Curved ruler

Abstract

The invention relates to the technical field of measuring tools, and discloses a bending ruler capable of being universal in inner diameter and outer diameter and used for avoiding obstacles and accurately measuring taper holes, the bending ruler comprises a bending plate-shaped body, coaxial sliding sleeves are fixed at the two ends, and two offset positioning devices are respectively installed in the sliding sleeves in a sliding and locking mode. Each offset positioning device consists of a main ruler, a ruler frame capable of sliding along the main ruler, a positioning part provided with an arc-shaped notch and an adjusting rod which is inserted into a sliding sleeve and can slide and rotate, a mounting clamp at the end part of the main ruler can respectively clamp a micrometer or an ejector pin, and a fine adjustment mechanism consisting of a fine adjustment bolt and the like is arranged on one side of the ruler frame and is used for driving the main ruler to do micro axial displacement. The extending length of the ejector pin is adjustable, a lightening hole is formed in the body, an auxiliary positioning device with a supporting rod and positioning parts can be installed on the edge of the body, and the auxiliary positioning device and the two positioning parts jointly form three-point supporting on the end face of a workpiece. The bending ruler is simple in structure and convenient to adjust, and high-precision and repeated measurement under the working conditions of deep holes and the like can be achieved under the condition that obstacles such as a boring rod exist in the holes.

Description

Technical Field

[0001] This invention relates to the field of measuring tool technology, specifically to a curved ruler that can be used for both inner and outer diameter measurements, and is suitable for precise measurement of obstacles and conical holes. It is applicable to the dimensional inspection of large shaft holes, deep holes, and in situations where there are obstacles such as boring bars and spindles. Background Technology

[0002] In machining and equipment maintenance, measuring the diameter of large, deep holes, or holes with obstructions within them, is a common yet challenging task. For example, when boring deep holes on a machine tool, a boring bar is often present at the center of the hole; during the assembly or maintenance of large shaft systems, spindles, supports, fixtures, and other structures are often present inside the hole. These obstructions occupy the center of the hole, making it difficult to directly use traditional measuring tools such as inside micrometers and dial indicators, which require placement along the hole's center.

[0003] In actual production, to obtain hole diameter values ​​without continuously opening and closing the tooling and disassembling the boring bar or spindle, operators typically use simple tools such as calipers and templates to estimate or compare values ​​while navigating around obstacles, and then indirectly verify them using standard measuring tools. This method is highly arbitrary, significantly influenced by the operator's experience, has large measurement errors and poor repeatability, and is not conducive to ensuring fitting accuracy. It often requires additional processes such as grinding and finishing, resulting in a waste of time and costs.

[0004] While there are electronic measuring instruments on the market that can solve the above problems, they are expensive, making them difficult for some small and medium-sized enterprises to purchase. Furthermore, these instruments require high and strict maintenance and are subject to environmental limitations; for example, some electronic measuring instruments may malfunction due to electromagnetic interference in environments with welding operations. Therefore, widespread adoption is difficult, and the high cost is a significant drawback.

[0005] Chinese utility model patent CN 202119363 U, entitled "Measuring Ruler for Measuring Inner Diameter," discloses a structure for measuring inner diameter around obstacles using a semi-circular arc ruler base in conjunction with an inner micrometer and a center pin. This solution, by arranging a micrometer and a center pin at both ends of the semi-circular arc ruler base, allows it to bypass the boring bar and measure the inner diameter of deep holes, thus solving the problem of obstacle-around measurement to a certain extent. However, this solution still has the following shortcomings: The ruler base relies on only two points of contact for positioning and measurement, lacking a stable support structure. When the operator holds the ruler, it is prone to swinging, which affects the repeatability and accuracy of the measurement. It is mainly used for measuring the inner diameter of cylindrical holes, but it cannot be used for converting the size of conical holes, and it is not convenient to measure the depth and accurately locate the damaged area of ​​the hole wall. It is primarily designed for measuring the inner diameter of cylindrical holes, but cannot measure the outer diameter. Therefore, there is a need for a bending ruler that, while inheriting obstacle avoidance capabilities, can further achieve universal inner and outer diameters, has stable support positioning and fine-tuning mechanisms, and can perform cone hole measurement and damage depth measurement, so as to improve measurement accuracy, repeatability and applicability under complex working conditions. Summary of the Invention

