CN113843994B

CN113843994B - Intelligent injection molding machine control system and method based on gram weight of injection molding product

Info

Publication number: CN113843994B
Application number: CN202110967931.9A
Authority: CN
Inventors: 李君�; 李素君; 林娅丹; 张�雄; 张贤宝; 葛先钗; 施王宵
Original assignee: Sino Holdings Group Co ltd
Current assignee: Sino Holdings Group Co ltd
Priority date: 2021-08-23
Filing date: 2021-08-23
Publication date: 2023-05-26
Anticipated expiration: 2041-08-23
Also published as: CN113843994A

Abstract

The invention discloses an intelligent injection molding machine control system based on gram weight of an injection molding product, which comprises a manipulator, wherein the manipulator is provided with a piece taking module, and a plurality of piece taking measuring units are arranged on the piece taking module and are used for fixing and measuring gravity of the piece taking of the injection molding product; the manipulator is connected with the conveying module, and the conveying module is used for screening injection molding products according to the gram weights of the injection molding products calculated through measurement and conveying the injection molding products. The invention also discloses an intelligent injection molding machine control method based on the gram weight of the injection molding product, which comprises the following steps: the related data of the idle load and the standard component are called; taking and measuring data of the injection molding part; calculating and detecting data; and (5) screening and conveying injection molding parts. According to the invention, the gravity sensor and the force sensor are directly combined on the manipulator, so that the manipulator can finish the gram weight detection of the injection molding part in the process of transferring the injection molding part from the mold to the conveying device, the time for independently carrying out the gram weight detection is saved, and the working efficiency is improved.

Description

Intelligent injection molding machine control system and method based on gram weight of injection molding product

Technical Field

The invention relates to the field of injection molding machines, in particular to an intelligent injection molding machine control system and method based on gram weight of injection molding products.

Background

Plastic products are mainly produced by injection molding processes, and injection molding machines are the main production equipment. A typical injection molding process includes the following six steps: and (3) die assembly, injection, pressure maintaining, cooling, die opening and ejection, wherein after ejection, a manipulator grabs an injection molding product and places the injection molding product on a conveyor belt to be conveyed to a specified position. In the injection molding process, products after injection molding are not identical due to various burst factors and random conditions, and the main difference is that the weight of the injection molded products is not identical due to different distribution densities of raw materials or the weight of the products is different due to other factors such as bubbles in the products, so that weight detection is needed to distinguish whether the products are qualified. The traditional weight detection is manual spot check detection, weigh one by one, and this kind of manual spot check can satisfy certain detection requirement, but manual detection is efficient, and the cost of labor is high, and troublesome operation is inconvenient, easily leaks error detection false detection.

An on-line weighing device disclosed in Chinese patent literature has a publication number of CN112577577A and a publication date of 2021-03-30, and comprises a body, a supporting mechanism, a weighing sensor and a controller. The supporting mechanism is used for supporting the product to be detected and is arranged above the body; the weighing sensor is connected with the supporting mechanism and is used for weighing the weight of the product to be detected supported by the supporting mechanism and generating a weight signal; the controller is located in the body and is electrically connected with the weighing sensor, and the controller is used for generating weight data according to the weight signal of the weighing sensor and storing the weight data. The on-line weighing device can realize automatic weighing of products, saves labor cost and improves production efficiency. However, the online weighing device is an independent weighing tool, and a manipulator is required to weigh the removed injection molding part on the device, and then the injection molding part is placed at different positions according to the weight condition, so that a large improvement space is still provided.

Disclosure of Invention

The invention provides an intelligent injection molding machine control system and method based on the gram weight of an injection molding product, which overcome the defect that in the prior art, an independent measuring tool is needed for measuring the gram weight of the injection molding product, so that the step of transferring to the measuring tool and then transferring to the conveying belt is needed to be added in the process of grabbing the injection molding product by a manipulator and transferring to the conveying belt, and the gram weight detection of the injection molding product is finished in the process of transferring the injection molding product from a mold to the conveying module by the manipulator by directly combining a gravity sensor and a force sensor on the manipulator, so that the time for independently carrying out the gram weight detection is saved, and the working efficiency is improved.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

the intelligent injection molding machine control system based on the gram weight of the injection molding product comprises a manipulator, wherein the manipulator is provided with a piece taking module, a plurality of piece taking measuring units are arranged on the piece taking module, and the piece taking measuring units are used for fixing and measuring the weight of the piece taking of the injection molding product; the manipulator is connected with the conveying module, and the conveying module is used for screening injection molding products according to the gram weights of the injection molding products calculated through measurement and conveying the injection molding products.

