A paving machine screed attitude adjustment mechanism and adaptive adjustment method

Abstract

The application discloses a paving machine screed posture adjusting mechanism and a self-adaptive adjusting method, which comprises a servo motor, a worm gear, a strain measuring force mechanism, a threaded rod and a supporting and pulling rod; the worm gear is connected with the output end of the servo motor, one side of the worm gear is connected with the strain measuring force mechanism, one end of the strain measuring force mechanism, which is far away from the worm gear, is provided with a threaded rod, the threaded rod is provided with external threads, one end of the threaded rod, which is far away from the worm gear, is provided with the supporting and pulling rod, the supporting and pulling rod is nested on the threaded rod, the supporting and pulling rod is provided with internal threads and is screw-connected with the threaded rod; the input end of the servo motor is connected with the output end of an adaptive neural network fuzzy PID, and the data output end of the strain measuring force mechanism is connected with the input end of the adaptive neural network fuzzy PID. The displacement of the supporting and pulling rod can be accurately and reliably adjusted, and the posture of the screed is restored.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of paver, and relates to a paver screed posture adjusting mechanism and a self-adaptive adjusting method. BACKGROUND

[0002] The paver uniformly spreads the mixed asphalt on the road base according to a certain thickness and cross-sectional shape, can preliminarily vibrate and compact, and accurately ensures the thickness, width, pavement camber, flatness and compactness of the paving layer, and is mainly used in highway, urban road, airport, parking lot and wharf engineering operations. The paver mainly comprises a paving host (engine, transmission system, walking mechanism, chassis, etc.), a feeding device (receiving hopper, scraper conveyor, spiral feeder, etc.), a working device (vibrator, screed, etc.) and a control system.

[0003] Different road surfaces have different construction requirements, and the required screed posture is also different. The supporting rod is used to adjust the posture of the screed of the paver. Before the paver works, the initial posture of the screed is adjusted, and the pre-tightening force of the supporting rod is determined. However, during the working process, the screed contacts and interacts with the hot asphalt mixture, extrudes and flattens the mixture, and at the same time, is subjected to the reaction force of the mixture. The position of the supporting rod changes, and the stress balance of the supporting rod changes. At this time, the original pre-tightening force cannot maintain the initial posture of the screed, and the position of the supporting rod needs to be restored.

[0004] In actual operation, the position of the supporting rod is manually restored, but manual operation is time-consuming and laborious, resulting in low paving efficiency. Some pavers use automatic screed posture adjustment, but the conventional automatic screed posture adjustment can only give the supporting rod a force towards the initial position, and cannot accurately control the position restoration of the supporting rod. SUMMARY

[0005] The present application aims to overcome the shortcomings of the prior art, and provides a paver screed posture adjusting mechanism and a self-adaptive adjusting method, which can accurately and reliably adjust the displacement of the supporting rod and restore the posture of the screed.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] A paver screed posture adjusting mechanism, comprising a servo motor, a worm gear, a strain measuring force mechanism, a threaded rod and a supporting rod.

[0008] The worm gear is connected with the output end of the servo motor, one side of the worm gear is connected with the strain measuring force mechanism, one end of the strain measuring force mechanism away from the worm gear is provided with a threaded rod, the threaded rod is provided with external threads, and the end of the threaded rod away from the worm gear is provided with the supporting rod. The supporting rod is nested on the threaded rod, and the supporting rod is provided with internal threads and is threadedly connected with the threaded rod.

[0009] The servo motor input end is connected with the adaptive neural network fuzzy PID output end, and the data output end of the strain force measuring mechanism is connected with the adaptive neural network fuzzy PID input end.

[0010] Preferably, the servo motor output end is connected with a worm, and the worm gear meshes with the worm.

[0011] Preferably, the speed reduction ratio of the worm gear and the worm is 40-100.

[0012] Preferably, the strain force measuring mechanism comprises two flanges, an elastic unit and a rigidity unit, the elastic unit and the rigidity unit are located between and connected with the two flanges, and the two flanges are connected with the worm gear and the threaded rod respectively; strain gauges are arranged at the two ends of the concentrated load area and the connecting end of the elastic unit, and the rigidity unit is arranged at the position close to the edge of the two flanges.

