A convenient method and device for detecting indication error of steel tape measure

Abstract

A convenient method and device for detecting the indication error of a steel tape measure comprises the following steps: sequentially placing a steel tape measure, a glass fixing plate, and an electric rotary table assembly on the same horizontal line of a housing front plate; pulling out the hook of the steel tape measure, passing it through the glass fixing plate, and inserting it into the shaft groove of the rotating shaft of the winding wheel mechanism; starting the test at the first target detection point at the 1000mm scale line: measuring the fixed distance value Lg between the marking line on the glass fixing plate and the electric rotary table assembly; calculating the horizontal target distance Lx'1 that the electric rotary table needs to rotate, Lx'1 = Lb1-Lg, Lb1 = 1000mm; rotating the electric rotary table to reach the horizontal target distance Lx'1, reading the deviation value L1 between the marking line on the glass fixing plate and the target detection point scale line at this time, and obtaining the error value; and so on, completing the remaining detection points meter by meter. The present invention occupies little space and is fast, accurate, efficient, and convenient.

Description

Technical Field

[0001] The present invention belongs to the technical field of steel tape measure indication error calibration, and specifically relates to a convenient steel tape measure indication error detection method and detection device. Background Art

[0002] As a basic measuring tool in industrial manufacturing, construction and other fields, the accuracy of steel tape measures directly affects product quality and engineering reliability.

[0003] According to the JJG 4-2015 Steel Tape Verification Procedure, the existing steel tape inspection method mainly uses comparative measurements using standard steel tapes. However, during production and use, steel tapes are prone to measurement deviations due to material deformation, scale marking errors, and environmental factors. The cumulative error is particularly significant for large-sized steel tapes (over 5m).

[0004] Current mainstream calibration technology for steel tape measure indication errors still faces the following technical bottlenecks: First, the calibration device lacks adaptability. Traditional calibration devices often use a 5-meter-long calibration table, which requires a large laboratory space. Furthermore, the standard ruler and the measured ruler must be placed side by side and manually aligned with weights. This makes it difficult to adapt to steel tape measures of varying sizes (e.g., from 0-30,000 mm to 0-100,000 mm), forcing segmented measurement. Furthermore, the insufficient rigidity of the support structure can easily cause the tape to bend or deflect, affecting calibration accuracy. Although some improved devices utilize support slides and zero adjustment components to adjust the length, they still rely on manual operation, resulting in low efficiency. Second, manual operation introduces errors. The current calibration process requires visual comparison of the scales of the standard ruler and the measured ruler, with point-by-point error recording. For example, conventional methods require aligning the zero point of the master ruler with the measured ruler before manually moving the reading microscope for measurement at multiple comparison points (e.g., 1-meter, 2-meter, and 5-meter intervals). This repetitive operation can easily lead to visual fatigue and positioning deviations, resulting in cumulative errors of ±1.5 mm (according to domestic standards) or even higher. In addition, tension control relies on manually hanging a heavy hammer. If the standard tension (such as 49N) is not followed, additional errors will be generated due to elastic deformation. -5 1000 metric tons (1000 metric tons / °C) is temperature-sensitive, but most calibration environments lack temperature control and rely solely on room temperature (20°C ± 8°C). This results in ineffective compensation for temperature drift errors. Furthermore, insufficient leveling of the tape measure or an uneven support surface can introduce geometric errors. For example, a 0.4m height difference between the ends of a 30m tape measure can result in an error of 2.6mm. Fourth, the tape measure strip is made of stainless steel, posing a risk of hand-cutting during manual operation.

[0005] Chinese invention patent CN117928331B discloses a calibration device for a steel tape measure used for measurement, comprising a test platform, a steel tape measure body placed on the test platform surface, a tape measure strip housed within the steel tape measure body, a positioning mechanism provided on the test platform surface that cooperates with the steel tape measure body, the positioning mechanism comprising a clamping assembly and an extension assembly, and a protective mechanism provided on the test platform surface that cooperates with the tape measure strip, the protective mechanism comprising a squeeze column, a support assembly, and a pressing assembly. This invention provides auxiliary squeezing and positioning functions. By providing a support assembly and a pressing assembly that cooperate with each other, the position of the squeeze column can be automatically adjusted as the tape measure strip extends and retracts within the steel tape measure body, thereby protecting the tape measure from squeezing, effectively improving the stability of the tape measure during testing and resolving the issue with existing calibration devices where the tape measure strip easily falls off and automatically rewinds into the steel tape measure body, posing a risk of cutting the palm. However, the existing JJG 4-2015 steel tape measure calibration method is still used, requiring a large space for the test platform, and no intelligent measurement solution is provided for steel tape measurement.

