CN215548423U - Hand-held machine tool and system thereof - Google Patents

Abstract

The utility model relates to a hand-held power tool, comprising: a housing having a handle portion for gripping by a user; a motor having a motor shaft; the output shaft is driven by the motor shaft and is used for being connected with the working head in a matching mode; wherein the rated power of the motor is between 60W-200W, and the ratio of the rated power of the motor to the diameter of the handle part is between 1.6W/mm-7.2W/mm. Compared with the prior art, the handheld machine tool disclosed by the utility model has the advantages that a design more conforming to human engineering is obtained under the condition of ensuring certain working capacity, and the holding experience of a user is improved. The utility model also relates to a hand-held power tool system.

Description

Hand-held machine tool and system thereof

Technical Field

The utility model relates to a hand-held power tool.

The utility model also relates to a system comprising the hand-held power tool.

Background

The conventional hand-held power tools generally use a brush motor as a power element. The power of the electric machine is positively correlated with its structural dimensions, in particular the radial dimensions. The energy density of the brush motor is low, the structural size of the motor is large on the premise of ensuring certain working capacity, the integral structural size of the handheld machine tool is further large, and the holding burden of a user is increased. Such as existing 20V straight grinding tools, the diameter of the brush motor is up to 38mm, so that the diameter of the handle portion for the user to hold is up to 52 mm. In addition, the conventional hand-held power tool generally incorporates a power supply device or is detachably connected to the power supply device, and the user needs to bear the weight of the power supply device when performing work with the hand-held power tool.

SUMMERY OF THE UTILITY MODEL

In order to overcome the above-mentioned drawbacks of the prior art, the present invention is directed to a hand-held power tool that has the advantages of being more ergonomic and user-friendly while ensuring a certain working capacity.

The technical scheme of the utility model is as follows: a hand-held power tool, comprising: a housing including a handle portion for gripping by a user; a motor housed in the housing and having a motor shaft; the output shaft is driven by the motor shaft and is used for being connected with the working head in a matching mode; the rated power of the motor is between 60W and 200W, and the ratio of the rated power of the motor to the diameter of the handle part is between 1.6W/mm and 7.2W/mm.

In one embodiment, the motor is an outer rotor brushless motor, and the diameter of the brushless motor is 18mm-25 mm.

In one embodiment, the handle portion has a center line, and the length of the hand-held power tool in the direction of the center line is between 160mm and 200 mm.

In one embodiment, the hand-held power tool further comprises an interface for connecting an external dc power source via a cable.

In one embodiment, the operating speed of the output shaft is between 5000rpm and 35000 rpm.

In one embodiment, the hand-held power tool is designed as a straight grinder; the housing includes a first cylindrical portion that houses the output shaft and a second cylindrical portion that forms the handle portion; the minimum outer diameter of the first cylinder part is between 19mm and 27 mm; the maximum outer diameter of the second cylinder part is between 28mm and 37 mm.

In one embodiment, the housing extends in a lengthwise direction, having a first end and a second end; at least part of the output shaft extends out of the first end to be matched and connected with the working head; a center of gravity of the hand-held power tool is disposed proximate the first end and between 1/4 a length of the hand-held power tool and 1/2 a length of the hand-held power tool.

In one embodiment, the hand-held power tool is designed as an angle grinder, the housing further comprising a head housing arranged at an angle to the handle portion, the head housing accommodating the motor.

Compared with the prior art, the handheld machine tool adopts the outer rotor brushless motor as a driving source, the power of the motor is between 60W and 200W, and the working capacity is strong; and the ratio of the rated power to the diameter of the handle portion is set within a reasonable range, thereby achieving a more ergonomic design that is easier for the user to hold.

The other technical scheme of the utility model is as follows: a hand-held power tool, comprising: a housing including a handle portion for gripping by a user; a motor housed in the housing and having a motor shaft; the output shaft is driven by the motor shaft and is used for being connected with the working head in a matching mode; the interface is used for being connected with an external direct current power supply through a cable; the rated power of the motor is between 60W and 200W, and the ratio of the rated power of the motor to the weight of the hand-held power tool is between 0.29W/g and 1.6W/g.

Compared with the prior art, the handheld machine tool adopts the outer rotor brushless motor as a driving source, the power of the motor is between 60W and 200W, and the working capacity is strong; and the power supply device is arranged externally, and the ratio of rated power to the weight of the whole machine is set within a reasonable range, so that the design which is small in holding burden of a user and more in line with human engineering is obtained.

In order to solve the above technical problem, the present invention provides a hand-held power tool system, including: a hand-held power tool; an adapter including a mounting part for connecting an external DC power supply; the adapter is connected to the hand-held power tool via a cable and transmits the electric power of the external dc power supply to the hand-held power tool.

In one embodiment, an operating unit is provided on the adapter, and the operating unit is used for adjusting the operating speed of the motor.

In one embodiment, the external dc power source is a battery pack for electric power tools, and the rated voltage of the battery pack is 20V.

Compared with the prior art, the handheld machine tool system reduces the holding burden of a user by the technical means of externally arranging the power supply device; an outer rotor brushless motor is adopted as a driving source of the handheld machine tool, the power of the motor is between 60W and 200W, and the working capacity is strong; furthermore, the ratio of the rated power of the motor to the diameter of the handle part is set within a reasonable range, so that the motor is more convenient for a user to hold and is highly user-friendly.

