Differential pressure method-based food production line packaging seal detection device and method

Abstract

The application relates to the technical field of food production and packaging, in particular to a food production line packaging and sealing detection device based on a pressure difference method, which comprises a conveying assembly and a packaging bag body. The two side surface pressures in the packaging bag body are fed back by the contact between the rollers and the two side surfaces of the packaging bag body after being pressed, so that it is determined which side is the air leakage side. After the rollers contact the surface of the packaging bag body, the rollers drive the inclined rods to fold inward under the action of the reaction force of the packaging bag body, and the elastic ropes are stretched. If both sides are air leakage, the stretching amounts of the elastic ropes on both sides are the same, the elastic coefficients of the elastic ropes are the same, the pulling forces on the sliding blocks are the same after being enlarged by one time through the movable pulleys, and the pulling forces on both sides of the sliding blocks are the same, so that the sliding blocks remain stationary in the rectangular box. The internal pressure of the side with slight air leakage and the side without air leakage forms a pressure difference.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of food production packaging, in particular to a food production line packaging sealing detection device and method based on differential pressure method. BACKGROUND

[0002] In the food production and processing process, in order to ensure that the packaged food has a long shelf life, it is often necessary to detect the sealing of the packaged food bag. Generally, a food packaging sealing test instrument is used to apply pressure and time to the sample according to the set parameters; during the test, the leakage of the sample is observed.

[0003] Most of the sealing leakage points in the prior art are at the heat-sealed ports on both sides of the sealed packaging bag. The probability of air leakage at the heat-sealed port on the assembly line is generally high due to problems in the heat-sealing process, such as insufficient knife pressure, excessively high or low temperature, etc. Therefore, when air leakage frequently occurs on the same side of the food packaging, the heat-sealing process needs to be corrected in time to avoid low yield.

[0004] When a small amount of air leakage occurs on one side of the food packaging bag, a pressure gradient will occur inside the packaging bag, i.e. the pressure on the air leakage side is lower, and the pressure on the non-air leakage side is higher than that on the air leakage side, thereby causing a pressure difference.

[0005] Some existing food packaging sealing detection devices can only detect the overall air leakage of the packaging. When a small amount of air leakage occurs on one side of the food packaging bag, it is not possible to determine which side of the two sealed ports is the air leakage side, thereby making it inconvenient to perform subsequent error correction procedures and inconvenient to improve the yield. To this end, we propose a food production line packaging sealing detection device and method based on differential pressure method to solve the above problems. SUMMARY

[0006] The purpose of the present application is to provide a food production line packaging sealing detection device and method based on differential pressure method to solve the problems raised in the background.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a food production line packaging sealing detection device based on differential pressure method, comprising a conveying assembly and a packaging bag body, the conveying assembly comprising a first conveying belt, a workbench being arranged on the left side of the first conveying belt, an overall preliminary inspection assembly and a sorting assembly being arranged on the workbench, the overall preliminary inspection assembly comprising a pressure applying mechanism, the pressure applying mechanism comprising two electric push rods, a U-shaped rod being arranged on the top of the electric push rods, an overall pressure feedback mechanism being arranged in the U-shaped rod, a pressure plate being arranged at both ends of the U-shaped rod, a two-side re-inspection assembly being arranged on the right pressure plate for determining the air leakage side of the packaging bag body, the two-side re-inspection assembly comprising a local pressure feedback mechanism and a pressure difference amplification mechanism.

[0008] Further preferably, the local pressure feedback mechanism comprises a horizontal plate arranged on the pressing plate, a horizontal rod slidably connected to the two sides of the horizontal plate, the horizontal rod is fixedly connected to the horizontal plate through an external hexagonal bolt, a diagonal rod is rotatably connected to the outer side end of the horizontal rod, the upper half of the diagonal rod is shorter than the lower half, a U-shaped plate is fixedly connected to the bottom end of the diagonal rod, a rolling distance sensor is embedded in the U-shaped plate and a roller is rotatably connected to the U-shaped plate.

