Reciprocating saw with cutter lifting function and method for calculating cutter lifting amplitude

Abstract

The invention discloses a reciprocating saw with a cutter lifting function, belongs to the technical field of reciprocating saws, and solves the technical problem that parts for cutter lifting in a reciprocating saw in the prior art cannot be reduced. The reciprocating saw with the cutter lifting function comprises a shell with a containing cavity, a motor, a first gear, a crank, a reciprocating rod, a cutter lifting frame and a fulcrum part, the motor, the first gear, the crank, the reciprocating rod, the cutter lifting frame and the fulcrum part are contained in the containing cavity, the first gear comprises a tooth part and a base part which rotate coaxially, the tooth part is meshed with an output shaft of the motor, and the two ends of the crank are rotationally connected with the first gear and the reciprocating rod respectively. The base part comprises a fixed diameter part and a variable diameter part, the fixed diameter part has an invariable outer radius R1, the linear distance between the outer contour of the variable diameter part and the circle center of the fixed diameter part continuously changes between R1 and L1, the fulcrum part provides a fulcrum for deflection of the reciprocating rod towards the two sides, and the shell is stopped on one side; and the cutter lifting frame is supported between the other side and the base part and moves along with one of the reciprocating rod and the base part. The invention further provides a calculation method of the cutter lifting amplitude.

Description

Technical Field

[0001] The invention relates to the technical field of reciprocating saws, in particular to a reciprocating saw with a blade lifting function. Background Art

[0002] A reciprocating saw is a common cutting tool that uses a reciprocating rod to drive the saw blade to do back and forth cutting motion. Its cutting efficiency is higher than that of traditional manual or other cutting tools. Among them, the blade lifting device used is one of the key factors to improve cutting efficiency.

[0003] In the prior art, the reciprocating saw with a blade lifting function (specifically, please refer to the Chinese invention patent with publication number CN107626978A and the name of reciprocating cutting tool) has the following working principle: the reciprocating rod is forced to lift the blade under the action of the power mechanism through the cooperation of the actuator and the push member. The working principles of some other reciprocating saws with a blade lifting function are roughly the same, and at least two additional components are required, one of which is used to generate a change in motion, and the other transmits the change in motion to the reciprocating rod of the reciprocating saw, so that the reciprocating rod can lift the blade. However, these two additional components lead to an increase in the number of parts in the reciprocating saw, which increases the material cost on the one hand, and the labor cost of assembly on the other hand, resulting in an increase in the cost of the reciprocating saw with a blade lifting function. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and propose a reciprocating saw with a blade lifting function, thereby solving the technical problem that the number of parts for lifting the blade in the reciprocating saw in the prior art cannot be reduced.

[0005] In order to achieve the above technical objectives, the present invention proposes a reciprocating saw with a knife lifting function, comprising a shell with a cavity and a motor, a first gear, a crank, a reciprocating rod, a knife lifting frame, and a fulcrum portion accommodated in the cavity, wherein the first gear comprises a coaxially rotating tooth portion and a base portion, the tooth portion meshes with the output shaft of the motor, and the two ends of the crank are respectively rotatably connected to the first gear and the reciprocating rod, the base portion comprises a sizing portion and a reducing portion, the sizing portion has a constant outer radius R1, an extreme point is provided on the outer contour of the reducing portion, the linear distance between the extreme point and the center of the sizing portion is L1, and the linear distance between the outer contour of the reducing portion and the center of the sizing portion continuously changes between R1 and L1, the fulcrum portion provides a fulcrum for the reciprocating rod to deflect to both sides, the shell is stopped at one side, the knife lifting frame is supported between the other side and the base portion and moves with one of the reciprocating rod and the base portion, and the reciprocating rod has:

[0006] In the flat blade state, the blade lifting frame is supported on the sizing portion to make the reciprocating rod reciprocate along a straight line; and

[0007] In the knife lifting state, the reciprocating rod swings along the fulcrum to move the knife lifting frame and is supported on the diameter reducing portion to achieve knife lifting.

[0008] The reciprocating saw of the present invention uses a first gear and a blade lifting frame, and the base includes a fixed diameter portion and a variable diameter portion. The change of motion is generated by the rotation of the first gear, and the blade lifting frame is supported on the base to realize the transmission of the changed motion, thereby realizing the lifting of the blade of the reciprocating saw. Compared with the prior art, the reciprocating saw of the present invention saves a component, thereby reducing the cost of the reciprocating saw. At the same time, the reciprocating saw of the present invention drives the reciprocating rod to deflect or reset through the force between the reciprocating saw and the object to be cut, and there is no need to set up an additional driving component to drive the reciprocating rod, which further simplifies the structure of the blade lifting mechanism and further reduces the cost of the reciprocating saw.

[0009] Preferably, the reducing portion includes a first reducing portion and a second reducing portion, the connection point of the first reducing portion and the second reducing portion constitutes the extreme point, the first reducing portion and the second reducing portion extend from both ends of the fixed diameter portion to the extreme point respectively and the outer diameters gradually decrease, L1<R1.

[0010] By adopting the above-mentioned technical solution, the linear motion of the reciprocating rod and the lifting of the knife can be realized through the appropriate setting of the base. The setting method of the first gear is simple, which helps to reduce the production cost of the reciprocating saw.

[0011] Preferably, the reducing portion includes a first reducing portion and a second reducing portion, the connection point of the first reducing portion and the second reducing portion constitutes the extreme point, the first reducing portion and the second reducing portion extend from both ends of the fixed diameter portion to the extreme point respectively and the outer diameters gradually increase, L1>R1.

[0012] By adopting the above-mentioned technical solution, the linear motion of the reciprocating rod and the lifting of the knife can be realized through the appropriate setting of the base. The setting method of the first gear is simple, which helps to reduce the production cost of the reciprocating saw.

[0013] Preferably, the first gear is a face gear, the tooth portion protrudes along the axial direction of the first gear, and the rotation axis of the output shaft of the motor is perpendicular to the rotation axis of the first gear.

[0014] By adopting the above technical solution, the extension direction of the output shaft of the motor can be consistent with the linear motion direction of the reciprocating rod, and the reciprocating saw is arranged to extend along the length direction. On the one hand, the reciprocating saw is made more compact, and on the other hand, it is easier to apply force when holding the reciprocating saw for cutting.

[0015] Preferably, it further comprises a second gear meshing with the output shaft of the motor, and the first gear and the second gear rotate in opposite directions.

[0016] By adopting the above-mentioned technical solution, a second gear is set to rotate coaxially with the first gear and in the opposite direction of rotation. The unbalanced inertial force generated by the rotation of the first gear and the unbalanced inertial force generated by the rotation of the second gear offset each other, thereby reducing the vibration of the reciprocating saw during movement and improving the stability of the reciprocating saw during operation.

[0017] Preferably, the tool lifting frame includes a first supporting portion and a second supporting portion, the first supporting portion supports the reciprocating rod, the first gear and the second gear are mirror-arranged, and the second supporting portion is supported on the base of the first gear and the base of the second gear.

