Straight type constant-torque impact electric tool

Abstract

The invention discloses a straight type constant-torque impact electric tool, and relates to the field of electric tools. The power mechanism is arranged in the shell so as to output rotating power; the speed reducing mechanism is arranged in the shell and is in transmission connection with the power mechanism so as to reduce the output rotating speed of the power mechanism and amplify the torque; the impact mechanism is arranged in the shell and is in transmission connection with the speed reducing mechanism so as to convert the output power transmitted by the speed reducing mechanism into impact torque and output the impact torque; and the control module is electrically connected with the power mechanism and is used for adjusting and displaying the torque gear. Fine control over the torque can be achieved, meanwhile, the torque output stability is improved, abrasion of impact parts is reduced, and the overall service life of the tool is prolonged.

Description

Technical Field

[0001] This invention relates to the field of power tools, and particularly to a linear constant torque impact power tool. Background Technology

[0002] Straight-type impact torque screwdrivers are handheld electric tightening tools powered by an electric motor. They can efficiently and quickly complete the assembly of threaded connections. Their advantage lies in achieving high-precision torque control, making them primarily suitable for tightening and assembly scenarios with strict torque accuracy requirements. Their applications cover multiple key industries, including automotive assembly and parts processing, engine manufacturing, electronic component assembly, rail transit equipment assembly, white goods production, and construction machinery assembly.

[0003] In terms of working principle, a straight impact torque screwdriver converts rotational kinetic energy into tightening deformation energy of the threaded connection by using an electrically driven high-speed rotating component inside the machine. This allows the threaded connection to be precisely tightened to a preset torque value. Its basic structure typically consists of functional components and auxiliary components. The functional components include an impact component for achieving impact torque output, a reduction component for adjusting speed and amplifying torque, and a control component for precisely controlling torque parameters. The auxiliary components include a housing for protection and grip, and a power supply component for powering the tool.

[0004] Most conventional straight-line impact tools on the market today use a direct-drive transmission system between a motor and a reducer, which generally results in a lack of torque control or insufficient torque accuracy. Some tools are only equipped with mechanically graduated torque adjustment mechanisms, which can only achieve coarse torque adjustment and cannot meet the requirements of high-precision assembly. Summary of the Invention

[0005] To address the issues of insufficient torque control or inadequate precision in existing straight impact tools, this invention establishes a power mechanism, a reduction mechanism, and an impact mechanism, and configures a control module integrating current detection, timing statistics, and parameter storage functions. By comparing the driving current of the power mechanism with the preset identification current calibration value in real time and statistically analyzing the effective rotational work time, the power output is regulated, achieving precise torque control. This also improves torque output stability, reduces wear on impact components, and extends the overall service life of the tool.

[0006] To achieve the above objectives, the present invention provides a linear constant torque impact power tool, comprising:

[0007] case;

[0008] A power mechanism is disposed within the housing to output rotational power;

[0009] A speed reduction mechanism is disposed inside the housing and is connected to the power mechanism for transmission, so as to reduce the output speed of the power mechanism and amplify the torque;

[0010] An impact mechanism is disposed within the housing and is connected to the reduction mechanism for transmission, so as to convert the output power transmitted by the reduction mechanism into impact torque and output it.

[0011] The control module, electrically connected to the power mechanism, is used to adjust and display the torque gear.

[0012] The control module pre-stores the gear speed, effective rotation duration and identification current calibration value corresponding to several constant torque gears; the identification current calibration value is the minimum value of the power mechanism drive current fluctuation range after the power tool is loaded.

[0013] The control module detects the real-time drive current of the power mechanism and compares it with the identified current calibration value. It then calculates the duration during which the real-time drive current is not less than the identified current calibration value and drives the power mechanism according to the gear speed until the calculated duration is not less than the effective rotational work time, thereby achieving torque control.

[0014] This invention, by setting up a power mechanism, a reduction mechanism, an impact mechanism, and a control module, utilizes the pre-stored speed, effective rotational work duration, and identification current calibration value corresponding to multiple sets of fixed torque gears in the control module. Through real-time detection of the power mechanism's drive current, comparison with the identification current calibration value, and statistical analysis of the effective work duration, it not only achieves torque regulation, avoiding over-tightening or under-tightening problems, but also simplifies the operation process and improves work efficiency by combining gear adjustment and display functions.

[0015] Optionally, the power mechanism includes:

[0016] Drive motor;

[0017] The motor connecting sleeve, specifically tubular, is fixedly connected to the drive motor;

[0018] A drive shaft is inserted into the motor connecting sleeve, and one end of it is coaxially and fixedly connected to the output end of the drive motor.

[0019] The output gear is coaxially and fixedly connected to the end of the transmission shaft opposite to the drive motor, and is also connected to the reduction mechanism to transmit rotational power.

[0020] There are multiple first support bearings, which are coaxially fixed between the motor connecting sleeve and the transmission shaft to support the rotation of the transmission shaft.

[0021] Optionally, the deceleration mechanism includes:

[0022] An internal gear ring is fixedly connected to the housing.

[0023] The planetary gears are multiple and arranged circumferentially along the output gear. Each planetary gear meshes with the output gear and the internal gear ring to reduce speed and increase torque.

[0024] Optionally, the impact mechanism includes:

[0025] The torque transmission shaft is rotatably disposed within the housing and is connected to multiple planetary gears to receive the power after deceleration and torque amplification.

[0026] An impact block assembly is connected to the torque transmission shaft to convert rotational power into impact torque;

[0027] A torque output shaft is rotatably disposed within the housing. The torque output shaft is provided with an impact-receiving part that cooperates with the impact block assembly to receive and output impact torque.

[0028] Optionally, the impact block assembly includes:

[0029] The impact block body is specifically ring-shaped and is sleeved on the torque transmission shaft;

[0030] The inner wall of the impact block body is provided with a first limiting groove that matches the limiting steel ball, and the torque transmission shaft is provided with a second limiting groove that matches the limiting steel ball, so as to limit the movement stroke of the impact block body and enable the impact block body to convert rotational power into impact torque.

