阅读说明：本技术 一种焊管自动化气密性检测装置 (Automatic air tightness detection device for welded pipe ) 是由 杜兴吉 凌张伟 唐萍 汤杰 蒋政培 陈永贵 缪存坚 孔帅 郑慕林 于 2019-11-20 设计创作，主要内容包括：本发明涉及自动化检测技术领域。技术方案是：一种焊管自动化气密性检测装置,包括气密检测器件、PLC控制器,其特征在于：该装置还包括机架、相互平行且向下倾斜布置以输送焊管的若干输入台架、安装在输入台架末端以检测焊管气密性的气密试验机构、设置在气密试验机构旁边以分选合格管和不合格管的分选机构、用于接收不合格管的废料架以及用于接收和传送合格管至下一工位的过渡料架；所述输入台架、气密试验机构、分选机构和过渡料架沿焊管的输送方向依序布置；各作业机构均与PLC控制器电连接以进行统一控制。该装置采用气压式检测法来检测焊管的气密性,避免了气泡检测法中焊管生锈、腐蚀等问题,能够避免人工检测误差,提高产品质量。(The invention relates to the technical field of automatic detection. The technical scheme is as follows: the utility model provides an automatic air tightness detection device of welded tube, includes airtight detection device, PLC controller, its characterized in that: the device also comprises a frame, a plurality of input racks which are parallel to each other and are arranged downwards in a downward inclined mode to convey the welded pipes, an airtight test mechanism which is installed at the tail end of each input rack to detect the airtightness of the welded pipes, a sorting mechanism which is arranged beside the airtight test mechanism to sort the qualified pipes and the unqualified pipes, a waste material rack which is used for receiving the unqualified pipes and a transition material rack which is used for receiving and conveying the qualified pipes to the next station; the input rack, the air tightness testing mechanism, the sorting mechanism and the transition material rack are sequentially arranged along the conveying direction of the welded pipe; all the operation mechanisms are electrically connected with the PLC for unified control. The device adopts the vapour-pressure type detection method to detect the gas tightness of welded tube, has avoided among the bubble detection method welded tube to rust, corrode scheduling problem, can avoid artifical detection error, improves product quality.)

1. The utility model provides an automatic air tightness detection device of welded tube, includes airtight detection device, PLC controller, its characterized in that: the device also comprises a frame (1), a plurality of input racks (2) which are parallel to each other and are arranged downwards in an inclined way to convey the welded pipes (7), an airtight testing mechanism (3) which is arranged at the tail ends of the input racks to detect the airtightness of the welded pipes, a sorting mechanism (4) which is arranged beside the airtight testing mechanism to sort the qualified pipes and the unqualified pipes, a waste material rack (5) for receiving the unqualified pipes and a transition material rack (6) for receiving and conveying the qualified pipes to the next station; the input rack, the air tightness testing mechanism, the sorting mechanism and the transition material rack are sequentially arranged along the conveying direction of the welded pipe; all the operation mechanisms are electrically connected with the PLC for unified control;

the air tightness test mechanism comprises a rotary main shaft (31) which is transversely and horizontally arranged, a plurality of material stirring clamping assemblies (33) which are arranged at the tail end of an input rack and used for stirring down welded pipes from the input rack in sequence and clamping the welded pipes, two groups of turntable feeding assemblies (32) which are respectively arranged at two ends of the rotary main shaft and used for driving the rotary main shaft and driving the material stirring clamping assemblies to rotate at equal angles, a movable sealing end (34) and a fixed sealing end (35) which are respectively arranged at two ends of the welded pipes and used for sealing the welded pipes; a plurality of material shifting clamping assemblies are arranged on the rotating main shaft at equal intervals; the movable sealing end can be positioned on the machine frame in a sliding mode along the length direction of the rotating main shaft so as to seal the welded pipes with different lengths.

2. The automated welded tube airtightness detection apparatus according to claim 1, wherein: the input rack comprises a vertical column (21) which is vertically arranged, the bottom of the vertical column can move transversely through a rolling pair, a diagonal frame (22) which is obliquely fixed at the top of the vertical column, a protective layer (23) which is arranged on the surface of the diagonal frame, and a stop block (24) which is arranged at the tail end of the diagonal frame and used for positioning the position of a welded pipe.

