Nodular cast iron pipe jacking core rod vibration forming device and method thereof
By using a vibration forming device with a split outer mold and an inner mold, combined with the mechanical coupling of a high-frequency vibrator and a hinged disc cutter, the problems of insufficient vibration and difficult demolding in the traditional ductile iron pipe jacking production have been solved, achieving high-density forming and rapid demolding, thus improving the quality of finished products and production efficiency.
Patent Information
- Application Number
- CN202510976646.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-16
- Publication Date
- 2025-11-07
AI Technical Summary
Traditional ductile iron pipe jacking production suffers from problems such as insufficient external mold vibration, low energy transfer efficiency, difficulty in demolding, and low production efficiency, which affect the quality of finished products and the production cycle.
The device employs a split outer and inner mold vibration molding device, combined with the mechanical coupling of a high-frequency vibrator and a hinged disc cutter, to achieve efficient transmission of vibration force and rapid demolding. Vibration energy is evenly distributed along the pipe length through five vibration transmission layers, and dry-hard concrete is used without the need for high-temperature curing.
It improves the density and compressive strength of concrete, enhances the surface quality of finished products, shortens the production cycle, reduces costs, and achieves resource-intensive production.
Smart Images
Figure CN120902115A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of ductile cast iron pipe jacking manufacturing technology, and particularly relates to a ductile cast iron pipe jacking core rod vibration forming device and a method thereof. BACKGROUND
[0002] With the increase of the types (water supply, sewage, rainwater, power, gas, heat, communication, and reclaimed water) and the number of urban pipelines, underground space is narrow and crowded. The pipelines of subsequent construction, such as reclaimed water, are forced to be buried deeper, generally 6-10 meters, because the shallow underground space has been occupied by other pipelines. At the same time, due to the factors such as pipeline burial depth, short distance between adjacent pipelines, and narrow construction site, only jacking method can be used for construction. The selected pipe material needs to withstand a large axial jacking force in construction, and once the pipeline is damaged in operation, it is difficult to detect the leakage point, and the repair is difficult and very expensive. Based on the above reasons, the jacking construction has very high requirements for the pipe material, such as large stiffness and mechanical strength, excellent and reliable external corrosion-resistant coating, and safe and reliable joint sealing. The traditional jacking pipe material has its own weaknesses, such as the external corrosion-resistant coating of steel pipe is easily damaged in the jacking process and is difficult to repair, and is easily subjected to electrochemical corrosion under the action of soil; the mechanical properties of organic material pipe material such as PE are poor; and the self-weight of reinforced concrete pipe material is too large, and the interface sealing safety is poor. Ductile cast iron material has similar mechanical properties to carbon steel, such as high mechanical strength and good toughness, and has unique corrosion resistance of cast iron, and has gradually become the safest and most reliable pipe material in the field of water supply and drainage in the world.
[0003] However, the traditional ductile cast iron pipe jacking production process has the following problems: 1. The outer mold is vibrated, and the inner mold ductile cast iron is not moved. Due to the heavy weight of the outer mold and the small number of tamping wheels of the outer mold, the vibration force is seriously insufficient, and only wet cement mortar can be used for production of jacking products, which affects the surface quality and dimensional accuracy of the finished product; 2. The energy transmission efficiency of the ordinary vibration process is low, which easily leads to uneven density of concrete; 3. The overall type circumferential split half-open mold structure has a long and narrow joint, and needs to be removed and cured in a horizontal room, so the qualified rate of the finished product is low; 4. The repair cycle is long, and the production efficiency is limited.
[0004] The present application proposes a vibration forming process integrating ductile cast iron pipe and split type outer mold vertical demolding. SUMMARY
[0005] The technical problem to be solved by the present application is to provide a ductile cast iron pipe jacking core rod vibration forming device and a method thereof, which realize high-density forming of jacking pipe, rapid demolding, and resource-intensive production.