[0013] Further, the elastic unit is of Z-shaped structure, the included angles between the two ends and the middle part are both 90°, and strain gauges are arranged at the two ends and the middle part of the connecting end of the elastic unit along the two sides of the axial direction of the strain force measuring mechanism.

[0014] Further, the rigidity unit is arranged obliquely to the end surface of the flange.

[0015] Further, the elastic unit and the rigidity unit are both two groups, and are alternately and uniformly distributed along the same circumferential direction of the flange.

[0016] Preferably, the worm gear is connected with one strain force measuring mechanism, one threaded rod and one bracing rod respectively at the two sides, and the two threaded rods are provided with external threads in opposite directions respectively.

[0017] A paving machine screed posture adaptive adjustment method of the mechanism, comprising the following processes:

[0018] S1, the strain force measuring mechanism monitors the displacement of the bracing rod when the screed contacts the mixture, and converts the displacement into the force F1 borne by the deformation of the bracing rod;

[0019] S2, the adaptive neural network fuzzy PID controls the servo motor, and further controls the displacement and tension of the bracing rod, and the strain force measuring mechanism monitors the bracing rod tension F2 at this time;

[0020] S3, the adaptive neural network fuzzy PID judges whether F1 is equal to F2, if yes, the force borne by the bracing rod reaches balance, the bracing rod returns to the fixed point position, and the posture of the screed has been adjusted to the initial posture; if not, S2 is repeated until F1 is equal to F2.

[0021] Preferably, before S1, the initial posture of the screed is determined before paving, the pre-tightening force F0 of the bracing rod is determined, after S1 is completed, whether the pre-tightening force F0 of the bracing rod is equal to F1 is judged, if equal, the position of the bracing rod is not changed, and the posture of the screed is not changed; if the pre-tightening force F0 is less than F1, the bracing rod is displaced, the posture of the screed is changed, and S2 is performed.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] The change of the tension of the bracing rod is controlled by the strain force measuring mechanism and the servo motor, the worm and the threaded rod are used for adjusting the tension of the bracing rod to control the dynamic posture of the screed; the strain force measuring mechanism is used for measuring the deformation of the bracing rod, the servo motor is used for controlling the movement position of the automatic adjusting mechanism, the displacement of the bracing rod is accurately and reliably adjusted, the posture of the screed is restored, and the posture control ability of the screed of the paver is improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a structural schematic view of the adjusting mechanism of the present application;

[0025] Figure 2 It is a front view of the adjusting mechanism of the present application;

[0026] Figure 3 It is a top view of the adjusting mechanism of the present application;

[0027] Figure 4 It is a side view of the adjusting mechanism of the present application;

[0028] Figure 5 It is a structural schematic view of the strain force measuring mechanism of the present application;

[0029] Figure 6 It is a flow chart of the self-adaptive adjustment of the posture of the screed of the present application.

[0030] Wherein: 1-servo motor; 2-worm; 3-worm gear; 4-strain force measuring mechanism; 5-threaded rod; 6-bracing rod; 7-flange plate; 8-elastic unit; 9-rigidity unit; 10-strain gauge. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application; based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0032] It should be noted that the words "front", "rear", "left", "right", "up" and "down" used in the following description refer to directions in the accompanying drawings, and the words "inside" and "outside" refer to directions toward or away from the geometric center of a specific component, respectively.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0034] like Figures 1-4 As shown in FIG, the screed posture adjustment mechanism of the paver according to the present invention includes a servo motor 1, a worm gear 3, a worm 2, a strain force measuring mechanism 4, a threaded rod 5 and a support rod 6.

[0035] The worm 2 is connected to the output end of the servo motor 1, the servo motor 1 drives the worm 2 to rotate, the worm wheel 3 is engaged with the worm 2, and one side of the worm wheel 3 is connected to the strain force measuring mechanism 4. A threaded rod 5 is provided at the end of the strain force measuring mechanism 4 away from the worm 2, and an external thread is provided on the threaded rod 5. A support rod 6 is provided at the end of the threaded rod 5 away from the worm wheel 3, and the support rod 6 is nested on the threaded rod 5. The support rod 6 is provided with an internal thread and is threadedly connected to the threaded rod 5.

[0036] In the present application, the strain measuring mechanism 4, the threaded rod 5 and the support rod 6 can be set on one side of the worm gear 3, or on both sides. When both sides are set, the two support rods 6 are connected to the same ironing plate, and the two support rods 6 are subjected to the same force.

