Tool for quickly detecting the position of a tenon groove in a large-size disc

Abstract

The tool for rapidly detecting the position degree of the mortise of a large-size disc part of the application comprises a spring, a lever, a micrometer, an end face positioning plate, a positioning block and a main body with a special-shaped structure, the inner end face of the main body is provided with a continuously arranged groove, a pull pin is arranged in the groove, the lever is arranged in a T-shaped structure and contains three positioning references, the three references are tightly attached to the working face, the end face and the bottom face of the mortise of the part during detection to fix the measuring tool, ensure that the measuring head on the other side is at a fixed position during each detection, ensure that good reproducibility can be obtained during detection by different persons, two new gripping handles are additionally arranged to facilitate the force exertion of the detection personnel and improve the measuring efficiency.

Description

Technical Field

[0001] This invention belongs to the technical field of testing tools, and particularly relates to a tool for quickly testing the position accuracy of tenons and grooves in large-sized discs. Background Technology

[0002] For the positional inspection of tenon grooves on disc-shaped parts, two methods are generally used. The first method is to use a CMM coordinate measuring machine to inspect the entire surface and contour of the tenon groove, fit the centerline of the tenon groove, and then give the positional accuracy of the tenon groove. The disadvantage of this method is that it is time-consuming, taking at least 3 hours per part, and when inspecting oblique tenons, improper probe tilting angle can cause interference with the part. The second method is to use a common normal micrometer to directly measure the difference in distance from the tip of the tenon groove end face to the working surface of the tenon groove and convert it. This method depends on the skill level of the inspector and the stability of the inspection. The repeatability and reliability of the inspection are not good, so the measurement efficiency of both methods is low.

[0003] In view of this, the present invention is hereby proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a tool for rapidly detecting the positional accuracy of tenons and grooves in large-sized disc components, thus solving the technical problem of low measurement efficiency in existing measurement methods. The technical solution of this invention has many beneficial effects, as described below:

[0005] A tool for quickly detecting the positional accuracy of tenons and grooves in large-sized disc components includes a spring, a lever, a dial indicator, an end-face positioning plate, a positioning block, and a main body with an irregular structure. The inner end face of the main body has continuously arranged grooves, and a pull pin is disposed within each groove. The lever is arranged in a T-shape.

[0006] The central area of ​​the large end of the lever is rotatably mounted on one end of the main body. A spherical measuring head is installed on one end of the large end of the lever, and the other end of the large end of the lever is a free end for the operator to hold and rotate. The small end of the lever is also a free end, and a flat contact is provided on the small end of the lever near the free end. The flat contact is used to connect with the measuring end of the dial indicator. The position of the pull pin corresponds to the position of the free end. The two ends of the spring are respectively hooked onto the pull pin and the free end. The measuring head can make point contact with the working surface of the disc. The end face positioning plate and positioning block are respectively installed on the side of the other end of the main body, and a ball head pin is installed on the end face. The end face positioning plate and positioning block are used for positioning the main body, and the ball head pin is used for the inspector to hold the main body with their fingers.

[0007] The dial indicator is installed on the outer end face of the main body near the lever, and the measuring end of the dial indicator can contact the flat contact when it is activated.

[0008] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0009] This invention utilizes a three-directional positioning structure to accurately position the measuring instrument and the part, ensuring the stability of measurement results and eliminating complete reliance on the operator's skill. It offers good interchangeability; the modular design allows for easy replacement of different positioning components for parts of varying sizes, providing versatility and interchangeability. It boasts high accuracy: the positioning datum perfectly aligns with the design drawing datum, reducing errors caused by datum conversion and providing a more intuitive and accurate reflection of the part's position. It has a long service life: all components (especially the measuring head) undergo wear-resistant treatment, effectively extending service life and measurement accuracy. It is portable: compact and portable, operable by a single person, suitable for various measurement environments, and offers convenient and efficient operation. Finally, it is cost-effective: its simple structure and compact components significantly reduce testing costs, allowing for extended use of a single measuring instrument. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram from a first perspective of the present invention;

