Switching device for electric hammer function

Abstract

A switching device for electric hammer functions includes a transmission mechanism and a shifting mechanism. The transmission mechanism includes an intermediate shaft, a power gear, a rocker bearing, and a clutch. The inner ring of the rocker bearing is extended with a connecting portion, and the stopper is extended with a transmission portion. The clutch is sleeved on the connecting portion and the transmission portion through a spline. A spring is provided between the rocker bearing and the clutch. An intermediate shaft gear is sleeved in the intermediate shaft, and the intermediate shaft gear is provided with an annular groove. The shifting mechanism includes a shifting post and a shifting piece on a knob. The shifting piece is connected in the annular groove, and the shifting post is located between the clutch and the shifting piece. The transmission mechanism of the present invention simplifies the connection relationship, makes the structure relatively simple, reduces the manufacturing difficulty, is convenient to assemble, and basically adopts standard parts, which can greatly reduce the manufacturing cost; the shifting mechanism is composed of a simply punched shifting piece, a torsion spring, and a compression spring, which is relatively convenient to assemble, can reduce the technical level requirements of the operator, and greatly reduce the human resource cost.

Description

Technical Field

[0001] The present invention relates to an electric tool, and more particularly to a switching device arranged in an electric hammer and used for switching functions between a hammer, a drill and a hammer-drill in the electric hammer. Background Art

[0002] Electric hammers generally have the functions of hammering, drilling, or both hammering and drilling. The conversion between the functions is generally achieved by changing the transmission mode between the gear adjustment mechanism and the transmission mechanism through a shift mechanism.

[0003] On November 12, 2014, the Chinese Patent Office announced an invention patent (announcement number: CN102837295B), which discloses an electric hammer transmission mechanism, which has a large gear, an intermediate gear, an intermediate shaft, and a clutch gear. The large gear is meshed with the intermediate gear, and the intermediate gear and the clutch gear can be slidably sleeved on the intermediate shaft. A keyway matching structure that matches each other is provided between the clutch gear and the intermediate shaft, and between the intermediate gear and the intermediate shaft. The shift mechanism is connected to the clutch gear and the intermediate gear respectively, and is characterized in that the dimension of the keyway matching structure between the intermediate gear and the intermediate shaft along the axial direction of the intermediate shaft is smaller than the length of the gear teeth on the intermediate gear, the outer peripheral surface of one end of the intermediate gear is meshed with the large gear, and the keyway matching structure between the intermediate gear and the intermediate shaft is located on the inner peripheral surface of the other end of the intermediate gear, and a first cavity is provided in the middle of the inner peripheral surface of the intermediate gear, and the keyway matching structure of the first cavity and the intermediate gear is provided. The structures are fitted together, the size of the first cavity along the axial direction of the intermediate shaft is larger than the size of the keyway matching structure of the intermediate gear along the axial direction of the intermediate shaft, a first bearing is arranged on the intermediate gear, the inner ring of the first bearing is the intermediate gear, the outer ring of the first bearing is provided with a groove, the shift mechanism is connected in the groove, the ball in the first bearing is biased to one side of the outer ring, the outer ring extends along the axial direction of the intermediate shaft toward the large gear and forms an extension portion, the groove is located in the extension portion, the inner diameter of the extension portion is smaller than the inner diameter of the outer ring portion contacted by the ball, the gap between the inner circumference of the extension portion and the outer circumference of the cylindrical portion of the intermediate gear is much smaller than the diameter of the ball, the gear teeth on the intermediate gear are located on the outer side of the first bearing, the inner circumference of the outer ring of the first bearing is provided with a second cavity on the inner side of the ball, the groove is annular, and the groove is arranged on the outer circumference of the outer ring extension portion.

[0004] This kind of electric hammer transmission mechanism has a complex structure and various connection methods. It uses more non-standard parts, such as the first bearing, the second bearing, the rocker bearing, etc., and uses more spline structures. We know that the price difference between non-standard parts and standard parts is large, at least several times, and as high as more than ten times, so the manufacturing cost is also high; in addition, the shift mechanism also uses more parts, such as the first paddle, the second paddle, the linkage plate, the toothed protrusion, the pin shaft, etc., and then use spiral springs and springs to connect them together. Not only is the manufacturing cost high, but the difficulty of assembly is also high, and higher requirements are placed on the technical level of the operators, so the cost of human resources will also be greatly increased. Summary of the invention

[0005] In order to overcome the above defects, the technical problem to be solved by the present invention is to provide a switching device for the electric hammer function which has a simple structure, is easy to assemble and has a low manufacturing cost.

