A screw measuring instrument for steel pipe

Abstract

The present invention belongs to the technical field of metallurgical industry detection instruments and tools, and provides a screw track measuring instrument in a steel pipe, comprising: a support seat; a bracket, the bracket is fixedly assembled on the support seat, and a horizontal track and a vertical track extending along the axial direction thereof are provided on the bracket, the vertical track passes through the bracket and intersects with the horizontal track vertically; a slider is slidably assembled in the horizontal track; a dial indicator, the dial indicator comprises a round dial, a sleeve and a measuring rod, the lower end of the measuring rod is provided with a ball, the sleeve is inserted in the vertical track, the sleeve is fixedly connected to the slider, so that the dial indicator can slide along the axial direction of the bracket with the slider, and the measuring rod can be extended and retracted along the radial direction of the bracket; a pull rod, the pull rod has a scale, the pull rod is concentrically inserted in the horizontal track, one end of the pull rod is fixedly connected to the slider, and the other end can extend outside the bracket. The screw track depth value and pitch can be measured by a single person, and the instrument has the advantages of small detection accuracy error value, large detection specification range, long detection distance, short single detection time and simple and convenient operation.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgical industry detection instruments and tools, and in particular relates to a steel pipe internal screw measuring instrument. Background Art

[0002] When rolling steel pipes, internal threads are easily generated. Existing quality inspection tools and instruments cannot directly and accurately detect the depth and pitch of the internal threads. To detect the depth of the internal threads on the inner wall of the steel pipe, the existing internal thread depth detection method is steel ruler + feeler gauge. Due to the limited space of the inner hole size of the steel pipe, conventional detection tools and instruments cannot be used, especially small-diameter steel pipes cannot be detected, resulting in difficulty in measuring the depth and pitch of the internal screw channel, large errors, and low efficiency. The specific measurement shortcomings and deficiencies are as follows: 1. The measurement error is greater than 0.4mm; 2. When measuring small-sized steel pipes, it can only be estimated based on experience; 3. It can only be tested within 600mm of the end of the steel pipe; 4. The single measurement time is as long as 8-10 minutes, and the thickness of the feeler gauge needs to be continuously changed according to the depth of the steel ruler and the screw channel; 5. Two people are required to cooperate in the measurement, one person fixes the steel ruler, and the other uses the feeler gauge.

[0003] Therefore, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Summary of the invention

[0004] The purpose of the present invention is to provide a steel pipe inner screw thread measuring instrument, which can quickly and accurately detect the inner screw thread size of the steel pipe.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A steel pipe internal screw measuring instrument, comprising:

[0007] Support seat;

[0008] A bracket, the bracket is fixedly mounted on the support seat, the bracket is provided with a horizontal track and a vertical track extending along its axial direction, the vertical track passes through the bracket and intersects with the horizontal track vertically;

[0009] A slider is slidably mounted in the horizontal track;

[0010] A dial indicator, the dial indicator comprises a round dial, a sleeve and a measuring rod sleeved in the sleeve, a ball bearing is arranged at the lower end of the measuring rod, the sleeve is inserted in a vertical track, the sleeve is fixedly connected to the slider, so that the dial indicator can slide along the axial direction of the bracket with the slider, and the measuring rod can be extended and retracted along the radial direction of the bracket;

[0011] A pull rod is provided with a scale, the pull rod is coaxially inserted into the horizontal track, one end of the pull rod is fixedly connected to the slider, and the other end can extend out of the bracket.

[0012] As described above, the screw track measuring instrument in steel pipe, preferably, has two support seats, one of which is fixed at one end of the bracket, and the other is fixed at the middle position of the bracket, and the height difference between the two support seats is less than 0.02mm, so as to ensure that the height difference between the two ends of the bracket is less than 0.02mm.

[0013] As described above, in the steel pipe internal screw measuring instrument, preferably, the support seat is provided with a support hole for inserting the bracket, and the bracket is fixedly connected to the support seat by a positioning screw.