[0031] A return spring is sleeved on the torque transmission shaft. The torque transmission shaft and the impact block body are respectively provided with a first annular protrusion and a second annular protrusion. The first annular protrusion and the second annular protrusion abut against the two ends of the return spring to reset the impact block body.

[0032] Optionally, the impact block assembly further includes:

[0033] The ball assembly has a recessed portion formed on the side of the second annular protrusion near the return spring, and the ball assembly is rotatably embedded in the recessed portion.

[0034] A spacer is fitted onto the torque transmission shaft and located between the return spring and the ball assembly;

[0035] The return spring elastically abuts against the impact block body through the ball bearing assembly and the spacer pad to reduce the friction between the return spring and the impact block body.

[0036] Optionally, the impact mechanism further includes:

[0037] The second support bearing is sleeved on the torque output shaft to support the rotation of the torque output shaft;

[0038] An O-ring is fitted onto the torque output shaft and abuts against one side of the second support bearing;

[0039] A buffer washer is disposed inside the housing and sleeved on the torque output shaft. It is located between the second support bearing and the impacted part and abuts against both of them.

[0040] A third support bearing is disposed inside the housing and sleeved on the torque transmission shaft to support the rotation of the torque transmission shaft.

[0041] Optionally, the deceleration mechanism further includes:

[0042] Multiple positioning pins are respectively inserted into each of the planetary gears and fixedly connected to the first annular protrusion, so as to enable the speed reduction mechanism and the impact mechanism to be connected in transmission.

[0043] A limiting washer is fitted onto the torque transmission shaft and abuts against the end of the positioning pin that is away from the first annular protrusion.

[0044] Optionally, the power tool further includes a locking mechanism, the locking mechanism comprising:

[0045] A self-locking sleeve is fitted onto the front end of the torque output shaft and can move along the axial direction of the torque output shaft. The inner wall of the self-locking sleeve is provided with a limiting step.

[0046] A self-locking spring is sleeved on the torque output shaft and located inside the self-locking sleeve, with one end abutting against the limiting step of the self-locking sleeve.

[0047] The self-locking steel ball has a hollow front end for mounting a tool head. A limit hole is formed radially at the front end of the torque output shaft, and the self-locking steel ball is embedded in the limit hole to cooperate with the limit step and the tool head.

[0048] An axial positioning component is fixed to the front end of the torque output shaft and abuts against the self-locking spring. The axial positioning component includes a retaining ring and a limiting ring. A groove is formed on the outer wall of the front end of the torque output shaft, and the retaining ring is engaged in the groove. The limiting ring is sleeved on the torque output shaft and located between the retaining ring and the self-locking spring to axially limit the self-locking spring.

[0049] Optionally, the control module includes:

[0050] A drive unit is electrically connected to the power mechanism to receive control signals and drive the power mechanism to operate at a set speed.

[0051] The storage unit has a built-in storage chip to pre-store the speed, effective rotation duration and identification current calibration value corresponding to several torque gears.

[0052] A current detection unit is electrically connected to the power mechanism and the drive unit to detect the drive current of the power mechanism in real time and transmit the detection data to the drive unit.

[0053] A timing unit, electrically connected to the drive unit, starts timing when the drive unit determines that the real-time drive current is not less than the identification current calibration value, and feeds back timing data;

[0054] The interactive unit includes a display screen and adjustment buttons. The display screen is used to display the current torque setting, working status, and timing data. The adjustment buttons are used to input or switch the torque setting.

[0055] Compared with the above-mentioned background technology, the technical solution provided by the present invention has at least the following technical effects:

[0056] Firstly, this invention uses a control module to pre-store the speed, effective rotation duration, and current calibration value corresponding to multiple torque gears. Combined with real-time detection of the drive current of the power mechanism, it can detect the load status in real time. At the same time, by statistically analyzing the effective work duration where the real-time drive current is not less than the current calibration value, it can achieve start-stop control of power output, effectively avoiding over-tightening or under-tightening and significantly improving torque control accuracy. The preset multiple gear parameters also enhance the flexibility of torque adaptation, which can meet the tightening needs of different industries and working conditions. With the gear adjustment and display functions of the control module, the operation process is simplified, the cost of manual intervention is reduced, and the work efficiency and assembly quality are guaranteed.

[0057] Secondly, this invention possesses excellent structural stability. By rationally planning the assembly layout of the power mechanism, reduction mechanism, and impact mechanism inside the housing, the three form a stable transmission link, ensuring smooth and efficient power transmission. In conjunction with the control module's regulation of gear speed, fluctuations in the power output process are reduced, and impacts and wear between components are minimized. The overall structure is compact and the force is balanced, which not only improves the operational reliability of the tool in high-frequency operation scenarios but also extends the overall service life of the tool. Attached Figure Description

[0058] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0059] Figure 1 This is a front view provided for an embodiment of the present invention;

[0060] Figure 2 A cross-sectional view provided for an embodiment of the present invention;

[0061] Figure 3 This is an exploded view provided for an embodiment of the present invention.

[0062] Explanation of reference numerals in the attached figures:

[0063] 1. Housing; 11. Front housing; 12. First handle housing; 13. Second handle housing;

[0064] 2. Power mechanism; 21. Drive motor; 22. Motor connecting sleeve; 23. Transmission shaft; 24. Output gear; 25. First support bearing; 26. Limit ring;

[0065] 3. Reduction mechanism; 31. Internal gear ring; 32. Planetary gear; 33. Locating pin; 34. Limit washer;

[0066] 4. Impact mechanism; 41. Torque transmission shaft; 421. Impact block body; 422. Limiting steel ball; 423. Return spring; 424. Ball assembly; 425. Separating shim; 43. Torque output shaft; 44. Second support bearing; 45. O-ring; 46. Buffer washer; 47. Third support bearing;

[0067] 5. Locking mechanism; 51. Self-locking sleeve; 52. Self-locking spring; 53. Self-locking steel ball; 541. Snap ring; 542. Limiting ring;

[0068] 61. Display screen; 62. Adjustment button; 63. Power switch; 64. Forward / reverse switch; 65. LED light;

[0069] 7. Power connection cable. Detailed Implementation

[0070] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0071] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0072] As described in the background section, most common straight-line impact tools on the market currently use a direct connection between a motor and a reducer to output power, which generally suffers from a lack of torque control or insufficient torque control accuracy. Some tools are only equipped with a mechanically graduated torque adjustment mechanism, which can only achieve coarse torque adjustment and cannot meet the requirements of high-precision assembly.

