Method for measuring and rejecting eccentricity of porcelain parts and blanks of porcelain insulators

Abstract

The present application relates to a kind of porcelain insulator porcelain piece and blank eccentricity measurement and rejection method, belong to the technical field of insulator quality detection.The method includes positioning to be measured piece;Measure the wall thickness of to be measured piece under different angles, and calculate the eccentricity of to be measured piece according to the wall thickness of to be measured piece;According to the preset rejection threshold analysis eccentricity, judge whether to need to remove to be measured piece.The present application is positioned after to porcelain insulator, detects the wall thickness of porcelain insulator at different angles, and calculates eccentricity by wall thickness measurement result, judges whether porcelain insulator needs to be removed according to the rejection threshold based on quality management Westgard Sigma multi-rule, can let manufacturer know the eccentricity information of disc type suspension porcelain insulator, formulate rejection scheme, improve the consistency of final product, can provide eccentricity data to user, increase the information of product, improve market competitiveness.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of insulator quality detection, and particularly relates to a method and a measuring system for measuring and removing the eccentricity of a porcelain piece and a blank of a porcelain insulator. BACKGROUND

[0002] A disc-type suspension porcelain insulator is an important equipment component of a power transmission and transformation system, and is widely used in power grid systems such as high-voltage transmission lines and transformer substations, and plays a mechanical support and power insulation role for a power transmission conductor. The porcelain piece of the disc-type suspension porcelain insulator has a cylindrical or conical inner hole in structure, and the inner hole and the outer wall should be concentric in structure design. In actual production, the inner hole and the outer wall often have eccentricity. The eccentricity will cause uneven stress of the final product and reduce the insulation distance on one side. In order to improve the product quality, it is necessary to check and remove the eccentricity of the blank and the porcelain piece during production.

[0003] Since the disc-type suspension insulator has a complex shape, there is no tool that can directly measure the eccentricity between the inner hole circle and the outer wall circle of the blank or the porcelain piece. The present application provides a method for measuring and removing the eccentricity of a disc-type suspension porcelain insulator porcelain piece or blank, and provides a calculation method for the eccentricity and a removal threshold value that meets the Westgard Sigma multi-rule of quality management.

[0004] Specifically, the following problems actually exist in the existing measurement work of porcelain insulators:

[0005] 1. In the traditional method for measuring the eccentricity of the porcelain piece and the blank, a steel ruler, an inside caliper, a vernier, etc. are used, and there is a certain damage to the blank head and the inner hole and a large error in the measurement process; the measurement efficiency is low, the operation is difficult, and the manual labor intensity is large.

[0006] 2. In the traditional measurement method, although the vernier and the inside caliper can be used to measure the outer wall circle and the inner hole circle, and then the side wall thickness is calculated by difference, it is impossible to judge whether there is a difference between the side wall thicknesses on both sides, and it is impossible to remove the products with eccentricity.

[0007] 3. Since the cylindrical porcelain piece head and the inner hole are covered with a layer of porcelain sand, the traditional measurement method cannot accurately measure the size of the porcelain piece head and the inner hole.

[0008] 4. In the process of measuring by using a steel ruler, a vernier, an inside caliper, etc., it is often limited to a certain position, the measurement range is too small, and it is impossible to accurately judge whether the product has eccentricity. SUMMARY

[0009] The purpose of the present application is to provide a method for measuring and removing the eccentricity of a porcelain insulator porcelain piece and a blank.

[0010] The application achieves the above-mentioned purpose through the following technical solutions.

[0011] A method for measuring and removing the eccentricity of a porcelain piece and a blank of a porcelain insulator, the porcelain piece and the blank of the porcelain insulator are both the measured objects of the method, and the method comprises the following steps:

[0012] Step one, positioning the measured object to align the outer wall axis of the measured object with the measuring station;

[0013] Step two, measuring the wall thickness of the measured object at different angles, and calculating the eccentricity of the measured object according to the wall thickness, the calculation method of the eccentricity is as follows:

[0014] ;

[0015] Wherein, dE is the range of N wall thickness measurement results; is the maximum wall thickness in N wall thickness measurements, is the minimum wall thickness in N wall thickness measurements, k is the intermediate quantity, and d is the eccentricity;

[0016] Step three, analyzing the eccentricity of the measured object, when the eccentricity of the measured object exceeds the preset removal threshold, removing the measured object, and the establishment method of the removal threshold is as follows:

[0017] ;

[0018] Wherein, is the removal threshold of the measured object, s is the standard deviation of two-dimensional normal distribution, and P is the probability value obtained by querying Westgard Sigma multiple rules.

[0019] As a further optimization scheme of the application, in step three, the calculation method of the standard deviation of two-dimensional normal distribution is as follows:

[0020] ;

[0021] Wherein, is the average value of the eccentricity of a batch of porcelain pieces or blanks calculated in advance.

[0022] A measuring system for implementing the above-mentioned method, the system comprises a positioning mechanism, a thickness measuring mechanism and a control module, the positioning mechanism is used for axial positioning of the measured object, the thickness measuring mechanism is used for collecting the wall thickness data of the measured object at different angles and sending the wall thickness data to the control module, after receiving the wall thickness data, the control module obtains the eccentricity of the measured object according to the calculation method of the eccentricity, and judges whether the measured object needs to be removed based on the removal threshold.