[0009] Further preferably, the pressure difference amplification mechanism comprises a rectangular box fixedly connected to the top of the horizontal plate, a sliding block slidably connected in the rectangular box, a movable pulley arranged on the two sides of the sliding block, an elastic rope wound outside the movable pulley, one end of the elastic rope fixedly connected to the inner wall of the rectangular box, the other end of the elastic rope passing out of the rectangular box and fixedly connected to the top end of the diagonal rod, a rectangular hole arranged on the top of the sliding block, a vertical plate arranged in the rectangular hole, the vertical plate rotatably connected to the top inner wall of the rectangular box, a clamping rod arranged on the two sides of the vertical plate, the clamping rod fixedly connected to the rectangular hole, a hanging block fixedly connected to the bottom of the vertical plate, an angle sensor arranged in the hanging block.

[0010] Further preferably, a limiting mechanism is arranged between the diagonal rod and the horizontal rod, the limiting mechanism comprises two fixed plates fixedly connected to the bottom of the horizontal rod, a limiting rod fixedly connected between the two fixed plates, a moving block slidably connected to the outside of the limiting rod, a connecting rod rotatably connected between the moving block and the diagonal rod, a second spring fixedly connected between the moving block and the fixed plate, the second spring movably sleeved on the outside of the limiting rod.

[0011] Further preferably, the overall pressure feedback mechanism comprises two first cavities and a second cavity arranged in the U-shaped rod, the second cavity is in communication with the first cavity through a connecting pipe, a pressure sensor is arranged in the second cavity, a sliding plate is slidably connected in the first cavity, a rectangular rod is fixedly connected to the bottom of the sliding plate, a counterweight and a top plate are respectively fixedly connected to the top of the pressing plates on the left and right sides, the bottom end of the rectangular rod slidably extends out of the U-shaped rod and is respectively fixedly connected to the counterweight and the top plate, a first spring is fixedly connected between the sliding plate and the bottom inner wall of the U-shaped rod, the first spring is movably sleeved on the outside of the rectangular rod.

[0012] Further preferably, the two-side rechecking assembly moves longitudinally forward and backward through a rechecking driving mechanism, the rechecking driving mechanism comprises a motor fixedly connected to the outside of the top plate, a screw rod fixedly connected to the output shaft end of the motor and extending into the top plate, the screw rod is rotatably connected to the top plate through a bearing, the horizontal plate is threadedly connected to the screw rod, a square rod is fixedly connected between the two inner walls of the top plate, and the horizontal plate is slidably connected to the square rod.

[0013] Further preferably, the sorting assembly comprises a boss and a second conveying belt, the top of the boss is provided with an air cylinder, the movable end of the air cylinder is fixedly connected with a push plate, the second conveying belt is arranged on the right side of the first conveying belt, and a discharging inclined plate is arranged between the second conveying belt and the first conveying belt.

[0014] Further preferably, the bottom end of the electric push rod is fixedly connected to the top of the workbench, the top of the workbench is provided with a standard sample placing groove, the left pressing plate is centrally arranged above the standard sample placing groove, and the right pressing plate is centrally arranged above the first conveying belt.

[0015] A method for detecting food production line packaging sealing based on a differential pressure method, comprising the following steps:

[0016] S1: the packaging bag body with standard sealing performance is centrally placed in the standard sample placing groove, and the first conveying belt is controlled to centrally place the sampling packaging bag body below the right pressing plate;

[0017] S2: the electric push rod drives the pressing plate to move downward through the U-shaped rod, the two pressing plates apply downward pressure to the packaging bag body, the sliding plate moves upward, the pressure in the first cavity and the second cavity increases, and the first spring is stretched;

[0018] S3: when the packaging bag body of the sample to be detected is sealed, the two sliding plates move synchronously, the pressure in the two first cavities increases synchronously, the electric push rod descends by a certain distance, the pressure in the second cavity remains constant, and if the packaging bag body of the sample to be detected leaks, the value of the pressure sensor in the second cavity decreases;

[0019] S4: the motor is started to drive the two rechecking assemblies to move backward, the rollers are in contact with the two sides of the packaging bag body, with continuous slight leakage, the pressure on the leakage side decreases, the reaction force on the rollers decreases, that is, the folding angle between the inclined rod and the horizontal rod increases, the elastic deformation amount of the elastic cord on the leakage side decreases, the sliding block moves in the opposite direction, the clamping rod drives the vertical plate to have an angular deviation, the value of the angle sensor changes, and meanwhile, the fitting force between the packaging bag body and the rollers decreases, that is, the friction force between the rollers and the leakage side of the packaging bag body decreases, the rolling distance of the rollers decreases, and the value of the rolling distance sensor on the leakage side is smaller than that on the non-leakage side;

[0020] S5: whether leakage occurs is determined according to the value change of the pressure sensor, the leakage side is determined according to the values of the rolling distance sensor and the angle sensor, and then the packaging bag body with leakage is pushed to the second conveying belt by the air cylinder to be screened out.

