Patent Publication Number: US-2022234227-A1

Title: Hair Clipper

Description:
CROSS REFERENCE TO THE RELATED APPLICATIONS 
     This application is based upon and claims priority to Chinese Patent Applications No. 202120205872.7, filed on Jan. 26, 2021, and No. 202110680964.5, filed on Jun. 18, 2021, the entire contents of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention relates to the technical field of pet supplies, and more particularly, to a hair clipper. 
     BACKGROUND 
     In the process of raising pets, for the health of the pets and to make the pets cuter, it is usually necessary to shear the hair of the pets regularly. Therefore, the hair clipper becomes an indispensable tool for grooming and raising pets. 
     At present, the commonly used hair clippers are electric hair clippers, which include a main body and a cutter head assembly. A motor is provided in the main body to drive an electric clipper head disposed in the cutter head assembly. During operation, the friction between a stationary blade and a movable blade increases the temperature of the electric clipper head, and therefore, a heat dissipation device is necessarily disposed on the cutter head assembly. However, in the prior art, the heat dissipation device is disposed on a cutter holder of the cutter head, which not only increases the complexity and cost of the structure of the cutter head, but also leads to the poor heat dissipation effect due to the small contact area between the heat dissipation device and the blades and the low heat conduction efficiency. In addition, due to the complex structure of the cutter head in the prior art, it is not conducive to mounting lights or other auxiliary elements on the hair clipper. 
     SUMMARY 
     I. Technical Problems to be Resolved 
     In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a hair clipper, to resolve the technical problems of complex structure and poor heat dissipation effect of a cutter head of the existing hair clipper. 
     II. Technical Solutions 
     To achieve the above objectives, the present invention mainly adopts the following technical solutions: 
     According to a first aspect, an embodiment of the present invention provides a hair clipper, including a main body and a cutter head assembly fixed on the main body; a motor is disposed in the main body, and an eccentric shaft of the motor protrudes from a front end of the main body; 
     the cutter head assembly includes a heat dissipation device, a stationary blade and a movable cutter assembly; 
     the heat dissipation device includes a heat dissipation plate and a mounting structure, the mounting structure is integrated with the heat dissipation plate, a rear side of the mounting structure is provided with a bottom plate, and a front side of the mounting structure is provided with a vertically communicated accommodation cavity; 
     the stationary blade is fixed on the bottom plate of the mounting structure; 
     the movable cutter assembly is disposed in the accommodation cavity, and the movable cutter assembly includes a torsion spring, a movable cutter base and a movable blade; the movable blade is fixed at a front end of the movable cutter base, a rear end of the movable cutter base is provided with a connection structure protruded upwardly, and comb fingers of the movable blade are in contact with comb fingers of the stationary blade; 
     the torsion spring is fixed on the mounting structure, both ends of the torsion spring are provided with pressure rods, and rear ends of the pressure rods are fixed on the movable blade and press the comb fingers of the movable blade to be in tight contact with the comb fingers of the stationary blade; and 
     the cutter head assembly is fixed at the front end of the main body, the eccentric shaft is movably matched with the connection structure of the movable cutter base, and drives the movable cutter base to swing left and right under the action of the motor to realize shearing actions of the movable blade and the stationary blade. 
     Optionally, a main control circuit board electrically connected to the motor is further disposed in the main body; and 
     the main control circuit board is provided with a power compensation module, and the power compensation module controls output power of the motor based on the resistance acting on the cutter head assembly during the shearing actions. 
     Optionally, the front end of the main body is provided with a light-emitting diode (LED) light, and a light control circuit board connected to the LED light is further disposed in the main body; and 
     the light control circuit board is provided with a brightness adjustment module and an environment brightness sensing module, and the brightness adjustment module automatically adjusts the brightness of the LED light based on brightness data sensed by the environment brightness sensing module. 
     Optionally, the light control circuit board is further provided with a display module, the display module includes a plurality of LED chips, and the LED chips are controlled by the light control circuit board to display at least one character, pattern or symbol for indicating a working state of the hair clipper; and 
     a housing of the main body is provided with a display panel corresponding to the display module, and the display panel is provided with a light-transmitting structure corresponding to the character, pattern or symbol. 
     Optionally, the light control circuit board is further provided with a working state indicator and a blade life indicator; and 
     each of the working state indicator and the blade life indicator is provided with a light pipe, and the housing is provided with a light-transmitting hole corresponding to the light pipe. 
     Optionally, the light control circuit board is provided with a smart mode button, and the smart mode button is configured to send a signal to the main control circuit board to turn on a smart selection function of a shear mode; or 