[0006] Chinese invention patent CN116972709B discloses a method and system for analyzing the error of steel tape measurement calibration. The method has the technical effects of high degree of automation, precise calibration and high calibration efficiency to a certain extent. It provides two embodiments. The overall idea is: zero point correction of the steel tape measurement calibration device; when the steel tape measurement reaches a predetermined position, the clamping unit grabs the steel tape measurement and cooperates with the measuring block and fixes the measuring block and the measuring end of the steel tape measurement by the pressing block. At this time, the steel tape measurement is fixed by the clamping unit; the sliding of the measuring block is controlled, and the sliding distance of the measuring block is recorded, and the sliding distance is used as the standard distance; the image of the zero point line and the scale line of the steel tape measurement is performed by the CCD sensor to establish a verification image set; the processing network is configured according to the acquisition parameters of the CCD sensor, and the recognition processing of the verification image set is performed by the processing network to generate a scale recognition result; error analysis is performed based on the standard distance and the scale recognition result to generate an error calibration result. The document states that the relative sliding distance of the measuring block is used as the standard displacement, and CCD is used to capture images to calculate the error of the steel tape. When the steel tape reaches the position, the clamping unit activates and secures the steel tape to ensure that it does not move or shake during the measurement process. Therefore, this solution, which uses sliding as the standard distance, requires a large motion platform and a large space for the calibration table, at least 5m to meet the testing requirements of most steel tapes. Furthermore, it does not explain how to test long-range steel tapes, such as 50m, and cannot achieve automatic testing of long-range steel tapes.

[0007] Chinese invention patent CN116164608B discloses a semi-automated, efficient steel tape measure calibration device. The device comprises a calibration platform, a positioning block disposed on the calibration platform, and a clamping device configured as a fixture. A fixture is also provided on one side of the clamping device on the calibration platform, and a measuring structure is provided on the other end of the fixture. The measuring structure is used to measure the steel tape measure. A limiter is provided on the other side of the measuring structure on the calibration platform. This device positions the steel tape measure between the positioning blocks. When a soft capsule is squeezed, a first slider within the guide block is squeezed out, thereby driving the limiter connected to the first slider to move, thereby achieving zero positioning. At this point, the limiter slot continues to advance, automatically recording the error value. By fixing the measured distance, section calibration is achieved, thereby increasing the calibration efficiency of the steel tape measure to a certain extent. However, this solution also uses a standard ruler for manual comparison measurement, requiring a large space on the calibration platform and resulting in a low degree of automation.

[0008] Similarly, the solutions disclosed in Chinese utility model patents CN222718812U, CN222579103U, CN221781396U, CN221484376U, CN221425521U, etc. all use a large horizontal calibration platform to calibrate the steel tape, and the calibration platform occupies a large space.

[0009] Therefore, it is urgent to develop a method that occupies a small space and uses a motor to drive the steel tape measure to automatically extend and retract the tape measure, so as to achieve fast, accurate and convenient detection of the steel tape measure. Summary of the Invention

[0010] One of the technical problems to be solved by the present invention is to provide a fast, accurate, efficient and convenient method for detecting the indication error of a steel tape measure.

[0011] The second technical problem to be solved by the present invention is to provide a device for detecting the indication error of a steel tape measure which occupies little space and is fast, accurate, efficient and convenient.