[0073] To address the issues of insufficient torque control or inadequate precision in existing straight impact tools, this invention establishes a power mechanism 2, a reduction mechanism 3, and an impact mechanism 4. It also incorporates a control module integrating current detection, timing statistics, and parameter storage functions. By comparing the driving current of the power mechanism 2 with a preset calibration value and calculating the effective rotational work duration in real time, the power output is precisely controlled. This achieves improved torque output stability, reduces wear on impact components, and extends the overall tool lifespan.

[0074] This invention provides a linear constant torque impact power tool, referring to... Figures 1-3 It includes a housing 1, a power mechanism 2, a reduction mechanism 3, an impact mechanism 4, a control module, a locking mechanism 5, a power connection cable 7, and a plug. The housing 1 provides a mounting platform and protection for all components. The power mechanism 2 outputs rotational power. The reduction mechanism 3 reduces the output speed of the power mechanism 2 and amplifies the torque. The impact mechanism 4 converts the output power transmitted by the reduction mechanism 3 into impact torque for output. The control module adjusts and displays the torque level and implements torque control. The locking mechanism 5 enables quick locking and unlocking of the tool head. The power connection cable 7 and plug connect to an external power source to provide operating power for the entire machine.

[0075] Furthermore, in the exemplary embodiment, the housing 1 includes a front housing 11, a first handle housing 12, and a second handle housing 13, which are fastened together by bolts to form a complete outer shell. The front housing 11 is made of aluminum alloy, while the first handle housing 12 and the second handle housing 13 are made of engineering plastic.

[0076] Furthermore, in the exemplary embodiment, the front shell 11 is a cylindrical structure with an open front end, formed by die casting of aluminum alloy. Its inner wall has multiple mounting positions and mating structures adapted to the internal mechanism. Bearing mounting holes are provided on its front inner wall, the diameter of which matches the outer ring size of the second support bearing 44 of the impact mechanism 4 mentioned below, for fixing the second support bearing 44; the middle of the inner wall of the front shell 11 corresponds to the position of the internal gear ring 31 mentioned below, and an annular first mating part is integrally formed therein. The inner end face of the first mating part is provided with internal threads to mate with the external threads on the internal gear ring 31 mentioned below.

[0077] Furthermore, in the exemplary embodiment, the first handle shell 12 and the second handle shell 13 are symmetrical semi-shell structures, integrally molded using an injection molding process. The inner walls of both handle shells have pre-drilled mounting positions for other mechanisms, including a motor housing, a control module mounting slot, a power connection cable 7 routing channel, and bolt fixing posts. Simultaneously, the outer surface of the handle shell is machined with an anti-slip grip texture, consisting of alternating raised and recessed stripes, increasing friction during gripping and improving operational comfort. The handle's length and diameter are also adapted to the size of the human hand to reduce fatigue during prolonged use.

[0078] Furthermore, in the exemplary embodiment, the power mechanism 2 includes a drive motor 21, a motor connecting sleeve 22, a transmission shaft 23, an output gear 24, a first support bearing 25, and a limiting ring 26. The drive motor 21 provides a power source; the motor connecting sleeve 22 positions the drive motor 21 and the transmission shaft 23; the transmission shaft 23 transmits the rotational power of the drive motor 21; the output gear 24 is connected to the reduction mechanism 3 to transmit power; the first support bearing 25 supports the rotation of the transmission shaft 23; and the limiting ring 26 restricts the axial position of the first support bearing 25 to prevent axial movement of the first support bearing 25 during high-speed operation.

[0079] Furthermore, in the exemplary embodiment, the drive motor 21 is fixedly mounted in the aforementioned motor receiving cavity so that the drive motor 21 remains fixed during the operation of the entire machine, avoiding displacement or vibration.

[0080] Furthermore, in the exemplary embodiment, the motor connecting sleeve 22 is specifically a tubular structure with openings at both ends. An annular flange is integrally formed on the side facing the front housing 11 for connecting the reduction mechanism 3. A flat square portion is integrally formed on the side facing the drive motor 21 for engaging with the end face of the drive motor, so that the output shaft end of the drive motor 21 coaxially extends into the inner hole of the motor connecting sleeve 22 and forms a fixed and coaxial assembly relationship. Further, a positioning countersunk hole is provided on the side of the flat square portion facing the drive motor 21, and a motor boss that mates with the positioning countersunk hole is provided on the front end face of the drive motor 21 to ensure the coaxiality of the drive motor 21 and the motor connecting sleeve 22. The annular flange is fixedly connected to the internal gear ring 31 mentioned below by bolts. Through the tight fit of the flange surface and the tightening of the bolts, the coaxiality and assembly accuracy of the motor connecting sleeve 22, the drive motor 21 and the internal gear ring 31 are ensured, and the foundation for smooth power transmission is laid.

[0081] Furthermore, in the exemplary embodiment, the drive shaft 23 is made of alloy steel, and its outer diameter is smaller than the inner diameter of the motor connecting sleeve 22. The drive shaft 23 passes through the inner diameter of the motor connecting sleeve 22, and one end of it is coaxially and fixedly connected to the output shaft end of the drive motor 21 through a keyway fit to achieve rigid torque transmission. The other end of the drive shaft 23 extends to the outside of the motor connecting sleeve 22 and is coaxially and fixedly connected to the hub of the output gear 24 through an interference fit.

