A special gauge for measuring the length of an inner step of a deep hole and a measuring method

Abstract

This invention provides a dedicated measuring tool and method for measuring the length of a step inside a deep hole. The measuring tool includes a gauge cylinder with a through hole; a dial indicator whose measuring rod is inserted into and fixed in a through hole at one end of the gauge cylinder; a measuring rod inserted into a through hole at the other end of the gauge cylinder, with a support block and a small measuring block fixedly disposed at its middle part and exposed end, respectively; a large measuring block fixed at the end of the gauge cylinder away from the dial indicator, with its inner end located inside the gauge cylinder as a limiting element for the support block; a spring sleeved on the measuring rod; and a reference block with a corresponding through hole featuring a step, the length of which is set as the maximum limit dimension of the step length inside the hole of the workpiece to be measured. This invention achieves measurement by directly measuring the length of the step inside a deep hole, which reduces the measurement difficulty, avoids error accumulation, and effectively solves the problem of accurately measuring the length of the step inside a deep hole of a bushing with precision requirements.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding technology, and in particular to a special measuring tool and method for measuring the length of a step inside a deep hole. Background Technology

[0002] Shipbuilding often requires the machining of various bushings, including a stepped hole D2 at the bottom of a deep hole, with a length of L. 2+0.10 +0.05 The L2 dimension needs to be strictly controlled, thus requiring accurate measurement. Calculating L2 = CA - CB by measuring the depth from surface C to surfaces A and B not only results in large measurement errors but is also cumbersome and inefficient. Therefore, a dedicated measuring tool and method for measuring the step length inside deep holes is urgently needed. Summary of the Invention

[0003] In view of the above-mentioned problems existing in the prior art, the present invention provides a special measuring tool and method for measuring the length of the inner step in a deep hole, so as to solve the technical problems of large measurement error and low measurement efficiency existing in the prior art.

[0004] This invention provides a special measuring tool for measuring the length of a step inside a deep hole, comprising: A gauge tube, wherein a through hole is provided inside the gauge tube along its axial direction; A dial indicator, wherein the measuring rod of the dial indicator is inserted into a through hole at one end of the gauge cylinder, and the dial indicator is fixedly connected to the gauge cylinder; A measuring rod is inserted into the through hole of the gauge tube at the other end of the measuring rod. A support block and a small measuring block are fixedly installed in the middle of the rod body and the exposed end, respectively. The outer diameter of the support block matches the inner diameter of the through hole of the gauge tube, and the outer diameter of the small measuring block matches the inner diameter of the step inside the hole of the workpiece to be measured. A large measuring block is fixed to the end of the gauge cylinder away from the dial indicator, with its inner end located inside the gauge cylinder as a limiting member of the support block, and the measuring rod passing through the through hole in the middle of the large measuring block. A spring is sleeved on the measuring rod, with one end abutting against the support block and the other end abutting against the cylinder of the gauge tube on the side near the dial indicator. A reference block is provided with a stepped through hole. The length of the step inside the through hole is set as the maximum limit dimension of the step length inside the hole of the workpiece to be measured, and the thickness of the small measuring block is less than the maximum limit dimension of the step length inside the hole of the workpiece to be measured.

[0005] In one embodiment, the end of the measuring rod is provided with a thread, and the small measuring block is pressed and fixed to the threaded end of the measuring rod by a nut.

[0006] In one embodiment, the large test block is fixed to the gauge cylinder by screwing.

[0007] In one embodiment, the dial indicator is fixed to the gauge cylinder by a fastening screw. The fastening screw is screwed onto the gauge cylinder, and its end passes through the cylinder body of the gauge cylinder and abuts against the measuring rod of the dial indicator, thereby pressing and fixing the measuring rod of the dial indicator onto the gauge cylinder.

[0008] In one embodiment, a reduced-diameter milling head is provided at the end of the measuring rod near the dial indicator.

[0009] In one embodiment, the measuring tool is made of alloy tool steel.

[0010] In one embodiment, the two end faces of the small measuring block are perpendicular to its center line, and the perpendicularity error is ≤0.01mm.

[0011] In one embodiment, the outer end face of the large measuring block is perpendicular to its center line, and the perpendicularity is ≤0.01mm.

[0012] In one embodiment, the through hole inside the gauge cylinder has a variable diameter structure, with the diameter of the hole on the side closer to the dial indicator being smaller than the diameter of the hole on the other side.

