Anti-moment electric saw

Abstract

The application discloses an anti-moment electric saw, which comprises a gun body, a cutter head assembly and a moment balance mechanism. The gun body comprises a shell and a power assembly installed in the shell. The cutter head assembly comprises a transmission shaft, a connecting mechanism and a cutter head. The transmission shaft is slidingly connected in the shell, one end of the transmission shaft extends out of the shell and is coaxially connected with the cutter head assembly through the connecting mechanism. The center of mass A of the cutter head assembly is located on the axis of the transmission shaft. The moment balance mechanism comprises a counterweight. The center of mass C of the counterweight is substantially located on the axis of the transmission shaft. The power assembly is drivingly connected with the counterweight and can drive the counterweight to reciprocate in the shell. The acceleration direction of the counterweight is opposite to the acceleration direction of the cutter head assembly, and the acceleration size of the counterweight is proportional to the acceleration size of the cutter head assembly, so that the inertial force of the counterweight is substantially equal to the inertial force of the cutter head assembly. The anti-moment electric saw can balance the resultant force of the cutter head assembly and reduce the vibration of the gun body.

Description

Technical Field

[0001] This invention relates to the field of chainsaw technology, and more particularly to a torque-resistant chainsaw. Background Technology

[0002] See existing chainsaws Figure 6 The saw includes a gun body 91 and a blade assembly 92 mounted on the output end of the gun body. The center of mass 93 of the blade assembly is located approximately on the axis 94 of the blade assembly, while the center of mass 95 of the gun body is located below the axis of the blade assembly and is at a considerable distance from it. When the chainsaw is in operation, the user holds the gun body, and the blade assembly has a large inertial force F during its high-speed axial reciprocating motion. After this inertial force acts on the gun body, it will cause the gun body to be subjected to a torque M rotating around the center of mass of the gun body. The magnitude of the inertial force is proportional to the acceleration of the blade assembly. As the acceleration of the blade assembly changes continuously during its movement, its inertial force changes repeatedly. When the user holds the gun body, in order to ensure the stability of the gun body, it is necessary to resist this constantly changing inertial force, which results in a large vibration and affects the user experience. Summary of the Invention

[0003] To address the drawback of excessive vibration in existing chainsaws, this invention proposes a torque-resistant chainsaw where a counterweight balances the net external force on the cutter head assembly, thereby reducing the vibration of the saw body.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A torque-resistance chainsaw includes: a gun body, a cutter head assembly, and a torque balancing mechanism; the gun body includes a housing and a power assembly installed within the housing; the cutter head assembly includes a drive shaft, a connecting mechanism, and a cutter head, the drive shaft being slidably connected within the housing, the power assembly being driven by the drive shaft and capable of driving the drive shaft to reciprocate axially, one end of the drive shaft extending outside the housing and being coaxially connected to the cutter head assembly via the connecting mechanism, the center of mass A of the cutter head assembly being located on the axis of the drive shaft; the torque balancing mechanism includes a counterweight, the center of mass C of the counterweight being substantially located on the axis of the drive shaft, the power assembly being driven by the counterweight and capable of driving the counterweight to reciprocate within the housing; the acceleration direction of the counterweight is opposite to the acceleration direction of the cutter head assembly, and the magnitude of the acceleration of the counterweight is proportional to the magnitude of the acceleration of the cutter head assembly, such that the inertial force of the counterweight is substantially equal to the inertial force of the cutter head assembly.

[0006] With the above settings, firstly, the inertial force of the counterweight can balance the inertial force of the cutter head assembly, reducing the net external force on the gun body in the axial direction of the transmission shaft; secondly, the center of mass C of the counterweight is basically located on the axis of the transmission shaft, and the torque caused by the inertial force of the counterweight can balance the torque caused by the inertial force of the cutter head assembly, thereby reducing the vibration of the gun body.