[0006] This invention addresses the problems of unstable positioning, inconvenient adjustment, and limited measurement accuracy and repeatability of existing obstacle avoidance measuring tools by providing a universal bending ruler for both inner and outer diameters. This bending ruler achieves stable support positioning and high-precision fine-tuning measurement while ensuring a simple and reliable structure by incorporating a coaxial sliding sleeve, a rotatable offset positioning device, a fine-tuning mechanism, and an adjustable auxiliary positioning device. It is suitable for measuring the inner and outer diameters of complex working conditions such as deep holes and large holes.

[0007] The technical means employed in this invention are as follows: A curved ruler includes a curved plate-shaped body with two identical sliding sleeves coaxially arranged at both ends of the body; two identical offset positioning devices are slidably installed in the two sliding sleeves respectively; a micrometer and a center pin are detachably installed on the two identical offset positioning devices respectively.

[0008] Furthermore, the offset positioning device includes: a main ruler and a frame sleeved on the main ruler. The main ruler can slide axially within the frame. A positioning part is fixedly provided at the top of the frame, and an adjusting rod is screwed to the bottom. A mounting clamp is fixedly provided at the first end of the main ruler, and a locking bolt is provided on the side wall of the mounting clamp for locking and fixing the clamped part.

[0009] Furthermore, a fine-tuning mechanism is fixedly installed at the end of the ruler frame away from the mounting fixture.

[0010] Furthermore, the fine-tuning mechanism includes: a fine-tuning device body that is sleeved on the main scale and can slide axially; a fine-tuning bolt is inserted through the fine-tuning device body; one end of the fine-tuning bolt is fixedly set on the side of the scale frame and extends parallel to the axis of the main scale; a fine-tuning nut is threadedly connected to the fine-tuning bolt; the fine-tuning nut is located in the notch of the fine-tuning device body, and its two end faces abut against the two end faces of the notch respectively; a locking bolt is provided on the upper wall of the fine-tuning device body for locking the main scale.

[0011] Furthermore, the positioning part is provided with an arc-shaped notch to accommodate the measuring head of a micrometer or a pin fixed on the mounting fixture.

[0012] Furthermore, the extension length of the ejector pin is adjustable.

[0013] Furthermore, the main body is provided with several weight-reducing holes to reduce the overall weight of the bending ruler while ensuring rigidity.

[0014] Furthermore, it also includes an auxiliary positioning device, which includes: an auxiliary positioning device body, one end of which is fixed to the body, and the other end is fixedly connected to one end of the support rod, and the other end of the support rod is fixedly connected to the positioning part.

[0015] Furthermore, the length of the support rod is adjustable.

[0016] Furthermore, the auxiliary positioning device is detachable.

[0017] Compared with the prior art, the present invention has the following beneficial effects: By using two coaxial sliding sleeves in conjunction with a rotatable offset positioning device, the micrometer and the center pin can be adjusted within a large range of axial distance and obstacle-around angle, enabling measurement to be completed without removing obstacles inside the hole; By using the positioning part at the top of the offset positioning device and the auxiliary positioning device together to form a stable three-point support plane with the end face being measured, the shaking of the measuring instrument during operation is effectively suppressed, and the repeatability and accuracy of measurement are significantly improved. By setting a fine-tuning mechanism, the main scale and mounting fixture can still be finely adjusted axially after the coarse adjustment is completed, which makes it easy for the operator to accurately control the contact state between the micrometer measuring rod or pin and the surface being measured. The coaxial relationship between the arc-shaped notch and the center line of the probe ensures that the direction of the measuring force is consistent with the calibration reference, thus reducing geometric errors. The adjustable pin extension length structure helps to adapt to the measurement needs of different apertures, different step heights and different end face shapes, thus improving the applicability of the bending ruler. The weight-reducing holes on the main body effectively reduce the overall weight while ensuring rigidity, reducing fatigue during long-term handheld operation and improving the stability of the measurement process. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure; Figure 2 This is a schematic diagram of the offset positioning device; Figure 3 This is a schematic diagram of the fine-tuning mechanism in the offset positioning device; Figure 4 This is a schematic diagram of the auxiliary positioning device; Figure 5This is a schematic diagram for measuring the inner diameter of an object with an obstacle present.

