WO2019020108A1

WO2019020108A1 - Electric tool and drill adapter thereof

Info

Publication number: WO2019020108A1
Application number: PCT/CN2018/097408
Authority: WO
Inventors: 郑祥格; 李毅
Original assignee: 博世电动工具（中国）有限公司
Priority date: 2017-07-28
Filing date: 2018-07-27
Publication date: 2019-01-31
Also published as: BR112020001341A2; CN207757558U; DE112018003832T5

Abstract

Provided are a drill adapter and an electric tool mounted with the drill adapter. The drill adapter comprises: a body (100) having a mounting end for insertion into the electric tool and a receiving end for detachably receiving a drill bit (500, 510), characterized in that the body (100) is provided with first, second and third limit features that limit the depth of insertion of the drill adapter into the electric tool, the first, second and third limit features act independently in turn when the drill adapter is located within the electric tool, the first limit feature is defined by a flange (130) protruding from an outer circumference of the body (100), the second limit feature is defined by a keyway (110) formed in an outer circumference of the body (100) in an axial direction to an end surface of the mounting end, and the third limit feature is defined by a receiving blind hole (120) which is adjacent to the mounting end in the outer circumference of the body (100) and is circumferentially spaced from the keyway (110).

Description

Power tool and its drill adapter

Technical field

The present application relates to power tools, particularly electric hammer drills, and drill adapters therefor.

Background technique

Power tools such as electric drills and electric hammer drills have been widely used. In the case of a hammer drill, for example, a drill adapter is usually provided to achieve the corresponding function by installing the drill bit through the drill adapter when only the drill mode is required.

In order to avoid contact with the hammer drill ram that linearly reciprocates the electric hammer drill, the drill adapter needs to be designed to be separated from the hammer drill ram at all times after insertion of the hammer drill. Although the drill adapter of the prior art has a structure for preventing the impact hammer from hitting the rod, the structure is relatively simple, and may be invalid after being repeatedly disassembled and used by the site personnel.

Further, according to the prior art, when the drill bit is detached from the adapter, it is necessary to first press the outer sleeve of the adapter toward the power tool. Because the power tool is likely to accidentally touch the workpiece to be processed during use, the outer sleeve of the adapter is accidentally pressed, and there is a possibility that the drill bit accidentally falls out from the adapter.

In addition, during installation of the drill adapter to the power tool, it is desirable to rotate the adapter about the central axis from time to time such that the mounting handle of the adapter is aligned with the locking structure in the power tool. However, because the outer sleeve of the prior art drill adapter is rotatable relative to the mounting handle, such a hand held outer sleeve is less likely to align the mounting handle with the locking structure, increasing the difficulty of installing the adapter during field construction.

Utility model content

In view of the above problems, the present application is directed to an improved drill adapter, whereby the safety of the disassembly operation can be significantly improved, and the drill can be prevented from accidentally falling out of the adapter due to accidental contact during normal operation of the power tool. It can reduce the difficulty of installation relative to power tools.

According to an aspect of the present application, a drill adapter for a power tool is provided, comprising:

a body having a mounting end for insertion into a power tool and a receiving end for detachably receiving a drill bit, wherein the body is provided to limit insertion of the drill adapter into the power tool First, second and third limit features of the depth, the first, second and third limit features acting in sequence when the drill adapter is located within the power tool, the first limit The bit feature is defined by a flange formed from a periphery of the body, the second stop feature being defined by a keyway formed in an outer circumference of the body that leads axially to an end face of the mounting end, and A third limit feature is defined by a receiving blind hole in the outer circumference of the body adjacent the mounting end and circumferentially spaced from the keyway.

In the context of the present application, the first, second, and third limit features function independently in turn, meaning that when the first limit feature is active, the second and third limit features are inactive; the first limit When the feature fails, the second limit feature works, but the third limit feature does not work; when the first and second limit features fail, only the third limit feature acts.

