 1 is a structural sketch of an inclined L-shaped cast pipe part;

[0018] Figures 2(a) to 2(c) is a schematic diagram of the external circle precision turning positioning device for the inclined L-shaped cast pipe part of the present invention. Among them, Fig. 2(a) is the front view, Fig. 2(b) is the side view, and Fig. 2(c) is the sectional view taken along the A-A plane of Fig. 2(a);

[0019] Figure 3 It is a three-dimensional view of the outer circle precision turning positioning device for the inclined L-shaped cast pipe parts of the present invention.

[0020] In the figure: 1 connecting disk, 2 base plate, 3 side plate, 4 counterweight, 5 positioning block, 6 mandrel, 7 nut, 8 positioning pin shaft, 9 hexagon socket head bolt, 10 portal-shaped limiting frame, 11 pressing plate, 12 V-shaped positioning block, 13 arc-shaped positioning block, 14 cylindrical pin, 15 thin hexagon nut, 16 bolt. Specific embodiments

[0021] The following further illustrates the specific embodiments of the present invention in conjunction with the accompanying drawings and technical solutions.

[0022] As shown in Figures 2(a) to 2(c) and Figure 3 the outer circle precision turning positioning device for the inclined L-shaped cast pipe parts of the present invention includes a connecting disk 1, a base plate 2, a side plate 3, a counterweight 4, a positioning block 5, a mandrel 6, a nut 7, a positioning pin shaft 8, a hexagon socket head bolt 9, a portal-shaped limiting frame 10, a pressing plate 11, a V-shaped positioning block 12, an arc-shaped positioning block 13, a cylindrical pin 14, a thin hexagon nut 15 and a bolt 16.

[0023] The main function of the outer end face of the connecting disk 1 is completed by the stepped outer circle surface. The small outer circle surface is used to connect the machine tool and the positioning device, and the large outer circle surface is used for fixture alignment; the connecting disk 1, the base plate 2 and the side plate 3 are fixed in position by welding; the base plate 2 is horizontally arranged, and one end of it is welded to the inner end face of the connecting disk 1; the two side plates 3 are vertically arranged on both sides of the base plate 2 and are respectively welded to the side edge of the base plate 2 and the inner end face of the connecting disk 1; there are multiple counterweights 4, which are arc-shaped blocks and are installed at equal intervals on the tops of the two side plates 3. The two ends of the counterweight 4 are respectively connected to the two side plates 3 through hexagon socket head bolts 9, which is a detachable structure. By the counterweight 4, the center of gravity of the positioning device and the part as a whole is ensured to be on the axis of the spindle faceplate of the machine tool.

[0024] The positioning block 5, the portal-shaped limiting frame 10 and the base plate 2 are fixed in position by bolts, threaded holes and nuts; the main function of the positioning block 5 is completed by the inclined plane with a fixed angle and the positioning pin shaft 8. Under the combined action of the inclined plane of the positioning block 5 and the cylindrical surface of the positioning pin shaft 8, the inclined L-shaped pipe part is automatically centered, and then it is fastened by the mandrel 6 and the nut 7 to limit the axial and radial movement of the part.

[0025] The pressing plate 11 is installed on the top of the portal-shaped limit frame 10 through the cylindrical pin 14 and the nut 7, and is detachable. The arc-shaped positioning block 13 is installed on the lower surface of the pressing plate 11. The V-shaped positioning block 12 is installed on the base plate 2 through the hexagon thin nut 15 and the bolt 16 and is located between the portal-shaped limit frames 10. The arc-shaped positioning block 13 and the V-shaped positioning block 12 are opposite to each other up and down. With the auxiliary support of the V-shaped positioning block 12 and the arc-shaped positioning block 13, it is ensured that the surface to be machined does not move slightly.

[0026] The outer circle precision turning positioning method for the inclined L-shaped cast pipe parts adopts the above positioning device, and the specific steps are as follows:

[0027] (1) Remove the counterweight 4 and the pressing plate 11, and place the inclined L-shaped cast pipe parts in the positioning device; install the flange end of the inclined L-shaped cast pipe parts on the inclined surface of the positioning block 5 and the positioning pin shaft 8, and install the end to be machined of the flange end in the portal-shaped limit frame 10; take the inclined surface of the positioning block 5 as the positioning surface of the outlet of the flange end of the inclined L-shaped cast pipe parts, and ensure the angular relationship of the outlets on both sides of the inclined L-shaped cast pipe parts through the inclined surface angle of the positioning block 5, and limit the end to be machined through the portal-shaped limit frame 10.

[0028] (2) Install the bottom end of the mandrel 6 on the internal thread of the positioning block 5, pass the top end of the mandrel 6 through the opening of the inclined L-shaped cast pipe parts and tighten it with the nut 7, and limit the axial and radial movement of the inclined L-shaped cast pipe parts on the positioning device through the positioning block 5, the positioning pin shaft 8 and the nut 7.

[0029] (3) Install the pressing plate 11 on the portal-shaped limit frame 10 and fasten it through the cylindrical pin 14 and the nut 7, so that the arc-shaped positioning block 13 presses on the cylindrical surface of the inclined L-shaped cast pipe parts. The arc-shaped surface of the arc-shaped positioning block 13 increases the fitting area between the fixture and the casting surface of the inclined L-shaped cast pipe parts, making the clamping of the inclined L-shaped cast pipe parts more reliable.

[0030] (5) Use the hexagon socket head cap screw 9 to fasten the counterweight 4 and the side plate 3. Through the counterweight 4, the overall force on the fixture and the inclined L-shaped cast pipe parts is more uniform, and the center of gravity always remains unchanged during high-speed rotation.

