Tire changing jig

Abstract

To provide a tire changing jig that can reduce the burden on businesses performing tire changes and can be used regardless of whether or not hub bolts are present. [Solution] The device comprises a flexible string-like member 12 and a columnar member 14 connected to one end of the string-like member 12. Both the string-like member 12 and the columnar member 14 are characterized by being thick enough to be inserted into the mounting hole of the wheel to be mounted. The string-like member 12 is thinner than the columnar member 14, and a tapered portion 14c is provided at the connection point between the columnar member 14 and the string-like member 12 to reduce the step difference caused by the difference in thickness between the two.

Description

Technical Field

[0001] The present invention relates to a tool for replacing vehicle tires, and particularly to a tire replacement tool suitable for reducing the burden on the body when replacing tires at home.

Background Art

[0002] The replacement of vehicle tires is performed after lifting the vehicle body. Therefore, it is necessary to lift the heavy tire to a predetermined height and align it with the mounting position, which places a large burden on the body.

[0003] For this reason, as tools for reducing the burden during tire replacement, those disclosed in Patent Documents 1 and 2 have been proposed. The tool disclosed in Patent Document 1 is a straight bolt that screws into the hub of the vehicle body. By inserting this bolt into the mounting hole of the tire wheel, alignment in the lifted state becomes easier. By using such a tool, it is considered that the alignment of the wheel becomes easier. However, there is no change in the basic operation of lifting and aligning the wheel, and the reduction rate of the burden in the tire replacement work is small.

[0004] Furthermore, the jig disclosed in Patent Document 2 has a flexible cylindrical deformable member attached to the tip of a rigid columnar member. Such a jig is used by inserting the cylindrical deformable member and the columnar member into the mounting holes of the tire wheel to be attached, and then connecting the flexible cylindrical member to the hub bolt provided on the hub. Specifically, by lifting the columnar member upward with the flexible cylindrical member connected to the hub bolt, the hub bolt and the columnar member become horizontal, and alignment can be performed simply by sliding the tire wheel. With a jig having such features, the burden of lifting the wheel and alignment can be reduced. However, with the jig disclosed in Patent Document 2, it is necessary to connect the flexible cylindrical member to the hub bolt while the jig is inserted into the wheel. Therefore, the connection work itself must be performed in a position hidden by the wheel, resulting in poor work efficiency. In addition, the jig disclosed in Patent Document 2 cannot be used on vehicles that do not have hub bolts. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Utility Model Registration No. 3065945 Gazette [Patent Document 2] Utility Model Registration No. 3134118 Gazette [Overview of the project] [Problems that the invention aims to solve]

[0006] Therefore, the purpose of this invention is to provide a tire changing jig that can reduce the burden on businesses that perform tire changing work and can be used regardless of whether or not hub bolts are present. [Means for solving the problem]

[0007] The tire changing jig according to the present invention, which solves the above problems, comprises a flexible string-like member and a columnar member connected to one end of the string-like member, and is characterized in that the string-like member and the columnar member are each of a thickness that can be inserted into the mounting hole of the wheel to be attached.

[0008] Furthermore, in a tire changing jig having the above-described features, the string-like member should be thinner than the columnar member, and a tapered portion should be provided at the connection point between the columnar member and the string-like member to reduce the step difference caused by the difference in thickness between the two. With these features, it becomes possible to smoothly transfer the tire (wheel) that has been moved by the string-like member to the columnar member.

[0009] Furthermore, in a tire changing jig having the above-described features, the string-like member is preferably rotatably connected to one end of the columnar member. This feature prevents twisting of the string-like member when attaching or detaching the columnar member from the wheel.

[0010] Furthermore, in a tire changing jig having the above-described features, the string-like member can be made of wire, and a covering material can be provided to cover at least a portion of the string-like member. With these features, it is possible to prevent damage to the inside of the mounting hole in the wheel when sliding the tire (wheel) onto the string-like member. In addition, wear on the string-like member can be reduced, and the lifespan (usable years) of the jig can be extended.

