Impact rotary tool

Abstract

An object of the present disclosure is to reduce vibrations generated in the radial direction when a fastening member is tightened. An impact rotary tool (10) includes a hammer (30) and an anvil (1) that transmits a rotary impact force from the hammer (30) to an end tool (20). The anvil (1) includes a first member (11) and a second member (12). The first member (11) holds the end tool (20) thereon. The first member (11) is fitted in the second member (12). The rotary impact force is applied to the second member (12). The first member (11) and the second member (12) are configured to be fitted into each other in a fitting portion (100). The fitting portion (100) has a permitting mechanism (111A, 121A). The permitting mechanism (111A, 121A) permits misalignment of a first rotation axis (AX1) and a second rotation axis (AX2). The first rotation axis (AX1) is a rotation axis of the first member (11). The second rotation axis (AX2) is a rotation axis of the second member (12).

Description

Technical Field

[0001] This disclosure generally relates to an impact rotary tool, and more specifically to an impact rotary tool having the ability to reduce vibrations generated when fastening members such as screws or bolts are tightened. Background Technology

[0002] JP H07-237152 A discloses a rotary impact tool including an anvil that transmits rotary impact force from a hammer to an end tool, the hammer being capable of both rotary and reciprocating motion. In the rotary impact tool of JP H07-237152 A, the anvil includes: an end tool attachment member for attaching the end tool; and a rotary impact transmission member that transmits the rotary impact force from the hammer to the end tool attachment member, with a damper disposed between the two members. Summary of the Invention

[0003] Technical issues

[0004] In the rotary impact tool of JP H07-237152 A, a damper located between the end tool attachment member and the rotary impact transmission member helps to reduce axial vibrations generated when fastening members such as screws are tightened.

[0005] However, in the rotary impact tool of JP H07-237152 A, the end-tool attachment member and the rotary impact transmission member are connected together and fixed to each other, wherein the rotation axis of the former is aligned with the rotation axis of the latter (in other words, misalignment of the rotation axis of the former relative to the rotation axis of the latter is not permitted). Therefore, misalignment of the rotation axis of the latter with the direction of insertion of a fastening member such as a screw (hereinafter referred to as the "insertion direction") also causes misalignment of the rotation axis of the former with the insertion direction, thereby generating vibration in the radial direction.

[0006] Therefore, the purpose of this disclosure is to provide an impact rotation tool that helps reduce radial vibrations generated when fasteners such as screws are tightened.

[0007] Solution to the problem

[0008] The impact rotary tool according to an aspect of this disclosure includes a hammer and an anvil that transmits a rotary impact force from the hammer to an end tool. The anvil includes a first member and a second member. The first member holds the end tool thereon. The first member is fitted into the second member. A rotary impact force is applied to the second member. The first and second members are configured to engage with each other in a fitting portion. The fitting portion has a allowing mechanism. The allowing mechanism allows misalignment between a first rotation axis and a second rotation axis. The first rotation axis is the rotation axis of the first member. The second rotation axis is the rotation axis of the second member.

[0009] Advantages of the present invention

[0010] The impact rotating tool according to this disclosure achieves the advantage of helping to reduce such vibrations generated in the radial direction when fastening components such as screws are tightened. Attached Figure Description

[0011] Figure 1 This is an exploded perspective view of an anvil that forms part of an impact rotary tool according to an embodiment of the present disclosure;

[0012] Figure 2 This is a side view of the anvil;

[0013] Figure 3A This is a cross-sectional view of the anvil in a state that does not lead to misalignment;

[0014] Figure 3B This is a cross-sectional view of the anvil in a state that leads to misalignment;

[0015] Figure 4A This is a cross-sectional view of the mating portion of the anvil in the presence of a spherical convex curved surface that is part of the second surface;

[0016] Figure 4B This is a cross-sectional view of the mating portion of the anvil in the presence of a spherical convex curved surface that is part of the first surface;

[0017] Figure 4C This is a cross-sectional view of the mating portion of the anvil in the presence of spherical convex curved surfaces that are corresponding portions of the first and second surfaces;

[0018] Figure 5A This is a cross-sectional view of the mating portion of the anvil in the presence of a spherical convex curved surface covering almost the entire second surface;

[0019] Figure 5B This is a cross-sectional view of the mating portion of the anvil in the presence of a spherical convex curved surface covering almost the entire first surface;

[0020] Figure 5C This is a cross-sectional view of the mating portion of the anvil in the presence of spherical convex curved surfaces that respectively cover almost the entire first and second surfaces;

