Device and method for measuring perpendicularity of head supporting surface of high-strength bolt to axis of polished rod

Abstract

The invention provides a device for measuring the perpendicularity of a high-strength bolt head supporting surface to a polished rod axis, and the device comprises a pedestal, a lever dial indicator, a standard sample piece, a dial indicator clamping assembly, and a bolt clamping assembly, the middle part of a bottom plate of the pedestal is provided with a cubic structure, and the bolt clamping assembly is fixed on the pedestal at one side of the cubic structure. And the dial indicator clamping assembly is fixed on the base on one side of the cubic structure and is used for clamping a lever dial indicator and enabling the lever dial indicator to move on the top surface of the cubic structure. According to the invention, the perpendicularity of the bolt head supporting surface to the polished rod axis can be rapidly measured, and the purpose of high-efficiency acceptance inspection of products is achieved.

Description

Technical Field

[0001] This invention belongs to the field of machining technology and relates to a measuring device and method for measuring the perpendicularity of the head support surface of a high-strength bolt to the axis of a smooth rod. Background Technology

[0002] In aircraft manufacturing, high-strength bolts are widely used in the connection of critical components such as landing gear, load-bearing beams, and engine parts. These components bear enormous loads and complex stress states during aircraft takeoff, landing, and flight, requiring extremely high reliability and precision in their connections. Besides ensuring the dimensional tolerances of the bolts, strictly controlling geometrical tolerances is also crucial for ensuring the reliability and stability of high-strength bolt connections. The perpendicularity of the bolt head bearing surface to the axis of the smooth rod is one of the most critical indicators of geometrical tolerance requirements. Good perpendicularity ensures uniform force distribution during bolt tightening, avoids localized stress concentration, and reduces the risk of bolt fatigue failure.

[0003] According to the "Tolerances for Form and Position of Bolts and Screws" (HB7360-1996), the perpendicularity of the bolt head bearing surface to the smooth shank axis should not exceed 0.08 mm. The general requirements for bolts stipulate that the perpendicularity of the bolt head bearing surface to the smooth shank axis should not exceed 0.01S mm (S is the hexagonal width of the bolt). For bolts with a diameter ≥ 10 mm, the perpendicularity requirement is no greater than 0.14 mm. Therefore, the "Tolerances for Form and Position of Bolts and Screws" standard places very high demands on the perpendicularity of the bolt head bearing surface to the smooth shank axis.

[0004] At present, there are mainly three methods for measuring the perpendicularity of the supporting surface of the bolt head: The first method is to use a comprehensive gauge for detection. Insert the bolt into the guiding hole of the precision comprehensive gauge, and the end face of the gauge contacts the supporting surface of the bolt head. When the two fit tightly without gaps, it is judged as qualified; otherwise, it is unqualified. The second method is to use a lever dial indicator based on a V-block for detection. Place the bolt in the V-block to position it radially. The measuring head of the lever dial indicator leans on the supporting surface of the bolt. Rotate the bolt to measure the end face runout of the supporting surface. Move the lever dial indicator on the platform, and pull the measuring head from the innermost side to the outermost side of the supporting surface to obtain a reading difference of the sub-dial of the lever dial indicator - the parallelism of the supporting surface relative to the horizontal plane. The maximum values of the end face runout and parallelism of the supporting surface are the perpendicularity errors of the supporting surface of the bolt head. The third method is to use special equipment for detection, such as laser machine measurement, coordinate measuring machine measurement, etc. Measure the data of each position of the part through the equipment, and then analyze and process it through the software system to finally obtain the perpendicularity index of the supporting surface of the bolt head. The first method has a simple detection method and high efficiency, and is suitable for detecting a large number of products. However, this method has two disadvantages. One is that it cannot detect the perpendicularity error of the supporting surface of the bolt head with "hollowed-out center" (the thickness of the supporting surface is small in the middle and large on the outside). In actual production, generally, process methods are used to prevent the bolt from having the "hollowed-out center" situation before using the comprehensive gauge method for detection with confidence. The other disadvantage is that it can only qualitatively judge whether it is qualified and cannot quantitatively determine the error size. The second method can measure quantitatively, but the operation difficulty is relatively large. In addition, when moving the lever dial indicator on the platform to measure the parallelism, since it is manually moved, the moving direction of the measuring head cannot be directly opposite to the axis of the bolt shank, and the measured data is relatively smaller than the actual value. The third method has high measurement accuracy, but the equipment cost is high and requires professional operation. Summary of the Invention

[0005] The object of the present invention is to provide a measuring device and method for the perpendicularity of the supporting surface of a high-strength bolt head to the axis of the shank, which can quickly complete the measurement of the perpendicularity of the supporting surface of the bolt head to the axis of the shank, so as to achieve the purpose of efficient acceptance of products.

