Writing brush

Abstract

The utility model discloses a writing brush which comprises a brush holder and a wooden brush cap, a convex ring is arranged on the periphery of the front portion of the brush holder, a containing cavity for containing the front portion of the brush holder is formed in the tail end of the wooden brush cap, a concave ring matched with the convex ring in a clamped mode is arranged on the inner side wall of the containing cavity, and at least one expansion joint is formed in the side wall of the wooden brush cap. The expansion joint extends from an inlet of the storage cavity to the front end of the wooden pen cap and penetrates through the wooden pen cap in the thickness direction, and the length of the expansion joint in the axis direction of the wooden pen cap is larger than the distance from the concave ring to the tail end of the wooden pen cap in the axis direction of the wooden pen cap. The wooden pen cap has the advantages that the expansion joint is arranged on the wooden pen cap, so that the problem that the existing wooden pen cap is easy to crack to cause connection failure with a pen holder is solved. When the pen cap is clamped with the pen holder, the pen holder can be inserted and taken out through elastic deformation of the expansion joint, stress is dispersed, pen cap cracking caused by stress concentration is avoided, the service life of the pen cap is prolonged, and the stability of connection between the pen cap and the pen holder is guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model relates to the calligraphy tool field, concretely relates to a writing brush. BACKGROUND

[0002] The traditional writing brush is usually composed of a brush rod and a brush cap, and the brush cap is used for protecting the brush hair from being damaged. For example, the technical scheme of a kind of telescopic writing brush disclosed in Chinese patent publication No. CN207955095U, wherein a wooden protective brush cap is adopted. As a traditional Chinese writing tool, the wooden brush cap meets the natural and simple aesthetic of the traditional Chinese writing tool, and satisfies the emotional recognition of users to traditional materials.

[0003] Generally, the brush cap and the brush rod are connected by clamping, that is, an annular flange is arranged on the outer periphery of the brush rod, and an annular groove is arranged on the inner wall of the brush cap, so as to realize the connection of the brush cap and the brush rod by clamping the annular flange and the annular groove. However, after adopting the wooden brush cap, the wooden material has poor elasticity, and long-term clamping may cause the wooden brush cap to crack, which not only affects the appearance of the brush cap, but also makes the brush cap unable to be clamped with the brush rod, resulting in the failure of the connection between the brush cap and the brush rod. UTILITY MODEL CONTENT

[0004] The utility model aims to provide a writing brush, which can effectively solve the problem of cracking of the existing wooden brush cap and the failure of connection with the brush rod.

[0005] In order to solve the above technical problems, the utility model is realized by the following technical scheme:

[0006] A writing brush includes a brush rod and a wooden brush cap, a convex ring is arranged on the outer periphery of the front part of the brush rod, a receiving cavity for accommodating the front part of the brush rod is formed in the tail end of the wooden brush cap, and a concave ring for clamping the convex ring is arranged on the inner side wall of the receiving cavity,

[0007] At least one expansion joint is formed in the side wall of the wooden brush cap, the expansion joint extends from the entrance of the receiving cavity to the front end of the wooden brush cap, the expansion joint penetrates the thickness direction of the wooden brush cap, and the length of the expansion joint along the axis direction of the wooden brush cap is greater than the distance from the concave ring to the tail end of the wooden brush cap along the axis direction of the wooden brush cap.

[0008] In the above writing brush, the expansion joint is arranged along the axis direction of the wooden brush cap.

[0009] In the above writing brush, the extension path of the expansion joint is linear, wavy or zigzag.

[0010] In the above writing brush, a circular hole for preventing stress concentration is arranged at the end of the expansion joint away from the entrance of the receiving cavity, the circular hole penetrates the side wall of the receiving cavity, and the diameter of the circular hole is greater than the width of the expansion joint.

[0011] In the above-mentioned writing brush, the length of the expansion joint along the axis direction of the wooden brush cap is less than the depth of the receiving cavity.

[0012] In the above-mentioned writing brush, the cross section of the convex ring is semicircular or trapezoidal, and the cross section shape of the concave ring matches that of the convex ring.

[0013] In the above-mentioned writing brush, the outer periphery of the middle section is provided with the convex ring.

