Overload protection constant-force ejector rod

By designing an overload protection constant force push rod and utilizing a combined structure of a sleeve, an unloading rod, and a friction plate, the constant force push rod can automatically adjust its length under different loads. This solves the problem of cracking caused by excessive mold constraints during the preparation of large annular concrete cement products, ensuring the stability of the product shape and size.

CN223383668UActive Publication Date: 2025-09-26SUZHOU CONCRETE CEMENT PROD RES INST
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Patent Information

Application Number
CN202422617143.9
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-10-29
Publication Date
2025-09-26
Estimated Expiration
2034-10-29

AI Technical Summary

Technical Problem

During the preparation process of large-scale annular concrete cement products, the risk of concrete cracking is relatively high due to the excessive restraint of the mold. Existing technologies make it difficult to effectively protect the shape and size of concrete products.

Method used

An overload protection constant force push rod is designed, which includes a sleeve, an unloading rod, a friction plate and an adjusting screw. By adjusting the friction between the friction plate and the unloading rod, the constant force push rod can automatically adjust its length under different loads, provide moderate constraint or relaxation, and avoid overload damage.

Benefits of technology

It effectively protects concrete products from cracking during the pouring process, ensures the stability of shape and size, reduces the occurrence of cracks, and is suitable for the manufacture of annular concrete products of different diameters.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model discloses an overload protection constant-force ejector rod which comprises a sleeve, an unloading rod, a friction plate, an adjusting screw and an adjusting rod. A tube cavity is formed in one end part of the sleeve; one end part of the unloading rod extends into the pipe cavity, and a spacing distance is formed between the extending end of the unloading rod and the cut-off end of the pipe cavity; the friction plate is arranged between the unloading rod and the pipe cavity, and the friction plate is pressed on the unloading rod; the adjusting screw is connected to the sleeve through threads, extends into the pipe cavity and abuts against the friction plate. One end of the adjusting rod is connected to the other end of the sleeve, and the connecting length between the adjusting rod and the sleeve is adjustable. According to the constant-force ejector rod, when the force applied to the constant-force ejector rod is smaller than the friction force between the unloading rod and the friction plate, the constant-force ejector rod cannot stretch out and draw back; when the force applied to the constant-force ejector rod is larger than the friction force between the unloading rod and the friction plate, relative sliding occurs between the unloading rod and the friction plate, and the external force applied by the constant-force ejector rod can be relaxed.
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Description

Technical Field

[0001] The utility model relates to the technical field of construction engineering, in particular to an overload protection constant force push rod. Background Art

[0002] With the advancement of science and technology, large annular cement concrete products are increasingly appearing, such as wind turbine towers and utility pipeline corridors. The production of these products often encounters concrete cracking, a major cause of which is excessive mold restraint. Shrinkage is a fundamental characteristic of concrete. If concrete shrinks under strong restraint, it will generate significant tensile stresses within the concrete, leading to cracking. Large annular concrete products are typically large, thin-walled components, posing a greater risk of cracking during production.

[0003] The inner formwork provides restraint against concrete shrinkage. Because large, ring-shaped concrete cement products are generally tall, the inner formwork is installed with multiple support rods in the middle and upper sections, in addition to being fixed at the bottom. These rods enhance the restraint provided by the inner formwork. This restraint is useful during concrete pouring, ensuring the shape and dimensions of the concrete product. However, if this restraint is too strong as the concrete shrinks, it can cause cracking. Utility Model Content

[0004] The purpose of the utility model is to provide an overload protection constant force push rod with overload protection function in view of the deficiencies in the prior art.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] An overload protection constant force push rod, comprising:

[0007] a cannula, one end of which is provided with a lumen;

[0008] An unloading rod, one end of which extends into the lumen, and a distance is provided between the end of the unloading rod extending into the lumen and the cut-off end of the lumen;

[0009] a friction plate, disposed between the unloading rod and the inner wall of the tube cavity, the friction plate being pressed onto the unloading rod;

[0010] an adjusting screw, threadably connected to the sleeve, one end of the adjusting screw extending into the tube cavity and resting against the friction plate, so that the friction plate is pressed against the unloading rod and a set friction force is generated between the friction plate and the unloading rod;

[0011] An adjusting rod has one end connected to the other end of the sleeve, and the connection length between the adjusting rod and the sleeve can be adjusted.

