A bar grate device for a jaw crusher and a jaw crusher

Abstract

The application discloses a strip sieve device for a jaw crusher and the jaw crusher and relates to the field of mine machinery. The strip sieve device for the jaw crusher comprises an upper base, a lower base and a strip sieve. The upper base is used for being fixedly installed below a plate feeder. The lower base is used for being fixedly connected with the jaw crusher. The strip sieve is obliquely arranged between the upper base and the lower base. The strip sieve comprises a bearing framework, a supporting web, a front supporting plate, a rear supporting plate and a limiting block. The bottom of the rear supporting plate is provided with the limiting block. The lower base is provided with a limiting hole. The rear supporting plate is fixed to the lower base only through the limiting block and the limiting hole. The application systematically solves the coupling technical problems of the existing strip sieve device, such as easy connection, insufficient rigidity, frequent ore clamping and difficult maintenance.

Description

Technical Field

[0001] This invention relates to the field of mining machinery, and more particularly to a bar screen device for a jaw crusher and a jaw crusher. Background Technology

[0002] In a crushing system, a bar screen is usually installed above the jaw crusher. The bar screen pre-screens the ore before crushing, and small particles are directly screened out, which can improve the efficiency of subsequent jaw crushing operations.

[0003] However, existing bar screen devices have many defects in structural design and connection methods, making it difficult to meet the demands of high-load, high-impact crushing conditions. Firstly, the supporting webs of bar screens mostly adopt rectangular cross-section structures, which have weak load-bearing and deformation capacity. Under repeated impacts from ore, they are prone to bending deformation or even breakage, resulting in insufficient overall rigidity of the screen. Secondly, the rear support plate and lower base of existing bar screens are generally fixed by bolts or welding. While welded structures offer high connection strength, they are extremely inconvenient to assemble and disassemble. Once wear or deformation occurs, on-site maintenance and replacement are extremely difficult. Bolted connections, under long-term high-frequency vibration, are prone to loosening of the threaded joints. Furthermore, due to the limited space in the working area of ​​the bar screen, manual inspection and bolt tightening are not only labor-intensive and inefficient, but also pose a safety risk to personnel entering the crusher inlet. More importantly, once the bolt connection loosens, it will directly cause the spacing between adjacent bar screens to shift, resulting in uncontrolled particle size distribution and affecting the stability of subsequent crushing operations.

[0004] In addition, existing bar screens suffer from serious problems such as ore jamming and short wear-resistant block lifespan. Ore easily gets stuck between the bars, causing screen blockage and requiring regular shutdowns for cleaning, which seriously affects production continuity; wear-resistant blocks wear out quickly and need to be replaced frequently, further increasing equipment maintenance costs.

[0005] In summary, existing jaw crusher bar screen devices generally face systemic technical challenges such as "easy loosening of connections, insufficient rigidity, frequent ore jamming, and difficult maintenance." These defects are interconnected and mutually reinforcing, and have long remained unresolved. Particularly regarding connection and fixing methods, those skilled in the art are constrained by traditional design inertia, generally believing that bolt tightening or welding is necessary to ensure connection reliability under high impact and strong vibration conditions. Therefore, there is a lack of technical inspiration to break through existing fixing methods.

[0006] Specifically, in the field of jaw crusher grating screens, a stable technical consensus has long existed: because grating screens directly bear the high-intensity impact of falling ore, and jaw crushers generate continuous low-frequency heavy-load vibrations during operation, the rear support plate and lower base must be connected by bolts to ensure sufficient preload, or by welding to ensure the permanentity of the connection. This technical bias has led those skilled in the art to always seek solutions within the framework of "how to enhance bolt loosening prevention" (such as increasing bolt specifications, adding anti-loosening washers, shortening inspection cycles, etc.), without ever considering the possibility of completely abandoning bolts and using a wedge-fitting method to achieve "vibration-based vibration control." Summary of the Invention