3. The automated welded tube airtightness detection apparatus according to claim 2, wherein: the material shifting and clamping assembly comprises a material shifting disc (331) fixed on the rotating main shaft, at least one clamping and positioning disc (332) which is coaxially arranged with the material shifting disc and can rotate relative to the material shifting disc, and a first air cylinder (333) of which the base is hinged with the material shifting disc and the push rod is hinged with the clamping and positioning disc; the radius of the material stirring disc is larger than that of the clamping positioning disc; a plurality of first notches are uniformly formed in the outer edge of the stirring plate, so that a plurality of stirring hooks (335) for stirring and taking the welded pipes are formed on the stirring plate; the right side face of the material stirring hook is positioned in the first notch, a first protrusion (336) bent towards the inside of the first notch is arranged on the side face, and the left side face of the material stirring hook is positioned in the other adjacent first notch; a plurality of second notches which correspond to the first notches one to one are formed in the clamping positioning disc; a second bulge (337) bent towards the inside of the second notch is arranged in the second notch so as to be matched with the first bulge to clamp the welded pipe together; the stirring plate is provided with an arc-shaped hole (334) extending along the circumferential direction; the clamping positioning plate and a hinge pin of the first cylinder push rod extend into the arc-shaped hole and can move along the arc-shaped hole.

4. The automated welded tube airtightness detection apparatus according to claim 3, wherein: an inclined plate (338) which inclines downwards to convey welded pipes is arranged at the outlet of the welded pipes of the material shifting clamping assembly; the tail end of the inclined plate is located right above the waste material rack.

5. The automated welded tube airtightness detection apparatus according to claim 4, wherein: the number of the clamping positioning plates and the number of the first air cylinders are two, and the two clamping positioning plates are respectively arranged on two sides of the material stirring plate; the two first air cylinders respectively drive the two clamping positioning discs to synchronously rotate.

6. The automated welded tube airtightness detection apparatus according to claim 5, wherein: the turntable feeding assembly comprises a fluted disc (321) fixed on the rotary main shaft, a second cylinder (322) vertically arranged below the fluted disc and corresponding to the position of teeth of the fluted disc, a pawl (323) hinged to the tail end of a push rod of the second cylinder and applying force to the fluted disc upwards in a single direction to push the fluted disc to rotate, and a third cylinder (324) arranged below the fluted disc to limit the rotation of the fluted disc; and a roller (326) is arranged at the tail end of the push rod of the third cylinder so as to be propped between two adjacent teeth of the fluted disc to brake the fluted disc.

7. The automated welded tube airtightness detection apparatus according to claim 6, wherein: the sorting mechanism comprises a sorting plate (41) which is hinged on the rack and positioned above the waste rack, and a pushing cylinder (42) which is arranged on the rack and drives the sorting plate to swing around a hinged axis through a connecting rod.

8. The automated welded tube airtightness detection apparatus according to claim 7, wherein: the movable sealing end comprises a sliding frame (341), a plurality of pulleys (342) which are rotatably positioned at the bottom of the sliding frame to drive the sliding frame to move transversely, a plurality of fourth cylinders (343) which are horizontally arranged on the sliding frame, and a sealing head (344) which is fixed at the tail end of a push rod of each fourth cylinder and is in sealing connection with one end of the welded pipe; and a sealing gasket (345) is arranged in the sealing plug to ensure the sealing performance.

9. The automated welded tube airtightness detection apparatus according to claim 8, wherein: the fixed sealing end comprises a fixed frame (351), a plurality of fifth cylinders (352) horizontally arranged on the fixed frame, and an inflation head (353) which is fixed at the tail end of a push rod of the fifth cylinder and is in sealing connection with the other end of the welding pipe; an inflation hole (354) is formed in the inflation head; the number of the fourth cylinders is the same as that of the fifth cylinders; and the fourth cylinder and the fifth cylinder are in one-to-one correspondence with the positions of the welded pipes in the first notch.

