A crack width gauge

Abstract

This utility model relates to crack detection and discloses a crack width measuring instrument, including a measuring instrument body, a probe communicatively connected to the measuring instrument body, and a detachable positioning component mounted on the measuring instrument body. The positioning component includes a mounting part and a positioning block. The mounting part is snapped onto the outer periphery of the measuring instrument body. Multiple fixing seats and snap-fit ​​seats are arranged opposite each other on the side edge of the mounting part away from the measuring instrument body. The snap-fit ​​seats are provided with mounting grooves and snap-fit ​​doors. A rotating rod is provided on the side of the positioning block. Both ends of the rotating rod are inserted into the fixing seats and the mounting groove, respectively. When the snap-fit ​​door is closed, it is used to fix the rotating rod. The positioning block also has mounting holes, and the probe is detachably connected to the mounting holes. This utility model can adapt to crack measurement in different directions without frequent adjustments to the position of the measuring instrument body.

Description

Technical Field

[0001] This utility model relates to the field of crack detection, specifically to a crack width measuring instrument. Background Technology

[0002] Crack width gauges are key equipment for monitoring the structural safety of building engineering projects, mainly used for the accurate measurement of crack width on the surface of concrete structures such as buildings, bridges, and tunnels. They capture crack images through an optical probe, process them using a built-in algorithm, and display the width data on the instrument body, providing quantitative evidence for structural health assessment. Traditional equipment requires the operator to hold the instrument body and probe with both hands, which can easily affect measurement stability due to hand tremors and fatigue from prolonged operation. Therefore, the inventors developed a crack width gauge that allows for multi-directional probe placement to solve the above problems. In the prior art, Chinese patent application CN221527642U discloses an improved crack width gauge, which uses a box fixed to the side of the instrument body, with a retractable chuck inside the box to fix the width measuring probe, enabling one-handed operation. Specifically, the probe is rigidly connected to the instrument body through placement holes on the chuck, a self-locking slide rail, and locking components (such as a telescopic spring, locking block, and elastic locking plate), reducing shaking (see claims 1-7 and figures).

[0003] However, the aforementioned existing technologies still have the following technical problems: once the probe is fixed, it can only be parallel to the instrument body, and the measurement angle cannot be adjusted. In actual testing, the crack orientation is complex and varied (such as inclined, top, or sidewall cracks), requiring the operator to frequently adjust their body posture or even hold the probe with both hands to adapt to the orientation, resulting in low measurement efficiency and making it difficult to implement in narrow spaces. Utility Model Content

[0004] The present invention aims to provide a crack width measuring instrument to adapt to crack detection in different orientations.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A crack width measuring instrument includes a measuring instrument body, a probe communicatively connected to the measuring instrument body, and a positioning component detachably mounted on the measuring instrument body. The positioning component includes a mounting part and a positioning block. The mounting part is snapped onto the outer periphery of the measuring instrument body. Multiple fixing seats and snap-fit ​​seats are arranged opposite each other on the side edge of the mounting part away from the measuring instrument body. The snap-fit ​​seats are provided with mounting grooves and snap-fit ​​doors. A rotating rod is provided on the side of the positioning block. Both ends of the rotating rod are inserted into the fixing seats and the mounting groove, respectively. When the snap-fit ​​door is closed, it is used to fix the rotating rod. The positioning block also has a mounting hole, and the probe is detachably connected to the mounting hole.

[0007] Beneficial effects:

[0008] 1. The positioning block and the mounting part are connected by a rotating rod. When the latch door is closed, the rotating rod can be locked to quickly fix the angle of the positioning block. When the latch door is open, the positioning block can rotate around the rotating rod, and the positioning block and the rotating rod can be placed around the mounting part to allow for different probe positions. Depending on the placement position, it can adapt to crack measurements in different directions (such as vertical, horizontal, and inclined) without frequent adjustments to the position of the width measuring instrument. Furthermore, for uneven, curved, or narrow corner structures, the cooperation between the latch door and the rotating rod allows the positioning block to adjust with the surface contour, ensuring that the probe always maintains the optimal measurement position perpendicular to the crack, overcoming the limitations of traditional fixed structures in complex scenarios.

[0009] 2. The positioning component uses structural design to help fix the probe position. The probe is installed in the mounting hole and the mounting part is fixed to the width measuring instrument body, which provides a stable measurement platform for the probe and avoids the need for the hand to hold the probe directly to measure the crack. This reduces the impact of hand shaking on the probe positioning and is suitable for precise positioning measurement at specific locations on the crack.

