A symmetrical reference arm with external armored cable and an OCT system

Abstract

The application relates to the field of welding detection, and provides a symmetrical reference arm with an external armored cable and an OCT system, characterized by comprising an incident optical fiber, a delay optical path, an emission optical fiber and a reference arm armored cable which are sequentially arranged according to an optical path; the reference arm armored cable is processed through a port mirror surface, and the port mirror surface processing step comprises the following steps: the traditional reference arm armored cable port is cut flat and plated with a metal film, so that the traditional reference arm armored cable port forms a mirror surface reflection. The application solves the problem that in an existing OCT welding penetration detection system, a reference arm signal arm optical path difference is easily affected by temperature, so that the OCT welding penetration detection system has the ability of accurate pre-welding ranging; the reference arm and the signal arm optical path are matched to the maximum extent, system dispersion is reduced, and the detection quality of the OCT system is improved; the optical path difference does not need to be adjusted through algorithm fitting or active temperature control, so that the OCT system is more stable, faster in response and lower in cost; and an additional ranging device is not needed, so that the production line cost can be reduced.

Description

Technical Field

[0001] This invention relates to the field of welding inspection technology, specifically to a symmetrical reference arm with external armor and an OCT system. Background Technology

[0002] In laser welding, pre-weld distance measurement is crucial for ensuring welding quality. Changes in the workpiece machining distance during welding can lead to serious quality problems such as incomplete welds, burn-through, and porosity. Traditional pre-weld distance measurement, due to its inherent limitations, often employs a side-axis method. This involves placing the rangefinder to one side of the welding equipment and then calculating the distance through calibration. Alternatively, additional cycles are required to switch between the distance measurement and machining positions, severely impacting production efficiency. In some applications, environmental constraints necessitate subtracting the workpiece thickness from its bottom height to obtain the required height. These methods cannot directly measure the workpiece machining distance, and their accuracy is easily affected by the condition of the fixture.

[0003] The coaxial measurement characteristics of the OCT welding penetration depth detection system (Optical Coherence Tomography Welding Penetration Depth Detection System) can effectively solve this problem. Furthermore, as an important device for laser welding quality monitoring, the OCT welding penetration depth detection system has been introduced into laser welding production lines. If it can also perform distance measurement, the cost of a distance measuring instrument can be eliminated.

[0004] However, the OCT welding penetration depth detection system achieves the ranging function by measuring the optical path difference between the reference arm and the signal arm. Due to the requirements of the application environment, the signal arm of the OCT welding penetration depth detection system contains a long armored cable (armored cable is short for armored cable) that is suspended outside the cabinet and connects the cabinet and the OCT probe. This long armored cable is more than 10 meters long. The reference arm patch cord used to compensate for the armored cable is a bare fiber of equal length coiled in the cabinet. The two long optical fibers are in different environments and are quite long. Changes in ambient temperature can easily cause temperature drift in the optical path difference between the two arms, which seriously affects the accuracy of ranging. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention aims to provide a symmetrical reference arm and OCT system with an externally armored cable. To solve these problems, this invention employs the following technical solution: A symmetrical reference arm with external armor cable includes an incident optical fiber, a delay optical path, an outgoing optical fiber, and a reference arm armor cable arranged sequentially according to the optical path. The reference arm armored cable undergoes port mirror treatment, which includes: flat-cutting the port of the traditional reference arm armored cable and depositing a metal film to make the port of the traditional reference arm armored cable form a mirror reflection.

[0006] Optionally, the delayed optical path includes an incident collimator, a movable delayer, and an exit collimator arranged sequentially according to the optical path.

[0007] The incident collimator is connected to the incident optical fiber, and the exit collimator is connected to the exit optical fiber.

[0008] Optionally, the movable delay unit includes a movable slider and a rear reflector. The movable slider is slidably connected to a slide rail, which is connected inside the optical path cabinet. The rear reflector is connected to the movable slider.

[0009] Optionally, the rear reflector is one of a mirror assembly or a cornerstone.

[0010] An OCT system includes an optical path cabinet, a signal arm armored cable, and an OCT probe. The optical path cabinet is equipped with a symmetrical reference arm with an external armored cable, the reference arm armored cable extends to the outside of the optical path cabinet, the reference arm armored cable is connected to the OCT probe, and the OCT probe is connected to the optical path cabinet through the signal arm armored cable.

