A jigsaw

Abstract

The application discloses a curve saw, which comprises a lifting tool structure, the lifting tool structure comprising a lifting tool trigger, a lifting tool frame and a lifting tool push rod in mutual abutment with the two, the lifting tool trigger comprising a first connecting part, a second connecting part and a bending part in mutual connection with the two, wherein the bending part is formed by being downwardly inclined from the lower end of the first connecting part towards the side where the motor is located. The lifting tool trigger is rotationally connected with the support frame through a fixing pin and can swing along a plane perpendicular to the output direction of the motor with the fixing pin as the fulcrum under the action of the eccentric wheel, so as to push the lifting tool push rod to move up and down and further push the lifting tool frame to swing, thereby realizing the lifting of the lifting tool. During the swinging of the lifting tool trigger, the fixing pin as the swinging fulcrum can bear most of the force, thereby reducing the force between the lifting tool trigger and the eccentric wheel, avoiding force concentration, reducing the wear between the two and prolonging the service life of the curve saw.

Description

Technical Field

[0001] This application relates to a jigsaw, and more specifically to a jigsaw blade lifting structure. Background Technology

[0002] A jigsaw is a power tool with a reciprocating saw blade used to cut curves of different shapes. It mainly uses a reciprocating rod to hold the saw blade, and the transmission structure drives the reciprocating rod to move up and down, which in turn drives the saw blade to perform reciprocating cutting action.

[0003] Most jigsaws on the market today use a crank-slider mechanism to convert the rotational motion of a motor into the reciprocating motion of a reciprocating rod. To improve cutting efficiency and reduce blade wear, a lifting mechanism is usually added. Conventional lifting mechanisms primarily use a lifting rod to directly drive a guide wheel bracket to lift the blade. For example, CN202862284U discloses a lifting mechanism where one end of the lifting rod is directly fitted onto the eccentric protrusion of an eccentric wheel through a drive hole. The eccentric wheel directly drives the lifting rod up and down, while the other end of the lifting rod directly acts on the drive end of the guide wheel bracket, controlling the guide wheel to lift intermittently, thus achieving blade jumping and lifting. However, in this method, the connection between the lifting rod and the eccentric protrusion experiences concentrated stress, which easily leads to wear, resulting in a rough cutting surface, vibration burrs, and other problems, thus affecting the cutting effect and reducing the jigsaw's lifespan. Utility Model Content

[0004] The purpose of this application is to provide a jigsaw that can reduce wear and improve cutting results.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: A jigsaw is provided, comprising a reciprocating rod, a reciprocating rod drive structure, a motor, and a housing. The motor has an output shaft rotatable about a first axis. One end of the reciprocating rod holds a saw blade. The reciprocating rod drive structure converts the rotational motion of the motor into the up-and-down reciprocating motion of the reciprocating rod. The jigsaw is characterized by further including a blade-lifting structure. The blade-lifting structure includes a blade-lifting trigger, a blade-lifting frame, and blade-lifting push rods that abut against both. The blade-lifting trigger can swing under the action of the reciprocating rod drive structure, and drives the blade-lifting frame to swing via the blade-lifting push rods to act on the saw blade, thereby lifting the saw blade. The blade-lifting trigger 11 includes a first connecting portion and a second connecting portion, and a bent portion connecting the first connecting portion and the second connecting portion. The planes containing the first connecting portion and the second connecting portion are parallel to each other and both are perpendicular to the first axis A. The bent portion slopes downwards from the lower end of the first connecting portion toward the side where the motor is located.

[0006] Furthermore, the blade lifting holder includes a bracket, one end of which is vertically rotatably connected to a guide wheel, and the other end is a trigger end. The bracket is vertically rotatably connected to the housing via a pin. The guide wheel abuts against the saw blade, and the trigger end abuts against the lower end of the blade lifting push rod. The second connecting part is provided with a cam surface facing the blade lifting holder, and the upper end of the blade lifting push rod abuts against the cam surface.

[0007] As another preferred embodiment, the reciprocating rod drive structure includes a drive pinion disposed at the end of the output shaft, an eccentric wheel meshing with the drive pinion, and a support frame for mounting the eccentric wheel and fixing it relative to the housing. The tool lifting trigger is disposed between the eccentric wheel and the support frame. The eccentric wheel has a first eccentric protrusion on the side facing the motor that can be connected to the tool lifting trigger to drive the tool lifting trigger to swing.