     the main control circuit board is provided with a gear switch, and the gear switch is configured to turn on or off the hair clipper and to control the output power of the motor through gear adjustment; or 
     the main control circuit board is further provided with a cutter head reset switch, and the cutter head reset switch is configured to reset, after the cutter head assembly is replaced, service life of the cutter head assembly displayed on the display module, or reset a display color of the blade life indicator; and 
     the housing of the main body is provided with button holes corresponding to the smart mode button, the gear switch and the cutter head reset switch, respectively. 
     Optionally, the heat dissipation plate is plate-shaped, and a front side surface of the heat dissipation plate is provided with a heat dissipation structure and a light-transmitting structure; and 
     an upper end of the heat dissipation plate is inclined towards the main body, and left and right walls of the heat dissipation plate extend backwards to be integrally connected to form the mounting structure with a top opening. 
     Optionally, the mounting structure includes a limiting portion and a fixing portion disposed on the bottom plate; 
     the fixing portion is provided with two limiting grooves with openings facing the heat dissipation plate, and a clamping groove is disposed between the two limiting grooves; 
     the limiting portion is disposed on a front side of the fixing portion; 
     the torsion spring includes two torsion portions, ends of the two torsion portions adjacent to each other are connected by a U-shaped rod, ends of the two torsion portions far away from each other are respectively provided with the pressure rods, and the pressure rods are perpendicular to the two torsion portions; and 
     the two torsion portions are respectively placed in the two limiting grooves, the U-shaped rod is clamped in the clamping groove, the two pressure rods are respectively located on two sides of the limiting portion, and displacements of left and right swing of the two pressure rods are limited by the limiting portion. 
     Optionally, a cutter head fixing plate is further disposed on an outer side of the front end of the main body, and each of both sides of the cutter head fixing plate is provided with an elastic piece, a through hole is disposed between two elastic pieces, and the eccentric shaft penetrates out of the through hole and is movably matched with the connection structure of the movable cutter base; and 
     the mounting structure is further provided with an elastic piece clamping groove matched with the elastic piece. 
     Optionally, an upper surface of the stationary blade is tightly attached to a bottom surface of the mounting structure, and the upper surface of the stationary blade and the bottom surface of the mounting structure are both smooth planes. 
     III. Advantages 
     The present invention has the following advantages: 
     1. The stationary blade and the movable cutter assembly are directly mounted on the heat dissipation device. Compared with the prior art, this not only increases a contact area between the blades and the heat dissipation device, realizes a good heat dissipation function, but also reduces the cutter holder of the cutter head assembly in the prior art, which simplifies the structure of the cutter head assembly and reduces the production cost. 
     2. The cutter head assembly is fixed to the main body by the elastic pieces for easy disassembly. 
     3. The LED light and the light control circuit board are provided to facilitate use of the hair clipper in the case of low ambient light, and adjusting the brightness of the LED light based on the ambient brightness. 
     4. The display module or indicator is provided to display the working state of the hair clipper through the character, symbol or pattern. 
     5. Different shear modes are provided, and the power compensation module is disposed on the main control circuit board. When the smart selection function of a shear mode is turned on, the power compensation module can adjust the motor power in real time based on load of the cutter head assembly. This avoids the following problem: When the motor works at high power and high speed under low load, useless power is generated, thereby increasing the energy loss of the battery, shortening the service life of cutter head assembly and increasing frictional heat. In addition, unsmooth shearing is avoided when the motor works at low power and low speed under high load. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic perspective view of Embodiment 1 of a hair clipper according to the present invention; 
         FIG. 2  is a schematic exploded view of the hair clipper in  FIG. 1 ; 
         FIG. 3  is a schematic perspective view of a front end of a cutter head assembly in  FIG. 1 ; 
         FIG. 4  is a schematic perspective view of a rear end of the cutter head assembly in  FIG. 3 ; 
         FIG. 5  is a schematic side view of the cutter head assembly in  FIG. 3 ; 
         FIG. 6  is a schematic exploded view of the cutter head assembly in  FIG. 4 ; 
         FIG. 7  is a schematic perspective view of Embodiment 2 of a hair clipper according to the present invention; 
         FIG. 8  is a schematic exploded view of the hair clipper in  FIG. 7 ; 
         FIG. 9  is a graph showing a relationship between a working time of a rechargeable hair clipper in the prior art and a temperature of a cutter head; 
         FIG. 10  is a graph showing a relationship between a working time of a plug-in hair clipper in the prior art and a temperature of a cutter head; and 
         FIG. 11  is a graph showing a relationship between a working time of a hair clipper of the present invention and a temperature of a cutter head. 
     