[0014] In the above-mentioned writing brush, the middle section is provided with a radially outwardly protruding shoulder, and the diameter of the shoulder is greater than the diameter of the receiving cavity.

[0015] In the above-mentioned writing brush, one end of the middle section is connected to the wooden brush body through threads or interference fit, and the other end of the middle section is provided with a fixing cavity for fixing the brush hair.

[0016] In the above-mentioned writing brush, the inner wall of the receiving cavity is coated with a moisture-proof coating, and the moisture-proof coating covers the inner surfaces of the concave ring and the expansion joint.

[0017] Compared with the prior art, the utility model has the advantages that:

[0018] By means of the expansion joint formed in the wooden brush cap, the problem that the wooden brush cap is prone to cracking and thus fails to be connected to the brush rod is solved. When the brush cap is connected to the brush rod, the elastic deformation of the expansion joint can adapt to the insertion and removal of the brush rod, stress is dispersed, and the brush cap is prevented from cracking due to stress concentration, the service life of the brush cap is prolonged, and the stability of the connection between the brush cap and the brush rod is ensured. The expansion joint solves the problem of cracking of the brush cap, ensures that the brush cap can continuously and effectively protect the brush hair, and prevents the brush hair from being damaged during storage. While meeting the functional requirements, the wooden brush cap meets the emotional recognition of users for traditional materials and satisfies the aesthetic feeling of natural and simple traditional craftsmanship. The design of the expansion joint does not damage the overall appearance and traditional craftsmanship characteristics of the writing brush. Under different environmental humidity, the wooden brush cap will expand or contract due to the change in humidity. The presence of the expansion joint enables the brush cap to better adapt to such changes, and the brush cap can maintain good use performance in both dry northern regions and humid southern regions, and is not prone to cracking or loose connection with the brush rod due to environmental factors.

[0019] Further, the expansion joint is arranged along the axis direction of the wooden brush cap. The expansion joint arranged along the axis direction of the wooden brush cap can more evenly disperse stress when the brush cap is connected to the brush rod. When the brush rod is inserted into or removed from the brush cap, stress is evenly distributed along the expansion joint parallel to the axis, thereby avoiding local stress concentration. Compared with the expansion joint arranged in other directions, this mode can better protect the structure of the brush cap, further reduce the risk of cracking of the brush cap, and ensure the stability of the connection between the brush cap and the brush rod.

[0020] Further, the extension path of the expansion joint is linear, wavy or zigzag. Different shapes give the cap different expansion characteristics. Compared with linear expansion joints, wavy and zigzag expansion joints increase the length and deformation space of the expansion joint. When the cap is connected with the pen shaft, the special-shaped expansion joint can better adapt to the insertion and extraction of the pen shaft, provide more flexible expansion performance, effectively relieve the stress on the cap, and further reduce the possibility of cap cracking.

[0021] Further, the end of the expansion joint away from the entrance of the receiving cavity is provided with a circular hole for preventing stress concentration, the circular hole penetrates the side wall of the receiving cavity, and the diameter of the circular hole is greater than the width of the expansion joint. When the pen shaft is inserted or extracted from the wooden cap, the expansion joint will be subjected to a certain stress, and the circular hole at the end can effectively disperse these stresses, avoiding excessive concentration of stress at the end of the expansion joint. Because stress concentration is one of the important reasons for the cracking of wooden caps, this design can greatly reduce the risk of cap cracking, prolong the service life of the cap, and ensure that the connection between the cap and the pen shaft remains stable.

[0022] Further, the length of the expansion joint along the axis of the wooden cap is less than the depth of the receiving cavity. The length of the expansion joint along the axis of the wooden cap is less than the depth of the receiving cavity, which can ensure that the cap still has sufficient structural strength even if the expansion joint is opened. If the expansion joint is too long, it may weaken the structure of the cap, causing the cap to deform or be damaged during use. By properly controlling the length of the expansion joint, the cap can provide the necessary elasticity while maintaining its strength, able to withstand external forces during normal use and protect the brush hair from damage.

[0023] Further, the cross section of the protruding ring is semicircular or trapezoidal, and the cross section shape of the concave ring matches the protruding ring. This design enables the protruding ring and the concave ring to be more tightly and stably connected. The semicircular or trapezoidal cross-sectional shape increases the contact area and friction between the protruding ring and the concave ring, making the connection between them more secure and less likely to come loose or fall off, effectively ensuring the stability of the connection between the cap and the pen shaft during use and storage of the brush.

