Handheld reamer with controllable rotating speed

Abstract

The handheld reamer comprises a shell with a grip, a rotary driver with an output shaft, an eccentric gear, a driven gear and a supporting rod limited to move on a straight line are arranged in the shell, a first elastic piece is arranged between the supporting rod and the shell, an expansion head opposite to the other end of the supporting rod is arranged on the shell, and the expansion head is connected with the eccentric gear and the driven gear. The supporting rod is switched back and forth between an initial position and an expansion position, a first sensing unit, a second sensing unit and a controller are arranged on the shell, a signal unit is arranged on the supporting rod, when the supporting rod moves forwards to the expansion position, the first sensing unit senses the signal unit and feeds back a signal to the controller, and the controller controls the output shaft to rotate at a first rotating speed; when the supporting rod retreats backwards to the initial position, the second sensing unit senses the signal unit and feeds back the signal to the controller, the controller controls the output shaft to rotate at the second rotating speed, the first rotating speed is higher than the second rotating speed, and the structure achieves the effect of controlling the supporting rod to move forwards slowly and retreat quickly.

Description

Technical Field

[0001] The utility model relates to a handheld reamer, in particular to a handheld reamer with controllable rotation speed. Background Art

[0002] Due to the high cost of copper pipes, PEX pipes are often used as a substitute for copper pipes in pipeline construction. PEX pipes can be connected to accessories (such as pipe joints) in various ways. In order to connect PEX pipes to accessories, the pipe opening of the PEX pipe needs to be expanded, and then the accessories are inserted into the expanded end of the PEX pipe. Currently, desktop pipe expanders are used to expand the pipe opening of PEX pipes, which is not only troublesome to operate and costly, but also inconvenient to carry and use.

[0003] In order to solve the above problems, a handheld reaming machine has appeared on the market. The structure of the reaming machine includes a shell with a holding portion, a motor as a power source, a transmission assembly and a strut rod limited to move in a straight line are arranged in the shell, the transmission assembly includes an eccentric gear and a driven gear, the eccentric gear is connected to the motor and driven to rotate by the motor, the rotation center of the eccentric gear is parallel to the axis of the eccentric gear and does not overlap, the driven gear is installed on one end of the strut, a first elastic member is provided between the strut and the shell, the elastic force of the first elastic member drives the strut rod to move toward one side of the eccentric gear, so that the driven gear always rests on the outer periphery of the eccentric gear and meshes with the eccentric gear, an expansion head opposite to the other end of the strut is provided on the shell, the expansion head is formed by a plurality of reaming claws, and a second elastic member is connected to the expansion head to drive each reaming claw to mate with the middle, when the eccentric gear rotates and pushes the driven gear and the strut rod to move synchronously toward one side of the expansion head, one end of the strut rod is inserted into the expansion head to open a plurality of reaming claws formed in a circle, and expand the pipe fitting sleeved on the outside of the expansion head.

[0004] The existing hole expander uses the eccentric rotation of the eccentric gear to make the support rod move back and forth, thereby expanding the pipe mouth of the pipe outside the expansion head. Because the eccentric gear is a circular gear, under the drive of the constant speed motor, the time for the support rod to move from the initial position to the expansion position to open the hole expansion claws for hole expansion is the same as the time for the support rod to retreat from the expansion position to the initial position. However, in order to ensure that the pipe will not be cracked in the process of moving the support rod forward to open the hole expansion claws, and the process of retreating the support rod to do useless work is short, the support rod needs to move forward at a slow speed and retreat at a fast speed. The existing hole expander cannot meet this condition well. Utility Model Content

[0005] Based on the fact that the above-mentioned reamer cannot adjust the forward moving speed and the retracting speed of the support rod, the utility model provides a handheld reamer with controllable rotation speed.

[0006] The technical solution adopted by the utility model to solve the above technical problems is: a hand-held reamer with controllable speed, including a shell with a grip, a rotating driver with an output shaft, an eccentric gear, a driven gear and a strut restricted to move in a straight line are arranged in the shell, the eccentric gear is connected to the output shaft and driven to rotate eccentrically by the output shaft, the driven gear is arranged on the end of the strut opposite to the eccentric gear, a first elastic member is arranged between the strut and the shell, the first elastic member has an elastic force that pushes the strut to move toward one side of the eccentric gear, so that the driven gear located at the end of the strut always abuts against the outer periphery of the eccentric gear and meshes with the eccentric gear during the rotation of the eccentric gear, an expansion head opposite to the other end of the strut is arranged on the shell, the expansion head is surrounded by a plurality of reaming claws, and a plurality of reaming claws are connected to the expansion head. A second elastic member is connected to drive each reaming claw to align toward the middle, and when the eccentric gear rotates eccentrically, the strut makes a reciprocating motion back and forth, and the strut switches back and forth between an initial position and an extended position in which the reaming claw is inserted into the expansion head and expanded. A first sensing unit, a second sensing unit and a controller are provided on the outer shell, and a signal unit that cooperates with the first sensing unit and the second sensing unit is provided on the strut. When the strut moves forward to the extended position, the first sensing unit senses the signal unit and feeds back the signal to the controller, and the controller controls the output shaft to rotate at a first speed. When the strut retreats backward to the initial position, the second sensing unit senses the signal unit and feeds back the signal to the controller, and the controller controls the output shaft to rotate at a second speed, and the first speed is faster than the second speed.

