A bending machine deformation detection mechanism

Abstract

The application discloses a bending machine deformation detection mechanism and method, which comprises a deformation sensor and a control system; the bending machine comprises a lower side plate and a slider located directly above the lower side plate, and the height of the slider can be lowered; 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 slider to the elastic deformation B of the lower side plate; the deformation sensor is arranged on the lower side plate or the slider and can be used for detecting the elastic deformation of the lower side plate or the slider. The application can realize real-time detection of bending deformation while saving cost. Especially when bending a large-format thick plate, the bending precision of the plate can be improved, and the waste of the plate can be reduced. Especially when the application is equipped with the function of an intelligent bending production line, closed-loop real-time intelligent automatic control can be realized. Further, the application can calculate and compensate the initial deviation of the upper and lower dies, so that the installation and debugging are more convenient.

Description

TECHNICAL FIELD

[0001] The present application relates to a bending detection device, in particular to a bending machine deformation detection mechanism. BACKGROUND

[0002] The bending machine is an indispensable equipment for metal plate processing. With the expansion of bending processing in heavy industry such as engineering machinery and ship, the processing plate thickness and processing width are increasing year by year, and the deformation of the bending machine is also increasing. For example, the thick plate of the boom and the arm of the crane often produces waste due to the failure to meet the bending accuracy requirements, causing great waste. Figure 9 As shown in FIG. 1, it shows the deformation cloud of the slider and the lower side plate of the bending machine under the action of the bending load. It can be seen that the slider and the lower side plate have large deformation, thereby seriously affecting the bending processing precision of the bending machine when bending the plate, as shown in FIG. 2, causing plate waste. Figure 11 SUMMARY

[0003] The technical problem to be solved by the present application is to solve the above-mentioned problems of the prior art, and to provide a bending machine deformation detection mechanism which can detect the bending deformation in real time while saving cost.

[0004] To solve the above technical problems, the technical scheme adopted by the present application 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 deformation detection parts; the two deformation detection parts are respectively 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] The control system is internally provided with a deformation ratio coefficient K; wherein the deformation ratio 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 deformation detection parts A through a point, and the elastic deformation amount of the rigid beam is zero; wherein the deformation detection part A is the lower side plate or the slider.

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

[0010] When the deformation detection part A is the lower side plate, the elastic deformation amount B of the lower side plate can be detected, and the elastic deformation amount A of the slider is KxB.

[0011] ​When the deformed part A to be detected is a slide block, the elastic deformation A of the slide block can be detected, and the elastic deformation B of the lower plate = A / K.

[0012] The control system obtains the elastic deformation of another deformed part to be detected according to the elastic deformation of the deformed part A to be detected detected by the deformation sensor and the deformation ratio coefficient K equation, and further obtains the elastic deformations A and B of the whole bending machine; the control system drives the compensation mechanism to compensate the bending machine according to the elastic deformations A and B of the bending machine, and further realizes the closed-loop control of the precision of the whole bending machine.

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

[0014] The deformation sensor is arranged at the middle of the rigid beam, and the two ends of the rigid beam are connected to the deformed part A to be detected by "point".

[0015] The deformation sensor has two, which are arranged at the top of the two ends of the rigid beam, and the middle of the rigid beam is connected to the deformed part A to be detected.

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

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

[0018] Step 2, obtain the deformation ratio coefficient K: obtain the deformation ratio coefficient K by experimental detection or analysis method; wherein the deformation ratio coefficient K is the ratio of the elastic deformation A of the slide block to the elastic deformation B of the lower plate.

[0019] Step 3, measure the elastic deformation: during the bending process of the bending machine, the elastic deformation of the lower plate or the slide block is directly measured by using the deformation sensor.

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

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

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

[0023] Step 2A-2, bending: using the bending machine model constructed in step 2A-1, the workpiece to be bent is simulated to bend, and the deformation curves of the lower side plate and the slider during the bending process are obtained.

[0024] Step 2A-3, calculating the simulation elastic deformation B of the lower side plate: subtracting the difference between the maximum simulation deformation and the minimum simulation deformation in the lower side plate deformation curve, the simulation elastic deformation B is obtained.

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

[0026] Step 2A-5, calculating the deformation ratio coefficient K, then: K = simulation elastic deformation A / simulation elastic deformation B.

