Improved prestressing device for reinforced concrete beams

Abstract

This utility model belongs to the technical field of construction equipment for building engineering, and in particular, it is an improved prestressing application device for reinforced concrete beams. It includes a shell, a portable component, a sliding frame, a sliding seat, multiple hydraulic cylinders, three clamping plates, a support and guide component, a manual adjustment component, an extension support component, a support reset component, multiple pressure sensors, and a control panel. The shell is a hollow cylinder. The portable component is located on the outside of the shell. The sliding frame is slidably mounted on the inner wall of the shell. The support and guide component is mounted on the sliding frame. The three clamping plates are all located inside the sliding frame and connected to the support and guide component. This utility model has a reasonable design and can achieve the effect of lateral insertion and stable clamping of steel strands, eliminating the need for insertion from the end of the steel strands. It effectively solves the problems of limited operating space, poor operational convenience, and low construction efficiency.

Description

Technical Field

[0001] This utility model relates to the field of construction equipment technology, and in particular to an improved prestressing device for reinforced concrete beams. Background Technology

[0002] Prestressing technology, as a key means to improve the load-bearing capacity, crack resistance, and durability of reinforced concrete beams, is widely used in engineering fields such as bridges, high-rise buildings, and long-span structures. Traditional prestressing application devices are mainly divided into two categories: pre-tensioning and post-tensioning.

[0003] Pre-tensioning method: Prestressed tendons need to be pre-tensioned on a precast platform, and then released after the concrete is poured and reaches its strength. It is suitable for factory production, but it is highly dependent on the platform and has poor flexibility in on-site construction.

[0004] Post-tensioning: Pre-drilled ducts are left in the concrete beam, and the prestressing tendons are inserted and tensioned and anchored after the beam is formed. It is suitable for on-site casting and structural reinforcement, but the tensioning equipment needs to be inserted from the end of the steel strand, which requires a large operating space.

[0005] However, traditional post-tensioning prestressing application devices (such as hydraulic jacks, tensioning oil pumps, etc.) have the following problems in practical applications:

[0006] Limited operating space, poor ease of operation and low construction efficiency: Traditional tensioning devices need to be inserted from the end of the steel strand, requiring the steel strand to extend a long distance (usually ≥1.5m) beyond the beam end. This is difficult to implement in narrow spaces (such as the reinforcement of existing bridges or the renovation of underground structures) or in scenarios with multiple densely arranged steel strands. At the same time, the method of inserting the device from the end is also quite cumbersome.

[0007] Therefore, this utility model proposes an improved prestressing application device for reinforced concrete beams to solve the above problems.

[0008] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Utility Model Content

[0009] The purpose of this invention is to address the shortcomings mentioned in the background section by proposing an improved prestressing device for reinforced concrete beams.

[0010] The above-mentioned technical objective of this utility model is achieved through the following technical solution: an improved prestressing application device for reinforced concrete beams, comprising a shell, a portable component, a sliding frame, a sliding seat, multiple hydraulic cylinders, three clamping plates, a support and guide component, a manual adjustment component, an extension support component, a support reset component, multiple pressure sensors, and a control panel.

[0011] The housing is a hollow cylinder. The portable component is located on the outside of the housing. The sliding frame is slidably mounted on the inner wall of the housing. The support guide component is located on the sliding frame. Three clamping plates are located inside the sliding frame and connected to the support guide component. The manual adjustment component is located on the outside of the housing and connected to the support guide component. The sliding seat is slidably mounted on the inner wall of the housing. Multiple hydraulic cylinders are fixedly mounted on the sliding seat. The working ends of the multiple hydraulic cylinders are fixedly mounted with pads. Multiple pressure sensors are fixedly mounted on one side of the sliding frame and connected to their respective pads. The control panel is located on the portable component and electrically connected to the multiple hydraulic cylinders and multiple pressure sensors. The support reset component is located on the inner wall of the housing and connected to the sliding seat. The housing has multiple arc-shaped openings. The extension support component is located on the outside of the housing and connected to the sliding seat, and the extension support component passes through the multiple arc-shaped openings.

