CN118189785B - A device for detecting outer diameter of casting pipe - Google Patents

Abstract

A device for detecting the outer diameter of a casting pipe comprises a casting pipe body and a positioning ring, wherein the casting pipe body can pass through the positioning ring, and two clamping assemblies are symmetrically arranged on the circumference of the positioning ring, and two detection assemblies are symmetrically arranged on the circumference of the positioning ring, and the detection assembly comprises a measuring seat, a positioning frame and a measuring rod, wherein the positioning frame is fixed to the upper end of the measuring seat, and a scale bar is provided on the outer wall of the measuring rod, and the measuring rod passes through the measuring seat, and an adjusting rod passing through the positioning frame is arranged on the top of the measuring rod, and as the measuring rod moves, the distance between the bottom end of the measuring seat and the bottom end of the measuring plate can be intuitively read, and this process does not require manual use of a scale to detect the casting pipe body, and the positioning ring will not be supported by a human hand, which can improve the stability of the positioning ring when detecting the outer diameter of the casting pipe body, and thus can improve the accuracy of the outer diameter of the casting pipe body when detecting.

Description

A device for detecting outer diameter of casting pipe

Technical Field

The invention relates to the field of detection devices, in particular to a casting pipe outer diameter detection device.

Background technique

Castings are metal shaped objects obtained by various casting methods, that is, the smelted liquid metal is poured into a pre-prepared mold by pouring, injection, suction or other casting methods, and after cooling and subsequent processing such as grinding, the resulting object has a certain shape, size and performance. The outer diameter of the casting tube needs to be tested after it is manufactured;

Most of the existing casting pipes are tested using a ruler. Due to the different types of casting pipes, when the outer diameter of the casting pipe is large, the stability of the ruler will be low when the ruler is manually picked up to test it. If the human hand shakes, the accuracy of the casting pipe during testing will be reduced.

Summary of the invention

1. Technical issues to be resolved

In view of the deficiencies in the prior art, the present invention provides a device for detecting the outer diameter of a casting pipe.

(II) Technical solution

To achieve the above object, the present invention provides the following technical solutions: a casting pipe outer diameter detection device, comprising a casting pipe body and a positioning ring, the casting pipe body can penetrate the positioning ring, and two clamping components are symmetrically arranged on the circumference of the positioning ring, and two detection components are symmetrically arranged on the circumference of the positioning ring;

The detection assembly includes a measuring seat, a positioning frame and a measuring rod. The two measuring seats are symmetrically fixed on the upper end and the lower end of the positioning ring. The positioning frame is fixed on the upper end of the measuring seat. The outer wall of the measuring rod is provided with a scale bar. The measuring rod passes through the measuring seat. The lower end of the measuring rod is provided with a measuring plate that contacts the casting pipe body. The top end of the measuring rod is provided with an adjusting rod that passes through the positioning frame. A toggle block is fixedly provided on the top end of the adjusting rod. Limiting grooves are symmetrically provided on both sides of the measuring rod. Two limiting assemblies for limiting the measuring rod are symmetrically provided on the positioning frame. Two positioning assemblies are symmetrically provided at both ends of the measuring plate.

The locking mechanism is a function of the locking cam which is actuated by the locking cam and the retaining member is a function of the locking cam being coupled to the locking cam and the retaining member being coupled to the locking cam and the retaining member being coupled to the locking cam.

In order to improve the stability of the measuring rod when in use, the improvements of the present invention are that the limit assembly includes a limit rod, a push plate is fixedly arranged on the outer end of the limit rod, and second guide rods are provided on both sides of the positioning frame, which pass through the two ends of the push plate, and two positioning grooves are symmetrically arranged inside the positioning frame, and a clamping slot and a first empty slot are provided on the inner wall of the positioning slot, and the first empty slot is connected to the clamping slot, one end of the limit rod can be inserted into the interior of the positioning slot, and one end of the limit rod is provided with a cavity, and a spring is provided inside the cavity, and one end of the spring is provided with a clamping block matching the clamping slot, one side of the positioning frame is provided with a U-shaped rod, and two ends of the U-shaped rod are provided with second driving rods that can pass through the first empty slot, and the end of the limit rod away from the push plate is provided with a limit block inserted into the interior of the limit slot, and the clamping slot, clamping block and limit block are all trapezoidal.

