A resonant crusher vibration device with fixed frequency and amplitude regulation and its soft start / stop method

Abstract

This invention belongs to the field of highway maintenance machinery technology, specifically relating to a resonant crusher vibration device with fixed-frequency amplitude adjustment and its soft start-stop method. It includes a counterweight box, a lifting cylinder, a vibration damping frame, an excitation box, connecting stiffeners, and shear-type rubber vibration dampers. The counterweight box is hinged to the vibration damping frame via the lifting cylinder, and the vibration damping frame is connected to the excitation box via the shear-type rubber vibration dampers and connecting stiffeners. It breaks through the limitations of frequency and amplitude coupling, achieving continuous adjustment within the amplitude range while maintaining a constant resonant frequency. It can cover the crushing needs of cement concrete pavements with strength grades of C30~C60 and thicknesses of 150mm~300mm, and the adjustment process does not require machine shutdown, effectively improving construction efficiency. A control strategy of zeroing before start-up and loading after start-up; unloading before shutdown and zeroing after shutdown is proposed, avoiding the impact hazards of crossing the resonance zone during equipment start-up and shutdown, significantly extending the service life of the synchronous gears and the crusher hammers, and reducing equipment maintenance costs.

Description

Technical Field

[0001] This invention belongs to the field of highway maintenance machinery technology, specifically relating to a resonant crusher vibration device with fixed frequency amplitude adjustment and its soft start-stop method. Background Technology

[0002] my country's highway infrastructure construction has fully entered a new stage of high-quality development, emphasizing both construction and maintenance, with maintenance as the primary focus. Cement concrete pavement, with its advantages of high load-bearing capacity, good durability, and low life-cycle cost, occupies a core position in my country's highway network. By the end of 2025, the total length of cement concrete pavement in operation nationwide reached 2.315 million kilometers, accounting for 41.8% of the total paved area. A large number of early-stage pavements have entered a period of high incidence of structural defects, urgently requiring targeted treatment and structural reconstruction. Resonant crushing technology applies high-frequency, low-amplitude vibrations to old cement concrete pavements, causing forced vibrations and resonance when the excitation frequency approaches its natural frequency. This uniformly breaks down rigid concrete slabs into granular layers with good interlocking structures. This technology has significant advantages such as uniform particle size, minimal disturbance to the base layer, effective suppression of reflective cracking in asphalt overlays, and good utilization of old materials, making it the mainstream process for the "white-to-black" transformation of old cement pavements.

[0003] Existing resonant crushers generally employ a dual-shaft counter-rotating inertial vibrator structure. The core consists of two parallel excitation shafts, a fixed eccentric block, synchronous gears, and a damping system. The eccentric block is rigidly connected to the excitation shafts via splines or welding. A hydraulic motor drives the two excitation shafts to rotate in opposite directions at equal speeds. The horizontal centrifugal forces generated by the eccentric blocks cancel each other out, while the vertical centrifugal forces are superimposed to form a pure vertical harmonic excitation force, driving the crusher hammer to achieve high-frequency vibration operation. Although this structure is simple in principle and reliable in operation, the following technical defects urgently need to be addressed in engineering applications: 1. Fixed excitation amplitude and poor adaptability to working conditions. The optimal vibration amplitude required for cement concrete pavement of different thicknesses and strength grades varies significantly. However, the eccentricity of traditional vibration devices is fixed, the excitation amplitude is not adjustable, the equipment is difficult to cover a variety of working conditions, and it cannot be dynamically adjusted according to the crushing stage (primary crushing, fine crushing).

[0004] 2. Resonance during start-up and shutdown poses serious risks and shortens equipment lifespan. During equipment start-up and shutdown, the excitation frequency inevitably passes through the system's resonant frequency range, causing severe vibration and impact. This leads to accelerated fatigue damage of key components such as vibrator bearings, synchronous gears, and breaker hammers. In actual engineering projects, the average service life of bearings is significantly reduced, resulting in a high equipment failure rate.

[0005] 3. The breaker hammer has a single posture, resulting in low energy utilization. Traditional breaker hammers can only impact the road surface perpendicularly, leading to predominantly tensile crack propagation and energy concentration primarily in the surface layer. However, the tensile-shear composite strength of concrete is far lower than its pure tensile strength. A proper hammer inclination angle can generate both tensile and shear stresses during impact, forming a tensile-shear composite crack and significantly improving breaking efficiency. However, in traditional devices, the hammer is rigidly connected to the vibratory box, preventing adjustment of its working posture and hindering the utilization of the advantages of tensile-shear composite breaking.

