Current type variable-speed cordless electric wrench

Abstract

The utility model discloses a current type variable-speed cordless electric wrench, which particularly relates to the technical field of electric wrenches and comprises a handle, a clutch component, a gear component and a counter-force arm are sequentially arranged at one end of the handle, a shell is fixed at the other end of the handle, and an electronic component is arranged in the shell. The clutch assembly comprises a third-stage gear assembly, a fourth-stage gear assembly and a double-clutch structure which are arranged in a clutch shell and are in transmission connection in sequence. In a high-speed output state, the fourth-stage gear assembly does not participate in torque transmission and does not have a torque amplification effect; in the low-speed state, the fourth-stage gear assembly participates in torque transmission, the output rotating speed is reduced, and the overall reduction ratio participating in torque transmission of the wrench is conveniently changed, so that the output torque of the wrench and the speed of an output shaft are changed, the reduction ratio is automatically switched when the wrench is no-load and loaded, and the tightening efficiency during no-load operation of the wrench is effectively improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to electric tool technical field, concretely relates to a current type variable speed cordless electric wrench. BACKGROUND

[0002] The electric wrench is a kind of electric fixed-torque tool for the fixed-torque assembly of threaded fastener, and is suitable for the tightening of high-strength bolts. It is widely used in the fields of steel structure bridge, factory building, chemical industry, power equipment installation and the like, and is also used in occasions where the torque or axial force of bolt fastener is strictly required. Among them, the current type electric wrench is a kind of electric wrench that controls the output torque by monitoring the current signal of the motor during operation. Its working principle is based on the relationship between the change of current value and the torque value during the tightening process of the motor. When the motor starts to work, the current will rise with the increase of load. Through the built-in control system, the current of the motor can be adjusted according to the preset torque value, so as to realize accurate torque control. When the predetermined torque is reached, the motor stops working, thereby completing the tightening work of the bolt.

[0003] With the rapid development of science and technology, the traditional manual tool cannot meet the tightening demand of large bolts on the construction site, and with the improvement of process requirements, the precision requirement of tightening torque is also increasing. The pure current type electric wrench is affected by control precision, current sampling precision and sampling frequency, and the reducer mechanism itself also has a certain influence on the output torque efficiency of the motor. Based on this, the utility model provides a current type variable speed cordless electric wrench. SUMMARY

[0004] The utility model aims at providing a current type variable speed cordless electric wrench, which realizes automatic switching of reduction ratio when the wrench is in idle and loaded state, and effectively improves the tightening efficiency of the wrench in idle operation.

[0005] In order to realize the above-mentioned purpose, the utility model provides the following technical scheme: a current type variable speed cordless electric wrench, comprising a handle, the handle one end is sequentially provided with clutch assembly, gear assembly and counterforce arm, and the handle other end is fixed with the casing, the casing is equipped with electronic assembly in.

[0006] The clutch assembly comprises third stage gear assembly, fourth stage gear assembly and double clutch structure which are sequentially transmissionally connected in clutch housing, the double clutch structure both ends outside are respectively equipped with clutch seat and clutch cover, three steel balls are equipped in the clamping groove in the clutch seat, the clutch seat outside is equipped with circular groove;

[0007] In high-speed output state, the vertical direction torque received in the clutch assembly is less than the critical value, so that the fourth stage gear assembly does not participate in torque transmission;

[0008] When the clutch assembly is subjected to a vertical moment greater than a critical value in a low speed state, the fourth gear assembly participates in torque transmission.

[0009] Preferably, the fourth planetary carrier of the fourth gear assembly is fixedly connected with the clutch assembly by screws, and the deep groove ball bearing is assembled at the input end of the clutch assembly.

[0010] In a high speed output state, the three steel balls are in the clamping grooves, the clutch sleeve is provided with a wave spring for pressing the electronic assembly, so that the three steel balls cannot be lifted, and the fourth gear assembly does not participate in transmission and has no torque amplification effect.

[0011] In a low speed state, the three steel balls leave the clamping grooves and enter the circular grooves, the fourth gear assembly participates in torque transmission, and the output speed is reduced.

[0012] Preferably, the handle is internally provided with a motor, the motor output shaft is sequentially connected with the first gear assembly and the second gear assembly, and the second gear assembly is fixedly connected with the third central gear of the third gear assembly.

[0013] Preferably, the gear assembly comprises the fifth gear assembly and the sixth gear assembly which are sequentially arranged in the shell, and the fifth central gear of the fifth gear assembly is in driving connection with the double clutch structure.

[0014] Preferably, the sixth gear assembly is connected with an output shaft at an end away from the fifth gear assembly, the reaction arm is arranged on a side of the shell away from the clutch assembly, and the reaction arm is sleeved on the outside of the output shaft.

[0015] Preferably, the reaction arm is provided with a reversing switch for controlling the rotation direction of the motor, and the handle is further provided with a start-stop switch for providing a start signal and a running signal for the motor.