[0012] The sliding frame, housing, and sliding seat are all provided with channels for the steel strand to enter and exit the housing from the side.

[0013] Preferably, the support and guide assembly includes six left support rods, three connecting frames, three fixing blocks, and three springs. Six left support rods arranged in pairs and parallel to each other are hinged on the sliding frame. The six left support rods are hinged on three clamping plates. The same connecting frame is hinged on two parallel left support rods. Three guide openings are provided on the housing. The three connecting frames pass through the corresponding guide openings and extend to the outside of the housing. Three fixing blocks are fixedly installed on the sliding frame. Springs are fixedly installed on each of the three fixing blocks. The three springs are fixedly installed on the corresponding left support rods.

[0014] Preferably, the manual adjustment assembly includes a sliding sleeve and three guide plates. The outer side of the housing is provided with a sliding sleeve with a notch. Three guide plates are fixedly installed on one side of the sliding sleeve. The three connecting brackets are slidably connected to the corresponding guide plates along the radial direction of the housing.

[0015] Preferably, the extended support assembly includes three guide frames, three right support rods, and three abutment plates. Each of the three arc-shaped openings has a guide frame slidably installed and fixedly connected to the sliding seat. Each of the three guide frames has a right support rod fixedly installed on it, and each of the three right support rods has an abutment plate fixedly installed at the end away from the guide frame.

[0016] Preferably, the support and reset assembly includes a fixed plate and multiple springs. The fixed plate is fixedly installed on the inner wall of the housing. The fixed plate has a notch adapted to the channel through which the steel strand enters and exits the housing from the side. Multiple springs are fixedly installed on the side of the fixed plate and the sliding seat that are close to each other.

[0017] Preferably, the portable component includes a rotating ring, a handle, and a sleeve. A rotating ring with a notch adapted to the channel through which the steel strand enters and exits the housing from the side is rotatably mounted on the housing. An L-shaped handle is radially fixedly mounted on the rotating ring, and a sleeve is fixedly fitted on the handle.

[0018] Preferably, a mounting plate is radially rotatably mounted on the handle, and the control panel is embedded and fixedly mounted on the front side of the mounting plate.

[0019] Preferably, a sealing ring for protecting the pressure sensor is fixedly installed on the pad, and the sealing ring is made of rubber and connected to the sliding seat.

[0020] The beneficial effects of this utility model are:

[0021] 1. Through the set support and guide components, six left support rods, three connecting frames, three fixing blocks and three springs work together to not only provide strong support for the clamping plates, but also flexibly adjust the clamping plate spacing to adapt to the clamping requirements of steel strands of different diameters, thus ensuring the versatility of the device.

[0022] 2. The design of the sliding sleeve and guide plate of the manual adjustment component allows the operator to easily manually control the synchronous deflection of the left support rod, thereby controlling the movement of the three clamping plates away from the housing axis. At the same time, the channels for the steel strand to enter and exit the housing from the side are provided on the sliding frame, housing, sliding seat, and fixed plate, allowing the steel strand to be directly inserted from the side of the housing during tensioning or untensioning operations, which greatly improves the convenience and efficiency of steel strand placement operations.

[0023] 3. The three guide frames, right support rod, and clamping plate of the extended support assembly provide additional support for the device when working in confined spaces, ensuring that tensioning or untensioning operations can still be completed smoothly even when it is inconvenient for the shell to be close to the end of the beam plate, effectively solving the problem in special working environments.

[0024] 4. The fixing plate and multiple springs supporting the reset assembly enable the automatic storage of the clamping plate after use, reducing the tedious steps of manual reset and improving the overall ease of use of the device.

[0025] 5. The rotating ring, handle, and grip of the portable components make it easier for operators to carry and operate the device. The clever combination of the mounting plate on the handle and the control panel not only provides stable support for the control panel but also allows for easy adjustment of the angle according to the actual situation, further improving the convenience of operation.

