Wheel nut looseness checker

Abstract

To provide a checker for loosening of a wheel nut that is improved in appearance so as to enable users to increase, and further to provide a checker for loosening of a wheel nut that is added with functions so as to enable users to increase.SOLUTION: A checker 100 for loosening of a wheel nut is constituted of a lid body 1 comprising at a wall inside a first inner wall surface 11 having a plurality of valley parts which engage with a top of a wheel nut N, and a wheel cover 2, a doughnut-shaped disk having an exposure hole for a hub H at a center thereof, which comprises an opening part 20 through which the wheel nut N is exposed, where and index 14 is formed on a surface of the lid body 1.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a wheel nut looseness checker that checks for looseness of wheel nuts used when mounting tires on automobiles, particularly large vehicles such as trucks and buses. [Background technology]

[0002] Shocking footage on television shows and shocking news reports often feature truck tire detachment accidents. Under the current new ISO method (see Non-Patent Document 1), truck tires have wheel nuts that are tightened clockwise on both the left and right sides. This makes it easy for the nut on the left rear tire to loosen when going around a curve, leading to tire detachment accidents.

[0003] Therefore, various methods have been devised to prevent loosening of wheel nuts. Non-patent document 2 and non-patent document 3 are methods for detecting loosening of wheel nuts. In addition, for a product such as that described in non-patent document 2, there is also an application such as that described in patent document 1. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Utility Model Registration No. 3146831 [Patent Document 2] Japanese Utility Model Application Publication No. 39-28924 [Patent Document 3] Japanese Utility Model Application Publication No. 59-83210 [Non-patent literature]

[0005] [Non-Patent Document 1] Japan Automobile Manufacturers Association, Inc. | Regarding the Handling of New ISO-Type Wheels [Retrieved July 17, 2021], Internet (http: / / www.tenken-seibi.com / tenken / pdf / iso-wheel.pdf) [Non-patent document 2] Racten|Checkpoint YELLOW [Retrieved July 14, 2021], Internet (https: / / item.rakuten.co.jp / norauto / cpy33-100 / ) [Non-patent document 3] Japan Automobile Manufacturers Association, Inc. | News Release: "Use of the Linked Nut Rotation Indicator" [Retrieved July 14, 2021], Internet (https: / / release.jama.or.jp / sys / news / detail.pl?item_id=1936) [Non-patent document 4] YOKOHAMA | Truck and Bus Tire Top: Preventing Uneven Wear [Retrieved July 14, 2021], Internet (https: / / www.y-yokohama.com / product / truckbustire / wearout / ) Summary of the Invention [Problem to be solved by the invention]

[0006] However, the reality is that wheel nut looseness checkers such as those described in Non-Patent Document 2 and Non-Patent Document 3 are not widely used. One of the reasons for this is that, even though people understand that wheel nut looseness checkers are effective, they do not look very good when actually installed because they have protruding indicators.

[0007] Although cost and durability are important for large vehicles such as trucks and buses, truck tire hubcaps are also sold, and decorative features around the tire are also important factors for drivers. Therefore, if the appearance can be improved, it will lead to increased use of wheel nut looseness checkers.

[0008] Furthermore, wheel nut looseness checkers such as those described in Non-Patent Document 2 and Non-Patent Document 3 are relatively thin, making installation less user-friendly, especially when wearing protective gloves. Furthermore, if wheel nut looseness checkers were equipped with functions other than detecting loose wheel nuts, their use would become even more widespread.

[0009] For example, since simply detecting loosening is insufficient to prevent loosening, a function to prevent loosening has been considered. Regarding preventing loosening, Patent Documents 2 and 3 disclose methods for preventing loosening by providing a plate or ring that is immobile relative to the object. As shown in Figure 2, Patent Document 2 has four hexagonal holes into which the wheel nut fits, and a ring with engaging pawls. This fit prevents the wheel nut from loosening. Patent Document 3 discloses a circular plate with four 18-valve star-shaped holes and pawls extending in all directions. These 18-valve star-shaped holes make it easier to insert the wheel nut into the four holes in Patent Document 3 than in Patent Document 2.