    
    
     REFERENCE NUMERALS 
       10 : cutter head assembly;  100 : heat dissipation device;  110 : heat dissipation plate;  120 : mounting structure;  121 : limiting portion;  122 : fixing portion;  1221 : limiting groove;  123 : accommodation cavity;  124 : buckle;  200 : stationary blade;  300 : movable cutter assembly;  310 : movable cutter base;  320 : movable blade;  321 : pressure rod fixing hole;  330 : torsion spring;  331 : torsion portion;  332 : U-shaped rod;  333 : pressure rod;  40 : main body;  410 : cutter head fixing plate;  411 : elastic piece;  420 : motor;  421 : eccentric shaft;  430 : LED light;  440 : light control circuit board;  441 : display module;  442 : smart mode button;  450 : main control circuit board;  451 : gear switch;  452 : cutter head reset switch;  453 : charging plugboard;  460 : battery;  471 : upper cover;  4711 : display panel;  472 : lower cover;  473 : handle housing;  481 : blade life indicator;  482 : power indicator;  483 : working mode indicator. 
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     To facilitate better understanding of the present invention, the present invention will be described in detail below in conjunction with the accompanying drawings and through specific examples. Azimuth terms such as “front”, “rear”, “upper”, “lower” mentioned in this specification are based on orientations in  FIG. 1 . A direction facing a cutter head assembly is defined as “front”, and a direction facing a main body  40  is defined as “rear”. 
     A hair clipper provided in an embodiment of the present invention includes a main body and a cutter head assembly fixed on the main body; a front end of the main body is provided with an LED light, a motor is disposed in the main body, and an eccentric shaft of the motor protrudes from eth front end of the main body; 
     the cutter head assembly includes a heat dissipation device, a stationary blade and a movable cutter assembly; 
     the heat dissipation device includes a heat dissipation plate and a mounting structure, the mounting structure is connected to the heat dissipation plate, a rear side of the mounting structure is provided with a bottom plate, and a front side of the mounting structure is provided with a vertically communicated accommodation cavity; 
     the stationary blade is fixed on the bottom plate of the mounting structure; 
     the movable cutter assembly is disposed in the accommodation cavity, and the movable cutter assembly includes a torsion spring, a movable cutter base and a movable blade; the movable blade is fixed at a front end of the movable cutter base, a rear end of the movable cutter base is provided with a connection structure protruded upwardly, and comb fingers of the movable blade are in contact with comb fingers of the stationary blade; 
     the torsion spring is fixed on the mounting structure, both ends of the torsion spring are provided with pressure rods, and rear ends of the pressure rods are fixed on the movable blade and press the comb fingers of the movable blade to be in tight contact with the comb fingers of the stationary blade; and 
     the cutter head assembly is fixed at the front end of the main body, the eccentric shaft is movably matched with the connection structure of the movable cutter base, and drives the movable cutter base to swing left and right under the action of the motor to realize shearing actions of the movable blade and the stationary blade. 
     In the hair clipper of this embodiment, through the cutter head assembly, the stationary blade and the movable cutter assembly are directly mounted on the heat dissipation device. Compared with the prior art, this not only increases a contact area between the blades and the heat dissipation device, realizes a good heat dissipation function, but also reduces the cutter holder of the cutter head assembly in the prior art, which simplifies the structure of the cutter head assembly and reduces the production cost. In addition, the LED light is provided to facilitate use of the hair clipper in the case of low ambient light. 
     For better understanding of the above technical solutions, exemplary embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. Although the accompanying drawings show exemplary embodiments of the present invention, it should be understood that the present invention may be implemented in various forms and should not be limited to the embodiments set forth herein. On the contrary, the embodiments are provided to provide a clearer more and thorough understanding of the present invention, and the scope of the present invention can be fully conveyed to those skilled in the art. 
     Embodiment 1 
     Referring to  FIG. 1  to  FIG. 6 , the hair clipper of this embodiment includes a main body  40  and a cutter head assembly  10  fixed on a front side of the main body  40 . 
     As shown in  FIG. 3  to  FIG. 6 , the cutter head assembly  10  includes a heat dissipation device  100 , a stationary blade  200  and a movable cutter assembly  300 . 
     The heat dissipation device  100  includes a heat dissipation plate  110  and a mounting structure  120 . The heat dissipation plate  110  is plate-shaped, and its upper end is inclined towards the main body  40 , that is, inclined backwards. A front side surface of the heat dissipation plate  110  is provided with a heat dissipation structure and a light-transmitting structure. In practical applications, to improve the heat dissipation effect, the heat dissipation structure may be a wave-shaped or elongated heat dissipation fin. Open grooves may be disposed between heat dissipation fins to form a light-transmitting structure. 
