Device and method for detecting zero variation of steel tape

Abstract

The invention relates to a device and method for detecting the zero variation of a steel tape, and relates to the technical field of metrological verification devices, and the device comprises a fixed table which is used for fixing a tape body of the steel tape in a locked state; the sliding mechanism and the fixed table are arranged at an interval, and the sliding mechanism is used for fixing a ruler hook of the steel tape in a locked state; the driving and measuring mechanism is connected with the sliding mechanism and used for driving the sliding mechanism to be close to or far away from the fixed table and measuring the displacement amount of the sliding mechanism, and when the driving and measuring mechanism drives the sliding mechanism to be close to or far away from the fixed table to a limit position, a tape hook of the steel tape is in a maximum compression state or a maximum stretching state; and the zero position variation is obtained through the displacement of the sliding mechanism. The problems that in the prior art, a ruler body needs to be stretched to the upper surface of a reticle plate, especially when the inner size of a steel tape hook is limited, it is difficult to ensure that the ruler hook is in the maximum compression state in the stretching process, and the zero position variation of the steel tape hook is difficult to accurately measure are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of measurement and calibration devices, and in particular to a device and method for detecting zero-position variation of a steel tape measure. Background Art

[0002] According to the national metrological verification regulations for steel tape measures, the indication error of steel tape measures is verified using a comparison method. This involves comparing the tape to be tested with a standard ruler, measuring the indication error at various locations and within specified ranges, and then performing a composite determination. However, in the actual production and application of steel tape measures, particularly those with hooks, when measuring internal and external dimensions, the outer and inner sides of the hook, respectively, contact the measured object, serving as the starting point for measurement, the zero point of the tape measure. To eliminate the influence of the hook thickness on measurement results, the hook and tape are connected using a rivet structure and a flexible connection. The hook can be stretched and compressed, with its extension and compression ranges set to two fixed values, ensuring consistent results when measuring internal and external dimensions. This indicates that hook displacement is one of the main sources of indication error for steel tape measures. This has been verified in the manufacturing, use, and weekly inspection of steel tape measures. According to statistics, the main reason for steel tape measures to indicate out-of-tolerance readings, even when the tape is free of creases, curls, or unevenness, is that the zero-position fluctuation of the hook exceeds the preset range. Therefore, in practical applications, testing the zero-position fluctuation of the hook can be used to quickly determine and screen the conformity of steel tape measures. Only those tapes that have passed the initial screening can then be subsequently calibrated and used, shortening testing time and improving efficiency.

[0003] In the prior art, such as a steel tape measure zero position calibration device with patent number CN106440988A, it includes a base plate, on which one side end portion of the upper end surface of the base plate is vertically installed a limit plate perpendicular to the base plate, the limit plate is located in the end surface on the inner side of the base plate, and a ruler hook inner size limit block, a ruler hook outer size limit block and a depth scale head limit block are installed in parallel with each other, respectively used to limit the ruler hook and the depth scale head of the steel tape measure, a scale plate is fixedly installed on the upper end surface of the other side end of the base plate, the upper surface of the scale plate has only a plurality of scale lines evenly spaced in the same direction extending from one side end portion of the base plate where the limit plate is installed to the other side end portion where the scale plate is not installed, a microscope stand is installed on the outer edge of the base plate next to the scale plate, the microscope stand is used to movably fix a reading microscope, and the reading microscope is located at a corresponding position above the scale plate when in the installed state.

[0004] However, in the prior art, when limiting the inner and outer dimensions of the steel tape measure hook, the tape measure body needs to be stretched to the upper surface of the scale plate. In particular, when limiting the inner dimension of the steel tape measure hook, it is difficult to ensure that the tape measure hook is in the maximum compression state during the stretching process, and there is a problem that it is difficult to accurately measure the zero position change of the steel tape measure hook. Summary of the Invention

[0005] The present application provides a device and method for detecting the zero-position variation of a steel tape measure, which can solve the problem in the prior art that when limiting the inner and outer dimensions of the steel tape measure hook, the tape measure body needs to be stretched to the upper surface of a scale plate. In particular, when limiting the inner dimension of the steel tape measure hook, it is difficult to ensure that the hook is in a maximum compression state during the stretching process, resulting in difficulty in accurately measuring the zero-position variation of the steel tape measure hook.