[0010] However, the 18-valley star-shaped hole of Patent Document 3 has the problem that the 18-valley star-shaped hole cannot be fitted onto the wheel nut unless the angles of all four of the 18 valleys match the vertices of the four wheel nuts. Furthermore, neither Patent Document 2 nor Patent Document 3 has the function of detecting looseness of wheel nuts as Patent Document 1 and Non-Patent Document 2 and Non-Patent Document 3 do.

[0011] Other possible functions include the following: As shown in the diagram of an example of changing the position of truck and bus tires in Non-Patent Document 4, tire rotation involves replacing the inside of a double rear tire (also called a twin tire or dual tire) with a single front tire.

[0012] A typical tire rotation involves first removing the wheel with the tire attached from the axle, then removing the tire from the wheel, rotating the removed tire, and then reattaching the tire to the designated wheel. This is called "tire reassembly," and the wheel itself remains in the same position as when it was first installed.

[0013] On the other hand, it is also possible to rotate the wheel without removing the tire from the wheel, by rotating the wheel with the tire still attached. This is the so-called "tire removal and installation" process, and in this case the wheel itself will be moved to a different position from its original position.

[0014] When tire positioning is performed by "removing and attaching tires," the process is more efficient than when "reassembling tires" because it eliminates the need to remove and attach tires to wheels. However, as described in the new ISO method in non-patent document 1, dual tires are fixed and mounted as a set on two uneven wheels, with the convex surfaces, which should be the outer surfaces, aligned with each other. Therefore, foreign objects such as stones and mud can get into the opposing surfaces of the wheels (the convex surfaces), causing scratches and dirt. If a wheel with such scratches or dirt is used as the front wheel, the convex surface will become the outer surface, exposing the scratches and dirt.

[0015] While dirt can be easily cleaned, exposed scratches on the wheel surface are particularly unwelcome for truck owners. This is because scratches on the wheel surface not only have an aesthetic impact, but can also create a negative image of a company that does not provide proper maintenance. Scratches on the wheel surface can also cause sunlight to be scattered, potentially impairing the vision of drivers of passenger cars traveling or parked next to the truck. Due to these issues, tire positioning is typically performed by "tire reassembly," which reduces the efficiency of tire positioning. This issue is not addressed in either Patent Document 2 or Patent Document 3. In other words, a conceivable function is to hide surface scratches on wheels that occur when using double tires, etc., in order to improve the efficiency of tire positioning.

[0016] Therefore, an object of the present invention is to provide a wheel nut looseness checker that can increase the number of users by improving its appearance. Another object of the present invention is to provide a wheel nut looseness checker that is easy to install. Still another object of the present invention is to provide a wheel nut looseness checker that can increase the number of users by adding functions. [Means for solving the problem]

[0017] In order to achieve the above object, the wheel nut loosening checker of the present invention comprises a lid body having a first inner wall surface with multiple valleys on the inside of the wall that engage with the apex of the wheel nut, and a wheel cover which is a donut-shaped circular plate with an exposure hole for the hub in the center and an opening through which the wheel nut is exposed, and is characterized in that an indicator is formed on the surface of the lid body.

[0018] The wheel nut loosening checker of the present invention has an indicator formed on the surface of the lid, rather than a protrusion as in the past, which improves its appearance. Furthermore, because it is composed of the lid that covers the wheel nuts and the wheel cover, it is possible to create a unified color or pattern, which enhances its decorativeness.

[0019] For example, in Patent Document 3, the wheel cover cannot be fitted unless all four angles of the hexagon of the wheel nut match the angle of an 18-point star. In contrast, the wheel nut loosening checker of the present invention has a separate cover that engages with the wheel nut and the wheel cover, making it easy to fit onto the wheel nut and improving installation workability. Furthermore, the cover, which is formed with an index, covers the wheel nut, so it can be firmly gripped even when wearing protective gloves, which also improves installation workability.

[0020] Furthermore, with this wheel cover, scratches on the wheel surface that occur when using double tires can be hidden with the wheel cover. In other words, since the wheel cover has the function of hiding scratches on the wheel surface, when changing the position of tires, it is possible to actively adopt the method of changing the position by "removing and attaching the tire" rather than by "reassembling the tire," thereby making the work of changing the position of tires more efficient.

[0021] In addition, in the wheel nut loosening checker of the present invention, it is preferable that the cover body has an exterior portion with an outer shape formed outside the wall, the exterior portion is larger than the opening of the wheel cover, and the indicator is formed as a recess on the top surface.

