Auxiliary pressure applying device, pressure applying method and electric upsetting method for electric upsetting part

Abstract

The invention belongs to the technical field of electric upsetting forming, and particularly relates to an auxiliary pressure applying device for an electric upsetting part, a pressure applying method and an electric upsetting method.The pressure applying device comprises a synchronous telescopic box, and the synchronous telescopic box comprises a box body and a synchronous driving mechanism; the box body is provided with an axial through hole into which the electric upsetting piece is inserted, so that the electric upsetting piece can be propped against an anvil electrode on the anvil cylinder after being inserted into the box body; the box body comprises a telescopic part and a fixed part, the telescopic part and the fixed part are in sliding connection in the axial direction, and the telescopic part is driven by the synchronous driving mechanism to move in the axial direction along with the anvil cylinder; the feeding mechanism is used for introducing solid particles into the box body; and the flow valve is used for adjusting the flow of the solid particles entering the box body. Solid particles can be compacted along with deformation of the electric upset part, the electric upset part is subjected to counter-acting force of the solid particles, and external pressure applied to the surface of the electric upset part is gradually increased by synchronously increasing the solid particles, so that the plastic deformation process of the electric upset part is optimized, grain refinement is promoted, and the quality of a final product is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of electric upsetting, and in particular relates to an auxiliary pressure-applying device, a pressure-applying method and an electric upsetting method for an electric upsetting piece. Background Art

[0002] At present, the domestic valve blanks are mainly formed by electric upsetting process, and its quality directly affects the die forging and the overall quality of the final valve. However, although the traditional electric upsetting process can effectively form electric upsetting parts, there are still certain challenges in actual operation. Especially in the electric upsetting process, due to uneven force, defects often occur on the surface of the electric upsetting parts, such as cracks, high surface roughness, etc., which may affect the quality of the final valve. In addition, during the electric upsetting process, due to high-speed deformation and high temperature, the grains on the surface of the material are often coarse, which not only affects the strength and durability of the parts, but also may lead to unstable performance of the final product. Therefore, how to further optimize the surface quality of the electric upsetting parts, refine the grain structure, and improve the forming accuracy during the electric upsetting process has become an urgent problem to be solved in valve manufacturing. Summary of the invention

[0003] The present application provides an auxiliary pressure-applying device for an electric upsetting piece to solve related technical problems.

[0004] The present invention is realized by the following technical scheme: an auxiliary pressure device for electric upsetting parts, comprising:

[0005] A synchronous telescopic box, the synchronous telescopic box comprising a box body and a synchronous driving mechanism;

[0006] The box body has an axial through hole for inserting the electric upsetting piece, so that the electric upsetting piece can abut against the anvil electrode on the anvil cylinder after being inserted into the box body; the box body includes a telescopic part and a fixed part, the telescopic part and the fixed part are axially slidably connected, and the telescopic part is driven by the synchronous drive mechanism to follow the axial movement of the anvil cylinder;

[0007] A feeding mechanism, used for introducing solid particles into the box;

[0008] The flow valve is used to adjust the flow of solid particles entering the box.

[0009] Furthermore, the synchronous drive mechanism includes a speed acquisition unit, a telescopic mechanism and a controller;

[0010] The speed acquisition unit is used to acquire the axial movement speed of the anvil cylinder and send it to the controller;

[0011] The telescopic mechanism is used to drive the telescopic part to move axially;

[0012] The controller is used to control the synchronous movement of the telescopic mechanism according to the axial movement speed.

[0013] Furthermore, the telescopic mechanism is a linear slide rail, and the slider and guide rail of the linear slide rail are respectively connected to the telescopic part and the fixed part

[0014] Furthermore, the telescopic mechanism is a telescopic rod, and the telescopic end and the fixed end of the telescopic rod are respectively connected to the telescopic part and the fixed part.

[0015] Furthermore, it also includes a one-way valve, which is arranged in the feeding mechanism.

[0016] Furthermore, the flow valve is arranged in the box body and connected to the discharge port of the feeding mechanism.

[0017] Furthermore, the box body is made of metal or alloy material.