[0007] Furthermore, the power assembly includes: a motor, a reducer, and a cam; both the motor and the reducer are installed in the housing, the motor and the reducer are connected in transmission, and the output shaft of the reducer is vertically positioned below the transmission shaft; the cam includes a cylinder, a cantilever, and a drive pin, the cylinder is eccentrically mounted on the output shaft of the motor, the cantilever is fixedly connected to one side of the upper end of the cylinder, the drive pin is mounted on the upper side of the cantilever, and the axis of the output shaft of the reducer is located between the axis of the cylinder and the axis of the drive pin; the cutter head assembly also includes a drive component, the drive component is fixedly connected to the lower side of the transmission shaft, the lower side of the drive component is provided with a first transmission groove, the extension direction of the first transmission groove is perpendicular to the transmission shaft, the width of the first transmission groove is adapted to the outer diameter of the drive pin, and the drive pin is slidably connected in the first transmission groove; the counterweight is provided with a second transmission groove, the extension direction of the second transmission groove is parallel to the extension direction of the first transmission groove, the width of the second transmission groove is adapted to the outer diameter of the cylinder, and the cylinder passes through the second transmission groove.

[0008] With the above configuration, the motor drives the cutter head assembly via a drive pin; the motor also drives the counterweight via an eccentrically positioned cylinder.

[0009] Furthermore, the counterweight includes: a counterweight body, a transmission ring, and a connecting rod; the counterweight body is slidably connected in the gun body; the inner side of the transmission ring forms a second transmission groove, and the transmission ring is located on the side of the counterweight body near the cutter head assembly; the connecting rod is fixedly connected between the transmission ring and the counterweight body.

[0010] Furthermore, the cutter head includes: a cutter head body, a connecting key, and an annular protrusion; the connecting key is cylindrical and coaxially fixedly connected to one end of the cutter head body, and the outer end of the drive shaft is provided with a socket adapted to the connecting key, into which the connecting key is inserted; the annular protrusion is fixedly connected to the outer periphery of the connecting key, and the connecting mechanism is a nut, with the nut sleeved at the end of the cutter head, one end of the nut having an inwardly extending flange, and the other end of the nut being threadedly connected to the outer end of the drive shaft, the flange pressing the annular protrusion onto the drive shaft.

[0011] With the above setup, the cutter head is mounted on the drive shaft via a nut.

[0012] Furthermore, the cutter head also includes: a positioning plate; the positioning plate is fixedly connected to the end of the connecting key away from the cutter head body, and the positioning plate is parallel to the cutting direction of the cutter head body; the cutter head assembly also includes a positioning mechanism, which includes a slider and a spring, one end of the slider is provided with a positioning groove adapted to the positioning plate, the positioning plate is embedded in the positioning groove to position the cutting direction of the cutter head, the slider is slidably connected in the socket, and the spring is provided in the socket, one end of the spring is connected to the slider to press the slider against the end of the cutter head.

[0013] The above settings make it easier to position the cutter head body when installing the cutter head.

[0014] Furthermore, a through hole is provided inside the drive shaft, which passes through both ends of the drive shaft. One end of the through hole forms an insertion port. The positioning mechanism also includes a steel ball. On the side of the steel ball away from the cutter head, a spring is placed between the slider and the steel ball. A boss is provided on the side wall of the through hole, which supports the steel ball so that the spring is in a compressed state.

[0015] With the above configuration, the drive shaft supports the spring via a boss and steel balls.

[0016] Furthermore, a cavity is provided in the gun body, and an air inlet is provided at the end of the cavity away from the blade assembly. The outer end of the air inlet is connected to the outside atmosphere, and the inner end of the air inlet is connected to the cavity. A filter screen is provided at the outer end of the air inlet, and a first one-way valve structure is provided at the inner end of the air inlet. Outside air can enter the cavity through the first one-way valve structure. A counterweight is slidably connected in the cavity, and there is a gap between the outer periphery of the counterweight and the side wall of the cavity. A guide hole is provided on the counterweight, and the drive shaft passes through the guide hole and is slidably connected to the counterweight. The counterweight, drive shaft and first one-way valve structure make the end of the cavity away from the blade assembly form a basically sealed compression chamber.

[0017] The gun body also includes a dust baffle, which is fixedly connected to the housing. The dust baffle is arranged around the connecting mechanism, and an opening facing the blade is formed between the dust baffle and the housing.

[0018] A first air hole is provided at one end of the drive shaft, which penetrates both the inner and outer sides of the drive shaft. The outer end of the first air hole is located in the accommodating space. A second air hole is provided on the slider. One end of the second air hole extends to the side wall of the through hole and forms an air outlet. The other end of the second air hole penetrates to the end of the slider away from the cutter head and forms an air inlet that communicates with the through hole.