[0010] 3. The mounting section is fixed to the outer periphery of the width measuring instrument body by snap-fit, which can be quickly disassembled and assembled without tools. This allows users to flexibly replace the positioning components according to measurement needs, or disassemble and store the equipment when not in use, thus reducing the size of the device.

[0011] 4. When the latch door on the mounting bracket is closed, it can firmly fix the rotating rod, preventing the positioning block from shifting due to external forces (such as hand tremors or vibrations) during the measurement process, ensuring the stability of the probe position and improving the accuracy of crack width measurement.

[0012] 5. Detachable components (such as positioning blocks and probes) can be stored separately, reducing the overall size of the equipment and making it convenient for inspection personnel to carry between different locations, suitable for on-site inspection scenarios.

[0013] Preferably, as an improvement, the snap-lock door includes a door body and interlocking male and female snaps, the male snap being mounted on the door body and the female snap being mounted on the mounting part.

[0014] Beneficial effects: The male and female latches engage with each other through slots or convex-concave structures, allowing the door to be closed and locked with one hand without the need for tools. When closing the latched door, the engagement pressure of the male and female latches can be evenly applied to the rotating rod to ensure that the positioning block angle is fixed. When opening, the positioning block can be rotated freely to adapt to the measurement needs of cracks in different directions.

[0015] Preferably, as an improvement, an anti-slip layer is provided on the inner wall of the door body.

[0016] Beneficial effects: Anti-slip layers typically use elastic materials such as rubber and silicone, or textured designs such as serrations and convex dots. Such designs have high surface friction. Therefore, when the latch door is closed, the anti-slip layer fits tightly against the surface of the rotating rod, which can increase the friction between the rotating rod and the latch door, and increase the pressure of the door body on the rotating rod. The elastic material of the anti-slip layer can adapt to the surface of the rotating rod (such as metal or plastic). Even if there are slight rust or wear on the surface of the rotating rod, the deformation ability of the anti-slip layer can fill the gap, maintain sufficient friction, and avoid locking failure due to a decrease in surface smoothness.

[0017] Preferably, as an improvement, the outer periphery of the handle is provided with an anti-slip rubber layer, the surface of which has a network of protrusions or grooves.

[0018] Beneficial effects: The grid texture formed by the protrusions and grooves (such as diamonds and honeycomb patterns) can increase the contact area between the rubber layer and the skin of the hand, improve the friction between the hand and the handle, maintain a stable grip, prevent the width measuring instrument from slipping out of the hand, and make it easier for the operator to hold.

[0019] Preferably, as an improvement, the mounting part is provided with a flexible claw on the side near the width measuring instrument body for mounting the positioning component on the width measuring instrument body.

[0020] Beneficial effects: The elastic design of the flexible jaws makes it easy to install the positioning component onto the width measuring instrument body without the need for additional tools, making it suitable for quick on-site installation; the adjustability of the flexible jaws allows the positioning component to be installed not only on the outer periphery of the width measuring instrument body, but also on other testing equipment (such as endoscopes and laser rangefinders) through the adapter slot, achieving "one component for multiple devices" and expanding its application scenarios.

[0021] Preferably, as an improvement, the rotating rod is a telescopic rod, and the positioning block is fixedly connected to the outer sleeve of the telescopic rod.

[0022] Beneficial effects: The design of the telescopic rod allows operators to adjust the position of the positioning block at different locations on the installation part according to the location of the crack, thus facilitating testing by the operator.

[0023] Preferably, as an improvement, the fixed base is provided with a groove in the axial direction, and a spring positioning pin is placed in the groove. The outer periphery of the rotating rod is provided with a shaped groove in the axial direction, and the spring positioning pin is engaged in the shaped groove.

[0024] Beneficial effect: After the spring positioning pin is inserted into the irregular hole, the elastic force of the spring forms a mechanical lock, which prevents the telescopic rod from loosening due to vibration, contact or gravity during the measurement process.

[0025] Preferably, as an improvement, the spring positioning pin includes a housing, and a top pin and a compression spring installed inside the housing and connected sequentially from top to bottom, with the two ends of the compression spring abutting against the bottom of the positioning pin and the bottom of the housing, respectively.