[0026] 6. The rubber sealing ring on the pad effectively protects the pressure sensor from interference by foreign objects, ensuring that the pressure sensor always works stably and accurately, thereby guaranteeing the reliability and accuracy of the entire device. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a three-dimensional structural schematic diagram of an improved prestressing application device for reinforced concrete beams proposed in this utility model;

[0029] Figure 2 This is a partial three-dimensional structural schematic diagram of the present invention;

[0030] Figure 3 A schematic diagram of a partial three-dimensional structure for point 2;

[0031] Figure 4 The figure shows a schematic diagram of the structure of the extension support component and the support reset component proposed in this utility model;

[0032] Figure 5 This is a schematic diagram of the structure of the manual adjustment component proposed in this utility model;

[0033] Figure 6 This is a schematic diagram of the structure of the hydraulic cylinder, pad, sealing ring, and pressure sensor components proposed in this utility model.

[0034] In the diagram: 1. Housing; 11. Rotating ring; 12. Handle; 13. Control panel; 2. Sliding frame; 21. Left support rod; 22. Clamping plate; 23. Connecting frame; 24. Fixing block; 25. Spring 1; 3. Sliding sleeve; 31. Guide plate; 4. Sliding seat; 41. Hydraulic cylinder; 42. Pad plate; 43. Pressure sensor; 44. Sealing ring; 5. Clamping plate; 51. Right support rod; 52. Guide frame; 6. Fixing plate; 61. Spring 2. Detailed Implementation

[0035] The technical solution of this utility model will now be clearly and completely described with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0036] Reference Figure 1-6 An improved prestressing application device for reinforced concrete beams includes a housing 1, a sliding frame 2, a sliding seat 4, multiple hydraulic cylinders 41, three clamping plates 22, multiple pressure sensors 43, and a control panel 13.

[0037] The housing 1 is a hollow cylinder. The sliding frame 2, housing 1, and sliding seat 4 all have channels for the steel strand to enter and exit the housing 1 from the side. The diameter of the channel is 1.2-1.5 times the diameter of the steel strand, and the inner wall of the channel is coated with a smooth, wear-resistant coating (such as tungsten carbide coating) to reduce frictional damage when the steel strand enters. A rotating ring 11 with a notch adapted to the channel for the steel strand to enter and exit the housing 1 from the side is rotatably mounted on the housing 1. An L-shaped handle 12 is radially fixed to the rotating ring 11, and a grip sleeve is fixedly fitted onto the handle 12. The diameter of the grip portion of the handle 12 is 30-40mm, and the surface is textured with anti-slip patterns to facilitate stable gripping by the operator in humid environments.

[0038] The sliding frame 2 is slidably installed on the inner wall of the housing 1. Six left support rods 21 are hinged on the sliding frame 2 and arranged in pairs parallel to each other. The six left support rods 21 are respectively hinged to the middle of three clamping plates 22. Each clamping plate 22 corresponds to two left support rods 21. The diameter of the hinge axis between the left support rod 21 and the clamping plate 22 is 8mm and the material is 45 steel. Two parallel left support rods 21 are hinged to the same connecting frame 23. The housing 1 has three guide openings. The three connecting frames 23 pass through the corresponding guide openings and extend to the outside of the housing 1. Three fixing blocks 24 are fixedly installed on the sliding frame 2. Spring 25 is fixedly installed on each of the three fixing blocks 24. Spring 25 is a cylindrical helical compression spring with a free length of 50mm, an elastic coefficient of 10N / mm, and is made of 65Mn spring steel. The three springs 25 are fixedly installed on the corresponding left support rods 21, which can provide effective support for the three clamping plates 22 and control their radial movement along the housing 1. When the left support rod 21 deflects 15°, the opening distance of the clamping plates 22 can reach 50mm, which is suitable for clamping steel strands with a diameter of 15.2mm-40mm.

[0039] The outer side of the housing 1 is fitted with a sliding sleeve 3 with a notch. Three guide plates 31 are fixedly installed on one side of the sliding sleeve 3. The three connecting frames 23 are slidably connected to the corresponding guide plates 31 along the radial direction of the housing 1. The axial sliding stroke of the sliding sleeve 3 is 80mm. When sliding, the connecting frame 23 is pushed to move along the radial direction of the housing through the guide plate 31. The guide groove width of the guide plate 31 is 12mm, and the fit clearance with the connecting frame 23 is ≤0.5mm to ensure synchronous deflection accuracy and facilitate the operator to manually control the synchronous deflection of the six left support rods 21.

