An automobile part surface quality detection device

Abstract

The utility model discloses a kind of automobile parts surface quality detection devices, it is related to automobile parts detection technical field, including computer system, controller, electric platform, stereoscopic microscope and newly added protective cover, annular shielding cloth, filter membrane placement subassembly and control component.The protective cover is installed in the top of electric platform, filter membrane placement area is located in the protective cover, the objective lens of stereoscopic microscope passes through the top observation hole of protective cover and extends into chamber;Annular shielding cloth center is fixed with objective lens, outer edge is connected with protective cover, it is circular ring organ pleat structure and has XYZ axis telescopic redundancy;Placement subassembly is the telescopic box of sealable sliding, control component includes butyl rubber glove and hose.The device is isolated exogenous pollution by closed environment and sealing structure, reduce the dependence on high-grade clean room, adapt microscope movement and convenient operation, effectively improve detection precision, stability and versatility, suitable for automobile parts surface cleanliness detection.

Description

Technical Field

[0001] This utility model relates to the field of automotive parts testing technology, and in particular to an automotive parts surface quality testing device. Background Technology

[0002] The surface cleanliness of automotive parts is a key indicator affecting the assembly precision, operational reliability, and service life of the entire vehicle. This is especially true for precision components such as engine blocks, fuel injection system parts, and bearings. Residual metal shavings, non-metallic particles, and fibrous impurities on their surfaces can easily cause problems such as component wear, oil passage blockage, and seal failure after assembly, potentially leading to vehicle malfunctions. Therefore, the automotive industry generally adheres to international standards such as VDA19 and ISO16232 to rigorously test the surface cleanliness of parts, ensuring that the particle size and quantity of contaminants meet quality requirements.

[0003] Current automotive component surface cleanliness testing processes primarily rely on a combination of extraction, filtration, and microscopic analysis. The core components of the corresponding testing equipment include: a filter membrane for trapping contaminants on the component surface, an electrically driven platform capable of precise X / Y / Z-axis movement, a stereomicroscope for high-definition optical imaging, and a computer system integrating cleanliness analysis software. The specific testing process is as follows: first, contaminants on the component surface are separated into a cleaning solution using a dedicated extraction device; then, the contaminants are filtered through the filter membrane to ensure all contaminants are trapped on the membrane surface. Next, the contaminant-laden filter membrane is placed on the electrically driven platform, and high-definition optical imaging of the membrane is performed using the stereomicroscope. The electrically driven platform, through precise X / Y / Z-axis movement, works in conjunction with the microscope to complete a comprehensive scan of the entire filter membrane. The computer system's host computer contains cleanliness analysis software, which incorporates a metal / non-metal / fiber differentiation algorithm. This software can perform particle identification and data statistics on the received microscopic images, automatically generating a test report, which is then displayed on a monitor.

[0004] However, existing cleanliness testing devices have significant drawbacks in practical use: because the filter membrane carrying contaminants is directly exposed to the testing environment for imaging and scanning, floating dust, clothing fibers of operators, and exogenous particles brought by airflow in the laboratory environment are very likely to settle on the surface of the filter membrane, forming "false positive" contaminants and causing the test data to be distorted; at the same time, in order to avoid environmental interference, existing tests must be carried out in a Class 1000 (ISO 7) or higher cleanroom, which not only significantly increases the cost of laboratory construction and operation and maintenance, but also limits the applicable scenarios of the testing device (such as on-site temporary testing and the inability to meet the low-cost testing needs of small and medium-sized enterprises), seriously affecting the stability, accuracy and versatility of cleanliness testing. Utility Model Content

[0005] To address the aforementioned technical problems, this invention provides a device for inspecting the surface quality of automotive parts that can perform imaging scanning of filter membranes in a closed environment, reducing dependence on the cleanliness of the inspection environment and improving inspection accuracy.

