Deformation detection mechanism of bending machine

Abstract

The invention discloses a bending machine deformation detection mechanism and method. The bending machine deformation detection mechanism comprises a deformation sensor and a control system. The bending machine comprises a lower side plate and a sliding block located over the lower side plate, and the height of the sliding block can be decreased. A deformation proportionality coefficient K is built in the control system; wherein the deformation proportionality coefficient K is the ratio of the elastic deformation A of the sliding block to the elastic deformation B of the lower side plate; the deformation sensor is arranged on the lower side plate or the sliding block and can be used for detecting the elastic deformation amount of the lower side plate or the sliding block. According to the invention, the bending deformation can be detected in real time while the cost is saved. And particularly, when a large-breadth thick plate is bent, the bending precision of the plate can be improved, and waste of the plate is reduced. Particularly, when the intelligent bending production line is provided with the function, closed-loop real-time intelligent automatic control can be achieved. Furthermore, the initial deviation of upper and lower die installation can be calculated and compensated, and installation and debugging are more convenient.

Description

Technical Field

[0001] The invention relates to a bending detection device, in particular to a bending machine deformation detection mechanism. Background Art

[0002] Bending machines are essential equipment for sheet metal processing. With the expansion of bending processing in heavy industries such as engineering machinery and shipbuilding, the thickness and width of processed plates are increasing year by year, and the deformation effect of bending machines is also increasing. For example, thick plates such as the boom and forearm of a crane often produce scrap due to the failure of bending accuracy to meet the requirements, resulting in great waste. Fig. 9 As shown in the figure, it shows the deformation cloud diagram of the slider and the lower side plate of the bending machine under the action of the bending load. It can be seen that both the slider and the lower side plate have large deformations, which seriously affects the bending processing accuracy of the bending machine when bending the plate. Fig.11 As shown, resulting in waste of plate. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a bending machine deformation detection mechanism in view of the above-mentioned deficiencies in the prior art, wherein the bending machine deformation detection mechanism can perform real-time detection of bending deformation while saving costs.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A bending machine deformation detection mechanism, comprising a rigid beam, a deformation sensor and a control system;

[0006] The bending machine comprises two deformed parts to be detected; the two deformed parts to be detected are a lower side plate and a slider, wherein the slider is located directly above the lower side plate, and the height of the slider can be lowered.

[0007] A deformation proportionality coefficient K is built into the control system; wherein the deformation proportionality coefficient K is the ratio of the elastic deformation amount A of the slider to the elastic deformation amount B of the lower side plate, K=A / B.

[0008] The rigid beam is connected to one of the deformed parts A to be detected through a "point", and the elastic deformation of the rigid beam is zero; wherein the deformed part A to be detected is the lower side plate or the slider.

[0009] The deformation sensor is arranged on the deformed part A to be detected or the rigid beam, and can be used to detect the relative deformation displacement between the rigid beam and the deformed part A to be detected; since the elastic deformation of the rigid beam is zero, the detection value of the deformation sensor is the elastic deformation of the deformed part A to be detected.

[0010] When the deformed part A to be detected is the lower side plate, it can be used to detect the elastic deformation B of the lower side plate, and the elastic deformation A of the slider = K×B.

[0011] When the deformation part A to be detected is a slider, it can be used to detect the elastic deformation amount A of the slider, and the elastic deformation amount B of the lower side plate = A / K.

[0012] The control system calculates the elastic deformation of another deformed part to be detected based on the elastic deformation of the deformed part A detected by the deformation sensor and the deformation proportional coefficient K equation, and then obtains the elastic deformations A and B of the entire bending machine; the control system drives the compensation mechanism to compensate the bending machine based on the elastic deformations A and B of the bending machine, thereby realizing closed-loop control of the overall accuracy of the bending machine.

[0013] The deformation sensor is arranged at one end of the top of the rigid beam, and the middle part and the other end of the rigid beam are both connected to the deformed part A to be detected through a "point".