According to the invention, the number of the workpiece taking measuring units in the workpiece taking module arranged on the manipulator corresponds to the number and the positions of products which can be produced by injection molding in the injection molding machine die at one time, the workpiece taking measuring units can grasp and fix injection molding, and the injection molding is placed at a designated position on the conveying module along with the movement of the manipulator. In this process, the side of the picking module provided with the picking measuring unit is oriented horizontally, facing the product in the mould, while the side of the picking module provided with the picking measuring unit is facing vertically downwards, facing the transfer module, when the product is placed on the transfer module. In the whole process, the pick-up module has a ninety-degree rotation process, and the actual gram weight of the injection molding and other information related to the injection molding are analyzed and obtained according to the force change in the whole process detected by the gravity sensor and the limit force sensor which are arranged on the pick-up measuring unit.

Preferably, the manipulator includes a piece taking module and a positioning module connected with the piece taking module, and the positioning module includes: the rotating unit is fixedly connected with the picking module and used for driving the picking module to rotate; the vertical sliding unit is used for determining the position of the pick-up module in the vertical direction through up-and-down sliding; and the horizontal sliding unit is used for determining the position of the pick-up module in the horizontal direction through sliding in the horizontal direction. The positioning module is used for adjusting the space position of the workpiece taking module, so that the workpiece taking module cannot touch the injection molding machine body in the whole process of grabbing injection molding between the moving die and the fixed die.

Preferably, the workpiece taking measurement unit comprises a connecting rod, one end of the connecting rod is fixed on the workpiece taking measurement unit through a rotating device, and the other end of the connecting rod is fixedly connected with the injection molding fixing device; the connecting rod is sleeved with a limiting ring fixed on the workpiece taking measuring unit, the cross section of the limiting ring is in a semicircular arc shape, and the arc-shaped vertex is tangent with the surface of the connecting rod. The limiting ring is provided with a limiting force sensor, and the rotating device is provided with a gravity sensor.

In the workpiece taking measuring unit, the connecting rod is rigid, the limiting ring sleeved on the connecting rod is used for limiting the radial position change of the connecting rod, after the injection molding workpiece is grabbed and fixed on the injection molding workpiece fixing device, the connecting rod has a radial movement trend due to the moment generated by gravity, but the moment generated by acting force with a certain magnitude is arranged between the connecting rod and the limiting ring to balance the moment generated by gravity due to the limitation of the limiting ring. Because the cross section of the limiting ring is in a semicircular arc shape, the vertex of the arc is tangent to the surface of the connecting rod, acting force can be concentrated on one point, and the measuring accuracy of the limiting force sensor is improved. And when the connecting rod is axially vertical, the total gravity can be measured by using a gravity sensor to indirectly calculate the gram weight of the injection molding piece.

Preferably, the conveying module is provided with a plurality of lifting devices which are the same as the picking measuring units on the picking module in number and corresponding to the picking measuring units in position, and the lifting devices lift according to the gram weights of placed injection molding products and stay at positions with different heights.

Preferably, the conveying module comprises a top layer platform, a first layer platform, a second layer platform and a bottom layer platform which are spaced at the same height; the first layer of platform is connected with a layer of conveyor belt; the two-layer platform is connected with a two-layer conveyor belt; the bottom layer platform is connected with a bottom layer conveying belt.

The conveying module is divided into four layers, the injection molding pieces are transferred by the manipulator and then are firstly placed on the top-layer platform, the lifting devices on the top-layer platform correspond to the injection molding pieces one by one, and the lifting devices are also provided with force sensors. When the gram weight of the injection molding part is within a preset qualified gram weight range, the lifting device is lowered to a two-layer platform, and the qualified injection molding part is conveyed through a two-layer conveying belt; when the gram weight of the injection molding part is smaller than a preset qualified gram weight range, the lifting device is lowered to a layer of platform, and the injection molding part is conveyed by a layer of conveyor belt; when the gram weight of the injection molding part is greater than a preset qualified gram weight range, the injection molding part is lowered to a bottom layer platform and is conveyed by a bottom layer conveying belt.