[0021] Compared with the prior art, the method has the advantages that:

[0022] 1. The electric push rod drives the U-shaped rod to move downward, the U-shaped rod drives the pressing plate at both ends to exert downward pressure on the packaging bag body, the packaging bag body is pressed and fixed, the packaging bag body itself has internal pressure, the surface is tight after being pressed, and a counterforce is formed on the pressing plate, after the electric push rod descends by a certain distance, the sliding plate slides upward in the first cavity, the first cavity and the second cavity are connected through the connecting pipe, the pressure in the first cavity and the second cavity is increased and kept stable after the electric push rod stops descending, when the sample to be measured leaks, the pressure in the right packaging bag body gradually decreases, the counterforce becomes smaller, and under the action of the positive pressure of the second cavity, the pressing plate gradually descends, so that whether the packaging bag body leaks as a whole can be confirmed through the value decrease of the pressure sensor in the second cavity, and the degree of leakage can be detected through the value change of the pressure sensor.

[0023] 2. The two side pressures in the packaging bag body are fed back through the contact between the rollers and the two side surfaces of the packaging bag body after being pressed, so that it is judged which side is the leakage side, after the rollers contact the surface of the packaging bag body, the rollers drive the inclined rods to fold inward under the action of the counterforce of the packaging bag body, and the elastic ropes are stretched, if both sides leak, the two elastic ropes are stretched by the same amount, the elastic coefficient of the elastic ropes is the same, the tension on the sliding block is doubled after being enlarged by the movable pulley, and the tension on both sides of the sliding block is the same, so that the sliding block remains stationary in the rectangular box, and the internal pressure of the side with slight leakage is different from that of the side without leakage.

[0024] 3. The packaging bag body is continuously pressed as the electric push rod gradually descends, so that the pressure gradient continuously exists and is enlarged, the pressure on the leakage side is small, the counterforce on the roller is small, the moving block is driven to slide outward on the limiting rod under the resetting action of the second spring, the bottom end of the inclined rod is driven to rotate outward through the connecting rod, that is, the top end of the inclined rod rotates inward, the folding angle between the inclined rod and the horizontal rod becomes larger, the deformation amount of the elastic rope becomes smaller as the top end of the inclined rod rotates inward, the tension on one side of the sliding block becomes smaller, and the tension on the other side of the sliding block still exists, the tension difference is enlarged through the amplification of the movable pulley, the sliding block slides to the side with larger tension, the vertical plate is swung to the side with larger tension through the clamping rod, the clamping rod is arranged on the upper half of the vertical plate, the swinging amplitude of the vertical plate is enlarged, so that the positive and negative values of the angle change can be read through the angle sensor, and right rotation is positive, that is, left leakage, and left rotation is negative, that is, right leakage.

[0025] 4. The adhesion between the leakage side and the roller decreases, so that the friction of the roller decreases, when the rechecking driving mechanism drives the roller to rotate, the rotation distance of the roller on the leakage side is smaller than that on the non-leakage side, so that the difference in the values of the rolling distance sensor can also confirm the leakage side. DRAWINGS

[0026] Figure 1 It is a front perspective structural schematic diagram of the present application;

[0027] Figure 2 It is a back perspective structural schematic diagram of the present application;

[0028] Figure 3 It is a U-shaped rod internal section plane structural schematic diagram of the present application;

[0029] Figure 4 It is a top plate internal section plane structural schematic diagram of the present application;

[0030] Figure 5 It is a partial pressure feedback mechanism and re-inspection internal driving mechanism connection structural schematic diagram of the present application;

[0031] Figure 6 It is a roller position schematic diagram when the packaging bag body left side heat seal port leaks of the present application;

[0032] Figure 7 It is a slider and movable pulley connection three-dimensional structural schematic diagram of the present application;

[0033] Figure 8 It is a rectangular box internal section structural schematic diagram of the present application;

[0034] Figure 9 It is a Figure 4 It is a middle A area enlarged three-dimensional structural schematic diagram.

