A method for improving oil uniformity of an automobile lightweight production line

Abstract

The application provides a method for improving the oiling uniformity of a light-weight automobile production line, wherein an electric field balance baffle is arranged below a blade beam at the operating side and the driving side of a strip conveying roller way; the electric field balance baffle is adjacent to the edge of the strip, and the distance between the two is adjusted by a driving mechanism to form an electric field transfer distance that can make the edge effect of the strip transfer to the electric field balance baffle; a quick oil guiding structure that is communicated with an oil return system is arranged at the electric field balance baffle, and the oil mist and oil drops focused by the baffle are quickly guided out to maintain the electric field balance ability of the baffle; the oil return system processes the recovered oil that is not sprayed to the surface of the strip according to the oil specifications by using corresponding oil product multiplexing devices, so that the moving path of the recovered oil particles in the electric field of the blade beam is uniformly matched with the oiling area of the strip; the oil product multiplexing devices include parallelly arranged external circulation filtering devices and vacuum oil purifying machine devices; and the application can make the moving path of the oil particles in the electric field match with the strip in the oiling process, and improve the oiling uniformity of the surface of the strip.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile production, and in particular to a method for improving oiling uniformity of an automobile lightweight production line. BACKGROUND

[0002] In the oiling process of the automobile lightweight production line, a high-voltage electrostatic field is formed between the blade beam and the aluminum strip; when the pre-oil is sprayed from the blade gap of the blade beam, the oil is charged with positive and negative charges, and under the action of the electric field force, the charged oil particles move quickly along the electric lines of force in the electric field to the direction of the strip and form an oil film on the surface of the strip. However, due to the influence of the roller structure and the strip, the electric field is not uniform, and the movement of the oil particles in the electric field is affected by the conductivity corresponding to the purity of the oil, so that the movement of the oil particles to the strip will exceed the design expectation. In addition, the water residue in the oil directly affects the conductivity of the oil, which will directly affect the oil atomization effect. The uneven distribution of charges in the oil leads to good atomization effect in some local areas and poor atomization effect in other local areas, and the oil distribution on the surface of the strip after being sprayed by the blade beam is uneven, and the oil quantity per unit area per unit time is large, which will lead to local oil shortage and local oil excess on the surface of the aluminum plate. During the stamping process in the automobile main plant, the aluminum plate deforms greatly under the action of the stamping die, and the area with less oil on the surface of the aluminum plate will cause poor lubrication between the aluminum plate and the die due to the lack of oil, which will further cause stamping cracking during the stamping process, and the aluminum plate is scrapped. How to solve the above problems is a research direction. SUMMARY

[0003] The present application provides a method for improving the oiling uniformity of an automobile lightweight production line, which can match the movement path of the oil particles in the electric field with the strip in the oiling process, and improve the oiling uniformity of the surface of the strip.

[0004] The present application adopts the following technical solutions.

[0005] The application discloses a method for improving the oiling uniformity of a light-weight automobile production line, which is used for optimizing the oiling uniformity of an electric field oiling process of a strip for automobile production, the electric field oiling process is arranged at a strip conveying roller way, and an oil mist of a pre-oiling process oil product is sprayed to the strip through a knife beam electric field, the method is characterized in that an electric field balance baffle for balancing the electric field of the electric field oiling process is arranged below the knife beam at the operating side and the driving side of the strip conveying roller way; the electric field balance baffle is adjacent to the edge of the strip, and the distance between the electric field balance baffle and the edge of the strip is adjusted through a driving mechanism to form an electric field transfer distance, which can make the edge effect of the strip transferred to the electric field balance baffle; a quick oil guiding structure which is communicated with an oil return system is arranged at the electric field balance baffle, the quick oil guiding structure quickly guides the oil mist droplets focused by the baffle out to maintain the electric field balance ability of the baffle; the oil return system processes the recovered oil which is not sprayed to the surface of the strip according to different specifications of the oil product through corresponding oil product multiplexing devices, and the moving path of the processed recovered oil droplets in the electric field of the knife beam is uniformly matched with the oiling area of the strip.

[0006] The material of the electric field balance baffle is the same as that of the strip, and the quick oil guiding structure comprises an oil-repellent layer covering the surface of the electric field balance baffle, when the oil droplets of the electric field oiling process fall on the electric field balance baffle, the oil droplets flow into the oil return system along the oil-repellent layer with the vibration of the baffle.

[0007] The electric field balance baffle is made of an aluminum alloy material, the strip is an aluminum strip, and the electric field transfer distance ranges from 10 mm to 15 mm.

[0008] The driving mechanism is used for driving the electric field balance baffle to move, and the driving mechanism comprises a motor and a screw rod mechanism connected with the motor.