Specific embodiments of the present invention are disclosed in detail with reference to the following description and drawings, indicating the manner in which the principles of the utility model may be employed. It should be understood that the embodiments of the utility model are not so limited in scope. The embodiments of the utility model include many variations, modifications and equivalents within the spirit and scope of the appended claims. Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments, in combination with or instead of the features of the other embodiments.

Drawings

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. In addition, the shapes, the proportional sizes, and the like of the respective members in the drawings are merely schematic for facilitating the understanding of the present invention, and do not specifically limit the shapes, the proportional sizes, and the like of the respective members of the present invention. Those skilled in the art, having the benefit of the teachings of this invention, may choose from the various possible shapes and proportional sizes to implement the utility model as a matter of case.

Fig. 1 is a schematic illustration of a hand-held power tool system according to a first embodiment of the utility model;

fig. 2 is a sectional view of the hand-held power tool system of fig. 1, in relation to the hand-held power tool;

fig. 3 is a schematic illustration of the hand-held power tool shown in fig. 2, with reference to the locking unit;

FIG. 4 is a schematic illustration of the hand-held power tool of FIG. 2, with the locking element in place;

fig. 5 is a dimensional schematic of the hand-held power tool shown in fig. 2;

fig. 6 is an exploded view of the hand-held power tool shown in fig. 2, with components inside the housing omitted;

fig. 7 is a schematic illustration of a hand-held power tool system according to a second embodiment of the utility model;

FIG. 8 is a partial cross-sectional view of the hand-held power tool system of FIG. 7, illustrating the flow of cooling air;

fig. 9 is a schematic illustration of the hand-held power tool system of fig. 7, in relation to the hand-held power tool;

fig. 10 is a dimensional schematic of the hand-held power tool of fig. 9;

fig. 11 is an exploded view of the hand-held power tool shown in fig. 9, with components inside the housing omitted;

fig. 12 is a sectional view of the hand-held power tool shown in fig. 2, with the spindle lock engaged;

fig. 13 is a sectional view showing positioning of the outer rotor brushless motor according to the first and second embodiments of the present invention.

Reference numerals of the above figures:

10. a housing; 12. a stator; 13. a metal sleeve; 14. details; 15. the mouth of the tiger; 16. an adapter; 17. a switching element; 18. a speed regulating button; 19. a plastic coupling; 21. a rotor; 23. a motor shaft; 24. a fan insert; 25. an output shaft; 27. a fan; 26. fastening screws; 29. a connecting portion; 31. a first groove; 33. a locking sleeve; 35. a first protrusion; 37. a locking member; 39. a working head; 41. a head housing portion; 43. a handle portion; 47. a cable; 49. a battery pack; 51. a shield; 53. an air outlet; 55. an air inlet; 57. an operating button; 59. an annular spring; 61. a third groove; 63. a locking pin; 65. a first inclined plane; 67. a second inclined plane; 69. a third inclined plane; 71. a fourth slope; 73. cutting a groove; 75. a first half portion; 77. a second half; 79. a first section; 81. a second section; 83. pressing a plate; 85. a clamping groove; 87. and clamping the protrusion.

Detailed Description

The details of the present invention can be more clearly understood in conjunction with the accompanying drawings and the description of the embodiments of the present invention. However, the specific embodiments of the present invention described herein are for the purpose of illustration only and are not to be construed as limiting the utility model in any way. Any possible variations based on the present invention may be conceived by the skilled person in the light of the teachings of the present invention, and these should be considered to fall within the scope of the present invention. It will be understood that when an element is referred to as being "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 "mounted," "connected," and "connected" are to be construed broadly and may include, for example, mechanical or electrical connections, communications between two elements, direct connections, indirect connections through intermediaries, and the like. 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.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 to 6, a hand-held power tool 100 and a system thereof according to a first embodiment of the present invention are shown. In the present exemplary embodiment, the hand-held power tool 100 is designed as a straight grinder.

As shown in fig. 1, the hand-held power tool system comprises a direct current grinder 100 and an adapter 16, wherein the adapter 16 is provided with a mounting for connecting an external direct current power source 49. When the adapter 16 is connected to the external dc power supply 49 and connected to the dc mill 100 through the cable 47, the power of the external dc power supply 49 is transmitted to the dc mill 100 through the adapter 16 for operation thereof.

In the present embodiment, the external dc power supply 49 is configured as a power tool-common battery pack.

As shown in fig. 1 and 2, in the present exemplary embodiment, the hand-held power tool 100 comprises a housing 10. The housing 10 extends in a longitudinal direction, and has a first end and a second end in the extending direction thereof. Wherein the second end is provided with an interface 11 for connecting a cable 47.

At least part of the side walls of the housing 10 form handle portions for gripping by a user.

The housing 10 accommodates a motor therein. The motor is an outer rotor brushless motor and comprises a stator 12, a rotor 21 and a motor shaft 23 connected with the rotor 21.

In a possible embodiment, one of the housing 10 and the stator 12 is provided with a first groove, and the other is provided with a first projection for cooperating with the first groove. The housing 10 is fixed to the stator 12 by the cooperation of the first protrusion and the first groove, so that the motor shaft 23 can rotate with the rotor 21 relative to the stator 12.

Of course, the stator 12 and the housing 10 may be fixed relative to each other by other types of fitting, which is not limited in this application.