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

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

[0029]

[0030] Wherein:

[0031]

[0032] In the formula, q is the uniform pressure on the bottom surface of the slider or the top surface of the lower side plate.

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

[0034] E1 is the elastic modulus of the slider.

[0035] I1 is the cross-sectional moment of inertia of the slider.

[0036] b1 is the thickness of the slider.

[0037] h1 is the height of the slider.

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

[0039]

[0040] Wherein:

[0041]

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

[0043] I2 is the cross-sectional moment of inertia of the lower side plate.

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

[0045] h2 - height of the lower side plate.

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

[0047]

[0048] Step 2B-4, simplifying the deformation ratio coefficient K calculation model: substituting W1 in step 2B-1 and W2 in step 2B-2 into step 2B-3, and simplifying 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 ratio coefficient K is obtained by artificial testing on site.

[0052] In step 2, the deformation ratio coefficient K is obtained by the plate test folding method, which includes the following steps.

[0053] Step 2C-1, constructing a bending angle deviation equation: select two plates, respectively marked as plate one and plate two; set the angle deviation of the middle and both ends of the plate one when the bending machine is bent as θ1, and the deformation measurement value of the deformation sensor when the plate one is bent as D1; the angle deviation of the middle and both ends of the plate two when the bending machine is bent as θ2, and the deformation measurement value of the deformation sensor when the plate two is bent as D2, then two bending angle deviation equations are constructed, which are as follows:

[0054] θ1 = W(D1 + KD1 + E)

[0055] θ2 = W(D2 + KD2 + E)

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

[0057] E - initial parallelism deviation of the upper and lower dies, which is an unknown quantity;

[0058] Step 2C-2, constructing a proportional coefficient equation about the bending angle deviation: subtracting the two bending angle deviation equations constructed in step 2C-1, and solving to obtain the equation about the proportional coefficient K of the bending angle deviation, which is specifically expressed as:

[0059]

[0060] Step 2C-3, obtaining θ1 and D1: the plate one is subjected to a bending experiment with a set angle, and the angle deviation of the middle and both ends of the plate one after bending is measured to obtain θ1; at the same time, the deformation value D1 of the deformation sensor during the bending process is recorded.

[0061] Step 2C-4, obtaining θ2 and D2: the plate two is subjected to a bending experiment with a set angle, and the angle deviation of the middle and both ends of the plate two after bending is measured to obtain θ2; at the same time, the deformation value D2 of the deformation sensor during the bending process is recorded.

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

[0063] Further comprising step 2C-6, calculating the initial upper and lower die parallelism deviation E, and the specific calculation formula is:

[0064]

[0065] The present application has the following beneficial effects: the present application can detect the deformation of the machine tool in real time, and further achieve closed-loop control of precision deviation; especially when bending a large-format thick plate, the bending precision of the plate can be improved, and the waste of the plate can be reduced. Especially when the intelligent bending production line is equipped with this function, closed-loop real-time intelligent automatic control can be realized. In addition, the present application does not require manual intervention, which greatly improves the intelligent level. For example, the large arm bending process of the engineering machinery crane has high precision requirements. The open-loop control of the prior art cannot overcome the influence of the deformation of the machine tool on the precision, and the precision is unstable, which often causes batch rejection of the plate and is difficult to meet the requirements. Further, the present application can calculate and compensate the initial deviation of the upper and lower dies, which is more convenient for installation and debugging. BRIEF DESCRIPTION OF DRAWINGS

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

[0067] Figure 2 A structural schematic diagram of a deformation sensor mounted on a lower side plate is shown.

[0068] Figure 3 A structural schematic diagram of a deformation sensor mounted on a slider is shown.

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

[0070] Figure 5A third preferred installation of the deformation sensor on the slider is shown.

[0071] Figure 6 A simulation diagram for solving the deformation scale factor K by finite analysis is shown.

[0072] Figure 7 A schematic diagram for obtaining the deformation scale factor K by on-site manual testing is shown.

[0073] Figure 8 A schematic diagram of the force when the deformation scale factor K is solved by the analytical method is shown.

[0074] Figure 9 A deformation cloud chart of the slide plate and the lower side plate in the prior art is shown.