[0007] A further preferred technical solution of the utility model is: two signal units are arranged on the support rod to respectively cooperate with the first sensing unit and the second sensing unit.

[0008] A further preferred technical solution of the utility model is: the first induction unit and the second induction unit are Hall sensors fixed on the housing, and the signal unit is a magnet fixed on the support rod.

[0009] A further preferred technical solution of the utility model is: the eccentric gear is a circular gear, the outer periphery of the eccentric gear has an engagement point that engages with the driven gear, the eccentric gear has a rotation center point connected to the output shaft, and when the support rod is in the extended position or the initial position, the axis of the eccentric gear, the rotation center point of the eccentric gear and the meshing point of the eccentric gear are in a straight line.

[0010] A further preferred technical solution of the present invention is that the first sensing unit and the second sensing unit are arranged front and back in the moving direction of the support rod.

[0011] Another topic: A hand-held reamer with controllable speed, comprising a housing with a handle, a rotary driver with an output shaft, an eccentric gear, a driven gear and a strut restricted to move in a straight line are arranged in the housing, the eccentric gear is connected to the output shaft and driven to rotate eccentrically by the output shaft, the driven gear is arranged on the end of the strut opposite to the eccentric gear, a first elastic member is arranged between the strut and the housing, the first elastic member has an elastic force that pushes the strut to move toward one side of the eccentric gear, so that the driven gear located at the end of the strut always abuts against the outer periphery of the eccentric gear and meshes with the eccentric gear during the rotation of the eccentric gear, an expansion head opposite to the other end of the strut is arranged on the housing, the expansion head is surrounded by a plurality of reaming claws, and a driving gear is connected to the expansion head The second elastic member moves each reaming claw toward the middle, and the support rod reciprocates back and forth when the eccentric gear rotates eccentrically. The support rod switches back and forth between the initial position and the extended position where the reaming claws are inserted into the expansion head and expanded. A third sensing unit and a controller are provided on the outer shell, and a signal unit that cooperates with the third sensing unit is provided on the eccentric gear. The signal unit is set away from the rotation center of the eccentric gear. When the support rod moves forward to the extended position or retreats to the initial position, the third sensing unit senses the signal unit and feeds back a signal to the controller. The controller controls the output shaft to rotate at the third speed for a first set time, and then rotates at the fourth speed for a second set time. The third speed and the fourth speed are different speeds.

[0012] A further preferred technical solution of the utility model is: the third sensing unit is a Hall sensor fixed on the housing, and the signal unit is a magnet fixed on the eccentric gear.

[0013] A further preferred technical solution of the utility model is: the eccentric gear is a circular gear, and the eccentric gear has a rotation center point connected to the output shaft. During the eccentric rotation of the eccentric gear, the signal unit, the axis of the eccentric gear and the rotation center point of the eccentric gear are always on the same straight line.

[0014] A further preferred technical solution of the utility model is: the eccentric gear has an engagement point on its outer periphery for engaging with the driven gear, and when the support rod is in the extended position or the initial position, the axis of the eccentric gear, the rotation center point of the eccentric gear and the engagement point of the eccentric gear are in a straight line.

[0015] A further preferred technical solution of the utility model is: the axis of the signal unit and the eccentric gear are on the same side of the rotation center point of the eccentric gear. When the eccentric gear rotates until the third sensing unit senses the signal unit, the axis of the eccentric gear and the meshing point of the eccentric gear are respectively located on two opposite sides of the rotation center point of the eccentric gear. At this time, the support rod is in the initial position, and the third rotation speed is slower than the fourth rotation speed.

[0016] Compared with the prior art, the advantages of the utility model are that a first sensing unit, a second sensing unit and a controller are provided on the outer shell, and a signal unit that cooperates with the first sensing unit and the second sensing unit is provided on the support rod. When the support rod moves forward to the extended position, the first sensing unit senses the signal unit and feeds back the signal to the controller, and the controller controls the output shaft to rotate at a first speed. When the support rod retreats backward to the initial position, the second sensing unit senses the signal unit and feeds back the signal to the controller, and the controller controls the output shaft to rotate at a second speed. The first speed is faster than the second speed, so that the support rod has a slow forward movement to avoid bursting of the pipe during the hole expansion process, and has a fast backward movement to reduce the time of useless work when the support rod retreats, thereby improving efficiency, so as to achieve the effect of long forward movement time and short retreat time of the support rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be described in further detail below in conjunction with the accompanying drawings and preferred embodiments, but those skilled in the art will appreciate that these drawings are drawn only for the purpose of explaining the preferred embodiments and therefore should not be used as a limitation on the scope of the present invention. In addition, unless otherwise specified, the drawings are only schematically representing the composition or structure of the described object and may contain exaggerated displays, and the drawings are not necessarily drawn to scale.