[0022] According to the wheel nut loosening checker of the present invention, the exterior part of the lid body can also serve to secure the wheel cover. Furthermore, when an index is printed or attached to the surface of the lid body, for example, there is a risk that the surface index will disappear or peel off if it comes into contact with a guardrail or the like. However, the index of the present invention is recessed into the top surface of the exterior part, so it will not easily disappear even if it comes into contact with a guardrail or the like.

[0023] In the wheel nut loosening checker of the present invention, it is preferable that an outer wall surface on the outer side of the wall of the lid body engages with a second inner wall surface on the inner side of the opening of the wheel cover.

[0024] According to the wheel nut loosening checker of the present invention, loosening of the wheel nuts can be prevented as well as the loosening can be detected by the indicator, since the outer wall surface of the lid body and the second inner wall surface of the wheel cover engage with each other.

[0025] In addition, in the wheel nut loosening checker of the present invention, it is preferable that grooves extending radially from the center of the exposure hole are formed on the back surface of the wheel cover. With the wheel nut loosening checker of the present invention, even when a wheel cover is attached, the presence of grooves on the back surface of the wheel cover can prevent a decrease in heat dissipation from the wheel. [Brief explanation of the drawings]

[0026] [Figure 1] A is an image of the wheel cover of the prototype of the wheel nut looseness checker of the first embodiment of the present invention, and B is an image of the wheel cover and the cover body. [Figure 2] A is a cross-sectional view showing the wheel nut loosening checker of embodiment 1 mounted on a double tire (rear wheel), B is a view (partial cross-sectional view) taken along the arrow IIB-IIB of A, and C is a cross-sectional view showing the wheel nut loosening checker mounted on a single tire (front wheel). [Figure 3] This is an image of a prototype of the wheel nut looseness checker of the present invention actually attached to a wheel. [Figure 4] 1A is a perspective view showing the front side of a wheel nut looseness checker according to a second embodiment of the present invention, and FIG. 1B is a perspective view showing the back side thereof. [Figure 5] 1A is a plan view showing the front surface of a wheel nut looseness checker according to a second embodiment of the present invention, and FIG. 1B is a bottom view showing the rear surface thereof. [Figure 6] FIG. 1A is a perspective view showing the front surface of a wheel cover according to a second embodiment of the present invention, and FIG. [Figure 7] FIG. 10A is a plan view showing the front surface of a wheel cover according to a second embodiment of the present invention, and FIG. 10B is a bottom view showing the rear surface thereof. [Figure 8] A is a cross-sectional view showing the wheel nut loosening checker of embodiment 2 attached to a double tire (rear wheel), B is a view (partial cross-sectional view) taken along the arrow VIIIB-VIIIB of A, and C is a cross-sectional view showing the wheel nut loosening checker attached to a single tire (front wheel). [Figure 9] 1A is a plan view of a wheel cover showing a modification of the second embodiment of the present invention, and FIG. 1B is a plan view showing a state in which a lid portion of the modification of the second embodiment is attached. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, a mode for carrying out the present invention will be described with reference to the embodiments and drawings, but the embodiments shown below are not intended to limit the present invention to those described herein, and the present invention is equally applicable to various modifications without departing from the technical idea set forth in the claims. Note that in each drawing used for explanation in this specification, each component is shown at a different scale so that each component can be recognized on the drawing, and is not necessarily shown in proportion to its actual size.

[0028] [Embodiment 1] 1 and 2, the main parts of the wheel nut looseness checker 100 of this embodiment will be described. The wheel nut looseness checker 100 of this embodiment is made up of multiple lid bodies 1 and one wheel cover 2. The wheel cover 2 has openings 20 formed therein through which the wheel nuts N are exposed. The openings 20 engage with the lid bodies 1, and the lid bodies 1 are formed to engage with the wheel nuts N.

[0029] Fig. 1A is an image of a prototype of wheel cover 2, and Fig. 1B is an image of a prototype of part of wheel cover 2 and one lid body 1. Fig. 2A is a cross-sectional view showing the wheel nut loosening checker 100 of the embodiment attached to a double tire, Fig. 2B is a view taken along the arrows IIB-IIB in Fig. 2A, and Fig. 2C is a cross-sectional view showing the wheel nut loosening checker 100 attached to a single tire.

