A deep hole straightness measuring device and a deep hole straightness measuring method

Abstract

A deep hole straightness measuring device and a measuring method thereof, the measuring device comprises a main measuring structure and auxiliary measuring structures on both sides thereof; sensors are respectively arranged in four ports of a cross-shaped protective cover in the main measuring structure, the main measuring structure can be extended and retracted according to different measured hole diameters, and the sensor is ensured to contact with the measured inner wall when measuring the inner diameter of the deep hole; the auxiliary measuring structures are arranged on both sides of the main measuring structure, and are respectively provided with springs and anchor bolts pressed on the protective cover by a pressure cover, so as to ensure the parallelism of the measuring device with the measured deep hole axial section and the full contact of the main measuring structure with the lower generatrix of the hole during measurement; data fitting is performed by means of sensors and an external computer system to obtain the centerline straightness error of the axial section; the invention has the advantages of simple structure, convenient operation, precision and reliability, portability and high efficiency, and low cost.

Description

Technical Field

[0001] The invention relates to the technical field of deep hole straightness measurement, and in particular to a deep hole straightness measurement device and a measurement method thereof. Background Art

[0002] A deep hole refers to a hole whose ratio of depth to diameter is greater than 10, and the measurement of deep hole straightness has always been a difficult problem that needs to be overcome in metrology. At present, common deep hole straightness measurement methods mainly include the lever method, optical instrument detection method, etc. The lever method is an approximate measurement method. It measures the straightness of a deep hole by the principle that the measuring element senses the change in the position of the center of the measured section. Its accuracy is low, and the measuring equipment is bulky, which is not convenient for application and mass production; although the optical collimation method can achieve high-precision measurement of deep hole straightness, it requires strict and cumbersome centering and adjustment operations in the early stage, and this method is easily disturbed and has a relatively high economic cost. It is only suitable for specific occasions in the laboratory and is difficult to popularize; the relative comparison method effectively avoids the problem of centering during the measurement process, making the operation easier and the measurement accuracy relatively improved, but during the measurement process, the friction between the sensor and the lower busbar of the hole is prone to experimental errors, affecting the measurement effect. Summary of the invention

[0003] In order to overcome the deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide a deep hole straightness measuring device and a measuring method thereof, which can ensure the parallelism between the measuring device and the measured deep hole axial section, and at the same time can press the sensor against the measured inner hole wall, and accurately calculate the deep hole straightness through data measurement and acquisition. It has the advantages of simple structure, easy operation, precision and reliability, portability, high efficiency and low cost.

[0004] In order to achieve the above object, the present invention adopts the following technical solution:

[0005] A deep hole straightness measuring device comprises a main measuring structure and auxiliary measuring structures connected to two sides thereof;

[0006] The main measurement structure includes a cross-shaped protective sleeve 13, and sensors 10 are respectively arranged in the four ports of the cross-shaped protective sleeve 13. The outer surfaces of the four ends of the cross-shaped protective sleeve 13 are provided with first springs 12, and the outer ring of the first spring 12 is provided with a first sliding sleeve 9. The top of the first sliding sleeve 9 is provided with a first gland 11, and the bottom of the first gland 11 is provided with an external thread, which is connected to the internal thread provided on the inner wall of the port of the cross-shaped protective sleeve 13; the top of the sensor 10 extends out from a small hole provided in the center of the first gland 11;

