Pump and draw traction control system

Abstract

This invention discloses a drawing traction control system, comprising: Step A1: setting the maximum drawing limit force N1 and setting the drawing limit displacement L1 of the tractor; Step A2: starting the tractor and measuring the drawing traction force N2 of the tractor; Step A3: comparing N1 and N2, if N1 is greater than N2, then proceeding to Step A4; if N1 is less than N2, then proceeding to Step A6; Step A4: keeping the drawing traction force N2 of the tractor unchanged and measuring the displacement L2 of the tractor; Step A5: the traction control system compares L1 and L2, if L1 is greater than L2, then proceeding to Step A4; if L1 is less than L2, then proceeding to Step A7; Step A6: reducing the drawing traction force N2 of the tractor and proceeding to Step A3; Step A7: drawing the finished product in a steady state; by controlling the traction force during drawing, a smooth transition from the drawing start to the stable drawing state is achieved, reducing the occurrence of drawing breakage and improving the drawing success rate.

Description

Technical Field

[0001] This invention relates to the field of drawing and molding technology, and in particular to a drawing and traction control system. Background Technology

[0002] Aluminum alloy shells can be formed using a drawing process. The aluminum alloy is pulled out from the drawing mold, and the elongated aluminum alloy shell can be directly obtained by utilizing the forming gap of the drawing mold. This process is highly efficient and the structure is relatively stable.

[0003] Currently, the drawing process generally uses a tractor to move the material, and the drawing mold is set to be fixed or movable relative to the tractor. During operation, the clamps hold the material, and the tractor pulls the clamps to move, so that the material passes through the drawing gap of the drawing mold, thereby obtaining a profile corresponding to the drawing gap.

[0004] However, during the initial drawing stage (from a standstill to the stable drawing of the material), the tractor needs to apply a large traction force to pull the material. If the traction force is too large, the material is easily broken, resulting in a low drawing success rate. The material needs to be output and clamped again, which delays a lot of working time and affects production efficiency. This is especially true for drawing shells with unequal wall thicknesses. Due to the force imbalance caused by the unequal wall thickness, the traction force is easily fluctuated. The actual traction force is different from the theoretical traction force set by the drive system, which can easily cause problems such as wall thickness fluctuation or drawing breakage. Summary of the Invention

[0005] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a drawing and traction control system that can reduce the occurrence of drawing interruptions during the initial drawing stage and improve the drawing success rate.

[0006] According to a first aspect of the present invention, a traction control system includes:

[0007] Step A1: Power on the traction control system, set the maximum lifting limit force N1, and set the lifting limit displacement L1 of the tractor vehicle;

[0008] Step A2: The tractor unit is started, the starting traction force N2 of the tractor unit is measured, and the feedback is sent to the traction control system;

[0009] Step A3: The traction control system compares the values ​​of N1 and N2. If N1 is greater than N2, proceed to step A4; if N1 is less than N2, proceed to step A6.

[0010] Step A4: Keep the starting traction force N2 of the tractor constant, measure the displacement L2 of the tractor, and feed it back to the traction control system;

[0011] Step A5: The traction control system compares the values ​​of L1 and L2. If L1 is greater than L2, proceed to step A4; if L1 is less than L2, proceed to step A7.

[0012] Step A6: Reduce the starting traction force N2 of the tractor and proceed to step A3;

[0013] Step A7: Steady-state extraction of finished products.

[0014] The extraction traction control system according to embodiments of the present invention has at least the following beneficial effects: through the above control process, the traction force in the extraction state is controlled, so as to achieve a smooth transition from the unstable state in the initial stage to the stable extraction state, reduce the occurrence of extraction breakage, and improve the extraction success rate.

[0015] According to a second aspect of the present invention, a traction control system includes:

[0016] Step A1: Power on the traction control system, set the maximum lifting limit force N1, and set the lifting limit displacement L1 of the tractor vehicle;

[0017] Step A2: The tractor unit is started, the starting traction force N2 of the tractor unit is measured, and the feedback is sent to the traction control system;

[0018] Step A3: The traction control system compares the values ​​of N1 and N2. If N1 is greater than N2, proceed to step A4; if N1 is less than N2, proceed to step A6.

[0019] Step A4: Keep the starting traction force N2 of the tractor constant, measure the displacement L2 of the tractor, and feed it back to the traction control system;

[0020] Step A5: The traction control system compares the values ​​of L1 and L2. If L1 is greater than L2, proceed to step A4; if L1 is less than L2, proceed to step A7.

