Hot and cold blank mixed loading clamp of heating furnace

Abstract

The utility model discloses a hot and cold blank mixed loading clamp for a heating furnace, which relates to the technical field of blank forging and comprises a clamping arm body made of an elastic metal material and a detachable heat-resistant insert arranged at a workpiece contact end of the clamping arm body. The heat-resistant insert with the thermal expansion coefficient smaller than that of the clamping arm body is adopted, self-generated pressure stress is generated on the connecting interface of the insert and the arm body through the material thermal expansion difference under the high-temperature clamping working condition, thermal deformation is effectively compensated, and the insert is prevented from loosening; when the heat-resistant insert is in direct contact with a high-temperature blank, creep deformation and oxidation are resisted, the structural rigidity is maintained, the elastic arm body plays the advantage of high toughness during low-temperature clamping, and flexible clamping force is provided to avoid embrittlement. The partition material design synchronously solves the contradiction between softening failure of a high-temperature area and insufficient elasticity of a low-temperature area of a traditional clamp under the working condition of alternate cooling and heating, the service life is prolonged, and the clamping stability is guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of billet forging technology, specifically a fixture for mixing hot and cold billets in a heating furnace. Background Technology

[0002] In the production practices of the metallurgical and forging industries, heating furnaces need to frequently alternately clamp high-temperature billets that have just been taken out of the furnace with cold billets that are at room temperature. This operation mode of alternating hot and cold billets places extremely stringent requirements on the fixtures.

[0003] Currently, most traditional clamps are manufactured from a single metal material. However, this single-material structure cannot simultaneously meet the contradictory performance requirements of "rigid heat resistance" in high-temperature zones and "elastic clamping" in non-high-temperature zones when dealing with mixed hot and cold billet loading conditions. In high-temperature zones, the material is prone to creep, softening, and accelerated oxidation, leading to a decrease in structural strength. In low-temperature zones where elasticity is required, the single heat-resistant material is often too hard and lacks toughness, making it prone to brittle or fatigue fracture, thus reducing the overall service life of the clamp. Therefore, we propose a clamp for mixing hot and cold billets in a heating furnace. Summary of the Invention

[0004] The purpose of this utility model is to provide a mixing fixture for hot and cold billets in a heating furnace to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a heating furnace cold and hot billet mixing fixture, comprising: a clamping arm; the body of the clamping arm is made of an elastic metal material; the workpiece contact end of the clamping arm is provided with a detachable heat-resistant insert, the thermal expansion coefficient of the heat-resistant insert being less than that of the clamping arm body material.

[0006] Preferably, the heat-resistant insert is connected to the clamping arm via a mechanical fitting structure; the mechanical fitting structure includes a protrusion on the side of the heat-resistant insert and a groove at the end of the clamping arm, with the protrusion and groove being interference-fitted.

[0007] Preferably, the side wall of the heat-resistant insert is provided with an anti-disengagement locking hole; the corresponding position of the clamping arm is provided with a limiting hole; and a locking bolt penetrating through the anti-disengagement locking hole and the limiting hole is provided in both.

[0008] Preferably, the elastic metal material is spring steel; the heat-resistant insert is made of nickel-based alloy material.

[0009] Preferably, the heat-resistant insert has a cooling cavity inside; the opening of the cooling cavity extends to the side of the heat-resistant insert and is sealed by a removable sealing cap; the cooling cavity is filled with phase change energy storage material.

[0010] Preferably, the walls of the cooling cavity are provided with heat-conducting ribs; the heat-conducting ribs are perpendicularly connected to the workpiece contact surface of the heat-resistant insert.

[0011] Preferably, a first stepped groove is provided on the outer side of the limiting hole; a second stepped groove is provided on the outer side of the anti-loosening locking hole; and the nut of the locking bolt is engaged with the second stepped groove.

[0012] Preferably, an annular sleeve is provided in the first stepped groove; the annular sleeve has an internal thread that mates with the external thread of the locking bolt; one end of the annular sleeve is interference-fitted with the first stepped groove, and the other end has a hexagonal structure.