[0008] Furthermore, the support frame and the second connecting part are connected to each other by a fixing pin parallel to the first axis. The lifting knife trigger can swing along a plane perpendicular to the first axis with the fixing pin as the fulcrum under the action of the first eccentric protrusion.

[0009] As another preferred embodiment, the end of the first connecting part is provided with a driving hole that can be fitted onto the first eccentric protrusion. The driving hole is an open U-shaped hole with an inwardly protruding stop at its edge. The stop always overlaps with the support frame to limit the knife lifting trigger to always be located between the support frame and the eccentric wheel.

[0010] As another preferred embodiment, the lower end of the support frame is provided with a clearance portion, which includes an inclined portion that matches the shape of the bent portion and a recessed portion that can accommodate the second connecting portion.

[0011] Furthermore, the lower part of the recess protrudes towards the lifting trigger to form a protrusion, and the protrusion extends vertically to form a guide groove that allows the lifting push rod to slide up and down.

[0012] Furthermore, the recessed portion is provided with a first relief groove adjacent to the upper end of the guide groove, and the first relief groove is formed concavely relative to the recessed portion.

[0013] Furthermore, the recessed portion is provided with a second relief groove adjacent to the lower end of the guide groove, and the second relief groove is formed concavely relative to the recessed portion.

[0014] As another preferred embodiment, the jigsaw further includes a balance block disposed between the lifting trigger and the eccentric wheel. One side of the eccentric wheel is provided with a second eccentric protrusion that can be connected to the balance block. The balance block can reciprocate up and down under the action of the second eccentric protrusion.

[0015] Compared with the prior art, the beneficial effects of this application are as follows: The jigsaw provided in this application uses a reciprocating rod drive structure to move the reciprocating rod up and down to achieve the cutting action of the saw blade. Simultaneously, it drives a lifting mechanism to reciprocate and lift the saw blade, improving cutting quality and efficiency. The lifting mechanism includes a lifting trigger with a bent portion, which is inclined towards the direction of the motor. Correspondingly, the support frame in the reciprocating rod drive structure also has a corresponding clearance portion, thereby reducing the thickness of both, saving installation space, and making the internal structure of the jigsaw more compact. Furthermore, the lifting trigger and the support frame are connected by a fixing pin, allowing the lifting trigger to swing along a plane perpendicular to the first axis, i.e., the motor output shaft, using the fixing pin as a fulcrum. Compared to existing technologies, where the lifting member directly reciprocates up and down under the action of the eccentric wheel, with all the force concentrated at the connection between the lifting member and the eccentric wheel, the swing fulcrum, i.e. the fixed pin, in this application can bear most of the force during the swinging process of the lifting trigger, thereby significantly reducing the force at the connection between the lifting trigger and the eccentric wheel, avoiding stress concentration, reducing wear at the connection, improving the cutting effect, and extending the tool's service life. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall internal structure of a jigsaw;

[0017] Figure 2 This is a schematic diagram of the jigsaw blade lifting structure;

[0018] Figure 3 Another schematic diagram of the jigsaw blade lifting structure;

[0019] Figure 4 This is an exploded view of the jigsaw's lifting blade structure.

[0020] Figure 5 This is a schematic diagram of the jigsaw support frame;

[0021] Figure 6 Schematic diagram of the jigsaw tool lifting trigger;

[0022] Figure 7 This is a schematic diagram of the eccentric wheel of a jigsaw.

[0023] Figure 8 This is a schematic diagram of the balance block for a jigsaw. Detailed Implementation

[0024] The present application will be further described below with reference to specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0025] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0026] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0027] In the description of this application, it should be noted that directional terms such as “center”, “lateral”, “longitudinal”, “length”, “width”, “thickness”, “upper”, “lower”, “front”, “rear”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer”, “clockwise”, and “counterclockwise” indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this application.