[0075] Figure 10 A deformation curve diagram of the slide plate and the lower side plate in the finite analysis is shown.

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

[0077] Among them:

[0078] 10. rack; 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 instrument. DETAILED DESCRIPTION

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

[0084] In the description of the present application, 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, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and "first", "second" and the like do not represent the importance of the parts, and therefore cannot be understood as a limitation on the present application. The specific dimensions used in the present embodiment are only for the purpose of illustrating the technical solutions and do not limit the protection scope of the present application.

[0085] As shown in Figure 1 and Figure 2 , the bending machine comprises a rack 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 slider is capable of descending in height.

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

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

[0089] The control system, also known as a deformation compensation mechanism, has a built-in deformation ratio coefficient K; wherein the deformation ratio 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.

[0090] As shown in Figure 10 , it shows the deformation curve of the slider and the lower side plate under working condition 1 and working condition 2 obtained by using finite element analysis method; wherein working condition 1 and working condition 2 are two different working conditions, wherein the abscissa is the size coordinate along the length direction of the die, and the ordinate is the deformation amount.

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

[0092] The above-mentioned deformation sensor is preferably but not limited to 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 is connected to the lower side plate or the slider in a "point" connection mode (preferably but not limited to hinged connection), so that the slider or the lower side plate is elastically deformed, while the rigid beam only has a rigid body displacement and does not have an elastic deformation, that is, the elastic deformation amount 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. Wherein, the deformation sensor detects the displacement between the rigid beam and the slider or the lower side plate, and 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, and the principle is the same, which is an equivalent alternative.

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

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

[0096] Preferred installation mode 1

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

[0098] Preferred installation mode 2

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

[0100] Preferred installation mode 3

[0101] As shown in Figure 5 , the deformation sensor has two, which are arranged at the top of the two ends of the rigid beam, and the middle of the rigid beam is connected with the lower side plate or the slider. This installation mode can predict the bending machine load deviation according to the feedback values of the two deformation sensors when the feedback values of the two deformation sensors 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 = K x B.

[0103] When the deformation sensor is arranged on the lower side plate, 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.

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

[0105] Step 1, installing a deformation sensor: arranging a deformation sensor on a deformation part A to be detected or a rigid beam.

[0106] Step 2, obtaining a deformation ratio coefficient K: obtaining a deformation ratio coefficient K by experimental detection or analysis method; wherein the deformation ratio 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.

[0107] In the present application, the deformation ratio coefficient K is preferably obtained by four preferred embodiments.

[0108] Example 1

[0109] As shown in Figure 6 , the above deformation ratio coefficient K is obtained by a finite analysis method, and specifically comprises the following steps.

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

[0111] Step 2A-2, bending: using the bending machine model built in step 2A-1, multiple simulation bending is performed on the workpiece to be bent, and the deformation curve of the lower side plate or the slider during the bending process is recorded.

[0112] Step 2A-3, calculating the simulation elastic deformation amount B of the lower side plate: subtracting the difference between the maximum simulation deformation amount and the minimum simulation deformation amount in the lower side plate deformation curve, the simulation elastic deformation amount B is obtained.

[0113] Step 2A-4, calculating the simulation elastic deformation amount A of the slider: subtracting the difference between the maximum simulation deformation amount and the minimum simulation deformation amount in the slider deformation curve, the simulation elastic deformation amount A is obtained.

[0114] Step 2A-5, calculating the deformation ratio coefficient K, then: K = simulation elastic deformation amount A / simulation elastic deformation amount B, in Figure 6 , the deformation ratio coefficient K is calculated as:

[0115]

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

[0117] Example 2

[0118] As Figure 8 shown, the above deformation ratio coefficient K is obtained by analytical method, specifically including the following steps:

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

[0120]

[0121] Wherein:

[0122]

[0123] In the formula, q is the uniform pressure on the bottom surface of the slider or the top surface of the lower side plate.

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

[0125] E1 is the elastic modulus of the slider.

[0126] I1 is the sectional moment of inertia of the slider.

[0127] b1 is the thickness of the slider.

[0128] h1 is the height of the slider.

