CN116297130B - Simple nail-shooting type wood decay detection instrument and assessment method - Google Patents

Abstract

The invention discloses a simple nail-shooting type wood decay detecting instrument and an evaluating method, wherein the instrument comprises a shell component and steel nails, and further comprises the following components: the ejection mechanism is connected with the shell assembly through the limit cylinder and is used for providing impact power for the steel nails; the impact assembly is connected with the shell assembly through a linear bearing and is used for impacting the steel nails; the limiting assembly A is connected with the ejection mechanism and used for limiting the ejection mechanism; according to the invention, steel nails can be shot into wood to be detected and sound wood with constant impulse, and the wood decay degree is estimated through the steel nail distance of the wood shot into the steel nails and related parameters, so that the aim of detecting and evaluating the wood member decay degree under different tree species, water content and biological influence factors is fulfilled.

Description

A simple nail-shooting wood decay detection instrument and evaluation method

Technical field

The invention belongs to the technical field of wood minimal damage detection, and in particular relates to a simple nail-shooting wood decay detection instrument and evaluation method.

Background technique

There are many ancient wooden structures in our country. These cultural treasures with important historical, artistic and scientific values are the material carriers that bear witness to the evolution of Chinese civilization. As a biological material, wood will undergo decay and insect infestation during long-term use due to natural weathering and biological intrusions such as insects and microorganisms, resulting in a reduction in mechanical properties. Therefore, ancient buildings using wood as structural materials must regularly conduct surveys on the condition of the wood structure materials to check for decay, insect infestation, etc., and carry out corresponding protective treatments to ensure the safety of ancient wooden structures. How to scientifically detect the internal decay of wooden components without destroying the original wooden components, and more accurately determine the degree of decay and remaining mechanical strength of wooden components, is an important issue in the current maintenance and protection process of ancient wooden structures. technical challenge.

At present, our country mostly uses a method of combining qualitative visual inspection and simple tapping to survey the material condition of wooden structures of ancient buildings, but it is not possible to make a quantitative evaluation of the material condition. Although the research on stress wave, ultrasonic and impedance instrument detection technologies has attracted the attention of scientific researchers, these methods are still in the experimental stage and lack corresponding evaluation standards. They require many accessories, complicated connections, and cumbersome installation processes. The detection efficiency has been greatly reduced, and there is still a long way to go before widespread application.

Therefore, at this stage, it is necessary to develop a mature non-destructive testing instrument and evaluation method to scientifically classify the decay levels of wooden components on the basis of simple and efficient investigation of the decay of wooden components, which is beneficial to the overall wooden structure of ancient buildings. The accurate assessment of structural safety is of great significance to the scientific application and development of ancient building wooden structure protection projects.

Contents of the invention

In view of the shortcomings of the existing technology, the present invention provides a simple nail-shooting wood decay detection instrument and evaluation method, which solves the above problems.

In order to achieve the above objectives, the present invention is implemented through the following technical solutions: a wood decay assessment method, including the following steps:

S1. Obtain the moisture content MC _i of the wood at the measured point, the length L i of the steel nail that enters the wood being measured through a simple nail-shooting wood decay detection instrument with constant momentum, and the length L ₀ that enters the _intact wood;

S2. Subtract the length L _i of the steel nail that enters the wood under test with constant momentum and the length L ₀ that enters the intact wood, and then divide by the length L ₀ of the steel nail that enters the intact wood to obtain the corresponding measurement point of the decayed wood. Nail penetration depth increase rate;

S3. Comprehensive consideration of wood species, biological damage and moisture content of measuring points to construct a calculation model for the comprehensive evaluation index P of wooden components. The calculation model of P is:

Among them, L ₀ represents the length of the steel nail entering the intact wood; n represents the number of measuring points, n ≥ 10; L _i represents the detection length of the i-th measuring point; MC _i represents the wood moisture content (%) at the i-th measuring point ), represents the moisture content influence function; w _s represents the corrosion resistance coefficient of tree species. The durability of commonly used wood can be divided into non-durable tree species, slightly durable tree species and (strongly) durable tree species. The corresponding corrosion resistance coefficients in the present invention are respectively 1, 0.9, 0.8; w _b represents the biological invasion coefficient. If the environment where the component is located is invaded by bats, termites, borers, carpenter bees and other biological organisms, the biological invasion coefficient is 1.2. If there is no biological invasion, the biological invasion coefficient is 1.0;

S4. Classify the degree of decay of wooden components according to the index P.

On the basis of the above technical solutions, the present invention also provides the following optional technical solutions:

Further technical solution: The specific grading method for grading the degree of decay of wooden components according to the index P is:

If P is 0, the degree of decay of wooden components is level 0;

If 0<P≤25%, the degree of decay of wooden components is level 1;

If 26% ≤ P ≤ 60%, the degree of decay of the wooden components is level 2;

If 61%≤P≤90%, the degree of decay of wooden components is level 3;

If P>90%, the degree of decay of wooden components is level 4.

