Rotary clamping device

Abstract

The invention discloses a rotary clamping device which comprises a base and a workbench arranged on the base through a supporting bearing, a fixing ring is fixedly connected to the workbench, a lead screw seat and three supporting seats are fixedly connected to the fixing ring at intervals, a lower sliding ring is placed on the fixing ring, a horizontal lead screw penetrates through the lead screw seat, and the lead screw and the lead screw seat are provided with an axial positioning device. One end of the lead screw is connected with a lead screw nut through threads, the lower end of the lead screw nut is fixedly connected with a lower core shaft, and the lower core shaft is arranged in an inner hole of a convex lug fixedly connected with the lower sliding ring; the outer ends of the three clamping jaws are hinged to respective supporting seats, the middles of the clamping jaws penetrate through respective sliding sleeves in a sliding mode, the sliding sleeves are all arranged on the lower sliding ring, the lower ends of the sliding sleeves are all fixedly connected with lower rotating shafts, and the lower rotating shafts are all arranged in respective sleeve holes of the lower sliding ring; the clamping function is achieved through rotation of the clamping jaws, the device has the advantages of being small in size and large in application range, a workpiece can be easily rotated, and the detection efficiency and safety can be improved.

Description

Technical Field

[0001] The invention relates to a rotary clamping device, in particular to a rotary clamping device used for flaw detection. Background Art

[0002] like Figure 1 As shown in the figure, the flange pipe joint commonly used in the fields of boilers is a standard flange + pipe joint butt structure. The diameter D1 of the flange 31 is larger than the diameter D2 of the pipe joint 32, and the height H1 of the flange 31 is smaller than the height H2 of the pipe joint 32, presenting a "long-legged mushroom" shape. The flange 31 and the pipe joint 32 are butt-welded into a whole, and the butt weld needs to be subjected to radiographic (RT) flaw detection after welding. During flaw detection, the workpiece is placed upright on the flaw detection flat car table, and the radiation source is fixed on the head of the movable frame, which can move in the XYZ direction (left and right, front and back, up and down). According to the factors such as the diameter, wall thickness, radiation source power, and flaw detection standard requirements of the flange pipe joint, the film is attached to the pipe wall, and the radiation source is placed inside or outside the pipe for exposure inspection according to actual needs. The height of the radiation source is consistent with the height of the weld. When multiple exposure inspections are required, the pipe seat needs to be manually rotated to a certain angle after each exposure until the entire welding annular seam area is fully covered by multiple exposures. The pipe diameter D2 of the flange pipe joint ranges from tens to hundreds, the flange height H1 is small, and the pipe joint length H2 is large. Due to the height limitation of the head of the gantry, the flange pipe joint needs the pipe joint (small end) to be at the bottom and the flange (large end) to be at the top, and placed upside down with the top larger and the bottom smaller. At present, in the process of joint flaw detection, the existing clamping device is similar to the three-jaw clamping structure of the machine tool. The three jaws slide radially to achieve loosening and clamping. The jaw drive includes manual, electric, pneumatic and other methods; but the applicable diameter range of the clamping device is relatively small. To expand the applicable range, the external dimensions of the clamping device need to be increased or divided into multiple clamping devices. The flange pipe joint has the characteristics of many diameter specifications and large spans. To achieve a wide range of specifications, the volume of the clamping device is relatively large, which affects its applicability; in addition, when multiple exposures are required during the detection process, the workpiece needs to be manually rotated to a certain angle after each exposure. There is no rotation device to assist in the manual rotation process. Large-sized flange pipe joints have the problem of difficulty in rotation and the safety risk of tipping, and the detection efficiency and safety are low. Summary of the invention

[0003] The purpose of the present invention is to provide a rotary clamping device to address the above-mentioned deficiencies in the prior art. The device realizes the clamping function by rotating the clamping jaws, has the advantages of small size and wide application range, can easily rotate the workpiece, and can improve detection efficiency and safety.