[0129] Step 2B-2: Calculate the deformation W2 of the lower side plate. The specific calculation formula is as follows:

[0130]

[0131] in:

[0132]

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

[0134] I2 – 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 calculation model for the deformation scaling factor K:

[0138]

[0139] Step 2B-4, Simplify the calculation model for the deformation scaling factor K: Substitute W1 from Step 2B-1 and W2 from 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 requires no operation and only inputs the necessary parameters, but it is only suitable for the shape of standard sliders and the lower side plate of the frame. The calculation accuracy is insufficient in special and complex cases.

[0143] Example 3

[0144] like Figure 7 As shown, the deformation ratio coefficient K was obtained by manual testing on-site using measuring instrument 50.

[0145] Example 4

[0146] In step 2, the deformation ratio coefficient K is obtained through the trial bending method of the sheet metal, specifically including the following steps:

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

[0148] θ1=W(D1+KD1+E)

[0149] θ2=W(D2+KD2+E)

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

[0151] E is the initial parallelism deviation of the upper and lower dies, which is an unknown quantity;

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

[0153]

[0154] Step 2C-3, obtaining θ1 and D1: perform a bending experiment on plate one at a set angle, and measure the angle deviation of the middle and both ends of the bent plate one to obtain θ1; at the same time, record the deformation value D1 of the deformation sensor during the bending process.

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

[0156] Step 2C-5, calculating 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 about the bending angle deviation constructed in step 2C-2, to calculate the deformation proportional coefficient K.

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

[0158]

[0159] The deviation of the middle angle precision of the actually bent plate from the angle precision of the two ends is calculated. Generally, the upper die of the bending machine is assembled below the slider, and the lower die is assembled above the lower side plate of the machine 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 precision.

[0160] If the deformation sensor detects the deformation amount of the lower side plate, the calculation idea of the deformation sensor arranged on the slider is similar, which will not be described here.

[0161] Step 3, measuring the elastic deformation amount: during the bending process of the bending machine, the elastic deformation amount of the lower side plate or the slider is directly measured by using the deformation sensor.

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

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

Claims

1. A deformation detection mechanism for a bending machine, characterized in that: The bending machine comprises a rigid beam, a deformation sensor and a control system. The bending machine comprises two deformed parts to be detected, namely 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. The control system is internally provided with a deformation proportionality coefficient K; 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 plate, ; The rigid beam is connected to one of the deformed parts to be detected A through a "point", and the elastic deformation of the rigid beam is zero. The deformation sensor is arranged on the deformed part to be detected A or the rigid beam, and can be used to detect the relative deformation displacement of the rigid beam and the deformed part to be detected A. When the deformed part to be detected A is the lower side plate, the elastic deformation B of the lower side plate can be detected, and the elastic deformation A of the slider is K times the elastic deformation B of the lower side plate. When the deformed part to be detected A is the slider, the elastic deformation A of the slider can be detected, and the elastic deformation B of the lower side plate is A divided by K. The control system calculates the elastic deformation of the other deformed part to be detected according to the elastic deformation of the deformed part to be detected A detected by the deformation sensor and the deformation coefficient K, and further obtains the elastic deformations A and B of the whole bending machine.

2. The bending machine deformation detection mechanism according to claim 1, characterized in that: The control system drives the compensation mechanism to compensate the bending machine according to the elastic deformations A and B of the bending machine, and further realizes the closed-loop control of the bending machine precision.

3. 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 and the other end of the rigid beam are connected to the deformed part to be detected A through a "point".

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

5. A method for detecting deformation of a bending machine based on the deformation detection mechanism of any one of claims 1-4, characterized in that: The deformation sensor has two, which are arranged at the top of the two ends of the rigid beam, and the middle of the rigid beam is connected to the deformed part to be detected A. The method comprises the following steps: Step 1, installing the deformation sensor: arranging the deformation sensor on the deformed part to be detected A or the rigid beam; Step 2, obtaining the deformation coefficient K: obtaining the deformation coefficient K through experimental detection or analysis method; wherein the deformation coefficient K is the ratio of the elastic deformation A of the slider to the elastic deformation 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 by using the deformation sensor; 6. The method according to claim 5, characterized in that: Step 4, calculating the other elastic deformation: according to the deformation coefficient K in step 2 and the elastic deformation obtained in step 3, the elastic deformation of the slider or the lower side plate is calculated; when the measured value in step 3 is the elastic deformation B of the lower side plate, the elastic deformation A of the slider is K times the elastic deformation B of the lower side plate; when the measured value in step 3 is the elastic deformation A of the slider, the elastic deformation B of the lower side plate is A divided by K. In step 2, the deformation coefficient K is obtained by finite analysis method, which comprises 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, simulating the bending of the workpiece to be bent, and obtaining the deformation curves of the lower side plate and the slider during the bending process. Step 2A-3, calculate the simulation elastic deformation B of the lower side plate: subtract the difference between the maximum simulation deformation and the minimum simulation deformation in the lower side plate deformation curve to obtain the simulation elastic deformation B; Step 2A-4, calculate the simulation elastic deformation A of the slider: subtract the difference between the maximum simulation deformation and the minimum simulation deformation in the slider deformation curve to obtain the simulation elastic deformation A; Step 2A-5, calculate the deformation ratio coefficient K, then: K = simulation elastic deformation A / simulation elastic deformation B.