[0018] The second supporting portion is supported on the base of the first gear and the base of the second gear, so that the first gear and the second gear can more stably support the tool lifter, reduce or avoid sliding during the movement of the tool lifter, and improve the stability of the reciprocating rod movement.

[0019] Preferably, the device further comprises a first counterweight body and a second counterweight body, wherein the first counterweight body rotates with the first gear and is eccentrically arranged relative to the first gear, and the second counterweight body rotates with the second gear and is eccentrically arranged relative to the second gear.

[0020] By adopting the above-mentioned technical solution, a first counterweight and a second counterweight are provided, and a first gear and a second gear eccentrically rotate with the first counterweight and the second counterweight respectively, so that the rotation speed of the first counterweight and the second counterweight is different from the rotation speed of the first gear and the second gear, and the rotation speed of the first counterweight and the second counterweight forms a variable angular velocity, so that the unbalanced inertia force generated by the first counterweight and the second counterweight is a second-order inertia force, which can completely offset the output inertia force of the first gear and the second gear, thereby achieving the effect of reducing vibration.

[0021] Preferably, it further includes a guide frame, which includes a guide groove, and part of the reciprocating rod is slidingly limited in the guide groove. The deflection of the reciprocating rod drives the deflection of the guide frame. The shell is stopped on one side of the guide frame, and the tool lifting frame is supported on the other side.

[0022] The above-mentioned technical solution avoids direct contact between the reciprocating rod and the shell and the tool lifter, thereby reducing the wear of the reciprocating rod, the shell and the tool lifter, reducing the movement resistance of the reciprocating rod, and increasing the service life of the reciprocating rod.

[0023] Preferably, the guide frame is rotatably connected to the tool lifting frame, and the outer shell is provided with a guide groove for guiding the movement direction of the guide frame.

[0024] By adopting the above-mentioned technical solution, the guide frame is rotatably connected to the tool lifting frame, so that the guide frame can move together with the tool lifting frame and the reciprocating rod, thereby avoiding the misalignment and wear caused by the asynchronous movement between the reciprocating rod and the guide frame, and improving the service life of the reciprocating rod and the guide frame. At the same time, the guide groove can also completely wrap the reciprocating rod to enable better sliding fit between the two, and the design structure of the guide frame is simpler, thereby reducing costs.

[0025] Preferably, the guide frame is rotatably connected to the shell, and the reciprocating rod comprises a reciprocating rod body and a sliding portion provided on the reciprocating rod body, and the sliding portion is located in the guide groove and slides along the guide groove.

[0026] By adopting the above-mentioned technical scheme, since the guide frame is rotatably connected to the outer shell, the rotation axes of the guide frame and the reciprocating rod are different, and the guide frame does not move with the reciprocating rod. Therefore, there will be a misalignment between the deflection of the reciprocating rod and the guide frame. The sliding part on the reciprocating rod body cooperates with the guide groove to realize the sliding of the reciprocating rod relative to the guide groove. At the same time, the reciprocating rod can deflect relative to the guide groove around the sliding part, thereby avoiding interference between the reciprocating rod body and the guide frame, avoiding extrusion friction between the movement of the reciprocating rod body and the guide frame, and improving the service life of the reciprocating rod and the guide frame.

[0027] Preferably, the sliding part is a roller provided on a connecting shaft between the reciprocating rod and the crank, and the sliding part rotates around the connecting shaft.

[0028] By adopting the above-mentioned technical solution, the two points between the roller and the fulcrum are connected to a straight line to determine the swing direction of the reciprocating rod, thereby reducing the resistance between the crank, the reciprocating rod and the fulcrum, and ensuring smooth movement of the crank and the reciprocating rod.

[0029] Preferably, the fulcrum portion comprises a base and a rotating portion, the rotating portion is limited in rotation by the base, the rotating portion is provided with an inner hole, the reciprocating rod is slidably fitted in the inner hole, and the center of the inner hole forms the fulcrum.

[0030] By adopting the above-mentioned technical solution and through the above-mentioned arrangement, the rotating part can rotate relative to the base and the sliding fit between the reciprocating rod and the inner hole of the rotating part helps to reduce the friction between the reciprocating rod and the fulcrum part, thereby reducing the resistance between the reciprocating rod and the rotating part during the process of linear motion of the reciprocating rod and lifting the knife, thereby improving the working efficiency of the reciprocating saw.

[0031] Preferably, it further includes a locking rod that can rotate relative to the outer shell, and the locking rod is provided with a stop portion and a knife lifting portion, and the locking rod has a locked state and an unlocked state. In the locked state, the stop portion corresponds to the position of the knife lifting frame and the stop portion stops the knife lifting frame. In the unlocked state, the knife lifting portion corresponds to the position of the knife lifting frame and there is a movable gap between the knife lifting portion and the knife lifting frame.

[0032] By adopting the above-mentioned technical solution, the blade lifting function of the reciprocating saw can be turned on or off as needed, and the operator can choose according to his needs, thereby improving the user experience of the reciprocating saw.

[0033] Preferably, the knife lifting part includes at least a first knife lifting part and a second knife lifting part, and the movable gap between the first knife lifting part and the knife lifting frame is larger than the movable gap between the second knife lifting part and the knife lifting frame.

[0034] By adopting the above-mentioned technical solution, the blade lifting range of the reciprocating saw can be adjusted, and the operator can switch between at least two blade lifting ranges of the reciprocating saw as needed, thereby further improving the user experience of the reciprocating saw.

[0035] The present invention further proposes a method for calculating the blade lifting amplitude of a reciprocating saw with a blade lifting function. Using the reciprocating saw with a blade lifting function as described in the above embodiment, the calculation method is as follows:

[0036]

[0037] Wherein, R is the linear distance between the rotation connection point of the first gear and the crank and the rotation axis of the first gear, L is the linear distance between the rotation connection points at both ends of the crank, α is the angle between the crank and the linear motion direction of the reciprocating rod, β is the angle between the reciprocating rod and the linear motion direction of the reciprocating rod, θ is the angle between the guide groove and the linear motion direction of the reciprocating rod, and L 1 is the horizontal distance between the rotation axis of the first gear and the rotation connection point of the guide frame, L 2 is the straight-line distance between the rotation connection point of the guide frame and the fulcrum provided by the fulcrum portion, L 0 is the straight-line distance between the preset sawtooth point and the rotation connection point of the crank, x 1 ,y 1 They respectively correspond to the coordinates of the rotational connection points of the crank and the reciprocating rod relative to the rotational connection points of the guide frame, and x and y correspond to the coordinates of the preset sawtooth points.

[0038] The above formula can be used to calculate the blade lifting amplitude of a preset sawtooth point, thereby facilitating determination of the maximum blade lifting amplitude of the reciprocating saw. The calculable blade lifting amplitude of the reciprocating saw is beneficial to the design of the reciprocating saw.