[0012] The present invention is achieved in that:

[0013] One of the technical solutions:

[0014] A convenient method for detecting the indication error of a steel tape measure comprises the following steps:

[0015] Step 1: sequentially place a steel tape measure, a glass fixing plate, and an electric rotating platform assembly on the same horizontal line of a housing front panel; the electric rotating platform assembly includes an electric rotating platform and a rolling wheel mechanism connected thereto;

[0016] Step 2: Pull out the hook of the steel tape measure, pass it through the glass fixing plate, and insert the hook into the shaft groove of the electric rotating table assembly;

[0017] Step 3: Clear the electric rotary table;

[0018] Step 4: Start the test at the first target detection point at the 1000mm mark:

[0019] Measure the fixed distance value Lg between the marking line on the glass fixing plate and the left side of the shaft groove of the rotating shaft of the rolling wheel mechanism;

[0020] Calculate the horizontal target distance Lx'1 that the electric rotary stage needs to rotate: Lx'1 = Lb1 - Lg, where Lb1 is the nominal value of the first target detection point, i.e., 1000 mm. Rotate the electric rotary stage to reach the horizontal target distance Lx'1. Read the deviation L1 between the marking line on the glass fixing plate and the engraved line of the first target detection point at this time. Calculate the error value △L1 = -L1 for the first target detection point.

[0021] Step 5: Start the test at the second target detection point at the 2000m mark:

[0022] Rotate the electric rotary stage to the horizontal target distance Lx'2, Lx'2 = Lb2 - Lb1 = 2000mm - 1000mm, where Lb2 is the nominal value of the second target detection point, i.e. 2000mm. Read the deviation value L2 between the marking line on the glass fixing plate and the 2000mm scale line of the second target detection point, and obtain the error value △L2 = -L2 of the second target detection point;

[0023] Similarly, the remaining inspection points are completed meter by meter according to the JJG 4-2015 steel tape measurement calibration requirements. After the inspection is completed, the electric rotary table is reversed to the origin.

[0024] Technical solution 2:

[0025] A detection device for implementing the above-mentioned convenient method for detecting the indication error of a steel tape measure comprises: the housing, a steel tape measure clamp, the glass fixing plate, and the electric rotating stage assembly fixedly mounted in sequence on the same horizontal line of the front panel of the housing;

[0026] The electric rotating table of the electric rotating table assembly is installed inside the housing, and the rotating shaft of the scroll wheel mechanism extends out of the front plate of the housing, with the shaft groove formed at one end and the other end fixedly connected to the electric rotating table;

[0027] The steel tape measure is fixedly mounted on the steel tape measure fixture, the middle portion of the glass fixing plate has a U-shaped groove, and the top portion has a marking line parallel to the scale on the steel tape measure;

[0028] The hook of the steel tape measure passes through the U-shaped groove of the glass fixing plate and is inserted into the shaft groove of the electric rotating table assembly. The steel tape measure is pulled horizontally by the rotation of the electric rotating table, and the error value is obtained based on the distance between the marking line on the glass fixing plate and the target detection point engraved line on the steel tape measure.

[0029] Furthermore, a rolling wheel assembly is provided on each side of the glass fixing plate and is installed in the housing;

[0030] The two rolling wheel lifting assemblies are symmetrically arranged;

[0031] Each of the rolling wheel lifting assemblies has two rollers, which are respectively arranged at the upper and lower parts of the steel tape measure, to realize the rotational movement and lifting and pressing action of the two rollers, so as to stabilize and flatten the steel tape measure.

[0032] Furthermore, each of the rolling wheel lifting assemblies includes: a motor, a transmission mechanism, a first rotating wheel, a second rotating wheel, a first transmission shaft, a second transmission shaft, a third transmission shaft, a gear box, and the two rollers;

[0033] The driving shaft wheel of the motor drives the first rotating wheel and the second rotating wheel to rotate in the same direction through the transmission mechanism;

[0034] One end of the first transmission shaft is connected to the center of the first rotating wheel, and the other end is connected to the lower roller of the two rollers;

[0035] One end of the second transmission shaft is connected to the center of the second rotating wheel, and the other end passes through the gear box and extends out of the gear box; a gear transmission mechanism is provided in the gear box, and inside the gear box, the second transmission shaft drives the third transmission shaft to rotate in the opposite direction through the gear transmission mechanism, and one end of the third transmission shaft extends out of the gear box and connects to the upper roller of the two rollers;

[0036] A wheel lifting mechanism is fixedly installed above the gear box, and the wheel lifting mechanism includes: a lifting top plate, a lifting pressure plate and a knob shaft;

[0037] The top lifting plate is installed on the gear box in a sloped manner, the top of the top lifting plate abuts the top of the "7"-shaped lifting and pressure plate, the middle of the lifting and pressure plate is fixedly connected to the extended end of the knob shaft, and the bottom of the lifting and pressure plate abuts the middle of the top lifting plate; turning the knob on the knob shaft rotates the lifting and pressure plate, and then pushes the top lifting plate, thereby lifting or lowering the upper roller.