[0021] Figure 6A This is a cross-sectional view of the mating portion of the anvil when the second surface has a convex curved surface as its rounded corners;

[0022] Figure 6B This is a cross-sectional view of the mating portion of the anvil when the first surface has a convex curved surface as its rounded corners; and

[0023] Figure 6C This is a cross-sectional view of the mating portion of the anvil, where both the first and second surfaces have convex curved surfaces that serve as their rounded corners. Detailed Implementation

[0024] The accompanying drawings, which are referenced in the following description of the embodiments, are all schematic diagrams. Therefore, the proportions of the dimensions (including thickness) of the various components shown in the drawings do not always reflect their actual proportions. Note that the embodiments described below are merely exemplary embodiments among the various embodiments of this disclosure and should not be construed as limiting. Rather, the exemplary embodiments can be readily modified in various ways according to design choices or any other factors without departing from the scope of this disclosure.

[0025] (1) Impact Rotary Tool

[0026] The impact rotation tool 10 according to an exemplary embodiment includes, for example, Figures 1-3A Anvil 1 is shown.

[0027] The anvil 1 transmits the rotational impact force from the hammer 30 to the end tool 20. The rotational impact force includes an impact force applied axially and a rotational force applied about the axis. As used herein, "axial" refers to a direction aligned with the axis of rotation AX2 (described later), and the phrase "about the axis" means "about the axis of rotation AX2." The end tool 20 is used to tighten fasteners such as screws or bolts using the rotational impact force.

[0028] (2) Anvil

[0029] The anvil 1 includes a first component 11 and a second component 12. The first component 11 holds the end tool 20 thereon. The first component 11 is fitted into the second component 12. A rotational impact force is applied to the second component 12.

[0030] Specifically, the rear end of the first member 11 is fitted into the front end of the second member 12. The end tool 20 is attached to the front end of the first member 11. The front end of the first member 11 is movable relative to the second member 12 in a radial direction (i.e., in a direction intersecting the axial direction).

[0031] When the end tool 20 engages with a fastening member such as a screw, the rotational impact force applied from the hammer 30 to the rear end of the second member 12 is transmitted to the end tool 20 via the second member 12 and the first member 11. This allows the rotational impact force to be applied to the fastening member such as the screw, thereby causing the fastening member such as the screw to be pressed and tightened in, for example, the direction in which the screw hole extends.

[0032] (3) Fitting part

[0033] The fitting portion 100 is a portion in which the first member 11 and the second member 12 fit into each other.

[0034] The fitting portion 100 includes a first fitting portion 111 and a second fitting portion 121. The first fitting portion 111 forms part of the first member 11 and fits into the second member 12. The first fitting portion 111 has a first surface 111A as one of its surfaces. The second fitting portion 121 forms part of the second member 12 and fits into the first member 11. The second fitting portion 121 has a second surface 121A as one of its surfaces. The first surface 111A and the second surface 121A face each other.

[0035] More specifically, the first fitting portion 111 and the second fitting portion 121 each have a cylindrical shape with alternating cut portions and non-cut portions. The fitting portion 100 is formed by engaging the non-cut portion of the first fitting portion 111 with the cut portion of the second fitting portion 121.

[0036] (4) Permitting agencies

[0037] The fitting part 100 according to this embodiment has a accommodating mechanism (111A, 121A).

[0038] The permissive mechanisms (111A, 121A) allow for misalignment between the first rotation axis AX1 and the second rotation axis AX2. The first rotation axis AX1 is the rotation axis of the first component 11. The second rotation axis AX2 is the rotation axis of the second component 12.

[0039] As used in this article, when Figure 3B When the angle θ formed between the first rotation axis AX1 and the second rotation axis AX2 exceeds a predetermined first threshold θ1, it results in "misalignment".

[0040] The first threshold θ1 can be equal to 0 degrees, for example, but it can also be greater than 0 degrees (for example, an angle falling within the range of 0.5 degrees to 2 degrees).

[0041] It can be seen that the allowable mechanism (111A, 121A) allows the first rotation axis AX1 to remain aligned with the direction of insertion of the fastener even if the second rotation axis AX2 is not aligned with the direction of insertion of the fastener, thereby helping to reduce the vibration generated in the radial direction when the fastener is tightened.

[0042] (4-1) Means of implementing the permitting agency

[0043] The permissive mechanism (111A, 121A) according to this embodiment is implemented by forming at least a portion of the first surface 111A and / or at least a portion of the second surface 121A into a convex curved shape. As described above, the first surface 111A and the second surface 121A face each other.

[0044] (4-1-1) Configuration of convex curved surface

[0045] The portion to be formed into a convex surface shape (hereinafter referred to as "convex surface portion") may exist, for example, on a first surface 111A or a second surface 121A.

[0046] Specifically, for example, such as Figure 4A , Figure 5A and Figure 6A As shown, the convex curved surface portion can exist on the second surface 121A. Or, for example, as... Figure 4B , Figure 5B and Figure 6B As shown, the convex curved surface portion can also exist on the first surface 111A.

[0047] Note that in this case, such as Figure 4A , Figure 5A and Figure 6A As shown or Figure 4B , Figure 5B and Figure 6B As shown, other surfaces (i.e., surfaces without convex portions) are typically flat surfaces. However, this is merely an example and should not be construed as limiting. Alternatively, other surfaces may also be formed as concave surfaces with a curvature less than that of the convex portions.

[0048] This makes it possible to implement the permitting agency (111A, 121A) through a simple method.

[0049] (4-1-1a) Preferred Configuration #1

[0050] Preferably, there is a convex curved surface portion to form part of the first surface 111A or the second surface 121A.

[0051] A convex curved surface portion according to this embodiment may exist to form, for example, as shown in the figure. Figure 4A A portion of the second surface 121A shown or as Figure 4B A portion of the first surface 111A shown.

[0052] Note that in this case, the remaining portion of the one surface (i.e., the surface with the convex curved portion) and other surfaces (i.e., the surfaces without the convex curved portion) are generally as follows: Figure 4A or Figure 4BThe flat surface shown is merely an example and should not be construed as limiting. Alternatively, the remaining portion of this surface and other surfaces may also be formed as concave surfaces with a curvature less than that of the convex surface portion.

[0053] This reduces the contact area between the first surface 111A and the second surface 121A, thereby enabling the implementation of permissive mechanisms (111A, 121A) that allow for a wide range of misalignment in a simple manner.

[0054] (4-1-1b) Preferred Configuration #2

[0055] Alternative locations, for example, such as Figure 5A and 5B As shown, the convex curved surface portion may also exist to cover almost the entire first surface 111A or second surface 121A.

[0056] This increases the contact area between the first surface 111A and the second surface 121A, thereby enabling the implementation of a highly durable permissive mechanism (111A, 121A) through a simple method.

[0057] (4-1-1c) Other configurations

[0058] Other alternative locations, such as... Figure 4C and Figure 5C As shown, convex curved surface portions may also exist to form part of each of the first surface 111A and the second surface 121A. In this case, each of the first surface 111A and the second surface 121A may be as follows: Figure 4C The portion shown is only a convex curved surface, or it could be as follows: Figure 5C Almost all of the surfaces shown are convex curved surfaces; use whichever is appropriate.

[0059] (4-1-2) Shape of the convex curved surface

[0060] The convex surface portion can have, for example, a constant curvature (i.e., it can have a spherical shape). However, the curvature does not have to be constant.

[0061] (4-1-2a) Preferred shape

[0062] The convex curved surface portion can, for example, have the following characteristics: Figure 4A The second surface 121A shown Figure 4B The first surface 111A shown Figure 4C The first surface 111A and the second surface 121A shown are... Figure 5A The second surface 121A shown Figure 5B The first surface 111A shown, and Figure 5CThe spherical shape in the first surface 111A and the second surface 121A shown.

[0063] This makes it possible to implement the permitting agency (111A, 121A) in a simpler way.

[0064] (4-1-2b) Alternative Shape

[0065] Alternatively, the convex surface portion can also be, for example, a curved surface whose curvature is greatest at its ends and gradually decreases with increasing distance from the ends (i.e., a so-called "rounded surface"), such as in, for example Figure 6A The second surface 121A shown Figure 6B The first surface 111A shown, and Figure 6C The curved surfaces in the first surface 111A and the second surface 121A shown.

[0066] However, the convex surface does not have to be a spherical surface or a rounded surface; it can also be a smooth convex surface.

[0067] (5) Restricting agencies

[0068] Preferably, the fitting portion 100 also has a limiting mechanism (14, 15). The limiting mechanism (14, 15) is a mechanism for limiting misalignment.

[0069] As used herein, limiting misalignment can be, for example, setting the angle θ to a value less than a predetermined second threshold θ2 (where θ1 < θ2). For example, the second threshold θ2 can be, but is not necessarily, 5 degrees. Alternatively, the second threshold θ2 can also fall within, for example, the range of 4 to 6 degrees or the range of 3 to 7 degrees, whichever is more suitable.

[0070] The anvil 1 is made durable by limiting misalignment through the limiting mechanism (14, 15).

[0071] (5-1) Centering component

[0072] The limiting mechanism (14, 15) includes a shaft-shaped centering member 14. The centering member 14 is arranged within the fitting portion 100.

[0073] This makes it possible to implement restrictive mechanisms through simple methods (14, 15).

[0074] (5-2) Elastic member

[0075] The limiting mechanisms (14, 15) also include an annular elastic member 15. The elastic member 15 is configured to surround the outer periphery of the fitting portion 100.

[0076] For example, a groove may be provided circumferentially along the outer periphery of the fitting portion 100, and the elastic member 15 may be fitted into the groove.

[0077] The misalignment is limited by the elastic member 15, which enables the implementation of a highly durable limiting mechanism (14, 15) by a simple method.

[0078] (6) Vibration damper

[0079] The anvil 1 also includes a vibration damper 13. The vibration damper 13 is arranged within the fitting portion 100. The vibration damper 13 reduces axial vibrations generated when the fastening members are tightened.

[0080] (7) Axial clearance

[0081] The centering member 14 and the damper 13 have an axial gap between the first member 11 and the second member 12. This axial gap not only allows the damper 13 to expand and contract, but also helps to allow or limit misalignment.

[0082] As described above, the impact rotary tool 10 according to this embodiment can help reduce radial vibration by allowing misalignment through the allowable mechanism (111A, 121A) and limiting misalignment through the limiting mechanism (14, 15), while ensuring sufficient durability of the anvil 1. In addition, the impact rotary tool 10 can also help reduce axial vibration by using the vibration damper 13.

[0083] (8) Summary

[0084] The impact rotary tool (10) according to the first aspect includes: a hammer (30); and an anvil (1) for transmitting a rotary impact force from the hammer (30) to an end tool (20). The anvil (1) includes a first member (11) and a second member (12). The first member (11) holds the end tool (20) thereon. The first member (11) is fitted into the second member (12). A rotary impact force is applied to the second member (12). The first member (11) and the second member (12) are configured to fit into each other in a fitting portion (100). The fitting portion (100) has a permissive mechanism (111A, 121A). The permissive mechanism (111A, 121A) permisses misalignment of a first rotation axis (AX1) with a second rotation axis (AX2). The first rotation axis (AX1) is the rotation axis of the first member (11). The second rotation axis (AX2) is the rotation axis of the second member (12).

[0085] According to this aspect, the misalignment of the first rotation axis of the first member of the anvil and the second rotation axis of the second member of the anvil allows the first rotation axis to remain aligned with the insertion direction of the fastening member even if the second rotation axis is not aligned with the insertion direction of the fastening member, thereby helping to reduce vibrations generated in the radial direction.

[0086] Conversely, as described in the background section, a rotary impact tool in which the first and second components are fitted and fixed to each other does not allow the first axis of rotation of the first component to be misaligned with the second axis of rotation of the second component, thereby generating vibration in the radial direction.

[0087] In the impact rotary tool (10) according to the second aspect, which can be implemented in conjunction with the first aspect, the fitting portion (100) includes a first fitting portion (111) and a second fitting portion (121). The first fitting portion (111) forms part of the first member (11) and fits into the second member (12). The first fitting portion (111) has a first surface (111A) as one of its surfaces. The second fitting portion (121) forms part of the second member (12) and fits into the first member (11). The second fitting portion (121) has a second surface (121A) as one of its surfaces. The first surface (111A) and the second surface (121A) face each other. The allowable mechanism (111A, 121A) is implemented by forming at least a portion of the first surface (111A) and / or at least a portion of the second surface (121A) into a convex curved shape.

[0088] This makes it possible to implement the licensing mechanism in a simple way.

[0089] In the impact rotating tool (10) according to the third aspect, which can be implemented in conjunction with the second aspect, the allowable mechanism (111A, 121A) is implemented by forming a portion of the first surface (111A) or the second surface (121A) into a convex curved shape.

[0090] This enables the implementation of permissible mechanisms that allow for large-scale misalignment by reducing the contact area between the first and second surfaces using a simple method.

[0091] In the impact rotating tool (10) according to the fourth aspect, which can be implemented in conjunction with the second aspect, the allowable mechanism (111A, 121A) is implemented by forming almost all of the first surface (111A) or almost all of the second surface (121A) into a convex curved shape.

