CN113442097A

CN113442097A - Working head and swing power tool

Info

Publication number: CN113442097A
Application number: CN202010226379.3A
Authority: CN
Inventors: 钱富; 鲁义刚; 张士松
Original assignee: Positec Power Tools Suzhou Co Ltd
Current assignee: Positec Power Tools Suzhou Co Ltd
Priority date: 2020-03-27
Filing date: 2020-03-27
Publication date: 2021-09-28
Anticipated expiration: 2040-03-27
Also published as: CN113442097B

Abstract

The invention relates to a working head, which can be mounted on an output shaft of a swing power tool, comprising: a working part; the mounting part is connected with one end of the working part, a first surface and a second surface which are arranged oppositely back to back are formed on two sides of the mounting part, the first surface is used for facing the output shaft, and the first surface is provided with a central hole with a central axis and a gap for communicating the central hole with an external space; the connecting piece is fixed on the second surface of the mounting part, a through hole is formed in the connecting piece, the edge of the connecting piece extends and is communicated with the opening of the through hole, the through hole corresponds to the central hole, and the opening corresponds to the notch. According to the working head, the connecting sheet is arranged on the second surface of the mounting part, so that the strength of the mounting part is increased, the working head can be prevented from slipping during working, and the working efficiency is improved.

Description

Working head and swing power tool

Technical Field

The invention relates to the field of power tools, in particular to a working head which is adapted to an output shaft of a swing power tool, and also relates to the swing power tool with the working head.

Background

The swing power tool generally includes a housing, a motor housed in the housing, an output shaft for mounting a working head, and an eccentric transmission mechanism connected between a motor shaft of the motor and the output shaft, the eccentric transmission mechanism converting a rotational motion of the motor shaft into a swing motion of the output shaft about its own axis. Therefore, after the free end of the output shaft is connected with different working heads, such as a straight saw blade, a circular saw blade, a triangular sanding disc and the like, the power tool can be swung to realize various operations, such as sawing, cutting, sanding, scraping and the like, so as to meet different working requirements.

The working head adapted to the output shaft of a swing power tool generally comprises a mounting portion, as disclosed in chinese patent application CN105234903A, which is provided with a central hole and a U-shaped opening communicating with the central hole. After the working head is matched and connected with the driving part of the output shaft, two opposite side edges of the U-shaped opening are matched with the driving part to transmit torque, and a fixing piece penetrates through the central hole and is fixed with the output shaft, so that the working head is locked on the output shaft, and the output shaft can reliably transmit the torque to the working head.

The inventor discovers that in the process of implementing the technical scheme: the working head of the type is easy to elastically deform in the working process, so that a gap is formed between the mounting part and the driving part of the output shaft, the working head slips when working, and the noise is increased along with the slipping.

Disclosure of Invention

In view of the above, it is desirable to provide a work head that avoids slippage during operation.

A working head mountable to an output shaft of a swing power tool, comprising:

a working part;

the mounting part is connected with one end of the working part, a first surface and a second surface which are arranged oppositely back to back are formed on two sides of the mounting part, the first surface is used for facing the output shaft, and the first surface is provided with a central hole with a central axis and a gap for communicating the central hole with an external space;

the connecting piece is fixed on the second surface of the mounting part, a through hole is formed in the connecting piece, the edge of the connecting piece extends and is communicated with the opening of the through hole, the through hole corresponds to the central hole, and the opening corresponds to the notch.

According to the working head, the connecting sheet is arranged on the second surface of the mounting part, so that the strength of the mounting part is increased, the working head can be prevented from slipping during working, and the working efficiency is improved.

In one embodiment, the connecting piece is welded to the second surface.

In one embodiment, the connecting piece and the mounting portion are integrally formed.

In one embodiment, the connecting piece has a thickness of 1mm-2 mm.

In one embodiment, the outer contour of the projection area of the first surface on the second surface falls within the outer contour of the shadow area of the connecting piece on the second surface.

In one embodiment, the mounting portion includes a bottom plate and a side wall, the bottom plate is spaced apart from the first surface, the side wall connects the bottom plate and the first surface, and a surface of the bottom plate facing away from the side wall forms the second surface.

