Maintenance crack pouring device for highway traffic engineering

Abstract

The invention discloses a maintenance crack pouring device for road traffic engineering, and belongs to the technical field of road traffic, the maintenance crack pouring device comprises a pump body, a gear set, a floating side plate and a power unit, the floating side plate is movably arranged on the outer side of the end face of the gear set, and a gap compensation mechanism is arranged between the floating side plate and the pump body; the clearance compensation mechanism comprises an elastic element and a hydraulic auxiliary assembly, the elastic element provides initial pre-tightening force, and the hydraulic auxiliary assembly dynamically adjusts the attaching pressure of the floating side plate and the gear set according to the medium pressure. The clearance compensation mechanism is arranged between the floating side plate and the pump body, and dynamic self-adaptive adjustment of the gear end face clearance is achieved through the synergistic effect of the elastic element and the hydraulic auxiliary assembly. Initial pre-tightening force is provided through the elastic element, the hydraulic auxiliary assembly dynamically adjusts attaching pressure according to medium pressure, leakage of rubber in a high-pressure cavity is effectively restrained, and the phenomenon that rubber is not sucked back thoroughly due to insufficient negative pressure of a pump cavity is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of highway traffic, in particular to a maintenance crack pouring device for highway traffic engineering. BACKGROUND

[0002] In the field of road maintenance, cracks as one of the most typical forms of disease seriously affect the stability and service life of road structure. As the core equipment of crack pouring technology, the performance of crack pouring machine directly determines the repair quality. The existing crack pouring machine generally uses a low-pressure gear pump as a power unit for its discharge system. However, in long-term engineering practice, three major technical bottlenecks have been exposed, which not only restrict the efficiency of the equipment, but also have a systematic impact on the durability of the crack pouring process.

[0003] When the gear end face and the side plate cooperate with a gap that expands from the design value of 0.05-0.1mm due to wear, the glue in the high-pressure cavity will flow back through the gap during the suction process. This leakage leads to insufficient negative pressure in the pump cavity. According to actual measurements, the negative pressure value decreases by 35%-40% compared to the initial state in the later wear stage, directly causing incomplete glue suction. The unrecycled glue solidifies and adheres to the inner wall of the flow channel after cooling, forming a solidified layer with a thickness of 0.3-0.8mm, which becomes the main cause of gun blockage during subsequent operation. In a construction season, statistics show that the frequency of equipment downtime for cleaning due to side plate leakage reaches 0.8-1.2 times per kilometer, seriously affecting the construction progress requirement of 15-20 kilometers per day.

[0004] The trapped oil phenomenon in the gear meshing area forms a closed cavity. When the gear pump switches from the pressure-out state to the oil suction state, the glue in the trapped oil area cannot be discharged in time. In winter construction sites, the phenomenon is more serious. The solidification speed of residual glue is 2-3 times faster than at normal temperature, forming solidified particles with a particle size of 2-5mm that block the intermeshing flow channel. This type of blockage can cause a decrease in pump volume rate, which is manifested as a fluctuation in glue output pressure (±0.3MPa) during crack pouring, resulting in a 10%-15% void rate in crack filling. Field tests show that the secondary cracking rate of crack pouring sections with trapped oil residue problems increases by 22% within 12 months, mainly due to the infiltration of rainwater into the base layer due to incomplete glue filling, causing structural damage.

[0005] The inherent limitation of low-pressure pump design is particularly obvious when processing high-viscosity crack pouring glue (viscosity >=8000 mPa.s at 25 DEG C), the pressure difference between the inlet and outlet thereof can only be maintained at 0.2-0.5 MPa, which is 60%-80% lower than that of a higher-pressure pump (1.5-3.0 MPa), and this insufficient pressure difference causes the glue to flow at a speed lower than 0.1 m / s in the discharge pipeline (inner diameter 12-16 mm) during the back suction stroke, which cannot overcome the adhesion force of the pipeline wall to complete complete emptying, and the residual glue forms a bonding layer with uneven thickness at the pipeline bend and valve connection, and after 50-80 operation cycles, the effective cross-sectional area of the flow passage is reduced by 30%-40%, which eventually causes regional blockage, and more importantly, the glue that is not completely emptied is locally overheated when heated next time, which causes the aging index of the crack pouring glue to increase, and the tensile strength and elongation at break thereof decrease, which seriously affects the fatigue resistance of the sealing layer. SUMMARY

[0006] In view of the above-mentioned defects of the prior art, the present application provides a maintenance crack pouring device for highway traffic engineering.

[0007] To achieve the above object, the present application is implemented by the following technical solutions: A maintenance crack pouring device for highway traffic engineering, comprising a pump body, a gear set, a floating side plate and a power unit, the floating side plate is movably arranged on the outer side of the end face of the gear set, and a gap compensation mechanism is arranged between the floating side plate and the pump body. The gap compensation mechanism comprises an elastic element and a hydraulic auxiliary assembly, the elastic element provides an initial pre-tightening force, and the hydraulic auxiliary assembly dynamically adjusts the fitting pressure of the floating side plate and the gear set according to the medium pressure.

[0008] Preferably, the edge of the floating side plate is provided with an inclined edge, and the extension direction of the inclined edge forms a preset angle with the rotation direction of the gear set.

[0009] Preferably, a flow guide groove is formed in the surface of the floating side plate, the inner corner of the floating side plate is a circular arc structure, the flow guide groove extends along the tangent direction of the circular arc structure to connect the high-pressure side and the low-pressure side of the floating side plate, and the center of the circular arc structure is located on the outside of the meshing area of the gear set.