An intelligent injection molding machine control method based on gram weight of an injection molding product comprises the following steps:

s1, a database is called, and intrinsic data of each force sensor in the no-load moving process of the manipulator and standard data of each force sensor in the moving process of the manipulator grabbing fixed standard parts are called when initial setting is carried out;

s2, taking and measuring, namely after the injection molding machine is used for injection molding of the product, the measuring manipulator is used for grabbing and fixing the injection molding piece to move and placing the injection molding piece into the measuring data of each force sensor in the process of the transmission module;

s3, calculating and detecting, namely calculating gram weight of the injection molding piece by combining the measurement data, the standard data and the inherent data, and detecting and analyzing gravity center deviation condition and uniformity of material distribution of the injection molding piece;

s4, screening and conveying, wherein after the injection molding is placed on the conveying module, the conveying module screens according to the gram weight condition of the injection molding, and the injection molding is placed on different conveying belts for conveying.

Preferably, the intrinsic data includes intrinsic gravity G measured by a gravity sensor at no load ₀ And the force variation F measured by the limit force sensor ₀ (θ) and inherent moment arm L ₀ The method comprises the steps of carrying out a first treatment on the surface of the The standard data comprises standard gram weight m ₀ Gravity G obtained in the same way after the manipulator grabs and fixes the standard part ₁ And force variation F ₁ (θ), and a standard weight measurement G calculated from the above data _{Label (C)} ＝G ₁ -G ₀ Moment arm distance L from its center of gravity when the standard is fixed _{Label (C)} 。

Preferably, the measurement data includes a gravity value G measured by a gravity sensor after the manipulator grabs and fixes the injection molding ₂ Change F of force measured by limit force sensor ₂ (theta) and the rotation process of the injection molding part along with the connecting rod at the angular speed omega when the connecting rod is in a vertical stateMeasurement f of a central limit force sensor _ω 。

Preferably, the injection-molded part has a gram weight m _Measuring ＝G _Measuring /g＝(G ₂ -G ₀ ) Force arm distance L of gravity center of injection molding part _Measuring ＝F _Measuring (θ)·L ₀ /m _Measuring ＝(F ₂ (θ)-F ₀ (θ))·L ₀ /m _Measuring The offset distance r of the gravity center of the injection molding part relative to the standard part meets the equation f _ω ·L ₀ ＝m _Measuring ·ω ² ·r·L _Measuring 。

The invention has the following beneficial effects: the gravity sensor and the force sensor are directly combined on the manipulator, so that the manipulator can finish the gram weight detection of the injection molding piece in the process of transferring the injection molding piece from the mold to the conveying module, the time for independently carrying out the gram weight detection is saved, and the working efficiency is improved; the gravity center offset position of the injection molding piece can be calculated through the change of the force detected by each force sensor on the piece taking measuring unit in the transfer process of the injection molding piece, and whether the gravity center position of the injection molding piece is qualified or not can be detected while the gram weight is detected; the material distribution uniformity of the injection molding piece or the difference between the material distribution uniformity of the injection molding piece and the material distribution of the standard piece can be obtained by analyzing and comparing the data collected by each force sensor during the transfer of the injection molding piece with the data collected by each force sensor during the transfer of the standard piece, the angle of the injection molding piece can be measured and detected by the data, and the product qualification rate is improved.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic view of a pick-up measurement unit of the present invention;

FIG. 3 is a rotational schematic view of a pick-up module according to the present invention;

FIG. 4 is a schematic view of a rotation of an injection molding in an embodiment of the invention;

in the figure: 1. a manipulator; 2. a transfer module; 11. a pick-up module; 110. a pick-up measuring unit; 111. a limiting ring; 112. a connecting rod; 113. a rotating device; 114. an injection molding piece fixing device; 115. a limit force sensor; 116. a gravity sensor; 117; an injection molding piece to be tested; 1171. the gravity center of the injection molding part; 12. a first rotating lever; 13. a rotating block; 14. a second rotating lever; 15. a vertical sliding block; 16. a slide bar; 17. a horizontal sliding block; 21. a sliding groove; 22. a top layer platform; 221. a lifting device; 23. a layer of platform; 231. a layer of conveyor belt; 24. a two-layer platform; 241. a two-layer conveyor belt; 25. a bottom layer platform; 251. a bottom conveyor belt.