[0014] The deformation sensor is arranged in the middle of the rigid beam, and both ends of the rigid beam are connected to the deformed part A to be detected through a "point".

[0015] There are two deformation sensors, which are respectively arranged at the top of both ends of the rigid beam, and the middle part of the rigid beam is connected to the deformed part A to be detected.

[0016] A bending machine deformation detection method comprises the following steps.

[0017] Step 1: Install the deformation sensor: install the deformation sensor on the deformation-to-be-detected part A or the rigid beam.

[0018] Step 2, obtaining the deformation proportional coefficient K: obtaining the deformation proportional coefficient K by experimental detection or analysis; wherein the deformation proportional coefficient K is the ratio of the elastic deformation A of the slider to the elastic deformation B of the lower side plate.

[0019] Step 3: Measure the elastic deformation: During the bending process of the bending machine, use a deformation sensor to directly measure the elastic deformation of the lower side plate or the slider.

[0020] Step 4, calculate another elastic deformation: according to the deformation proportional coefficient K in step 2 and the elastic deformation obtained in step 3, calculate the elastic deformation of the slider or the lower side plate; when the measured value in step 3 is the elastic deformation B of the lower side plate, the elastic deformation of the slider A=K×B; when the measured value in step 3 is the elastic deformation A of the slider, the elastic deformation B of the lower side plate B=A / K.

[0021] In step 2, the deformation proportionality coefficient K is obtained by a finite analysis method, which specifically includes the following steps:

[0022] Step 2A-1, constructing a bending machine model: constructing a bending machine model using finite element software.

[0023] Step 2A-2, bending: Use the bending machine model constructed in step 2A-1 to simulate the bending of the workpiece to be bent, and obtain the deformation curves of the lower side plate and the slider during the bending process.

[0024] Step 2A-3, calculating the simulated elastic deformation B of the lower side panel: subtracting the difference between the maximum simulated deformation and the minimum simulated deformation in the deformation curve of the lower side panel to obtain the simulated elastic deformation B.

[0025] Step 2A-4, calculating the simulated elastic deformation A of the slider: subtracting the difference between the maximum simulated deformation and the minimum simulated deformation in the slider deformation curve to obtain the simulated elastic deformation A.

[0026] Step 2A-5, calculate the deformation proportional coefficient K, then: K = simulated elastic deformation amount A / simulated elastic deformation amount B.

[0027] In step 2, the deformation proportional coefficient K is obtained by an analytical method, which specifically includes the following steps:

[0028] Step 2B-1, calculate the slider deformation W1, the specific calculation formula is:

[0029]

[0030] in:

[0031]

[0032] Where, q is the uniformly distributed pressure on the bottom surface of the slider or the top surface of the lower side plate.

[0033] l is the length of the uniformly distributed load on the bottom surface of the slider or the top surface of the lower side plate.

[0034] E1——Elastic modulus of the slider.

[0035] I1——section moment of inertia of the slider.

[0036] b1——the thickness of the slider.

[0037] h1 – The height of the slider.

[0038] Step 2B-2, calculate the deformation of the lower side plate W2, the specific calculation formula is:

[0039]

[0040] in:

[0041]

[0042] Where, E2 is the elastic modulus of the lower side plate.

[0043] I2——section moment of inertia of the lower side plate.

[0044] b2——thickness of the lower side plate.

[0045] h2 – height of the lower side panel.

[0046] Step 2B-3, construct a deformation ratio coefficient K calculation model:

[0047]

[0048] Step 2B-4, simplify the calculation model of deformation ratio coefficient K: Substitute W1 in step 2B-1 and W2 in step 2B-2 into step 2B-3, and simplify to obtain:

[0049]

[0050] When the slider and the lower side plate are made of the same material, E1=E2.

[0051] In step 2, the deformation proportionality coefficient K is obtained through on-site manual testing.