[0039] Preferably, α is calculated by the following system of equations:

[0040]

[0041] Among them, L 3is the distance between the rotation axis of the tool lift and the support point of the guide frame, L 4 is the distance between the rotation axis of the tool lift and the support point of the base, L 5 is the horizontal distance between the rotation axis of the tool lift and the rotation axis of the first gear, L 6 is the vertical distance between the linear motion direction of the reciprocating rod and the rotation axis of the knife lifting bracket, δ is the angle between the rotation axis of the knife lifting bracket and the vertical direction in the flat knife state, φ is the extreme value of the rotation angle between the rotation axis of the knife lifting bracket and the line between the support point of the guide frame in the knife lifting state, x 2 ,y 2 Corresponding to the extreme value of the change of the support point of the tool lift and the guide frame, t 1 The upper point of the base corresponding to the critical point when the flat knife state switches to the raised knife state, t 2 The upper point of the base corresponds to the maximum value of the knife lifting amplitude.

[0042] According to the change of the outer contour of the variable diameter part, the movement change process or extreme point of α can be determined, so that the change of the outer contour of the variable diameter part can be reversely deduced according to the required blade lifting amplitude of the reciprocating saw, which is convenient for the design of the variable diameter part and reduces the trial and error cost.

[0043] Other features and advantages of the present invention will be disclosed in detail in the following specific embodiments and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The present invention will be further described below in conjunction with the accompanying drawings:

[0045] Figure 1 An exploded view of the internal components of a reciprocating saw according to an embodiment of the present invention;

[0046] Figure 2 is a side view of a first gear and a second gear in an embodiment of the present invention;

[0047] Figure 3 is a schematic diagram of a first gear in an embodiment of the present invention;

[0048] Figure 4 is another schematic diagram of the first gear in an embodiment of the present invention;

[0049] Figure 5 Another exploded view of the internal components of a reciprocating saw according to an embodiment of the present invention;

[0050] Figure 6 is a schematic diagram of a first gear, a second gear and a balancing mechanism in an embodiment of the present invention;

[0051] Figure 7A cross-sectional view of a reciprocating saw in an embodiment of the present invention;

[0052] Figure 8 for Figure 7 The enlarged view of point A in the middle;

[0053] Fig. 9 for Figure 7 Another enlarged view of the center A;

[0054] Fig.10 It is a simplified schematic diagram of the structure of the crank-connecting rod mechanism of the reciprocating saw in an embodiment of the present invention;

[0055] Fig.11 It is a simplified schematic diagram of the structure of the first gear and the tool lifter in an embodiment of the present invention;

[0056] Fig.12 It is a simplified schematic diagram of the running track of the first supporting portion of the tool lifting frame in an embodiment of the present invention;

[0057] Reference numerals:

[0058] 100. Motor;

[0059] 200, crank;

[0060] 300, reciprocating mechanism, 310, reciprocating rod, 311, reciprocating rod body, 312, sliding part, 320, knife seat;

[0061] 400, knife lifting frame, 410, first supporting portion, 420, second supporting portion, 430, locking rod, 431, stopping portion, 432, knife lifting portion, 4321, first knife lifting portion, 4322, second knife lifting portion, 433, movable gap;

[0062] 500, first gear, 501, tooth portion, 502, base portion, 5021, sizing portion, 5022, reducing portion, 5023, first reducing portion, 5024, second reducing portion, 5025, extreme point, 510, second gear, 511, transmission body, 520, first counterweight body, 521, second counterweight body, 522, transmission groove, 530, coupling body, 531, first shaft body, 532, shaft hole, 533, second shaft body;

[0063] 600, fulcrum portion, 610, base, 620, rotating portion, 621, inner hole;

[0064] 700, guide frame, 710, guide groove;

[0065] 800. Control panel. DETAILED DESCRIPTION

[0066] The technical solutions of the embodiments of the present invention are explained and described below in conjunction with the drawings of the embodiments of the present invention, but the following embodiments are only preferred embodiments of the present invention, not all. Based on the embodiments in the implementation mode, other embodiments obtained by those skilled in the art without creative work are all within the protection scope of the present invention.

[0067] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0068] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly defined.

[0069] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0070] like Figures 1 to 4 , Figure 7 As shown, in an embodiment of the present invention, a reciprocating saw with a knife lifting function is proposed, including a shell with a cavity and a motor 100, a first gear 500, a crank 200, a knife lifting frame 400, and a fulcrum portion 600 accommodated in the cavity. The reciprocating saw also includes a reciprocating mechanism 300, and the reciprocating mechanism 300 includes a reciprocating rod 310 and a knife seat 320 installed on the reciprocating rod 310. The reciprocating rod 310 is accommodated in the cavity, and the knife seat 320 is used to install a saw knife. The knife seat 320 is arranged on the outside of the shell and moves with the reciprocating rod 310.

[0071] The first gear 500 includes a coaxially rotating toothed portion 501 and a base portion 502, and the toothed portion 501 meshes with the output shaft of the motor 100. The two ends of the crank 200 are respectively rotatably connected to the first gear 500 and the reciprocating rod 310, and the rotation of the first gear 500 drives the reciprocating rod 310 to reciprocate through the crank 200. The base portion 502 includes a sizing portion 5021 and a reducing portion 5022, the sizing portion 5021 has a constant outer radius R1 and the center of the sizing portion 5021 coincides with the rotation axis of the first gear 500, and an extreme point 5025 is provided on the outer contour of the reducing portion 5022, and the linear distance between the extreme point 5025 and the center of the sizing portion 5021 is L1, and the linear distance between the outer contour of the reducing portion 5022 and the center of the sizing portion 5021 continuously changes between R1 and L1.

[0072] The fulcrum portion 600 provides a fulcrum for the reciprocating rod 310 to swing to both sides, the housing is stopped at one side of the reciprocating rod 310, and the tool lifting frame 400 is supported between the other side of the reciprocating rod 310 and the base 502 and moves with one of the reciprocating rod 310 and the base 502. The tool lifting frame 400 includes a first support portion 410 and a second support portion 420, the first support portion 410 corresponds to the position of the reciprocating rod 310, and the second support portion 420 corresponds to the position of the base 502.

[0073] A stop block for stopping the reciprocating rod 310 may be provided on the outer shell, or a stop portion 431 for stopping the reciprocating rod 310 may be integrally formed on the outer shell.

[0074] In the flat knife state, the rotation of the first gear 500 makes the second support part 420 and the sizing part 5021 relative to each other, the second support part 420 is supported on the sizing part 5021, and the first support part 410 is supported on the reciprocating rod 310. Since the outer diameter of the sizing part 5021 remains unchanged, the knife lifting frame 400 remains stationary, and the stopper of the outer shell and the static support of the knife lifting frame 400 limit the movement direction of the reciprocating rod 310, so that the reciprocating rod 310 reciprocates along a straight line.