[0035] In the figure: 1, conveying assembly; 2, overall preliminary inspection assembly; 3, both sides re-inspection assembly; 4, sorting assembly; 5, packaging bag body; 6, standard sample placement groove;

[0036] 11, first conveying belt; 12, workbench;

[0037] 21, pressure applying mechanism; 211, electric push rod; 212, U-shaped rod; 213, pressing plate; 214, rectangular rod; 215, top plate; 216, counterweight; 22, overall pressure feedback mechanism; 221, first cavity; 222, second cavity; 223, connecting pipe; 224, sliding plate; 225, first spring; 226, pressure sensor;

[0038] 31, local pressure feedback mechanism; 311, horizontal plate; 312, horizontal rod; 313, inclined rod; 314, U-shaped plate; 315, roller; 316, rolling distance sensor; 32, pressure difference amplification mechanism; 321, rectangular box; 322, sliding block; 323, rectangular hole; 324, vertical plate; 325, clamping rod; 326, hanging block; 327, angle sensor; 328, movable pulley; 329, elastic rope; 33, limiting mechanism; 331, fixed plate; 332, limiting rod; 333, moving block; 334, connecting rod; 335, second spring; 34, re-inspection driving mechanism; 341, motor; 342, screw rod; 343, square rod;

[0039] 41, boss; 42, air cylinder; 43, push plate; 44, blanking inclined plate; 45, second conveying belt. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0041] EMBODIMENT

[0042] Please refer to Figures 1-9 The present application provides a technical solution: a food production line packaging sealing detection device based on pressure difference method, comprising a conveying assembly 1 and a packaging bag body 5, the conveying assembly 1 comprising a first conveying belt 11, the left side of the first conveying belt 11 being provided with a workbench 12, the workbench 12 being provided with an overall preliminary inspection assembly 2 and a sorting assembly 4, the overall preliminary inspection assembly 2 comprising a pressing mechanism 21, the pressing mechanism 21 comprising two electric push rods 211, the top of the electric push rod 211 being provided with a U-shaped rod 212, the inside of the U-shaped rod 212 being provided with an overall pressure feedback mechanism 22, both ends of the U-shaped rod 212 being provided with a pressure plate 213, the right side of the pressure plate 213 being provided with a two-side re-inspection assembly 3 for determining the air leakage side of the packaging bag body 5, the two-side re-inspection assembly 3 comprising a local pressure feedback mechanism 31 and a pressure difference amplification mechanism 32;

[0043] Under the above arrangement, the U-shaped rod 212 is driven to move downward by the electric push rod 211, the two-end pressing plate 213 is driven by the U-shaped rod 212 to exert downward pressure on the packaging bag body 5, the packaging bag body 5 is pressed and fixed, the packaging bag body 5 itself has internal pressure, the surface is tight after being pressed, and the pressing plate 213 forms a reaction force, the electric push rod 211 is lowered by a certain distance, the sliding plate 224 slides upward in the first cavity 221, the first cavity 221 is connected with the second cavity 222 through the connecting pipe 223, so that the pressure in the first cavity 221 increases and remains stable after the electric push rod 211 stops descending, when the sample to be measured leaks, the pressure in the right packaging bag body 5 gradually decreases, the reaction force becomes smaller, and the pressing plate 213 gradually descends under the action of the positive pressure of the second cavity 222, so that whether the packaging bag body 5 leaks can be confirmed by the decrease of the value of the pressure sensor 226 in the second cavity 222, and the degree of leakage can be detected by the change amount of the value of the pressure sensor 226.

[0044] In this embodiment, specifically: the local pressure feedback mechanism 31 includes a horizontal plate 311, which is arranged on the pressing plate 213, and a horizontal rod 312 is slidably connected to the inside of the horizontal plate 311 on both sides, the horizontal rod 312 is fixedly connected to the horizontal plate 311 through an external hexagonal bolt, a diagonal rod 313 is rotatably connected to the outside end of the horizontal rod 312, the upper half of the diagonal rod 313 is shorter than the lower half, a U-shaped plate 314 is fixedly connected to the bottom end of the diagonal rod 313, a rolling distance sensor 316 is embedded in the U-shaped plate 314 and a roller 315 is rotatably connected to the U-shaped plate 314.