[0006] In a first aspect, an embodiment of the present application provides a device for detecting zero-position variation of a steel tape measure, comprising: A fixing platform, which is used to fix the steel tape in a locked state; a sliding mechanism, which is spaced apart from the fixing platform, and is used to fix the hook of the steel tape measure in a locked state; A driving and measuring mechanism is connected to the sliding mechanism, and is used to drive the sliding mechanism toward or away from the fixed platform and measure the displacement of the sliding mechanism. When the driving and measuring mechanism drives the sliding mechanism toward or away from the fixed platform to an extreme position, the hook of the steel tape measure is in a maximum compression state or a maximum tension state, and the zero position variation is obtained by the displacement of the sliding mechanism.

[0007] In one embodiment, the sliding mechanism comprises: a sliding block, spaced apart from the fixed platform and connected to the driving and measuring mechanism; A clamping assembly is arranged on the sliding block and is used for clamping the hook of the steel tape measure.

[0008] In one embodiment, a threaded hole is provided on the sliding block, and the drive measuring mechanism includes a measuring unit and a drive screw, wherein the drive screw passes through the measuring unit and is rotatably connected to the measuring unit. The drive screw passes through the threaded hole and drives the sliding block to move closer to or away from the fixed platform by rotation. The measuring unit is spaced apart from the sliding block, and the displacement of the sliding block is obtained by recording the number of rotations of the drive screw.

[0009] In one embodiment, a forward ratchet and a reverse ratchet are provided at the end of the drive screw, and the reverse ratchet is located between the forward ratchet and the measuring unit. The forward ratchet and the reverse ratchet are both used to drive the drive screw to rotate, and when the hook of the steel tape measure is in a maximum compression state or a maximum tension state, the reverse ratchet or the forward ratchet begins to slip.

[0010] In one embodiment, it further includes a fixed slide rail, which is arranged along the moving direction of the sliding block. A T-shaped slide groove is provided in the slide rail, and the sliding block is slidably arranged in the T-shaped slide groove.

[0011] In one embodiment, the clamping assembly comprises: a fixed plate, which is arranged on the upper side of the sliding block; a moving block, which is spaced apart from the fixed plate and movably disposed on the upper side of the sliding block, and is used to cooperate with the fixed plate to clamp the hook of the steel tape measure; A locking screw and a locking nut, wherein the locking screw passes through the fixed plate and extends into the moving block, the locking screw is rotatably connected to the fixed plate and is threadedly connected to the moving block, and the locking nut is arranged on the locking screw and is used to abut against the side of the fixed plate away from the moving block so that the moving block abuts against the fixed plate.

[0012] In one embodiment, a centering mechanism is further included, wherein the centering mechanism includes: Two spaced-apart baffles are respectively located on both sides of the steel tape measure; The driving assembly is arranged on the fixing platform and connected to the two baffles, and is used for driving the two baffles to move closer to or away from each other so that the baffles are pressed against the body of the steel tape measure.

[0013] In one embodiment, a guide hole perpendicular to the steel tape body is provided on the fixed platform, and the drive assembly includes a center gear and two racks. The center gear is rotatably disposed in the fixed platform, and the rack is L-shaped. The long side of the rack is engaged with the center gear, and the middle part of the short side of the rack extends out of the guide hole and is connected to the baffle. When the center gear rotates, it drives the rack to move, so that the two baffles are closer to or farther away from each other.

[0014] In a second aspect, an embodiment of the present application further provides a method for detecting the zero position variation of a steel tape measure, which is implemented using the above-mentioned device for detecting the zero position variation of a steel tape measure, and includes the following steps: After pulling out the steel tape measure to a set length, lock it and fix the body and hook of the steel tape measure respectively; Starting the driving and measuring mechanism to move the sliding mechanism closer to or farther from the fixed platform to an extreme position, and recording the displacement of the sliding mechanism; The zero position variation of the steel tape measure is obtained according to the displacement of the sliding mechanism.

[0015] In one embodiment, after the driving and measuring mechanism is started to move the sliding mechanism closer to or farther from the fixed platform to an extreme position and the displacement of the sliding mechanism is recorded, the method further includes: The displacement of the sliding mechanism is reset, and the driving and measuring mechanism is restarted to make the sliding mechanism move in the reverse direction, so that the sliding mechanism approaches or moves away from the fixed platform to an extreme position.