[0014] As described above, the screw track measuring instrument in steel pipe is preferably equipped with a rolling bearing at the lower part of the support seat, and the support seat and the rolling bearing are connected by a pin shaft so that the bracket can move linearly along the axial direction of the steel pipe to be measured.

[0015] As described above, in the steel pipe internal screw measuring instrument, preferably, the sliding block is provided with a mounting hole adapted to the sleeve, and the sleeve is inserted into the mounting hole.

[0016] As described above, the screw track measuring instrument in steel pipe is preferably provided with a screw hole on the slider, the central axis of the screw hole is perpendicularly intersected with the central axis of the sleeve, a clamping bolt is provided in the screw hole, the sleeve is fixedly connected to the slider by the clamping bolt, and a plurality of the clamping bolts are evenly distributed along the circumference of the sleeve.

[0017] As described above, the screw track measuring instrument in a steel pipe is preferably coated with a curing agent in the mounting hole.

[0018] As described above, in the steel pipe internal screw measuring instrument, preferably, the end of the bracket is provided with a notch to facilitate pulling the pull rod out of the bracket.

[0019] As described above, the screw track measuring instrument in steel pipe, preferably, the horizontal track has a total length of 400mm, and its running parallelism is 0.01mm; the vertical track has a total length of 400mm, and its running parallelism is 0.01mm, and its perpendicularity accuracy error with the horizontal cross track is less than 0.002 degrees.

[0020] As described above, the screw track measuring instrument inside a steel pipe is preferably provided with a socket for inserting the pull rod at the center position of the end of the bracket, the diameter of the socket is 10 mm, the socket is connected to the horizontal track, and the fitting clearance between the pull rod and the socket is a transition fit, and the fitting clearance is 0.02-0.05 mm.

[0021] Beneficial effects:

[0022] When the present invention is in use, the operator places the internal screw measuring instrument on the inner wall of the steel pipe to be tested so that it is basically parallel to the center line of the steel pipe, ensures that the support seat of the measuring instrument contacts the inner wall of the steel pipe and does not shake, then grasps the bracket with the left hand, grasps the pull rod with the scale with the right hand, moves it back and forth, moves the dial indicator measuring rod to the required position, reads the value indicated by the pointer on the circular dial of the dial indicator, then pulls the pull rod with the right hand to move the dial indicator measuring rod back and forth, and the operator records the maximum and minimum values ​​of the pointer swing and subtracts the two to calculate the screw depth value; at the same time, according to the front and rear positions of the dial indicator and the digital difference indicated by the pull rod at the end of the detection rod bracket, the pitch of the screw can be quickly understood. Therefore, the present invention has the following advantages: 1. The detection accuracy error value can reach within 0.05mm; 2. The detection specification range is large, and the inner diameter of the detected steel pipe is ≥80mm; 3. The detection distance is long, and the steel pipe end can be detected within 1.5m; 4. The single detection time is <5min; 5. It can be operated by one person and the operation is simple and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0024] Figure 1 It is a structural schematic diagram of the steel pipe internal screw measuring instrument of the present invention;

[0025] Figure 2 for Figure 1 B view.

[0026] The names corresponding to the various figure marks in the figure are: 1. support seat; 2. bracket; 3. dial indicator; 4. pull rod; 5. slider; 6. rolling bearing; 7. pin shaft; 8. clamping bolt; 9. positioning screw; 21. horizontal track; 22. vertical track; 23. notch; 31. round dial; 32. sleeve; 33. measuring rod; 34. ball. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0028] In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention. The terms "connected" and "connected" used in the present invention should be understood in a broad sense. For example, they can be fixed connections or detachable connections; they can be directly connected or indirectly connected through intermediate components. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0029] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0030] The design principle of the present invention is: an instrument is designed according to the minimum size of the inner diameter of the steel pipe to be detected and the outer size of the dial indicator 3, the inner thread depth value is intuitively read through the swing value of the pointer of the dial indicator 3, and the pitch is directly calculated from the pull rod 4 with a scale according to the periodic change value of the pointer when the dial indicator 3 moves.