[0038] Furthermore, the top lifting plate in each of the wheel lifting mechanisms is also in contact with a fine-tuning component;

[0039] The two fine-tuning components are symmetrically arranged;

[0040] Each of the fine-tuning components includes: a rotary rod, a knurled wheel, a threaded support, a hand wheel, and a light support;

[0041] One end of the rotating rod is fixedly connected to the straight knurled wheel; the threaded support, the hand wheel and the optical support are sequentially arranged on the rotating rod;

[0042] The threaded support and the side edges of the optical support are fixedly mounted on the front panel of the housing;

[0043] A spring plate is provided on the top of the optical support, and a steel ball is provided between the spring plate and the straight knurled wheel;

[0044] The other end of the rotating rod is in contact with the top lifting plate, and the rotating rod is pressed against the top lifting plate by rotating the hand wheel to fine-tune the distance between the two rollers.

[0045] Furthermore, the steel tape measure clamp includes: an L-shaped fixing bracket, two cylindrical seats, and a U-shaped support rod; the vertical end of the L-shaped fixing bracket is fixed to the front panel of the casing, and the two cylindrical seats are located at the horizontal end of the L-shaped fixing bracket close to the vertical end; the two ends of the U-shaped support rod are bent downward and extend into the two cylindrical seats and are fixedly connected by springs.

[0046] The advantages of the present invention are:

[0047] 1. The entire detection device is highly compact, compact and flexible, and requires little laboratory space;

[0048] 2. Direct measurement is achieved by generating a standard distance through an electric rotating table, changing the traditional steel tape comparison method and reducing the error introduced by tensile deformation during the traditional steel tape measurement process;

[0049] 3. Two pairs of upper and lower rollers with adjustable gaps are used to protect the inspected steel tape, which reduces the error introduced by the curling deformation of the inspected steel tape and improves the detection accuracy. At the same time, the two pairs of rollers can realize the lifting and lowering function to facilitate the loading and unloading of the inspected steel tape;

[0050] 4. The electric rotating table assembly is used to rotate to realize the retraction and extension of the inspected steel tape, providing the initial zero position of the inspected steel tape and also retracting the inspected tape to further protect the inspected steel tape and avoid cutting the palm;

[0051] 5. Use exclusive steel tape measure fixture to achieve quick loading and unloading of the inspected steel tape measure;

[0052] 6. The U-shaped groove of the glass fixing plate is used for the steel tape to move through, and the deviation value between the marking line on it and the scale line of the steel tape can be read, which makes reading convenient and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The present invention will be further described below in conjunction with embodiments with reference to the accompanying drawings.

[0054] Figure 1 It is a schematic diagram of the appearance structure of the detection device of the present invention in use state.

[0055] Figure 2 It is a front perspective view of the front panel of the housing in the detection device of the present invention (without the steel tape clamp).

[0056] Figure 3 It is a schematic diagram of the back of the housing front plate in the detection device of the present invention.

[0057] Figure 4 It is a structural schematic diagram of the first rolling wheel lifting assembly in the detection device of the present invention.

[0058] Figure 5 It is a structural schematic diagram of the second rolling wheel lifting assembly in the detection device of the present invention.

[0059] Figure 6 It is a schematic structural diagram of the first fine-tuning component in the detection device of the present invention.

[0060] Figure 7 It is a schematic structural diagram of the second fine-tuning component in the detection device of the present invention.

[0061] Figure 8 It is a structural schematic diagram of the scroll wheel mechanism in the detection device of the present invention.

[0062] Figure 9 It is a schematic structural diagram of the steel tape measure clamp in the detection device of the present invention.