[0028] This application provides a jigsaw 1, see [link]. Figure 1 The jigsaw 1 includes a reciprocating rod 20, a reciprocating rod drive structure 30, a motor 40, and a housing 50. One end of the reciprocating rod 20 holds a saw blade 60. The reciprocating rod drive structure 30 converts the rotational motion of the motor 40 into the up-and-down reciprocating motion of the reciprocating rod 20, thereby driving the saw blade 60 to perform up-and-down reciprocating motion to achieve the cutting operation. It is understandable that... Figure 1 Only half of the casing is shown in the image to visually demonstrate the internal structure of the jigsaw 1. The jigsaw 1 also includes a lifting structure 10, which directly acts on the saw blade 60 to lift the saw blade 60, reducing friction and resistance during the cutting process, improving cutting efficiency, and reducing wear on the saw blade 60.

[0029] See Figures 2 to 4The blade lifting structure 10 includes a blade lifting trigger 11, a blade lifting frame 12, and a blade lifting push rod 13 that abuts against both. The blade lifting trigger 11 can swing under the action of the reciprocating rod drive structure 30, and drives the blade lifting frame 12 to swing through the blade lifting push rod 13 to act on the saw blade 60, thereby lifting the saw blade 60.

[0030] Specifically, see Figures 2 to 7 In this embodiment, the reciprocating rod drive structure 30 includes a drive pinion 31, an eccentric wheel 32 meshing with the drive pinion 31, and a support frame 33 for mounting the eccentric wheel 32, wherein the support frame 33 is fixedly mounted on the housing 50. The motor 40 has an output shaft 41, which is rotatable about a first axis A. A first mounting hole 331 is provided on the support frame 33 at a corresponding position to allow the output shaft 41 to pass through. Preferably, in this embodiment, a first bearing 411 is also provided between the output shaft 41 and the first mounting hole 331. The drive pinion 21 is disposed at the end of the output shaft 41 and meshes with the eccentric wheel 32 to realize transmission. Preferably, in this embodiment, the drive pinion 31 and the output shaft 41 are integrally formed. The support frame 33 is also provided with a second mounting hole 332, and the eccentric wheel 32 is mounted by cooperating with the second mounting hole 332 on the support frame 33 through a mounting shaft 323. Preferably, in this embodiment, a second bushing 3231 is also fitted outside the mounting shaft 323. An eccentric pin 321 is provided on the side of the eccentric wheel 32 near the reciprocating rod 20, which can be connected to the reciprocating rod 20 to drive the reciprocating rod 20 to perform up-and-down reciprocating motion; a first eccentric protrusion 3221 is provided on the other side of the eccentric wheel 32, i.e., the side facing the motor 40, which can be connected to the lifting structure 10, i.e., the lifting trigger 11, to drive the lifting trigger 11 to reciprocate, thereby realizing the lifting function. That is, see... Figure 1 A support frame 33 and a tool lifting trigger 11 are sequentially arranged on the output shaft 41 along the direction from the motor 40 to the drive pinion 31. Preferably, a cooling fan 70 for heat dissipation is also provided between the motor 40 and the support frame 33.

[0031] Further, see Figure 2 and Figure 5 The support frame 33 has mounting protrusions 333 at its upper and lower ends, and correspondingly, the housing 50 has mounting grooves (not shown in the figure). The mounting protrusions 333 cooperate with the mounting grooves to fix the support frame 33 relative to the housing 50. Furthermore, the support frame 33 also has screw holes 335 at its upper and lower ends, and two fasteners 51 pass through the screw holes 335 at the upper and lower ends of the support frame 33 and the housing 50, respectively, thereby better fixing the support frame 33 relative to the housing 50.

[0032] In this embodiment, see Figure 2The lifting trigger 11 passes through the output shaft 41 and is positioned between the support frame 33 and the eccentric wheel 32, bending towards the direction of the motor 40. Specifically, see... Figures 2 to 4 as well as Figure 6 The lifting trigger 11 includes a first connecting portion 111, a second connecting portion 112, and a bent portion 113 connecting the two. The planes containing the first connecting portion 111 and the second connecting portion 112 are parallel to each other and both are perpendicular to the first axis A. The bent portion 113 slopes downwards from the lower end of the first connecting portion 111 toward the side where the motor 40 is located; that is, the second connecting portion 112 is closer to the motor 40 than the first connecting portion 111. The first connecting portion 111 has a first through hole 1111 corresponding to the first mounting hole 331 of the support frame 33, allowing the output shaft 41 to pass through. The end of the first connecting portion 111 also has a drive hole 1112, which can be fitted onto the first eccentric protrusion 3221 of the eccentric wheel 32 to achieve connection and transmission between the eccentric wheel 32 and the lifting trigger 11. The second connecting part 112 is provided with a second through hole 1121, and correspondingly, the support frame 33 is provided with a third mounting hole 333 at a corresponding position. A fixing pin 3331 parallel to the first axis A passes through both the second through hole 1121 and the third mounting hole 333, realizing the mutual connection between the support frame 33 and the knife-lifting trigger 11. Since the support frame 33 is fixed relative to the housing 50, the knife-lifting trigger 11 can swing along a plane perpendicular to the first axis A with the fixing pin 3331 as the fulcrum under the action of the first eccentric protrusion 3221.