10. The automated welded tube airtightness detection apparatus according to claim 9, wherein: the rotating main shaft is a hollow pipe; an inner pipe (311) is arranged in the rotating main shaft; rotary joints (312) connected with an air pump are respectively and hermetically arranged on the two sides of the inner pipe; and the inner pipe and the rotating main shaft are correspondingly provided with air inlet holes (313) connected with the first air cylinders in the material poking and clamping assemblies.

Technical Field

The invention relates to the technical field of automatic detection, in particular to an automatic airtightness detection device for a welded pipe.

Background

In the production of welded pipes, the welded pipes after finishing processing all need to be subjected to an air tightness detection test, and many production enterprises adopt the traditional method of a bubble method, namely, the two ends of the welded pipes are sealed and then immersed in water, gas with certain pressure is introduced, no bubble is emitted by visual observation, and a leakage point is determined according to the position of the bubble. The method can only be observed by naked eyes and cannot be quantitatively described, the detection result depends on experience, responsibility and the like of detection personnel to a certain extent, the detection result is greatly influenced by human factors, the results measured by different measuring personnel have differences, moreover, when the welded pipe to be detected is put into water, the welded pipe is embroidered, rotten and candled, and the like, so that the subsequent drying and other processes are needed, and the workload is increased.

The air pressure type detection method is characterized in that air is used as a measuring medium, air with certain pressure is introduced into a welded pipe to be detected, then a pressure sensor measures the air pressure value of the inflated welded pipe and converts the differential pressure value of two times into a leakage rate, and therefore whether the welded pipe leaks or not is judged. The method has the advantages of high detection precision, low cost, simple and convenient operation, no influence from subjective factors, no pollution and the like, and does not need to dry the welded pipe after the test. Therefore, it is necessary to design a device for detecting the airtightness of the welded tube by using a pneumatic detection method to overcome the defects in the prior art of the bubble detection method.

Disclosure of Invention

The invention aims to provide an automatic air tightness detection device for welded pipes, which adopts an air pressure type detection method to detect the air tightness of the welded pipes, avoids the problems of rusting, corrosion and the like of the welded pipes in a bubble detection method, does not need a subsequent drying procedure, can simultaneously detect the air tightness of a plurality of welded pipes, has the characteristics of high detection precision, low cost, simple and convenient operation and high automation degree, can avoid manual detection errors and improves the product quality.

The technical scheme provided by the invention is as follows:

the utility model provides an automatic air tightness detection device of welded tube, includes airtight detection device, PLC controller, its characterized in that: the device also comprises a frame, a plurality of input racks which are parallel to each other and are arranged downwards in a downward inclined mode to convey the welded pipes, an airtight test mechanism which is installed at the tail end of each input rack to detect the airtightness of the welded pipes, a sorting mechanism which is arranged beside the airtight test mechanism to sort the qualified pipes and the unqualified pipes, a waste material rack which is used for receiving the unqualified pipes and a transition material rack which is used for receiving and conveying the qualified pipes to the next station; the input rack, the air tightness testing mechanism, the sorting mechanism and the transition material rack are sequentially arranged along the conveying direction of the welded pipe; all the operation mechanisms are electrically connected with the PLC for unified control;

the air tightness test mechanism comprises a rotary main shaft which is transversely and horizontally arranged, a plurality of material stirring clamping assemblies which are arranged at the tail end of an input rack and used for sequentially stirring down welded pipes from the input rack and clamping the welded pipes, two groups of turntable feeding assemblies which are respectively arranged at two ends of the rotary main shaft and used for driving the rotary main shaft and driving the material stirring clamping assemblies to rotate at equal angles, and a movable sealing end and a fixed sealing end which are respectively arranged at two ends of the welded pipes and used for sealing the welded pipes; a plurality of material shifting clamping assemblies are arranged on the rotating main shaft at equal intervals; the movable sealing end can be positioned on the machine frame in a sliding mode along the length direction of the rotating main shaft so as to seal the welded pipes with different lengths.

The input rack comprises a vertical column which is vertically arranged, the bottom of the vertical column can move transversely through a rolling pair, an oblique strip frame which is obliquely fixed at the top of the vertical column, a protective layer which is arranged on the surface of the oblique strip frame, and a stop block which is arranged at the tail end of the oblique strip frame and used for positioning the position of a welded pipe.