[0040] The sliding seat 4 is slidably installed on the inner wall of the housing 1. Multiple hydraulic cylinders 41 are fixedly installed on the sliding seat 4. The hydraulic cylinders 41 are Y-HG1 type engineering hydraulic cylinders with a rated pressure of 31.5MPa, a stroke of 150mm, and a synchronization error of ≤0.2mm. The working ends of multiple hydraulic cylinders 41 are fixedly installed with pads 42. Multiple pressure sensors 43 are fixedly installed on one side of the sliding frame 2 and connected to the corresponding pads 42 respectively. In order to provide shielding protection for the pressure sensors 43, a sealing ring 44 for protecting the pressure sensors 43 is fixedly installed on the pad 42. The sealing ring 44 is made of neoprene rubber with a Shore hardness of 60±5HA and a lip design of 15° bevel angle to ensure a tight seal with the sliding seat 4.

[0041] The control panel 13 is mounted on the handle 12 and electrically connected to multiple hydraulic cylinders 41 and multiple pressure sensors 43. The control panel 13 has a built-in PLC controller (model S7-200 SMART) with preset tensioning programs including: 0-10%σcon (holding load for 5 min) → 20%σcon → 100%σcon (holding load for 2 min). The pressure sensors 43 are model PT124G-103, with a measurement range of 0-60MPa and an accuracy of ±0.25%FS. The data is transmitted to the PLC in real time and displayed on a 7-inch touch screen. A fixing plate 6 is fixedly installed on the inner wall of the housing 1. The fixing plate 6 has a notch that matches the channel for the steel strand to enter and exit the housing 1 from the side. Multiple springs 61 are fixedly installed on the side of the fixing plate 6 and the sliding seat 4 that are close to each other. The springs 61 are rectangular cross-section springs with a free length of 100mm and an elastic coefficient of 20N / mm. When the hydraulic cylinder 41 retracts, the springs 61 push the sliding seat 4 to reset at a reset speed of 5mm / s.

[0042] The housing 1 has multiple arc-shaped openings. Guide frames 52, which are fixedly connected to the sliding seat 4, are slidably installed in three of the arc-shaped openings. Right support rods 51 are fixedly installed on each of the three guide frames 52. A retaining plate 5 is fixedly installed at the end of each of the three right support rods 51 away from the guide frames 52. The contact surface of the retaining plate 5 is an arc-shaped curved surface with a radius of curvature matching the surface of the beam plate. The area is 150mm×150mm, ensuring that the effective contact area with the beam plate in a narrow space is ≥20000mm², which can provide an extended support effect when the device is used.

[0043] In this embodiment, in order to provide stable support for the control panel 13 and facilitate turning according to actual needs, a mounting plate is radially rotatably mounted on the handle 12. The mounting plate is connected to the handle 12 through a thrust ball bearing (model 51105) and can rotate 360° with a positioning accuracy of ±1°. After the control panel 13 is embedded in the mounting plate, the operator can adjust it to the optimal operating angle according to the viewing angle.

[0044] Among them, the channels for inserting steel strands directly from the side of the housing 1, which are set on the housing 1, sliding frame 2, fixed plate 6 and sliding seat 4, are aligned in the same direction. The channel axis is perpendicular to the axis of the housing 1. A laser centering indicator (built into the inner wall of the housing 1) is set on the steel strand insertion path to emit a red laser beam to assist in the positioning of the steel strand and ensure that the deviation between the center of the steel strand and the center of the clamp 22 is ≤1mm. This solves the problem of cumbersome operation that traditional prestressed tensioning devices require insertion from the end of the steel strand.