[0016] The beneficial effects of the technical solutions provided in the embodiments of the present application include: When using the device for detecting the zero position variation of a steel tape measure, a fixed platform is used to fix the steel tape measure in a locked state, a sliding mechanism is spaced apart from the fixed platform, the sliding mechanism is used to fix the hook of the steel tape measure in a locked state, a driving and measuring mechanism is connected to the sliding mechanism, and is used to drive the sliding mechanism toward or away from the fixed platform and measure the displacement of the sliding mechanism. When the driving and measuring mechanism drives the sliding mechanism 3 toward or away from the fixed platform to an extreme position, the hook of the steel tape measure is in a maximum compression state or a maximum tension state, and the zero position variation is obtained by the displacement of the sliding mechanism. After the steel tape measure is pulled out to a set length and locked, the steel tape measure body and hook are fixed respectively, the driving and measuring mechanism is started, the sliding mechanism is moved toward or away from the fixed platform to an extreme position, and the displacement of the sliding mechanism is recorded. Based on the displacement of the sliding mechanism, the zero position variation of the steel tape measure is obtained. Since the steel tape measure is in a locked state when the driving measuring mechanism drives the sliding mechanism to move closer to or away from the fixed platform, the displacement of the sliding mechanism is essentially the relative movement of the ruler hook and the ruler body, reducing other factors, such as the influence of the expansion and contraction of the steel tape measure. Therefore, when the ruler hook of the steel tape measure moves from the maximum compression state to the maximum extension state, or from the maximum extension state to the maximum compression state, the displacement of the sliding mechanism obtained is the zero position change of the steel tape measure. The measured zero position change has high accuracy and the measurement process is simple and convenient. It solves the problem in the prior art that when limiting the inner and outer dimensions of the steel tape measure hook, the ruler body needs to be stretched to the upper surface of the scale plate. In particular, when limiting the inner dimension of the steel tape measure hook, it is difficult to ensure that the ruler hook is in the maximum compression state during the stretching process, and there is a problem that it is difficult to accurately measure the zero position change of the steel tape measure hook. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 The figure is a schematic structural diagram of an embodiment of a device for detecting zero-position variation of a steel tape measure according to the present invention.

[0019] Figure 2 The figure is a schematic top view of the structure of an embodiment of a device for detecting zero position variation of a steel tape measure according to the present invention.

[0020] Figure 3 The figure is a schematic cross-sectional view of an embodiment of a device for detecting zero-position variation of a steel tape measure according to the present invention.

[0021] Figure 4 The present invention is a schematic structural diagram of a driving assembly in an embodiment of a device for detecting zero-position variation of a steel tape measure.

[0022] In the figure: 1. Fixed table; 11. Bracket; 12. Clamping mechanism; 121. Clamping block; 122. Clamping screw; 2. Steel tape measure; 3. Sliding mechanism; 31. Sliding block; 32. Clamping assembly; 321. Fixed plate; 322. Moving block; 323. Locking screw; 324. Locking nut; 33. Mounting plate; 4. Drive measuring mechanism; 41. Measuring unit; 42. Drive screw; 421. Forward ratchet; 422. Reverse ratchet; 43. Differential cylinder; 44. Fixed sleeve; 5. Slide rail; 6. Centering mechanism; 61. Baffle; 62. Drive assembly; 621. Center gear; 622. Rack; 7. Guide hole; 8. Base. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0024] The embodiments of the present application provide a device and method for detecting the zero-position variation of a steel tape measure, which can solve the problem in the prior art that when limiting the inner and outer dimensions of the steel tape measure hook, the tape measure body needs to be stretched to the upper surface of the scale plate. In particular, when limiting the inner dimension of the steel tape measure hook, it is difficult to ensure that the hook is in the maximum compression state during the stretching process, resulting in difficulty in accurately measuring the zero-position variation of the steel tape measure hook.

[0025] like Figure 1 and Figure 2 As shown, on the one hand, the present application provides a device for detecting the zero position variation of a steel tape measure, which includes: A fixing platform 1, which is used to fix the steel measuring tape 2 in a locked state; A sliding mechanism 3 is spaced apart from the fixed platform 1 and is used to fix the hook of the steel tape measure 2 in a locked state; The driving and measuring mechanism 4 is connected to the sliding mechanism 3 and is used to drive the sliding mechanism 3 towards or away from the fixed platform 1 and measure the displacement of the sliding mechanism 3. When the driving and measuring mechanism 4 drives the sliding mechanism 3 towards or away from the fixed platform 1 to the extreme position, the hook of the steel tape 2 is in the maximum compression state or the maximum tension state, and the zero position variation is obtained by the displacement of the sliding mechanism 3.