[0018] The present invention also provides an auxiliary pressure-applying method for an electric upsetting piece, using the auxiliary pressure-applying device for an electric upsetting piece, comprising the following steps:

[0019] Collect the axial movement speed of the anvil cylinder;

[0020] Controlling the box to extend synchronously at the axial movement speed;

[0021] Calculate the volume increment ΔV of the box according to the elongation of the box;

[0022] Calculating a target flow rate for maintaining the distribution density of solid particles in the box according to the volume increment;

[0023] The opening degree of the flow valve is controlled according to the target flow rate.

[0024] The present invention also provides an electric upsetting method. During the upsetting process of the electric upsetting piece, the auxiliary pressure-applying method of the electric upsetting piece is simultaneously used to apply pressure to the electric upsetting piece: under the condition of keeping the distribution density unchanged, the electric upsetting piece compacts the solid particles as it is upsetting and deformed, and the electric upsetting piece is subjected to the reaction force of the solid particles. The external pressure of the electric upsetting piece is gradually increased by increasing the solid particles.

[0025] Furthermore, the solid particles are sand particles.

[0026] Compared with the prior art, the beneficial effects of the present invention include:

[0027] 1. The auxiliary pressure-applying device for the electric upsetting piece provided by the present invention can increase the external pressure on the electric upsetting piece by increasing the solid particles in the box body. After entering the box body, the solid particles can be evenly wrapped around the electric upsetting piece, thereby providing uniform pressure for the electric upsetting piece; and the synchronous movement provided by the synchronous telescopic box avoids hindering the axial movement of the electric upsetting piece, ensuring that the electric upsetting piece can move with the anvil cylinder, thereby ensuring the smooth progress of the electric upsetting process.

[0028] 2. As the electric upsetting progresses, the volume of the box gradually expands, which will cause the distribution density of the solid particles to decrease. The decrease in distribution density will cause the same deformation of the electric upsetting piece to fail to produce the same extrusion force on the solid particles, and the reaction force on the electric upsetting piece will decrease, that is, the pressure cannot be increased uniformly. In order to ensure that the distribution density of the box remains consistent during the expansion process and the external pressure gradually increases uniformly, the present invention calculates the target flow rate based on the volume increment and distribution density of the box, and controls the sand flow rate in combination with a flow valve to achieve precise density control.

[0029] 3. The present invention applies uniform external pressure to the electric upsetting piece during the electric upsetting process, thereby optimizing the plastic deformation process of the electric upsetting piece, promoting grain refinement, and improving the quality of the final product. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 It is a schematic diagram of the electric upsetting process in this specific implementation mode;

[0032] Figure 2 (a) is a diagram showing the initial shape of the electric upsetting piece before the start of electric upsetting in this specific embodiment;

[0033] Figure 2 (b) is a morphological diagram of the electric upsetting piece during the electric upsetting process in this specific embodiment;

[0034] Figure 2 (c) is a diagram showing the morphology of the electric upsetting piece after the electric upsetting is completed in this specific embodiment. DETAILED DESCRIPTION

[0035] During the electric upsetting process, due to the uneven force on the electric upsetting parts, defects such as cracks and high surface roughness often occur on the surface of the electric upsetting parts.

[0036] Example 1

[0037] In order to provide uniform pressure to the electric upsetting parts, refer to Figure 1 As shown, this embodiment provides an auxiliary pressure-applying device for an electric upsetting piece, comprising:

[0038] A synchronous telescopic box, the synchronous telescopic box comprising a box body 8 and a synchronous driving mechanism;

[0039] The box body 8 has an axial through hole for inserting the electric upsetting piece, so that the electric upsetting piece can abut against the anvil electrode 2 on the anvil cylinder 1 after being inserted into the box body; the box body 8 includes a telescopic part and a fixed part, the telescopic part and the fixed part are connected in an axial sliding manner, and the telescopic part is driven by the synchronous driving mechanism to follow the axial movement of the anvil cylinder;

[0040] A feeding mechanism 12, used for introducing solid particles into the box 8;

[0041] The flow valve 10 is used to adjust the flow of solid particles entering the box 8 .