In one embodiment, the inner wall of the central hole is provided with a plurality of internal fitting holes, the internal fitting holes include a plurality of first internal fitting holes and a plurality of second internal fitting holes distributed around the central axis, the first internal fitting holes and the second internal fitting holes have different concave depths, the first surface is further provided with a plurality of positioning holes distributed around the central axis on the periphery of the central hole, and the side wall is provided with a plurality of openings distributed around the central axis.

In one embodiment, the mounting portion includes a bottom plate, and two side surfaces of the bottom plate respectively form the first surface and the second surface, wherein the notch extends from an outer edge of the bottom plate toward the central hole and is communicated with the central hole.

In one embodiment, the working portion is fixedly attached to the second surface.

An oscillating power tool is also provided having a working head as described in any of the previous embodiments. When the tool is concretely implemented, the working head is connected to an output shaft of the swing power tool and is fastened through the fixing piece. Because the connecting sheet is arranged on the second surface of the mounting part of the working head, the strength of the mounting part can be increased, the working head can be prevented from slipping during working, and the working efficiency is improved.

Drawings

Fig. 1 is a schematic view of an oscillating power tool according to an embodiment of the present invention.

FIG. 2 is a schematic partial cross-sectional view of the oscillating power tool of FIG. 1 taken along line A-A.

Fig. 3 is a perspective view of an embodiment of the working head of the present invention.

FIG. 4 is a perspective view of another angle of the working head of the present invention.

FIG. 5 is a perspective view of another embodiment of the working head of the present invention.

The relevant elements in the figures are numbered correspondingly as follows:

100. a swing power tool; 10. a housing; 110. a first bearing; 120. a second bearing; 20. an output shaft; 30. a motor shaft; 40. an eccentric wheel; 50. a shifting fork; 510. an extension arm; 60. a working head; 610. a working part; 620. an installation part; 621. a first surface; 622. a second surface; 623. a central bore; 6231. a first internal mating bore; 6232. a second internal mating bore; 6233. positioning holes; 6234. opening a hole; 624. a notch; 6241. a side edge; 625. connecting sheets; 6251. a through hole; 6252. an opening; 626. an outer edge; 601. a base plate; 602. a side wall; 70. a fixing member; 710. a bolt; 720. and (7) pressing a plate.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

The preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

Referring to fig. 1, fig. 1 is a schematic cross-sectional view illustrating an oscillating power tool 100 according to an embodiment of the present invention, which includes a housing 10, an output shaft 20 extending in the housing 10, a motor shaft 30 disposed in the housing 10, an eccentric 40 connected to the motor shaft 30, and a fork 50 engaged with the eccentric 40. The free end of the output shaft 20 extends out of the housing 10 and is connected with a working head 60. The working head 60 is fixed to the output shaft 20 by a fixing member 70. In the embodiment of the present invention, the working head 60 is a straight saw blade. It will be readily apparent to those skilled in the art that the working head 60 may also be other accessories such as a circular saw blade, a triangular sanding disc, a scraper blade, etc. In the present embodiment, the swing power tool 100 is embodied as a hand-held tool. A battery pack may be coupled to the housing 10 to provide power to the motor.

The housing 10 has a downwardly facing work port so that the output shaft 20 can extend out of the housing 10 to connect with the work head 60. The housing 10 is provided with an upper bearing chamber and a lower bearing chamber, which are respectively provided with a first bearing 110 and a second bearing 120 for supporting the output shaft 20 together, so that the output shaft 20 is stably and reliably supported, and the swing power tool 100 is ensured to stably work. The output shaft 20 is a hollow shaft having a threaded structure therein and is adapted to mate with a fastener 70 inserted into the interior of the output shaft 20.

Referring to fig. 1 and 2, one end of the shift fork 50 is fixedly connected to the output shaft 20, and the connection point is located between the first bearing 110 and the second bearing 120 on the output shaft 20. Referring to fig. 2, the other end of the fork 50 is provided with a pair of extension arms 510 covering the outer circumference of the eccentric wheel 40. Here, torque is transmitted between the output shaft 20 and the motor shaft 30 through the eccentric 40, the fork 50, and the like to convert the rotation of the motor shaft 30 about its own axis into the swing motion of the output shaft 20, and the eccentric transmission mechanism is a common structure applied to swing power tools in the industry and will not be described in detail herein.