[0063] Figure 10 It is a structural schematic diagram of the glass fixing plate in the detection device of the present invention.

[0064] Figure 11 It is a block diagram of the system control principle in the detection device of the present invention.

[0065] Figure 12 It is a schematic diagram of the software execution flow of the present invention. DETAILED DESCRIPTION

[0066] like Figures 1 to 12 As shown, a convenient method for detecting the indication error of a steel tape measure comprises the following steps:

[0067] Step 1: Place the steel tape measure 1, the glass fixing plate 2, and the electric rotating platform assembly 3 on the same horizontal line on the front plate 41 of a housing 4. The electric rotating platform assembly 3 includes an electric rotating platform 31 and a rolling wheel mechanism 32 connected thereto.

[0068] Step 2: Pull out the hook of the steel tape measure 1, pass it through the glass fixing plate 2, and insert the hook into the shaft groove 3211 of the rotating shaft 321 of the rolling wheel mechanism 32;

[0069] Step 3: The electric rotating stage 31 is reset;

[0070] Step 4: Start the test at the first target detection point at the 1000mm mark:

[0071] Measure the fixed distance Lg between the marking line 21 on the glass fixing plate 2 and the left side of the shaft groove 3211 of the rotating shaft 321;

[0072] Calculate the horizontal target distance Lx'1 that the electric rotary table 31 needs to rotate: Lx'1 = Lb1 - Lg, where Lb1 is the nominal value of the first target detection point, i.e., 1000 mm. (Assuming Lg is 250.01 mm, then Lx'1 = Lb1 - Lg = 1000 - 250.01 = 749.99 mm). Rotate the electric rotary table 31 to reach the horizontal target distance Lx'1. Read the deviation L1 between the marking line on the glass fixing plate 2 and the engraved line at the first target detection point at this time, and obtain the error value △L1 = -L1 for the first target detection point.

[0073] Step 5: Start the test at the second target detection point at the 2000m mark:

[0074] Rotate the electric rotary table 31 to reach the horizontal target distance Lx'2, where Lx'2 = Lb2 - Lb1 = 2000 mm - 1000 mm, where Lb2 is the nominal value of the second target detection point, i.e., 2000 mm. Read the deviation value L2 between the marking line on the glass fixing plate 2 and the 2000 mm scale line of the second target detection point at this time, and obtain the error value △L2 = -L2 of the second target detection point;

[0075] Similarly, the remaining detection points are completed meter by meter according to the JJG 4-2015 steel tape calibration requirements. After the detection is completed, the electric rotating table 31 is reversed to the origin.

[0076] A detection device for implementing the above-mentioned convenient method for detecting the indication error of a steel tape measure comprises: a housing 4, a steel tape measure clamp 11, a glass fixing plate 2, and an electric rotating stage assembly 3 fixedly mounted on the same horizontal line of a front plate 41 of the housing 4;

[0077] The electric turntable assembly 3 includes: an electric turntable 31 (model E-RMPG40) and a scroll wheel mechanism 32 connected to it; the electric turntable 31 is mounted on the rear vertical plate 42 inside the housing 4, and the rotating shaft 321 of the scroll wheel mechanism 32 extends out of the front plate 41 of the housing 4. Its end is defined by an axis groove 3211, and the other end is fixedly connected to the electric turntable 31; the scroll wheel mechanism 32 includes the rotating shaft 321 and a bearing 322 for easy installation and fixation, a flange 323, and a limiting shaft 324 for limiting the bearing 322.

[0078] The steel tape measure 1 is fixedly mounted on the steel tape measure fixture 11. The glass fixing plate 2 has a U-shaped groove in the middle and a marking line 21 on the top that is parallel to the scale on the steel tape measure 1.

[0079] The hook of the steel tape measure 1 passes through the U-shaped groove of the glass fixing plate 2 and is inserted into the shaft groove 3211. The steel tape measure 1 is pulled horizontally by the rotation of the electric rotating platform 31, and the error value is obtained according to the distance between the marking line 21 on the glass fixing plate 2 and the target detection point scale line on the steel tape measure 1.