[0026] When using the device for detecting the zero position variation of a steel tape measure, a fixed platform 1 is used to fix the steel tape measure 2 in a locked state, a sliding mechanism 3 is spaced apart from the fixed platform 1, and the sliding mechanism 3 is used to fix the hook of the steel tape measure 2 in a locked state. A driving and measuring mechanism 4 is connected to the sliding mechanism 3 and is used to drive the sliding mechanism 3 toward or away from the fixed platform 1 and measure the displacement of the sliding mechanism 3. When the driving and measuring mechanism 4 drives the sliding mechanism 3 toward or away from the fixed platform 1 to the extreme position, the hook of the steel tape measure 2 is in the maximum compression state or the maximum tension state, and the zero position variation is obtained by the displacement of the sliding mechanism 3. The steel tape measure 2 is pulled out to a set length and locked, and the steel tape measure 2 is fixed. The driving and measuring mechanism 4 is started to move the sliding mechanism 3 toward or away from the fixed platform 1 to the extreme position, and the displacement of the sliding mechanism 3 is recorded. The zero position variation of the steel tape measure 2 is obtained based on the displacement of the sliding mechanism 3. Since the steel tape measure 2 is in a locked state when the driving measuring mechanism 4 drives the sliding mechanism 3 to approach or move away from the fixed platform 1, the displacement of the sliding mechanism 3 is essentially the relative movement between the ruler hook and the ruler body, reducing other factors, such as the influence of the expansion and contraction of the steel tape measure 2. Therefore, when the ruler hook of the steel tape measure 2 moves from the maximum compression state to the maximum extension state, or from the maximum extension state to the maximum compression state, the obtained displacement of the sliding mechanism 3 is the zero position change of the steel tape measure 2. The measured zero position change has high accuracy and the measurement process is simple and convenient. It solves the problem in the prior art that when limiting the inner size and outer size of the ruler hook of the steel tape measure, the ruler body needs to be stretched to the upper surface of the scale plate. In particular, when limiting the inner size of the ruler hook of the steel tape measure, it is difficult to ensure that the ruler hook is in the maximum compression state during the stretching process, and there is a problem that it is difficult to accurately measure the zero position change of the ruler hook of the steel tape measure.

[0027] In this example, the fixed platform 1 includes a bracket 11 and a clamping mechanism 12. The clamping mechanism 12 is arranged on the bracket 11. The clamping mechanism 12 includes a clamping block 121 and a clamping screw 122. The clamping screw 122 passes through the clamping block 121 and extends into the bracket 11. By rotating the clamping screw 122, the clamping block 121 is pressed against the upper surface of the bracket 11, and the body of the steel tape measure 2 is fixed by the clamping block 121.

[0028] In this example, a base 8 is further included, and the fixed platform 1 , the sliding mechanism 3 and the driving and measuring mechanism 4 are all arranged on the base 8 .

[0029] like Figure 1 and Figure 2 As shown, in some optional embodiments, the sliding mechanism 3 includes: A sliding block 31 is spaced apart from the fixed platform 1 and connected to the driving and measuring mechanism 4; The clamping assembly 32 is provided on the sliding block 31 and is used for clamping the hook of the steel tape measure 2 .

[0030] In this embodiment, the structure of the sliding mechanism 3 is specifically described. The sliding mechanism 3 includes a sliding block 31 and a clamping assembly 32, wherein the sliding block 31 is spaced apart from the fixed platform 1 and is connected to the driving and measuring mechanism 4. The clamping assembly 32 is arranged on the sliding block 31 and is used to clamp the hook of the steel tape measure 2. The structure is simple and easy to manufacture.

[0031] like Figure 1 、 Figure 2 and Figure 3 As shown, in some optional embodiments, a threaded hole is provided on the sliding block 31, and the driving measuring mechanism 4 includes a measuring unit 41 and a driving screw 42. The driving screw 42 passes through the measuring unit 41 and is rotatably connected to the measuring unit 41. The driving screw 42 passes through the threaded hole and drives the sliding block 31 to approach or move away from the fixed platform 1 by rotating. The measuring unit 41 is spaced apart from the sliding block 31, and the displacement of the sliding block 31 is obtained by recording the number of rotations of the driving screw 42.