[0037] When both sides are set, a strain measuring mechanism 4 is connected to each side of the worm wheel 3, and a threaded rod 5 is set at the end of the strain measuring mechanism 4 away from the worm 2. The two threaded rods 5 are respectively provided with external threads in opposite directions, and a support rod 6 is set at the end of the two threaded rods 5 away from the worm 2. The support rod 6 is nested on the threaded rod 5, and the support rod 6 is provided with an internal thread and is threadedly connected to the threaded rod 5.

[0038] When the worm gear 3 rotates, it provides torque to the two strain measuring mechanisms 4.

[0039] The servo motor 1 provides a power source for applying the force to the support rod 6 and controls the rotation angle of the motor to achieve the loading of the target force.

[0040] The reduction ratio of the worm wheel 3 and the worm 2 is 40 to 100, which can increase the torque of the servo motor 1 by 40 to 100 times and transmit it to the power transmission screw.

[0041] The strain measuring mechanism 4 measures the strain of the strain amplifying device on the force measuring mechanism through the strain gauge 10 and calculates the magnitude of the force applied to the support rod according to the formula.

[0042] like Figure 5 As shown, the strain measurement mechanism 4 includes two flanges 7, two elastic units 8, and a stiffness unit 9. The two flanges 7 are respectively connected to the worm gear 3 and the threaded rod 5. The two elastic units 8 and the stiffness unit 9 are located between the two flanges 7 and connected to the two flanges 7. The two elastic units 8 are located on both sides of the flanges 7. The elastic units 8 have a Z-shaped structure, with both ends and the middle part at an angle of 90°. The two ends are respectively connected to the two flanges 7. Strain gauges 10 are respectively provided on both ends of the connection end of the elastic unit 8 and on both sides of the middle part along the axial direction of the strain measurement mechanism 4.

[0043] There are two groups of elastic units 8 and rigidity units 9, which are alternately and evenly distributed along the same circumferential direction of the flange 7. A rigidity unit 9 is arranged between the two elastic units 8. The two ends of the rigidity unit 9 are respectively connected to the two flanges 7, and the two ends of the rigidity unit 9 are respectively connected to different circumferential positions of the two flanges 7, so that the rigidity unit 9 is inclined relative to the axis, that is, the rigidity unit 9 is inclined to the end face of the flange 7, and adjacent rigidity units 9 are arranged in parallel.

[0044] Flange 7 is used for connection, transmitting force and motion. Elastic element 8 can be considered a rectangular cantilever beam with fixed ends and a concentrated load in the middle. This amplifies the axial deformation of the elastic body, increasing the sensitivity of strain gauge 10. When the elastic body is subjected to tension, the inclination angle between stiffness element 9 and flange 7 increases, increasing the load-bearing capacity and providing a certain degree of stiffness to the elastic body.

[0045] The threaded rod 5 converts the rotational motion into linear motion along the axial direction of the support rod 6. The force transmission spirals at both ends of the worm gear 3 rotate in opposite directions. When the worm gear 3 rotates, it generates thrust or tension on the support rods 6 at both ends.

[0046] There are inner spiral screw sleeves at both ends of the support rod 6 that cooperate with the threaded rod 5. In commonly used pavers, the rotational movement of the support rod 6 is itself restricted, and there is no need to set up an additional rotation restriction mechanism. Therefore, when the inner spiral rotates, it can provide thrust or pulling force for the support rod 6.

[0047] The worm 2 drives the worm wheel 3 to rotate to drive the whole supporting and pulling rod 6 to rotate, the adjusting mechanism has one end screw thread left-handed and the other end screw thread right-handed, so as to realize the purpose of adjusting the displacement between the two fixed points of the supporting and pulling rod 6. The specific implementation method is that the servo motor 1 drives the worm 2 to rotate, the worm 2 drives the worm wheel 3 to rotate at a reduced speed, the worm wheel 3 drives the two side screw rods 5 to rotate reversely through the strain force measuring mechanism 4, the screw rods 5 drive the two end supporting and pulling rods 6 to approach or move away from each other, the displacement of the supporting and pulling rod 6 is adjusted, and then the tension of the supporting and pulling rod 6 is applied. Since the worm wheel 3, the worm 2 and the screw rod 5 have the effects of speed reduction and self-locking with the supporting and pulling rod 6, the pushing force is amplified and kept constant under the double self-locking.