Detailed Description

The invention is further described below with reference to the drawings and detailed description.

As shown in fig. 1, an intelligent injection molding machine control system based on gram weight of an injection molding product comprises a manipulator 1, wherein the manipulator 1 is provided with a piece taking module 11, the piece taking module 11 is provided with a plurality of piece taking measuring units 110, and the piece taking measuring units 110 are used for fixing and measuring gravity of the piece taking of the injection molding product; the manipulator 1 is connected with a conveying module 2, and the conveying module 2 is used for screening injection molding products according to the gram weights of the injection molding products calculated through measurement and conveying.

The manipulator 1 includes getting a module 11 and with get a module connected's positioning module, positioning module includes: the rotating unit is fixedly connected with the picking module and used for driving the picking module to rotate; the vertical sliding unit is used for determining the position of the pick-up module in the vertical direction through vertical sliding; and the horizontal sliding unit is used for determining the position of the pick-up module in the horizontal direction through sliding in the horizontal direction. The positioning module is used for adjusting the space position of the workpiece taking module, so that the workpiece taking module cannot touch the injection molding machine body in the whole process of grabbing injection molding between the moving die and the fixed die.

As shown in fig. 2, the pick-up measuring unit 110 includes a connecting rod 112, one end of which is fixed to the pick-up measuring unit by a rotating device 113, and the other end of which is fixedly connected to an injection molding fixing device 114; the connecting rod is sleeved with a limiting ring 111 fixed on the workpiece taking measuring unit, the cross section of the limiting ring is in a semicircular arc shape, and the vertex of the arc shape is tangent with the surface of the connecting rod. The limiting ring is provided with a limiting force sensor 115, and the rotating device is provided with a gravity sensor 116.

The conveying module 2 is provided with a plurality of lifting devices 221 which are the same in number and corresponding to the picking measurement units on the picking module in position, and the lifting devices lift according to the gram weights of placed injection molding products and stay at positions at different heights.

The conveying module comprises a top layer platform 22, a first layer platform 23, a second layer platform 24 and a bottom layer platform 25 which are spaced at the same height; one layer of platform is connected with one layer of conveyor belt 231; the two-layer platform is connected with a two-layer conveyor belt 241; the bottom stage is connected to a bottom conveyor 251.

The intrinsic data comprises intrinsic gravity G measured by a gravity sensor at no load ₀ And the force variation F measured by the limit force sensor ₀ (θ) and inherent moment arm L ₀ The method comprises the steps of carrying out a first treatment on the surface of the The standard data includes standard gram weight m ₀ Gravity G obtained in the same way after the manipulator grabs and fixes the standard part ₁ And force variation F ₁ (θ), and a standard weight measurement G calculated from the above data _{Label (C)} ＝G ₁ -G ₀ Moment arm distance L from its center of gravity when the standard is fixed _{Label (C)} 。

The measurement data comprise a gravity value G measured by a gravity sensor after the manipulator grabs and fixes the injection molding piece ₂ Change F of force measured by limit force sensor ₂ (theta) and the measured value f of the limit force sensor in the process that the injection molding part rotates along with the connecting rod at the angular speed omega when the connecting rod is in a vertical state _ω 。

Gram weight m of injection molded part _Measuring ＝G _Measuring /g＝(G ₂ -G ₀ ) Force arm distance L of gravity center of injection molding piece _Measuring ＝F _Measuring (θ)·L ₀ /m _Measuring ＝(F ₂ (θ)-F ₀ (θ))·L ₀ /m _Measuring The offset distance r of the gravity center of the injection molding part relative to the standard part meets the equation f _ω ·L ₀ ＝m _Measuring ·ω ² ·r·L _Measuring 。

As shown in fig. 1, in the embodiment of the present invention, the manipulator 1 includes a pick-up module 11, and two rows and two columns of four pick-up measurement units 110 are uniformly disposed on the pick-up module 11. The pick-up module 11 is fixedly connected with the first rotating rod 12, the first rotating rod 12 passes through a through hole on the rotating block 13 and is connected with the rotating block 13, and the first rotating rod 12 can rotate in the through hole. The rotating block 13 is fixedly connected with a second rotating rod 14, the second rotating rod 14 is connected with a vertical sliding block 15, and the second rotating rod 14 can rotate around a central shaft of the second rotating rod. The sliding rod 16 is slidably connected with the vertical sliding block 15 through a through hole in the center of the vertical sliding block 15, and the sliding rod 16 is fixed on the horizontal sliding block 17.