[0013] In addition, embodiments of the present invention also provide a method for measuring the length of a step inside a deep hole, implemented based on a special measuring tool for measuring the length of a step inside a deep hole as described in any embodiment of the present invention, including the following steps: Step S1, using a reference block to calibrate the dial indicator to zero, specifically includes: Step S11: Select a reference block of appropriate size corresponding to the model of the workpiece to be tested; Step S12: Make the outer end of the small measuring block of the measuring tool contact and fit with the inner end face of the reference block through-hole stage. Step S13: Adjust the position of the outer end face of the large measuring block so that the outer end face of the large measuring block is in contact with the outer end face of the reference block through-hole stage, set the large pointer of the dial indicator to zero, and record the reading of the small pointer. Step S2, using the zeroed measuring tool, measures the step length of the workpiece to be measured, specifically including: Step S21: Insert the measuring tool into the deep hole of the workpiece to be measured, so that the outer end face of the small measuring block of the measuring tool contacts and fits with the inner end face of the deep hole stage of the workpiece to be measured, and the outer end face of the large measuring block contacts and fits with the outer end face of the deep hole stage of the workpiece to be measured under the action of the spring. Step S22: Read the dial indicator reading and obtain the measured value of the step length inside the deep hole of the workpiece by calculating the difference between the reading and the pointer reading in step S13.

[0014] Compared with the prior art, the beneficial effects of the special measuring tool and method for measuring the length of the inner step in deep hole provided by the embodiments of the present invention are as follows: The embodiments of the present invention achieve measurement by directly measuring the length of the inner step in deep hole, which reduces the measurement difficulty and avoids error accumulation. It effectively solves the problem of accurate measurement of the length dimension of the inner step in deep hole of bushing with accuracy requirements, supports the inner step length of deep hole to meet the required processing accuracy, and has the advantages of fast speed, high accuracy, convenient operation and reusability. Moreover, it can also realize the measurement of different models of workpieces to be measured by changing the reference block and small measuring block, which has strong versatility and is especially suitable for measuring the key dimensions of parts in batch production. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a special measuring tool for measuring the length of a step inside a deep hole, provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of a special measuring tool for measuring the length of a step inside a deep hole during zero-point calibration, provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of the structure of a special measuring tool for measuring the length of a step inside a deep hole during actual measurement, provided by an embodiment of the present invention. Figure 4 This is a schematic diagram of the workpiece to be measured, which is related to a special measuring tool for measuring the length of a step inside a deep hole provided in an embodiment of the present invention.

[0016] Figure label: 1. Dial indicator; 2. Gauge cylinder; 3. Spring; 4. Measuring rod; 5. Support block; 6. Large measuring block; 7. Small measuring block; 8. Reference block; 9. Fastening screw; 10. Workpiece to be measured. Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] Various embodiments and features of this application are described herein with reference to the accompanying drawings.

[0019] These and other features of this application will become apparent from the following description of preferred forms of embodiments given as non-limiting examples, with reference to the accompanying drawings.

[0020] It should also be understood that although this application has been described with reference to some specific examples, those skilled in the art can certainly implement many other equivalent forms of this application, which have the features described in the claims and are therefore all within the scope of protection defined herein.

[0021] The above and other aspects, features and advantages of this application will become more apparent when taken in conjunction with the accompanying drawings and in view of the following detailed description.

[0022] Specific embodiments of this application are described below with reference to the accompanying drawings; however, it should be understood that the claimed embodiments are merely examples of this application, which can be implemented in various ways. Well-known and / or repeated functions and structures are not described in detail to ascertain the true intent based on the user's historical operations, and to avoid unnecessary or redundant details that would obscure this application. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely serve as the basis and representative basis for the claims to teach those skilled in the art to use this application in various ways with substantially any suitable detailed structure.

[0023] This specification may use the phrases “in one embodiment,” “in another embodiment,” “in yet another embodiment,” or “in other embodiments,” all of which may refer to one or more of the same or different embodiments according to this application.