[0009] The knife beam comprises an upper knife beam and a lower knife beam, in the electric field oiling process, the upper knife beam is a negative electrode, the lower knife beam is a positive electrode, the strip is grounded as zero, and a high-voltage electrostatic field is formed between the knife beam and the strip, when the pre-oiling is sprayed out from the blade gap of the knife beam, the oil droplets are charged with positive and negative charges, under the action of the electric field force, the charged oil droplets quickly move to the strip along the electric lines of force in the electric field, the same-pole repulsion effect in the moving process makes the oil droplets collide with each other, the oil droplets become smaller, the farther from the blade gap, the smaller the oil droplets, and the more the number, until the oil mist is formed, and the oil mist is adsorbed on the surface of the aluminum material to form an oil film.

[0010] The length of the knife beam is greater than that of the strip, and an oil collecting basin of the oil return system is arranged below the knife beam, after the process oil which is not sprayed to the surface of the strip is returned to the oil collecting basin, the process oil is sucked to the oil product multiplexing device corresponding to the pre-oiling oil product through an oil return pump of the oil return system, the recovered oil is formed after impurities are filtered through the external circulation filtering device and water is removed through the vacuum oil purifier device, and the moving performance of the oil droplets of the recovered oil in the electric field is similar to or equal to that of the pre-oiling oil product.

[0011] The oil return pump is communicated with the oil multiplexing device through an oil return pipeline, different specifications of oil in the oil collecting basin correspond to different oil multiplexing devices, and an electromagnetic valve is arranged at the oil return pipeline connected with the oil multiplexing device and is locked synchronously with the electric field oil coating process; when the current pre-coating oil specification is set in the electric field oil coating process, the electromagnetic valve of the oil return pipeline corresponding to the oil specification is opened, and the electromagnetic valves of the remaining oil return pipelines are closed.

[0012] In the method, all process oil crude oil or recycled oil is treated by the external circulation filtering device, the oil liquid is repeatedly filtered through the filter cartridge filter by suction circulation, the oil product cleanliness is improved, and the impurities in the oil liquid are reduced; the external circulation filtering device is provided with a heating bin for heating the oil liquid, and the applicable oil products include oil liquid with a melting point lower than 65℃;

[0013] The use method of the external circulation filtering device is as follows: the movable semicircular wall of the external circulation filtering device shell is opened, the oil drum is horizontally forked into the heating bin by a forklift, and the movable semicircular wall is closed; the heating bin heats the solid oil in the oil drum into liquid oil, and then the suction pump of the external circulation filtering device starts to suck, the oil liquid is controlled to pass through the filter and the backflow branch for continuous circulation filtering through the three-way control valve, and after a predetermined time, the oil liquid is controlled to be transported to the direction of the tool beam of the processing station through the three-way control valve again, so as to ensure the cleanliness of the output oil liquid, avoid the impurities in the oil liquid from blocking the output hole of the tool beam, and match the movement performance of the oil particles in the output oil liquid with the electric field transfer distance in the electric field of the tool beam.

[0014] The vacuum oil purifier device is connected in parallel with the external circulation filtering device, when the external circulation filtering device filters the impurities in the oil liquid, the vacuum oil purifier device removes the water in the oil liquid to reduce the water content of the oil liquid, improve the electrical conductivity of the oil liquid, and improve the uniformity of the oil liquid atomization, thereby improving the uniformity of the tool beam oil coating,

[0015] The vacuum oil purifier device is composed of a vacuum heating tank, a fine filter, a condenser, a primary filter, a water blocking box, a vacuum pump, an oil discharge pump and an electrical cabinet; the vacuum pump extracts the air in the vacuum heating tank to form a vacuum, the external oil liquid enters the primary filter under the action of atmospheric pressure, and then enters the vacuum heating tank for heating to 40-75℃; when the oil passes through the automatic oil float valve after heating, the high-speed rotating spray wing separates the oil into a semi-mist state, the water in the oil rapidly evaporates into water vapor in the vacuum environment and is continuously sucked into the condenser by the vacuum pump, and the water vapor entering the condenser is cooled and then restored into water and discharged, so as to remove the water in the oil liquid.