[0031] like Figure 1-2 As shown, a steel pipe internal screw measuring instrument comprises:

[0032] Support seat 1;

[0033] The bracket 2 is fixedly mounted on the support base 1. The bracket 2 is provided with a horizontal track 21 and a vertical track 22 extending along its axial direction. The vertical track 22 passes through the bracket 2 and intersects with the horizontal track 21 vertically.

[0034] A slider 5 is slidably mounted in the horizontal track 21;

[0035] The dial gauge 3 includes a round dial 31, a sleeve 32 and a measuring rod 33 sleeved in the sleeve 32. The sleeve 32 is inserted into the vertical track 22. The sleeve 32 is fixedly connected to the slider 5 so that the dial gauge 3 can slide along the axial direction of the bracket 2 with the slider 5, and the measuring rod 33 can be extended and retracted along the radial direction of the bracket 2. A ball 34 is provided at the lower end of the measuring rod.

[0036] The pull rod 4 has a scale on it. The pull rod 4 is concentrically inserted into the horizontal track 21. One end of the pull rod 4 is fixedly connected to the slider 5, and the other end can extend outside the bracket 2.

[0037] In order to improve the detection accuracy and enable the detection personnel to detect the screw depth value and pitch conveniently, intuitively and quickly, the instrument adopts the dial indicator 3 to detect the screw depth. The ball 34 at the bottom of the measuring rod 33 is in direct contact with the screw on the inner wall of the steel pipe. The change value of the screw depth is measured by the tiny straight line up and down movement of the measuring rod 33 of the dial indicator 3, and then through the rack and gear connected to it in the circular dial 31, the linear movement of the measuring rod 33 is amplified by the gear and converted into the rotation of the needle on the circular dial 31. There are 100 equally divided scales printed on the circular dial 31, that is, each division value is equivalent to the movement of the measuring rod 33 by 0.01mm, and each rotation of the pointer represents the movement of the measuring rod 33 by 1mm. In this way, the measurer can directly subtract the original value from the maximum value to calculate the screw depth value.

[0038] In this embodiment, there are two support seats 1, one of which is fixed at one end of the bracket 2, and the other is fixed at the middle position of the bracket 2. Specifically, one of the support seats is fixed at the front end of the bracket, and the other is fixed at a position close to the rear hand-held portion of the bracket. At the same time, in order to reduce the processing error of the two support seats and ensure that the processing error is less than 0.02mm, it is particularly required that the two support seats must be placed together for processing during production to reduce the error caused by separate processing, so as to ensure that the height difference of the two support seats is less than 0.02mm, thereby ensuring that the height difference of the two ends of the bracket 2 is less than 0.02mm.

[0039] The horizontal track 21 and the vertical track 22 are located between the two support seats 1. The two support seats 1 have a limiting effect on the movement of the slider 5. The support seat 1 is provided with a support hole for inserting the bracket 2, and the bracket 2 is fixedly connected to the support seat 1 by a positioning screw 9. The positioning screw 9 is located at the upper part of the support seat 1.

[0040] In other embodiments, there are three support seats 1 , one support seat 1 is disposed at each end of the bracket 2 , and one support seat 1 is disposed in the middle of the bracket 2 .

[0041] Since the instrument needs to be moved frequently, in order to reduce the error caused by wear caused by sliding friction, the support seat 1 uses a rolling bearing 6 as a support point. In this embodiment, the lower part of the support seat 1 is equipped with a rolling bearing 6, and the support seat 1 and the rolling bearing 6 are connected by a pin 7 so that the bracket 2 can move linearly along the axial direction of the steel pipe to be measured. A rolling bearing 6 is respectively provided at both ends of the pin 7, and there are a total of 4 rolling bearings 6 on the two support seats 1 as support points for the bracket 2. By utilizing the characteristics of high positioning accuracy, flexible rotation, and wear resistance of the rolling bearing 6, the measurement accuracy of the instrument can be improved, and the movement is convenient, reliable, and durable.