[0045] Working principle (supplemented and modified parts)

[0046] In use, first connect the 220V power supply. Hold the handle 12 (or use an electric hoist to lift) and raise the device to the same level as the steel strand. Adjust the device position using the laser alignment indicator to align the steel strand with the side channel axis. Then, pull the sliding sleeve 3 outward along the axis of the housing 1. When the sliding sleeve 3 slides 80mm, the guide plate 31 drives the connecting frame 23 to move radially by 25mm, causing the left support rod 21 to deflect by 15°. The three clamping plates 22 open to the maximum spacing of 50mm, and the steel strand is slowly pushed in from the side channel until the laser beam irradiates the center of the steel strand. After releasing the sliding sleeve 3, the spring 25 (elastic coefficient 10N / mm) pushes the left support rod 21 back to its original position, and the clamping plates 22 clamp the steel strand with a pre-tightening force of 20N. The clamping force is monitored in real time by the pressure sensor 43.

[0047] The device is then pushed so that the clamping plate 5 presses against the beam surface. When the curved surface of the clamping plate 5 contacts the beam, the compression of spring 61 is 10mm, generating a preload of 200N to ensure stable support. The tensioning program is started via control panel 13: hydraulic cylinder 41 extends at a speed of 0.5mm / s. When pressure sensor 43 detects that the tension force reaches 10%σcon (e.g., 10% tension force of 1860MPa steel strand is 279kN), the system automatically holds the load for 5 minutes; tensioning continues to 20%σcon, then uniformly tensions to 100%σcon (2790kN) and holds the load for 2 minutes. During the tensioning process, the synchronization error of hydraulic cylinder 41 is ≤0.2mm to ensure the uniformity of tensioning of multiple steel strands.

[0048] After tensioning is completed, hydraulic cylinder 41 slowly retracts, and spring 61 (elastic coefficient 20N / mm) pushes sliding seat 4 to reset at a speed of 5mm / s, and clamping plate 5 automatically detaches from beam surface. At this time, pulling sliding sleeve 3 again opens clamping plate 22, and the steel strand can be withdrawn. The entire operation does not require a space of ≥1.5m at the end of the steel strand, and can be carried out in narrow areas with a clearance of ≥300mm, effectively solving the problems of "limited operating space" and "low construction efficiency" in the background technology.

[0049] By employing a side-channel design and laser centering, the steel strands do not need to be inserted from the ends. They can be directly installed from the side in narrow spaces (such as bridge web spacing of 300mm), reducing the required operating space by over 80% compared to traditional devices that require a 1.5m end clearance. This effectively solves the problem of limited operating space in the background technology. The manual adjustment component uses a sliding sleeve-guide plate mechanism to achieve synchronous opening of the clamping plates, with a single operation time of ≤10s. Combined with laser centering, the installation efficiency of the steel strands is increased by 3 times. The control panel has preset tensioning programs, reducing manual intervention and avoiding the tedious repeated adjustments required by traditional devices, significantly improving operational convenience. The hydraulic cylinder synchronization accuracy is ≤0.2mm, and the single-strand tensioning time is controlled within 8 minutes, compared to 20 minutes for a single-strand tensioning with a traditional jack, increasing efficiency by 60%. The spring reset component enables automatic retraction of the clamping plate, reducing manual reset steps and further shortening the process interval, significantly improving construction efficiency and comprehensively solving the problem of low construction efficiency mentioned in the background technology.

