Impact Tools

Abstract

To provide an impact tool having further vibration absorbing and noise reducing effects. [Solution] An impact tool 1 comprising a rear end cap member 50 attached to a tool body 10, and a tip end cap member 60 attached to the tip of the rear end cap member 50 and having an insertion hole portion 65 through which a tip tool 30 is inserted, wherein the rear end cap member 50 is freely swingable separately from the tool body 10, and the tip end cap member 60 is freely swingable separately from the rear end cap member 50, a vibration absorbing coil spring 70 is arranged in an internal space S formed between the tool body 10 and the cap member 40, the tip end cap member 60 is biased toward the tip side more than the tool body 10, and a tip tool return coil spring 80 is arranged between the tip tool 10 and the tip side cap member 60, and the tip tool 10 is biased toward the rear side relative to the tip side cap member 60.

Description

[Technical field]

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

[0002] Conventionally, as an impact tool that applies an impact to a workpiece to excavate or cut the workpiece, there has been known one that has a cylinder inside the tool body and a tip tool that reciprocates within the cylinder (see, for example, Patent Document 1).

[0003] Also known is an impact tool that is provided with a cap that covers the rear end of the tip tool to prevent the tip tool from jumping out (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 59-176683 [Patent Document 2] Japanese Utility Model Application Publication No. 51-105667 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned impact tool, the tip tool violently reciprocates inside the cylinder, so that strong vibrations are transmitted to the hands of the worker, making it difficult to work for long periods of time. In addition, the violent collision between the parts can cause loud noise, so there is room for improvement in these problems.

[0006] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an impact tool which has even greater vibration absorbing and noise reducing effects. [Means for solving the problem]

[0007] The present invention provides an impact tool comprising: a tool body equipped with a drive source; a long tip tool having a tip portion protruding forward with respect to the tool body in a state where the tip tool is attached slidably in a front-rear direction with respect to the tool body; and a cap member attached to a front end of the tool body and covering a base end of the protruding portion of the tip tool, the tip tool being inserted into the cap member so that a tip portion of the tip tool protrudes forward from the cap member, and the tip tool is reciprocated using the drive source to apply an impact to a workpiece from the tip portion of the tip tool, the cap member comprising: a rear end side cap member attached to the tool body; and a front end side cap member attached to the front of the rear end side cap member and having an insertion hole portion through which the tip tool is inserted, the tip side cap member is attached to the rear end side cap member and is capable of swinging independently of the tool body, and the tip side cap member is attached to the rear end side cap member and is capable of swinging independently of the rear end side cap member, a vibration absorbing coil spring elastically compressed within a range in which the tip of the tool body and the tip side cap member are disposed in an internal space formed between the tool body and the cap member, the tip side cap member is biased toward the tip side relative to the tool body, a tip tool return coil spring elastically compressed within a range in which the tip tool can be deformed is disposed between the tip tool and the tip side cap member, and the tip tool is biased toward the rear side relative to the tip side cap member, and a portion of the tip tool located in the internal space has a large diameter portion having a diameter larger than an inner diameter of the insertion hole portion.

[0008] In this configuration, the cap member has a function of preventing the tip tool from jumping out from the tip side of the cap member. Furthermore, the cap member covers the root end of the inserted portion of the tip tool, thereby reducing sound leakage and improving the silencing effect. The cap member is configured as a rear end side cap member and a tip end side cap member, and is allowed to swing independently of the tool body, thereby obtaining an effect of absorbing impacts and suppressing damage to parts due to stress concentration. The vibration absorbing coil spring has a function of biasing the cap member forward from the tool body, and absorbs impacts and vibrations generated by the cap member. Furthermore, the tip tool return coil spring has a function of biasing the tip tool backward from the cap member, thereby causing the tip tool to move quickly backward during operation of the impact tool, thereby increasing the number of impacts applied per unit time. Effect of the Invention

[0009] The impact tool of the present invention has an effect of preventing the tip tool from jumping out, and also has an effect of reducing vibration transmitted to the hand of the operator and an effect of silencing noise. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a partial cross-sectional side view of the impact tool according to the embodiment. [Diagram 2] 1A and 1B are enlarged side cross-sectional views of an impact tool according to an embodiment of the present invention, in which (a) shows the state in which the cap member has moved furthest toward the tip side in response to the force of the vibration absorbing coil spring, and (b) shows the state in which the cap member has moved furthest toward the rear end side against the force of the vibration absorbing coil spring. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The embodiment of the present invention will be described according to the examples. Note that the present invention is not limited to the examples shown below, and design changes are possible as appropriate. For convenience, the examples are described by specifying the beginning and end, but the present invention is not limited thereto.

