Impact tools

Abstract

To provide an impact tool with vibration absorption and noise reduction effects. [Solution] The impact tool 1 comprises a first coil spring member 30 attached to the front end of the tool body 10, and a second coil spring member 50 disposed inside the first coil spring member 30. The second coil spring member 50 is elastically compressed within a range of elastic deformation between the tip of the tool body 10 and a flat washer 40 locked to the tip tool 20. The first coil spring member 30 comprises a coil-shaped portion 31 in which strands are wound in a spiral shape, and a U-shaped portion 32 formed further forward than the coil-shaped portion 31, with the portion including the tip of the strands being U-shaped. The tip tool 20 is inserted through a gap A facing the curved portion of the U-shaped portion 32, and the U-shaped portion 32 and the tip tool 20 are locked together.

Description

Technical Field

[0001] The present invention relates to an impact tool that applies an impact force to a workpiece using a tip tool attached to the tip of a tool body.

Background Art

[0002] Conventionally, as an impact tool that impacts a workpiece to excavate or cut the workpiece, there is known one that includes a cylinder in a tool body and a tip tool that reciprocates in the cylinder (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such an impact tool, since the tip tool reciprocates violently in the cylinder, strong vibrations are transmitted to the operator's hand, making it difficult to perform the work for a long time. In addition, noise may increase due to the violent collision of members with each other, so there is room for improving these problems.

[0005] Therefore, an object of the present invention is to provide an impact tool having a further vibration absorption effect and a sound insulation effect.

Means for Solving the Problems

[0006] The first invention of the present invention comprises a tool body on which a drive source is disposed; an elongated end piece that is slidably mounted to the tool body in the front-rear direction and slides back and forth in accordance with the driving force from the drive source, and has a tip portion that extends forward relative to the tool body; a first coil spring member attached to the front end of the tool body, with the portion of the end piece near the base inserted inside; and a second coil spring member disposed inside the first coil spring member, with the portion of the end piece near the base inserted inside, wherein the second coil spring member comprises the front end of the tool body and the portion of the end piece near the tip The impact tool is characterized in that it is elastically deformable within a range between a locking portion that is locked to the tool body and the first coil spring member, the first coil spring member comprising a coil-shaped portion in which the strands are formed in a spiral shape and a U-shaped portion which is positioned towards the tip of the coil-shaped portion and in which the portion including the tip of the strands is formed in a U shape, the base end of the coil-shaped portion being locked to the front end of the tool body and the tip fitting being inserted into the gap portion facing the curved portion of the U-shaped portion so that the U-shaped portion and the tip fitting are locked together, and furthermore the U-shaped portion is elastically deformable in a direction intersecting the central axis of the coil-shaped portion so that the U-shaped portion can be locked and detached from the tip fitting.

[0007] In this configuration, the first coil spring member covers the gap between the base end of the tip and the tool body, thereby suppressing noise leakage from the tool body and improving the noise reduction effect. Furthermore, since the second coil spring member is attached to the tip in a state of elastic compression within its elastic deformable range, vibrations generated in the tool body and tip are transmitted to the second coil spring member and absorbed by the second coil spring member, which has the advantage. More specifically, the vibrations transmitted to the second coil spring member are converted into thermal energy, dramatically reducing vibrations and noise transmitted to the operator, etc. The specifications of the first and second coil spring members can be appropriately selected to obtain the optimal effect according to the usage environment. In addition, since the U-shaped portion of the first coil spring member is elastically deformable in a direction intersecting the central axis of the coil-shaped portion, the tip can be hooked onto or detached from the groove of the U-shaped portion while the base end of the first coil spring member remains attached to the tool body. Furthermore, when the U-shaped portion is removed from the tip and the tip is removed from the tool body, the second coil spring member can be removed while the first coil spring member remains attached to the tool body, allowing the second coil spring member to be replaced as needed.