[0042] In this embodiment, the box has three sections, A, B, and C, wherein section A is a telescopic section, and sections B and C are combined into a fixed section, one end of section B is fixedly connected to section C, and the other end is slidably connected to section A. At the beginning of electric upsetting, sections A and C are butted together, and section B overlaps behind AC to form an initial electric upsetting clamping length (A+C). At this time, the total length of sections A and B is equal to the initial clamping length of the rod blank.

[0043] Of course, the box can also be designed as a two-section structure with only section A and section C, with section A slidingly connected to section C, but the maximum length of the two-section structure is smaller than that of the three-section structure.

[0044] In this embodiment, the synchronous driving mechanism includes a speed acquisition unit, a telescopic mechanism and a controller;

[0045] The speed acquisition unit is used to acquire the axial movement speed of the anvil cylinder and send it to the controller;

[0046] The telescopic mechanism is used to drive the telescopic part to move axially;

[0047] The controller is used to control the synchronous movement of the telescopic mechanism according to the axial movement speed.

[0048] The speed acquisition unit may be a linear speed sensor in the prior art, for example, a position sensor is used to measure the speed.

[0049] The telescopic mechanism can be in various forms, as long as it can drive the telescopic part to make axial movement. This embodiment provides two telescopic mechanisms:

[0050] First, the telescopic mechanism is a linear slide rail, and the slider and guide rail of the linear slide rail are respectively connected to the telescopic part and the fixed part

[0051] Secondly, the telescopic mechanism is a telescopic rod, and the telescopic end and the fixed end of the telescopic rod are connected to the telescopic part and the fixed part respectively.

[0052] In this embodiment, a one-way valve 11 is also included, and the one-way valve is arranged in the feeding mechanism 12. The one-way valve is used to control the flow direction of the sand in the box body. It ensures that the sand can only enter the box body and cannot flow out in the reverse direction.

[0053] In this embodiment, the flow valve 10 is disposed in the box body 8 and connected to the discharge port of the feeding mechanism.

[0054] Compared with setting the flow valve in the feeding mechanism, setting the flow valve in the box will not affect the feeding speed of the feeding mechanism and can meet the needs of fast feeding.

[0055] In this embodiment, the box body is made of metal or alloy material, the box body is not easy to deform, and is heat-resistant and pressure-resistant.

[0056] Example 2

[0057] This embodiment provides an auxiliary pressure-applying method for an electric upsetting piece, using the auxiliary pressure-applying device for an electric upsetting piece in Embodiment 1, and comprising the following steps:

[0058] The axial movement speed v of the anvil cylinder 1 is collected by the position sensor 13;

[0059] Controlling the box 8 to extend synchronously at the axial movement speed v;

[0060] Calculate the volume increment ΔV of the box body according to the elongation of the box body 8;

[0061] Calculating a target flow rate for maintaining the distribution density of solid particles in the box according to the volume increment ΔV;

[0062] The opening degree of the flow valve is controlled according to the target flow rate.

[0063] In this embodiment, the solid particles are sand particles. Initially, the amount of sand entering the box is precisely controlled by adjusting the feeding mechanism 12 and the flow valve 10 to ensure that the initial distribution density of the sand in the box reaches a predetermined value when the electric upsetting starts. Initial box volume: Assuming that the initial volume of the box is V and the corresponding initial distribution density is ρ, the total mass of the initial sand is:

[0064] m=ρ·V (1)

[0065] As the anvil cylinder 1 retreats, the volume of the box body continues to increase, and the volume increment of the box body is ΔV. The relationship between the unit elongation and the capacity increment can be calibrated in advance, and the elongation can be calculated based on the axial movement speed v and the movement time.

[0066] The gradual expansion of the box volume will cause the distribution density of the solid particles to decrease, and the decrease in distribution density will cause the same deformation of the electric upsetting piece to fail to produce the same extrusion force on the solid particles, so the reaction force on the electric upsetting piece will decrease, that is, the pressure cannot be increased uniformly. In order to ensure that the distribution density of the box remains consistent during the expansion process and the external pressure gradually increases uniformly, this embodiment calculates the target flow rate based on the volume increment and distribution density of the box, and controls the sand flow rate in combination with a flow valve to achieve precise density control.