[0082] Furthermore, in the exemplary embodiment, the output gear 24 is drive-connected to the reduction mechanism 3 described below to transmit rotational power.

[0083] Specifically, there are two first support bearings 25, which are of the same specification and model. The two first support bearings 25 are respectively installed at both ends of the inner hole of the motor connecting sleeve 22. The outer ring of the first support bearing closer to the drive motor 21 abuts against the inner hole of the motor connecting sleeve 22, and the inner ring is fitted onto the shaft section of the drive shaft 23 near the drive motor 21; the outer ring of the first support bearing 25 farther away from the drive motor 21 abuts against the inner hole of the motor connecting sleeve 22, and the inner ring is fitted onto the shaft section of the drive shaft 23 near the output gear 24.

[0084] Furthermore, two limiting steps are provided in the inner hole of the motor connecting sleeve 22 to axially limit the two aforementioned first support bearings 25 respectively. At the same time, corresponding to the first support bearing near the drive motor 21, the transmission shaft 23 has an annular protrusion at this location to axially limit the first support bearing in the other direction, thereby achieving bidirectional axial limiting of the first support bearing.

[0085] Furthermore, in the exemplary embodiment, the limiting ring 26 is an annular structure, employing a retaining ring for holes. It is engaged in the inner groove of the motor connecting sleeve 22 on the side away from the drive motor 21, corresponding to the first support bearing 25 on the side away from the drive motor 21. The limiting ring 26 and the limiting step of the motor connecting sleeve 22 together form a bidirectional axial limiting of the first support bearing 25. With the bidirectional support of the two first support bearings 25, the transmission shaft 23 can rotate stably, distributing radial load and suppressing radial runout, thereby improving the transmission accuracy of the entire power mechanism 2.

[0086] Furthermore, in the exemplary embodiment, the output gear 24 is located on the side away from the drive motor 21 and is fixed to the extended end of the transmission shaft 23. Its gear teeth are exposed and mesh with the planetary gear 32 of the reduction mechanism 3 described below to achieve power transmission.

[0087] As an optional implementation, the first support bearing 25 is a deep groove ball bearing; the drive motor 21 is a series-wound motor, and its output speed can be adjusted by the control module.

[0088] Furthermore, in the exemplary embodiment, the reduction mechanism 3 includes an internal gear ring 31, a planetary gear 32, a locating pin 33, and a limiting washer 34. The internal gear ring 31 is used to fixably connect to the housing 1 and the motor connecting sleeve 22, and provides a base for meshing and rotation of the planetary gear 32; the planetary gear 32 meshes with the output gear 24 of the power mechanism 2 and the internal gear ring 31, achieving speed reduction and torque increase; the locating pin 33 passes through the planetary gear 32 and is connected to the impact mechanism 4 for transmission; the limiting washer 34 limits the axial position of the locating pin 33.

[0089] Furthermore, in the exemplary embodiment, the internal gear ring 31 has an annular structure, with its outer circumference fitting against the inner wall of the housing 1. One axial end of the internal gear ring 31 is fixedly connected to the flange of the motor connecting sleeve 22 away from the drive motor 21 by bolts, ensuring the coaxiality of the internal gear ring 31, the motor connecting sleeve 22, and the drive motor 21. Furthermore, a first annular step is formed on the side of the internal gear ring 31 near the motor connecting sleeve 22, and a corresponding first mating part is integrally formed on the inner wall of the housing 1 at the position corresponding to the first annular step. A second annular step is formed on the abutting end face of the internal gear ring 31 and the flange of the motor connecting sleeve 22, and a corresponding second mating part is integrally formed on the flange of the motor connecting sleeve 22 at the position corresponding to the second annular step, thereby further improving the assembly accuracy and thus further improving the structural stability and service life of the present invention.

[0090] Furthermore, in the exemplary embodiment, there are three planetary gears 32 with the same specifications and models. The three planetary gears 32 are evenly distributed along the circumference of the output gear 24 and are all located inside the first annular protrusion on the torque transmission shaft 41 of the impact mechanism 4 (hereinafter referred to as the first annular protrusion). The first annular protrusion has three accommodating grooves evenly distributed along the circumference. The size of the accommodating grooves is adapted to the planetary gears 32. The planetary gears 32 are correspondingly placed in each accommodating groove and are rotatably set in the accommodating grooves by the positioning pins 33. The teeth of each planetary gear 32 mesh with the teeth of the output gear 24 and the teeth of the internal gear ring 31 to form a planetary transmission structure. The speed reduction and torque amplification are achieved through gear meshing.

[0091] Furthermore, in the exemplary embodiment, there are three positioning pins 33, corresponding one-to-one with the planetary gears 32. One end of the positioning pin 33 passes through the central hole of the planetary gear 32 and forms a rotational engagement with the planetary gear 32. The other end of the positioning pin 33 is fixed to the inner wall of the receiving groove of the first annular protrusion, so that the planetary gear 32 can rotate stably in the receiving groove, and at the same time transmit the rotational power of the planetary gear 32 to the torque transmission shaft 41.

[0092] Furthermore, in the exemplary embodiment, the limiting washer 34 is an annular structure, sleeved on the torque transmission shaft 41 (hereinafter referred to as the torque transmission shaft). One side of the washer abuts against the end of the positioning pin 33 that is away from the inner wall of the receiving groove, and the other side is in contact with the inner end face of the internal gear ring 31. The axial clamping achieves axial limiting of the positioning pin 33, preventing axial displacement of the positioning pin 33 during power transmission, thereby ensuring the meshing accuracy of the planetary gear 32 with the output gear 24 and the internal gear ring 31.

[0093] Furthermore, in the exemplary embodiment, the impact mechanism 4 includes a torque transmission shaft 41, an impact block assembly, a torque output shaft 43, a second support bearing 44, an O-ring 45, a buffer washer 46, and a third support bearing 47. The torque transmission shaft 41 receives the power transmitted from the reduction mechanism 3 and transmits it to the impact block assembly; the impact block assembly converts the rotational power into impact torque; the torque output shaft 43 receives the impact torque and outputs it outwards; the second support bearing 44 supports the rotation of the torque output shaft 43; the O-ring 45 seals and protects the second support bearing 44; the buffer washer 46 buffers the impact load; and the third support bearing 47 supports the rotation of the torque transmission shaft 41.

