Impact tool

Abstract

To provide an impact tool having a further vibration absorption effect and silent effect.SOLUTION: An impact tool 1 includes a rear end side cap member 50 mounted on a tool body 10, and a tip side cap member 60 that is mounted at the tip of the rear end side cap member 50 and includes an insertion hole part 65 to which a tip tool 30 is inserted. The rear end side cap member 50 is swingable separately from the tool body 10, the tip side cap member 60 is swingable separately from the rear end side cap member 50, in an internal space S formed between the tool body 10 and the cap member 40, a vibration absorption coil spring 70 is arranged, the tip side cap member 60 is energized to the tip side rather than the tool body 10, between the tip tool 10 and the tip side cap ember 60, a tip tool return coil spring 80 is arranged, and the tip tool 10 is energized to the rear side with respect to the tip side cap member 60.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an impact tool that imparts an impact to a workpiece by the action of a mechanism in which a tip reciprocates.

Background Art

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

[0003] Also, there is known an impact tool provided with a cap that covers the rear end portion of the tip in order to prevent the tip from protruding (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In such an impact tool, since the tip 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. Also, since the noise may increase due to the violent collision of the members with each other, there is room for improving these problems.

[0006] Therefore, an object of the present invention is to provide an impact tool having a further vibration absorption effect and a soundproofing effect.

Means for Solving the Problems

[0007] The present invention relates to an impact tool comprising a tool body having a drive source, a long tip tool slidably attached to the tool body in the front-rear direction and having a tip portion that projects forward with respect to the tool body, and a cap member attached to the front end portion of the tool body and covering the root end portion of the projected portion of the tip tool. The tip tool is inserted through the cap member and the tip end of the tip tool projects forward from the cap member. The impact tool imparts an impact to a workpiece from the tip end of the tip tool by reciprocating the tip tool using the drive source. The cap member includes a rear end side cap member attached to the tool body and a tip end side cap member attached to the tip of the rear end side cap member and having an insertion hole portion through which the tip tool is inserted. The rear end side cap member is swingable independently of the tool body when attached to the tool body. The tip end side cap member is swingable independently of the rear end side cap member when attached to the rear end side cap member. An elastic vibration-absorbing coil spring that elastically contracts within an elastically deformable range is disposed between the tip of the tool body and the tip end side cap member in an internal space formed between the tool body and the cap member. The tip end side cap member is biased toward the tip end side with respect to the tool body. A tip tool return coil spring that elastically contracts within an elastically deformable range is disposed between the tip tool and the tip end side cap member. The tip tool is biased toward the rear side with respect to the tip end side cap member. The impact tool is characterized in that a portion of the tip tool located in the internal space has a diameter larger than the inner diameter of the insertion hole portion.

[0008] In such a configuration, the cap member has a function of preventing the tip tool from protruding from the tip side of the cap member. Further, by covering the root end portion of the portion where the tip tool is protruded by the cap member, sound leakage is reduced and the silent effect is improved. And, by configuring the cap member as a rear end side cap member and a tip side cap member and making it swingable independently of the tool body, an impact absorption effect and an effect of suppressing breakage of parts due to stress concentration can be obtained. Further, the vibration absorption coil spring has a function of biasing the cap member forward from the tool body, and absorbs the impact and vibration generated by the cap member. Furthermore, the tip tool return coil spring has a function of biasing the tip tool rearward from the cap member, so that the tip tool quickly moves rearward during the operation of the impact tool and increases the number of impact applications per unit time.

Advantages of the Invention

[0009] The impact tool of the present invention has an effect of preventing the tip tool from protruding, and also has an effect of reducing the vibration transmitted to the operator's hand and a silent effect.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0011] Embodiments of the present invention will be described according to examples. Note that the present invention is not limited to the examples shown below, and design changes can be made as appropriate. Also, for convenience, the front and rear are defined and described in the examples, but the present invention is not limited thereby.

[0012] As shown in Fig. 1, the impact tool 1 uses, for example, compressed air as a driving source and includes a tool body 10. A cylinder portion 20 that is long in the front-rear direction is provided inside the tool body 10. Further, a long tip tool 30 that reciprocates slidably in the front-rear direction within the cylinder portion 20 by the action of the introduced compressed air is attached to the cylinder portion 20. Specifically, the tip tool 30 is composed of a portion where a large-diameter flange portion 31 is formed and is arranged within the cylinder portion 20, and a portion that is located on the front end side of the flange portion 31 and has a smaller diameter than the flange portion 31. And such a smaller-diameter portion protrudes forward from the front end portion of the tool body 10, and the tip contacts the workpiece W.