[0020] In the diagram: 1. Main body 2. Sliding sleeve 201. Locking bolt 3. Offset positioning device 31. Main scale 32. Scale frame 33. Mounting clamp 331. Locking bolt 34. Positioning part 341. Arc-shaped notch 342. End face 35. Adjusting rod 36. Fine adjustment mechanism 361. Fine adjustment device body 362. Fine adjustment bolt 363. Fine adjustment nut 364. Locking bolt 4. Center pin 5. Micrometer 6. Auxiliary positioning device 601. Auxiliary positioning device body 602. Support rod 603. Fastening nut 604. Fixing bolt. Detailed Implementation

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. 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.

[0023] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings. In the description of this invention, it should be understood that directional terms such as "front, back, up, down, left, right," "lateral, vertical, horizontal," and "top, bottom," etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner or outer contours relative to the outline of each component itself. For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., may be used here to describe the spatial positional relationship between one device or feature and other devices or features as shown in the figures. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if a device in the accompanying drawings is inverted, a device described as "above" or "on top of" other devices or structures will subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0024] like Figure 1 As shown, the present invention provides a curved ruler, including a body 1, two sliding sleeves 2, two offset positioning devices 3, a center pin 4, a micrometer 5, and an auxiliary positioning device 6.

[0025] The main body 1 has a curved plate-like structure, and several weight-reducing holes are formed along its length. These weight-reducing holes can be circular or other suitable shapes, and are arranged approximately symmetrically along the vertical direction of the main body 1 to maintain sufficient bending stiffness while reducing weight. The outer edge of the main body 1 forms a gripping area for the operator, thus facilitating stable handholding.

[0026] Two sliding sleeves 2 are fixedly connected to both ends of the main body 1, and the axes of the two sliding sleeves 2 are coaxial. The sliding sleeve 2 is a cylindrical structure and can be fixed to the main body 1 by welding, bolting, or integral machining. The line connecting its axis and the bending center of the main body 1 is in the same plane. Each sliding sleeve 2 has a locking bolt 201 threadedly connected to its side wall for locking the offset positioning device 3 installed inside the sliding sleeve 2. The two offset positioning devices 3 are slidably installed in the two sliding sleeves 2 respectively, and have the same structure.

[0027] like Figure 2 As shown, each offset positioning device 3 includes a main ruler 31, a ruler frame 32, a mounting clamp 33, a positioning part 34, and an adjusting rod 35.

[0028] The main scale 31 is a graduated strip with graduations along its length to aid in recording offset positions. The scale frame 32 is a graduated rectangular frame structure that fits over the main scale 31 and can slide relative to it along its axial direction. The scale frame 32 and the main scale 31 are connected by a sliding groove and fasteners, ensuring smooth sliding and allowing for locking of their relative positions when needed using screws or locking blocks. By reading the relative positional relationship between the graduations on the scale frame 32 and the main scale 31, the offset distance can be determined.