Optionally, the flange has a locating surface facing the mounting end to define the first stop feature and contact the power tool.

Optionally, the positioning surface is a slope surface or a step surface.

Optionally, the keyway has a locating surface facing the mounting end to define the second stop feature and contact the power tool.

Optionally, the positioning surface is a slope surface or a step surface.

Optionally, the receiving blind hole has a partially spherical recess to define the third limiting feature.

Optionally, an outer diameter of a portion of the body that is located on a side toward the receiving end with respect to the flange is slightly larger than a side of the body that is located toward a side of the mounting end with respect to the flange. Part of the outer diameter.

Optionally, the drill adapter further includes an outer sleeve, the outer sleeve being axially slidably mounted around the body at the receiving end, between the outer sleeve and the receiving end a locking structure for axially limiting a bit received within the receiving end, wherein the locking structure has a structure that is incapable of axially limiting the bit when the outer sleeve moves away from the mounting end .

Optionally, the outer sleeve is non-rotatable relative to the body.

Optionally, the outer wall of the receiving end has a flat section, and the inner wall of the outer sleeve has a flat section, and the two flat sections are in contact with each other.

Optionally, the receiving end portion includes a receiving cavity, and the locking structure includes a ball that can partially protrude into the receiving cavity, the ball is moved when the outer sleeve moves away from the mounting end It is movable radially away from the receiving volume.

Optionally, the receiving end has an axial extension, the outer surface of the axial extension having a shape that can cooperate with other parts.

In accordance with another aspect of the present application, a power tool is provided that includes a rotatable mounting shaft tube, wherein the aforementioned bit adapter is mounted within the mounting shaft tube.

Optionally, the power tool is an electric hammer drill and further includes a hammer drill ram, the drill adapter installed within the hammer drill always maintaining a safe distance from the hammer drill ram.

With the above technical solution of the present application, the multi-level limit feature can ensure that the drill adapter always maintains a safe distance from the hammer drill ram in the electric hammer drill, thereby improving operational safety and reliability. In addition, due to the different design of the outer diameter of the body relative to both sides of the flange, the sealing of the dust cap mounted on the body is improved. In addition, since the removal of the drill requires the outer casing to be pulled away from the mounting end, the possibility of mis-disassembly of the drill bit due to accidental pressing of the outer casing during construction is avoided. Furthermore, the fact that the outer sleeve cannot rotate relative to the body also improves the ease of installation of the drill adapter.

DRAWINGS

The foregoing and other aspects of the present application will be more fully understood from the following description of the appended claims. It should be noted that the proportions of the various figures may be different for the purpose of clarity, but this does not affect the understanding of the present application. In the drawing:

1 is a schematic longitudinal cross-sectional view of a drill adapter in accordance with an embodiment of the present application, wherein the drill adapter is equipped with a drill bit;

Figure 2 is a schematic cross-sectional perspective view of the drill adapter shown in Figure 1;

Figure 3 is a schematic longitudinal sectional view showing the assembly of the drill adapter shown in Figures 1 and 2 in a hammer drill;

4 is a longitudinal cross-sectional view schematically showing the assembly of the drill adapter as shown in FIGS. 1 and 2 in a hammer drill, wherein the longitudinal section of FIG. 3 is oriented about the longitudinal center axis with respect to the longitudinal section of FIG. Rotate 90 degrees;

Figure 5 shows schematically that a drill bit adapter according to the present application is fitted with another drill bit;

FIG. 6 schematically shows a perspective view of a drill adapter in accordance with another embodiment of the present application.

Detailed ways

In the drawings of the present application, structurally identical or functionally similar features are denoted by the same reference numerals.