[0016] Preferably, the electronic assembly comprises a servo controller and a communication board assembly; the servo controller is internally provided with a main controller one, the main controller one is connected with a motor drive module at the output end for driving control of the motor; the motor is connected with a speed reducer for amplifying the power provided by the motor to meet the final output torque requirement, the speed reducer is internally provided with an angle module for controlling the output angle, and the angle module is installed directly below the second gear assembly; the main controller one is connected with a current sampling module at the input end for collecting the phase current flowing through the motor to improve the output torque accuracy.

[0017] Preferably, the communication board assembly comprises a second main controller, the second main controller is connected with the first main controller through a serial communication module, a display screen is arranged at an output end of the second main controller, and the display screen is used for displaying relevant contents; the second main controller is connected with a server through a WIFI module, and the second main controller is connected with matched host computer software through a USB interface, and finally the final tightening torque result is sent to the server or the host computer software; the communication board assembly is connected with a storage module used for storing data, and a key is connected with an input end of the second main controller.

[0018] Preferably, the handle bottom is provided with a lithium battery, and the lithium battery provides power for the wrench through a power management module.

[0019] In the above technical scheme, the technical effects and advantages of the utility model are provided:

[0020] 1. The clutch assembly of the utility model is convenient for changing the overall speed reduction ratio of the wrench torque transmission, thereby changing the output torque and output shaft speed of the wrench, realizing automatic switching of the speed reduction ratio of the wrench in the idle state and the loaded state, and effectively improving the tightening efficiency of the wrench in the idle state.

[0021] 2. The current and speed double feedback control structure is adopted, and the output torque precision of the wrench is improved.

[0022] 3. The current type variable speed cordless electric wrench is a high-efficiency and convenient large-torque output tool, and can be applied to the tightening site of large bolts. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a whole front view structure of the utility model;

[0024] Figure 2 It is a whole side view structure of the utility model;

[0025] Figure 3 It is Figure 2 A-A sectional view of the utility model;

[0026] Figure 4 It is Figure 3 A partial structure view of the utility model;

[0027] Figure 5 It is a clutch assembly structure view of the utility model;

[0028] Figure 6 It is Figure 5 B-B sectional view of the utility model;

[0029] Figure 7 It is an electronic assembly schematic view of the utility model;

[0030] Figure 8 It is a calibrating instrument structure view.

[0031] BRIEF DESCRIPTION OF DRAWINGS

[0032] 1 counterforce arm;

[0033] 2 gear assembly, 21 housing, 22 fifth stage gear assembly, 23 sixth stage gear assembly, 24 fifth stage central gear, 25 output shaft;

[0034] 3 clutch assembly, 31 third stage central gear, 32 third stage gear assembly, 33 fourth stage gear assembly, 34 clutch seat, 35 steel ball, 36 double clutch structure, 37 clutch housing, 38 clutch cover, 39 clamping groove, 310 circular groove;

[0035] 4 housing, 5 electronic assembly, 6 lithium battery, 7 handle, 8 motor, 9 first stage gear assembly, 10 second stage gear assembly, 11 reversing switch, 12 start-stop switch;

[0036] 13 display, 14 industrial computer, 15 dynamic sensor, 16 bolt simulator, 17 stop block. DETAILED DESCRIPTION

[0037] In order to make the technical personnel in the art better understand the technical scheme of the utility model, the utility model will be further described in detail below in combination with the drawings.

[0038] The utility model provides a current formula variable speed cordless electric wrench as shown in Figures 1-6 A current formula variable speed cordless electric wrench, including handle 7, handle 7 inside is equipped with motor 8, selects brush DC motor, and motor 8 output shaft is sequentially transmission connection with first stage gear assembly 9 and second stage gear assembly 10;Counterforce arm 1 is equipped with reversing switch 11, for responsible control motor 8's direction of rotation (0 clockwise rotation, 1 counterclockwise rotation), handle 7 still is equipped with start-stop switch 12, for motor 8 provides start signal, rotation signal.

[0039] Handle 7 one end is sequentially provided with clutch assembly 3, gear assembly 2 and counterforce arm 1, clutch assembly 3 includes being arranged in clutch housing 37 and sequentially transmission connection's third stage gear assembly 32, fourth stage gear assembly 33 and double clutch structure 36, and double clutch structure 36 both ends outside is equipped with clutch seat 34 and clutch cover 38, and three steel balls 35 are arranged in the clamping groove 39 in clutch seat 34, and the circular groove 310 is arranged on the outside of clutch seat 34, and the third stage central gear 31 of second stage gear assembly 10 and third stage gear assembly 32 is fixedly connected.

[0040] The gear assembly 2 comprises a fifth-stage gear assembly 22 and a sixth-stage gear assembly 23 arranged in the housing 21 in sequence, the fifth-stage center gear 24 of the fifth-stage gear assembly 22 is in transmission connection with the double clutch structure 36, the output shaft 25 is connected to the end of the sixth-stage gear assembly 23 away from the fifth-stage gear assembly 22, and the reaction arm 1 is arranged on the side of the housing 21 away from the clutch assembly 3 and is sleeved outside the output shaft 25.