[0006] This utility model discloses a surface quality inspection device for automotive parts, comprising a computer system, a controller, an electric platform, and a stereomicroscope. The computer system includes a monitor and a host computer, with a keyboard and mouse connected to the host computer. Cleanliness analysis software is installed within the host computer. The controller is used for adjusting the electric platform. The stereomicroscope is mounted on the fixed end of the position adjustment mechanism of the electric platform. A filter membrane placement area is provided on the electric platform. A standard C-interface is provided at the top of the stereomicroscope tube, and an industrial-grade CCD image sensor (resolution ≥ 20 megapixels) is sealed and installed at the C-interface. The image sensor is connected to the computer host computer via a USB data cable. The device also includes:

[0007] A protective cover is installed on the top of an electric cargo platform. The filter membrane placement area is located inside the protective cover. The top of the protective cover is set as a transparent plate. An observation hole communicating with the chamber of the protective cover is opened in the middle of the top of the protective cover. The objective lens of the stereomicroscope extends into the chamber of the protective cover through the observation hole.

[0008] The annular shielding cloth has a central hole that is fixedly connected to the middle of the objective lens by a clamp, and the outer edge of the annular shielding cloth is fixedly connected to the outer wall of the protective cover located above the observation hole. The annular shielding cloth has a stretching redundancy in the XYZ axes.

[0009] A filter membrane insertion assembly is provided on the side wall of the protective cover;

[0010] The protective cover is equipped with control components on both the left and right side walls for picking up and placing filter membranes and positioning filter membranes.

[0011] Furthermore, the annular shielding fabric is configured with an accordion pleat structure, and the pleats of the accordion pleats are all concentric rings.

[0012] Furthermore, the insertion component includes a telescopic box. The bottom front end of the protective cover communicates with the chamber of the protective cover through a telescopic hole. The telescopic box is slidably installed in the telescopic hole. The top of the telescopic box is provided with a shallow groove for placing the filter membrane. The front end of the telescopic box is provided with a control baffle, and the rear end is provided with a limit plate. When the control baffle is in close contact with the protective cover, the front end of the telescopic box is aligned with the front end of the protective cover, and the telescopic box seals the telescopic hole. When the telescopic box is pulled out so that the limit plate is in close contact with the inner wall of the protective cover, the shallow groove is exposed on the outside, and the rear area of ​​the telescopic box seals the telescopic hole.

[0013] Furthermore, the control assembly includes a hose and a control glove connected to the hose, the control glove being a nitrile glove, and the left and right walls of the protective cover having insertion holes that communicate with the hose on the corresponding sides.

[0014] Furthermore, permanent magnet particles are embedded in the palm part of the control glove, and magnetic materials are provided on both the left and right sides of the inner wall of the front side of the protective cover. The control glove can be magnetically attracted to the inner wall of the corresponding side of the protective cover through the permanent magnet particles.

[0015] Furthermore, the annular shielding fabric is provided with a flexible pleated skeleton adapted to accordion pleats from the center to the edge, and multiple flexible pleated skeletons are evenly distributed.

[0016] Furthermore, a vent pipe communicating with the chamber of the protective cover is provided on one side of the top of the protective cover. A filter screen is installed inside the vent pipe, and a dust-free sponge pad is provided at the bottom of the filter screen.

[0017] Furthermore, stainless steel tweezers are placed on the electric loading platform inside the protective cover.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] 1. Construct a closed testing environment by sealing it with a combination of protective cover and ring-shaped shielding cloth to effectively isolate external particles such as floating dust and clothing fibers in the laboratory environment, avoid "false positive" test results caused by filter membrane contamination, and significantly improve the accuracy and stability of cleanliness testing.

[0020] 2. It does not rely on high-level cleanrooms, reducing the construction and maintenance costs of the testing environment, expanding the applicability of the device in low-cost testing scenarios such as on-site temporary testing and small and medium-sized enterprises, and improving its versatility.

[0021] 3. The ring-shaped shielding cloth adopts a circular accordion pleat structure and is equipped with a flexible pleated skeleton. It has sufficient extensibility in the three directions of XYZ, which can flexibly adapt to the movement of the stereomicroscope objective lens, without limiting the movement accuracy of the equipment, and can continuously maintain the integrity of the seal.

[0022] 4. The filter membrane placement component improves the isolation effect of the filter membrane placement process. The control component allows operators to perform internal operations outside the closed environment. With the built-in stainless steel tweezers, it not only avoids direct hand contact with the filter membrane and prevents contamination, but also improves the convenience of filter membrane positioning and placement.