[0007] This invention discloses a bar screen device for a jaw crusher and a jaw crusher. The device utilizes a wedge-shaped inclined surface to form a self-locking structure between a limiting block and a limiting hole. When the crusher vibrates during operation, the vibration energy is transmitted to the trapezoidal inclined surface of the limiting block via the rear support plate. The wedge effect of the inclined surface transforms the vibration impact into a positive pressure that further wedges the limiting block into the limiting hole, making the connection increasingly tighter under dynamic load. This fundamentally eliminates the problem of gap widening and positional movement caused by the attenuation of preload in bolted connections. Simultaneously, the wedge-shaped structure of the limiting block eliminates the need for bolt fasteners, avoiding the disadvantages of difficult disassembly and inconvenient maintenance associated with welding methods. Building upon this foundation, the T-shaped cross-section of the grating and the convex arc-shaped wear-resistant blocks work synergistically to allow fine-grained ore to slide smoothly along the convex arc surface without easily getting stuck. Even if ore does occasionally get stuck, it can be easily removed from above. The supporting web of the triangular rib plate disperses the impact load and shear force to the upper and lower bases through its hypotenuse, effectively avoiding the root stress concentration and early fracture problems common in rectangular cross-section rib plates, and significantly improving the overall support stiffness and deformation resistance of the grating screen. The above four technical features work together—the wedge-shaped limiting block solves the connection reliability problem, the triangular rib plate solves the load-bearing stiffness problem, and the T-shaped cross-section and the convex arc-shaped wear-resistant blocks jointly solve the problems of ore getting stuck and wear—forming an organic whole that systematically solves the coupled technical problems of existing grating screen devices, such as "easy loosening of connections, insufficient stiffness, frequent ore getting stuck, and difficult maintenance."

[0008] To achieve the above objectives, the present invention adopts the following technical solution: According to a first aspect of the present invention, a bar screen device for a jaw crusher is provided, comprising an upper base, a lower base, and a bar screen, wherein the upper base is for fixed installation below a plate feeder, the lower base is for fixed connection with a jaw crusher, and the bar screen is inclinedly arranged between the upper base and the lower base, wherein: The bar screen includes a support frame, a support web, a front support plate, a rear support plate, and a limiting block; The bottom of the rear support plate is provided with the limiting block, and the lower base is provided with a limiting hole. The rear support plate is fixed to the lower base only by the engagement of the limiting block and the limiting hole.

[0009] Furthermore, the limiting block has a trapezoidal inclined surface, and the limiting hole has a mating inclined surface with the same slope as the trapezoidal inclined surface, and the limiting block and the limiting hole are engaged through the trapezoidal inclined surface; The taper ratio between the trapezoidal inclined surface and the mating inclined surface is 1:5 to 1:10; the trapezoidal inclined surface is used to convert vibration energy into positive pressure that causes the limiting block to wedge into the limiting hole when the bar screen device is subjected to vibration.

[0010] Furthermore, there is no bolt connection between the rear support plate and the lower base, which avoids the attenuation of the preload of the threaded pair under vibration environment.

[0011] Furthermore, the taper between the trapezoidal inclined surface of the limiting block and the mating inclined surface of the limiting hole is set such that when the strip screen device is vibrated, the limiting block has a self-locking tendency to wedge into the limiting hole; the self-locking tendency is achieved by converting vibration energy into wedge force through the wedge effect of the trapezoidal inclined surface.

[0012] Furthermore, the supporting web is a triangular stiffener structure, the angle between the right-angled side and the hypotenuse of the triangular stiffener is 30° to 60°, and the vertex of the triangle faces the lower base downwards; the triangular stiffener disperses and transmits the impact load and shear force to the upper base and the lower base through the hypotenuse.

[0013] Furthermore, a wear-resistant block is provided above the supporting frame. The upper surface of the wear-resistant block is a convex arc surface with a radius of curvature of 340mm to 360mm and a thickness of 80mm to 100mm. The convex arc surface is used to guide the ore to make tangential contact along the arc surface to reduce impact wear and ore jamming.

[0014] Furthermore, the wear-resistant block is inverted onto the support frame via a groove and is fixedly connected to the support frame by bolts; the wear-resistant block can be replaced independently through the inverted groove.

[0015] Furthermore, the cross-section of the grid of the grating screen is T-shaped, which is used to guide fine ore particles to slide down along both sides of the grid through the narrow slit structure.

[0016] Furthermore, both the upper base and the lower base have a U-shaped structure, and I-beams are welded to the inner sides of the upper base and the lower base as reinforcing ribs to enhance the structural strength of the base.

[0017] According to a second aspect of the present invention, a jaw crusher is provided, comprising a crusher body and a bar screen device for a jaw crusher as described in any of the above aspects, the bar screen device being disposed above the feed inlet of the crusher body.

[0018] The present invention has the following effects: 1. Limiting block wedge structure – significantly improving connection reliability The limiting block engages with the limiting hole via a trapezoidal inclined surface, and the rear support plate is fixed to the lower base solely by this wedge, eliminating the need for bolt connections. By completely eliminating bolt fasteners, the problems of bolt preload decay and loosening caused by thread wear under long-term high-frequency vibration are fundamentally eliminated. Simultaneously, the drawbacks of difficult assembly / disassembly and inconvenient maintenance associated with welded connections are avoided. Furthermore, the wedge effect of the trapezoidal inclined surface utilizes the unavoidable vibration energy during equipment operation, converting vibration impact into positive pressure that further wedges the limiting block into the limiting hole. This makes the connection increasingly tighter under dynamic loads, achieving passive self-locking of the connection structure without the need for any additional anti-loosening components or periodic manual tightening. Test data shows that in Example 1, which uses the limiting block wedge structure, the bolt loosening cycle exceeds 720 hours, while in Comparative Example 1, which uses bolt connections, it is only 120 hours, extending the cycle by more than six times.