The material shifting clamping assembly comprises a material shifting disc fixed on the rotating main shaft, at least one clamping positioning disc which is coaxially arranged with the material shifting disc and can rotate relative to the material shifting disc, and a first air cylinder, wherein a base is hinged with the material shifting disc, and a push rod of the first air cylinder is hinged with the clamping positioning disc; the radius of the material stirring disc is larger than that of the clamping positioning disc; a plurality of first notches are uniformly formed in the outer edge of the stirring plate, so that a plurality of stirring hooks for stirring and taking welded pipes are formed on the stirring plate; the right side face of the material stirring hook is positioned in the first notch, a first bulge bent towards the inside of the first notch is arranged on the side face, and the left side face of the material stirring hook is positioned in the other adjacent first notch; a plurality of second notches which correspond to the first notches one to one are formed in the clamping positioning disc; a second bulge bent towards the inside of the second notch is arranged in the second notch so as to be matched with the first bulge to clamp the welded pipe; the material stirring plate is provided with an arc-shaped hole extending along the circumferential direction; the clamping positioning plate and a hinge pin of the first cylinder push rod extend into the arc-shaped hole and can move along the arc-shaped hole.

An inclined plate which inclines downwards to convey welded pipes is arranged at the outlet of the welded pipes of the material stirring clamping assembly; the tail end of the inclined plate is located right above the waste material rack.

The number of the clamping positioning plates and the number of the first air cylinders are two, and the two clamping positioning plates are respectively arranged on two sides of the material stirring plate; the two first air cylinders respectively drive the two clamping positioning discs to synchronously rotate.

The rotary table feeding assembly comprises a fluted disc fixed on the rotary main shaft, a second cylinder vertically arranged below the fluted disc and corresponding to the position of teeth of the fluted disc, a pawl hinged to the tail end of a push rod of the second cylinder and applying force to the fluted disc upwards in a single direction to push the fluted disc to rotate, and a third cylinder arranged below the fluted disc to limit the rotation of the fluted disc; and the tail end of the push rod of the third cylinder is provided with a roller so as to be propped against between two adjacent teeth of the fluted disc to brake the fluted disc.

Sorting mechanism is including articulating the sorting plate that just is located the waste material frame top in the frame and installing in the frame and order about the swing promotion cylinder of sorting plate around articulated axis through the connecting rod.

The movable sealing end comprises a sliding frame, a plurality of pulleys rotatably positioned at the bottom of the sliding frame to drive the sliding frame to move transversely, a plurality of fourth cylinders horizontally arranged on the sliding frame, and a sealing head fixed at the tail end of a push rod of each fourth cylinder and hermetically connected with one end of the welded pipe; and a sealing gasket is arranged in the sealing plug to ensure the sealing performance.

The fixed sealing end comprises a fixed frame, a plurality of fifth cylinders horizontally arranged on the fixed frame, and an inflation head which is fixed at the tail end of a push rod of the fifth cylinder and is in sealing connection with the other end of the welded pipe; an inflation hole is formed in the inflation head; the number of the fourth cylinders is the same as that of the fifth cylinders; and the fourth cylinder and the fifth cylinder are in one-to-one correspondence with the positions of the welded pipes in the first notch.

The rotating main shaft is a hollow pipe; an inner pipe is arranged in the rotating main shaft; rotary joints connected with an air pump are respectively and hermetically arranged on the two sides of the inner pipe; and the inner pipe and the rotating main shaft are correspondingly provided with air inlets connected with the first air cylinders in the material poking and clamping assemblies.

The invention has the beneficial effects that:

1. in the turntable feeding assembly, the pawl is hinged on the second cylinder, and the pawl applies force to the fluted disc in a single direction, so that the fluted disc can only rotate in a single direction at equal angles under the pushing of the pawl, the positions of subsequent welded pipes, the positions of the plugging cylinders and the positions of the sealing cylinders are convenient to correspond one to one, and the detection efficiency is improved.