[0011] Optionally, the signal arm armor cable is connected to an optical fiber patch cord, the length of which is equal to the sum of the incident optical fiber and the outgoing optical fiber.

[0012] Optionally, the reference arm armor cable has the same length as the signal arm armor cable, and the reference arm armor cable has the same material as the signal arm armor cable.

[0013] Optionally, the fiber optic cable of the reference arm armor cable is the same as the fiber optic cable of the signal arm armor cable.

[0014] Optionally, the connector models at both ends of the reference arm armor cable are the same as those at both ends of the signal arm.

[0015] Optionally, the optical path length in the delayed optical path is the same as the optical path length in the free space of the signal arm.

[0016] The present invention has the following beneficial effects: To address the issue that the optical path difference between the reference arm and the signal arm in existing OCT welding penetration detection systems is easily affected by temperature, thereby enabling the system to accurately measure distances before welding. To maximize the matching of optical path lengths between the reference arm and the signal arm, reduce system dispersion, and improve the detection quality of the OCT system; It eliminates the need for algorithm fitting or active temperature control to adjust the optical path difference, resulting in more stable and faster response, and lower cost. No additional ranging device is required, which can reduce production line costs. Attached Figure Description

[0017] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a symmetrical reference arm with an external armor cable and a delay optical path in an OCT system according to the present invention; Figure 2 This is a structural schematic diagram of a symmetrical reference arm and OCT system with an external armored cable according to the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In the description of this invention, it should be noted that the terms "vertical," "upper," "lower," "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0021] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or a connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] like Figures 1-2 As shown, a symmetrical reference arm with external armor cable includes an incident optical fiber, a delay optical path, an outgoing optical fiber, and a reference arm armor cable arranged sequentially according to the optical path. The reference arm armored cable undergoes port mirror treatment, which includes: flat-cutting the port of the traditional reference arm armored cable and depositing a metal film to make the port of the traditional reference arm armored cable form a mirror reflection.

[0023] Based on the above scheme, the delayed optical path includes an incident collimator, a movable delay unit, and an exit collimator arranged sequentially according to the optical path.

[0024] The incident collimator is connected to the incident optical fiber, and the exit collimator is connected to the exit optical fiber.

[0025] In a preferred embodiment, the movable delay unit includes a movable slider and a rear reflector. The movable slider is slidably connected to a slide rail, which is connected inside the optical path cabinet. The rear reflector is connected to the movable slider.

[0026] In some embodiments, the rear reflector is one of a mirror assembly or a cornerstone.

[0027] like Figures 1-2 As shown, an OCT system includes an optical path cabinet, a signal arm armored cable, and an OCT probe. The optical path cabinet is equipped with a symmetrical reference arm with an external armored cable, which extends to the outside of the optical path cabinet. The reference arm armored cable is connected to the OCT probe, and the OCT probe is connected to the optical path cabinet through the signal arm armored cable.

[0028] Based on the above scheme, in order to reduce the impact of environmental changes on the system ranging accuracy, the reference arm and signal arm are designed symmetrically to control system chromatic aberration to the maximum extent and enhance signal quality. The signal arm armored cable is connected to an optical fiber patch cord, and the length of the optical fiber patch cord is equal to the sum of the incident optical fiber and the outgoing optical fiber to ensure that the optical fiber lengths of the reference arm and the signal arm are matched in the optical path cabinet.

[0029] Furthermore, the reference arm armor cable has the same length as the signal arm armor cable, and the reference arm armor cable is made of the same material as the signal arm armor cable.

[0030] Furthermore, the fiber optic cable of the reference arm armor cable is the same type as the fiber optic cable of the signal arm armor cable. Furthermore, the connector models at both ends of the reference arm armor cable are the same as those at both ends of the signal arm.

[0031] The reference arm armored cable and the signal arm armored cable are identical in length, material, and end connectors. The reference arm armored cable and the signal arm armored cable are located at adjacent interface positions on the optical path cabinet and OCT probe. When the reference arm armored cable and the signal arm armored cable are connected to the optical path cabinet and OCT probe, ensuring that the environment in which the reference arm armored cable and the signal arm armored cable are located is consistent can eliminate the optical path change caused by changes in ambient temperature.

[0032] Preferably, the optical path length in the delayed optical path is the same as the optical path length in the free space of the signal arm, so as to reduce system dispersion.