[0048] The strain force measuring mechanism 4 monitors the stress condition of the supporting and pulling rod 6 in the paving process. The strain gauge 10 is a key component of strain measurement. When the screed is subjected to the action force of the mixture and a slight displacement occurs, the displacement is transmitted to the supporting and pulling rod 6, the strain gauge 10 constantly deforms slightly with the change of the strain, the resistance value changes slightly, and through the cable connected with the converter, the slight deformation is converted into an electrical signal and output to the self-adaptive neural network fuzzy PID. The converter is usually an amplifier that amplifies the slight electrical signal sent by the strain gauge 10 and converts it into voltage, current and other forms, and finally displays the stress size on the digital display screen. The relationship between strain and stress is shown in the following formula:

[0049] ε = σ / E

[0050] In the formula, ε is the strain, σ is the stress value, and E is the elastic modulus of the strain gauge 10.

[0051] The screed posture adjusting mechanism described in the application can stretch or compress the supporting and pulling rod 6, adjust the position of the supporting and pulling rod 6, keep it on the initial fixed point, change the tension of the supporting and pulling rod 6, and make the tension of the supporting and pulling rod 6 resist the action force during the screed operation, so as to keep the initial posture of the screed;

[0052] The strain force measuring mechanism 4 collects the strain of the supporting and pulling rod 6 during the paving machine operation, and converts the strain into the action force; the stress condition of the screed during the operation is displayed at any time.

[0053] The servo motor 1 is regulated by the self-adaptive neural network fuzzy PID, and then the automatic adjusting mechanism is controlled to adjust the position of the supporting and pulling rod 6 and change the tension of the supporting and pulling rod 6 to adapt to the changes in the operation process.

[0054] As shown in Figure 6 The screed posture self-adaptive regulating process using the above mechanism includes the following steps:

[0055] 1) The initial posture of the screed is determined before paving, the fixed point position and the pre-tightening force of the supporting and pulling rod 6 are determined, and the pre-tightening force F0 of the supporting and pulling rod 6 at this time is output.

[0056] 2) strain gauge 4 monitors the displacement of the brace rod 6 when the screed contacts the mixture, converts the displacement into the force F1 that the brace rod 6 is subjected to, and outputs the force F1 that the brace rod 6 is subjected to at this time, and judges whether the pre-tightening force F0 of the brace rod 6 is equal to F1, if equal, the position of the brace rod 6 does not change, the posture of the screed does not change, and no posture adjustment is needed; if the pre-tightening force F0 is less than F1, the brace rod 6 is displaced, the posture of the screed changes, and posture recovery is needed.

[0057] 3) the adaptive neural network fuzzy PID control servo motor 1 controls the displacement and tension of the brace rod 6, and the strain gauge 4 monitors and outputs the tension F2 of the brace rod 6 at this time, and judges whether F1 is equal to F2, if equal, the force on the brace rod 6 reaches equilibrium, the brace rod 6 returns to the fixed point position, and the posture of the screed has been adjusted to the initial posture; if not equal, the above steps are repeated until F1 is equal to F2.

[0058] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it being understood that the scope of the present teachings will be limited only by the appended claims. Notably, any connection is intended to be a mechanical or electrical connection unless otherwise specifically stated or otherwise evident from context, such as electrical charging or electrical power supply. Furthermore, the use of "a", "an", "the" and "at least one" are intended to include one or more of the items specified, including the possibility of multiple items. It is further noted that the claims can be drafted to exclude any optional feature or element, including features or elements expressed by "a" or "an", "comprising", "including", "containing", "consisting of", "consisting essentially of" or the like. Additionally, the term "about" is used to indicate that a value, parameter, measurement, or other quantity is within a reasonable range of the recited value, parameter, measurement, or other quantity, such as within 10% of the recited value, parameter, measurement, or other quantity, or within a range of 10% of the recited value, parameter, measurement, or other quantity. The term "consisting essentially of" is used to include the recited elements or steps, and any additional elements or steps that do not materially affect the basic and novel characteristics of the claimed teachings. The term "consisting of" is used to include the recited elements or steps, and any additional elements or steps that do not materially affect the basic and novel characteristics of the claimed teachings.