[0013] Compared with traditional technologies, the beneficial effects of this utility model are:

[0014] This device innovatively employs an elastic metal material to construct the clamping arm body, and incorporates a detachable heat-resistant insert with a lower coefficient of thermal expansion at the end that directly contacts the high-temperature blank. This partitioned material design effectively resolves the contradictory requirements of traditional single-material heat-resistant steel clamps, which cannot simultaneously meet the demands of "rigid heat resistance" in high-temperature zones and "elastic clamping" in low-temperature zones. The heat-resistant insert resists creep, softening, and oxidation in high-temperature zones, maintaining structural strength and shape stability; while the elastic arm body provides good toughness and elastic clamping force in low-temperature zones, avoiding the risk of brittle or fatigue fracture, thereby extending the overall service life of the clamp.

[0015] The heat-resistant insert is detachably mounted on the end of the clamping arm via a mechanical fitting structure and locking bolt structure, allowing the heat-resistant insert—the critical component most susceptible to wear, damage, or performance degradation under high-temperature environments—to be replaced individually. Compared to traditional integral clamps, which require complete scrapping once a part is damaged, this design enables modular replacement of core vulnerable components, reducing spare parts costs and replacement time, effectively minimizing equipment downtime, and improving production efficiency.

[0016] The fixture has a cooling cavity filled with phase change energy storage material inside the heat-resistant insert, which is sealed by a removable sealing cover. When the phase change material absorbs a large amount of heat transferred from the heat-resistant insert, it undergoes a phase change, which can effectively delay the rapid rise in the temperature of the insert body and reduce the adverse effects of high temperature on the performance of the insert material. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0018] Figure 2 This is a schematic diagram of the connection between the heat-resistant insert and the clamping arm of this utility model;

[0019] Figure 3 This is a schematic diagram of the heat-resistant insert structure of this utility model;

[0020] Figure 4 This is a schematic diagram of the cooling cavity structure of this utility model.

[0021] In the figure: 1-clamping arm; 2-heat resistant insert; 3-protrusion; 4-groove; 5-anti-loosening locking hole; 6-limiting hole; 7-locking bolt; 8-cooling cavity; 9-sealing cover; 10-heat-conducting rib; 11-first stepped groove; 12-second stepped groove; 13-annular sleeve. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model. Example

[0023] Please see Figures 1-4 The illustration shows a clamping fixture for mixing hot and cold billets in a heating furnace, comprising: a clamping arm 1; the body of the clamping arm 1 is made of an elastic metal material, giving the fixture body excellent elastic deformation capability and fatigue resistance. When clamping a room temperature cold billet, the elastic arm can undergo moderate bending deformation, providing flexible clamping force and avoiding the risk of brittle fracture; the workpiece contact end of the clamping arm 1 is provided with a detachable heat-resistant insert 2, the thermal expansion coefficient of the heat-resistant insert 2 is less than that of the clamping arm 1 body material. This design actively offsets thermal stress under high-temperature conditions through the gradient difference in thermal expansion coefficients—when clamping a high-temperature billet, the expansion of the heat-resistant insert 2 is less than that of the elastic arm, causing a clamping force to be generated at the interface between the insert and the arm body, avoiding loosening of the connection or separation of the interface due to uneven thermal expansion, and ensuring high-temperature clamping stability.

[0024] The following describes some embodiments of this application in detail with reference to the accompanying drawings:

[0025] Please see Figures 1-4 By employing an elastic metal material to construct the clamping arm 1 body, and placing a detachable heat-resistant insert 2 with a lower coefficient of thermal expansion at the end that directly contacts the high-temperature blank, this partitioned material design effectively resolves the contradictory requirements of traditional single-material heat-resistant steel clamps, which cannot simultaneously meet the demands of "rigid heat resistance" in high-temperature zones and "elastic clamping" in low-temperature zones. The heat-resistant insert 2 resists creep, softening, and oxidation in high-temperature zones, maintaining structural strength and shape stability; while the elastic arm body provides good toughness and elastic clamping force in low-temperature zones, avoiding the risk of brittle or fatigue fracture, thereby extending the overall service life of the clamp.