[0031] (6) Install the positioning device with the inclined L-shaped cast pipe parts installed on the lathe, use the hexagon thin nut 15, the bolt 16 and the V-shaped positioning block 12 to assist in supporting the inclined L-shaped pipe parts, and re-align the outer circle to be machined by adjusting the positions of the hexagon thin nut 15, the bolt 16 and the V-shaped positioning block 12, ensuring that the runout of the outer circle to be machined is not greater than 0.05 mm. After the machining work is completed, remove the positioning device from the lathe.

Claims

1. An outer circle precision turning positioning device for inclined L-shaped casting pipe parts, characterized in that, The positioning device described above includes a connecting plate (1), a base plate (2), side plates (3), counterweight blocks (4), positioning blocks (5), mandrels (6), nuts (7), positioning pin shafts (8), socket head cap screws (9), U-shaped limit frames (10), pressing plates (11), V-shaped positioning blocks (12), arc-shaped positioning blocks (13), cylindrical pins (14), hexagon thin nuts (15), and bolts (16); The described connecting plate (1) is vertically arranged. Its outer end has a stepped outer circular surface. The small outer circular surface is used to connect to the machine tool, and the large outer circular surface is used for aligning the positioning device. Its inner end face is a horizontal plane. The described base plate (2) is horizontally arranged, and one end of it is welded to the inner end face of the connecting plate (1). The two described side plates (3) are vertically arranged on both sides of the base plate (2), and are respectively welded to the side edges of the base plate (2) and the inner end face of the connecting plate (1). There are multiple described counterweight blocks (4), which are arc-shaped blocks and are installed at equal intervals on the tops of the two side plates (3). The two ends of the counterweight block (4) are respectively connected to the two side plates (3) through socket head cap screws (9); The described positioning block (5) is installed on the base plate (2) near the connecting plate (1) through a hexagon thin nut (15) and a bolt (16). The surface of the positioning block (5) is an inclined plane. The positioning block (5) is provided with a positioning pin shaft (8) and a mandrel (6). The flange end of the inclined L-shaped cast pipe part is buckled on the positioning block (5). Through the combined action of the inclined plane of the positioning block (5), the positioning pin shaft (8), and the mandrel (6), the inclined L-shaped cast pipe part is automatically centered. The top end of the mandrel (6) passes through the corresponding opening at the top end of the inclined L-shaped cast pipe part, and then is locked through a nut (7) to achieve the positioning of the flange end of the inclined L-shaped cast pipe part and restrict the axial and radial movement of the part; The described U-shaped limit frame (10) is composed of two L-shaped plates arranged opposite to each other and is installed at the end of the base plate (2) far from the connecting plate (1). The opening of the U-shaped limit frame (10) faces upward. The described V-shaped positioning block (12) is installed on the base plate (2) through a hexagon thin nut (15) and a bolt (16) and is located in the middle gap of the U-shaped limit frame (10). The end to be machined of the inclined L-shaped cast pipe part is located inside the U-shaped limit frame (10), and the height of the part is adjusted through the V-shaped positioning block (12). The described pressing plate (11) is installed at the top opening of the U-shaped limit frame (10) through a cylindrical pin (14) and a nut (7), and together with the U-shaped limit frame (10) forms a square structure. The described arc-shaped positioning block (13) is installed on the lower surface of the pressing plate (11). The arc-shaped positioning block (13) is matched with the profile of the inclined L-shaped cast pipe part, and the pressing plate (11) presses the inclined L-shaped cast pipe part tightly inside the U-shaped limit frame (10).

2. The outer circle precision turning positioning method for inclined L-shaped casting pipe parts, adopting the positioning device described in claim 1, is characterized in that, The specific steps are as follows: (1)Remove the counterweight (4) and the pressure plate (11), and place the inclined L-shaped cast pipe parts in the positioning device; install the flange end of the inclined L-shaped cast pipe parts on the inclined surface of the positioning block (5) and the positioning pin shaft (8), and install the end to be machined in the portal-shaped limit frame (10); use the inclined surface of the positioning block (5) as the positioning surface of the flange end outlet of the inclined L-shaped cast pipe parts, and ensure the angular relationship of the outlets on both sides of the inclined L-shaped cast pipe parts through the inclined surface angle of the positioning block (5), and limit the end to be machined through the portal-shaped limit frame (10). (2)Install the bottom end of the mandrel (6) onto the internal thread of the positioning block (5), pass the top end of the mandrel (6) through the opening of the inclined L-shaped cast pipe parts and tighten it with the nut (7), and restrict the axial and radial movement of the inclined L-shaped cast pipe parts on the positioning device through the positioning block (5), the positioning pin shaft (8) and the nut (7). (3)Install the pressure plate (11) on the portal-shaped limit frame (10), and fasten it with the cylindrical pin (14) and the nut (7), so that the arc-shaped positioning block (13) presses on the cylindrical surface of the inclined L-shaped cast pipe parts. (4)Use the hexagon socket head cap screw (9) to fasten the counterweight (4) and the side plate (3), and make the overall force on the fixture and the inclined L-shaped cast pipe parts more uniform through the counterweight (4), so that the center of gravity remains unchanged during high-speed rotation. (5)Install the positioning device equipped with the inclined L-shaped cast pipe parts on the lathe, and use the thin hexagon nut (15), the bolt (16) and the V-shaped positioning block (12) to assist in supporting the inclined pipe parts. Re-align the outer circle to be machined by adjusting the positions of the thin hexagon nut (15), the bolt (16) and the V-shaped positioning block (12), and ensure that the runout of the outer circle to be machined is not greater than 0.05 mm. After the machining work is completed, remove the positioning device from the lathe.

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