[0006] To solve the above technical problems, the technical scheme adopted by the present application is: The utility model provides a nodular cast iron pipe jacking core rod vibration forming device, including outer mould, inner mould, base and the core rod vibration equipment of setting in the inside of inner mould; The outer mould is split type, including upper half mould and lower half mould, and a positioning guide pin is embedded in the cavity of the outer mould; The inner mould is a nodular cast iron pipe; The core rod vibration equipment includes a mandrel, a plurality of sets of vibration transmission layers arranged equidistantly along the axial direction on the mandrel, and a high-frequency vibrator connected with the mandrel;The vibration transmission layer includes a disc cutter holder fixed on the mandrel, three sets of jacking disc cutters arranged uniformly along the circumferential direction of the disc cutter holder, and three sets of hydraulic cylinders fixedly connected to the disc cutter holder; The base is a disc, and a mandrel hole, an inner mould groove and an outer mould groove are respectively arranged outward from the center of the disc.
[0007] The further improvement of the technical scheme of the present application is that the jacking disc cutter has a wedge-shaped tooth surface, and the jacking disc cutter is movably arranged in the disc cutter holder.
[0008] The further improvement of the technical scheme of the present application is that the vibration transmission layer is arranged in 3-6 sets.
[0009] The further improvement of the technical scheme of the present application is that the cylinder barrel of the hydraulic cylinder is fixedly connected with the disc cutter holder, the top of the piston of the hydraulic cylinder is provided with a hinge, the hinge main shaft is fixedly connected with the top of the piston, and the two ends of the hinge are fixedly connected with the corresponding jacking disc cutters.
[0010] The further improvement of the technical scheme of the present application is that the model of the nodular cast iron pipe is DN800-DN2600.
[0011] The further improvement of the technical scheme of the present application is that the distance between the inner mould groove and the outer mould groove on the base is in the range of 80-200 mm.
[0012] A nodular cast iron pipe jacking core rod vibration forming method includes the following steps: S1, fix the base on the vibration platform, place the inner mould in the inner mould groove of the base, spray the inner surface of the outer mould with a high-molecular release agent, and then place the outer mould in the outer mould groove of the base to form a uniform cavity between the inner mould and the outer mould; S2, make the jacking disc cutters on the mandrel shrink in the disc cutter holder, lift the mandrel from the vibration platform through the mandrel hole of the base disc into the inner mould, start the hydraulic cylinder, make the piston tightly press the hinge, and make the hinge tightly press the jacking disc cutters to the inner wall of the inner mould; S3, adjust the proportion of concrete, configure and put dry hard concrete into the cavity, start the high-frequency vibrator to drive the mandrel to vibrate, form the ductile cast iron pipe, remove the outer mold after jacking, release the hydraulic cylinder, retract the piston to pull the hinge, put the jacking disc cutter on the mandrel into the disc cutter holder, lower the mandrel below the vibration platform, and hoist the mandrel together with the base and the inner mold to the corresponding area for curing; S4, after the concrete hardens, remove the base to form the ductile cast iron pipe product.
[0013] The further improvement of the technical scheme of the application is that in S2, the hydraulic cylinder is radially clamped against the inner wall of the ductile cast iron pipe with a pressure of 10-15 MPa.
[0014] The further improvement of the technical scheme of the application is that in S3, the frequency of the high-frequency vibrator is 50-100 Hz, and the vibration duration is 60-120 s after feeding.
[0015] The further improvement of the technical scheme of the application is that in S3, the outer mold is pulled out with an inclination of 1:30-1:60, and the outer mold pulling speed is 3-6 mm / s.
[0016] Due to the adoption of the above technical scheme, the application has achieved the following technical progress: 1. The application directly uses the ductile cast iron pipe as the inner mold, realizes vibration force transmission through mechanical coupling of the hinge disc cutter and the mandrel, omits the manufacturing cost of the traditional inner mold, and finally forms the pipe structure layer.
[0017] 2. The application sets five vibration transmission layers in the inner wall of the ductile cast iron pipe, each layer has three groups of hinge disc cutters, the axial layer spacing is 1 meter, forms a "five-point three-section" vibration network, makes the vibration energy uniformly distributed along the pipe length (wave attenuation rate <5%), solves the concrete density gradient problem caused by traditional single-point vibration, solves the quality problem of surface cracks of the ductile cast iron pipe, reduces the existence of pores and holes, greatly improves the surface quality, the concrete density is ≥98%, the compressive strength is increased by 25%, and the surface quality and internal quality are improved.
[0018] 3. The hinge disc cutter in the application adopts a radial adjustable design (adjustment range ±15 mm), forms multi-point contact with the inner wall of the ductile cast iron pipe through the hydraulic locking mechanism, and the vibration energy transmission efficiency is increased by more than 40%.