[0011] Furthermore, in a tire changing jig having the above-described features, it is preferable to provide an engaging portion at the tip of the string-like member. This feature makes it possible to attach a handle element to the tip of the string-like member. This makes it easier to apply the force required to lift the tire.

[0012] Furthermore, in a tire changing jig having the above-described features, it is desirable that the columnar member be structured to be separable into one end and the other end. With these features, it becomes possible to select and switch the columnar member depending on the mounting configuration of the tire changing jig to the hub. Also, if the string-like member becomes damaged, it becomes possible to replace only the end to which the string-like member is connected. [Effects of the Invention]

[0013] A tire changing jig with these features can reduce the burden on the workers who perform tire changing work. Furthermore, it can be used regardless of whether or not hub bolts are present. [Brief explanation of the drawing]

[0014] [Figure 1] This is a side view showing an example of a tire changing jig according to an embodiment. [Figure 2] This is a disassembled cross-sectional view of a tire changing jig according to an embodiment. [Figure 3] This is a perspective view showing the usage configuration of the tire changing jig according to the embodiment. [Figure 4] This is a diagram illustrating a tire changing method using a tire changing jig according to an embodiment. [Figure 5] This is a partial side cross-sectional view showing an example of a tire changing jig that is compatible with cases where the hub is equipped with hub bolts. [Figure 6] This is a perspective view illustrating an example of an application of a tire changing method using a tire changing jig according to the embodiment. [Modes for carrying out the invention]

[0015] Hereinafter, embodiments relating to the tire changing jig and tire changing method of the present invention will be described in detail with reference to the drawings. The embodiments shown below are some of the preferred forms for carrying out the present invention, and even if some of the configuration is changed, it can still be considered part of the present invention as long as the effects are achieved. In the embodiments below, the term "tire 50" refers to a wheel 52 with the tire body 54 assembled on it (see Figure 3).

[0016] [Structure] As shown in Figure 1, the tire changing jig 10 according to this embodiment is basically composed of a string-like member 12 and a columnar member 14. The string-like member 12 is of a thickness that can be inserted through the mounting hole 52a of the wheel 52, and the specific material and properties are not limited as long as it is a flexible string-like (linear) member. For this reason, it may be a rope or string made of fibers, or a resin tape, but preferably it is a material that can support the weight of the tire 50 to be replaced and has abrasion resistance that allows it to slide through the mounting hole 52a. For this reason, a suitable example of a member is a metal wire.

[0017] The columnar member 14 is connected (screwed) to the vehicle body hub 60 or to a hub bolt (not shown) provided on the hub 60, and is an element that supports and positions the tire 50. The specific configuration of the columnar member 14 is not limited to any columnar member of a thickness that can be inserted into the mounting hole 52a of the wheel 52. Therefore, its cross-sectional shape may be polygonal, but it is preferable to have a circular shape. When sliding the wheel 52 along the columnar member 14, it is possible to reduce the risk of damaging the inside of the mounting hole 52a.

[0018] Furthermore, the material of the columnar member 14 is not limited as long as it can support the weight of the tire 50. For example, in addition to steel, it may be made of composite materials such as hard resin, light metal, or fiber-reinforced plastic. Also, as mentioned above, the columnar member 14 may be made of a cylindrical member if it can support the weight of the tire 50 depending on the material or shape.

[0019] The string-shaped member 12 only needs to be connected to one end of the columnar member 14. In this embodiment, the string-shaped member 12 is connected to the columnar member 14 so as to be rotatable. With such a configuration, when the columnar member 14 is screwed onto or removed from the hub 60 or the hub bolt, it is possible to avoid the occurrence of torsion in the string-shaped member 12. Further, in the tire changing jig 10 according to this embodiment, the thickness of the string-shaped member 12 is configured to be sufficiently thinner than the thickness of the columnar member 14, giving the string-shaped member 12 good flexibility and reducing the weight of the entire jig. For this reason, a tapered portion 14c is provided at the connecting-side end portion of the columnar member 14 with the string-shaped member 12, and it is configured to reduce the step between the string-shaped member 12. With such a configuration, it becomes possible to smoothly transfer the wheel 52 slid on the string-shaped member 12 to the columnar member 14.