[0080] A rolling wheel assembly (a first rolling wheel assembly 51 and a second rolling wheel assembly 52) is provided on both sides of the glass fixing plate 2 and is installed in the housing 4;

[0081] The first rolling wheel lifting assembly 51 and the second rolling wheel lifting assembly 52 are symmetrically arranged and have the same structure;

[0082] The first rolling wheel lifting assembly 51 has upper and lower rollers 5101 and 5102, and the second rolling wheel lifting assembly 52 has upper and lower rollers 5201 and 5202, which are respectively arranged at the upper and lower parts of the steel tape measure 1, to realize the rotational movement and lifting and pressing action of the rollers 5101, 5102, 5201, and 5202, so as to stabilize and flatten the steel tape measure 1.

[0083] The following takes the first rolling wheel lifting assembly 51 as an example to illustrate its specific structure, including: a motor 5103, a transmission mechanism 5104 (belt drive or gear drive, a pulley is used in this embodiment, and gear drive can also be used in actual practice), a first rotating wheel 5105, a second rotating wheel 5106, a first transmission shaft 5107, a second transmission shaft 5108, a third transmission shaft 5109, a gear box 5110, and two rollers 5101 and 5102.

[0084] The motor 5103 is mounted on the rear vertical plate 42 inside the housing 4 via two support columns 51031. The drive shaft 51032 of the motor 5103 drives the first rotating wheel 5105 and the second rotating wheel 5106 to rotate in the same direction through the transmission mechanism 5104;

[0085] One end of the first transmission shaft 5107 is connected to the center of the first rotating wheel 5105, and the other end is connected to the lower roller 5102 of the two rollers;

[0086] One end of the second transmission shaft 5108 is connected to the center of the second rotating wheel 5106 , and the other end passes through the gear box 5110 and extends out of the gear box 5110 ;

[0087] A gear transmission mechanism is provided within the gear box 5110. Within the gear box 5110, the second transmission shaft 5108 drives the third transmission shaft 5109 to rotate in the opposite direction through the gear transmission mechanism. One end of the third transmission shaft 5109 extends outside the gear box 5110 and connects to the upper roller 5101 of the two rollers.

[0088] A wheel-lifting mechanism is fixedly installed above the gearbox 5110. The wheel-lifting mechanism includes: a top-lifting plate 5111, a lifting and pressing plate 5112, and a knob shaft 5113. The top-lifting plate 5111 is installed on the gearbox 5110 in a sloped manner. The top of the top-lifting plate 5111 abuts against the top of the "7"-shaped lifting and pressing plate 5112. The middle of the lifting and pressing plate 5112 is fixedly connected to the extended end of the knob shaft 5113, and the bottom of the lifting and pressing plate 5112 abuts against the middle of the top-lifting plate 5111. Turning the knob 5114 on the knob shaft 5113 rotates the lifting and pressing plate 5112, which in turn pushes the top-lifting plate 5111, thereby raising or lowering the upper roller 5101. The top-lifting plate 5111 in the wheel-lifting mechanism also abuts against a first fine-tuning component 61.

[0089] The first fine-tuning component 61 and the second fine-tuning component 62 are symmetrically arranged and have the same structure;

[0090] The following describes the specific structure of the first fine-tuning assembly 61 as an example. The first fine-tuning assembly 61 includes: a rotating rod 611, a straight knurled wheel 612, a threaded support 613, a handwheel 614, and an optical support 615. One end of the rotating rod 611 is fixedly connected to the straight knurled wheel 612; the threaded support 613, the handwheel 614, and the optical support 615 are sequentially installed on the rotating rod 611; the side edges of the threaded support 613 and the optical support 615 are fixedly mounted on the front panel 41 of the housing 4.

[0091] A spring plate 616 is provided at the top of the optical support 615, and a steel ball 617 is provided between the spring plate 616 and the straight knurled wheel 612; the other end of the rotating rod 611 is in contact with the top lifting plate 5111, and by rotating the hand wheel 614, the rotating rod 611 is pressed against the top lifting plate 5111 to fine-tune the distance between the two rollers 5101 and 5102.