As shown in fig. 2, all the pick-up measuring units 110 on the pick-up module 11 have the same structural function, and one pick-up measuring unit 110 includes a connecting rod 112, one end of the connecting rod 112 is fixed on the pick-up measuring unit 110 by a rotating device 113, and the other end of the connecting rod 112 is fixedly connected with an injection molding fixing device 114. The workpiece taking measuring unit 110 is provided with a limiting ring 111, the limiting ring 111 is sleeved on the connecting rod 112, the cross section of the limiting ring 111 is in a semicircular arc shape, and the vertex of the arc shape is tangent with the surface of the connecting rod 112. A limit force sensor 115 is provided on the limit ring 111 for measuring the acting force between the connecting rod 112 and the limit ring 111, and a gravity sensor 116 is provided on the rotating device 113 for measuring the tensile force at the connection of the connecting rod 112 and the rotating device 113 when the connecting rod 112 is in a vertical state.

The manipulator 1 is connected with the transmission module 2 through the sliding connection of the horizontal sliding block 17 and the sliding groove 21, and the whole manipulator 1 is driven to move on the transmission module 2 through the interaction of the horizontal sliding block 17 on the sliding groove 21. The entire transfer module 2 is divided into four layers including a top layer 22, a first layer 23, a second layer 24 and a bottom layer 25. Four lifting devices 221 corresponding to the four pick-and-place measuring units 110 on the pick-and-place module 11 are uniformly arranged on the top platform 22. The structure and function of each lifting device 221 are the same, and the lifting device 221 can lift up and down between four layers of platforms and can stay on the top layer platform 22, the first layer platform 23, the second layer platform 24 or the bottom layer platform 25 as required. A layer of conveyor belt 231 connected with the layer of platform 23 is arranged at the same height of the layer of platform 23, and can convey injection molding pieces on the layer of platform 23; the two-layer conveying belt 241 connected with the two-layer platform 24 is arranged at the same height of the two-layer platform 24, so that injection molding pieces on the two-layer platform 24 can be conveyed; the bottom layer conveying belt 251 connected with the bottom layer platform 25 is arranged at the same height of the bottom layer platform 25, and can convey injection molding pieces on the bottom layer platform 25. A force sensor is also provided in the lifting device 221 for measuring the weight of the finished injection molded part placed on the lifting device 221.

The specific operation process of the invention is as follows:

the initialization is needed before the first use, and the whole process of taking the injection molding, detecting by a force sensor, placing the injection molding and the like is not needed to be set in no-load mode. The detected force changes throughout the course of the respective force sensor when empty are measured and recorded as intrinsic data. As shown in fig. 3, the position of each component of the pick-up module 11 when the injection molding is just removed is simulated, the side of the pick-up module 11 provided with the pick-up measuring unit 110 is horizontally oriented, the connecting rod 112 is axially horizontal at this time, and the force F between the connecting rod 112 and the stop collar 111 is detected by the stop force sensor 115 ₀ Stress point toDistance L of rotating device 113 ₀ Then the moment F can be obtained ₀ ·L ₀ The magnitude represents the inherent gravity G of the connecting rod 112 and the injection molding fixture 114 in the pick-and-place measuring unit 110 at this time ₀ The moment M generated ₀ . Then the surface provided with the pick-up measuring unit 110 is rotated ninety degrees clockwise as shown in fig. 3 to be vertically downward, the connecting rod 112 is axially vertical, no acting force exists between the connecting rod 112 and the limiting ring 111, and the gravity sensor 116 detects the inherent gravity G of the connecting rod 112 and the injection molding fixing device 114 ₀ . At the same time, the force between the connecting rod 112 and the limiting ring 111 follows the inherent gravity G during the whole process of rotating the picking module 11 ninety degrees from zero ₀ Is changed by a moment change, which can be expressed as F ₀ (θ)·L ₀ ＝M ₀ And (θ), where θ is the angle through which the pick-up module 11 rotates.