FIG. 1 schematically shows a longitudinal cross-sectional view of a drill adapter in accordance with one embodiment of the present application. The drill adapter includes a body 100. The body 100 includes a mounting end for mounting in a power tool and a receiving end for receiving a drill bit along a longitudinal direction. Two key grooves 110 that are diametrically opposite to each other are formed in the mounting end for contact with corresponding keys in the power tool to define a longitudinal position of the bit adapter in the power tool and/or to rotate the body 100 by the power tool . The keyway 110 is opened in the body 100 in the longitudinal direction to the exposed end face of the mounting end.

Two receiving blind holes 120, which are diametrically opposite to each other, are also formed in the mounting end portion of the body 100, wherein each of the receiving blind holes 120 may be disposed in the circumferential direction of the two key grooves 110 by 90 degrees. After the drill adapter is inserted into the power tool, the receiving blind hole 120 can receive the ball of the power tool, thereby also defining the longitudinal position of the drill adapter in the power tool.

A receiving cavity 150 is formed in the receiving end of the body 100 for receiving the drill bit 500. The longitudinal inner wall of the receiving cavity 150 is non-cylindrical so as to be complementary to the outer wall shape of the drill bit 500. For example, in FIG. 1, the inner wall of the receiving cavity 150 is hexagonal in shape to complement the shape of the hexagonal outer wall of the drill bit 500 such that upon insertion of the drill bit 500 into the receiving cavity 150, the body 100 is relied upon by such complementary shape. The drill bit 500 can be driven to rotate.

An outer sleeve 200 is slidably sleeved outside the receiving end of the body 100. A ring of protrusions 210 extends radially inwardly in the inner wall of the outer cover 200. The inner diameter of the ring protrusion 210 is equal to or slightly larger than the outer diameter of the receiving end of the body 100. Further, a ring flange 160 is formed on the body 100 for blocking the outer sleeve 200 from moving further along the axial direction of the body 100 toward the mounting end of the body 100. An inner wall section 220 is also formed in the inner wall of the outer sleeve 200 adjacent to the ring protrusion 210. The inner diameter of the inner wall section 220 is substantially larger than the outer diameter of the receiving end of the body 100 such that when the outer sleeve 200 is mounted around the receiving end of the body 100, a space is defined between the inner wall section 220 and the outer circumference of the body 100. . A coil spring 800 can be installed in this space. A stop ring 300 can also be mounted in this space. One end of the coil spring 800 abuts against the ring protrusion 210 and the other end abuts against the stop ring 300. In order to prevent the stop ring 300 from running out, the retaining ring 400 axially constraining the stop ring 300 is mounted in the annular groove 170 of the body 100.

As shown in FIG. 1, when the outer sleeve 200 is mounted in position about the body 100, the outer sleeve 200 can be moved away from the mounting end of the body 100 under the application of a pulling force by the operator, and after the tension is released, at the coil spring 800. Under the action, it can be automatically reset.

A radial bore 140 (Fig. 2) is formed adjacent the flange 160 in the body 100, for example, two radially opposed radial bores are in communication with the receiving pocket 150. A ball 133 is mounted in the radial bore 140. In order to prevent the balls 133 from falling into the receiving cavity 150, the radial holes 140 can be formed to be slightly reduced in inner diameter toward the receiving cavity 150, so that the balls 133 located in the radial holes 140 can only partially extend into the receiving Inside the cavity 150. In the state shown in FIG. 1, the protrusion 210 of the outer sleeve 200 can contact the ball 133 to prevent it from being radially withdrawn, so that the ball 133 is partially received in the positioning groove 520 of the drill bit 500, defining the drill bit 500 in the receiving cavity. Axial position within 150. When the drill bit 500 needs to be disassembled, the outer sleeve 200 is axially pulled away from the mounting end of the body 100 such that the projection 210 axially exits the ball 133 while the drill bit 500 is pulled outwardly so that the ball 133 can move radially toward the outer sleeve 200 and completely Retreat into the radial bore 140. In this way, the drill bit 500 can be easily pulled out of the receiving cavity 150.