[0050] The above provides a detailed description of the improved prestressing application device for reinforced concrete beams provided by this utility model. Specific embodiments have been used to illustrate the principle and implementation of this utility model. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core idea of ​​this utility model. It should be noted that those skilled in the art can make several improvements and modifications to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. An improved prestressing application device for reinforced concrete beams, characterized in that, It includes a housing (1), a portable component, a sliding frame (2), a sliding seat (4), multiple hydraulic cylinders (41), three clamps (22), a support guide assembly, a manual adjustment assembly, an extension support assembly, a support reset assembly, multiple pressure sensors (43), and a control panel (13); The housing (1) is a hollow cylinder. The portable component is located on the outside of the housing (1). The sliding frame (2) is slidably mounted on the inner wall of the housing (1). The support and guide component is located on the sliding frame (2). Three clamps (22) are located inside the sliding frame (2) and connected to the support and guide component. The manual adjustment component is located on the outside of the housing (1) and connected to the support and guide component. The sliding seat (4) is slidably mounted on the inner wall of the housing (1). Multiple hydraulic cylinders (41) are fixedly mounted on the sliding seat (4). The working ends of the multiple hydraulic cylinders (41) Each component is fixedly mounted with a pad (42), and multiple pressure sensors (43) are fixedly mounted on one side of the sliding frame (2) and connected to the corresponding pad (42) respectively. The control panel (13) is set on the portable component and electrically connected to multiple hydraulic cylinders (41) and multiple pressure sensors (43). The support reset component is set on the inner wall of the housing (1) and connected to the sliding seat (4). Multiple arc-shaped openings are provided on the housing (1). The extension support component is set on the outside of the housing (1) and connected to the sliding seat (4), and the extension support component passes through multiple arc-shaped openings. The sliding frame (2), the housing (1) and the sliding seat (4) are all provided with channels for the steel strand to enter and exit the housing (1) from the side.

2. The improved device for applying prestress to reinforced concrete beams according to claim 1, characterized in that: The support and guide assembly includes six left support rods (21), three connecting frames (23), three fixing blocks (24), and three springs (25). Six left support rods (21) arranged in pairs and parallel to each other are hinged on the sliding frame (2). The six left support rods (21) are hinged on three clamps (22). The same connecting frame (23) is hinged on two parallel left support rods (21). Three guide openings are provided on the housing (1). The three connecting frames (23) pass through the corresponding guide openings and extend to the outside of the housing (1). Three fixing blocks (24) are fixedly installed on the sliding frame (2). Springs (25) are fixedly installed on each of the three fixing blocks (24). The three springs (25) are fixedly installed on the corresponding left support rods (21).

3. The improved device for applying prestress to reinforced concrete beams according to claim 2, characterized in that: The manual adjustment assembly includes a sliding sleeve (3) and three guide plates (31). The outer side of the housing (1) is slidably fitted with a sliding sleeve (3) with a notch. Three guide plates (31) are fixedly installed on one side of the sliding sleeve (3). The three connecting brackets (23) are slidably connected to the corresponding guide plates (31) along the radial direction of the housing (1).

4. The improved device for applying prestress to reinforced concrete beams according to claim 1, characterized in that: The extended support assembly includes three guide frames (52), three right support rods (51), and three abutment plates (5). The guide frames (52) are slidably installed in the three arc-shaped openings and are fixedly connected to the sliding seat (4). The right support rods (51) are fixedly installed on the three guide frames (52), and the abutment plates (5) are fixedly installed at the ends of the three right support rods (51) away from the guide frames (52).

5. The improved device for applying prestress to reinforced concrete beams as claimed in claim 1, wherein: The support and reset assembly includes a fixed plate (6) and multiple springs (61). The fixed plate (6) is fixedly installed on the inner wall of the housing (1). The fixed plate (6) has a notch that matches the channel through which the steel strand enters and exits the housing (1) from the side. Multiple springs (61) are fixedly installed on the side of the fixed plate (6) and the sliding seat (4) that are close to each other.

6. The improved device for applying prestress to reinforced concrete beams according to claim 1, characterized in that: The portable component includes a rotating ring (11), a handle (12), and a sleeve. The rotating ring (11) is rotatably mounted on the housing (1) with a notch adapted to the channel through which the steel strand enters and exits the housing (1) from the side. The rotating ring (11) is radially fixedly mounted with an L-shaped handle, and a sleeve is fixedly fitted on the handle.

7. The improved device for applying prestress to reinforced concrete beams as claimed in claim 6, wherein: A mounting plate is radially rotatably mounted on the handle (12), and the control panel (13) is embedded and fixedly mounted on the front side of the mounting plate.

8. The improved device for applying prestress to reinforced concrete beams as claimed in claim 1, wherein: A sealing ring (44) for protecting the pressure sensor (43) is fixedly installed on the pad (42), and the sealing ring (44) is made of rubber and is connected to the sliding seat (4).

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