A simple nail-shooting wood decay detection instrument, based on the above-mentioned wood decay assessment method, includes a shell component and steel nails, and also includes:

The ejection mechanism is connected to the housing assembly through the limiting cylinder and is used to provide impact power to the steel nails;

An impact assembly, connected to the housing assembly through a linear bearing, for impacting the steel nails; and

Limiting component A, connected with the ejection mechanism, is used to limit the ejection mechanism;

The ejection mechanism impacts the impact component with constant momentum after the limit component A is released, prompting the impact component to move linearly in the housing. The impact component rushes out of the housing component by pushing the steel nails embedded in it and shoots into the wood. This method obtains the length of the steel nails shot into the intact wood and the decayed wood. At the same time, the length of the steel nails shot into the decayed wood and the intact wood is brought into the decayed wood assessment method to evaluate the degree of decay of the decayed wood. Achieve the purpose of simple and rapid detection and evaluation of the decay degree of wooden components under different tree species, moisture content and biological influencing factors.

Further technical solution: the shell assembly includes a shell cap and a shell body. The shell body is composed of a cylinder A, a cylinder B, a cylinder C and a cylinder D that are linearly arranged and fixedly connected in sequence. The cylinder A. The inner diameters of cylinders B and C decrease in sequence. The inner diameters of cylinders C and D are equal. The outer diameters of cylinders A, B and C are equal. And are both larger than the outer diameter of the cylinder D. The cylinder D is threadedly connected to the linear bearing threadedly connected to the shell cap. The limiting cylinder is threadedly connected to the cylinder A.

Further technical solution: the ejection mechanism includes a shell, a rod, a slider and an elastic member A. The rod is fixedly connected to the slider. The rod and the slider are both slidingly matched with the shell. The shell is connected to the limiter. The cylinder is in sliding fit, the housing is connected to the limiting component A, the slider is connected to the housing through the elastic member A, and it also includes:

The limiting component B is connected to the housing and is used to limit the slider.

Further technical solution: the limiting component A includes a limiting disc and a rotating cap. The limiting disc is used in conjunction with an installation slot provided at the end of the housing. The rotating cap is passed through an installation slot provided at the end of the housing. The external thread A on the top is detachably connected to the shell thread. The shell, the limiting disk and the rotating cap are arranged linearly in sequence. The limiting disk slides with the cylinder B. The outer diameter of the limiting disk is equal to the inner diameter of cylinder B, and the outer diameter of the limiting disk is larger than the inner diameter of the limiting cylinder.

Further technical solution: the impact assembly includes a limit block A and a cylindrical shaft. The cylindrical shaft is in sliding fit with the linear bearing. The two limit blocks A are symmetrically arranged on the cylindrical shaft and are threadedly connected to the cylindrical shaft. The limit block A is provided with a groove for placing steel nails, and the limit block A, the cylindrical shaft and the central axis of the rod body coincide with each other.

Further technical solution: the shell cap is provided with an internal thread A from the end far away from the through hole to the end close to the through hole, the barrel D is provided with an internal thread B, and the shell cap and the shell body are respectively passed through the internal thread A And the internal thread B is threaded with the linear bearing. The wall thickness of the non-threaded area of the shell cap is greater than the wall thickness of the threaded area. The barrel A has an internal thread from the end far away from the shell cap to the end close to the shell cap. C. The cylinder A is threadedly connected to the limiting cylinder through the internal thread C.

Further technical solution: the limit component B includes a button, a telescopic rod, a support frame, a slide tube, a mounting bracket and a limit block B. The button is in sliding fit with the housing, and the telescopic rod is hingedly connected to the button and the support frame. , the support frame is fixedly connected to the casing, the telescopic rod is hingedly connected to the mounting frame, the mounting frame is fixedly connected to the limit block B, the mounting frame is in sliding fit with the slide tube fixedly connected to the inner wall of the casing, The mounting bracket is connected to the slide tube through an elastic member B, and the limiting block B is used in conjunction with the limiting groove opened on the sliding block. The limiting block B is a wedge-shaped block.