[0042] By installing a support seat with rolling bearings at the front and rear ends of the horizontal track and the vertical track, the overall forward and backward movement of the instrument can be achieved and the horizontality of the bracket can be ensured.

[0043] In order to ensure the flexibility and reliability of the instrument movement, the support seat 1 must be installed on the bracket 2 and firmly positioned before the bearing shaft hole position is machined on the machine tool based on the track to ensure manufacturing accuracy. The bracket 2 material is 42CrMo quenched and tempered to ensure the strength of the spare parts and reduce deformation.

[0044] The slider 5 is provided with a mounting hole adapted to the sleeve 32, and the sleeve 32 is inserted into the mounting hole. The slider 5 is provided with a screw hole, the central axis of the screw hole is perpendicularly intersected with the central axis of the sleeve 32, and a clamping bolt 8 is provided in the screw hole. The sleeve 32 is fixedly connected to the slider 5 through the clamping bolt 8, and the two clamping bolts 8 are evenly distributed along the circumference of the sleeve 32. A curing agent is applied in the mounting hole. Due to the positioning by the double clamping bolts 8 and the strengthening fixing effect of the curing agent, not only the positioning reliability of the dial indicator 3 and the convenience of disassembly can be guaranteed, but also the error caused by the sliding of the dial indicator 3 itself to the instrument can be reduced, thereby ensuring the test accuracy.

[0045] In other embodiments, four clamping bolts 8 are evenly distributed around the circumference of the sleeve 32 .

[0046] In this embodiment, the vertical track 22 has a total length of 400 mm and a running parallelism of 0.01 mm. Specifically, when the slider moves in the track, the height change error value within the moving range of 400 mm is ≤ 0.01 mm, and the error value is the detection value on the reference working platform. The vertical track 22 has a total length of 400 mm and a running parallelism of 0.01 mm. The verticality accuracy error between the vertical track 22 and the horizontal cross track is less than 0.002 degrees.

[0047] A socket for inserting the pull rod is provided at the center of the end of the bracket 2. The diameter of the socket is 10 mm. The socket is connected to the horizontal track 21. The fitting clearance between the pull rod 4 and the socket is a transition fit, and the fitting clearance is 0.02-0.05 mm. A notch 23 is provided at the end of the bracket 2 to facilitate pulling the pull rod 4 out of the bracket 2. The diameter of the notch 23 is larger than the diameter of the socket.

[0048] In order to ensure the stability and convenience of the slider 5 moving in the horizontal track 21, the clearance between the tie rod 4 and the slider 5 should not be too large, and a transition fit is preferably used. In addition, in order to firmly connect the tie rod 4 and the slider 5, a threaded connection is adopted between the tie rod 4 and the slider 5, and thread glue is applied between the two. Specifically, an external thread section is provided at the end of the tie rod 4, and a threaded hole adapted to the external thread section is opened on the slider 5.

[0049] The working principle and operation method of the present invention are as follows:

[0050] The operator places the internal screw measuring instrument on the inner wall of the steel pipe to be tested, so that it is basically parallel to the center line of the steel pipe, and ensures that the 14 rolling bearings 6 of the support seat of the measuring instrument are in contact with the inner wall of the steel pipe at the same time without shaking, then grabs the bracket 2 with the left hand, grabs the pull rod 4 with the scale with the right hand, moves it back and forth, moves the measuring rod 33 of the dial indicator 3 to the required position, reads the value indicated by the pointer on the round dial 31 of the dial indicator 3, and then pulls the pull rod 4 with the right hand to move the measuring rod 33 of the dial indicator 3 back and forth. After the operator records the maximum and minimum values ​​of the pointer swing, the two are subtracted to calculate the screw depth value. At the same time, the operator can quickly understand the pitch of the screw according to the front and rear positions of the dial indicator 3 and the digital difference indicated by the pull rod 4 at the end of the detection rod bracket 2.