As shown in fig. 13, in the present embodiment, a plurality of first protrusions 35 are provided on the inner wall of the housing 10 at intervals in the circumferential direction. A plurality of first grooves 31 are correspondingly formed on the outer wall of the stator 12. The first plurality of grooves 31 and the first plurality of protrusions 35 cooperate with each other so as to remain relatively stationary therebetween. The rotor 21 is fixedly connected with a motor shaft 23. The fixed connection may be a screw connection, a bolt connection, a welding, an integral molding, or the like. So that the motor shaft 23 can rotate together with the rotor 21.

As shown in fig. 2, the housing 10 also accommodates an output shaft 25. The output shaft 25 extends at least partially out of the first end for mating with the working head. In the present embodiment, the output shaft 25 is connected to the motor shaft 23 without relative rotation, and is directly driven by the motor shaft 23. That is, there is no gear transmission, reduction gearbox, etc. between the motor shaft 23 and the output shaft 25, so that the hand-held power tool 100 has a smaller overall size and lighter weight, and is convenient for an operator to carry and use.

Further, the output shaft 25 is supported in the metal sleeve 13 through a bearing, and the metal sleeve 13 is supported in the housing 10. The metal sleeve 13 can provide better support for the output shaft 25 due to the higher structural strength of the metal sleeve 13.

Because the brushless motor has higher energy density than the brush motor, under the condition of the same power, the brushless motor has smaller diameter, shorter length and stronger anti-stalling capability; further, the hand-held power tool 100 using the brushless motor as the driving source has a smaller overall size and is more convenient to carry and store.

In the present embodiment, the rated power of the brushless motor is 60W-120W, and the diameter of the motor is 18mm-25 mm. In contrast, the diameter of the brush motor can reach about 38mm under the same power.

More preferably, the outer rotor brushless motor has a diameter of 23mm and an axial dimension of 10 mm.

More preferably, the rated power of the outer rotor brushless motor is 100W.

In the present embodiment, the rotation speed of the output shaft 25 is 5000rpm to 35000 rpm.

As shown in fig. 1 and 2, the housing 10 extends in the longitudinal direction and includes a first cylindrical portion 79 and a second cylindrical portion 81; the first cylindrical portion 79 accommodates the output shaft 25, and the second cylindrical portion 81 forms the handle.

The first barrel portion 79 also includes a detail 14 for finger gripping. When the user holds the device in one hand by performing a pen-like gesture, the thin portion 14 is held by the fingers and the handle portion is held in the jaw. Here, the portion of the handle portion supported by the tiger mouth is defined as the tiger mouth portion 15.

As shown in fig. 2, the first cylindrical portion 79 gradually decreases and increases in radial dimension from left to right, and the second cylindrical portion 81 is cylindrical as a whole. The thin portion 14 has a minimum outside diameter D1 of the first barrel portion 79, the minimum outside diameter D1 being in the range of 19mm to 27 mm.

Preferably, as shown in FIG. 5, the minimum outside diameter dimension D1 of the detail 14 is 22 mm.

As shown in fig. 5, the handle portion has a centerline X1. In the present exemplary embodiment, the length L1 of the hand-held power tool 100 in the direction of the center line X1 is between 160mm and 200 mm.

Preferably, the length L1 of the hand-held power tool 100 in the direction of the handle center line X1 is 187 mm.

In the present exemplary embodiment, the center of gravity of hand-held power tool 100 is situated close to the first end and between 1/4 and 1/2 of the overall length of hand-held power tool 100. That is, when the user holds the hand-held power tool with one hand in a posture while holding the pen, the center of gravity of the hand-held power tool 100 is located between the mouth portion 15 and the thin portion 14.

Preferably, the center of gravity of the hand-held power tool 100 is located on the side of the mouth 15 facing the thin portion 14. As shown in fig. 2, for example, the center of gravity of the hand-held power tool 100 is located approximately to the left of the tiger mouth 15.

Since the ratio of the weight of the motor to the overall weight of the hand-held power tool 100 is large, its layout influences the position of the overall center of gravity. In the present exemplary embodiment, the electric motor is therefore arranged close to the first end and between the first end and 1/2 of the overall length of the hand-held power tool 100. That is, when the hand-held power tool 100 is divided into two sections in its longitudinal extension, the motor is located entirely within the section adjacent to the output shaft 25.

As shown in fig. 2, the motor shaft 23, the output shaft 25 and the handle portion extend in the same direction, so that vibration and noise caused by different shafts can be reduced.

In particular, the output shaft 25 is connected to the motor shaft 23 in a rotationally fixed manner by means of a plastic coupling 19. The other end of the output shaft 25 is provided with a locking unit for fitting the working head 39.

As shown in fig. 3 and 4, the locking unit includes a locking sleeve 33 and a locker 37. The locking part 37 is sleeved in the locking sleeve 33, and a through channel for the working head 39 to penetrate through is arranged in the locking part 37; the locking sleeve 33 is connected with the output shaft 25; so that the locking member 37 can abut between the output shaft 25 and the locking sleeve 33, and the locking member 37 restricts the movement of the working head 39.

Specifically, one end of the lock sleeve 33 is connected to the output shaft 25. As shown in fig. 3, the right end of the lock sleeve 33 is connected to the output shaft 25. The connection means may be a screw connection, a bolt connection, or the like. Further, a first inclined surface 65 is provided on an inner wall of the other end of the locking sleeve 33. The end surface of the output shaft 25 is provided with a second slope 67. Further, the relative inclination of the first and second inclined surfaces 65 and 67. The first inclined surface 65 and the second inclined surface 67 form a locking space therebetween. As shown in fig. 4, the outer wall of the locking member 37 is provided with a third inclined surface 69 and a fourth inclined surface 71 at intervals in the axial direction, which are respectively engaged with the first inclined surface 65 and the second inclined surface 67. So that the locking piece 37 can be abutted between the output shaft 25 and the locking sleeve 33 when the locking sleeve 33 is moved toward the output shaft 25.