[0026] Beneficial effects: The housing provides an axial guide track for the top pin, ensuring that the top pin moves only in the vertical direction and avoiding locking failure caused by radial offset.

[0027] Preferably, as an improvement, a limiting step is provided on the top of the housing, and an annular flange is provided on the outer periphery of the top pin. The annular flange cooperates with the limiting step to limit the maximum stroke of the top pin.

[0028] Beneficial effects: The rigid contact between the annular flange and the limiting step can very precisely limit the maximum outward extension of the top pin, ensuring that its movement range is within the predetermined design value and avoiding overtravel; the limiting step effectively blocks the annular flange, thereby preventing the top pin from accidentally detaching completely from the housing during the return stroke or operation, improving the reliability and safety of the structure; the limiting function is achieved by utilizing the housing structure itself and the flange on the top pin, eliminating the need for additional complex limiting parts (such as retaining rings, screw limiting blocks, etc.), simplifying the structure, and reducing manufacturing costs and assembly difficulty;

[0029] Preferably, as an improvement, the positioning block is fitted with a rubber sleeve, which has an opening that matches the positioning hole.

[0030] Beneficial effects: The rubber sleeve, wrapped around the locating block, effectively prevents hard collisions, friction, or scratches between the locating block and the probe, protecting the surface quality of the locating block and the workpiece; the rubber sleeve increases the friction between the contact surface of the locating block and the locating part, helping to prevent the locating workpiece from loosening or shifting under slight external force or vibration, improving the stability of the positioning; the opening on the rubber sleeve that precisely matches the locating hole ensures that the function of the locating hole is not affected, and the locating pin or related components can still be smoothly and accurately inserted into the locating hole, ensuring positioning accuracy; the elastic edge of the rubber sleeve provides a certain degree of flexible guidance during assembly, making it easier for the workpiece to be smoothly fitted into or aligned with the locating block, making the assembly operation smoother. Attached Figure Description

[0031] Figure 1 This is a structural schematic diagram of Embodiment 1 of the present utility model.

[0032] Figure 2 This is a schematic diagram of the mounting part in Embodiment 1 of this utility model.

[0033] Figure 3 This is a partial enlarged view of the latch door according to Embodiment 1 of this utility model.

[0034] Figure 4This is an installation diagram of Embodiment 1 of the present utility model.

[0035] Figure 5 This is a cross-sectional view of the spring positioning pin in Embodiment 2 of this utility model.

[0036] Figure 6 This is a structural diagram of the rubber sleeve in Embodiment 3 of this utility model.

[0037] The reference numerals in the accompanying drawings of the instruction manual include: 1. Width measuring instrument body; 11. Handle part; 12. Display part; 2. Probe; 3. Mounting part; 31. Fixing base; 311. Groove; 32. Snap-fit ​​base; 32. Mounting groove; 321. Snap-fit ​​door; 3221. Door body; 3222. Male snap-fit; 3222. Female snap-fit; 3223. Elastic pawl; 4. Positioning block; 41. Rotating rod; 411. Positioning hole; 42. Mounting hole; 5. Spring positioning pin; 51. Housing; 511. Limiting step; 52. Top pin; 521. Annular flange; 53. Compression spring; 6. Rubber sleeve. Detailed Implementation

[0038] The following detailed description illustrates the specific implementation method:

[0039] Example 1

[0040] like Figures 1-3 As shown, this embodiment provides a crack width measuring instrument, including a measuring instrument body 1, a probe 2 communicatively connected to the measuring instrument body 1, and a positioning component detachably mounted on the measuring instrument body 1. Specifically, the measuring instrument body 1 includes an integrally formed handle 11 and a display 12. The display 12 is equipped with a display screen and operation buttons such as a power switch, a measurement mode switching key, and a focus adjustment key. The focus adjustment key is used to control the focusing distance of the probe 2. The handle 11 has an anti-slip rubber layer on its outer periphery, and the surface of the anti-slip rubber layer has a network of protrusions or grooves to facilitate the operator's grip. The probe 2 includes an LED light source, an image sensor, and an optical lens. The LED light source is used to illuminate the crack being measured, and the image sensor is used to acquire images of the crack. It is worth noting that the measuring instrument body 1 and the probe 2 can be existing width measuring instruments available on the market.