[0007] The auxiliary measurement structure includes a first connector 6b and a second connector 6c symmetrically arranged on both sides of the center of the cross-shaped protective sleeve 13, one end of the first connector 6b and one end of the second connector 6c are fixedly connected to the cross-shaped protective sleeve 13 by a slotted screw respectively, the other end of the first connector 6b is threadedly connected to one end of the first cylinder 8, the other end of the first cylinder 8 is threadedly connected to one end of the third connector 6, the other end of the third connector 6 is fixedly connected to one side of the first protective sleeve 2 by a slotted screw, the other side of the first protective sleeve 2 is fixedly connected to one end of the fourth connector 6a by a slotted screw, the other end of the fourth connector 6a is threadedly connected to one end of the second cylinder 1, and the other end of the second cylinder 1 is externally connected to a propulsion rod; the outer surface of the top of the first protective sleeve 2 is provided with a second spring 5, the outer ring of the second spring 5 is provided with a second sliding sleeve 3, and the second sliding sleeve A second gland 4 is provided at the top of the first protective sleeve 2, and an external thread is provided at the bottom of the second gland 4, and the external thread is connected to the internal thread provided in the port of the first protective sleeve 2; the bottom of the first protective sleeve 2 is threadedly connected to the first anchor bolt 7; the other end of the second connector 6c is threadedly connected to one end of the third cylinder 14, and the other end of the third cylinder 14 is threadedly connected to one end of the fifth connector 6d, and the other end of the fifth connector 6d is fixedly connected to one side of the second protective sleeve 15 through a slotted screw, and a third spring 5a is provided on the outer surface of the top of the second protective sleeve 15, and a third sliding sleeve 17 is provided on the outer ring of the third spring 5a, and a third gland 16 is provided at the top of the third sliding sleeve 17, and an external thread is provided at the bottom of the third gland 16, and the external thread is connected to the internal thread provided in the port of the second protective sleeve 15; the bottom of the second protective sleeve 15 is threadedly connected to the second anchor bolt 18.

[0008] The sensor 10 is a displacement sensor.

[0009] The sensor 10 is connected to an external computer system via a data signal.

[0010] The span L between the first anchor bolt 7 and the second anchor bolt 18 is 120 mm.

[0011] A measuring method for a deep hole straightness measuring device:

[0012] 1) Before measuring, assemble the measuring device and place it on the V-block, and use a micrometer to adjust the distance between the second gland 4 and the first anchor bolt 7, and the distance between the third gland 16 and the second anchor bolt 18 to the diameter of the measured borehole pipe + 1mm;

[0013] 2) Initializing the sensor 10: placing the measuring device on a smooth surface, and then recording and reading the initial reading of the sensor 10 as a relative zero point through an external computer system;

[0014] 3) Place the measuring device into the hole to be measured, press the sensor 10 against the inner wall of the hole to be measured, and use the four sensors 10 and an external computer system to collect and process data to obtain the position of the center of the axial section;

[0015] 4) After measuring one point, the push rod pushes the measuring device to smoothly advance a certain distance along the axial direction of the hole, and the measurement is repeated multiple times to obtain the center of multiple groups of axial sections in the same way;

[0016] 5) Finally, the data measured in step 4) are fitted by an external computer system software connected to the data signal of the sensor 10 to obtain multiple groups of shaft section centerline straightness error data, and the largest error value is taken as the evaluation of the centerline straightness error of the measured shaft.

[0017] In the step 4), more than 10 sets of shaft section center data are measured.

[0018] During the measurement process, the measuring device compares each group of data measured by the sensor with the relative zero point initialized by the sensor 10 in step 2).

[0019] The measuring device is axially advanced in the measured hole each time by a distance equal to the span between the first anchor bolt 7 and the second anchor bolt 18, or is specifically adjusted according to the collected data points.

[0020] The beneficial effects of the present invention are:

[0021] Sensors 10 are respectively arranged in the four ports of the cross-shaped protective sleeve 13 in the main measuring structure, and the outer surfaces of the four ends of the cross-shaped protective sleeve 13 are provided with a first spring 12 and a first sliding sleeve 9. A first pressure cover 11 is arranged on the top of the first sliding sleeve 9. The first pressure cover 11 is pressed tightly on the protective sleeve 13, and the top of the sensor 10 extends out from a small hole arranged in the center of the first pressure cover 11; the main measuring structure can be expanded and contracted according to the different apertures of the measured hole, and the sensor is ensured to contact the inner wall of the measured hole when measuring the inner diameter of the hole.

[0022] The auxiliary measuring structure is arranged on both sides of the main measuring structure, and the second sleeve 3, the second spring 5 and the third sleeve 17, the third spring 5a are pressed onto the first protective sleeve 2 and the second protective sleeve 15 respectively through the second pressure cover 4 and the third pressure cover 16. The bottom of the first protective sleeve 2 is threadedly connected with the first anchor bolt 7, and the bottom of the second protective sleeve 15 is threadedly connected with the second anchor bolt 18, to ensure the parallelism of the entire device with the axial section of the measured hole and the full contact of the main measuring structure with the lower generatrix of the hole during measurement; in addition, the top of the second sleeve 3 and the bottom fulcrum of the first anchor bolt 7 are on the same circle in the XZ axis plane, and the top of the third sleeve 17 and the bottom fulcrum of the second anchor bolt 18 are on the same circle in the XZ axis plane. This structure makes the main measuring structure relatively stable in the hole.