[0019] 4. The jacking disc cutter in the application adopts a wedge-shaped tooth surface design, the hydraulic cylinder is radially clamped against the inner wall of the ductile cast iron pipe (pressure 10-15 MPa), realizes efficient vibration force transmission (energy utilization rate ≥85%), and at the same time avoids damaging the pipe body. 5. In this invention, the outer mold is divided into upper and lower halves. The upper half of the mold is first demolded by moving along the guide pin (demolding speed ≤5mm / s), and the lower half of the mold is demolded after a delay of 10-15 minutes to avoid concrete collapse. 6. This invention utilizes the synergistic effect of dry-hard concrete and high-frequency micro-vibration (vibration frequency 50-60Hz, amplitude 0.2-0.5mm) to achieve water-free molding and eliminate the need for high-temperature steam curing, significantly reducing production costs; the production cycle for a single piece is shortened to less than 6 hours, compared to 24 hours in the traditional method; the curing time is shortened to 48 hours, compared to 7 days in the traditional process. Attached Figure Description
[0020] Figure 1 This is a cross-sectional view of the vibration forming device for the ductile iron pipe jacking mandrel in this invention; Among them, 1. outer mold, 2. inner mold, 3. mandrel, 4. disc cutter holder, 5. ejector disc cutter, 6. cylinder, 7. piston, 8. hinge. Detailed Implementation
[0021] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments: like Figure 1 As shown, the ductile iron pipe jacking mandrel vibration molding device includes an outer mold 1, an inner mold 2, a base, and a mandrel vibration device disposed inside the inner mold 2; The outer mold 1 is a split steel mold, including an upper mold and a lower mold. The outer mold 1 has a pre-embedded positioning guide pin in its cavity. The inner walls of both the upper and lower molds are provided with a draft angle of 1:30-1:60. After the mold is closed, it forms an annular cavity (wall thickness 80-200mm) with the outer wall of the inner mold 2.
[0022] The inner mold 2 is a standard ductile iron pipe (DN800-DN2600). The mandrel vibration device includes a mandrel 3, several sets of vibration transmission layers equidistantly arranged on the mandrel 3 along the axial direction, and a vibration motor connected to the mandrel 3; the vibration transmission layer includes a disc cutter holder 4 fixed on the mandrel 3, three sets of jacking disc cutters 5 evenly arranged along the circumference of the disc cutter holder 4, and three sets of hydraulic cylinders fixedly connected to the disc cutter holder 4; the jacking disc cutter 5 has a wedge-shaped tooth surface, the contact area between the wedge-shaped tooth surface of the jacking disc cutter 5 and the inner wall of the inner mold 2 is ≥70%, the tooth surface hardness is HRC55-60, and the jacking disc cutter is movably arranged inside the disc cutter holder 4; the cylinder barrel 6 of the hydraulic cylinder is fixedly connected to the disc cutter holder 4, the piston 7 of the hydraulic cylinder is provided with a hinge 8 at the top, the main shaft of the hinge 8 is fixedly connected to the top of the piston 7, and both ends of the hinge 8 are fixedly connected to the corresponding jacking disc cutter 5; The base is a disc with a mandrel 3 holes, an inner mold 2 groove and an outer mold 1 groove respectively set from the center outwards, for positioning the mandrel 3, the inner mold 2 and the outer mold 1.
