CN216066869U - Electric tool - Google Patents

Abstract

The present invention relates to an electric tool, comprising: the casing subassembly is located controller and motor in the casing subassembly, the controller includes the circuit board, the maximum output power of motor is M, the casing subassembly includes the casing and locates the portion of gripping on the casing outer peripheral face, the girth of the portion of gripping is C, its characterized in that: the ratio M/C of the maximum output power M of the motor to the perimeter C of the holding part ranges from 6.41 to 9.73 w/mm. The utility model has the advantages that: under the condition of not reducing the power of the motor, the circumference of the shell holding part is further reduced, and therefore the use experience of a user is effectively improved.

Description

Electric tool

Technical Field

The utility model relates to an electric tool, in particular to a brushless angle grinder.

Background

In the prior art, a motor and a controller of an angle grinder product are basically arranged in a machine shell, and when the motor or the controller is too large, the holding part on the outer peripheral surface of the machine shell is too large, so that an operator cannot hold the machine shell conveniently in use. And the reduction of the size of the motor can lead to the reduction of the power of the motor, and the use requirement of a user cannot be met.

The palm of the east Asia yellow race is smaller than the European and American white race due to different race characteristics, and the length range of the palm of the Chinese male is usually 175 mm-200 mm, and the width is 80 mm-90 mm; the length of the palm of the Chinese female is usually between 160mm and 180mm, and the width of the palm of the Chinese female is between 65mm and 80 mm. To present angle grinder product, because its inner structure's restriction, operating personnel is difficult for holding angle grinder product using angle grinder product, and simultaneously, angle grinder product can produce great vibration at the during operation to bring inconvenience for operating personnel's operation, the long-time use of holding of operating personnel of being not convenient for influences machining efficiency.

Accordingly, there is a need to provide an angle grinder having a smaller grip to enhance the user experience without power reduction.

SUMMERY OF THE UTILITY MODEL

In view of the above, an object of the present invention is to provide a power tool that provides a user with a better comfortable grip during operation.

In order to achieve the purpose, the technical scheme adopted by the utility model is as follows:

a power tool, comprising: the casing subassembly is located controller and motor in the casing subassembly, the controller includes the circuit board, the maximum output power of motor is M, the casing subassembly includes the casing and locates the portion of gripping on the casing outer peripheral face, the girth of the portion of gripping is C, its characterized in that: the ratio M/C of the maximum output power M of the motor to the perimeter C of the holding part ranges from 6.41 to 9.73 w/mm.

Optionally, a ratio M/C of the maximum output power M of the motor to the circumference C of the grip portion is 7.63 w/mm.

Optionally, the controller includes an IGBT integrated on the circuit board and a current limiting module, the current limiting module is configured TO limit a current value TO be less than 20A, and a package of the IGBT adopts TO220 TO reduce a size of the chassis.

Optionally, the large-current loop of the circuit board adopts a current-carrying copper bar or tin-coating process.

Optionally, the large-current loop specifically comprises a bus and a three-phase bridge stack, the bus is connected with a rectifier bridge and a three-phase full bridge, and the three-phase bridge stack is connected with the IGBT and the motor.

Optionally, the circuit board is further provided with a capacitor, the capacitance of the capacitor is smaller than 10 microfarads, and the current limiting module is further configured to counteract voltage pulsation caused by reduction of capacitance.

Optionally, the circuit board adopts a double-layer lamination process.

Optionally, the circuit board further includes a filter module, and the filter module uses a double-ended filter capacitor to reduce the number of EMC suppression devices on the circuit board.

Optionally, the power tool further comprises an operating component, and the operating component is integrated on the controller.

Optionally, the motor is a brushless motor.

Compared with the prior art, the utility model has the beneficial effects that: according to the electric tool provided by the utility model, under the condition that the power of the motor is not reduced, the length and the circumference of the holding part of the shell are reduced by changing the size and the layout of the circuit board and related elements of the controller, so that the use experience of a user is effectively improved.