[0013] Also, a cap member 40 is fitted on the outer peripheral surface of the front end portion of the tool body 10. More specifically, the cap member 40 includes a cylindrical rear end side cap member 50 attached to the tool body 10 and a disk-shaped front end side cap member 60 attached to the front end side of the rear end side cap member 50. A tool body thread groove 11 is formed on the outer peripheral surface of the front end portion of the tool body 10. Also, on the inner peripheral surface of the rear end side cap member 50, a rear end side thread groove 51 closer to the rear end and a rear end side thread groove 52 closer to the front end are formed on the front end side. Also, a front end side thread groove 61 is formed on the outer peripheral surface on the rear end side of the front end side cap member 60. The rear end side cap member 50 is attached to the tool body 10 by screwing the tool body thread groove 11 and the rear end side thread groove 51 closer to the rear end of the rear end side cap member 50, and the front end side cap member 60 is attached to the rear end side cap member 50 by screwing the rear end side thread groove 52 closer to the front end of the rear end side cap member 50 and the front end side thread groove 61 of the front end side cap member 60.

[0014] Note that, in a state where the rear end side cap member 50 is attached to the tool body 10, a gap (oscillation gap) is formed between the tool body thread groove 11 and the rear end side thread groove 51 closer to the rear end, and it has a structure where they are not tightened together. Thereby, the rear end side cap member 50 is individually swingable relative to the tool body 10 within a range where they do not separate from each other in the state of being attached to the tool body 10.

[0015] In addition, in a state where the tip-side cap member 60 is attached to the rear-end side cap member 50, a gap (swinging gap) is formed between the rear-end side screw groove 52 near the tip and the tip-side screw groove 61, and it has a so-called structure where they are not tightened to each other. As a result, the tip-side cap member 60 is swingable independently of the rear-end side cap member 50 within a range where they do not separate from each other while being attached to the rear-end side cap member 50.

[0016] The tip-side cap member 60 is provided with an insertion hole portion 65 through which the tip tool 30 is inserted. That is, the tip portion of the tip tool 30 protrudes forward from the tip-side cap member 60 through the insertion hole portion 65, while the outer diameter of the flange portion 31 is dimensioned to be larger than the hole diameter of the insertion hole portion 65, thereby constituting a structure for preventing the tip tool 30 from popping out.

[0017] Furthermore, a detent pin 68 is inserted through the rear-end side cap member 50 and the tip-side cap member 60 to prevent the tip-side cap member 60 from loosening and falling off during the operation of the impact tool 1. The detent pin 68 functions as a connecting means for connecting the rear-end side cap member 50 and the tip-side cap member 60 in the above-described manner, and has a connecting structure such that the rear-end side cap member 50 and the tip-side cap member 60 are not fixed without rattling. Specifically, a gap (swinging gap) is formed between the tip portion of the detent pin 68 and the portion of the tip-side cap member 60 into which the tip portion is inserted so that the tip-side cap member 60 can swing freely.

[0018] In addition, a vibration absorption coil spring 70 and a tip tool return coil spring 80 are respectively disposed in the internal space S formed between the tool body 10 and the cap member 40.

[0019] The vibration-absorbing coil spring 70 has the tip tool 30 and the tip tool return coil spring 80 inserted therein. In a state of being elastically deformed and compressed within the elastic deformation range, the rear end portion abuts against the front wall portion 10a of the tool body 10, and the front end portion abuts against the vibration-absorbing coil spring receiving surface portion 60a that hits the rear wall portion of the tip-side cap member 60. As a result, the tip-side cap member 60 is biased toward the tip side with respect to the tool body 10.

[0020] When restating the relationship between the tool body 10 and the cap member 40, when the crest diameter (outer diameter) of the tool body thread groove 11 is L1 and the trough diameter (inner diameter) of the rear-end-side thread groove 51 closer to the rear end is L2, L1 < L2 is set. Note that the trough diameter (inner diameter) of the tip-side thread groove 52 closer to the rear end is L2, which is equal to the trough diameter (inner diameter) of the rear-end-side thread groove 51 closer to the rear end, and the crest diameter (outer diameter) of the tip-side thread groove 61 is L1, which is equal to the crest diameter (outer diameter) of the tool body thread groove 11.

[0021] Note that the tool body thread groove 11, the rear-end-side thread groove 51 closer to the rear end, and the tip-side thread groove 52 closer to the rear end and the tip-side thread groove 61 are assumed to have the same screw pitch.

[0022] Furthermore, the tip-side cap member 60 is biased forward with respect to the tool body 10 by the vibration-absorbing coil spring 70. As a result, as shown in Fig. 2(a), within the movable range in the gap between the tool body thread groove 11 and the rear-end-side thread groove 51 closer to the rear end, the rear-end-side cap member 50 moves forward with respect to the tool body 10. Similarly, within the movable range in the gap between the tip-side thread groove 52 closer to the rear end and the tip-side thread groove 61, the tip-side cap member 60 moves forward with respect to the rear-end-side cap member 50.