[0012] Figure 2 This is a schematic diagram of the second perspective direction of the present invention;

[0013] Figure 3 This is a schematic diagram of the third-view direction of the present invention;

[0014] Figure 4 This is a schematic diagram of the main body of the present invention, wherein,

[0015] 1. Main body; 2. Spring; 3. Lever; 4. Dial indicator; 5. End face positioning plate; 6. Positioning block; 7. Measuring rod; 8. Measuring head; 9. Flat contact head; 10. Pull pin; 11. Ball head pin. Detailed Implementation

[0016] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0017] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that aspects can be practiced without these specific details. To enable those skilled in the art to better understand the invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of that feature. In the description of the invention, unless otherwise stated, "a plurality of" means two or more.

[0018] like Figures 1 to 4 The tool shown is for quickly detecting the position of the tenon groove in a large-sized disc. The large-sized disc, as a component, includes a main body 1 with an irregular structure (e.g., a combination of an arc-shaped structure and a broken line segment structure, or a question mark structure or other discontinuous or non-closed linear structure), a spring 2 (a hook-type spring 2), a lever 3, a dial indicator 4 or a percentage indicator, an end face positioning plate 5, and a positioning block 6. The inner end face of the main body 1 has continuously arranged grooves, and pull pins 10 are installed in the grooves. The lever 3 is arranged in a T-shape. Preferably, the large end and small end of the lever 3 adopt an arc-shaped transition structure.

[0019] The central area of ​​the large end of lever 3 is mounted on one end of the main body 1 in a rotating manner. One end of the large end of lever 3 is equipped with a measuring head 8 with a spherical structure. The other end of the large end of lever 3 is a free end, which is used by the operator to rotate it by hand. The small end of lever 3 is a free end. A flat contact 9 is provided on the small end of lever 3 near the free end. The flat contact 9 is used to connect with the measuring end of dial indicator 4 so that the dial indicator can read the value passively. The position of the pull pin 10 corresponds to the position of the free end. The two ends of the spring 2 are respectively hooked onto the pull pin 10 and the free end. The measuring head 8 can make point contact with the working surface of the disc for circumferential positioning. The side of the other end of the main body 1 is respectively equipped with an end face positioning plate 5 and a positioning block 6 for positioning the main body 1. For example, the length of the end face positioning plate 5 is greater than the height of the main body 1. The bottom surface of the end face positioning plate 5 has a pin hole. When the end face positioning plate 5 contacts the outer end face of the part, the pin can be inserted into the pin hole to limit the height of the main body 1 in the height direction of the part. The pin can also facilitate the operator to apply force so that the lower end face of the end face positioning plate 5 is in close contact with the end face of the part. The tenon groove on the side of the positioning block 6 is in close contact with the working surface near the center. With the use of the ball head pin 11, the tilt angle of the measuring instrument can be kept constant. A ball-head pin 11 (near the positioning block 6) is installed on one end face of the lever 3 of the main body 1, allowing the inspector to hold the measuring instrument with their fingers. For example, the ball-head pin 11 contacts the bottom surface of the tenon groove to ensure the distance of the measurement point relative to the center of the part. A dial indicator 4 is installed on the outer end face of the main body 1 near the lever 3. When the measuring end of the dial indicator 4 moves, it can contact the flat contact 9. Preferably, a measuring rod 7 is installed on the measuring end of the dial indicator 4. One end of the measuring rod 7 can contact the flat contact 9 under the drive of the lever 3, realizing the reading feedback of the dial indicator 4 and avoiding the influence of the inspector's technique and angle deviation on the final result when using a common normal micrometer. The flat contact 9 plays the role of transmitting the movement of the lever 3 into the movement of the measuring rod 7, and then performing accurate measurement through the measuring instrument. It should be noted that the tension of the spring 2 directly affects the contact force between the measuring head 8 and the part. The spring 2 is preferably an adjustable spring 2, which has a fixed force and can reduce the influence on the measurement result.