[0032] In this embodiment, a threaded hole is provided on the sliding block 31, and the driving measuring mechanism 4 includes a measuring unit 41 and a driving screw 42. The driving screw 42 passes through the measuring unit 41 and is rotatably connected to the measuring unit 41. The driving screw 42 passes through the threaded hole and drives the sliding block 31 to move closer to or away from the fixed table 1 by rotating. The measuring unit 41 is spaced apart from the sliding block 31, and the displacement of the sliding block 31 is obtained by recording the number of rotations of the driving screw 42, giving a specific driving method. The driving process is stable, and it is convenient to record the displacement of the sliding block 31.

[0033] In this example, the differential cylinder 43 and fixed sleeve 44 are both mounted on the drive screw 42. The fixed sleeve 44 has a scale on its bottom, allowing visual reading of the integer portion of the measured value. Fixed sleeve 44 contains an internal thread with a pitch of 0.5 mm, which cooperates with the external thread on the drive screw 42 to form a threaded substructure. The scale on differential cylinder 43 is used for fine visual readings, accurate to 0.01 mm and estimated to 0.001 mm. Each rotation of differential cylinder 43 causes the drive screw 42 to advance or retract one pitch, typically 0.5 mm. The scale lines on differential cylinder 43 divide the circumference of differential cylinder 43 into 50 equal parts, and the drive screw 42 moves 0.01 mm for every 1 / 50 of a rotation of differential cylinder 43. For visual reading, the main scale on fixed sleeve 44 is added to the decimal portion on differential cylinder 43 to obtain the measurement result.

[0034] like Figure 1 and Figure 2As shown, in some optional embodiments, a forward ratchet 421 and a reverse ratchet 422 are provided at the end of the drive screw 42, and the reverse ratchet 422 is located between the forward ratchet 421 and the measuring unit 41. The forward ratchet 421 and the reverse ratchet 422 are both used to drive the drive screw 42 to rotate, and when the hook of the steel tape measure 2 is in the maximum compression state or the maximum tension state, the reverse ratchet 422 or the forward ratchet 421 begins to slip.

[0035] In this embodiment, a forward ratchet 421 and a reverse ratchet 422 are provided at the end of the drive screw 42, and the reverse ratchet 422 is located between the forward ratchet 421 and the measuring unit 41. The forward ratchet 421 and the reverse ratchet 422 are both used to drive the drive screw 42 to rotate, and when the hook of the steel tape measure 2 is in the maximum compression state or the maximum tension state, the reverse ratchet 422 or the forward ratchet 421 begins to slip, and the drive screw 42 is driven to rotate forward by the forward ratchet 421, and the drive screw 42 is driven to rotate reversely by the reverse ratchet 422. When the hook of the steel tape measure 2 is in the maximum compression state or the maximum tension state, the reverse ratchet 422 or the forward ratchet 421 begins to slip, and excessive rotation will not cause damage between the hook and the tape of the steel tape measure 2.

[0036] In this example, when the preset measuring force of the ratchet is exceeded, an audible alarm is sounded and the ratchet begins to slip, informing the user that the measuring force has reached the preset value, ensuring that the same torque is used during the measurement process to obtain more accurate measurement results.

[0037] like Figure 1 and Figure 3 As shown, in some optional embodiments, a fixed slide rail 5 is further included, which is arranged along the moving direction of the sliding block 31. A T-shaped slide groove is provided in the slide rail 5, and the sliding block 31 can be slidably arranged in the T-shaped slide groove.

[0038] In this embodiment, the device for detecting the zero-position variation of a steel tape measure further includes a fixed slide rail 5, which is arranged along the moving direction of the sliding block 31. A T-shaped slide groove is provided in the slide rail 5, and the sliding block 31 can be slidably arranged in the T-shaped slide groove, giving a specific sliding method. The sliding of the sliding block 31 is realized by driving the screw 42, the sliding block 31 and the slide rail 5 in cooperation.

[0039] In this example, the sliding block 31 is partially engaged in the slide rail 5 , so that the sliding block 31 moves along the slide rail 5 under the action of the driving screw 42 .

[0040] like Figure 1 and Figure 2 As shown, in some optional embodiments, the clamping assembly 32 includes: A fixed plate 321 is provided on the upper side of the sliding block 31; The movable block 322 is spaced apart from the fixed plate 321 and is movably disposed on the upper side of the sliding block 31 for cooperating with the fixed plate 321 to clamp the hook of the steel tape measure 2; The locking screw 323 and the locking nut 324, the locking screw 323 passes through the fixed plate 321 and extends into the movable block 322, the locking screw 323 is rotatably connected to the fixed plate 321, and is threadedly connected to the movable block 322, and the locking nut 324 is set on the locking screw 323, and is used to abut on the side of the fixed plate 321 away from the movable block 322, so that the movable block 322 abuts on the fixed plate 321.