[0020] In this embodiment, the columnar member 14 has a split structure. Specifically, it is composed of a main body 14a connected to the hub 60 or the hub bolt, and a connecting portion 14b connected to the string-shaped member 12. The main body 14a and the connecting portion 14b only need to be able to be connected and split by a known joint form in addition to screwing or fitting. With such a configuration, it becomes possible to selectively switch the main body 14a to one corresponding to the connection to the hub 60 or one corresponding to the connection to the hub bolt, and it is also possible to switch according to the difference in the thickness (such as diameter) of the member to be connected. Further, when the string-shaped member 12 is damaged, only the connecting portion 14b can be replaced.

[0021] Here, the connection of the string-like member 12 to the connecting portion 14b can be as shown in Figure 2. Specifically, the connecting portion 14b has a through hole 14b1 at its tip end (one end as a tire changing jig 10). Between the main body 14a and the through hole 14b1, there is an internal space 14b2 that is larger in diameter than the through hole 14b1. The string-like member 12 has a diameter that allows it to pass through the through hole 14b1, and at the end that connects to the connecting portion 14b (the base end), there is a retaining means 12a that has a projected area larger than the through hole 14b1 and smaller than the internal space 14b2 after the through hole 14b1 has been passed through. The retaining means 12a can be selected in various ways depending on the material of the string-like member 12, and if the string-like member 12 is highly flexible, it may be a knot or the like. If the string-like member 12 is a wire, a crimping member can be used that fixes to the base end of the string-like member 12 by plastically deforming a metal piece or the like. With this configuration, the string-like member 12 can be fixed to the connecting part 14b (columnar member 14) in a rotatable manner.

[0022] In this embodiment, the tire changing jig 10 is configured to have an engaging portion 12b at the tip of the string-like member 12. With this configuration, an element that serves as a handle (not shown) is engaged with the tip of the string-like member 12. This makes it possible to apply the force required to pull up the tire. The specific configuration of the engaging portion 12b is not limited as long as it is configured to engage with the element that will serve as a handle. Therefore, a separate member may be provided, or as shown in Figures 1 and 2, the tip of the string-like member 12 may be folded back to form a ring. With this configuration, when the element that will serve as a handle is engaged, the engaging portion 12b, which is made up of a part of the string-like member 12, deforms according to the shape of the engaged member, thereby improving stability when pulling up the tire 50.

[0023] [Function and Effects] Next, with reference to Figures 4(A) to (D), a tire replacement method using the tire replacement jig 10 configured as described above will be explained. The tire replacement described below concerns the process of lifting the vehicle body (not shown), removing the tires that were previously installed, and then installing the new tires 50.

[0024] First, as shown in Figure 4(A), the tire changing jig 10 is attached to the hub 60. To attach the tire changing jig 10 to the hub 60, the male threaded portion 14a1 provided at the other end (base end side) of the columnar member 14 is screwed into the bolt hole (female threaded portion 60a) provided in the hub 60 (first step).

[0025] After attaching the tire changing jig 10 to the hub 60, the string-like member 12 is inserted through the mounting hole 52a of the wheel 52 on the tire 50 to be mounted. At this time, the tire 50 should be in an upright position with the tread surface facing the ground, and the mounting hole 52a through which the string-like member 12 is inserted should be the one located at the very top. Naturally, the string-like member 12 should be inserted from the inside to the outside, in line with the mounting direction of the wheel 52 (second step).