     Left and right walls of the heat dissipation plate  110  extend backwards to be integrally connected to form the mounting structure  120  with a top opening. The mounting structure  120  has a bottom plate that is not completely closed, and the bottom plate is located on a rear side of the mounting structure  120 , so that a vertically communicated accommodation cavity  123  is formed on a front side of the mounting structure  120 . A part of the movable cutter assembly  300  is inserted into the accommodation cavity  123  from the lower side of the heat dissipation device  100 . 
     In a feasible solution, the heat dissipation plate  110  and the mounting structure  120  can be integrally formed by aluminum alloy through die-casting. 
     The mounting structure  120  further includes a limiting portion  121  and a fixing portion  122  disposed on the bottom plate. The fixing portion  122  is provided with two limiting grooves  1221  with openings facing the heat dissipation plate  100 , and the two limiting grooves  1221  are symmetrically arranged and spaced apart from each other. The limiting portion  121  is disposed on a front side of the fixing portion  122  and is a U-shaped portion with an opening facing the fixing portion  122 . The limiting portion  121  includes a limiting base and limiting arms located on left and right sides of the limiting base, and the limiting arms are disposed in a one-to-one correspondence with the limiting grooves  1221  of the fixing portion  122 . 
     In addition, a rear end and left and right sides of the mounting structure  120  may all be provided with buckles  124  to detachably fix the heat dissipation device  100  to the main body  40  of the hair clipper. The mounting structure  120  is further provided with an elastic piece clamping groove matched with the elastic piece  411  (described below) on a cutter head fixing plate  410 . 
     A front end of the stationary blade  200  is provided with comb fingers. An upper surface of the stationary blade  200  is a smooth plane, and a lower surface is provided with a heat dissipation structure. The stationary blade  200  is fixed at the bottom of the mounting structure  120 . Preferably, the bottom of the mounting structure  120  is a smooth plane, so that the upper surface of the stationary blade  200  is tightly attached to the bottom surface of the mounting structure  120 . 
     The movable cutter assembly  300  includes a fixed member and a movable member. The movable member includes a movable cutter base  310  and a movable blade  320 , and the fixed member includes a torsion spring  330 . The movable cutter base  310  is provided with a movable blade fixing plate. A rear end of the movable blade fixing plate protrudes upward to form a protrusion. The protrusion is inserted into the accommodation cavity  123  from the lower side of the mounting structure  120 . A rear side of the protrusion is provided a connection structure, and an eccentric shaft hole (or an eccentric shaft mounting groove) is provided on the connection structure for movably matching with the eccentric shaft  421 . The movable blade  320  is fixed to a front end of the movable blade fixing plate by screws, and comb fingers of the movable blade  320  extend from the front end of the movable blade fixing plate to contact the comb fingers of the stationary blade  200 . Pressure rod fixing holes  321  are provided behind the comb fingers of the movable blade  320 . The torsion spring  330  has a left-right symmetric structure and includes two torsion portions  331 . Ends of the two torsion portions  331  adjacent to each other are connected by a U-shaped rod  332 , and ends far away from each other are respectively provided with the pressure rods  333 . 
     The two torsion portions  331  of the torsion spring  330  are fixed in the limiting grooves  1221  of the fixing portion  122  in a one-to-one correspondence, and hooks at the ends of the pressure rods  333  are placed in the pressure rod fixing holes  321  on the movable blade  320 . Under the action of the torsion spring  330 , the comb fingers of the movable blade  320  are in tight contact with the comb fingers of the stationary blade  200 . In this way, when driven by the movable cutter base  310  to move left and right, the movable blade  320  can cooperate with the stationary blade  200  to realize shearing actions. 
     In this embodiment, the movable cutter assembly  300  is disposed in the accommodation cavity  123  of the mounting structure  120 , the movable blade  320  contacts the stationary blade  200 , and the torsion spring  330  presses the movable blade  320  against the stationary blade  200  (that is, the torsion spring  330  prevents the movable cutter assembly  300  from moving up and down), so that the movable cutter assembly  300  is movably fixed on the mounting structure  120  under the combined action of the torsion spring  330  and the stationary blade  200 , and can swing left and right under the drive of the eccentric shaft  421 . To enable the pressure rods  333  of the torsion spring  330  to press the movable blade  320 , a clamping groove is disposed between the two limiting grooves  1221  of the fixing portion  122 . During assembly, the two torsion portions  331  are respectively placed in the limiting grooves  1221 , the U-shaped rod  332  is clamped in the clamping groove, to prevent the torsion portion  331  from rotating, so that the pressure rods  333  always press the movable blade  320 . In addition, the limiting portion  121  can limit left and right displacements of the torsion spring  330 , thereby limiting displacements of left and right movement of the movable cutter base  310 . 