[0016] In the oil coating process, the strip material is an aluminum plate strip material; the oil mist adopts an aluminum pre-spraying oil for automobile lightweight; the nozzle of the tool beam is located above the strip material, and the distance from the tool beam nozzle to the strip material is x, which is measured in meters;

[0017] Let g0 be the oil quantity per unit area per unit time at the jet axis of each nozzle, in kg / m 2 ·s; let g be the oil quantity per unit area per unit time at the atomized edge area of the oil spraying area of each nozzle, in kg / m 2 ·s;

[0018] When the oil quantity per unit area per unit time at a certain position of the oil spraying area of the nozzle is half of g0, the distance of the position to the jet axis is r0, in m;

[0019] The production line data of the oiling process is summarized by the amount of analysis method, and the criterion relationship formula of the oil quantity per unit area per unit time is obtained as follows:

[0020]

[0021] Among them:

[0022] τ: oil surface tension under different spraying pressures, N / m;

[0023] d: tool beam gap, m;

[0024] P: spraying pressure, MPa;

[0025] A and n are test constants;

[0026] According to the temperature-viscosity curve of the aluminum pre-spraying oil for automobile light weight, the relationship between the oil product kinematic viscosity and temperature is fitted to obtain the formula as follows:

[0027] μ = 319.65e -0.037T

[0028] μ: kinematic viscosity of oil, m 2 / s;

[0029] T: oil temperature, ℃;

[0030] In the oiling process, when g / g0 tends to 1, that is, the oil quantity per unit area per unit time at the edge area is equal to the oil quantity per unit area per unit time at the axis position, the atomization effect is best, and the Taylor cone shape is reached; and when the kinematic viscosity of the oil is 24-33 m 2 / s, the oil atomization effect is best.

[0031] The method optimizes the oil temperature to make the oil viscosity range reach 24-33 m 2 / s, and adjusts the tool beam voltage to make the oil in the oiling atomization spraying process have a Taylor cone shape before leaving the tool beam nozzle.

[0032] The method, the upper blade beam of the electrostatic oiler, the lower blade beam, the spray pressure p of the electrostatic oiler is 0.16 MPa, the gap d between the blade beams is 6·10 -5 m, the distance between the upper blade beam and the strip is 0.325 m, the distance between the lower blade beam and the strip is 218 mm; the test constant A is 4300, and n is 1.5.

[0033] According to the temperature-viscosity curve of the oil product, the optimal process temperature of the oil product is 55-65℃.

[0034] In the method, the voltage range of the negative electrode of the upper blade beam is set to 80-85KV, and the voltage range of the positive electrode of the lower blade beam is set to 75-80KV, so that the geometric shape of the oil liquid in the oil atomization spraying process before leaving the blade beam nozzle is Taylor cone shape.

[0035] The oiling uniformity index is set to the oil liquid quantity deviation value per unit area per unit time ≤15%,

[0036] The oil liquid density at 15℃ is 0.87g / cm 3 ; the flash point is ≥220℃; the oil liquid surface tension under 80KV voltage is 4.07N / m; the oil liquid viscosity at 65℃ is 27.89g / cm 3 ; and the calculation method of the optimal process parameters of the oiling process is as follows:

[0037] The oiling operation of the electrostatic oiler is tested by using the test constant, and the test results are summarized by using the dimensional analysis method, and the formula is obtained.

[0038]

[0039] Among them:

[0040] μ: the kinematic viscosity of the oil liquid, m 2 / s;

[0041] U: electric field voltage, KV;

[0042] τ: oil liquid surface tension under different voltages, N / m;

[0043] According to the above formula, the suitable temperature and voltage values of the Dejie E1 oil product are calculated, i.e. the temperature is 62℃, the optimal voltage value of the upper blade beam is 80-85KV, and the optimal voltage value of the lower blade beam is 75-80KV.

[0044] This invention features an electric field balancing baffle (material: aluminum alloy, 200mm wide). Controlled by a motor and lead screw, the baffle position (10-15mm from the strip edge) can be automatically adjusted according to the strip width in the secondary system. This increases the strip width, balances the electric field inside the oiling machine, and transfers the edge effect to the baffle, preventing the oil film at the strip edge from becoming too thick. At the same time, the baffle has a rapid oil guiding function, preventing oil from accumulating on the baffle during long-term use and affecting its electric field balance performance.

[0045] This invention modifies the return oil pipeline so that the process oil not sprayed onto the strip surface can be directly drawn through the pipeline to the external circulation filter device. After repeated circulation and filtration, impurities in the oil are eliminated to avoid affecting the conductivity of the oil. This allows the oil droplets to move to the strip surface along the designed path and form a uniform oil film coverage.

[0046] In this invention, multiple sets of return oil pipes are set up, and different oil products use different return oil pipes to lead to different external circulation filter devices, so as to minimize the chemical reaction caused by oil mixing, which may lead to oil deterioration or the generation of gum reaction products, and avoid uneven oil spray caused by clogging of the blade beam.

[0047] This invention controls the opening and closing of the return oil pipeline valve via a solenoid valve, forming an interlock with the selection of the oil type for the train. For example, when using oil type #1, the #1 return oil pipeline valve will automatically open, guiding the oil into the #1 oil external circulation filter device. This minimizes the risk of chemical reactions caused by oil mixing, which could lead to oil deterioration or the formation of gum-like reactants, and also prevents uneven oil spraying caused by clogging of the cutter beam.