A plurality of cutting grooves 73 extending from the third inclined surface 69 to the fourth inclined surface 71 are formed in the outer wall of the locking member 37 along the circumferential direction; so that the first inclined surface 65 acts on the third inclined surface 69 of the locking member 37 continuously when the locking sleeve 33 is tightened, and the width of the cut groove 73 is compressed, thereby holding the working head 39 tightly. That is, under the action of the first inclined surface 65, the second inclined surface 67, the third inclined surface 69 and the fourth inclined surface 71, when the working head 39 penetrates through the through passage, one side of the locking member 37 close to the cutting groove 73 is contracted towards the working head 39, so that the working head 39 is limited from moving axially.

When mounting, the locking member 37 is first inserted into the output shaft 25 such that the fourth inclined surface 71 abuts against the second inclined surface 67. The locking sleeve 33 is then threaded onto the output shaft 25 and the threaded connection is made to a loose fit. The working head 39 is then inserted into the through passage in the retaining member 37 until the predetermined depth desired by the user is reached. Finally, the locking sleeve 33 is tightened, so that the first inclined surface 65 of the locking sleeve 33 is continuously abutted with the third inclined surface 69 of the locking member 37, and the front end of the locking member 37 is forced to tightly hold the output shaft 25.

In the present embodiment, the hand-held power tool 100 further includes: a fan 27 disposed within the housing 10. The fan 27 is used to dissipate heat of the outer rotor brushless motor.

Further, as shown in fig. 2, a fan insert 24 is fixedly disposed on the motor shaft 23. The fixing mode can be screw fixation, bolt fixation, welding fixation, integral forming fixation and the like. The fan 27 is fixed to the fan insert 24.

A spindle lock is provided on the fan insert 24. As shown in fig. 12, the spindle lock includes a locking pin 63 and an operation knob 57 for user operation. The locking pin 63 can abut against the fan insert 24 under the action of the operating knob 57 to limit the rotation of the motor shaft 23 and ultimately the output shaft 25, so that the working head 39 can be mounted or dismounted.

Since the radial dimension of the output shaft 25 is smaller than the radial dimension of the fan insert 24, the locking pin 63 acts on the fan insert 24 to avoid damage to the output shaft 25 as compared to acting on the output shaft 25.

Further, as shown in fig. 12, an annular spring 59 is provided in the housing 10. An annular spring 59 is connected to the operating knob 57 and provides a force urging the operating knob 57 away from the fan insert 24. A third recess 61 is provided on the inner end of the operating knob 57. One end of the locking pin 63 is inserted into the third groove 61, and the other end is in contact with the fan insert 24.

Further, the housing 10 is provided with an air outlet 53 close to the fan 27 and an air inlet 55 far from the fan 27. For example, as shown in FIG. 1, the intake vent 55 is disposed in the second cylindrical portion 81.

Since the screw connection requires the radial dimensions of the power tool 100, the housing 10 is of screwless design in order to reduce the dimensions of the power tool 100. Specifically, the housing 10 is formed by a pair of left and right housing halves which are distributed along the center line X1. As shown in fig. 6, for example, the left and right housing halves are first half 75 and second half 77, respectively. The first half 75 and the second half 77 are of screwless design in appearance. Specifically, the first half 75 and the second half 77 may be fixedly connected by a snap and a pin. Further, one of the first half portion 75 and the second half portion 77 is provided with a catching groove 85, and the other is provided with a catching protrusion 87.

Optimally, the design with regard to the operation of the hand-held power tool 100 is achieved by: the ratio of the nominal power of the hand-held power tool 100 to the diameter of the handle part is preferably selected. It is conceivable that if the ratio of the power rating of the hand-held power tool 100 to the diameter of the handle portion is too small, this means that the handle portion is thick and inconvenient to grip. As a consequence, the operator is quickly fatigued. The optimum ratio of the nominal power of the hand-held power tool 100 to the diameter of the handle part also depends on the power range in which the hand-held power tool 100 is arranged. In the present embodiment, the power rating of the hand-held power tool 100 is between 60W and 120W, and the ratio of the power rating to the diameter of the handle portion is between 1.6W/mm and 4.3W/mm.

Another ergonomic design of the hand-held power tool 100 can be achieved by: the ratio of the rated power of the hand-held power tool 100 to the total machine weight is preferably selected. The weight of the hand-held power tool 100 results from the total weight of all components of the hand-held power tool 100, without taking into account the weight of the cable 47 and the battery pack 49, and also the weight of the working head, the protective hood and possibly other accessories which are inserted, if any. It is conceivable that a ratio of the rated power of the hand-held power tool 100 to the total machine weight which is too low means that the hand-held power tool 100 is heavier in the hand of the user. As a consequence, the operator is quickly fatigued. The optimum ratio of the rated power of the hand-held power tool 100 to the total machine weight also depends on the power range in which the hand-held power tool 100 is arranged. In the present embodiment, the rated power of the hand-held power tool 100 is 60W to 120W, and the ratio of the rated power to the total weight is 0.4W/g to 1W/g.