[0023] As a further optimization scheme of the present application, the system further comprises a gas supply mechanism and a driving mechanism connected with the control module, the positioning mechanism has a pneumatic actuator, the gas supply mechanism is used for positioning the outer wall axis of the measured member by the pneumatic actuator, the thickness measuring mechanism has two thickness measuring components, the driving mechanism is used for respectively placing the two thickness measuring components of the thickness measuring mechanism inside and outside the measured member, and relatively rotating the thickness measuring mechanism and the positioning mechanism about the outer wall axis of the measured member.

[0024] As a further optimization scheme of the present application, the positioning mechanism comprises a positioning seat, a containing cavity arranged inside the positioning seat, an air bag fixedly arranged on the upper part of the containing cavity, and a carrier plate arranged on the lower part of the containing cavity, and the carrier plate can slide in any horizontal direction on the bottom wall of the positioning seat.

[0025] As a further optimization scheme of the present application, the positioning mechanism further comprises a reset member, which is used for resetting the carrier plate to the axis of the positioning mechanism after the thickness measurement of each measured member is completed, and after the resetting, the axis of the carrier plate coincides with or is adjacent to the axis of the positioning mechanism.

[0026] As a further optimization scheme of the present application, the reset member comprises a counterweight arranged directly below the positioning seat, and a pull rope arranged between the counterweight and the carrier plate, when the measured member is positioned, the counterweight moves upward, the pull rope is kept relaxed, and the carrier plate is in a non-constrained state; after the thickness measurement of the measured member is completed, the counterweight moves downward, and the carrier plate is reset and constrained through the pull rope.

[0027] As a further optimization scheme of the present application, the bottom of the carrier plate is uniformly provided with a plurality of rolling balls in the circumferential direction, the center of the bottom wall of the positioning seat protrudes upward to form a guide member, a wire groove corresponding to the pull rope is arranged in the guide member and penetrates the bottom wall of the positioning seat.

[0028] As a further optimization scheme of the present application, the system further comprises a support, a load sensor is fixedly arranged between the support and the positioning seat, an air cylinder is fixedly arranged on the support, the air cylinder is arranged below the counterweight in a sliding mode, the gas supply mechanism comprises an air pump, a shunt pipe connected with the air outlet of the air pump, and an air pressure sensor and a three-way valve arranged on the shunt pipe, the air bag and the air cylinder are communicated with the shunt pipe, a clamping component corresponding to the counterweight is arranged on the support, and a flow resistance member is arranged on the branch of the shunt pipe connected with the air bag.

[0029] As a further optimization scheme of the present application, the driving mechanism comprises a lifting assembly and a rotary driving member fixedly arranged on the output end of the lifting assembly, the thickness measuring mechanism comprises a mounting bracket fixedly arranged on the output end of the rotary driving member, one thickness measuring component of the thickness measuring mechanism is arranged in the middle of the mounting bracket, and the other thickness measuring component of the thickness measuring mechanism is arranged at one end of the mounting bracket, and a counterweight component is arranged at the other end of the mounting bracket.

[0030] The present application has the following beneficial effects:

[0031] 1) The present application can detect the wall thickness of the porcelain insulator at different angles by the thickness measuring part, calculate the eccentricity by the wall thickness measurement result, and meet the rejection threshold of the Westgard Sigma multi-rule of quality management, so that the manufacturer can know the eccentricity information of the disc type suspension porcelain insulator, formulate a rejection plan, and improve the consistency of the final product;

[0032] 2) The present application can automatically measure the wall thickness and eccentricity of the porcelain insulator at different heights, accurately obtain the size of the head and inner hole of the porcelain piece, has a large measurement range, high measurement efficiency, simple operation, and saves manpower;

[0033] 3) The eccentricity data obtained by the eccentricity measurement and rejection method can be provided to the user of the porcelain insulator product, increase the information of the product, and improve the market competitiveness;

[0034] 4) The positioning mechanism of the present application positions the porcelain insulator by pneumatic actuators, and the friction between the lower plate of the porcelain insulator and the positioning seat is small during positioning, so that each porcelain insulator can be moved to the center of the positioning mechanism, avoiding damage to the porcelain insulator during positioning, and improving the measurement accuracy;

[0035] 5) The present application resets the carrier plate after the eccentricity measurement is completed, avoiding the carrier plate moving to the inner wall of the positioning seat after multiple eccentricity measurements, and the pneumatic actuators cannot reset the porcelain insulator;

[0036] 6) When the pneumatic actuators are inflated, the gas supply mechanism also inflates the air cylinder, and the counterweight of the reset part is lifted, avoiding the self-weight of the counterweight restricting the movement of the carrier plate. After the eccentricity measurement is completed, the gas in the air cylinder is discharged through the shunt pipe and the three-way valve, and the counterweight resets the carrier plate by its own weight, further improving the positioning effect and improving the measurement accuracy;

[0037] 7) When positioning the porcelain insulator, the positioning air source is used to automatically synchronize the contact to constrain the porcelain insulator carrier plate. During the preparation stage and the measurement process, the reset part does not generate interference force to the carrier plate. After the measurement is completed, the positioning of the porcelain insulator is released, and the constraint force to the porcelain insulator carrier plate is automatically restored, realizing automatic positioning and resetting. The carrier plate resetting and the porcelain insulator positioning do not interfere with each other, and the resetting operation does not need to add an additional power source. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a side view cross-sectional schematic diagram of the present application when measuring the wall thickness E1;