[0092] The steel tape measure clamp 11 comprises an L-shaped fixing bracket 111, two cylindrical seats 112, and a U-shaped support rod 113. The vertical end of the L-shaped fixing bracket 111 is fixed to the front panel 41 of the housing 4, and the two cylindrical seats 112 are located at the horizontal end of the L-shaped fixing bracket 111 near the vertical end. The two ends of the U-shaped support rod 113 are bent downward and extend into the two cylindrical seats 112, which are fixed together via springs. To secure the steel tape measure 1, the U-shaped support rod 113 is pulled upward a distance, the steel tape measure 1 is placed on the horizontal end of the L-shaped fixing bracket 111, and the U-shaped support rod 113 is released. Under the restoring force of the spring, the U-shaped support rod 113 firmly clamps the top of the steel tape measure 1.

[0093] The driving of the electric rotating platform 31 and the first rolling wheel lifting assembly 51 and the second rolling wheel lifting assembly 52 are achieved by designing a control circuit board (the system control principle block diagram is shown in FIG. Figure 11 As shown in the figure), it can be realized by accurately positioning each target detection point. The detection process is designed by software (see the software execution flow chart for details). Figure 12 ) is realized by pressing a button on the operation panel 7 to start the driving of the electric rotating table 31 and the first rolling wheel lifting assembly 51 and the second rolling wheel lifting assembly 52 and to perform the detection process.

[0094] The entire detection device of the present invention is highly compact, small and flexible, and the laboratory space occupied by the detection device is small; direct measurement is achieved by generating a standard distance through an electric rotating table, which changes the traditional steel tape comparison method and reduces the error introduced by tensile deformation in the traditional steel tape detection process; two pairs of upper and lower rollers with adjustable gaps to protect the inspected steel tape are used to press the inspected steel coil, reducing the error introduced by the curling deformation of the inspected steel tape itself and improving the detection accuracy. At the same time, the two pairs of rollers can realize the up and down lifting function to facilitate the loading and unloading of the inspected steel tape; the electric rotating table is used to drive the winding wheel mechanism to rotate to realize the retraction and release of the inspected steel tape, provide the initial zero position of the inspected steel tape, and also retract the inspected tape body to further protect the inspected steel tape and avoid cutting the palm; a dedicated steel tape clamp is used to realize fast loading and unloading of the inspected steel tape; a U-shaped groove of a glass fixing plate is used for the steel tape to move through, and the deviation value between the marking line on it and the scale line of the steel tape is read, and the reading is convenient and efficient.

[0095] The above embodiments and drawings do not limit the product form and style of the present invention. Any appropriate changes or modifications made by ordinary technicians in the relevant technical field should be deemed to be within the patent scope of the present invention.