[0006] The technical solution of the present invention to solve the problems existing in the prior art is: a switching device for electric hammer function, which includes a transmission mechanism and a shifting mechanism. The transmission mechanism includes an intermediate shaft, and the outer peripheral side of one end of the intermediate shaft is sequentially sleeved with a power gear, a rocker bearing, and a clutch. The power gear is fixedly connected to the intermediate shaft, and the rocker bearing is slidably connected to the intermediate shaft. It is characterized in that the outer surface of the other end of the intermediate shaft is provided with a stopper, the inner ring of the rocker bearing extends to one side of the clutch with a connecting part, and the stopper extends to one side of the clutch with a transmission part, and the clutch is slidably sleeved on the connecting part and the transmission part through a keyway matching structure, and the axial length of the transmission part is less than that of the clutch. axial length, the diameter of the stopper is larger than the diameter of the transmission part, a spring is arranged between the rocker bearing and the clutch, a circular blind hole is arranged on the end surface of the other end of the intermediate shaft, an intermediate shaft gear is rotatably sleeved in the circular blind hole, a polygonal blind hole is arranged on the bottom surface of the circular blind hole, an end of the intermediate shaft gear facing the polygonal blind hole is provided with a polygonal part matching the polygonal blind hole, one end of the intermediate shaft gear located outside the circular blind hole is meshed with a large gear, an annular groove is arranged on the outside of the large gear, the shift mechanism comprises a shift post and a shift piece on the knob, the shift piece is connected in the annular groove, the shift post is located between the clutch and the shift piece, and the shift piece is connected with a compression spring.

[0007] In the electric hammer of the present invention, the output shaft of the motor is a gear shaft, the power gear is meshed with the output shaft of the motor, the large gear is fixedly sleeved on the outer peripheral side of the rotating sleeve, the diameter of the stop part is larger than the diameter of the transmission part, and the setting of the stop part can play a limiting role on the clutch, ensuring that the clutch can be connected to the keyway matching structure of the connecting part and the transmission part at the same time under the action of the spring. When the knob is turned to make the shift column move to the clutch side to the maximum, the shift column pushes the clutch to move to the swing rod bearing side and disengages from the transmission part, so that the rotation of the motor drives the rotating sleeve to rotate through the power gear, the intermediate shaft, the intermediate shaft gear, and the large gear in turn, and the drill shaft sleeved in the rotating sleeve with a circumferential fixed gap realizes the drilling function; when the knob is turned to make the shift column move to the paddle side to the maximum, the shift column pushes the paddle and the intermediate shaft gear in turn, and makes the polygonal part of the intermediate shaft gear disengage from the polygonal blind hole of the intermediate shaft, so that the rotation of the motor rotates through the power gear, the intermediate shaft, the clutch, and the inner ring of the swing rod shaft in turn, and the rotation of the inner ring of the swing rod bearing drives the swing rod to swing through the steel balls in the inclined steel ball groove, and the swing of the swing rod is transmitted to the drill shaft through the piston and the hammer rod to realize the hammer function; when the knob is turned to make the shift column return to the middle state, the clutch cooperates with the key slot of the connection part and the transmission part at the same time, and the polygonal part of the intermediate shaft gear is connected to the polygonal blind hole of the intermediate shaft, so that the rotation of the motor can drive the drill shaft to rotate and realize the hammer drilling function at the same time.

[0008] It can be seen from the above technical solutions and working principles that the structure of the technical solution of the present invention is relatively simple, the connection method is simplified, the assembly is convenient, the transmission mechanism basically adopts standard parts, the manufacturing is convenient, and the manufacturing cost can be greatly reduced.

[0009] As a further technical solution, one end of the paddle is a sliding piece, and the other end of the paddle is a U-shaped plug-in piece with an outward opening, the sliding piece is connected to the plug-in piece at a 90° angle, and the opening of the plug-in piece is connected to the annular groove. The paddle is made at a right angle, and the opening of the plug-in piece can pull the intermediate shaft gear to move through the movement of the sliding piece, thereby controlling the connection or disconnection between the intermediate shaft and the intermediate shaft gear.