[0020] The tool or measuring instrument can be fixed in all directions relative to the part by means of three positioning references: the pin, the two ends, and the ball head pin 11. For this type of special tenon position measuring instrument, its degrees of freedom in the working state have been completely restricted. Its position, orientation, and tilt angle relative to the part are unique. The design of the reference positioning block / ball head greatly improves the detection accuracy and efficiency, and is more scientific and effective than traditional methods.

[0021] In one specific implementation, the end of the lever 3 furthest from the measuring head 8 is provided with an arc-shaped groove or arc-shaped notch. The arc-shaped groove or arc-shaped notch is used to improve the operator's hand grip strength and enable them to hold the lever 3 tightly. The central area of ​​the large end of the lever 3 is hinged to one end of the main body 1, and the lever 3 can rotate freely relative to the main body 1, which is convenient for installation.

[0022] In one specific implementation, the inner end face of the main body 1 is provided with an arc-shaped transition part. The arc-shaped transition part is used for the transition of the end of the main body 1 away from the lever 3 with a line segment structure, or the end of the main body 1 adjacent to the lever 3 is provided with a three-segment broken line structure, and a dial indicator 4 is installed on the outer end face of the middle broken line.

[0023] Furthermore, a dial indicator clip and a clip nut are fitted on the outer end face of the middle fold line to accommodate the installation of dial indicator 4, and to theoretically compensate for the readings fed back by the dial indicator. The common normal micrometer measures the distance from the tip of the first mortise to the working surface of the adjacent mortise. This distance does not directly reflect the actual difference in mortise width, so it is necessary to eliminate this difference. Specifically...

[0024] The height and width values ​​of the tenon groove are converted into the circumferential offset A1=a×(c / b)×sin(α)+tan(β)×cos(α), where α is the principal inclination angle of the tenon groove, β is the secondary inclination angle of the tenon groove, the length of the tenon groove measured by the dial indicator is recorded as c, the length of the tenon groove of the part is b, and the difference between the inlet and outlet of the single groove T value is not greater than a.

[0025] Under the condition that the dimensions of the tenon and groove at n points on the circumference are all qualified, the angle values ​​of the bottom corners on both sides of the tenon and groove are converted into the offset of the length of the circumferential arc A2=B1 / n, where the difference of the bottom corner angle values ​​on both sides of the tenon and groove is B. When calculated according to the maximum wear condition, the tolerance corresponds to the length of the circumferential arc B1.

[0026] The tenon is a double-angle tenon, with a tenon height H. The measured position occupies the height difference h, and the maximum tolerance is C. The deviation in the radial direction of the part is C. (h / H), converted to the deviation C1 in the arc direction, and the converted deviation C2 in the arc direction corresponding to the measured width direction of 0.03257mm;

[0027] The positional tolerance of the tenon groove of the part in the arc direction is required to be X = A1 + B1 / n + C1 + C2 + the measurement tolerance of the common normal in the arc direction.

[0028] How to use the measurement process:

[0029] 1. Clean the part to be measured.

[0030] 2. Hold the screw of the end face positioning plate with your left hand and apply downward force toward the center of the part. Hold the main body of the measuring tool with your right hand, press the ball head pin tightly against the bottom surface of the left tenon groove, and press the positioning block tightly against the right working surface of the left tenon groove to complete the positioning of the measuring tool.

[0031] 3. Press the lever to make the measuring head make normal contact with the left working surface of the right tenon groove.

[0032] 4. Record the dial indicator reading.

[0033] 5. Release the measuring tool and remove it to continue measuring the thickness between adjacent tenons.

[0034] 6. Compare the differences in the values ​​of each tenon and groove, and record the difference between the maximum and minimum values ​​as the positional accuracy of the tenon and groove.

[0035] This method actually measures the vertical distance between the clear tip of one mortise and the nearest profile of the other mortise and tenon. First, we determine that the mortise and tenon positional accuracy includes two aspects: the angular difference between the center planes of each mortise and tenon and the difference in their extreme radii. That is, the difference in the angle of the mortise and tenon center lines and the difference in their outer radii. When simplifying the double-angled mortise and tenon into a straight mortise and tenon, we consider the difference in the fixed height and width of the mortise and the difference in the angle of the bottom corners on both sides of the mortise and tenon.