[0012] As shown in FIG. 1, the impact tool 1 is driven by compressed air, for example, and includes a tool body 10. A cylinder section 20 that is long in the front-rear direction is provided inside the tool body 10. A long tip tool 30 that reciprocates freely in the front-rear direction inside the cylinder section 20 by the action of the introduced compressed air is attached to the cylinder section 20. Specifically, the tip tool 30 is composed of a portion in which a large-diameter flange section 31 is formed and a portion that is located on the front end side of the flange section 31 and has a smaller diameter than the flange section 31. The small-diameter portion is projected forward from the front end of the tool body 10, and the tip contacts the workpiece W.

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

[0014] When the rear end cap member 50 is attached to the tool body 10, a gap (gap for swinging) is formed between the tool body thread groove 11 and the rear end thread groove 51 near the rear end, so that they are not fastened to each other. As a result, when attached to the tool body 10, the rear end cap member 50 is able to swing independently of the tool body 10 within a range that does not cause them to come apart.

[0015] Furthermore, with the tip end cap member 60 attached to the rear end cap member 50, a gap (gap for swinging) is formed between the rear end thread groove 52 near the tip and the tip end thread groove 61, resulting in a structure in which they are not fastened to each other. As a result, while attached to the rear end cap member 50, the tip end cap member 60 is able to swing independently of the rear end cap member 50 within a range in which they do not come apart from each other.

[0016] Further, 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 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 set to a dimension larger than the hole diameter of the insertion hole portion 65, thereby forming a structure to prevent the tip tool 30 from jumping out.

[0017] Furthermore, a rotation-stop pin 68 is inserted between the rear end cap member 50 and the tip end cap member 60 to prevent the tip end cap member 60 from loosening and coming off during operation of the impact tool 1. The rotation-stop pin 68 functions as a connecting means for connecting the rear end cap member 50 and the tip end cap member 60 in the above-mentioned manner, and has a connecting structure that prevents the rear end cap member 50 and the tip end cap member 60 from being fixed without rattling, and specifically, a gap (swing gap) is formed between the tip of the rotation-stop pin 68 and the part of the tip end cap member 60 into which the tip is inserted so that the tip end cap member 60 can swing freely.

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

[0019] The vibration absorbing coil spring 70 has the tip tool 30 and the tip tool return coil spring 80 inserted therein, and in a state where it is elastically compressed within a range in which it can be elastically deformed, its rear end abuts against the tip wall portion 10a of the tool body 10, and its tip abuts against the vibration absorbing coil spring receiving surface portion 60a that corresponds to 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 more than the tool body 10.

[0020] To state the relationship between the tool body 10 and the cap member 40 again, if the diameter (outer diameter) of the crest of the tool body screw groove 11 is L1 and the diameter (inner diameter) of the root of the rear end side screw groove 51 near the rear end is L2, L1 <L2 It is said that. In addition, the valley diameter (inner diameter) of the tip-side thread groove 52 near the rear end is L2, which is equal to the valley diameter (inner diameter) of the rear-end thread groove 51 near 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] The tool body thread groove 11 and the rear end thread groove 51 closer to the rear end, and the rear end thread groove 52 and the front end thread groove 61 closer to the front end, have the same thread pitch.

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

[0023] Incidentally, the rear end cap member 50 and the front end cap member 60, which have moved forward as described above, can move rearward 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 thread groove 51 closer to the rear end, the rear end thread groove 52 closer to the front end, and the front end thread groove 61 can move the front end cap member rearward by a total of L3 within a range where the thread groove crests are not exceeded.