[0029] The positioning part 34 is fixedly disposed in the top area of ​​the ruler frame 32. The positioning part 34 can be a plate-shaped or block-shaped structure, and its end face 342 is processed to form a plane that fits the end face to be measured. Preferably, the positioning part 34 is provided with an arc-shaped notch 341, the center of which is located on or close to the straight line where the center of the micrometer 5 or the probe 4 is located. When the micrometer 5 or the probe 4 is installed by the mounting clamp 33, its probe can partially extend into the arc-shaped notch 341, so that the center line of the probe overlaps with the plane where the end face 342 is located, and has a clear and stable geometric relationship. Thus, when the positioning part 34 is in contact with the end face to be measured, the probe can accurately contact the outer edge of the measured orifice or the predetermined position, reducing measurement error.

[0030] The mounting clamp 33 is fixedly mounted at one end of the main scale 31, preferably a clamping structure with clamping bolts. When installing the micrometer 5, the sleeve or shank of the micrometer 5 is placed into the clamping groove of the mounting clamp 33. It can be directly fixed by interference fit, or it can be clamped and fixed by clearance fit and locking bolt 331. When it is necessary to install the ejector pin 4, the ejector pin 4 is fixed in the mounting clamp 33 in the same way as when installing the micrometer 5. Since the mounting clamp 33 is an openable and closable clamping structure, the micrometer 5 and the ejector pin 4 can be easily removed from or interchanged from the corresponding offset positioning device 3.

[0031] The upper end of the adjusting rod 35 is fixedly connected to the bottom of the ruler frame 32 by a thread, and the lower end of the adjusting rod 35 is inserted into the inner hole of the corresponding sliding sleeve 2. The adjusting rod 35 and the sliding sleeve 2 are clearance fit or small interference fit, and are fitted with locking bolts 201 to ensure that the adjusting rod 35 can slide along the axial direction of the sliding sleeve 2 and rotate around the axis of the sliding sleeve 2. When it is necessary to adjust the measuring span or the obstacle angle, loosen the locking bolts 201 on the corresponding sliding sleeve 2, and the operator can push the offset positioning device 3 to move along the axial direction of the sliding sleeve 2 and rotate it at a certain angle as needed; after adjusting to the appropriate position, tighten the locking bolts 201 to lock and fix the adjusting rod 35 and the entire offset positioning device 3 in the sliding sleeve 2.

[0032] The two offset positioning devices 3 have identical structures. They clamp the micrometer 5 and the pin 4 respectively through their respective mounting clamps 33, thus forming a measuring end and a positioning end based on the same structure.

[0033] like Figure 2 , Figure 3 As shown, a fine-tuning mechanism 36 is provided at the end of the ruler frame 32 away from the mounting clamp 33. The fine-tuning mechanism 36 includes a fine-tuning device body 361, a fine-tuning bolt 362, a fine-tuning nut 363, and a locking bolt 364.

[0034] One end of the fine-tuning bolt 362 is fixedly disposed on the side of the ruler frame 32 away from the mounting clamp 33, and extends parallel to the axial direction of the main ruler 31. The fine-tuning device body 361 has a clamping cavity or guide groove for accommodating the main ruler 31 and a through hole for the fine-tuning bolt 362 to pass through. The fine-tuning device body 361 is simultaneously sleeved on the main ruler 31 and the fine-tuning bolt 362, and can slide along the axial direction of the main ruler 31 and the fine-tuning bolt 362.

[0035] A radial notch is provided at the axial center of the through hole through which the fine-tuning bolt 362 passes, so that the fine-tuning nut 363, after being threaded onto the fine-tuning bolt 362, can be located within the radial central notch. The two ends of the fine-tuning nut 363 abut against the two end faces of the central notch, and its outer surface portion protrudes from the outer surface of the fine-tuning device body 361. Thus, when the fine-tuning nut 363 is rotated, the fine-tuning nut 363 moves axially along the fine-tuning bolt 362, and pushes the fine-tuning device body 361 to slide axially along the fine-tuning bolt 362 through the interaction with the two end faces of the central notch.

[0036] The locking bolt 364 is threaded onto the upper wall of the fine-tuning device body 361, with its end extending into the clamping cavity or guide groove of the fine-tuning device body 361 to lock the main scale 31 within the fine-tuning device body 361. In use, the locking bolt 364 is first loosened, allowing the main scale 31 to move axially within the scale frame 32 with a relatively large stroke to complete the coarse adjustment position setting. Once the main scale 31 is close to the target position, the locking bolt 364 is tightened to reliably lock the main scale 31 within the fine-tuning device body 361. Then, the fine-tuning nut 363 is rotated, moving axially along the fine-tuning bolt 362 and pushing the fine-tuning device body 361 to slide axially along the fine-tuning bolt 362. Since the main scale 31 is locked within the fine-tuning device body 361, it undergoes a slight axial displacement relative to the scale frame 32 along with the fine-tuning device body 361, thereby achieving fine adjustment of the measurement point position. When it is necessary to reset the approximate position of the main scale 31, the locking bolt 364 can be loosened. At this time, the rotation of the fine-tuning nut 363 only drives the fine-tuning device body 361 to move relative to the main scale 31 and the scale frame 32, while the main scale 31 can be manually moved quickly and over a wide range along the axis, which is convenient for operation.

[0037] Preferably, the ejector pin 4 comprises two parts: a needle bar and a needle seat. The needle bar is installed in the needle seat via a threaded connection, and the needle seat is then clamped and fixed by the mounting clamp 33. By screwing in or out the needle bar, the extension length of the ejector pin 4 relative to the needle seat can be changed, thereby making the extension length of the ejector pin 4 adjustable to meet the measurement needs of different hole diameters or end face heights.

[0038] Preferably, such as Figure 1As shown, an auxiliary positioning device 6 can be provided at the edge of the main body 1 to increase stability during measurement. The auxiliary positioning device 6 includes an auxiliary positioning device body 601, a support rod 602, and a positioning part 34. One end of the auxiliary positioning device body 601 is fixed at the edge of the main body 1, and the other end of the auxiliary positioning device body 601 is fixedly connected to one end of the support rod 602. The other end of the support rod 602 is fixedly connected to the positioning part 34.

[0039] Preferably, such as Figure 4 As shown, one end of the auxiliary positioning device body 601 forms an open structure, the width of which is slightly larger than the thickness of the body 1, allowing it to be clamped at the edge of the body 1. A threaded through hole is provided on the side wall of the open portion of the auxiliary positioning device body 601, and a fixing bolt 604 is threaded into this threaded through hole. When the fixing bolt 604 is tightened, its end extends into the opening and presses against the body 1, thus firmly clamping and fixing the auxiliary positioning device body 601 to the body 1. When the fixing bolt 604 is loosened, the auxiliary positioning device 601 can be removed from the body 1.

[0040] Preferably, such as Figure 4 As shown, an internally threaded through hole is provided at the connection between the auxiliary positioning device body 601 and the support rod 602, and an external thread is provided at one end of the support rod 602 to mate with it, and a fastening nut 603 is screwed onto the external thread. By screwing the support rod 602 in or out, the distance between the positioning part 34 and the auxiliary positioning device body 601 can be changed, thereby adjusting the position of the auxiliary support point in space; when the position is adjusted to a suitable position, the support rod 602 is locked onto the auxiliary positioning device body 601 by the fastening nut 603, thereby realizing the adjustable length of the support rod 602.

[0041] In the measurement state, such as Figure 5 As shown, the positioning part 34 on the auxiliary positioning device 6 and the positioning part 34 on the two offset positioning devices 3 abut against the end face of the workpiece being measured. The end face 342 of the positioning part 34 is in close contact with the end face being measured, forming three support points, thereby forming a stable three-point support plane on the end face being measured.

[0042] It should be noted that when measuring the inner diameter, the positioning parts 34 of the two offset positioning devices 3 and the positioning parts 34 of the auxiliary positioning device 6 are installed in the direction of extending outward from the outer arc side of the main body 1; when measuring the outer diameter or other special conditions are required, the two offset positioning devices 3 and the auxiliary positioning device 6 can be removed, reversed and reinstalled, so that each positioning part 34 extends outward from the inner arc side of the main body 1 to adapt to different measurement space and posture requirements.