[0019] When the cutter head is installed in the socket, the inner end of the first air hole coincides with the air outlet end of the second air hole;

[0020] After the blade is removed from the insertion port, the inner end of the first air hole is offset from the outlet end of the second air hole, and the slider blocks the first air hole.

[0021] The steel ball and spring form a second one-way valve structure with the conveying direction facing the receiving space. When the steel ball contacts the boss, the second one-way valve structure is closed. When the steel ball separates from the boss, the compression chamber is connected to the second air hole through the through hole.

[0022] With the above configuration, the counterweight acts as a piston, which can blow air into the housing space to maintain a high-pressure state in the housing space. This prevents dust generated during the operation of the chainsaw from spreading into the housing space and adhering to the drive shaft, thereby preventing dust from entering the housing through the gap between the housing and the drive shaft and affecting the normal operation of the gun.

[0023] Furthermore, the first one-way valve structure is configured as a rubber valve plate, with one end of the rubber valve plate installed on the cavity, and the rubber valve plate covering the inside of the air inlet. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a chainsaw used in an embodiment.

[0025] Figure 2 This is a schematic diagram of the internal structure of the chainsaw used in this embodiment.

[0026] Figure 3 This is a cross-sectional view of the chainsaw used in an embodiment.

[0027] Figure 4 for Figure 3 Enlarged view of point D.

[0028] Figure 5 This is a schematic diagram of the first vent outputting air outward in an embodiment.

[0029] Figure 6 This is a schematic diagram of an existing chainsaw. Detailed Implementation

[0030] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0031] See Figures 1 to 5 A torque-resistant chainsaw includes: a gun body, a cutter head assembly 3, and a torque balancing mechanism; the gun body includes a housing 5 and a power assembly 6 installed within the housing 5; the cutter head assembly 3 includes a drive shaft 31, a connecting mechanism 32, and a cutter head 33, the drive shaft 31 being slidably connected within the housing 5, the power assembly 6 being drively connected to the drive shaft 31 and capable of driving the drive shaft 31 to reciprocate axially, one end of the drive shaft 31 extending outside the housing 5 and being coaxially connected to the cutter head assembly 3 via the connecting mechanism 32, the cutter head assembly 3... The center of mass A is located on the axis of the transmission shaft 31; the torque balancing mechanism includes a counterweight 41, the center of mass C of the counterweight 41 is basically located on the axis of the transmission shaft 31, the power component 6 is connected to the counterweight 41 and can drive the counterweight 41 to reciprocate in the housing 5; the acceleration direction of the counterweight 41 is opposite to the acceleration direction of the cutter head assembly 3, and the magnitude of the acceleration of the counterweight 41 is proportional to the magnitude of the acceleration of the cutter head assembly 3, so that the inertial force of the counterweight 41 is basically equal to the inertial force of the cutter head assembly 3.

[0032] With the above settings, firstly, the inertial force of the counterweight 41 can balance the inertial force of the cutter head assembly 3, reducing the net external force on the gun body in the axial direction of the transmission shaft 31; secondly, the center of mass of the counterweight 41 is basically located on the axis of the transmission shaft 31, and the torque caused by the inertial force of the counterweight 41 can balance the torque caused by the inertial force of the cutter head assembly 3, thereby reducing the vibration of the gun body.

