Dynamic tensioning turning clamp

Abstract

The invention discloses a dynamic tensioning turning clamp, and belongs to the technical field of machining. The fixture comprises a fixture body, the fixture body is provided with a base plate, the base plate is coaxially connected with a disc, and a lining is coaxially arranged in the center of the disc; the driving disc is connected with the lining through a driving shaft; a dynamic supporting mechanism for rotationally tensioning the inner circle of the workpiece to be machined is arranged in the circumferential direction of the disc, and a backing ring for limiting the axial position of the workpiece to be machined is further arranged in the circumferential direction of the disc; by the adoption of the dynamic tensioning turning clamp, when the diameter of a workpiece is increased due to temperature rise in the turning process, all the supporting rods can automatically adapt to the diameter change of the workpiece, but the supporting force is kept constant, and the precision of the circular shape of the turned workpiece is high.

Description

Technical Field

[0001] The present invention relates to a dynamic tension turning fixture, belonging to the technical field of machining. Background Art

[0002] In the machinery industry, turning of ring-shaped workpieces is quite common. When the diameter of the workpiece is not large, general fixtures such as three-jaw and four-jaw chucks can be used for clamping. When high precision requirements are imposed on the workpiece, special elastic fixtures can also be designed for clamping. However, when the diameter of the workpiece is large and the batch size is limited, using traditional elastic fixtures is uneconomical.

[0003] For example, in a chemical equipment of a hydrogenation reactor, there is an important ring-shaped workpiece (see the attached Figure 3 workpiece 9), with a diameter of more than 600 mm and four circumferentially evenly distributed mounting holes. When workers perform turning processing, they directly use four bolts to pass through the 4 holes to fixedly install the workpiece on the side of the disc 12. Due to thermal deformation, and the points where the 4 holes are located are restricted by the bolts and cannot move, other arc segments expand and arch outwards, and the workpiece becomes non-circular. After the outer circle is turned into a circle and naturally cooled, the arched segments of the arc segments concave inwards, and the workpiece is no longer a regular circle. After measurement, the roundness error is greater than 0.5 mm, exceeding the technical allowable value. For this situation, a large amount of coolant can be used for cooling during turning, and at the same time, the process measures of separating rough machining and finish machining are adopted. Separating rough machining and finish machining affects the production efficiency, and because the diameter is large, using traditional elastic fixtures is uneconomical. Therefore, it is best to design a simple and economical dynamic tension turning fixture. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a dynamic tension turning fixture; To achieve the above purpose / to solve the above technical problems, the present invention is implemented by the following technical solutions: A dynamic tension turning fixture includes: A fixture body, the fixture body is provided with a base plate, the base plate is coaxially connected with a disc, and a bushing is coaxially arranged at the center of the disc; A driving disc, the driving disc is connected with the bushing through a driving shaft; The disc is circumferentially provided with a dynamic support mechanism for rotating and tensioning the inner circle of the workpiece to be machined, and the disc is also circumferentially provided with a spacer ring for restricting the axial position of the workpiece to be machined.

[0005] Optionally, the dynamic support mechanism includes a support rod, a torsion spring and a pin shaft II. The pin shaft II is circumferentially arranged on the disc and is far from the center of the disc. The support rod is matched with the pin shaft II through a pin hole. A pin shaft I fixedly connected with the driving disc is provided at the near center end of the support rod. The inner end of the torsion spring is connected with the driving shaft, and the outer end is fixed to the disc through a fixing pin.

[0006] Optionally, radial guide grooves for sliding with the first pin shaft are circumferentially and uniformly arranged on the driving disk.

[0007] Optionally, a support block is fixedly arranged at the end of the support rod far from the center, for radially supporting the workpiece to be processed.

[0008] Optionally, a hexagonal center hole for cooperating with a hex wrench is arranged at the right end of the driving shaft.

[0009] Optionally, a nut for fixing the driving disk is arranged on the driving shaft.

[0010] Optionally, an arc-shaped limiting groove is arranged on the driving disk, and a limiting pin is fixedly arranged on the disk, for cooperating with the arc-shaped limiting groove to limit the extreme position of the rotation of the driving disk.

[0011] Optionally, the substrate and the disk are fixedly connected through a connecting plate.

[0012] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: By adopting the dynamic tensioning turning fixture of the present invention, when the diameter of the workpiece increases due to temperature rise during turning, each support rod can automatically adapt to the diameter change of the workpiece, but maintain a constant supporting force, so that the circular shape accuracy of the turned workpiece is high; The dynamic tensioning turning fixture of the present invention has a simple structure, is convenient to manufacture, and has a low cost. Description of the Drawings

[0013] Figure 1 The front view of the turning fixture provided by the embodiment of the present invention is shown; Figure 2 The rear view of the turning fixture provided by the embodiment of the present invention is shown; Figure 3 The exploded view of the turning fixture provided by the embodiment of the present invention is shown.

[0014] In the figure: 1, fixture body; 2, support rod; 3, bushing; 4, driving shaft; 5, driving disk; 6, nut; 7, torsion spring; 8, spacer ring; 9, workpiece to be processed; 11, substrate; 12, disk; 13, connecting plate; 14, second pin shaft; 15, limiting pin; 16, fixing pin; 21, pin hole; 22, first pin shaft; 23, support block; 51, radial guide groove; 52, limiting groove. Detailed Embodiments

[0015] In order to make the technical means, creative features, achieved purposes and functions of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

[0016] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0017] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific circumstances.

[0018] As Figures 1 - 3 shown, a dynamic tensioning turning fixture is disclosed, including: A fixture body 1, the fixture body 1 is provided with a base plate 11, the base plate 11 is coaxially connected with a disc 12, and a bushing 3 is coaxially arranged at the center of the disc 12; A driving disc 5, the driving disc 5 is connected with the bushing 3 through a driving shaft 4; The disc 12 is circumferentially provided with a dynamic support mechanism for rotating and tensioning the inner circle of the workpiece 9 to be machined, and the disc 12 is also circumferentially provided with a spacer ring 8 for restricting the axial position of the workpiece 9 to be machined.

[0019] The dynamic support mechanism includes a support rod 2, a torsion spring 7, and a second pin 14. The second pin 14 is circumferentially arranged on the disc 12 and the second pin is far from the center of the disc 12. The support rod 2 is matched with the second pin 14 through a pin hole 21. A first pin 22 which is slidably connected with the driving disc 5 is fixedly arranged at the near center end of the support rod 2. The inner end of the torsion spring 7 is connected with the driving shaft 4, and the outer end is fixed to the disc 12 through a fixing pin 16.

[0020] In the specific implementation process of this embodiment, the fixture body 1 is fixedly connected into an integral body by a base plate 11 and a disc 12 which are coaxially and parallelly arranged through a connecting plate 13. The fixture body 1 is fixedly connected with the machine tool spindle through the base plate 11.

[0021] The bushing 3 is coaxially and fixedly arranged at the center of the disc 12. The driving shaft 4 passes through the center of the disc 12 and is in sliding fit with the inner hole of the bushing 3. The right end of the driving shaft 4 is provided with a hexagonal center hole for cooperating with a hexagon wrench. The driving disc 5 is coaxially and fixedly arranged at the right end of the driving shaft 4 and is pressed by a nut 6. Radial guide grooves 51 are circumferentially and uniformly arranged around the driving disc 5, with 8 in the illustration. The driving disc 5 enables the support rods 2 to rotate synchronously, and the far center ends of the support rods 2 enclose a circle. An arc-shaped limiting groove 52 with the center of the driving disc 5 as the arc center is also provided on the driving disc 5, with 2 in the illustration. The torsion spring 7 is arranged inside the disc 12. The inner end of the torsion spring 7 is fixed to the left end of the driving shaft 4, and the outer end of the torsion spring 7 is fixed to the disc 12 through a fixing pin 16. A limiting pin 15 is also fixedly arranged outside the disc 12, and the limiting pin 15 cooperates with the arc-shaped limiting groove 52 formed on the driving disc 5 to limit the extreme position of the rotation of the driving disc 5. Pin shafts two 14 are circumferentially and uniformly fixedly arranged outside the disc 12, with 8 pin shafts two in the illustration, and the pin shafts two 14 are far from the center of the disc 12. The support rods 2 are hingedly arranged outside the disc 12 through pin holes 21 in cooperation with the pin shafts two 14. A pin shaft one 22 is fixedly arranged at the near center end of the support rod 2, and the pin shaft one 22 is in precise sliding fit with the radial guide grooves 51 on the periphery of the driving disc 5. A support block 23 is fixedly arranged at the far center end of the support rod 2 to radially support the workpiece to be processed 9. The pin hole 21 is close to the far center end of the support rod 2 to reduce the torque of the driving disc 5 and increase the supporting force on the workpiece to be processed 9. A cushion ring 8 is also fixedly arranged outside the disc 12 to control the axial position of the workpiece to be processed 9. Working description: Lock the lathe spindle, use a hexagon wrench to rotate the driving shaft 4 and the driving disc 5 clockwise, drive the support rods 2 to rotate counterclockwise with the pin shafts two 14 as the fulcrums. The circle formed by the outer ends (far center ends) of the support rods 2 becomes smaller. Place the workpiece to be processed 9 into the installation position, and the left end face of the workpiece fits with the right end face of the cushion ring 8; loosen the hexagon wrench, the driving shaft 4 and the driving disc 5 rotate clockwise and reset under the action of the torsion spring 7, the support rods 2 rotate clockwise with the pin shafts two 14 as the fulcrums, and the circle formed by the outer ends of the support rods 2 becomes larger to support the inner circle of the workpiece to be processed 9. When placing the workpiece to be processed, make the inner boss where the hole is located on the workpiece to be processed abut against (be located at) the left side of the outer end of the support rod 2. (During normal turning, the lathe spindle drives the workpiece to rotate counterclockwise, and the turning tool gives the workpiece a clockwise torque. The inner boss abuts against the left side of the outer end of the support rod 2, making each support rod have a tendency to rotate clockwise. The outer ends of the support rods 2 always fit with the inner circle of the workpiece to be processed, and the magnitude of the supporting force is determined by the torsion spring and basically remains constant; when the diameter of the workpiece to be processed increases due to temperature rise during turning, each support rod 2 will automatically adapt to the change but maintain the supporting force constant; if four bolts are directly used to pass through 4 holes to fixedly install the workpiece on the side of the disc 12.)Due to thermal deformation, and the points where the four holes are located are restricted by bolts and cannot move, the other arc segments expand and arch outwards, causing the workpiece to become non-circular. After the outer circle is turned into a circle and naturally cooled, the arched segments of the arc concave inwards, and the workpiece is no longer a regular circle. During actual processing, the diameter of the workpiece is more than 600 millimeters. After measurement, the roundness error is greater than 0.5 millimeters, exceeding the technical allowable value, indicating that the deformation is still significant. The above description is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. A dynamic tension turning fixture, characterized in that Comprising: A fixture body (1), the fixture body (1) is provided with a base plate (11), the base plate (11) is coaxially connected with a disc (12), and a bushing (3) is coaxially arranged at the center of the disc (12); A driving disc (5), the driving disc (5) is connected with the bushing (3) through a driving shaft (4); A dynamic support mechanism for rotationally tensioning the inner circle of a workpiece to be machined (9) is circumferentially arranged on the disc (12), and a packing ring (8) for restricting the axial position of the workpiece to be machined (9) is also circumferentially arranged on the disc (12).

2. The dynamic tension turning fixture according to claim 1, wherein The dynamic support mechanism includes a support rod (2), a torsion spring (7) and a second pin shaft (14), the second pin shaft (14) is circumferentially arranged on the disc (12), and the second pin shaft is far from the center of the disc (12), the support rod (2) is matched with the second pin shaft (14) through a pin hole (21), a first pin shaft (22) fixedly connected with the driving disc (5) is arranged at the near center end of the support rod (2), the inner end of the torsion spring (7) is connected with the driving shaft (4), and the outer end is fixed to the disc (12) through a fixing pin (16).

3. The dynamic tension turning fixture according to claim 2, wherein Radial guide grooves (51) slidable with the first pin shaft (22) are circumferentially and uniformly arranged on the driving disc (5).

4. The dynamic tension turning fixture according to claim 3, characterized in that A support block (23) is fixedly arranged at the end of the support rod (2) far from the center for radially supporting the workpiece to be machined (9).

5. The dynamic tension turning fixture according to claim 1, wherein A hexagonal center hole for cooperating with a hexagon wrench is arranged at the right end of the driving shaft (4).

6. The dynamic tension turning fixture according to claim 1, characterized in that A nut (6) for fixing the driving disc (5) is arranged on the driving shaft (4).

7. The dynamic tension turning fixture according to claim 1, characterized in that, An arc-shaped limiting groove (52) is arranged on the driving disc (5), and a limiting pin (15) is fixedly arranged on the disc (12) for cooperating with the arc-shaped limiting groove (52) to limit the extreme position of the rotation of the driving disc (5).

8. The dynamic tension turning fixture according to claim 1, wherein The base plate (11) and the disc (12) are fixedly connected through a connecting plate (13).

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