[0033] In order to match the movement trajectory of the lifting trigger 11, preferably, the first through hole 1111 is an inclined elliptical hole.

[0034] Preferably, in this embodiment, the driving hole 1112 is an open U-shaped hole, which is fitted onto the first eccentric protrusion 3221 from bottom to top. More preferably, the edge of the driving hole 1112 is also provided with an inwardly protruding stop portion 1113. The stop portion 1113 ensures that during the reciprocating motion of the lifting trigger 11, the stop portion 1113 always overlaps with the support frame 33. That is, the stop portion 1113 is always blocked by the support frame 33, thus ensuring that the lifting trigger 11 will not overstep and disengage from the first eccentric protrusion 3221, ensuring that the lifting trigger 11 is always located between the support frame 33 and the eccentric wheel 32. This further limits the movement area of ​​the lifting trigger 11, better realizing the connection between the lifting trigger 11 and the first eccentric protrusion 3221.

[0035] It is understood that in other embodiments, the drive hole 1112 may also be provided as a closed hole, as long as it can be fitted onto the first eccentric protrusion 3221 and allow the lifting trigger 11 to swing along a plane perpendicular to the first axis A with the fixed pin 3331 as the fulcrum under the action of the eccentric wheel 32.

[0036] The tool lifting push rod 13 is positioned between the tool lifting trigger 11 and the tool lifting holder 12. (See also...) Figures 2 to 6 In this embodiment, the blade lifting holder 12 includes a bracket 121 vertically rotatably connected to the housing 60 via a pin 123. One end of the bracket 121 is vertically rotatably connected to a guide wheel 122, and the other end is a trigger end 124. The guide wheel 122 abuts against the saw blade 60, and the trigger end 124 abuts against the lower end of the blade lifting push rod 13. The second connecting portion 112 of the blade lifting trigger member 11 has a cam surface 1122 facing the blade lifting holder 12. The upper end of the blade lifting push rod 13 abuts against the cam surface 1122.

[0037] When the lifting trigger 11 swings under the action of the first eccentric protrusion 3221, it drives the lifting push rod 13 downward through the cam surface 1122. The other end of the lifting push rod 13 then acts on the trigger end 124 of the bracket 121, forcing the bracket 121 to swing. This causes the guide wheel 122 to act on the saw blade 60, thus lifting the saw blade 60. It can be understood that when the saw blade 60 falls back, it reacts to the guide wheel 122, forcing the bracket 121 to swing in the opposite direction again. This, in turn, pushes the lifting push rod 13 upward through the trigger end 124, resetting the lifting push rod 13. This process repeats, thus achieving the jumping lifting of the saw blade 60.

[0038] In this embodiment, a tool-lifting trigger 11 that can swing relative to the support frame 33 is provided, and the fixed pin 3331 serves as the swing fulcrum. The mutual abutment between the cam surface 1122 and the tool-lifting push rod 13 forces the tool-lifting frame 12 to swing, thereby lifting the tool. A lever structure is formed between the swing fulcrum (fixed pin 3331), the abutment point between the cam surface 1122 and the tool-lifting push rod 13, and the contact point between the drive hole 1112 and the first eccentric protrusion 3321. This transfers most of the force at the contact point between the drive hole 1112 and the first eccentric protrusion 3321 to the swing fulcrum (fixed pin 3331). This application utilizes the swing fulcrum (fixed pin 3331) to bear most of the force, reducing wear between the drive hole 1112 and the first eccentric protrusion 3331 and extending the tool's service life.