[0051] It is to be understood that the above description is only exemplary and the embodiments of the present application do not limit this. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A screw measuring instrument for steel pipes, characterized in that: The screw thread measuring instrument in the steel pipe is used to measure the screw thread depth value and screw thread pitch, and comprises: Support seat; there are two support seats, one of which is fixed at one end of the bracket, and the other support seat is fixed at the middle position of the bracket; A bracket, the bracket is fixedly mounted on the support seat, the bracket is provided with a horizontal track and a vertical track extending along its axial direction, the vertical track passes through the bracket and intersects with the horizontal track vertically; A slider, the slider being slidably assembled in the horizontal track; A dial indicator, the dial indicator comprises a round dial, a sleeve and a measuring rod sleeved in the sleeve, a ball bearing is arranged at the lower end of the measuring rod, the sleeve is inserted in a vertical track, the sleeve is fixedly connected to the slider, so that the dial indicator can slide along the axial direction of the bracket with the slider, and the measuring rod can be extended and retracted along the radial direction of the bracket; A pull rod, the pull rod has a scale, the pull rod is coaxially inserted into the horizontal track, one end of the pull rod is fixedly connected to the slider, and the other end can extend outside the bracket, The rolling bearing is mounted on the lower part of the support seat, and the support seat and the rolling bearing are connected by a pin shaft so that the bracket can move linearly along the axial direction of the steel pipe to be tested. Move the measuring rod to the required position, the ball at the bottom of the measuring rod is in direct contact with the screw channel on the inner wall of the steel pipe, read the value indicated by the pointer on the circular dial of the dial indicator, and then move the measuring rod back and forth. The change in screw channel depth is calculated by the small straight line up and down movement of the measuring rod. Subtract the maximum and minimum values ​​of the pointer swing, and calculate the screw channel depth value. According to the periodic change value of the pointer when the dial indicator moves, the pitch is directly calculated from the pull rod with the scale.

2. The steel pipe internal screw measuring instrument according to claim 1, characterized in that: The height difference between the two support seats is less than 0.02 mm, so as to ensure that the height difference between the two ends of the bracket is less than 0.02 mm.

3. The steel pipe internal screw measuring instrument according to claim 2, characterized in that: The support seat is provided with a support hole for inserting the bracket, and the bracket is fixedly connected to the support seat by a positioning screw.

4. The steel pipe internal screw measuring instrument according to claim 1, characterized in that: The sliding block is provided with a mounting hole adapted to the sleeve, and the sleeve is inserted into the mounting hole.

5. The steel pipe internal screw measuring instrument according to claim 4, characterized in that: The slider is provided with a screw hole, the central axis of the screw hole is perpendicularly intersected with the central axis of the sleeve, a clamping bolt is arranged in the screw hole, the sleeve is fixedly connected to the slider via the clamping bolt, and a plurality of the clamping bolts are evenly distributed along the circumference of the sleeve.

6. The steel pipe internal screw measuring instrument according to claim 4, characterized in that: The installation hole is coated with a curing agent.

7. The steel pipe internal screw measuring instrument according to claim 1, characterized in that: A notch is provided at the end of the bracket to facilitate pulling the pull rod out of the bracket.

8. The steel pipe internal screw measuring instrument according to claim 1, characterized in that: The horizontal track is 400 mm long and its running parallelism is 0.01 mm; the vertical track is 400 mm long and its running parallelism is 0.01 mm, and its verticality accuracy error with the horizontal cross track is less than 0.002 degrees.

9. The steel pipe internal screw measuring instrument according to claim 1, characterized in that: A socket for inserting the pull rod is provided at the center of the end of the bracket, the diameter of the socket is 10 mm, the socket is connected to the horizontal track, the fitting clearance between the pull rod and the socket is a transition fit, and the fitting clearance is 0.02-0.05 mm.

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