[0023] 5. The combination design of the vent tube, filter and dust-free sponge pad ensures air circulation inside the protective cover to prevent condensation, and filters the incoming air to further maintain internal cleanliness; the magnetic design of the permanent magnet particles embedded in the control gloves can prevent the gloves from shaking and interfering with the detection operation, improving ease of use.

[0024] 6. The overall structure is simple and compact with a high degree of modularity. The transparent plate at the top of the protective cover does not affect observation. The coordinated work of each component ensures both detection accuracy and operational flexibility and structural stability, making it easy to promote and apply. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of this utility model;

[0026] Figure 2 This is a schematic diagram of the installation structure of the control glove of this utility model;

[0027] Figure 3 This is a schematic diagram of the connection structure between the air vent and the filter screen of this utility model;

[0028] Figure 4 This is a schematic diagram of the installation structure of the permanent magnet particles of this utility model;

[0029] The following are labels in the attached diagram: 1. Controller; 2. Electric platform; 3. Stereo microscope; 4. Display; 5. Main unit; 6. Filter membrane placement area; 7. Protective cover; 8. Annular shielding cloth; 9. Telescopic box; 10. Shallow groove; 11. Control baffle; 12. Limiting plate; 13. Control glove; 14. Permanent magnet particles; 15. Flexible pleated skeleton; 16. Ventilation tube; 17. Filter screen; 18. Dust-free sponge pad; 19. Stainless steel tweezers. Detailed Implementation

[0030] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit the scope of this utility model.

[0031] like Figures 1 to 4 As shown, this utility model discloses a surface quality inspection device for automotive parts, comprising a computer system, a controller 1, an electric platform 2, and a stereomicroscope 3. The computer system includes a monitor 4 and a host 5. The host 5 is connected to a keyboard and mouse and contains cleanliness analysis software. The controller 1 is used for adjusting the electric platform 2. The stereomicroscope 3 is mounted on the fixed end of the position adjustment mechanism of the electric platform 2. The electric platform 2 is provided with a filter membrane placement area 6. The device also includes:

[0032] The protective cover 7 is installed on the top of the electric carrying platform 2. The filter membrane placement area 6 is located inside the protective cover 7. The top of the protective cover 7 is set as a transparent plate. An observation hole communicating with the chamber of the protective cover 7 is opened in the middle of the top of the protective cover 7. The objective lens of the stereomicroscope 3 extends into the chamber of the protective cover 7 through the observation hole.

[0033] The annular shielding cloth 8 is fixedly connected to the center of the objective lens by a clamp, and the outer edge of the annular shielding cloth 8 is fixedly connected to the outer wall of the protective cover 7 located above the observation hole. The annular shielding cloth 8 has a telescopic redundancy in the XYZ axes.

[0034] A filter membrane insertion assembly is provided on the side wall of the protective cover 7;

[0035] The protective cover 7 is provided with control components for picking up and placing filter membranes and positioning filter membranes on both the left and right side walls.

[0036] In this embodiment,

[0037] Protective cover 7: Installed on the top of the electric platform 2, forming a closed detection chamber that encloses the filter membrane placement area 6. Its core function is to isolate dust, fibers and other contaminants from the external environment, providing a clean space for filter membrane detection. The transparent plate at the top does not affect the detection and observation, and the observation hole in the middle is used for the objective lens of the stereomicroscope 3 to extend into, ensuring the imaging function.

[0038] Annular shielding cloth 8: The central hole is fixed to the objective lens by a clamp, and the outer edge is connected to the outer wall of the protective cover 7. Its core function is to seal the gap between the observation hole and the objective lens. At the same time, its XYZ axis extension redundancy can accommodate the three-dimensional movement of the objective lens and avoid the sealing structure restricting the movement of the equipment. The annular shielding cloth can be made of PTFE coated fiberglass cloth, silicone coated nylon cloth or microfiber PTFE composite cloth, but is not limited to the above materials. The choice can be made according to the actual needs.

[0039] Filter membrane placement assembly: Located on the side wall of the protective cover 7, its core function is to provide a sealed access channel for the filter membrane, which greatly reduces the degree to which the internal clean environment is damaged.