[0045] In this embodiment, specifically: the pressure difference amplification mechanism 32 includes a rectangular box 321, which is fixedly connected to the top of the horizontal plate 311, a sliding block 322 is slidably connected in the rectangular box 321, a movable pulley 328 is arranged on both sides of the sliding block 322, an elastic rope 329 is wound outside the movable pulley 328, one end of the elastic rope 329 is fixedly connected to the inner wall of the rectangular box 321, the other end is arranged out of the rectangular box 321 and is fixedly connected to the top end of the diagonal rod 313, a rectangular hole 323 is formed in the top of the sliding block 322, a vertical plate 324 is arranged in the rectangular hole 323, the vertical plate 324 is rotatably connected to the inner wall of the top of the rectangular box 321, a clamping rod 325 is arranged on both sides of the vertical plate 324, the clamping rod 325 is fixedly connected to the rectangular hole 323, a hanging block 326 is fixedly connected to the bottom of the vertical plate 324, and an angle sensor 327 is arranged in the inside of the hanging block 326.

[0046] Under the above settings, the two-side pressure feedback in the packaging bag body 5 is realized by the contact of the roller 315 with the two sides of the packaging bag body 5 after being pressed, so as to determine which side is the air leakage side. After the surface of the roller 315 contacts the packaging bag body 5, the roller 315 drives the inclined rod 313 to fold inward under the action of the reaction force of the packaging bag body 5. If both sides are air leakage, the two elastic ropes 329 are stretched by the same amount, the elastic coefficient of the elastic rope 329 is the same, the tension on the sliding block 322 is doubled after being enlarged by the movable pulley 328, and the tension on both sides of the sliding block 322 is the same, so that the sliding block 322 remains stationary in the rectangular box 321. The internal pressure of the side with slight air leakage is different from that of the side without air leakage. As the electric push rod 211 gradually descends to continuously press the packaging bag body 5, the pressure gradient is continuously present and enlarged. The pressure on the air leakage side is small, the reaction force on the roller 315 is small, and the moving block 333 is driven to slide outward on the limiting rod 332 under the restoring action of the second spring 335. The inclined rod 313 is driven to rotate outward at the bottom end through the connecting rod 334, that is, the top end of the inclined rod 313 rotates inward, the folding angle between the inclined rod 313 and the horizontal rod 312 increases, the deformation amount of the elastic rope 329 decreases, the tension on one side of the sliding block 322 decreases, and the tension on the other side of the sliding block 322 still exists. After being enlarged by the movable pulley 328, the tension difference is enlarged, the sliding block 322 slides to the side with larger tension, the vertical plate 324 is swung to the side with larger tension through the clamping rod 325, the clamping rod 325 is arranged on the upper half of the vertical plate 324, the swinging range of the vertical plate 324 is enlarged, and thus the positive and negative values of the angle change can be read by the angle sensor 327. The right rotation is positive, that is, the left side leaks air, and the left rotation is negative, that is, the right side leaks air.

[0047] At the same time, the adhesion between the air leakage side and the roller 315 decreases, the friction of the roller 315 decreases, and when the re-examination driving mechanism 34 drives the roller 315 to rotate, the rotation distance of the roller 315 on the air leakage side is smaller than that on the non-air leakage side, so that the value difference of the rolling distance sensor 316 can also confirm the air leakage side.

[0048] In the embodiment, specifically, a limiting mechanism 33 is arranged between the inclined rod 313 and the horizontal rod 312. The limiting mechanism 33 includes two fixed plates 331 fixedly connected to the bottom of the horizontal rod 312, a limiting rod 332 fixedly connected between the two fixed plates 331, a moving block 333 slidingly connected to the outside of the limiting rod 332, a connecting rod 334 rotatably connected between the moving block 333 and the inclined rod 313 through a hinge, a second spring 335 fixedly connected between the moving block 333 and the fixed plate 331, and the second spring 335 movably sleeved on the outside of the limiting rod 332.