[0026] After inserting the string-like member 12 through the mounting hole 52a of the wheel 52, the tire 50 is lifted by pulling up a portion of the inserted string-like member 12, specifically the engaging portion 12b at the tip of the string-like member 12, as shown in Figure 4(B). The tire 50 is lifted until the mounting hole 52a of the wheel reaches a height above the mounting position of the columnar member 14, as shown in Figure 4(C). At this time, since the string-like member 12 is supported by the columnar member 14 whose base end is fixed to the hub 60, half of the weight of the tire 50 is loaded onto the columnar member 14 side by the principle of a movable pulley. Therefore, the force required to lift the tire 50 (the force to lift the string-like member 12) is half the weight of the tire 50, and the lifting distance is doubled. Since the height to which the tire 50 is lifted during tire replacement is generally only a few centimeters, doubling the distance does not have much effect. On the other hand, the ability to lift a 50-liter tire with minimal effort is a significant advantage in reducing the burden during tire changes.

[0027] After the tire 50 is lifted by pulling up the string-like member 12, the tire 50 is moved along the string-like member 12 toward the columnar member 14, so that the columnar member 14 can be inserted into the mounting hole 52a, as shown in Figure 4(D). Here, by pulling up the string-like member 12 at a position close to the tip of the columnar member 14, the tire 50 can be lifted with less force, and the tire 50 moves along the inclination of the string-like member 12 due to gravity, so that the columnar member 14 is inserted into the mounting hole 52a (third step).

[0028] After inserting the columnar member 14 into the mounting hole 52a, the wheel 52 (tire 50) is moved along the columnar member 14 and pressed against the hub 60. With the wheel 52 pressed against the hub 60, mounting bolts (not shown) are inserted into the mounting holes 52a through which the columnar member 14 has not been inserted, and the tire 50 is temporarily fastened to the hub 60. After temporarily fastening the tire 50 with the mounting bolts, the weight of the tire 50 is supported by the mounting bolts. Then, the columnar member 14 is removed from the hub 60, the mounting bolts are inserted into the removed mounting holes 52a, and screwed into the female threaded portions 60a. After screwing the mounting bolts into all the female threaded portions 60a, the mounting bolts are tightened to the specified torque, completing the installation (replacement) of the tire 50 (step 4).

[0029] This tire changing method allows the tire 50 to be lifted with minimal force. Furthermore, the columnar member 14 can be used as a guide to position the tire 50 (wheel 52). Therefore, it is possible to avoid prolonged periods of bending over when lifting and positioning the tire 50, thereby reducing the effort and strain required for tire changing.

[0030] In the above description and drawings, an example is given in which the columnar member 14 is screwed into the female threaded portion 60a provided on the hub 60. However, in the case of a configuration in which the tire 50 is fixed with hub bolts and nuts (not shown), as shown in Figure 5, a female threaded portion 14a2 is provided on the other end (base end side) of the columnar member 14, and this female threaded portion 14a2 is screwed onto the hub bolt. In this case, after pressing the wheel 52 against the hub 60, a fixing nut is screwed onto the hub bolt.

[0031] [Modification] In the above embodiment, the tire changing jig 10 is shown as an example in which the string-like member 12 is made of a metal wire. In such a configuration, it is preferable to cover the string-like member 12 with a covering material such as a flexible protective tube (not shown) made of resin or a material softer than the material of the wheel 52. By covering the string-like member 12 with a protective tube, it is possible to prevent the inside of the mounting hole 52a from being damaged by friction with the string-like member 12 when the tire 50 is lifted and the wheel 52 is moved along the string-like member 12. In addition, the effective diameter of the string-like member 12 is increased by the protective tube, so the step difference that occurs between the string-like member 12 and the columnar member 14 is substantially reduced. This makes it possible to make the operation of moving the wheel 52 from the string-like member 12 to the columnar member 14 smoother.