[0006] 4. The amplitude adjustment method is cumbersome and cannot be adjusted online. Traditional vibration devices require stopping the machine, opening the excitation box cover, replacing eccentric blocks of different masses, or changing the angle of the movable eccentric block via pins to change the excitation amplitude. Each adjustment takes a long time, and in harsh environments, the pins are prone to jamming and the eccentric blocks to corrode, further increasing the difficulty of adjustment. This offline adjustment method severely disrupts the continuity of construction and cannot dynamically adjust parameters according to real-time changes in road conditions. Summary of the Invention

[0007] To address the technical problems existing in the vibration devices of the current resonant crusher, this invention provides a resonant crusher vibration device with fixed frequency amplitude adjustment and its soft start / stop method.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A vibration device for a resonant crusher with fixed frequency and amplitude adjustment includes a counterweight box, a lifting cylinder, a vibration damping frame, an excitation box, connecting stiffeners, and a shear-type rubber vibration damper; the counterweight box is hinged to the vibration damping frame via the lifting cylinder, and the vibration damping frame is connected to the excitation box via the shear-type rubber vibration damper and the connecting stiffeners. The excitation box is equipped with an eccentricity adjustment mechanism, which can synchronously adjust the included angle of the eccentric blocks to achieve stepless amplitude adjustment of the frequency under the condition that the excitation shaft rotates at a constant speed without stopping. Different specifications of connecting stiffeners can be replaced to adjust the tilt angle of the excitation box relative to the vibration damping frame, thereby changing the impact angle of the breaker hammer on the road surface to form a tension-shear composite crushing. Two excitation shafts rotating synchronously in opposite directions drive the eccentric blocks to rotate. The horizontal centrifugal forces generated by the eccentric blocks cancel each other out and the vertical centrifugal forces are superimposed to form a pure vertical excitation force to drive the breaker hammer to complete the road crushing operation.

[0009] The lifting cylinders are arranged in pairs on both sides of the counterweight box. The lower end of the lifting cylinder is hinged to the counterweight box, and the upper end is hinged to the upper part of the vibration damping frame. The left and right side plates of the vibration damping frame are symmetrically fixedly equipped with shear-type rubber vibration dampers. One end of the shear-type rubber vibration damper is fixedly connected to the vibration damping frame, and the other end is detachably equipped with a connecting rib or other angle vibration damper connecting rib. The other end of the connecting rib or other angle vibration damper connecting rib is fixed to the outer wall of the excitation box. The entire excitation box is suspended below the vibration damping frame.

[0010] The vibration box includes a vibration box body, an active vibration shaft, an active gear, side eccentric blocks, a driven vibration shaft, a driven gear, a central eccentric block, an eccentricity adjustment mechanism, and a breaker hammer. The active and driven vibration shafts are installed parallel to each other inside the vibration box body. The active vibration shaft is fixedly equipped with an active gear and two sets of side eccentric blocks, and the driven vibration shaft is fixedly equipped with a driven gear and two sets of side eccentric blocks. The active and driven gears mesh with each other to achieve equal-speed, opposite-rotation of the active and driven vibration shafts. A central eccentric block is assembled between two sets of side eccentric blocks on a single active or driven vibration shaft. The eccentricity adjustment mechanism is arranged at the lower part of one side of the driven vibration shaft and meshes with the central eccentric block. The breaker hammer is detachably fixed to the bottom end face of the vibration box body.

[0011] The eccentricity adjustment mechanism consists of a piston rod, a cylinder, and a herringbone tooth adjustment gear. The cylinder is slidably sleeved on the outside of the piston rod, and the end face of the cylinder is rigidly connected to the herringbone tooth adjustment gear. The piston rod has a central oil passage inside, and the inner cavity of the cylinder is divided into a rodless chamber and a rod chamber. Pressurized oil enters the rodless chamber and pushes the cylinder forward along the piston rod. The herringbone tooth adjustment gear drives the central eccentric block to rotate relative to the side eccentric block, reducing the deflection angle between the central and side eccentric blocks and increasing the overall vibration force. Pressurized oil enters the rod chamber and pulls the cylinder backward, increasing the deflection angle between the central and side eccentric blocks and reducing the overall vibration force. When the deflection angle is adjusted to 180°, the centroids of the central and side eccentric blocks are arranged in opposite directions, the combined equivalent eccentricity is zero, and the overall vibration force disappears completely.

[0012] The total static torque M of the single active excitation shaft and the eccentric block on the upper side of the driven excitation shaft S =m1e1, Total static moment of the eccentric block M m =m2e2, the static moments of all eccentric components of the active and driven excitation shafts are equal; the combined equivalent eccentricity is determined only by the deflection angle α of the central and side eccentric blocks, and is independent of the rotational angular velocity of the active and driven excitation shafts. Under the condition that the mass, equivalent stiffness, damping and excitation frequency of the excitation system remain basically unchanged, the steady-state vibration amplitude of the breaker head is linearly positively correlated with the combined equivalent eccentricity. Different deflection angles α are matched with amplitude and construction conditions: α=135°~180°, hammer amplitude 5~8mm, suitable for pre-crushing and fine crushing of thin pavement layers; α=90°~135°, hammer amplitude 8~14mm, suitable for conventional crushing of medium-strength concrete; α=45°~90°, hammer amplitude 14~18mm, suitable for crushing of high-strength and thick pavement layers; α=0°~45°, hammer amplitude 18~20mm, suitable for crushing of ultra-thick and ultra-high-strength concrete pavement.