In order to make the U-shaped rod installed more firmly, the present invention has the following improvements: stoppers are fixedly provided at both ends of the U-shaped rod, the stoppers are located at the outer ends of the second driving rods, and the stoppers are magnets, and the positioning frame is made of iron.

In order to improve the stability of the measuring plate during adjustment, the improvements of the present invention are as follows: the positioning assembly includes a guide groove and a support plate, the guide grooves are located on both sides of the measuring plate, a third guide rod is fixedly arranged at the bottom end of the support plate, both ends of the third guide rod can pass through the guide groove, and the third guide rod can move inside the guide groove, a fixed seat is provided on the inner wall of the positioning ring, and the top end of the support plate is rotatably connected to the fixed seat.

In order to facilitate the adjustment of the position of the positioning ring on the casting pipe body, the present invention is improved in that a plurality of balls contacting the casting pipe body are provided on the outer wall of the clamping block.

In order to prevent the bottom rod from falling off, the present invention has the following improvements: a telescopic rod is fixedly arranged on the upper end of the positioning seat, a top plate is fixedly arranged on the top end of the first driving rod and the vertical rod, and the top plate is fixed on the top of the telescopic rod.

Furthermore, the present invention is improved in that the toggle block, the adjusting rod, the measuring rod and the measuring plate are an integrated structure, and the cross bar, the supporting plate and the positioning rod are an integrated structure.

In order to make the structure more convenient to take, the present invention is improved in that a plurality of second empty grooves are provided inside the positioning ring.

(III) Beneficial effects

Compared with the prior art, the present invention provides a casting pipe outer diameter detection device, which has the following beneficial effects:

The casting pipe outer diameter detection device, when the driving wheel is rotating, the positioning rod can move on the positioning seat through the action of the threaded structure, and at this time the support plate will drive the clamping block to move, so that multiple clamping blocks can all contact the outer wall of the casting pipe body, and the arc rod is provided to facilitate the synchronous operation of the two bottom rods, so that the two driving wheels can rotate synchronously, and then the two positioning rods can move synchronously, which can ensure that the casting pipe body is clamped in the middle position of the positioning ring, and with the movement of the measuring rod, the distance between the bottom end of the measuring seat and the bottom end of the measuring plate can be intuitively read. In this process, there is no need to manually take a scale to detect the casting pipe body, and the positioning ring will not be supported by the human hand, which can improve the stability of the positioning ring when detecting the outer diameter of the casting pipe body, and thus can improve the accuracy of the outer diameter of the casting pipe body during detection;

When the card block moves to the position of the card slot, it will just enter the inside of the card slot, at this time the spring will reset, and the limit block will be inserted into the inside of the limit slot, and there will be a certain friction between the limit block and the limit slot, so as to provide a limit effect for the measuring rod, so that the position of the measuring rod is not easy to move after the toggle block is subjected to external force, which can improve the stability of the measuring rod after adjustment, and thus improve the accuracy of the measuring rod when reading;

When the casting pipe body is in a tilted state, the operator can support the positioning ring with one hand and operate the corresponding toggle block with the other hand to separate the measuring plate from the casting pipe body. The positioning ring can be moved freely on the casting pipe body, which is convenient for temporary detection of multiple positions on the casting pipe body and has few limitations during use.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a top view of a three-dimensional structure of the present invention;

FIG2 is a front view of FIG1 of the present invention;

FIG3 is a side view of FIG1 of the present invention;

FIG4 is a top view of FIG1 of the present invention;

FIG5 is a schematic diagram of the matching structure of the limiting block and the limiting groove in the present invention;

FIG6 is a schematic diagram of the matching structure of the card block and the card slot in the present invention;

FIG7 is a schematic diagram of a partial enlarged structure of point A in FIG1 of the present invention;

FIG8 is a schematic diagram of a partial enlarged structure of point B in FIG1 of the present invention;

FIG9 is a schematic diagram of a partial enlarged structure of point C in FIG2 of the present invention;

In the figure: 1, casting pipe body; 2, positioning ring; 3, positioning seat; 4, positioning rod; 5, support plate; 6, clamping block; 7, first guide rod; 8, driving wheel; 9, bottom rod; 10, first driving rod; 11, limit seat; 12, vertical rod; 13, top plate; 14, telescopic rod; 15, measuring seat; 16, measuring rod; 17, measuring plate; 18, toggle block; 19, positioning frame; 20, limit slot; 21, limit rod; 22, limit block; 23, second guide rod; 24, U-shaped rod; 25, stopper; 26, positioning slot; 27, clamping slot; 28, first empty slot; 29, clamping block; 30, support plate; 31, third guide rod; 32, guide slot; 33, push plate; 34, arc rod; 35, adjustment rod.