A method of using a simple nail-shooting wood decay detection instrument, based on the above-mentioned simple nail-shooting wood decay detection instrument, the specific steps are:

S1. Record the length of the steel nail, and push the shell to slide along the limiting cylinder to embed the shell into the shell body. At the same time, the rod body presses the impact component, and the impact component gives the rod body a reaction force. This reaction force pushes the rod body to shrink into the shell. In the body, at the same time, the rod pushes the slider to squeeze the elastic member A until the slider is limited by the limiter component B, completing the power accumulation operation of the ejection mechanism;

S2. Pass the steel nail through the through hole on the shell cap, insert the tail of the steel nail into the groove of the limit block A, and push the steel nail until the steel nail is completely retracted into the shell assembly. The cylindrical shaft is pushed by the limit block A to move linearly along the linear bearing, and the cylindrical shaft is pushed by another limit block A to push the rod body to move linearly. At this time, the shell extends out of the housing assembly and resets under the push of the rod body;

S3. Relevant technicians hold the shell and shell components with both hands and press the shell cap vertically against the measured surface;

S4. Release the limit of the slider by the limiter component B. At this time, the elastic member A uses its own elasticity to push the slider to move linearly along the housing. At the same time, the slider pushes the rod body to extend out of the housing and hits the limit block A. The method pushes the cylindrical shaft to slide quickly along the linear bearing to eject the steel nail embedded in the groove;

S5. Calculate the depth of the steel nail into the wood to be tested and the intact wood, and obtain the degree of decay of the wood component to be measured based on the decayed wood assessment method.

beneficial effects

The present invention provides a simple nail-shooting wood decay detection instrument and evaluation method, which has the following beneficial effects compared with the existing technology:

1. In the present invention, the length L _i of the steel nail entering the decayed wood is subtracted from the length L ₀ of the steel nail entering the intact wood, and then divided by the length L ₀ of the steel nail entering the intact wood, to obtain the increase in the nail penetration depth of the decaying wood measuring point. rate, and further comprehensively consider factors such as the rot resistance of wood species, biological damage, and moisture content of measuring points, to grade the degree of decay of wooden components, and achieve a quantitative assessment of the degree of decay of wooden components under the influence of multiple factors;

2. The present invention can achieve repeated measurement of the decay degree of wood of different tree species with minimal damage to nail holes. The device is easy to assemble, efficient to operate, has stable energy emission, and the evaluation is scientific and reasonable;

3. The fixed impact energy released by the ejection mechanism of the present invention can be transmitted from the rod body to the cylindrical shaft of the linear bearing with extremely small friction coefficient. The cylindrical shaft then transmits the energy to the tail end of the steel nail along a straight line. During the process, the direction of the impact force is constant, and there is no additional impact. Friction consumption can effectively ensure the stability of the energy when the steel nail is shot into the wood being measured, and ensure the effectiveness of the length of the steel nail shot into the wood.

Description of drawings

Figure 1 is a schematic three-dimensional structural diagram of the hidden 1/4 shell component of the present invention.

Figure 2 is a schematic structural diagram of the housing assembly and impact assembly of the present invention.

Figure 3 is a schematic structural diagram of the ejection mechanism hiding 1/2 of the casing of the present invention.

Figure 4 is an enlarged schematic diagram of the structure of part A in Figure 3 of the present invention, that is, a schematic structural diagram of the limiting component B.

Figure 5 is a schematic diagram of the connection between the sliding tube, the mounting bracket and the elastic member B in the limiting assembly B of the present invention.

Figure 6 is a schematic structural diagram of the ejection mechanism and limiting component A of the present invention.

Notes on reference numbers: 1. Shell assembly; 101. Shell cap; 102. Shell body; 1021. Cylinder A; 1022. Cylinder B; 1023. Cylinder C; 1024. Cylinder D; 2. Impact assembly; 201. Limit block A; 202. Cylindrical shaft; 3. Ejection mechanism; 301. Housing; 302. Rod body; 303. Slider; 304. Button; 305. Elastic member A; 306. Storage tube; 307. Limit Slot; 308, telescopic rod; 309, support frame; 310, slide tube; 311, mounting frame; 312, limit block B; 313, elastic member B; 4, limit cylinder; 5, linear bearing; 6, limit Position component A; 601, limit disc; 602, rotating cap; 7, limit component B.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention and are not intended to limit the present invention.

The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

A wood decay assessment method that includes the following steps:

S1. Obtain the moisture content MC _i of the wood at the measured point, the length L i of the steel nail that enters the wood being measured through a simple nail-shooting wood decay detection instrument with constant momentum, and the length L ₀ that enters the _intact wood;

S2. Subtract the length L _i of the steel nail that enters the wood under test with constant momentum and the length L ₀ that enters the intact wood, and then divide by the length L ₀ of the steel nail that enters the intact wood to obtain the corresponding measurement point of the decayed wood. Nail penetration depth increase rate;

S3. Comprehensive consideration of wood species, biological damage and moisture content of measuring points to construct a calculation model for the comprehensive evaluation index P of wooden components. The calculation model of P is:

Among them, L ₀ represents the length of the steel nail entering the intact wood; n represents the number of measuring points, n ≥ 10; L _i represents the detection length of the i-th measuring point; MC _i represents the wood moisture content (%) at the i-th measuring point ), represents the moisture content influence function; w _s represents the corrosion resistance coefficient of tree species. The durability of commonly used wood can be divided into non-durable tree species, slightly durable tree species and (strongly) durable tree species. The corresponding corrosion resistance coefficients in the present invention are respectively 1, 0.9, 0.8; w _b represents the biological invasion coefficient. If the environment where the component is located is invaded by bats, termites, borers, carpenter bees and other biological organisms, the biological invasion coefficient is 1.2. If there is no biological invasion, the biological invasion coefficient is 1.0;

S4. Classify the degree of decay of wooden components according to the index P. The grading standards are as shown in the following table:

Decay degree classification of wooden components Index P (%) 0 0 1 0～25 2 26～60 3 61～90 4 >90

Please refer to Figures 1 to 6, which is a simple nail-shooting wood decay detection instrument provided by an embodiment of the present invention. Based on the above-mentioned wood decay assessment method, it includes a housing assembly 1 and a steel nail (not marked in the figure) ,Also includes:

The ejection mechanism 3 is connected to the housing assembly 1 through the limiting cylinder 4 and is used to provide impact power to the steel nails;

The impact component 2 is connected to the housing component 1 through the linear bearing 5 and is used to impact the steel nails; and

The limiting component A6 is connected to the ejection mechanism 3 and is used to limit the ejection mechanism 3;

The ejection mechanism 3 impacts the impact component 2 with constant momentum after the limit component A6 releases the limit, prompting the impact component 2 to move linearly in the housing, and the impact component 2 rushes out of the housing component by pushing the steel nails embedded in it. 1. The length of the steel nails shot into the intact wood and the decayed wood is obtained by the method of inserting the nails into the decayed wood and the intact wood. At the same time, the degree of decay of the decayed wood is determined by bringing the length of the steel nails injected into the decayed wood and intact wood into the decayed wood assessment method. The evaluation method achieves the purpose of simple and rapid detection and evaluation of the decay degree of wooden components under different tree species, moisture content and biological influencing factors.

Specifically, the shell assembly 1 includes a shell cap 101 and a shell body 102. The shell body 102 is composed of a cylinder A1021, a cylinder B1022, a cylinder C1023 and a cylinder D1024 that are linearly arranged and fixedly connected in sequence. The inner diameters of cylinder A1021, cylinder B1022 and cylinder C1023 decrease in sequence. The inner diameters of cylinder C1023 and cylinder D1024 are equal. The outer diameters of cylinder A1021, cylinder B1022 and cylinder C1023 The diameters are equal and larger than the outer diameter of the cylinder D1024. The cylinder D1024 is detachably connected to the shell cap 101 through the linear bearing 5. The linear bearing 5 is threadedly connected to the shell cap 101 and the cylinder D1024. The limiting circle Barrel 4 is threadedly connected to barrel A1021. The purpose of this arrangement is to facilitate relevant technical personnel to place the ejection mechanism 3, impact component 2 and limiting component A6.

Specifically, the shell cap 101 is a cylinder with a hollow interior and a capped front end. The shell cap 101 is provided with a through hole for placing steel nails (not marked in the figure). The purpose of this arrangement is to facilitate relevant technical personnel to place the steel nails on the impact component 2 inside the housing component 1 .

Specifically, the shell cap 101 is provided with an internal thread A (not marked in the figure) from the end far away from the through hole to the end close to the through hole, and the barrel D1024 is provided with an internal thread B (not marked in the figure). , the shell cap 101 and the shell body 102 are threadedly connected to the linear bearing 5 through internal threads A and B respectively, and the cylinder A1021 has an internal thread C at one end from the end away from the shell cap 101 to one end of the shell cap 101 , the cylinder A1021 is threadedly connected to the limiting cylinder 4 through the internal thread C, and the wall thickness of the non-threaded area of the shell cap 101 is greater than the wall thickness of the threaded area. The purpose of this arrangement is to disassemble and install the limiting cylinder 4 and the linear bearing 5 on the shell cap 101 and the shell body 102 to facilitate the later assembly and disassembly of the entire device. At the same time, since the wall thickness of the non-threaded area of the shell cap 101 is larger than The wall thickness of the threaded area can limit the installation position of the linear bearing 5, causing one end of the linear bearing 5 to be stuck at the junction of the threaded area and the sub-threaded area inside the shell cap 101.