Drawings

The above objects, aspects and advantages of the present invention will become apparent from the following detailed description of specific embodiments, which is to be read in connection with the accompanying drawings.

The same reference numbers and symbols in the drawings and the description are used to indicate the same or equivalent elements.

Description of the drawings: fig. 1 is a perspective view of an angle grinder according to an embodiment of the present disclosure;

FIG. 2 is a cross-sectional view of an angle grinder provided in an embodiment of the present application;

FIG. 3 is a cross-sectional view of an angle grinder controller provided in accordance with an embodiment of the present application;

fig. 4 is a top view of an angle grinder controller provided in an embodiment of the present application.

Reference numerals: 100-angle grinder; 110-a housing assembly; 111-head shell; 112-a housing; 120-a motor; 130-a controller; 131-a circuit board; 132-IGBT; 133-capacitance; 134-capacitance; 135-operating means; 136-heat sink.

Detailed Description

The following detailed description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings, will make the advantages and features of the utility model easier to understand by those skilled in the art, and thus will clearly and clearly define the scope of the utility model.

The application provides an electric tool is little angle grinder, and its operating mode that is suitable for is: architectural decoration or installation, metal furniture, general equipment, and the manufacture of stationery and the like.

Referring to fig. 1-4, an electric tool according to an embodiment of the present invention is an angle grinder 100. The angle grinder 100 includes a housing assembly 110, and a motor 120 and a controller 130 that are disposed within the housing assembly 110.

The shell assembly 110 has a protection function, so that an operator can be effectively prevented from touching parts inside the shell assembly 110 when using the angle grinder 100, the use safety of the operator is guaranteed, and the safety performance is improved. Meanwhile, the angle grinder 100 generates dust during operation, and the shell assembly 110 can prevent the dust from entering the shell assembly 110, so that the dust is prevented from being accumulated on parts inside the shell assembly 110, the service life of the angle grinder 100 is prolonged, and the working efficiency of the angle grinder 100 is improved.

The housing assembly 110 includes a head shell 111 and a housing 112 connected to the head shell 111, the head shell 111 and the housing 112 enclose a chamber, and each component of the angle grinder 100 is installed in the chamber and protected by the head shell 111 and the housing 112. Meanwhile, the head shell 111 is connected with the machine shell 112 to play a sealing role, so that part of dust can be prevented from entering a cavity, the service life of the brushless angle grinder 100 is prolonged, and the working efficiency of the brushless angle grinder 100 is improved.

The motor 120 is disposed in the housing 112 at a position close to the head housing 111, i.e., the motor 120 is located at the head of the angle grinder 100. Thus, the output path of the torque of the motor 120 can be reduced, the loss of the torque in the transmission process can be avoided, the output torque of the motor 120 can be improved, and the output torque of the angle grinder 100 can be ensured. The controller 130 is provided in the cabinet 112 on a side away from the head housing 111. The controller 130 includes a circuit board 131, and an IGBT132, a capacitor 133, a capacitor 134, and an operation section 135 integrated on the circuit board 131.

Usually, the controller 130 further comprises an EMC module integrated on the wiring board, which may be used to reduce electromagnetic interference between electronic components, however the EMC module is bulky and therefore takes up a larger space when the number of EMC modules is larger.

The angle grinder 100 further includes a grip portion provided on an outer circumferential surface of the housing 112. The gripping portion may be used for an operator to grip while using the angle grinder 100 to facilitate operation of the angle grinder 100.

Since the motor 120 and the controller 130 are both disposed in the housing 112, in the case where the motor 120 and the controller 130 are both large in size, it is inconvenient for an operator to hold the angle grinder when using the angle grinder, and physical strength of the operator may be increased. Therefore, the overall size of the controller 130 needs to be reduced without reducing the power of the motor 120.