[0008] The second invention of the present invention comprises a tool body on which a drive source is disposed; an elongated end piece that is slidably mounted to the tool body in the front-rear direction and slides back and forth in accordance with the driving force from the drive source, and has a tip portion that extends forward relative to the tool body; an outer coil spring member attached to the front end of the tool body, with the portion of the end piece near the base inserted inside; and an inner coil spring member disposed inside the outer coil spring member, with the portion of the end piece near the base inserted inside, wherein the outer coil spring member has a coil spring shape in which strands are wound in a spiral, and includes a body-side coil spring member that is locked to the front end of the tool body, and a portion of the outer coil spring member with strands wound in a spiral The impact tool is characterized by comprising a front coil spring member having a coil spring shape, a fitting coil portion which at least a part of which is fitted into a helical groove formed between adjacent strands of the main body coil spring portion, and a support coil portion which is positioned in front of the tool body and has a U-shaped portion at its tip through which the tip tool is inserted, wherein the U-shaped portion is formed in a U-shape that opens outward by the portion including the tip of the strands constituting the front coil spring member, and the inner coil spring member is arranged elastically compressed within an elastically deformable range between a first locking portion which is locked to the U-shaped portion of the front coil spring portion and a second locking portion which is locked to the tip tool at the base end side of the first locking portion.

[0009] In this configuration, the outer coil spring member covers the gap between the base end of the tip and the tool body, thereby suppressing noise leakage from the tool body and improving the noise reduction effect. Furthermore, since the inner coil spring member is elastically compressed within its elastic deformable range, with its base end supported by the tip and its tip supported by the tool body via the outer coil spring member, vibrations generated in the tool body and tip are absorbed by the inner and outer coil spring members. More specifically, vibrations transmitted to the inner and outer coil spring members are converted into thermal energy, dramatically reducing vibrations and noise transmitted to the operator. In addition, by appropriately selecting the specifications of the outer coil spring member (body-side coil spring member and front-side coil spring member) and the inner coil spring member, the optimal effect according to the usage environment can be obtained. In particular, since the outer coil spring member in this invention is composed of two members, a body-side coil spring member and a front-side coil spring member, the specifications of each can be precisely set according to the usage environment.

[0010] Furthermore, since the front coil spring member has a U-shaped section, it can accommodate various shapes of tip sections, allowing the tip section to be inserted through the U-shaped section. For example, even if the tip section is wider than the main shaft of the tip section, such as a barrel shape or a flathead screwdriver shape, it can be inserted through the U-shaped section and attached. This provides the excellent advantage of making it easy to replace or maintain the tip section and inner coil spring member by releasing the engagement between the front coil spring member and the main body coil spring member and removing the front coil spring member.

[0011] The third invention of the present invention comprises a tool body on which a drive source is arranged and which has a substantially cylindrical mounting portion at its front end; an elongated tip that is slidably mounted to the tool body in the front-rear direction and slides back and forth in accordance with the driving force from the drive source, and has a portion that extends forward from the mounting portion of the tool body; an outer coil spring member attached to the mounting portion of the tool body and covering the portion of the tip near the base end; and an inner coil spring member disposed inside the outer coil spring member and into which the portion of the tip near the base end is inserted, wherein a helical fitting groove is formed on the outer circumferential surface of the mounting portion of the tool body, and the outer coil spring member has a coil spring shape in which strands are wound in a helical manner. The impact tool is characterized in that it comprises a main body coil spring member which is attached to the mounting portion by being fitted into a fitting groove in the mounting portion, and a front coil spring member which has a coil spring shape in which strands are wound in a spiral shape and at least a part of it is fitted into a spiral groove formed between adjacent strands of the main body coil spring member, and a support coil portion which is positioned in front of the mounting portion and has an insertion portion at its tip through which the tip tool is inserted, and the inner coil spring member is arranged to be elastically compressed within an elastically deformable range between a first locking portion which is locked into the insertion portion of the front coil spring member and a second locking portion which is locked to the tip tool at the base end side of the first locking portion.