[0024] Further, the outer periphery of the middle section is provided with the protruding ring. This structural design makes the functions of each part of the brush more specific and independent. The middle section, as a key component connecting the brush hair and the pen shaft body, has the protruding ring arranged therein, which can better realize the connection function of the cap and the pen shaft, while not affecting the overall structural integrity of the wooden pen shaft body, making the overall structure of the brush more reasonable and stable.

[0025] Further, the middle section is provided with a radially outwardly protruding shoulder, the diameter of the shoulder > the diameter of the receiving cavity. This design can effectively limit the insertion depth of the cap on the pen barrel, avoid the cap from being inserted too much to squeeze the brush hair, protect the shape and integrity of the brush hair, and ensure that the brush hair can maintain good writing performance during use.

[0026] Further, one end of the middle section is connected with the wooden pen barrel body through thread or interference fit, and the other end of the middle section is provided with a fixing cavity for fixing the brush hair. The one end of the middle section is connected with the wooden pen barrel body through thread or interference fit, and both the two connection modes have good stability and detachability. When the thread connection is adopted, the installation and disassembly of the middle section and the pen barrel body can be easily realized through rotation, so that the assembly during production and the maintenance and replacement when the middle section or the pen barrel body is damaged can be facilitated. The interference fit can tightly connect the two, without the need of an additional fixing device, so that the simplicity of the brush structure is ensured, and the separation can also be realized through appropriate tools and methods when disassembly is needed. The other end of the middle section is provided with the fixing cavity for fixing the brush hair, and this design provides a stable fixing environment for the brush hair. The fixing cavity can tightly bind the brush hair therein, prevent the brush hair from being loose or falling off during use, ensure that the brush hair can normally play a writing function, and prolong the service life of the brush.

[0027] Further, the inner wall of the receiving cavity is coated with a moisture-proof coating, and the moisture-proof coating covers the inner surfaces of the concave ring and the expansion joint. The inner wall of the receiving cavity is coated with the moisture-proof coating, and the inner surfaces of the concave ring and the expansion joint are covered, so that the external moisture can be effectively prevented from entering the cap. A humid environment can easily cause the wooden pen barrel and the cap to be damp and deformed, mildewed and rotted, and affect the service life and appearance of the brush. The moisture-proof coating can form a barrier to reduce the erosion of the pen barrel and the cap by the moisture, and protect the material performance of the pen barrel and the cap. BRIEF DESCRIPTION OF DRAWINGS

[0028] Fig. 1 It is a structure schematic view of the brush pen of the utility model;

[0029] Fig. 2 It is a structure schematic view of the wooden cap in the utility model;

[0030] Fig. 3 It is a structure schematic view of the middle section in the utility model.

[0031] The reference signs are:

[0032] The pen barrel 10, the convex ring 11, the wooden pen barrel body 12, the middle section 13, the shoulder 131, the fixing cavity 132, the brush hair 14, the wooden cap 20, the receiving cavity 21, the concave ring 22, the expansion joint 23, and the round hole 24. DETAILED DESCRIPTION

[0033] A brush pen comprises a pen barrel 10 and a wooden pen cap 20, the outer periphery of the front part of the pen barrel 10 is provided with a protruding ring 11, the tail end of the wooden pen cap 20 is provided with a receiving cavity 21 for accommodating the front part of the pen barrel 10, the inner side wall of the receiving cavity 21 is provided with a recessed ring 22 matched with the protruding ring 11,

[0034] At least one expansion joint 23 is formed in the side wall of the wooden pen cap 20, the expansion joint 23 extends from the entrance of the receiving cavity 21 to the front end of the wooden pen cap 20, the expansion joint 23 penetrates the thickness direction of the wooden pen cap 20, and the length of the expansion joint 23 along the axis direction of the wooden pen cap 20 is greater than the distance from the recessed ring 22 to the tail end of the wooden pen cap 20 along the axis direction of the wooden pen cap 20.

