CN110614605A - Power tool - Google Patents

Abstract

The invention claims a power tool, comprising a shell, a motor arranged in the shell, an output shaft driven by the motor, and a torsion adjusting mechanism, wherein the torsion adjusting mechanism can adjust the torsion value transmitted from the motor to the output shaft; the power tool further comprises a control circuit used for controlling the motor and an operating piece capable of being arranged relatively to the shell in a movable mode, the motion of the operating piece can select the torque force adjusting mechanism to act with the control circuit alternatively, and when the operating piece selects the control circuit to act, the control circuit controls the motor to stop when an electric signal of the motor reaches a preset threshold value. When the invention works, the torque force adjusting mechanism and the control circuit can be selected by the operating piece in an alternative mode, so that the switching between the mechanical torque force adjusting function gear and the electronic torque force adjusting function gear is realized, and the mechanical torque force adjustment and the electronic torque force adjustment are integrated on the operating piece.

Description

Power tool

Technical Field

The invention belongs to the technical field related to power tools, and particularly relates to a power tool with a torque adjusting function.

Background

In daily life and various engineering works, power tools such as electric power tools and pneumatic power tools have become popular. Especially, some hand tools have a plurality of functions of drilling, cutting, polishing, disassembling and assembling screws due to the fact that the working heads can be replaced, are particularly favored by users, and have wide market prospects.

A common screwdriver is provided with a torsion adjusting mechanism so as to meet the requirements of screws with different sizes on different torsion. Before screwing, the torque value of the output shaft is selected and set, and when the output torque reaches the preset torque value, the transmission from the motor to the output shaft is released and interrupted to prevent the screw head from being damaged due to overlarge torque. However, the gun drill with the mechanical torque adjustment requires that a user can roughly judge the torque required by screws with different sizes, and further has certain capability requirements on the user; and requires an additional torque setting operation before use.

In the prior art, an electronic torque adjusting scheme for automatic stop according to abrupt change of a torque value is also provided, and the torque adjusting scheme does not require a user to judge an approximate torque value required by a current screw, and can automatically cut off the drive of a motor according to the torque value judgment of a current output shaft. However, this solution has a hysteresis, that is to say there is a delay time between the torque value reaching the preset value and the motor drive being switched off, during which there is a possibility of the screw being damaged by the excessive torque value.

Therefore, the torque adjustment in the prior art also has a certain room for improvement.

Disclosure of Invention

In view of the above, it is necessary to provide a power tool for solving the technical problems in the prior art.

Concretely, a power tool includes a housing, a motor provided in the housing, an output shaft driven by the motor, and a torque force adjusting mechanism capable of adjusting a torque force value transmitted from the motor to the output shaft; the power tool also comprises a control circuit for controlling the motor and an operating piece which can be movably arranged relative to the shell, the movement of the operating piece can select the torque force adjusting mechanism to act with the control circuit alternatively, and when the operating piece selects the control circuit to act, the control circuit controls the motor to stop when the electric signal of the motor reaches a preset threshold value; when the operating piece selects the torque force adjusting mechanism to act, the torque force adjusting mechanism sets different torque force threshold values through the operating piece, and the torque force adjusting mechanism can interrupt transmission from the motor to the output shaft when the load of the output shaft reaches the torque force threshold values.

As a preferable mode of the present invention, when the operating element selects the control circuit to function, the operating element triggers the control circuit by signal triggering to function the control circuit.

As a preferable scheme of the present invention, a signal generator for emitting a trigger signal is disposed on the operating element, the control circuit includes a trigger for receiving the trigger signal, and when the signal generator and the trigger are at a predetermined relative position, the trigger receives the trigger signal emitted by the signal generator and starts the control circuit to control the motor.

As a preferable aspect of the present invention, the signal generator is a magnetic member fixed to the operation member, and the trigger is a hall sensor.

As a preferable scheme of the present invention, the control circuit further includes a controller for controlling the motor to operate, the controller is connected to the trigger, the trigger outputs a feedback signal to the controller when receiving the trigger signal, the controller starts the control of the motor when the feedback signal reaches a predetermined value, and the controller interrupts the control of the motor when the feedback signal is lower than the predetermined value.

As a preferred scheme of the present invention, the controller includes a receiving module, a determining module, and a control module, the receiving module is configured to receive the feedback signal in real time, and the determining module is configured to determine whether the feedback signal reaches a predetermined value, and the control module starts control over the motor or interrupts control over the motor according to a determination result.