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of the utility model;

[0019] Figure 2 This is a schematic diagram of the internal structure of the main housing of the utility model;

[0020] Figure 3 This is a state diagram of the support rod of Example 1 when it is in the initial position;

[0021] Figure 4 It is a state diagram of the first embodiment when the support rod is in the extended position;

[0022] Figure 5 This is a partial exploded view of Example 1;

[0023] Figure 6 It is a schematic diagram of the support rod structure of the first embodiment;

[0024] Figure 7 This is a state diagram of the second embodiment when the support rod is in the initial position;

[0025] Figure 8 This is a state diagram of the second embodiment when the support rod is in the extended position;

[0026] Fig. 9 This is a schematic diagram of the eccentric gear structure of Embodiment 2;

[0027] Fig.10This is a schematic diagram of the internal structure of the eccentric gear after being disassembled in the second embodiment;

[0028] Fig.11 It is a cutaway schematic diagram of the utility model.

[0029] In the figure: 1. handle; 2. main body; 3. reaming claw; 4. battery pack installation part; 5. power switch; 6. expansion head; 7. upper half shell; 8. lower half shell; 9. sleeve; 10. front ring; 11. eccentric gear; 12. output shaft; 13. bearing; 14. driven gear; 15. pin shaft; 16. guide groove; 17. support rod; 18. support spring; 19. first sensing unit; 20. support seat; 21. signal unit; 22. second sensing unit; 23. meshing point; 24. rotation center point; 25. axis of eccentric gear; 26. cam Block; 27, main casing; 28, first annular groove; 29, extended edge; 30, window; 31, first inner ring edge; 32, third induction unit; 33, connecting hole; 34, drive motor; 35, planetary gear reducer; 36, axial line of output shaft; 37, support hole; 38, moving direction of support rod; 39, guide ring; 40, first outer ring edge; 41, third annular groove; 42, second annular groove; 43, second inner ring edge; 44, annular retaining ring; 45, fourth annular groove; 46, elastic rubber ring; 47, groove; 48, convex edge. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It will be appreciated by those skilled in the art that these descriptions are merely illustrative and exemplary and should not be construed as limiting the scope of protection of the present invention.

[0031] It should be noted that like reference numerals denote similar items in the following drawings, and thus, once an item is defined in one drawing, it may not be further defined or explained in subsequent drawings.

[0032] Embodiment 1

[0033] Figure 1-Figure 6 , Fig.11 As shown, a speed-controllable hand-held reamer comprises a shell with a handle 1, in which a rotary driver with an output shaft 12, an eccentric gear 11, a driven gear 14 and a strut 17 restricted to move in a straight line are arranged, the eccentric gear 11 is connected to the output shaft 12 and is driven to rotate eccentrically by the output shaft 12, the driven gear 14 is arranged on the end of the strut 17 opposite to the eccentric gear 11, a first elastic member is arranged between the strut 17 and the shell, the first elastic member has an elastic force that pushes the strut 17 to move toward one side of the eccentric gear 11, so that during the rotation of the eccentric gear 11, the driven gear 14 located at the end of the strut 17 is always against the outer periphery of the eccentric gear 11 and meshes with the eccentric gear 11.

[0034] Preferably, the housing includes a handle 1 and a main body 2 connected to the handle 1 , the rotary driver is installed in the handle 1 , and the eccentric gear 11 , the driven gear 14 and the support rod 17 are installed in the main body 2 .

[0035] Preferably, the rotary driver includes a driving motor 34 and a planetary gear reducer 35, the motor shaft of the driving motor 34 is connected to the input end of the planetary gear reducer 35, the output end of the planetary gear reducer 35 is connected to the output shaft 12, a bearing 13 is provided between the output shaft 12 and the outer casing for supporting the output shaft 12, a connecting hole 33 is provided on the eccentric gear 11, the output shaft 12 passes through the connecting hole 33 of the eccentric gear 11 and is fixed to the eccentric gear 11, and when the driving motor 34 is started, the output shaft 12 drives the eccentric gear 11 to rotate eccentrically.

[0036] The eccentric gear 11 is a circular gear, and the axis of the eccentric gear 11 is parallel to the axis 36 of the output shaft and is not colinear, so that the outer edge of the eccentric gear 11 and the rotation center of the eccentric gear 11 have different distances. The driven gear 14 is pushed by the first elastic member to the outer periphery of the eccentric gear 11, and reciprocates back and forth with the eccentric rotation of the eccentric gear 11. The driven gear 14 is a circular gear.