[0052] In step 2, the deformation proportional coefficient K is obtained by a plate trial folding method, which specifically includes the following steps.

[0053] Step 2C-1, constructing a bending angle deviation equation: select two plates, marked as plate 1 and plate 2 respectively; assume that the angle deviation between the middle and the two ends of plate 1 when the bending machine bends is θ1, and the deformation measurement value of the deformation sensor when plate 1 is bent is D1; ​​the angle deviation between the middle and the two ends of plate 2 when the bending machine bends is θ2, and the deformation measurement value of the deformation sensor when plate 2 is bent is D2, then the following two bending angle deviation equations are constructed, specifically:

[0054] θ1=W(D1+KD1+E)

[0055] θ2=W(D2+KD2+E)

[0056] Where, W is the proportional relationship between the bending angle and the upper die feed, which is a known value;

[0057] E——Initial parallelism deviation of upper and lower dies, unknown quantity;

[0058] Step 2C-2, constructing a proportional coefficient equation for the bending angle deviation: subtract the two bending angle deviation equations constructed in step 2C-1, and solve to obtain an equation for the proportional coefficient K of the bending angle deviation. The specific expression is:

[0059]

[0060] Step 2C-3, obtaining θ1 and D1: performing a bending experiment on sheet 1 at a set angle, and measuring the angle deviations between the middle and both ends of sheet 1 after bending to obtain θ1; at the same time, during the bending process, the deformation value D1 of the deformation sensor is recorded.

[0061] Step 2C-4, obtain θ2 and D2: perform a bending experiment on the sheet 2 at a set angle, measure the angle deviation between the middle and both ends of the sheet 2 after bending, and obtain θ2; at the same time, during the bending process, record the deformation value D2 of the deformation sensor.

[0062] Step 2C-5, calculate the deformation proportional coefficient K: substitute θ1 and D1 obtained in step 2C-3, and θ2 and D2 obtained in step 2C-4 into the proportional coefficient equation for bending angle deviation constructed in step 2C-2, so as to calculate the deformation proportional coefficient K.

[0063] The step 2C-6 is also included, calculating the initial upper and lower mold parallelism deviation E, and the specific calculation formula is:

[0064]

[0065] The present invention has the following beneficial effects: the present invention can detect the deformation of the machine tool in real time, and thus achieve closed-loop control of the precision deviation; especially when bending large-format thick plates, it can improve the bending accuracy of the plates and reduce the waste of the plates. Especially when the intelligent bending production line is equipped with this function, closed-loop real-time intelligent automatic control can be achieved. In addition, the present invention does not require manual intervention, and it is of great significance to improve the level of intelligence. For example, the bending processing of the boom of an engineering machinery crane requires very high precision. Then the precision open-loop control of the prior art cannot overcome the influence of the machine tool deformation problem on the precision, the precision is unstable, and the batch scrapping of the plates is often caused, which is difficult to meet the requirements. Furthermore, the present invention can calculate and compensate for the initial deviation of the upper and lower mold installation, and installation and debugging are more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 A schematic diagram of the bending machine is shown.

[0067] Figure 2 Shows a schematic diagram of the structure where the deformation sensor is installed on the lower side plate.

[0068] Figure 3 A schematic diagram showing the structure of the deformation sensor installed on the slider.

[0069] Figure 4 A schematic diagram showing a second preferred installation method of the deformation sensor on the slider is shown.

[0070] Figure 5A schematic diagram showing a third preferred installation method of the deformation sensor on the slider is shown.

[0071] Figure 6 A simulation diagram showing the deformation proportionality factor K solved by finite element analysis.

[0072] Figure 7 A schematic diagram showing the deformation proportionality coefficient K obtained by on-site manual testing.

[0073] Figure 8 The force diagram when the deformation proportionality coefficient K is solved by analytical method is shown.

[0074] Fig. 9 The deformation cloud diagram of the skateboard and the lower side plate in the prior art is shown.