[0067] In order to keep the distribution density at the initial distribution density, the additional sand mass ΔM is also obtained according to the above formula (1). The flow valve adjusts the inflow speed of the sand according to the calculated volume of sand to be supplemented, ensuring that the amount of sand flowing in matches the volume increment ΔV and the required sand mass ΔM. The sand flow rate is controlled according to the opening of the flow valve 10. The relationship between the sand flow rate Q and the time t can be expressed as:

[0068]

[0069] As the electric upsetting process proceeds, the flow valve adjusts the inflow of sand according to the volume increment of each expansion to keep the distribution density in the box unchanged.

[0070] Example 3

[0071] This embodiment provides an electric upsetting method. During the upsetting process of the electric upsetting piece, the auxiliary pressure-applying method of the electric upsetting piece in Embodiment 2 is simultaneously used to apply pressure to the electric upsetting piece: under the condition of keeping the distribution density unchanged, the electric upsetting piece compacts the solid particles as it is upsetting and deformed, and the electric upsetting piece is subjected to the reaction force of the solid particles. The external pressure of the electric upsetting piece is gradually increased by increasing the solid particles.

[0072] In this embodiment, the component system of the electric upsetting process includes the electric upsetting system and the auxiliary pressure-applying device of the electric upsetting piece in Embodiment 1.

[0073] The electric upsetting system consists of an electric upsetting machine, a current source and a heating device, which are mainly responsible for providing the necessary pressure, temperature and movement to achieve plastic deformation of the electric upsetting piece. The electric upsetting machine includes an anvil cylinder 1, a clamping cylinder 4 and an upsetting cylinder 6, which are responsible for providing mechanical pressure and movement to ensure that the electric upsetting piece 5 is evenly stressed and deformed smoothly during the electric upsetting process. The current source includes a secondary transformer 3, which is used to convert the high voltage of the power supply into a low voltage and high current suitable for the electric upsetting process to produce the required heating effect. The heating device includes an anvil electrode 2 and a clamping electrode 7. The current heats the electric upsetting piece through the contact resistance between the two electrodes and the self-resistance, providing the necessary local heating so that the electric upsetting piece reaches a temperature suitable for plastic deformation.

[0074] Specific implementation process:

[0075] 1. System preparation stage

[0076] Electric upsetting system preparation:

[0077] Electric upsetting machine: First, check the working status of the electric upsetting machine, including the normal operation of the anvil cylinder, clamping electrode and upsetting cylinder, to ensure that the mechanical pressure and movement can act evenly on the electric upsetting parts. Current source adjustment: Start the current source system and set the appropriate voltage and current output. The secondary transformer converts the high voltage into a low voltage and high current suitable for electric upsetting to ensure that the current passes through the anvil electrode and the clamping electrode to heat the electric upsetting parts to a suitable plastic deformation temperature. Heating device debugging: Confirm that the current conduction between the anvil electrode and the clamping electrode is good.

[0078] Auxiliary pressure device preparation:

[0079] Box installation: Install the box 8 on the electric upsetting machine. The bottom of the box can be supported by a support frame, and the lower end of the support frame is slidably connected to the ground rail to follow the movement of the telescopic part. Figure 2 As shown in (a), the initial form of the electric upsetting piece 5 is in a rod blank state, and the initial length of the box body is the clamping length of the electric upsetting piece, ensuring that the box body can surround the electric upsetting piece and effectively apply external pressure.

[0080] Telescopic mechanism debugging: Check the working status of the linear slide 9 to ensure that the telescopic mechanism can accurately and synchronously expand the box volume according to the movement of the anvil cylinder to adapt to the change in the size of the electric upsetting head. Position sensor calibration: Calibrate the position sensor 13 to monitor the retreat speed of the anvil cylinder 1 in real time and accurately control the expansion speed of the box.

[0081] Electric upsetting process and synchronous control

[0082] Start the electric upsetting machine, the secondary transformer 3, the anvil electrode 2, the electric upsetting piece 5 and the clamping electrode 7 form a circuit and are energized. At the same time, the anvil cylinder 1 and the upsetting cylinder 6 remain stationary, and the electric upsetting piece is gradually preheated to the forging temperature range under the action of its own internal resistance and the Joule heat generated by the contact between the anvil electrode and the end face of the electric upsetting piece.