[0006] The present invention adopts the following technical solutions:

[0007] A measuring device for the perpendicularity of the supporting surface of a high-strength bolt head to the axis of the shank includes a base 1, a lever dial indicator 9, a standard sample 12, a dial indicator clamping assembly, and a bolt clamping assembly. A cube structure is set up in the middle of the bottom plate of the base 1. The bolt clamping assembly is fixed on the base 1 on one side of the cube structure and is used for clamping the standard sample 12 and bolt parts. The dial indicator clamping assembly is fixed on the base 1 on one side of the cube structure and is used for clamping the lever dial indicator 9 and enabling it to move on the top surface of the cube structure.

[0008] The dial indicator clamping assembly includes a top rod screw 2, a support arm 3, a first spring 4, a sliding plate 5, a locking screw 6, a guide plate 7, and a limiting pin 8; the bolt clamping assembly includes a V-shaped frame 10, a compression spring 11, a first arc-shaped component 13, a second arc-shaped component 14, a compression component 15, a cover 16, a handle 17, and a second spring 18.

[0009] The base 1 is a rectangular base plate with a recess at the bottom to avoid the connecting hexagonal screws. The center of the base plate has a cubic structure with four threaded holes on the upper surface of the cubic structure, which cooperate with screws to connect and fix the two guide plates 7. One side of the base plate of the cubic structure has two threaded holes, which cooperate with hexagonal screws to connect the support arm 3. The other side of the base plate has two round holes and two threaded holes. The round holes cooperate with positioning pins for positioning the V-shaped frame 10, and the threaded holes cooperate with hexagonal screws to connect the V-shaped frame 10.

[0010] The support arm 3 is a guide element, which is an inverted T-shaped cuboid structure. It has two threaded holes in the horizontal direction, which are fixed to the base 1 by internal hex bolts. It has a round hole and a threaded hole in the vertical direction, with the round hole directly above the threaded hole. The round hole is used to fix one end of the first spring 4. The side of the support arm 3 has a pin hole that communicates with the round hole, which is used to insert a pin to hook and fix the first spring 4. The threaded hole is connected to the push rod screw 2 for threaded transmission and to limit the movement direction of the push rod screw 2.

[0011] The push rod screw 2 is a transmission element. Its main body is a threaded rod. One end contacts the slide plate 5 and is used to push the slide plate 5 to move left and right. The other end is made into a truncated cone. The outer circle of the truncated cone is knurled to prevent slipping and facilitate manual rotation. The truncated cone is connected to the threaded rod to form a round boss, which is a transition part used to make room and facilitate finger rotation of the screw.

[0012] Guide plate 7 is a limiting element used to limit the movement direction of slide plate 5. There are two guide plates 7, which are cuboid structures and are symmetrically arranged along the length of base 1 on the top edge of the cubic structure of base 1. The top surface of guide plate 7 has two elliptical holes, which are used to fix it to base plate 1 with screws. The two guide plates 7 have 90° V-shaped grooves on opposite sides, and ball bearings are placed in the V-shaped grooves for slide plate 5 between the two guide plates 7. The two ends of the V-shaped grooves have round holes for installing limiting pins 8 to prevent the ball bearings from falling off.

[0013] The sliding plate 5 is a sliding element used to move the lever dial indicator 9. The sliding plate 5 has an L-shaped block structure with 90° V-shaped grooves on both sides of the bottom structure, which cooperate with the V-shaped grooves of the two guide plates 7 to achieve sliding. The longitudinal structure is a straight slot structure with a round hole in the middle of the slot for clamping the lever dial indicator 9. The straight slot structure can enlarge the round hole for easy installation. The outer walls of the two sides of the sliding plate 5 next to the round hole have R-shaped grooves to improve the deformation capacity of the straight slot. The straight slot has a threaded hole in the vertical direction, which is connected to the locking screw 6 to reduce the width of the slot and press the lever dial indicator 9. There is another round hole below the straight slot structure for fixing the other end of the first spring 4. The side of the sliding plate 5 has a pin hole that communicates with and is perpendicular to the round hole for inserting a pin to connect and fix it to the other hook of the first spring 4.

[0014] The locking screw 6 has a similar structure to the push rod screw 2. It engages with the threaded hole at the top of the slide plate 5 to press the slotted part of the slide plate 5 and press the lever dial indicator 9.

[0015] The lever dial indicator 9 is a measuring element used for perpendicularity measurement. It is a general-purpose standard part, consisting of five main components: a probe, a measuring rod, a mechanical transmission system, an indicating dial and pointer, and a clamping rod. The diameter of the clamping rod is the same as the original size of the central hole in the slide plate 5, and the lever dial indicator 9 is clamped and fixed by the slide plate 5.