[0075] In the knife lifting state, the rotation of the first gear 500 causes the second support part 420 and the diameter-changing part 5022 to be positioned relative to each other, with a gap therebetween. Since the outer diameter of the diameter-changing part 5022 changes continuously, the gap between the second support part 420 and the diameter-changing part 5022 changes continuously.

[0076] In this embodiment, when the reciprocating saw is cutting, the teeth of the saw blade are pressed against the object to be cut, and the reaction force of the object on the saw blade acts on the blade holder 320. The force on the blade holder 320 is transmitted to the reciprocating rod 310 through the fulcrum, so that the reciprocating rod 310 has a tendency to swing to one side. The gap between the second support part 420 and the diameter reducing part 5022 allows the tool lifting frame 400 to have a movable space. The swing force of the reciprocating rod 310 acts on the tool lifting frame 400 to make the tool lifting frame 400 move and be supported on the diameter reducing part 5022. Since the gap between the second support part 420 and the diameter reducing part 5022 changes continuously, the reciprocating rod 310 swings accordingly and the swing angle gradually changes. The angle between the movement direction of the saw blade on the blade holder 320 and the original straight line direction gradually changes, thereby achieving the lifting and resetting of the blade. During the lifting process, the angle between the saw blade and the object to be cut gradually changes, thereby improving the cutting efficiency.

[0077] The first gear 500 rotates one circle to realize the blade leveling, blade lifting and resetting of the reciprocating saw. The difference between R1 and L1 limits the maximum swing amplitude of the reciprocating rod 310, thereby limiting the blade lifting amplitude of the reciprocating saw.

[0078] In this embodiment, the knife lifting frame 400 is rotatably connected to the outer shell. In the flat knife state, the second support part 420 is supported on the fixed diameter part 5021. In the knife lifting state, the knife lifting frame 400 rotates to ensure that the second support part 420 remains supported on the variable diameter part 5022 as the variable diameter part 5022 changes.

[0079] In some other embodiments, the knife lifting frame 400 can also slide relative to the outer shell. In the flat knife state, the second support part 420 is supported on the fixed diameter part 5021. In the knife lifting state, the knife lifting frame 400 slides so that the second support part 420 remains supported on the variable diameter part 5022 as the variable diameter part 5022 changes.

[0080] The reciprocating saw of the present invention includes a first gear 500 and a blade lifting frame 400. The first gear 500 includes a tooth portion 501 and a base 502. The base 502 includes a sizing portion 5021 and a reducing portion 5022. The rotation of the first gear 500 generates a change in motion through the base 502. The blade lifting frame 400 is supported on the base 502 to realize the transmission of the motion change and thus realize the lifting of the blade of the reciprocating saw. Compared with the prior art, the reciprocating saw of the present invention eliminates a component, thereby reducing the cost of the reciprocating saw. At the same time, the reciprocating saw of the present invention drives the reciprocating rod 310 to deflect and reset through the action force between the reciprocating saw and the object to be cut. There is no need to additionally set a driving component to drive the reciprocating rod 310, which further simplifies the structure of the blade lifting mechanism and further reduces the cost of the reciprocating saw.

[0081] It should be noted that the rotation of the first gear 500 causes the crank 200 to have a tendency to sway during the movement, and the sway tendency of the crank 200 is transmitted to the reciprocating rod 310 so that the reciprocating rod 310 also has a tendency to sway. When the reciprocating saw is started without bearing a load, the sway tendency of the reciprocating rod 310 drives the reciprocating rod 310 and the tool lift 400 to move and reset. Since the force is small, the force can be ignored when the reciprocating saw is cutting an object.

[0082] In this embodiment, the reciprocating saw further includes a control panel 800, and the control panel 800 is used to control the movement of the reciprocating saw.

[0083] In order to reduce the wear between the tool lifting frame 400 and the base 502 and the reciprocating rod 310, the first support portion 410 and the second support portion 420 are configured as roller portions.

[0084] In one embodiment, Figure 2 , Figure 3 , Figure 7 As shown, based on the reciprocating saw of the above embodiment, the linear distance between the outer contour of the variable diameter portion 5022 and the rotation axis continuously changes between R1 and L1. The variable diameter portion 5022 includes a first variable diameter portion 5023 and a second variable diameter portion 5024. The extreme point 5025 is the connection point of the first variable diameter portion 5023 and the second variable diameter portion 5024. The linear distance between the extreme point 5025 and the rotation axis X1 of the first gear 500 is L1. The first variable diameter portion 5023 and the second variable diameter portion 5024 extend from the two ends of the fixed diameter portion 5021 to the extreme point 5025 respectively, and the outer diameter gradually decreases. L1<R1.

[0085] Exemplarily, when the blade lifting frame 400 can rotate relative to the housing, the first support portion 410 and the second support portion 420 are arranged below the reciprocating rod 310, and the rotation connection point between the blade lifting frame 400 and the housing is arranged between the first support portion 410 and the second support portion 420. In the blade lifting state, the deflection of the reciprocating rod 310 drives the first support portion 410 to move downward, and the rotation of the blade lifting frame 400 drives the second support portion 420 to move upward and be supported on the diameter reducing portion 5022. The reciprocating saw changes from the blade lifting state to the blade flat state, the outer contour of the diameter reducing portion 5022 gradually changes toward the sizing portion 5021, the second support portion 420 gradually moves downward to reset and drives the first support portion 410 to reset, and the reciprocating rod 310 returns to the linear motion state.

[0086] Exemplarily, when the knife lifting frame 400 can slide relative to the housing, the first support portion 410 is disposed below the reciprocating rod 310, and the second support portion 420 is disposed above the base 502, the knife lifting frame 400 slides in a direction substantially parallel to the line connecting the first support portion 410 and the second support portion 420. In the knife lifting state, the deflection of the reciprocating rod 310 drives the first support portion 410 to move downward, and the sliding of the knife lifting frame 400 drives the second support portion 420 to move downward and be supported on the diameter reducing portion 5022. The reciprocating saw changes from the knife lifting state to the knife leveling state, the outer contour of the diameter reducing portion 5022 gradually changes toward the sizing portion 5021, the second support portion 420 gradually moves upward to reset and drives the first support portion 410 to reset, and the reciprocating rod 310 returns to the linear motion state.

[0087] Through the appropriate arrangement of the base 502, the linear motion of the reciprocating rod 310 and the lifting of the blade can be realized. The arrangement of the first gear 500 is simple, which helps to reduce the production cost of the reciprocating saw.

[0088] In another embodiment, Figure 2 , Figure 4 , Figure 7 As shown, based on the reciprocating saw of the above embodiment, the linear distance between the outer contour of the variable diameter portion 5022 and the rotation axis continuously changes between R1 and L1. The variable diameter portion 5022 includes a first variable diameter portion 5023 and a second variable diameter portion 5024. The extreme point 5025 is the connection point of the first variable diameter portion 5023 and the second variable diameter portion 5024. The linear distance between the extreme point 5025 and the rotation axis X1 of the first gear 500 is L1. The first variable diameter portion 5023 and the second variable diameter portion 5023 extend from the two ends of the fixed diameter portion 5021 to the extreme point 5025 respectively, and the outer diameter gradually increases, L1>R1.