[0048] In this invention, all process oils, crude oils, or recycled oils must use an external circulation filtration device. By pumping the circulating oil, the oil is repeatedly passed through the filter element to improve the cleanliness of the oil and reduce impurities in the oil. This is to prevent impurities in the oil from affecting the conductivity of the oil, so that the oil droplets can move to the surface of the strip along the designed path and form a uniform oil film coverage.

[0049] In this invention, the vacuum oil purifier and the external circulation filter of the oiling machine are connected in parallel. While filtering impurities in the oil, the water in the oil is removed, thereby reducing the water content of the oil, increasing the conductivity of the oil, and improving the uniformity of oil atomization, thus improving the uniformity of oiling the blade beam. Attached Figure Description

[0050] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0051] Appendix Figure 1 This is a schematic diagram of an electric field equilibrium baffle;

[0052] Appendix Figure 2 This is a schematic diagram of an external circulation filtration device;

[0053] Figure 1 is a schematic diagram of the Taylor cone morphology; Figure 3 Figure 2 is a schematic diagram of the present application, in which a single nozzle sprays oil onto the strip.

[0054] Figure 3 is a schematic diagram of the present application, in which a single nozzle sprays oil onto the strip. Figure 4 Figure 4 is a schematic diagram of the present application, in which a single nozzle sprays oil onto the strip. DETAILED DESCRIPTION

[0055] As shown in the figure, a method for improving the oiling uniformity of an automobile lightweight production line, for optimizing the oiling uniformity of an electric field oiling process for a strip used in automobile production, the electric field oiling process being provided at a strip conveying roller bed, and an oil mist of a pre-oiling process oil product being sprayed from a knife beam electric field to the strip 50, the method being provided with an electric field balance baffle for balancing the electric field of the electric field oiling process below the knife beam at the operating side and the driving side of the strip conveying roller bed; the electric field balance baffle 20 is in close proximity to the edge of the strip, and the distance between the two is adjusted by a driving mechanism to form an electric field transfer distance that can make the edge effect of the strip transferred to the electric field balance baffle; a quick oil guiding structure that is in communication with an oil return system is provided at the electric field balance baffle, and the quick oil guiding structure quickly guides the oil mist droplets focused by the baffle outwards to maintain the electric field balance ability of the baffle; the oil return system processes the recovered oil that is not sprayed onto the surface of the strip according to different specifications of the oil product with a corresponding oil product multiplexing device, so that the moving path of the processed recovered oil droplets in the electric field of the knife beam is uniformly matched with the oiling area of the strip; the oil product multiplexing device includes an external circulation filtering device and a vacuum oil purifier device arranged in parallel.

[0056] The material of the electric field balance baffle is the same as that of the strip, and the quick oil guiding structure includes an oil-repellent layer covering the surface of the electric field balance baffle, when the oil droplets of the electric field oiling process fall on the electric field balance baffle, the oil droplets flow into the oil return system along the oil-repellent layer due to the vibration of the baffle.

[0057] The electric field balance baffle is made of aluminum alloy, and the strip is an aluminum strip, and the electric field transfer distance is in the range of 10-15 mm.

[0058] The driving mechanism is used to drive the movement of the electric field balance baffle, and the driving mechanism includes a motor 40 and a screw rod mechanism 30 connected to the motor.

[0059] The knife beam includes an upper knife beam and a lower knife beam, in the electric field oiling process, the upper knife beam is the negative electrode, the lower knife beam is the positive electrode, and the strip is grounded to zero, so that a high-voltage electrostatic field is formed between the knife beam and the strip, when the pre-oiling oil is sprayed from the gap of the blade of the knife beam, the oil droplets are charged with positive and negative charges, under the action of the electric field force, the charged oil droplets quickly move towards the strip along the electric lines of force in the electric field, the same-pole repulsion effect in the movement process makes the oil droplets collide with each other, and the oil droplets become smaller, the farther away from the blade, the smaller the oil droplets, and the more the number, until a uniform oil mist is formed, and an oil film is formed on the surface of the aluminum material by adsorption.

[0060] The length of the blade beam is greater than the strip, and the oil collecting basin of the oil return system is arranged below the blade beam. After the process oil not sprayed to the surface of the strip flows into the oil collecting basin, the oil return pump of the oil return system sucks the process oil into the oil product multiplexing device corresponding to the pre-coating oil product, filters impurities through the external circulation filter device, removes water through the vacuum oil purifier device, and forms the recovered oil. The movement performance of the oil particles in the electric field is similar or identical to that of the pre-coated oil product.