[0039] To further limit the movement of the lifting trigger 11 and save installation space, making the internal structure of the jigsaw 1 more compact, see [reference needed]. Figures 2 to 5The lower end of the support frame 33 is provided with a clearance portion 334, which includes an inclined portion 3341 that matches the shape of the bent portion 113 of the knife-lifting trigger member 11, and a recessed portion 3342 for accommodating the second connecting portion 112 of the knife-lifting trigger member 11. More preferably, a third mounting hole 333 is provided in the clearance portion 334. Even further, the third mounting hole 333 is provided within the recessed portion 3342.

[0040] More preferably, the support frame 33 is provided with a guide groove 131 for the lifting push rod 13 to slide up and down. Specifically, see Figure 5 The lower part of the recessed portion 3342 of the support frame 33 protrudes towards the knife-lifting trigger 11 to form a protrusion 3343, which forms a guide groove 131 through the upper and lower parts. The knife-lifting push rod 13 passes through the guide groove 131 and can slide up and down relative to the guide groove 131 under the action of the cam surface 1122 of the knife-lifting trigger 11 and the trigger end 124 of the bracket 121.

[0041] To save installation space, further preferred options are available, see [link to previous section]. Figure 5 The recessed portion 3342 is provided with a first clearance groove 132 adjacent to the upper end of the guide groove 131, and the first clearance groove 132 is recessed relative to the recessed portion 3342. When the lifting push rod 13 moves upward under the action of the lifting frame 12, at least part of it can be accommodated in the first clearance groove 132. In addition, the first clearance groove 132 can further limit the maximum stroke of the lifting push rod 13 when it moves upward. At the same time, in order to better achieve the abutment between the lower end of the lifting push rod 13 and the trigger end 124 of the lifting frame 12, the recessed portion 3342 is further provided with a second clearance groove 133 adjacent to the lower end of the guide groove 131. The second clearance groove 133 is also recessed relative to the recessed portion 3342. In this way, when the lifting push rod 13 moves downward under the action of the lifting trigger 11, it can be ensured that at least part of it is exposed to the guide groove 131, thereby better achieving the abutment with the trigger end 124. Preferably, the inner walls of the first clearance groove 132 and the second clearance groove 133 are arc surfaces that conform to the outer contour of the lifting push rod 13.

[0042] To further reduce the vibration of the jigsaw 1, the jigsaw 1 is also equipped with a balance block 80. In this embodiment, the participants Figures 1 to 4 The balance block 80 is positioned between the tool-lifting trigger 11 and the eccentric wheel 32. Specifically, see... Figure 3 , Figure 4 and Figure 6 , Figure 7On the opposite side of the eccentric pin 321, the eccentric wheel 32 is provided with a first eccentric protrusion 3221 and a second eccentric protrusion 3222. The first eccentric protrusion 3221 is used to cooperate with the drive hole 1112 of the lifting trigger 11. The balance block 80 is provided with a first balance hole 801 and a second balance hole 802. The second balance hole 802 allows the output shaft 41 of the motor 40 to pass through for mounting the balance block 80; the first balance hole 801 is used to cooperate with the second eccentric protrusion 3222. When the eccentric wheel 32 rotates, the balance block 80 will reciprocate up and down under the action of the second eccentric protrusion 3222, and the vibration of the jigsaw 1 will be reduced by inertia. More preferably, to further achieve relative fixation of the balance block 80, symmetrical strip holes 804 are provided on both sides of the balance block 80. Correspondingly, fourth mounting holes 336 are symmetrically provided on the support frame 33. One end of each of the two sliding pins 337 is fixedly disposed in the two fourth mounting holes 336, and the other end is inserted into the corresponding strip holes 804. When the balance block 80 moves up and down reciprocating under the action of the second eccentric protrusion 3222, the sliding pins 337 can slide up and down in their corresponding strip holes 804.

[0043] When the motor 40 starts, its rotation is transmitted to the eccentric wheel 32 via the drive gear 31 at the end of the output shaft 41. The eccentric pin 321 on one side of the eccentric wheel 32 drives the reciprocating rod 20 to move up and down, thereby driving the saw blade 60 to perform reciprocating cutting operations. The first eccentric protrusion 3221 on the other side of the eccentric wheel 32 drives the lifting trigger 11 to move back and forth through the drive hole 1112. During the swinging motion of the lifting trigger 11, the cam surface 1122 of its second connecting part 112 pushes the lifting push rod 13 to move downward in the guide groove 131, thereby pushing the lifting frame 12 to swing through the trigger part 121, ultimately lifting the saw blade 60 by the guide wheel 122 at the other end of the lifting frame 12. When the saw blade 60 falls back, the lifting frame 12 swings in the opposite direction through the guide wheel 122, thereby pushing the lifting push rod 13 upward through the trigger end 124, realizing the reset of the lifting push rod 13. This process is repeated to achieve the jumping and lifting of the saw blade at 60 degrees.