[0043] The working process of this invention will be described below in conjunction with specific application scenarios.

[0044] 1. When measuring the inner diameter of a conical hole with obstructions: 1. Based on the approximate size of the hole to be measured, the operator loosens the locking bolts 201 on the two sliding sleeves 2 and moves the two offset positioning devices 3 along the axial direction of the sliding sleeves 2 to a suitable distance, so that the distance between the probe of the micrometer 5 and the center pin 4 is slightly smaller than the diameter of the hole to be measured. By rotating the adjusting rod 35 of the offset positioning device 3, the line connecting the micrometer 5 and the center pin 4 can bypass the area where obstacles such as the boring bar are located inside the hole. After adjustment, tighten the locking bolts 201 on each sliding sleeve 2 to lock the two offset positioning devices 3 in the predetermined position in the sliding sleeve 2.

[0045] 2. Place the body 1 near the end face of the workpiece to be measured, so that the positioning part 34 on the auxiliary positioning device 6 and the positioning part 34 on the two offset positioning devices 3 abut against the end face of the workpiece to be measured. At this time, the end faces 342 of the three positioning parts 34 are in contact with the end face to be measured, forming a stable three-point support plane, which provides a reliable geometric reference for subsequent readings.

[0046] 3. After the three-point support is established, loosen the locking bolts 364 of the fine-tuning mechanism 36 on the two offset positioning devices 3, allowing the main scale 31 to move appropriately relative to the scale frame 32. Once the probes of the center pin 4 and micrometer 5 are close to the predetermined measurement points on the hole wall, tighten the locking bolts 364 to complete the coarse adjustment locking. Subsequently, the operator can make minor adjustments to the relative position of the main scale 31 and the scale frame 32 by rotating the fine-tuning nut 363, ensuring that the probes of the center pin 4 and micrometer 5 are precisely aligned and lightly pressed against the measurement positions on the hole wall.

[0047] 4. Once the probe of the micrometer 5 is in close contact with the hole wall and has reached a stable state, read the value of the micrometer 5. This will give you the measured hole diameter or allow you to calculate the target size by matching it with the predetermined structural dimensions. If necessary, repeat the above steps at different circumferential positions of the hole to obtain multiple sets of data for evaluating the roundness or overall accuracy of the hole.

[0048] II. Quick calculation of the size of the large or small end of the tapered hole: Let the taper of the measured conical hole be... According to the definition of taper, in a tapered hole with an axial length of... Within a certain range, its diameter changes With axial length The following conditions must be met: Right now: In this invention, the scale of the main ruler 31 is adjusted to make the relative offset between the main ruler 31 and the ruler frame 32 a preset value. The offset The operator determines the taper ratio of the measured conical hole. Preset, for example, when the taper is At that time, offset Set as .

[0049] After establishing the three-point positioning and completing the measurement, the micrometer reading is recorded as follows: In the geometric settings of this embodiment, Offset corresponding to the diameter of the small end section of the tapered hole This corresponds to the distance along the axis of the tapered hole between the small-end section and the large-end section. From the taper relationship, the diameter of the large end of the tapered hole can be obtained. With small end diameter The relationship is: If the larger end is chosen as the reference, then the diameter of the smaller end of the tapered hole is... for: With taper as Taking the conical hole as an example, when the offset At that time, there were: At this point, if the micrometer reading Let be the diameter of the small end of the conical hole, then the diameter of the large end of the conical hole is: In this embodiment, the operator only needs to set the offset of the offset ruler to... After recording the micrometer reading, execute "reading + "This gives the diameter of the large end of the tapered hole; conversely, if the large end is used as the reference for measurement, then the small end diameter = reading - " Through the above geometric conversion, the present invention can achieve rapid and accurate measurement of the conical hole size without complex calculations.