[0016] V-shaped bracket 10 is a fixing element. Its bottom is positioned on the base 1 by a positioning pin and fixed by an internal hex screw. It is used to fix the standard sample 12 or bolt parts. V-shaped bracket 10 has a "P" shaped structure. The outer side of its head has a vertically arranged 90° V-shaped groove for positioning and aligning the standard sample 12 or bolt parts. The head of V-shaped bracket 10 has two symmetrical upper and lower recesses on both sides. The recesses have threaded holes for limiting and fixing the first arc-shaped part 13 and the second arc-shaped part 14. The upper end face of V-shaped bracket 10 has a groove in the middle to avoid the probe of the lever dial indicator 9. One side of the upper end face has a threaded hole for fixing the compression spring 11.

[0017] The compression spring 11 is in the shape of a question mark and has a thin plate structure. It has good elasticity and a round hole at its end. It is fixed to the V-shaped bracket 10 with screws. The curved part presses against the upper end face of the standard sample 12 or the bolt part to prevent it from moving.

[0018] The first arc-shaped component 13 is U-shaped and has a thin-walled structure. Its two side arms are fixedly connected to the recess on the upper side of the V-shaped frame 10 by screws. Its upper end face is in contact with the standard sample 12 or the bolt head support surface clamped on the V-shaped frame 10 to define the position.

[0019] The second arc-shaped component 14 is also U-shaped with a thin-walled structure. Its two side arms are fixedly connected to the recess on the lower side of the V-shaped frame 10 by screws. The middle part is provided with one large and two small round holes. The large round hole is used to connect with the round rod of the clamping component 15, and the two small holes are fixed together with the cover 16 by rivets.

[0020] The cover 16 is a stepped support plate structure. The support plate is rhomboid in shape with rounded transitions on both sides and round holes at both ends. It is fixed to the inner side of the second arc-shaped part 14 by riveting. The cover 16 has a through hole in the middle of the stepped shaft for the clamping part 15 to pass through.

[0021] One end of the clamping member 15 is a 90° V-shaped claw, which cooperates with the V-groove of the V-shaped frame 10 to clamp the screw part of the standard sample 12 or the bolt part. The other end is a thin shaft structure with a second spring 18. The end passes through the cover 16 and the second arc-shaped member 14 and is threaded to the handle 17.

[0022] The handle 17 is tapered in shape and has a blind hole thread inside, which is fixed to the clamping member 15.

[0023] The two ends of the second spring 18 are pressed against the 90° V-shaped claw end faces of the cover 16 and the clamping member 15, providing clamping force to the clamping member 15.

[0024] Standard sample 12 is a calibration element used for calibration before the device is used. Standard sample 12 has a stepped shaft structure, with the inner end face of the thick shaft perpendicular to the axis of the thin shaft. The inner end face of the thick shaft rests on the first arc-shaped part 13, and the thin shaft is placed in the 90° V-groove of the V-frame 10 and clamped by the clamping part 15.

[0025] A method for measuring the perpendicularity of a high-strength bolt head support surface to the axis of a smooth rod, based on the aforementioned perpendicularity measuring device, includes the following steps:

[0026] Step 1: Install and fix the standard sample 12. First, place the verticality measuring device on the marble platform, ensuring it is stable. Manually pull the handle 17 to move the clamping member 15 away from the V-shaped bracket 10, compressing the second spring 18. Then, place the standard sample 12 in the V-groove of the V-shaped bracket 10, with the inner end face of the thick shaft of the standard sample 12 pressed tightly against the upper end face of the first arc-shaped member 13. Next, release the handle 17, and the second spring 18 pushes the clamping member 15's claws to press the thin shaft portion of the standard sample 12, fixing the standard sample 12 in place. Finally, rotate the clamping spring 11 to press it against the upper end face of the thick shaft of the standard sample 12, preventing it from moving upwards.

[0027] Step 2, install the lever dial indicator 9. First, unscrew the top screw 2 to allow the first spring 4 to return to its non-elastic deformation state. Rotate the locking screw 6 counterclockwise to expand the slot and central hole of the slide plate 5. Insert the round rod of the lever dial indicator 9 into the central hole, adjust the dial of the lever dial indicator 9 so that the dial faces upward, and rotate the locking screw 6 clockwise to clamp the lever dial indicator 9.

[0028] Step 3: Adjust the dial indicator 9. First, screw in the ejector rod screw 2 to push the slider 5 to drive the dial indicator 9 to move horizontally to the right, and adjust the height of the probe of the dial indicator 9 slightly higher than the inner end face of the rough shaft of the standard sample 12; lower the probe, rotate the ejector rod screw 2, and move the probe of the dial indicator 9 to below the inner end face of the rough shaft of the standard sample 12 and contact the inner end face of the rough shaft of the standard sample 12.