[0035] By forming the expansion joint 23 on the wooden pen cap 20, the problem that the wooden pen cap 20 is prone to cracking and causes the connection with the pen barrel 10 to fail is solved. When the pen cap is matched with the pen barrel 10, the elastic deformation of the expansion joint 23 can adapt to the insertion and removal of the pen barrel 10, stress is dispersed, the pen cap is prevented from cracking due to stress concentration, the service life of the pen cap is prolonged, and the stability of the connection between the pen cap and the pen barrel 10 is ensured. The expansion joint 23 solves the problem of pen cap cracking, ensures that the pen cap can continuously and effectively protect the brush hair 14, avoids damage to the brush hair 14 during storage, meets the functional requirements, and the wooden pen cap 20 meets the natural and simple aesthetic of the brush pen, and meets the emotional recognition of users on the traditional material. The design of the expansion joint 23 does not damage the overall appearance and traditional process characteristics of the brush pen on the basis of solving the problem. Under different environmental humidity, the wooden pen cap 20 will expand and contract due to the change in humidity. The existence of the expansion joint 23 enables the pen cap to better adapt to such changes, and whether in dry northern regions or humid southern regions, the pen cap can maintain good use performance and is not prone to cracking or loose connection with the pen barrel 10 due to environmental factors.

[0036] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the drawings. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0037] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0038] In addition, the terms "first", "second", "third", etc. are used only for descriptive purposes and should not be construed as implying or suggesting relative importance or an indicated number of technical features. Thus, features defined with "first", "second", etc. can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0039] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or communicate with each other; it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0040] Referring to Figs. 1 to 3 For an embodiment of the present application, a brush includes a brush shaft 10 and a wooden brush cap 20. The brush shaft 10 can be made of wood or rustic material. The front part of the brush shaft 10 is provided with a brush hair 14. The tail end of the wooden brush cap 20 is provided with a receiving cavity 21 for accommodating the front end of the brush hair 14. When the brush is not in use, the front end of the brush is inserted into the wooden brush cap 20, and the brush hair 14 is protected by the wooden brush cap 20.

[0041] In order to stably connect the wooden brush cap 20 and the brush shaft 10, and at the same time, to facilitate the user to pull out the brush cap, a protruding ring 11 is arranged on the outer periphery of the front part of the brush shaft 10. The protruding ring 11 slightly protrudes from the surface of the brush shaft 10 in the radial direction. At the same time, a recessed ring 22 is arranged on the inner wall of the receiving cavity 21 of the wooden brush cap 20. The protruding ring 11 and the recessed ring 22 are connected by clamping, so as to stably connect the wooden brush cap 20 and the brush shaft 10. However, the above structure requires that the wooden brush cap 20 produces a small amount of deformation when it is inserted into the brush shaft 10 or pulled out. Due to the characteristics of wood material, after a period of use, the wooden brush cap 20 will crack.

[0042] Therefore, the embodiment is provided with at least one expansion joint 23 on the side wall of the wooden cap 20, the expansion joint 23 extends from the entrance of the receiving cavity 21 to the front end of the wooden cap 20, the expansion joint 23 is required to be not perpendicular to the axis direction of the wooden cap 20, the expansion joint 23 penetrates the thickness direction of the wooden cap 20, that is, the receiving cavity 21 can be communicated with the outside through the expansion joint 23, which ensures that the wooden cap 20 can be elastically deformed during the process that the convex ring 11 enters the receiving cavity 21 to be clamped with the concave ring 22, disperses the local stress, avoids the cracking problem of the traditional wooden cap 20 caused by hard extrusion, and the length of the expansion joint 23 along the axis direction of the wooden cap 20 is greater than the distance from the concave ring 22 to the tail end of the wooden cap 20 along the axis direction of the wooden cap 20, which ensures that the expansion joint 23 covers the area of the concave ring 22, provides sufficient deformation space, makes the wooden cap 20 adapt to multiple clamping operations, and improves the connection reliability. In view of the defect that the elasticity of the wooden material is insufficient, the expansion joint 23 design makes up for the short board of the mechanical properties of wood, and in combination with the concave-convex matching structure, the traditional wooden process is retained while the practicability is enhanced.