Then selecting a standard part of the corresponding injection molding product, wherein the standard part is an injection molding part with uniform and flawless parts and perfect injection molding, and the standard quality is m ₀ The standard part is placed in a mould according to the position after injection molding, then the manipulator 1 simulates the process of taking the part to fix the standard part on the injection molding fixing device 114, and the force change F between the connecting rod 112 and the limiting ring 111 of the taking module 11 in the rotation process from zero degrees to ninety degrees can be obtained by repeating the testing steps when the empty load is carried out ₁ (θ), and a test reading G of the gravity sensor 116 with the connecting rod 112 vertical ₁ Then the gravity G of the standard component is tested _{Label (C)} ＝G ₁ -G ₀ G when the system is normal _{Label (C)} ＝m ₀ g, g is gravitational acceleration. At the same time according to F _{Label (C)} (θ)·L ₀ ＝F ₁ (θ)·L ₀ -F ₀ (θ)·L ₀ ＝G _{Label (C)} ·L _{Label (C)} Calculating the moment arm distance L of the gravity center of the standard component when the standard component is fixed _{Label (C)} ，F _{Label (C)} (θ) is the equivalent force change of the standard gravity acting on the contact point of the connecting rod 112 and the limiting ring 111 by using the connecting rod 112 as a lever, F ₁ (θ) and F _{Label (C)} (θ) are cosine functions. Then when the connecting rod 112 is vertical, the rotating device 113 drives the connecting rod 112 to start rotating at the angular speed omega, so that the markThe standard piece also starts to rotate at the angular speed omega, and the gravity center of the standard piece is overlapped with the extension line of the axis of the connecting rod 112 when the standard piece is fixed, so that the gravity center just falls on the rotating shaft, and the pressure f between the connecting rod 112 and the limiting ring 111 measured at the moment is zero. And saving the data obtained by measuring the standard parts into a database of the system of the invention, and comparing the measured results of the injection molding parts to be tested. The data also includes the picking module 11 and the space position coordinates of each picking measuring unit 110, wherein the picking module 11 can enable the extension line of the axis of the connecting rod 112 in the picking measuring unit 110 to coincide with the gravity center of the standard part when the manipulator 1 picks the standard part.

After the injection molding machine completes the injection molding production of the injection molded product, the manipulator 1 performs a pick-up operation. The manipulator 1 slides to one side of the conveying module 2, which is close to the injection molding machine, through the horizontal sliding block 17, one side of the picking module 11, which is provided with the picking measuring unit 110, is opposite to the injection molding product, the height of the vertical sliding block 15 and the position of the horizontal sliding block 17 are adjusted to enable the picking measuring unit 110 to correspond to the injection molding product one by one, and the selected position is the space position coordinates of the picking module 11 and the picking measuring unit 110 stored in the database. The injection molded product is then secured to the connecting rod 112 by the injection molded securing device 114 and removed from the mold. At this time, the force F between the connecting rod 112 and the stop collar 111 is measured by the stop force sensor 115 ₂ The direction of the force is vertically upward, and the connecting rod 112 is horizontally oriented in the axial direction. After the injection molding is removed, the manipulator 1 is moved to the side of the transfer module 2 away from the injection molding machine by means of the horizontal slide block 21, so that the injection molding is removed, and the connecting rod 112 is still axially horizontal. Then the first rotating rod 12 is rotated to enable the surface of the picking module 11 provided with the picking measuring unit 110 to vertically face downwards to the top platform 22, the connecting rod 112 is axially in a vertical state, and the gravity sensor 116 detects the total gravity G of the connecting rod 112, the injection molding fixing device 114 and the injection molding ₂ There is no force between the connecting rod 112 and the stop collar 111. During the rotation of the picking module 11, the force F ₂ F can be used as the change of the rotation angle theta ₂ (θ) is shown. According to the measured data, the injection molding to be measured can be obtainedGravity G of the piece _Measuring ＝G ₂ -G ₀ The gram weight mass of the injection molding piece is m _Measuring ＝G _Measuring /g, the equivalent force of the gravity of the injection molding at the contact point of the connecting rod 112 and the limiting ring 111 is changed to F _Measuring (θ)＝F ₂ (θ)-F ₀ From which the moment arm distance L of the center of gravity of the injection-molded part can be calculated _Measuring ＝F _Measuring (θ)·L ₀ /m _Measuring 。