[0040] Control components: Located on the left and right sides of the protective cover 7, their core function is to allow operators to reach in from outside the enclosed environment to perform operations such as picking up, placing, and positioning the filter membrane, avoiding direct contact between the hands and the filter membrane or contamination of the internal environment.

[0041] As a preferred embodiment of the above, the annular shielding cloth 8 is configured as an accordion pleat structure, and the pleats of the accordion pleats are all concentric rings.

[0042] In this embodiment,

[0043] The ring-shaped accordion-pleated shielding cloth 8: Its core function is to distribute the stretching redundancy of the shielding cloth evenly within a 360° range, ensuring that the shielding cloth can be stretched or compressed synchronously when the objective lens moves in any horizontal direction (XY axis) and vertical direction (Z axis), thus ensuring a sealing effect and avoiding local tension that could affect the movement accuracy of the equipment.

[0044] As a preferred embodiment of the above embodiment, the insertion component includes a telescopic box 9. The bottom front end of the protective cover 7 is connected to the cavity of the protective cover 7 and has a telescopic hole. The telescopic box 9 is slidably installed in the telescopic hole. The top end of the telescopic box 9 is provided with a shallow groove 10 for placing the filter membrane. The front end of the telescopic box 9 is provided with a control baffle 11, and the rear end is provided with a limiting plate 12. When the control baffle 11 is in close contact with the protective cover 7, the front end of the telescopic box 9 is aligned with the front end of the protective cover 7, and the telescopic box 9 seals the telescopic hole. When the telescopic box 9 is pulled out so that the limiting plate 12 is in close contact with the inner wall of the protective cover 7, the shallow groove 10 is exposed on the outside, and the rear area of ​​the telescopic box 9 seals the telescopic hole.

[0045] In this embodiment,

[0046] Telescopic box 9: It is slidably installed in the telescopic hole at the bottom front end of the protective cover 7. The shallow groove 10 at the top is used to place the filter membrane. Its core function is to achieve "sealed" transfer of the filter membrane. When pulled out, the shallow groove 10 is exposed for placing the filter membrane, and the rear area is still sealed by the telescopic hole. When pushed in, the control baffle 11 is close to the protective cover 7, completely sealing the telescopic hole. The filter membrane is placed in a relatively fast manner throughout the process, which greatly reduces the amount of external pollutants entering the protective cover 7 through the pick-up and drop-off channel.

[0047] Control baffle 11: Its core function is to align the front end of the protective cover 7, ensuring the flatness of the device's appearance and the integrity of its seal. At the same time, the control baffle 11 makes the pushing and pulling process of the telescopic box 9 more convenient.

[0048] Limiting plate 12: Its core function is to limit the pull-out stroke of telescopic box 9, so as to prevent telescopic box 9 from completely detaching from protective cover 7 and causing sealing failure.

[0049] As a preferred embodiment of the above, the control assembly includes a hose and a control glove 13 communicating with the hose. The control glove 13 is a nitrile glove, and the left and right walls of the protective cover 7 are provided with insertion holes communicating with the hose on the corresponding side.

[0050] In this embodiment,

[0051] Hose: Connects to the insertion hole of the protective cover 7. Its core function is to provide a mounting carrier and movement space for the operating glove 13, allowing the operator's hands to move flexibly within the hose range, while isolating the direct flow of external air to the inside of the protective cover 7.

[0052] Nitrile gloves (operation gloves 13): Their core function is to act as an isolation barrier between the operator's hands and the internal environment, preventing hand oils and dust from contaminating the filter membrane or the internal environment. Nitrile material is low in dust and antistatic, meeting the requirements for cleanroom testing.

[0053] As a preferred embodiment of the above, the palm part of the control glove 13 is embedded with permanent magnet particles 14, and the left and right sides of the inner sidewall of the front side of the protective cover 7 are provided with magnetic materials. The control glove 13 can be magnetically attracted to the inner sidewall of the corresponding side of the protective cover 7 through the permanent magnet particles 14.

[0054] In this embodiment,

[0055] Permanent magnet particles 14 (embedded in the palm of the control glove 13): Their core function is to cooperate with the magnetic material on the inner wall of the protective cover 7 to temporarily fix the control glove 13, preventing the glove from shaking randomly when not in operation and interfering with the filter membrane or detection equipment. The permanent magnet particles 14 can be glued to the control glove 13, or the control glove 13 can be customized. During the customization process, the manufacturer can install the permanent magnet particles 14 on the control glove 13.