[0019] 2. Triangular stiffeners supporting the web – significantly enhancing load-bearing stiffness and impact resistance. The supporting web adopts a triangular stiffener structure, with the vertices of the triangles facing downwards. When subjected to ore impact, the triangular stiffeners distribute the vertical impact load F and horizontal shear force FQ to the upper and lower bases through their hypotenuses, avoiding weld cracking or premature fracture caused by stress concentration at the right angle root in traditional rectangular stiffeners. Mechanical analysis shows that the bending stiffness of the triangular stiffeners is significantly better than that of rectangular stiffeners of the same cross-sectional size, effectively resisting bending deformation caused by bending moment M. Long-term use of the lower grating screen is less prone to plastic deformation, ensuring the dimensional stability of the screening gap.

[0020] 3. T-shaped cross-section grid – Optimization of anti-jamming performance The grid has a T-shaped cross-section, which has a higher flexural section modulus than traditional rectangular or trapezoidal cross-sections, enhancing the flexural stiffness of the grid itself and resulting in less deformation under the same load. Simultaneously, the narrow slot structure of the T-shaped cross-section, combined with its inclined arrangement, allows fine-grained ore to slide smoothly along both sides of the grid under gravity, preventing it from getting stuck in the gaps. Even if some ore does get stuck, it can be easily removed from above.

[0021] 4. Convex arc-shaped wear-resistant blocks – dual improvement in wear resistance and flowability. The wear-resistant block has a convex arc surface on its upper surface, with a radius of curvature of 340mm to 360mm and a thickness of 80mm to 100mm. This convex arc design ensures that the ore makes tangential contact with the wear-resistant block during descent, rather than a head-on impact, reducing impact wear and cutting effects and effectively slowing down the wear rate. Simultaneously, the convex arc surface guides the ore's descent, allowing it to roll smoothly along the arc surface and preventing large ore particles from rebounding and getting stuck in the gaps between the bars. Wear tests have verified that a 90mm thick wear-resistant block can remain effective for a long time under high-impact conditions, avoiding the insufficient service life caused by insufficient thickness (<60mm) and the obstruction of ore flow and increased costs caused by excessive thickness (>120mm).

[0022] Furthermore, the four technical features mentioned above are not functionally superimposed, but rather form an interlocking synergistic relationship through structural coupling. The wedge-shaped locking block ensures the spatial positioning accuracy of the grid screen, making the force path of the triangular stiffener clear and controllable; the stable support of the triangular stiffener provides a stable force environment for the locking block, preventing excessive deformation from affecting the wedge self-locking. Together, they constitute the structural foundation of "reliable connection + high-efficiency load bearing". On this basis, the T-shaped cross-section grid bears the upper impact load and transmits it to the triangular stiffener, forming a dual bending resistance system of "upper load bearing + lower support"; at the same time, the narrow slot structure of the T-shaped cross-section and the arc-shaped guide of the convex arc wear-resistant block form a "guiding + dredging" combination in the anti-jamming function - the convex arc surface allows the ore to slide tangentially, and the T-shaped inclined surface facilitates the smooth discharge of fine ore particles. Together, they reduce the jamming frequency to 0-0.2 times / shift. The improved anti-jamming performance, in turn, reduces abnormal impact loads, preventing random overload damage to the limit block and triangular stiffener, forming a positive cycle of "anti-jamming → load reduction → stable connection → fatigue resistance," achieving a qualitative change in overall reliability that cannot be achieved by a single feature.

[0023] In summary, the four features—the wedge-shaped limiting block, the triangular stiffener, the T-shaped cross-section, and the convex arc wear-resistant block—form an organic whole through the aforementioned functional coupling. The wedge-shaped limiting block solves the connection reliability, the triangular stiffener ensures the load-bearing rigidity, and the T-shaped cross-section and the convex arc wear-resistant block jointly optimize the anti-jamming and wear-resistant performance. The four features are interdependent and mutually conditional, and none can be omitted, thus achieving the comprehensive goal of "maintenance-free, anti-jamming, and long service life".