Detailed ways

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Referring to Fig. 1 to Fig. 9, a device for detecting the outer diameter of a casting pipe of the present invention comprises a casting pipe body 1 and a positioning ring 2, wherein the casting pipe body 1 can penetrate the positioning ring 2, and two clamping components are symmetrically arranged on the circumference of the positioning ring 2, and two detection components are symmetrically arranged on the circumference of the positioning ring 2;

The detection assembly includes a measuring seat 15, a positioning frame 19 and a measuring rod 16. The two measuring seats 15 are symmetrically fixed at the upper end and the lower end of the positioning ring 2. The positioning frame 19 is fixed at the upper end of the measuring seat 15. The outer wall of the measuring rod 16 is provided with a scale bar. The measuring rod 16 passes through the measuring seat 15. The lower end of the measuring rod 16 is provided with a measuring plate 17 that contacts the casting pipe body 1. The top of the measuring rod 16 is provided with an adjusting rod 35 that passes through the positioning frame 19. The top of the adjusting rod 35 is fixedly provided with a toggle block 18. The two sides of the measuring rod 16 are symmetrically provided with limit grooves 20. Two limit assemblies for limiting the measuring rod 16 are symmetrically provided on the positioning frame 19. Two positioning assemblies are symmetrically provided at both ends of the measuring plate 17.

The clamping assembly comprises a positioning seat 3, a bottom rod 9 and a positioning rod 4, the two positioning seats 3 are symmetrically fixed on the left and right sides of the positioning ring 2, the positioning rod 4 penetrates the positioning seat 3, and the outer side of the positioning rod 4 is rotatably provided with a driving wheel 8 penetrated by the positioning seat 3, and the driving wheel 8 is threadedly connected to the positioning rod 4, and two support plates 5 are symmetrically arranged on the inner end of the positioning rod 4, and a cross bar is fixedly arranged at one end of the support plate 5 away from the positioning rod 4, and clamping blocks 6 contacting the casting pipe body 1 are rotatably arranged at both ends of the cross bar, and a third empty groove is arranged inside the positioning seat 3, and a first guide rod 7 inserted into the third empty groove is arranged on the support plate 5, and a limiting seat 11 located on one side of the driving wheel 8 is fixedly arranged on the positioning seat 3, and a first driving rod 10 and a vertical rod 12 are symmetrically arranged on the upper end of the bottom rod 9, and the first driving rod 10 is meshed with the driving wheel 8, and the vertical rod 12 penetrates the limiting seat 11, and the two bottom rods 9 are connected by an arc rod 34;

When the structure is used, take the positioning ring 2, pass the casting pipe body 1 through the positioning ring 2, and then clamp the casting pipe body 1 through two clamping components. At this time, after the position of the positioning ring 2 can be positioned on the casting pipe body 1, the outer diameter of the casting pipe body 1 can be further detected by the detection component;

When the clamping assembly is in use, first an upward force is provided to the bottom rod 9. When this force is greater than the friction force between the driving wheel 8 and the positioning rod 4, the first driving rod 10 can drive the driving wheel 8 to rotate through the meshing effect. Since the position of the driving wheel 8 is fixed on the outer side of the positioning seat 3, when the driving wheel 8 is rotating, the positioning rod 4 can move on the positioning seat 3 through the effect of the threaded structure. At this time, the support plate 5 will drive the clamping block 6 to move, so that multiple clamping blocks 6 can all contact the outer wall of the casting pipe body 1. In this process, the first guide rod 7 will move in the third empty groove, thereby improving the stability of the support plate 5 when moving. The arc rod 34 is provided to facilitate the synchronous operation of the two bottom rods 9, so that the two driving wheels 8 can rotate synchronously, and then the two positioning rods 4 can move synchronously, which can ensure that the casting pipe body 1 is clamped in the middle position of the positioning ring 2;