[0010] Preferably, the elastic element is a variable stiffness elastic element, and the hydraulic auxiliary assembly comprises a temperature control valve and a hydraulic chamber, the temperature control valve switches the connection state of the hydraulic chamber and the high-pressure area or the low-pressure area of the pump body according to the medium temperature.

[0011] Preferably, a anti-sticking sleeve is sleeved around the variable stiffness elastic element, the material of the anti-sticking sleeve is a low surface energy material, and the inner wall of the anti-sticking sleeve is matched with the outer contour shape of the variable stiffness elastic element.

[0012] Preferably, a mating surface between the floating side plate and the pump body is provided with a labyrinth sealing structure, and the labyrinth sealing structure includes at least one annular groove.

[0013] Preferably, a filter unit is provided at the inlet end of the gear set, and the filter unit includes a magnetic adsorption component and a filter screen.

[0014] Preferably, the surface of the inclined cutting edge is coated with an anti-stick coating, and the surface energy of the anti-stick coating is smaller than the surface tension of the medium.

[0015] Preferably, the inner wall of the pump body is provided with a guide groove, the outer edge of the floating side plate is embedded in the guide groove, and the cross-sectional shape of the guide groove is a shape that limits the circumferential rotation of the floating side plate.

[0016] Preferably, a pressure balancing hole is provided on the back side of the floating side plate, and the pressure balancing hole passes through the floating side plate and connects the high-pressure area of ​​the gear set with the hydraulic chamber of the clearance compensation mechanism.

[0017] Compared with the prior art, the present invention has at least the following benefits: 1. The present invention achieves dynamic adaptive adjustment of the gear end face clearance by providing a gap compensation mechanism between the floating side plate and the pump body, utilizing the synergistic effect of elastic elements and hydraulic auxiliary components. This design directly addresses the core issue of "rubber backflow caused by wear and tear between the gear end face and the side plate" in the background technology. By providing initial preload force through elastic elements and dynamically adjusting the fitting pressure according to the medium pressure through hydraulic auxiliary components, the leakage of rubber in the high-pressure chamber is effectively suppressed, and the phenomenon of incomplete rubber back-absorption caused by insufficient negative pressure in the pump chamber is avoided. This fundamentally reduces the formation of a solidified layer on the inner wall of the flow channel after shutdown and cooling, reduces the frequency of spray gun clogging, and significantly improves the continuous operation capacity and construction efficiency of the grouting equipment.

[0018] 2. The inclined cutting edge and surface guide groove design on the edge of the floating side plate can effectively release the trapped oil pressure in the gear meshing area by guiding the flow direction of the rubber and connecting the high-pressure side and the low-pressure side, breaking the vicious cycle of "closed cavity causing rubber retention and solidification" in the background technology, reducing the generation of particle size solidified particles, reducing the risk of decreased volume rate of the pump body, improving the stability of the rubber output pressure, thereby reducing the void rate of crack filling and inhibiting the secondary cracking problem caused by loose rubber filling.

[0019] 3. The combination of variable stiffness elastic parts and temperature control valves enables the gap compensation mechanism to automatically switch the pressure compensation mode according to the medium temperature, solving the temperature sensitivity problem of "low-temperature curing acceleration and high-temperature spring softening" in the background technology, ensuring that the device can maintain stable sealing under different seasonal working conditions, and avoiding gap control failure and abnormal curing of rubber due to temperature fluctuations.

[0020] 4. The labyrinth seal structure, anti-sticking coating and guide groove are designed, the adhesion resistance of high viscosity rubber in the flow channel is reduced through mechanical drag reduction and material anti-adhesion characteristics, the accumulation of adhesive layer at the pipe bend and valve is reduced by the interception of impurity particles by the filtering unit, the problem of reducing the cross-sectional area of the flow channel is solved, and the local overheating and aging of the rubber is avoided, and the fatigue resistance of the sealing layer is improved.

[0021] 5. The pressure balance hole and guide groove are arranged to ensure the accurate axial movement of the floating side plate and the balanced pressure field, avoid abnormal wear caused by circumferential rotation and local pressure mutation, and prolong the service life of the core components such as gear set and side plate from the aspects of “friction reduction” and “wear resistance” in combination with the adsorption of ferromagnetic particles by the filtering unit, thereby reducing the equipment maintenance frequency and cost. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0023] Figure 1 It is a perspective view of a maintenance crack pouring device for highway traffic engineering of the present application; Figure 2 It is an enlarged structure schematic view of A of the present application; Figure 1 Figure 3 It is a side sectional view structure schematic view of the pump body of the present application; Figure 4 It is a structure schematic view of the elastic element, hydraulic chamber, inclined blade, flow guide groove and pressure balance hole of the present application; Figure 5 It is a guide groove installation position structure schematic view of the present application; Figure 6 It is a force balance verification curve diagram of the floating side plate gap compensation mechanism of the present application; Figure 7 It is a curve diagram of the influence of gear rotational speed on fluid dynamic pressure film thickness and gap of the present application; Figure 8 It is an experimental diagram of the influence of spring pre-tightening force on the compensation ability of the floating side plate of the present application; Figure 9 It is a temperature control valve response delay experimental curve diagram of the present application; Figure 10 It is a trapped oil pressure comparison experimental diagram of the gear pump of the present application; Figure 11 It is a key parameter relationship and effect comparison diagram of the present application;​ Figure 12 a parameter correlation heat map of the present application; Figure 13 a temperature-gap measurement error bar chart of the present application; Figure 14 a error source contribution degree Pareto chart of the present application.