[0043] Further, the expansion joint 23 is arranged along the axis direction parallel to the wooden cap 20, the expansion joint 23 parallel to the axis makes the cap produce axial symmetric deformation during clamping, uniformly disperses the stress during the cooperation of the convex ring 11 and the concave ring 22, avoids the risk of cracking of the wooden cap 20 caused by local stress concentration, improves the structural durability, and the linear expansion joint 23 can be efficiently processed through laser cutting or precision milling process, reduces the processing difficulty and cost, and at the same time ensures the accuracy (such as width, depth consistency) of the expansion joint 23, avoids the process defects caused by complex shape.

[0044] Further, the extension path of the expansion joint 23 is linear, wavy or zigzag; linear: retains axial symmetry, provides uniform elastic deformation path, ensures that the cap can still restore to its original state after multiple clamping, prolongs the service life; wavy or zigzag: disperses stress concentration points through non-linear path design, reduces the risk of crack propagation of the wooden cap 20 caused by excessive local stress, and is especially suitable for brittle materials such as wood.

[0045] On the basis of the above embodiment, the end of the expansion joint 23 away from the entrance of the receiving cavity 21 is provided with a circular hole 24 for preventing stress concentration, the circular hole 24 penetrates the side wall of the receiving cavity 21, and the diameter of the circular hole 24 is greater than the width of the expansion joint 23. By providing the circular hole 24 at the end of the expansion joint 23, the stress concentration at the tip of the expansion joint 23 is dispersed, the cracking problem of the wooden cap 20 caused by excessive local stress is avoided, and it is especially suitable for brittle materials such as wood. The diameter of the circular hole 24 is greater than the width of the expansion joint 23, a smooth transition area is formed, the risk of crack propagation is reduced, and the service life of the cap is prolonged. The circular hole 24 can be processed by conventional processes such as drilling or laser cutting, without the need for complex equipment, and is compatible with the traditional processing flow of the wooden cap 20, reducing production cost and ensuring accuracy.

[0046] In the embodiment, the length of the expansion joint 23 along the axis direction of the wooden cap 20 is less than the depth of the receiving cavity 21, that is, the expansion joint 23 does not open to the bottom of the receiving cavity 21. By limiting the length of the expansion joint 23 to be less than the depth of the receiving cavity 21, it is ensured that the expansion joint 23 only acts on the clamping area of the cap (near the concave ring 22), avoiding the decrease of the overall structural strength of the cap due to the excessive length of the expansion joint 23, while retaining sufficient elastic deformation ability to prevent cracking, thereby maintaining the durability of the wooden cap 20 and ensuring effective stress release when the concave ring 22 is clamped with the convex ring 11.

[0047] In the embodiment, the cross section of the convex ring 11 is semicircular, and the cross section shape of the concave ring 22 matches that of the convex ring 11. In addition to making the cross section of the convex ring 11 semicircular, the circular arc design makes the stress uniformly dispersed when the convex ring 11 contacts with the concave ring 22, avoiding the risk of cracking of the wooden cap 20 due to local stress concentration. The cross section of the convex ring 11 can also be made into a trapezoidal shape, and the inclined surface of the trapezoidal shape provides a progressive clamping to enhance the connection stability and prevent accidental falling due to external impact. The shape matching of the concave ring 22 and the convex ring 11 (such as the trapezoidal groove corresponding to the trapezoidal convex ring 11) ensures close fitting when clamped, reduces the gap or friction loss caused by shape deviation, and prolongs the service life of the wooden cap 20. The semicircular or trapezoidal cross section can be realized by numerical control carving or laser cutting process, which has high processing precision and controllable cost, and is especially suitable for precise machining requirements of non-elastic materials such as wood.

[0048] On the basis of the above embodiment, the pen barrel 10 includes a wooden pen barrel body 12 and a middle section 13 arranged at the front end of the wooden pen barrel body 12 for connecting the pen hair 14. The outer periphery of the middle section 13 is provided with the convex ring 11. The convex ring 11 is concentrated on the middle section 13 rather than the pen barrel 10 body, so that the stress area is localized, avoiding the overall structure fatigue or cracking of the wooden pen barrel body 12 due to repeated clamping. The middle section 13 can be made of metal or high-strength composite material to enhance the wear resistance of the convex ring 11 and prolong the service life of the connection structure. The middle section 13 can be designed as a separate component from the pen barrel 10 body, which is convenient for replacement or maintenance. If the middle section 13 is worn out after long-term use, only the middle section 13 needs to be replaced without replacing the entire pen barrel 10, which reduces the maintenance cost and improves the product economy. The middle section 13 and the pen barrel 10 body can be made of different materials (such as metal middle section 13 + wooden pen barrel 10), which takes into account the functional and traditional process requirements. The metal middle section 13 provides a high-strength and precise convex ring 11 structure, and the wooden pen barrel 10 retains the cultural attributes, solving the inherent defects of insufficient elasticity of wood.