[0013] The connecting stiffener plate and other angle damper connecting stiffener plate are provided with multiple sets of angle positioning mounting surfaces, or have multiple mounting holes of 0°, 5°, 7°, 9°, and 11°. By changing the connecting stiffener plate of different specifications or other angle damper connecting stiffener plates, or by switching the mounting hole positions on the stiffener plate, the breaker hammer head can form an impact tilt angle of 7°~9°. When the breaker hammer head hits the road surface, it simultaneously generates tensile stress and shear stress, generating tensile-shear composite cracks and improving the energy utilization rate of breaker crushing.

[0014] The lifting cylinder adjusts the ground pressure and working height of the breaker head by its own extension and retraction. The herringbone tooth adjusting gear adopts a large helix angle herringbone tooth structure. The helical teeth on both sides of the herringbone tooth adjusting gear synchronously mesh with the driven helical gear of the active excitation shaft and the driven excitation shaft with the central eccentric block, ensuring that the rotation angle adjustment of the central eccentric block on the active excitation shaft and the driven excitation shaft is synchronized, eliminating residual excitation force in the horizontal direction. The breaker head is a split structure and is locked and fixed to the bottom of the excitation box by 8 sets of countersunk bolts.

[0015] A method for starting and stopping a resonant crusher vibration device with fixed frequency amplitude adjustment includes the following steps: Step 1: Pre-start adjustment: After receiving the start command, the control system delivers pressurized oil to the cylinder of the eccentricity adjustment mechanism, drives the herringbone tooth adjustment gear to rotate, and adjusts the deflection angle α of the middle eccentric block and the side eccentric block of the active excitation shaft and the driven excitation shaft to 180°. The combined equivalent eccentricity is returned to zero, and the excitation force and vibration amplitude of the breaker hammer are synchronously returned to zero. Step 2, Zero-excitation start-up: Start the hydraulic power system to drive the input end of the active excitation shaft extending outside the excitation box to rotate. Through the meshing transmission of the active gear and the driven gear, the driven excitation shaft is driven to synchronously and smoothly accelerate in the opposite direction to the preset constant resonance working speed, and the excitation frequency is maintained to match the natural resonance frequency of the cement concrete pavement throughout the process. Step 3, Smooth Loading Operation: After the rotational speeds of the active and driven excitation shafts stabilize, the control system slowly reduces the deflection angle α of the central and side eccentric blocks to the target working angle within 3-5 seconds via the hydraulic directional valve. The vibration amplitude of the breaker head smoothly rises from zero to the set value. The deflection angle α can be adjusted in real time throughout the road construction process, and the excitation amplitude of the breaker head can be dynamically and steplessly adjusted. Step 4, Smooth Unloading and Shutdown: After the single-section road breaking operation is completed, the control system slowly increases the deflection angle α of the central eccentric block and the side eccentric block to 180° within 3 to 5 seconds, and the vibration amplitude of the breaker hammer gradually returns to zero. Step 5, Zero-vibration shutdown: After confirming that the excitation force of the breaker hammer is completely zero, shut down the hydraulic power system. The active and driven excitation shafts will decelerate smoothly and stop rotating without impact.

[0016] Throughout the crushing operation, the active and driven excitation shafts are locked at a constant resonant speed, breaking through the technical constraint of strong coupling between excitation frequency and amplitude in traditional resonant equipment. The vibration amplitude of the crusher hammer is changed independently by adjusting the deflection angle α of the central and side eccentric blocks, and the excitation frequency remains constant throughout the entire process.

[0017] The entire process of equipment startup and shutdown relies on adjusting the central and side eccentric blocks to 180° to achieve a zero-vibration state for the whole machine. This allows the zero-vibration force to pass through the system's resonance range, reducing the fatigue damage caused by resonance impact to the active and driven vibration shafts, their matching bearings, the meshing active and driven gears, and the bottom crusher hammer. This extends the service life of the core components of the device and reduces the overall failure rate and daily maintenance costs.

[0018] Compared with the prior art, the beneficial effects of this invention are: 1. Fixed-frequency stepless amplitude regulation significantly improves adaptability to various working conditions: Breaking through the limitation of "frequency and amplitude coupling", it achieves continuous adjustment within the amplitude range while maintaining a constant resonant frequency. It can cover the crushing needs of cement concrete pavements with strength grades of C30 to C60 and thicknesses of 150mm to 300mm, and the adjustment process does not require machine shutdown, effectively improving construction efficiency.