[0026] The heat-resistant insert 2 is connected to the clamping arm 1 via a mechanical fitting structure. This structure includes a protrusion 3 on the side of the heat-resistant insert 2 and a groove 4 at the end of the clamping arm 1, with the protrusion 3 and groove 4 interlocked. The interference fit between the protrusion 3 on the side of the insert and the groove 4 at the end of the clamping arm 1 utilizes the radial compressive stress generated by the elastic deformation of the metal to create a self-locking effect. In high-temperature environments, the interference fit compensates for differences in material thermal expansion, preventing the insert from falling off. During disassembly, the interference fit can be broken by external force to achieve quick replacement, balancing connection reliability and ease of maintenance.

[0027] In addition, the side wall of the heat-resistant insert 2 is provided with an anti-disengagement locking hole 5; the corresponding position of the clamping arm 1 is provided with a limiting hole 6; a locking bolt 7 is provided through both the anti-disengagement locking hole 5 and the limiting hole 6. The bolt preload can suppress the micro-displacement of the insert under vibration or impact, while the depth design of the limiting hole 6 controls the axial travel of the bolt to avoid over-tightening and deformation of the elastic arm. This structure constitutes a second layer of failure protection in addition to mechanical fitting.

[0028] In this technical solution, the elastic metal material is spring steel. By utilizing the high yield strength, excellent anti-relaxation properties and elastic recovery ability of spring steel, the clamping arm 1 is ensured to maintain a stable clamping force during repeated hot and cold cycles, thus avoiding the accumulation of plastic deformation. The heat-resistant insert 2 is made of nickel-based alloy material. Relying on the solid solution strengthening effect and high-temperature oxidation resistance of nickel-based alloy, it maintains high hardness and creep resistance at high temperatures, thus extending the high-temperature service life of the insert.

[0029] In this technical solution, a first stepped groove 11 is provided on the outer side of the limiting hole 6; a second stepped groove 12 is provided on the outer side of the anti-loosening locking hole 5; the nut of the locking bolt 7 mates with the second stepped groove 12 to prevent high-temperature oxidation or impact damage to the threads. The contact surface between the bolt head and the side wall of the stepped groove generates a radial constraint force, which inhibits the bolt from spinning loose under thermal vibration, and is especially suitable for high-frequency thermal shock conditions.

[0030] In addition, an annular sleeve 13 is provided within the first stepped groove 11; the annular sleeve 13 has an internal thread that mates with the external thread of the locking bolt 7; one end of the annular sleeve 13 is interference-fitted with the first stepped groove 11, and the other end has a hexagonal structure. The interference fit between the sleeve and the clamping arm 1 avoids fretting wear caused by relative displacement of the threaded pair at high temperatures. The hexagonal outer end allows for separate disassembly and replacement of the sleeve using a wrench. When high temperatures cause the threads to rust or seize, only the sleeve needs to be replaced instead of the entire clamping arm 1, reducing maintenance costs.

[0031] The working principle of this device is as follows:

[0032] When clamping room temperature billets, the clamping arm 1, made of an elastic metal material (such as spring steel), plays a crucial role. Its high elastic modulus allows the arm to undergo controllable bending deformation, generating a uniform elastic clamping force, avoiding damage to the surface of the cold billet, and preventing the arm from fracturing due to low temperature brittleness.

[0033] When in contact with high-temperature billets, the heat-resistant insert 2 (such as a nickel-based alloy) serves as the direct contact end, utilizing its high thermal strength to resist the heat of the billet. The insert's lower coefficient of thermal expansion means that its volume expansion at high temperatures is less than that of the clamping arm 1 body, forming self-generated compressive stress at the connection interface, effectively compensating for the difference in thermal expansion, preventing the insert from loosening and falling off, and ensuring high-temperature clamping rigidity;

[0034] The protrusion 3 on the side of the insert is interference-fitted with the groove 4 of the arm body, generating initial clamping force through the elastic deformation of the metal. During thermal cycling, the interference adjusts adaptively: at high temperatures, the arm body expands, increasing the interference and enhancing locking; after cooling, it returns to its initial state, avoiding plastic damage; the locking bolt 7 passes through the insert's anti-disengagement locking hole 5 and the arm body's limiting hole 6, forming axial constraint; the bolt nut is sunk into the second stepped groove 12 to avoid high-temperature oxidation; the depth of the first stepped groove 11 limits the bolt's stroke, preventing over-locking and deformation of the elastic arm body; the stepped groove structure generates radial constraint force under thermal vibration, inhibiting bolt self-spinning loosening. Under high-temperature conditions, the annular sleeve 13 acts as a sacrificial part to isolate the locking bolt 7 from the clamping arm 1 body: the sleeve's internal thread engages with the bolt, and its outer wall is interference-fitted with the first stepped groove 11, eliminating fretting wear of the thread pair.