[0021] Step A6: Reduce the starting traction force N2 of the tractor, measure the displacement L2 of the tractor, and feed it back to the traction control system. Compare the magnitudes of L1 and L2. If L1 is greater than L2, proceed to step A3; if L1 is less than L2, proceed to step A7.

[0022] Step A7: Steady-state extraction of finished products.

[0023] The extraction traction control system according to embodiments of the present invention has at least the following beneficial effects: through the above control process, the traction force in the extraction state is controlled, so as to achieve a smooth transition from the unstable state in the initial stage to the stable extraction state, reduce the occurrence of extraction failure, improve the extraction success rate, and avoid excessive travel of the tractor during the extraction stage.

[0024] According to some embodiments of the present invention, the tensile strength of the material to be drawn is P under a set elongation A, the cross-sectional area of ​​the drawing die or the cross-sectional area of ​​the finished product is S, and a correction coefficient K is set; N1 = P * S * K.

[0025] According to some embodiments of the present invention, the set elongation A is 26% to 28%.

[0026] According to some embodiments of the present invention, the elongation after fracture of the drawn material is greater than 30%.

[0027] According to some embodiments of the present invention, the maximum tensile strength of the drawn material is higher than 105 MPa.

[0028] According to some embodiments of the present invention, the setting correction coefficient K = 1.05-1.25.

[0029] According to some embodiments of the present invention, in step A6, a judgment condition is added: the displacement L2 of the tractor is measured and fed back to the traction control system; the magnitudes of L1 and L2 are compared; if L1 is greater than L2, step A3 is executed; if L1 is less than L2, step A7 is executed.

[0030] According to some embodiments of the present invention, the starting displacement limit L1 is 480mm-520mm.

[0031] According to some embodiments of the present invention, a drawing and traction control system is used for drawing and forming a housing having a thick side and a thin side with opposite and unequal wall thicknesses, the wall thickness of the thick side being D and the wall thickness of the thin side being d. The drawing mold includes an inner mold and an outer mold. The outer mold is provided with a drawing cavity extending along the drawing direction. The inner mold is capable of being inserted into the drawing cavity. A drawing gap corresponding to the housing is formed between the outer edge of the inner mold and the inner wall of the drawing cavity. The drawing gap includes a wide slit and a narrow slit respectively corresponding to the thick side and the thin side of the housing. The material is set to pass through the drawing mold from front to back. The front part of the inner mold is deflected toward one side of the narrow slit relative to the drawing direction of the drawing mold.

[0032] According to some embodiments of the present invention, the inclination angle of the inner mold relative to the drawing direction of the drawing mold is greater than 0° and less than 10°.

[0033] According to some embodiments of the present invention, the inclination angle of the inner mold relative to the drawing direction of the drawing die is 2° * D / d. Attached Figure Description

[0034] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0035] Figure 1 This is a schematic diagram of the control principle of the extraction traction control system according to Embodiment 1 of the present invention;

[0036] Figure 2 This is a schematic diagram of the extraction and traction system according to an embodiment of the present invention;

[0037] Figure 3 This is a cross-sectional schematic diagram of the housing according to an embodiment of the present invention;

[0038] Figure 4 This is a schematic diagram of the control principle of the extraction traction control system in Embodiment 2 of the present invention.

[0039] Figure label:

[0040] Inner mold 100, outer mold 200, drawing gap 201, thick edge 901, thin edge 902, chuck 910. Detailed Implementation

[0041] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0042] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0043] In the description of this invention, the use of "first" and "second" is for the purpose of distinguishing technical features only, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of the technical features indicated.

[0044] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0045] Example 1

[0046] like Figure 1 As shown, the extraction traction control system according to an embodiment of the present invention includes the following steps:

[0047] Step A1: Power on the traction control system, set the maximum lifting limit force N1, and set the lifting limit displacement L1 of the tractor vehicle;

[0048] Step A2: The tractor unit is started, the starting traction force N2 of the tractor unit is measured, and the feedback is sent to the traction control system;

[0049] Step A3: The traction control system compares the values ​​of N1 and N2. If N1 is greater than N2, proceed to step A4; if N1 is less than N2, proceed to step A6.

[0050] Step A4: Keep the starting traction force N2 of the tractor constant, measure the displacement L2 of the tractor, and feed it back to the traction control system;

[0051] Step A5: The traction control system compares the values ​​of L1 and L2. If L1 is greater than L2, proceed to step A4; if L1 is less than L2, proceed to step A7.

[0052] Step A6: Reduce the starting traction force N2 of the tractor and proceed to step A3;

[0053] Step A7: Steady-state extraction of finished products.