[0039] Figure 2 is a top view cross-sectional schematic diagram of the present application when measuring 6 wall thicknesses E1-E6 on the circumference;

[0040] Figure 3 is a top view schematic diagram of the present application when measuring the circumferential wall thickness E1-E8;

[0041] Figure 4 is a system block diagram of the present application measuring system;

[0042] Figure 5 is a schematic diagram of the structure of the present application measuring system in non-working state;

[0043] Figure 6 is a schematic diagram of the structure of the present application measuring system in working state;

[0044] Figure 7 is a schematic diagram of the internal structure of the positioning mechanism of the present application;

[0045] Figure 8 is an enlarged view of A in Figure 7

[0046] Figure 9 is an enlarged view of B in Figure 7

[0047] Figure 10 is an enlarged view of C in Figure 7

[0048] Figure 11 is a side view of the thickness measuring mechanism of the present application with a hanging assembly.

[0049] In the figure: 1, positioning mechanism; 2, thickness measuring mechanism; 3, air supply mechanism; 4, driving mechanism; 5, support; 11, positioning seat; 12, containing cavity; 13, air bag; 14, carrier plate; 15, reset member; 16, ball; 17, guide member; 18, wire slot; 19, load cell; 21, mounting bracket; 22, counterweight component; 23, mounting disc; 24, annular track; 25, hanging wheel; 26, limiting plate; 27, top plate; 28, telescopic member; T1, thickness measuring component one; T2, thickness measuring component two; 31, air pump; 32, shunt pipe; 33, air pressure sensor; 34, three-way valve; 41, lifting assembly; 42, rotary driving member; 51, operation table; 52, supporting plate; 53, mounting table; 151, counterweight member; 152, pull rope; 153, air cylinder; 154, stopper; 155, ball head; 156, clamping component; 321, main pipe; 322, branch pipe one; 323, branch pipe two; 324, choke pipe; 325, baffle; W, object to be measured; O1, axis one; O2, axis two. DETAILED DESCRIPTION

[0050] ​​​The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content. Example

[0051] like Figures 1-5 As shown, a method for measuring and rejecting eccentricity of porcelain insulator components and blanks is disclosed. This method is applicable to disc-type suspension porcelain insulators, including both porcelain components and blanks. The porcelain components and blanks mentioned above are the test pieces W of this method. The method specifically includes the following steps:

[0052] Step 1: Place the workpiece W to be measured on the positioning mechanism 1. The inner diameter of the positioning mechanism 1 is slightly larger than the diameter of the outer wall of the workpiece W. The positioning mechanism 1 positions the workpiece W so that its outer wall axis is aligned with the measuring station, making the outer wall axis of the workpiece W coaxial with the axis of the positioning mechanism 1. The axis of the positioning mechanism 1 is the measuring station. The outer wall axis of the workpiece W is denoted as axis one O1, and the inner wall axis of the workpiece W is denoted as O2. The wall thickness of the workpiece W is measured using the thickness measuring mechanism 2. This thickness measuring mechanism 2 has two thickness measuring components: thickness measuring component one T1 and thickness measuring component two T2. In the preparation stage for eccentricity measurement, thickness measuring component one T1 of the thickness measuring mechanism 2 is placed inside the workpiece W, and thickness measuring component two T2 of the thickness measuring mechanism 2 is placed outside the workpiece W.

[0053] The thickness measuring mechanism 2 can be a contact thickness measuring device, such as a vernier caliper; it can also be a non-contact thickness measuring device. In this embodiment, a non-contact thickness measuring device is used to measure the wall thickness of the workpiece W. Specifically, the non-contact thickness measuring device is preferably a laser thickness measuring device. In other embodiments, infrared thickness measuring devices or ultrasonic thickness measuring devices can be used to replace the thickness measuring mechanism 2 in this embodiment.

[0054] Step 2: The thickness measuring mechanism 2 rotates around the axis of the positioning mechanism 1, that is, around axis O1, and measures the wall thickness N times at N rotation angles. The wall thickness is recorded as follows. And according to the wall thickness Calculate the eccentricity d between the inner and outer centers of the workpiece W to be measured. The eccentricity d is obtained by the following three equations:

[0055] ;

[0056] Where dE is the range of the N wall thickness measurements; The maximum wall thickness from N wall thickness measurements. Let k be the minimum wall thickness from N wall thickness measurements, and k be an intermediate value. In this embodiment, as... Figure 2As shown, N is 6, and 6 wall thicknesses are measured. In addition, in other embodiments, the number of measurements of the wall thickness can also be increased , for example Figure 3 As shown in the embodiment, 8 measurements are measured. Here, the more the number of measurements of the wall thickness , the more accurate the calculation result.

[0057] In step two, the thickness measuring mechanism 2 can also be controlled to be stationary, and the porcelain piece or blank is rotated by rotating the positioning mechanism 1 to measure the wall thickness of the porcelain piece or blank at different angles.