[0029] Step 4: Detect whether the accuracy of the perpendicularity measuring device is qualified. Select a point on the inner end face of the rough shaft of the standard sample block for measurement. First, rotate the standard sample 12 one week, and remember the position of the maximum change of the pointer scale on the dial of the dial indicator 9. If the reading difference ≤ 0.02, it is determined that the device accuracy is qualified.

[0030] Step 5: Install and fix the bolt part. First, unscrew the ejector rod screw 2 to make the probe of the dial indicator 9 away from the standard sample 12, rotate the compression spring 11 to loosen the bolt, then pull the handle 17, take out the standard sample 12 and put in the bolt part. Place the screw rod of the bolt part in the V-groove of the V-block 10, and the supporting surface of the bolt head is closely attached to the upper end face of the first arc-shaped part 13. Loosen the handle 17 to clamp the bolt part. Finally, rotate the compression spring 11 to press the upper end face of the bolt head to prevent it from moving upward.

[0031] Step 6: Detect the perpendicularity of the bolt part. Repeat Step 3 to make the probe of the dial indicator 9 contact the supporting surface of the bolt head, and measure the end face runout value and parallelism. The maximum value between the two is the perpendicularity error; if the perpendicularity error ≤ 0.08, it is determined that the perpendicularity of the supporting surface of the bolt head is qualified; if the perpendicularity error > 0.08, it is determined that the perpendicularity of the supporting surface of the bolt head is unqualified. Among them:

[0032] The method for measuring the end face runout value is: Select three points on the supporting surface of the bolt head for measurement. The three points are the innermost position, the middle position, and the outermost position of the supporting surface. The measurement method for each point: Rotate the bolt head and turn it one week, record the position of the maximum change of the pointer scale on the dial of the dial indicator 9 for each point, and the reading difference is the end face runout value.

[0033] The method for measuring parallelism is: Pull the probe of the dial indicator 9 from the innermost side to the outermost side of the supporting surface of the bolt head, and the obtained reading difference is the parallelism of the supporting surface relative to the horizontal plane.

[0034] Step 7: Take out the bolt part. Unscrew the ejector rod screw 2 to drive the dial indicator 9 away from the bolt part, then rotate the compression spring 11 to loosen the bolt part, pull the handle 17, and take out the bolt part to complete one perpendicularity measurement.

[0035] The beneficial effects of the present invention:

[0036] 1. This invention measures the perpendicularity of the bolt head bearing surface to the smooth rod axis by detecting the circular runout of the end face of the bolt head bearing surface and the parallelism of the bearing surface relative to the horizontal plane. The measurement method is simple, the measurement difficulty is low, and the detection accuracy is high.

[0037] 2. This invention can achieve horizontal movement of the lever dial indicator through a ball bearing guide rail, resulting in smooth movement, low friction, and high accuracy in linear movement;

[0038] 3. This invention can detect the perpendicularity of the bearing surface of bolt heads of various diameters (smooth rod length ≤ 70mm), and has strong applicability;

[0039] 4. This invention is small in size and simple in structure;

[0040] 5. The invention has low manufacturing cost. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of a verticality measuring device, where (a) is the front view and (b) is the top view.

[0042] Figure 2 This is an isometric drawing of a verticality measuring device.

[0043] Figure 3 This is a schematic diagram of the base.

[0044] Figure 4 This is a schematic diagram of the push rod screw.

[0045] Figure 5 This is a schematic diagram of the outrigger.

[0046] Figure 6 This is a diagram of a skateboard.

[0047] Figure 7 This is a schematic diagram of the locking screw.

[0048] Figure 8 This is a schematic diagram of the guide plate.

[0049] Figure 9 The percentage represents the intended leverage.

[0050] Figure 10 This is a schematic diagram of a V-shaped frame.

[0051] Figure 11 This is a schematic diagram of a compression spring.

[0052] Figure 12 This is a schematic diagram of a standard sample.

[0053] Figure 13 This is a schematic diagram of the first arc-shaped component.

[0054] Figure 14 This is a schematic diagram of the second arc-shaped component.

[0055] Figure 15 This is a schematic diagram of the clamping component.

[0056] Figure 16 This is a schematic diagram of the cover.

[0057] Figure 17 This is a schematic diagram of the handle.