[0089] Exemplarily, when the knife lifting frame 400 can rotate relative to the housing, the first support portion 410 and the second support portion 420 are arranged below the reciprocating rod 310, and the rotation connection point between the knife lifting frame 400 and the housing is arranged between the first support portion 410 and the second support portion 420. In the knife lifting state, the rotation of the knife lifting frame 400 drives the second support portion 420 to move downward and be supported on the diameter reducing portion 5022, and the first support portion 410 moves upward to drive the reciprocating rod 310 to swing. The reciprocating saw changes from the knife lifting state to the knife leveling state, and the outer contour of the diameter reducing portion 5022 gradually changes toward the sizing portion 5021. The force of the knife seat 320 drives the reciprocating rod 310 to swing and reset, and the first support portion 410 moves downward and resets with the reciprocating rod 310 and drives the second support portion 420 to move upward and reset, and the reciprocating rod 310 returns to the linear motion state.

[0090] Exemplarily, when the knife lifting frame 400 can slide relative to the housing, the first support portion 410 is disposed below the reciprocating rod 310, and the second support portion 420 is disposed above the reciprocating rod 310, the knife lifting frame 400 slides in a direction substantially parallel to the line connecting the first support portion 410 and the second support portion 420, and in the knife lifting state, the diameter reducing portion 5022 is supported on the second support portion 420 and drives the second support portion 420 to move upward, and the first support portion 410 moves with the second support portion 420 and thus moves upward with the deflection of the reciprocating rod 310. The reciprocating saw changes from the knife lifting state to the knife leveling state, the reciprocating rod 310 deflects and moves under the action of the knife holder 320, the reciprocating rod 310 drives the first support portion 410 to move downward and reset, the second support portion 420 moves downward and resets with the first support portion 410, and the reciprocating rod 310 returns to the linear motion state.

[0091] Through the appropriate arrangement of the base 502, the linear motion of the reciprocating rod 310 and the lifting of the blade can be realized. The arrangement of the first gear 500 is simple, which helps to reduce the production cost of the reciprocating saw.

[0092] In order to reduce the wear of the reciprocating rod 310, as Figure 1 , Figure 5 , Figure 7 As shown, in one embodiment, the reciprocating saw based on the above embodiment further includes a guide frame 700, the guide frame 700 is provided with a guide groove 710, the reciprocating rod 310 slides along the guide groove 710, the deflection of the reciprocating rod 310 drives the guide frame 700 to deflect, the housing stops at one side of the guide frame 700 to limit the deflection of the reciprocating rod 310 to one side, and the tool lifting frame 400 is supported at the other side of the guide frame 700 so that the deflection of the reciprocating rod 310 to the other side is transmitted to the tool lifting frame 400. The tool lifting frame 400 supports the reciprocating rod 310 by supporting the guide frame 700.

[0093] In this way, direct contact between the reciprocating rod 310 and the housing and the tool lifter 400 is avoided, thereby reducing the wear of the reciprocating rod 310 , the housing and the tool lifter 400 , reducing the movement resistance of the reciprocating rod 310 , and increasing the service life of the reciprocating rod 310 .

[0094] In one embodiment, the guide frame 700 is rotatably connected to the housing, the reciprocating rod 310 includes a reciprocating rod body 311 and a sliding portion 312 disposed on the reciprocating rod body 311, the sliding portion 312 is located in the guide groove 710 and slides, and the force of the knife seat 320 drives the reciprocating rod 310 to swing and rotate through the fulcrum portion 600, so that the swing of the reciprocating rod 310 drives the guide frame 700 to swing. The first support portion 410 slidably supports the guide frame 700. Since the guide frame 700 is rotatably connected to the outer shell, the rotation axes of the guide frame 700 and the reciprocating rod 310 are different, and the guide frame 700 does not move with the reciprocating rod 310. Therefore, there will be a misalignment between the deflection of the reciprocating rod 310 and the guide frame 700. The sliding portion 312 on the reciprocating rod body 311 cooperates with the guide groove 710 to realize the sliding of the reciprocating rod 310 relative to the guide groove 710. At the same time, the reciprocating rod 310 can deflect relative to the guide groove 710 around the sliding portion 312, thereby avoiding interference between the reciprocating rod body 311 and the guide frame 700, avoiding extrusion friction between the movement of the reciprocating rod body 311 and the guide frame 700, and improving the service life of the reciprocating rod 310 and the guide frame 700.

[0095] It is understandable that the guide frame 700 may be in the form of a plate, on which a guide groove 710 is provided for the sliding portion 312 to slide, and the extension direction of the plate-shaped guide frame 700 is parallel to the movement direction of the reciprocating rod body 311 to avoid interference with the movement of the reciprocating rod body 311. The guide frame 700 may also be in the form of a cylinder, on at least one side of the cylinder wall there is a guide groove 710 for the roller to slide, and a through hole is provided through the guide frame 700, in which the reciprocating rod body 311 reciprocates, and the reciprocating rod body 311 does not contact the cylinder wall of the guide frame 700 during the movement.

[0096] Preferably, in the present embodiment, the sliding portion 312 is a roller disposed on a connecting shaft between the reciprocating rod 310 and the crank 200 , and the roller rotates around the connecting shaft.

[0097] It can be understood that the straight line connecting the rotating shaft, the sliding part 312 and the fulcrum determines the swing direction of the reciprocating rod 310 .

[0098] By arranging the sliding part 312 on the connecting shaft between the reciprocating rod 310 and the crank 200 and rotating it around the connecting shaft, the straight line between the sliding part 312 and the fulcrum determines the yaw direction of the reciprocating rod 310, thereby reducing the resistance between the crank 200, the reciprocating rod 310 and the fulcrum part 600, ensuring smooth movement of the crank 200 and the reciprocating rod 310.

[0099] In some other embodiments, the sliding portion 312 may also be a sliding block protruding from the reciprocating rod 310 .

[0100] In one embodiment, the guide frame 700 is rotatably connected to the tool lifting frame 400. Due to the existence of the fulcrum portion 600, the force of the tool holder 320 drives the reciprocating rod 310 to rotate and swing through the fulcrum portion 600. The guide frame 700 swings along with the rotation of the reciprocating rod 310. The outer shell is provided with a guide groove for guiding the movement direction of the guide frame 700. The rotatable connection between the guide frame 700 and the tool lifting frame 400 enables the guide frame 700 to move together with the tool lifting frame 400.

[0101] The reciprocating rod 310 passes through the guide frame 700, and the guide groove 710 is sleeved on the reciprocating rod 310. The tool lifting frame 400 supports the guide frame 700 through the rotation connection point between the tool lifting frame 400 and the guide frame 700, thereby supporting the reciprocating rod 310.