[0061] The oil return pump and the oil product multiplexing device are communicated through the oil return pipeline. Different oil products in the oil collecting basin correspond to different oil product multiplexing devices. The electromagnetic valve at the oil return pipeline connected to the oil product multiplexing device is locked synchronously with the electric field coating process. When the current pre-coated oil product is set in the electric field coating process, the electromagnetic valve of the oil return pipeline corresponding to the oil product is opened, and the electromagnetic valves of the remaining oil return pipelines are closed.

[0062] In the method, all process oil crude oil or recycled recovered oil is treated by the external circulation filter device. By sucking the circulating oil, the oil repeatedly passes through the filter, improving the cleanliness of the oil and reducing impurities in the oil. The external circulation filter device is provided with a heating bin for heating the oil. The applicable oil products include oil with a melting point lower than 65℃.

[0063] The use method of the external circulation filter device is as follows: open the movable semicircular wall of the external circulation filter device shell, use a forklift to horizontally fork the oil drum into the heating bin, and close the movable semicircular wall. The heating bin heats the solid oil in the oil drum into liquid oil, and then the suction pump of the external circulation filter device starts to suck. The oil first passes through the filter and the return branch for continuous circulation filtering under the control of the three-way control valve. After a predetermined time, the oil is transported to the direction of the blade beam of the processing station again under the control of the three-way control valve, so as to ensure the cleanliness of the output oil and avoid the blockage of the blade beam output hole by impurities in the oil. In addition, the movement performance of the oil particles in the electric field of the blade beam is matched with the electric field transfer interval.

[0064] The vacuum oil purifier device is connected in parallel with the external circulation filter device. When the external circulation filter device filters impurities in the oil, the vacuum oil purifier device removes water from the oil to reduce the water content of the oil, improve the electrical conductivity of the oil, and improve the uniformity of the oil mist, thereby improving the uniformity of the blade beam coating.

[0065] The vacuum oil purifier device is composed of a vacuum heating tank, a fine filter, a condenser, a primary filter, a water blocking tank, a vacuum pump, an oil discharge pump and an electrical cabinet; the vacuum pump extracts air in the vacuum heating tank to form a vacuum, oil outside is under the action of atmospheric pressure, enters the primary filter, and removes larger particles, and then enters the vacuum heating tank and is heated to 40-75 DEG C, when the oil after heating passes through the automatic oil floating valve, the high-speed rotating spray wing separates the oil into a semi-mist, the water in the oil rapidly evaporates into water vapor under the vacuum environment and is continuously sucked into the condenser by the vacuum pump, the water vapor entering the condenser is cooled and then reduced into water and discharged, so as to remove the water in the oil.

[0066] In the oiling process, the strip is an aluminum plate strip; the oil mist is an aluminum pre-spraying oil for automobile lightweight; the nozzle of the knife beam is above the strip, and the distance from the nozzle of the knife beam to the strip is x, which is in meters;

[0067] Let g0 be the oil quantity per unit area per unit time at the jet axis of each nozzle, in kg / m 2 ·s; let g be the oil quantity per unit area per unit time at the atomization edge area of the oil spraying coverage area of each nozzle, in kg / m 2 ·s;

[0068] When the oil quantity per unit area per unit time at a certain position of the oil spraying coverage area of the nozzle is half of g0, the distance from the position to the jet axis is r0, which is in meters;

[0069] The production line data of the oiling process is summarized by the amount of analysis method, and the criterion relationship formula of the oil quantity per unit area per unit time is obtained as follows:

[0070]

[0071] Among them:

[0072] τ: oil surface tension under different spraying pressures, N / m;

[0073] d: knife beam gap, m;

[0074] P: spraying pressure, MPa;

[0075] A and n are test constants;

[0076] According to the temperature-viscosity curve of the aluminum pre-spraying oil for automobile lightweight, the relationship between the oil product kinematic viscosity and temperature is fitted to obtain the production line data, which is expressed in a formula as follows:

[0077] μ = 319.65e -0.037T

[0078] μ: kinematic viscosity of oil, m 2 / s;

[0079] T: oil temperature, ℃;

[0080] In the oiling process, when g / g0 tends to 1, that is, the oil quantity per unit area per unit time in the edge area is equal to the oil quantity per unit area per unit time at the axis position, the atomization effect is optimal, and the Taylor cone shape is reached; and when the kinematic viscosity of the oil is 24-33 m 2 / s, the oil atomization effect is optimal.

[0081] The method optimizes the oil temperature to make the oil viscosity range reach 24-33 m 2 / s, and adjusts the voltage of the blade beam to make the oil in the oiling atomization spraying process have a Taylor cone shape before leaving the blade beam nozzle.