     In some embodiments, the fixing portion  122  and the torsion spring  330  may alternatively adopt other structures according to actual needs, as long as the torsion spring  330  can press the movable blade  320 . 
     In some embodiments, the stationary blade  200  may be fixed to the bottom of the heat dissipation device  100  in a variety of manners, such as by screws or buckles, as long as the upper surface of the stationary blade  200  is attached to and can be detached from the lower surface of the heat dissipation device  100 . 
     In this embodiment, the contact surfaces of the stationary blade  200  and the mounting structure  120  are both smooth planes, which increases a contact area between the stationary blade  200  and the heat dissipation device  100 . In addition, the heat dissipation structure is disposed on the lower surface of the stationary blade  200 , which improves the heat dissipation effect. In some embodiments, in order to further improve the heat dissipation effect, a layer of thermally conductive adhesive may further be filled between the stationary blade  200  and the mounting structure  120 . 
     In the cutter head assembly of this embodiment, the stationary blade and the movable cutter assembly are directly mounted on the heat dissipation device. Compared with the prior art, this not only increases the contact area between the blades and the heat dissipation device, realizes a good heat dissipation function, but also reduces the cutter holder of the cutter head assembly in the prior art, which simplifies the structure of the cutter head assembly and reduces the production cost. 
     Still referring to  FIG. 1  and  FIG. 2 , the main body  40  includes a housing, the cutter head fixing plate  410 , a motor  420 , an LED light  430 , a light control circuit board  440 , a display module  441 , a main control circuit board  450  and a battery  460 . 
     The cutter head fixing plate  410  is fixed on a front end of the motor  420 . Each of both sides of the cutter head fixing plate  410  is provided with the elastic piece  411 , and the elastic piece  411  extends away from the motor  420 . The elastic piece  411  is clamped in an elastic piece clamping groove provided on the mounting structure  120  to fix the cutter head assembly on the front side of the main body  40 . 
     The cutter head fixing plate  410  is further provided with a through hole located between the two elastic pieces  411 , and the eccentric shaft  421  of the motor  420  penetrates out of the through hole. 
     The main control circuit board  450  is fixed behind the motor  420  and is electrically connected to the motor  420 . The main control circuit board  450  is used to control the motor  420  and the light control circuit board  440 . A gear switch  451  is disposed on an upper side of the main control circuit board  450 . The gear switch  451  is configured to turn on or off the hair clipper, and may further be used to select a working mode of the hair clipper (for example, a silent working mode or a strong working mode). The gear switch  451  may be a key switch or a sliding switch, which may be set as required. 
     In practical applications, the gear switch  451  may be in electrical contact with the main control circuit board  450  through a gear switch elastic piece (for example, gold-plated beryllium bronze) to realize switch and gear adjustment. 
     In practical applications, the hair clipper may realize automatic gear shifting in the smart mode (described below). The power compensation module can adjust the power of the motor  420  into different gears in real time based on the load of the cutter head assembly. For example, a first gear is a silent working mode, and the power of the motor  420  is small; a second gear is a strong working mode, and the power of the motor  420  is large. When exiting the smart mode, if the gear switch  451  stays in the first gear, the motor  420  enters the silent working mode; if the gear switch  451  stays in the second gear, the motor  420  enters the strong working mode. 
     The rear end of the main control circuit board  450  is further provided with a cutter head reset switch  452 . The cutter head reset switch  452  is configured to reset, after the cutter head assembly  10  is replaced, service life of the cutter head assembly  10  displayed on the display module  441 , or reset a display color of the blade life indicator  481  (referring to  FIG. 8 ). 
     In practical applications, the cutter head reset switch  452  may also be used to control the LED light  430 . For example, clicking the cutter head reset switch  452  may turn on or off the LED light  430 , and long pressing the cutter head reset switch  452  (for example, pressing for 5 seconds) realizes the reset function. 
     In practical applications, the blades (the stationary blade and the movable blade) of the hair clipper have certain service life. When the blades reach an upper limit of the service life after long time use, and are seriously worn, it is necessary to replace the cutter head assembly  10  or the blades. After replacement, the cutter head reset switch  452  is configured to reset the service life of the cutter head assembly  10  or the blades, recount the working time of the blades, and reset the service life of the cutter head assembly  10  displayed on the display module  441  or reset the display color of the blade life indicator  481 . 