[0012] In some embodiments, a plurality of friction plates are arranged at intervals along the circumferential direction of the unloading rod, and / or a plurality of friction plates are arranged at intervals along the axial direction of the unloading rod.

[0013] In some embodiments, each of the friction plates is abutted against at most two of the adjusting screws, and the adjusting screws are tightened with a torque wrench, and the friction force of the friction plate is adjusted by setting a torque value.

[0014] In some embodiments, the inner diameter of the lumen is greater than the sum of twice the thickness of the friction plate and the outer diameter of the unloading rod.

[0015] In some embodiments, the other end of the sleeve is connected to one end of the adjusting rod through a thread, and the length of the threaded engagement between the two can be adjusted.

[0016] In some embodiments, the adjusting rod is further provided with a wrench position for clamping a wrench when tightening the adjusting rod, and there is a spacing distance between the wrench position and the other end of the adjusting rod.

[0017] In some embodiments, the other end of the unloading rod is provided with a first connection portion connected to the mold, and the other end of the adjusting rod is provided with a second connection portion connected to the mold.

[0018] In some embodiments, the other end of the sleeve is connected to one end of the adjusting rod via a thread, and the second connecting portion can be rotatably arranged around the axis of the adjusting rod relative to the mold.

[0019] In some embodiments, the first connecting portion and the second connecting portion have the same or different structures.

[0020] In some embodiments, the first connecting portion and the second connecting portion are both conical or hemispherical.

[0021] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: in the overload protection constant force push rod of the present invention, when the force applied to the constant force push rod is less than the friction force between the unloading rod and the friction plate, the constant force push rod exhibits rigidity and will not expand or contract; when the force applied to the constant force push rod is greater than the friction force between the unloading rod and the friction plate, relative sliding occurs between the unloading rod and the friction plate, and the unloading rod will retract into the tube cavity of the sleeve, thereby reducing the length of the constant force push rod, thereby relaxing the external force applied by the constant force push rod. In this way, when pouring concrete products, the constant force push rod can provide appropriate restraining force for the concrete products to ensure the shape and size of the concrete products; and when the restraining force is overloaded, the restraining force can be reduced in time to protect the concrete products and reduce the occurrence of cracks in the concrete products. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Attachment Figure 1 Schematic diagram of the structure of the overload protection constant force push rod of this embodiment.

[0023] Among them: 1. sleeve; 11. tube cavity; 111. second end; 12. threaded hole; 2. unloading rod; 21. first end; 22. first connecting part; 3. friction plate; 4. adjusting screw; 5. adjusting rod; 51. external thread; 52. wrench position; 53. second connecting part. DETAILED DESCRIPTION

[0024] The following is a clear and complete description of the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0025] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like are based on the directions or positional relationships shown in the accompanying drawings, such as Figure 1 In the drawings, the left side is referred to as "left," the right side is referred to as "right," the upper side is referred to as "up," and the lower side is referred to as "down." Directions perpendicular to the paper in the drawings are referred to as "front" and "back." This is intended solely to facilitate the description of the present invention and to simplify the description. It is not intended to indicate or imply that the device or apparatus referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, it should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] like Figure 1 As shown, the overload protection constant force push rod of the present invention includes a sleeve 1, an unloading rod 2, a friction plate 3, an adjusting screw 4 and an adjusting rod 5.

[0027] A lumen 11 is provided in the cannula 1 , and the lumen 11 passes through one end surface of the cannula 1 .

[0028] One end of the unloading rod 2 extends into the lumen 11 of the cannula 1. The end of the unloading rod 2 extending into the lumen 11 is denoted as a first end 21, and the end of the lumen 11 is denoted as a second end 111. A distance is provided between the first end 21 and the second end 111. In this way, the unloading rod 2 can slide relative to the cannula 1 in a direction of retracting into the lumen 11 of the cannula 1, thereby shortening the constant force push rod.

[0029] The friction plate 3 is arranged between the unloading rod 2 and the inner wall of the tube cavity 11 of the sleeve 1. The friction plate 3 is pressed on the unloading rod 2 so that friction force is generated between the friction plate 3 and the unloading rod 2.