[0033] In this application, the housing 5 is made of plastic, which is lightweight and has high strength; the cutter head 33 is a one-piece molded structure made of metal, which has good strength; the connecting mechanism 32 can use ordinary fasteners to install the cutter head 33 on the outer end of the drive shaft 31; the power component 6 synchronously drives the drive shaft 31 and the counterweight 41 to reciprocate; when the electric saw is working, refer to Figure 3 The center of mass C of the counterweight 41 is basically located on the axis of the drive shaft 31. That is, the distance from the center of mass C of the counterweight to the axis of the drive shaft is less than or equal to the outer diameter of the drive shaft. The smaller the distance from the center of mass C of the counterweight to the axis of the drive shaft, the better the balance effect of the counterweight. In this application, the center of mass C of the counterweight is located on the axis of the drive shaft and inside the housing. When the acceleration direction of the counterweight 41 is opposite to the acceleration direction of the cutter head assembly 3, and the magnitude of the acceleration of the counterweight 41 is proportional to the magnitude of the acceleration of the cutter head assembly 3, according to the formula for calculating inertial force: inertial force equals mass multiplied by acceleration, by designing the mass of the counterweight and the cutter head assembly, the inertial forces of the two are basically the same, that is, the ratio of the inertial force of the counterweight to the inertial force of the cutter head assembly is 95% to 105%. At this point, the inertial force of the counterweight 41 will basically offset the inertial force of the cutter assembly 3, which can reduce the net external force on the gun body in the direction of the transmission shaft 31 axis, thereby reducing the vibration of the gun body. In addition, in this application, the center of mass D of the gun body is located below the axis of the transmission shaft 31. The distance from the inertial force of the cutter assembly 3 to the center of mass D of the gun body is L1, and the distance from the inertial force of the counterweight 41 to the center of mass D of the gun body is L2. Since the center of mass C of the counterweight 41 and the center of mass A of the cutter assembly 3 are both located on the axis of the transmission shaft 31, L1 and L2 are equal. When the inertial force F1 of the counterweight 41 is basically equal to the inertial force F2 of the cutter assembly 3, the torque caused by the inertial force of the counterweight 41 basically offsets the torque caused by the cutter assembly 3, further reducing the vibration of the gun body.

[0034] In one implementation, the power assembly 6 includes: a motor 61, a reducer 63, and a cam 62; both the motor 61 and the reducer are installed in the housing 5, with the motor and reducer being connected in transmission. The output shaft of the reducer is vertically positioned below the transmission shaft 31. The cam 62 includes a cylinder 621, a cantilever 622, and a drive pin 623. The cylinder 621 is eccentrically mounted on the output shaft of the motor 61, the cantilever 622 is fixedly connected to one side of the upper end of the cylinder 621, and the drive pin 623 is mounted on the upper side of the cantilever 622. The axis of the reducer's output shaft is located between the axis of the cylinder 621 and the axis of the drive pin 623. (The last sentence appears to be an unrelated fragment: "cutter head assembly.") Component 3 also includes a driving component 34, which is fixedly connected to the lower side of the transmission shaft 31. A first transmission groove 341 is provided on the lower side of the driving component 34. The extension direction of the first transmission groove 341 is perpendicular to the transmission shaft 31. The width of the first transmission groove 341 is adapted to the outer diameter of the driving pin 623. The driving pin 623 is slidably connected in the first transmission groove 341. A second transmission groove 411 is provided on the counterweight block 41. The extension direction of the second transmission groove 411 is parallel to the extension direction of the first transmission groove 341. The width of the second transmission groove 411 is adapted to the outer diameter of the cylinder 621. The cylinder 621 passes through the second transmission groove 411.

[0035] With the above configuration, motor 61 drives the cutter head assembly 3 through drive pin 623; motor 61 drives counterweight block 41 through eccentrically set cylinder 621.

[0036] In this application, the motor 61 can be a brushless motor, which has the characteristics of quiet operation; the axis of the cylinder 621, the axis of the output shaft of the reducer, and the axis of the drive pin 623 are parallel to each other; the transmission shaft 31 and the counterweight 41 can only slide in the direction of the axis of the transmission shaft 31 within the housing 5; when the motor 61 drives the cam 62 to rotate, the drive pin 623 and the cylinder 621 both rotate synchronously around the axis of the output shaft of the reducer; the drive pin 623 drives the cutter head assembly 3 to reciprocate through the first transmission groove 341, and during the process, the drive pin 623 slides back and forth in the first transmission groove 341; the cylinder 621 drives the counterweight 41 to reciprocate through the second transmission groove 411, and during the process, the drive pin 623 slides back and forth in the first transmission groove 341. The blade slides back and forth in the second transmission groove 411. In this application, the axis of the drive pin 623 and the axis of the cylinder 621 are located on opposite sides of the axis of the output shaft of the reducer, so that the acceleration direction of the blade assembly 3 is opposite to the acceleration direction of the counterweight 41. At the same time, the magnitude of the acceleration of the blade assembly 3 is proportional to the magnitude of the acceleration of the counterweight 41. In particular, when the axis of the drive pin 623 and the axis of the cylinder 621 are symmetrically arranged on opposite sides of the axis of the output shaft of the reducer, the magnitude of the acceleration of the blade assembly 3 is equal to the magnitude of the acceleration of the counterweight 41. At this time, when the mass of the counterweight 41 is equal to the mass of the blade assembly 3, the inertial force of the counterweight 41 is equal to the inertial force of the blade assembly 3.