[0058] In the diagram: 1-base; 2-top rod screw; 3-support arm; 4-first spring; 5-slide plate; 6-locking screw; 7-guide plate; 8-limit pin; 9-lever dial indicator; 10-V-block; 11-compression spring; 12-standard sample; 13-first arc-shaped part; 14-second arc-shaped part; 15-compression part; 16-cover; 17-handle; 18-second spring. Detailed Implementation

[0059] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] A measuring device for the perpendicularity of a high-strength bolt head support surface to the axis of a smooth rod, such as... Figure 1 and Figure 2 It includes: base 1, top rod screw 2, support arm 3, first spring 4, slide plate 5, locking screw 6, guide plate 7, limit pin 8, lever dial indicator 9, V-shaped frame 10, compression spring 11, standard sample 12, first arc-shaped part 13, second arc-shaped part 14, compression part 15, cover 16, handle 17, and second spring 18.

[0061] like Figure 3 The base 1 is a rectangular base plate with a recess at the bottom to avoid the connecting hexagonal screws. The center of the base plate has a cubic structure with four threaded holes on the upper surface of the cubic structure, which cooperate with screws to connect and fix the two guide plates 7. One side of the base plate of the cubic structure has two threaded holes, which cooperate with hexagonal screws to connect the support arm 3. The other side of the base plate has two round holes and two threaded holes. The round holes cooperate with positioning pins for positioning the V-shaped frame 10, and the threaded holes cooperate with hexagonal screws to connect the V-shaped frame 10.

[0062] like Figure 5The support arm 3 is a guide element, which is an inverted T-shaped cuboid structure. It has two threaded holes in the horizontal direction, which are fixed to the base 1 by internal hex bolts. It has a round hole and a threaded hole in the vertical direction, with the round hole directly above the threaded hole. The round hole is used to fix one end of the first spring 4. The side of the support arm 3 has a pin hole that communicates with the round hole, which is used to insert a pin and connect and fix it to the hook of the first spring 4. The threaded hole is connected to the push rod screw 2 for threaded transmission and to limit the movement direction of the push rod screw 2.

[0063] like Figure 4 The push rod screw 2 is a transmission element. Its main body is a threaded rod. One end contacts the slide plate 5 and is used to push the slide plate 5 to move left and right. The other end is made into a truncated cone. The outer circle of the truncated cone is knurled to prevent slipping and facilitate manual rotation. The truncated cone is connected to the threaded rod to form a round boss, which is a transition part used to make room and facilitate finger rotation of the screw.

[0064] like Figure 8 The guide plate 7 is a limiting element used to limit the movement direction of the slide plate 5. There are two guide plates 7, which are cuboid structures and are symmetrically arranged along the length of the base 1 on the top edge of the cubic structure of the base 1. The top surface of the guide plate 7 has two elliptical holes, which are used to fix it to the base plate 1 with screws. The two guide plates 7 have 90° V-shaped grooves on opposite sides, and ball bearings are placed in the V-shaped grooves for the slide plate 5 to slide between the two guide plates 7. The two ends of the V-shaped grooves have round holes for installing limiting pins 8 to prevent the ball bearings from falling off.

[0065] like Figure 6 The sliding plate 5 is a sliding element used to move the lever dial indicator 9. The sliding plate 5 has an L-shaped block structure with 90° V-shaped grooves on both sides of the bottom structure, which cooperate with the V-shaped grooves of the two guide plates 7 to achieve sliding. The longitudinal structure is a straight slot structure with a round hole in the middle of the slot for clamping the lever dial indicator 9. The straight slot structure can enlarge the round hole for easy installation. The outer walls of the two sides of the sliding plate 5 next to the round hole have R-shaped grooves to improve the deformation capacity of the straight slot. The straight slot has a threaded hole in the vertical direction, which is connected to the locking screw 6 to reduce the width of the slot and press the lever dial indicator 9. There is another round hole below the straight slot structure for fixing the other end of the first spring 4. The side of the sliding plate 5 has a pin hole that communicates with and is perpendicular to the round hole for inserting a pin to connect and fix it to the other hook of the first spring 4.

[0066] like Figure 7 The locking screw 6 has a similar structure to the top screw 2 and engages with the threaded hole at the top of the slide plate 5 to press the slotted part of the slide plate 5 and press the lever dial indicator 9.

[0067] like Figure 9The lever dial indicator 9 is a measuring element used for perpendicularity measurement. It is a general-purpose standard part, generally consisting of five parts: a probe, a measuring rod, a mechanical transmission system, an indicating dial and pointer, and a clamping rod. The diameter of the clamping rod is the same as the original size of the central hole in the slide plate 5, and the lever dial indicator 9 is clamped and fixed by the slide plate 5.

[0068] like Figure 10 The V-shaped bracket 10 is a fixing element. Its bottom is positioned on the base 1 by a positioning pin and fixed by an internal hex screw. It is used to fix the standard sample 12 or bolt parts. The V-shaped bracket 10 has a "P" shaped structure. The outer side of its head has a vertically arranged 90° V-shaped groove for positioning and aligning the standard sample 12 or bolt parts. The head of the V-shaped bracket 10 has two symmetrical upper and lower recesses on both sides. The recesses have threaded holes for limiting and fixing the first arc-shaped part 13 and the second arc-shaped part 14. The upper end face of the V-shaped bracket 10 has a groove in the middle to avoid the probe of the lever dial indicator 9. There is a threaded hole on one side of the upper end face for fixing the compression spring 11.