[0094] Furthermore, in the exemplary embodiment, the torque transmission shaft 41 is made of alloy steel and has an overall stepped shaft structure. The shaft diameter is adapted to each mating component as needed along the power transmission direction. One end is connected to the planetary gear 32 of the reduction mechanism 3 via a positioning pin 33. The connection is achieved by the fixed fit between the positioning pin 33 and the receiving groove. The other end extends to the inside of the impact block assembly. The shaft has an integrally formed second limiting groove and a first annular protrusion. The second limiting groove is a spiral groove, and its shape is adapted to the shape of the limiting steel ball 422. It is used to guide the movement of the limiting steel ball 422 and link it with the impact block body 421. The first annular protrusion is an annular protrusion structure. Three receiving grooves are evenly opened in the circumference inside. It is used to install the planetary gear 32 and the positioning pin 33. At the same time, it works with the return spring 423 mentioned below to realize the reset of the impact block body 421.

[0095] Furthermore, in the exemplary embodiment, the impact block assembly includes an impact block body 421, a limiting steel ball 422, a return spring 423, a ball assembly 424, and a separator 425. The components work together to achieve the conversion and reset of the impact torque.

[0096] Furthermore, in the exemplary embodiment, the impact block body 421 has an annular structure and is made of alloy steel. It is sleeved on the torque transmission shaft 41, and the inner wall is uniformly provided with a first limiting groove that matches the limiting steel ball 422. The outer wall is integrally formed with a second annular protrusion. The side of the second annular protrusion near the return spring 423 is machined with a concave part. The concave part is an arc-shaped groove structure used to accommodate the ball assembly 424 and provide it with rolling space. The front end of the impact block body 421 is provided with multiple protruding parts. The end face of the protruding parts is the impact surface, which is used to contact the impacted part of the torque output shaft 43 and transmit the impact load.

[0097] Furthermore, in the exemplary embodiment, there are two limiting steel balls 422. The aforementioned first limiting groove and second limiting groove correspond to and cooperate with the limiting steel balls 422. The limiting steel balls 422 are made of high-hardness bearing steel and are embedded in the cooperation space of the first limiting groove and the second limiting groove, while also being in contact with the two groove walls. When the torque transmission shaft 41 rotates, the impact block body 421 is driven to move synchronously through the guiding effect of the groove wall, thereby realizing the linkage transmission of power.

[0098] Furthermore, in the exemplary embodiment, the return spring 423 is a cylindrical helical spring made of spring steel. It is sleeved on the torque transmission shaft 41, with one end abutting against the first annular protrusion of the torque transmission shaft 41 and the other end abutting against the separator 425. It generates axial elastic force through its own elastic deformation, and pushes the impact block body 421 back to the initial position after the impact action is completed, preparing for the next impact.

[0099] Furthermore, in the exemplary embodiment, the ball assembly 424 consists of multiple small steel balls, made of the same bearing steel as the limiting steel ball 422. The steel balls are independent of each other and can roll freely. The ball assembly 424 is rolled and embedded in the inner recess of the impact block body 421, with its outer diameter slightly larger than the depth of the inner recess, ensuring rolling friction when in contact with the separating gasket 425.

[0100] Furthermore, in the exemplary embodiment, the separator 425 is an annular thin sheet structure made of wear-resistant alloy. It is sleeved on the torque transmission shaft 41, located between the return spring 423 and the ball assembly 424, and cooperates with the ball assembly 424 to form a bearing structure. The separator 425 isolates the return spring 423 from the ball assembly 424, preventing direct friction between the spring end and the ball assembly 424; it also evenly transmits the axial thrust of the return spring 423 to the ball assembly 424, ensuring balanced force on the impact block body 421. Simultaneously, the rolling motion of the ball assembly 424 significantly reduces frictional loss between the return spring 423 and the impact block body 421.

[0101] Furthermore, in the exemplary embodiment, the torque output shaft 43 is made of alloy steel and has an overall stepped shaft structure. It passes through the mounting hole at the front end of the housing 1, and the shaft body is provided with an impact-receiving part that mates with the protruding part of the impact block body 421. The plane of the impact-receiving part fits against the impact surface of the impact block body 421 to ensure the transmission of impact load. The front end of the torque output shaft 43 is a hollow internal hexagonal mounting hole, the size of which is adapted to a standard tool head for mounting the tool head. A buffer washer 46, a second support bearing 44, and an O-ring 45 are sequentially fitted on the outer side of the shaft body along the power transmission direction. The tail end corresponds to the protruding part of the impact block assembly. It receives the impact torque through the reciprocating impact of the impact block body 421 and transmits it to the tool head.

[0102] Furthermore, in the exemplary embodiment, the third support bearing 47 is a deep groove ball bearing, which is sleeved on the end of the torque transmission shaft 41 near the reduction mechanism 3. The outer ring tightly abuts against the inner wall step of the internal gear ring 31, and the inner ring is interference-fitted onto the tail section of the torque transmission shaft 41, thereby supporting the stable rotation of the torque transmission shaft 41 and reducing radial runout and friction loss during its rotation.

[0103] Furthermore, in the exemplary embodiment, the second support bearing 44 is a needle roller bearing. It is sleeved in the middle of the torque output shaft 43, with the outer ring tightly fixed in the bearing mounting hole of the housing 1, and the inner ring sleeved on the corresponding shaft segment of the torque output shaft 43. Axial limiting is achieved through the cooperation of the inner wall step of the housing 1 and the buffer washer 46, thereby supporting the stable rotation of the torque output shaft 43.