[0102] The rotational connection between the guide frame 700 and the tool lifting frame 400 enables the guide frame 700 to move together with the tool lifting frame 400 and the reciprocating rod 310, thereby avoiding misalignment and wear caused by the asynchronous movement between the reciprocating rod 310 and the guide frame 700, and improving the service life of the reciprocating rod 310 and the guide frame 700. At the same time, the guide groove 710 can also completely wrap the reciprocating rod 310 to enable a better sliding fit between the two. The design structure of the guide frame 700 is simpler, thereby reducing costs.

[0103] In one embodiment, Figure 1 , Figure 5 , Figure 7 As shown, the fulcrum part 600 includes a base 610 and a rotating part 620. The rotating part 620 is limited in rotation at the base 610. The rotating part 620 is provided with an inner hole 621. The reciprocating rod 310 is slidably fitted in the inner hole 621. The center of the inner hole 621 forms a fulcrum.

[0104] The rotating part 620 has an arc-shaped outer surface, and a groove that matches the shape of the rotating part 620 is provided on the side wall of the base 610, so that the rotating part 620 can rotate relative to the base 610. The base 610 can be equipped with a screw that limits the rotating part 620 on one side of the side wall, and a limiting groove is provided in the center of the outer surface of the rotating part 620. The screw extends into the limiting groove to limit the rotating part 620 from separating from the base 610, and the rotating part 620 can rotate around the apex of the screw. The base 610 can also be a split structure, which is wrapped by wrapping the rotating part 620 up and down, left and right, or front and back to limit the rotating part 620 from separating from the base 610.

[0105] Exemplarily, the fulcrum portion 600 is a spherical bearing, the inner ring of the spherical bearing is the rotating portion 620 , and the outer ring of the spherical bearing is the base 610 .

[0106] Through the above arrangement, the rotating part 620 can rotate relative to the base 610 and the sliding fit between the reciprocating rod 310 and the inner hole 621 of the rotating part 620 helps to reduce the friction between the reciprocating rod 310 and the fulcrum part 600, thereby reducing the resistance between the reciprocating rod 310 and the rotating part 620 during the linear motion of the reciprocating rod 310 and the lifting of the knife, thereby improving the working efficiency of the reciprocating saw.

[0107] like Figure 1 , Figure 5 , Figures 7 to 9 As shown, in one embodiment, the reciprocating saw based on the above embodiment further includes a locking rod 430 that can rotate relative to the outer shell, and a stop portion 431 and a knife lifting portion 432 are provided on the locking rod 430. The locking rod 430 has a locked state and an unlocked state. In the locked state, the stop portion 431 corresponds to the position of the knife lifting frame 400 and the stop portion 431 stops the knife lifting frame 400. In the unlocked state, the knife lifting portion 432 corresponds to the position of the knife lifting frame 400 and there is a movable gap 433 between the knife lifting portion 432 and the knife lifting frame 400.

[0108] Rotating the locking rod 430 can make the stopper 431 or the blade lifting part 432 correspond to the position of the blade lifting frame 400. When the stopper 431 corresponds to the position of the blade lifting frame 400, the stopper 431 and the blade lifting frame 400 are interference fit or the gap between the stopper 431 and the blade lifting frame 400 is small, and the blade lifting frame 400 cannot move or the range of movement is very small, so that the reciprocating rod 310 maintains a straight line or a substantially straight line movement, thereby turning off the blade lifting function of the reciprocating saw. When the blade lifting part 432 corresponds to the position of the blade lifting frame 400, since there is a movable gap 433 between the blade lifting part 432 and the blade lifting frame 400, the blade lifting frame 400 can move, thereby turning on the blade lifting function of the reciprocating saw.

[0109] In this embodiment, if Figure 8 As shown, the locking rod 430 is provided with a flat position, which forms a knife lifting portion 432, and the locking rod 430 forms a stopper portion 431 on the arc-shaped outer surface on the other side of the flat position. When the knife lifting portion 432 corresponds to the knife lifting frame 400, there is a movable gap 433 between the two.

[0110] Through the above settings, the blade lifting function of the reciprocating saw can be turned on or off as needed, and the operator can choose according to his needs, thereby improving the user experience of the reciprocating saw.

[0111] In one embodiment, Fig. 9 As shown, based on the reciprocating saw of the above embodiment, the knife lifting part 432 includes at least a first knife lifting part 4321 and a second knife lifting part 4322, and the movable gap 433 between the first knife lifting part 4321 and the knife lifting frame 400 is larger than the movable gap 433 between the second knife lifting part 4322 and the knife lifting frame 400.

[0112] The movable gap 433 between the first blade lifting portion 4321 and the blade lifting frame 400 allows one end of the blade lifting frame 400 to be always supported on the diameter reducing portion 5022 when the diameter reducing portion 5022 corresponds to the blade lifting frame 400. The movable gap 433 between the second blade lifting portion 4322 and the blade lifting frame 400 allows one end of the blade lifting frame 400 to be supported on the diameter reducing portion 5022 on a partial path of rotation of the diameter reducing portion 5022 when the diameter reducing portion 5022 corresponds to the blade lifting frame 400. In this way, the blade lifting range of the reciprocating saw can be adjusted, and the operator can switch among multiple blade lifting ranges of the reciprocating saw as needed, further improving the user experience of the reciprocating saw.

[0113] It can be understood that the knife lifting part 432 can also be provided with a third knife lifting part, a fourth knife lifting part, etc., and the movable gaps 433 between the first knife lifting part 4321, the second knife lifting part 4322, the third knife lifting part, the fourth knife lifting part and the knife lifting frame 400 are different, so as to realize the reciprocating saw with multiple knife lifting amplitude gears.

[0114] In one embodiment, Figure 1 , Figure 2 As shown, based on the reciprocating saw of the above embodiment, the first gear 500 is an end gear, the tooth portion 501 protrudes along the axial direction of the first gear 500, and the rotation axis of the output shaft of the motor 100 is perpendicular to the rotation axis of the first gear 500. Among them, the tooth portion 501 is a bevel tooth portion 501, and a bevel gear is provided on the output shaft of the motor 100. In this way, the extension direction of the output shaft of the motor 100 can be consistent with the linear motion direction of the reciprocating rod 310, and the reciprocating saw is arranged to extend along the length direction. On the one hand, the reciprocating saw is made more compact, and on the other hand, it is easier to apply force when holding the reciprocating saw for cutting.

[0115] In one embodiment, the reciprocating saw based on the above embodiment further includes a second gear 510 meshing with the output shaft of the motor 100 , and the first gear 500 and the second gear 510 rotate coaxially and in opposite directions.

[0116] For example, the first gear 500 is a spur gear, the second gear 510 is also a spur gear, the output shaft of the motor 100 is provided with a spur gear, the output shaft of the motor 100 is directly meshed with the first gear 500, and the output shaft of the motor 100 is meshed with the second gear 510 through an idler gear. The first gear 500 and the second gear 510 can rotate coaxially, or can be arranged on both sides of the output shaft to rotate.