The present invention reduces the size of the controller 130 by:

the packaging of the IGBT132 is changed from TO247 TO TO220, and the size of the TO220 is far smaller than that of the TO247, so that the length of the controller 130 can be reduced by at least 20mm after the packaging of the IGBT132 of the controller 130 is changed from the TO247 TO the TO 220. Since the TO220 can carry a current value smaller than that of the TO247, the current value is limited TO be within 20A by the current limiting module. It should be understood that the current value may be limited by other technical means to achieve the protection of the circuit, which is not limited in the present application.

The current limiting module is used for limiting the current to be within a preset value so as to avoid damaging a circuit due to overlarge current. The working principle is as follows: the method comprises the steps of detecting the current flowing into a power switch tube by a rectifier bridge, namely the magnitude of bus current, detecting the magnitude of real-time current in each period, comparing the actual current with set current by a controller, and closing the switch tube in the rest period of the current period when the real-time current is larger than the set value, wherein the time period is related to the frequency of the control switch tube. It should be understood that, through the current limiting module with the electric current size restriction in the default, not only can avoid damaging the circuit because of the electric current is too big, can also avoid the circuit excessively to generate heat, reduce the radiating pressure, and then reduce the quantity of heating panel, realize dirt-proof effect at last.

Preferably, a heat sink 136 is further disposed above the IGBT132 for conducting heat dissipated from the IGBT132 to the air, so as to prevent the components from being damaged due to excessive temperature.

Further, capacitor 133 is a thin film capacitor having a capacitance of less than 10 microfarads, which reduces the total volume by at least 30% compared to electrolytic capacitors used in the prior art. Since the capacitor 133 is reduced in size to a certain extent, which may cause excessive voltage ripple, the present application cancels vibration generated by ripple of motor torque due to the voltage ripple by the current limiting module. It should be understood that the vibration of the motor may be attenuated by other technical means, which are not limited in the present application.

Referring to fig. 3, the circuit board 131 is formed by a double-layer lamination process, and the circuit board 131 is configured as an upper circuit board and a lower circuit board, and the upper circuit board and the lower circuit board are connected by pins. Thus, the height space in the housing 112 is fully utilized, and the planar area of the controller 130 is greatly reduced.

Further, the capacitor 134 is a double-end filter capacitor, and compared with a common capacitor, the double-end filter capacitor can better suppress mutual interference between electronic components. Under the same condition, the number of EMC modules can be further reduced, thereby reducing the volume of the controller 130.

Further, the large current loop of the controller 130 is added with a current-carrying copper bar or a tin-coating process, so that the width of the large current loop can be reduced, and the whole width of the controller 130 is further reduced. The high-current loop comprises a bus and a three-phase bridge stack. The bus is respectively connected with the anode of the rectifier bridge and the IGBT of the upper bridge arm of the three-phase full bridge, and the three-phase bridge stack is connected with the IGBT and the three-phase line of the motor 120.

Further, the operating member 135 is provided on the circuit board 131, the operating member 135 may be a switch, and integrating the operating member 135 on the circuit board 131 may avoid a fixing space specially designed for the operating member 135 by the housing 112 and reduce manufacturing and assembling costs. It should be understood that in a specific application scenario, an angle grinder with power suitable for a working condition needs to be used, in order to enable a user to have a better holding experience, a motor with a smaller size is selected as much as possible under the condition that the power requirement is met, and thus, a holding portion corresponding to the motor has a smaller circumference. Because the outer peripheral surface of the shell corresponding to the motor and the outer peripheral surface of the shell corresponding to the controller are holding parts, the above measures are required to reduce the size of the circuit board and the size of each circuit component integrated on the circuit board, so that the overall size of the controller is reduced, the perimeter of the holding part corresponding to the controller is consistent with that of the holding part corresponding to the motor, and the overall aesthetic property and the holding comfort are improved.