[0075] Fig.10 Schematic diagram of the deformation curves of the finite analysis slide plate and lower side plate are shown.

[0076] Fig.11 A schematic diagram of the bending angle deviation of the plate in the prior art is shown.

[0077] Among them are:

[0078] 10. Frame; 11. Slider; 12. Lower side plate;

[0079] 21. Upper die; 22. Lower die;

[0080] 30. Control system;

[0081] 40. Deformation sensor; 41. Rigid beam;

[0082] 50. Measuring instruments. DETAILED DESCRIPTION

[0083] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific preferred embodiments.

[0084] In the description of the present invention, it should be understood that the terms "left side", "right side", "upper part", "lower part" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. "First", "second" and the like do not indicate the importance of the components, and therefore cannot be understood as limiting the present invention. The specific dimensions used in this embodiment are only for illustrating the technical solution, and do not limit the scope of protection of the present invention.

[0085] like Figure 1 and Figure 2 As shown, the bending machine includes a frame 10, a bending die and a bending machine deformation detection mechanism.

[0086] The frame includes a lower side plate 12 and a slider 11 located directly above the lower side plate, and the height of the slider can be lowered.

[0087] The bending die includes an upper die 21 and a lower die 22, wherein the upper die is mounted at the bottom of the slider and the lower die is mounted at the top of the lower side plate.

[0088] like Figure 1 , Figure 2 and Figure 3 As shown, a deformation detection mechanism for a bending machine includes a deformation sensor 40 and a control system 30.

[0089] The control system, also called the deformation compensation mechanism, has a built-in deformation proportional coefficient K; wherein the deformation proportional coefficient K is the ratio of the elastic deformation A of the slider to the elastic deformation B of the lower side plate.

[0090] like Fig.10 As shown, it shows a schematic diagram of the deformation curves of the slide plate and the lower side plate under working condition 1 and working condition 2 obtained by using the finite analysis method; wherein working condition 1 and working condition 2 are two different working conditions, wherein the horizontal axis is the dimensional coordinate along the length direction of the mold, and the vertical axis is the deformation amount.

[0091] The deformation sensor is preferably arranged on the lower plate or the slider through a rigid beam 41, and can be used to detect the elastic deformation of the lower plate or the slider. The rigid beam is preferably arranged horizontally, but is not limited to being arranged horizontally.

[0092] The above deformation sensors are preferably but not limited to the following two types:

[0093] 1) Contact type: The contact type installation method is that the fixed part of the sensor is installed on the slider or the lower side plate, and the probe is placed on the rigid beam. The rigid beam and the lower side plate or the slider are connected in a "point" connection manner (preferably but not limited to hinged connection). In this way, the slider or the lower side plate undergoes elastic deformation, while the rigid beam only undergoes rigid body displacement and does not undergo elastic deformation, that is, the elastic deformation of the rigid beam is zero (that is, the force deformation is equivalent to 0). The deformation sensor can detect the displacement between the rigid beam and the slider or the lower side plate. Among them, the deformation sensor detects the displacement between the rigid beam and the slider or the lower side plate. The slider or the lower side plate is an elastic body relative to the rigid beam. As an alternative, the deformation sensor can also be installed on the rigid beam. The principle is exactly the same, which is an equivalent replacement.

[0094] 2) Non-contact type, such as a point laser sensor, can be installed on a skateboard or a lower side plate, and the light emitted by the point laser sensor is projected onto the rigid beam; conversely, the point laser sensor can also be installed on the rigid beam, which is considered equivalent.

[0095] The deformation sensor has the following three preferred installation methods on the lower side plate or the slider.

[0096] Preferred installation method 1

[0097] like Figure 2 and Figure 3 As shown, the deformation sensor is arranged in the middle of the rigid beam, and both ends of the rigid beam are connected to the lower side plate or the slider.