[0069] like Figure 11 The compression spring 11 is in the shape of a question mark and has a thin plate structure. It has good elasticity and a round hole at its end. It is fixed to the V-shaped bracket 10 with screws. The curved part presses against the upper end face of the standard sample 12 or the bolt part to prevent it from moving.

[0070] like Figure 13 The first arc-shaped part 13 is U-shaped and has a thin-walled structure. Its two side arms are fixedly connected to the recess on the upper side of the V-shaped frame 10 by screws. Its upper end face is in contact with the standard sample 12 or the bolt head support surface clamped on the V-shaped frame 10 to define the position.

[0071] like Figure 14 The second arc-shaped component 14 is also U-shaped with a thin-walled structure. Its two side arms are fixedly connected to the recess on the lower side of the V-shaped frame 10 by screws. The middle part is provided with one large and two small round holes. The large round hole is used to connect with the round rod of the clamping component 15, and the two small holes are fixed together with the cover 16 by rivets.

[0072] like Figure 16 The cover 16 is a stepped support plate structure. The support plate is rhomboid in shape with rounded transitions on both sides and round holes at both ends. It is fixed to the inner side of the second arc-shaped part 14 by riveting. The cover 16 has a through hole in the middle of the stepped shaft for the clamping part 15 to pass through.

[0073] like Figure 15 One end of the clamping member 15 is a 90° V-shaped claw, which cooperates with the V-groove of the V-shaped frame 10 to clamp the screw part of the standard sample 12 or the bolt part. The other end is a thin shaft structure with a second spring 18. The end passes through the cover 16 and the second arc-shaped member 14 and is threaded to the handle 17.

[0074] like Figure 17 The handle 17 is tapered in shape and has a blind hole thread inside, which is fixed to the clamping member 15.

[0075] The two ends of the second spring 18 are pressed against the 90° V-shaped claw end faces of the cover 16 and the clamping member 15, providing clamping force to the clamping member 15.

[0076] like Figure 12 The standard sample 12 is a calibration element used for calibration before the device is used. The standard sample 12 has a stepped shaft structure, with the inner end face of the thick shaft perpendicular to the axis of the thin shaft. The inner end face of the thick shaft rests on the first arc-shaped part 13, and the thin shaft is placed in the 90° V-groove of the V-shaped bracket 10 and clamped by the clamping part 15.

[0077] A method for measuring the perpendicularity of a high-strength bolt head support surface to the axis of a smooth rod, based on the aforementioned perpendicularity measuring device, includes the following steps:

[0078] Step 1: Install and fix the standard sample 12. First, place the verticality measuring device on the marble platform, ensuring it is stable. Manually pull the handle 17 to move the clamping member 15 away from the V-shaped bracket 10, compressing the second spring 18. Then, place the standard sample 12 in the V-groove of the V-shaped bracket 10, with the inner end face of the thick shaft of the standard sample 12 pressed tightly against the upper end face of the first arc-shaped member 13. Next, release the handle 17, and the second spring 18 pushes the clamping member 15's claws to press the thin shaft portion of the standard sample 12, fixing the standard sample 12 in place. Finally, rotate the clamping spring 11 to press it against the upper end face of the thick shaft of the standard sample 12, preventing it from moving upwards.

[0079] Step 2, install the lever dial indicator 9. First, unscrew the top screw 2 to allow the first spring 4 to return to its non-elastic deformation state. Rotate the locking screw 6 counterclockwise to expand the slot and central hole of the slide plate 5. Insert the round rod of the lever dial indicator 9 into the central hole, adjust the dial of the lever dial indicator 9 so that the dial faces upward, and rotate the locking screw 6 clockwise to clamp the lever dial indicator 9.

[0080] Step 3, adjust the lever dial indicator 9. First, screw in the top screw 2, push the slider 5 to move the lever dial indicator 9 horizontally to the right, and adjust the height of the lever dial indicator 9 probe to be slightly higher than the inner end face of the standard sample 12 coarse shaft; lower the probe, rotate the top screw 2, and move the lever dial indicator 9 probe to below the inner end face of the standard sample 12 coarse shaft and in contact with the inner end face of the standard sample 12 coarse shaft.

[0081] Step 4: Check if the perpendicularity measuring device is accurate. Select a point on the inner end face of the standard sample block's coarse shaft for measurement. First, rotate the standard sample block 12 times. Remember the position of the maximum change in the pointer scale on the dial of lever dial indicator 9. If the reading difference is ≤0.02, the device is considered to be accurate.