[0024] The reference numerals in the figures represent respectively: 1, pump body; 2, gear set; 3, floating side plate; 4, power unit; 5, elastic element; 6, temperature control valve; 7, hydraulic cavity; 8, inclined blade; 9, flow guide groove; 10, guide groove; 11, filter unit; 12, pressure balance hole. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the protection scope of the present application.

[0026] It needs to be mentioned that part of the structure of the present scheme is small in size and inconvenient to show. The structure not shown will be described below and a detailed textual description will be given.

[0027] The following medium is a high-viscosity crack pouring glue, such as heated asphalt material.

[0028] As shown in Figures 1-5 A maintenance crack pouring device for highway traffic engineering is composed of a pump body 1, a gear set 2, a floating side plate 3, a power unit 4 and a gap compensation mechanism, wherein the power unit 4 is a 7.5kW variable frequency motor, which is rigidly connected with the pump body 1 through a flange plate; The gear set 2 is driven to rotate to suck the high-viscosity medium from the feeding port of the pump body 1 and discharge it from the discharging port after being extruded by the meshing of the gear set 2, the gear set 2 is a parallel arrangement of driving teeth and driven teeth (modulus m=4, number of teeth z1=20 / z2=25, material 20CrMnTi carburizing and quenching, tooth surface hardness HRC58-62), the two gears are installed on the pump body 1 through a driving shaft (diameter Φ25mm) and a driven shaft (diameter Φ22mm), and the shafts are supported at both ends by deep groove ball bearings (rated speed 3000r / min); The bearing outer ring is interference-fitted with the bearing hole of the pump body 1 (interference amount 0.02mm), and the inner ring is clearance-fitted with the shaft neck (clearance 0.01mm), and when assembling, the parallelism of the two shafts is calibrated by a laser centering instrument to ensure that the initial gap between the gear end face and the floating side plate (3) is 0.05mm; The floating side plate 3 is in a circular flat structure, arranged on both end faces of the gear set 2, and the outer edge is processed to be convex, forming a 0.05mm sliding fit with the guide groove 10 on the inner wall of the pump body 1, and the groove is sprayed with a solid lubricating coating of molybdenum disulfide (thickness 20μm) to limit the circumferential rotation of the floating side plate 3 and allow axial translation; At least one annular labyrinth groove is provided on the mating surface of the floating side plate 3 and the pump body 1, filled with high-temperature-resistant graphite lubricating grease to form a multi-stage throttling seal; The gap compensation mechanism includes an elastic element 5 and a hydraulic auxiliary assembly. The elastic element 5 is a double-pitch variable stiffness spring (material 60Si2MnA, 350℃ tempering treatment), with a free length of 50mm, an outer diameter of 30mm, and a wire diameter of 5mm. It is installed between the back seat of the floating side plate 3 and the rear end cover of the pump body 1 through two end compression bolts, and the bolts are pre-tightened to 25Nm (initial pre-tightening force 500N, initial compression amount 8mm) using a torque wrench. The spring is circumferentially sleeved with a polytetrafluoroethylene anti-sticking sleeve (not shown in the figure, wall thickness 1mm, inner diameter 30.2mm, gap with spring 0.1mm), which is formed by hot pressing process (temperature 280℃, pressure 5MPa) or other equivalent low surface energy materials (such as PTFE coating, coating surface energy ≤15mN / m); The hydraulic auxiliary assembly includes a temperature control valve 6 and a hydraulic chamber 7. The temperature control valve 6 is a bimetallic strip temperature control switch (model KSD301, action temperature 80℃±5℃), which is installed vertically in the blind hole on the side wall of the pump body 1 (hole depth 20mm, not penetrating the pump body) through threads. The valve core extends to the back of the floating side plate 3 through a Φ4mm red copper pipe (wall thickness 0.5mm) along the preformed channel on the inner wall of the pump body 1 to connect the hydraulic chamber 7; The hydraulic chamber 7 is an annular cavity, which is provided on the back of the floating side plate 3, and the edge is matched with the annular groove of the end cover of the pump body 1 through a fluororubber lip seal ring (not shown in the figure) to form an independent hydraulic space, which separates the asphalt flow channel inside the pump body through the floating side plate 3; It is worth mentioning that the annular groove structure (not shown in the figure) has been reserved in the initial design of the pump body, and its position is staggered by 5mm from the guide groove 10, ensuring that the two functions are independent (the guide groove 10 is responsible for circumferential positioning, and the annular groove is responsible for hydraulic sealing), and the groove depth is greater than the compression amount of the seal ring (1.0mm>0.5mm), avoiding interference with the movement of the floating side plate; When the floating side plate 3 moves axially, the lip edge deforms elastically (maximum compression amount 0.5mm), forming a dynamic sealing interface, allowing the floating side plate 3 to move freely within a stroke of 0.05-1.5mm, while ensuring that the hydraulic oil leakage is ≤0.08mL / min; The material of the seal ring is FKM fluororubber, with a temperature resistance range of -20℃-200℃, and the surface is treated with PTFE coating (surface energy ≤18mN / m), reducing the adhesion resistance of hydraulic oil; When the medium temperature ≥ 80℃, the temperature control valve 6 valve core switches to the high pressure area of the pump body (pressure is taken at 50mm downstream of the discharge port, a Φ2mm stainless steel filter screen is built-in, the aperture is 0.1mm, preventing the particles of the rubber compound from entering the hydraulic system), the hydraulic oil enters the hydraulic cavity 7 through the copper pipe, the hydraulic oil is completely isolated from the asphalt medium; Among them, the hydraulic oil is Mobil DTE25 anti-wear hydraulic oil or equivalent grade (such as anti-wear hydraulic oil with viscosity grade ISO VG 46), the density is 0.86g / cm³, and the density difference with asphalt is ≥0.15g / cm³; The temperature control valve 6 valve core surface is coated with a diamond-like coating (thickness 2μm, surface energy ≤15mN / m), which does not directly contact the asphalt, and a one-way valve is arranged at the inlet end of the copper pipe (shown in the figure, opening pressure 0.05MPa), preventing the asphalt from flowing backward; When the temperature < 80℃, the valve core switches to the low pressure area (pressure is taken near the inlet), the hydraulic oil in the hydraulic cavity 7 returns to the low pressure area of the pump body through the copper pipe, the pressure decreases to 0.1MPa within 2 seconds, and the floating side plate (3) retreats 0.5mm under the action of the double-pitch spring 5.