[0024] It should be noted that the improvement in the aforementioned technical effect exceeds the reasonable expectations of those skilled in the art. According to conventional understanding, changing the rear support plate from a bolted connection to a wedge connection would generally lead those skilled in the art to expect that the connection reliability would be at most comparable to or even less than that of a bolted connection; however, experimental results show that the bolt loosening cycle (>720h) of the wedge-fitting structure of the limiting block is not only superior to that of a bolted connection (120h), but also more than six times longer. This significant improvement, exceeding expectations, fully demonstrates the non-obviousness of the technical solution of this invention. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the installation position of the present invention; Figure 2 This is a schematic diagram of the overall structure of the bar screen in Example 1; Figure 3 This is a force analysis diagram of the bar screen in Example 1; Figure 4 This is a schematic diagram of the bar screen structure in Example 1; Figure 5 This is a schematic diagram of the cross-section of the bar screen in Example 1; Figure 6 yes Figure 2 A magnified view of a section at point A in the middle; Figure 7 This is a schematic diagram of the overall structure of the bar screen in Comparative Example 1; Figure 8 This is a force analysis diagram of the bar screen in Comparative Example 1; Figure 9 This is a schematic diagram of the grid sieve structure in Comparative Example 1; Figure 10 This is a schematic diagram of the cross-section of the bar screen in Comparative Example 1; Figure 11 This is a schematic diagram of the overall structure of the bar screen in Comparative Example 2; Figure 12 This is the front view of the bar screen in Scale 2; Figure 13 This is a schematic diagram of the bar screen structure in Comparative Example 2; Figure 14 This is a schematic diagram of the cross-section of the bar screen in Comparative Example 2; Figure 15 yes Figure 11 Enlarged view of a portion of point A in the middle.

[0026] Reference numerals: 1. Plate feeder; 2. Jaw crusher; 3. Bar screen; 301. Support frame; 302. Support web; 303. Front support plate; 304. Rear support plate; 305. Limiting block; 4. Upper base; 5. Lower base; 6. Wear-resistant block; 7. Front support plate bolt; 8. Wear-resistant block bolt; 9. Limiting hole; 10. Upper base I-beam; 11. Lower base I-beam; 12. Rear support plate bolt; 13. Weld.

[0027] Appendix Figure 3 , Figure 8 , Figure 12 In the diagram, F represents the vertical impact load of the material acting on the bar screen. h F is the horizontal load of the material acting on the bar screen; N The vertical support reaction forces of the upper and lower bases on the supporting web are used to balance the vertical impact load F; FQ The horizontal shear force borne at the connection between the upper and lower bases and the supporting web is used to balance the horizontal load F. h M is the bending moment borne by the supporting web, causing the lower side of the supporting web to be under tension. Detailed Implementation

[0028] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this specification.

[0029] To address the structural defects and shortcomings of existing bar screens used in jaw crushers, and to improve the stability and robustness of the bar screen structure, this invention provides a bar screen device for jaw crushers. This bar screen is easy to install and less prone to ore jamming. The specific solution is as follows: A bar screen device for a jaw crusher includes an upper base, a lower base, a bar screen, and wear-resistant blocks. The upper base is located below a plate feeder, and the lower base is connected to the jaw crusher. The bar screen consists of a support frame, a support web, a front support plate, a rear support plate, and a limiting block. The bar screen is arranged at an inclination, and its cross-section is T-shaped. The wear-resistant blocks are located above the support frame, and the upper surface of the wear-resistant blocks is convex. The support web has a triangular rib structure.

[0030] Furthermore, the upper base seat is fixedly installed below the plate feeder by welding. Both the upper and lower base seats are U-shaped, and I-beams are welded to their inner sides as reinforcing ribs. The upper base seat is provided with through holes.

[0031] Furthermore, the upper surface of the limiting block is a trapezoidal slope, and its slope is consistent with the slope of the inner wall of the limiting hole.

[0032] Furthermore, the front support plate is connected to the upper base by bolts, and the rear support plate is fixed only by the engagement of the limiting block and the limiting hole.

[0033] Furthermore, a wear-resistant block is located above the load-bearing frame. The wear-resistant block is much thicker than the load-bearing frame and has through holes on its sides. The wear-resistant block is connected to the load-bearing frame by bolts. Below the load-bearing frame is a supporting web, which is a triangular stiffener structure. Under the same impact load F, the bending deformation is significantly reduced. At the same time, the triangular structure can effectively absorb the shear force F. Q The stress is distributed to the upper and lower bases, avoiding stress concentration that could lead to weld cracking. The bending stiffness is greatly improved, and it can effectively resist the bending deformation caused by the bending moment M.