[0023] The measured values ​​are obtained by four sensors 10, and the center of the axial section is calculated by the relevant software of the externally connected computer system. After repeated measurements and calculations, the center points of other axial sections are obtained, and then data fitting is performed to obtain the centerline straightness error of the axial section.

[0024] In summary, the present invention has the advantages of simple structure, convenient operation, precision and reliability, portability, high efficiency and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of the measuring device of the present invention.

[0026] Figure 2 It is a top view of the measuring device of the present invention.

[0027] Figure 3 It is a schematic diagram of the main measurement structure of the present invention.

[0028] Figure 4 This is the principle diagram of axial measurement of the present invention.

[0029] Figure 5 This is a schematic diagram of radial measurement for the present invention.

[0030] Figure 6 It is a three-dimensional stereogram of the measuring device of the present invention.

[0031] In the figure: 1. second cylinder; 2. second protective sleeve; 3. second sliding sleeve; 4. second pressure cover; 5. second spring; third spring 5a; 6. third connecting head; fourth connecting head 6a; first connecting head 6b; second connecting head 6c; fifth connecting head 6d; 7. first anchor bolt; 8. first cylinder; 9. first sliding sleeve; 10. sensor; 11. first pressure cover; 12. first spring; 13. cross-shaped protective sleeve; 14. third cylinder; 15. second protective sleeve; 16. third pressure cover; 17. third sliding sleeve; 18. second anchor bolt. DETAILED DESCRIPTION

[0032] The present invention will be described in detail below with reference to the accompanying drawings.

[0033] See also Figure 1 , Figure 2 , a deep hole straightness measuring device, comprising a main measuring structure and auxiliary measuring structures connected to both sides thereof;

[0034] The main measurement structure includes a cross-shaped protective sleeve 13, and sensors 10 are respectively arranged in the four ports of the cross-shaped protective sleeve 13. The outer surfaces of the four ends of the cross-shaped protective sleeve 13 are provided with first springs 12, and the outer ring of the first spring 12 is provided with a first sliding sleeve 9. The top of the first sliding sleeve 9 is provided with a first gland 11, and the bottom of the first gland 11 is provided with an external thread, which is connected to the internal thread provided on the inner wall of the port of the cross-shaped protective sleeve 13; the top of the sensor 10 extends out from a small hole provided in the center of the first gland 11;

[0035] The auxiliary measurement structure includes a first connector 6b and a second connector 6c symmetrically arranged on both sides of the center of a cross-shaped protective sleeve 13, one end of the first connector 6b and one end of the second connector 6c are fixedly connected to the cross-shaped protective sleeve 13 by a slotted screw, the other end of the first connector 6b is threadedly connected to one end of the first cylinder 8, the other end of the first cylinder 8 is threadedly connected to one end of the third connector 6, the other end of the third connector 6 is fixedly connected to one side of the first protective sleeve 2 by a slotted screw, the other side of the first protective sleeve 2 is fixedly connected to one end of the fourth connector 6a by a slotted screw, the other end of the fourth connector 6a is threadedly connected to one end of the second cylinder 1, and the other end of the second cylinder 1 is externally connected to a propulsion rod; a second spring 5 is arranged on the outer surface of the top of the first protective sleeve 2, a second sliding sleeve 3 is arranged on the outer ring of the second spring 5, a second pressure cover 4 is arranged on the top of the second sliding sleeve 3, an external thread is arranged on the bottom of the second pressure cover 4, and the external thread is connected to the internal thread arranged in the port of the first protective sleeve 2; the bottom of the first protective sleeve 2 is threadedly connected to the first anchor bolt 7;

[0036] The other end of the second connector 6c is threadedly connected to one end of the third cylinder 14, the other end of the third cylinder 14 is threadedly connected to one end of the fifth connector 6d, the other end of the fifth connector 6d is fixedly connected to one side of the second protective sleeve 15 by a slotted screw, the outer surface of the top of the second protective sleeve 15 is provided with a third spring 5a, the outer ring of the third spring 5a is provided with a third sleeve 17, the top of the third sleeve 17 is provided with a third pressure cover 16, the bottom of the third pressure cover 16 is provided with an external thread, the external thread is connected to the internal thread provided in the port of the second protective sleeve 15; the bottom of the second protective sleeve 15 is threadedly connected to the second anchor bolt 18; the top of the second sleeve 3 and the bottom fulcrum of the first anchor bolt 7 are on the same circle in the XZ axis plane, and the third sleeve 17 and the bottom fulcrum of the second anchor bolt 18 are on the same circle in the XZ axis plane, so as to determine the center of the hole and ensure the stability of the device in the hole.