[0010] As a further technical solution, it also includes a casing, wherein a strip-shaped protrusion is provided at the position of the slide in the casing, and the slide is provided with a U-shaped slide groove with an opening facing outward at the position of the protrusion, and the protrusion is located in the slide groove, and a limit screw is screwed on the protrusion, and the diameter of the limit screw head is greater than the width of the slide groove. The slide can have a U-shaped slide groove or a long slide hole at the position of the protrusion, and the present invention adopts a U-shaped slide groove. The strip-shaped protrusion is provided in the U-shaped slide groove for guidance to ensure that the direction of movement of the paddle is accurate, and the limit screw head on the protrusion and the casing are used to clamp the slide to ensure that the slide moves along the strip-shaped protrusion.

[0011] As a further technical solution, the outer end of one side of the U-shaped slide groove of the slide is bent toward the side away from the housing to form a positioning column, and the outer side of the side is bent toward the side away from the housing to form a positioning plate, and the outer end of the other side of the U-shaped slide groove of the slide is rolled toward the side away from the housing to form a positioning groove, and a torsion spring is sleeved on the positioning column, one end of the torsion spring is inserted into the positioning groove, and the other end of the torsion spring abuts against the positioning plate, and the insert is flanged toward the side away from the slide at a position close to the slide, and one end of the compression spring is sleeved on the flange, and the other end of the compression spring abuts against the housing. The positioning column, the positioning plate, and the positioning groove are provided for the purpose of installing the torsion spring, and the torsion spring can transfer the elasticity of the torsion spring to the shifting column, so that the shifting column has elastic and flexible characteristics when pushing the intermediate shaft gear; the flange is provided for the purpose of installing the compression spring, so that it has flexible characteristics when pushing the intermediate shaft gear to reset and connecting with the intermediate shaft. Flexible connection can eliminate the impact damage to the key or gear teeth that may be caused by hard connection.

[0012] As a further technical solution, the intermediate shaft gear is provided with a rotation stopper on the outer side of the annular groove, the housing is provided with a rotation stopper plate at a position close to the rotation stopper, and the rotation stopper plate is provided with a rotation stopper hole matching the rotation stopper. The purpose of setting the rotation stopper and the rotation stopper hole is that when the electric hammer is in the hammer function, the rotation stopper of the intermediate shaft gear can enter the rotation stopper hole, and the rotation stopper plate fixedly connected to the housing ensures that the drill shaft will not rotate, so as to effectively avoid the drill shaft from rotating unexpectedly and causing the quality of the work.

[0013] The paddle is punched by a punching machine to form a sliding piece, an insert, a U-shaped slide groove, a positioning column, a positioning plate, a positioning groove, and a flange that are connected together. The processing is simple and the manufacturing cost is low. The shift mechanism is only composed of a simple stamped paddle and a torsion spring and a compression spring. The assembly is relatively convenient, which can reduce the technical level requirements of the operating personnel and greatly reduce the human resource cost.

[0014] As a further technical solution, the spring is a pagoda spring. The spring can be a cylindrical spring, a pagoda spring, or a convex spring. Considering the factors of installation space, bearing capacity, and shock absorption, the technical solution of the present invention adopts a pagoda spring.

[0015] As a further technical solution, the keyway matching structure is a spline structure. The keyway matching structure can adopt a flat key structure or a spline structure. Compared with flat keys, splines have advantages such as large load-bearing capacity, good centering, good guidance, small stress concentration, and long service life, so the technical solution of the present invention adopts a spline structure.

[0016] As a further technical solution, the polygonal blind hole is a hexagonal blind hole, and the polygonal portion is a hexagonal portion. The polygon can be a quadrangle, a pentagon, or a hexagon. Considering the utilization rate of the material and the mechanical strength, the present invention adopts a hexagonal blind hole and a hexagonal portion.

[0017] Beneficial effects: The transmission mechanism of the present invention simplifies the connection relationship, makes the structure relatively simple, reduces the manufacturing difficulty, is convenient for assembly, and basically adopts standard parts, which can greatly reduce the manufacturing cost; the shift mechanism is composed of a simple punched shift piece and a torsion spring and a compression spring, which is relatively easy to assemble, can reduce the technical level requirements of the operating personnel, and greatly reduce the human resource cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a cross-sectional view of an electric hammer with the switching device;

[0019] Figure 2 yes Figure 1 The R part is enlarged in the figure;

[0020] Figure 3 It is a three-dimensional diagram of the electric hammer switching device;

[0021] Figure 4 is a schematic diagram of the paddle of the present invention being installed on the housing;

[0022] Figure 5 yes Figure 4 AA section view in;

[0023] Figure 6 is a three-dimensional diagram of the rocker bearing of the present invention;

[0024] Figure 7 is a stereogram of the intermediate shaft in the present invention;

[0025] Figure 8 is a three-dimensional diagram of the intermediate shaft gear in the present invention;

[0026] Fig. 9 It is a three-dimensional diagram of the plectrum of the present invention.