2. In the material shifting clamping assembly, the material shifting disc is fixedly connected with the rotating main shaft, and the material shifting disc is driven by the rotating main shaft to rotate in a single direction, so that a welded pipe hook on the input rack is taken into the first notch; and because the clamping positioning disc and the material stirring disc can rotate relatively, when the first cylinder drives the clamping positioning disc to rotate reversely relative to the material stirring disc, the second notch on the clamping positioning disc and the first notch of the material stirring disc are matched to clamp the welded pipe tightly, so that preparation is made for the subsequent air tightness detection of the welded pipe.

3. The sliding frame can transversely slide through the pulleys, so that the sealing detection of the welded pipes with different lengths is facilitated.

4. The sorting mechanism can distinguish unqualified pipes from qualified pipes, and is convenient to manage.

5. The invention can be provided with a plurality of fourth cylinders and fifth cylinders, thereby simultaneously carrying out air tightness detection on a plurality of welded pipes and greatly improving the working efficiency.

6. The invention solves the problems of rusting, corrosion and the like of the welded pipe in the bubble detection method, does not need a subsequent drying procedure, avoids the error of manual detection, realizes the automation of the detection of the air tightness of the welded pipe, and has the advantages of high detection precision and detection efficiency, low cost, reliable work and good market prospect.

Drawings

Fig. 1 is a schematic front view of the present invention.

Fig. 2 is a schematic front view (left view direction in fig. 1) of the air tightness testing mechanism according to the present invention.

Fig. 3 is a schematic front view of the turntable feeding assembly according to the present invention.

Fig. 4 is a schematic front view of the setting member according to the present invention.

Fig. 5 is a schematic side view of the material setting out clamping assembly according to the present invention in a clamping state.

Fig. 6 is a front view of the input stage according to the present invention.

Fig. 7 is a schematic front view of the air tightness testing mechanism and the waste rack according to the present invention.

Fig. 8 is a schematic front view of the sorting mechanism and the transition rack according to the present invention.

Fig. 9 is a schematic cross-sectional structure view of the rotating spindle according to the present invention.

Fig. 10 is a left side view of the movable seal end according to the present invention.

Fig. 11 is a schematic front view of the movable seal end according to the present invention.

Fig. 12 is a left side view of the fixed seal end of the present invention.

Fig. 13 is a front view of the fixed seal end according to the present invention.

1-a frame; 2-an input stage; 21-upright column; 22-a diagonal frame; 23-a protective layer; 24-a stop block; 25-a roller; 26-a guide rail; 3-an air-tightness testing mechanism; 31-a rotating spindle; 311-an inner tube; 312-a rotary joint; 313-air intake holes; 32-a carousel feed assembly; 321-a fluted disc; 322-a second cylinder; 323-pawl; 324-a third cylinder; 325-baffle plate; 326-a roller; 33-a kick-off clamping assembly; 331-material stirring disc; 332-clamping the positioning plate; 333-a first cylinder; 334-arc shaped holes; 335-kick-off hook; 336-a first protrusion; 337-second protrusions; 338-sloping plate; 34-moving the sealed end; 341-sliding frame; 342-a pulley; 343-a fourth cylinder; 344-blocking head; 345-a gasket; 35-fixing the sealed end; 351-a fixed frame; 352-fifth cylinder; 353-an inflation head; 354-inflation holes; 4-a sorting mechanism; 41-a sorting plate; 42-pushing the air cylinder; 5-a waste rack; 6-a transition material rack; 7-welding the tube.

Detailed Description

The following further description is made with reference to the embodiments shown in the drawings.

The automatic airtightness detection device for the welded pipe shown in fig. 1 comprises a rack 1, a plurality of input racks 2, an airtightness testing mechanism 3, a sorting mechanism 4, a waste rack 5, a transition rack 6, an airtightness detection device (existing equipment) and a PLC controller. The input rack, the air tightness testing mechanism, the sorting mechanism and the transition material rack are sequentially arranged along the conveying direction of the welded pipe 7 (namely, the left and right directions in the figure 1, the same below).