[0032] It should be noted that the covering material referred to here does not necessarily have to cover the entire length of the string-like member 12; it is sufficient if it covers at least a portion of it. This is because a similar effect can be achieved if the mounting hole 52a of the wheel 52 is located on the covering material. In other words, if the covering material is short, the flexibility of the string-like member 12 will not be impaired even if the covering material itself is not flexible. Therefore, when using a short covering material, or when arranging multiple short covering materials in a continuous manner to avoid hindering the bending of the string-like member 12, it is sufficient if the material has a lower hardness (softer) than the wheel 52, for example, a resin pipe. Furthermore, the covering material does not need to be tightly fitted to the string-like member 12. When using a short covering material, it is possible to slide the covering material smoothly against the string-like member 12 if there is a gap between the string-like member 12 and the pipe or tube.

[0033] [Examples of tire changing methods] In the above embodiment, the explanation is based on the premise that there is only one tire changing jig 10 used when changing a tire. However, multiple tire changing jigs 10 may be used when changing a tire.

[0034] As an example, as shown in Figure 6, it is preferable to perform the tire change using two tire changing jigs 10. More specifically, the male threaded portion 14a1 of the columnar member 14 of the tire changing jig 10 is screwed into two adjacent female threaded portions 60a of the hub 60. Here, it is desirable to select a female threaded portion 60a to which the tire changing jig 10 is attached that is located above the center of the hub 60. This is because it allows for stability when the tire 50 is lifted.

[0035] After attaching the tire changing jig 10, the string-like members 12 are inserted through the mounting holes 52a of the wheel 52 on the tire 50, in the same manner as in the second step described above. At this time, the string-like members 12 of each tire changing jig 10 are inserted in a one-to-one relationship with the corresponding mounting holes 52a.

[0036] After inserting the string-like member 12 through the mounting hole 52a of the wheel 52, a handle (not shown) is engaged with the engaging portion 12b of the string-like member 12, connecting the ends of the two string-like members 12 via the handle. Then, by pulling up the handle, the two string-like members 12 are pulled up simultaneously. In this way, by connecting the two string-like members 12 via the handle, it becomes possible to pull up both string-like members 12 simultaneously with one hand. As a result, the tire 50, which is pulled up along with the pulling up of the string-like members 12, can maintain a stable state.

[0037] Furthermore, by using multiple string-like members 12 (two in the example shown in Figure 6), the tire 50 (wheel 52) will not rotate around the mounting hole 52a through which the string-like member 12 is inserted. This makes it easier to position the wheel 52. As mentioned above, the same procedure can be performed even if the hub 60 is equipped with hub bolts (not shown). In this case, as mentioned above, it is preferable to use a tire changing jig 10 of the type shown in Figure 5, which has a female threaded portion 14a2 at the base end of the columnar member 14. [Explanation of Symbols]

[0038] 10... Tire changing jig, 12... String-like member, 12a... Retaining means, 12b... Engaging part, 14... Columnar member, 14a... Main body, 14a1... Male threaded part, 14a2... Female threaded part, 14b... Connecting part, 14b1... Through hole, 14b2... Internal space, 14c... Tapered part, 50... Tire, 52... Wheel, 52a... Mounting hole, 54... Tire body, 60... Hub, 60a... Female threaded part.

Claims

1. A tire changing jig comprising a flexible string-like member and a columnar member connected to one end of the string-like member, wherein the string-like member and the columnar member are each of a thickness that allows them to be inserted into the mounting holes of the wheel to be fitted.

2. The tire changing jig according to claim 1, characterized in that the string-like member is thinner than the columnar member, and a tapered portion is provided at the connection point between the columnar member and the string-like member to reduce the step difference caused by the difference in thickness between the two.

3. The tire changing jig according to claim 2, characterized in that the string-like member is rotatably connected to one end of the columnar member.

4. The tire changing jig according to claim 3, characterized in that the string-like member is a wire and is provided with a covering material that covers at least a part of the string-like member.

5. The tire changing jig according to claim 4, characterized in that an engaging portion is provided at the tip of the string-like member.

6. The tire changing jig according to any one of claims 1 to 5, characterized in that the columnar member has a structure that allows it to be separated into one end and the other end.

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