[0092] This aspect enables the implementation of a permissive mechanism with high durability by increasing the contact area between the first and second surfaces.

[0093] In the impact rotary tool (10) according to the fifth aspect, which can be implemented in conjunction with the third or fourth aspect, the portion of the first surface (111A) or the second surface (121A) formed as a convex surface has a constant curvature.

[0094] This makes it possible to implement the licensing mechanism in a simpler way.

[0095] In the impact rotating tool (10) according to the sixth aspect, which can be implemented in conjunction with any of the first to fifth aspects, the fitting part (100) also has a limiting mechanism (14, 15). The limiting mechanism (14, 15) limits misalignment.

[0096] This ensures sufficient durability of the anvil by limiting misalignment.

[0097] In the impact rotating tool (10) according to the seventh aspect, which can be implemented in conjunction with the sixth aspect, the fitting part (100) is formed in a cylindrical shape. The limiting mechanism (14, 15) has a shaft-shaped centering member (14). The centering member (14) is arranged inside the fitting part (100).

[0098] This makes it possible to implement restrictive measures through simple methods.

[0099] In the impact rotating tool (10) according to the eighth aspect, which can be implemented in conjunction with the seventh aspect, the limiting mechanism (14, 15) further includes an annular elastic member (15). The elastic member (15) is arranged to surround the outer periphery of the fitting portion (100).

[0100] This makes it possible to implement highly durable limiting mechanisms using simple methods.

[0101] In the impact rotary tool (10) according to the ninth aspect, which can be implemented in conjunction with the seventh or eighth aspect, the anvil (1) further includes a damper (13). The damper (13) is arranged within the fitting portion (100). A gap aligned with the second axis of rotation (AX2) is left between the centering member (14) and the damper (13) between the first member (11) and the second member (12).

[0102] This helps reduce radial vibration by allowing and limiting misalignment, while also helping to reduce axial vibration by expanding and contracting the damper.

[0103] List of reference numerals

[0104] 10 Impact Rotary Tools

[0105] 20 End-of-line tools

[0106] 30 hammers

[0107] 1. Anvil

[0108] 100 chimeric part

[0109] 11 First Component

[0110] 111 First fitting part

[0111] 111A First Surface

[0112] 12 Second component

[0113] 121 Second chimeric part

[0114] 121A Second Surface

[0115] 13. Vibration dampers

[0116] 14 Centering components

[0117] 15. Elastic members

[0118] AX1 First axis of rotation

[0119] AX2 Second axis of rotation

Claims

1. An impact rotary tool comprising a hammer and an anvil configured to transmit a rotary impact force from the hammer to a tip tool, the anvil comprising: a first member configured to hold the tip tool thereon; and a second member into which the first member is fitted, and to which the rotary impact force is applied, the first member and the second member being configured to be fitted into each other in a fitting portion, the fitting portion having an allowance mechanism configured to allow misalignment of a first rotation axis, which is a rotation axis of the first member, and a second rotation axis, which is a rotation axis of the second member, the fitting portion further having a restriction mechanism configured to restrict the misalignment and formed in a cylindrical shape, the restriction mechanism including: a shaft-shaped centering member arranged inside the fitting portion, and an annular elastic member provided so as to surround an outer periphery of the fitting portion.

2. The impact rotary tool according to claim 1, wherein the fitting portion includes: a first fitting portion that forms a part of the first member and is fitted into the second member, the first fitting portion having a first surface as one surface thereof; and a second fitting portion that forms a part of the second member and is fitted into the first member, the second fitting portion having a second surface as one surface thereof, the first surface and the second surface facing each other, and the allowance mechanism is implemented by forming at least a part of the first surface and / or at least a part of the second surface in a convex curved surface shape.

3. The impact rotary tool according to claim 2, wherein the allowance mechanism is implemented by forming a part of the first surface or a part of the second surface in the convex curved surface shape.

4. The impact rotary tool according to claim 2, wherein the allowance mechanism is implemented by forming almost all of the first surface or almost all of the second surface in the convex curved surface shape.

5. The impact rotary tool according to claim 3 or 4, wherein the part of the first surface or the part of the second surface formed in the convex curved surface shape has a constant curvature.

6. The impact rotary tool according to claim 1, wherein the anvil further includes a damper arranged inside the fitting portion, and the centering member and the damper leave a gap between the first member and the second member in alignment with the second rotation axis. ​

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