[0019] 2. Zero-vibration soft start-stop, extending the life of core components: The proposed control strategy of "zeroing before start-up and loading after start-up; unloading before shutdown and zeroing after shutdown" avoids the impact hazards of passing through the resonance zone during equipment start-up and shutdown, which greatly extends the service life of synchronous gears and breaker hammers and reduces equipment maintenance costs.

[0020] 3. Adjustable hammerhead tilt angle improves crushing efficiency: The multi-angle design of the connecting ribs allows the hammerhead to adopt various working postures such as vertical, forward tilt, and backward tilt. When the hammerhead is used at a small tilt angle of 7°~9°, the crack propagation mode changes from a single tension type to a tension-shear composite type, which greatly improves energy utilization. Attached Figure Description

[0021] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0022] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0023] Figure 1 This is a schematic diagram of the overall structure of the vibration device; Figure 2 This is a schematic diagram showing the angle adjustment of the excitation box of the vibration device. Figure 3 This is a top sectional view of the overall structure of the vibration box; Figure 4 These are the front and left sectional views of the overall structure of the vibration box; Figure 5 This is a schematic diagram of the eccentricity adjustment mechanism. Figure 6 Schematic diagram of different eccentric block angle states; Figure 7 This is a flowchart of the soft start / stop operation.

[0024] Wherein: 1 is the counterweight box, 2 is the lifting cylinder, 3 is the vibration damping frame, 4 is the excitation box, 5 is the connecting stiffener, 6 is the shear-type rubber vibration damper, 7 is the connecting stiffener for other angle vibration dampers, 41 is the excitation box body, 42 is the active excitation shaft, 43 is the active gear, 44 is the side eccentric block, 45 is the driven excitation shaft, 46 is the driven gear, 47 is the center eccentric block, 48 is the eccentricity adjustment mechanism, 481 is the piston rod, 482 is the cylinder body, 483 is the herringbone tooth adjustment gear, and 49 is the breaker hammer. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. These descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the claims of the present invention. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0027] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0028] This embodiment provides a resonant crusher vibration device with fixed-frequency amplitude adjustment, such as... Figure 1 , Figure 2 As shown, it consists of a counterweight box 1, a lifting cylinder 2, a vibration damping frame 3, a vibration excitation box 4, a connecting stiffener 5, and a shear-type rubber vibration damper 6. The vibration excitation box 4 is the core working unit, which integrates the vibration excitation system and the eccentricity adjustment mechanism 48.

[0029] The counterweight box 1 is hinged to the vibration damping frame 3 via two sets of lifting cylinders 2, used to adjust the working height and ground pressure of the breaker hammer 49. The vibration damping frame 3 is a box-shaped welded structure with shear-type rubber vibration dampers 6 symmetrically arranged on its left and right sides. One end of the shear-type rubber vibration damper 6 is connected to the vibration damping frame 3 by bolts, and the other end is fixedly connected to the side plate of the excitation box 41 by connecting stiffeners 5. When it is necessary to adjust the hammer tilt angle, the standard connecting stiffener 5 can be replaced with connecting stiffeners 7 of other angle vibration dampers, realizing the rapid switching of the angle between the breaker hammer 49 and the road surface.

[0030] The core structure of the excitation box 4 is as follows Figure 3 , Figure 4 As shown, the device consists of a vibration housing 41, an active vibration shaft 42, an active gear 43, side eccentric blocks 44, a driven vibration shaft 45, a driven gear 46, a central eccentric block 47, an eccentricity adjustment mechanism 48, and a breaker hammer 49. The active vibration shaft 42 and the driven vibration shaft 45 are arranged parallel to each other inside the vibration housing 41. The input end of the active vibration shaft 42 extends out of the housing and is connected to a hydraulic motor. The active gear 43 and two sets of side eccentric blocks 44 are fixedly connected to the shaft, and a central eccentric block 47 is installed between the two sets of side eccentric blocks 44. The driven vibration shaft 45 is correspondingly equipped with a driven gear 46 and two sets of side eccentric blocks 44, and a central eccentric block 47 is also provided between the two sets of side eccentric blocks 44.

[0031] The eccentricity adjustment mechanism 48 is arranged on the lower part of one side of the driven excitation shaft 45, and its structure is as follows: Figure 5As shown, it consists of a piston rod 481, a cylinder 482, and a herringbone tooth adjusting gear 483. The cylinder 482 is mounted on the piston rod 481 and slides freely along the axial direction. It is fixed to the end face of the herringbone tooth adjusting gear 483 via a bearing. The herringbone tooth adjusting gear 483 simultaneously meshes with driven helical gears fixed to the end faces of two central eccentric blocks 47. The breaker hammer 49 adopts a split structure and is fixed to the bottom end face of the vibratory box 41 by eight sets of countersunk bolts.