As a preferred scheme of the present invention, when the control module starts controlling the motor, the receiving module is further configured to receive a current signal on the motor in real time, the determining module is further configured to determine whether the current signal received by the receiving module reaches a preset threshold, and when the current signal received by the receiving module determined by the determining module reaches the preset threshold, the control module controls the motor to stop.

As a preferable scheme of the present invention, the torque force adjusting mechanism includes a clutch member, the power tool further includes at least one stage of planetary gear train, the planetary gear train includes a planetary gear, a planetary carrier, and an annular gear, the clutch member is capable of engaging with or disengaging from the annular gear, the annular gear is fixed when the clutch member is engaged with the annular gear, and the annular gear is capable of rotating when the clutch member is disengaged from the annular gear.

As a preferable aspect of the present invention, the torque adjusting mechanism further includes an elastic element that is provided to engage the clutch member with the ring gear, and a torque adjusting ring that is capable of adjusting a deformation amount of the elastic element, and when the load of the output shaft reaches the torque threshold value, the clutch member is separated from the ring gear.

As a preferable aspect of the present invention, the torque adjusting ring is in threaded connection with the operating member, so that the rotation of the operation can drive the torque adjusting ring to move axially and adjust the deformation of the elastic element.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:

the power tool provided by the invention has the advantages that through reasonable structure arrangement, when the power tool works, the torque force adjusting mechanism and the control circuit can be selected in an alternative mode through the operating part, so that the switching between the mechanical torque force adjusting function gear and the electronic torque force adjusting function gear is realized, the mechanical torque force adjustment and the electronic torque force adjustment are integrated on the operating part, and the power tool is convenient to operate and use; meanwhile, the power tool integrates a mechanical torque adjusting function and an electronic torque adjusting function, so that the advantages and the disadvantages of the mechanical torque adjusting function and the electronic torque adjusting function are complemented when the power tool is used, and the use requirement of people on the power tool is further met.

Drawings

Fig. 1 is a sectional view of a power tool provided by the present invention.

Fig. 2 is a schematic structural diagram of the power tool provided by the present invention.

Fig. 3 is a sectional view a-a in fig. 2.

Fig. 4 is a schematic structural diagram of the torque force adjusting mechanism of the present invention.

FIG. 5 is a schematic structural diagram of an operating element according to the present invention.

Fig. 6 is a sectional view of the torque adjusting mechanism of the present invention.

Fig. 7 is a block diagram of a controller according to the present invention.

10, a shell; 20. an output shaft; 30. a motor; 40. a torque force adjusting mechanism; 41. a clutch member; 42. a planet wheel; 43. a planet carrier; 44. an inner gear ring; 45. an elastic element; 46. a torsion adjusting ring; 51. a Hall plate; 52. a magnet; 53. a controller; 101. an operating member; 411. a friction disk; 412. a support pillar; 431. a planet shaft; 531. a receiving module; 532. a judgment module; 533. and a control module.

Detailed Description

Referring to fig. 1 and 2, the power tool claimed in the present invention includes a housing 10, a motor 30 disposed in the housing 10, an output shaft 20 driven by the motor 30, and a torque adjusting mechanism 40, wherein the torque adjusting mechanism 40 is capable of adjusting a torque value transmitted from the motor 30 to the output shaft 20. That is, the present embodiment may use the torque adjustment mechanism 40 to achieve mechanical torque adjustment of the power tool.

In this embodiment, the power tool further includes a control circuit (not shown) for controlling the motor 30 and an operating element 101 movably disposed relative to the housing 10, wherein the movement of the operating element 101 can selectively select the torque adjusting mechanism 40 to operate with the control circuit, and when the operating element 101 selects the control circuit to operate, the control circuit controls the motor to stop when the electric signal of the motor 30 reaches a preset threshold. That is, when the power tool of the present embodiment is in operation, the torque adjusting mechanism 40 can be selected to perform mechanical torque adjustment on the output torque of the motor 30 by operating the operating element 101, or the control circuit can control the motor 30, and finally the motor 30 is controlled to stop when the electrical signal, specifically, the current signal, of the motor 30 reaches a preset threshold value.