[0036] Difference in fixed height and width of the tenon groove: Tolerance A, i.e., the stability of the tenon groove broach width, is related to the wear coefficient of the tenon groove. According to the design drawing requirements, the difference between the inlet and outlet of the single groove T value should not be greater than a. The length of the tenon groove on the part is b, and the length of the tenon groove corresponding to the measurement position is c. The theoretical difference is A1 (in the direction of the circumferential arc length).

[0037] Based on the definition of the width deviation 'a' of the tenon groove inlet and outlet, and combined with the geometric characteristics of the double inclination angle, the corrected formula for calculating the circumferential offset is as follows:

[0038] Calculation formula:

[0039] A1=a×(c / b)×sin(α)+tan(β)×cos(α)

[0040] Parameter description:

[0041] -a: Deviation in the width of the tenon and groove inlet / outlet (design given value)

[0042] -c: Measurement position corresponds to the length of the tenon groove (actual length of the measured section).

[0043] -b: Total length of the tenon groove in the part (design reference length)

[0044] -α: Principal inclination angle of the tenon (usually a dovetail angle, such as 55° or 60°)

[0045] -β: Tenon groove secondary inclination angle (forming a double inclination angle structure with the main inclination angle)

[0046] Derivation process:

[0047] 1. Decomposition of inlet and outlet deviation: Decompose 'a' into a component along the length of the tenon groove (a∥) and a component in the vertical direction (a⊥).

[0048] a∥=a×(c / b) / / Length scaling

[0049] a⊥=a×(c / b)×tan(β) / / Amplification effect in tilt direction

[0050] 2. Geometric projection synthesis: Projecting the decomposed components onto the circumferential direction.

[0051]

[0052] Application example:

[0053] When the tenon parameters are:

[0054] -a=0.08mm (difference in width between inlet and outlet)

[0055] -c=60mm (length of the detection section)

[0056] -b=240mm (total length)

[0057] -α = 55° (principal tilt angle)

[0058] -β=10° (secondary tilt angle)

[0059] The calculation yields:

[0060] A1=0.08×(60 / 240)×sin55°+tan10°×cos55°

[0061] ≈0.02×0.8192+0.1763×0.5736

[0062] ≈0.02×0.894≈0.0179mm

[0063] Technical points:

[0064] 1. For double-tilt structures, the influence of the primary and secondary tilt angles needs to be calculated separately before vector synthesis.

[0065] 2. Measurement location c should be selected in the stress concentration area (usually 1 / 3 of the distance from the end of the tenon).

[0066] 3. During high-precision machining, the dynamic change of the β angle caused by thermal deformation must be considered.

[0067] 4. This formula is applicable to mass production scenarios with precision levels below ISO2768-m.

[0068] Verification method:

[0069] The actual width of the tenon and groove inlet and outlet can be detected by a coordinate measuring machine, and the theoretical offset A1 can be calculated by substituting it into the formula and compared with the measured value for verification (allowable error ±0.005mm).

[0070] The difference in the bottom angle values ​​on both sides of the tenon groove: tolerance B, which is the stability of the tenon groove cutter angle, is related to the wear coefficient of the tenon groove and the stability of the cutter mounting. Calculated according to the maximum wear condition, the tolerance corresponds to the circumferential arc length as B1 (circumferential arc length direction). Under the condition that the dimensions of the tenon grooves at n points on the circumference are all qualified, the change between two adjacent grooves is B1 / n (circumferential arc length direction).

[0071] Furthermore, since the tenon groove of this part is a double-angle tenon groove, it is controlled by "the difference between the measured values ​​of a groove to points W and V and the difference between the nominal values ​​to these points is not greater than C" and "T° ± t′". The tenon groove height is H mm, and the measurement position occupies the height difference h, so the resulting deviation is C. (h / H) (radial direction), converted to arc direction is C1mm. And T°+-t′ corresponds to 0.03257mm in the measured width direction (measurement direction), converted to arc direction is C2mm.