[0027] In the figure: casing 1, intermediate shaft 2, power gear 3, rocker bearing 4, clutch 5, stopper 6, connecting part 7, transmission part 8, pagoda spring 9, circular blind hole 10, intermediate shaft gear 11, hexagonal blind hole 12, hexagonal part 13, large gear 14, annular groove 15, stopper 16, stop plate 17, stop hole 18, knob 19, shift column 20, shift piece 21, slide piece 22, slide groove 23, insert piece 24, positioning column 25, positioning plate 26, positioning groove 27, torsion spring 28, flange 29, compression spring 30, protrusion 31, limit screw 32, rotating sleeve 33, output shaft 34. DETAILED DESCRIPTION

[0028] The present invention will be further described below through specific embodiments in conjunction with the accompanying drawings.

[0029] Embodiment: A switching device for electric hammer function, as shown in the figure, comprises a transmission mechanism, a shifting mechanism and a housing 1, wherein the transmission mechanism comprises an intermediate shaft 2, and a power gear 3, a rocker bearing 4 and a clutch 5 are sleeved on the outer peripheral side of one end of the intermediate shaft 2 in sequence, and a motor is arranged in the housing 1, and the output shaft 34 of the motor is a gear shaft, and the power gear 3 is meshed with the output shaft 34 of the motor, and the power gear 3 is fixedly connected to the intermediate shaft 2, and the rocker bearing 4 is slidably connected to the intermediate shaft 2, and a stopper 6 is arranged on the outer surface of the other end of the intermediate shaft 2, and a connecting portion 7 is extended from the inner ring of the rocker bearing 4 to the clutch 5 side, and a transmission portion 8 is extended from the stopper 6 to the clutch 5 side, and the clutch 5 is connected by a spline joint. The structure is slidably sleeved on the connecting portion 7 and the transmission portion 8, the axial length of the transmission portion 8 is smaller than the axial length of the clutch 5, the diameter of the stop portion 6 is larger than the diameter of the transmission portion 8, a pagoda spring 9 is provided between the rocker bearing 4 and the clutch 5, a circular blind hole 10 is provided on the end surface of the other end of the intermediate shaft 2, an intermediate shaft gear 11 is rotatably sleeved in the circular blind hole 10, a hexagonal blind hole 12 is provided on the bottom surface of the circular blind hole 10, and a hexagonal portion 13 matching the hexagonal blind hole 12 is provided on one end of the intermediate shaft gear 11 facing the hexagonal blind hole 12, and a large gear 14 is meshed at one end of the intermediate shaft gear 11 located outside the circular blind hole 10, and the large gear 14 is fixedly sleeved on the rotating sleeve 3 3, the intermediate shaft gear 11 is provided with an annular groove 15 on the outer side of the large gear 14, the intermediate shaft gear 11 is provided with a stopper 16 on the outer side of the annular groove 15, the housing 1 is provided with a stopper plate 17 at a position close to the stopper 16, the stopper plate 17 is provided with a stopper hole 18 matching the stopper 16, the shift mechanism includes a shift post 20 and a shifter 21 on the knob 19, one end of the shifter 21 is a slide 22, the slide 22 is provided with a U-shaped slide groove 23 with an opening facing outward, the other end of the shifter 21 is a U-shaped plug 24 with an opening facing outward, the slide 22 is connected to the plug 24 at a 90° angle, the opening of the plug 24 is connected to the annular groove 15, and the slide groove 23 is connected to the annular groove 15. The outer end of one side of the clutch 3 is bent toward the side away from the housing 1 to form a positioning column 25, and the outer side of the side is bent toward the side away from the housing 1 to form a positioning plate 26. The outer end of the other side of the slide groove 23 is bent toward the side away from the housing 1 to form a positioning groove 27. A torsion spring 28 is sleeved on the positioning column 25, one end of the torsion spring 28 is inserted into the positioning groove 27, and the other end of the torsion spring 28 abuts against the positioning plate 26. The shift column 20 is located between the clutch 5 and the torsion spring 28. The insert 24 is flanged 29 at a position close to the slide 22 toward the side away from the slide 22. The flange 29 is connected to a compression spring 30, one end of the compression spring 30 is sleeved on the flange 29, and the other end of the compression spring 30 abuts against the housing 1.A strip-shaped protrusion 31 is provided in the housing 1 at the position of the slide slot 23. The protrusion 31 is located in the slide slot 23. A limit screw 32 is screwed on the protrusion 31. The diameter of the head of the limit screw 32 is greater than the width of the slide slot 23.