[0059] It is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments and applications other than the examples provided would be apparent to those of skill in the art upon reading the above description. The scope of the teachings should, therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated by reference for the purpose of the present teachings. Any incorporation by reference of any article or reference which adds, modifies or expands upon any aspect of the subject matter disclosed herein is expressly contemplated as part of this detailed description of the teachings. The omission of any aspect of the subject matter disclosed herein from any incorporation by reference of any article or reference is expressly contemplated as part of this detailed description of the teachings.

Claims

1. A paver screed posture adjustment mechanism, characterized in that: It includes a servo motor (1), a worm gear (3), a strain measuring mechanism (4), a threaded rod (5) and a support rod (6); The worm wheel (3) is connected to the output end of the servo motor (1), and one side of the worm wheel (3) is connected to the strain force measuring mechanism (4). A threaded rod (5) is provided at one end of the strain force measuring mechanism (4) away from the worm (2), and an external thread is provided on the threaded rod (5). A support rod (6) is provided at one end of the threaded rod (5) away from the worm wheel (3), and the support rod (6) is nested on the threaded rod (5). The support rod (6) is provided with an internal thread and is threadedly connected to the threaded rod (5); The input end of the servo motor (1) is connected to the output end of the adaptive neural network fuzzy PID, and the data output end of the strain force measuring mechanism (4) is connected to the input end of the adaptive neural network fuzzy PID; The strain force measuring mechanism (4) includes two flanges (7), an elastic unit (8) and a stiffness unit (9). The elastic unit (8) and the stiffness unit (9) are located between the two flanges (7) and connected to the two flanges (7). The two flanges (7) are connected to the worm gear (3) and the threaded rod (5) respectively. Strain gauges (10) are provided at the concentrated load area and both ends of the connection end of the elastic unit (8). The stiffness unit (9) is provided near the edge of the two flanges (7). The elastic unit (8) is a Z-shaped structure, with both ends and the middle portion forming an angle of 90°. Strain gauges (10) are respectively provided on both ends of the connection end of the elastic unit (8) and on both sides of the middle portion along the axial direction of the strain measuring mechanism (4).

2. The screed posture adjustment mechanism for a paver according to claim 1, characterized in that: The output end of the servo motor (1) is connected to a worm (2), and the worm wheel (3) is meshed with the worm (2).

3. The screed posture adjustment mechanism for a paver according to claim 1, characterized in that: The reduction ratio of the worm wheel (3) and the worm (2) is 40-100.

4. The screed posture adjustment mechanism for a paver according to claim 1, characterized in that: The stiffness unit (9) and the end surface of the flange (7) are arranged to be inclined.

5. The screed posture adjustment mechanism for a paver according to claim 1, characterized in that: The elastic units (8) and the stiffness units (9) are both in two groups and are evenly distributed alternately along the same circumference of the flange (7).

6. The screed posture adjustment mechanism for a paver according to claim 1, characterized in that: A strain measuring mechanism (4), a threaded rod (5) and a support rod (6) are respectively connected to both sides of the worm wheel (3), and the two threaded rods (5) are respectively provided with external threads of opposite rotation directions.

7. A method for adaptively adjusting the posture of a paver screed based on the mechanism according to any one of claims 1 to 6, characterized in that: The following processes are included: S1, the strain measuring mechanism (4) monitors the displacement of the support rod (6) when the screed plate contacts the mixture, and converts it into the force exerted on the deformation of the support rod (6). ; S2, adaptive neural network fuzzy PID control servo motor (1), thereby controlling the displacement and tension of the support rod (6), the strain measuring mechanism (4) monitors the tension of the support rod (6) at this time ; S3, adaptive neural network fuzzy PID judgment Is it equal to If they are equal, the force on the support rod (6) reaches equilibrium, the support rod (6) returns to the fixed point position, and the screed plate posture is adjusted to the initial posture; if they are not equal, repeat S2 until equal .

8. The method for self-adapting the posture of a paver screed according to claim 7, characterized in that: Before S1, determine the initial posture of the screed plate before paving and determine the preload force of the support rod (6) After S1 is completed, the preload force of the support rod (6) is determined. Is it equal to , if they are equal, the position of the support rod (6) does not change, and the screed posture does not change; if the preload force Less than , the support rod (6) is displaced, the posture of the screed changes, and S2 is performed.

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