[0082] In the method, the blade beam includes an upper blade beam and a lower blade beam of an electrostatic oiling machine, the spraying pressure p of the electrostatic oiling machine is 0.16 MPa, the gap d between the blade beams is 6·10 -5 m, the distance between the upper blade beam and the strip is 0.325 m, the distance between the lower blade beam and the strip is 218 mm; the test constant A is 4300, and n is 1.5.

[0083] According to the temperature-viscosity curve of the oil, the optimal process temperature of the oil is determined to be 55-65℃;

[0084] In the method, the voltage range of the negative electrode of the upper blade beam is set to 80-85 KV, and the voltage range of the positive electrode of the lower blade beam is set to 75-80 KV, so that the oil in the oiling atomization spraying process has a Taylor cone shape before leaving the blade beam nozzle.

[0085] The oiling uniformity index is set to the oil quantity deviation per unit area per unit time ≤15%,

[0086] The oil density at 15℃ is 0.87 g / cm 3 ; the flash point is ≥220℃; the oil surface tension under 80 KV voltage is 4.07 N / m;

[0087] The oil viscosity at 65℃ is 27.89 g / cm 3 ; and the calculation method of the optimal process parameters of the oiling process is as follows:

[0088] The oiling operation of the electrostatic oiling machine is tested by using the test constant, and the test results are summarized by using the dimensional analysis method, and the formula is obtained as

[0089]

[0090] Among them:

[0091] μ: kinematic viscosity of oil, m 2 / s;

[0092] U: electric field voltage, KV;

[0093] τ: oil surface tension under different voltage, N / m;

[0094] According to the above formula, the suitable temperature and voltage value of Deji E1 oil product is calculated, that is, the temperature is 62℃, the optimal voltage value of the upper tool bar is 80-85KV, and the optimal voltage value of the lower tool bar is 75-80KV.

[0095] In this example, the oil used is Multidraw Drylube E1 aluminum pre-spraying oil for automobile lightweight.

[0096] In this example, the external circulation filtering device comprises a heating bin 1 provided with an inlet and an outlet, an oil tank 2 placed inside the heating bin, an output pipeline 3 connected inside the oil tank, a suction pump 4 and a filter sequentially arranged on the output pipeline along the oil flow direction, a reflux branch 5 connected to the output pipeline after the filter, and the reflux branch connected to the oil tank.

[0097] The filter sequentially comprises a double filter 6 and a single filter 7 along the oil flow direction.

[0098] A three-way control valve 8 is arranged at the joint of the reflux branch and the output pipeline.

[0099] The output end of the output pipeline is connected in parallel with a machining station branch 9 and a waste discharge branch 10, the waste discharge branch leads to a waste discharge tank 11, and pneumatic valves 12 are arranged on the machining station branch and the waste discharge branch.

[0100] The heating bin comprises a cylindrical bin wall, the bin wall is composed of a fixed semicircular wall and a movable semicircular wall, one side edge of the movable semicircular wall is hinged to one side edge of the fixed semicircular wall, the fixed semicircular wall and the movable semicircular wall are connected by a lock buckle for opening and closing control, and a circular bin cover is fixedly connected to the top end of the fixed semicircular wall.

[0101] The bin cover is provided with through holes for the output pipeline and the reflux branch to extend into, and the pipelines of the output pipeline and the reflux branch extending into the bin cover area are hoses 18, which are convenient for pulling out or penetrating into the oil tank.

[0102] The inside of the bin wall is filled with heat conducting oil for heating the solid oil inside the oil tank into liquid oil. In addition to the hose part, the pipelines of the output pipeline and the reflux branch are double-layer pipelines, the inner middle pipeline transports oil, and the outer pipeline transports heat conducting oil, so that the oil has a heat preservation and heating effect during transportation.

[0103] The working principle of the outer circulation filtering device is as follows: opening the movable semicircular wall, the forklift horizontally forks the oil drum into the heating bin, and closes the movable semicircular wall. The heating bin heats the solid oil in the oil drum into liquid oil, and then the suction pump starts to suck. After a certain period of time, the oil is filtered and circulated through the return branch under the control of the three-way control valve, and then the oil is transported to the processing station under the control of the three-way control valve, which can ensure the cleanliness of the output oil and the good surface oil coating quality of the aluminum plate.