The mechanical torque adjustment on the power tool specifically refers to the adjustment of the torque adjustment mechanism 40 by the operation element 101 to realize the function of adjusting different torque output values of the torque adjustment mechanism 40, thereby realizing the output operation of different torque values when the power tool is in operation. That is, when the operating element 101 adjusts the torque adjusting mechanism 40, the transmission ratio of the power tool can be adjusted by a certain connecting structure, and the output torque of the output shaft 20 can be adjusted.

Specifically, the torque force adjusting mechanism 40 comprises a clutch member 41, at least one stage of planetary gear train, the planetary gear train 42 comprises planetary gears 42, a planetary carrier 43 and a ring gear 44, wherein the clutch member 41 can be engaged with or disengaged from the ring gear 44, and when the clutch member 41 is engaged with the ring gear 44, the ring gear 44 is fixed, so that the torque force output of the torque force adjusting mechanism 40 to the output shaft 20 is realized; when the clutch 41 is disengaged from the ring gear 44, the ring gear 44 can rotate, so that the ring gear 44 idles with the planetary gears 42, and the torque adjusting mechanism 40 interrupts the torque output to the output shaft 20. That is, the torque adjusting mechanism 40 of the present embodiment achieves torque adjustment of the output shaft 20, specifically, by engagement of the clutch member 41 with the inner ring gear 44. Wherein, the torque force adjusting mechanism 40 preferably comprises a three-stage planetary gear train.

The output shaft 20 is specifically assembled on the planet carrier 43, and is circumferentially limited and fixed relative to the planet carrier 43, the planet wheels 42 are provided in a plurality of numbers, preferably 3, and 3 planet wheels 42 are respectively provided on a plurality of planet shafts 431 on the planet carrier 43, and are also circumferentially limited and fixed relative to the planet shafts 431, and the ring gear 44 is provided outside the 3 planet wheels 42 and is respectively meshed with the 3 planet wheels 42.

It will be appreciated that when the clutch member 41 is engaged with the ring gear 44, the torque of the output shaft 20 is adjusted by applying force to the ring gear 44 by the clutch member 41 and by reacting the force.

To this end, the present embodiment further includes an elastic element 45 provided to the clutch member 41 to be engaged with the ring gear 44, and a torsion adjusting ring 46 capable of adjusting the amount of deformation of the elastic element 45. The elastic element 45 acts on the internal gear ring 44, and different deformation amounts of the elastic element 45 correspond to different acting forces of the elastic element 45 acting on the clutch piece 41, so that the clutch piece 41 adjusts different acting forces of the internal gear ring 44, and different torque adjustments of the torque adjusting mechanism 40 are realized. When the load of the output shaft 20 reaches the torque threshold, the acting force provided by the clutch 41 to fix the inner gear ring 44 is smaller than the reaction force generated when the output shaft 20 works, so that the clutch 41 is separated from the inner gear ring 44, the inner gear ring 44 rotates, and the output torque of the output shaft 20 is reduced to zero. Wherein, the elastic element 45 is preferably a compression spring; the clutch member 41 specifically includes a friction disc 411 in press-fit with the elastic member 45, and a plurality of support columns 412 provided on the friction disc 411 and facing the ring gear 44.

The torsion adjusting ring 46 is in threaded connection with the operating part 101, so that when the operating part 101 performs mechanical torsion adjustment, the operating part 101 is rotated, and the torsion adjusting ring 46 is driven to move axially under the action of the threaded connection, thereby adjusting the deformation of the elastic element 45.

In the present embodiment, when the operating member 101 selects the torque force adjusting mechanism 40 to act, the torque force adjusting mechanism 40 sets different torque force thresholds through the operating member 101, and the torque force adjusting mechanism 40 can interrupt transmission from the motor 30 to the output shaft 20 when the load of the output shaft 20 reaches the torque force thresholds. That is, in the mechanical torque adjustment 40 of the present embodiment, when the load of the output shaft 20 reaches the set torque threshold during the torque adjustment, the torque adjustment mechanism 40 is disengaged, so that the torque output of the output shaft 20 is zero.

The working principle and the tripping process of the torque adjusting mechanism 40 of the embodiment, which correspond to the mechanical torque adjustment, are the prior art, and refer to the power tool (application No. 201010506996.5; application No. 2010.09.29), the electric drill (application No. 2008101787926; application No. 2008.11.25), and the electric hammer tripping structure (application No. 2015202162138; application No. 2015.04.10) disclosed in the chinese patent literature, which are not specifically described herein.