[0041] When the handle 321 is in the unlock position, the locking nut 324 is tightened to the locking nut 323, and the locking nut 324 is tightened to the locking nut 323.

[0042] In this example, the movable block 322 is slidably mounted on the upper side of the sliding block 31 via a guide rail. A mounting plate 33 is also included. The mounting plate 33 is fixedly mounted on the sliding block 31 and is located on the side of the fixed plate 321 away from the movable block 322. A locking screw 323 passes through the mounting plate 33, and a locking nut 324 is located between the fixed plate 321 and the mounting plate 33 to improve the stability of the locking screw 323.

[0043] like Figure 1 and Figure 2 As shown, in some optional embodiments, a centering mechanism 6 is further included, and the centering mechanism 6 includes: Two spaced-apart baffles 61 are located on both sides of the steel tape measure 2; The driving assembly 62 is disposed on the fixed platform 1 and connected to the two baffles 61 for driving the two baffles 61 to move closer to or away from each other so that the baffles 61 are held against the steel tape 2 .

[0044] In this embodiment, the device for detecting the zero-position variation of the steel tape measure also includes a centering mechanism 6, which includes a driving component 62 and two spaced-apart baffles 61, wherein the two baffles 61 are respectively located on both sides of the body of the steel tape measure 2, and the driving component 62 is set on the fixed platform 1 and connected to the two baffles 61, and is used to drive the two baffles 61 to move closer to or away from each other, so that the baffles 61 are held against the body of the steel tape measure 2 to fix the lateral direction of the body of the steel tape measure 2, thereby preventing the body of the steel tape measure 2 from moving during the detection process and affecting the inspection results, and also conveniently positioning the body of the steel tape measure 2.

[0045] like Figure 1 、 Figure 2 and Figure 4 As shown, in some optional embodiments, a guide hole 7 perpendicular to the body of the steel tape measure 2 is provided on the fixed platform 1, and the driving assembly 62 includes a center gear 621 and two racks 622. The center gear 621 is rotatably disposed in the fixed platform 1, and the racks 622 are L-shaped. The long side of the rack 622 is engaged with the center gear 621, and the middle part of the short side of the rack 622 extends out of the guide hole 7 and is connected to the baffle 61. When the center gear 621 rotates, it drives the rack 622 to move, so that the two baffles 61 are closer to or farther away from each other.

[0046] In this embodiment, a guide hole 7 perpendicular to the body of the steel tape measure 2 is provided on the fixed platform 1, and the driving assembly 62 includes a center gear 621 and two racks 622. The racks 622 are L-shaped, and the center gear 621 is rotatably arranged in the fixed platform 1. The long side of the rack 622 is engaged with the center gear 621, and the middle part of the short side of the rack 622 extends out of the guide hole 7 and is connected to the baffle 61. When the center gear 621 rotates, it drives the rack 622 to move, so that the two baffles 61 are closer to or farther away from each other. Since the guide hole 7 limits the moving direction of the rack 622, the center gear 621 drives the rack 622 to move when it rotates, and then drives the two baffles 61 closer to or farther away from each other. The structure is simple and easy to implement.

[0047] like Figure 1 and Figure 2 As shown, on the other hand, the present application also provides a method for detecting the zero position variation of a steel tape measure, which is implemented using the above-mentioned device for detecting the zero position variation of a steel tape measure, and includes the following steps: Pull out the steel tape measure 2 to the set length and lock it, then fix the tape measure body and hook of the steel tape measure 2 separately; Start the driving and measuring mechanism 4 to move the sliding mechanism 3 closer to or farther from the fixed platform 1 to the extreme position, and record the displacement of the sliding mechanism 3; The zero position variation of the steel tape measure 2 is obtained according to the displacement of the sliding mechanism 3 .