[0030] The number of lid bodies 1 is the same as the number of wheel nuts N. For example, as described in Non-Patent Document 1, there are eight lid bodies 1 for a 19.5-inch truck wheel and ten lid bodies 1 for a 22.5-inch truck wheel. Figures 1 and 2 show the case where there are eight lid bodies 1.

[0031] The dome-shaped cover body 1 that covers the wheel nut N has a first inner wall surface 11 on the inside that engages with the wheel nut N, an outer wall surface 12 located on the outside thereof, and an exterior part 13 that is spaced a predetermined distance from the outer wall surface 12 and forms the outer shape.

[0032] Specifically, the first inner wall surface 11 is star-shaped with a plurality of equally spaced valleys. The number of valleys is an integer multiple (24 valleys in this embodiment) of the number (6) of vertices of the wheel nut N. The angle of the valleys of the first inner wall surface 11 is 120 degrees, the same as the angle of the vertices of the wheel nut N. The outer wall surface 12 is star-shaped with a plurality of equally spaced peaks (24 peaks in this embodiment), and the angle of these peaks is 120 degrees.

[0033] In addition, the exterior part 13 that forms the outer shape of the dome-shaped lid body 1 has hexagonal sides, and on the top surface thereof, an indicator 14 (arrow) indicating the orientation of the lid body 1 is formed by printing or the like, as shown in Figure 2B.

[0034] The wheel cover 2 is doughnut-shaped, with an outer diameter sized to fit into the recess of the wheel W, and an inner diameter opening (hub exposure hole) to expose the hub H. The wheel cover 2 is also formed with eight circular openings 20 through which each wheel nut N is exposed. A circular wall portion 21 protrudes from each opening 20, and a second inner wall surface 22 having equally spaced valleys that engage with the outer wall surface 12 of the lid body 1 is formed on the inside of this wall portion 21. This wall portion 21 is inserted into the gap between the outer wall surface 12 of the lid body 1 and the exterior portion 13. The second inner wall surface 22 that engages with the outer wall surface 12 of the lid body 1 is star-shaped, just like the outer wall surface 12.

[0035] The cover 1 and wheel cover 2 are made of elastic synthetic resin, and this elasticity is utilized to ensure that the first inner wall surface 11 of the cover 1 remains engaged with the wheel nut N, while the outer wall surface 12 of the cover 1 remains engaged with the second inner wall surface 22 of the wheel cover 2. Specifically, the mating surfaces may be provided with an inverse slope, a slot, an engaging claw, or an engaging recess / protrusion. The cover 1 and wheel cover 2 may be made of metal, in addition to synthetic resin. A metal film may also be formed on the surface of the synthetic resin to enhance decorativeness. Regarding synthetic resin, recycled materials are preferred as much as possible in order to realize a sustainable, recycling-oriented society.

[0036] 2A and 2B, a method for attaching the wheel nut loosening checker 100 to a double tire will be described. With the wheel nuts N threaded onto the double tire, the opening 20 of the wheel cover 2 is aligned with the position of the wheel nuts N and fitted onto the wheel W. Then, the eight lid bodies 1 are fitted onto the wheel nuts N one by one, and the lid bodies 1 are attached so that the outer wall surface 12 of the lid body 1 fits into the second inner wall surface 22 of the wheel cover 2.

[0037] At this time, the indicators 14 of each lid body 1 should be oriented as much as possible toward the center of the wheel W, as shown in FIG. 2B. In this embodiment, the number of valleys on the first inner wall surface 11 is 24, but it may be 18, for example. However, the inventor himself tried various numbers and found that when adjusting the indicators 14 of the lid body 1 to be oriented toward the center of the wheel W, the number of valleys on the first inner wall surface 11 that was easiest to adjust was 24.

[0038] In this way, in this embodiment, the cover body 1 that engages with the wheel nut N is separate from the wheel cover 2, so it is only necessary to align the cover body 1 fitted to the wheel nut N with the wheel cover 2 one by one, which means that it is not possible to fit it onto the wheel H unless all the star shapes are aligned at the same time, as in Patent Document 3, and workability is very good.