When the power tool of the embodiment works and the operating part 101 is used for selecting the control circuit to work, the control circuit controls the motor to stop when the electric signal of the motor reaches a preset threshold value. That is, the power tool of the present embodiment realizes the function of intelligent automatic stop, so that the power tool can feed back in real time according to the output torque of the output shaft 20 when in operation, and the power tool will stop once meeting special conditions.

Specifically, the operating element 101 triggers the control circuit in a signal triggering manner, so that the control circuit functions.

Specifically, a signal generator for emitting a trigger signal is arranged on the operating element 101, the control circuit includes a trigger for receiving the trigger signal, and when the signal generator and the trigger are at a predetermined relative position, the trigger receives the trigger signal emitted by the signal generator and starts the control circuit to control the motor 30. That is, only when the signal generator and the trigger are at specific positions, the trigger will receive the trigger signal from the signal generator and turn on the control circuit to function, so as to control the operation of the motor 30.

It can be understood that the trigger signal sent by the signal generator of this embodiment and received by the trigger may be set as a laser signal, a light signal, or a magnetic field signal, that is, when the signal generator works, the signal generator may send the laser signal, the light signal, or the magnetic field signal, and the trigger may receive the laser signal, the light signal, or the magnetic field signal, respectively, to implement signal transmission between the two. The signal between the signal generator and the trigger of the present embodiment is preferably a magnetic field signal.

The control circuit further comprises a controller 53 for controlling the motor 30 to work, wherein the controller 53 is connected with the trigger and is used for outputting a feedback signal when the trigger receives the trigger signal. And when the feedback signal received by the controller 53 reaches a predetermined value, the controller 53 starts the control of the motor 30, and when the feedback signal is lower than the predetermined value, the controller 53 interrupts the control of the motor 30.

In the present embodiment, the signal trigger is a magnetic component fixed on the operating element 101, preferably a magnet 52, referring to fig. 5, the magnet 52 is specifically embedded on the operating element 101 and is fixed in a limited manner relative to the operating element 101, and the fixing manner between the magnet 52 and the operating element 101 may be welded, tightly fitted, and the like, that is, the magnet 52 provided on the operating element 101 in the present embodiment does not change the original structure of the operating element 101. And the trigger is arranged as a hall plate 51, or other magnetic field receiver, for the corresponding magnet 27. It should be noted that the E-Clutch gear shown in fig. 5 is an electronic torque adjusting functional gear of the power tool claimed in the present application, and the 1 gear and the drill gear respectively represent mechanical torque adjusting functional gears.

As can be seen from the above, the hall plate 51 is applied to a power tool, and specifically, is used for receiving the magnetic field intensity of the magnet 52 on the operating element 101 and sending a feedback signal to the controller 53, and the controller 53 can start the control of the motor 30 according to whether the feedback signal sent by the hall plate 51 reaches a predetermined value. That is to say, the relative position between the magnet 52 and the hall plate 51 changes with the rotation of the operating element 101, and further the magnetic field strength of the magnet 52 received by the hall plate 51 changes, that is, the feedback signal sent by the hall plate 51 to the controller 53 changes accordingly, in this embodiment, specifically, when the magnet 52 is aligned with the hall plate 51, the hall plate 51 receives the magnetic field of the magnet and sends the feedback signal to the controller 53 to start the controller 53, so that the controller 53 controls the motor 30.

As can be seen from the above, the controller 53 is specifically configured to control the motor 30, and specifically, control the motor 30 to stop according to whether the current signal of the motor 30 during operation reaches the threshold, so as to implement the function of intelligent automatic stop of the power tool.

Referring to fig. 7, the controller 53 includes a receiving module 531, a determining module 532, and a control module 533, where the receiving module 451 is configured to receive a feedback signal sent by the hall plate 51 in real time, and the determining module 532 is configured to determine whether the feedback signal reaches a preset threshold, and the control module 533 starts controlling the motor 30 or interrupts controlling the motor 30 according to a determination result.