The ball 133, the coil spring 800 and the stop ring 300 generally form a locking structure between the outer sleeve 200 and the body 100 that is capable of restraining the drill bit 500, and such a locking structure is pulled away from the mounting end of the body 100. The outer sleeve 200 is brought to release.

A ring stop flange 130 is formed on the outer circumference of the body 100 of the drill adapter adjacent to the flange 160. The axial distance of the stop flange 130 from the exposed end surface of the mounting end of the body 100 is such that when the body 100 is mounted and fixed in position in the power tool, the exposed end surface of the mounting end of the body 100 is not associated with the power tool Any component is in contact.

Further, the outer diameter of the body 100 of the stopper flange 130 near the side of the flange 160 in the axial direction is set to be slightly larger than the outer diameter of the body 100 near the side of the mounting flange on the side of the stopper flange 130.

The assembly of the drill adapter in accordance with the present application in a power tool is described below with reference to Figures 3 and 4. In the following description, the electric tool is explained by taking an electric hammer drill as an example. It will be apparent to those skilled in the art that the drill adapter of the present application can be applied to other suitable power tools.

As shown in Figures 3 and 4, the electric hammer drill includes a mounting shaft tube 610 inside its housing that is rotatable by a motor (not shown) mounted inside the housing of the electric hammer drill. In addition, a hammer drill 620 is disposed coaxially with the mounting shaft tube 610 inside the housing of the electric hammer drill, which can be axially reciprocated by the motor.

Drive keys 640 extend radially inwardly of the inner wall of the mounting shaft tube 610, such as two drive keys 640 that are diametrically opposed to each other. The positions of the two drive keys 640 are set corresponding to the two keyways 110 on the drill adapter, so that when the drill adapter is inserted into the mounting shaft tube 610, the two keyways 110 can receive two drive keys 640, respectively, so as to The rotary drill adapter that mounts the shaft tube 610 is also driven to rotate.

Near the exposed end face of the mounting shaft tube 610, the inner wall of the mounting shaft tube 610 is formed with a ramp that complements the ramp of the stop flange 130 of the bit adapter (as shown in Figure 2) toward the mounting end, thereby After the adapter is inserted into the mounting axle tube 610, the ramp of the stop flange 130 contacts the ramp of the inner wall of the mounting axle tube 610, causing the drill adapter to be spaced a safe distance from the hammer drill 620. Due to the safety distance of the section, even if the operator mistakenly operates to start the hammer drill 620, the hammer drill 620 will never touch the drill adapter installed in place.

As shown in FIG. 4, a slope surface 641 is formed on the outward side of the drive key 640, which is complementary to the shape of the slope surface 111 of the key groove 110 (as shown in FIG. 2) so as to be in contact with the two slope surfaces. It is also possible to ensure that the drill adapter is separated from the hammer drill 620 by a safe distance.

Further, in the mounting shaft tube 610 of the electric hammer drill, a ball 630 capable of projecting toward the inner radial portion of the mounting shaft tube 610 is also mounted. Thus, when the bit adapter is inserted into the mounting shaft tube 610, the ball 630 first retracts radially outwardly, and then when the receiving blind hole 120 of the bit adapter reaches the position where the ball 630 is located, the ball 630 projects radially inwardly and receives Within the receiving blind hole 120 to limit the bit adapter, it is ensured that the bit adapter is separated from the hammer drill 620 by a safe distance. In the embodiment of the present application, the receiving blind hole 120 is formed in a partially spherical manner, which reduces the processing difficulty of receiving the blind hole and also avoids the possibility of axial sway when the ball 630 is restrained.