[0037] As one implementation, the counterweight 41 includes: a counterweight body 412, a transmission ring 413, and a connecting rod 414; the counterweight body 412 is slidably connected in the gun body; the inner side of the transmission ring 413 forms a second transmission groove 411, and the transmission ring 413 is disposed on the side of the counterweight body 412 near the cutter head assembly 3; the connecting rod 414 is fixedly connected between the transmission ring 413 and the counterweight body 412.

[0038] As one implementation, the cutter head 33 includes: a cutter head body 331, a connecting key 332, and an annular protrusion 333; the connecting key 332 is cylindrical and coaxially fixedly connected to one end of the cutter head body 331, and the outer end of the drive shaft 31 is provided with a socket 311 adapted to the connecting key 332, into which the connecting key 332 is inserted; the annular protrusion 333 is fixedly connected to the outer periphery of the connecting key 332, and the connecting mechanism 32 is a nut, which is sleeved on the end of the cutter head 33, and one end of the nut is provided with an inwardly extending flange 321, and the other end of the nut is threadedly connected to the outer end of the drive shaft 31, with the flange 321 pressing the annular protrusion 333 onto the drive shaft 31.

[0039] With the above configuration, the cutter head 33 is mounted on the drive shaft 31 via a nut.

[0040] In this application, the cutter head body 331 can refer to existing saws; the cutter head 33 is a one-piece molded structure; the socket 311 is adapted to the connecting key 332, and after the connecting key 332 is inserted into the socket 311, the cutter head 33 will not wobble; the nut can be fitted onto the connecting key 332 through the cutting end of the cutter head body 331, and after the nut is tightened on the outer end of the drive shaft 31, the flange 321 of the nut can press the annular protrusion 333 onto the drive shaft 31, thereby locking the cutter head 33 onto the drive shaft 31.

[0041] As one implementation, the cutter head 33 also includes: a positioning plate 334; the positioning plate 334 is fixedly connected to the end of the connecting key 332 away from the cutter head body 331, and the positioning plate 334 is parallel to the cutting direction of the cutter head body 331; the cutter head assembly 3 also includes a positioning mechanism 35, the positioning mechanism 35 includes a slider 351 and a spring 352, one end of the slider 351 is provided with a positioning groove 3511 adapted to the positioning plate 334, the positioning plate 334 is embedded in the positioning groove 3511 to position the cutting direction of the cutter head 33, the slider 351 is slidably connected in the socket 311, the spring 352 is provided in the socket 311, one end of the spring 352 is connected to the slider 351 to press the slider 351 against the end of the cutter head 33.

[0042] With the above settings, it is convenient to position the direction of the cutter head body 331 when installing the cutter head 33.

[0043] In this application, when the cutter head 33 is not installed in the socket 311, the slider 351 is located at the opening of the socket 311 under the action of the spring 352, so that the positioning groove 3511 is exposed to the outside. The slider 351 and the groove will not rotate relative to each other. When installing the cutter head 33, the positioning plate 334 is embedded in the positioning groove 3511. The positioning groove 3511 prevents the cutter head 33 from rotating around its own axis through the positioning plate 334, so as to lock the angle of the cutter head 33. The cutter head 33 is pushed into the groove, the connecting key 332 is inserted into the socket 311, the slider 351 slides inward along the socket 311, the spring 352 is compressed, and then the nut is tightened to complete the installation of the cutter head 33.

[0044] As one implementation, a through hole 312 is provided in the drive shaft 31, which passes through both ends of the drive shaft 31. One end of the through hole 312 forms an insertion port 311. The positioning mechanism 35 also includes a steel ball 353. The steel ball 353 is located on the side away from the cutter head 33. A spring 352 is disposed between the slider 351 and the steel ball 353. A boss 3121 is provided on the side wall of the through hole 312. The boss 3121 supports the steel ball 353 so that the spring 352 is in a compressed state.