[0034] The present invention also provides a jaw crusher, including a crusher body and a bar screen device for jaw crusher as described above, wherein the bar screen device is disposed above the feed inlet of the crusher body.

[0035] Example 1

[0036] Reference Figures 1 to 6 This application provides a bar screen device for a jaw crusher, including a plate feeder 1, a jaw crusher 2, a bar screen 3, an upper base 4, and a lower base 5. The upper base 4 is located below the plate feeder 1, and the lower base 5 is connected to the jaw crusher 2. The bar screen 3 is arranged at an inclination angle of 15° and the bar cross-section is T-shaped. The upper part of the supporting frame 301 is a wear-resistant block 6, and the upper surface of the wear-resistant block 6 is convex arc-shaped. The supporting web 302 is a triangular rib structure. The rear support plate 304 has a limiting block 305, and the upper surface is trapezoidal. The limiting block 305 is fastened and wedge-fitted into the limiting hole 9 of the lower base 5.

[0037] Specifically, the upper base seat 4 is welded and fixedly installed below the plate feeder 1. The upper base seat 4 is U-shaped, and an upper base I-beam 10 is welded to its inner side for fixed support. The surface of the upper base seat 4 has through holes and is connected to the front support plate 303 of the bar screen by front support plate bolts 7. The lower base seat 5 is welded and fixedly installed on the jaw crusher 2. The lower base seat 5 is U-shaped, and a lower base I-beam 11 is welded to its inner side for fixed support. The lower base seat 5 has a limiting hole 9, and a limiting block 305 is wedged into the limiting hole 9. The limiting block 305 and the limiting hole 9 are tightly wedged together. The front support plate 303 is trapezoidal, and has through holes at its lower end. The front support plate 303 is connected to the upper base seat 4 by front support plate bolts 7. The rear support plate 304 is trapezoidal, and a limiting block 305 is provided below the rear support plate 304. The limiting block 305 is fastened and wedge-fitted with the limiting hole 9. Above the bearing frame 301 is a wear-resistant block 6. The wear-resistant block 6 is 90mm thick, much larger than the bearing frame 301. The wear-resistant block 6 is upside down on the bearing frame 304 through a groove. The wear-resistant block 6 has through holes on its side. The wear-resistant block 6 is connected to the bearing frame 301 by wear-resistant block bolts 8. Below the bearing frame 301 is a supporting web plate 302. The supporting web plate 302 has a triangular rib structure. The supporting web plate 302 is used to support the wear-resistant block 6 and withstand bending moment and shear force. The triangular rib structure can improve the bending and impact resistance of the supporting web plate 302, reduce stress concentration and plastic deformation of the bearing frame, and improve the service life of the bar screen.

[0038] Example 1 features a simple and rationally designed structure. By adding a limiting block 305 to the rear support plate 304 of the bar screen 3 and opening a limiting hole 9 at the bottom of the lower base 5, the limiting block 305 of the bar screen 3 is effectively and securely connected to the limiting hole 9 of the lower base 5, preventing the bar screen 3 from shifting due to loose bolts. By increasing the thickness of the wear-resistant block 6 and making its upper surface convex, the wear resistance of the bar screen 3 is effectively improved, and it is less prone to ore jamming, reducing the labor intensity of personnel cleaning accumulated ore. By designing the support web 302 as a triangular rib structure, the overall support rigidity of the bar screen 3 is effectively improved, which can disperse the impact load of the ore and reduce stress concentration. Under long-term impact and rolling contact of the ore, the rear support plate 304 of the bar screen 3 is not prone to loosening, which can maintain the consistent spacing between adjacent bar screens, effectively ensuring the screening of ore and the stable operation of the jaw crusher.

[0039] In Example 1, the combination of a T-shaped cross-section and a convex arc wear-resistant block prevents fine-grained ore from getting stuck between the grids; the triangular stiffeners reduce the bending moment M, which generates bending stress, and the shear force F... Q The stress is distributed and transmitted by the hypotenuse of the triangle, avoiding stress concentration at the root of the traditional rectangular stiffener; the wedge-shaped connection of the limiting block eliminates bolt loosening caused by vibration, and the gap remains stable, thus ensuring continuous and uniform feeding of the jaw crusher.

[0040] Comparative Example 1 Reference Figures 7 to 10 Comparative Example 1 provides a bar screen device for a jaw crusher. The difference between the bar screen device for a jaw crusher in Comparative Example 1 and the one described in Example 1 is that: In Comparative Example 1, the bar screen is composed of a support frame 301, a support web 302, a front support plate 303, and a rear support plate 304. The bar screen 3 is arranged at an angle, and the bar cross-section is trapezoidal. The wear-resistant block 6 is wedge-fitted into the support frame 301 through grooves and connected to the support frame 301 by wear-resistant block bolts 8. The upper surface of the wear-resistant block 6 is flat. The support web 302 has a rectangular structure. The lower base 5 is provided with through holes and is connected to the rear support plate 304 of the bar screen by rear support plate bolts 12.