[0029] It should be noted that the temperature is an indirect representation parameter of pressure change, and a pressure sensor can be added for direct monitoring if necessary.

[0030] The floating side plate 3 edge is processed with a 45±2° inclined edge 8 with a width of 4mm, a tungsten carbide coating (thickness 50μm) is sprayed by laser cladding process, and a 0.03mm fluid dynamic pressure film is formed with the gear end face (bearing pressure 0.8MPa when the gear rotates at 200r / min), the edge design avoids the 5mm gear root circle to prevent interference; at least one circumferentially distributed flow guide groove 9 is provided on the surface, which extends along the tangent direction of the R15mm arc (the center distance from the gear meshing area edge is 5mm), the groove width is 3mm and the depth is 2mm, the inlet end is rounded R0.5mm, and the outlet end is communicated with the low pressure area; when the outlet pressure is 3MPa, the flow guide groove 9 guides the high pressure rubber compound into the low pressure area at a flow rate of 1.2m / s, and the measured oil pressure peak value is reduced from 4.5MPa to 3.2MPa; The gear set 2 inlet end is installed with a filter unit 11 through a quick-release clamp (304 stainless steel clamp, this clamp is prior art and will not be described), which is composed of an inner magnetic grid (neodymium iron boron permanent magnet, magnetic induction intensity 0.6T, thickness 10mm) and a metal filter screen (316L stainless steel, aperture Φ0.5mm, mesh 30 mesh, distance from the pump body 10mm) from inside to outside, the magnetic grid adsorbs ferromagnetic particles, and the filter screen intercepts >0.3mm impurities, which can be taken out and cleaned by loosening the clamp when disassembled; A pressure balance hole 12 is arranged at the center of the back of the floating side plate 3 and penetrates the floating side plate 3, and a stepped hole diameter (an inlet Φ1.2 mm, a middle Φ0.8 mm, and an outlet Φ1.5 mm, with a machining tolerance of ±0.02 mm) is adopted, and a 45° flow guide inclined surface (roughness Ra≤0.2 μm, PTFE coating is sprayed, and the inner wall roughness Ra≤1.6 μm) is machined at the inlet end, and a fluorine rubber O-ring (sectional diameter 1.8 mm, temperature resistance 200℃) is embedded at the outlet end, so that the differential pressure self-sealing (ΔP=0.05 MPa) between the hydraulic cavity 7 and the high pressure area is realized. The pressure balance hole 12 at the back of the floating side plate 3 realizes the pressure dynamic balance between the hydraulic cavity 7 and the high pressure area of the pump body through the stepped variable diameter structure and the fluid throttling effect. The stepped design of the pressure balance hole 12 is as follows: The inlet section (Φ1.2 mm) is used as the initial channel of the asphalt medium, and a preliminary throttling is formed by using a smaller hole diameter (Reynolds number Re≈2100, in the critical region of laminar flow); The middle section (Φ0.8 mm) accelerates the fluid through the Venturi effect (the flow rate is increased to 3.2 m / s), and a local low pressure area (pressure drop ΔP≈0.03 MPa) is formed; The outlet section (Φ1.5 mm) has a sudden drop in flow rate (to 1.4 m / s), and the pressure rises but retains a pressure difference of 0.05 MPa (ΔP=P high pressure area-P hydraulic cavity), which is just used to push the fluorine rubber O-ring to realize self-sealing; The fluorine rubber O-ring (sectional diameter 1.8 mm, Shore hardness 75A) embedded at the outlet end is elastically deformed under the action of the pressure difference: In static state, the O-ring forms an initial linear seal with the outlet end surface of the balance hole (contact stress≈0.5 MPa); When working, the 0.05 MPa pressure difference pushes the O-ring to the low pressure side (hydraulic cavity), so that the contact area between the sealing ring and the hole wall is expanded to 2.3 mm 2 , the contact stress is increased to 1.2 MPa (> saturated vapor pressure of hydraulic oil 0.8 MPa), and a no-leakage seal is realized; Temperature compensation, the elastic modulus of fluorine rubber decreases by 30% at 200℃, but the surface hardness is improved through the PTFE coating (thickness 15 μm), so that the contact stress is still maintained at more than 0.8 MPa at high temperature.

[0031] According to the Hagen-Poiseuille equation, the relationship between the flow rate Q in the balance hole and the pressure difference ΔP is:

[0032] Wherein, d = 0.8mm (middle diameter), μ = 1200mPa・s (180℃ asphalt viscosity), L = 15mm (total length of hole) calculated Q ≈ 0.08mL / min, which is completely matched with the hydraulic oil leakage index (≤0.08mL / min), proving that the design parameters are reasonable.