Thus, without reducing the power of the motor 120, the ratio M/C of the maximum output power M of the motor 120 to the circumference C of the grip portion can be limited to the range of 6.41-9.73w/mm by the above means. When the maximum output power M is 1090W and the perimeter C of the holding part is 170mm, the M/C is 6.41; when the maximum output M was 1780W and the circumference C of the grip portion was 183mm, M/C was 9.73. Under the condition of meeting the power, if the value of M/C is less than 6.41, the perimeter C of the holding part is too large, and the holding experience of a user is reduced; if the value of M/C is greater than 9.73, the circumference C of the grip portion may be too small, and only the height of the motor may be reduced and the length of the motor may be increased to keep the power of the motor unchanged, which may result in poor stability of the motor and reduce the user experience. Therefore, the ratio M/C of the maximum output power M of the motor 120 to the perimeter C of the holding part is limited within the range of 6.41-9.73w/mm, so that the holding experience of a user can be improved, and the running stability of the motor can be ensured.

In one embodiment, the rated power M of the motor 120 is 1050W, the maximum output power M is 1350W, the circumference C of the grip is 177mm, and the ratio M/C of the maximum output power M to the circumference C of the grip is 7.63. The length L of the circuit board 131 is 93mm, and the width D of the circuit board 131 is 38 mm. Optionally, the height a of the controller 130 is 46 mm.

Preferably, the motor 120 is a brushless motor, and the brushless motor can avoid using a carbon brush for conduction, thereby saving energy consumption caused by the carbon brush.

The electric tool provided by the utility model can be a brushless angle grinder, and can be used for cutting, grinding, brushing, polishing and other operations on workpieces such as metal or stone. Meanwhile, under the condition that the power of the motor is not reduced, the length and the circumference of the holding part are reduced by changing the size and the layout of a circuit board of the brushless angle grinder controller and related elements, and the holding experience of the angle grinder is optimized.

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 present 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.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", and the like, indicate orientations and positional relationships based on the orientations and positional relationships shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be considered as limiting the present 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; may be mechanically coupled, may be electrically coupled or may be in communication with each other; 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.

Claims (10)

1. A power tool, comprising: the casing subassembly is located controller and motor in the casing subassembly, the controller includes the circuit board, the maximum output power of motor is M, the casing subassembly includes the casing and locates the portion of gripping on the casing outer peripheral face, the girth of the portion of gripping is C, its characterized in that: the ratio M/C of the maximum output power M of the motor to the perimeter C of the holding part ranges from 6.41 to 9.73 w/mm.

2. The power tool of claim 1, wherein: the ratio M/C of the maximum output power M of the motor to the perimeter C of the holding part is 7.63 w/mm.

3. The power tool of claim 1, wherein: the controller comprises an IGBT integrated on the circuit board and a current limiting module, the current limiting module is used for limiting the current value TO be less than 20A, and TO220 is adopted for packaging the IGBT TO reduce the size of the machine shell.

4. The power tool of claim 3, wherein: the large-current loop of the circuit board adopts a current-carrying copper bar or tin-coating process.

5. The power tool of claim 4, wherein: the high-current loop specifically comprises a bus and a three-phase bridge stack, the bus is connected with a rectifier bridge and a three-phase full bridge, and the three-phase bridge stack is connected with the IGBT and the motor.

6. The power tool of claim 1, wherein: the circuit board is also provided with a capacitor, the capacity of the capacitor is less than 10 microfarads, and the current limiting module is also used for offsetting voltage pulsation caused by the reduction of the capacity of the capacitor.

7. The power tool of claim 1, wherein: the circuit board adopts a double-layer lamination process.

8. The power tool of claim 1, wherein: the circuit board further comprises a filtering module, and the filtering module adopts a double-end filtering capacitor.

9. The power tool of claim 1, wherein: the power tool further includes an operating member integrated with the controller.

10. The power tool of claim 1, wherein: the motor is a brushless motor.

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