[0082] Step 5: Install the fixing bolt part. First, unscrew the ejector rod screw 2 to move the probe of the lever dial indicator 9 away from the standard sample 12. Rotate the compression spring 11 to loosen the bolt. Then, pull the handle 17 to remove the standard sample 12 and place the bolt part. The screw rod of the bolt part is placed in the V-groove of the V-block 10, and the supporting surface of the bolt head is closely attached to the upper end surface of the first arc-shaped part 13. Loosen the handle 17 to clamp the bolt part. Finally, rotate the compression spring 11 to press the upper end surface of the bolt head to prevent it from moving upward.

[0083] Step 6: Detect the perpendicularity of the bolt part. Repeat Step 3 to make the probe of the lever dial indicator 9 contact with the supporting surface of the bolt head, and measure the end face runout value and parallelism. The maximum value between the two is the perpendicularity error. If the perpendicularity error ≤ 0.08, it is determined that the perpendicularity of the supporting surface of the bolt head is qualified; if the perpendicularity error > 0.08, it is determined that the perpendicularity of the supporting surface of the bolt head is unqualified. Among them:

[0084] The method for measuring the end face runout value is as follows: Select three points on the supporting surface of the bolt head for measurement. The three points are the innermost position, the middle position, and the outermost position of the supporting surface. The measurement method for each point: Rotate the bolt head and turn it one week, record the maximum change position of the pointer scale on the dial of the lever dial indicator 9 for each point, and the reading difference is the end face runout value.

[0085] The method for measuring the parallelism is as follows: Pull the probe of the lever dial indicator 9 from the innermost side to the outermost side of the supporting surface of the bolt head, and the obtained reading difference is the parallelism of the supporting surface relative to the horizontal plane.

[0086] Step 7: Remove the bolt part. Unscrew the ejector rod screw 2 to move the lever dial indicator 9 away from the bolt part. Then, rotate the compression spring 11 to loosen the bolt part, pull the handle 17, and remove the bolt part to complete one perpendicularity measurement.

[0087] The above are only some embodiments of the present invention, and thus do not limit the implementation mode and protection scope of the present invention. Those skilled in the art should make improvements and modifications within the protection scope of the present invention without departing from the disclosure of the present invention.

Claims

1. A measuring device for the perpendicularity of a high-strength bolt head support surface to the axis of a smooth rod, characterized in that, Includes a base (1), a lever dial indicator (9), a standard sample (12), a dial indicator clamping assembly, and a bolt clamping assembly. The base (1) has a cubic structure in the middle of its base plate. The bolt clamping assembly is fixed on the base (1) on one side of the cubic structure and is used to clamp the standard sample (12) and the bolt parts. The dial indicator clamping assembly is fixed on the base (1) on one side of the cubic structure and is used to clamp the lever dial indicator (9) and move it on the top surface of the cubic structure.

2. The measuring device for the perpendicularity of the high-strength bolt head support surface to the axis of the smooth rod according to claim 1, characterized in that, The base (1) has a recess at the bottom to avoid the connecting hexagonal screws. The dial indicator clamping assembly and the bolt clamping assembly are fixed to the base (1) by hexagonal screws.

3. The measuring device for the perpendicularity of the high-strength bolt head support surface to the axis of the smooth rod according to claim 1, characterized in that, The dial indicator clamping assembly includes a push rod screw (2), a support arm (3), a first spring (4), a sliding plate (5), and a guide plate (7); The support arm (3) is fixed on the base (1), and a round hole and a threaded hole are made on its upper part. One end of the first spring (4) is fixed in the round hole, and the threaded hole is threaded to the top rod screw (2). The guide plate (7) is a cuboid structure, consisting of two pieces, which are symmetrically arranged along the length of the base (1) on the top edge of the cubic structure of the base (1). The slide plate (5) is located between the two slide plates 7 and works with the slide plate (5) to achieve motion guidance. The upper part of the slide (5) holds the lever dial indicator (9), and the lower part has a round hole for fixing the other end of the first spring (4).

4. The measuring device for the perpendicularity of the high-strength bolt head support surface to the axis of the smooth rod according to claim 3, characterized in that, One end of the push rod screw (2) is in contact with the slide plate (5), and the other end is made into a frustum. The outer circle of the frustum is knurled. The frustum is connected to the threaded rod to form a round boss, which facilitates the rotation of the screw.

5. The measuring device for the perpendicularity of the high-strength bolt head support surface to the axis of the smooth rod according to claim 3, characterized in that, The two guide plates (7) are provided with V-shaped grooves on opposite sides, and the slide plate (5) is also provided with V-shaped grooves on both sides. Balls are placed in the V-shaped grooves for sliding fit, and limit pins (8) are installed at both ends of the V-shaped grooves to prevent the balls from falling off.