[0032] A hydraulic motor drives the active excitation shaft 42 to rotate, which meshes with the driven gear 46 through the active gear 43, causing the driven excitation shaft 45 to rotate in the opposite direction at the same speed. The side eccentric blocks 44 and the center eccentric block 47 on the two excitation shafts rotate at high speed with the shafts, each generating centrifugal force. The combined excitation force is transmitted to the excitation box 41 through the bearing housing of the excitation shaft, causing the entire excitation box 4 to vibrate at high frequency in the vertical direction; the vibration at the bottom of the excitation box 41 is transmitted to the breaking hammer 49 through the connecting bolts, and the hammer concentrates the vibration energy onto the cement concrete pavement, causing the pavement to undergo forced vibration and resonance, ultimately achieving uniform crushing.

[0033] The vibration generated by the excitation box 4 is transmitted to the vibration damping frame 3 through the shear-type rubber vibration damper 6. When the connecting stiffeners of different angles are replaced, the pitch angle of the excitation box 41 relative to the vibration damping frame 3 changes, and the impact angle between the crusher hammer 49 and the road surface changes accordingly. This allows for multiple working postures, enabling the hammering process to generate tensile-shear composite cracks and improve crushing efficiency.

[0034] In this embodiment, the eccentricity adjustment is achieved by hydraulically driving the herringbone tooth adjustment gear to move axially, simultaneously changing the angle between the central eccentric block and the side eccentric block on the two excitation shafts. The specific process is as follows: 1. When it is necessary to increase the excitation force, the pressure oil enters the rodless chamber of the cylinder 482 from the central oil passage inside the piston rod 481, pushing the cylinder 482 to drive the herringbone tooth adjusting gear 483 to move axially towards the front end along the piston rod 481; 2. The left and right helical tooth surfaces of the herringbone tooth adjusting gear 483 mesh with the driven helical gears on the two central eccentric blocks 47 respectively. The axial movement is converted into the rotational motion of the driven helical gears, which drives the central eccentric blocks 47 on the two excitation shafts to rotate synchronously in the opposite direction relative to the side eccentric block 44, so that the angle α between the centers of mass of the central eccentric block 47 and the side eccentric block 44 gradually decreases. 3. When it is necessary to reduce the excitation force, the pressure oil switches into the rod chamber of the cylinder 482, pulling the cylinder 482 to drive the herringbone tooth adjusting gear 483 to move axially to the rear end, driving the central eccentric block 47 to rotate in the opposite direction, and the included angle α gradually increases. 4. When α = 180°, the centers of mass of the central eccentric block 47 and the side eccentric block 44 are completely opposite, the resultant eccentricity is zero, and the excitation force is zero; when α = 0°, the centers of mass of the two are completely in the same direction, the resultant eccentricity reaches the maximum value, and the excitation force reaches the rated maximum value.

[0035] The working principle of this invention is as follows: 1. Biaxial Reverse Excitation Principle The mechanical inertial eccentric vibrator uses the centrifugal force generated by the high-speed rotating eccentric mass as the excitation force source. The centrifugal force of a single eccentric block is: (1) In the formula, m is the mass of a single eccentric block; ω is the angular velocity of the eccentric block; and e is the eccentricity of the eccentric block.

[0036] A dual-axis counter-rotating excitation structure is adopted, with eccentric blocks of identical parameters mounted on two excitation shafts, rotating synchronously in opposite directions at the same angular velocity. Let α be the angle between the centerlines of the two sets of eccentric blocks. The centrifugal force of a single eccentric block can be decomposed into horizontal and vertical components. The horizontal components completely cancel each other out; the vertical components are superimposed in magnitude, ultimately synthesizing a simple harmonic excitation force along the vertical direction. (2) The amplitude of the combined excitation force is: (3) 2. Fixed-frequency stepless amplitude modulation principle The original monolithic eccentric block is split into a side eccentric block and a central eccentric block. Let the total mass of the side eccentric block be m1, the eccentricity of the center of mass be e1, and the corresponding static moment M. s =m1e1; The total mass of the eccentric block is m2, the eccentricity of the center of mass is e2, and the corresponding static moment is M. m =m2e2; To ensure the structural symmetry and force balance of the biaxial excitation system, the static moments of the two sets of eccentric blocks are taken to be equal, that is: (4) The angle between the lines connecting the centroids of the central eccentric block and the side eccentric blocks to the axis is defined as the deflection angle α. According to the vector composition rule, the combined eccentricity of the two sets of eccentric blocks is: (5) Substituting the condition of equal static moments and simplifying using the double-angle formula, we can obtain the combined equivalent eccentricity: (6) Therefore, the combined eccentricity is only related to the deflection angle α and is independent of the excitation frequency. Combining this with the two-degree-of-freedom forced vibration model of the fully floating vibration system, under the premise of a constant excitation frequency and locally uniform road support stiffness, the steady-state amplitude of the hammer is linearly positively correlated with the combined eccentricity. Therefore, the expression for the adjustable excitation amplitude is: (7) In the formula, k is a proportionality coefficient related to the system's mass, stiffness, and damping. Therefore, when the excitation shaft speed ω remains constant and always at the road surface resonance frequency, the vibration amplitude can be continuously and independently adjusted by adjusting the deflection angle α without changing the excitation frequency. Figure 6 As shown, the amplitude ranges and applicable working conditions corresponding to different eccentric angles are as follows: When α=135°~180°, the central and lateral eccentric blocks are arranged in opposite directions with a large included angle, the combined equivalent eccentricity is small, the excitation force is about 38% of the rated maximum value, and the corresponding amplitude is 5~8mm. It is suitable for road pre-breaking and fine operation of thin pavement layer. When α = 90°~135°, the combined equivalent eccentricity is 70.7% of the rated value, the excitation force is about 70% of the rated maximum value, and the corresponding amplitude is 8~14mm, which is suitable for conventional crushing operations of medium strength pavement layers. When α=45°~90°, the central and lateral eccentric blocks are arranged in the same direction with a small included angle. The combined equivalent eccentricity is close to the rated value, the excitation force is about 92% of the rated maximum value, and the corresponding amplitude is 14~18mm. It is suitable for crushing operations of high-strength, thick pavement layers. When α = 0°~45°, the combined equivalent eccentricity reaches its maximum, corresponding to an amplitude of 18~20mm, which is suitable for breaking up ultra-thick and ultra-strong concrete pavements.