[0004] In order to achieve the above-mentioned purpose, a rotating clamping device of the present invention includes a base; it is characterized in that: a workbench is placed on the base through a supporting bearing, a fixing ring is fixedly connected to the workbench, a screw seat and three support seats are fixedly connected to the fixing ring at intervals, a lower sliding ring is placed on the fixing ring, a horizontal screw passes through the screw seat, and the screw and the screw seat are provided with an axial positioning device; one end of the screw is connected to the screw nut through a thread, the lower end of the screw nut is fixedly connected to a lower core shaft, and the lower core shaft is placed in the inner hole of the lug fixed to the lower sliding ring; the outer ends of the three jaws are hinged to their respective support seats, and the middle parts of each jaw slide through their respective sliding sleeves, the sliding sleeves are placed on the lower sliding ring, the lower ends of the sliding sleeves are fixedly connected to lower rotating shafts, and the lower rotating shafts are placed in their respective sleeve holes of the lower sliding ring.

[0005] The axial positioning device can be two baffles fixedly connected to the screw and arranged in an axial direction, and a clamping block fixedly connected to the screw seat, and the clamping block is placed between the two baffles; The above-mentioned axial positioning device can also be a rotating bearing arranged between the screw rod and the screw rod seat; both can make the screw rod only rotate without axial movement; When the present invention is used, the workpiece is placed on the workbench, and the screw is rotated, and the screw nut, the lower slide ring, and the sliding sleeve drive each clamping jaw to rotate around its hinge shaft. At the same time, the screw nut and the sliding sleeve can rotate, and the three clamping jaws can clamp or loosen the workpiece. The present invention realizes the clamping function by rotating the clamping jaws. Compared with the radial moving clamping device, the present invention has the advantages of small size and wide application range, and the workpiece can be easily rotated through the supporting bearing, which can improve the detection efficiency and safety. As a further improvement of the present invention, the upper end of a central shaft is fixedly connected to the workbench through a thread, the lower end of the central shaft is connected to the base through a bearing, and a threaded retaining ring is provided on the central shaft below the bearing; the central shaft can ensure the concentricity of the workbench when rotating, which is convenient for detection; As a further improvement of the present invention, an upper sliding ring is provided above the lower sliding ring at intervals, more than two connecting blocks are provided between the upper sliding ring and the lower sliding ring, the upper sliding ring and the lower sliding ring are both fixedly connected to the connecting blocks, the lugs fixedly connected to the upper sliding ring are provided with an inner hole, the upper end of the screw nut is fixedly connected to an upper core shaft, and the upper core shaft is placed in the inner hole; the upper sliding ring is provided with three sleeve holes, the upper end of each sliding sleeve is fixedly connected to an upper rotating shaft, and the upper rotating shaft is placed in its own sleeve hole; the upper sliding ring and the lower sliding ring are fixedly connected to form a frame, which can improve the strength of the device and facilitate clamping of the workpiece; As a further improvement of the present invention, a plurality of pressure plates fixedly connected to the fixed ring are provided on the radial outer side of the lower sliding ring, and the pressure plates partially cover the lower sliding ring from above; the rotation of the lower sliding ring can be limited and guided; As a further improvement of the present invention, a convex ring is provided at the upper end of the fixed ring, and the lower sliding ring is sleeved outside the convex ring, so as to facilitate the installation and rotational guidance of the lower sliding ring; As a further improvement of the present invention, the other end of the screw rod is a square head, which is convenient for rotating the screw rod; In summary, the present invention realizes the clamping function through the rotation of the clamping jaws, has the advantages of small size and wide application range, and can easily rotate the workpiece, thereby improving detection efficiency and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 It is the front view of the flange pipe joint.

[0007] Figure 2 FIG. 4 is a top view of an embodiment of the present invention.

[0008] Figure 3 for Figure 2 AA section view.

[0009] Figure 4 for Figure 2 BB cross-sectional view.

[0010] Figure 5 for Figure 2 CC cross-sectional view.

[0011] Figure 6 for Figure 2 DD cross-sectional view.