The input stages are arranged at equal intervals in the transverse direction (i.e., the direction perpendicular to the paper surface in fig. 1, the same below) and are parallel to each other, and convey the welded pipes in the longitudinal direction (i.e., the left-right direction in fig. 1) to the airtightness testing mechanism. The number of input stages may be determined by the length of the weldment and the distance between adjacent input stages is less than the length of the welded tubes. As shown in fig. 6, the input stage includes a pillar 21, a ramp 22, a protective layer 23, and a stopper 24. The upright columns are vertically arranged, the bottoms of the upright columns are provided with rollers 25, and the rollers and guide rails 26 transversely fixed on the ground form a rolling pair so as to adjust the distance between two adjacent input racks according to the length of a welded pipe. The oblique strip frame is obliquely and downwards fixed at the top of the upright post; the inclination of the oblique strip frame is 2-3 degrees to ensure that the welded pipe smoothly rolls downwards along the oblique strip frame under the action of gravity. The protective layer is arranged on the oblique strip frame and used for protecting the outer surface of the welded pipe; the protective layer is made of rubber or plastic. The stop block is arranged at the tail end of the oblique strip frame so as to position the welded pipe.

As shown in fig. 2, the air tightness testing mechanism is installed at the end of the input stage for detecting the air tightness of the welded pipe. The air tightness testing mechanism comprises a rotating main shaft 31, two groups of turntable feeding assemblies 32, a plurality of material shifting clamping assemblies 33, a movable sealing end 34 and a fixed sealing end 35. The rotating main shaft is transversely and horizontally arranged. The air tightness test mechanism further comprises a booster pump, a pressure reducing valve, an exhaust valve, an air inlet valve, a high-precision pressure gauge, a pressure sensor and a digital display meter (all conventional air tightness detection devices can be purchased and obtained, and are not shown in the figure).

Two groups of turntable feeding assemblies are respectively arranged at two ends of the rotating main shaft and synchronously drive the rotating main shaft to rotate in one direction. As shown in fig. 3, each set of turntable feed assemblies includes a toothed plate 321, a second cylinder 322, a pawl 323, and a third cylinder 324. The fluted disc is fixed on the rotating main shaft and integrally rotates along with the rotating main shaft. The second cylinder is vertically arranged below the fluted disc and corresponds to the tooth position of the fluted disc; the pawl is hinged to the tail end of the push rod of the second cylinder, and the pawl applies force to the fluted disc in an upward single direction so as to push the fluted disc to rotate in a single direction (in the invention, when the second cylinder moves upwards, under the blocking action of the baffle 325, the pawl applies upward thrust to the fluted disc so as to push the fluted disc to rotate clockwise; when the second cylinder moves downwards, the pawl rotates around a hinged shaft of the second cylinder, so that the fluted disc cannot be driven to rotate anticlockwise, and therefore, the fluted disc rotates in a single direction). The third cylinder is arranged below the fluted disc; the end of the push rod of the third cylinder is provided with a roller 326, and the roller is driven by the third cylinder to abut against two adjacent teeth of the fluted disc, so that the fluted disc is braked.

The material stirring clamping assemblies are arranged at the tail end of the input rack and are arranged on the rotating main shaft at equal intervals, and all the material stirring clamping assemblies rotate along with the rotating main shaft under the driving of the two groups of turntable feeding assemblies, so that the welded pipe is sequentially stirred down from the input rack and is clamped, and preparation is made for the air tightness detection of the subsequent welded pipe. The number of the material shifting clamping assemblies can be determined according to the length and the size of the welded pipe, and the distance between every two adjacent material shifting clamping assemblies is generally 1-2 m.

As shown in fig. 4 and 5, each group of material-shifting clamping assemblies comprises a material-shifting disc 331, a clamping positioning disc 332 and a first air cylinder 333; the number of the clamping positioning plate and the first air cylinder in the embodiment is two. The material shifting disc is fixed on the rotary main shaft. The two clamping positioning plates are respectively arranged at two sides of the material shifting plate and can be rotatably positioned on the rotating main shaft; the two clamping positioning plates and the material shifting plate can rotate relatively. The two first air cylinders respectively drive the two clamping positioning discs to synchronously rotate, wherein the base of the first air cylinder is hinged with the material shifting disc, and the push rod of the first air cylinder is hinged with the correspondingly driven clamping positioning disc; set up the arc hole 334 that extends toward the circumferencial direction on the stirring dish, the hinge pin inserts in the arc hole, and the both ends of hinge pin hang respectively behind the outside in arc hole, and articulated simultaneously a clamp positioning dish and first cylinder push rod respectively again (the hinge pin is articulated with two clamp positioning dishes and two first cylinder push rods altogether). During operation, the hinge pin moves along the arc-shaped hole under the driving of the first cylinder, and then drives the two clamping positioning plates to swing relative to the material stirring plate.

