CN-122007221-A - Self-resistance heating floating type section bar stretch bending jaw device

Abstract

The invention provides a self-resistance heating floating type section stretch bending jaw device, which can effectively reduce local stress concentration and rebound of a section clamping area through floating progressive multi-flap jaw design, is beneficial to improving the stretch forming precision and section surface quality, creatively integrates heating and cooling functions and jaws, can effectively improve the heating control precision and efficiency, replaces the traditional large heating and temperature control equipment such as an integral furnace and has obvious advantages in terms of manufacturing cost and energy consumption.

Inventors

• CHENG GANG
• LIU ZHIXING
• LIU JIANNIAN
• LI TAO
• ZHANG KUN

Assignees

• 航宇智造（北京）工程技术有限公司

Dates

Publication Date

20260512

Application Date

20260330

Claims (8)

1. 1. The self-resistance heating floating type section bar stretch bending jaw device is characterized by comprising a multi-petal jaw wedge block, a wedge block base, a conical driving sleeve, a telescopic cylinder, a self-resistance heating element and an insulating cooling unit; The jaw wedge block is arranged in the conical driving sleeve, the outer side surface of the jaw wedge block is tightly attached to the inner conical surface of the conical driving sleeve, the inner side surface of the jaw wedge block is used as a profile clamping surface, the rear end of the jaw wedge block is connected with a wedge block base, the wedge block base is fixedly connected with the front end of a piston rod of the telescopic cylinder, the cylinder body of the telescopic cylinder is fixedly connected with the conical driving sleeve, the jaw wedge block can move forwards and backwards along the inner conical surface of the conical driving sleeve under the driving of the telescopic cylinder, and the rear end of the jaw wedge block slides along the radial direction on the surface of the wedge block base, so that the clamping and opening actions of a jaw are realized; the insulating cooling unit is arranged on the outer conical surface of the conical driving sleeve and is connected with a cooling flow passage arranged in the jaw and an external cooling source to form a circulating cooling system.
2. 2. The self-resistance heating floating profile stretch bending jaw device as claimed in claim 1, wherein guide pins are arranged on the outer side surface and the rear end surface of the jaw wedge block, and corresponding axial guide grooves and radial floating sliding grooves are respectively arranged on the conical driving sleeve and the wedge block base.
3. 3. The self-resistance heating floating type section bar stretch bending jaw device as claimed in claim 1, wherein the jaw wedge block is in a 120-degree distributed form with 3 flaps.
4. 4. The self-resistance heating floating profile stretch bending jaw device according to claim 1, wherein the self-resistance heating element adopts a heating wire or a heating sheet, is connected with an external programmable heating power supply through an electrode interface, and is used for executing heating control according to a set heating curve.
5. 5. The self-resistance heating floating type profile stretch bending jaw device according to claim 1, wherein a pressure sensor and a thermocouple are further arranged in the device, measuring points of the pressure sensor and the thermocouple are arranged on a jaw wedge block and used for detecting clamping force and profile temperature, and a displacement sensor is further arranged for detecting jaw clearance and profile deformation.
6. 6. The self-resistance heating floating type section bar stretch bending jaw device according to claim 1, wherein the rear end of the telescopic oil cylinder is connected with the action mechanism and a section bar stretch bending equipment machine tool mounting seat through an insulating and heat-insulating seat, and the machine tool mounting seat is also provided with a corresponding insulating and heat-insulating element.
7. 7. A profile stretch-bending forming method performed by the self-resistance heated floating profile stretch-bending jaw device according to any one of claims 1-6, characterized by comprising the steps of: Step 1, inputting profile materials, section sizes and target bending angle parameters; step 2, determining an optimal forming temperature window T, heating time T and cooling rate v based on material thermoplastic data and finite element simulation; Step 3, setting initial parameters including heating power and clamping force; Step 4, clamping the jaw and executing stretching operation, wherein during the period, current output is regulated based on a PID algorithm according to deviation delta T of real-time temperature T fed back by the thermocouple and set temperature T, and a current output value I adjust is obtained based on the following formula, I adjust = K p ×ΔT + K i ∫ΔTdt + K d d (delta T)/dt, wherein K p 、K i 、K d is a PID control parameter; Step 5, after forming in place, regulating the flow Q of the cooling liquid according to the set cooling rate v, and cooling the profile to below room temperature; And 6, after the forming is finished, releasing the profile and taking out.
8. 8. The method of claim 7, wherein step 2 further comprises setting a spring back compensation amount based on the simulation result, wherein the spring back compensation amount is calculated according to a preset over-bending amount Δθ, wherein Δθ is calculated according to an empirical formula about material properties, forming temperature and bending radius.