[0035] When the heat-resistant insert 2 fails due to high temperature wear, it is only necessary to remove the locking bolt 7 and use mechanical tools to break the interference fit between the protrusion 3 and the groove 4 to replace the insert, without scrapping the entire fixture. Example

[0036] This embodiment is an optimization of the structure in Embodiment 1. Specifically, as follows: Figure 3 and Figure 4 As shown, the heat-resistant insert 2 has a cooling cavity 8 inside; the opening of the cooling cavity 8 extends to the side of the heat-resistant insert 2 and is closed by a removable sealing cap 9; the cooling cavity 8 is filled with a phase change energy storage material; the phase change energy storage material in the cooling cavity 8 absorbs the instantaneous heat load conducted from the high-temperature blank to the insert by utilizing its latent heat of phase change, thereby slowing down the temperature rise rate of the insert and preventing the material from softening at high temperature.

[0037] Furthermore, the cooling cavity 8 has heat-conducting ribs 10 distributed on its cavity wall; the heat-conducting ribs 10 are perpendicularly connected to the workpiece contact surface of the heat-resistant insert 2, and the ribs greatly increase the heat exchange area, quickly transferring the heat from the blank contact area to the core area of ​​the phase change material, avoiding local overheating of the insert surface and improving temperature uniformity.

[0038] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0039] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A fixture for mixing hot and cold billets in a heating furnace, comprising: Clamping arm (1); The feature is that the body of the clamping arm (1) is made of elastic metal material; the workpiece contact end of the clamping arm (1) is provided with a detachable heat-resistant insert (2), and the thermal expansion coefficient of the heat-resistant insert (2) is less than that of the body material of the clamping arm (1).

2. The heating furnace hot and cold billet mixing fixture according to claim 1, characterized in that: The heat-resistant insert (2) is connected to the clamping arm (1) through a mechanical fitting structure; the mechanical fitting structure includes a protrusion (3) on the side of the heat-resistant insert (2) and a groove (4) at the end of the clamping arm (1), and the protrusion (3) and the groove (4) are interference fit.

3. The heating furnace hot and cold billet mixing fixture according to claim 1, characterized in that: The heat-resistant insert (2) has an anti-detachment locking hole (5) on its side wall; the clamping arm (1) has a limiting hole (6) at the corresponding position; the anti-detachment locking hole (5) and the limiting hole (6) are provided with locking bolts (7) that pass through them.

4. The heating furnace hot and cold billet mixing fixture according to claim 1, characterized in that: The elastic metal material is spring steel; the heat-resistant insert (2) is made of nickel-based alloy material.

5. A heating furnace hot and cold billet mixing fixture according to claim 1, characterized in that: The heat-resistant insert (2) has a cooling cavity (8) inside; the opening of the cooling cavity (8) extends to the side of the heat-resistant insert (2) and is closed by a removable sealing cap (9); the cooling cavity (8) is filled with phase change energy storage material.

6. A heating furnace hot and cold billet mixing fixture according to claim 5, characterized in that: The cooling cavity (8) has heat-conducting ribs (10) distributed on its cavity wall; the heat-conducting ribs (10) are perpendicularly connected to the workpiece contact surface of the heat-resistant insert (2).

7. A heating furnace hot and cold billet mixing fixture according to claim 3, characterized in that: The limiting hole (6) is provided with a first stepped groove (11) on the outside; the anti-loosening locking hole (5) is provided with a second stepped groove (12) on the outside; the nut of the locking bolt (7) is engaged with the second stepped groove (12).

8. A heating furnace hot and cold billet mixing fixture according to claim 7, characterized in that: The first stepped groove (11) is provided with an annular sleeve (13); the annular sleeve (13) is provided with an internal thread that mates with the external thread of the locking bolt (7); one end of the annular sleeve (13) is interference-fitted with the first stepped groove (11), and the other end is a hexagonal structure.

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