[0072] The positional tolerance requirement of the tenon groove is X (arc direction) = difference in fixed height and width of the tenon groove (arc direction) + difference in bottom angle on both sides of the tenon groove (circumferential arc length direction) + difference in inclination angle (arc direction) + common normal measurement tolerance (arc direction) = A1 + B1 / n + C1 + C2 + common normal measurement tolerance (arc direction).

[0073] The product provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from the principles of the invention, and these improvements and modifications also fall within the protection scope of the invention claims.

Claims

1. A tool for quickly detecting the positional accuracy of mortise and tenon joints in large-sized discs, characterized in that, The main body includes a spring, a lever, a dial indicator, an end face positioning plate, a positioning block, and an irregularly shaped structure. The inner end face of the main body has continuously arranged grooves, and a pull pin is installed within each groove. The lever is arranged in a T-shape. The central area of ​​the large end of the lever is rotatably mounted on one end of the main body. A spherical measuring head is installed on one end of the large end of the lever, and the other end of the large end of the lever is a free end for the operator to hold and rotate. The small end of the lever is also a free end, and a flat contact is provided on the small end of the lever near the free end. The flat contact is used to connect with the measuring end of the dial indicator. The position of the pull pin corresponds to the position of the free end. The two ends of the spring are respectively hooked onto the pull pin and the free end. The measuring head can make point contact with the working surface of the disc. The end face positioning plate and positioning block are respectively installed on the side of the other end of the main body, and a ball head pin is installed on the end face. The end face positioning plate and positioning block are used for positioning the main body, and the ball head pin is used for the inspector to hold the main body with their fingers. The dial indicator is installed on the outer end face of the main body near the lever, and the measuring end of the dial indicator can contact the flat contact when it is activated.

2. The tool according to claim 1, characterized in that, The lever has an arc-shaped groove or arc-shaped notch at the end furthest from the measuring head. The arc-shaped groove or arc-shaped notch is used to improve the operator's grip strength and enable them to hold the lever firmly.

3. The tool according to claim 1, characterized in that, The central area of ​​the large end of the lever is hinged to one end of the main body, and the lever can rotate freely relative to the main body.

4. The tool according to claim 1, characterized in that, The inner end face of the main body is provided with an arc-shaped transition portion, which is used for a line segment structure transition on the end of the main body away from the lever, or... The main body is configured with a three-segment broken line structure near one end of the lever, and the dial indicator is installed on the outer end face of the middle broken line.

5. The tool according to claim 4, characterized in that, The outer end face of the middle fold line is fitted with a dial indicator clip and a clip nut to accommodate the installation of the dial indicator.

6. The tool according to claim 4, characterized in that, The dial indicator is equipped with a measuring rod at its measuring end. One end of the measuring rod can contact the flat contact head under the drive of a lever, thereby realizing the reading feedback of the dial indicator.

7. The tool according to claim 6, characterized in that, Theoretical compensation for the readings fed back by the dial indicator includes, The height and width values ​​of the tenon groove are converted into the circumferential offset A1=a×(c / b)×sin(α)+tan(β)×cos(α), where α is the principal inclination angle of the tenon groove, β is the secondary inclination angle of the tenon groove, the length of the tenon groove measured by the dial indicator is recorded as c, the length of the tenon groove of the part is b, and the difference between the inlet and outlet of the single groove T value is not greater than a. Under the condition that the dimensions of the tenon and groove at n points on the circumference are all qualified, the angle values ​​of the bottom corners on both sides of the tenon and groove are converted into the offset of the length of the circumferential arc A2=B1 / n, where the difference of the bottom corner angle values ​​on both sides of the tenon and groove is B. When calculated according to the maximum wear condition, the tolerance corresponds to the length of the circumferential arc B1. The tenon is a double-angle tenon with a height of H. The height difference between the measured position and the measured position is h. The maximum tolerance is C, and the deviation in the radial direction of the part is C. (h / H), converted to the deviation in the arc direction C1, and the deviation in the arc direction converted according to the measured width direction is C2; The positional tolerance of the tenon groove of the part in the arc direction is required to be X = A1 + B1 / n + C1 + C2 + the measurement tolerance of the common normal in the arc direction.

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