[0039] Furthermore, fitting the lid body 1 into the wheel cover 2 prevents the wheel nuts N from loosening. In other words, the wheel nut loosening checker 100 of this embodiment has a function to prevent the wheel nuts N from loosening. Furthermore, when an unexpected load is applied to the wheel nuts N, it is possible that the wheel nuts N will rotate. In such a case, the orientation of the indicator 14 of the lid body 1 will change as the wheel nuts N rotate, making it possible to know that the wheel nuts N have loosened (loosening detection function). In other words, the wheel nut loosening checker 100 of this embodiment has both a function to detect looseness of the wheel nuts N and a function to prevent loosening.

[0040] Furthermore, typical wheel nuts N used on automobile wheels are nuts with a seat. Therefore, as shown in the enlarged view of FIG. 2A, the thickness of the washer N1 of the wheel nut N creates a gap between the wheel W and the wheel nut fastener 100. This gap allows for faster dissipation of heat, such as brake heat. This gap may be enlarged by adding a protrusion to the wheel nut loosening checker 100.

[0041] Furthermore, as shown in Fig. 2C, the wheel nut looseness checker 100 of the present application can also be attached to a single tire. Incidentally, when rotating a tire, it is also possible to rotate the position of the wheel W with the tire still attached, without removing the tire from the wheel W, in order to prioritize work efficiency. Specifically, the wheel W with double rear tires shown in Fig. 2A is moved with the tire still attached to the single front tire as shown in Fig. 2C. This is not a so-called "tire reassembly" but rather a rotation by "removing and attaching the tire."

[0042] This type of tire rotation is efficient because it does not require removing the tire from the wheel W. However, since scratches occur on the opposing convex surfaces when using double tires as shown in FIG. 2A, the scratches on the wheel surface (convex surface) become exposed to the outside when using a single tire as shown in FIG. 2C.

[0043] However, with the wheel nut looseness checker 100 of this embodiment, this scratch can be covered and hidden by the wheel cover 2. Figure 3 shows an image of a prototype of the wheel nut looseness checker 100 actually attached to a wheel W.

[0044] Therefore, since there is no need to worry about scratches on the surface of the wheel W, tire rotation work can be actively performed by "removing and attaching tires." In other words, the wheel nut looseness checker 100 has the function of hiding scratches on the wheel surface, and by concealing the scratches, it not only improves aesthetics but also prevents the negative impression of poor maintenance. It also prevents diffuse reflection of light caused by scratches on the wheel surface, so there is no risk of obstructing the vision of drivers driving or parked next to the truck. It is also acceptable to print decorative elements on the surface of the wheel cover 22 to enhance its aesthetic appeal.

[0045] [Embodiment 2] The main parts of a wheel nut looseness checker 100A of the second embodiment will be described using Figures 4 to 8. Figures 4 and 5 show the wheel nut looseness checker 100A, Figures 6 and 7 show a wheel cover 2A, and Figure 8 shows the wheel nut looseness checker 100A attached to a tire. In the wheel nut looseness checker 100A of the second embodiment, parts that are identical in configuration to the wheel nut N looseness checker 100 of the first embodiment are given the same reference numerals and detailed description thereof will be omitted, while parts that are different in configuration and have the same name are given a suffix "A" after the reference numeral, and the differences will be described.

[0046] Specifically, while the wheel nut loosening checker 100 of embodiment 1 has two functions, namely, a function to detect loosening of wheel nuts N and a function to prevent loosening, the wheel nut loosening checker 100A of this embodiment does not have a function to prevent loosening of wheel nuts N, and is configured to only have a function to detect loosening of wheel nuts N.

[0047] The specific configuration of the wheel nut loosening checker 100 of embodiment 1 is that multiple equally spaced ridges (24 ridges) are formed on the outer wall surface 12 of the lid body 1, and multiple equally spaced valleys are formed on the second inner wall surface 22 of the wall portion 21 of the wheel cover 2, so that when the lid body 1 is fitted onto the wheel nut N, the outer wall surface 12 of the lid body 1 and the second inner wall surface 22 of the wall portion 21 of the wheel cover 2 engage with each other.

[0048] On the other hand, in the wheel nut loosening checker 100A of this embodiment, as shown in the enlarged view of Figure 8B, no ridges are formed on the outer wall surface 12A of the lid body 1A, and no valleys are formed on the second inner wall surface 22A of the wall portion 21A of the wheel cover 2A.When the lid body 1A is fitted onto the wheel nut N, the outer wall surface 12A of the lid body 1A and the second inner wall surface 22A of the wall portion 21A of the wheel cover 2A do not engage with each other, i.e., the configuration does not function to prevent loosening.