[0098] Preferred installation method 2

[0099] like Figure 4 As shown, the deformation sensor is arranged at one end of the top of the rigid beam, and the middle and the other end of the rigid beam are connected to the lower side plate or the slider. This installation method can linearly amplify the deformation ratio, reduce the sensitivity of the deformation sensor, and in turn improve the detection accuracy.

[0100] Preferred installation method 3

[0101] like Figure 5 As shown, there are two deformation sensors, which are respectively arranged at the top of both ends of the rigid beam, and the middle of the rigid beam is connected to the lower side plate or the slider. This installation method can predict the overload situation of the bending machine based on the feedback values ​​of the two deformation sensors: when the feedback values ​​of the deformation sensors on both sides are not equal.

[0102] When the deformation sensor is arranged on the lower side plate, it can be used to detect the elastic deformation amount B of the lower side plate, and the elastic deformation amount A of the slider is = K×B.

[0103] When the deformation sensor is disposed on the lower plate, it can be used to detect the elastic deformation amount A of the slider, and the elastic deformation amount B of the lower plate = A / K.

[0104] A bending machine deformation detection method comprises the following steps.

[0105] Step 1: Install the deformation sensor: install the deformation sensor on the deformation-to-be-detected part A or the rigid beam.

[0106] Step 2, obtaining the deformation proportional coefficient K: obtaining the deformation proportional coefficient K by experimental detection or analysis; wherein the deformation proportional coefficient K is the ratio of the elastic deformation A of the slider to the elastic deformation B of the lower side plate.

[0107] In the present invention, the deformation proportional coefficient K is preferably obtained by using four preferred embodiments.

[0108] Example 1

[0109] like Figure 6 As shown, the above deformation proportional coefficient K is obtained by a finite analysis method, which specifically includes the following steps.

[0110] Step 2A-1, constructing a bending machine model: constructing a bending machine model using finite element software.

[0111] Step 2A-2, bending: using the bending machine model constructed in step 2A-1, perform multiple simulated bending on the workpiece to be bent, and record the deformation curve of the lower side plate or the slider during the bending process.

[0112] Step 2A-3, calculating the simulated elastic deformation B of the lower side panel: subtracting the difference between the maximum simulated deformation and the minimum simulated deformation in the deformation curve of the lower side panel to obtain the simulated elastic deformation B.

[0113] Step 2A-4, calculating the simulated elastic deformation A of the slider: subtracting the difference between the maximum simulated deformation and the minimum simulated deformation in the slider deformation curve to obtain the simulated elastic deformation A.

[0114] Step 2A-5, calculate the deformation ratio coefficient K, then: K = simulated elastic deformation A / simulated elastic deformation B, Figure 6 In the above equation, the deformation proportional coefficient K is calculated as:

[0115]

[0116] The above limited analysis is convenient and accurate, but requires professional theoretical knowledge.

[0117] Example 2

[0118] like Figure 8 As shown, the above deformation proportional coefficient K is obtained by an analytical method, which specifically includes the following steps:

[0119] Step 2B-1, calculate the slider deformation W1, the specific calculation formula is:

[0120]

[0121] in:

[0122]

[0123] Where, q is the uniformly distributed pressure on the bottom surface of the slider or the top surface of the lower side plate.

[0124] l is the length of the uniformly distributed load on the bottom surface of the slider or the top surface of the lower side plate.

[0125] E1——Elastic modulus of the slider.

[0126] I1——section moment of inertia of the slider.

[0127] b1——the thickness of the slider.

[0128] h1 – The height of the slider.

[0129] Step 2B-2, calculate the deformation of the lower side plate W2, the specific calculation formula is:

[0130]

[0131] in:

[0132]

[0133] Where, E2 is the elastic modulus of the lower side plate.

[0134] I2——section moment of inertia of the lower side plate.

[0135] b2——thickness of the lower side plate.

[0136] h2 – height of the lower side panel.