[0104] Furthermore, in the exemplary embodiment, the buffer washer 46 is made of impact-resistant high-strength metal. An inner positioning groove for securing the buffer washer 46 is provided on the inner wall of the front housing. The buffer washer 46 is fitted onto the torque output shaft 43 and located between the second support bearing 44 and the impacted part. Both ends of the buffer washer 46 abut against the end face of the second support bearing 44, the inner wall of the front housing, and the side surface of the impacted part. When the torque output shaft 43 is subjected to an impact load, the buffer washer 46 absorbs the impact energy, reducing the impact damage to the second support bearing 44, the front housing, and the torque output shaft 43, thereby extending the service life of the components.

[0105] Furthermore, in the exemplary embodiment, the O-ring 45 is made of oil-resistant rubber, and its size is adapted to the clearance between the shaft segment of the torque output shaft 43 and the mounting hole of the housing 1. It is located inside the front housing 11 and sleeved on the torque output shaft 43, abutting against the outer end face of the second support bearing 44, and tightly fitting against the inner wall of the mounting hole of the housing 1 to form a sealing structure. This is used to prevent external dust and impurities from entering the bearing, while preventing internal lubricating oil leakage, thus ensuring the lubrication effect and service life of the bearing.

[0106] As an optional implementation, the impact block body 421, torque transmission shaft 41 and torque output shaft 43 are made of chromium-molybdenum alloy steel and have undergone quenching and tempering treatment; the limiting steel ball 422 and the ball assembly 424 are made of GCr15 bearing steel and have undergone carburizing and quenching treatment; the buffer washer 46 is made of silicone; and the second support bearing 44 and the third support bearing 47 are angular contact ball bearings.

[0107] Furthermore, in the exemplary embodiment, the locking mechanism 5 includes a self-locking sleeve 51, a self-locking spring 52, a self-locking steel ball 53, and an axial positioning component, specifically a retaining ring 541 and a limiting ring 542. The self-locking sleeve 51 cooperates with the self-locking steel ball 53 to lock and unlock the tool head; the self-locking spring 52 provides elastic force for the reset of the self-locking sleeve 51; the self-locking steel ball 53 limits the tool head; the retaining ring 541 fixes the axial position of the limiting ring 542; and the limiting ring 542 axially limits the self-locking spring 52. All components work together to achieve rapid loading and unloading of the tool head.

[0108] Furthermore, in the exemplary embodiment, the self-locking sleeve 51 is made of lightweight alloy material and has an overall tubular structure. It is sleeved on the front end of the torque output shaft 43. The inner wall is machined with stepped limiting steps along the axial direction. The limiting steps are adapted to the self-locking steel ball 53 and are used to squeeze or release the self-locking steel ball 53. The outer wall of the self-locking sleeve 51 is provided with anti-slip texture to facilitate manual axial pushing operation. Its axial length is adapted to the front end extension dimension of the torque output shaft 43 to ensure that the pushing stroke can completely release the limiting of the self-locking steel ball 53.

[0109] Furthermore, in the exemplary embodiment, the self-locking spring 52 is a cylindrical helical compression spring made of spring steel. It is sleeved on the torque output shaft 43 and located inside the self-locking sleeve 51. One end abuts against the limiting step of the self-locking sleeve 51, and the other end abuts against the limiting retaining ring 542. In its natural state, it pushes the self-locking sleeve 51 to the initial position, so that the limiting step always compresses the self-locking steel ball 53, maintaining the locked state of the tool head.

[0110] Furthermore, in the exemplary embodiment, there are two self-locking steel balls 53, which are made of high-hardness bearing steel. Two limiting holes are evenly opened radially at the front end of the torque output shaft 43. The two self-locking steel balls 53 are respectively embedded in the two limiting holes, with part of the self-locking steel ball 53 protruding from the inner and outer walls of the torque output shaft 43. The part protruding from the inner wall is used to engage with the groove on the outer periphery of the tool head, thus limiting the tool head; the part protruding from the outer wall cooperates with the limiting step of the self-locking sleeve 51, changing its position through the compression or release of the step to complete the locking and unlocking switching.

[0111] Furthermore, in the exemplary embodiment, the limiting retaining ring 542 is an annular structure made of metal and sleeved on the torque output shaft 43. The limiting retaining ring 542 is located between the retaining ring 541 and the self-locking spring 52. Its inner diameter matches the outer diameter of the torque output shaft 43, and its outer diameter is slightly smaller than the inner diameter of the self-locking sleeve 51 to avoid interference with the inner wall of the self-locking sleeve 51. One side of the limiting retaining ring 542 abuts against the end of the self-locking spring 52, and the other side abuts against the retaining ring 541. The retaining ring 542 achieves axial positioning by fixing itself, thereby providing support for the self-locking spring 52 and limiting the maximum compression stroke of the self-locking spring 52.

[0112] Furthermore, in the exemplary embodiment, the retaining ring 541 is a shaft elastic retaining ring made of spring steel. An annular groove adapted to the retaining ring 541 is provided on the outer wall of the front end of the torque output shaft 43. The retaining ring 541 is engaged in the groove, while blocking the axial displacement of the retaining ring 542, thus preventing the retaining ring 542 from falling off the torque output shaft 43.

[0113] Furthermore, in the exemplary embodiment, the front end of the torque output shaft 43 is a hollow internal hexagonal mounting hole, the specifications of which are compatible with standard tool heads, ensuring that the tool head can rotate synchronously to transmit torque after insertion; the limiting hole is opened at the rear end of the mounting hole, corresponding to the groove position after the tool head is inserted, ensuring that the self-locking steel ball 53 can be inserted into the groove to achieve reliable locking.