Specifically, the ejection mechanism 3 includes a housing 301, a rod 302, a slider 303 and an elastic member A305. The rod 302 is fixedly connected to the slider 303. Both the rod 302 and the slider 303 are in sliding fit with the housing 301. , the elastic member A305 is located in the housing 301, the elastic member A305 is fixedly connected to the slider 303 and the housing 301, the housing 301 slides with the limiting cylinder 4, the housing 301 and the limiting cylinder 4 Component A6 Connect also includes:

The limiting component B7 is connected to the housing 301 and is used to limit the slider 303 . Relevant technicians push the housing 301 to slide along the limiting cylinder 4 to embed the housing 301 into the housing 102. At this time, the rod 302 presses against the impact component 2, and the impact component 2 gives a reaction force to the rod 302. The reaction force Push the rod body 302 to retract into the housing 301. At the same time, the rod body 302 pushes the slider 303 to squeeze the elastic member A305 until the slider 303 is limited by the limiter assembly B7 to complete the power accumulation operation of the ejection mechanism 3. Relevant technicians can release it as needed. The limiting component B7 limits the slider 303. At this time, the elastic member A305 uses its own elasticity to push the slider 303 to move linearly along the housing 301. At the same time, the slider 303 pushes the rod 302 to extend out of the housing 301 and hit the impact component 2. The purpose of providing impact power for the steel nail is to provide impact power for the impact component 2, that is, to empower the steel nail.

Preferably, the elastic member A305 is any one of a spring, a compression spring and an elastic steel plate.

Preferably, the limiting assembly B7 includes a button 304, a telescopic rod 308, a support frame 309, a sliding tube 310, a mounting bracket 311 and a limiting block B312. The button 304 is in sliding fit with the housing 301, and the telescopic rod 308 Both ends are hinged with the button 304 and the support frame 309 respectively. The support frame 309 is fixedly connected to the inner wall of the housing 301. The telescopic rod 308 is hinged to the mounting frame 311. The mounting frame 311 is fixedly connected to the limiting block B312. The mounting bracket 311 is in sliding fit with the sliding tube 310 fixedly connected to the inner wall of the housing 301. The mounting bracket 311 is connected to the sliding tube 310 through an elastic member B313. The elastic member B313 is located in the sliding tube 310 and is connected to the sliding tube 310. The inner wall and the mounting bracket 311 are fixedly connected, and the limiting block B312 is used in conjunction with the limiting groove 307 opened on the slider 303. The limiting block B312 is a wedge-shaped block. When the slider 303 squeezes the elastic member A305 and moves linearly along the housing 301, it contacts the limiter block B312 and presses the limiter B312. The limiter B312 moves linearly under the pressure of the slider 303. At this time, the limiter is limited. Block B312 pushes the mounting frame 311 to squeeze the elastic member B313 and slides along the slide tube 310. At the same time, the mounting frame 311 pushes the telescopic rod 308 to swing. The telescopic rod 308 pulls the button 304 for linear movement. At the same time, the elastic member B313 gives the mounting frame 311 a reaction. The reaction force uses the mounting bracket 311 to push the limit block B312 against the outer wall of the slider 303 until the limiter B312 snaps into the limiter groove 307 to complete the limit of the slider 303. When the limiter B312 is released, When the slider 303 is limited, press the button 304 to drive the telescopic rod 308 to swing, and the telescopic rod 308 pushes the mounting bracket 311 to slide along the slide tube 310, urging the limiter B312 to move away from the limiter groove 307, and the slide is released. The purpose of limiting the position of the block 303 is to perform a controllable limiting process on the slider 303.

Preferably, the elastic member B313 is any one of a spring, a compression spring and an elastic steel plate.

Specifically, the limiting assembly A6 includes a limiting disc 601 and a rotating cap 602. The limiting disc 601 is used in conjunction with an installation slot (not marked in the figure) opened at the end of the housing 301, so The screw cap 602 is threadedly detachably connected to the housing 301 through the external thread A (not shown in the figure) opened in the installation slot. The housing 301, the limiting disk 601 and the screw cap 602 are arranged linearly in sequence, so The limiting disc 601 is in sliding fit with the cylinder B1022. The outer diameter of the limiting disc 601 is equal to the inner diameter of the cylinder B1022. The outer diameter of the limiting disc 601 is larger than the inner diameter of the limiting cylinder 4. The purpose of this arrangement is to confine the ejection mechanism 3 within the housing assembly 1 and to enable the ejection mechanism 3 to perform linear motion within the housing assembly 1 .

Specifically, the length of the rod 302 when not working is less than or equal to the difference between the length of the barrel B1022 and the thickness of the limiting disc 601 . The purpose of this arrangement is to ensure that the rod 302 has a sufficient displacement path within the housing assembly 1 .

Specifically, the impact assembly 2 includes a limiting block A201 and a cylindrical shaft 202. The cylindrical shaft 202 is in sliding fit with the linear bearing 5. The two limiting blocks A201 are symmetrically arranged on the cylindrical shaft 202 and are in contact with the cylindrical shaft 202. Threaded connection, the limiting block A201 is provided with a groove for placing steel nails (not marked in the figure), the central axis of the limiting block A201, the cylindrical shaft 202 and the rod body 302 coincide with each other. Relevant technicians can pass the steel nail through the through hole opened on the shell cap 101 and insert it into the groove opened on the limit block A201. At the same time, the ejection mechanism 3, which has completed the force accumulation, can hit another limit block. A201 is used to push the cylindrical shaft 202 to slide quickly along the linear bearing 5 to eject the steel nail embedded in the groove. The purpose of this setting is to install the steel nail and serve as an intermediate transmission member to provide injection for the steel nail. power.