[0054] Through the above control process, the traction force in the initial pumping state is controlled, achieving a smooth transition from the unstable state in the initial stage to the stable pumping state, reducing the occurrence of pumping interruption, and thus improving the pumping success rate.

[0055] In some embodiments of the present invention, the present invention can be used for cold drawing forming of shells with unequal walls. When drawing shells with unequal walls, it is easy for unbalanced forces to occur. By using the above control method, the occurrence of breakage and insufficient thickness during the drawing of shells with unequal walls can be reduced, thus satisfying the production and manufacturing of shells with unequal wall cold drawing deformation.

[0056] Specifically, such as Figure 3 As shown, the housing is a square housing used as a battery housing for new energy vehicles. It has two opposing long sides with equal wall thickness, and opposing but unequal wall thicknesses, a thick side 901 and a thin side 902. The wall thickness of the thick side 901 is D, and the wall thickness of the thin side 902 is d. The wall thickness of the thick side 901 is greater than that of the thin side 902. When the thick side 901 and the thin side 902 are being pulled out, force imbalance is very likely to occur. By controlling the traction force in the initial pulling state, the transition from the unstable state in the initial stage to the stable pulling state is smoothed, reducing the occurrence of pulling breakage.

[0057] In some embodiments of the present invention, in step A7, when the product is in a steady state, the traction force N3 is kept constant or the traction force is controlled to drive the tractor to move within a set variable range, so as to achieve stable product drawing.

[0058] Specifically, in step A7, the traction force acting on the tractor during steady-state drawing of the finished product is less than the starting traction force N2. That is, the traction force during the starting stage should be greater than the traction force under steady-state conditions. The tractor needs a larger starting force to enable the traction to start from static state, so as to ensure that the tractor can start drawing normally.

[0059] In some embodiments of the present invention, the tensile strength of the material to be drawn is P under a set elongation A, the cross-sectional area of ​​the drawing mold or the cross-sectional area of ​​the finished product is S, a correction coefficient K is set, N1 = P * S * K, and the maximum limiting force N1 for drawing is set according to the tensile strength P under the set elongation A to avoid over-drawing.

[0060] In some embodiments of the present invention, the elongation rate A is set to 26% to 28%, that is, the tensile strength of the material with an elongation rate of 26% to 28% is used to calculate the maximum limiting force N1 for starting to pull.

[0061] Specifically, in the embodiments of the present invention, the material is used to draw shells with unequal wall thicknesses. The elongation after breakage of the material is greater than 30%. Setting the elongation A to 26% to 28% can better control the traction force and reduce the occurrence of breakage.

[0062] In some embodiments of the present invention, setting the elongation rate A to 26%, 27%, or 28% can enable the drawing traction system to smoothly transition from the unstable state at the initial stage to the stable drawing state, thereby improving the drawing success rate.

[0063] In some embodiments of the present invention, the maximum tensile strength of the material being drawn is higher than 105 MPa, which can reduce the occurrence of material breakage.

[0064] Specifically, aluminum alloy material in the F state has a tensile strength higher than 105 MPa, an elongation after fracture greater than 30%, and an average grain size ≤75 μm. When used to draw shells with unequal wall thicknesses, it has a good drawing effect, good stability of the finished product wall thickness, is not easy to break, and has a high drawing success rate.

[0065] In some embodiments of the present invention, a correction coefficient K = 1.05-1.25 is set to obtain a more suitable maximum limiting force N1 for starting the pump.

[0066] Specifically, setting the correction coefficient K too large can easily break the material during extraction, while setting it too small will result in low extraction efficiency. Setting an appropriate correction coefficient to correct P*S will obtain a more suitable limiting force and improve the efficiency of the extraction stage.

[0067] In some embodiments of the present invention, a suitable upper limit of traction force can be obtained when the correction coefficient K is set to 1.05, 1.1 or 1.25.

[0068] The starting displacement limit L1 is the acceleration distance of the tractor, which can be set according to the specific product or drawing equipment. In some embodiments of the present invention, the starting displacement limit L1 = 480mm-520mm, which is suitable for drawing requirements of shells with different wall thicknesses.

[0069] Specifically, the casing is a square casing used as a battery casing for new energy vehicles. It has two opposing long sides with equal wall thickness, and opposing but unequal wall thicknesses for a thick side 901 and a thin side 902. The wall thickness of the thick side 901 is D, and the wall thickness of the thin side 902 is d. The wall thickness of the thick side 901 is greater than that of the thin side 902. If the starting displacement limit L1 is too large, it can easily cause the thin side 902 to break. If it is too small, the drawing efficiency is low and the product of the starting section is unstable. When the starting displacement limit L1 is 480mm, 500mm or 520mm, the drawing effect is better and a high starting efficiency is guaranteed.