Prior to inserting the drill adapter into the mounting shaft tube 610 of the electric hammer drill, the mounting end of the drill adapter first passes through the central bore of the dust cap 700. The inner diameter of the center hole of the dust cap 700 is set to be slightly smaller than the outer diameter of the body 100 near the side of the mounting end on the side of the stopper flange 130. The dust cap 700 passes over the stop flange 130 until it contacts the flange 160 of the drill adapter. Since the outer diameter of the body of the stopper flange 130 near the side of the flange 160 is set to be slightly larger than the outer diameter of the body 100 of the stopper flange 130 near the side of the mounting end, The interference fit between the portion of the body 100 in the axial direction of the stop flange 130 near the side of the flange 160 and the center hole of the dust cap 700 in the axial direction of the dust cap 700 further ensures the sealability of the drill adapter. Then, the drill adapter carries the dust cap 700 with its mounting end inserted into the mounting shaft tube 610.

The stop flange 130 forms a first limiting structure for axially limiting the drill adapter between the first limiting feature and the mounting shaft tube 610, and the slope 111 of the keyway 110 serves as a second limiting feature and a driving key. A second limit structure for axially limiting the drill adapter is formed between the slopes 641 of the 640, and the ball adapter 630 and the receiving blind hole 120 are used as the third limit feature to form an axial limit on the drill adapter. The third limit structure.

In accordance with a preferred embodiment of the present application, the body 100 of the drill adapter is configured such that the first, second, and third limit structures function independently of each other after the bit adapter is inserted into place within the mounting shaft tube 610. For example, when the bit adapter is inserted into position within the mounting shaft tube 610, only the first stop structure functions, i.e., only the ramp of the stop flange 130 contacts the ramp of the mounting shaft tube 610, while the slope of the keyway 110 The face 111 is spaced from the ramp 641 of the drive key 640 and the ball 630 is not fully centered in the receiving blind hole 120. When the drill adapter is worn due to long-term disassembly and assembly, the slope 111 of the keyway 110 and/or the slope 641 of the drive key 640 is worn, so that the drill adapter is further moved forward in the mounting shaft 610, the keyway 110 is The slope 111 is in contact with the slope 641 of the drive key 640, that is, the second limit structure is active at this time, but the third limit structure still has no effect. Only when the slope 111 of the keyway 110 and/or the slope 641 of the drive key 640 wears, so that the drill adapter is further moved forward into position within the mounting shaft tube 610, the third limit structure acts, ie, the ball The 630 is completely centered in the receiving blind hole 120.

According to the present application, because of the design of the limit features that act sequentially on the drill adapter, the drill adapter does not remain with the hammer drill 620 of the electric hammer drill even if it is repeatedly disassembled under severe working conditions. The safety distance increases the safety and reliability of the drill adapter.

Because of this compact design of the drill adapter of the present application, the distance between the two axial end faces of the body 100 of the drill adapter shown in Figure 1 can be only 45 millimeters.

Fig. 5 schematically shows the same drill adapter as Fig. 1 according to the present application, but with another drill bit 510 installed therein. The receiving cavity 150 of the body 100 of the drill adapter is configured to be capable of receiving drill bits of different sizes. As shown, although the drill bit 510 has a significantly longer mounting handle than the drill bit 500, the mounting handle of the drill bit 510 can also be inserted into the receiving pocket 150 of the same drill adapter and retained by the balls 133.

FIG. 6 schematically shows a perspective view of a drill adapter in accordance with another embodiment of the present application. The drill adapter differs from that shown in Figure 2 in that its receiving end extends further outwardly and the outer surface 105 has a shape such as a square (as shown) or a hexagon so that the drill adapter itself can also be used as A tool to screw the nut.

Moreover, as shown in FIG. 2, in an alternative embodiment of the present application, the outer sleeve 200 is designed to be non-rotatable relative to the body 100. For example, this can ensure that the outer sleeve 200 cannot be rotated relative to the body 100 by machining a flat section 100a in the outer wall of the body 100 and forming a flat section 210a in the inner wall of the protrusion 210 such that they are in contact with each other. Thus, when inserting the drill adapter into the mounting sleeve 610 of the electric hammer drill, the operator can conveniently grasp the rotation of the outer sleeve 200 such that the keyway 110 is aligned with the drive key 640.