The rotation means 113 rotate the connecting rod 112 at an angular velocity ω and the injection-molded part is rotated at an angular velocity ω as shown in fig. 4, at which time the horizontal force f between the connecting rod 112 and the stop collar 111 is measured _ω The moment balance has a relation f _ω ·L ₀ ＝m _Measuring ·ω ² ·r·L _Measuring From this, the distance r between the actual center of gravity of the injection molding 117 to be measured and the rotation axis can be calculated, and when the material of the injection molding is uniform or the material distribution of the injection molding is the same as that of the standard part, the center of gravity should be coincident with the rotation axis, and the offset distance is 0, and the horizontal acting force f _ω When the material of the injection molding part is uneven or different from the material of the standard part, the center of gravity deviates from the rotation axis by a distance r, and the horizontal acting force f _ω The deviation distance of the gravity center can be calculated according to the horizontal acting force instead of zero. The actual gram weight m of the injection molding piece can be measured in the process of taking and transferring the injection molding piece through the manipulator 1 _Measuring Meanwhile, the actual gravity center position of the injection molding part can be obtained through detection of force change between the connecting rod 112 and the limiting ring 111 in the transfer process, and whether the material distribution of the injection molding part meets the requirement or not and whether the material distribution of the injection molding part is consistent with the standard part or not can be indirectly known.

After the above process is completed, the four pick-up and measurement units 110 to which the injection molding is connected vertically downward correspond one by one to the four lifting devices 221 on the top stage 22 in the transfer module 2. The rotation device 113 in the take-off measuring unit 110 stops rotating, and the injection molding fixing device 114 is disengaged from the injection molding so that the injection molding falls onto the upper surface of the elevating device 221, and only one injection molding is placed on each elevating device 221. Because the lifting device 221 is also provided with a force sensor, the gravity of the injection molding piece falling on the surface of the lifting device 221 can be detectedThe gravity measured at this time was G _Verification G to the same injection molding piece _Verification And G _Measuring Performing difference comparison, if the difference value of the two is within a preset error range, indicating that the system works normally, and continuing to transmit injection molding; if the difference value of the two is beyond the set error range, the difference between the measurement result in the manipulator 1 and the measurement result of the transmission module 2 is larger, and a problem or a fault is necessarily caused in the whole process, and an alarm is sent at the moment, and related personnel carry out manual inspection in advance to find the cause of the problem.

In the continuing transfer work, G _Verification And G _Measuring The actual grammage of the injection molded article is estimated by using either or both of the average value and the two values as a screening standard, and the lifting device 221 determines the number of layers to be stopped after lowering according to the actual grammage of the injection molded article on the surface of the injection molded article. In the advanced setting of the conveying module, setting a qualified mass range of the injection molding, and when the actual gram weight of the injection molding falls within the qualified mass range, stopping the lifting device 221 on the two-layer platform 24, and conveying the injection molding with qualified gram weight to a specified position through the two-layer conveying belt 241; if there is an injection molding with a center of gravity deviation exceeding a set center of gravity threshold among the injection molding with qualified gram weight, a marking device is arranged in the two-layer platform 24 to mark the injection molding with unqualified center of gravity and distinguish the injection molding with qualified center of gravity. When the actual grammage of the injection-molded part is smaller than the minimum value of the set acceptable mass range, the lifting device 221 stays on the one-layer platform 23, is conveyed to a specified position through the one-layer conveying belt 231, and processes the injection-molded part with the unqualified center of gravity position in the same manner as the injection-molded part with the qualified grammage. When the actual gram of the injection-molded article is greater than the maximum value of the set acceptable mass range, the lifting device 221 stays on the bottom layer platform 25, is conveyed to a specified position by the bottom layer conveyor belt 251, and processes the injection-molded article in which the gravity center position is not acceptable in the same manner as the injection-molded article in which the gram weight is acceptable. The whole process is used for measuring the gram weight of the injection molding product and detecting the gravity center position and the quality distribution qualification degree in the injection molding transfer process, and simultaneously, the gram weight screening of the injection molding product is finished.

The foregoing embodiments are further illustrative and explanatory of the invention, as is not restrictive of the invention, and any modifications, equivalents, and improvements made within the spirit and principles of the invention are intended to be included within the scope of the invention.