[0037] The sensor 10 is a displacement sensor.

[0038] The sensor 10 is connected to an external computer system for data signals.

[0039] The span L between the first anchor bolt 7 and the second anchor bolt 18 is 120 mm.

[0040] Based on the above-mentioned measurement method of a deep hole straightness measuring device:

[0041] 1) Before measuring, assemble the measuring device and place it on the V-block, and use a micrometer to adjust the distance between the second gland 4 and the first anchor bolt 7, and the distance between the third gland 16 and the second anchor bolt 18 to the diameter of the measured borehole pipe + 1mm;

[0042] 2) Initializing the sensor 10: placing the measuring device on a smooth surface, and then recording and reading the initial reading of the sensor 10 as a relative zero point through an external computer system;

[0043] 3) Place the measuring device into the hole to be measured, press the sensor 10 against the inner wall of the hole to be measured, and use the four sensors 10 and an external computer system to perform data acquisition and processing to obtain the position of the center of the axial section;

[0044] 4) After measuring one point, the push rod pushes the measuring device to smoothly advance a certain distance along the axial direction of the hole, and the measurement is repeated multiple times to obtain the center of multiple groups of axial sections in the same way;

[0045] 5) Finally, the data measured in step 4) are fitted by an external computer system software connected to the data signal of the sensor 10 to obtain multiple groups of shaft section centerline straightness error data, and the largest error value is taken as the evaluation of the centerline straightness error of the measured shaft.

[0046] In the step 4), more than 10 sets of shaft cross-section center data are measured.

[0047] During the measurement process, each group of data measured by the sensor is compared with the relative zero point initialized by the sensor 10 in step 2) to avoid human errors caused by precise centering and measurement errors caused by friction.

[0048] The device is in the measured hole, and the distance of each axial advancement is the span between the first anchor bolt 7 and the second anchor bolt 18, or is specifically adjusted according to the collected data points.

[0049] The working principle of the present invention is:

[0050] See also Figures 1 to 3Before measurement, the measuring device of the present invention is assembled and placed on a V-block, and the distance between the second gland 4 and the first anchor bolt 7 is initially adjusted to the diameter of the measured bore tube + 1mm with a micrometer, and the sensor 10 is initialized, and then the device of the present invention is placed in the bore tube. The first anchor bolt 7 and the second anchor bolt 18 constitute two supporting points. The mathematical principle that there is only one straight line between the two points is used to ensure that the measuring device is fully in contact with the lower generatrix of the hole; the circle formed by the second sleeve 3 and the first anchor bolt 7 and the circle formed by the third sleeve 17 and the second anchor bolt 18 respectively ensure that the device of the present invention remains relatively stable in the measuring hole; the push rod externally connected to the second cylinder 1 is used to smoothly push the measuring device of the present invention in the bore tube, and the distance pushed each time is the span between the anchor bolt 7 and the anchor bolt 8, that is, L=120mm, or it is specifically adjusted according to the collected data points and then the data is collected. After repeated measurements, multiple groups of data are measured, and these data are fitted with an external computer system software to evaluate the axis straightness.