[0058] Step three, for a certain type of porcelain insulator product produced by the manufacturer, the eccentricity of the measured piece W is analyzed. When the eccentricity d of the measured piece W exceeds the preset rejection threshold , that is , the measured piece W is rejected. In order to obtain a high consistency product to meet the Westgard Sigma Multiple Rules of quality management, the establishment method of the rejection threshold is as follows:

[0059] ;

[0060] Where s is the two-dimensional normal distribution standard deviation of the eccentricity d of a batch of porcelain pieces or blanks calculated in advance. When the measured piece W is a porcelain piece, the two-dimensional normal distribution standard deviation is calculated based on a batch of porcelain pieces prepared in advance. When the measured piece W is a blank, the two-dimensional normal distribution standard deviation is calculated based on a batch of blanks prepared in advance. is the average eccentricity of the batch of porcelain pieces or blanks, is the rejection threshold for each subsequent porcelain piece or blank detection. P is the probability value obtained by querying the Westgard Sigma Multiple Rules. For example, when the product has a quality requirement of 3 Sigma, the P value is 0.9973.

[0061] Second embodiment

[0062] This embodiment relates to a measurement system for implementing the above-mentioned eccentricity measurement and rejection method, which comprises a positioning mechanism 1 and a thickness measuring mechanism 2, as shown in Figures 4-9 ​As shown, the positioning mechanism 1 is used for axial positioning of the workpiece W, so that the axis O1 of the workpiece W coincides with the axis of the positioning mechanism 1, and the thickness measuring mechanism 2 is used for collecting wall thickness data of the workpiece W at multiple angles, and the thickness measuring mechanism 2 is connected with a control module, and the control module is used for calculating eccentricity data according to the wall thickness data. The thickness measuring components of the positioning mechanism 1 are divided into thickness measuring component one T1 and thickness measuring component two T2, and both the thickness measuring component one T1 and the thickness measuring component two T2 are laser ranging devices, and both sides of the laser ranging devices are provided with emitting probes and receiving probes. The emitting probes of the two laser ranging devices are consistent in height, and the two emitting probes are oppositely arranged.

[0063] The system further comprises a gas supply mechanism 3 and a driving mechanism 4 connected with the control module, the positioning mechanism 1 has a pneumatic actuator, the gas supply mechanism 3 is used for positioning the outer wall axis of the workpiece W by the pneumatic actuator, and the driving mechanism 4 is used for respectively placing the two thickness measuring components T1, T2 of the thickness measuring mechanism 2 inside and outside the workpiece W, and rotating the thickness measuring mechanism 2 around the axis O1.

[0064] The driving mechanism 4 comprises a lifting assembly 41 and a rotary driving member 42 fixed to the output end of the lifting assembly 41. The thickness measuring mechanism 2 comprises a mounting bracket 21 fixed to the output end of the rotary driving member 42, and the mounting bracket 21 is in the shape of F and has one horizontal rod and two vertical rods, one vertical rod is arranged at the middle of the lower side of the horizontal rod, and the other vertical rod is arranged at one end of the lower side of the horizontal rod, a rotating rod is fixed to the middle of the upper side of the horizontal rod, and the horizontal rod is fixedly connected with the output end of the rotary driving member 42 through the rotating rod. One thickness measuring component T1 of the thickness measuring mechanism 2 is arranged at the bottom of the middle vertical rod of the mounting bracket 21, and the other thickness measuring component T2 of the thickness measuring mechanism 2 is arranged at the bottom of the vertical rod at one end of the mounting bracket 21, and a counterweight component 22 is fixed to the other end of the lower side of the horizontal rod of the mounting bracket 21, so as to balance the weight on both sides of the mounting bracket 21.

[0065] In the preparation stage of the eccentricity measurement, the workpiece W is first inserted into the positioning mechanism 1, the positioning mechanism 1 positions the workpiece W by the pneumatic actuator, so that the axis O1 of the workpiece W coincides with the axis of the positioning mechanism 1, and the positioning of the workpiece W is completed. Then the rotary driving member 42 and the mounting bracket 21 are moved downward by the lifting assembly 41, so that the thickness measuring component one T1 is in the inside of the workpiece W, and the thickness measuring component two T2 is in the outside of the workpiece W, and the preparation stage of the wall thickness measurement is completed. In this embodiment, the center of the thickness measuring component one T1 is located on the axis O1 of the workpiece W, and the rotating rod on the mounting bracket 21 is coaxially arranged with the positioning mechanism 1.

[0066] In the formal stage of the eccentricity measurement, the wall thickness of the workpiece W at different angles is first measured The rotating driving member 42 rotates the first thickness measuring component T1 and the second thickness measuring component T2 to different angles through the mounting frame 21 in the measuring process, and the first thickness measuring component T1 and the second thickness measuring component T2 cooperate with the control module to measure the wall thickness of the workpiece W at different positions. Specifically, the first thickness measuring component T1 and the second thickness measuring component T2 emit laser at the same angle, and detect the distance one between the first thickness measuring component T1 and the inner wall of the workpiece W and the distance two between the second thickness measuring component T2 and the outer wall of the workpiece W, respectively. The distance between the first thickness measuring component T1 and the second thickness measuring component T2 is always kept unchanged, which is recorded as the thickness measuring component distance. The wall thickness at the angle is obtained by subtracting the distance one and then the distance two from the thickness measuring component distance The control module realizes the above calculation process. The control module calculates the eccentricity d and the rejection threshold according to the eccentricity measurement and rejection method described in the first embodiment, and realizes the eccentricity measurement and rejection of the porcelain piece or blank of the porcelain insulator.