[0137] Step 2B-3, construct a deformation ratio coefficient K calculation model:

[0138]

[0139] Step 2B-4, simplify the calculation model of deformation ratio coefficient K: Substitute W1 in step 2B-1 and W2 in step 2B-2 into step 2B-3, and simplify to obtain:

[0140]

[0141] When the slider and the lower side plate are made of the same material, E1=E2.

[0142] The above analytical method does not require any operation and only requires the input of necessary parameters. However, it is only suitable for the shapes of standard sliders and lower side panels of the rack, and the calculation accuracy is insufficient for special and complex situations.

[0143] Example 3

[0144] like Figure 7 As shown, the deformation proportional coefficient K is obtained by manually testing on site using a measuring instrument 50.

[0145] Example 4

[0146] In step 2, the deformation proportional coefficient K is obtained by the plate trial folding method, which specifically includes the following steps:

[0147] Step 2C-1, constructing a bending angle deviation equation: select two plates, marked as plate 1 and plate 2 respectively; assume that the angle deviation between the middle and the two ends of plate 1 when the bending machine bends is θ1, and the deformation measurement value of the deformation sensor when plate 1 is bent is D1; ​​the angle deviation between the middle and the two ends of plate 2 when the bending machine bends is θ2, and the deformation measurement value of the deformation sensor when plate 2 is bent is D2, then the following two bending angle deviation equations are constructed, specifically:

[0148] θ1=W(D1+KD1+E)

[0149] θ2=W(D2+KD2+E)

[0150] Where, W is the proportional relationship between the bending angle and the upper die feed, which is a known value;

[0151] E——Initial parallelism deviation of upper and lower dies, unknown quantity;

[0152] Step 2C-2, constructing a proportional coefficient equation for the bending angle deviation: subtract the two bending angle deviation equations constructed in step 2C-1, and solve to obtain an equation for the proportional coefficient K of the bending angle deviation. The specific expression is:

[0153]

[0154] Step 2C-3, obtaining θ1 and D1: performing a bending experiment on sheet 1 at a set angle, and measuring the angle deviations between the middle and both ends of sheet 1 after bending to obtain θ1; at the same time, during the bending process, the deformation value D1 of the deformation sensor is recorded.

[0155] Step 2C-4, obtain θ2 and D2: perform a bending experiment on the sheet 2 at a set angle, measure the angle deviation between the middle and both ends of the sheet 2 after bending, and obtain θ2; at the same time, during the bending process, record the deformation value D2 of the deformation sensor.

[0156] Step 2C-5, calculate the deformation proportional coefficient K: substitute θ1 and D1 obtained in step 2C-3, and θ2 and D2 obtained in step 2C-4 into the proportional coefficient equation for bending angle deviation constructed in step 2C-2, so as to calculate the deformation proportional coefficient K.

[0157] Step 2C-6, calculate the initial upper and lower mold parallelism deviation E, the specific calculation formula is:

[0158]

[0159] The calculation is based on the deviation between the middle angle accuracy and the angle accuracy of the two ends of the actual bent sheet. Generally, the upper die of the bending machine is installed under the slider, and the lower die is installed on the lower side plate of the frame. The initial installation parallelism deviation of the upper and lower dies is inevitable. If the deviation cannot be predicted and compensated, it will inevitably affect the bending accuracy.

[0160] Assuming that the deformation sensor detects the deformation of the lower side plate, the calculation idea of ​​setting the deformation sensor on the slider is similar and will not be repeated here.

[0161] Step 3: Measure the elastic deformation: During the bending process of the bending machine, use a deformation sensor to directly measure the elastic deformation of the lower side plate or the slider.

[0162] Step 4, calculate another elastic deformation: according to the deformation proportional coefficient K in step 2 and the elastic deformation obtained in step 3, calculate the elastic deformation of the slider or the lower side plate; when the measured value in step 3 is the elastic deformation B of the lower side plate, the elastic deformation of the slider A=K×B; when the measured value in step 3 is the elastic deformation A of the slider, the elastic deformation B of the lower side plate B=A / K.