[0037] Preferably, the main body 2 includes a main housing 27, a sleeve 9 and a front ring 10. The bottom of the main housing 27 is provided with a plug-in portion extending downward. The handle 1 is a cavity with a cavity inside and an opening facing upward. The plug-in portion of the main housing 27 is inserted into the handle 1 from the opening at the top of the handle 1 and the main housing 27 and the handle 1 are fixed together by screws. The sleeve 9 is installed in the main housing 27 and fixed relatively to the main housing 27, and a part of the front end of the sleeve 9 extends out from the opening on the front side of the main housing 27. The front ring 10 is threadedly connected to the front end of the sleeve 9.

[0038] Figure 1 , Figure 2 , Fig.11 As shown, preferably, the main shell 27 includes an upper half shell 7 and a lower half shell 8, which are fixed by screws after being matched together, and the handle 1 includes a left half shell and a right half shell, which are fixed by screws after being matched together, and the plug-in part is integrally formed with the lower half shell 8.

[0039] Preferably, a housing cavity for installing the sleeve 9 is provided in the main housing 27, the sleeve 9 is a circular tubular structure, the housing cavity is an inner cavity structure adapted to the shape of the sleeve 9, a first annular groove 28 is provided on the outer wall of the sleeve 9, a first inner ring edge 31 is provided on the inner wall of the housing cavity to be snap-fitted with the first annular groove 28, the first inner ring edge 31 is snap-fitted in the first annular groove 28 to limit the movement of the sleeve 9 relative to the main housing 27, and the support rod 17 is inserted in the sleeve 9 to move. The sleeve 9 is fixed relatively to the main housing 27 by the clamping force of the upper half shell 7 and the lower half shell 8.

[0040] Preferably, a support seat 20 is provided at the rear end of the strut 17 opposite to the eccentric gear 11, and the shape of the support seat 20 is adapted to the shape of the inner cavity of the sleeve 9. The support seat 20 rests on the inner wall of the sleeve 9 to support the rear end of the strut 17. A guide ring 39 is provided between the front end of the strut 17 and the sleeve 9. The guide ring 39 is located inside the front end of the sleeve 9 and is sleeved on the outside of the strut 17. The guide ring 39 is supported on the front end of the strut 17. The support seat 20 and the guide ring 39 guide the strut 17 so that the strut 17 moves in a straight line, and the moving direction 38 of the strut is perpendicular to the axial centerline 36 of the output shaft.

[0041] Preferably, the support rod 17 is a cylindrical rod body, and the support rod 17 moves linearly along the axis direction thereof.

[0042] Preferably, a second inner ring edge 43 is provided on the inner wall of the front end pipe mouth of the sleeve 9, and a first outer ring edge 40 is provided on the outer wall of the guide ring 39. The shape of the first outer ring edge 40 is adapted to the shape of the inner wall of the sleeve 9, and the first outer ring edge 40 is against the inner side of the second inner ring edge 43. A second annular groove 42 is provided on the inner periphery of the second inner ring edge 43. A third annular groove 41 is provided on the outer wall of the guide ring 39. The notches of the third annular groove 41 and the second annular groove 42 are opposite to each other. An annular clamp 44 is provided and is clamped in the third annular groove 41 and the second annular groove 42 at the same time to limit the movement of the guide ring 39 relative to the sleeve 9.

[0043] Preferably, the first elastic member is a support spring 18 which is sleeved on the outside of the support rod 17, one end of the support spring 18 rests on the guide ring 39, and the other end of the support spring 18 rests on the support seat 20. The support spring 18 has an elastic force that pushes the support rod 17 to move toward the rear side of the eccentric gear 11 and acts on the support seat 20.

[0044] Preferably, two oppositely arranged protrusions 26 are provided on the side of the support seat 20 opposite to the eccentric gear 11, and there is a spacing between the two protrusions 26 for accommodating the driven gear 14. A pin shaft 15 is inserted into the center of the driven gear 14, and both ends of the pin shaft 15 are rotatably connected to the protrusions 26 on both sides, and the axis center line of the eccentric gear 11 is parallel to the axis center line of the driven gear 14.

[0045] Both ends of the pin 15 protrude from the protrusions 26 on both sides. The rear end of the sleeve 9 is provided with two extended edges 29 extending therefrom. The two extended edges 29 correspond to the protruding ends of the pin 15 respectively. The two extended edges 29 are provided with guide grooves 16 for the ends of the pin 15 to be inserted and slided. The rear end of the extended edge 29 has a notch for the pin 15 to enter the guide groove 16. The guide groove 16 cooperates with the pin 15 to guide the moving direction 38 of the support rod, and the groove walls on both sides of the guide groove 16 abut against the ends of the pin 15 to limit the rotation of the support rod 17 relative to the sleeve 9.