[0114] Specifically, the tool head installation process is as follows: Manually push the self-locking sleeve 51 axially towards the head of the torque output shaft 43. The self-locking sleeve 51 drives the self-locking spring 52 to compress towards the limiting ring 542. At this time, the limiting step of the self-locking sleeve 51 disengages from the self-locking steel ball 53, releasing the compression and limiting of the self-locking steel ball 53, allowing the self-locking steel ball 53 to move freely within the limiting hole. Align the tool head with the internal hexagonal mounting hole of the torque output shaft 43 and insert it to the preset depth, so that the groove on the outer circumference of the tool head is precisely aligned with the self-locking steel ball 53 in the limiting hole. Release the self-locking sleeve 51, and the self-locking spring 52 resets under the action of elastic potential energy, pushing the self-locking sleeve 51 back axially. The limiting step of the self-locking sleeve 51 re-compresses the self-locking steel ball 53, causing part of the self-locking steel ball 53 to be inserted into the groove of the tool head, forming axial and circumferential limiting, thus completing the locking and fixing of the tool head. The disassembly process of the tool head is as follows: Repeat the pushing operation during installation, manually push the self-locking sleeve 51 axially, causing the self-locking spring 52 to compress, the limiting step to disengage from the self-locking steel ball 53, and release the compression limit; at this time, the self-locking steel ball 53 moves outward from the limiting hole under the compression of the tool head groove, completely disengaging from the tool head groove, and releasing the limitation on the tool head; pull the tool head out directly to complete the disassembly; after releasing the self-locking sleeve 51, the self-locking spring 52 pushes the self-locking sleeve 51 back to its original position, and the self-locking steel ball 53 returns to its initial position under the slight compression of the limiting step, waiting for the next assembly.

[0115] Furthermore, in the exemplary embodiment, the control module includes a drive unit, a storage unit, a current detection unit, a timing unit, a speed detection unit, and an interaction unit. These units are integrated and connected via a circuit board to collaboratively achieve torque level adjustment, speed control, torque control, and human-machine interaction functions. Specifically, the drive unit drives the power mechanism 2; the storage unit stores pre-stored parameter data; the current detection unit detects the drive current of the power mechanism 2; the timing unit calculates the effective working time; the speed detection unit detects the speed of the power mechanism 2; and the interaction unit enables user operation and information feedback.

[0116] Furthermore, in the exemplary embodiment, the control module is integrated onto a circuit board, which is bolted to a circuit board mounting position within the housing 1. The drive unit is an integrated drive chip, soldered onto the circuit board and electrically connected to the drive motor 21 of the power mechanism 2 via a wire harness. It also communicates with the current detection unit, timing unit, and speed detection unit. After receiving the control signal, the drive unit outputs an appropriate drive voltage and current, causing the drive motor 21 to operate at the set speed.

[0117] Furthermore, in the exemplary embodiment, the storage unit is a surface-mount memory chip, which is soldered onto the circuit board and communicates bidirectionally with the drive unit via a data bus. The memory chip has multiple sets of torque gear parameters built in, including the gear speed, effective rotational work duration, and identification current calibration value for each gear. The identification current calibration value is the minimum value of the drive current fluctuation range of the drive motor 21 after the power tool is loaded.

[0118] Furthermore, in the exemplary embodiment, the current detection unit consists of a sampling resistor and a signal amplification chip. The sampling resistor is connected in series in the power supply circuit of the drive motor 21, and the signal amplification chip is soldered onto the circuit board and electrically connected to the sampling resistor. The current detection unit collects the operating current of the drive motor 21 in real time. After amplification and filtering by the signal amplification chip, the detection data is converted into a digital signal and transmitted to the drive unit, providing a basis for the drive unit to determine the load status and start the timing unit.

[0119] Furthermore, in the exemplary embodiment, the timing unit is a timing chip, soldered onto the circuit board and electrically connected to the drive unit. When the drive unit determines that the real-time drive current is not less than the identification current calibration value, it sends a start signal to the timing unit, and the timing unit begins to count the duration and feed back the data in real time; when the counted duration reaches the effective rotation work duration pre-stored in the storage unit, the timing unit sends a stop signal to the drive unit, and the drive unit immediately stops the drive motor 21 from running, completing one constant torque operation.

[0120] Furthermore, in the exemplary embodiment, the speed detection unit consists of a Hall sensor and a signal processing circuit. The Hall sensor is fixed to the housing 1 of the drive motor 21, and the signal processing circuit is soldered onto the circuit board and electrically connected to the Hall sensor. The speed detection unit detects the actual speed of the drive motor 21 in real time, converts the speed data into an electrical signal, and transmits it to the drive unit. The drive unit compares the actual speed with the preset gear speed to stabilize the motor speed at a preset value.

[0121] Furthermore, in the exemplary embodiment, the interaction unit includes a display screen 61, an adjustment button 62, a power switch 63, a forward / reverse switch 64, and an LED light 65. Each component is electrically connected to the circuit board and is installed at a preset opening in the first handle housing 12 or the second handle housing 13. The display screen 61 is used to display the current torque setting, working status, timing data, and fault prompts; the adjustment button 62 is a push-button type elastic button installed on one side of the display screen 61, used by the user to input or switch the torque setting; the power switch 63 is installed at the rear of the handle housing and is used to control the power supply of the entire machine; the forward / reverse switch 64 is a toggle switch used to switch the rotation direction of the drive motor 21, adapting to tightening and disassembly operations; the LED light 65 is installed at the rear of the housing 1, connected to the circuit board via wires, and provides feedback on the tool's working status through flashing signals.

[0122] The user starts the machine via power switch 63, selects the working direction via forward / reverse switch 64, and selects the target torque level via adjustment button 62. The drive unit retrieves the corresponding speed, effective rotational work duration, and identification current calibration value from the storage unit, and the drive motor 21 operates according to the speed level. The current detection unit detects the current of the drive motor 21 in real time, and the speed detection unit detects the motor speed in real time and feeds it back to the drive unit, which maintains a stable speed. When the current detection unit detects that the current has reached the identification current calibration value, the drive unit starts the timing unit. When the timing unit calculates the effective rotational work duration, the drive unit stops the drive motor 21, the display screen 61 shows that the work is completed, and the LED light 65 remains constantly lit as a reminder.

[0123] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0124] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the present invention.

