Actuator cylinder assembly detection method

Abstract

The invention discloses an actuator cylinder assembly detection method, which belongs to the field of mechanical assembly, and is characterized in that by arranging a pressure sensor, pressure data generated in the installation process of an actuator cylinder is transmitted in real time and recorded in a host; and the qualified assembly data of the actuator cylinder of the model recorded in the host is called out to be compared with the data collected by the pressure sensor, and the assembly condition is output in real time, so that the problem that the assembly condition of the actuator cylinder is difficult to detect in the prior art is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of mechanical assembly, and particularly relates to a method for detecting the assembly of an actuating cylinder. Background Art

[0002] During the assembly process of the piston and the cylinder body of an aircraft actuating cylinder, the assembly quality often varies due to different assemblers. If the assembly is improper, leakage may occur. It is manifested that there is no abnormality during the performance test after the assembly is completed. However, after the actuating cylinder is installed on the aircraft and used for a period of time, some actuating cylinders will show leakage. Since the machining quality and material quality of the actuating cylinder have been strictly controlled before assembly, it can be inferred that the difference lies in the assembly link.

[0003] Among the assemblers, there are both experienced technical workers and inexperienced novices. In order to solve the problem that the assembly quality varies from person to person, the research group has carried out research on automatic assembly technology and quality determination methods.

[0004] The idea of the present invention to solve the problem is to use a robotic arm for assembly to reduce or eliminate the assembly quality difference caused by the differences of assemblers, and to establish a judgment basis for assembly quality by constructing a multi-factor coupling model for the installation of functional accessory sealing rings, so as to explore a control method for the assembly quality of functional accessories. Summary of the Invention

[0005] Aiming at the problems in the prior art that it is impossible to accurately judge the assembly quality and the supervision efficiency of the assembly quality is relatively low, the present invention provides a method for detecting the assembly of an actuating cylinder, including the following steps: Step 1: Store the pressure data representing the qualified installation of the actuating cylinder and establish a qualified database; Step 2: Collect the pressure data generated during the installation process of the actuating cylinder; Step 3: Transmit the pressure data collected in Step 2 to the qualified database for comparison, and use a discriminant model for detection; Step 4: Output the detection result.

[0006] Preferably, in Step 2, the pressure sensor is used to record and collect the magnitude of the assembly thrust and the linearity of the assembly thrust.

[0007] Preferably, the qualified database set in Step 1 records the qualified assembly data of various models of actuating cylinders.

[0008] Preferably, before performing Step 2, the assembler uses a through-hole tooling to pre-tighten and physically inspect the snap ring and O-ring seal combination of the actuating cylinder; If the retaining ring of the actuator can directly pass through the O-ring assembly, the assembly is considered qualified, and the assembly step is entered and the assembly data is detected; otherwise, it is considered unqualified and needs to be reassembled.

[0009] Preferably, there are peaks in the assembly thrust collected by the pressure sensor; in step two: if the position data where the assembly thrust peak appears does not match the qualified position data recorded in the qualified database, an unqualified assembly message is output; if the linearity of the assembly thrust collected by the pressure sensor does not match the linearity of the assembly thrust recorded in the qualified database, an unqualified assembly message is output.

[0010] Preferably, the assembly thrust peak refers to the maximum value of the assembly thrust when the sealing assembly of the actuator enters and exits the oil groove.

[0011] Preferably, the discriminant model used in step three is established as follows: Let: x_1 be the position of the sealing assembly before entering the mating surface, x _2 be the position where the sealing assembly completely enters the mating surface, and x _3 be the position where the sealing assembly completely enters the oil groove; x is the piston displacement, Fmax is the maximum assembly thrust, x _ Fmax is the piston displacement corresponding to the maximum assembly thrust, delta_ x _ Fmax is the allowable error of the maximum assembly thrust position, delta_ x _ Fmax_range is the displacement range to be considered for analyzing the shape of the maximum assembly thrust, F_average is the average value of the assembly thrust within the displacement range to be considered for the shape of the maximum assembly thrust, Per is F_average / Fmax, The following judgment is made for each oil groove: First, judge the position of the peak, Within the interval x∝(x_1, x _3), find Fmax and obtain x _ Fmax It is necessary to satisfy formula 1: x _2 - delta_ x _ Fmax ≤ x _ Fmax ≤ x _2 + delta_ x _ Fmax; Then, judge the sharpness of the peak, Within the interval x∝(x _ Fmax - delta_ x _ Fmax_range, x _ Fmax + delta_x _ Fmax_range), it is necessary to satisfy formula 2: It is necessary to satisfy formula 3: The average pressure F_average ≤ Per * Fmax. Meeting the requirements of Formula 1, Formula 2, and Formula 3 simultaneously indicates a qualified assembly.