[0041] The lower base 5 and the rear support web 304 are bolted together. Under prolonged impact and vibration from the ore, the bolts are prone to loosening and require periodic tightening. The bar screen support web 302 has a rectangular structure, and the bending moment M is borne by the entire web section, resulting in more uniform stress distribution. However, the rectangular stiffeners have weaker resistance to deformation than the triangular stiffeners, and the bar screen may experience slight deformation after long-term use. The bar section is trapezoidal, which has poor anti-jamming effect and is prone to causing ore jamming. The structural configuration of Comparative Example 1—the bolted rear support plate, the rectangular support web, the trapezoidal bar section, and the flat wear-resistant block upper surface—covers a combination of several of the most common technical solutions in the field of jaw crusher bar screens.

[0042] Comparative Example 2 Reference Figures 11 to 15 Comparative Example 2 provides a bar screen device for a jaw crusher. The difference between the bar screen device for a jaw crusher in Comparative Example 2 and the above-mentioned Embodiments 1 and 2 is that: In Comparative Example 2, the bar screen is composed of a support frame 301, a front support plate 303, and a rear support plate 304. The bar screen 3 is arranged at an angle, and the bar cross-section is rectangular. The wear-resistant block 6 is wedge-fitted onto the support frame 301 through grooves and connected to the support frame 301 by wear-resistant block bolts 8. The upper surface of the wear-resistant block 6 is flat, and the surface of the lower base 5 is connected to the rear support plate 304 of the bar screen by welding.

[0043] The lower base 5 and the rear support plate 304 are connected by weld 13. This welded connection is inconvenient to assemble and disassemble, difficult to maintain, and prone to vibration and abnormal noise during operation, making it impossible to guarantee the stable and continuous operation of the jaw crusher. The removal of the supporting web plate from the bar screen results in weak load-bearing capacity, and the lower support frame 301 is prone to deformation and breakage after long-term use. The wear-resistant blocks have a rectangular cross-section, which easily leads to material jamming, requiring regular cleaning of accumulated ore. Furthermore, the flat wear-resistant blocks 6 wear quickly and have a short service life.

[0044] In this application's technical solution, the four technical features—triangular ribs, T-shaped cross-section, wedge-shaped limiting blocks, and convex arc wear-resistant blocks—work synergistically and are indispensable. Using only one or two of these features (such as in Comparative Example 1) cannot simultaneously achieve the effects of "maintenance-free, anti-jamming, and long service life." In particular, the wedge-shaped limiting blocks replacing bolt fixing have never been used in the field for jaw crusher grate screens because conventional designs assume bolt tightening is necessary under vibration conditions. This application takes the opposite approach, utilizing the vibration self-locking principle (the trapezoidal inclined surface becomes tighter with vibration), achieving an unexpected improvement in reliability.

[0045] In existing technologies, triangular stiffeners are mostly used in building trusses, T-shaped sections are used in tracks, wedge-shaped limiting blocks are used for mold fixing, and convex arc surfaces are used in chutes. This application is the first to apply the above four features, which belong to different technical fields, to the jaw crusher's bar screen simultaneously. The purpose is not to simply add functions, but to solve the systemic problem of "loose bolts - stuck ore - deformation failure" that is coupled together.

[0046] As shown in Table 1, this application, through the combination of triangular stiffeners, T-shaped cross-sections, wedge-shaped limiting blocks, and convex arc wear-resistant blocks, significantly outperforms existing solutions in terms of ore jamming frequency, connection reliability, and structural deformation resistance. The bolt loosening cycle is extended to more than 6 times that of the comparative embodiment 2, demonstrating the non-superimposed synergistic effect of the combined technical features.