[0012] In this configuration, similar to the second invention described above, it is possible to achieve improved noise reduction and reduced vibration and noise transmitted to workers, while also obtaining the optimal effect according to the usage environment. Furthermore, by shaping the insertion portion of the support coil section to match the shape of the tip, various shapes of tip components can be attached. [Effects of the Invention]

[0013] The impact tool according to the first invention of this invention has the effect of reducing vibrations transmitted to the hands of workers and others, as well as a noise reduction effect. Furthermore, the impact tools of the second and third inventions have the effect of reducing vibrations transmitted to the hands of workers and others, as well as a noise reduction effect, similar to the impact tool of the first invention. [Brief explanation of the drawing]

[0014] [Figure 1] This is an explanatory diagram of the impact tool according to Example 1. [Figure 2] This is a partially enlarged side cross-sectional view of the impact tool according to Example 1. [Figure 3] This is an explanatory diagram showing the U-shaped portion of Example 1 detached from the tip tool. [Figure 4] This is an explanatory diagram of the impact tool according to Example 2. [Figure 5] This is an explanatory diagram showing the state in which the front coil spring of Example 2 has been detached. [Figure 6] This is a cross-sectional view of the impact tool according to Example 2. [Modes for carrying out the invention]

[0015] Embodiments of the present invention will be described according to Examples 1 and 2. However, the present invention is not limited to the embodiments shown below, and design modifications can be made as appropriate. Furthermore, for convenience, Examples 1 and 2 are described with a defined order, but this does not limit the present invention. [Examples]

[0016] As shown in FIG. 1 and the like, the impact tool 1 of Example 1 includes a tool body 10 in which a drive source (not shown) is disposed. The tool body 10 includes a cylinder portion 11 that is long in the front-rear direction inside, and a hammer 12 that slides back and forth according to the driving force of the drive source is disposed in the cylinder portion 11. Further, at the front end portion of the cylinder portion 11, a long tip tool 20 having an exposed portion 21 whose tip portion protrudes forward with respect to the tool body 10 is disposed in a state of being slidably attached to the tool body 10 in the front-rear direction. Then, the tip tool 20 to which a striking force is applied by the hammer 12 repeatedly colliding with the rear end portion of the tip tool 20 slides back and forth.

[0017] Further, at the front end portion of the tool body 10, a first coil spring member 30 into which the rear end portion of the exposed portion 21 of the tip tool 20 is inserted is attached.

[0018] More specifically, the first coil spring member 30 includes a coil-shaped portion 31 in which the wire is wound in a spiral shape at the rear end portion (that is, the portion closer to the base end portion). Further, a U-shaped portion 32 in which a portion including the tip of the wire is formed in a U shape is provided on the tip side of the coil-shaped portion 31. Furthermore, a bridge portion 33 that connects the coil-shaped portion 31 and the U-shaped portion 32 is provided. The bridge portion 33 is not spiral like the coil-shaped portion 31, and extends from the coil-shaped portion 31 to the U-shaped portion 32 with a gentle curved shape.

[0019] Further, a substantially cylindrical attachment portion 13 is provided at the front end portion of the tool body 10, and a screwing groove portion 35 to which the coil-shaped portion 31 of the first coil spring member 30 can be screwed is formed on the outer peripheral surface of the attachment portion 13. The first coil spring member 30 is locked to the attachment portion 13 of the tool body 10 by screwing the rear end portion of the coil-shaped portion 31 into the screwing groove portion 35.

[0020] In addition, in the U-shaped portion 32, the exposed portion 21 of the tip tool 20 is inserted into the gap portion A facing the curved portion, and the U-shaped portion 32 and the tip tool 20 are engaged with each other. In this state, the first coil spring member 30 is in a tension state.

[0021] In the exposed portion 21 of the tip tool 20, a flange portion (locking portion) 22 having an outer diameter larger than that of other portions is formed. A flat washer 40 in a state where the tip tool 20 is inserted is locked to a position closer to the tip of the flange portion 22. In Example 1, the flange portion 22 corresponds to the locking portion according to the present invention.

[0022] Also, a second coil spring member 50 that is elastically deformed and elastically contracted is disposed between the front end portion of the tool body 10 and the flat washer 40. That is, the wire of the second coil spring member 50 is disposed on the outer periphery of the rear end portion of the exposed portion 21 of the tip tool 20, and further, the wire of the first coil spring member 30 is disposed on the outer periphery thereof.

