JPH10175178A - Operation mode switching device for hammer drill - Google Patents

Abstract

(57) [Problem] To provide an inexpensive operation mode switching device with good operability. SOLUTION: A second gear 10 to which rotation from an intermediate shaft 7 is transmitted is disposed on a cylinder 17 holding a tip tool 18 so as to be rotatable and movable in the axial direction.
A first clutch mechanism 12 for controlling rotation transmission by an axial movement of 0 is provided, and a third gear 11 that is rotatable and movable in the axial direction is disposed on a cylinder 17 axis. A second clutch mechanism for controlling is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation mode switching device for controlling rotation transmission and impact transmission to a tip tool in a hammer drill having a striking mechanism and a rotation transmitting mechanism.

[0002]

2. Description of the Related Art Conventionally, hammer drills are mainly devices which can freely switch between two operation modes such as "rotation and hitting" or "rotation only". The rotation of the motor is transmitted to the intermediate shaft via the pinion and the first gear,
The rotation is constantly transmitted to the second gear meshing with the second pinion on the intermediate shaft, and the tip tool is rotated through the cylinder. On the other hand, the sleeve which is always in spline engagement with the intermediate shaft, and the motion converting member rotatably and loosely fitted on the intermediate shaft are engaged with the pawl, and the rotation of the motor transmitted to the intermediate shaft is moved. The piston was reciprocated by transmitting it to the conversion member. As a result, the hitting force is transmitted to the tip tool via the hitting element and the meson, using the generated air spring. In addition, these switchings have been made possible by operating a switching member connected to the outside of the outer frame member, thereby moving the sleeve in the axial direction and releasing the claw engagement between the sleeve and the motion conversion member.

In addition to the above switching device, a switching device capable of switching between three operation modes of "rotation and hitting", "rotation only", and "hitting only" is described in Japanese Patent Application Laid-Open No. Hei 3-504697. It has been configured to control the impact or rotation transmission to the tip tool by the axial movement of the intermediate shaft.

[0004]

As described above, the conventional hammer drill is either a "rotation and hitting" or a "rotation only".
However, such a two-mode device has been mainstream, and there has been a problem that it is not possible to adapt to a work performed only by hitting, such as fishing, because there is no mode of only hitting.

[0005] "Rotation and blow", "rotation only",
Some hammer drills capable of switching between three modes of "strike only" are configured to control the striking or rotation transmission to the tool bit by moving the intermediate shaft in the axial direction. There is a problem that the operation mode switching device becomes expensive.

SUMMARY OF THE INVENTION An object of the present invention is to provide a small-sized hammer drill having a simple and inexpensive three-mode function.

[0007]

A second gear, to which the rotation of a motor is transmitted, is rotatably and axially movable on a cylinder holding a tool bit through an intermediate shaft and a second pinion. Providing a first clutch mechanism for controlling rotation transmission by axial movement of the cylinder, disposing a third gear capable of axial movement on the cylinder, and providing a second clutch mechanism for controlling impact transmission by axial movement of the third gear. Thus, the first clutch mechanism and the second
When the clutch mechanisms are connected together, "rotation and hitting", when the first clutch mechanism is connected and the second clutch mechanism is disengaged, "rotation only", and when the first clutch mechanism is disengaged and the second clutch mechanism is connected, "hitting only". This is achieved by obtaining the operation mode of

By operating the switching member connected to the outside of the outer frame member to operate the first clutch mechanism and the second clutch mechanism, a simple and easy-to-operate operation mode switching device can be obtained. Achieved.

[0009]

1 to 3, there is shown an example in which a second gear 10 and a third gear 11 are provided so as to be movable along a tool axis. Second pinion 6 on cylinder 17 axis
A second gear 10 to which rotation from the motor is constantly transmitted is disposed on the cylinder 17 so as to be rotatable and axially movable, and a third gear 11 for transmitting rotation to the motion conversion member 4 via the sleeve gear 5 is disposed on the cylinder 17. Set up. The second gear 10 and the cylinder 17 form a first clutch mechanism 12, and the third gear 11 is a second gear 10 and a second clutch mechanism 1.
Arrange to form 3. The second gear 10 and the third gear 11 are respectively provided with a spring 19 and a spring 2
0, and the first clutch mechanism and the second clutch mechanism are arranged so as to be connected to each other.

The rotation of the motor 1 is transmitted from the pinion 2 to the intermediate shaft 7 via the first gear 3, transmitted to the second gear via the second pinion 6 provided on the intermediate shaft 7, and transmitted to the cylinder 17 by the first clutch mechanism. Giving rotation. At the same time, the rotation of the second gear 10 is transmitted to the third gear 11 by the second clutch
Motion conversion member 4 via sleeve gear 5 loosely fitted thereon
To reciprocate the piston 14. As a result, the striking force is transmitted to the tip tool 18 via the striking element 15 and the intermediate element 16 using the generated air spring. This results in a "rotate and hit" mode.

When the second gear 10 is moved toward the motor 1 by operating the switching member 8 connected to the outside of the outer frame member 9, the first clutch mechanism 12 is disengaged, and the second tool 10 is moved to the tip tool 18. Interrupt rotation transmission. At this time, the second
The clutch mechanism 13 remains connected, and “only hits”
Mode is obtained.

On the other hand, the operation of the switching member 8 causes the third gear 11 to move.
Is moved to the motor 1 side, the second clutch mechanism 1
3 is disengaged and the transmission of the impact to the tip tool 18 is interrupted. At this time, the first clutch mechanism 12 remains connected,
A "rotation only" mode is obtained.

[0013]

According to the present invention, it is possible to provide a small hammer drill having an operation mode switching device with a simple structure and good operability.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an operation mode of “rotation and impact” according to the present invention.

FIG. 2 is a longitudinal sectional view showing an operation mode of “rotation only” according to the present invention.

FIG. 3 is a longitudinal sectional view showing an operation mode of “hit only” according to the present invention.

[Explanation of symbols]

1 is a motor, 4 is a motion conversion member, 8 is a switching member, 9 is an outer frame member, 10 is a second gear, 11 is a third gear, 12
Denotes a first clutch mechanism, 13 denotes a second clutch mechanism, 17 denotes a cylinder, and 18 denotes a tip tool.

Claims (2)

[Claims] 1. A motor, a motion converting member for converting a rotational force of the motor into a striking force, a striking mechanism for transmitting a striking force to the tip tool by the striking force converted by the motion converting member, and a tip tool. A second gear is rotatably and axially movable on a cylinder holding the tool bit, and the second gear is transmitted by the axial movement of the second gear. And a third gear rotatable and axially movable on the cylinder, and a second clutch mechanism for controlling the impact transmission by the axial movement of the third gear. Operating mode switching device for hammer drills. 2. The first clutch mechanism and the second clutch mechanism are controlled by operating a switching member connected to the outside of the outer frame member to move the second gear and the third gear in the axial direction of the tool bit. The operation mode switching device for a hammer drill according to claim 1, wherein: