Automatically assembling next word slot eccentric shaft and installing tool eccentric error compensation method

Abstract

The present application relates to a kind of automatic assembly next word slot eccentric shaft and installation tool eccentric error compensation method, steps are as follows:1) determine the distance d0 of installation tool rotation center and eccentric shaft rotation center in X axis direction;2) installation tool automatically drives eccentric shaft rotation θ1;3) installation tool moves d0×sinθ1 along the vertical direction of installation tool center line A and eccentric shaft center line B;4) installation tool automatically drives eccentric shaft rotation θ2;5) installation tool moves d0×cosθ1×sinθ2 along the vertical direction of installation tool center line A and eccentric shaft center line B;6) by analogy, when the kth time, the distance that installation tool center needs to move is 7) until adjustment is completed.This method can avoid the interference of installation tool head and eccentric shaft slot by the automatic position adjustment of installation tool, so that the operation process can be carried out smoothly.

Description

Technical Field

[0001] This invention belongs to the field of mechanical processing technology, and relates to error compensation methods in the field of mechanical technology. Specifically, it relates to an eccentricity error compensation method between an eccentric shaft and an installation tool in an automated assembly manufacturing process. Background Technology

[0002] In the assembly process of certain products, eccentric shafts are required for parameter adjustments. The end of the eccentric shaft is usually designed with a slot, and an installation tool with a matching end size is used for adjustment. Since it is an adjustment process, the eccentric shaft cannot be adjusted in one go; it needs to be tested and rotated for adjustment simultaneously. Therefore, in the automated assembly process of robotic arms, this automatic tightening tool can cause interference problems due to the inconsistency of the rotation center.

[0003] like Figure 1 As shown, the rotation center of the installation tool and the rotation center of the eccentric shaft are not on the same axis, and the shape of the tool head and the slot are both rectangular. At the starting point, the rotation centers of the two are a certain distance apart due to visual inspection or other errors. When they rotate around their respective rotation centers, this distance will cause the center lines of their rectangular heads to gradually deviate, resulting in contact interference between the tool edge and the inner side of the slot of the eccentric shaft, which may seriously damage the tool or the eccentric shaft.

[0004] Such interference does not exist when adjustments are made manually because humans correct errors visually. However, in automated tools, where this closed-loop correction is lacking, interference is unavoidable. Summary of the Invention

[0005] Technical problems to be solved

[0006] To avoid the shortcomings of the prior art, the present invention provides a method for compensating for the eccentricity error between the eccentric shaft and the installation tool in automatic assembly, so as to solve the interference problem of lacking a fully closed-loop correction condition.

[0007] Technical solution

[0008] A method for compensating for eccentricity error between a slotted eccentric shaft and an installation tool during automatic assembly is characterized by the following steps: During automatic assembly, the installation tool intermittently rotates the slotted eccentric shaft according to the adjustment result. Through automatic position adjustment of the installation tool, interference between the tool head and the slot of the eccentric shaft is avoided.

[0009] Step 1: Determine the distance d0 between the rotation center of the installation tool and the rotation center of the eccentric shaft in the X-axis direction;

[0010] Step 2: The installation tool automatically rotates the eccentric shaft by θ1;

[0011] Step 3: Move the installation tool along the perpendicular direction of the installation tool centerline A and the eccentric shaft centerline B by d0×sinθ1;

[0012] Step 4: The installation tool automatically rotates the eccentric shaft by θ2;

[0013] Step 5: Move the installation tool along the perpendicular direction of the installation tool centerline A and the eccentric shaft centerline B by d0×cosθ1×sinθ2;

[0014] Step 6: Following this pattern, when the k-th iteration occurs, the distance the installation tool center needs to move is... Until the adjustment is complete.

[0015] Beneficial effects

[0016] This invention provides a method for compensating for eccentricity errors between an eccentric shaft and an installation tool in an automated assembly process. This method ensures the smooth operation of automated assembly under limited conditions. Even in the absence of visual image compensation, by adjusting the calculated error compensation, the entire assembly process can continue without causing damage to tools or products due to interference. Attached Figure Description

[0017] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0018] Figure 1 This is a diagram showing the rotational error analysis.

[0019] Figure 2 This is an interference processing diagram. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0021] During the adjustment process, to prevent the installation tool head from interfering with the eccentric shaft head groove, the center line of the installation tool head needs to be aligned with the center line of the eccentric shaft slot. This means moving the installation tool's rotation center O2 along the perpendicular lines from center lines A and B to O′2, as shown in the attached diagram. Figure 2 As shown. The distance moved is:

[0022] O2O′2=d0×sinθ1 (1)

[0023] Where: d0 - the distance in the X direction between the center of the initial installation tool and the center of the eccentric shaft;

[0024] θ1 - Rotation angle.

[0025] After the automatic installation tool adjusts the angle θ1, it moves along O2O′2 to O′2, then stops and waits for the second adjustment input. Upon receiving the second tightening angle θ2 instruction, it continues adjusting.