[0056] Magnetic material (set on the left and right sides of the inner front wall of the protective cover 7): Its core function is to attract the permanent magnet particles 14 embedded in the glove, providing a fixed support for the glove and improving the ease of operation. When the control glove 13 is not in use, the operator can magnetically attach the control glove 13 to the inner wall of the protective cover 7 to avoid the control glove 13 being placed randomly and affecting the testing process.

[0057] As a preferred embodiment of the above, the annular shielding cloth 8 is provided with a flexible pleated skeleton 15 adapted to the accordion pleats from the center to the edge, and multiple flexible pleated skeletons 15 are evenly distributed.

[0058] In this embodiment,

[0059] Flexible pleated frame 15 (evenly distributed on the annular shielding cloth 8): Its core function is to support the annular accordion pleat structure of the annular shielding cloth 8, prevent the pleats from collapsing or deforming, ensure that the shielding cloth can maintain its shape after repeated stretching and contraction, and enhance the stretching stability of the shielding cloth to prevent it from getting stuck or being pulled when the equipment moves. The flexible pleated frame 15 can be made of stainless steel wire or stainless steel ultra-thin narrow sheet, etc., and is not limited to the above two. It can be selected according to actual needs.

[0060] As a preferred embodiment of the above embodiment, a vent pipe 16 communicating with the chamber of the protective cover 7 is provided on one side of the top end of the protective cover 7, a filter screen 17 is installed inside the vent pipe 16, and a dust-free sponge pad 18 is provided at the bottom of the filter screen 17.

[0061] In this embodiment,

[0062] Ventilation tube 16: Located on one side of the top of the protective cover 7, its core function is to enable air circulation between the inside and outside of the protective cover 7, and to prevent condensation caused by poor air circulation inside, which would affect the condition of the filter membrane and the imaging effect.

[0063] Filter 17: Installed inside the vent pipe 16, its core function is to filter the external air entering the protective cover 7, intercepting pollutants such as dust and particles in the air, and ensuring the cleanliness of the incoming air.

[0064] Dust-free sponge pad 18: Located at the bottom of filter 17, its core function is to further filter fine particles, while buffering the airflow to prevent the airflow from directly impacting the filter membrane and causing particle displacement. It also has a certain moisture absorption capacity to help prevent condensation.

[0065] As a preferred embodiment of the above embodiment, stainless steel tweezers 19 are placed on the electric loading platform 2 inside the protective cover 7;

[0066] In this embodiment,

[0067] Stainless steel tweezers 19 (placed inside the protective cover 7 on the electric loading platform 2): The core function is to allow operators to pick up the filter membrane with the assistance of the control gloves 13, avoiding direct contact between the hands and the filter membrane. At the same time, the stainless steel material generates little dust, is easy to clean, meets the requirements of clean testing, and can accurately locate the edge of the filter membrane, protecting the pollutant trapping area in the middle of the filter membrane.

[0068] The working principle of this utility model is as follows:

[0069] This invention achieves accurate detection of the surface cleanliness of automotive parts by constructing a closed and clean testing environment, combined with a sealed structure adapted to the movement of the equipment and convenient operating components. The specific workflow is as follows: The operator first places the filter membrane carrying contaminants into the shallow groove 10 of the extended telescopic box 9, and pushes the telescopic box 9 in to seal it; then, the operator puts both hands into the nitrile gloves on the left and right sides, and uses the internal stainless steel tweezers 19 to accurately position the filter membrane in the filter membrane placement area 6 of the electric carrying platform 2; the protective cover 7 and the annular shielding cloth 8 form a closed space, and the vent pipe 16 introduces clean air through the filter screen 17 and the dust-free sponge pad 18 to avoid condensation and contamination; after the equipment is started, the controller 1 controls the electric carrying platform 2 to move along the XYZ axis, and the objective lens of the stereo microscope 3 passes through the observation hole to perform a full scan of the filter membrane. The annular accordion pleat structure of the annular shielding cloth 8 adapts to the movement of the objective lens and keeps it sealed; the high-definition image captured by the microscope is transmitted to the computer system, the cleanliness analysis software completes particle identification, statistics and report generation, and finally the test results are presented on the display 4. The entire process does not rely on high-level cleanrooms, effectively isolating external contaminants while balancing detection accuracy, ease of operation, and equipment compatibility.