[0049] It needs to be further explained that the extension amount of the two lateral horizontal rods 312 in the horizontal plate 311 can be adjusted synchronously through the external hexagonal bolts, so that the packaging bag body 5 of different sizes can be applied, the longer the extension amount of the horizontal rod 312 is, the greater the deformation amount of the elastic rope 329 is, the greater the pulling force generated after the elastic rope 329 is elongated is, the greater the pulling force difference formed by the two sides of the sliding block 322 is, and the more obvious the detection effect is;

[0050] In the embodiment, specifically: the overall pressure feedback mechanism 22 includes two first cavities 221 and a second cavity 222 arranged in the U-shaped rod 212, the second cavity 222 is communicated with the first cavity 221 through a connecting pipe 223, the second cavity 222 is provided with a pressure sensor 226, the first cavity 221 is slidably connected with a sliding plate 224, the bottom of the sliding plate 224 is fixedly connected with a rectangular rod 214, the top of the left and right two pressing plates 213 is fixedly connected with a counterweight 216 and a top plate 215 respectively, the bottom end of the rectangular rod 214 extends to the outside of the U-shaped rod 212 and is fixedly connected with the counterweight 216 and the top plate 215 respectively, a first spring 225 is fixedly connected between the sliding plate 224 and the inner wall of the bottom of the U-shaped rod 212, and the first spring 225 is movably sleeved outside the rectangular rod 214;

[0051] In the embodiment, specifically: the two sides of the rechecking assembly 3 are moved longitudinally forward and backward through the rechecking driving mechanism 34, the rechecking driving mechanism 34 includes a motor 341, the motor 341 is fixedly connected outside the top plate 215, the output shaft end of the motor 341 extends into the top plate 215 and is fixedly connected with a screw rod 342, the screw rod 342 is rotatably connected with the output shaft of the motor 341 through bearings and the top plate 215, the horizontal plate 311 is threadedly connected with the screw rod 342, the two inner walls of the top plate 215 are fixedly connected with a square rod 343, and the horizontal plate 311 is slidably connected with the square rod 343;

[0052] In the embodiment, specifically: the sorting assembly 4 includes a boss 41 and a second conveying belt 45, the top of the boss 41 is provided with an air cylinder 42, the movable end of the air cylinder 42 is fixedly connected with a push plate 43, the second conveying belt 45 is arranged on the right side of the first conveying belt 11, and a discharging inclined plate 44 is arranged between the second conveying belt 45 and the first conveying belt 11;

[0053] In the embodiment, specifically: the bottom end of the electric push rod 211 is fixedly connected to the top of the workbench 12, the top of the workbench 12 is provided with a standard sample placing groove 6, and the left pressing plate 213 is centrally arranged above the standard sample placing groove 6, and the right pressing plate 213 is centrally arranged above the first conveying belt 11;

[0054] It needs to be further explained that the model of the pressure sensor is PTL407; the model of the angle sensor is TSO-D24; and the model of the rolling distance sensor is KDM-8000;

[0055] A method for detecting the sealing of a food production line package based on a differential pressure method, comprising the following steps:

[0056] S1: The package body 5 with standard sealing performance is placed in the standard sample placement groove 6, and the first conveying belt 11 is controlled to place the sampled package body 5 in the right side of the pressing plate 213;

[0057] S2: The electric push rod 211 drives the pressing plate 213 to move downward through the U-shaped rod 212, and the two side pressing plates 213 apply downward pressure to the package body 5, the sliding plate 224 moves upward, the pressure in the first cavity 221 and the second cavity 222 increases, and the first spring 225 is stretched;

[0058] S3: When the package body 5 of the sample to be detected is sealed, the two side sliding plates 224 move synchronously, the pressure in the two first cavities 221 increases synchronously, the electric push rod 211 descends by a certain distance, the pressure in the second cavity 222 remains constant, and if the package body 5 of the sample to be detected leaks, the value of the pressure sensor 226 in the second cavity 222 decreases;

[0059] S4: The motor 341 is started to drive the two side rechecking assemblies 3 to move backward, the rollers 315 contact the two sides of the package body 5, as the continuous slight leakage, the pressure on the leakage side decreases, the reaction force on the rollers 315 decreases, i.e. the folding angle between the inclined rod 313 and the horizontal rod 312 increases, the elastic deformation amount of the elastic cord 329 on the leakage side decreases, the sliding block 322 moves in the opposite direction, the clamping rod 325 drives the vertical plate 324 to have an angular deviation, the angular sensor 327 has a value change, and at the same time, the adhesion between the package body 5 and the rollers 315 decreases, i.e. the friction between the rollers 315 and the leakage side of the package body 5 decreases, the rolling distance of the rollers 315 decreases, and the rolling distance sensor 316 has a smaller value than the non-leakage side;

[0060] S5: Whether there is leakage is determined by the value change of the pressure sensor 226, the leakage side is determined by the values of the rolling distance sensor 316 and the angular sensor 327, and then the package body 5 with leakage is pushed to the second conveying belt 45 by the air cylinder 42 for screening.