[0048] When using the device for detecting the zero position variation of a steel tape measure, a fixed platform 1 is used to fix the steel tape measure 2 in a locked state, a sliding mechanism 3 is spaced apart from the fixed platform 1, and the sliding mechanism 3 is used to fix the hook of the steel tape measure 2 in a locked state. A driving and measuring mechanism 4 is connected to the sliding mechanism 3 and is used to drive the sliding mechanism 3 toward or away from the fixed platform 1 and measure the displacement of the sliding mechanism 3. When the driving and measuring mechanism 4 drives the sliding mechanism 3 toward or away from the fixed platform 1 to the extreme position, the hook of the steel tape measure 2 is in the maximum compression state or the maximum tension state, and the zero position variation is obtained by the displacement of the sliding mechanism 3. The steel tape measure 2 is pulled out to a set length and locked, and the steel tape measure 2 is fixed. The driving and measuring mechanism 4 is started to move the sliding mechanism 3 toward or away from the fixed platform 1 to the extreme position, and the displacement of the sliding mechanism 3 is recorded. The zero position variation of the steel tape measure 2 is obtained based on the displacement of the sliding mechanism 3. Since the steel tape measure 2 is in a locked state when the driving measuring mechanism 4 drives the sliding mechanism 3 to approach or move away from the fixed platform 1, the displacement of the sliding mechanism 3 is essentially the relative movement between the ruler hook and the ruler body, reducing other factors, such as the influence of the expansion and contraction of the steel tape measure 2. Therefore, when the ruler hook of the steel tape measure 2 moves from the maximum compression state to the maximum extension state, or from the maximum extension state to the maximum compression state, the obtained displacement of the sliding mechanism 3 is the zero position change of the steel tape measure 2. The measured zero position change has high accuracy and the measurement process is simple and convenient. It solves the problem in the prior art that when limiting the inner size and outer size of the ruler hook of the steel tape measure, the ruler body needs to be stretched to the upper surface of the scale plate. In particular, when limiting the inner size of the ruler hook of the steel tape measure, it is difficult to ensure that the ruler hook is in the maximum compression state during the stretching process, and there is a problem that it is difficult to accurately measure the zero position change of the ruler hook of the steel tape measure.

[0049] like Figure 1 and Figure 2 As shown, in some optional embodiments, after the driving and measuring mechanism 4 is started to move the sliding mechanism 3 closer to or farther from the fixed platform 1 to the extreme position and the displacement of the sliding mechanism 3 is recorded, the method further includes: The displacement of the sliding mechanism 3 is reset, and the driving and measuring mechanism 4 is restarted to make the sliding mechanism 3 move in the reverse direction, so that the sliding mechanism 3 approaches or moves away from the fixing platform 1 to the extreme position.

[0050] In this embodiment, after the driving and measuring mechanism 4 is started to move the sliding mechanism 3 closer to or farther away from the fixed platform 1 to the extreme position and the displacement of the sliding mechanism 3 is recorded, the displacement of the sliding mechanism 3 is reset and the driving and measuring mechanism 4 is restarted to move the sliding mechanism 3 in the opposite direction, so that the sliding mechanism 3 is closer to or farther away from the fixed platform 1 to the extreme position. This can eliminate the influence of the initial relative position of the ruler tape and the ruler hook on the measurement result, and there is no need to ensure that the initial relative position of the ruler tape and the ruler hook is the extreme position, which has higher applicability.

[0051] In this example, this step can be repeated to obtain two sets of data: the tension zero displacement and the thrust zero displacement, and their average value is calculated as the final measurement result of the two; the above two measurement results are compared with the standard displacement of the hook specified in the steel tape measure manufacturing standard, and the difference is the zero position change of the hook when subjected to tension and thrust.

[0052] In the description of this application, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0053] It should be noted that, in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0054] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A device for detecting zero position variation of a steel tape measure, characterized in that: include: A fixing platform (1) for fixing the body of a steel measuring tape (2) in a locked state; a sliding mechanism (3) spaced apart from the fixed platform (1), the sliding mechanism (3) being used to fix the hook of the steel tape measure (2) in a locked state; A driving and measuring mechanism (4) is connected to the sliding mechanism (3) and is used to drive the sliding mechanism (3) to approach or move away from the fixed platform (1) and measure the displacement of the sliding mechanism (3). When the driving and measuring mechanism (4) drives the sliding mechanism (3) to approach or move away from the fixed platform (1) to an extreme position, the hook of the steel tape measure (2) is in a maximum compression state or a maximum tension state, and the zero position variation is obtained by the displacement of the sliding mechanism (3).

2. A device for detecting zero position variation of a steel tape measure according to claim 1, characterized in that: The sliding mechanism (3) comprises: a sliding block (31) spaced apart from the fixed platform (1) and connected to the driving and measuring mechanism (4); A clamping assembly (32) is provided on the sliding block (31) and is used for clamping the hook of the steel measuring tape (2).