The radius of the material stirring disc is larger than that of the clamping positioning disc. A plurality of (eight in the figure) first notches are uniformly formed in the outer edge of the material stirring disc, so that a plurality of (eight in the figure 4) material stirring hooks 335 for stirring and taking welded pipes are formed on the material stirring disc; the right side face of the material poking hook is positioned in the first notch, the side face is provided with a first protrusion 336 bent towards the inside of the first notch, and the left side face of the material poking hook is positioned in the other adjacent first notch and is provided with an inclined surface. Each clamping positioning disc is provided with a plurality of (eight in the figure) second notches which correspond to the first notches one by one; and a second protrusion 337 bent towards the inside of the second notch is arranged in the second notch so as to be matched with the first protrusion to clamp the welded pipe together, and the inner wall of the other side of the second notch is provided with an inclined plane. When the welding pipe clamping device works, the two first air cylinders contract, the material stirring plate and the two clamping and positioning plates are integrated, the two groups of turntable feeding assemblies drive the rotating main shaft to rotate by 45 degrees, and the material stirring hook on the material stirring plate stirs a next welding pipe from the input rack to the first notch; then, the two groups of turntable feeding assemblies continue to rotate, the material stirring disc is driven by the rotating main shaft to rotate 45 degrees again, and the next material stirring hook stirs the next welded pipe into the corresponding first notch from the input rack (the material stirring disc of the embodiment stores four welded pipes at most); and then the two first cylinders extend to drive the two clamping positioning plates to rotate reversely relative to the material stirring plate, so that the second notches on the clamping positioning plates are matched with the first notches on the material stirring plate and the welded pipe is clamped tightly, and preparation is made for subsequent air tightness detection of the welded pipe.

The movable sealing end and the fixed sealing end are respectively arranged at two ends of the welded pipe and used for sealing the welded pipe. During operation, the sliding frame can adjust and fix the interval between the sealing ends according to the length of the welded pipe, so that the air tightness of the welded pipes with different lengths can be detected.

As shown in fig. 10 and 11, the movable sealing end includes a sliding frame 341, a pulley 342, a fourth cylinder 343, and a blocking head 344. Four pulleys are rotatably arranged at the bottom of the sliding frame so as to facilitate the transverse movement of the sliding frame and adapt to welded pipes with different lengths. The fourth cylinder is horizontally arranged on the sliding frame. The blocking head is fixed at the tail end of a push rod of the fourth cylinder so as to be in sealing connection with one end of the welded pipe; a sealing pad 345 is installed in the sealing head to ensure the sealing performance.

As shown in fig. 12 and 13, the fixed sealing end includes a fixed frame 351, a fifth cylinder 352 and an inflation head 353. The fixing frame is fixed on the ground. The fifth cylinder is horizontally arranged on the fixed frame. And the inflation head is fixed at the tail end of a push rod of the fifth cylinder so as to be in sealing connection with the other end of the welded pipe. The inflation head is provided with an inflation hole 354 for facilitating inflation of a booster pump (not shown in the figure) into the welding pipe through the inflation hole. The number of the fourth cylinder is the same as that of the fifth cylinder, and the number of the fourth cylinder is four in the embodiment, so that the air tightness of the plurality of welded pipes can be detected at the same time. The four fourth cylinders and the four fifth cylinders are in one-to-one correspondence with the positions of the four welded pipes in the first notch.