[0061] Although embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for detecting the sealing of a package in a food production line based on the differential pressure method, comprising a conveying assembly (1) and a package body (5), characterized in that: The conveying assembly (1) comprises a first conveying belt (11), a workbench (12) is arranged on the left side of the first conveying belt (11), a whole preliminary inspection assembly (2) and a sorting assembly (4) are arranged on the workbench (12), the whole preliminary inspection assembly (2) comprises a pressing mechanism (21), the pressing mechanism (21) comprises two electric push rods (211), the top of the electric push rod (211) is provided with a U-shaped rod (212), the inside of the U-shaped rod (212) is provided with a whole pressure feedback mechanism (22), the two ends of the U-shaped rod (212) are provided with pressing plates (213), the right pressing plate (213) is provided with a two-side reinspection assembly (3), which is used for determining the air leakage side of the packaging bag body (5), and the two-side reinspection assembly (3) comprises a local pressure feedback mechanism (31) and a pressure difference amplification mechanism (32).

2. The differential pressure method based food production line package seal detection apparatus according to claim 1, characterized in that: The local pressure feedback mechanism (31) comprises a horizontal plate (311), the horizontal plate (311) is arranged on the pressing plate (213), the inside of the horizontal plate (311) is slidably connected with a horizontal rod (312), the horizontal rod (312) is fixedly connected with the horizontal plate (311) through an external hexagonal bolt, the outer side end of the horizontal rod (312) is rotatably connected with an inclined rod (313), the upper half of the inclined rod (313) is shorter than the lower half, the bottom end of the inclined rod (313) is fixedly connected with a U-shaped plate (314), the U-shaped plate (314) is embedded with a rolling distance sensor (316) and rotatably connected with a roller (315).

3. The differential pressure method based food production line package seal detection apparatus according to claim 2, characterized in that: The pressure difference amplification mechanism (32) comprises a rectangular box (321), the rectangular box (321) is fixedly connected with the top of the horizontal plate (311), the rectangular box (321) is slidably connected with a sliding block (322), the two sides of the sliding block (322) are provided with a movable pulley (328), the movable pulley (328) is provided with an elastic rope (329) outside, one end of the elastic rope (329) is fixedly connected with the inner wall of the rectangular box (321), the other end is arranged out of the rectangular box (321) and is fixedly connected with the top end of the inclined rod (313), the top of the sliding block (322) is provided with a rectangular hole (323), the rectangular hole (323) is provided with a vertical plate (324), the vertical plate (324) is rotatably connected with the top inner wall of the rectangular box (321), the two sides of the vertical plate (324) are provided with clamping rods (325), the clamping rods (325) are fixedly connected with the rectangular hole (323), the bottom of the vertical plate (324) is fixedly connected with a hanging block (326), the inside of the hanging block (326) is provided with an angle sensor (327).

4. The differential pressure method based food production line package seal detection apparatus according to claim 3, characterized in that: The limiting mechanism (33) is arranged between the inclined rod (313) and the cross rod (312), and comprises two fixed plates (331) fixedly connected at the bottom of the cross rod (312), a limiting rod (332) fixedly connected between the two fixed plates (331), a moving block (333) slidingly connected to the outer side of the limiting rod (332), a connecting rod (334) rotatably connected between the moving block (333) and the inclined rod (313), and a second spring (335) fixedly connected between the moving block (333) and the fixed plate (331) and movably sleeved on the outer side of the limiting rod (332).