In the illustrated embodiment, the stop flange 130 is continuously formed on the outer circumference of the body 100. However, in an alternative embodiment, the stop flange 130 may also be formed discontinuously on the outer circumference of the body 100. In addition, although the first limiting structure is realized by the surface contact between the stop flange 130 and the mounting shaft tube 610, in an alternative embodiment, the first surface can also be implemented by step contact. Limit structure.

As shown in FIG. 2, in an alternative embodiment, a flat section 100b is formed in the body 100 adjacent the annular groove 170, for example, it may be coplanar with the flat section 100a to facilitate disassembly and assembly of the retaining ring 400.

Although the specific embodiments of the present application are described in detail herein, they are given for the purpose of explanation and are not intended to limit the scope of the application. Various alternatives, modifications, and adaptations are conceivable without departing from the spirit and scope of the application.

Claims

A drill adapter for a power tool, comprising:

a body (100) having a mounting end for insertion into a power tool and a receiving end for detachably receiving a drill bit (500, 510), wherein the body (100) is provided with a restriction The first, second, and third limit features of the depth of the drill adapter inserted into the power tool, the first, second, and third limits when the drill adapter is positioned within the power tool The features function in sequence, the first stop feature being defined by a flange (130) projecting from the periphery of the body (100), the second stop feature being in the periphery of the body (100) a formed keyway (110) that opens axially to an end face of the mounting end, and the third limit feature is adjacent to the mounting end and the keyway by an outer circumference of the body (100) 110) circumferentially spaced apart receiving blind holes (120) defined.
The bit adapter of claim 1 wherein said flange (130) has a locating surface toward said mounting end to define said first stop feature and contact said power tool.
The drill adapter of claim 2 wherein said locating surface is a ramp or stepped surface.
A drill adapter according to claim 2 or 3, wherein the keyway (110) has a locating surface facing the mounting end to define the second stop feature and contact the power tool.
The drill adapter of claim 4 wherein said locating surface is a slope or stepped surface.
A drill adapter according to claim 2 or 3, wherein the receiving blind bore (120) has a partially spherical recess to define the third stop feature.
A drill adapter according to claim 2 or 3, wherein an outer diameter of a portion of the body (100) with respect to the flange (130) on a side facing the receiving end is slightly larger than the outer diameter The outer diameter of the body (100) with respect to the flange (130) is located at a portion facing the mounting end side.
The drill adapter of claim 7, wherein the drill adapter further comprises an outer sleeve (200), the outer sleeve (200) being capable of pivoting around the body (100) at the receiving end Slidably mounted, a locking structure is provided between the outer sleeve (200) and the receiving end to axially limit the drill bit (500, 510) received in the receiving end, wherein The locking structure has a structure that does not axially limit the drill bit (500, 510) as the outer sleeve (200) moves away from the mounting end.
The drill adapter of claim 8 wherein said outer sleeve (200) is non-rotatable relative to said body (100).
The drill adapter according to claim 9, wherein the outer wall of the receiving end has a flat section, and the inner wall of the outer sleeve (200) has a flat section, and the two flat sections are mutually contact.
The drill adapter of claim 8 wherein said receiving end includes a receiving pocket (150), said locking structure including a ball (13) that is partially extendable into said receiving pocket (150) The ball (133) is movable radially away from the receiving cavity (150) as the outer sleeve (200) moves away from the mounting end.
A drill adapter according to claim 2 or 3, wherein the receiving end has an axial extension, the outer surface of the axial extension having a shape that can be mated with other parts.
A power tool comprising a rotatable mounting shaft tube (610), characterized in that a drill adapter according to any one of claims 1 to 12 is mounted within the mounting shaft tube (610).
The power tool according to claim 13, wherein said power tool is an electric hammer drill, and further comprising a hammer drill ram (620), the drill adapter installed in said electric hammer drill is always said The hammer drill ram (620) maintains a safe distance.