When the detection assembly is in use, the measuring rod 16 and the measuring seat 15 have a certain friction force, and this friction force is greater than the gravity of the measuring rod 16 itself, and then a downward force is provided to the toggle block 18, so that the adjusting rod 35 can drive the measuring rod 16 to move. Here, there is no mandatory provision for the length of the adjusting rod 35, and further, the two measuring plates 17 can both contact the outer wall of the casting pipe body 1. As for the scale bar on the outer wall of the measuring rod 16, there is no mandatory provision for its accuracy, and the scale bars on the outer walls of the two measuring rods 16 have the same specifications. It should be noted here that the distance between the bottom ends of the two measuring seats 15 is X2, and the distance between the bottom end of the measuring seat 15 and the bottom end of the measuring plate 17 is X1. The outer diameter of the casting pipe body 1 can be obtained by subtracting two X1 from X2, and then its size is engraved on the measuring rod 16. The outer wall can be, that is, the so-called scale bar. At this time, with the movement of the measuring rod 16, the distance between the bottom end of the measuring seat 15 and the bottom end of the measuring plate 17 can be read intuitively, which is defined as X3 here. At this time, X3 does not represent the actual distance between the bottom end of the measuring seat 15 and the bottom end of the measuring plate 17, but represents the actual distance of the outer diameter of the casting pipe body 1. This process does not require manual use of a scale to detect the casting pipe body 1. The positioning ring 2 will not be supported by the human hand, which can improve the stability of the positioning ring 2 when detecting the outer diameter of the casting pipe body 1, thereby improving the accuracy of the outer diameter of the casting pipe body 1 during detection. It should be noted here that after the position of the measuring rod 16 is adjusted, it is necessary to observe whether the scale values on the two measuring rods 16 are consistent. If they are inconsistent, it can be explained that the outer diameter of the casting pipe body 1 is not circular.

The lack of a limiting structure at the measuring rod 16 will affect the stability of the measuring rod 16 after adjustment, and will cause the measuring rod 16 to be inaccurate when reading. The limiting assembly includes a limiting rod 21, and a push plate 33 is fixedly arranged at the outer end of the limiting rod 21. Second guide rods 23 penetrating the two ends of the push plate 33 are arranged on both sides of the positioning frame 19. Two positioning grooves 26 are symmetrically arranged inside the positioning frame 19. A card slot 27 and a first empty slot 28 are arranged on the inner wall of the positioning groove 26. The first empty slot 28 is connected to the card slot 27. One end of the limiting rod 21 can be inserted into the interior of the positioning groove 26, and one end of the limiting rod 21 is provided with a cavity, a spring is provided inside the cavity, one end of the spring is provided with a clamping block 29 that cooperates with the clamping groove 27, one side of the positioning frame 19 is provided with a U-shaped rod 24, and both ends of the U-shaped rod 24 are provided with a second driving rod that can penetrate the first empty groove 28, and the end of the limiting rod 21 away from the push plate 33 is provided with a limiting block 22 inserted into the interior of the limiting groove 20, and the clamping groove 27, the clamping block 29 and the limiting block 22 are all trapezoidal;

When the position of the measuring rod 16 is adjusted, a thrust is provided to the limit rod 21, and the push plate 33 moves along the second guide rod 23, and the block 29 first compresses the spring, and the block 29 is first located inside the cavity. When the block 29 moves to the position of the slot 27, it just enters the slot 27, and the spring is reset. At this time, the limit block 22 is inserted into the limit groove 20, and there is a certain friction between the limit block 22 and the limit groove 20, so as to provide a limiting effect for the measuring rod 16, so that the position of the measuring rod 16 is not easy to move after the toggle block 18 is subjected to external force, and the stability of the measuring rod 16 after adjustment can be improved, thereby improving the accuracy of the measuring rod 16 when reading;

Stoppers 25 are fixedly arranged at both ends of the U-shaped rod 24. The stoppers 25 are located at the outer ends of the second driving rods. The stoppers 25 are magnets. The material of the positioning frame 19 is iron.

