JPS6029432Y2 - Tool attachment/detachment device for hammer drills, etc. - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a tool attachment/detachment device for hammer drills, etc.

Conventionally, the above-mentioned device includes a roller supported movably in the radial direction on the main body and a roller that presses the roller in the radial direction.
Generally known are those that consist of a rib, and those that have a chuck member fastened by a screw threaded into the main body.

However, the above-mentioned conventional devices not only have a complicated structure but also require high machining accuracy, so they have the common drawback of high cost, and the latter in particular has the drawback that it takes time to attach and detach tools.

Therefore, in view of the above-mentioned conventional difficulties, the present invention was developed to provide a tool attachment/detachment device that has an extremely simple structure, can be manufactured at low cost, and is capable of attaching and detaching tools easily and reliably. The drawings obtained and showing the embodiments of the present invention will be described in detail below.

FIG. 1 shows a hammer drill which is an embodiment of the present invention, in which a tool 2 attached to the tip of a front cap 1 receives rotation and impact force from an adapter 3 to which power is transmitted from a drive source (not shown). In response to this, Anaki is configured to do the following.

Thus, the tool attachment/detachment device a of the present invention, as shown in FIGS. 1 to 3, has a tool attachment hole 4 formed in the center of the front cap 1, and a sleeve 5 rotatably mounted on the front cap 1. The tool mounting hole 6 is provided eccentrically by the relative eccentricity, and the tool 2 is attached and detached by aligning both the mounting holes 4 and 6 concentrically as shown in FIG. 3A, and The tool 2 is relatively eccentric by being displaced as shown in FIG. be.

In this case, at least the portion of the front cap 1 into which the sleeve 5 is fitted is formed to have a circular cross section, and the tool attachment hole 4 is formed eccentrically by making the peripheral wall 1a unevenly thick. There is.

The sleeve 5 is formed in a cup shape from a peripheral wall 5a and a front wall 5b, and the tool mounting hole 6 is eccentrically formed in the front wall 5b that covers the front end of the front cap 1.
, the guide pin 7 implanted in the peripheral wall 4a of the cap 1 and the guide groove 8 provided long in the circumferential direction in the peripheral wall 5a are slidably engaged with the front cap 1, and the effective length of the guide groove 8 is fixed. The exterior is held so that it can be rotated back and forth within a certain range.

Furthermore, the guide groove 8 changes from the tool attachment/detachment state in which both the tool attachment holes 4 and 6 are aligned as shown in FIG. The length of the sleeve 5 is set in advance so that it can rotate relative to the front cap 1 within the range of a tool holding state in which the sleeve 5 is displaced by an eccentric amount. In addition, a positioning mechanism is provided to position the sleeve 5 with respect to the front cap 1.

In the positioning mechanism, a stopper ball 9 is loosely fitted into a hole 5C formed in the peripheral wall 5a of the sleeve 5, and is elastically biased in the axial direction by a leaf spring 10 attached to the outer periphery of the sleeve 5. On the peripheral wall 1a of the front cap 1,
At least two stopper recessed holes 11.11 are formed at a predetermined angle so that the stopper ball 9 can be engaged in each of the above states.

In addition, in the tool holding state, as shown in FIG. 3B, the flange 2a of the tool 2 engages with the deviated portion of the tool mounting holes 4 and 6, that is, the edge of one side of the tool mounting hole 6. This allows the tool 2 to be held without coming off.

As explained above, according to the tool attachment/detachment device for a hammer drill or the like according to the present invention, the tool attachment hole 4 between the front cap 1 and the sleeve rotatably fitted to the cap 1,
6 is eccentrically arranged by an appropriate amount, the diameter of the tool mounting hole is substantially expanded or contracted by rotating the sleeve 5, so the tool 2 can be easily and easily attached or removed by simply rotating the sleeve 5. In addition, since the rotational torque of the sleeve 5 can be reduced, tool attachment/detachment operations can be performed smoothly.Furthermore, the simple structure allows for miniaturization, and as a result, tools such as hammer drills can be used in narrow spaces. It has effects such as being suitable as an attachment/detachment device.

[Brief explanation of the drawing]

Fig. 1 is a partial vertical sectional side view of a hammer drill equipped with a tool attachment/detachment device according to the present invention, and Fig. 2 is a partial longitudinal side view of a hammer drill equipped with a tool attachment/detachment device according to the present invention.
3 A and 3B are cross-sectional views taken along the line ■-■ in FIG. 1, where A shows the tool in a detached and attached state, and B shows the tool in a held state. 1...Front cap, 2...Tool, 4, 6...Tool mounting hole, 5...Sleeve.

Claims (1)

[Scope of utility model registration request] The sleeve 5 is fitted into the front cap 1 so as to be rotatable by a predetermined angle, and the tool mounting holes 4 and 6 are formed to be eccentric by an appropriate amount relative to each other, and the tool 2 is held by the difference in eccentricity between the two tool mounting holes. A tool attachment/detachment device for a hammer drill, etc., characterized in that it is configured as follows.