[0117] Exemplarily, the first gear 500 is an end face gear, and the second gear 510 is also an end face gear accordingly. The tooth portions of the first gear 500 and the second gear 510 are bevel tooth portions, and a bevel gear is correspondingly provided on the output shaft of the motor 100. The first gear 500 and the second gear 510 are mirror-imaged and respectively meshed with the upper and lower ends of the output shaft of the motor 100.

[0118] By providing a second gear 510 that rotates coaxially with the first gear 500 and in the opposite direction, the unbalanced inertial force generated by the rotation of the first gear 500 and the unbalanced inertial force generated by the rotation of the second gear 510 offset each other, thereby reducing the vibration of the reciprocating saw during movement and improving the stability of the reciprocating saw during operation.

[0119] In one embodiment, Figure 5 , Figure 6 As shown, based on the above embodiment, the reciprocating saw further includes a balancing mechanism, which includes a first counterweight body 520 and a second counterweight body 521. The first counterweight body 520 rotates with the first gear 500 and is eccentrically arranged relative to the first gear 500. The second counterweight body 521 rotates with the second gear 510 and is eccentrically arranged relative to the second gear 510.

[0120] In this embodiment, the balancing mechanism also includes two connecting bodies 530, the middle part of one side of the connecting body 530 protrudes outward and constitutes a first shaft body 531, and an axial hole 532 is set in the first shaft body 531 along its axial direction, and the axial hole 532 is for the second shaft body 533 to penetrate, the first counterweight body 520 and the second counterweight body 521 are respectively mounted on the two first shaft bodies 531 and rotate around the first shaft body 531, and the two second shaft bodies 533 are respectively connected to the center positions of the first gear 500 and the second gear 510 and are coaxially arranged, and a plurality of bearings are mounted on the second shaft body 533, and the bearings are arranged in the outer shell to facilitate the two second shaft bodies 533 to rotate with the first gear 500 and the second gear 510 respectively, thereby reducing friction, and the center of the axial hole 532 is eccentrically arranged relative to the center of the first shaft body 531, that is, there is a distance between the centers of the two circles.

[0121] Among them, a transmission body 511 is respectively protruded on one side of the first gear 500 and the second gear 510, and a transmission groove 522 is recessed inwardly on one side of the first counterweight body 520 and the second counterweight body 521. The transmission body 511 cooperates with the transmission groove 522 to form a sliding pair. Through the linear motion cooperation of the transmission body 511 in the transmission groove 522, the rotation of the first gear 500 and the second gear 510 in the eccentric state can respectively drive the first counterweight body 520 and the second counterweight body 521 to rotate.

[0122] By providing the first counterweight 520 and the second counterweight 521, and the first gear 500 and the second gear 510 eccentrically rotate with the first counterweight 520 and the second counterweight 521 respectively, a difference is generated between the rotation speed of the first counterweight 520 and the second counterweight 521 and the rotation speed of the first gear 500 and the second gear 510, and the rotation speed of the first counterweight 520 and the second counterweight 521 forms a variable angular velocity, so that the unbalanced inertia force generated by the first counterweight 520 and the second counterweight 521 is a second-order inertia force, which can completely offset the output inertia force of the first gear 500 and the second gear 510, thereby achieving the effect of reducing vibration.

[0123] The specific working principle of the balancing structure and the balancing method of the counterweight in this embodiment are detailed in Chinese invention patent application with publication number CN118123121A and titled A Balancing Structure, Balancing Method and Electric Tool for an Electric Tool.

[0124] In one embodiment, Figure 1 , Figure 2 As shown, the first gear 500 and the second gear 510 are arranged in a mirror image, and the second support portion 420 is supported on the base 502 of the first gear 500 and the base 502 of the second gear 510 .

[0125] In this embodiment, the first gear 500 and the second gear 510 are face gears, and the output shaft of the motor 100 directly meshes with the first gear 500 and the second gear 510 so that the first gear 500 and the second gear 510 rotate coaxially, and the first gear 500 and the second gear 510 rotate in opposite directions. The tool lifting frame 400 is supported on the base 502 of the first gear 500 and the second gear 510, so that the first gear 500 and the second gear 510 can more stably support the tool lifting frame, reduce or avoid sliding during the movement of the tool lifting frame 400, and improve the stability of the movement of the reciprocating rod 310.

[0126] Among them, since the rotation directions of the first gear 500 and the second gear 510 are opposite, the outer contours of the first gear 500 and the second gear 510 will overlap at a certain time node, and the second support part 420 is configured to be supported on the extreme point 5025 at this time node. This time node is the time node of the maximum amplitude of the reciprocating rod 310 lifting the knife.

[0127] In some other embodiments, the first gear 500 and the second gear 510 may also be spur gears, and the output shaft of the motor 100 is meshed with the first gear 500 through an idle gear, and the output shaft of the motor 100 is meshed with the second gear 510 through two idle gears, so that the first gear 500 and the second gear 510 rotate coaxially, and the first gear 500 and the second gear 510 are mirror-imaged and rotate in opposite directions.

[0128] Based on the above embodiments, the present invention further proposes a method for calculating the blade lifting amplitude of a reciprocating saw with a blade lifting function, such as Fig.10 As shown, the structure of the crank 200, reciprocating rod 310, guide frame 700, and fulcrum 600 is simplified into a connecting rod mechanism, and the rotation connection point of the guide frame 700 is simplified to a straight line in the linear motion direction of the reciprocating rod 310, and the blade lifting amplitude of the reciprocating saw is calculated.

[0129] The calculation method is as follows:

[0130]

[0131] Wherein, R is the linear distance between the rotation connection point of the first gear 500 and the crank 200 and the rotation axis of the first gear 500, L is the linear distance between the rotation connection points at both ends of the crank 200, α is the angle between the crank 200 and the linear motion direction of the reciprocating rod 310, β is the angle between the reciprocating rod 310 and the linear motion direction of the reciprocating rod 310, θ is the angle between the guide groove 710 and the linear motion direction of the reciprocating rod 310, and L 1 is the horizontal distance between the rotation axis of the first gear 500 and the rotation connection point of the guide frame 700, L 2 is the straight-line distance between the rotation connection point of the guide frame 700 and the fulcrum provided by the fulcrum portion 600, L 0 is the linear distance between the preset sawtooth point and the rotation connection point of the crank 200, x 1 ,y 1 They respectively correspond to the coordinates of the rotation connection point of the crank 200 and the reciprocating rod 310 relative to the rotation connection point of the guide frame 700, and x and y correspond to the coordinates of the preset sawtooth points.

[0132] By solving the motion trajectory of x and y or the extreme points of x and y, the motion trajectory of the tool lifting amplitude of the preset sawtooth point or the tool lifting amplitude of the preset sawtooth point can be obtained.

[0133] Among them, R, L, L 1 , L 2 , L 0 is a fixed value, x 1 ,y 1 , β, and θ change with α.

[0134] α can be input as a fixed value or its movement change process as needed, and the fixed value is the extreme value of α.