     In practical applications, the power compensation module may be disposed on the main control circuit board  450 , to control the power of the motor  420  based on the resistance acting on the blades during the shearing actions (that is, adjust the power of the motor  420  in real time based on the load of the cutter head assembly). For example, after the smart mode selection function is turned on, if the hair is dense, the resistance increases, and the power compensation module controls a working voltage of the motor at 3.4 V, increases the output power of the motor  420 , and enters the strong working mode; if there are fewer hairs, the resistance decreases, the power compensation module controls the working voltage of the motor at 3.0 V, reduces the output power of the motor  420 , and enters the silent working mode. The power compensation module avoids the following problem: When the motor  420  works at high power and high speed under low load, useless power is generated, thereby increasing the energy loss of the battery  460 , shortening the service life of cutter head assembly  10  and increasing frictional heat. In addition, unsmooth shearing is avoided when the motor  420  works at low power and low speed under high load. 
     The light control circuit board  440  and the main control circuit board  450  may be electrically connected through an  8 P connection line. The LED light  430  is electrically connected to the light control circuit board  440 . The light control circuit board  440  may further be provided with an environment brightness sensing module and a brightness adjustment module. The environment brightness sensing module can automatically sense brightness data of the environment, and the brightness adjustment module adjusts the brightness of the LED light  430  based on the brightness data. The display module  441  is disposed on the light control circuit board  440 . The display module  441  is provided with LED chips arranged in a matrix, and can light up different LED chips under the control of the light control circuit board  440 , to display different characters, symbols or patterns for displaying working states of the hair clipper. The light control circuit board  440  is further provided with a smart mode button (SMART button)  442 . The smart mode button  442  is disposed behind the display module  441  for turning on or off the smart mode selection function of the hair clipper. 
     In practical applications, the character, symbol or pattern displayed by the display module  441  may be used to display battery power, blade service life, working modes, and/or cutter head temperature prompts. 
     The housing of the main body  40  includes an upper cover  471 , a lower cover  472  and a handle housing  473 . The upper cover  471  and the lower cover  472  cooperate with each other to form a housing which is closed in the vertical direction. The cutter head fixing plate  410 , the motor  420  and the light control circuit board  410  are located on a front side of the housing. The light control circuit board  410  is fixed on the upper cover  471  and located above the motor  420 ; the LED light  430  is fixed at a front end of the housing; the eccentric shaft  421  of the motor  420  and the elastic pieces  411  of the cutter head fixing plate  410  protrude from the front end of the housing; the elastic pieces  411  are clamped in the elastic piece clamping grooves provided on the mounting structure  120 , to fix the cutter head assembly  10  on the front side of the housing; the eccentric shaft  421  is inserted into the eccentric shaft hole (or an eccentric shaft mounting groove) of the connection structure of the movable cutter base  310 , to realize movable matching with the movable cutter base  310 , and drives the movable cutter base  310  to swing left and right under the action of the motor  420 , to realize the shearing actions of the movable blade  320  and the stationary blade  200 . The main control circuit board  450  and the battery  460  are disposed on a rear side of the housing. The battery  460  is electrically connected to the main control circuit board  450  and is disposed under the main control circuit board  450 . 
     In practical applications, the motor  420  may be fixed on a motor fixing frame, which may be disposed on the lower cover  472  or the upper cover  471  according to actual needs. The motor fixing frame may be plate-shaped, and an anti-vibration rubber ring may be further disposed between the motor fixing frame and the motor  420 , to reduce vibration of the motor  420  and protect the motor  420 . 
     The upper cover  471  is provided with a display panel  4711  corresponding to the display module  441 , and the display panel  4711  is provided with a light-transmitting structure to make the character, pattern or symbol on the display module  441  visible. The upper cover  471  is further provided with button holes corresponding to the gear switch  451  and the cutter head reset switch  452 , respectively. 
     The lower cover  472  is provided with a battery compartment for storing the battery  460 . 
     The lower cover  472  and the upper cover  471  are further provided with buckle clamping grooves corresponding to the buckles  124  on the mounting structure  120 . The buckles  124  are matched with the buckle clamping grooves, and the elastic pieces  411  are matched with the elastic piece clamping grooves on the mounting portion  120 , to jointly fix the cutter head assembly  10  on the front side of the main body  40 . 
     The handle housing  473  is sleeved over the rear portion of the housing to facilitate grasping the hair clipper, and is provided with a button hole corresponding to the gear switch  451 . 