In the present embodiment, due to the use of the outer rotor brushless motor, the size of the housing 10 can be made as small as possible without sacrificing the power of the hand-held power tool 100; also, the diameter of the handle portion is sized within a reasonable range for better gripping by the user.

In one possible embodiment, the diameter dimension D2 of the handle portion is between 28-37 mm.

Preferably, the diameter dimension D2 of the handle portion is between 31-33 mm.

In one possible embodiment, the overall weight of the hand-held power tool 100 is between 125g and 145 g.

According to the direct grinding machine, on one hand, through the selection of the outer rotor brushless motor, the structural size of the motor is greatly reduced on the premise of not sacrificing the working capacity of the direct grinding machine, so that the radial size of the handle part is more beneficial to being held by a user, and the holding experience of the user is improved; on the other hand, through the external arrangement of the power supply device and the selection of the outer rotor brushless motor, the weight of the machine tool 100 is greatly reduced on the premise of not sacrificing the working capacity of the direct grinding machine, and the holding burden of a user is reduced.

Fig. 7 to 11 show a hand-held power tool 100' and its system according to a second embodiment of the utility model. In the present exemplary embodiment, the hand-held power tool 100' is designed as an angle grinder.

Please refer to fig. 7 and 8. Fig. 7 shows a schematic view of the angle grinder 100' according to an embodiment of the present application connected to the adapter 16. Fig. 8 shows a schematic partial structure diagram of an angle grinder 100' according to an embodiment of the present disclosure.

As shown in fig. 7 and 8, a hand-held power tool 100 'according to an embodiment of the present application comprises a housing 10'. The housing 10' includes a head portion 41 and a handle portion 43. The end of the handle part 43 remote from the head part 41 is provided with an interface for connecting a cable 47, via which interface 11 'the hand-held power tool 100' is connected to the adapter 16.

The head unit 41 is disposed at an angle to the handle unit 43, and houses a motor therein. Specifically, the head housing portion 41 is disposed in a vertical direction, and the angle between the head housing portion and the handle portion 43 is between 90 degrees and 110 degrees. That is, the handle portion 43 is designed to be vertical or tilted up with respect to the horizontal.

Preferably, as shown in fig. 7, the head housing portion 41 is disposed perpendicular to the handle portion 43; and the head housing portion 41 and the handle portion 43 are T-shaped.

As shown in fig. 10, the handle portion 43 has a center line X1'. The length L1 ' of the hand-held power tool 100 ' in the direction of the center line X1 ' is between 172.3mm and 192.3 mm.

Preferably, the length L1 ' of the hand-held power tool 100 ' in the direction of the center line X1 ' is 182.3 mm.

In the present embodiment, the motor is an external rotor brushless motor, and includes a stator 12 ', a rotor 21', and a motor shaft 23 'connected to the rotor 21'.

In a possible embodiment, one of the housing 10 'and the stator 12' is provided with a first recess, and the other is provided with a first projection for cooperating with the first recess. The housing 10 ' is fixed to the stator 12 ' by the engagement of the first protrusion and the first groove, so that the motor shaft 23 can rotate with the rotor 21 ' relative to the stator 12.

In this embodiment, the way in which the stator 12 'and the housing 10' are fitted to each other is the same as in the first embodiment, and will not be described again here.

In the present embodiment, the output shaft 25 ' is connected to the motor shaft 23 ' without relative rotation and is directly driven by the motor shaft 23 '. That is, there is no gear transmission and reduction box between the motor shaft 23 ' and the output shaft 25 ', so that the machine tool 100 ' has smaller overall size and lighter weight, and is convenient for the operator to carry and use.

Further, as shown in fig. 8, the axis of the motor shaft 23 'is arranged substantially coincident with the axis of the output shaft 25'. That is, the motor shaft 23 'is coaxially disposed with the output shaft 25', so that vibration and noise caused by different shafts can be reduced. And, the output shaft 25' is arranged coaxially with the head housing portion 41, so that the whole machine is more concentrated.

Further, the output shaft 25 ' is located on a side of the motor shaft 23 ' away from the handle portion 43, and at least partially extends out of the head portion 43 to engage the working head 39 '. As shown in fig. 8, the upper end of the output shaft 25 'is connected to the lower end of the motor shaft 23'.

As shown in fig. 8 and 9, the output shaft 25 has an internal thread at one end. The working head 39 ' can be directly fastened on the output shaft 25 ' through the fastening screw 26 matched with the internal thread, so that the working head 39 ' is convenient to disassemble. Further, a pressing plate 83 is disposed on a side of the working head 39 'facing away from the output shaft 25'. The pressure plate 83 is provided with a through hole for passing the fastening screw 26. The fastening screw 26 is connected to an internal thread in the output shaft 25' through a through hole. The working head 39 'is located between the pressure plate 83 and the output shaft 25'.

Because the brushless motor has higher energy density than the brush motor, under the condition of the same power, the brushless motor has smaller diameter, shorter length and stronger anti-stalling capability; further, the hand-held power tool 100' using the motor instead of the brush motor can reduce the size of the whole machine, and is more convenient to carry and store.

In the embodiment, the rated power of the brushless motor is between 80W and 200W, the diameter of the motor is between 18mm and 25mm, and the axial dimension is 24 mm.

Unlike the first embodiment, the angle grinder 100 'of the present embodiment includes a housing 10' including a head housing 41 and a handle portion 43 arranged at an angle to the head housing 41; and the outer rotor brushless motor is located in the head housing portion 41.