In this embodiment, when the swing power tool 100 is in operation, the output shaft 20 can perform a reciprocating swing motion around its own axis X at a high frequency of about 5000 to 30000 times per minute while maintaining a small swing angle of about 0.5 to 7 degrees.

Referring to fig. 3, fig. 3 is a perspective view of a working head 60 of an embodiment of an oscillating power tool 100 of the present invention. The working head 60 is a straight saw blade, and includes a working portion 610 and a mounting portion 620, wherein the mounting portion 620 is connected to an end portion of the working portion 610, and the mounting portion 620 is used for connecting to the output shaft 20 to transmit torque. The end of the working portion 610 away from the mounting portion 620 is provided with a saw-tooth structure.

As shown in fig. 3, the mounting portion 620 is formed with a first surface 621 and a second surface 622 oppositely arranged at both sides, the first surface 621 faces the output shaft 20 when being connected to the output shaft 20, and the first surface 621 is provided with a center hole 623 having a center axis Y, and a notch 624 communicating the center hole 623 with an external space. The notch 624 is particularly U-shaped. The notches 624 may mate with projections (not shown) on the output shaft 20 to transmit torque. Specifically, the notch 624 has two opposite sides 6241, and the included angle formed by the two sides 6241 is 60 degrees, so that when the mounting portion 620 is engaged with the output shaft 20, the sides 6241 can be engaged with the driving portion of the output shaft 20 to transmit the torque. Obviously, the included angle of the notch 624 may be set at an angle other than 60 degrees.

A central bore 623 is provided for the fastener 70 to pass therethrough. Referring to fig. 1, the fixing member 70 passes through the central hole 623 and extends into the output shaft 20, thereby fixing the working head 60 to the end of the output shaft 20. Specifically, the fixing member 70 includes a bolt 710 and a pressing plate 720 connected to the bolt 710, wherein the pressing plate 720 has a certain elasticity and is fixedly connected to the bolt 710, and the bolt 710 is tightly connected to the thread structure inside the output shaft 20. After the fixing member 70 is tightened, the pressing plate 720 elastically abuts against one side of the working head 60, so that the working head 60 can be prevented from being separated due to reciprocating or even impact load.

In this embodiment, the mounting portion 620 includes a bottom plate 601 and a side wall 602, the bottom plate 601 is spaced apart from the first surface 621, the side wall 602 connects the bottom plate 601 and the first surface 621, and a surface of the bottom plate 601 opposite to the side wall 602 forms the second surface 622. Specifically, the sidewall 602 extends upward from the edge of the bottom plate 601, and the first surface 621 is disposed at the top end of the sidewall 602.

The inner wall of the center hole 623 is provided with an inner matching hole, the inner matching hole comprises a plurality of first inner matching holes 6231 and a plurality of second inner matching holes 6232 distributed around the central axis Y, wherein the recess depths of the first inner matching holes 6231 and the second inner matching holes 6232 are different, the periphery of the center hole 623 on the first surface 621 is further provided with a plurality of positioning holes 6233 distributed around the central axis Y, and the side wall 602 is provided with a plurality of open holes 6234 distributed around the central axis. The apertures 6234 may also be used to mate with corresponding structures on the output shaft 20. Thus, the mounting portion 620 can be engaged with different types of output shafts 20, and in particular, different positioning structures are provided on different types of output shafts 20, so as to be engaged with different internal engaging holes or positioning holes or openings. The first internal fitting hole 6231, the second internal fitting hole 6232 and the positioning hole 6233 are all distributed on a circumference centered on the center of the center hole 623 and are uniformly arranged, although they are all provided except the notch 624. Thus, the mounting portion 620 can be coupled to the output shaft 20 at a plurality of rotation angles.