     In practical applications, the battery may be a rechargeable battery. In this case, the main control circuit board  450  is further provided with a charging plugboard  453  with a charging interface, and the housing and the handle housing  473  are provided with a charging hole corresponding to the charging interface. 
     In the hair clipper of this embodiment, the stationary blade and the movable cutter assembly are directly mounted on the heat dissipation device. Compared with the prior art, this not only increases a contact area between the blades and the heat dissipation device, realizes a good heat dissipation function, but also reduces the cutter base of the cutter head assembly in the prior art, which simplifies the structure of the cutter head assembly and reduces the production cost. The cutter head assembly is fixed to main body by the elastic piece clamping grooves and buckle clamping grooves for easy disassembly. The LED light is provided to facilitate use of the hair clipper in the case of low ambient light. The display module is provided, to display the working state of the hair clipper by using the character, symbol or pattern. 
     Embodiment 2 
     A hair clipper of this embodiment is proposed based on Embodiment 1, in which the display module in Embodiment 1 is replaced with a working state indicator and a blade life indicator. 
     Referring to  FIG. 7  and  FIG. 8 , in this embodiment, the working state indicator includes a power indicator  482  and a working mode indicator  483 . The power indicator  482  and the blade life indicator  481  are disposed on the front side of the light control circuit board  440 , and the working mode indicator  483  is disposed on the rear side of the light control circuit board  440 . The working mode indicator  483  includes a plurality of indicators arranged side by side. Different numbers of lighted indicators indicate different working modes of the hair clipper. For example, when fewer indicators are lighted, it indicates a silent working mode. When all the working mode indicators are lighted, it indicates a strong working mode. 
     In practical applications, indication meanings of the working state indicator and the blade life indicator  481  may alternatively be defined as required. For example, for the battery indicator  482 , always green indicates that the battery is fully charged; flashing green indicates that the battery is being charged; flashing red indicates that the battery is low; for the blade life indicator  481 , red indicated that the blade needs to be replaced, and the indicator “off” indicates that the blade has not reached the end of its service life. 
     In this embodiment, each indicator is provided with a light pipe, and the upper cover  471  of the main body  40  is provided with the light-transmitting hole corresponding to the light pipe. 
     In the hair clipper of this embodiment, the stationary blade and the movable cutter assembly are directly mounted on the heat dissipation device. Compared with the prior art, this not only increases a contact area between the blades and the heat dissipation device, realizes a good heat dissipation function, but also reduces the cutter base of the cutter head assembly in the prior art, which simplifies the structure of the cutter head assembly and reduces the production cost. The main body and the cutter head assembly are fixed by elastic piece clamping grooves and buckle clamping grooves for easy disassembly. The LED light is provided to facilitate use of the hair clipper in the case of low ambient light. The working state indicators are provided, to display the working state of the hair clipper through the character, symbol or pattern. 
     In practical applications, the hair of pets or animals is long and dense, and the prior-art clipper is easy to get stuck and cannot work normally. Especially as the running time of the hair clipper is prolonged, the temperature of the cutter head rises rapidly due to friction, and the pets or animals may be even burned. In addition, the handle housing of the hair clipper is far away from the cutter head and has low thermal conductivity. Consequently, the user of the hair clipper cannot sense the temperature increase of the cutter head or even a high temperature during the shearing process. As a result, the pets or animals feel uncomfortable or even struggle because of injury during the shearing process, and cannot cooperate well with the owner to complete the hair shearing, but the pet or animal owner may not find the real problem. The structure of the heat dissipation device of the present invention conforms to the aerodynamic structure design. It can dissipate heat more effectively, and can prevent the cutter head from overheating during the shearing process. Therefore, there is no risk of harming the pets, and the pets are more cooperative during the shearing process. 
     The following will further describe the heat dissipation function of the hair clipper of the present invention by comparing test data of the existing hair clipper with test data of the hair clipper of the present invention. 
     Specifically, for temperature test results of the prior-art hair clipper during use, refer to Table 1,  FIG. 9  and  FIG. 10 . The test room temperature is 24° C. In a no-load mode of the hair clipper, temperatures of three different positions on the stationary blade are monitored in real time for 60 minutes, and the temperatures of the three test points are recorded every minute. Ch1, Ch3 and Ch4 are test data of different test points at a prior-art chargeable hair clipper, and Ch6, Ch7 and Ch8 are test data of different test points at another prior-art clipper powered by a socket. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 1 
               