[0049] This configuration of the present embodiment not only has the function of detecting looseness and hiding surface scratches, but also prevents damage to the lid portion 1A and wheel cover 2A when the wheel nut N is loosened by an extremely large external force.

[0050] In addition, in the wheel nut loosening checker 100A of this embodiment, as in the first embodiment, the lid body 1 is configured to have an exterior portion 13A that forms the outer shape at a predetermined distance from the wall consisting of the first inner wall surface 11 and the outer wall surface 12. When the opening 20A of the wheel cover 2A is aligned with the position of the wheel nut N and fitted to the wheel W, the wheel cover 2A is pressed down and fixed by the exterior portion 13A of the lid body 1, which is larger than the opening 20A of the wheel cover 2A, as shown in Fig. 8A.

[0051] In addition, in the wheel nut loosening checker 100A of this embodiment, the indicator 14A formed on the top surface of the dome-shaped lid 1A is configured to be recessed by cutting or injection molding, as shown in the enlarged view of FIG. 8A. By forming the indicator 14A as a recess by cutting or the like, the indicator 14A is less likely to fade when rubbed against a car wash or card rail, compared to a printed indicator. Note that the design of the indicator 14A is a hexagonal design that emphasizes some of the corners, but the design of the indicator itself is not limited to the one shown in the figure, and various designs can be adopted.

[0052] Furthermore, in wheel nut looseness checker 100A of this embodiment, a large number of grooves 23 are formed on the rear surface of wheel cover 2A, as shown in FIG. 4B and other figures. The grooves 23 on the back surface of the wheel cover 2A are formed radially from the center of the opening (hub exposure hole) for exposing the hub H. The grooves 23 are provided to enhance heat dissipation and not to impede heat dissipation during braking when the wheel cover 2A is attached to the wheel W.

[0053] [Variations] FIG. 9A is a plan view of a wheel cover 2B showing a modification of the second embodiment, and FIG. 9B is a plan view showing a state in which the lid body 1A is attached to this wheel cover 2B. As shown in FIG. 9A, the wheel cover 2B has an arc-shaped mark 24 formed by recessing or printing along the center of the donut-shaped disk between the openings 20B. This mark 24 functions as a loosening detector when used together with the index 14A on the lid 1A. Specifically, as shown in FIG. 9B, the mark 24 is used with the index 14A on the lid 1A facing in the direction of the mark 24. In this case, if the wheel nut N loosens, the index 14A on the lid 1A will come out of alignment with the mark 24, allowing the loosening of the wheel nut N to be detected. In this way, the mark 24 indicating the orientation of the index 14A may be attached to the surface of the wheel cover 2B. [Explanation of symbols]

[0054] 100, 100A: Wheel nut looseness checker 1, 1A: Lid body 11, 11A: 1st inner wall surface 12, 12A: External wall surface 13, 13A: Exterior part 14, 14A: Indicator 2, 2A, 2B: Wheel covers 20, 20A, 20B: Opening 21, 21A: Wall part 22, 22A: Second inner wall surface 23: Groove 24: Mark N: Wheel nut W: Wheel

Claims

1. A cover body comprising: an exterior part that forms a dome-shaped outer shape that covers the wheel nut; a wall body that is made up of a first inner wall surface and an outer wall surface and is provided inside the exterior part with a gap from the exterior part, and the first inner wall surface has a plurality of valleys that engage with the apex of the wheel nut; a donut-shaped disk with an exposure hole for the hub in the center, and a wheel cover with an opening through which the wheel nut is exposed; It consists of A wheel nut looseness checker characterized in that an index is formed on the top surface of the exterior part of the lid body.

2. The exterior portion is larger than the opening of the wheel cover, 2. The wheel nut looseness checker according to claim 1, wherein the indicator is formed as a recess.

3. 2. The wheel nut looseness checker according to claim 1, wherein the outer wall surface of the lid body engages with a second inner wall surface inside the opening of the wheel cover.

4. 2. The wheel nut looseness checker according to claim 1, wherein grooves extending radially from the center of the exposure hole are formed on the rear surface of the wheel cover.

Images