[0012] Compared with the prior art, the technical solution of the present invention has the following advantages / beneficial effects: 1. The present invention uses a pressure sensor to detect the pressure data generated during the assembly process in real time and can compare it with the qualified assembly data built into the host computer to ensure that each detection is as accurate as possible.

[0013] 2. The present invention has a strictly enforced detection process sequence, comparing the pressure generated in each link with the normal data multiple times, reducing the detection results misjudged due to human factors, and increasing the accuracy of detection.

[0014] 3. The present invention not only determines the pressure generated during the assembly process but also determines the linearity of the assembly pressure, reducing misjudgments caused by unstable collection of the assembly pressure and improving the accuracy of detection. Description of the Drawings

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 is a flowchart of a method for detecting the assembly of an actuating cylinder according to the present invention.

[0017] Figure 2 is a flowchart for detecting the assembly quality of an actuating cylinder according to the present invention.

[0018] Figure 3 is a schematic diagram of an automatic assembly judgment mechanism used in an embodiment of the present invention.

[0019] Figure 4 is a schematic diagram of an automatic actuating cylinder assembly device used in an embodiment of the present invention.

[0020] The labels in the figure are respectively: 1 - safety fence, 2 - gantry crane, 21 - optical positioning module, 3 - elevator, 31 - rotating pressing arm, 4 - robotic arm, 5 - assembly, 6 - assembly table, 7 - host computer. Detailed Embodiments

[0021] To make the objectives, technical solutions and advantages of the present invention clearer, the following describes the technical solutions in the embodiments of the present invention clearly and completely. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed present invention, but merely represents the selected embodiments of the present invention.

[0022] It should be noted that similar reference numerals and letters denote similar items in the following figures. Therefore, once an item is defined in one figure, it may not be further defined and explained in subsequent figures.

[0023] Example 1: As Figure 1 shown, during manual assembly, the present invention sets a pressure sensor on the actuating cylinder to transmit and record the pressure data generated during the installation process of the actuating cylinder in real time in the host computer; and when assembling the actuating cylinder, the information of the actuating cylinder is recorded in the host computer, and the qualified assembly data of the actuating cylinder of this model recorded in the host computer is retrieved and compared with the data collected by the pressure sensor, and the assembly situation is output in real time.

[0024] The installation process of the actuating cylinder is divided into the following processes: 1. The first sealing assembly enters the mating surface 1.

[0025] 2. The first sealing assembly completely enters the mating surface 1.

[0026] 3. The first sealing assembly completely enters the first oil passage groove.

[0027] 4. The first sealing assembly completely enters the mating surface 2.

[0028] 5. The first sealing assembly slides and rubs against the mating surface 2, and at the same time, the second sealing assembly is about to reach the first mating surface.

[0029] 6. The first sealing assembly slides and rubs against the second mating surface, and at the same time, the second sealing assembly completely enters the first mating surface.

[0030] 7. The first sealing assembly slides and rubs against the second mating surface, and at the same time, the second sealing assembly slides and rubs against the second mating surface.

[0031] 8. The first sealing assembly completely enters the second oil passage groove, and at the same time, the second sealing assembly enters the second mating surface.

[0032] 9. The first sealing assembly enters the third mating surface, and at the same time, the second sealing assembly slides and rubs against the second mating surface.

[0033] The pressure sensor can record the magnitude of the assembly thrust and the linearity of the assembly thrust.

[0034] During the installation of the actuator, when the first seal enters the first mating surface, there will be a change in the assembly thrust, and when the second seal enters the first mating surface, there will also be a change in the assembly thrust.

[0035] When the seal assembly enters and exits the oil sump, if the force is uniform, the assembly thrust will increase linearly until it reaches the maximum value and then decrease linearly. Otherwise, it indicates that the seal assembly is not uniformly stressed, that is, the seal assembly has undergone irregular deformation.

[0036] The main unit records the qualified assembly data of various models of actuators and can allocate the recorded assembly data in real time during the actuator assembly process.

[0037] Before the assembly inspection, the assembly personnel use the through-hole tooling to pre-tighten and preliminarily inspect the snap ring and O-ring seal assembly of the actuator; If the snap ring and O-ring seal assembly of the actuator can pass, it is considered that the assembly of this combination is qualified, and it enters the assembly step and the assembly data is detected; otherwise, it is considered unqualified and needs to be reassembled.

[0038] If there is a peak in the assembly thrust recorded by the pressure sensor and the position data where the assembly thrust peak appears does not match the qualified position data recorded in the main unit, an assembly unqualified message is output.