As shown in fig. 7, the welded pipe outlet of the material pulling and clamping assembly is provided with a sloping plate 338 which slopes downwards to convey the welded pipe; the tail end of the inclined plate is positioned right above the waste material rack so as to convey unqualified pipes into the waste material rack. As shown in fig. 8, the sorting mechanism includes a sorting plate 41 and a push cylinder 42. One end of the sorting plate is hinged to the rack, and the other end of the sorting plate is located above the waste material rack and can be connected with the inclined plate. The pushing cylinder is installed on the rack and drives the sorting plate to rotate through the connecting rod. In the initial position, the sorting plate is connected with the inclined plate, and the inclination angle of the sorting plate is the same as that of the inclined plate. When the welded pipe is an unqualified pipe, the air cylinder is pushed to extend to drive the sorting plate to swing upwards (indicated by a double-dot chain line in figure 1), so that the waste material rack is opened, and the unqualified pipe falls into the waste material rack; when the welded pipe is qualified, the sorting plate covers above the waste material rack, and the welded pipe rolls to the transition material rack along the inclined plate and the sorting plate. The transition material rack is connected with the tail end of the sorting plate and used for receiving and conveying the qualified pipes to the next station.

As shown in fig. 9, the rotating main shaft is configured as a hollow tube to prevent the air tube of the first air cylinder in each material pulling and clamping assembly from winding during the rotation of the fluted disc. An inner tube 311 is arranged in the rotating main shaft; rotary joints 312 connected with an air pump are respectively and hermetically arranged on the two sides of the inner pipe; and the inner pipe and the rotating main shaft are correspondingly provided with air inlet holes 313 connected with the first air cylinders in the material poking and clamping assemblies. During operation, gas is connected into the first cylinders through the gas pipe connectors from the inner pipe in the rotating main shaft, and therefore the first cylinders are driven to act simultaneously.

All the air cylinders, the air tightness detecting device, the air tightness testing mechanism, the sorting mechanism, the input rack, the waste rack, the transition rack and other operation mechanisms are respectively and electrically connected with a PLC (programmable logic controller) (not shown in the figure) so as to ensure the working cooperation of all the mechanisms.

The working mode of the invention is as follows:

the welded tube rolls down neatly and slowly along the surface of the input stage and stops at the stop. The two groups of turntable feeding assemblies drive the rotating main shaft to rotate by 45 degrees, and the material shifting hook on the material shifting plate shifts a next welded pipe from the input rack to the first notch; then two sets of carousel feeding components continue to rotate, drive the plectrum dish through the rotating main shaft and rotate 45 once more, next plectrum hook is dialled next welded tube into corresponding first notch from the input rack again, can dial four welded tubes and carry out gas tightness test simultaneously at most. And then all the first cylinders extend simultaneously to drive the clamping positioning disc to reversely swing relative to the material stirring disc, so that the second notch on the clamping positioning disc is matched with the first notch on the material stirring disc and the welded pipe is clamped.

After the material stirring clamping assembly clamps the welded pipe, the fourth cylinder and the fifth cylinder respectively drive the inflation head and the plugging head to seal the corresponding welded pipe, the booster pump boosts low-pressure air to high-pressure air of 1.5MPa, and the high-pressure air is decompressed by the precise pressure reducing valve to reach the pressure required by air tightness detection. The exhaust valve is closed, the air inlet valve is opened, the air is stopped being inflated after the inflation pressure reaches the set requirement, the air inlet valve is closed simultaneously, the pressure sensor measures the air pressure value of the inflated welded pipe, the high-precision pressure gauge directly converts the detection result into the leakage amount and displays the leakage amount through the digital display meter, and therefore whether the welded pipe is qualified or not is judged. The whole process is fully automatic, the working efficiency is greatly enhanced, the influence of human factors is avoided, and the high-precision pressure detector is adopted, so that the detection precision is greatly improved, the requirement of high-precision airtight detection of the welded pipe is met, and the detection precision can reach +/-5 Pa.

After the airtight test is finished, the welded pipe is sequentially sent out through the inclined plate, if the airtight test is unqualified, the pushing cylinder on the transition material rack drives the sorting plate to rise, and the welded pipe falls into the waste material rack. If the airtight test of the welded pipe is qualified, the sorting plate directly rolls to the transition material rack and enters the next station through the transition material rack.

Finally, it should be noted that the above-mentioned list is only a specific embodiment of the present invention. It is obvious that the present invention is not limited to the above embodiments, but many variations are possible. All modifications which can be derived or suggested by a person skilled in the art from the disclosure of the present invention are to be considered within the scope of the invention.