In the art, the working head with the U-shaped notch is easily elastically deformed during operation, so that a gap is formed between the mounting portion 620 and the driving portion of the output shaft 20, which causes the working head 60 to slip during operation, and the noise is increased accordingly. In view of the above problems, the inventors have conducted intensive studies, and after careful analysis, the inventors have found that the above phenomenon occurs mainly because when the working head 60 is working, the central axis Y of the central hole 623 coincides with the axis X of the output shaft 20, and the U-shaped notch 624 is disposed on the outer edge of the mating surface opposite to the working portion 610 for transmitting the torque of the output shaft 20, so that the working portion 610 is far from the mating position of the U-shaped notch 624 and the output shaft 20, resulting in a long moment arm, and thus causing insufficient rigidity of the mounting portion 620, and further causing elastic deformation, slipping, and the like of the working head 60.

On the basis of the above research findings, the present embodiment improves the working head 60 against the above problems. As shown in fig. 3 and 4, the working head 60 of the present embodiment further includes a connection piece 625 fixed to the second surface 622 of the mounting portion 620. The connecting piece 625 is provided with a through hole 6251 and an opening 6252 extending from the edge of the connecting piece 625 and communicated with the through hole 6251, wherein the position of the through hole 6251 corresponds to the position of the central hole 623, and the position of the opening 6252 corresponds to the position of the notch 624. That is, an attachment tab 625 is added to the second surface 622, the attachment tab 625 being configured with features corresponding in shape and location to the central aperture 623 and the notch 624. Through setting up connection piece 625, the intensity of installation department 620 can increase, can prevent that work head 60 from appearing skidding at the during operation, improves work efficiency.

The connection piece 625 is provided in an unlimited manner. In this embodiment, the connecting tab 625 is welded to the second surface 622. In this case, the material of the connection piece 625 is not limited. Preferably, the connecting piece 625 is made of the same material as the mounting portion 620. The tab 625 is welded to the second surface 622 so that the tab 625 may also be removed for easy replacement. In addition, after the connecting piece 625 is removed, the working head 60 can still be used with the output shaft 20 to be used under normal working conditions. In another embodiment, the connecting piece 625 may be integrally formed with the mounting portion 620. The material of the connecting piece 625 is not limited.

In some embodiments, the connecting tab 625 has a thickness of 1mm to 2 mm. The connecting piece 625 with the thickness within the range is small in thickness, so that the fastening fit of the fixing piece 70 and the output shaft 20 is not affected while the strength of the mounting portion 620 is increased. I.e. without the need for a large adjustment of the fastening connection between the fixing member 70 and the output shaft 20 due to the provision of the connecting piece 625.

The shape and area of the connecting piece 625 itself are not limited, and the purpose of increasing the strength may be achieved. In some embodiments, the outer contour of the projected area of the first surface 621 on the second surface 622 falls within the outer contour of the shadow area of the connecting piece 625 on the second surface 622. In other words, the area of the pattern surrounded by the outer contour of the connecting plate 625 is larger than the area of the pattern surrounded by the outer contour of the first surface 621. In this way, the connecting piece 625 can cover a larger area of the second surface 622, effectively increasing the strength of the mounting portion 620. The shape of the outer contour of the connecting piece 625 is not limited in any way.

It is to be understood that the inner diameter of the through hole 6251 of the connecting piece 625 should be set to be not smaller than the inner diameter of the center hole 623. Specifically, in some embodiments, the inner wall of the through hole 6251 of the attachment piece 625 and the inner wall of the center hole 623 are just connected together in the direction in which the attachment piece 625 is laminated with the mounting portion 620, i.e., in the direction along the center axis Y.

In another embodiment, the inner wall of the through hole 6251 of the connecting piece 625 is offset from the inner wall of the central hole 623, wherein the inner wall of the through hole 6251 is further away from the central axis Y than the inner wall of the central hole 623 in a direction perpendicular to the central axis Y. In this case, in the present embodiment, the through hole 6251 should be broadly understood, and in fig. 4, the through hole 6251 is a circular hole, but the through hole 6251 is not limited to a circular hole, and may be a square hole or the like. That is, the shape of the inner contour of the through hole 6251 is not limited.

As shown in fig. 3 and 4, the working portion 610 is fixedly attached to the second surface 622. In one embodiment, the working portion 610 can be welded to the second surface 622, and the end surface of the working portion 610 is spaced apart from the connecting tab 625. In this embodiment, the connection plate 625 may be disposed after the installation portion 620 and the working portion 610 are prepared, so that the end surface of the working portion 610 is spaced from the connection plate 625, a welding space is reserved, and the connection plate 625 can be conveniently fixed by welding.