[0046] Preferably, both ends of the pin shaft 15 slide against the inner walls on both sides of the accommodating cavity, and also play a role in supporting the ends of the support rod 17.

[0047] The housing is provided with an expansion head 6 opposite to the front end of the support rod 17. The expansion head 6 is surrounded by a plurality of hole-expanding claws 3. The expansion head 6 is connected to a second elastic member for driving the expansion heads 6 to align toward the middle.

[0048] Preferably, the expansion head 6 is connected to the front ring 10, and a fourth annular groove 45 is provided on the inner wall of the front ring 10. A convex edge 48 is provided on the outer side of a plurality of reaming claws 3. When a plurality of reaming claws 3 are matched, the convex edges 48 are combined to form a second outer ring edge that is snap-fitted with the fourth annular groove 45. A space is provided between the reaming claws 3 and the front ring 10 for the reaming claws 3 to move outward and expand. The second elastic member includes an elastic rubber ring 46, which is sleeved on the outer side of the convex edges 48 of the plurality of reaming claws 3, and a groove 47 is provided on the convex edge 48 for the elastic rubber ring 46 to be snapped into.

[0049] When the eccentric gear 11 rotates eccentrically, the support rod 17 makes a reciprocating motion back and forth, and the support rod 17 switches back and forth between the initial position and the extended position in which the reaming claw 3 is expanded by being inserted into the expansion head 6. The eccentric gear 11 has an engagement point 23 on its outer periphery that engages with the driven gear 14, and the eccentric gear 11 has a rotation center point 24 that is connected to the output shaft 12. When the support rod 17 is in the extended position or the initial position, the axis 25 of the eccentric gear, the rotation center point 24 of the eccentric gear 11 and the engagement point 23 of the eccentric gear 11 are in a straight line. That is, when the eccentric gear 11 rotates to the position where the rotation center point 24 of the eccentric gear 11 is located between the axis 25 of the eccentric gear and the meshing point 23 of the eccentric gear 11, and the axis 25 of the eccentric gear, the rotation center point 24 of the eccentric gear 11 and the meshing point 23 of the eccentric gear 11 are in a straight line, the meshing point 23 of the eccentric gear 11 is in the position closest to the rotation center point 24 of the eccentric gear 11, and the support rod 17 is in the initial position. When the eccentric gear 11 rotates to the position where the axis 25 of the eccentric gear is located between the rotation center point 24 of the eccentric gear 11 and the meshing point 23 of the eccentric gear 11, and the axis 25 of the eccentric gear, the rotation center point 24 of the eccentric gear 11 and the meshing point 23 of the eccentric gear 11 are in a straight line, the meshing point 23 of the eccentric gear 11 is in the position farthest from the rotation center of the eccentric gear 11, and the support rod 17 is in the extended position.

[0050] When the support rod 17 is in the initial position, the axis 25 of the eccentric gear is directly behind the rotation center 24 of the eccentric gear 11, and the meshing point 23 of the eccentric gear 11 is directly in front of the rotation center 24 of the eccentric gear 11. When the axis 25 of the eccentric gear rotates from the position directly behind the rotation center 24 of the eccentric gear 11 to the position directly in front of the rotation center 24 of the eccentric gear 11, the support rod 17 is pushed forward by the eccentric gear 11 to move to the extended position, and the distance from the meshing point 23 of the eccentric gear 11 to the rotation center 24 of the eccentric gear 11 gradually increases during this process. When the axis 25 of the eccentric gear rotates from the position directly in front of the rotation center 24 of the eccentric gear 11 to the position directly behind the rotation center 24 of the eccentric gear 11, the support rod 17 is pushed back to the initial position by the support spring 18, and the distance from the meshing point 23 of the eccentric gear 11 to the rotation center 24 of the eccentric gear 11 gradually decreases during this process.

[0051] Figure 3-Figure 6 As shown, the housing is provided with a first sensing unit 19 , a second sensing unit 22 and a controller, and the support rod 17 is provided with a signal unit 21 that senses and cooperates with the first sensing unit 19 and the second sensing unit 22 .

[0052] Preferably, two signal units 21 are provided on the support rod 17 to respectively cooperate with the first sensing unit 19 and the second sensing unit 22 for sensing.

[0053] Preferably, the first sensing unit 19 and the second sensing unit 22 are Hall sensors fixed on the housing, and the signal unit 21 is a magnet fixed on the support rod 17. Alternatively, the first sensing unit 19 and the second sensing unit 22 may also be photoelectric switch sensors.

[0054] Preferably, the first sensing unit 19 and the second sensing unit 22 are arranged front and back in the moving direction 38 of the support rod. The first sensing unit 19 and the second sensing unit 22 are fixed on the main housing 27, and a window 30 is provided on the sleeve 9 to face the first sensing unit 19, so that when the signal unit 21 sensing and cooperating with the first sensing unit 19 moves into the sleeve 9 along with the support rod 17, the first sensing unit 19 can sense the signal unit 21 in the sleeve 9.