3. A device for detecting zero position variation of a steel tape measure according to claim 2, characterized in that: The sliding block (31) is provided with a threaded hole. The driving measuring mechanism (4) includes a measuring unit (41) and a driving screw (42). The driving screw (42) passes through the measuring unit (41) and is rotatably connected to the measuring unit (41). The driving screw (42) passes through the threaded hole and drives the sliding block (31) to approach or move away from the fixed platform (1) by rotating. The measuring unit (41) is spaced apart from the sliding block (31), and the displacement of the sliding block (31) is obtained by recording the number of rotations of the driving screw (42).

4. A device for detecting zero position variation of a steel tape measure according to claim 3, characterized in that: A forward ratchet (421) and a reverse ratchet (422) are provided at the end of the driving screw (42), and the reverse ratchet (422) is located between the forward ratchet (421) and the measuring unit (41). The forward ratchet (421) and the reverse ratchet (422) are both used to drive the driving screw (42) to rotate, and when the hook of the steel tape measure (2) is in a maximum compression state or a maximum tension state, the reverse ratchet (422) or the forward ratchet (421) begins to slip.

5. The device for detecting zero position variation of a steel tape measure according to claim 3, characterized in that: It also includes a fixed slide rail (5), which is arranged along the moving direction of the sliding block (31). A T-shaped slide groove is provided in the slide rail (5), and the sliding block (31) is slidably arranged in the T-shaped slide groove.

6. The device for detecting zero position variation of a steel tape measure according to claim 2, characterized in that: The clamping assembly (32) comprises: a fixed plate (321) disposed on the upper side of the sliding block (31); a movable block (322) spaced apart from the fixed plate (321), the movable block (322) being movably arranged on the upper side of the sliding block (31) and being used to cooperate with the fixed plate (321) to clamp the hook of the steel tape measure (2); A locking screw (323) and a locking nut (324), wherein the locking screw (323) passes through the fixed plate (321) and extends into the movable block (322), the locking screw (323) is rotatably connected to the fixed plate (321) and is threadedly connected to the movable block (322), and the locking nut (324) is arranged on the locking screw (323) and is used to abut against a side of the fixed plate (321) away from the movable block (322) so that the movable block (322) abuts against the fixed plate (321).

7. The device for detecting zero position variation of a steel tape measure according to claim 1, characterized in that: It also includes a centering mechanism (6), which includes: Two spaced-apart baffles (61) are respectively located on both sides of the steel tape measure (2); A driving assembly (62) is provided on the fixed platform (1) and connected to the two baffles (61), and is used to drive the two baffles (61) to move closer to or farther from each other, so that the baffles (61) are held against the body of the steel tape measure (2).

8. The device for detecting zero position variation of a steel tape measure according to claim 7, characterized in that: The fixed platform (1) is provided with a guide hole (7) perpendicular to the body of the steel tape measure (2). The driving assembly (62) includes a central gear (621) and two racks (622). The central gear (621) is rotatably arranged in the fixed platform (1). The racks (622) are L-shaped. The long sides of the racks (622) are engaged with the central gear (621). The middle part of the short sides of the racks (622) extends out of the guide hole (7) and is connected to the baffle (61). When the central gear (621) rotates, it drives the racks (622) to move, so that the two baffles (61) move closer to or farther away from each other.

9. A method for detecting zero position variation of a steel tape measure, characterized in that: The method is implemented using a device for detecting zero position variation of a steel tape measure according to any one of claims 1 to 8, comprising the following steps: After the steel tape measure (2) is pulled out to a set length and locked, the ruler body and the ruler hook of the steel tape measure (2) are fixed respectively; Starting the driving measuring mechanism (4) to move the sliding mechanism (3) closer to or farther from the fixed platform (1) to an extreme position, and recording the displacement of the sliding mechanism (3); The zero position variation of the steel tape measure (2) is obtained based on the displacement of the sliding mechanism (3).

10. A method for detecting zero position variation of a steel tape measure according to claim 9, characterized in that: After the driving measuring mechanism (4) is started to move the sliding mechanism (3) closer to or farther from the fixed platform (1) to an extreme position and the displacement of the sliding mechanism (3) is recorded, the method further comprises: The displacement of the sliding mechanism (3) is reset, and the driving and measuring mechanism (4) is restarted to cause the sliding mechanism (3) to move in the reverse direction, so that the sliding mechanism (3) moves closer to or farther from the fixed platform (1) to an extreme position.

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