[0047]

[0048] Table 1: Differences and Performance Comparisons between Examples and Comparative Examples It should be noted that the four technical features of this invention—the wedge-shaped limiting block structure, the triangular rib supporting the web, the T-shaped cross-section strips, and the convex arc-shaped wear-resistant block—come from different technical fields and each solves a single technical problem under different working conditions. The principle of the limiting block wedge structure originates from wedge self-locking fastening technology. Traditionally, it is mostly used for quick clamping under static load or low vibration conditions such as mold fixing and pipeline connection, solving the problem of convenient assembly and disassembly. It has not yet been applied to the connection and fixing of mining crushing equipment with high impact and strong vibration. The structure of the triangular stiffener supporting the web plate originates from the truss or bridge support system in building steel structure. It uses the geometric stability of triangles to improve the load-bearing capacity and solves the bending resistance problem of large span structures. It has not yet been integrated into the lower part of the grid of the bar screen as a local support structure. The cross-sectional shape of the T-section bar grid comes from the rail steel or profile structure. It uses the high bending section modulus of the T-section to resist bending deformation and solves the bending resistance and guidance problem under heavy load conditions in rail transit. It has not yet been used directly as the load-bearing grid of the bar screen. The curved shape of the convex arc wear-resistant block comes from the wear-resistant liner in the chute or pipeline. It uses the guiding effect of the convex arc surface on the material flow to reduce impact wear and solves the wear problem in the material conveying process. It has not yet been combined with the T-section bar grid for the anti-jamming design of the screening device.

[0049] This invention is the first to simultaneously apply the four technical features from different technical fields to a jaw crusher bar screen device. These four independent technical means, each serving different working conditions such as static clamping, building load-bearing, track guidance, and material conveying, are simultaneously migrated and integrated into a mining screening device that withstands high impact and strong vibration. Each feature requires adaptation adjustments for the specific working conditions of the bar screen during the migration process (such as selecting the taper ratio of the limit block, optimizing the included angle of the triangular rib, and determining the radius of curvature of the convex surface). Furthermore, the interface relationships between the features (such as matching the positioning accuracy of the limit block with the force path of the triangular rib, and the coordination between the T-section and the convex surface in anti-jamming function) require systematic design to achieve synergy. This cross-domain feature migration and system integration itself embodies a non-obvious technical concept. Moreover, the purpose of this invention is not simply the superposition of the functions of each feature, but rather to solve the interconnected and mutually causal systemic technical problem of "easy connection - insufficient rigidity - frequent jamming - severe wear."

[0050] In this invention, there is a close synergistic relationship among the four technical features: the wedge-shaped limiting block structure solves the fundamental problem of continuous attenuation of preload in traditional bolted connections under vibration, requiring frequent manual tightening. This structure utilizes the wedge effect of the trapezoidal inclined surface to convert vibration energy into positive pressure that causes the limiting block to further wedge into the limiting hole, achieving self-locking under dynamic loads; the supporting web of the triangular stiffener disperses and transmits impact loads and horizontal shear forces to the upper and lower bases through the hypotenuse, effectively avoiding early fracture caused by stress concentration at the root of the right angle in traditional rectangular cross-section stiffeners—this mechanical advantage provides stability in the wedge-shaped limiting block structure. Under the premise of the foundation, it can be fully utilized. If the rear support plate is still connected by bolts, even if the support web is triangular, the movement of the strip screen caused by the loosening of the bolts will still cause the triangular stiffener to bear additional bending moment, weakening its bending resistance advantage. The T-shaped cross section increases the bending section modulus of the cross section and enhances the bending stiffness of the strip itself. Together with the triangular stiffener, it forms a dual bending resistance system of "upper load + lower support". The convex arc-shaped wear-resistant block allows fine ore to slide smoothly along the arc surface. Combined with the narrow slot structure of the T-shaped cross section, it significantly reduces the probability of ore jamming. At the same time, the convex arc surface reduces the impact angle and cutting effect of ore on the wear-resistant block, extending the wear-resistant life.

[0051] The four features mentioned above do not function independently, but are interdependent and mutually conditional: the wedge-shaped limiting blocks ensure the spatial positioning accuracy of the grid screen, making the force path of the triangular stiffeners clear and controllable; the triangular stiffeners provide reliable support rigidity, allowing the bending resistance of the T-section grid bars to be fully utilized; the T-section and the convex arc wear-resistant blocks together optimize the ore flow state, reduce the randomness of impact loads, and thus mitigate the dynamic impact on the connecting and supporting structures. It is this synergistic effect that extends the bolt loosening cycle of Embodiment 1 of the present invention to more than 720 hours (compared to only 120 hours in Comparative Example 1), and reduces the ore jamming frequency to 0-0.2 times / shift (compared to 0.5-1 times / shift in Comparative Example 1), achieving the comprehensive technical effect of "maintenance-free, anti-jamming, and long service life". This effect is not a simple superposition that can be achieved when each feature is implemented individually, but a qualitative change produced by the synergistic effect of the four technical features—this is the core difference between the present invention and the prior art.