Referring to fig. 5, fig. 5 is a schematic structural view of another embodiment of the tool head 60 of the oscillating power tool 100 of the present invention.

The working head 60 includes a working portion 610 and a mounting portion 620, wherein the mounting portion 620 is connected to an end portion of the working portion 610, and the mounting portion 620 is used for connecting to the output shaft 20 to transmit torque. The mounting part 620 includes a base plate 601, and both side surfaces of the base plate 601 form the first surface 621 and the second surface 622, respectively. Wherein the first surface 621 is provided with a central hole 623 having a central axis Y and an outer edge 626, the outer edge 626 being provided with a U-shaped notch 624 extending towards said central hole 623 and communicating with said central hole 623. The notch 624 has two opposite sides 6241, and the included angle formed by the two sides 6241 is 60 degrees, so that when the mounting portion 620 is matched with the output shaft 20, the sides 6241 can be matched with the driving portion of the output shaft 20 to transmit torque.

The inner wall of the central hole 623 is provided with an internal fitting hole, the internal fitting hole comprises a plurality of first internal fitting holes 6231 and a plurality of second internal fitting holes 6232 distributed around the central axis Y, wherein the recessed depths of the first internal fitting holes 6231 and the second internal fitting holes 6232 are different, and the first surface 621 is further provided with a plurality of positioning holes 6233 distributed around the central axis Y on the periphery of the central hole 623. In this way, the mounting portion 620 can be mated with different types of output shafts 20. The first internal fitting hole 6231, the second internal fitting hole 6232 and the positioning hole 6233 are all distributed on a circumference centered on the center of the center hole 623 and are uniformly arranged, of course, except for the notch 624. Thus, the mounting portion 620 can be coupled to the output shaft 20 at a plurality of rotation angles.

In this embodiment, the second surface 622 of the working head 60 may also have a connecting plate 625 as illustrated in fig. 2 and 3. The connecting plate 625 is welded to the second surface 622 or is fixedly formed integrally with the base plate 601. Through setting up connection piece 625, the intensity of installation department 620 can increase, can prevent that work head 60 from appearing skidding at the during operation, improves work efficiency.

As shown in fig. 1, another embodiment of the present invention further provides an oscillating power tool 100 having the working head 60 of the previous embodiment. The working head 60 may be the working head shown in fig. 2 and 3, or the working head 60 shown in fig. 4. By providing the connecting piece 625 on the second surface 622 of the mounting portion 620, the strength of the mounting portion 620 is increased, so that the working head 60 can be prevented from slipping during operation, and the working efficiency is improved.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A working head mountable to an output shaft of a swing power tool, comprising:

a working part;

2. The work head of claim 1 wherein the connecting tab is welded to the second surface.

3. The work head of claim 1 wherein the connecting tab is integrally formed with the mounting portion.

4. A working head according to claim 2 or 3, wherein the thickness of the connection piece is 1mm-2 mm.

5. A work head according to claim 1, wherein the outer contour of the projected area of the first surface on the second surface falls within the outer contour of the shadow area of the connecting piece on the second surface.

6. The work head of claim 1 wherein the mounting section comprises a bottom plate and a side wall, the bottom plate being spaced from the first surface, the side wall connecting the bottom plate to the first surface, the surface of the bottom plate facing away from the side wall forming the second surface.

7. The working head of claim 6 wherein the inner wall of the central bore defines an internal mating bore, the internal mating bore including a first plurality of internal mating bores and a second plurality of internal mating bores distributed around the central axis, wherein the first and second internal mating bores have different recess depths, the first surface further defines a plurality of positioning holes distributed around the central axis on the periphery of the central bore, and the sidewall defines a plurality of openings distributed around the central axis.

8. The work head of claim 1 wherein the mounting portion comprises a base plate having side surfaces defining the first and second surfaces, respectively, wherein the notch extends from an outer edge of the base plate toward and communicates with the central bore.

9. The work head of claim 1 wherein the working portion is fixedly attached to the second surface.

10. An oscillating power tool, characterized by a working head according to any of claims 1-9.