[0030] A plurality of friction plates 3 can be evenly spaced along the circumferential direction and / or axial direction of the unloading rod 2, so that the friction force between the friction plate 3 and the unloading rod 2 is evenly distributed, so that the unloading rod 2 is subjected to balanced force.

[0031] The adjusting screw 4 is connected to the sleeve 1 through a thread, and one end of the adjusting screw 4 extends into the tube cavity 11 of the sleeve 1 and is pressed against the friction plate 3, thereby applying positive pressure to the friction plate 3, pressing the friction plate 3 onto the unloading rod 2, and generating a set friction force between the friction plate 3 and the unloading rod 2.

[0032] By controlling the torque of the adjusting screw 4 when tightening, the positive pressure exerted by the adjusting screw 4 on the friction plate 3 can be controlled, thereby controlling the friction force between the friction plate 3 and the unloading rod 2.

[0033] The number of adjusting screws 4 is determined by the required friction between the friction plate 3 and the unloading lever 2, and is generally no more than two. That is, each friction plate 3 is abutted against at most two adjusting screws 4. The two adjusting screws 4 can be spaced apart along the circumference or axial direction of the unloading lever 2. This ensures that the friction between the friction plate 3 and the unloading lever 2 is distributed as evenly as possible, resulting in a balanced force on the unloading lever 2.

[0034] One end of the adjusting rod 5 is connected to the other end of the sleeve 1, and the connection length between the adjusting rod 5 and the sleeve 1 can be adjusted. In this way, by adjusting the connection length between the adjusting rod 5 and the sleeve 1, the length of the entire constant force ram can be adjusted, making the constant force ram suitable for the production of annular concrete products of different diameters.

[0035] In this embodiment, a threaded hole 12 is provided at the other end of the sleeve 1, and an external thread 51 is provided at one end of the adjusting rod 5 to match the threaded hole 12. The other end of the sleeve 1 is connected to one end of the adjusting rod 5 through a thread, and the length of the threaded engagement between the two can be adjusted.

[0036] Adjustment rod 5 is also provided with a wrench position 52 for gripping a wrench when tightening adjustment rod 5. In this embodiment, wrench position 52 can be a hexagonal head, a square head, or other structural forms. A distance is provided between wrench position 52 and the other end of adjustment rod 5 to facilitate wrench operation.

[0037] The other end of the unloading rod 2 is provided with a first connecting portion 22, and the other end of the adjusting rod 5 is provided with a second connecting portion 53. The first connecting portion 22 and the second connecting portion 53 are both used to connect to the mold.

[0038] In this embodiment, since the adjusting rod 5 is connected to the sleeve 1 by threads, the second connecting portion 53 needs to be rotatable relative to the mold around the axis of the adjusting rod 5, so as to facilitate adjustment of the connection length between the adjusting rod 5 and the sleeve 1.

[0039] The first connecting portion 22 and the second connecting portion 53 may have the same or different structural forms. In this embodiment, both may be conical or hemispherical, which facilitates the processing and manufacturing of the constant force push rod. The first connecting portion 22 and the second connecting portion 53 may also adopt other structural forms.

[0040] When using the constant force ejector, the torque of the adjusting screw 4 is controlled when tightening, according to the required friction between the friction plate 3 and the unloading rod 2, thereby controlling the positive pressure exerted by the adjusting screw 4 on the friction plate 3 to meet the set requirements. The constant force ejector is placed at the required position inside the mold, and the wrench position 52 is clamped with a wrench to adjust the connection length between the adjusting rod 5 and the sleeve 1, thereby adjusting the length of the constant force ejector to the set value.

[0041] When the force applied to the constant-force push rod is less than the friction between the friction plate 3 and the unloading rod 2, the friction plate 3, the unloading rod 2, and the sleeve 1 form an integral structure, the constant-force push rod exhibits rigidity, and the unloading rod 2 does not expand or contract. When the force applied to the constant-force push rod is greater than the friction between the friction plate 3 and the unloading rod 2, because the inner diameter of the lumen 11 of the sleeve 1 is greater than the sum of twice the thickness of the friction plate 3 and the outer diameter of the unloading rod 2, the friction plate 3 and the unloading rod 2 will slide, and the unloading rod 2 will slide relative to the sleeve 1 in the direction of retracting into the lumen 11 of the sleeve 1, thereby relaxing the external force applied by the constant-force push rod.