[0024] The principles and features of the present invention are described below with reference to the accompanying drawings. The embodiments described are for illustrative purposes only and are not intended to limit the scope of the invention. The following description, in conjunction with... Figure 1-4 The preferred embodiments of the present invention will be described in further detail below: like Figure 1-4 As shown, this embodiment of the invention provides a special measuring tool for measuring the length of a step inside a deep hole, comprising: A gauge cylinder 2, wherein a through hole is provided inside the gauge cylinder 2 along its axial direction; A dial indicator 1, wherein the measuring rod of the dial indicator 1 is inserted into a through hole at one end of the gauge cylinder 2, and the dial indicator 1 is connected and fixed to the gauge cylinder 2; A measuring rod 4 is inserted into the through hole of the gauge tube 2 at the other end of the measuring rod 4. A support block 5 and a small measuring block 7 are fixedly installed in the middle of the rod body and the exposed end, respectively. The outer diameter of the support block 5 matches the inner diameter of the through hole of the gauge tube 2, and the outer diameter of the small measuring block 7 matches the inner diameter of the step inside the hole of the workpiece 10 to be measured. Under normal circumstances, the thickness of the small measuring block 7 is set to the minimum limit dimension of the step length inside the hole of the workpiece 10 to be measured, or its thickness is set to the depth value H of the step hole of the reference block 8 minus the deviation of the step length inside the measured hole minus 0.3mm. A large measuring block 6 is fixed to the end of the gauge cylinder 2 away from the dial indicator 1. Its inner end is located inside the gauge cylinder 2 as a limiting member of the support block 5, and the measuring rod 4 passes through the hole in the middle of the large measuring block 6. A spring 3 is sleeved on the measuring rod 4, with one end abutting against the support block 5 and the other end abutting against the cylinder of the gauge cylinder 2 on the side near the dial indicator 1; A reference block 8 is provided with a stepped through hole. The length of the step inside the through hole is set as the maximum limit dimension of the step length inside the hole of the workpiece to be tested 10, and the thickness of the small measuring block 7 is less than the maximum limit dimension of the step length inside the hole of the workpiece to be tested 10.

[0025] In one embodiment, the end of the measuring rod 4 is provided with a thread, and the small measuring block 7 is pressed and fixed to the threaded end of the measuring rod 4 by a nut. In this way, the small measuring block 7 can be securely installed and can be easily disassembled and replaced to meet the measurement needs of workpieces of different sizes and models.

[0026] In one embodiment, the large measuring block 6 is fixed to the gauge cylinder 2 by screwing. This ensures the stable installation of the large measuring block 6 and allows it to be easily disassembled and replaced to meet the measurement needs of workpieces of different sizes and models.

[0027] In one embodiment, the dial indicator 1 is fixed to the gauge cylinder 2 by a fastening screw 9. The fastening screw 9 is screwed onto the gauge cylinder 2, and its end passes through the cylinder body of the gauge cylinder 2 and abuts against the measuring rod of the dial indicator 1, thereby pressing and fixing the measuring rod of the dial indicator 1 onto the gauge cylinder 2.

[0028] In one embodiment, the end of the measuring rod 4 near the dial indicator 1 is provided with a reduced-diameter milling head so that the end of the measuring rod 4 can be inserted into place more easily.

[0029] In one embodiment, the measuring tool is made of alloy tool steel to ensure its service life.

[0030] In one embodiment, to ensure measurement accuracy, the two end faces of the small measuring block 7 are perpendicular to its center line, and the perpendicularity error is ≤0.01mm.

[0031] In one embodiment, to ensure measurement accuracy, the outer end face of the large measuring block 6 is perpendicular to its center line, and the perpendicularity is ≤0.01mm.

[0032] In one embodiment, the through hole inside the gauge cylinder 2 is a variable diameter structure, with the diameter of the hole on the side closer to the dial indicator 1 being smaller than the diameter of the hole on the other side.

[0033] In addition, embodiments of the present invention also provide a method for measuring the length of a step inside a deep hole, implemented based on a special measuring tool for measuring the length of a step inside a deep hole as described in any embodiment of the present invention, including the following steps: Step S1, using reference block 8 to calibrate the zero position of dial indicator 1, specifically including: Step S11: Select a reference block 8 of appropriate size corresponding to the model of the workpiece 10 to be tested; Step S12: Make the outer end of the small measuring block 7 of the measuring tool contact and fit with the inner end face of the perforation stage of the reference block 8. Step S13: Adjust the position of the outer end face of the large measuring block 6 so that the outer end face of the large measuring block 6 is in contact with the outer end face of the perforated stage of the reference block 8. Set the large pointer of the dial indicator 1 to zero and record the reading of the small pointer. Step S2, using the zeroed measuring tool, measures the step length of the workpiece 10 to be measured, specifically including: Step S21: Insert the measuring tool into the deep hole of the workpiece 10 to be measured, so that the outer end face of the small measuring block 7 of the measuring tool contacts and fits with the inner end face of the deep hole stage of the workpiece 10 to be measured, and the outer end face of the large measuring block 6 contacts and fits with the outer end face of the deep hole stage of the workpiece 10 under the action of the spring 3. Step S22: Read the reading of dial indicator 1, and obtain the measured value of the step length inside the deep hole of the workpiece 10 by calculating the difference between the reading and the pointer reading in step S13.