6. The measuring device for the perpendicularity of the high-strength bolt head support surface to the axis of the smooth rod according to claim 3, characterized in that, The top of the slide plate (5) has a slotted structure with a round hole in the middle for clamping the lever dial indicator (9). The slotted structure has a threaded hole in the vertical direction for connecting with the locking screw (6) to press the lever dial indicator (9).

7. The measuring device for the perpendicularity of the high-strength bolt head support surface to the axis of the smooth rod according to claim 1, characterized in that, The bolt clamping assembly includes a V-shaped bracket (10), a compression spring (11), a first arc-shaped component (13), a second arc-shaped component (14), a clamping component (15), a cover (16), and a second spring (18); The V-shaped bracket (10) is fixed to the base (1) and is used to cooperate with the clamping part (15) for positioning, aligning the standard sample (12) or bolt parts; The compression spring (11) is in the shape of a question mark and has a thin plate structure. It is fixed on the V-shaped frame (10) and is used to compress the upper end face of the standard sample (12) or the bolt part. The first arc-shaped part (13) is U-shaped, with its two side arms fixedly connected to the V-shaped frame (10). Its upper end face is in contact with the standard sample (12) or the bolt head support surface clamped on the V-shaped frame (10) to limit the position. The second arc-shaped component (14) is also U-shaped, with its two side arms fixedly connected to the first arc-shaped component (13) on the V-shaped frame (10), and a through hole in its middle. The cover (16) is fixed to the inside of the second arc-shaped part (14), which has a through hole for the clamping part (15) to pass through; The clamping member (15) is fitted with a second spring (18), and its end passes through the cover (16) and the second arc-shaped member (14) and is threaded to the handle 17; the second spring (18) provides clamping force to the clamping member (15).

8. The measuring device for the perpendicularity of the high-strength bolt head support surface to the axis of the smooth rod according to claim 7, characterized in that, The V-shaped frame (10) has a vertically arranged V-shaped groove on the outer side of its head, and the clamping part (15) has a V-shaped claw at its end, which cooperates with the V-shaped groove of the V-shaped frame (10) to clamp the standard sample (12) or the screw part of the bolt part.

9. A measuring device for the perpendicularity of a high-strength bolt head support surface to the axis of a smooth rod according to claim 7, characterized in that, A handle (17) is installed on the outer end of the clamping member (15).

10. A method for measuring the perpendicularity of a high-strength bolt head support surface to the axis of a smooth rod, implemented based on the perpendicularity measuring device described in any one of claims 1-9, characterized in that... Includes the following steps: Step 1, Install and fix the standard sample (12); First, stabilize the verticality measuring device and clamp the standard sample (12) onto the bolt clamping assembly; Step 2, install the lever dial indicator (9); clamp the lever dial indicator (9) onto the dial indicator clamping assembly; Step 3, adjust the lever dial indicator (9); adjust the height of the lever dial indicator (9) to be slightly higher than the inner end face of the coarse shaft of the standard sample (12); move the lever dial indicator (9) to below the inner end face of the coarse shaft of the standard sample (12) and make contact with the inner end face of the coarse shaft of the standard sample (12); Step 4: Check whether the accuracy of the perpendicularity measuring device is qualified; select a point on the inner end face of the coarse shaft of the standard sample block for measurement. First, rotate the standard sample (12) one revolution and remember the position of the maximum change of the pointer scale on the dial of the lever dial indicator (9). If the reading difference is ≤0.02, the device is judged to be qualified. Step 5, install the fixing bolt parts; take out the standard sample (12) and clamp the bolt parts; Step 6, check the perpendicularity of the bolt parts; repeat step 3, bring the lever dial indicator (9) probe into contact with the bolt head support surface, and measure the end face runout and parallelism. The maximum value between the two is the perpendicularity error; if the perpendicularity error ≤ 0.08, the perpendicularity of the bolt head support surface is deemed qualified; if the perpendicularity error > 0.08, the perpendicularity of the bolt head support surface is deemed unqualified; where: The method for measuring the end face runout is as follows: Select three points on the support surface of the bolt head for measurement. The three points are the innermost, middle, and outermost positions of the support surface. Rotate the bolt head and rotate it one revolution. Record the position of the maximum change of the pointer scale on the dial of the lever dial indicator (9) at each point. The difference in readings is the end face runout value. The parallelism measurement method is as follows: pull the probe of the lever dial indicator (9) from the innermost side to the outermost side of the bolt head support surface, and obtain a reading difference, which is the parallelism of the support surface relative to the horizontal plane; Step 7: Remove the bolt parts.

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