Specifically, the length of the cylindrical shaft 202 is greater than the linear bearing length 5, and the sum of the lengths of the cylindrical shaft 202 and the two-end limit blocks 201 is less than the sum of the inner lengths of the cylinder C1023, cylinder D1024 and the shell cap 101 . The purpose of this arrangement is to ensure that the cylindrical shaft 202 has a sufficient displacement path within the housing assembly 1 .

Specifically, the length of the limiting cylinder 4 is greater than the length of the cylinder A1021. The purpose of this arrangement is to facilitate relevant technical personnel to screw the limiting cylinder 4 into the cylinder A1021.

Specifically, the outer walls of the shell cap 101 and the spin cap 102 are both provided with vertical stripes (not marked in the figure). The purpose of this arrangement is to increase the contact friction by improving the surface roughness of the two, making it easier for relevant personnel to hold.

As an alternative to the above embodiment, the simple nail-shooting wood decay detection instrument includes a steel nail, a shooting tube and a rebound meter. The shooting tube is threadedly connected to the housing of the rebound meter at the output end, so The steel nail is in sliding fit with the shooting tube. The rebound instrument can give the steel nail specific kinetic energy and push the steel nail to linearly slide along the shooting tube to impact the object.

In the embodiment of the present invention, first, relevant technical personnel push the housing 301 to slide along the limiting cylinder 4 to cause the housing 301 to shrink into the housing body 102. At the same time, the rod 302 presses the impact component 2, and the impact component 2 gives the rod 302 reacts with a reaction force, which pushes the rod 302 to shrink into the housing 301. At the same time, the rod 302 pushes the slider 303 to squeeze the elastic member A305 until the slider 303 is limited by the limiting component B7 to complete the power accumulation operation of the ejection mechanism 3. ; Secondly, the relevant technicians pass the steel nail through the through hole on the shell cap 101, insert the tail of the steel nail into the groove of the limit block A201, and push the steel nail until the steel nail is completely retracted into the shell assembly. 1, at the same time, the steel nail pushes the cylindrical shaft 202 to move linearly along the linear bearing 5 through the limit block A201, and the cylindrical shaft 202 pushes the rod body 302 to move linearly through another limit block A201. At this time, the housing 301 is on the rod body 302. Push and extend the housing component 1 and reset it; then, the relevant technician holds the housing 301 and the housing component 1 with both hands respectively and presses the housing cap 101 vertically against the surface to be measured, and releases the pressure of the limiting component B7 on the slider 303 At this time, the elastic member A305 uses its own elasticity to push the slider 303 to move linearly along the housing 301. At the same time, the slider 303 pushes the rod 302 to extend out of the housing 301 and hits the limiter A201, pushing the cylindrical shaft 202 Slide quickly along the linear bearing 5 to eject the steel nail embedded in the groove; finally, calculate the depth of the steel nail into the wood to be measured and the intact wood, and obtain the wood to be measured based on the above decayed wood assessment method The degree of decay of components.

Please refer to Figures 1 to 6, a method of using a simple nail-shooting wood decay detection instrument. Based on the above-mentioned simple nail-shooting wood decay detection instrument, the specific steps are:

S1. Record the length of the steel nail, and push the housing 301 to slide along the limiting cylinder 4 to cause the housing 301 to shrink into the housing 102. At the same time, the rod 302 presses against the impact component 2, and the impact component 2 gives the rod 302 a reaction force. , the reaction force pushes the rod 302 to retract into the housing 301, and at the same time, the rod 302 pushes the slider 303 to squeeze the elastic member A305 until the slider 303 is limited by the limiting component B7, completing the power accumulation operation of the ejection mechanism 3;

S2. Pass the steel nail through the through hole in the shell cap 101, embed the tail of the steel nail in the groove of the limit block A201, and push the steel nail until the steel nail is completely retracted into the housing assembly 1, and at the same time The steel nail pushes the cylindrical shaft 202 to move linearly along the linear bearing 5 through the limit block A201. The cylindrical shaft 202 pushes the rod body 302 to move linearly through another limit block A201. At this time, the housing 301 extends under the push of the rod body 302. Housing assembly 1 and reset;

S3. Relevant technicians hold the shell 301 and the shell assembly 1 with both hands respectively and press the shell cap 101 vertically against the measured surface;

S4. Release the limitation of the slider 303 by the limiter assembly B7. At this time, the elastic member A305 uses its own elasticity to push the slider 303 to move linearly along the housing 301. At the same time, the slider 303 pushes the rod 302 to extend out of the housing 301 and pass through the housing 301. By hitting the limit block A201, the cylindrical shaft 202 is pushed to slide rapidly along the linear bearing 5, and the steel nail embedded in the groove is ejected;

S5. Calculate the depth of the steel nail that penetrates the wood to be measured and the intact wood, and obtain the degree of decay of the wood component to be measured based on the calculation method of decayed wood mentioned above.