[0083] Then, the anvil cylinder 1 and the upsetting cylinder 6 move to the left at a speed and an upsetting force P respectively, and the hot end of the electric upsetting piece 5 in the form of a rod blank is locally gathered under the upsetting force of the two cylinders. Figure 2 (b) as shown.

[0084] As the anvil cylinder 1 retreats, the volume of the box 8 continues to increase, and the flow valve 10 adjusts the inflow of sand according to the volume increment of each expansion to keep the distribution density of the sand in the box unchanged. At the same time, as the electric upsetting piece deforms, the external pressure applied to the surface of the electric upsetting piece gradually increases, thereby optimizing the plastic deformation process of the electric upsetting piece, promoting grain refinement, and improving the quality of the final product. After the electric upsetting is completed, the morphology of the electric upsetting piece is referenced Figure 2(c) as shown.

[0085] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection created by this application.

Claims

1. An auxiliary pressure device for electric upsetting, characterized in that: include: A synchronous telescopic box, the synchronous telescopic box comprising a box body and a synchronous driving mechanism; The box body has an axial through hole for inserting the electric upsetting piece, so that the electric upsetting piece can abut against the anvil electrode on the anvil cylinder after being inserted into the box body; the box body includes a telescopic part and a fixed part, the telescopic part and the fixed part are axially slidably connected, and the telescopic part is driven by the synchronous drive mechanism to follow the axial movement of the anvil cylinder; A feeding mechanism, used for introducing solid particles into the box; The flow valve is used to adjust the flow of solid particles entering the box.

2. The auxiliary pressure-applying device for electric upsetting according to claim 1, characterized in that: The synchronous driving mechanism includes a speed acquisition unit, a telescopic mechanism and a controller; The speed acquisition unit is used to acquire the axial movement speed of the anvil cylinder and send it to the controller; The telescopic mechanism is used to drive the telescopic part to move axially; The controller is used to control the synchronous movement of the telescopic mechanism according to the axial movement speed.

3. The auxiliary pressure-applying device for electric upsetting according to claim 2, characterized in that: The telescopic mechanism is a linear slide rail, and a slider and a guide rail of the linear slide rail are respectively connected to the telescopic part and the fixed part.

4. The auxiliary pressure-applying device for electric upsetting according to claim 2, characterized in that: The telescopic mechanism is a telescopic rod, and the telescopic end and the fixed end of the telescopic rod are connected to the telescopic part and the fixed part respectively.

5. The auxiliary pressure-applying device for electric upsetting according to claim 1, characterized in that: It also includes a one-way valve, which is arranged in the feeding mechanism.

6. The auxiliary pressure-applying device for electric upsetting according to claim 1, characterized in that: The flow valve is arranged in the box body and connected with the discharge port of the feeding mechanism.

7. The auxiliary pressure-applying device for electric upsetting according to claim 1, characterized in that: The box body is made of metal or alloy material.

8. An auxiliary pressure-applying method for electric upsetting, characterized in that: The auxiliary pressure-applying device for electric upsetting parts according to any one of claims 1 to 7 comprises the following steps: Collect the axial movement speed of the anvil cylinder; Controlling the box to extend synchronously at the axial movement speed; Calculate the volume increment of the box according to the elongation of the box; Calculating a target flow rate for maintaining the distribution density of solid particles in the box according to the volume increment; The opening degree of the flow valve is controlled according to the target flow rate.

9. An electric upsetting method, characterized in that: During the upsetting process of the electric upsetting piece, the auxiliary pressure-applying method of the electric upsetting piece as described in claim 8 is simultaneously used to apply pressure to the electric upsetting piece: under the condition of keeping the distribution density unchanged, the electric upsetting piece compacts the solid particles as it is upsetting and deformed, and the electric upsetting piece is subjected to the reaction force of the solid particles, and the external pressure of the electric upsetting piece is gradually increased by increasing the solid particles.

10. The electric upsetting method according to claim 9, characterized in that: The solid particles are sand particles.

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