[0049] Further, the middle section 13 is provided with a radially outwardly protruding shoulder 131, the diameter of the shoulder 131 is greater than the diameter of the receiving cavity 21. The shoulder 131 serves as a limiting structure. When the pen cap is inserted into the front end of the pen barrel 10, the diameter of the shoulder 131 is limited by the diameter of the receiving cavity 21, which ensures that the protruding ring 11 is accurately connected with the recessed ring 22, avoids misalignment or hard extrusion caused by excessive insertion, and reduces the risk of cracking of the wooden pen cap 20. When the shoulder 131 contacts the entrance end surface of the pen cap, the insertion pressure is converted into an evenly distributed reaction force in the axial direction, rather than being concentrated in the area of the recessed ring 22, reducing the deformation or cracking of the wooden pen cap 20 caused by local stress and prolonging the service life. The shoulder 131 provides a clear insertion termination point, preventing the user from damaging the pen cap or pen barrel 10 due to excessive force, improving safety in use, and is particularly suitable for structural adaptation of non-elastic materials such as wood.

[0050] For the connection of the middle section 13 and the wooden pen barrel body 12, one end of the middle section 13 can be connected with the wooden pen barrel body 12 through threads or interference fit. In this embodiment, interference fit is used, and a docking hole is opened at the front end of the wooden pen barrel body 12, and one end of the middle section 13 is inserted into the docking hole to realize interference fit. The middle section 13 is an independent component, which is detachably connected with the wooden pen barrel body 12 through threads or interference fit. If the middle section 13 is worn or damaged due to long-term use, only the middle section 13 needs to be replaced without replacing the entire pen barrel 10, reducing maintenance costs, reducing resource waste, and improving product economy. Thread connection provides precise mechanical locking, preventing the middle section 13 and the pen barrel 10 body from loosening during writing, ensuring the stability of the pen hair 14; interference fit realizes gapless connection through physical compression, avoiding disconnection caused by vibration or external force impact, prolonging the service life, and is particularly suitable for rigid structural adaptation of wooden materials. The middle section 13 can be made of high-strength metal or composite material, while the pen barrel 10 body remains wooden, balancing functionality and traditional process requirements. The metal middle section 13 provides wear resistance and anti-deformation ability, and the wooden pen barrel 10 maintains cultural attributes, solving the inherent defect of insufficient elasticity of wood. The other end of the middle section 13 is provided with a fixing cavity 132 for fixing the pen hair 14, and the pen hair 14 can be fixed in the fixing cavity 132.

[0051] Since the brush may have water vapor remaining in the brush hair 14 after use, the water vapor will affect the service life of the wooden cap 20. Therefore, the inner wall of the storage cavity 21 is coated with a moisture-proof coating, which covers the inner surface of the concave ring 22 and the expansion joint 23. The wooden cap 20 is prone to swelling or mildewing due to moisture, which causes the concave ring 22 to fail to cooperate with the convex ring 11. The moisture-proof coating (polyurethane / epoxy resin) blocks the penetration of moisture, prevents the wood from deforming or cracking after absorbing moisture, and maintains the dimensional stability and connection reliability of the cap. The coating covers the inner surface of the concave ring 22 and the expansion joint 23, focusing on the stress concentration area during clamping and the opening of the expansion joint 23 (moisture-prone area), thereby prolonging the service life of the wooden cap 20 and preventing overall failure caused by local corrosion.