[0070] In some embodiments of the present invention, the traction trolley is driven by a servo motor, and maintaining or changing the traction force is achieved by controlling the output of the servo motor.

[0071] like Figure 2 As shown, in some embodiments of the present invention, the drawing mold includes an inner mold 100 and an outer mold 200. The outer mold 200 is provided with a drawing cavity extending along the drawing direction. The inner mold 100 can be placed into the drawing cavity. A drawing gap 201 corresponding to the shell is formed between the outer edge of the inner mold 100 and the inner wall of the drawing cavity. The material passes through the drawing mold from front to back and is connected to the clamp 910. The clamp 910 is connected to the traction trolley. The core rod 300 and the outer mold 200 are connected and fixed or pulled. When the traction trolley moves backward, it can pull the material through the drawing mold, thereby drawing it into an elongated box.

[0072] Specifically, the traction trolley is driven by a servo motor to facilitate control of the traction force; a displacement sensor is installed at the traction trolley or the drawing mold to detect the displacement of the traction trolley or the material; a force sensor is installed at the core rod 300 or the clamp 910 to detect the real-time traction force.

[0073] In some embodiments of the present invention, the drawing gap 201 includes a wide slit and a narrow slit corresponding to the thick side 901 and the thin side 902 of the shell, respectively. The material is set to pass through the drawing mold from front to back. The front part of the inner mold 100 is deflected toward the narrow slit side relative to the drawing direction of the drawing mold, so as to reduce the force difference on the drawing mold when the material passes through the wide slit and the narrow slit. This can better balance the force, meet the drawing requirements of shells with unequal wall thickness, and improve product quality.

[0074] Specifically, after the inner mold 100 tilts towards the narrow slit side, the outer edge of the inner mold 100 at the wide slit will tilt at a small angle and form an angle of attack corresponding to the material input direction, increasing the force at the wide slit when the material is input. Similarly, the force at the narrow slit is reduced, thereby reducing the difference in drawing force and ensuring the quality of the drawn product.

[0075] In some embodiments of the present invention, the inclination angle of the inner mold 100 relative to the drawing direction of the drawing mold is selected according to the actual wall thickness difference.

[0076] Specifically, the inclination angle of the inner mold 100 relative to the drawing direction of the drawing mold is greater than 0° and less than 10°, which can achieve a good balance effect and meet the current drawing requirements of battery cases with different wall thicknesses.

[0077] Specifically, the tilt angle of the inner mold 100 relative to the drawing direction of the drawing mold can also be determined by the calculation formula: tilt angle = 2° * D / d, which can achieve a better balance effect.

[0078] Example 2

[0079] like Figure 4 As shown, the extraction traction control system according to an embodiment of the present invention includes the following steps:

[0080] Step A1: Power on the traction control system, set the maximum lifting limit force N1, and set the lifting limit displacement L1 of the tractor vehicle;

[0081] Step A2: The tractor unit is started, the starting traction force N2 of the tractor unit is measured, and the feedback is sent to the traction control system;

[0082] Step A3: The traction control system compares the values ​​of N1 and N2. If N1 is greater than N2, proceed to step A4; if N1 is less than N2, proceed to step A6.

[0083] Step A4: Keep the starting traction force N2 of the tractor constant, measure the displacement L2 of the tractor, and feed it back to the traction control system;

[0084] Step A5: The traction control system compares the values ​​of L1 and L2. If L1 is greater than L2, proceed to step A4; if L1 is less than L2, proceed to step A7.

[0085] Step A6: Reduce the starting traction force N2 of the tractor, measure the displacement L2 of the tractor, and feed it back to the traction control system. Compare the magnitudes of L1 and L2. If L1 is greater than L2, proceed to step A3; if L1 is less than L2, proceed to step A7.

[0086] Step A7: Steady-state extraction of finished products.

[0087] Through the above control process, the traction force in the initial pumping state is controlled, achieving a smooth transition from the unstable state in the initial stage to the stable pumping state, reducing the occurrence of pumping interruption, and thus improving the pumping success rate.

[0088] Furthermore, in step A6, a judgment condition is added: the displacement L2 of the tractor is measured and fed back to the traction control system. The magnitudes of L1 and L2 are compared. If L1 is greater than L2, step A3 is executed; if L1 is less than L2, step A7 is executed to avoid excessive movement of the tractor during the lifting phase.