[0037] 3. Zero-excitation soft start / stop method This embodiment also provides a soft start-stop method for resonant crushing operations using the above-mentioned vibration device, which can maintain the excitation shaft speed constant at the resonant operating frequency, such as... Figure 7 As shown, the specific steps include: Step 1: Pre-start adjustment: After the start command is issued, the control system drives the hydraulic cylinder to adjust the included angle α of the eccentric block to 180°. At this time, the resultant eccentricity is zero and the vibration amplitude is zero. Step 2, Zero-vibration start-up: Start the power system to smoothly accelerate the excitation shaft to the predetermined operating speed. At this point, the vibration amplitude is zero, the equipment operates smoothly without significant vibration; Step 3, Smooth Loading Operation: After the excitation shaft speed stabilizes, the control system slowly reduces the eccentric block angle α to the target working angle over 3-5 seconds via the reversing valve, allowing the vibration amplitude to smoothly increase from zero to the set value, thus initiating the crushing operation. During the operation, α can be adjusted in real time according to the road surface conditions to dynamically adjust the excitation force. Step 4: Smooth Unloading and Shutdown: After the operation is completed, the control system slowly increases the eccentric block angle α to 180° within 3 to 5 seconds, so that the vibration amplitude gradually returns to zero. Step 5, Zero-vibration shutdown: After the amplitude returns to zero, shut down the power system and allow the excitation shaft to decelerate smoothly to a stop.

[0038] During the start-up and shutdown process of a traditional resonant crusher, the excitation frequency inevitably passes through the system's resonance range, resulting in severe impact. This invention, by adjusting the eccentric torque to zero before starting and stopping, ensures that even if the excitation frequency passes through the resonance range, the system will not generate a resonance response because the excitation force amplitude is zero, thus fundamentally eliminating fatigue damage to core components caused by start-up and shutdown impacts.

[0039] The above description only illustrates the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention, and all such changes should be included within the protection scope of the present invention.

Claims

1. A resonant crusher vibration device with fixed-frequency amplitude adjustment, characterized in that: It includes a counterweight box (1), a lifting cylinder (2), a vibration damping frame (3), a vibration excitation box (4), a connecting stiffener (5), and a shear-type rubber vibration damper (6); the counterweight box (1) is hinged to the vibration damping frame (3) through the lifting cylinder (2), and the vibration damping frame (3) is connected to the vibration excitation box (4) through the shear-type rubber vibration damper (6) and the connecting stiffener (5); The excitation box (4) is equipped with an eccentricity adjustment mechanism. The eccentricity adjustment mechanism can synchronously adjust the included angle of the eccentric blocks and realize constant frequency stepless amplitude adjustment under the condition that the excitation shaft rotates at a constant speed without stopping. The connecting stiffeners (5) of different specifications can be replaced, and the tilt angle of the excitation box (4) relative to the damping frame (3) can be adjusted to change the angle of the crusher hammer impacting the road surface to form a tension-shear composite crushing. Two synchronously rotating excitation shafts in opposite directions drive the eccentric blocks to rotate. The horizontal centrifugal forces generated by the eccentric blocks cancel each other out, and the vertical centrifugal forces are superimposed on each other, forming a pure vertical excitation force to drive the breaker hammer to complete the road breaking operation.