[0163] The preferred embodiments of the present invention are described in detail above; however, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.

Claims

1. A bending machine deformation detection mechanism, characterized in that: It includes a rigid beam, a deformation sensor and a control system; The bending machine includes two deformed parts to be detected; the two deformed parts to be detected are a lower side plate and a slider, wherein the slider is located directly above the lower side plate, and the height of the slider can be lowered; A deformation proportionality coefficient K is built into the control system; wherein the deformation proportionality coefficient K is the ratio of the elastic deformation amount A of the slider to the elastic deformation amount B of the lower side plate, K=A / B; The rigid beam is connected to one of the deformed parts A to be detected through a "point", and the elastic deformation of the rigid beam is zero; wherein the deformed part A to be detected is the lower side plate or the slider; The deformation sensor is arranged on the deformed part A to be detected or the rigid beam, and can be used to detect the relative deformation displacement between the rigid beam and the deformed part A to be detected; since the elastic deformation of the rigid beam is zero, the detection value of the deformation sensor is the elastic deformation of the deformed part A to be detected; When the deformed part A to be detected is the lower side plate, it can be used to detect the elastic deformation B of the lower side plate, then the elastic deformation A of the slider = K × B; When the deformation part A to be detected is a slider, it can be used to detect the elastic deformation A of the slider, then the elastic deformation B of the lower side plate = A / K; The control system calculates the elastic deformation of another deformed part to be detected based on the elastic deformation of the deformed part A detected by the deformation sensor and the deformation proportional coefficient K, and then obtains the elastic deformations A and B of the entire bending machine; the control system drives the compensation mechanism to compensate the bending machine based on the elastic deformations A and B of the bending machine, thereby realizing closed-loop control of the overall accuracy of the bending machine.

2. The bending machine deformation detection mechanism according to claim 1, characterized in that: The deformation sensor is arranged at one end of the top of the rigid beam, and the middle part and the other end of the rigid beam are both connected to the deformed part A to be detected through a "point".

3. The bending machine deformation detection mechanism according to claim 1, characterized in that: The deformation sensor is arranged in the middle of the rigid beam, and both ends of the rigid beam are connected to the deformed part A to be detected through a "point".

4. The bending machine deformation detection mechanism according to claim 1, characterized in that: There are two deformation sensors, which are respectively arranged at the top of both ends of the rigid beam, and the middle part of the rigid beam is connected to the deformed part A to be detected.

5. A bending machine deformation detection method, characterized in that: The steps include: Step 1: Install the deformation sensor: install the deformation sensor on the deformation detection part A or the rigid beam; Step 2, obtaining the deformation proportional coefficient K: obtaining the deformation proportional coefficient K by experimental detection or analysis; wherein the deformation proportional coefficient K is the ratio of the elastic deformation amount A of the slider to the elastic deformation amount B of the lower side plate; Step 3, measuring the elastic deformation: during the bending process of the bending machine, the elastic deformation of the lower side plate or the slider is directly measured using a deformation sensor; Step 4, calculate another elastic deformation: according to the deformation proportional coefficient K in step 2 and the elastic deformation obtained in step 3, calculate the elastic deformation of the slider or the lower side plate; when the measured value in step 3 is the elastic deformation B of the lower side plate, the elastic deformation of the slider A=K×B; when the measured value in step 3 is the elastic deformation A of the slider, the elastic deformation B of the lower side plate B=A / K.

6. The bending machine deformation detection method according to claim 5, characterized in that: In step 2, the deformation proportionality coefficient K is obtained by a finite analysis method, which specifically includes the following steps: Step 2A-1, constructing a bending machine model: constructing a bending machine model by using finite element software; Step 2A-2, bending: using the bending machine model constructed in step 2A-1, simulate the bending of the workpiece to be bent, and obtain the deformation curves of the lower side plate and the slider during the bending process; Step 2A-3, calculating the simulated elastic deformation B of the lower side panel: subtracting the difference between the maximum simulated deformation and the minimum simulated deformation in the deformation curve of the lower side panel to obtain the simulated elastic deformation B; Step 2A-4, calculating the simulated elastic deformation A of the slider: subtracting the difference between the maximum simulated deformation and the minimum simulated deformation in the slider deformation curve to obtain the simulated elastic deformation A; Step 2A-5, calculate the deformation proportional coefficient K, then: K = simulated elastic deformation amount A / simulated elastic deformation amount B.