[0041] The positioning component includes a mounting part 3 and a positioning block 4. The mounting part 3 is snapped onto the outer periphery of the width measuring instrument body 1, and an elastic claw 33 is provided on the side of the mounting part 3 closest to the width measuring instrument body 1 for mounting the positioning component onto the width measuring instrument body. Specifically, there are four elastic claws 33, located at the four corners of the width measuring instrument body 1. Multiple fixing seats 31 and snap-fit ​​seats 32 are arranged opposite each other on the edge of the mounting part 3 away from the width measuring instrument body 1. The snap-fit ​​seat 32 is provided with a mounting groove 321 and a snap-fit ​​door 322. The snap-fit ​​door 322 includes a door body 3221, and interlocking male snap-fit ​​3222 and female snap-fit ​​3223. The male snap-fit ​​3222 is mounted on the door body 3221, and the female snap-fit ​​3223 is mounted on the mounting part 3. Specifically, the male snap-fit ​​3222 includes a hook, a spring compressed inside the hook, and a locking piece. The hook part passes through the locking piece. The female snap-fit ​​3223 is a slot. Its working process can be divided into three stages: snapping, locking, and unlocking. During the fastening phase, the operator aligns the hook with the slot and presses it down firmly. At this time, the spring inside the hook is compressed, undergoing elastic deformation and generating compressive force. This deformation allows the hook to smoothly enter the slot. The spring's elasticity provides cushioning and adaptability for the hook's movement, preventing damage to parts due to excessive force. Once the hook is fully inside the slot, the locking phase begins. The spring begins to recover its deformation, releasing its stored elastic potential energy and pressing the hook firmly into the slot. Simultaneously, the protrusion at the end of the hook fits tightly against the edge of the slot, forming a mechanical locking structure that restricts the hook's movement. Furthermore, the rough texture of the contact surface between the hook and the slot increases friction, further preventing the hook from loosening. These multiple mechanisms work together to ensure the fastener is securely locked. To unlock the fastener, the operator pulls or presses the locking plate; the structure connecting the locking plate and the hook causes the hook to move. This action causes the spring to be compressed again, releasing the clamping force on the hook and breaking the engagement structure between the hook and the slot. When the applied external force is sufficient to overcome the engagement resistance and friction, the hook disengages from the slot, and the latch is successfully unlocked. The entire process is convenient and efficient. A rotating rod 41 is provided on the side of the positioning block 4. The two ends of the rotating rod 41 are placed in the fixed seat 31 and the mounting groove 321, respectively, so that the positioning block 4 is connected to the mounting part 3 through the rotating rod 41. The latch door 322 can open or close the mounting groove 321, thereby releasing or clamping the rotating rod 41. The positioning block 4 is also provided with a mounting hole 42, and the probe 2 can be detachably connected in the mounting hole 42.

[0042] Preferably, an anti-slip layer is provided on the inner wall of the door body 3221.

[0043] The working principle is as follows:

[0044] 1. Equipment Assembly: The operator uses the elastic claws 33 of the mounting part 3 to snap the positioning component onto the outer periphery of the width measuring instrument body 1. The four elastic claws 33 correspond to the corners of the width measuring instrument body 1 to achieve stable assembly. Then, one end of the rotating rod 41 is inserted into the fixed base, and the other end is placed into the mounting groove 321. The latch door 322 is closed, and the female latch 3223 is pressed down to make the male latch 3222 and the female latch 3223 interlock, thereby pressing and fixing the rotating rod. Finally, the probe 2 is inserted into the mounting hole 42 of the positioning block 4 to complete the equipment assembly.

[0045] 2. On-site operation: The operator holds the handle 11, aligns the positioning block 4 with the vertical direction of the crack to be tested, inserts the rotating rod 41 on the positioning block 4 into the mounting groove 321, and locks it with the latch door 322 to prevent the rotating rod 41 from rotating. Then, the probe 2 is placed in the positioning hole 411. At this time, the probe 2 is above the crack. Press the measurement mode switch key, the LED light source of the probe 2 illuminates the crack, and the image sensor collects the crack image through the optical lens and transmits it to the width measuring instrument body 1 through the communication connection. If it is necessary to adjust the clarity, the focus adjustment key can be used to control the focus of the probe 2.

[0046] 3. After the test is completed, the detachable positioning component and probe 2 should be cleaned and stored, and the power should be turned off.