Another criterion for reflecting the compactness of the hand-held power tool 100 ' and the efficiency of the motor is the ratio of the diameter D1 ' of the head housing part 41 to the diameter D2 ' of the handle part 43. An ergonomic hand-held power tool 100' is obtained in particular when the ratio of the diameter of the head part 41 to the diameter of the handle part 43 is between 0.9 and 1.1.

In the present embodiment, the diameter D1' of the head housing part 41 is between 29mm and 37 mm.

Preferably, the design with regard to the operation of the hand-held power tool 100' is implemented by: the ratio of the nominal power of the hand-held power tool 100' to the diameter of the handle portion 43 is preferably selected. It is conceivable that if the ratio of the power rating of the hand-held power tool 100' to the diameter of the handle portion 43 is too small, this means that the handle portion 43 is thick and inconvenient to grip. As a consequence, the operator is quickly fatigued. The optimum ratio of the nominal power of the hand-held power tool 100 'to the diameter of the handle portion 43 also depends on the power range in which the hand-held power tool 100' is arranged. In the present exemplary embodiment, the power rating of the hand-held power tool 100' is between 80W and 200W, and the ratio of the power rating to the diameter of the handle portion 43 is between 2.1W/mm and 7.2W/mm.

In one possible embodiment, the diameter D2' of the handle portion 43 is between 28mm and 37 mm. It is particularly preferred that the diameter D2' of the handle portion 43 be between 31mm and 33 mm.

Here, the radial dimension of the handle portion 43 may be defined by the circumferential length thereof. In a possible embodiment, the circumference of the handle portion 43 is between 85mm and 120mm, particularly preferably 100 mm.

Another ergonomic design of the hand-held power tool 100' can be achieved by: the ratio of the rated power of the hand-held power tool 100' to the total machine weight is preferably selected. The weight of the hand-held power tool 100 'results from the total weight of all components of the hand-held power tool 100', without taking into account the weight of the cable 47 'and the battery pack 49', and also the weight of the working head, the protective hood and any other accessories that may be inserted, if any. If the ratio of the rated power of the hand-held power tool 100 'to the total machine weight is too high, this means that the hand-held power tool 100' is heavy in the hand of the user. As a consequence, the operator is quickly fatigued. The optimum ratio of the rated power of the hand-held power tool 100 'to the total machine weight also depends on the power range in which the hand-held power tool 100' is arranged. In the present embodiment, the rated power of the hand-held power tool 100' is between 80W and 200W, and the ratio of the rated power to the weight of the entire machine is between 0.35W/g and 1.1W/g.

In one possible embodiment, the handheld power tool 100' has a weight of between 185g and 205 g.

In the present embodiment, the rotation speed of the output shaft 25' ranges from 14000rpm to 24000 rpm.

In order to coordinate the ratio of the working head 39 'with respect to the hand-held power tool 100', and at the same time to ensure the working efficiency of the working head 39 'itself, so that the power tool 100' is compact and efficient as a whole, in the present embodiment the working head 39 'is a ring-shaped element, and the diameter of the working head 39' is in the range of 36mm to 55 mm.

Further, the working head 39' may comprise a cutting or sanding element in the form of a disc. A disc-shaped cutting or sanding element is mounted perpendicularly to the output shaft 25'.

Further, as shown in fig. 8, the hand-held power tool 100 ' has a guard 51 detachably connected to the housing 10 ' when the working head 39 ' is a cutting blade. The shroud 51 is adapted to receive at least a portion of the working head 39 'to prevent work debris from being splashed adjacent the operator by the machine tool 100' during operation.

Further, as shown in fig. 10, as the distance H1 between the center line X1 'of the handle portion 43 and the end surface of the output shaft 25' for engagement with the working head 39 'is larger, the gyroscopic effect generated by the hand-held power tool 100' during the relevant work is more significant, which may cause discomfort in gripping by the user. When the distance H1 between the center line X1 ' of the handle portion 43 and the end surface of the output shaft 25 ' for mating with the working head 39 ' is smaller, the closer the hand of the user holding the hand-held power tool 100 ' is to the working head 39 ', which may cause danger and inconvenience of work; further, the smaller the distance H1 between the center line X1 ' of the handle portion 43 and the end surface of the output shaft 25 ' for mating with the working head 39 ', the less the heat dissipation of the brushless motor is facilitated. Specifically, as shown in fig. 7 and 8, when the distance H1 between the center line X1 ' of the handle portion 43 and the end surface of the output shaft 25 ' for mating with the working head 39 ' is smaller, it is also explained to a certain extent that the motor housed inside the head housing 41 is arranged more upward; this makes the space between the brushless motor and the inner wall of the handle portion 43 small, that is, the space of the flow passage provided for the heat radiation flow in the housing 10' small, thereby being disadvantageous for the heat radiation of the motor.

Therefore, the distance H1 between the center line X1 ' of the handle portion 43 and the end surface of the output shaft 25 ' for engagement with the working head 39 ' should be arranged within a reasonable range. In the present embodiment, the distance H1 between the center line X1 ' of the handle portion 43 and the end surface of the output shaft 25 ' for mating with the working head 39 ' is 29.7mm to 44.72 mm.

Preferably, the distance H1 between the center line X1 ' and the end face of the output shaft 25 ' for mating with the working head 39 ' is 44.72 mm.

When the distance is 0, the hand-held power tool 100' is of the straight shank type.