[0042] Two specific embodiments of the constant force mandrel design are given below.

[0043] Example 1: Design of 30T constant force mandrel

[0044] For a 30T constant-force ram, the friction between the friction plate 3 and the unloading rod 2 is 30T. The roughness of the friction plate 3 and the unloading rod 2 is controlled to keep the friction coefficient between 0.4 and 0.5. If calculated as 0.4, the positive pressure should be 75T. If four friction plates 3 are used, each plate 3 uses two adjusting screws 4 to apply positive pressure, and the pressure of each adjusting screw 4 is 937.5kg. The torque can be calculated based on the diameter and pitch of the adjusting screws 4.

[0045] Example 2: Design of 40T constant force mandrel

[0046] For a 40T constant-force ram, the friction between the friction plate 3 and the unloading rod 2 is 40T. The roughness of the friction plate 3 and the unloading rod 2 is controlled to keep the friction coefficient between 0.4 and 0.5. If calculated as 0.4, the positive pressure should be 100T. If four friction plates 3 are used, each plate 3 uses two adjusting screws 4 to apply positive pressure, with the pressure of each adjusting screw 4 being 1250kg. The torque can be calculated based on the diameter and pitch of the adjusting screws 4.

[0047] This constant force ram can be used in the production of annular concrete products. During pouring, it provides the appropriate restraining force to maintain the product's shape and size. If the restraining force becomes excessive, it can be reduced immediately, protecting the concrete product and reducing cracks.

[0048] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those familiar with the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications based on the spirit of the present invention are intended to be included in the scope of protection of the present invention.

Claims

1. An overload protection constant force push rod, characterized by: include: a cannula, one end of which is provided with a lumen; An unloading rod, one end of which extends into the lumen, and a distance is provided between the end of the unloading rod extending into the lumen and the cut-off end of the lumen; a friction plate, disposed between the unloading rod and the inner wall of the tube cavity, the friction plate being pressed onto the unloading rod; an adjusting screw, threadably connected to the sleeve, one end of the adjusting screw extending into the tube cavity and resting against the friction plate, so that the friction plate is pressed against the unloading rod and a set friction force is generated between the friction plate and the unloading rod; An adjusting rod has one end connected to the other end of the sleeve, and the connection length between the adjusting rod and the sleeve can be adjusted.

2. The overload protection constant force push rod according to claim 1, characterized in that: A plurality of friction plates are arranged at intervals along the circumferential direction of the unloading rod, and / or a plurality of friction plates are arranged at intervals along the axial direction of the unloading rod.

3. The overload protection constant force push rod according to claim 2, characterized in that: Each of the friction plates is abutted against and matched with at most two of the adjusting screws.

4. The overload protection constant force push rod according to claim 2, characterized in that: The inner diameter of the tube cavity is greater than the sum of twice the thickness of the friction plate and the outer diameter of the unloading rod.

5. The overload protection constant force push rod according to claim 1, characterized in that: The other end of the sleeve is connected to one end of the adjusting rod through a thread, and the length of the threaded engagement between the two can be adjusted.

6. The overload protection constant force push rod according to claim 5, characterized in that: The adjusting rod is also provided with a wrench position for clamping a wrench when tightening the adjusting rod, and there is a spacing distance between the wrench position and the other end of the adjusting rod.

7. The overload protection constant force push rod according to claim 1, characterized in that: The other end of the unloading rod is provided with a first connection portion connected to the mold, and the other end of the adjusting rod is provided with a second connection portion connected to the mold.

8. The overload protection constant force push rod according to claim 7, characterized in that: The other end of the sleeve is connected to one end of the adjusting rod through a thread, and the second connecting portion can be rotatably arranged around the axis of the adjusting rod relative to the mold.

9. The overload protection constant force push rod according to claim 7, characterized in that: The structures of the first connecting portion and the second connecting portion are the same or different.

10. The overload protection constant force push rod according to claim 9, characterized in that: The first connecting portion and the second connecting portion are both conical or hemispherical.