[0023] A ductile cast iron pipe jacking mandrel vibration forming method, comprising the following steps: S1, fix the base on the vibration platform, place the inner mold 2 in the inner mold 2 groove of the base, spray the outer mold 1 inner surface with a high polymer release agent, and then place it in the outer mold 1 groove of the base, so that the inner mold 2 and the outer mold 1 form a uniform cavity; S2, the jacking disc cutter 5 on the mandrel 3 is in a state of being retracted in the disc cutter holder 4, the mandrel 3 is lifted from the vibration platform through the base mandrel 3 hole into the inner mold 2, the hydraulic cylinder is started, the piston 7 is pressed tightly against the hinge 8, the hinge 8 drives the jacking disc cutter 5 to be pressed tightly against the inner wall of the inner mold 2, and the hydraulic cylinder is pressed tightly against the inner wall of the inner mold 2 with a pressure of 10-15Mpa; S3, adjust the proportion of the concrete, configure the dry hard concrete, and pour it into the cavity, start the high-frequency vibrator to drive the mandrel 3 to vibrate, form the ductile cast iron pipe, and then pull out the outer mold 1, release the pressure of the hydraulic cylinder, retract the piston 7, and make the jacking disc cutter 5 on the mandrel 3 retract in the disc cutter holder 4, lower the mandrel 3 below the vibration platform, and hoist the base and the inner mold 2 together to the corresponding area for solidification; the frequency of the high-frequency vibrator is 50-100Hz, and the vibration duration is 60-120s after pouring; the outer mold 1 pulling out slope is 1:30-1:60, and the outer mold 1 pulling out speed is 3-6mm / s; S4, after the concrete hardens, the base is removed, and the ductile cast iron pipe product is formed.
[0024] Example 1: DN1000 pipe jacking production 1. Inner mold 2 installation: Select DN1000 ductile cast iron pipe, install four vibration transmission layers on the inner wall, a total of 12 groups of hinges 8 and 24 disc cutters (spacing 1500mm); the mandrel 3 is driven into the ductile cast iron pipe by the oil cylinder (pressure 15MPa), and the disc cutter contact point is locked. 2. Material distribution and vibration: After the outer mold 1 is closed, C50 dry hard concrete is poured; start the high-frequency vibrator (55Hz / 0.3mm) for 90s. 3. Step demolding: The pulling out slope is 1:50; after the vibration stops, stand for 30min, hydraulic jacking upper mold (speed 3mm / s); the lower mold is demolded after a delay of 12min, and immediately cover the moisture-proof curing film after demolding. 4. Finished product index: Ellipticity error ≤1.5mm, end face flatness ≤0.8mm; 28-day compressive strength ≥60MPa. Example 2: DN1200 pipe jacking production 1. Inner mold 2 assembly: Select a DN1200 ductile iron pipe, clean the inner wall and install five vibration transmission layers with a total of 15 sets of hinges 8 and 30 disc cutters (layer spacing 1000mm, 3 sets per layer); insert the mandrel 3 into the ductile iron pipe and start the hydraulic system to make the disc cutter teeth tightly adhere to the inner wall of the pipe (pressure 12MPa). 2. Fabric and Vibration: After the outer mold 1 is closed, C50 dry-hard concrete is poured in; the high-frequency vibrator (60Hz / 0.5mm) is started and run for 100 seconds. 3. Stepped demolding: Draft angle 1:60; after vibration stops, let stand for 30 minutes, then hydraulically lift the upper half of the mold (speed 3mm / s); demold the lower half of the mold after a 15-minute delay, and immediately cover with a moisturizing and curing film after demolding. 4. Concrete compaction effect: Core sampling and testing after molding: The density of the upper / middle / lower layers were 98.2%, 98.5%, and 98.3%, respectively; the corresponding values for the traditional process were 95.1%, 97.4%, and 93.8%. Example 3: DN800 pipe jacking production 1. Inner mold 2 assembly: Select a DN800 ductile iron pipe, clean the inner wall and install three vibration transmission layers, a total of 9 sets of hinges 8 and 18 disc cutters (layer spacing 3000mm, 3 sets per layer); insert the mandrel 3 into the ductile iron pipe and start the hydraulic system to make the disc cutter teeth tightly adhere to the inner wall of the pipe (pressure 13MPa). 2. Fabric and Vibration: After the outer mold 1 is closed, C50 dry-hard concrete is poured in; the high-frequency vibrator (50Hz / 0.4mm) is started and run for 80 seconds. 3. Stepped demolding: Draft angle 1:40 After the vibration stops, let it stand for 20 minutes, then hydraulically lift the upper half of the mold (speed 4mm / s); the lower half of the mold is demolded after a 10-minute delay, and immediately covered with a moisturizing and curing film after demolding.
[0025] In summary, the present invention enables high-density molding of jacking pipes, rapid demolding, and resource-intensive production.