When it is necessary to reset the measuring rod 16, take the U-shaped rod 24, and insert the second driving rods at both ends of the U-shaped rod 24 through the first slot 28 to provide a thrust to the U-shaped rod 24, so that the stopper 25 can contact the positioning frame 19, and there will be a magnetic attraction between the stopper 25 and the positioning frame 19. At this time, the second driving rod can push the block 29 out of the slot 27. Since the block 29 is trapezoidal and both sides of the block 29 have inclined surfaces, even if the second driving rod does not push the block 29 into the slot 27, the second driving rod can push the block 29 out of the slot 27. When the push plate 33 is pushed out completely, a pulling force is provided to the limit rod 21, which can also make the block 29 disengage from the slot 27 and compress the spring of the block 29, so that the limit block 22 can be pulled out of the limit slot 20. The structure is simple and the operation is convenient. The number of limit rods 21 is not specified here, and according to the actual situation, a limit block 22 or other limiting objects can be temporarily installed at one end of the second guide rod 23 to limit the push plate 33, so as to prevent the limit rod 21 from falling on the positioning frame 19.

In the present structure, the measuring plate 17 lacks a supporting structure, which will affect the stability of the measuring plate 17 when clamping the casting pipe body 1. The positioning assembly includes a guide groove 32 and a support plate 30. The guide groove 32 is located on both sides of the measuring plate 17. A third guide rod 31 is fixedly arranged at the bottom end of the support plate 30. Both ends of the third guide rod 31 can penetrate the guide groove 32, and the third guide rod 31 can move inside the guide groove 32. A fixing seat is provided on the inner wall of the positioning ring 2. The top end of the support plate 30 is rotatably connected to the fixing seat. When the position of the measuring plate 17 moves, the support plate 30 can be tilted, and at this time, the third guide rod 31 will move inside the guide groove 32, thereby providing a supporting structure for the measuring plate 17, improving the stability of the measuring plate 17 when clamping the casting pipe body 1, and further improving the accuracy of the measuring rod 16 when reading.

In the present structure, a plurality of balls contacting the casting pipe body 1 are provided on the outer wall of the clamping block 6. When the present structure detects the outer diameter of the casting pipe body 1, due to a certain friction between the measuring plate 17 and the casting pipe body 1, when the casting pipe body 1 is in a horizontal state, there is no need to manually support the positioning ring 2. When the casting pipe body 1 is in an inclined state, the operator can support the positioning ring 2 with one hand and operate the corresponding toggle block 18 with the other hand to separate the measuring plate 17 from the casting pipe body 1, so that the positioning ring 2 can move freely on the casting pipe body 1, which is convenient for temporary detection of multiple positions on the casting pipe body 1, and has low limitations during use.

Furthermore, a telescopic rod 14 is fixedly provided at the upper end of the positioning seat 3, and a top plate 13 is fixedly provided at the top of the first driving rod 10 and the vertical rod 12. The top plate 13 is fixed to the top of the telescopic rod 14. When the bottom rod 9 is raised or lowered, the top plate 13 can drive the telescopic rod 14 to extend or retract. The top plate 13 can limit the first driving rod 10 to prevent the first driving rod 10 from detaching from the driving wheel 8.

Furthermore, the toggle block 18, the adjusting rod 35, the measuring rod 16 and the measuring plate 17 may be an integrated structure, and the cross bar, the supporting plate 5 and the positioning rod 4 may be an integrated structure.

Furthermore, the positioning ring 2 can be made of aluminum alloy. Aluminum alloy has the advantages of high hardness and not easy to be damaged. The interior of the positioning ring 2 is provided with a plurality of second empty grooves. The plurality of second empty grooves can make the positioning ring 2 lighter when being taken.

In the description of this article, it should be noted that relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims (7)