Among them, the specific operation method of the limit component B7 is:

The limiting block B312 performs linear motion under the pressure of the linearly moving slider 303. At this time, the limiting block B312 pushes the mounting bracket 311 to squeeze the elastic member B313 and slides along the sliding tube 310. At the same time, the mounting bracket 311 pushes the telescopic rod 308 to move. Swing, the telescopic rod 308 pulls the button 304 to perform linear motion, and at the same time, the elastic member B313 gives the mounting bracket 311 a reaction force. The reaction force uses the mounting bracket 311 to push the limit block B312 against the outer wall of the slider 303 until the limit block B312 snaps in. In the limit slot 307, the limit of the slider 303 is completed. When the limiter B312 is released to limit the slider 303, the telescopic rod 308 is driven to swing by pressing the button 304, and the telescopic rod 308 pushes the mounting bracket 311 along the The sliding barrel 310 slides to urge the limiting block B312 to move away from the limiting groove 307, thereby releasing the limitation on the sliding block 303.

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that these entities or operations are mutually exclusive. any such actual relationship or sequence exists between them. Furthermore, the terms "comprises," "comprises," or any other variation thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also those not expressly listed other elements, or elements inherent to the process, method, article or equipment.

Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art will understand that various changes, modifications, and substitutions can be made to these embodiments without departing from the principles and spirit of the invention. and modifications, the scope of the invention is defined by the appended claims and their equivalents.

Claims (10)