[0045] With the above configuration, the drive shaft 31 supports the spring 352 via the boss 3121 and the steel ball 353.

[0046] As one implementation, a cavity 7 is provided in the gun body. An air inlet 8 is provided at the end of the cavity 7 away from the blade assembly 3. The outer end of the air inlet 8 is connected to the outside atmosphere, and the inner end of the air inlet 8 is connected to the cavity 7. A filter screen 9 is provided at the outer end of the air inlet 8, and a first one-way valve structure 10 is provided at the inner end of the air inlet 8. Outside air can enter the cavity 7 through the first one-way valve structure 10. A counterweight is slidably connected in the cavity 7. There is a gap between the outer periphery of the counterweight and the side wall of the cavity 7. A guide hole 4121 is provided on the counterweight. The drive shaft 31 passes through the guide hole 4121 and is slidably connected to the counterweight. The counterweight, the drive shaft 31 and the first one-way valve structure 10 make the end of the cavity 7 away from the blade assembly 3 form a basically sealed compression chamber 71.

[0047] The gun body also includes a dust baffle 11, which is fixedly connected to the housing 5. The dust baffle 11 is arranged around the connecting mechanism 32, and an accommodating space 12 with an opening facing the blade 33 is formed between the dust baffle 11 and the housing 5.

[0048] A first air hole 313 is provided at one end of the drive shaft 31. The first air hole 313 passes through both the inner and outer sides of the drive shaft 31. The outer end of the first air hole 313 is located in the accommodating space 12. A second air hole 3512 is provided on the slider 351. One end of the second air hole 3512 extends to the side wall of the through hole 312 and forms an air outlet. The other end of the second air hole 3512 passes through to the end of the slider 351 away from the cutter head 33 and forms an air inlet communicating with the through hole 312.

[0049] When the blade 33 is installed in the socket 311, the inner end of the first air hole 313 coincides with the air outlet end of the second air hole 3512.

[0050] After the blade 33 is removed from the insertion port 311, the inner end of the first air hole 313 is offset from the air outlet end of the second air hole 3512, and the slider 351 blocks the first air hole 313.

[0051] The steel ball 353 and the spring 352 form a second one-way valve structure with the conveying direction facing the receiving space 12. When the steel ball 353 contacts the boss 3121, the second one-way valve structure is closed. When the steel ball 353 is separated from the boss 3121, the compression chamber 71 is connected to the second air hole 3512 through the through hole 312.

[0052] With the above configuration, the counterweight 41 acts as a piston, which can blow air into the accommodating space 12 to maintain a high pressure state in the accommodating space 12, preventing dust generated during the operation of the chainsaw from spreading into the accommodating space 12 and adhering to the drive shaft 31, thereby preventing dust from entering the housing 5 through the gap between the housing 5 and the drive shaft 31 and affecting the normal operation of the gun.

[0053] In this application, a circular mounting port is provided on one side of the housing 5. One end of the drive shaft 31 extends to the outside of the housing 5 through the mounting port. There is a gap between the mounting port and the drive shaft 31. When the electric saw is working, a large amount of dust or sawdust is spread in the air. In order to prevent dust from entering the housing 5 through the gap and affecting the normal operation of the electronic components inside the housing 5, a sealing ring is provided at the gap. However, due to the working characteristics of the electric saw, the sealing ring will heat up or wear during the reciprocating motion of the drive shaft 31. Over time, the sealing performance of the sealing ring will be damaged, and dust will easily adhere to the outer surface of the drive shaft 31 and then enter the housing 5 through the mounting port through the movement of the drive shaft 31.

[0054] In this application, the outer side of the counterweight does not contact the side wall of the cavity 7. Specifically, the outer periphery of the counterweight body does not contact the side wall of the cavity to prevent the counterweight from generating heat through friction during movement, which could lead to overheating of the gun body. Specifically, the gap between the outer periphery of the counterweight body and the side wall of the cavity 7 is one millimeter, which prevents the counterweight from rubbing against the cavity 7 and also hinders air leakage in the compression chamber 71 to a certain extent. The guide hole 4121 is provided on the counterweight body, and the drive shaft passes through the counterweight body. The drive shaft 31 supports the counterweight and guides the counterweight, so that the counterweight can move stably along the axial direction of the drive shaft 31.