[0030] The above-described embodiment is only a preferred solution of the present invention and does not limit the present invention in any form. There are other variations and modifications without exceeding the technical solution described in the claims.

[0031] The contents not described in detail in this specification belong to the prior art known to those skilled in the art.

Claims

1. A switching device for electric hammer function, comprising a housing, a transmission mechanism, and a shifting mechanism, wherein the transmission mechanism comprises an intermediate shaft, and a power gear, a rocker bearing, and a clutch are sleeved on the outer peripheral side of one end of the intermediate shaft in sequence, the power gear is fixedly connected to the intermediate shaft, the rocker bearing is slidably connected to the intermediate shaft, a motor is arranged in the housing, the output shaft of the motor is a gear shaft, and the power gear is meshed with the output shaft of the motor, characterized in that: A stopper is provided on the outer surface of the other end of the intermediate shaft, a connecting part is extended toward one side of the clutch by the inner ring of the swing arm bearing, a transmission part is extended toward one side of the clutch by the stopper, the clutch is slidably sleeved on the connecting part and the transmission part through a keyway matching structure, the axial length of the transmission part is less than the axial length of the clutch, the diameter of the stopper is greater than the diameter of the transmission part, a spring is provided between the swing arm bearing and the clutch, a circular blind hole is provided on the end surface of the other end of the intermediate shaft, an intermediate shaft gear is rotatably sleeved in the circular blind hole, a polygonal blind hole is provided on the bottom surface of the circular blind hole, a polygonal part matching the polygonal blind hole is provided on one end of the intermediate shaft gear facing the polygonal blind hole, a large gear is meshed at one end of the intermediate shaft gear located outside the circular blind hole, an annular groove is provided on the outside of the large gear of the intermediate shaft gear, the shift mechanism comprises a shift post and a shift piece on the knob, the shift piece is connected in the annular groove, the shift post is located between the clutch and the shift piece, and the shift piece is connected with a compression spring.

2. The switching device for the electric hammer function according to claim 1, characterized in that: One end of the paddle is a sliding piece, and the other end of the paddle is a U-shaped plug-in piece with an outward opening. The sliding piece is connected to the plug-in piece at an angle of 90 degrees, and the opening of the plug-in piece is connected to the annular groove.

3. The switching device for electric hammer function according to claim 2, characterized in that: A strip-shaped protrusion is provided at the position of the slide in the casing, and the slide is provided with a U-shaped slide groove with an outward opening at the position of the protrusion. The protrusion is located in the slide groove, and a limiting screw is screwed on the protrusion. The diameter of the limiting screw head is larger than the width of the slide groove.

4. The switching device for electric hammer function according to claim 3, characterized in that: The outer end of one side of the U-shaped slide groove of the slide is bent toward the side away from the casing to form a positioning column, and the outer side of the side is bent toward the side away from the casing to form a positioning plate, and the outer end of the other side of the U-shaped slide groove of the slide is bent toward the side away from the casing to form a positioning groove, and a torsion spring is sleeved on the positioning column, one end of the torsion spring is inserted into the positioning groove, and the other end of the torsion spring abuts against the positioning plate, and the insert is flanged toward the side away from the slide at a position close to the slide, one end of the compression spring is sleeved on the flange, and the other end of the compression spring abuts against the casing.

5. The switching device for electric hammer function according to any one of claims 3 to 4, characterized in that: The intermediate shaft gear is provided with a rotation-stopping portion on the outer side of the annular groove, and the casing is provided with a rotation-stopping plate at a position close to the rotation-stopping portion, and the rotation-stopping plate is provided with a rotation-stopping hole matched with the rotation-stopping portion.

6. The switching device for electric hammer function according to any one of claims 1 to 4, characterized in that: The spring is a pagoda spring.

7. The switching device for electric hammer functions according to any one of claims 1 to 4, characterized in that: The keyway matching structure is a spline structure.

8. The switching device for electric hammer functions according to any one of claims 1 to 4, characterized in that: The polygonal blind hole is a hexagonal blind hole, and the polygonal portion is a hexagonal portion.

Images