[0044] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A jigsaw, comprising a reciprocating rod, a reciprocating rod drive structure, a motor, and a housing, wherein the motor has an output shaft rotatable about a first axis A, one end of the reciprocating rod holds a saw blade, and the reciprocating rod drive structure converts the rotational motion of the motor into the up-and-down reciprocating motion of the reciprocating rod, characterized in that, The jigsaw also includes a blade lifting structure, which includes a blade lifting trigger, a blade lifting frame, and a blade lifting push rod that abuts against the blade lifting trigger and the blade lifting frame respectively. The blade lifting trigger can swing under the action of the reciprocating rod drive structure, and drives the blade lifting frame to swing through the blade lifting push rod to act on the saw blade, thereby lifting the saw blade. The lifting trigger includes a first connecting part and a second connecting part, as well as a bent part connecting the first connecting part and the second connecting part. The planes on which the first connecting part and the second connecting part are located are parallel to each other and both are perpendicular to the first axis A. The bent part is inclined downward from the lower end of the first connecting part toward the side where the motor is located.

2. The jigsaw as described in claim 1, characterized in that, The blade lifting bracket includes a support, one end of which is vertically rotatably connected to a guide wheel, and the other end is a trigger end. The support is vertically rotatably connected to the housing via a pin, the guide wheel abuts against the saw blade, and the trigger end abuts against the lower end of the blade lifting push rod. The second connecting part is provided with a cam surface facing the lifting tool holder, and the upper end of the lifting tool push rod abuts against the cam surface.

3. The jigsaw as described in claim 1, characterized in that, The reciprocating rod drive structure includes a drive pinion disposed at the end of the output shaft, an eccentric wheel meshing with the drive pinion, and a support frame for mounting the eccentric wheel and fixing it relative to the housing. The tool lifting trigger is disposed between the eccentric wheel and the support frame. The eccentric wheel has a first eccentric protrusion on the side facing the motor that can be connected to the tool lifting trigger to drive the tool lifting trigger to swing.

4. The jigsaw as described in claim 3, characterized in that, The support frame and the second connecting part are connected to each other by a fixing pin parallel to the first axis A. The lifting knife trigger can swing along a plane perpendicular to the first axis A with the fixing pin as the fulcrum under the action of the first eccentric protrusion.

5. The jigsaw as described in claim 3, characterized in that, The first connecting part has a drive hole at its end that can be fitted onto the first eccentric protrusion. The drive hole is an open U-shaped hole with an inwardly protruding stop at its edge. The stop always overlaps with the support frame to limit the knife lifting trigger to always be located between the support frame and the eccentric wheel.

6. The jigsaw as described in claim 3, characterized in that, The lower end of the support frame is provided with a clearance portion, which includes an inclined portion that matches the shape of the bent portion and a recessed portion that can accommodate the second connecting portion.

7. The jigsaw as described in claim 6, characterized in that, The lower part of the recess protrudes towards the knife-lifting trigger to form a protrusion, and the protrusion extends vertically to form a guide groove that allows the knife-lifting push rod to slide up and down.

8. The jigsaw as described in claim 7, characterized in that, The recessed portion is provided with a first relief groove adjacent to the upper end of the guide groove, and the first relief groove is formed concavely relative to the recessed portion.

9. The jigsaw as described in claim 7, characterized in that, The recessed portion is provided with a second relief groove adjacent to the lower end of the guide groove, and the second relief groove is formed concavely relative to the recessed portion.

10. The jigsaw as described in claim 3, characterized in that, The jigsaw also includes a balance block disposed between the lifting trigger and the eccentric wheel. A second eccentric protrusion is provided on one side of the eccentric wheel, which can be connected to the balance block. The balance block can reciprocate up and down under the action of the second eccentric protrusion.

Images