2. The resonant crusher vibration device with fixed frequency amplitude adjustment according to claim 1, characterized in that: The lifting cylinders (2) are arranged in pairs on both sides of the counterweight box (1). The lower end of the lifting cylinder (2) is hinged to the counterweight box (1) and the upper end is hinged to the upper part of the vibration damping frame (3). The left and right side plates of the vibration damping frame (3) are symmetrically fixedly equipped with shear-type rubber vibration dampers (6). One end of the shear-type rubber vibration damper (6) is fixedly connected to the vibration damping frame (3), and the other end is detachably equipped with a connecting rib plate (5) or other angle vibration damper connecting rib plate (7). The other end of the connecting rib plate (5) or other angle vibration damper connecting rib plate (7) is fixed to the outer wall of the excitation box (4). The excitation box (4) is suspended as a whole below the vibration damping frame (3). The lifting cylinder (2) adjusts the ground pressure and the working height of the breaker hammer (49) by its own extension and retraction.

3. The resonant crusher vibration device with fixed frequency amplitude adjustment according to claim 1, characterized in that: The excitation box (4) includes an excitation box body (41), an active excitation shaft (42), an active gear (43), side eccentric blocks (44), a driven excitation shaft (45), a driven gear (46), a central eccentric block (47), an eccentricity adjustment mechanism (48), and a breaker hammer (49). The active excitation shaft (42) and the driven excitation shaft (45) are installed in parallel inside the excitation box body (41). The active excitation shaft (42) is fixedly fitted with the active gear (43) and two sets of side eccentric blocks (44), and the driven excitation shaft (45) is fixedly fitted with the driven gear (46) and... Two sets of side eccentric blocks (44), the driving gear (43) and the driven gear (46) mesh with each other to achieve the same speed and opposite rotation of the driving excitation shaft (42) and the driven excitation shaft (45); a middle eccentric block (47) is assembled between the two sets of side eccentric blocks (44) on a single driving excitation shaft (42) or driven excitation shaft (45); the eccentricity adjustment mechanism (48) is arranged at the lower part of one side of the driven excitation shaft (45), and the eccentricity adjustment mechanism (48) meshes with the middle eccentric block (47); the bottom end face of the excitation box (41) can be detachably fixed to the crusher hammer (49).

4. The resonant crusher vibration device with fixed frequency amplitude adjustment according to claim 3, characterized in that: The eccentricity adjustment mechanism (48) consists of a piston rod (481), a cylinder (482), and a herringbone tooth adjustment gear (483). The cylinder (482) is slidably sleeved on the outside of the piston rod (481), and the end face of the cylinder (482) is rigidly connected to the herringbone tooth adjustment gear (483). The piston rod (481) has a central oil passage inside, and the inner cavity of the cylinder (482) is divided into a rodless cavity and a rod cavity. Pressure oil is introduced into the rodless cavity to push the cylinder (482) forward along the piston rod (481). The herringbone tooth adjustment gear (483) drives the central eccentric block (47) to rotate relative to the side eccentric block (44). The deflection angle between the central eccentric block (47) and the side eccentric block (44) decreases, and the overall vibration force increases. Pressure oil is introduced into the rodless cavity to push the cylinder (482) forward along the piston rod (481). When the rod chamber is inserted, the cylinder (482) is pulled backward, the deflection angle of the central eccentric block (47) and the side eccentric block (44) increases, and the excitation force of the whole machine decreases. When the deflection angle is adjusted to 180°, the centroids of the central eccentric block (47) and the side eccentric block (44) are arranged in opposite directions, the combined equivalent eccentricity returns to zero, and the excitation force of the whole machine disappears completely. The herringbone tooth adjustment gear (483) adopts a herringbone tooth structure with a large helix angle. The helical teeth on both sides of the herringbone tooth adjustment gear (483) mesh synchronously with the driven helical gear of the active excitation shaft (42) and the driven excitation shaft (45) matched with the central eccentric block (47), ensuring that the rotation angle adjustment of the central eccentric block (47) on the active excitation shaft (42) and the driven excitation shaft (45) is synchronized, and eliminating the residual excitation force in the horizontal direction.

5. The resonant crusher vibration device with fixed frequency amplitude adjustment according to claim 3, characterized in that: The total static torque M of the single active excitation shaft (42) and the eccentric block (44) on the upper side of the driven excitation shaft (45) S =m1e1、Center eccentric block (47) Total static moment M m =m2e2, the static moments of all eccentric components of the active excitation shaft (42) and the driven excitation shaft (45) are equal; the combined equivalent eccentricity is determined only by the deflection angle α of the middle eccentric block (47) and the side eccentric block (44), and is independent of the rotational angular velocity of the active excitation shaft (42) and the driven excitation shaft (45). Under the condition that the mass, equivalent stiffness, damping and excitation frequency of the excitation system remain basically unchanged, the steady-state vibration amplitude of the breaker head (49) is linearly positively correlated with the combined equivalent eccentricity. Different deflection angles α match amplitude and construction conditions: α=135°~180°, the amplitude of the breaker hammer (49) is 5~8mm, suitable for pre-breaking and fine breaking of thin pavement layers; α=90°~135°, the amplitude of the breaker hammer (49) is 8~14mm, suitable for conventional breaking of medium strength concrete; α=45°~90°, the amplitude of the breaker hammer (49) is 14~18mm, suitable for breaking of high strength and thick pavement layers; α=0°~45°, the amplitude of the breaker hammer (49) is 18~20mm, suitable for breaking of ultra-thick and ultra-high strength concrete pavement.