[0012] Figure 7 for Figure 3 EE cross-section diagram.

[0013] Figure 8 for Figure 3 Cross-sectional view of the middle base and workbench in the other direction.

[0014] Fig. 9 for Figure 7 Side view of the middle sleeve.

[0015] Fig.10 for Figure 5 Side view of the center lead screw nut.

[0016] Fig.11 It is a top view of the embodiment of the present invention in a released state. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with the accompanying drawings.

[0018] like Figures 2 to 10As shown, a rotary clamping device of this embodiment comprises a base 1, a workbench 3 placed on the base through a supporting bearing 2, an upper end of a central shaft 4 is fixedly connected to the workbench 3 through a thread, and the lower end of the central shaft 4 is connected to the base 1 through a bearing 5, and a threaded retaining ring 6 is provided on the central shaft 4 below the bearing 5; a fixing ring 9 is fixedly connected to the workbench 3 through a plurality of pads 7 and connecting bolts 8, a screw seat 10 and three support seats 11 uniformly distributed in the circumferential direction are fixedly connected to the fixing ring 9 at intervals, a lower sliding ring 12 is placed on the fixing ring 9, a convex ring is provided on the upper end of the fixing ring 9, and a lower sliding ring 12 is placed on the fixing ring 9. The sliding ring 12 is sleeved outside the convex ring, and several pressure plates 13 are provided on the radial outer side of the lower sliding ring 12, which are fixedly connected to the fixing ring 9 by screws. The pressure plates 13 partially cover the lower sliding ring 12 at the top; an upper sliding ring 18 is provided above the lower sliding ring 18 at intervals, and three connecting blocks 17 are provided at equal intervals between the upper sliding ring 18 and the lower sliding ring 12. The upper sliding ring 18 and the lower sliding ring 12 are fixedly connected to the connecting blocks 17 by bolts; a horizontal screw rod 14 passes through the screw rod seat 10, and the screw rod 14 and the screw rod seat 10 are provided with an axial positioning device, which is welded and fixed to the screw rod. Two baffles 15 arranged on the rod 14 and arranged in the axis, and a block 16 fixedly connected to the screw seat 10 by screws, the block 16 is placed between the two baffles 15; one end of the screw 14 is connected to the screw nut 19 by a thread, and the other end of the screw 14 is a square head; the two ends of the screw nut 19 are respectively fixedly connected with an upper mandrel 20 and a lower mandrel 21, the upper mandrel 20 is placed in the inner hole of the lug fixedly connected to the upper sliding ring 18, and the lower mandrel 21 is placed in the inner hole of the lug fixedly connected to the lower sliding ring 12; the outer ends of the three clamps 22 are hinged to their respective support seats 11 through screws 23, and the screws 23 As hinge shafts, they pass through their respective clamping jaws 22 and are connected to the support seat 11. Gaskets and nuts are provided at both ends of the screw rod 23. The middle of each clamping jaw 22 slides through its own sliding sleeve 26. The sliding sleeves 26 are placed between the upper sliding ring 18 and the lower sliding ring 12. The three sliding sleeves 26 are evenly distributed in the circumferential direction. The two ends of the sliding sleeve 26 are fixedly connected with an upper rotating shaft 27 and a lower rotating shaft 28. The upper rotating shaft 27 is placed in the respective sleeve holes of the upper sliding ring 18, and the lower rotating shaft 28 is placed in the respective sleeve holes of the lower sliding ring 12. The workbench 3 can also be provided with a plurality of longitudinal tightening screws 29 through threads. When the present invention is used, it is placed on the flatbed of the flaw detection vehicle, and the workpiece is placed upside down on the workbench 3. The screw nut 19 is moved by rotating the screw 14, and the screw nut 19, the lower slide ring 12, and the sliding sleeve 26 drive each clamping jaw 22 to rotate around its hinge axis. At the same time, the screw nut 19 and the sliding sleeve 26 can rotate around the axis at both ends to ensure the freedom of rotation of each clamping jaw. The three clamping jaws 22 can clamp (such as Figure 2 as shown) or loosen (as shown Fig.11The workpiece is shown in the figure, and the sliding sleeve 26 limits and loads the rotation of each clamping jaw 22 to ensure the clamping force and clamping effect; the present invention realizes the clamping function by rotating the clamping jaw 22, and has the advantages of small size and wide application range compared with the radial movement clamping device, and the worktable 3 and the workpiece can be easily rotated by the supporting bearing 2 to avoid tipping. For the workpiece with light weight, the worktable 3 can be fixed at the detection position by the tightening screw 29, which can improve the detection efficiency and safety; The central axis 4 can ensure the concentricity of the worktable when it rotates, which is convenient for detection and improves accuracy; the upper sliding ring 18 and the lower sliding ring 12 are fixedly connected to form a frame, which can improve the strength of the device and facilitate clamping of the workpiece; The present invention is not limited to the above-mentioned embodiments. For example, the above-mentioned axial positioning device may also be replaced by a rotating bearing disposed between the screw rod 14 and the screw rod seat 10, so that the screw rod can only rotate but not move axially. The above embodiments have been described, but it should be understood that the above embodiments are only for the purpose of example and description, and are not intended to limit the present invention to the scope of the described embodiments.