When the control module 533 starts controlling the motor 30, the receiving module 451 is further configured to receive a current signal of the motor 30 in real time, the determining module 532 is further configured to determine whether the current signal received by the receiving module 451 reaches a preset threshold, and when the current signal received by the receiving module 451 and determined by the determining module 532 reaches the preset threshold, the control module 533 controls the motor 30 to stop. It should be noted that, when the power tool is in operation, different torque output values are in one-to-one correspondence with current signals of the motor 30, so that the receiving module 451 implements feedback monitoring on the torque output of the power tool during operation.

In summary, the power tool provided by the invention, through reasonable structural arrangement, when in work, can select the torque force adjusting mechanism and the control circuit by the operation part in an alternative way, so as to realize the switching between the mechanical torque force adjusting function gear and the electronic torque force adjusting function gear, and the mechanical torque force adjustment and the electronic torque force adjustment are integrated on one operation part, thereby being convenient for operation and use; meanwhile, the power tool integrates a mechanical torque adjusting function and an electronic torque adjusting function, so that the advantages and the disadvantages of the mechanical torque adjusting function and the electronic torque adjusting function are complemented when the power tool is used, and the use requirement of people on the power tool is further met.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. A power tool comprising a housing, a motor disposed within the housing, an output shaft driven by the motor, and a torque adjustment mechanism capable of adjusting a torque value transmitted from the motor to the output shaft; the method is characterized in that: the power tool also comprises a control circuit for controlling the motor and an operating piece which can be movably arranged relative to the shell, the movement of the operating piece can select the torque force adjusting mechanism to act with the control circuit alternatively, and when the operating piece selects the control circuit to act, the control circuit controls the motor to stop when the electric signal of the motor reaches a preset threshold value; when the operating piece selects the torque force adjusting mechanism to act, the operating piece sets different torque force threshold values of the torque force adjusting mechanism, the torque force adjusting mechanism sets different torque force threshold values through the operating piece, and the torque force adjusting mechanism can interrupt transmission from the motor to the output shaft when the load of the output shaft reaches the torque force threshold values.

2. The power tool of claim 1, wherein: when the operating part selects the control circuit to act, the operating part triggers the control circuit in a signal triggering mode to enable the control circuit to act.

3. The power tool of claim 2, wherein: the operating piece is provided with a signal generator for sending a trigger signal, the control circuit comprises a trigger for receiving the trigger signal, and when the signal generator and the trigger are at a preset relative position, the trigger receives the trigger signal sent by the signal generator and starts the control circuit to control the motor.

4. The power tool of claim 3, wherein: the signal generator is a magnetic part fixed on the operating part, and the trigger is a Hall sensor.

5. The power tool of claim 3, wherein: the control circuit further comprises a controller used for controlling the motor to work, the controller is connected with the trigger, the trigger outputs a feedback signal to the controller when receiving the trigger signal, the controller starts control over the motor when the feedback signal reaches a preset value, and the controller interrupts control over the motor when the feedback signal is lower than the preset value.

6. The power tool of claim 5, wherein: the controller comprises a receiving module, a judging module and a control module, wherein the receiving module is used for receiving the feedback signal in real time, and the judging module is used for judging whether the feedback signal reaches a preset value or not, and the control module starts the control on the motor or interrupts the control on the motor according to the judgment result.

7. The power tool of claim 6, wherein: when the control module starts to control the motor, the receiving module is also used for receiving a current signal on the motor in real time, the judging module is also used for judging whether the current signal received by the receiving module reaches a preset threshold value, and when the current signal received by the receiving module judged by the judging module reaches the preset threshold value, the control module controls the motor to stop.

8. The power tool of claim 1, wherein: the torque force adjusting mechanism comprises a clutch piece, the power tool further comprises at least one stage of planetary gear train, the planetary gear train comprises a planetary gear, a planetary carrier and an inner gear ring, the clutch piece can be matched with or separated from the inner gear ring, the inner gear ring is fixed when the clutch piece is matched with the inner gear ring, and the inner gear ring can rotate when the clutch piece is separated from the inner gear ring.

9. The power tool of claim 8, wherein: the torque force adjusting mechanism further comprises an elastic element which enables the clutch piece to be matched with the inner gear ring, and a torque force adjusting ring which can adjust the deformation amount of the elastic element, wherein when the load of the output shaft reaches the torque force threshold value, the clutch piece is separated from the inner gear ring.

10. The power tool of claim 9, wherein: the torque adjusting ring is in threaded connection with the operating part, so that the rotation of the operation can drive the torque adjusting ring to axially move and adjust the deformation of the elastic element.