Claims

1. A method for improving the uniformity of oil coating in an automotive lightweight production line, used to optimize the oil coating uniformity of an electric field oil coating process for automotive production strips, characterized in that: The electric field oiling process is located at the strip conveyor rollers. Oil mist of the pre-coating process oil is sprayed onto the strip through the electric field of the blade beam. An electric field balancing baffle is installed below the blade beam on both the operating and transmission sides of the strip conveyor rollers to balance the electric field of the oiling process. The electric field balancing baffle is adjacent to the edge of the strip, and the distance between them is adjusted by a drive mechanism to create an electric field transfer distance that allows the edge effect of the strip to be transferred to the electric field balancing baffle. A rapid oil guiding structure connected to the oil return system is provided at the electric field balancing baffle. This rapid oil guiding structure maintains the electric field balance capability of the baffle by quickly discharging the oil mist and droplets focused by the baffle. The oil return system uses corresponding oil reuse devices to process the recycled oil that was not sprayed onto the strip surface, according to the different specifications of the oil. This ensures that the movement path of the treated recycled oil droplets in the blade beam electric field is uniformly matched with the oiling area of ​​the strip. The oil reuse device includes an external circulation filter and a vacuum oil purifier connected in parallel. The return oil pump in the return oil system is connected to the oil reuse device via a return oil pipeline. Different specifications of oil in the oil collection basin correspond to different oil reuse devices. The return oil pipeline connected to the oil reuse device is equipped with a solenoid valve that locks synchronously with the electric field oiling process. When the electric field oiling process sets the current pre-coated oil specification, the solenoid valve of the return oil pipeline corresponding to that oil specification opens, and the solenoid valves of the other return oil pipelines close. In the method described above, all process oil crude oil or recycled oil is treated by an external circulation filtration device. By pumping the circulating oil, the oil is repeatedly passed through the filter element to improve the cleanliness of the oil and reduce impurities in the oil. The external circulation filtration device is equipped with a heating chamber for heating the oil, and is suitable for oils with a melting point below 65°C. The method of using the external circulation filter device is as follows: open the movable semi-circular wall of the external circulation filter device housing, use a forklift to horizontally insert the oil drum into the heating chamber, and close the movable semi-circular wall; the heating chamber heats the solid oil inside the oil drum into liquid oil, and then the suction pump of the external circulation filter device starts to suck. The oil is controlled by the three-way control valve to first pass through the filter and return branch for continuous circulation and filtration. After the predetermined time is reached, the oil is then controlled by the three-way control valve to be transported to the direction of the cutting beam at the processing station to ensure the cleanliness of the output oil, prevent impurities in the oil from clogging the output hole of the cutting beam, and match the movement performance of the oil droplets in the electric field of the cutting beam with the electric field transfer distance. The vacuum oil purifier is connected in parallel with the external circulation filter. While the external circulation filter is filtering impurities from the oil, the vacuum oil purifier removes water from the oil to reduce its water content, increase its conductivity, and improve its atomization uniformity, thereby improving the uniformity of oil coating on the blade beam. The vacuum oil purifier consists of a vacuum heating tank, a fine filter, a condenser, a primary filter, a water trap, a vacuum pump, an oil discharge pump, and an electrical cabinet. The vacuum pump extracts air from the vacuum heating tank to create a vacuum. Under atmospheric pressure, the external oil enters the primary filter to remove larger particles. Then, it enters the vacuum heating tank and is heated to 40–75°C. After heating, the oil passes through an automatic oil float valve, where a high-speed rotating spray blade separates the oil into a semi-mist. The water in the oil rapidly evaporates into water vapor under vacuum and is continuously drawn into the condenser by the vacuum pump. The water vapor entering the condenser is cooled and then reverts back to water before being discharged, thus achieving the effect of removing water from the oil.

2. The method for improving the uniformity of oil coating in an automotive lightweighting production line according to claim 1, characterized in that: The material of the electric field balancing baffle is the same as that of the strip. The rapid oil guiding structure includes an oleophobic layer covering the surface of the electric field balancing baffle. When oil droplets from the electric field oiling process fall onto the electric field balancing baffle, the oil droplets flow into the oil return system along the oleophobic layer due to the vibration of the baffle.

3. The method for improving the uniformity of oil coating in an automotive lightweighting production line according to claim 1, characterized in that: The electric field balancing baffle is made of aluminum alloy, the strip is made of aluminum strip, and the electric field transfer spacing ranges from 10 to 15 mm.

4. The method for improving the uniformity of oil coating in an automotive lightweighting production line according to claim 1, characterized in that: The drive mechanism is used to drive the electric field balance baffle to move. The drive mechanism includes a motor and a lead screw mechanism connected thereto.

