JPH052882U - Hammer tool - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention relates to a striking tool having a motion converting mechanism, a striking mechanism and a rotation transmitting mechanism. The purpose of this invention is that the tip tool is restrained during work. At this time, the impact tool body is prevented from being swung around, and the safety of this type of impact tool is further increased. [Structure] Second gear 1 on 17th pinion shaft
9, a metal 11, a steel ball 20, a holder 21, a plate 23, a spring 22 and a slip clutch, and a third gear 24 on the outer circumference of the cylinder 13.
Each has a slip clutch composed of a clutch 25 and a spring 29. Even if one of the slip clutches does not operate due to damage, seizure, fluctuation of slip torque, etc., the other slip clutch operates, so that the safety of the impact tool can be improved.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an impact tool such as an electric hammer drill having a motion conversion mechanism section, an impact mechanism section, and a rotation transmission mechanism section.

[0002]

[Prior Art]

 A conventional striking tool will be described with reference to FIG. FIG. 2 is a vertical side view showing an example of a hammer drill according to the prior art. The rotary motion of the rotor 2 is converted into a reciprocating motion by the first gear 6, the crankshaft 5, and the piston 9. Further, due to the fluctuation in the compression of the air chamber 26, the striking element 14 is reciprocated to strike the intermediate striking element 15. The impact is transmitted from the intermediate striker 15 to the drill bit 16.

The rotational movement of the rotor 2 is transmitted in the order of the first gear 6, the second pinion 7, the second gear 19, the third pinion 17, and the third gear 24. Further, since the third gear 24 is key-coupled to the cylinder 13 and the intermediate striker 15 is engaged with the cylinder 13 by the spline 27, the intermediate striker 15 rotates. Therefore, the rotation is transmitted to the drill bit 16 engaged with the intermediate striker 15 and the hexagonal shank 28.

A second gear 19 is engaged with the outer circumference of the third pinion 17 via a metal 18 so as to be able to idle. Further, a holder 21 accommodating the steel ball 20 is engaged with the outer circumference of the third pinion 17 by the width across flats. The steel ball 20 is pressed against the second gear 19 by the spring 22 via the plate 23. When the drill bit 16 is constrained during work, the third pinion 17 and the second gear 19 tend to be constrained, but the steel ball that presses the second gear 19 by the load of the spring 22. When 20 exceeds a certain torque, it starts to slide. Therefore, even if the holder 21 accommodating the steel ball 20 and the third pinion 17 are restrained, the second gear 19 idles. This prevents the hammer drill body from swinging around even if the drill bit 16 is restrained during work. Conventionally, the above-mentioned slip clutch mechanism is provided only on one shaft of the rotation transmission mechanism.

[0005]

[Problems to be solved by the device]

 In the conventional striking tool, the slip clutch mechanism that regulates the torque transmitted to the tip tool is provided only on one shaft of the rotation transmission mechanism, so the slip clutch is damaged, seizure, and slip torque. When the tool no longer operates due to fluctuations in the tool, the impact tool body is swung around when the tip tool is restrained, and there is a problem that the safety of the operator cannot be ensured.

An object of the present invention is to eliminate the above-mentioned problems of the prior art and increase the safety of this type of impact tool.

[0007]

[Means for Solving the Problems]

 The above-mentioned object is achieved by providing slip clutches on two or more shafts of the rotation transmitting mechanism for restricting the torque transmitted to the tip tool.

[0008]

[Action]

 In the impact tool configured as described above, even if one of the two slip clutches fails to operate due to damage, seizure, fluctuation of slip torque, or the like, the other slip clutch operates.

[0009]

【Example】

 Hereinafter, the present invention will be described with reference to the accompanying drawings. FIG. 1 is a vertical sectional side view showing an embodiment of a hammer drill according to the present invention.