[0055] Preferably, the signal units 21 corresponding to the first sensing unit 19 and the second sensing unit 22 can be fixed on both sides of the same position of the support rod 17, and the spacing between the first sensing unit 19 and the second sensing unit 22 in the moving direction 38 of the support rod is the same as the distance the support rod 17 moves forward or backward.

[0056] Working principle: put the pipe to be expanded on the outside of the expansion head 6, start the drive motor 34, and the output shaft 12 drives the eccentric gear 11 to rotate eccentrically around the axis of the output shaft 12. When the eccentric gear 11 rotates to the point where the axis 25 of the eccentric gear is directly behind the rotation center point 24 of the eccentric gear 11, the distance between the axis line of the driven gear 14 and the rotation center point 24 of the eccentric gear 11 is the shortest, and the support rod 17 is in the initial position. At this time, the second sensing unit 22 senses the signal unit 21 and feeds back to the controller. The controller controls the speed of the drive motor 34 to slow down, so that the output shaft 12 rotates at the second speed. 12 drives the eccentric gear 11 to rotate. During the rotation of the eccentric gear 11, the distance between the axis line of the driven gear 14 and the rotation center point 24 of the eccentric gear 11 gradually increases. The eccentric gear 11 pushes the driven gear 14 and the support rod 17 to move forward until the axis 25 of the eccentric gear rotates to the front of the rotation center point 24 of the eccentric gear 11. At this position, the axis line of the driven gear 14 is farthest from the rotation center point 24 of the eccentric gear 11. The support rod 17 is in the extended position. The front end of the support rod 17 is inserted into the expansion head 6 to expand the plurality of reaming claws 3 in a circle to the extended state. The reaming claws 3 in the extended state are The mouth of the pipe sleeved on the outside is stretched open to complete the expansion of the pipe. At this time, the signal unit 21 that cooperates with the first sensing unit 19 moves forward with the support rod 17 to the sensing position of the first sensing unit 19. The first sensing unit 19 senses the signal unit 21 and feeds back the signal to the controller. The controller controls the speed of the driving motor 34 to increase, so that the output shaft 12 rotates at the first speed. The output shaft 12 drives the eccentric gear 11 to rotate. During the rotation of the eccentric gear 11, the distance between the axis line of the driven gear 14 and the rotation center point 24 of the eccentric gear 11 gradually decreases, and the support spring 18 pushes the support rod 17 to retreat backward so that the driven gear 14 It is always meshed with the eccentric gear 11 until the axis 25 of the eccentric gear rotates to the rear of the rotation center 24 of the eccentric gear 11, at which position the axis of the driven gear 14 is closest to the rotation center 24 of the eccentric gear 11, and the support rod 17 returns to the initial position. At this time, the signal unit 21 that is inductively matched with the second sensing unit 22 retreats with the support rod 17 to the sensing position of the second sensing unit 22. The second sensing unit 22 senses the signal unit 21 and feeds back a signal to the controller. The controller controls the speed of the driving motor 34 to slow down, so that the output shaft 12 rotates at the second speed, and the above operation is repeated to form a cycle. The first speed is faster than the second speed.

[0057] The controller controls the strut 17 to move forward slowly to avoid bursting of the pipe during hole expansion, and to move backward quickly to reduce the time of useless work of the strut 17 when it retreats, thereby improving efficiency, so as to achieve the effect of long forward movement time and short retreat time of the strut 17.

[0058] Preferably, the end of the support rod 17 opposite to the expansion head 6 is conical, and the inner surface of the reaming claw 3 is provided with a groove, which forms a conical support hole 37 for the support rod 17 to be inserted into after a plurality of reaming claws 3 are matched.

[0059] The driving motor 34, the first induction unit 19 and the second induction unit 22 are electrically connected to the controller.

[0060] A battery pack mounting portion 4 is provided at the bottom of the handle 1 , and a power switch 5 is provided on the handle 1 .

[0061] Embodiment 2

[0062] The speed-controllable hand-held reamer of this embodiment differs from the first embodiment only in the control structure of the speed of the output shaft 12, and the other structures are the same. The specific contents are as follows:

[0063] Figure 7-Figure 10 As shown, a third sensing unit 32 and a controller are provided on the outer shell, and a signal unit 21 which senses and cooperates with the third sensing unit 32 is provided on the eccentric gear 11. The signal unit 21 is set away from the rotation center of the eccentric gear 11. When the support rod 17 moves forward to the extended position or retracts to the initial position, the third sensing unit 32 senses the signal unit 21 and feeds back a signal to the controller. The controller controls the output shaft 12 to rotate at a third speed for a first set time, and then rotates at a fourth speed for a second set time. The third speed and the fourth speed are different speeds.