[0055] When the chainsaw is in operation, with the cutter head 33 mounted on the drive shaft 31, see [reference needed]. Figure 4 At this time, the accommodating space 12 is connected to the through hole 312 through the first air hole 313 and the second air hole 3512. The steel ball 353 is pressed against the boss 3121 under the action of the spring 352 to prevent outside air from flowing back into the housing 5 through the through hole 312. When the counterweight body 412 is squeezed by the power component to compress the compression chamber 71, the air pressure in the compression chamber 71 increases. The first one-way valve structure 10 can prevent air leakage from the air inlet 8. The air in the compression chamber 71 pushes the steel ball 353 away, the spring 352 compresses, and the air enters the accommodating space 12 through the through hole 312, the second air hole 3512, and the first air hole 313. The counterweight body 412 returns to its original position in the direction of the cutter head assembly 3. When the volume of the compression chamber 71 increases, the air pressure inside the compression chamber 71 becomes lower than the external atmospheric pressure. Under the action of the spring 352, the steel ball 353 is pressed back onto the boss 3121, preventing outside air from entering the compression chamber 71 through the steel ball 353. In addition, outside air enters the compression chamber 71 through the filter screen 9 and the first one-way valve structure 10, replenishing the air in the compression chamber 71. In this cycle, air is continuously output from the first air hole 313. After the air enters the receiving space 12, the receiving space 12 is under high pressure, preventing dust caused by the operation of the electric saw from spreading into the receiving space 12 and adhering to the surface of the drive shaft 31, thereby preventing dust from entering the housing 5 through the drive shaft 31. Among them, the air inlet 8 faces away from the cutter head assembly 3, so there is less dust. In addition, the filter screen 9 can filter dust from entering the housing 5 through the air inlet 8, and the filter screen 9 can be made detachable for easy replacement.

[0056] When the chainsaw is not in use, after the blade 33 is removed from the socket 311, the spring 352 pushes the slider 351 to move out of the socket 311. The inner end of the first air hole 313 is misaligned with the air outlet end of the second air hole 3512. At the same time, the slider 351 blocks the socket 311 to prevent foreign objects from entering the housing through the first air hole 313 and the socket 311.

[0057] As one implementation, the first one-way valve structure 10 is configured as a rubber valve plate, with one end of the rubber valve plate installed on the cavity 7, and the rubber valve plate covering the inside of the air inlet 8.

[0058] In this application, the rubber valve plate is relatively soft. When the air pressure in the compression chamber 71 increases, the rubber valve plate is pressed against the inside of the air inlet 8 to prevent air leakage from the air inlet 8. When the air pressure in the compression chamber 71 is lower than the external atmospheric pressure, the outside air can push open the rubber valve plate and enter the compression chamber 71.