Claims

1. A method for measuring a deep hole straightness measuring device, wherein the device for measuring the straightness of a deep hole comprises a main measuring structure and auxiliary measuring structures connected to both sides thereof; characterized in that: The main measurement structure comprises a cross-shaped protective sleeve (13), wherein four ports of the cross-shaped protective sleeve (13) are respectively provided with sensors (10), the outer surfaces of the four ends of the cross-shaped protective sleeve (13) are provided with first springs (12), the outer ring of the first spring (12) is provided with a first sliding sleeve (9), the top of the first sliding sleeve (9) is provided with a first gland (11), the bottom of the first gland (11) is provided with external threads, and the external threads are connected to the internal threads provided on the inner wall of the port of the cross-shaped protective sleeve (13); the top of the sensor (10) protrudes from a small hole provided in the center of the first gland (11); The auxiliary measurement structure comprises a first connector (6b) and a second connector (6c) symmetrically arranged on both sides of the center of the cross-shaped protective sleeve (13); one end of the first connector (6b) and one end of the second connector (6c) are respectively fixedly connected to the cross-shaped protective sleeve (13) by a slotted screw; the other end of the first connector (6b) is threadedly connected to one end of the first cylinder (8); the other end of the first cylinder (8) is threadedly connected to one end of the third connector (6); the other end of the third connector (6) is fixedly connected to one side of the first protective sleeve (2) by a slotted screw; the other side of the first protective sleeve (2) is fixedly connected to one end of the fourth connector (6a) by a slotted screw; the other end of the fourth connector (6a) is threadedly connected to one end of the second cylinder (1); the other end of the second cylinder (1) is externally connected to a propulsion rod; the outer surface of the top of the first protective sleeve (2) is provided with a second spring (5); the outer ring of the second spring (5) is provided with a second sliding sleeve (3); the second sliding sleeve ( 3) A second gland (4) is provided at the top, and an external thread is provided at the bottom of the second gland (4), and the external thread is connected to the internal thread provided in the port of the first protective sleeve (2); the bottom of the first protective sleeve (2) is threadedly connected to the first anchor bolt (7); the other end of the second connecting head (6c) is threadedly connected to one end of the third cylinder (14), and the other end of the third cylinder (14) is threadedly connected to one end of the fifth connecting head (6d), and the other end of the fifth connecting head (6d) is fixedly connected to one side of the second protective sleeve (15) through a slotted screw, and a third spring (5a) is provided on the outer surface of the top of the second protective sleeve (15), and a third sliding sleeve (17) is provided on the outer ring of the third spring (5a), and a third gland (16) is provided at the top of the third sliding sleeve (17), and an external thread is provided at the bottom of the third gland (16), and the external thread is connected to the internal thread provided in the port of the second protective sleeve (15); the bottom of the second protective sleeve (15) is threadedly connected to the second anchor bolt (18); The sensor (10) is a displacement sensor; The sensor (10) is connected to an external computer system data signal; The measuring method of the deep hole straightness measuring device specifically comprises the following steps: 1) Before measuring, assemble the measuring device and place it on a V-block. Use a micrometer to adjust the distance between the second gland (4) and the first anchor bolt (7), and the distance between the third gland (16) and the second anchor bolt (18) to the diameter of the borehole being measured + 1 mm. 2) Initializing the sensor (10): placing the measuring device on a smooth surface, and then recording and reading the initial reading of the sensor (10) as a relative zero point through an external computer system; 3) placing the measuring device into the hole to be measured, pressing the sensor (10) against the inner wall of the hole to be measured, and using the four sensors (10) and an external computer system to perform data acquisition and processing to obtain the position of the center of the axial cross section; 4) After measuring one point, the push rod pushes the measuring device to smoothly advance a certain distance along the axial direction of the hole, and the measurement is repeated multiple times to obtain the center points of multiple sets of axial sections in the same way; 5) Finally, the data measured in step 4) are fitted by an external computer system software connected to the data signal of the sensor (10) to obtain multiple sets of shaft section centerline straightness error data, and the largest error value is taken as the centerline straightness error of the measured shaft.

2. The measuring method of a deep hole straightness measuring device according to claim 1, characterized in that: The span L between the first anchor bolt (7) and the second anchor bolt (18) is 120 mm.

3. The measuring method of a deep hole straightness measuring device according to claim 1, characterized in that: In the step 4), more than 10 sets of shaft cross-section center data are measured.

4. The measuring method of a deep hole straightness measuring device according to claim 1, characterized in that: A deep hole straightness measuring device compares data measured by a sensor with the relative zero point initialized by the sensor (10) in step 2) during the measuring process.

5. The measuring method of a deep hole straightness measuring device according to claim 1, characterized in that: In the deep hole straightness measuring device, the distance of each axial advancement in the measured hole is the span between the first anchor bolt (7) and the second anchor bolt (18), or is specifically adjusted according to the collected data points.

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