             
            
               
                   
                   
               
               
                   
                 Temperature 
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Time 
                 Ch1 
                 Ch3 
                 Ch4 
                 Ch6 
                 Ch7 
                 Ch8 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 1 
                 26.6 
                 26.7 
                 26.9 
                 30.8 
                 30.3 
                 31.5 
               
               
                 10 
                 38.4 
                 40.4 
                 40.3 
                 42.0 
                 41.3 
                 43.4 
               
               
                 20 
                 47.4 
                 48.9 
                 48.7 
                 45.2 
                 44.7 
                 46.2 
               
               
                 30 
                 52.4 
                 55.0 
                 54.0 
                 46.2 
                 45.6 
                 47.3 
               
               
                 40 
                 53.4 
                 55.7 
                 54.8 
                 47.1 
                 46.8 
                 47.9 
               
               
                 50 
                 40.0 
                 41.6 
                 39.3 
                 46.6 
                 46.6 
                 47.3 
               
               
                 60 
                 34.9 
                 35.5 
                 34.4 
                 47.9 
                 47.8 
                 49.4 
               
               
                   
               
            
           
         
       
     
     It can be learned from Table 1 and  FIG. 9  that a temperature rise curve of the chargeable hair clipper is relatively fast. The temperature rises continuously within 40 minutes, and the maximum temperature is 57.1° C. When the power is depleted in 40 minutes, the hair clipper stops, and the temperature drops slowly. It can be learned from Table 1 and  FIG. 10  that the plug-in hair clipper heats up faster in the first 15 minutes, and then slowly heats up, with a maximum temperature of 49.4° C. 
     For the temperature test results of the hair clipper of the present invention during use, refer to Table 2 and  FIG. 11 . The test room temperature is 24° C. In a no-load mode of the hair clipper, temperatures of three different positions on the stationary blade are monitored in real time for 60 minutes, and the temperatures of the three test points are recorded every minute. T1, T2 and T3 are the temperatures of the three test points. 
     
       
         
           
               
               
             
               
                   
                 TABLE 2 
               
             
            
               
                   
                   
               
               
                   
                 Temperature 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Time 
                 T1 
                 T2 
                 T3 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 1 
                 25.5 
                 25.3 
                 25.2 
               
               
                   
                 10 
                 35.7 
                 35.8 
                 33.7 
               
               
                   
                 20 
                 42.2 
                 42.1 
                 39.9 
               
               
                   
                 30 
                 42.6 
                 42.6 
                 40.7 
               
               
                   
                 40 
                 42.8 
                 42.6 
                 41.3 
               
               
                   
                 50 
                 42.8 
                 42.6 
                 41.6 
               
               
                   
                 60 
                 42.4 
                 42.4 
                 41.7 
               
               
                   
                   
               
            
           
         
       
     
     It can be learned from Table 2 and  FIG. 11  that the temperature rise curve of the hair clipper of the present invention is relatively even, continuously rising from a room temperature of 24° C. to 42.9° C. 15 minutes later, the blade temperature stabilizes and remains at about 42° C. 
     Comparing Table 1 with Table 2 and comparing  FIGS. 9 and 10  with  FIG. 11 , it can be learned that, compared with that of the prior-art hair clippers, the structure design of the heat dissipation device of the hair clipper of the present invention conforms to the aerodynamic structure design. Therefore, its temperature rises steadily, and it can dissipate heat well during the working process, so that the temperature of the blade of the hair clipper is maintained at about 42° C. This can prevent the cutter head from overheating during the shearing process, so there is no risk of harming the pets. The pets are more cooperative during the shearing process, achieving better user experience. 
     In the description of the present invention, it should be understood that terms such as “first” and “second” are used merely for a descriptive purpose, and should not be construed as indicating or implying a relative importance, or implicitly indicating the number of indicated technical features. Thus, features defined with “first” and “second” may explicitly or implicitly include one or more of the features. In the description of the present invention, “a plurality of” means two or more, unless otherwise specifically defined. 
     In the present invention, unless otherwise clearly specified, the terms “installation”, “interconnection”, “connection” and “fixation” etc. are intended to be understood in a broad sense. For example, the “connection” may be a fixed connection, removable connection or integral connection; may be a mechanical connection or electrical connection; may be a direct connection or indirect connection using a medium; and may be a communication or interaction between two elements. Those of ordinary skill in the art may understand specific meanings of the above terms in the present invention based on a specific situation. 
     In the present invention, it should be understood that terms such as “first” and “second” are used merely for a descriptive purpose, and should not be construed as indicating or implying a relative importance, or implicitly indicating the number of indicated technical features. In addition, that the first feature is “over”, “above”, and “on” the second feature includes that the first feature is directly above and diagonally above the second feature, or simply indicates that an altitude of the first feature is higher than that of the second feature. “A first feature is under and below a second feature” includes “the first feature is directly under or obliquely under the second feature” or simply means that “the first feature is lower than the second feature”. 
     In the description of the present specification, the description with reference to the terms “one embodiment”, “some embodiments”, “example”, “specific example”, or “some examples” means that specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In the present specification, the schematic representation of the above terms is not necessarily directed to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more of embodiments or examples. In addition, a person skilled in the art may combine different embodiments or examples described in this specification and characteristics of the different embodiments or examples without mutual contradiction. 
     Although the examples of the present invention have been illustrated and described above, it will be appreciated that the above examples are illustrative and should not be construed as limiting the scope of the present invention. Changes, modifications, substitutions and variations can be made to the above examples by a person of ordinary skill in the art within the scope of the present invention.