Claims

1. A linear constant torque impact power tool, characterized in that, include: case; A power mechanism is disposed within the housing to output rotational power; A speed reduction mechanism is disposed inside the housing and is connected to the power mechanism for transmission, so as to reduce the output speed of the power mechanism and amplify the torque; An impact mechanism is disposed within the housing and is connected to the reduction mechanism for transmission, so as to convert the output power transmitted by the reduction mechanism into impact torque and output it. The control module, electrically connected to the power mechanism, is used to adjust and display the torque gear. The control module pre-stores the gear speed, effective rotation duration and identification current calibration value corresponding to several constant torque gears; the identification current calibration value is the minimum value of the power mechanism drive current fluctuation range after the power tool is loaded. The control module detects the real-time drive current of the power mechanism and compares it with the identified current calibration value. It then calculates the duration during which the real-time drive current is not less than the identified current calibration value and drives the power mechanism according to the gear speed until the calculated duration is not less than the effective rotational work time, thereby achieving torque control.

2. The linear constant torque impact power tool according to claim 1, characterized in that, The power mechanism includes: Drive motor; The motor connecting sleeve, specifically tubular, is fixedly connected to the drive motor; A drive shaft is inserted into the motor connecting sleeve, and one end of it is coaxially and fixedly connected to the output end of the drive motor. The output gear is coaxially and fixedly connected to the end of the transmission shaft opposite to the drive motor, and is also connected to the reduction mechanism to transmit rotational power. There are multiple first support bearings, which are coaxially fixed between the motor connecting sleeve and the transmission shaft to support the rotation of the transmission shaft.

3. The linear constant torque impact power tool according to claim 2, characterized in that, The deceleration mechanism includes: An internal gear ring is fixedly connected to the housing. The planetary gears are multiple and arranged circumferentially along the output gear. Each planetary gear meshes with the output gear and the internal gear ring to reduce speed and increase torque.

4. The linear constant torque impact power tool according to claim 3, characterized in that, The impact mechanism includes: The torque transmission shaft is rotatably disposed within the housing and is connected to multiple planetary gears to receive the power after deceleration and torque amplification. An impact block assembly is connected to the torque transmission shaft to convert rotational power into impact torque; A torque output shaft is rotatably disposed within the housing. The torque output shaft is provided with an impact-receiving part that cooperates with the impact block assembly to receive and output impact torque.

5. The linear constant torque impact power tool according to claim 4, characterized in that, The impact block assembly includes: The impact block body is specifically ring-shaped and is sleeved on the torque transmission shaft; The inner wall of the impact block body is provided with a first limiting groove that matches the limiting steel ball, and the torque transmission shaft is provided with a second limiting groove that matches the limiting steel ball, so as to limit the movement stroke of the impact block body and enable the impact block body to convert rotational power into impact torque. A return spring is sleeved on the torque transmission shaft. The torque transmission shaft and the impact block body are respectively provided with a first annular protrusion and a second annular protrusion. The first annular protrusion and the second annular protrusion abut against the two ends of the return spring to reset the impact block body.

6. The linear constant torque impact power tool according to claim 5, characterized in that, The impact block assembly also includes: The ball assembly has a recessed portion formed on the side of the second annular protrusion near the return spring, and the ball assembly is rotatably embedded in the recessed portion. A spacer is fitted onto the torque transmission shaft and located between the return spring and the ball assembly; The return spring elastically abuts against the impact block body through the ball bearing assembly and the spacer pad to reduce the friction between the return spring and the impact block body.

7. The linear constant torque impact power tool according to claim 4, characterized in that, The impact mechanism also includes: The second support bearing is disposed inside the housing and sleeved on the torque output shaft to support the rotation of the torque output shaft; An O-ring is fitted onto the torque output shaft and abuts against one side of the second support bearing; A buffer washer is fitted onto the torque output shaft, located between the second support bearing and the impacted part, and abuts against both. A third support bearing is disposed inside the housing and sleeved on the torque transmission shaft to support the rotation of the torque transmission shaft.

8. The linear constant torque impact power tool according to claim 5, characterized in that, The deceleration mechanism also includes: Multiple positioning pins are respectively inserted into each of the planetary gears and fixedly connected to the first annular protrusion, so as to enable the speed reduction mechanism and the impact mechanism to be connected in transmission. A limiting washer is fitted onto the torque transmission shaft and abuts against the end of the positioning pin that is away from the first annular protrusion.

9. The linear constant torque impact power tool according to claim 4, characterized in that, The linear constant torque impact power tool further includes a locking mechanism, which comprises: A self-locking sleeve is fitted onto the front end of the torque output shaft and can move along the axial direction of the torque output shaft. The inner wall of the self-locking sleeve is provided with a limiting step. A self-locking spring is sleeved on the torque output shaft and located inside the self-locking sleeve, with one end abutting against the limiting step of the self-locking sleeve. The self-locking steel ball has a hollow front end for mounting a tool head. A limit hole is formed radially at the front end of the torque output shaft, and the self-locking steel ball is embedded in the limit hole to cooperate with the limit step and the tool head. An axial positioning component is fixed to the front end of the torque output shaft and abuts against the self-locking spring. The axial positioning component includes a retaining ring and a limiting ring. A groove is formed on the outer wall of the front end of the torque output shaft, and the retaining ring is engaged in the groove. The limiting ring is sleeved on the torque output shaft and located between the retaining ring and the self-locking spring to axially limit the self-locking spring.

10. The linear constant torque impact power tool according to claim 1, characterized in that, The control module includes: A drive unit is electrically connected to the power mechanism to receive control signals and drive the power mechanism to operate at a set speed. The storage unit pre-stores the speed, effective rotational work duration and identification current calibration value corresponding to several constant torque gears. A current detection unit is electrically connected to the power mechanism and the drive unit to detect the drive current of the power mechanism in real time and transmit the detection data to the drive unit. A timing unit, electrically connected to the drive unit, starts timing when the drive unit determines that the real-time drive current is not less than the identification current calibration value, and feeds back timing data; The interactive unit includes a display screen and adjustment buttons. The display screen is used to display the current torque setting, working status, and timing data. The adjustment buttons are used to input or switch the torque setting.

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