[0064] The first set time and the second set time correspond to a time period when the support rod 17 moves forward and a time period when the support rod 17 moves backward, respectively.

[0065] Preferably, the third sensing unit 32 is a Hall sensor fixed on the housing, and the signal unit 21 is a magnet fixed on the eccentric gear 11. Alternatively, the third sensing unit 32 may also be a photoelectric switch sensor.

[0066] The eccentric gear 11 and the driven gear 14 are both circular gears. The eccentric gear 11 has a rotation center point 24 connected to the output shaft 12. During the eccentric rotation of the eccentric gear 11, the signal unit 21, the axis 25 of the eccentric gear and the rotation center point 24 of the eccentric gear 11 are always on the same straight line.

[0067] Preferably, the signal unit 21 and the axis 25 of the eccentric gear are on the same side of the rotation center point 24 of the eccentric gear 11. When the eccentric gear 11 rotates until the third sensing unit 32 senses the signal unit 21, the axis 25 of the eccentric gear and the meshing point 23 of the eccentric gear 11 are respectively located on two opposite sides of the rotation center point 24 of the eccentric gear 11, that is, the axis 25 of the eccentric gear is located directly behind the rotation center point 24 of the eccentric gear 11, and the meshing point 23 of the eccentric gear 11 is located directly in front of the rotation center point 24 of the eccentric gear 11. At this time, the strut 17 is in the initial position, then the above-mentioned first set time corresponds to the time period of the strut 17 moving forward, and the second set time corresponds to the time period of the strut 17 moving backward, and the third speed is slower than the fourth speed.

[0068] Working principle: put the pipe to be expanded on the outside of the expansion head 6, start the drive motor 34, and the output shaft 12 drives the eccentric gear 11 to rotate eccentrically around the axis of the output shaft 12. When the eccentric gear 11 rotates to the point where the axis 25 of the eccentric gear is directly behind the rotation center 24 of the eccentric gear 11, the distance between the axis line of the driven gear 14 and the rotation center 24 of the eccentric gear 11 is the shortest, and the support rod 17 is in the initial position. At this time, the third sensing unit 32 senses the signal unit 21 and feeds back to the control unit 21. The controller first controls the speed of the driving motor 34 to decelerate and rotate slowly for the first set time, and then controls the speed of the driving motor 34 to accelerate and rotate quickly for the second set time, so that the output shaft 12 rotates at the third speed for the first set time, and then rotates at the fourth speed for the second set time. The third speed is slower than the fourth speed. During the first set time, the distance between the axis of the driven gear 14 and the rotation center point 24 of the eccentric gear 11 gradually increases, and the eccentric gear 11 pushes the driven gear 14 and the support rod 17 to move forward until the eccentric gear 11 is driven. The axis 25 of the central gear rotates to the front of the rotation center 24 of the eccentric gear 11. At this position, the axis of the driven gear 14 is farthest from the rotation center 24 of the eccentric gear 11. The support rod 17 is in the extended position. The front end of the support rod 17 is inserted into the expansion head 6 to expand the plurality of hole-expanding claws 3 in a circle to the expanded state. The hole-expanding claws 3 in the expanded state expand the pipe opening on the outside to complete the hole expansion of the pipe. Within the second set time, the axis of the driven gear 14 is aligned with the rotation center 24 of the eccentric gear 11. The distance to the rotation center point 24 gradually becomes smaller, and the support spring 18 pushes the strut 17 backward so that the driven gear 14 is always engaged with the eccentric gear 11 until the axis 25 of the eccentric gear rotates to the rear of the rotation center point 24 of the eccentric gear 11. At this position, the axis line of the driven gear 14 is closest to the rotation center point 24 of the eccentric gear 11, and the strut 17 returns to the initial position. At this time, the third sensing unit 32 senses the signal unit 21 again and feeds back the signal to the controller, and the above operation is repeated to form a cycle.

[0069] The controller controls the strut 17 to move forward slowly to avoid bursting of the pipe during hole expansion, and to move backward quickly to reduce the time of useless work of the strut 17 when it retreats, thereby improving efficiency, so as to achieve the effect of long forward movement time and short retreat time of the strut 17.

[0070] The above is an introduction to the hand-held reamer with controllable speed provided by the utility model. This article uses specific examples to illustrate the principle and implementation method of the utility model. The description of the above embodiments is only used to help understand the utility model and its core ideas. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the utility model, the utility model can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the utility model.