[0033] The axial gap between the gear shaft and the floating side plate 3 is calibrated by the following steps: 1. The driving shaft and the driven shaft are installed in the pump body 1, and the bearing end cover is pre-tightened; 2. The floating side plate 3 is installed, and the initial gap is measured to be 0.05mm by using a plug gauge; 3. The elastic element 5 is installed, and the bolt is pre-tightened to 25N・m; 4. The idle running is carried out, the floating amount of the side plate is monitored by using a displacement sensor, and the thickness of the bearing end cover gasket is adjusted (the accuracy is ±0.01mm) until the gap is stable; Under high temperature working conditions, the stiffness of the double-pitch spring increases with the increase of temperature (the change rate is 0.5% / ℃), and the stiffness increases from 150N / mm to 200N / mm at 180℃, and the total compression amount is 9.5mm (initial 8mm+temperature additional 1.5mm), and the gap is controlled to be within 0.08mm under the cooperation of the hydraulic cavity pressure (2.95MPa); After the power unit 4 is started, the driving gear rotates counterclockwise (the turning direction is adjusted by the motor phase sequence), the driven gear meshes clockwise, and the negative pressure (vacuum degree ≤-0.08MPa) is formed in the meshing cavity when the tooth top is separated, the medium enters the inter-tooth groove through the filter unit 11, the volume decreases when the tooth top meshes, and the medium is compressed (compression ratio 1.8:1), and is discharged from the discharge port; The operation process is as follows: the crack sealing glue is heated to 180℃±5℃, the pump body is preheated to 100℃, the motor is started at 50r / min, and gradually accelerated to 200r / min (acceleration gradient 50r / min / 30s), the outlet pressure is adjusted to 0.8MPa by using a PID controller, the axial displacement of the floating side plate is monitored in real time by using a laser displacement sensor (range ±2mm, accuracy 0.001mm), the motor is reversed at 20r / min for 30 seconds during back suction, the outlet pressure is less than 0.1MPa, and the residual glue discharge rate is greater than or equal to 98%; The maintenance cycle is to disassemble the filter unit 11 every 50 hours for ultrasonic cleaning, and the cleaning is triggered according to the operation time; The spring force gauge is used to detect the stiffness of the elastic element 5 every 200 hours (allowable deviation ±3%), and the spring performance is ensured by manual calibration.

[0034] Experimental example 1: force balance verification of floating side plate gap compensation mechanism; Verify whether the resultant force of the elastic element (spring) and the hydraulic cavity at different temperatures can control the gap within the design range (0.05-0.1mm); The calculation formula is:

[0035] Experimental equipment:

[0036] Experimental steps: 1. Install the double-pitch spring between the floating side plate back and the pump body rear end cover, pre-tighten the compression bolt to 25 N·m using a torque wrench, and set a Teflon anti-sticking sleeve; 2. Connect the hydraulic cavity to the temperature control valve through a copper pipe, and install a pressure sensor on the copper pipe to monitor the hydraulic oil pressure in real time; 3. Align the laser displacement sensor with the end face of the floating side plate to monitor the axial gap with the gear set (initial gap set to 0.05 mm); 4. Fix the pump body assembly in the circulating tank to ensure temperature uniformity (tank air speed ≥ 2 m / s); 5. Start the data acquisition system, record the spring force, hydraulic cavity pressure (low pressure area), and gap at room temperature, force input 80°C signal through the temperature control valve test bench, observe the hydraulic cavity pressure, spring compression, and gap, and record the data; 6. Gradually increase the temperature by 20°C, 50°C, 80°C, 120°C, 150°C, and 180°C, and maintain each temperature point for 30 minutes (ensure thermal equilibrium of the assembly), measure the real-time load on both ends of the spring using a spring dynamometer (disconnect one end of the bolt, quickly measure and reset), record the pressure in real time (connect to the high pressure area when the temperature is ≥ 80°C, and connect to the low pressure area when the temperature is < 80°C), continuously collect data using the laser displacement sensor, take the average value within 10 seconds, repeat the test 3 times at each temperature point, and take the average value to reduce random errors.

[0037] The force balance verification of the floating side plate gap compensation mechanism is shown in Figure 6 At room temperature (20°C), the elastic element (variable stiffness spring) provides an initial pre-tightening force of 500 N, the hydraulic cavity is connected to the low pressure area (pressure 0.1 MPa), and the gap is stable at the design value of 0.05 mm; At high temperature (180°C), the temperature control valve switches to the high pressure area, the hydraulic cavity pressure rises to 2.95 MPa, the spring stiffness increases to 200 N / mm with the temperature rise, the resultant force controls the gap at 0.08 mm, which does not exceed the design upper limit of 0.1 mm, and the temperature and gap are positively correlated (slope 0.0005 mm / °C), but through force balance control, the gap fluctuation is limited within ±0.03 mm; The hydraulic cavity pressure and spring force dynamically superimpose with temperature, satisfying the force balance equation, ensuring that the sealing force matches the medium pressure, and avoiding high pressure leakage; Through the synergy of elastic element and hydraulic auxiliary assembly, the problem of rubber backflow caused by the expansion of gap after the wear of traditional side plate is solved. The measured negative pressure drop is reduced from 35%-40% to within 10% in the later wear stage, and the rubber backflow is completely improved to 98%. The combination of variable stiffness spring and temperature control valve makes the device maintain stable gap in a wide temperature range of-20-200°C, avoiding abnormal wear caused by spring softening at high temperature or excessive rigidity at low temperature.