[0034] in, I. Special measuring tool for the length of the inner step in deep holes 1. Made of alloy tool steel that is not easily deformed and has good wear resistance; 2. The small measuring block 7 is fixed to one end of the external thread of the measuring rod 4 with a nut; a through hole is provided in the middle of the small measuring block 7, the through hole is concentric with the center line, and the two end faces of the small measuring block 7 are perpendicular to the center line, with a perpendicularity error ≤0.01mm.

[0035] 3. The measuring rod of dial indicator 1 with the measuring head is fastened to the hole at the rear end of gauge cylinder 2 with M6 fastening screw 9; 4. Under the push of spring 3, the gauge cylinder 2 causes the large measuring block 6 to press tightly against the outer end face of the perforation stage; 5. The large measuring block 6 is screwed onto the front end of the inspection cylinder 2 using a threaded connection. The large measuring block 6 is cylindrical and consists of three sections that increase in size from left to right. The middle section has an external thread, and a through hole is provided at the center of the middle axis. The right end face is perpendicular to the center of the large measuring block 6 with a perpendicularity of ≤0.01mm. The three sections are concentric with the center of the large measuring block 6. The outer diameter of the large measuring block 6 is larger than the inner hole D2 of the workpiece 10 to be measured, but smaller than the inner hole D3 diameter of the workpiece 10 to be measured.

[0036] 6. Before measurement, use reference block 8 to calibrate the zero position of dial indicator 1; 7. The hole depth during the fabrication of reference block 8, i.e., the distance H between the two end faces D and E, is the dimension to be measured and is set as the maximum limit dimension of L2; 8. The measuring rod 4 consists of four sections. The first, second, and third sections are all cylindrical sections. The diameters of the first and second sections are equal, while the diameter of the second cylindrical section is larger than that of the first and second cylindrical sections. The fourth section is a screw section with the smallest diameter among the four sections. The measuring rod 4 is inserted into the through hole of the gauge cylinder 2 at the other end of the gauge cylinder 2. The first cylindrical section is at the innermost part of the gauge cylinder 2, the second cylindrical section acts as a support, the large measuring block 6 is fitted over the third cylindrical section, and the screw section is equipped with a locking nut 5 and a small measuring block 7. The outer diameter of the third cylindrical section matches the inner diameter of the through hole in the gauge cylinder 2, and the outer diameter of the small measuring block 7 matches the inner diameter of the step inside the hole of the workpiece 10 to be measured. II. Measurement Methods 1. Before measurement, the standard value of dial indicator 1 must be adjusted (the depth of the inner step hole to be measured, the maximum limit dimension of L2). 2. If L2+0.10mm, then use L2+0.10mm to calibrate dial indicator 1, and set the reading of dial indicator 1 to zero; 3. First, make the end face of the small measuring block 7 of the measuring instrument contact and fit with the D end face of the reference block 8; 4. Hold the gauge cylinder 2 with your left hand and gently compress the spring 3 so that the end face of the large measuring block 6 contacts and fits against the E end face of the reference block 8. At this time, set the large pointer of the dial indicator 1 to zero and record the reading of the small pointer. 5. Insert the adjusted special measuring tool for measuring the length of the deep hole step into the hole D2 to be measured, and the actual length of the deep hole can be measured. 6. Use the same method as when calibrating percentage chart 1; 7. First, make the end face of the small test block 7 contact and fit with the end face of the bushing A; 8. Next, make the end face of the large measuring block 6 contact and fit with the end face of the bushing B; 9. At this point, if the small pointer reading of dial indicator 1 is consistent, the large pointer reading is the relative difference between the length dimension of stepped hole D2 and the reference value; 10. When the reading of the large pointer is 0 to 0.05 mm smaller than the reference value (i.e., when the reading of the pointer is 0 to 0.05 mm when it rotates forward), the length L2 of the stepped hole D2 is within the tolerance range, which is a qualified size.

[0037] The measuring tool described in this embodiment of the invention can measure the length of stepped holes of various lengths by changing the distance H between the two end faces D and E in the reference block 8. It has the characteristics of simple structure, uncomplicated manufacturing, convenient operation, fast speed, high precision, and reusability, and is especially suitable for measuring the critical dimensions of parts in mass production.

[0038] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within its spirit and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of the present invention.