Claims

1. A hand-held reamer with controllable speed, comprising a shell with a handle, a rotating driver with an output shaft, an eccentric gear, a driven gear and a strut restricted to move in a straight line are arranged in the shell, the eccentric gear is connected to the output shaft and driven by the output shaft to rotate eccentrically, the driven gear is arranged on the end of the strut opposite to the eccentric gear, a first elastic member is arranged between the strut and the shell, the first elastic member has an elastic force that pushes the strut to move to one side of the eccentric gear, so that the driven gear located at the end of the strut always abuts against the outer periphery of the eccentric gear and meshes with the eccentric gear during the rotation of the eccentric gear, an expansion head opposite to the other end of the strut is arranged on the shell, the expansion head is surrounded by a plurality of reaming claws, a second elastic member that drives each reaming claw to mate with the middle is connected to the expansion head, when the eccentric gear rotates eccentrically, the strut makes a back-and-forth reciprocating motion, the strut switches back and forth between an initial position and an expansion position where the reaming claws are inserted into the expansion head to expand, characterized in that The shell is provided with a first sensing unit, a second sensing unit and a controller, and the support rod is provided with a signal unit that cooperates with the first sensing unit and the second sensing unit. When the support rod moves forward to the extended position, the first sensing unit senses the signal unit and feeds back the signal to the controller, and the controller controls the output shaft to rotate at a first speed. When the support rod retreats backward to the initial position, the second sensing unit senses the signal unit and feeds back the signal to the controller, and the controller controls the output shaft to rotate at a second speed. The first speed is faster than the second speed.

2. The speed-controllable hand-held reamer according to claim 1, characterized in that: The support rod is provided with two signal units which respectively cooperate with the first sensing unit and the second sensing unit for sensing.

3. The speed-controllable hand-held reamer according to claim 1 or 2, characterized in that: The first induction unit and the second induction unit are Hall sensors fixed on the housing, and the signal unit is a magnet fixed on the support rod.

4. The speed-controllable hand-held reamer according to claim 1 or 2, characterized in that: The eccentric gear is a circular gear, and has an engagement point on its outer periphery for engaging with the driven gear. The eccentric gear has a rotation center point connected to the output shaft. When the support rod is in the extended position or the initial position, the axis of the eccentric gear, the rotation center point of the eccentric gear and the engagement point of the eccentric gear are in a straight line.

5. The speed-controllable hand-held reamer according to claim 1 or 2, characterized in that: The first sensing unit and the second sensing unit are arranged front and back in the moving direction of the support rod.

6. A hand-held reamer with controllable speed, comprising a shell with a handle, a rotating driver with an output shaft, an eccentric gear, a driven gear and a strut restricted to move in a straight line are arranged in the shell, the eccentric gear is connected to the output shaft and driven by the output shaft to rotate eccentrically, the driven gear is arranged on the end of the strut opposite to the eccentric gear, a first elastic member is arranged between the strut and the shell, the first elastic member has an elastic force that pushes the strut to move to one side of the eccentric gear, so that the driven gear located at the end of the strut always rests on the outer periphery of the eccentric gear and meshes with the eccentric gear during the rotation of the eccentric gear, an expansion head opposite to the other end of the strut is arranged on the shell, the expansion head is surrounded by a plurality of reaming claws, a second elastic member is connected to the expansion head to drive each reaming claw to mate toward the middle, when the eccentric gear rotates eccentrically, the strut makes a back-and-forth reciprocating motion, the strut switches back and forth between an initial position and an expansion position where the reaming claws are inserted into the expansion head to expand, characterized in that A third sensing unit and a controller are provided on the outer shell, and a signal unit that cooperates with the third sensing unit for sensing is provided on the eccentric gear. The signal unit is set offset from the rotation center of the eccentric gear. When the support rod moves forward to the extended position or retracts to the initial position, the third sensing unit senses the signal unit and feeds back a signal to the controller. The controller controls the output shaft to rotate at a third speed for a first set time, and then rotates at a fourth speed for a second set time. The third speed and the fourth speed are different speeds.

7. The speed-controllable hand-held reamer according to claim 6, characterized in that: The third sensing unit is a Hall sensor fixed on the housing, and the signal unit is a magnet fixed on the eccentric gear.

8. The hand-held reamer with controllable rotation speed according to claim 6, characterized in that: The eccentric gear is a circular gear having a rotation center point connected to the output shaft. During the eccentric rotation of the eccentric gear, the signal unit, the axis of the eccentric gear and the rotation center point of the eccentric gear are always on the same straight line.

9. The speed-controllable hand-held reamer according to claim 8, characterized in that: The eccentric gear has an engagement point on its outer periphery for engaging with the driven gear. When the support rod is located at the extended position or the initial position, the axis of the eccentric gear, the rotation center of the eccentric gear and the engagement point of the eccentric gear are in a straight line.

10. The hand-held reamer with controllable rotation speed according to claim 9, characterized in that: The axis of the signal unit and the eccentric gear are on the same side of the rotation center of the eccentric gear. When the eccentric gear rotates until the third sensing unit senses the signal unit, the axis of the eccentric gear and the meshing point of the eccentric gear are respectively located on two opposite sides of the rotation center of the eccentric gear. At this time, the support rod is in the initial position, and the third rotation speed is slower than the fourth rotation speed.

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