[0038] Experimental Example 2: Influence of Gear Rotational Speed on Fluid Dynamic Pressure Film Thickness and Gap; The influence of gear rotational speed on the gap between floating side plate and gear end face, fluid dynamic pressure film thickness and trapped oil pressure is analyzed to determine the sensitive speed range.

[0039] Experimental Equipment:

[0040] Experimental Steps: 1. Set the motor speed to 50 r / min, preheat the pump body to 100°C, adjust the initial gap of the floating side plate to 0.05 mm, inject 180°C asphalt medium, and run for 5 minutes to ensure stability; 2. Speed point setting: 50, 100, 150, 200, 250, 300 r / min, each speed maintained for 15 minutes, real-time monitoring by laser displacement sensor, taking average value (sampling frequency 10 Hz), calculating dynamic pressure film thickness by formula:

[0041] Where μ is viscosity, n is rotational speed, d is gear diameter, k is constant, and p is load pressure; The trapped oil pressure is recorded by the pressure sensor as the peak pressure in the gear meshing area.

[0042] The influence of gear rotational speed on fluid dynamic pressure film thickness and gap is shown in Figure 7 When the rotational speed is below 150 r / min, the fluid dynamic pressure film thickness increases linearly with the speed (slope 0.002 μm / (r / min)), and the gap remains at 0.05-0.08 mm. When the rotational speed exceeds 200 r / min, the film thickness growth slows down, and the gap fluctuation increases (±0.02 mm), indicating that there is an optimal speed range (150-200 r / min).

[0043] The peak trapped oil pressure increases quadratically with the speed (P peak =0.005n 2 +0.004n+0.58). The trapped oil pressure at 200 r / min is 28.9% lower than that at 100 r / min (due to the effect of flow guide groove); When the rotating speed is 200 r / min, the dynamic pressure film thickness is 0.8 μm, which is just between the roughness of the gear end face (Ra≤0.2 μm) and the particle size of the rubber (≤0.5 mm), and an ideal fluid lubrication state is formed; The stable dynamic pressure film is formed between the gear and the side plate by optimizing the rotating speed range and designing the flow guide groove, and the direct contact wear is reduced, and the actual bearing life is prolonged from 500 hours to 1200 hours; The peak value of the trapped oil pressure is reduced from 4.5 MPa to 3.2 MPa, the output pressure fluctuation of the crack sealing rubber is ≤±0.1 MPa, the crack filling cavity rate is reduced from 10-15% to less than 5%, and the durability of the sealing layer is improved.

[0044] Experimental Example 3: Influence of spring pre-tightening force on compensation capacity of floating side plate; The influence of spring pre-tightening torque (20-30 N·m) on the initial gap, temperature compensation amount and spring fatigue life of the floating side plate is analyzed.

[0045] Experimental equipment:

[0046] Experimental steps: 1. Pre-tightening torque is divided into 5 groups: 20, 23, 25, 28, 30 N·m, corresponding to initial pre-tightening force: 400 N, 460 N, 500 N, 560 N, 600 N (force arm 0.05 m), 3 same springs are installed in each group, and the test repeatability is tested. 2. The initial gap (design value 0.05 mm) and the natural frequency of the spring under each pre-tightening force are measured (by a laser vibration tester), a high temperature trigger is simulated manually (hydraulic chamber pressure 2.95 MPa), and the gap compensation amount (ΔL=initial gap-high temperature gap) is recorded. 3. The spring is placed in a 180℃ constant temperature box, and a cyclic load (pre-tightening force±20%) is applied, and the fatigue life (breaking cycle number) is recorded.

[0047] The influence of spring pre-tightening force on the compensation capacity of floating side plate is shown in Figure 8 As the pre-tightening force increases from 400 N to 600 N, the initial gap deviation decreases from +0.02 mm to -0.01 mm, the high temperature compensation amount increases from 1.2 mm to 1.8 mm, but the spring fatigue life decreases from 8 million cycles to 5 million cycles Figure 8 (normal distribution fitting).

[0048] When the pre-tightening force is 25 N·m (500 N), the compensation amount is 1.5 mm, and the fatigue life is 6.8 million times, which balances the response speed and durability; The pre-tightening force increases by 100 N, the spring natural frequency increases by 5 Hz (from 20 Hz to 35 Hz), the high temperature response delay decreases by 0.3 seconds, but the thermal aging stiffness attenuation rate increases by 2% / 100 hours; Optimizing the pre-tightening force parameter (25 N·m) makes the spring life increase by 36% under high frequency temperature cycle, and reduces the maintenance frequency (from calibration every 200 hours to 500 hours).

[0049] The pre-tightening force matches the spring stiffness, ensuring that the side plate completes 0.5 mm displacement compensation within 0.1 seconds, adapting to the frequent start-stop working conditions of the crack sealing machine.

[0050] Experimental Example 4: Temperature Control Valve Response Delay Simulation Experiment; When the medium temperature steps change, the response time of the temperature control valve and the time for the hydraulic chamber pressure to reach a stable value are simulated to verify whether the design requirements (response time ≤ 2 seconds) are met; Based on the first-order system dynamic characteristic theory, the temperature control valve and the hydraulic pipeline are simplified as an inertial link, and the time constant and delay characteristics are analyzed through the step response curve.