[0023] In the impact tool 1 of the present Example 1, the hammer 12 moves back and forth to repeatedly apply an impact to the tip tool 20, and the tip tool 20 to which the impact is applied moves back and forth to apply an impact to a workpiece (not shown) that abuts against the tip of the tip tool 20, thereby excavating or grinding the surface of the workpiece. Here, when the hammer 12 applies an impact to the tip tool 20 or when the tip tool 20 applies an impact to the workpiece, fine vibrations are generated from the tool body 10 and the tip tool 20. Such vibrations can be reduced by the first coil spring member 30 and the second coil spring member 50 absorbing the vibrations and converting them into thermal energy.

[0024] Furthermore, the first coil spring member 30 can be detached from the tool tip 20 by releasing the U-shaped portion 32 from the tool tip 20 and twisting the bridge portion 33 while the rear end of the first coil spring member 30 remains screwed to the tool body 10, as shown in Figure 3. In other words, the U-shaped portion 32 is elastically deformable in a direction intersecting the central axis of the coil-shaped portion 31. By detaching the U-shaped portion 32 from the tool tip in this way, a replacement method is provided that allows for the replacement of the tool tip 20 and the second coil spring member 50 while maintaining the state in which the rear end of the first coil spring member 30 remains screwed to the tool body 10. The tip 20 is replaced relatively frequently depending on the nature of the work, and by changing the second coil spring member 50 according to the size and shape of the tip 20, vibrations and noise generated can be effectively reduced. By making these replaceable without removing the first coil spring member 30 from the tool body 10, work efficiency is greatly improved. [Examples]

[0025] As shown in Figures 4 and 6, the impact tool 61 of Embodiment 2 is equipped with a tool body 10 similar to that of Embodiment 1 described above. The tool body 10 is equipped with a drive source (not shown), a cylinder section 11, and a hammer 12. A long end piece 70, having an exposed portion 71 that extends forward relative to the tool body 10, is slidably attached to the tool body 10 in the front-rear direction. The rear end of the end piece 70 is slidably positioned inside the front end of the cylinder section 11 in the front-rear direction, and the hammer section 12 repeatedly strikes the rear end, applying an impact force that causes it to slide back and forth.

[0026] As shown in Figures 5 and 6, a screw groove 35 is provided on the outer circumferential surface of the mounting portion 13 of the tool body 10, similar to the embodiment 1 described above. The coil spring member 81 on the main body side, in which strands of wire are wound spirally, is fitted into the screw groove 35 and screwed in, thereby locking the coil spring member 81 on the mounting portion 13.

[0027] A front coil spring member 85, which has a continuous strand of wire wound in a spiral shape, is fitted and attached to the main body coil spring member 81. The fitting coil portion 86 that constitutes the rear part of the front coil spring member 85 is fitted into a spiral groove 83 formed between adjacent strands of the main body coil spring member 81, thereby locking the front coil spring member 85 to the main body coil spring member 81. Here, as shown in Figure 6, in this embodiment, as an example, the pitches of the front coil spring member 85 and the main body coil spring member 81 are made different from each other, and the inner diameter of the front coil spring member 85 is made smaller than the outer diameter of the main body coil spring member 81. The main body coil spring member 81 is press-fitted and installed so as to push the front coil spring member 85 open. As a result, the strands of the fitting coil portion 86 and the strands of the main body coil spring member 81 intersect, and the fitting coil portion 86 is pushed outward and fitted together. This generates an inward tightening force on the fitting coil portion 86, and this force firmly fits the fitting coil portion 86 and the main body coil spring portion 81 together. For these reasons, in the impact tool 61 of this embodiment 2, the fastening structure is such that loosening in the winding direction (in other words, the moment direction in the coil spring member) of the front coil spring member 85 is suppressed by vibrations (for example, vibrations in the front-rear direction or radial direction of the hammer 12) caused by the hammer 12 repeatedly colliding with the tip tool 20. As a result, the loosening of the fit between the front coil spring member 85 and the main body coil spring portion 81 is suppressed, and the fitted state can be stably maintained for a relatively long period of time.

[0028] With the fitting coil portion 86 attached to the main body coil spring member 81 in this manner, the support coil portion 87, which is connected forward from the fitting coil portion 86, protrudes forward from the tool body 10. The main body coil spring member 81 and the front coil spring member 85 constitute the outer coil spring member 80, and this outer coil spring member 80 covers the rear of the exposed portion 71 of the tip tool 70.