Claims

1. A rotary clamping device, comprising a base; characterized in that: A workbench is placed on the base through a supporting bearing, and a fixing ring is fixedly connected to the workbench, and a screw seat and three support seats are fixedly connected to the fixing ring at intervals, a lower sliding ring is placed on the fixing ring, and a horizontal screw passes through the screw seat, and the screw and the screw seat are provided with axial positioning devices; one end of the screw is connected to the screw nut through a thread, and the lower end of the screw nut is fixedly connected to a lower core shaft, and the lower core shaft is placed in the inner hole of the lug fixed to the lower sliding ring; the outer ends of the three jaws are hinged to their respective support seats, and the middle parts of each jaw slide through their respective sliding sleeves, and the sliding sleeves are placed on the lower sliding ring, and the lower ends of the sliding sleeves are fixedly connected to lower rotating shafts, and the lower rotating shafts are placed in their respective sleeve holes of the lower sliding ring.

2. A rotary clamping device according to claim 1, characterized in that: The axial positioning device comprises two baffles fixedly connected to the screw rod and arranged in axial direction, and a clamping block fixedly connected to the screw rod seat, wherein the clamping block is arranged between the two baffles.

3. A rotary clamping device as claimed in claim 1, characterized in that: The axial positioning device is a rotating bearing arranged between the screw and the screw seat.

4. A rotary clamping device according to any one of claims 1 to 3, characterized in that: The upper end of a central shaft is fixedly connected with the workbench through a thread, the lower end of the central shaft is connected with the base through a bearing, and a threaded retaining ring is arranged on the central shaft below the bearing.

5. A rotary clamping device as claimed in claim 4, characterized in that: An upper sliding ring is arranged above the lower sliding ring, and more than two connecting blocks are arranged between the upper sliding ring and the lower sliding ring. The upper sliding ring and the lower sliding ring are both fixedly connected to the connecting blocks. The lug to which the upper sliding ring is fixedly connected is provided with an inner hole. The upper end of the screw nut is fixedly connected with an upper core shaft, and the upper core shaft is placed in the inner hole. The upper sliding ring is provided with three sleeve holes, and the upper end of each sliding sleeve is fixedly connected with an upper rotating shaft, and the upper rotating shaft is placed in its respective sleeve holes.

6. A rotary clamping device according to claim 5, characterized in that: A plurality of pressure plates fixedly connected to the fixing ring are arranged on the radial outer side of the lower sliding ring, and the pressure plates partially cover the lower sliding ring at the upper part.

7. A rotary clamping device according to claim 6, characterized in that: A convex ring is arranged on the upper end of the fixing ring, and the lower sliding ring is sleeved outside the convex ring.

8. A rotary clamping device according to claim 7, characterized in that: The other end of the screw rod is a square head.

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