In order to increase the accessibility of the hand-held power tool 100' to the work requirement in tight spaces, the dimensions of the head housing part 41 in the vertical direction should also be arranged within reasonable limits. In the present embodiment, the distance H2 between the top surface of the head housing portion 41 and the end surface of the output shaft 25' is 39.2mm to 69.2 mm.

Preferably, the distance H2 between the top surface of the head housing portion 41 and the end surface of the output shaft 25' is 69.2 mm.

Further, the distance H3 between the top surface of the head housing portion 41 in the axial direction of the output shaft 25' and the end surface of the hood 51 is between 38mm and 80 mm. Particularly preferably, H3 is 78.5 mm.

The hand-held power tool 100' according to an embodiment of the present application further comprises: a circuit board (not shown) for controlling the operation of the brushless motor is provided in the handle portion 43.

Because the energy density of the brushless motor is larger than that of the brush direct current motor, the heat generated by the brushless motor during working is also higher than that of the brush direct current motor. Also, a large amount of heat is generated on the circuit board for controlling the operation of the motor. For this purpose, the hand-held power tool 100' of the present exemplary embodiment is also provided with a heat dissipation unit.

As shown in fig. 7 and 8, the heat dissipation unit at least includes: a fan 27 'fixedly provided on the output shaft 25'; an air inlet 55 'provided in the handle portion 43 and an air outlet 53' provided in the head portion.

As described above, in order to obtain a good heat dissipation effect, a certain space must be left between the motor and the inner wall of the handle portion 43 for the heat dissipation airflow to pass through. In the present embodiment, the distance between the top surface of the brushless motor and the inner wall of the topmost end of the handle portion 43 in the vertical direction is between 2mm and 5 mm.

In a possible embodiment, the head shell part can also be obliquely arranged with the handle part; the handle part is provided with an air inlet, and the head shell part is provided with an air outlet. When the fan rotates, the heat dissipation airflow flows through the circuit board and the motor in sequence to dissipate heat of the circuit board and the motor. At this time, in order to obtain a good heat dissipation effect, a certain space is required to be reserved between the inner wall of the handle part and the motor for the heat dissipation airflow to pass through; that is, the plane of extension of the topmost inner wall of the handle portion does not intersect the motor.

The handle portion 43 is also provided with a switching element 17 for controlling the starting or closing of the outer rotor brushless motor.

Further, since the screw connection needs to occupy the radial dimension of the machine tool 100 ', in order to reduce the size of the machine tool 100 ', the housing 10 ' is designed to have an appearance without screws. Specifically, the housing 10 'includes a pair of left and right housing halves that are snap-fit together and extend along the centerline X1' of the handle portion. As shown in fig. 11, for example, the left and right housing halves are first and second halves 75 'and 77', respectively. The first half 75 'and second half 77' are of screwless design in appearance. Specifically, the first half 75 'and the second half 77' may be fixedly connected by a snap and a pin. Further, one of the first half portion 75 'and the second half portion 77' is provided with a catching groove, and the other is provided with a catching protrusion.

In a possible embodiment, in order to enhance the supporting performance of the head casing portion 41 for the motor, the head casing portion 41 may be screwed.

According to the angle grinder 100 ', on one hand, through the external arrangement of a power supply device and the selection of an outer rotor brushless motor, on the premise of not sacrificing the working capacity of the angle grinder 100 ', the weight of the machine tool 100 ' is greatly reduced, and the holding burden of a user is reduced; on the other hand, through the selection of outer rotor brushless motor, under the prerequisite that does not sacrifice angle grinder 100' self working capability, reduced the structure size of motor greatly for the radial dimension of handle portion 43 does benefit to the user more and grips, has promoted the user and has gripped the experience.

Fig. 1 to 13 show a hand-held power tool and a system thereof according to the present application. The hand-held power tool is connected to the adaptor 16 via a cable 47 and receives electric power from an external dc power supply 49 transmitted from the adaptor 16. The adapter 16 is provided with a mounting portion for connecting an external direct-current power supply 49. That is, the hand-held machine tool of the application reduces the weight of the whole machine through the external technical means of the power supply device, thereby reducing the holding burden of a user.

Further, the present application provides a hand-held power tool comprising: a housing, at least part of the side walls of the housing forming a handle portion, the handle portion having a radial dimension of 28mm to 37 mm; the rated power of the outer rotor brushless motor is between 60 and 200W; and the output shaft is connected with the motor shaft in a non-relative-rotation manner and is directly driven by the motor shaft, and the output shaft is used for being matched and connected with the working head.

The handheld power tool described in the present application uses an outer rotor brushless motor with a rated power of 60 to 200W as a power component. Under the condition of the same power, the motor has smaller diameter, shorter length and stronger anti-stalling capability than a brush motor. And then use this motor to replace the hand-held type tool machine that has the brush motor can reduce the volume of complete machine, so also can reduce the size of handle portion, and then more conveniently carry and save.

Further, the hand-held power tool according to the present application has a ratio of nominal power to the diameter of the handle portion of between 1.6W/mm and 7.2W/mm, whereby an ergonomic and powerful design is obtained.

Another ergonomic configuration of the hand-held power tool is defined by the ratio of the rated power of the hand-held power tool to the weight of the entire hand-held power tool, so that a design is obtained which ensures the operating capability and facilitates the handling by the user. In the embodiment, the ratio of the rated power of the hand-held tool to the weight of the whole machine is between 0.29W/g and 1.6W/g.