Claims
1. A ductile cast iron pipe jacking core rod jarring molding device, characterized in that: The utility model relates to a pipe jacking core rod vibration forming device of nodular cast iron pipe, which comprises an outer mold (1), an inner mold (2), a base and a core rod vibration device arranged inside the inner mold (2). The outer mold (1) is split type and comprises an upper half mold and a lower half mold, and a positioning guide pin is pre-embedded in the mold cavity of the outer mold (1). The inner mold (2) is a nodular cast iron pipe. The core rod vibration device comprises a core shaft (3), a plurality of groups of vibration transmission layers arranged equidistantly on the core shaft (3) in the axial direction and a high-frequency vibrator connected with the core shaft (3); the vibration transmission layer comprises a disc cutter holder (4) fixed on the core shaft (3), three groups of jacking disc cutters (5) arranged uniformly in the circumferential direction of the disc cutter holder (4) and three groups of hydraulic cylinders fixedly connected with the disc cutter holder (4). The base is a disc, and a core shaft (3) hole, an inner mold (2) groove and an outer mold (1) groove are respectively arranged outward from the center of the disc.
2. The ductile cast iron pipe jacking core rod jolt forming device according to claim 1, characterized in that: The jacking disc cutter (5) has a wedge-shaped tooth surface, and the jacking cutter disc can be movably arranged in the disc cutter holder (4).
3. The ductile cast iron pipe jacking core rod jolt forming device according to claim 1, characterized in that: The vibration transmission layer is arranged as 3-6 groups.
4. The ductile iron pipe jacking core rod jolt ramming device according to claim 1, characterized in that: The cylinder barrel (6) of the hydraulic cylinder is fixedly connected with the disc cutter holder (4), the top of the piston (7) of the hydraulic cylinder is provided with a hinge (8), the main shaft of the hinge (8) is fixedly connected with the top of the piston (7), and the two ends of the hinge (8) are fixedly connected with the corresponding jacking disc cutters (5).
5. The ductile iron pipe jacking core rod jolt ramming device according to claim 1, characterized in that: The model of the nodular cast iron pipe is DN800-DN2600.
6. The ductile iron pipe jacking core rod jolt ramming device according to claim 1, characterized in that: The distance between the inner mold (2) groove and the outer mold (1) groove on the base ranges from 80 mm to 200 mm.
7. A ductile cast iron pipe jacking core rod vibroforming method, characterized by, The pipe jacking core rod vibration forming device of the nodular cast iron pipe according to claims 1-6 comprises the following steps: S1, fix the base on the vibration platform, place the inner mold (2) in the inner mold (2) groove of the base, spray a high-molecular release agent on the inner surface of the outer mold (1) and then place the outer mold (1) in the outer mold (1) groove of the base, so that the inner mold (2) and the outer mold (1) form a uniform cavity; S2, make the jacking disc cutters (5) on the core shaft (3) shrink in the disc cutter holder (4), lift the core shaft (3) from the vibration platform and make it pass through the core shaft (3) hole of the base and enter the inside of the inner mold (2), start the hydraulic cylinder, make the piston (7) tightly press the hinge (8), and make the hinge (8) drive the jacking disc cutters (5) tightly press the inner wall of the inner mold (2); S3, adjust the proportion of the concrete, configure dry-hard concrete and pour it into the cavity, start the high-frequency vibrator to drive the core shaft (3) to vibrate, form the nodular cast iron pipe, pull out the outer mold (1), make the hydraulic cylinder release pressure, make the piston (7) retract, make the jacking disc cutters (5) on the core shaft (3) shrink in the disc cutter holder (4), lower the core shaft (3) below the vibration platform, and hoist the base and the inner mold (2) to the corresponding area for solidification; S4, after the concrete hardens, remove the base to form the nodular cast iron pipe product.
8. The ductile cast iron pipe jacking core rod jolt forming method according to claim 7, characterized by: In S2, the radial pressure of the hydraulic cylinder on the inner wall of the nodular cast iron pipe is 10-15 MPa.
9. The ductile cast iron pipe jacking core rod jolt forming method according to claim 7, characterized in that: In S3, the frequency of the high-frequency vibrator is 50-100 Hz, and the vibration duration is 60-120 s after the material is poured.
10. The ductile cast iron pipe jacking core rod jolt forming method according to claim 7, characterized in that: In S3, the pull-out slope of the outer mold (1) is 1:30-1:60, and the pull-out speed of the outer mold (1) is 3-6 mm / s.