6. The resonant crusher vibration device with fixed frequency amplitude adjustment according to claim 2, characterized in that: The connecting stiffener plate (5) and the connecting stiffener plate (7) of other angle dampers are provided with multiple sets of angle positioning mounting surfaces, or have multiple mounting holes of 0°, 5°, 7°, 9° and 11°. By changing the connecting stiffener plate (5) of different specifications and the connecting stiffener plate (7) of other angle dampers or by switching the mounting hole positions on the stiffener plate, the breaker hammer (49) can form a multi-angle impact tilt angle. When the breaker hammer (49) hammers the road surface, it simultaneously generates tensile stress and shear stress, generating tensile-shear composite cracks and improving the energy utilization rate of the breaker. The breaker hammer (49) is a split structure and is locked and fixed to the bottom of the excitation box (41) by 8 sets of countersunk bolts.

7. A method for starting and stopping a resonant crusher vibration device based on the fixed-frequency amplitude adjustment according to any one of claims 1 to 6, characterized in that, Includes the following steps: Step 1, Pre-start adjustment: After receiving the start command, the control system delivers pressurized oil to the cylinder (482) of the eccentricity adjustment mechanism (48), drives the herringbone tooth adjustment gear (483) to rotate, and adjusts the deflection angle α of the middle eccentric block (47) and the side eccentric block (44) of the active excitation shaft (42) and the driven excitation shaft (45) to 180°, so that the combined equivalent eccentricity is zero, and the excitation force and vibration amplitude of the breaker hammer (49) are synchronously zeroed. Step 2, Zero-excitation start: Start the hydraulic power system to drive the input end of the active excitation shaft (42) extending out of the excitation box (41) to rotate. Through the meshing transmission of the active gear (43) and the driven gear (46), the driven excitation shaft (45) is driven to synchronously and smoothly accelerate in the opposite direction to the preset constant resonance working speed. The excitation frequency is maintained to match the inherent resonance frequency of the cement concrete pavement throughout the process. Step 3, Smooth Loading Operation: After the rotational speeds of the active excitation shaft (42) and the driven excitation shaft (45) stabilize, the control system slowly reduces the deflection angle α of the central eccentric block (47) and the side eccentric block (44) to the target working angle within 3 to 5 seconds through the hydraulic reversing valve. The vibration amplitude of the breaker hammer (49) smoothly rises from zero to the set value. The deflection angle α can be adjusted in real time throughout the road construction process, and the excitation amplitude of the breaker hammer (49) can be dynamically and steplessly adjusted. Step 4, Smooth Unloading and Shutdown: After the single-section road breaking operation is completed, the control system slowly increases the deflection angle α of the central eccentric block (47) and the side eccentric block (44) to 180° within 3 to 5 seconds, and the vibration amplitude of the breaking hammer (49) gradually returns to zero. Step 5, Zero-vibration shutdown: After confirming that the excitation force of the breaker hammer (49) is completely zero, shut down the hydraulic power system and the active excitation shaft (42) and the driven excitation shaft (45) decelerate smoothly without impact until they stop rotating.

8. The start-up and shutdown method of the resonant crusher vibration device with fixed frequency amplitude adjustment according to claim 7, characterized in that: Throughout the crushing operation, the active excitation shaft (42) and the driven excitation shaft (45) are locked at a constant resonant speed, breaking through the technical constraint of strong coupling between excitation frequency and amplitude in traditional resonant equipment. The vibration amplitude of the crusher hammer (49) can be changed independently by adjusting the deflection angle α of the central eccentric block (47) and the side eccentric block (44), and the excitation frequency remains constant throughout the entire process.

9. The start-up and shutdown method of the resonant crusher vibration device with fixed frequency amplitude adjustment according to claim 7, characterized in that: The entire process of equipment startup and shutdown relies on adjusting the central eccentric block (47) and the side eccentric block (44) to 180° to achieve a zero-vibration state of the whole machine. The zero-vibration force passes through the resonance range of the system, reducing the fatigue damage of resonance impact on the bearings of the active excitation shaft (42), the driven excitation shaft (45), the meshing active gear (43) and driven gear (46), and the bottom crushing hammer (49), extending the service life of the core components of the device, and reducing the failure rate and daily maintenance cost of the whole machine.

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