[0135] The above formula can be used to calculate the blade lifting amplitude of a preset sawtooth point, thereby facilitating determination of the maximum blade lifting amplitude of the reciprocating saw. The calculable blade lifting amplitude of the reciprocating saw is beneficial to the design of the reciprocating saw.

[0136] In one embodiment, Fig.11 , Fig.12 As shown, based on the above embodiment, the calculation method calculates α through the following equation group:

[0137]

[0138] Among them, L 3 is the distance between the rotation axis of the tool lift 400 and the support point of the guide frame 700, L 4 is the distance between the rotation axis of the tool lift 400 and the support point of the base 502, L 5 L is the horizontal distance between the rotation axis of the tool lift 400 and the rotation axis of the first gear 500, 6 is the vertical distance between the linear motion direction of the reciprocating rod 310 and the rotation axis of the knife lifting bracket, δ is the angle between the rotation axis of the knife lifting bracket 400 and the line connecting the support point of the guide frame 700 and the vertical direction in the knife flat state, φ is the extreme value of the rotation angle between the rotation axis of the knife lifting bracket 400 and the line connecting the support point of the guide frame 700 in the knife lifting state, and x 2 ,y 2 Corresponding to the extreme value of the support point of the tool lift 400 and the guide frame 700, t 1 The point on the base 502 corresponding to the critical point when the flat knife state switches to the raised knife state, t 2 The upper point of the base 502 corresponds to the maximum value of the knife lifting amplitude.

[0139] The motion change process or extreme point of α is solved and introduced into the aforementioned embodiment, so as to obtain the motion trajectory of the tool lifting amplitude of the preset sawtooth point or the tool lifting amplitude of the preset sawtooth point.

[0140] According to the change of the outer contour of the variable diameter part 5022, the movement change process or extreme point of α can be determined, so that the change of the outer contour of the variable diameter part 5022 can be reversely deduced according to the required blade lifting amplitude of the reciprocating saw, which facilitates the design of the variable diameter part 5022 and reduces the trial and error cost.

[0141] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes but is not limited to the contents described in the drawings and the above specific embodiments. Any modification that does not deviate from the functional and structural principles of the present invention will be included in the scope of the claims.

Claims

1. A reciprocating saw with a blade lifting function, characterized in that: The invention comprises a shell with a cavity and a motor, a first gear, a crank, a reciprocating rod, a tool lifter and a fulcrum portion accommodated in the cavity, wherein the first gear comprises a coaxially rotating tooth portion and a base portion, wherein the tooth portion meshes with the output shaft of the motor, and the two ends of the crank are respectively rotatably connected to the first gear and the reciprocating rod, and the base portion comprises a sizing portion and a reducing portion, wherein the sizing portion has a constant outer radius R1, and an extreme point is arranged on the outer contour of the reducing portion, and the linear distance between the extreme point and the center of the sizing portion is L1, and the linear distance between the outer contour of the reducing portion and the center of the sizing portion changes continuously between R1 and L1, and the fulcrum portion provides a fulcrum for the deflection of the reciprocating rod to both sides, and the shell is stopped at one side, and the tool lifter is supported between the other side and the base portion and moves with one of the reciprocating rod and the base portion, and the reciprocating rod has: In the flat knife state, the knife lifting frame is supported on the sizing portion to make the reciprocating rod reciprocate along a straight line; and in the knife lifting state, the reciprocating rod swings along the fulcrum to make the knife lifting frame move and be supported on the diameter-changing portion to achieve knife lifting.

2. The reciprocating saw with a blade lifting function according to claim 1, characterized in that: The reducing portion includes a first reducing portion and a second reducing portion, the connection point of the first reducing portion and the second reducing portion constitutes the extreme point, the first reducing portion and the second reducing portion extend from both ends of the fixed diameter portion to the extreme point respectively and the outer diameters gradually decrease, L1<R1.

3. The reciprocating saw with a blade lifting function according to claim 1, characterized in that: The reducing portion includes a first reducing portion and a second reducing portion, the connection point of the first reducing portion and the second reducing portion constitutes the extreme point, the first reducing portion and the second reducing portion extend from both ends of the fixed diameter portion to the extreme point respectively and the outer diameters gradually increase, L1>R1.

4. The reciprocating saw with a blade lifting function according to claim 1, characterized in that: The first gear is a face gear, the tooth portion protrudes along the axial direction of the first gear, and the rotation axis of the output shaft of the motor is perpendicular to the rotation axis of the first gear.

5. The reciprocating saw with a blade lifting function according to claim 1, characterized in that: It also includes a second gear meshing with the output shaft of the motor, and the first gear and the second gear rotate in opposite directions.

6. The reciprocating saw with a blade lifting function according to claim 1, characterized in that: It also includes a guide frame, which includes a guide groove, the reciprocating rod sliding limit is located in the guide groove, the deflection of the reciprocating rod drives the guide frame to deflect, the shell is stopped on one side of the guide frame, and the tool lifting frame is supported on the other side.

7. The reciprocating saw with a blade lifting function according to claim 6, characterized in that: The guide frame is rotatably connected to the tool lifting frame, and the shell is provided with a guide groove for guiding the movement direction of the guide frame.

8. The reciprocating saw with a blade lifting function according to claim 6, characterized in that: The guide frame is rotatably connected to the shell, and the reciprocating rod comprises a reciprocating rod body and a sliding portion arranged on the reciprocating rod body, wherein the sliding portion is located in the guide groove and slides along the guide groove.

9. The reciprocating saw with a blade lifting function according to claim 1, characterized in that: It also includes a locking rod that can rotate relative to the shell, and the locking rod is provided with a stop portion and a knife lifting portion. The locking rod has a locked state and an unlocked state. In the locked state, the stop portion corresponds to the position of the knife lifting frame and the stop portion stops the knife lifting frame. In the unlocked state, the knife lifting portion corresponds to the position of the knife lifting frame and there is a movable gap between the knife lifting portion and the knife lifting frame.

10. The method for calculating the blade lifting amplitude of a reciprocating saw with a blade lifting function according to claim 8, characterized in that: The calculation method is as follows: Among them, R is the straight-line distance between the rotation connection point of the first gear and the crank and the rotation axis of the first gear, L is the straight-line distance between the rotation connection points at both ends of the crank, α is the angle between the crank and the linear motion direction of the reciprocating rod, β is the angle between the reciprocating rod and the linear motion direction of the reciprocating rod, θ is the angle between the guide groove and the linear motion direction of the reciprocating rod, L1 is the horizontal distance between the rotation axis of the first gear and the rotation connection point of the guide frame, L2 is the straight-line distance between the rotation connection point of the guide frame and the fulcrum provided by the fulcrum part, L0 is the straight-line distance between the preset sawtooth point and the rotation connection point of the crank, x1 and y1 respectively correspond to the coordinates of the rotation connection point of the crank and the reciprocating rod relative to the rotation connection point of the guide frame, and x and y correspond to the coordinates of the preset sawtooth point.

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