[0070] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A surface quality inspection device for automotive parts, comprising a computer system, a control host (5), an electric loading platform (2), and a stereomicroscope (3), wherein the computer system includes a monitor (4) and a host (5), the host (5) is connected to a keyboard and a mouse, and cleanliness analysis software is installed inside the host (5); the control host (5) is used for the control of the electric loading platform (2); the stereomicroscope (3) is installed at the fixed end of the position adjustment mechanism of the electric loading platform (2); and a filter membrane placement area (6) is provided on the electric loading platform (2), characterized in that, Also includes: A protective cover (7) is installed on the top of an electric loading platform (2). The filter membrane placement area (6) is located inside the protective cover (7). The top of the protective cover (7) is set as a transparent plate. An observation hole communicating with the chamber of the protective cover (7) is opened in the middle of the top of the protective cover (7). The objective lens of the stereomicroscope (3) extends into the chamber of the protective cover (7) through the observation hole. The annular shielding cloth (8) has a central hole that is fixedly connected to the middle part of the objective lens by a clamp. The outer edge of the annular shielding cloth (8) is fixedly connected to the outer wall of the protective cover (7) located above the observation hole. The annular shielding cloth (8) has a stretching redundancy in the three directions of XYZ axis. A filter membrane insertion assembly is provided on the side wall of the protective cover (7); The protective cover (7) is provided with control components on both the left and right side walls for picking up and placing filter membranes and positioning filter membranes.

2. The automotive parts surface quality inspection device as described in claim 1, characterized in that, The annular shielding cloth (8) is configured with an accordion pleat structure, and the pleats of the accordion pleats are all concentric rings.

3. The automotive parts surface quality inspection device as described in claim 1, characterized in that, The insertion component includes a telescopic box (9). The front bottom of the protective cover (7) is connected to the cavity of the protective cover (7) with a telescopic hole. The telescopic box (9) is slidably installed in the telescopic hole. The top of the telescopic box (9) is provided with a shallow groove (10) for placing the filter membrane. The front end of the telescopic box (9) is provided with a control baffle (11), and the rear end is provided with a limit plate (12). When the control baffle (11) is in close contact with the protective cover (7), the front end of the telescopic box (9) is aligned with the front end of the protective cover (7), and the telescopic box (9) seals the telescopic hole. When the telescopic box (9) is pulled out so that the limit plate (12) is in close contact with the inner wall of the protective cover (7), the shallow groove (10) is exposed on the outside, and the rear area of ​​the telescopic box (9) seals the telescopic hole.

4. The automotive parts surface quality inspection device as described in claim 1, characterized in that, The control assembly includes a hose and a control glove (13) connected to the hose. The control glove (13) is a nitrile glove. The left and right walls of the protective cover (7) are provided with insertion holes that are connected to the hose on the corresponding side.

5. The automotive parts surface quality inspection device as described in claim 4, characterized in that, The palm part of the control glove (13) is embedded with permanent magnet particles (14), and the inner side wall of the front side of the protective cover (7) is provided with magnetic materials on both sides. The control glove (13) can be magnetically attracted to the inner side wall of the corresponding side of the protective cover (7) through the permanent magnet particles (14).

6. The automotive parts surface quality inspection device as described in claim 2, characterized in that, The annular shielding cloth (8) is provided with a flexible pleated skeleton (15) adapted to the accordion pleats from the center to the edge, and multiple flexible pleated skeletons (15) are evenly distributed.

7. The automotive parts surface quality inspection device as described in claim 1, characterized in that, The top side of the protective cover (7) is provided with a vent pipe (16) that communicates with the chamber of the protective cover (7). A filter screen (17) is installed inside the vent pipe (16), and a dust-free sponge pad (18) is provided at the bottom of the filter screen (17).

8. The automotive parts surface quality inspection device as described in claim 1, characterized in that, Stainless steel tweezers (19) are placed on the electric loading platform (2) inside the protective cover (7).

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