Claims

1. A convenient method for detecting the indication error of a steel tape measure, applied to a device for detecting the indication error of a steel tape measure, characterized in that: The detection device comprises: a housing, a steel tape measure fixture, a glass fixing plate, and an electric rotating platform assembly are fixedly mounted in sequence on the same horizontal line of the front panel of the housing; the electric rotating platform assembly comprises: an electric rotating platform and a rolling wheel mechanism connected thereto; A rolling wheel assembly is provided on each side of the glass fixing plate and is installed in the housing; the two rolling wheel assemblies are symmetrically arranged; Each of the rolling wheel lifting assemblies has two rollers, which are respectively arranged at the upper and lower parts of the steel tape measure, to realize the rotational movement and lifting and pressing action of the two rollers, so as to stabilize and flatten the steel tape measure; Each of the rolling wheel lifting assemblies also has a gear box, and a wheel lifting mechanism is fixedly installed above the gear box, and the wheel lifting mechanism includes: a lifting top plate, a lifting pressure plate and a knob shaft; The top lifting plate in each of the wheel lifting mechanisms also abuts against a fine-tuning component; The two fine-tuning components are symmetrically arranged; Each of the fine-tuning components includes: a rotary rod, a knurled wheel, a threaded support, a hand wheel, and a light support; One end of the rotating rod is fixedly connected to the straight knurled wheel; the threaded support, the hand wheel and the optical support are sequentially arranged on the rotating rod; The threaded support and the side edges of the optical support are fixedly mounted on the front panel of the housing; A spring plate is provided on the top of the optical support, and a steel ball is provided between the spring plate and the straight knurled wheel; The other end of the rotary rod is in contact with the top lifting plate, and by rotating the hand wheel, the rotary rod is pressed against the top lifting plate to fine-tune the distance between the two rollers; The detection method comprises the following steps: Step 1: Install the steel tape measure on the steel tape measure fixture; Step 2: Pull out the hook of the steel tape measure, pass it through the glass fixing plate, and insert the hook into the shaft groove of the rotating shaft of the rolling wheel mechanism; Step 3: Clear the electric rotary table; Step 4: Start the test at the first target detection point at the 1000mm mark: Measure the fixed distance value Lg between the marking line on the glass fixing plate and the left side of the shaft groove of the rotating shaft of the electric rotating table assembly; Calculate the horizontal target distance Lx'1 that the electric rotary stage needs to rotate: Lx'1 = Lb1 - Lg, where Lb1 is the nominal value of the first target detection point, i.e., 1000 mm. Rotate the electric rotary stage to reach the horizontal target distance Lx'1. Read the deviation L1 between the marking line on the glass fixing plate and the engraved line of the first target detection point at this time. Calculate the error value △L1 = -L1 for the first target detection point. Step 5: Start the test at the second target detection point at the 2000m mark: Rotate the electric rotary stage to the horizontal target distance Lx'2, Lx'2 = Lb2 - Lb1 = 2000mm - 1000mm, where Lb2 is the nominal value of the second target detection point, i.e. 2000mm. Read the deviation value L2 between the marking line on the glass fixing plate and the 2000mm scale line of the second target detection point, and obtain the error value △L2 = -L2 of the second target detection point; Similarly, the remaining inspection points are completed meter by meter according to the JJG 4-2015 steel tape measurement calibration requirements. After the inspection is completed, the electric rotary table is reversed to the origin.

2. A method for detecting the indication error of a portable steel tape measure according to claim 1, characterized in that: In the detection device, the electric rotating table of the electric rotating table assembly is installed inside the housing, and the rotating shaft of the scroll wheel mechanism extends out of the front plate of the housing, with the shaft groove formed at one end and the other end fixedly connected to the electric rotating table; The middle of the glass fixing plate is provided with a U-shaped groove, and the top is provided with a marking line which is parallel to the scale on the steel tape measure.

3. A portable method for detecting indication error of a steel tape measure according to claim 1, characterized in that: Each of the rolling wheel lifting assemblies further comprises: a motor, a transmission mechanism, a first rotating wheel, a second rotating wheel, a first transmission shaft, a second transmission shaft, and a third transmission shaft; The driving shaft wheel of the motor drives the first rotating wheel and the second rotating wheel to rotate in the same direction through the transmission mechanism; One end of the first transmission shaft is connected to the center of the first rotating wheel, and the other end is connected to the lower roller of the two rollers; One end of the second transmission shaft is connected to the center of the second rotating wheel, and the other end passes through the gear box and extends out of the gear box; a gear transmission mechanism is provided in the gear box, and inside the gear box, the second transmission shaft drives the third transmission shaft to rotate in the opposite direction through the gear transmission mechanism, and one end of the third transmission shaft extends out of the gear box and connects to the upper roller of the two rollers; The top lifting plate is installed on the gear box in a sloped manner, the top of the top lifting plate abuts the top of the "7"-shaped lifting and pressure plate, the middle of the lifting and pressure plate is fixedly connected to the extended end of the knob shaft, and the bottom of the lifting and pressure plate abuts the middle of the top lifting plate; turning the knob on the knob shaft rotates the lifting and pressure plate, and then pushes the top lifting plate, thereby lifting or lowering the upper roller.

4. A portable method for detecting indication error of a steel tape measure according to claim 1, characterized in that: The steel tape measure clamp includes: an L-shaped fixing bracket, two cylindrical seats, and a U-shaped support rod; the vertical end of the L-shaped fixing bracket is fixed to the front panel of the casing, and the two cylindrical seats are located at the horizontal end of the L-shaped fixing bracket close to the vertical end; the two ends of the U-shaped support rod are bent downward and extend into the two cylindrical seats and are fixedly connected by springs.

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