7. The bending machine deformation detection method according to claim 5, characterized in that: In step 2, the deformation proportional coefficient K is obtained by an analytical method, which specifically includes the following steps: Step 2B-1, calculate the slider deformation W1, the specific calculation formula is: in: Where, q is the uniform pressure on the bottom surface of the slider or the top surface of the lower side plate; l——The length of the uniformly distributed load on the bottom surface of the slider or the top surface of the lower side plate; E1——elastic modulus of the slider; I1——section moment of inertia of the slider; b1——the thickness of the slider; h1 – height of the slider; Step 2B-2, calculate the deformation of the lower side plate W2, the specific calculation formula is: in: Where, E2 is the elastic modulus of the lower side plate; I2——section moment of inertia of the lower side plate; b2——the thickness of the lower side plate; h2——the height of the lower side plate; Step 2B-3, construct a deformation ratio coefficient K calculation model: Step 2B-4, simplify the calculation model of deformation ratio coefficient K: Substitute W1 in step 2B-1 and W2 in step 2B-2 into step 2B-3, and simplify to obtain: When the slider and the lower side plate are made of the same material, E1=E2.

8. The bending machine deformation detection method according to claim 5, characterized in that: In step 2, the deformation proportionality coefficient K is obtained through on-site manual testing.

9. The bending machine deformation detection method according to claim 5, characterized in that: In step 2, the deformation proportional coefficient K is obtained by the plate trial folding method, which specifically includes the following steps: Step 2C-1, constructing a bending angle deviation equation: select two plates, marked as plate 1 and plate 2 respectively; assume that the angle deviation between the middle and the two ends of plate 1 when the bending machine bends is θ1, and the deformation measurement value of the deformation sensor when plate 1 is bent is D1; ​​the angle deviation between the middle and the two ends of plate 2 when the bending machine bends is θ2, and the deformation measurement value of the deformation sensor when plate 2 is bent is D2, then the following two bending angle deviation equations are constructed, specifically: θ1=W(D1+KD1+E) θ2=W(D2+KD2+E) Where, W is the proportional relationship between the bending angle and the upper die feed, which is a known value; E——Initial parallelism deviation of upper and lower dies, unknown quantity; Step 2C-2, constructing a proportional coefficient equation for the bending angle deviation: subtract the two bending angle deviation equations constructed in step 2C-1, and solve to obtain an equation for the proportional coefficient K of the bending angle deviation. The specific expression is: Step 2C-3, obtaining θ1 and D1: performing a bending experiment on sheet one at a set angle, and measuring the angle deviation between the middle and both ends of sheet one after bending, to obtain θ1; at the same time, during the bending process, the deformation value D1 of the deformation sensor is recorded; Step 2C-4, obtaining θ2 and D2: performing a bending experiment on sheet two at a set angle, and measuring the angle deviation between the middle and both ends of sheet two after bending, to obtain θ2; at the same time, during the bending process, the deformation value D2 of the deformation sensor is recorded; Step 2C-5, calculate the deformation proportional coefficient K: substitute θ1 and D1 obtained in step 2C-3, and θ2 and D2 obtained in step 2C-4 into the proportional coefficient equation for bending angle deviation constructed in step 2C-2, so as to calculate the deformation proportional coefficient K.

10. The bending machine deformation detection method according to claim 9, characterized in that: The step 2C-6 is also included, calculating the initial upper and lower mold parallelism deviation E, and the specific calculation formula is:

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