[0029] As shown in Figures 4-5, a U-shaped portion 88, which is roughly U-shaped in a front view, is formed at the front end of the support coil portion 87 of the front coil spring member 85 by the portion including the tip of the wires constituting the front coil spring member 85. This U-shaped portion 88 opens outward from the front coil spring member 85, and the inner gap X is formed so that the tip tool 70 can be inserted from the tip.

[0030] On the exposed portion 71 of the tip tool 70, a flange portion 72 is formed in the area covered by the outer coil spring member 80 (the portion near the rear end of the exposed portion 71), with an outer diameter larger than that of other parts (Figure 6). A flat washer 40 having an opening through which the exposed portion 71 is inserted is locked to the tip side of this flange portion 72. On the other hand, a flat washer 40 is locked to the rear end side of the U-shaped portion 88 of the front coil spring member 85, which is attached to the tool body 10 via the body-side coil spring member 81. Between the front and rear flat washers 40, 40 thus arranged, an inner coil spring member 90, in which strands of wire are wound spirally, is arranged in an elastically deformable range. This inner coil spring member 90 has an outer diameter smaller than the inner diameter of the outer coil spring member 80 and is positioned inside the outer coil spring member 80.

[0031] In the impact tool 61 of this embodiment 2, similar to embodiment 1 described above, the tip 70, which is repeatedly struck by the hammer 12, moves back and forth, thereby applying impact to the workpiece (not shown) that comes into contact with the tip of the tip 70, allowing the surface of the workpiece to be excavated or ground. The vibrations generated at this time are absorbed by the outer coil spring member 80 and the inner coil spring member 90 and converted into thermal energy, thereby reducing the vibrations.

[0032] Furthermore, in the configuration of Embodiment 2, with the inner coil spring member 90 positioned on the exposed portion 71 of the tip tool 70, the front coil spring member 85 is attached from the tip side of the tip tool 70, thereby compressing the inner coil spring member 90. At this time, since the U-shaped portion 88 through which the tip tool 70 is inserted opens outward, even tip tools 70 with wide tips, such as barrel-shaped or flathead screwdriver-shaped tips, can be inserted into the U-shaped portion 88. Moreover, since the front coil spring member 85 can be attached to and detached from the main body coil spring member 81 by rotating it spirally, the tip tool 70 can be replaced or maintained by removing it from the main body coil spring member 81. For these reasons, even when the tip tool 70 is replaced relatively frequently depending on the work, the attachment and detachment of the front coil spring member 85 can be easily performed, dramatically improving the efficiency of tip tool 70 replacement.

[0033] In Example 2, the threaded groove portion 35 of the tool body 10 corresponds to the fitting groove portion according to the present invention. The U-shaped portion 88 of the front coil spring member 85 corresponds to the insertion portion according to the present invention. The flat washer 40 locked to the U-shaped portion 88 corresponds to the first locking portion according to the present invention, and the flange portion 72 of the tip tool 70 and the flat washer 40 locked to the flange portion 72 correspond to the second locking portion according to the present invention.

[0034] In the above embodiments 1 and 2, the dimensions and shapes of each part can be freely selected as appropriate. For example, in Embodiment 1, there may be multiple second coil spring members 50. Furthermore, the impact tool 171 in Examples 1 and 2 may be held by the operator's hand, or it may be configured to be gripped by, for example, a robotic arm. Furthermore, in Embodiment 2, a U-shaped portion 88 is provided at the tip of the front coil spring member 85. However, the configuration is not limited to this, and any shape that allows the tip fitting 70 to be inserted from the tip may be used instead of the U-shaped portion 88, such as a circular or elliptical insertion portion. In this case, by making the insertion portion relatively large in diameter, a wide tip can be inserted in the same way as in Embodiment 2, and the same effects and advantages as in Embodiment 2 can be achieved. [Explanation of symbols]