[0051] Experimental steps: 1. Establish the differential equation of the temperature control valve-hydraulic chamber system:

[0052] Where τ is the time constant (s), K is the gain (MPa / ℃), and u(t) is the temperature step input (℃); According to the temperature control valve specification (KSD301) and the pipeline parameters (Φ4mm copper pipe length 0.3m), the model parameters are determined, τ=0.6s, K=0.037MPa / ℃; 2. Temperature from 20℃ to 80℃ (ΔT=60℃), simulate high temperature trigger scene, pressure chamber pressure p(t), sampling interval 0.02 seconds, monitoring time 5 seconds; 3. Use Euler method to solve the differential equation, the calculation steps are as follows:

[0053] Iterative calculation:

[0054] Repeat until t=5 seconds, record the pressure sequence ; 4. From the temperature step time, to the time required for the pressure to reach 95% of the stable value (2.95MPa) (i.e. the minimum t for p(t)≥2.8MPa), generate the pressure-time curve through data plotting tool, mark the delay time (t d ) and the rise time (t r ).

[0055] Temperature control valve response delay experiment, as shown in Figure 9 When the temperature is stepped from 20℃ to 80℃, the response time of the temperature control valve is 1.2 seconds, and 95% of the steady value (2.95MPa) of the hydraulic cavity pressure is reached in 2.8 seconds, meeting the design requirement (≤2 seconds).

[0056] The first-order system model fitting shows that the time constant τ=0.6 seconds and the gain K=0.037MPa / ℃, which is consistent with the theoretical calculation, verifying the matching of the temperature control valve and the pipeline parameters.

[0057] A response delay of ≤2 seconds can avoid the retention and solidification of high-temperature rubber in the gap. The actual measurement shows that the gap compensation is completed within 5 seconds after shutdown, and the residual amount of rubber is <0.1g.

[0058] The coordination of the temperature control valve and the hydraulic cavity enables the gap between the side plates to be adjusted within 2 seconds under high-temperature working conditions, which is 80% faster than the traditional mechanical compensation mechanism, reduces the flow channel blockage caused by rubber solidification, and improves the sealing reliability: the hydraulic cavity pressure intervenes in time under high temperature, increasing the side plate fitting pressure to 2.5 times that of the traditional device, preventing high-pressure rubber leakage, and increasing the emptying rate of the discharge pipeline from 70% to 98%.

[0059] Experimental Example 5: Comparison experiment of trapped oil pressure of gear pump; Through the volume change-pressure coupling model, the difference in trapped oil pressure peak value with and without flow guide groove is compared to verify the pressure relief effect of the flow guide groove; Based on the variable volume hydraulic theory, the trapped oil pressure peak value is proportional to the volume change rate when the gears are engaged, and the flow guide groove reduces the volume change rate by increasing the pressure relief channel.

[0060] Experimental steps: 1. Model establishment, define the trapped oil volume change function during gear engagement:

[0061] Wherein, V0=120mm 3 (Average volume), V1=40mm 3 (Volume change amplitude), ω=20.94rad / s (Gear angular velocity, corresponding to a speed of 200r / min); 2. No flow guide groove working condition calculation, trapped oil pressure peak value formula (ignoring oil compressibility):

[0062] Wherein, p0=0.8MPa (outlet pressure), ΔV=−V1=−40mm 3 (Volume reduction), K=1500MPa (oil bulk modulus); The calculation is:

[0063] 3. Calculation with guide groove working condition, the equivalent flow area of ​​the guide groove is A=3mm 2 , pressure relief time Δt=0.002s, volume change rate is corrected to:

[0064] Where η=0.6 (flow efficiency), the peak value of trapped oil pressure after correction is:

[0065] 4. Comparative verification: Use numerical calculation tools to generate pressure curves for the two working conditions, extract the peak value and calculate the drop:

[0066] Gear pump trapped oil pressure comparison experiment, such as Figure 10 As shown in the figure, when there is no guide groove, the peak value of trapped oil pressure reaches 500.8MPa (theoretical calculation), and the actual measurement is 4.5MPa; after the guide groove is set, the peak value drops to 3.2MPa, a decrease of 28.9% ( Figure 10 Curve comparison); The flow area of ​​the guide groove is 3mm² and the tangential direction design reduces the volume change rate of trapped oil by 40%, shortening the rubber retention time from 0.005 seconds to 0.002 seconds. The reduction in trapped oil pressure reduces the particle size of the cured rubber from 2-5mm to <1mm, improves the interception efficiency of the gear group inlet filter unit, and increases the pump volume rate from 85% to 95%.

[0067] The secondary cracking rate caused by trapped oil residue has dropped from 22% to 8%, the rubber filling density has been improved, the risk of rainwater infiltration has been significantly reduced, the guide groove has reduced the impact of gear meshing, the tooth surface wear has been reduced from 0.01mm / 100 hours to 0.003mm / 100 hours, and the gear set replacement cycle has been extended by 3 times.

[0068] Experimental Example 6: Data visualization and optimization experiment; 6.1 Data Analysis Experiment; The temperature response data of the elastic element and the hydraulic cavity, the gear speed influence data, etc. are graphically displayed to reveal the intrinsic relationship between the parameters.

[0069] Experimental equipment: Data collector: handheld multimeter (recording pressure and temperature), micrometer (measuring gap) Spreadsheet software: for data organization and statistics Drawing tools: engineering drawing board or computer-aided drafting software.

[0070] Experimental steps: 1. Aggregate previous experimental data (e.g. temperature-gap, speed-stuck oil pressure, etc.), remove outliers (e.g. sensor failure caused by jumping data).

[0071] 2. Select visualization methods: Trend analysis, using XY scatter plot to show the relationship between continuous variables (e.g. temperature-gap).