[0067] It should be noted that the two thickness measuring components T1 and T2 of the thickness measuring mechanism 2 are driven by the lifting assembly 41 in cooperation with the rotating driving member 42 to rotate at different heights. The eccentricity of the outer wall circle and the inner hole circle at different heights of the workpiece W can be measured. In the whole measuring process, the thickness measuring mechanism 2 measures the eccentricity at different heights of the workpiece W from top to bottom. After the eccentricity measurement at the previous height is completed, the eccentricity measurement at the next height is performed. If the eccentricity d at a certain height exceeds the rejection threshold , it is determined that the eccentricity measurement of the workpiece W fails, and the product is unqualified. At this time, the control module generates an alarm and stops measuring, and the operator discards this product, effectively avoiding the phenomenon that the eccentric product exists and flows into the next process. The above-mentioned rejection threshold does not exceed 1mm, and the eccentricity size error of the qualified porcelain insulator product can be controlled within the range of 0-1mm in the embodiment.

[0068] In other embodiments, the infrared thickness measuring device is used to replace the thickness measuring mechanism 2 in the embodiment, and the thickness measuring components T1 and T2 are replaced by infrared probes. The wall thickness can be calculated according to the infrared distance measuring principle. When the ultrasonic thickness measuring device is used to replace the thickness measuring mechanism 2 in the embodiment, the thickness measuring components T1 and T2 are replaced by ultrasonic probes, and the wall thickness is calculated by the propagation speed and time of ultrasonic waves in the medium. The above-mentioned alternative scheme can automatically compare whether the product wall thickness is within the standard requirement range, and solves the problem that the traditional measuring method cannot accurately measure the wall thickness. When the ultrasonic thickness measuring device is used, the blank and the porcelain piece can also be detected for defects, effectively preventing the defective products from flowing into the next process and causing quality problems.

[0069] In order to avoid the damage of the workpiece W during the detection process and improve the measurement accuracy, the positioning mechanism 1 fixes the workpiece W to the axis of the positioning mechanism 1 through the pneumatic actuator. For specific positioning process, please refer to Figures 7-9 The positioning mechanism 1 includes an open-top positioning seat 11, a containing cavity 12 arranged inside the positioning seat 11, an air bag 13 fixed to the upper part of the containing cavity 12, and a movable carrier plate 14 arranged at the lower part of the containing cavity 12. The carrier plate 14 can slide in any horizontal direction on the bottom wall of the positioning seat 11. The air bag 13 is annular in shape and has an annular cavity inside. The axis of the positioning mechanism 1 is the axis of the positioning seat 11. The containing cavity 12 includes an upper cavity and a lower cavity, and the inner diameter of the lower cavity is larger than that of the upper cavity. The carrier plate 14 is located in the lower cavity, and the air bag 13 is located in the upper cavity. The air bag 13 is the pneumatic actuator of the positioning mechanism 1.

[0070] During positioning, the workpiece W is inserted into the positioning seat 11, and at this time the air bag 13 is sleeved outside the workpiece W. The workpiece W is placed on the movable carrier plate 14, and the bottom of the carrier plate 14 is uniformly provided with a plurality of balls 16 in the circumferential direction, so that the friction between the carrier plate 14 and the positioning seat 11 is small. When the air bag 13 is inflated, if the workpiece W is not located at the axis of the positioning seat 11, the air bag 13 can push the workpiece W to the center of the positioning seat 11. Avoiding the decline of the measurement accuracy caused by the deviation of the placement position of different workpieces W. By positioning the workpiece W through the air bag 13, the force receiving area of the outer wall of the workpiece W is increased, and the impact force received by the workpiece W during positioning is reduced. Moreover, since the inner wall of the workpiece W has a small hole diameter, after accurate positioning, the inner wall can also avoid contact with the thickness measuring mechanism 2 during the measurement process. Provide sufficient protection for the inner and outer walls of the insulator. In addition, in some other embodiments, the positioning mechanism 1 can also be only an upper open cylindrical base, and the inner diameter of the base is slightly larger than the outer wall diameter of the porcelain or blank.

[0071] Further, after multiple eccentricity measurements, if the reset structure is not provided, the carrier plate 14 can move to the inner side wall of the positioning seat 11, so that the carrier plate 14 cannot move afterwards. At this time, there is a large friction between the workpiece W and the carrier plate 14, and the positioning accuracy of the workpiece W by the air bag 13 can be affected. Therefore, the reset member 15 is also arranged on the positioning mechanism 1, which is used to reset the carrier plate 14 to the axis of the positioning mechanism 1 after each wall thickness measurement of the workpiece W is completed. After resetting, the axis of the carrier plate 14 coincides with or is close to the axis of the positioning mechanism 1.

[0072] Specifically, the reset member 15 includes a counterweight 151 located directly below the positioning seat 11, and a pull rope 152 provided between the counterweight 151 and the carrier plate 14. When positioning the workpiece W, the air supply mechanism 3 drives the counterweight 151 to move upward, so that the pull rope 152 remains relaxed. At this time, the carrier plate 14 is in an unrestrained state. After the wall thickness measurement of the workpiece W is completed, the counterweight 151 is reset, and the pull rope 152 is pulled downward, so that the carrier plate 14 is reset. In this embodiment, the counterweight 151 is driven to move by the air supply mechanism 3. The bottom wall of the positioning seat 11 is centrally upwardly protruding to form a guide member 17, and the guide member 17 is provided with a wire slot 18 corresponding to the pull rope 152, and the wire slot 18 penetrates the bottom wall of the positioning seat 11. The inner wall of the guide member 17 is in a flared shape, and the guide member 17 protrudes upward, which can avoid the stress concentration phenomenon between the pull rope 152 and the positioning seat 11 during resetting, and ensure that the upper part of the pull rope 152 is close to a horizontal state when the pull rope 152 pulls the carrier plate 14, thereby improving the resetting pulling effect of the carrier plate 14 and reducing the wear of the pull rope 152 and the weight of the counterweight 151.