[0052] In summary, this invention discloses a bar screen device for a jaw crusher, comprising an upper base, a lower base, a bar screen, and wear-resistant blocks. The upper base is located below a plate feeder, and the lower base is connected to the jaw crusher. The bar screen consists of a supporting frame, a supporting web, a front support plate, a rear support plate, and a limiting block. The bar screen is arranged at an incline, and the bar cross-section is T-shaped. The wear-resistant block is located above the supporting frame, and its upper surface is convex. The supporting web has a triangular rib structure. The rear support plate has a limiting block, and its upper surface is trapezoidal. The limiting block is firmly engaged in the limiting hole of the lower base. The rear support plate of the bar screen adopts a limiting block structure, which is wedge-fitted into the limiting hole of the lower base, ensuring the stability of the bar screen structure and the stable operation of the jaw crusher. The supporting web of the bar screen adopts a triangular rib structure, which effectively improves the overall support rigidity of the bar screen, can disperse the impact load of ore, and reduce stress concentration. The wear-resistant block is wedge-fitted into the bearing frame through grooves and fixed by bolts. The thickness of the wear-resistant block is much larger than that of the bearing frame, which increases the wear resistance of the bar screen, reduces the number of replacements, and saves costs. The bar screen is inclined, with a T-shaped cross-section and a convex arc upper surface, which can reduce ore jamming and facilitate cleaning after jamming. The bar screen structure of this invention is reasonably designed, has good wear resistance, tight connection, and is not easy to jam, which can ensure the stable operation of the jaw crusher.

[0053] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A bar screen device for a jaw crusher, comprising an upper base, a lower base, and a bar screen, wherein the upper base is fixedly installed below a plate feeder, the lower base is fixedly connected to the jaw crusher, and the bar screen is inclinedly arranged between the upper base and the lower base, characterized in that: The bar screen includes a support frame, a support web, a front support plate, a rear support plate, and a limiting block; The bottom of the rear support plate is provided with the limiting block, and the lower base is provided with a limiting hole. The rear support plate is fixed to the lower base only by the engagement of the limiting block and the limiting hole.

2. The bar screen device for a jaw crusher according to claim 1, characterized in that: The limiting block has a trapezoidal inclined surface, and the limiting hole has a mating inclined surface with the same slope as the trapezoidal inclined surface. The limiting block and the limiting hole are engaged through the trapezoidal inclined surface. The taper ratio between the trapezoidal inclined surface and the mating inclined surface is 1:5 to 1:10; the trapezoidal inclined surface is used to convert vibration energy into positive pressure that causes the limiting block to wedge into the limiting hole when the bar screen device is subjected to vibration.

3. The bar screen device for a jaw crusher according to claim 1, characterized in that: There is no bolt connection between the rear support plate and the lower base, which avoids the attenuation of the preload of the threaded pair under vibration environment.

4. A bar screen device for a jaw crusher according to claim 1, characterized in that: The taper between the trapezoidal inclined surface of the limiting block and the mating inclined surface of the limiting hole is set such that when the strip screen device is vibrated, the limiting block has a self-locking tendency to wedge into the limiting hole; the self-locking tendency is achieved by converting vibration energy into wedge force through the wedge effect of the trapezoidal inclined surface.

5. A bar screen device for a jaw crusher according to claim 1, characterized in that: The supporting web is a triangular stiffener structure, and the angle between the right-angled side and the hypotenuse of the triangular stiffener is 30° to 60°, with the vertex of the triangle pointing towards the lower base. The triangular stiffener distributes the impact load and shear force to the upper base and the lower base through its hypotenuse.

6. A bar screen device for a jaw crusher according to claim 1, characterized in that: A wear-resistant block is provided above the supporting frame. The upper surface of the wear-resistant block is a convex arc surface with a radius of curvature of 340mm to 360mm and a thickness of 80mm to 100mm. The convex arc surface is used to guide the ore to make tangential contact along the arc surface to reduce impact wear and ore jamming.

7. A bar screen device for a jaw crusher according to claim 6, characterized in that: The wear-resistant block is inverted onto the support frame through a groove and is fixedly connected to the support frame by bolts; the wear-resistant block can be replaced independently through the inverted groove.

8. A bar screen device for a jaw crusher according to claim 1, characterized in that: The cross-section of the grating screen is T-shaped, which is used to guide fine ore particles to slide down along both sides of the grating through the narrow slit structure.

9. A bar screen device for a jaw crusher according to claim 1, characterized in that: Both the upper base and the lower base are U-shaped, and I-beams are welded to the inner sides of the upper base and the lower base as reinforcing ribs to enhance the structural strength of the base.

10. A jaw crusher, comprising a crusher body, characterized in that: It also includes a bar screen device for a jaw crusher as described in any one of claims 1 to 9, the bar screen device being disposed above the feed inlet of the crusher body.

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