[0072] Comparative analysis, using bar chart to compare the peak value of stuck oil pressure with and without guide vanes.

[0073] Distribution analysis, through histogram to show the probability distribution of spring fatigue life.

[0074] 6.2 Error analysis test; Quantify the uncertainty of experimental data, through error propagation analysis to optimize the measurement scheme.

[0075] Experimental steps: 1. Error source identification, sensor calibration deviation (e.g. laser displacement sensor ±0.001mm), environmental temperature fluctuation (±1℃) caused by spring stiffness change, human operation error (e.g. torque wrench reading deviation); 2. Error transfer calculation, total error of gap measurement:

[0076] 3. Visualization methods: Draw error bar chart, superimpose ±σ error range on temperature-gap curve; Make Pareto chart: sort by error contribution.

[0077] Figure 11 Heat map shows that temperature and gap (correlation coefficient 0.98), speed and stuck oil pressure (0.96) are strongly positively correlated, guiding through temperature control strategy to indirectly control gap, through speed optimization to reduce stuck oil risk.

[0078] Spring fatigue life obeys normal distribution (mean 4.84 million times, standard deviation 1.96 million times), prompting the need to control the pre-tightening force deviation within ±2% to ensure reliability.

[0079] Figures 13-14 Show, installation error (±0.002mm) and environmental temperature fluctuation (±1℃) are the main error sources, through laser centering calibration and constant temperature preheating process, the total gap error can be reduced from ±0.0024mm to ±0.001mm.

[0080] Data visualization reveals parameter coupling relationship, helps to establish "temperature-speed-pre-tightening force" collaborative control model, and improves the comprehensive efficiency of crack pouring device by 25%.

[0081] Error analysis guides the improvement of measurement process (such as torque wrench calibration, sensor preheating), and the experimental data repeatability error is reduced from 5% to 1.5%, which improves the consistency of research and production.

[0082] The above examples are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements will not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A maintenance crack pouring device for highway traffic engineering, comprising a pump body (1), a gear set (2), a floating side plate (3) and a power unit (4), characterized in that: The floating side plate (3) is movably arranged outside the end face of the gear set (2), and a gap compensation mechanism is arranged between the floating side plate (3) and the pump body (1); The gap compensation mechanism comprises an elastic element (5) and a hydraulic auxiliary assembly, the elastic element (5) provides an initial pre-tightening force, and the hydraulic auxiliary assembly indirectly reflects the change of the medium pressure by switching the communication state between the hydraulic cavity (7) and the high-pressure area / low-pressure area through the temperature control valve (6) according to the medium temperature, and dynamically adjusts the fitting pressure of the floating side plate (3) and the gear set (2).

2. The maintenance crack pouring device for highway traffic engineering according to claim 1, characterized in that, The edge of the floating side plate (3) is provided with an inclined blade (8), and the extension direction of the inclined blade (8) forms a preset angle with the rotating direction of the gear set (2).

3. The maintenance crack pouring device for highway traffic engineering according to claim 2, characterized in that, The surface of the floating side plate (3) is provided with a flow guide groove (9), the inner corner of the floating side plate (3) is a circular arc structure, the flow guide groove (9) extends along the tangent direction of the circular arc structure to connect the high-pressure side and the low-pressure side of the floating side plate (3), and the center of the circular arc structure is located outside the meshing area of the gear set (2).

4. The maintenance crack pouring device for highway traffic engineering according to claim 1, characterized in that, The elastic element (5) is a variable stiffness elastic element, the hydraulic auxiliary assembly comprises a temperature control valve (6) and a hydraulic cavity (7), and the temperature control valve (6) switches the communication state between the hydraulic cavity (7) and the high-pressure area or the low-pressure area of the pump body (1) according to the medium temperature.

5. The maintenance crack pouring device for highway traffic engineering according to claim 4, characterized in that, The circumferential sleeve of the variable stiffness elastic element is provided with an anti-sticking sleeve, the material of the anti-sticking sleeve is polytetrafluoroethylene or equivalent low surface energy material, and the inner wall of the anti-sticking sleeve is matched with the outer contour shape of the variable stiffness elastic element.

6. The maintenance crack pouring device for highway traffic engineering according to claim 1, characterized in that, The mating surface of the floating side plate (3) and the pump body (1) is provided with a labyrinth seal structure, and the labyrinth seal structure comprises at least one annular groove.

7. The maintenance crack pouring device for highway traffic engineering according to claim 1, characterized in that, The inlet end of the gear set (2) is provided with a filter unit (11), and the filter unit (11) comprises a magnetic adsorption component and a filter screen.

8. The maintenance crack pouring device for highway traffic engineering according to claim 2, characterized in that, The surface of the inclined blade (8) is coated with an anti-sticking coating, and the surface energy of the anti-sticking coating is less than the surface tension of the medium.

9. The maintenance crack pouring device for highway traffic engineering according to claim 1, characterized in that, The inner wall of the pump body (1) is provided with a guide groove (10), the outer side edge of the floating side plate (3) is embedded in the guide groove (10), and the cross-sectional shape of the guide groove (10) is a shape that limits the circumferential rotation of the floating side plate (3).

10. The maintenance crack pouring device for highway traffic engineering according to claim 1, characterized in that, The back surface of the floating side plate (3) is provided with a pressure balance hole (12), the pressure balance hole (12) penetrates the floating side plate (3) and connects the high-pressure area of the gear set (2) and the hydraulic cavity (7) of the gap compensation mechanism.

Images