[0089] In this embodiment, other parameter settings and mold configurations are similar to those in Embodiment 1, and will not be described in detail here.

[0090] Of course, the present invention is not limited to the above-described embodiments. Those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A traction control system, characterized in that, The drawing and traction control system is used for traction force control during the drawing process, from a stationary state to a stable drawing and pulling stage of the material. The drawing and traction control system includes: Step A1: Power on the traction control system, set the maximum limiting force N1 for pulling, set the limiting displacement L1 for pulling the tractor, set the tensile strength of the material to be pulled at the set elongation A as P, set the cross-sectional area of ​​the pulling mold or the cross-sectional area of ​​the finished product as S, set the correction coefficient K, N1=P*S*K. Step A2: The tractor unit is started, the starting traction force N2 of the tractor unit is measured, and the feedback is sent to the traction control system; Step A3: The traction control system compares the values ​​of N1 and N2. If N1 is greater than N2, proceed to step A4; if N1 is less than N2, proceed to step A6. Step A4: Keep the starting traction force N2 of the tractor constant, measure the displacement L2 of the tractor, and feed it back to the traction control system; Step A5: The traction control system compares the values ​​of L1 and L2. If L1 is greater than L2, proceed to step A4; if L1 is less than L2, proceed to step A7. Step A6: Reduce the starting traction force N2 of the tractor and proceed to step A3; Step A7: Steady-state extraction of finished products.

2. A traction control system, characterized in that, The drawing and traction control system is used for traction force control during the drawing process, from a stationary state to a stable drawing and pulling stage of the material. The drawing and traction control system includes: Step A1: Power on the traction control system, set the maximum limiting force N1 for pulling, set the limiting displacement L1 for pulling the tractor, set the tensile strength of the material to be pulled at the set elongation A as P, set the cross-sectional area of ​​the pulling mold or the cross-sectional area of ​​the finished product as S, set the correction coefficient K, N1=P*S*K. Step A2: The tractor unit is started, the starting traction force N2 of the tractor unit is measured, and the feedback is sent to the traction control system; Step A3: The traction control system compares the values ​​of N1 and N2. If N1 is greater than N2, proceed to step A4; if N1 is less than N2, proceed to step A6. Step A4: Keep the starting traction force N2 of the tractor constant, measure the displacement L2 of the tractor, and feed it back to the traction control system; Step A5: The traction control system compares the values ​​of L1 and L2. If L1 is greater than L2, proceed to step A4; if L1 is less than L2, proceed to step A7. Step A6: Reduce the starting traction force N2 of the tractor, measure the displacement L2 of the tractor, and feed it back to the traction control system. Compare the magnitudes of L1 and L2. If L1 is greater than L2, proceed to step A3; if L1 is less than L2, proceed to step A7. Step A7: Steady-state extraction of finished products.

3. The extraction traction control system according to claim 1 or 2, characterized in that, The set elongation rate A is 26% to 28%.

4. The extraction traction control system according to claim 3, characterized in that, The elongation after fracture of the extracted material is greater than 30%.

5. The extraction traction control system according to claim 3, characterized in that, The set correction coefficient K is 1.05-1.

25.

6. The extraction traction control system according to claim 1 or 2, characterized in that, The starting displacement limit L1 is 480mm-520mm.

7. The extraction traction control system according to claim 1 or 2, characterized in that, A drawing and traction control system is used for drawing and forming a housing, the housing having a thick side (901) and a thin side (902) with opposite and unequal wall thicknesses, the wall thickness of the thick side (901) being D and the wall thickness of the thin side (902) being d. The drawing mold includes an inner mold (100) and an outer mold (200), the outer mold (200) being provided with a drawing cavity extending along the drawing direction, the inner mold (100) being able to be placed into the drawing cavity, a drawing gap (201) corresponding to the housing being formed between the outer edge of the inner mold (100) and the inner wall of the drawing cavity, the drawing gap (201) including a wide slit and a narrow slit respectively corresponding to the thick side (901) and the thin side (902) of the housing, the material is set to pass through the drawing mold from front to back, the front part of the inner mold (100) is deflected toward the side of the narrow slit relative to the drawing direction of the drawing mold.

8. The extraction traction control system according to claim 7, characterized in that, The inclination angle of the inner mold (100) relative to the drawing direction of the drawing mold is greater than 0° and less than 10°.

9. The extraction traction control system according to claim 7, characterized in that, The inclination angle of the inner mold (100) relative to the drawing direction of the drawing mold is 2° * D / d.

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