[0050] III. Measurement and localization of borehole wall damage depth: When the wall of the hole being measured has damage such as grooves, scratches, or spalling, this invention uses an offset ruler to measure the depth of the damage and accurately locate it. 1. The positioning part 34 on the auxiliary positioning device 6 and the positioning part 34 on the two offset positioning devices 3 are placed together against the end face of the workpiece to be measured, and a stable support surface is established on the end face of the hole to be measured. 2. By adjusting the scale of the main scale 31, the center pin 4 and micrometer 5 are positioned at the bottom of the damaged area, and a stable reading is obtained through the fine-tuning mechanism. ; 3. Offset the offset ruler to a position avoiding the damaged area, and measure the aperture of the undamaged area under the same reference plane to obtain the reference reading. ; 4. The difference between the two measurement results As a measure of damage depth, the axial coordinates of the damage location can be further determined by using the offset scale, thus achieving a quantitative description of the damage depth and location.

[0051] Through the above structure and usage, the present invention can form a stable and reliable measurement geometry relationship in complex working conditions where there are obstacles inside the hole, by using a coaxial sliding sleeve, offset positioning device, fine adjustment mechanism and auxiliary positioning device, so as to achieve high-precision and repeatable measurement of inner diameter, tapered hole size and hole wall damage depth.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A curved ruler comprising a curved plate-shaped body (1), characterized in that: Two identical sliding sleeves (2) are coaxially arranged at both ends of the main body (1); Two identical offset positioning devices (3) are slidably installed in the two sliding sleeves (2); The micrometer (5) and the pin (4) are detachably mounted on the two identical offset positioning devices (3).

2. The bending ruler according to claim 1, characterized in that, The offset positioning device (3) includes: The main ruler (31) and the ruler frame (32) sleeved on the main ruler (31) are provided. The main ruler (31) can slide axially within the ruler frame (32). The top of the ruler frame (32) is fixedly provided with a positioning part (34), and the bottom is screwed with an adjusting rod (35). The first end of the main ruler (31) is fixedly provided with a mounting clamp (33). The side wall of the mounting clamp (33) is provided with a locking bolt (331) for locking and fixing the clamped part.

3. The bending ruler according to claim 2, characterized in that, A fine-tuning mechanism (36) is fixedly installed at the end of the ruler frame (32) away from the mounting clamp (33).

4. The bending ruler according to claim 3, characterized in that, The fine-tuning mechanism (36) includes: A fine-tuning device body (361) is fitted onto the main scale (31) and can slide axially. A fine-tuning bolt (362) is inserted inside the fine-tuning device body (361). One end of the fine-tuning bolt (362) is fixedly set on the side of the scale frame (32) and extends parallel to the axial direction of the main scale (31). A fine-tuning nut (363) is threaded onto the fine-tuning bolt (362). The fine-tuning nut (363) is located in the notch of the fine-tuning device body (361), and its two end faces abut against the two end faces of the notch respectively. A locking bolt (364) is provided on the upper wall of the fine-tuning device body (361) for locking the main scale (31).

5. The bending ruler according to claim 4, characterized in that, The positioning part (34) is provided with an arc-shaped notch (341) for accommodating the probe of the micrometer (5) or the pin (4) fixed on the mounting fixture (33).

6. The bending ruler according to claim 5, characterized in that, The extension length of the ejector pin (4) is adjustable.

7. The bending ruler according to claim 6, characterized in that, The main body (1) is provided with several weight-reducing holes to reduce the overall weight of the bending ruler while ensuring rigidity.

8. The bending ruler according to any one of claims 1 to 7, characterized in that, It also includes an auxiliary positioning device (6), which includes: The auxiliary positioning device body (601) has one end fixed on the body (1) and the other end fixedly connected to one end of the support rod (602). The other end of the support rod (602) is fixedly connected to the positioning part (34).

9. The bending ruler according to claim 8, characterized in that, The length of the support rod (602) is adjustable.

10. The bending ruler according to claim 8, characterized in that, The auxiliary positioning device (6) is detachable.

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