[0035] 1.61 Impact Tools 10 Tool body 11 Cylinder section 12 Hammers 20,70 Tip tools 21,71 Exposed part 22,72 Flange section 30 First coil spring member 31 Coil-shaped section 32,88 U-shaped part 33 Bridge section 35 Screw groove 40 Flat Washer 50 Second coil spring member 80 Outer coil spring member 81 Main body side coil spring member 83 Spiral groove 85 Front coil spring member 86 Mating coil section 87 Support coil section 90 Inner coil spring member A void area X void

Claims

1. The tool body on which the drive source is located, A long, elongated tip that is slidably mounted to the tool body in the front-rear direction and slides back and forth in accordance with the driving force from the drive source, and has a portion of its tip that extends forward relative to the tool body, A first coil spring member is attached to the front end of the tool body, with the portion of the tip end closer to the base end inserted inside it, A second coil spring member is positioned inside the first coil spring member, with the portion of the tip end closer to the base end inserted into the second coil spring member, Equipped with, The second coil spring member is, The front end of the tool body and the locking portion that engages with the tip of the tip are elastically deformable within a range that allows for elastic contraction. The first coil spring member is A coil-shaped section in which the strands are formed in a spiral shape, A U-shaped portion is located towards the tip of the aforementioned coil-shaped portion, and the portion including the tip of the strand is formed in a U-shape, Equipped with, The base end of the coil-shaped portion is locked to the front end of the tool body, and the tip is inserted into the gap portion facing the curved portion of the U-shaped portion, thereby locking the U-shaped portion and the tip together. Furthermore, the U-shaped portion is elastically deformable in a direction intersecting the central axis of the coil-shaped portion, and the U-shaped portion is detachably attached to the tip. An impact tool characterized by the following features.

2. The tool body on which the drive source is located, A long, elongated tip that is slidably mounted to the tool body in the front-rear direction and slides back and forth in accordance with the driving force from the drive source, and has a portion of its tip that extends forward relative to the tool body, An outer coil spring member is attached to the front end of the tool body, and the portion of the tip closer to the base end is inserted into it. An inner coil spring member is positioned inside the outer coil spring member, with the portion of the tip end closer to the base end being inserted into the inner coil spring member. Equipped with, The outer coil spring member is A coil spring member on the main body side, which has a coil spring shape in which strands are wound in a spiral, and is locked to the front end of the tool body, A front coil spring member having a coil spring shape in which strands are wound in a spiral, and having a fitting coil portion which at least a part of is fitted into a spiral groove formed between adjacent strands of the coil spring portion on the main body side, and a support coil portion which is positioned in front of the tool body and has a U-shaped portion at its tip through which the tip tool is inserted. Equipped with, The U-shaped portion is formed in a U-shape that opens outward, including the tip of the wire that constitutes the front coil spring member. The inner coil spring member is An impact tool characterized in that it is arranged elastically compressed within an elastically deformable range between a first locking portion that is locked to the U-shaped portion of the front coil spring and a second locking portion that is locked to the tip tool at the base end of the first locking portion.

3. A tool body having a drive source and a roughly cylindrical mounting portion at its front end, A long, elongated tip that is slidably mounted to the tool body in the front-rear direction and slides back and forth in accordance with the driving force from the drive source, and has a portion that extends forward from the mounting portion of the tool body, An outer coil spring member attached to the mounting portion of the tool body and covering the portion near the base end of the tip, An inner coil spring member is positioned inside the outer coil spring member, with the portion of the tip end closer to the base end being inserted into the inner coil spring member. Equipped with, A spiral fitting groove is formed on the outer circumferential surface of the mounting portion of the tool body. The outer coil spring member is The coil spring member on the main body side is attached to the mounting part by fitting into the fitting groove of the mounting part, which has a coil spring shape formed by winding strands of wire in a spiral shape, A coil spring member having a coil spring shape in which strands are wound in a spiral, having a fitting coil portion which is fitted into a spiral groove formed between adjacent strands of the main body coil spring member, and a support coil portion which is positioned in front of the mounting portion and has an insertion portion at its tip through which the end fitting is inserted. It is equipped with, The inner coil spring member is An impact tool characterized in that it is arranged elastically compressed within an elastically deformable range between a first locking portion that is locked to the insertion portion of the front coil spring member and a second locking portion that is locked to the tip tool at the base end side of the first locking portion.

Images