[0039] The assembly thrust peak refers to the maximum value of the assembly thrust when the seal assembly of the actuator enters and exits the oil sump; The position of the assembly thrust peak refers to the position where the seal assembly of the actuator completely enters the mating surface, and this position is related to the specific structure of the actuator; Let: x_1 be the position before the seal assembly enters the mating surface, x_2 be the position where the seal assembly completely enters the mating surface, and x_3 be the position where the seal assembly completely enters the oil sump; x is the piston displacement, Fmax is the maximum assembly thrust, x_Fmax is the piston displacement corresponding to the maximum assembly thrust, delta_x_Fmax is the allowable error of the maximum assembly thrust position, delta_x_Fmax_range is the displacement range to be considered for analyzing the shape of the maximum assembly thrust, F_average is the average value of the assembly thrust within the displacement range to be considered for the shape of the maximum assembly thrust, Per is F_average / Fmax, The following judgment is made for each oil sump: First, determine the position of the peak. Within the interval x ∝ (x_1, x_3), find Fmax and obtain x_Fmax. It is necessary to satisfy Formula 1: x_2 - delta_x_Fmax ≤ x_Fmax ≤ x_2 + delta_x_Fmax; Then, judge the sharpness of the peak. Within the interval x ∝ (x_Fmax - delta_x_Fmax_range, x_Fmax + delta_x_Fmax_range), it is necessary to satisfy Formula 2: It is necessary to satisfy Formula 3: F_average ≤ Per * Fmax. Meeting Formulas 1, 2, and 3 simultaneously means the assembly is qualified.

[0040] Embodiment 2: During the actual assembly process of the actuator, in addition to traditional manual assembly, an automatic assembly device can also be used for the assembly of the actuator.

[0041] As Figure 4 shown, the present invention uses an automatic actuator assembly device, including a safety fence 1, a gantry crane 2, an optical positioning module 21, a lift 3, a rotating pressing arm 31, a robotic arm 4, an assembly body 5, an assembly table 6, and a mainframe 7; the safety fence 1 is installed on both sides of the assembly table 6 and the robotic arm 4; the mainframe 7 is installed outside the safety fence 1; the gantry crane 3 is installed between the assembly table 6 and the safety fence 1; the robotic arm 4 is installed on one side of the assembly table 6; the lift 3 is installed on the assembly table 6, and the assembly body 5 is installed on both sides of the lift 3. Place the actuator tooling on the assembly body 5 through the robotic arm 4 of the automatic assembly device, and use the rotating pressing arm 31 on the lift 3 to assemble the actuator. The pressure sensor installed on the assembly table 6 records the assembly data in real time and transmits it to the mainframe 7.

[0042] The optical positioning module 21 monitors the installation of the actuator in real time, transmits the position information of the actuator to the mainframe 7, and the mainframe 7 controls the robotic arm 4 to adjust the position of the piston rod assembly to be centered with the outer cylinder axis.

[0043] The robotic arm 4 and the rotating pressing arm 31 realize the functions of grasping and assembling the actuator.

[0044] The installation table 6 and the assembly body 5 fix the actuator and the assembly parts.

[0045] The optical positioning module 21 is used for the visual positioning of the actuator, assisting the robotic arm 4 to adjust the position of the actuator.

[0046] As Figure 2 shown, before the start of the automatic assembly of the actuator, the assembler checks the snap ring and O-ring seal assembly of the actuator with the help of this through-hole tooling; If the snap ring and O-ring seal assembly of the actuator can pass, it is considered that the assembly of this combination is qualified, and then the automatic assembly device of the actuator is used for assembly; otherwise, it is considered unqualified and needs to be reassembled.

[0047] The automatic assembly device of the actuator first places the piston of the actuator on the assembly body 5, enters the actuator information, and finally performs automatic assembly.

[0048] The robotic arm 4 automatically grabs the piston and positions it through the optical positioning module 21 to ensure that the piston and the actuator cylinder body are in a concentric state; the rotating pressing arm 31 pushes the piston into the actuator cylinder body, and the assembly ends when the piston displacement reaches the specified value of this type of actuator.

[0049] The mainframe 7 controls the automatic operation of the automatic assembly device of the actuator and records and generates the assembly thrust linearity and the magnitude of the assembly thrust during the assembly process through the pressure sensor.

[0050] There is a peak in the assembly thrust recorded by the pressure sensor. When the position where the assembly thrust peak appears conforms to the qualified data built into the mainframe 7, the assembly qualified information is output.