Description

Self-resistance heating floating type section bar stretch bending jaw device Technical Field The invention belongs to the technical field of metal profile plastic forming equipment, and particularly relates to a self-resistance heating floating type profile stretch bending jaw device suitable for a titanium alloy and aluminum alloy material. Background At present, most of the jaws adopted in stretch bending forming processes of high-strength titanium alloy, aluminum alloy and other sectional materials are hydraulically driven traditional mechanical jaws, and the jaws have the obvious defect that ① have large forming force, so that the surface of the jaw is easy to crack and damage the inside of the jaw when the material is in a state of low temperature and poor plasticity. ② The cold work hardening of the contact area of the profile and the jaw is remarkable, and the rebound of the material is difficult to predict and control. ③ When the materials are not heated or heated unevenly, friction loss between the jaw and the section bar is increased, and the service life is seriously influenced. On the other hand, the integral furnace or induction heating equipment used in stretch bending forming under the heating condition has the problems of high energy consumption, low heating efficiency, difficult accurate control of the heating process, large occupied area of equipment and the like, and the lack of effective heat management means for the contact area is also an important factor causing local stress concentration and poor surface quality of the profile. Disclosure of Invention In view of the above, the invention provides a self-resistance heating floating type section stretch bending jaw device, which aims at the technical problems in the art and comprises a multi-petal jaw wedge block, a wedge block base, a conical driving sleeve, a telescopic oil cylinder, a self-resistance heating element and an insulating cooling unit; The jaw wedge block is arranged in the conical driving sleeve, the outer side surface of the jaw wedge block is tightly attached to the inner conical surface of the conical driving sleeve, the inner side surface of the jaw wedge block is used as a profile clamping surface, the rear end of the jaw wedge block is connected with a wedge block base, the wedge block base is fixedly connected with the front end of a piston rod of the telescopic cylinder, the cylinder body of the telescopic cylinder is fixedly connected with the conical driving sleeve, the jaw wedge block can move forwards and backwards along the inner conical surface of the conical driving sleeve under the driving of the telescopic cylinder, and the rear end of the jaw wedge block slides along the radial direction on the surface of the wedge block base, so that the clamping and opening actions of a jaw are realized; The insulating cooling unit is arranged on the outer conical surface of the conical driving sleeve, is connected with a cooling flow passage arranged in the jaw and an external cooling source to form a circulating cooling system, and a cooling medium enters the jaw from an inlet of the cooling flow passage, absorbs heat and flows out from an outlet of the cooling flow passage and returns to cool the profile. Further, guide pins are arranged on the outer side surface and the rear end surface of the jaw wedge block, and corresponding axial guide grooves and radial floating sliding grooves are respectively arranged on the conical driving sleeve and the wedge block base and used for realizing sliding guide and limiting of the jaw wedge block in a matched mode, and unnecessary movement is reduced. Further, the jaw wedge block can select a proper number of petals and a single petal structure according to the requirement, for example, the jaw wedge block specifically comprises 3 petals which are distributed at 120 degrees, wherein two petals form a jaw upper die, and the other petals serve as a jaw lower die. Further, the self-resistance heating element adopts an electric heating wire or a heating sheet, is connected with an external programmable heating power supply through an electrode interface, and is used for executing heating control according to a set heating curve. Further, the device is also provided with a pressure sensor and a thermocouple, the measuring points of which are arranged on the jaw wedge-shaped block and used for detecting the clamping force and the temperature of the section bar, and a displacement sensor is also arranged for detecting the jaw gap and the deformation of the section bar. Further, the rear end of the telescopic oil cylinder is connected with the actuating mechanism and the installation seat of the profile stretch bending equipment machine tool through an insulating and heat-insulating seat, and corresponding insulating and heat-insulating elements are also arranged on the installation seat of the machine tool and used for avoiding the influence of heat conduction to the machine tool on