[0073] The system further includes a support 5, which includes an operation table 51 and a supporting plate 52 provided below the top wall of the operation table 51. The operation table 51 is fixedly provided with a load sensor 19 between the positioning seat 11, and the positioning seat 11 is fixedly provided with a limiting rod at the bottom, which is embedded in the operation table 51 to limit the positioning seat 11 and improve the detection accuracy of the load sensor 19. The supporting plate 52 is fixedly provided with an air cylinder 153, and the counterweight 151 is slidingly arranged outside the air cylinder 153, which is a cylinder with an embedded counterweight. The air supply mechanism 3 includes an air pump 31, a shunt pipe 32 connected to the air outlet of the air pump 31, an air pressure sensor 33 and a three-way valve 34 provided on the shunt pipe 32, and the air bag 13 and the air cylinder 153 are both communicated with the shunt pipe 32. The support 5 further includes a mounting table 53 fixedly provided above the top wall of the operation table 51, and the lifting assembly 41 is fixedly provided on the mounting table 53. The rotating rod on the mounting bracket 21 penetrates the mounting table 53. The lifting assembly 41 is preferably a lead screw motor, and the rotating drive member 42 is preferably an electric motor. The rotating drive member 42 is fixedly arranged on a support bracket, which is threadedly connected with the output shaft of the lifting assembly 41. In addition, in some other embodiments, the lifting assembly 41 and the rotating drive member 42 can be replaced by other existing linear drive structures and rotating drive structures.

[0074] The shunt pipe 32 comprises a main pipe 321, a branch pipe one 322 and a branch pipe two 323. The main pipe 321 is fixedly arranged at the air outlet of the air pump 31. The air outlet of the main pipe 321 is provided with a three-way joint. The air inlets of the branch pipe one 322 and the branch pipe two 323 are connected with the main pipe 321 through the three-way joint. The air outlets of the branch pipe one 322 and the branch pipe two 323 are respectively communicated with the air cylinder 153 and the air bag 13. The air pressure sensor 33 and the three-way valve 34 are arranged on the main pipe 321. The upper and lower ports of the three-way valve 34 are fixedly arranged on the main pipe 321. The port on the side of the three-way valve 34 is communicated with the external atmosphere of the air supply mechanism 3. The control module is composed of a controller one, a controller two and a PC end. The controller one is connected with an alarm. When the product is unqualified, the controller two sends an alarm through the alarm to remind the operator to scrap the unqualified product. The controller one is preferably a PLC controller. The PLC controller is electrically connected with the PC end and is used for calculating the wall thickness and the rejection threshold . The calculation results are sent to the PC end for the operator to view. The controller two is preferably a single-chip microcomputer controller. The single-chip microcomputer controller is arranged on the mounting frame 21 and is wirelessly connected with the PLC controller. In addition, in some other embodiments, the single-chip microcomputer controller can be electrically connected with the PLC controller through an electric slip ring. The PLC controller can be connected with the PC end through a wireless signal. The lifting assembly 41 and the rotary driving member 42 of the driving mechanism 4, the load sensor 19 of the positioning mechanism 1, the air pump 31, the air pressure sensor 33 and the three-way valve 34 of the air supply mechanism 3 are electrically connected with the controller one. The two thickness measuring components T1 and T2 of the thickness measuring mechanism 2 are electrically connected with the controller two.

[0075] After the reset member 15 is arranged, in the specific positioning process, whether the workpiece W is placed on the loading plate 14 is detected by the load sensor 19 in cooperation with the control module. When the workpiece W is placed on the loading plate 14, if the pressure borne by the load sensor 19 exceeds the set value, it indicates that the workpiece W is placed on the loading plate 14. The system automatically performs the positioning of the workpiece W, the eccentricity measurement and the calculation of the rejection threshold.

[0076] When positioning, the air pump 31 fills the air bag 13 and the air cylinder 153 through the shunt pipe 32, expands the air bag 13, and moves the counterweight 151 upward, ensuring that the movement of the carrier plate 14 is not affected by the tension of the pull rope 152. In addition, during eccentricity measurement, the air pressure in the shunt pipe 32 is measured by the air pressure sensor 33 in cooperation with the control module, and the air pump 31 is adjusted by the control module to ensure that the air pressure in the shunt pipe 32 is stable during eccentricity measurement, i.e. after the air pump 31 is started for a period of time, the air pressure in the dry pipe 321 is within the set range. After the eccentricity calculation is completed, the air pump 31 is turned off, and the upper port of the three-way valve 34 is connected to the side port, at this time, the gas in the air bag 13 and the air cylinder 153 can be discharged to the outside through the shunt pipe 32 and the three-way valve 34, and the counterweight 151 resets the carrier plate 14 by its own weight. In addition, if the air pump 31 is a bidirectional pump, such as a Roots pump, the three-way valve 34 can be omitted, and the shunt pipe 32 can be supplied with air and discharged by the bidirectional pump.