Claims

1. The intelligent injection molding machine control system based on the gram weight of the injection molding product is characterized by comprising a mechanical arm, wherein the mechanical arm is provided with a piece taking module, a plurality of piece taking measuring units are arranged on the piece taking module, and the piece taking measuring units are used for fixing and measuring gravity of the piece taking of the injection molding product; the manipulator is connected with the conveying module, and the conveying module is used for screening injection molding products according to the gram weights of the injection molding products calculated by measurement and conveying the injection molding products;

the injection molding part fixing device comprises a part taking measuring unit, a part taking measuring unit and a part taking measuring unit, wherein the part taking measuring unit comprises a connecting rod, one end of the connecting rod is fixed on the part taking measuring unit through a rotating device, and the other end of the connecting rod is fixedly connected with the injection molding part fixing device; the connecting rod is sleeved with a limiting ring fixed on the workpiece taking measuring unit, the cross section of the limiting ring is in a semicircular arc shape, and the vertex of the arc shape is tangent with the surface of the connecting rod; the limiting ring is provided with a limiting force sensor, and the rotating device is provided with a gravity sensor.

2. The intelligent injection molding machine control system based on the gram weight of an injection molded product according to claim 1, wherein the manipulator comprises a pick-up module and a positioning module connected with the pick-up module, the positioning module comprises:

the rotating unit is fixedly connected with the picking module and used for driving the picking module to rotate;

the vertical sliding unit is used for determining the position of the pick-up module in the vertical direction through up-and-down sliding;

and the horizontal sliding unit is used for determining the position of the pick-up module in the horizontal direction through sliding in the horizontal direction.

3. The intelligent injection molding machine control system based on the gram weight of the injection molding product according to claim 1, wherein a plurality of lifting devices which are the same as the number and the positions of the workpiece taking measuring units on the workpiece taking module are arranged on the conveying module, and the lifting devices lift and stay at positions with different heights according to the gram weight of the placed injection molding product.

4. An intelligent injection molding machine control system based on injection molded product grammage according to claim 1 or 3, wherein the transfer module comprises a top layer platform, a first layer platform, a second layer platform and a bottom layer platform which are spaced at the same height; the first layer of platform is connected with a layer of conveyor belt; the two-layer platform is connected with a two-layer conveyor belt; the bottom layer platform is connected with a bottom layer conveying belt.

5. An intelligent injection molding machine control method based on gram weight of an injection molding product, which is suitable for the intelligent injection molding machine control system as claimed in claim 1, and is characterized by comprising the following steps:

s1, a database is called, and intrinsic data of stress conditions in the no-load moving process of a manipulator and standard data of stress conditions in the moving process of a fixed standard component are called when initial setting is carried out;

s2, taking and measuring, namely after the injection molding machine is used for injection molding of the product, the measuring manipulator is used for grabbing and fixing the injection molding piece to move and placing the injection molding piece into the measuring data of the stress condition in the process of the transmission module;

s4, screening and conveying, namely placing the injection molding on a conveying module, screening the injection molding according to the gram weight condition of the injection molding by the conveying module, and carrying out classified conveying on the injection molding.

6. The intelligent injection molding machine controller based on gram weight of injection molding product according to claim 5The method is characterized in that the intrinsic data comprises intrinsic gravity measured by a gravity sensor at no-load

And the force measured by the limit force sensor +.>

Intrinsic moment arm->

The method comprises the steps of carrying out a first treatment on the surface of the The standard data comprises standard part gram weight +.>

The weight obtained in the same way after the manipulator grabs the fixed standard part +.>

And force variation->

And standard weight measurement calculated from the above data +.>

Moment arm distance from the centre of gravity of the standard part when the standard part is fixed +.>

。

7. The method for controlling an intelligent injection molding machine based on gram weight of an injection molded product according to claim 5, wherein the measurement data comprises a gravity value measured by a gravity sensor after a manipulator grabs and fixes an injection molding piece

Force variation measured by limit force sensor>

And the injection-molded part is at an angular velocity +_ when the connecting rod is in a vertical state>

Measurement value of limit force sensor in rotation process along with connecting rod>

。

8. The intelligent injection molding machine control method based on the gram weight of the injection molded product according to claim 5, wherein the gram weight of the injection molded part is as follows

Moment arm distance of gravity center of injection molding piece

Offset distance of gravity center of injection molding part relative to standard part

Satisfy equation->

。/>