A motor (rotor 2 and stator 3) is provided in a housing 1 forming a main body frame, and a crankshaft 5 is rotatably supported in a crankcase 4 fixed to the housing 1. ing. A first gear 6 and a second pinion 7 are key-connected to the crankshaft 5, and the pinion of the rotor 2 meshes with the first gear 6. A piston 9 is attached to the crankshaft 5 via a connecting rod 8. Further, a cylinder case 10 fixed to the crank case 4 has a cylinder 13 rotatably supported therein, and a piston 9, a striker 14, and an intermediate striker 15 are slidable in the cylinder 13. Engaged. The intermediate striker 15 is engaged with the cylinder 13 by the spline 27, and the intermediate striker 15 and the drill bit 16 are engaged by the hexagonal shank 28.

Further, there is a third pinion 17 shaft perpendicular to the striking shaft, and the third pinion 17 is rotatably supported in the crank case 4 and the gear cover 18. A second gear 19 is engaged with the outer periphery of the third pinion 17 via a metal 11 so as to be able to idle. Further, a holder 21 accommodating the steel ball 20 is engaged with the outer circumference of the third pinion with a width across flats. The steel ball 20 is pressed against the second gear 19 by the spring 22 via the plate 23, and the second gear 19 meshes with the second pinion 7. A third gear 24 is engaged with the outer circumference of the cylinder 13 so as to idle, and meshes with a third pinion 17. Further, a clutch 25 is key-connected to the outer periphery of the cylinder 13 and is pressed rearward by a spring 29 to be clutch-engaged with a third gear 24. The rotational movement of the rotor 2 is converted into a reciprocating movement by the first gear 6, the crankshaft 5, the connecting rod 8 and the piston 9. Along with this, the air chamber 26 is compressed and fluctuated, and the striker 14 reciprocates to strike the intermediate striker 15 and transmit the strike to the drill bit 16. Further, the rotation is performed by the rotor 2, the first gear 6, the second pinion 7, the second gear 19, the steel ball 20, the holder 21, the third pinion 17, the third gear 24, the clutch 25, the cylinder 13, the intermediate part. The striker 15 and the drill bit 16 are transmitted in this order.

The slip clutch mechanism is arranged on the shaft of the third pinion 17 and on the outer circumference of the cylinder 13. The slip clutch on the 17th axle of the third pinion causes the steel ball 20 pressing the second gear 19 by the load of the spring 22 to slip out when the torque exceeds a certain value, and the second gear 19 idles. On the other hand, in the slip clutch on the outer periphery of the cylinder 13, when the torque of the third gear 24 and the clutch 25, which are clutch-engaged by the load of the spring 29, exceeds a certain torque, the clutch disengages and the third gear 24 idles.

[0013]

[Effect of the device]

 According to the present invention, the slip clutch for restricting the torque transmitted to the tip tool is provided on two or more shafts of the rotation transmission mechanism, so that one slip clutch is damaged, seized, or changes in slip torque occur. Even if it does not work due to other reasons, the other slip clutch operates, so that it is possible to enhance the safety for the worker.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of a hammer drill according to the present invention.

FIG. 2 is a vertical sectional side view showing an example of a hammer drill according to the related art.

[Explanation of symbols]

1 is a housing, 2 is a rotor, 3 is a stator, 4 is a crankcase, 5 is a crankshaft, 6 is a first gear, 7 is a second pinion, 8 is a connecting rod, 9 is a piston, 10 is a cylinder case, 11 is a metal, 13 is a cylinder, 14 is a hammer, 15 is an intermediate hammer, 16 is a drill bit, 17 is a pinion, 18 is a gear cover, 1
9 is a second gear, 20 is a steel ball, 21 is a holder, 22 and 29 are springs, 23 is a plate, 24 is a gear, 25 is a clutch, 26 is an air chamber, 27 is a spline, 28 is a Hexagonal shank.

Claims (1)

[Claims for utility model registration] 1. A rotary drive source, a conversion mechanism unit connected to the rotary drive source for converting rotational motion of the drive source into reciprocating motion, and connected to the conversion mechanism unit. In a striking tool having a striking mechanism section and a rotation transmitting mechanism section for transmitting rotation to a tip tool, a clutch for restricting torque transmitted to the tip tool is arranged on two or more shafts of the rotation transmitting mechanism section. A striking tool characterized by being installed.