Furthermore, the diameter of the handle part of the hand-held power tool is between 28mm and 37mm, and the weight of the whole machine is between 125g and 205 g.

The hand-held power tool is used in this application for connection to an adapter 16. In particular, the adapter 16 can be connected to different types of hand-held power tools. For example, the adapter 16 can be connected to a straight or angle grinder, which enables different types of hand-held power tools to share one adapter 16, thereby reducing the costs for the user.

Further, as shown in fig. 1 and 7, the hand-held power tool of the present application is connected to the interface of the adapter 16 via a cable 47. This makes it possible to operate the hand-held power tool while holding it. Since the cable 47 can be bent, the distance between the hand-held power tool and the adapter 16 can be changed during operation, so that the hand-held power tool can be moved conveniently, and the human-computer experience is better.

Further, the adapter 16 is provided with a mounting portion for connecting an external direct-current power supply 49. For example, as shown in fig. 1 and 7, the external dc power source is a battery pack for a power tool. The battery pack 49 is used to supply power to the hand-held power tool.

In one possible embodiment, the rated voltage of the battery pack is 20V.

Further, an operation unit 18 is provided on the adapter 16. The operating unit 18 serves to regulate the rotational speed of a motor arranged in the hand-held electrician tool. Specifically, the operation unit is a speed knob 18. The speed knob 18 is used to adjust the rotational speed of the motor.

Further, the adapter 16 further includes a switching element for controlling the turning on and off of the motor.

In a possible embodiment, as shown in fig. 7, the handle part of the hand-held power tool can also be provided with a switching element for controlling the operation of the motor. In this way, the user can carry out the relevant control of the electric motor when holding the hand-held power tool without having to go to the adapter 16 for the relevant operation.

All articles and references disclosed, including patent applications and publications, are hereby incorporated by reference for all purposes. The term "consisting essentially of …" describing a combination shall include the identified element, ingredient, component or step as well as other elements, ingredients, components or steps that do not materially affect the basic novel characteristics of the combination. The use of the terms "comprising" or "including" to describe combinations of elements, components, or steps herein also contemplates embodiments that consist essentially of such elements, components, or steps. By using the term "may" herein, it is intended to indicate that any of the described attributes that "may" include are optional. A plurality of elements, components, parts or steps can be provided by a single integrated element, component, part or step. Alternatively, a single integrated element, component, part or step may be divided into separate plural elements, components, parts or steps. The disclosure of "a" or "an" to describe an element, ingredient, component or step is not intended to foreclose other elements, ingredients, components or steps.

The embodiments in the present specification are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims (12)

1. A hand-held power tool, characterized in that it comprises:

a housing including a handle portion for gripping by a user;

a motor housed in the housing and having a motor shaft;

the output shaft is driven by the motor shaft and is used for being connected with the working head in a matching mode;

the rated power of the motor is between 60W and 200W, and the ratio of the rated power of the motor to the diameter of the handle part is between 1.6W/mm and 7.2W/mm.

2. The hand-held power tool according to claim 1, wherein the electric motor is an external rotor brushless motor having a diameter of between 18mm and 25 mm.

3. The hand-held power tool of claim 1, wherein the handle portion has a centerline, and wherein the length of the hand-held power tool in the direction of the centerline is between 160mm and 200 mm.

4. The hand-held power tool of claim 1, further comprising an interface disposed on the housing for connecting an external dc power source via a cable.

5. The hand-held power tool of claim 1, wherein the operating speed of the output shaft is between 5000rpm and 35000 rpm.

6. The hand-held power tool according to claim 1, wherein the hand-held power tool is configured as a straight grinder; the housing includes a first cylindrical portion that houses the output shaft and a second cylindrical portion that forms the handle portion; the minimum outer diameter of the first cylinder part is between 19mm and 27 mm; the maximum outer diameter of the second cylinder part is between 28mm and 37 mm.

7. The hand-held power tool of claim 6, wherein the housing extends in a lengthwise direction, having a first end and a second end; at least part of the output shaft extends out of the first end to be matched and connected with the working head; a center of gravity of the hand-held power tool is disposed proximate the first end and between 1/4 a length of the hand-held power tool and 1/2 a length of the hand-held power tool.

8. The hand-held power tool of claim 1, wherein the hand-held power tool is configured as an angle grinder, the housing further comprising a head housing portion disposed at an angle to the handle portion, the head housing portion housing the motor.

9. A hand-held power tool, characterized in that it comprises:

a housing including a handle portion for gripping by a user;

a motor housed in the housing and having a motor shaft;

the output shaft is driven by the motor shaft and is used for being connected with the working head in a matching mode;

the interface is arranged on the shell and used for being connected with an external direct current power supply through a cable;

the rated power of the motor is between 60W and 200W, and the ratio of the rated power of the motor to the weight of the hand-held power tool is between 0.29W/g and 1.6W/g.

10. A hand-held power tool system, comprising:

the hand-held power tool of any one of claims 1 to 9;

an adapter including a mounting part for connecting an external DC power supply; the adapter is connected to the hand-held power tool via a cable and transmits the electric power of the external dc power supply to the hand-held power tool.

11. Hand-held power tool system according to claim 10, characterized in that an operating unit is provided on the adapter for setting the operating speed of the electric motor.

12. The hand-held power tool system according to claim 10, wherein the external dc power source is a power tool universal battery pack having a voltage rating of 20V.

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