1. A wood decay assessment method, characterized by including the following steps: S1. Obtain the moisture content MC _i of the wood at the measured point, the length L i of the steel nail that enters the wood being measured through a simple nail-shooting wood decay detection instrument with constant momentum, and the length L ₀ that enters the _intact wood; S2. Subtract the length L _i of the steel nail that enters the wood under test with constant momentum and the length L ₀ that enters the intact wood, and then divide by the length L ₀ of the steel nail that enters the intact wood to obtain the corresponding measurement point of the decayed wood. Nail penetration depth increase rate; S3. Comprehensive consideration of wood species, biological damage and moisture content of measuring points to construct a calculation model for the comprehensive evaluation index P of wooden components. The calculation model of P is: Among them, L ₀ represents the length of the steel nail entering the intact wood; n represents the number of measuring points, n≥10; L _i represents the detection length of the i-th measuring point; MC _i represents the moisture content of the wood at the i-th measuring point, represents the influence function of moisture content; w _s represents the corrosion resistance coefficient of tree species. The durability of commonly used wood is divided into non-durable tree species, slightly durable tree species and durable tree species. The corresponding corrosion resistance coefficients are 1, 0.9, and 0.8 respectively; w _b represents biological damage. Coefficient, if there is biological damage to the environment of the wood, the biological damage coefficient is 1.2; if there is no biological damage, the biological damage coefficient is 1.0. The biological damage includes damage to the wood by bats, termites, borers and carpenter bees; S4. Classify the degree of decay of wooden components according to the index P. 2. A wood decay assessment method according to claim 1, characterized in that the specific grading method for grading the degree of decay of wooden components according to the index P is: If P is 0, the degree of decay of wooden components is level 0; If 0<P≤25%, the degree of decay of wooden components is level 1; If 26% ≤ P ≤ 60%, the degree of decay of the wooden components is level 2; If 61%≤P≤90%, the degree of decay of wooden components is level 3; If P>90%, the degree of decay of wooden components is level 4. 3. A wood decay assessment method according to claim 1, characterized in that the simple nail-shooting wood decay detection instrument includes a housing assembly and a steel nail, and further includes: The ejection mechanism is connected to the housing assembly through the limiting cylinder and is used to provide impact power to the steel nails; An impact assembly, connected to the housing assembly through a linear bearing, for impacting the steel nails; and Limiting component A, connected with the ejection mechanism, is used to limit the ejection mechanism; After the limit component A is released, the ejection mechanism impacts the impact component with constant momentum, causing the impact component to move linearly in the housing. The impact component rushes out of the housing component by pushing the steel nails embedded in it and shoots into the wood. In this way, the length of the steel nails shot into the intact wood and the decayed wood is obtained. At the same time, the length of the steel nails shot into the decayed wood and the intact wood is brought into the decayed wood assessment method to evaluate the degree of wood decay. The purpose of simple and rapid detection and evaluation of the decay degree of wooden components under different tree species, moisture content and biological influencing factors. 4. A wood decay assessment method according to claim 3, characterized in that the shell assembly includes a shell cap and a shell body, and the shell body consists of a cylinder A, a cylinder A and a cylinder that are linearly arranged and fixedly connected in sequence. It consists of cylinder B, cylinder C and cylinder D. The inner diameters of cylinder A, cylinder B and cylinder C decrease in sequence. The inner diameters of cylinder C and cylinder D are equal. The outer diameters of body A, barrel B and barrel C are equal and larger than the outer diameter of barrel D. The barrel D is threadedly connected to a linear bearing threaded on the shell cap. The limiting cylinder Threaded connection with barrel A. 5. A wood decay assessment method according to claim 4, characterized in that the ejection mechanism includes a shell, a rod body, a slider and an elastic member A, the rod body is fixedly connected to the slider, the rod body and The slide blocks are all in sliding fit with the housing, the housing is in sliding fit with the limiting cylinder, the housing is connected to the limiting assembly A, the slide block is connected to the housing through the elastic member A, and it also includes: The limiting component B is connected to the housing and is used to limit the slider. 6. A wood decay assessment method according to claim 5, characterized in that the limiting component A includes a limiting disc and a rotating cap, and the limiting disc is connected to a mounting hole provided at the end of the housing. The screw cap is used in conjunction with the slot. The screw cap is threadedly connected to the shell through the external thread A provided in the installation slot. The shell, the limiting disk and the screw cap are arranged linearly in sequence. The limiting disk and the screw cap are arranged linearly in sequence. The cylinder B is in a sliding fit. The outer diameter of the limiting disc is equal to the inner diameter of the cylinder B, and the outer diameter of the limiting disc is larger than the inner diameter of the limiting cylinder. 7. A wood decay assessment method according to claim 6, characterized in that the impact assembly includes a limiting block A and a cylindrical shaft, the cylindrical shaft is in sliding fit with a linear bearing, and the two limiting blocks A is symmetrically arranged on the cylindrical shaft and is threadedly connected to the cylindrical shaft. The limiting block A is provided with a groove for placing steel nails. The limiting block A, the cylindrical shaft and the central axis of the rod body coincide with each other. 8. A wood decay assessment method according to claim 7, characterized in that the shell cap is provided with an internal thread A from an end away from the through hole to an end close to the through hole, and the barrel D is provided with an internal thread A. Thread B, the shell cap and the shell body are threadedly connected to the linear bearing through internal threads A and B respectively. The wall thickness of the non-threaded area of the shell cap is greater than the wall thickness of the threaded area. The barrel A moves away from One end of the shell cap is provided with a section of internal thread C toward the end close to the shell cap. The cylinder A is threadedly connected to the limiting cylinder through the internal thread C. 9. A wood decay assessment method according to claim 8, characterized in that the limit component B includes a button, a telescopic rod, a support frame, a slide tube, an installation frame and a limit block B, and the button and The shell is slidingly matched, the telescopic rod is hinged to the button and the support frame, the support frame is fixedly connected to the shell, the telescopic rod is hinged to the mounting frame, the mounting frame is fixedly connected to the limit block B, and the installation The mounting bracket is slidably matched with the sliding cylinder fixedly connected to the inner wall of the housing. The mounting bracket is connected to the sliding cylinder through the elastic member B. The limiting block B is used in conjunction with the limiting groove provided on the sliding block. Bit block B is a wedge-shaped block. 10. A wood decay assessment method according to claim 9, characterized in that the specific steps of using the simple nail-shooting wood decay detection instrument are: S1. Record the length of the steel nail, and push the shell to slide along the limiting cylinder to embed the shell into the shell body. At the same time, the rod body presses the impact component, and the impact component gives the rod body a reaction force. This reaction force pushes the rod body to shrink into the shell. In the body, at the same time, the rod pushes the slider to squeeze the elastic member A until the slider is limited by the limiter component B, completing the power accumulation operation of the ejection mechanism; S2. Pass the steel nail through the through hole on the shell cap, insert the tail of the steel nail into the groove of the limit block A, and push the steel nail until the steel nail is completely retracted into the shell assembly. The cylindrical shaft is pushed by the limit block A to move linearly along the linear bearing, and the cylindrical shaft is pushed by another limit block A to push the rod body to move linearly. At this time, the shell extends out of the housing assembly and resets under the push of the rod body; S3. Relevant technicians hold the shell and shell components with both hands and press the shell cap vertically against the measured surface; S4. Release the limit of the slider by the limiter component B. At this time, the elastic member A uses its own elasticity to push the slider to move linearly along the housing. At the same time, the slider pushes the rod body to extend out of the housing and hits the limit block A. The method pushes the cylindrical shaft to slide quickly along the linear bearing to eject the steel nail embedded in the groove; S5. Calculate the depth of the steel nail that penetrates the wood to be tested and the intact wood, and obtain the degree of decay of the wood component to be measured based on the wood decay assessment method.