[0047] Example 2

[0048] like Figure 4 As shown, the difference between this embodiment and Embodiment 1 is that in this embodiment, the rotating rod 41 is a telescopic rod, and the positioning block 4 is fixedly connected to the outer sleeve of the telescopic rod. At this time, a groove 311 is provided axially inside the fixed seat 31, and a spring positioning pin 5 is placed inside the groove 311. A shaped groove is provided axially on the outer periphery of the rotating rod 41, and the spring positioning pin 5 is engaged in the shaped groove. Specifically, the shaped groove is an eccentric groove, and the groove faces towards the end closest to the fixed seat 31, preventing the telescopic rod from being easily removed from the spring positioning pin 5 after insertion, and restricting the rotation of the telescopic rod within the fixed seat 31. The spring positioning pin 5 includes a housing 51, and a top pin 52 and a compression spring 53 installed inside the housing 51, connected sequentially from top to bottom. The two ends of the compression spring 53 abut against the bottom of the top pin 52 and the bottom of the housing 51, respectively. Preferably, the top of the top pin 52 is arc-shaped to facilitate adjustment of the rotation position of the positioning block 4. Specifically, a limiting step 511 is provided on the top of the outer casing 51, and an annular flange 521 is provided on the outer periphery of the top pin 52. The annular flange 521 cooperates with the limiting step 511 to limit the maximum stroke of the top pin 52.

[0049] Example 3

[0050] like Figure 5As shown, the difference between this embodiment and the above embodiment is that in this embodiment, a rubber sleeve 6 is fitted on the positioning block 4, and the rubber sleeve 6 is provided with an opening that matches the positioning hole 411.

[0051] The above descriptions are merely embodiments of this utility model. Commonly known technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solution of this utility model. These modifications and improvements should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A crack width measuring instrument, characterized in that: The device includes a width measuring instrument body, a probe communicatively connected to the width measuring instrument body, and a positioning assembly detachably mounted on the width measuring instrument body. The positioning assembly includes a mounting part and a positioning block. The mounting part is snapped onto the outer periphery of the width measuring instrument body. Multiple fixing seats and snap-fit ​​seats are arranged opposite each other on the side edge of the mounting part away from the width measuring instrument body. The snap-fit ​​seats are provided with mounting grooves and snap-fit ​​doors. A rotating rod is provided on the side of the positioning block. The two ends of the rotating rod are respectively placed in the fixing seats and the mounting groove, so that the positioning block is connected to the mounting part through the rotating rod. The snap-fit ​​door can open or close the mounting groove, thereby releasing or clamping the rotating rod. The positioning block also has a mounting hole, and the probe is detachably connected to the mounting hole.

2. The crack width measuring instrument according to claim 1, characterized in that: The snap-lock door includes a door body and interlocking male and female snaps. The male snap is installed on the door body, and the female snap is installed on the mounting part.

3. A crack width measuring instrument according to claim 2, characterized in that: The inner wall of the door body is provided with an anti-slip layer.

4. A crack width measuring instrument according to claim 1, characterized in that: The width measuring instrument body includes an integrally formed handle and a display. The outer periphery of the handle is provided with an anti-slip rubber layer, and the surface of the anti-slip rubber layer has a network of protrusions or grooves.

5. A crack width measuring instrument according to claim 1, characterized in that: The mounting part is provided with elastic claws on the side near the width measuring instrument body, which are used to install the positioning component on the width measuring instrument body.

6. A crack width measuring instrument according to claim 1, characterized in that: The rotating rod is a telescopic rod, and the positioning block is fixedly connected to the outer sleeve of the telescopic rod.

7. A crack width measuring instrument according to claim 6, characterized in that: The fixed base has a groove in the axial direction, and a spring positioning pin is placed in the groove. The outer circumference of the rotating rod has a shaped groove in the axial direction, and the spring positioning pin is engaged in the shaped groove.

8. A crack width measuring instrument according to claim 7, characterized in that: The spring positioning pin includes a housing, and a top pin and a compression spring installed inside the housing and connected sequentially from top to bottom. The two ends of the compression spring abut against the bottom of the positioning pin and the bottom of the housing, respectively.

9. A crack width measuring instrument according to claim 8, characterized in that: The top of the housing is provided with a limiting step, and the outer periphery of the top pin is provided with an annular flange. The annular flange cooperates with the limiting step to limit the maximum stroke of the top pin.

10. A crack width measuring instrument according to claim 1, characterized in that: A rubber sleeve is fitted onto the positioning block, and the rubber sleeve has an opening that matches the positioning hole.

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