[0077] For larger porcelain insulators, the reset member 15 needs to be configured with a heavier counterweight 151, which may cause excessive energy consumption of the air supply mechanism 3. Please refer to Figures 7-10 , to address this situation, a clamping component 156 is also fixed below the top wall of the operation table 51, which is preferably a magnet, and the shape of the magnet is preferably annular. Correspondingly, the overall or part of the counterweight 151 is made of ferromagnetic metal. When positioning the measured object W, the air supply mechanism 3 fills the air cylinder 153 to move the counterweight 151 to the state of adhering to the magnet, and when the counterweight 151 adheres to the magnet, the sum of the magnetic force of the magnet and the pushing force provided by the air supply mechanism 3 to the counterweight 151 is not less than the weight of the counterweight 151. After the measurement is completed, the gas in the air cylinder 153 is discharged from the three-way valve 34, and the weight of the counterweight 151 is greater than the magnetic force of the magnet, and under the action of gravity, the counterweight 151 resets to play its role in resetting the carrier plate 14. In addition, in some other embodiments, the clamping component 156 can also be a sleeve, and the counterweight 151 is embedded in the sleeve after moving upward, and the sum of the friction force between the sleeve and the counterweight 151 and the pushing force provided by the air supply mechanism 3 to the counterweight 151 is not less than the weight of the counterweight 151, and the weight of the counterweight 151 is greater than the friction force between the sleeve and the counterweight 151.

[0078] On the basis of setting the clamping component 156, a flow resistance member is also arranged on the second branch pipe 233. The flow resistance member includes a flow resistance pipe 324 arranged on the second branch pipe 323. Figure 5 and Figure 6A choke pipe 324 is fixed between the branch pipe two 323 and the main pipe 321, and the choke pipe 324 further comprises a plurality of baffles 325 arranged inside the choke pipe 324 and staggered with each other. In other embodiments, a plurality of partitions can be arranged inside the choke pipe 324, and the adjacent partitions are provided with through holes staggered with each other. During the positioning process, the gas entering the branch pipe two 323 is intercepted by the choke pipe 324 cooperating with the baffles 325, so as to reduce the change rate of the gas pressure in the air bag 13. After a period of time after the air pump 31 supplies the gas, the counterweight 151 is connected with the clamping component 156, at this time, the air pump 31 reduces the power, and cooperates with the gas pressure sensor 33 and the controller to stabilize the gas pressure in the main pipe 321 within the set range. In this process, the gas pressure in the branch pipe two 323 and the air bag 13 is avoided to be too large, which can protect the measured piece W and the air bag 13.

[0079] In addition, a stopper 154 is fixed on the outer wall of the air cylinder 153, and the stopper 154 is used to support the counterweight 151 after the gas in the air cylinder 153 is discharged, so as to avoid that the pull rope 152 is kept in tension for a long time in the non-working state. The stopper 154 is preferably a convex ring fixed on the outer wall of the air cylinder 153, and an elastic buffer layer is arranged on the upper surface of the convex ring. In the case of arranging the stopper 154, although the loading plate 14 cannot be accurately reset to the axis of the positioning seat 11, the axis of the loading plate 14 is near the axis of the positioning seat 11, so that the outer wall of the loading plate 14 has sufficient spacing with the inner wall of the positioning seat 11. During the positioning process, the loading plate 14 has sufficient movable distance, the decrease of the reset accuracy does not affect the positioning accuracy, and the service life of the reset component 15 can be prolonged. The pull rope 152 is provided with a ball head 155 at both ends, and the two ball heads 155 are respectively rotationally connected with the bottom of the loading plate 14 and the top of the counterweight 151, so as to reduce the abrasion of the end of the pull rope 152.

[0080] In addition, in some other embodiments, a suspension assembly is further arranged on the thickness measuring mechanism 2. The suspension assembly comprises a mounting disc 23, an annular track 24 fixed on the bottom of the mounting disc 23, two hanging wheels 25 symmetrically arranged on the inner side of the annular track 24, two limiting plates 26 respectively fixed on the top of the two sides of the mounting disc 23, and a top plate 27 fixed on the top end of the limiting plate 26. The two hanging wheels 25 are respectively connected with the two ends of the horizontal rod of the mounting frame 21, the mounting disc 23 is hingedly connected with the rotating rod on the mounting frame 21, the lower surface of the top plate 27 is provided with an elastic buffer layer, and the limiting plate 26 penetrates through the top wall of the mounting table 53.

[0081] When the lifting assembly 41 lowers the thickness measuring component T1 to the inside of the workpiece W to be measured, the elastic buffer layer on the lower surface of the top plate 27 is in close contact with the top wall of the mounting table 53, and the mounting frame 21 can be hung below the annular track 24 through the lifting wheel 25, and the annular track 24 is hung on the mounting table 53 through the limiting plate 26 and the top plate 27, so that the deformation of the mounting frame 21 due to gravity can be reduced during the measurement of the wall thickness. After the measurement is completed, the thickness measuring component T1 can also be kept in this position, and the mounting frame 21 of the thickness measuring mechanism 2 is hung and supported by the hanging assembly, so as to avoid the decrease of the precision of the thickness measuring mechanism 2 after long-term use. In addition, a pair of telescopic members 28, which are preferably electromagnets, can be arranged on the mounting table 53, and a group of insertion holes corresponding to the telescopic members 28 are formed on the limiting plate 26. The eccentric measurement of the workpiece W can be performed at different heights, and the telescopic members 28 are inserted into the corresponding insertion holes at different measurement heights, so as to achieve the hanging support of the thickness measuring mechanism 2 at different measurement heights.