1. A device for detecting the outer diameter of a casting pipe, characterized in that it comprises a casting pipe body (1) and a positioning ring (2), wherein the casting pipe body (1) can penetrate the positioning ring (2), and two clamping components are symmetrically arranged on the circumference of the positioning ring (2), and two detection components are symmetrically arranged on the circumference of the positioning ring (2); The detection assembly comprises a measuring seat (15), a positioning frame (19) and a measuring rod (16), wherein the two measuring seats (15) are symmetrically fixed at the upper end and the lower end of the positioning ring (2), the positioning frame (19) is fixed at the upper end of the measuring seat (15), the outer wall of the measuring rod (16) is provided with a scale bar, the measuring rod (16) passes through the measuring seat (15), the lower end of the measuring rod (16) is provided with a measuring plate (17) contacting the casting pipe body (1), the top end of the measuring rod (16) is provided with an adjusting rod (35) passing through the positioning frame (19), the top end of the adjusting rod (35) is fixedly provided with a toggle block (18), the two sides of the measuring rod (16) are symmetrically provided with limit grooves (20), the positioning frame (19) is symmetrically provided with two limit assemblies for limiting the measuring rod (16), and two positioning assemblies are symmetrically provided at both ends of the measuring plate (17); The clamping assembly comprises a positioning seat (3), a bottom rod (9) and a positioning rod (4); the two positioning seats (3) are symmetrically fixed on the left and right sides of the positioning ring (2); the positioning rod (4) penetrates the positioning seat (3); a driving wheel (8) penetrated by the positioning seat (3) is rotatably provided on the outer side of the positioning rod (4); the driving wheel (8) is threadedly connected to the positioning rod (4); two support plates (5) are symmetrically provided on the inner end of the positioning rod (4); a cross bar is fixedly provided on one end of the support plate (5) away from the positioning rod (4); two ends of the cross bar are rotatably provided A clamping block (6) contacts the casting pipe body (1), a third slot is provided inside the positioning seat (3), a first guide rod (7) is provided on the support plate (5) and is inserted into the third slot, a limiting seat (11) is fixedly provided on the positioning seat (3) and is located on one side of the driving wheel (8), a first driving rod (10) and a vertical rod (12) are symmetrically provided at the upper end of the bottom rod (9), the first driving rod (10) is meshed with the driving wheel (8), the vertical rod (12) passes through the limiting seat (11), and the two bottom rods (9) are connected by an arc rod (34); The positioning assembly comprises a guide groove (32) and a support plate (30), wherein the guide groove (32) is located on both sides of the measuring plate (17), a third guide rod (31) is fixedly arranged at the bottom end of the support plate (30), both ends of the third guide rod (31) can penetrate the guide groove (32), and the third guide rod (31) can move inside the guide groove (32), a fixing seat is provided on the inner wall of the positioning ring (2), and the top end of the support plate (30) is rotatably connected to the fixing seat. 2. A casting pipe outer diameter detection device according to claim 1, characterized in that: the limit assembly comprises a limit rod (21), the outer end of the limit rod (21) is fixedly provided with a push plate (33), both sides of the positioning frame (19) are provided with second guide rods (23) penetrating the two ends of the push plate (33), the interior of the positioning frame (19) is symmetrically provided with two positioning grooves (26), the inner wall of the positioning groove (26) is provided with a clamping groove (27) and a first empty groove (28), the first empty groove (28) is communicated with the clamping groove (27), one end of the limit rod (21) can Inserted into the interior of the positioning groove (26), and one end of the limiting rod (21) is provided with a cavity, a spring is provided in the interior of the cavity, and one end of the spring is provided with a clamping block (29) that cooperates with the clamping groove (27), a U-shaped rod (24) is provided on one side of the positioning frame (19), and both ends of the U-shaped rod (24) are provided with a second driving rod that can pass through the first empty groove (28), and the end of the limiting rod (21) away from the push plate (33) is provided with a limiting block (22) inserted into the interior of the limiting groove (20), and the clamping groove (27), the clamping block (29) and the limiting block (22) are all trapezoidal. 3. A casting pipe outer diameter detection device according to claim 2, characterized in that: stoppers (25) are fixedly arranged at both ends of the U-shaped rod (24), the stoppers (25) are located at the outer ends of the second driving rod, and the stoppers (25) are magnets, and the positioning frame (19) is made of iron. 4. A casting pipe outer diameter detection device according to claim 3, characterized in that: a plurality of balls contacting the casting pipe body (1) are provided on the outer wall of the clamping block (6). 5. A casting pipe outer diameter detection device according to claim 4, characterized in that: a telescopic rod (14) is fixedly arranged at the upper end of the positioning seat (3), a top plate (13) is fixedly arranged at the top end of the first driving rod (10) and the vertical rod (12), and the top plate (13) is fixed on the top of the telescopic rod (14). 6. A casting pipe outer diameter detection device according to claim 5, characterized in that: the toggle block (18), the adjustment rod (35), the measuring rod (16) and the measuring plate (17) are an integrated structure, and the cross bar, the support plate (5) and the positioning rod (4) are an integrated structure. 7. A casting pipe outer diameter detection device according to claim 6, characterized in that a plurality of second empty grooves are provided inside the positioning ring (2).