[0023] Incidentally, as described above, the rear end side cap member 50 and the tip side cap member 60 that have moved forward can move backward against the biasing force of the vibration absorbing coil spring 70. That is, as shown in Fig. 2(b), the tool body thread groove 11, the rear end side thread groove 51 near the rear end, the rear end side thread groove 52 near the tip, and the tip side thread groove 61 can move the tip side cap member backward by L3 together within a range where they do not cross the crests of the thread grooves.

[0024] That is, when the impact tool 1 is operated, the vibration generated in the tool body 10 propagates to the rear end side cap member 50 and the tip side cap member 60, and the rear end side cap member 50 and the tip side cap member 60 can swing back and forth from the state shown in Fig. 2(a) to the state shown in Fig. 2(b), and can preferably absorb the unpleasant vibration transmitted to the operator.

[0025] With such a configuration, since the tool body 10 and the cap member 40 have a screwed structure, they are easy to attach and detach. While preferably preventing the tip tool 30 from protruding by the cap member 40, the tip tool 30 can be easily replaced. Further, the cap member 40 is swingable with respect to the tool body 10, and the vibration transmitted to the operator using the impact tool 1 can be reduced.

[0026] The tip tool return coil spring 80 has the tip tool 30 inserted therein and is in a state of being elastically compressed within an elastically deformable range. The rear end abuts against the front wall portion 31a of the flange portion 31 of the tip tool 30, and the front end abuts against the rear wall portion of the tip side cap member 60 and abuts against the tip tool return coil spring receiving surface portion 60b, which is a surface different from the vibration absorbing coil spring receiving surface portion 60a. Thereby, the tip tool 30 is biased toward the rear end side rather than the tip side cap member 60.

[0027] Such an impact tool 1 has a rear-end cap member 50 and a tip-end cap member 60 that are swingable with respect to a tool body 10, and is biased toward the tip end by a vibration-absorbing coil spring 70. During the operation of the impact tool 1, impacts and vibrations can be reduced to reduce noise. Further, by configuring the cap member 40 with two members, namely the rear-end cap member 50 and the tip-end cap member 60, an effect of increasing the vibration-absorbing effect and suppressing wear of parts can be obtained.

[0028] In the above embodiment, the dimensional shapes of the respective parts can be freely selected as appropriate. A plurality of vibration-absorbing coil springs 70 and tip tool return coil springs 80 may be provided respectively. Note that the impact tool of the present invention is applicable to, for example, an impact tool used underwater.

Explanation of reference numerals

[0029] 1 Impact tool 10 Tool body 10a Front wall portion of the tool body 11 Tool body thread groove 20 Cylinder portion 30 Tip tool 31 Flange portion (large-diameter portion) 31a Front wall portion of the flange portion 40 Cap member 50 Rear-end cap member 51 Rear-end side thread groove near the rear end 52 Rear-end side thread groove near the tip 60 Tip-end cap member 60a Vibration-absorbing coil spring receiving surface portion 60b Tip tool return coil spring receiving surface portion 61 Tip-end side thread groove 65 Insertion hole portion 68 Anti-rotation pin 70 Vibration-absorbing coil spring 80 Tip tool return coil spring S Internal space

Claims

【Claim 1】 A tool body having a drive source, A long tip tool that is slidably attached to the tool body in the front-rear direction and has a tip portion that protrudes forward with respect to the tool body, A cap member attached to the front end portion of the tool body and covering the root end portion of the protruding portion of the tip tool, and comprising: The tip tool is inserted through the cap member and the tip of the tip tool protrudes forward from the cap member, and an impact tool that reciprocates the tip tool using the drive source and imparts an impact to a workpiece from the tip of the tip tool, The cap member is: A rear end side cap member attached to the tool body, A front end side cap member attached to the tip of the rear end side cap member and having an insertion hole portion through which the tip tool is inserted, Comprising: The rear end side cap member is swingable independently of the tool body in a state of being attached to the tool body, The front end side cap member is swingable independently of the rear end side cap member in a state of being attached to the rear end side cap member, In the internal space formed between the tool body and the cap member, A vibration absorbing coil spring that is elastically deformed and compressed within an elastic deformation range is disposed between the tip of the tool body and the front end side cap member, and the front end side cap member is biased toward the tip side with respect to the tool body, A tip tool return coil spring that is elastically deformed and compressed within an elastic deformation range is disposed between the tip tool and the front end side cap member, and the tip tool is biased toward the rear side with respect to the front end side cap member, A portion of the tip tool located in the internal space has a diameter larger portion than the inner diameter of the insertion hole portion An impact tool characterized by the above.

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