[0051] The assembly thrust peak is the maximum value of the assembly thrust when the seal assembly enters and exits the oil groove; The position of the assembly thrust peak refers to the position where the seal assembly of the actuator completely enters the mating surface, and this position is related to the specific structure of the actuator; In order to improve the accuracy of the assembly detection of the actuator, we designed a judgment mechanism for determining whether the actuator assembly is successful. As Figure 3 shown, the following data is set to complete the detection of whether the actuator assembly is qualified: x_1 is the position before the seal assembly enters the mating surface, x_2 is the position where the seal assembly completely enters the mating surface, x_3 is the position where the seal assembly completely enters the oil groove; x is the piston displacement, Fmax is the maximum assembly thrust, x_Fmax is the piston position x corresponding to the maximum assembly thrust, delta_x_Fmax is the allowable error of the maximum assembly thrust position, The displacement range of delta_x_Fmax_range is the displacement range to be considered for analyzing the shape of the maximum assembly thrust. F_average is the average value of the assembly thrust within the displacement range to be considered for the shape of the maximum assembly thrust. Per is F_average / Fmax. The following judgments are made for each oil groove: First, judge the position of the peak. Within the interval of x ∝ (x_1, x_3), find Fmax and obtain x_Fmax. It is necessary to satisfy Equation 1: x_2 - delta_x_Fmax ≤ x_Fmax ≤ x_2 + delta_x_Fmax; Then judge the sharpness of the peak. Within the interval of x ∝ (x_Fmax - delta_x_Fmax_range, x_Fmax + delta_x_Fmax_range), it is necessary to satisfy Equation 2: It is necessary to satisfy Equation 3: F_average ≤ Per * Fmax. Meeting Equations 1, 2, and 3 simultaneously means the assembly is qualified.

[0052] The above is only the preferred embodiment of the present invention. It should be noted that the above preferred embodiment should not be regarded as a limitation of the present invention. The protection scope of the present invention should be defined by the scope defined in the claims. For those of ordinary skill in the art of this technology, within the spirit and scope of the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for detecting the assembly of an actuator, characterized in that: The following steps are involved: Step 1: Store the pressure data representing qualified installation of the actuator and establish a qualified database; Step 2: Collect the pressure data generated during the installation of the actuator; Step 3: The pressure data collected in step 2 is transferred to the qualified database for comparison and tested using the discriminant model; Step 4: Output the test results.

2. The method for detecting the assembly of an actuator according to claim 1, characterized in that: The second step records and collects the size of the assembly thrust and the linearity of the assembly thrust through the pressure sensor.

3. The method for detecting the assembly of an actuator according to claim 2, characterized in that: The qualified database of step 1 records the qualified assembly data of various types of actuators.

4. The method for detecting the assembly of an actuator according to claim 2, characterized in that: Before proceeding to step 2, the assembler uses the through-hole tooling to pre-tighten and physically inspect the retaining ring and O-ring assembly of the actuator; If the retaining ring of the actuator can pass directly through the O-ring assembly, the assembly is considered to be qualified and the assembly step is entered and the assembly data is tested; otherwise, it is considered unqualified and needs to be reassembled.

5. The method for detecting the assembly of an actuator according to claim 2, characterized in that: The assembly thrust collected by the pressure sensor has a peak; in step 2: if the position data of the assembly thrust peak does not match the qualified position data recorded in the qualified database, the assembly unqualified information is output; if the linearity of the assembly thrust collected by the pressure sensor does not match the linearity of the assembly thrust recorded in the qualified database, the assembly unqualified information is output.

6. The method for detecting the assembly of an actuator according to claim 5, characterized in that: The assembly thrust peak refers to the maximum assembly thrust of the sealing component of the actuator when it enters and leaves the oil groove.

7. The method for detecting the assembly of an actuator according to claim 6, characterized in that: The discriminant model establishment process used in step 3 is as follows: Assume: x_1 is the position before the seal assembly enters the mating surface, x_2 is the position when the seal assembly completely enters the mating surface, and x_3 is the position when the seal assembly completely enters the oil groove; x is the piston displacement, Fmax is the maximum assembly thrust, x _ Fmax is the piston displacement corresponding to the maximum assembly thrust, delta_ x _ Fmax is the allowable error of the maximum assembly thrust position, delta_ x _ Fmax_range is the displacement range to be considered for analyzing the maximum assembly thrust shape. F_average is the average value of the assembly thrust within the displacement range that needs to be considered for the maximum assembly thrust shape. Per is F_average / Fmax, The following judgments are made for each oil tank: First determine the location of the peak. In the interval x∝(x_1, x_3), find Fmax and get x_Fmax Formula 1 must be satisfied: x _2- delta_ x _ Fmax≤x _ Fmax≤x _2+ delta_ x _ Fmax; Then determine the sharpness of the peak. In the interval x∝(x_Fmax-delta_x_Fmax_range,x_Fmax+delta_x_Fmax_range), Formula 2 must be satisfied: Formula 3 must be satisfied: If F_average≤Per * Fmax and Formula 1, Formula 2 and Formula 3 are satisfied at the same time, the assembly is qualified.

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