[0026] Under multiple adjustments, the automatic installation tool may continue to move, from O′2 to O″2, with a moving distance of:

[0027] O′2O″2=d0×cosθ1×sinθ2 (2)

[0028] The distance moved from O″2 to O″′2 is:

[0029] O″2O″′2=d0×cosθ1×cosθ2×sinθ3 (3)

[0030] And so on, when it is the kth time, the distance that the installation tool center needs to move is:

[0031]

[0032] Where, k∈N * .

[0033] The projections of this distance onto the X-axis and Z-axis are as follows:

[0034]

[0035] By incorporating this adjustment distance into the control program, automatic error compensation can be performed.

[0036] To enable those skilled in the art to better understand the present invention, the present invention will be described in detail below with reference to specific embodiments.

[0037] Referring to the accompanying drawings, the embodiments of the present invention are as follows:

[0038] 1) Determine the distance d0 between the rotation center of the installation tool and the rotation center of the eccentric shaft in the X-axis direction;

[0039] 2) The installation tool automatically drives the eccentric shaft to rotate θ1;

[0040] 3) The installation tool moves d0×sinθ1 along the perpendicular direction of the installation tool centerline A and the eccentric shaft centerline B;

[0041] 4) The installation tool automatically drives the eccentric shaft to rotate θ2;

[0042] 5) The installation tool moves d0×cosθ1×sinθ2 along the perpendicular direction of the installation tool centerline A and the eccentric shaft centerline B;

[0043] 6) And so on, when it is the kth time, the distance that the center of the installation tool needs to move is... Until the adjustment is complete.

[0044] Example 1

[0045] A robotic arm gradually tightens the eccentric shaft of a product to achieve a specified torque value. The eccentric shaft end uses a slotted joint, and the tool used by the robotic arm is similar to a flathead screwdriver. As both rotate around their respective centers of rotation, their center lines gradually separate from the initial overlap, increasing in distance. This distance reaches its maximum when both have rotated 90°. Due to the small gap between the tool and the slotted joint, even a slight distance between their center lines will cause interference.

[0046] like Figure 1 As shown, insert the tool into the "I" slot, setting it to its initial state with both sides horizontal. Adjustments are then performed following these steps:

[0047] 1) Use calipers or a tool with precise graduations to measure the distance d0 = 2mm between the rotation center of the robot arm and the rotation center of the eccentric shaft in the X-axis direction;

[0048] 2) The robotic arm starts to rotate the installation tool by a set angle θ1 = 2°, and then stops rotating;

[0049] 3) The system extracts the current torque value of the eccentric shaft, T1 = 0.1 Nm, which is less than the target torque of 0.5 Nm, and the requirement is not met. Continue operation.

[0050] 4) The robot arm drives the installation tool to move d0×sinθ1=0.07mm along the perpendicular direction of the installation tool centerline A and the eccentric shaft centerline B. Its moving direction is opposite to the tightening direction.

[0051] 5) Then the robotic arm continues to tighten the eccentric shaft at the set angle θ2 = 3°. After completion, the current torque value T2 = 0.25 Nm is extracted.

[0052] 6) If T2 < 0.5 Nm, the torque value still does not meet the target torque requirement. The robot arm drives the installation tool to move along the perpendicular direction opposite to the tightening direction of center line A and center line B, d0×cosθ1×sinθ2=2×cos2°×sin3°=0.1 mm. Then, the eccentric shaft is tightened according to the set angle θ3=3°.

[0053] 7) Therefore, before each tightening, the robot arm needs to move the installation tool to make its centerline coincide with the centerline of the eccentric shaft. The distance moved in the kth movement is... Where, k∈N * .

[0054] 8) Until T n ≥0.5Nm, operation complete.

[0055] In actual computer programming, this distance needs to be decomposed onto the X and Z axes, resulting in the following projected distance:

[0056]

[0057] Therefore, by substituting this projection formula into the program, the robot arm can automatically calculate the distance each time and perform the operation, avoiding interference between the installation tool and the eccentric shaft.

[0058] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the scope of the technology disclosed in the present invention, and such modifications or substitutions should all be covered within the scope of protection of the present invention.

Claims

1. A method for automatically assembling an eccentric shaft with a slotted groove and compensating for eccentricity error with an installation tool, characterized in that: During automated assembly, the installation tool intermittently rotates the slotted eccentric shaft based on the adjustment results. Through automatic tool positioning, interference between the tool head and the eccentric shaft groove is avoided. The steps are as follows: Step 1: Determine the distance d0 between the rotation center of the installation tool and the rotation center of the eccentric shaft in the X-axis direction; Step 2: The installation tool automatically rotates the eccentric shaft by θ1; Step 3: Move the installation tool along the perpendicular direction of the installation tool centerline A and the eccentric shaft centerline B by d0×sinθ1; Step 4: The installation tool automatically rotates the eccentric shaft by θ2; Step 5: The installation tool moves d0×cosθ1×sinθ2 along the perpendicular direction of the installation tool centerline A and the eccentric shaft centerline B; Step 6: Following this pattern, when the k-th iteration occurs, the distance the installation tool center needs to move is... Until the adjustment is complete.

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