7. The method according to claim 5, characterized in that: In step 2, the deformation ratio coefficient K is obtained by analytical method, which specifically includes the following steps: Step 2B-1, calculating slider deformation The specific formula is: ； Wherein: ； In the formula, - uniform pressure on the bottom surface of the slider or on the top surface of the lower side plate - length of the uniform load on the slider bottom surface or on the top surface of the lower side plate; - the modulus of elasticity of the slider; - the cross-sectional moment of inertia of the slider; - the thickness of the slider; - height of the slider; Step 2B-2, calculating the lower side plate deformation amount The specific calculation formula is: ； Wherein: ； In the formula, - the modulus of elasticity of the lower side plate; - the cross-sectional moment of inertia of the lower side plate; - thickness of the lower side plate; - height of the lower side plate; Step 2B-3, construct a deformation ratio coefficient K calculation model: ； Step 2B-4, Simplified deformation scale factor K calculation model: Substitute the results of Step 2B-1 and Step 2B-2 into Step 2B-3, and simplify to get: ； When the slider and the lower side plate material are the same, .

8. The method according to claim 5, characterized in that: In step 2, the deformation ratio coefficient K is obtained by field manual test.

9. The method according to claim 5, characterized in that: In step 2, the deformation ratio coefficient K is obtained by plate test folding method, which specifically includes the following steps: Step 2C-1, constructing the bending angle deviation equation: select two plates, respectively marked as plate one and plate two; set the angle deviation of the middle and both ends of the plate one when the bending machine is bent as , the deformation measurement value of the deformation sensor when the plate one is bent as ; the angle deviation of the middle and both ends of the plate two when the bending machine is bent as , the deformation measurement value of the deformation sensor when the plate two is bent as , then the following two bending angle deviation equations are constructed, specifically: ； ； In the formula, The ratio between the bending angle and the work advance of the upper die is a known value. - deviation of parallelism of the initial upper and lower dies, unknown quantity; Step 2C-2, construct a proportion coefficient equation about the bending angle deviation: subtract the two bending angle deviation equations constructed in step 2C-1, and solve to obtain the proportion coefficient K equation about the bending angle deviation, the specific expression is: ； Step 2C-3, obtaining and : the plate one is subjected to the bending experiment with a set angle, and the angle deviation of the middle and both ends of the plate one after bending is measured to obtain ; at the same time, the deformation value of the deformation sensor is recorded during the bending process; Step 2C-4, obtaining and : the plate two is subjected to the bending experiment at the set angle, the angle deviation of the middle and both ends of the plate two after bending is measured, and the angle deviation is obtained ; at the same time, the deformation value of the deformation sensor during the bending process is recorded ; Step 2C-5, calculating the deformation scale factor K: the scale factor equation about the bending angle deviation constructed in Step 2C-2 is substituted with the bending angle deviation obtained in Step 2C-4 and the bending angle obtained in Step 2C-5, thereby calculating the deformation scale factor K. and the bending angle deviation obtained in Step 2C-4 and , the scale factor equation about the bending angle deviation constructed in Step 2C-2 is substituted with the bending angle deviation obtained in Step 2C-4 and the bending angle obtained in Step 2C-5, thereby calculating the deformation scale factor K.

10. The method according to claim 9, characterized in that: Also included is step 2C-6, calculating the initial upper and lower die parallelism deviation The specific formula is:

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