[0033] Implementation process: The light in the incident fiber is transmitted to the incident collimator and becomes a parallel beam to reduce divergence and coupling loss during free space propagation. The parallel beam enters the moving slider and is reflected N times by N back reflectors, thereby obtaining a longer effective optical path in a limited space.

[0034] By moving the slider along the slide rail, the propagation distance of light in the delayed optical path can be changed, thereby achieving continuous adjustment of the optical path of the reference arm. The slider's movement range can be designed according to requirements.

[0035] Depending on the reference arm length requirements and the optical path cabinet size requirements, different numbers of back reflectors can be set to obtain a larger optical path delay range without significantly increasing the size of the optical path cabinet.

[0036] The beam enters the output collimator and is recoupled into the output fiber, then into the subsequent reference arm armor cable.

[0037] After the optical signal propagates through the reference arm armored cable to the port, it undergoes mirror reflection at the port due to the port's mirror treatment. The optical signal is directly reflected by the port and returns along the original optical path, achieving an optical path folding structure without the need for an additional reflector. This method is simple in structure, highly stable, and avoids the installation misalignment and environmental interference problems caused by traditional external reflectors.

[0038] The reflector or cornerstone is mounted on a movable slider, which can move along the slide rail to adjust the light delay time. The range of movement of the movable slider can be designed according to requirements.

[0039] The specific number of reflectors or cornerstones can be set according to the reference arm length requirements and the optical path cabinet size requirements.

[0040] Beneficial effects of this invention: To address the issue that the optical path difference between the reference arm and the signal arm in existing OCT welding penetration detection systems is easily affected by temperature, thereby enabling the system to accurately measure distances before welding. To maximize the matching of optical path lengths between the reference arm and the signal arm, reduce system dispersion, and improve the detection quality of the OCT system; It eliminates the need for algorithm fitting or active temperature control to adjust the optical path difference, resulting in more stable and faster response, and lower cost. No additional ranging device is required, which can reduce production line costs.

[0041] The components, modules, mechanisms, and devices in this invention that are not described in detail are all general standard parts or components known to those skilled in the art. Their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A symmetrical reference arm with an externally armored cable, characterized in that, This includes the incident optical fiber, the delayed optical path, the outgoing optical fiber, and the reference arm armor cable, which are arranged sequentially according to the optical path. The reference arm armored cable undergoes port mirror treatment, which includes: flat-cutting the port of the traditional reference arm armored cable and depositing a metal film to make the port of the traditional reference arm armored cable form a mirror reflection.

2. The symmetrical reference arm for an externally armored cable according to claim 1, characterized in that, The delayed optical path includes an incident collimator, a movable delayer, and an exit collimator arranged sequentially according to the optical path. The incident collimator is connected to the incident optical fiber, and the exit collimator is connected to the exit optical fiber.

3. A symmetrical reference arm for an externally armored cable according to claim 2, characterized in that, The movable delay unit includes a movable slider and a rear reflector. The movable slider is slidably connected to a slide rail, which is connected inside the optical path cabinet. The rear reflector is connected to the movable slider.

4. A symmetrical reference arm for an externally armored cable according to claim 3, characterized in that, The rear reflector is one of a mirror assembly or a cornerstone.

5. An OCT system, characterized in that, The device includes an optical path cabinet, a signal arm armored cable, and an OCT probe. The optical path cabinet is equipped with a symmetrical reference arm with an external armored cable as described in any one of claims 1-4. The reference arm armored cable extends to the outside of the optical path cabinet and is connected to the OCT probe. The OCT probe is connected to the optical path cabinet through the signal arm armored cable.

6. An OCT system according to claim 5, characterized in that, The signal arm armor cable is connected to an optical fiber patch cord, the length of which is equal to the sum of the incident optical fiber and the outgoing optical fiber.

7. An OCT system according to claim 6, characterized in that, The reference arm armor cable has the same length as the signal arm armor cable, and the reference arm armor cable is made of the same material as the signal arm armor cable.

8. An OCT system according to claim 7, characterized in that, The fiber optic cable of the reference arm armor cable has the same fiber optic cable type as the fiber optic cable of the signal arm armor cable.

9. An OCT system according to claim 8, characterized in that, The connector models at both ends of the reference arm armor cable are the same as those at both ends of the signal arm.

10. An OCT system according to claim 5, characterized in that, The optical path length in the delayed optical path is the same as the optical path length in the free space of the signal arm.

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