Claims

1. A deep hole inner step length measuring special gauge, characterized in that, include: A gauge tube (2) has a through hole along its axial direction inside the gauge tube (2); A dial indicator (1) is provided, wherein the measuring rod of the dial indicator (1) is inserted into the through hole at one end of the gauge tube (2), and the dial indicator (1) is connected and fixed to the gauge tube (2); A measuring rod (4) is inserted into the through hole of the gauge tube (2) at the other end of the measuring rod (2). A support block (5) and a small measuring block (7) are fixedly provided in the middle part of the rod and the exposed end, respectively. The outer diameter of the support block (5) matches the inner diameter of the through hole of the gauge tube (2), and the outer diameter of the small measuring block (7) matches the inner diameter of the step inside the hole of the workpiece (10) to be measured. A large measuring block (6) is fixed to the end of the gauge tube (2) away from the dial indicator (1), and its inner end is located inside the gauge tube (2) as a limiting member of the support block (5), and the measuring rod (4) passes through the hole in the middle of the large measuring block (6); A spring (3) is sleeved on the measuring rod (4), with one end abutting against the support block (5) and the other end abutting against the cylinder of the gauge cylinder (2) on the side close to the dial indicator (1); A reference block (8) is provided with a step-shaped through hole. The step length inside the through hole is set as the maximum limit size of the step length inside the hole of the workpiece to be tested (10). The thickness of the small measuring block (7) is less than the maximum limit size of the step length inside the hole of the workpiece to be tested (10).

2. The special gauge for measuring the length of the inner step in the deep hole according to claim 1, characterized in that: The end of the measuring rod (4) is threaded, and the small measuring block (7) is pressed and fixed to the threaded end of the measuring rod (4) by a nut.

3. The special gauge for measuring the length of the inner step in the deep hole according to claim 1, characterized in that: The large measuring block (6) is fixed to the gauge cylinder (2) by screwing.

4. The special gauge for measuring the length of the inner step in the deep hole according to claim 1, characterized in that: The dial indicator (1) is fixed to the gauge cylinder (2) by a fastening screw (9). The fastening screw (9) is screwed onto the gauge cylinder (2), and its end passes through the cylinder body of the gauge cylinder (2) and abuts against the measuring rod of the dial indicator (1), pressing and fixing the measuring rod of the dial indicator (1) onto the gauge cylinder (2).

5. A special measuring tool for measuring the length of a step inside a deep hole according to claim 1, characterized in that: The measuring rod (4) has a reduced-diameter milling head at the end near the dial indicator (1).

6. A special measuring tool for measuring the length of a step inside a deep hole according to claim 1, characterized in that: The measuring tool is made of alloy tool steel.

7. A special measuring tool for measuring the length of a step inside a deep hole according to claim 1, characterized in that: The two ends of the small measuring block (7) are perpendicular to its center line, and the perpendicularity error is ≤0.01mm.

8. A special measuring tool for measuring the length of a step inside a deep hole according to claim 1, characterized in that: The outer end face of the large measuring block (6) is perpendicular to its center line, and the perpendicularity is ≤0.01mm.

9. A special measuring tool for measuring the length of a step inside a deep hole according to claim 1, characterized in that: The through hole inside the gauge tube (2) is a variable diameter structure, with the diameter of the hole on the side closer to the dial indicator (1) being smaller than that on the other side.

10. A method for measuring the length of a step inside a deep hole, implemented based on the special measuring tool for measuring the length of a step inside a deep hole as described in any one of claims 1-9, characterized in that, Includes the following steps: Step S1, using the reference block (8) to calibrate the zero position of the dial indicator (1), specifically including, Step S11: Select a reference block (8) of appropriate size corresponding to the model of the workpiece (10) to be tested. Step S12: Make the outer end of the small measuring block (7) of the measuring tool contact and fit with the inner end face of the perforation stage of the reference block (8); Step S13: Adjust the position of the outer end face of the large measuring block (6) so that the outer end face of the large measuring block (6) is in contact with the outer end face of the perforation stage of the reference block (8), set the large pointer of the dial indicator (1) to zero, and record the reading of the small pointer. Step S2, using the zeroed measuring tool, measures the step length of the workpiece (10) to be measured, specifically including, Step S21: Insert the measuring tool into the deep hole of the workpiece (10) to be measured, so that the outer end face of the small measuring block (7) of the measuring tool contacts and fits with the inner end face of the deep hole stage of the workpiece (10) to be measured, and the outer end face of the large measuring block (6) contacts and fits with the outer end face of the deep hole stage of the workpiece (10) under the action of the spring (3). Step S22: Read the reading of the dial indicator (1) and obtain the measured value of the step length inside the deep hole of the workpiece (10) by calculating the difference between the reading and the pointer reading in step S13.

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