[0059] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A torque-resistant electric saw, comprising: The gun body includes a housing and a power assembly installed within the housing; A cutter head assembly includes a drive shaft, a connecting mechanism, and a cutter head. The drive shaft is slidably connected in the housing. The power assembly is driven by the drive shaft and can drive the drive shaft to reciprocate axially. One end of the drive shaft extends outside the housing and is coaxially connected to the cutter head assembly through the connecting mechanism. The center of mass A of the cutter head assembly is located on the axis of the drive shaft. A torque balancing mechanism includes a counterweight, the center of mass C of which is substantially located on the axis of the transmission shaft. The power assembly is connected to the counterweight and can drive the counterweight to reciprocate within the housing. The acceleration direction of the counterweight is opposite to that of the cutter head assembly, and the magnitude of the acceleration of the counterweight is proportional to the magnitude of the acceleration of the cutter head assembly, such that the inertial force of the counterweight is substantially equal to the inertial force of the cutter head assembly. The feature is that the cutting head comprises: The blade body; A connecting key, which is cylindrical and coaxially fixed to one end of the cutter head body, is provided with a socket at the outer end of the drive shaft that is adapted to the connecting key, and the connecting key is inserted into the socket; An annular protrusion is fixedly connected to the outer periphery of the connecting key. The connecting mechanism is a nut, which is sleeved on the end of the cutter head. One end of the nut has an inwardly extending flange, and the other end of the nut is threaded to the outer end of the drive shaft. The flange presses the annular protrusion onto the drive shaft. A positioning plate is fixedly connected to the end of the connecting key away from the cutter head body, and the positioning plate is parallel to the cutting direction of the cutter head body; The cutter head assembly also includes a positioning mechanism, which includes a slider and a spring. One end of the slider is provided with a positioning groove that is adapted to the positioning plate. The positioning plate is embedded in the positioning groove to position the cutting direction of the cutter head. The slider is slidably connected in the socket. The spring is disposed in the socket, and one end of the spring is connected to the slider to press the slider against the end of the cutter head. The drive shaft has a through hole that passes through both ends of the drive shaft. One end of the through hole forms the insertion port. The positioning mechanism also includes a steel ball on the side away from the cutter head. The spring is disposed between the slider and the steel ball. A boss is provided on the side wall of the through hole. The boss supports the steel ball so that the spring is in a compressed state. The gun body has a cavity, and an air inlet is provided at the end of the cavity away from the blade assembly. The outer end of the air inlet is connected to the outside atmosphere, and the inner end of the air inlet is connected to the cavity. A filter screen is provided at the outer end of the air inlet, and a first one-way valve structure is provided at the inner end of the air inlet, allowing outside air to enter the cavity through the first one-way valve structure. A counterweight is slidably connected in the cavity, and there is a gap between the outer periphery of the counterweight and the side wall of the cavity. A guide hole is provided on the counterweight, and the drive shaft passes through the guide hole and is slidably connected to the counterweight. The counterweight, the drive shaft, and the first one-way valve structure form a basically sealed compression chamber at the end of the cavity away from the blade assembly. The gun body also includes a dust baffle plate, which is fixedly connected to the housing. The dust baffle plate is arranged around the connecting mechanism, and an opening facing the blade is formed between the dust baffle plate and the housing. A first air hole is provided at one end of the drive shaft, the first air hole penetrates the inner and outer sides of the drive shaft, and the outer end of the first air hole is located in the accommodating space. A second air hole is provided on the slider, one end of the second air hole extends to the side wall of the through hole and forms an air outlet, and the other end of the second air hole penetrates to the end of the slider away from the cutter head and forms an air inlet communicating with the through hole. When the blade is installed in the socket, the inner end of the first air hole coincides with the air outlet end of the second air hole; After the blade is removed from the insertion port, the inner end of the first air hole is offset from the air outlet end of the second air hole, and the slider blocks the first air hole. The steel ball and the spring form a second one-way valve structure with the conveying direction facing the receiving space. When the steel ball contacts the boss, the second one-way valve structure is closed. When the steel ball is separated from the boss, the compression chamber is connected to the second air hole through the through hole.

2. The torque-resistant electric saw according to claim 1, characterized in that, The power assembly includes: The motor and the reducer are both installed in the housing, the motor is connected to the reducer for transmission, and the output shaft of the reducer is vertically arranged below the transmission shaft; The cam includes a cylinder, a cantilever, and a drive pin. The cylinder is eccentrically mounted on the output shaft of the reducer. The cantilever is fixedly connected to one side of the upper end of the cylinder. The drive pin is mounted on the upper side of the cantilever. The axis of the output shaft of the reducer is located between the axis of the cylinder and the axis of the drive pin. The cutter head assembly also includes a drive member, which is fixedly connected to the lower side of the transmission shaft. The lower side of the drive member is provided with a first transmission groove, the extension direction of which is perpendicular to the transmission shaft. The width of the first transmission groove is adapted to the outer diameter of the drive pin, and the drive pin is slidably connected in the first transmission groove. The counterweight is provided with a second transmission groove, the extension direction of which is parallel to the extension direction of the first transmission groove. The width of the second transmission groove is adapted to the outer diameter of the cylinder, and the cylinder passes through the second transmission groove.

3. The torque-resistant electric saw according to claim 2, characterized in that, The counterweight includes: The counterweight body is slidably connected in the gun body; A transmission ring, the inner side of which forms the second transmission groove, is disposed on the side of the counterweight body near the cutter head assembly; A connecting rod is fixedly connected between the transmission ring and the counterweight body.

4. The torque-resistant electric saw according to claim 1, characterized in that, The first one-way valve is configured as a rubber valve plate, with one end of the rubber valve plate installed on the cavity and the rubber valve plate covering the inside of the air inlet.

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