[0052] The technical scheme of the utility model solves the problem of cracking of the wooden cap 20 and has comprehensive advantages in structure optimization, function expansion, service life extension, and user experience improvement, making it more competitive in the market. The core design is to open the expansion joint 23 on the side wall of the wooden cap 20, effectively solving the problem of cracking of the traditional wooden cap 20 due to poor expansion and long-term clamping. The expansion joint 23 extends from the entrance of the storage cavity 21 to the front end of the cap and penetrates the thickness direction, with a length greater than the distance from the concave ring 22 to the tail end of the cap, which can disperse stress when the cap is clamped with the pen barrel 10, prevent the cap from cracking, ensure stable connection of the cap with the pen barrel 10, and prolong the service life of the cap. The structure of the cap and the pen barrel 10 is optimized in multiple aspects. The expansion joint 23 is parallel to the cap axis, facilitating processing and manufacturing, and can also make stress dispersion more uniform; various extension paths (straight line, wave shape, or sawtooth shape) of the expansion joint 23 enhance expansion performance and optimize appearance design; the round hole 24 at the end of the expansion joint 23 prevents stress concentration, further reducing the risk of cap cracking; the convex ring 11 and the concave ring 22 adopt a semicircular or trapezoidal cross-section for tight clamping to improve connection stability. The pen barrel 10 adopts a combined structure of a wooden pen barrel body 12 and a middle section 13, which is connected through threads or interference fit with the pen barrel 10 body, facilitating production and assembly and later maintenance and replacement; the middle section 13 is provided with a shoulder 131 to prevent the cap from being inserted and squeezed too much, and also protects the brush hair 14 from external damage; the fixed cavity 132 of the middle section 13 effectively fixes the brush hair 14, ensuring writing performance. The inner wall of the storage cavity 21 is coated with a moisture-proof coating, which covers the inner surface of the concave ring 22 and the expansion joint 23, can block moisture, protect the pen barrel 10 and the cap from deformation and mildewing due to moisture, and prolong the overall service life of the brush; various designs meet the aesthetic and use needs of different users, improving user experience.

[0053] The above description is only a specific embodiment of the utility model, but the technical features of the utility model are not limited to this. Any changes or modifications made by those skilled in the art within the scope of the utility model are covered by the patent range of the utility model.

Claims

1. A calligraphy brush, comprising a brush handle and a wooden cap, wherein a raised ring is provided on the outer periphery of the front part of the brush handle, and the tail end of the wooden cap has a receiving cavity for accommodating the front part of the brush handle, and the inner sidewall of the receiving cavity has a recessed ring that engages with the raised ring, characterized in that, The wooden pen cap has at least one expansion joint on its side wall. The expansion joint extends from the entrance of the storage cavity to the front end of the wooden pen cap. The expansion joint runs through the thickness direction of the wooden pen cap. The length of the expansion joint along the axis of the wooden pen cap is greater than the distance from the concave ring along the axis of the wooden pen cap to the tail end of the wooden pen cap.

2. A writing brush as described in claim 1, characterized in that, The expansion joint is provided in a direction parallel to the axis of the wooden pen cap.

3. A writing brush as described in claim 2, characterized in that, The expansion joint can extend in a straight line, a wavy line, or a sawtooth shape.

4. A writing brush as described in claim 1, characterized in that, The expansion joint has a circular hole at the end away from the entrance of the storage cavity to prevent stress concentration. The circular hole penetrates the side wall of the storage cavity, and the diameter of the circular hole is greater than the width of the expansion joint.

5. A writing brush as described in claim 1, characterized in that, The length of the expansion joint along the axis of the wooden pen cap is less than the depth of the storage cavity.

6. A writing brush as described in claim 1, characterized in that, The cross-section of the convex ring is semi-circular or trapezoidal, and the cross-sectional shape of the concave ring matches that of the convex ring.

7. A writing brush as described in claim 1, characterized in that, The pen barrel includes a wooden pen barrel body and a middle section located at the front end of the wooden pen barrel body for connecting the pen bristles, and the middle section is provided with the convex ring on its outer periphery.

8. A writing brush as described in claim 7, characterized in that, The middle section is provided with a shoulder that protrudes outward in a radial direction, and the diameter of the shoulder is greater than the diameter of the receiving cavity.

9. A writing brush as described in claim 7, characterized in that, One end of the middle section is connected to the wooden pen body by a thread or interference fit, and the other end of the middle section is provided with a fixing cavity for fixing the brush bristles.

10. A writing brush as described in claim 1, characterized in that, The inner wall of the storage cavity is coated with a moisture-proof coating, which covers the inner surface of the concave ring and the expansion joint.

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