[0082] The above-described embodiments only express several embodiments of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be pointed out that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A method for measuring and rejecting eccentricity of porcelain pieces and blanks of porcelain insulators, characterized in that, The porcelain insulator porcelain piece and the blank are the measured pieces of the method, the method comprises the following steps: Step one, positioning the measured piece; Step two, measuring the wall thickness of the measured piece at different angles, and calculating the eccentricity of the measured piece according to the wall thickness, the calculation method of the eccentricity is as follows: ； wherein is the range of N wall thickness measurements; is the maximum wall thickness in the N wall thickness measurements, is the minimum wall thickness in the N wall thickness measurements, k is an intermediate quantity, and d is the eccentricity. Step three, analyze the eccentricity of the measured piece, when the eccentricity of the measured piece exceeds the preset rejection threshold, the measured piece is rejected, the establishment method of the rejection threshold is as follows: ； wherein, is the rejection threshold of the object to be measured, s is the standard deviation of the two-dimensional normal distribution, and P is the probability value obtained by querying the Westgard Sigma Multiple Rules. The above method is based on a measuring system, which comprises a positioning mechanism, a thickness measuring mechanism and a control module, the positioning mechanism is used for axial positioning of the measured piece, the thickness measuring mechanism is used for collecting the wall thickness data of the measured piece at different angles, and the wall thickness data is sent to the control module, after receiving the wall thickness data, the control module obtains the eccentricity of the measured piece according to the calculation method of the eccentricity, and judges whether the measured piece needs to be rejected based on the rejection threshold; The system also includes a gas supply mechanism and a driving mechanism connected with the control module, the positioning mechanism has a pneumatic actuator, the gas supply mechanism is used for positioning the outer wall axis of the measured piece, the thickness measuring mechanism has two thickness measuring components, the driving mechanism is used for placing the two thickness measuring components of the thickness measuring mechanism inside and outside the measured piece respectively, and the thickness measuring mechanism is relatively rotated with the positioning mechanism about the outer wall axis of the measured piece; The positioning mechanism comprises a positioning seat, a containing cavity arranged in the positioning seat, an air bag fixedly arranged on the upper part of the containing cavity, and a carrier plate arranged on the lower part of the containing cavity, the carrier plate can slide in any horizontal direction on the bottom wall of the positioning seat, and the bottom of the carrier plate is uniformly provided with a plurality of ball bearings in the circumferential direction; The positioning mechanism further comprises a reset member, which is used for resetting the carrier plate to the center of the positioning mechanism after each wall thickness measurement of the measured piece is completed; The reset member comprises a counterweight arranged directly below the positioning seat and a pull rope arranged between the counterweight and the carrier plate, during positioning of the measured piece, the gas supply mechanism drives the counterweight to move upward, so that the pull rope remains relaxed, at this time, the carrier plate is in a non-constrained state, after the wall thickness measurement of the measured piece is completed, the counterweight is reset, and the pull rope is pulled downward to reset the carrier plate; The system further comprises a support, a load sensor is fixedly arranged between the support and the positioning seat, and an air cylinder is fixedly arranged on the support, the air cylinder is slidingly arranged below the counterweight, the gas supply mechanism comprises an air pump, a shunt pipe connected with the air outlet of the air pump, and an air pressure sensor and a three-way valve arranged on the shunt pipe, the air bag and the air cylinder are in communication with the shunt pipe, the support is provided with a clamping component corresponding to the counterweight, and a flow resistance member is arranged on the branch of the shunt pipe connected with the air bag; A stopper is fixedly arranged on the outer side wall of the air cylinder, which is used for supporting the counterweight after the gas in the air cylinder is discharged, so as to avoid that the pull rope remains in a tension state for a long time in a non-working state.

2. The method for measuring and rejecting the eccentricity of porcelain parts and blanks of porcelain insulators according to claim 1, characterized in that: In step three, the calculation method of the two-dimensional normal distribution standard deviation is as follows: ； wherein, is the average value of the eccentricity of a batch of porcelain pieces or blanks calculated in advance.

3. The method of claim 1, wherein: the ceramic insulator is a porcelain part of a porcelain and steel insulator; and the ceramic blank is a porcelain blank of a porcelain and steel insulator. The center of the bottom wall of the positioning seat protrudes upward to form a guide member, and a wire slot corresponding to the pull rope is arranged through the guide member, and the wire slot penetrates through the bottom wall of the positioning seat.

4. The method of claim 1, wherein: The driving mechanism comprises a lifting assembly and a rotating driving member fixed to the output end of the lifting assembly, the thickness measuring mechanism comprises a mounting frame fixed to the output end of the rotating driving member, one thickness measuring component of the thickness measuring mechanism is arranged in the middle of the mounting frame, and another thickness measuring component of the thickness measuring mechanism is arranged at one end of the mounting frame, and a counterweight component is arranged at the other end of the mounting frame.

Images