5. The differential pressure method based packaging seal detection apparatus for food production lines according to claim 4, characterized in that: The overall pressure feedback mechanism (22) comprises two first cavities (221) and a second cavity (222) arranged in the U-shaped rod (212), the second cavity (222) is in communication with the first cavity (221) through a connecting pipe (223), the second cavity (222) is provided with a pressure sensor (226), the first cavity (221) is slidingly connected with a sliding plate (224), the bottom of the sliding plate (224) is fixedly connected with a rectangular rod (214), the top of the left and right two side pressing plates (213) is fixedly connected with a counterweight (216) and a top plate (215) respectively, the bottom end of the rectangular rod (214) slidingly extends out of the U-shaped rod (212) and is fixedly connected with the counterweight (216) and the top plate (215) respectively, a first spring (225) is fixedly connected between the sliding plate (224) and the bottom inner wall of the U-shaped rod (212), and the first spring (225) is movably sleeved on the outer side of the rectangular rod (214).

6. The differential pressure method based packaging seal detection apparatus for food production lines according to claim 5, characterized in that: The two-side rechecking assembly (3) moves longitudinally forward and backward through the rechecking driving mechanism (34), the rechecking driving mechanism (34) comprises a motor (341) fixedly connected to the outer side of the top plate (215), the output shaft end of the motor (341) extends into the top plate (215) and is fixedly connected with a screw rod (342), the screw rod (342) is rotatably connected with the output shaft of the motor (341) and the top plate (215) through a bearing, the cross plate (311) is threadedly connected with the screw rod (342), and square rods (343) are fixedly connected between the two side inner walls of the top plate (215), and the cross plate (311) is slidingly connected with the square rods (343).

7. The differential pressure method based packaging seal detection apparatus for food production lines according to claim 6, characterized in that: The sorting assembly (4) comprises a boss (41) and a second conveying belt (45), the top of the boss (41) is provided with an air cylinder (42), the movable end of the air cylinder (42) is fixedly connected with a push plate (43), the second conveying belt (45) is arranged on the right side of the first conveying belt (11), and a discharging inclined plate (44) is arranged between the second conveying belt (45) and the first conveying belt (11).

8. The differential pressure method based food production line package seal detection apparatus according to claim 7, characterized in that: The bottom end of the electric push rod (211) is fixedly connected to the top of the workbench (12), the top of the workbench (12) is provided with a standard sample placing groove (6), the left pressing plate (213) is centrally arranged above the standard sample placing groove (6), and the right pressing plate (213) is centrally arranged above the first conveying belt (11).

9. A method of detecting a package seal of a food production line based on a pressure difference method, using the package seal detecting apparatus for a food production line based on a pressure difference method according to claim 8, characterized by, The method comprises the following steps: S1: The packaging bag body (5) with standard sealing performance is placed in the standard sample placing groove (6), and the first conveying belt (11) is controlled to place the sampling packaging bag body (5) in the right pressing plate (213) below; S2: The electric push rod (211) drives the pressing plate (213) to move downward through the U-shaped rod (212), and the two pressing plates (213) apply downward pressure to the packaging bag body (5); the sliding plate (224) moves upward, the pressure in the first cavity (221) and the second cavity (222) increases, and the first spring (225) is stretched; S3: When the packaging bag body (5) of the sample to be detected is sealed, the two sliding plates (224) move synchronously, the pressure in the two first cavities (221) increases synchronously, the electric push rod (211) descends by a certain distance, the pressure in the second cavity (222) remains constant, and if the packaging bag body (5) of the sample to be detected leaks, the value of the pressure sensor (226) in the second cavity (222) decreases; S4: Start the motor (341) to drive the two rechecking assemblies (3) to move backward, the rollers (315) contact the two sides of the packaging bag body (5), and as the continuous slight leakage, the pressure on the leakage side decreases, the reaction force on the roller (315) decreases, that is, the folding angle between the inclined rod (313) and the horizontal rod (312) increases, the elastic deformation of the elastic rope (329) on the leakage side decreases, the sliding block (322) moves in the opposite direction, the clamping rod (325) drives the vertical plate (324) to have an angle offset, the angle sensor (327) changes in value, and at the same time, the contact force between the packaging bag body (5) and the roller (315) decreases, that is, the friction between the roller (315) and the leakage side of the packaging bag body (5) decreases, the rolling distance of the roller (315) decreases, and the rolling distance sensor (316) has a smaller value than the non-leakage side; S5: Determine whether there is leakage through the value change of the pressure sensor (226), determine the leakage side through the values of the rolling distance sensor (316) and the angle sensor (327), and then push the packaging bag body (5) with leakage to the second conveying belt (45) through the air cylinder (42) for screening.

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