5. The method for improving the uniformity of oil coating in an automotive lightweighting production line according to claim 1, characterized in that: The blade beam includes an upper blade beam and a lower blade beam. In the electric field oiling process, the upper blade beam is the negative pole and the lower blade beam is the positive pole. The strip is grounded to zero position, so that a high voltage electrostatic field is formed between the blade beam and the strip. When the pre-coated oil is sprayed out from the blade edge gap of the blade beam, the oil droplets are charged with positive and negative charges. Under the action of the electric field force, the charged oil droplets move rapidly towards the strip along the electric field lines. The like pole repulsion effect during the movement causes the oil droplet molecules to collide with each other, turning large oil droplets into small oil droplets. The farther away from the blade edge, the smaller the oil droplets become, and the more numerous they are, until a uniform oil mist is formed and adsorbed on the surface of the aluminum material to form an oil film. The length of the blade beam is greater than that of the strip. The oil collection basin of the oil return system is located below the blade beam. The process oil that is not sprayed onto the surface of the strip flows back to the oil collection basin and is then pumped by the oil return pump of the oil return system to the oil reuse device corresponding to the pre-coated oil. After impurities are filtered by the external circulation filter and water is removed by the vacuum oil purifier, the recovered oil is formed. The movement performance of the oil particles in the electric field of the recovered oil is similar to or equivalent to that of the pre-coated oil.

6. The method for improving the uniformity of oil coating in an automotive lightweighting production line according to claim 5, characterized in that: In the oiling process, the strip is an aluminum sheet / strip; the oil mist is automotive lightweight aluminum pre-spraying oil; the nozzle of the blade beam is located above the strip; the distance from the blade beam nozzle to the strip is x, in meters. Let g0 be the amount of oil per unit area per unit time along the jet axis of each nozzle, in kg / m². 2 •s; The amount of oil per unit area per unit time in the strip at the atomization edge of the spray coverage area of ​​each nozzle is g, in kg / m². 2 ·s; When the amount of oil per unit area per unit time at a certain position in the nozzle's oil spray coverage area is half of g0, the distance from that position to the jet axis is r0, in meters. By summarizing and organizing the production line data of the oiling process using the volumetric analysis method, the criterion relationship formula for the amount of oil per unit area per unit time is obtained as follows: in: τ: Surface tension of oil under different spray pressures, N / m; d: Cutter beam clearance, m; P: Spray pressure, MPa; A and n are experimental constants; Based on the temperature-viscosity curve of aluminum pre-coating oil for automotive lightweighting, the relationship between the kinematic viscosity of the oil and temperature was obtained by fitting production line data, and expressed by the formula: μ=319.65e -0.037T μ: Kinematic viscosity of the oil, m 2 / s; T: Oil temperature, °C; During the oiling process, when g / g0 approaches 1, meaning the amount of oil per unit area per unit time in the edge region is equal to the amount of oil per unit area per unit time at the axis position, the atomization effect is optimal, achieving a Taylor cone shape; and when the kinematic viscosity of the oil is between 24-33 m... 2 The oil atomization effect is optimal at a speed of / s.

7. The method for improving the uniformity of oil coating in an automotive lightweighting production line according to claim 1, characterized in that: The method optimizes the oil temperature to achieve an oil viscosity range of 24-33 μm. 2 / s, and by adjusting the blade voltage, the geometric shape of the oil in the oil atomization spraying process before leaving the blade nozzle is a Taylor cone shape.

8. The method for improving the uniformity of oil coating in an automotive lightweighting production line according to claim 6, characterized in that: In the method, the blade beam includes an upper blade beam and a lower blade beam of the electrostatic oiling machine. The spray pressure of the electrostatic oiling machine is p = 0.16 MPa, and the blade beam gap is d = 6.10 mm. -5 m, the distance between the upper blade beam and the strip is 0.325m, and the distance between the lower blade beam and the strip is 218mm; the experimental constants A = 4300, n = 1.5; Based on the temperature-viscosity curve of the oil, the optimal process temperature for the oil is determined to be 55-65℃. In the method, the voltage range of the upper blade beam negative electrode is set to 80-85KV, and the voltage range of the lower blade beam positive electrode is set to 75-80KV, so that the geometric shape of the oil in the oil atomization spraying process before leaving the blade beam nozzle is a Taylor cone shape. Let the oil coating uniformity index be defined as an oil volume deviation of ≤15% per unit area per unit time. Oil density at 15℃: 0.87 g / cm³ 3 ; Flash point: ≥220℃; Surface tension of oil at 80KV voltage: 4.07N / m; Viscosity of oil at 65℃: 27.89g / cm³ 3 The calculation method for the optimal process parameters of the oiling process is as follows: The oiling operation of the electrostatic oiler was tested using experimental constants, and the test results were summarized using dimensional analysis to obtain the following formula: in: μ: Kinematic viscosity of the oil, m 2 / s; U: Electric field voltage, kV; τ: Surface tension of oil under different voltages, N / m; Based on the above formula, the suitable temperature and voltage values ​​for Dejie E1 oil are calculated as follows: at a temperature of 62℃, the optimal voltage value for the upper cutter beam is 80-85KV, and the optimal voltage value for the lower cutter beam is 75-80KV.

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