[0024] In other words, when the impact tool 1 is operated, vibrations generated in the tool body 10 are transmitted to the rear end cap member 50 and the tip end cap member 60, and the rear end cap member 50 and the tip end cap member 60 can swing back and forth from the state shown in Figure 2(a) to the state shown in Figure 2(b), thereby effectively absorbing unpleasant vibrations transmitted to the operator.

[0025] With this configuration, the tool body 10 and the cap member 40 are easily detached because of their screw structure, and the cap member 40 can easily replace the tip tool 30 while suitably preventing the tip tool 30 from popping out. In addition, the cap member 40 is freely swingable relative to the tool body 10, so that the vibration transmitted to the operator using the impact tool 1 can be reduced.

[0026] With the tip tool 30 inserted therethrough, the tip tool return coil spring 80, in a state of being elastically compressed within an elastically deformable range, has its rear end abutting against the front wall portion 31a of the flange portion 31 of the tip tool 30, and its front end abutting against the rear wall portion of the tip side cap member 60 and abutting against the tip tool return coil spring receiving surface portion 60b, which is a surface portion different from the vibration absorbing coil spring receiving surface portion 60a. As a result, the tip tool 30 is urged toward the rear end side more than the tip side cap member 60.

[0027] In this impact tool 1, the rear end cap member 50 and the front end cap member 60 are urged toward the front end by the vibration absorbing coil spring 70 while being freely swingable relative to the tool body 10, and it is possible to reduce shocks, vibrations, and noise during operation of the impact tool 1. Also, by making the cap member 40 into a two-part configuration of the rear end cap member 50 and the front end cap member 60, it is possible to obtain an effect of increasing the vibration absorption effect and suppressing wear on parts.

[0028] In the above embodiment, the dimensions and shapes of each part can be freely selected as appropriate. A plurality of vibration absorbing coil springs 70 and a plurality of tip tool return coil springs 80 may be provided. The impact tool of the present invention can also be applied to an impact tool to be used underwater, for example. [Explanation of symbols]

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

Claims

[Claim 1] A tool body including a drive source and held by an operator; a long tip tool having a tip portion that is extended forward with respect to the tool body in a state where the tip tool is slidably attached to the tool body in a front-rear direction; a cap member attached to a front end portion of the tool body and covering a root end portion of the extended portion of the tip tool, an impact tool in which the tip tool is inserted into the cap member and a tip portion of the tip tool protrudes forward from the cap member, and the tip tool is reciprocated by the driving source to apply an impact to a workpiece from the tip portion of the tip tool, The cap member is a rear end cap member attached to the tool body; a tip end cap member attached to a tip of the rear end cap member and having an insertion hole through which the tip tool is inserted; Equipped with Further, a tool body screw groove is formed on the outer peripheral surface of the front end of the tool body, a rear end side screw groove near the rear end and a rear end side screw groove near the front end are formed in the rear end cap member, which screw into the tool body screw groove, and a front end side screw groove near the front end is formed in the front end cap member, the rear end cap member is independently pivotable relative to the tool body within a range in which the rear end cap member and the tool body do not separate from each other due to a pivot gap formed between the tool body thread groove and the rear end side thread groove near the rear end when the rear end cap member is attached to the tool body, the tip end cap member is attached to the rear end cap member and is independently pivotable relative to the rear end cap member within a range in which the tip end cap member and the rear end cap member do not separate from each other due to a pivot gap formed between the rear end thread groove near the tip end and the tip end thread groove, The internal space formed between the tool body and the cap member includes: a vibration absorbing coil spring that is elastically compressed within a range in which it can be elastically deformed is disposed between the tip of the tool body and the tip cap member, and the tip cap member is biased toward the tip side more than the tool body; A tip tool return coil spring elastically compressed within an elastically deformable range is disposed between the tip tool and the tip side cap member, the tip tool is biased toward the rear side with respect to the tip side cap member, the tip tool has a large diameter part larger in diameter than the inner diameter of the insertion hole part at a portion located in the internal space, a rear end part of the tip tool return coil spring abuts on a front wall part located in front of the large diameter part, and the large diameter part has a diameter larger than the inner diameter of the insertion hole part, thereby configuring an anti-jumping structure that prevents the reciprocating tip tool from coming out of the tip side cap member in the tip direction when the reciprocating tip tool moves forward. An impact tool characterized by:

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