[0041] High-speed output state: the three steel balls 35 are in the clamping grooves 39, the spring against the wave spring in the clutch sleeve 38 is arranged to press the electronic assembly 5 tightly, so that the three steel balls 35 cannot be lifted up, at this time, the transmission of the wrench torque is realized by driving the double clutch structure 36 to rotate through the fourth-stage gear assembly 33, since the fourth-stage planet carrier of the fourth-stage gear assembly 33 is fixedly connected to the clutch assembly 3 through a screw, the deep groove ball bearing is assembled at the input end of the clutch assembly 3, and the clutch assembly 3 rotates together with the double clutch structure 36, that is, the fourth-stage planet carrier rotates, which is equivalent to that the fourth-stage gear assembly 33 does not participate in the transmission and has no torque amplification effect.

[0042] That is, in the high-speed output state, when the vertical moment received in the clutch assembly 3 is less than the critical value, the fourth-stage gear assembly 33 does not participate in the torque transmission, the total speed reduction ratio of the torque transmission is small, the output torque of the wrench is small, but the speed of the output shaft of the wrench is faster, and the wrench can quickly complete the no-load pre-tightening operation.

[0043] Low-speed state: in the low-speed state, as the torque of the wrench increases, when the input torque of the fourth-stage gear assembly 33 is greater than the pre-tightening torque of the die compression spring of the double clutch structure 36, the die compression spring is compressed, and the spring against the wave spring of the clutch sleeve 38 is also compressed, since there is no pressure, the steel balls 35 leave the clamping grooves 39 and enter the circular grooves 10, at this time, the clutch assembly 3 rotates as a whole, the fourth-stage gear assembly 33 participates in the torque transmission, and the output speed is reduced.

[0044] That is, in the low-speed state, when the vertical moment received in the clutch assembly 3 is greater than the critical value, the fourth-stage gear assembly 33 participates in the torque transmission, the total speed reduction ratio of the torque transmission is increased, and the output torque of the wrench is greater.

[0045] As shown in Figures 1-3 and Figure 7 , the housing 4 is fixed to the other end of the handle 7, and the electronic assembly 5 is arranged in the housing 4, the electronic assembly 5 comprises a servo controller and a communication board assembly.

[0046] The servo controller is internally provided with a main controller one, the output end of the main controller one is connected with a motor driving module, which is used for driving control of the motor 8, the input end of the main controller one is connected with a current sampling module, which is used for collecting the phase current flowing through the motor 8, the current flows through a sampling resistor to obtain a corresponding voltage value, the main controller one collects the resistance voltage value through an analog input channel, and indirectly obtains the current flowing through the motor 8, the output current and the output torque of the wrench are approximately linearly related, the torque signal is processed by the calibrator, and the result of the real torque output by the wrench is fed back;

[0047] Specifically, the calibrator structure is as shown in Figure 8 The wrench is installed on one side of the top of the calibrator rack, a stop block 17 is arranged on one side of the torque arm 1 of the wrench, and a display 13 is arranged on the top of the calibrator rack.

[0048] The torque signal of the dynamic sensor 15 in the calibrator is input into the industrial computer 14, the industrial computer 14 processes the torque signal and feeds back the result of the real torque output by the wrench to the display 13, the corresponding relationship between the calibration current and the torque is determined, so that the output torque of the wrench can be changed by adjusting the target torque of the display screen in the electronic component 5 below. When the output torque of the output shaft 25 of the wrench is large, the first-stage gear assembly 9, the second-stage gear assembly 10, the third-stage gear assembly 32, the fifth-stage gear assembly 22 and the sixth-stage gear assembly 23 participate in the transmission of the output torque of the motor 8; when the output torque of the output shaft 25 of the wrench is small, the first-stage gear assembly 9, the second-stage gear assembly 10, the third-stage gear assembly 32, the fourth-stage gear assembly 33, the fifth-stage gear assembly 22 and the sixth-stage gear assembly 23 participate in the transmission of the output torque of the motor 8, at this time, the speed reduction ratio of the whole wrench is increased, and the output torque of the output shaft 25 is greatly improved under the condition that the output torque of the motor 8 is the same. The current feedback link is introduced to improve the output torque accuracy of the wrench.

[0049] The motor 8 is also connected to a speed reducer for amplifying the power provided by the motor 8 to meet the final output torque requirement; the speed reducer is provided with an angle module for controlling the output angle, and the angle module is installed directly below the second-stage gear assembly 10, and the gear sensor is used as the angle module, which is a special chip MT36xx for automobile speed measurement; with the rotation of the gear, the cutting chip senses the increase and decrease of the magnetic flux density; when the magnetic flux density increases beyond the predefined hysteresis level, the output is opened (low level); when the magnetic flux density decreases beyond the hysteresis level, the output is closed (output high level). The gear rotates one circle, and the angle module outputs three pulses; the main controller one collects the angle pulse signals, combines the wrench output torque judgment condition, and finally converts the angle signals into the angle of the bolt tightened by the wrench. Through the introduction of the speed feedback link, the running state of the motor 8 can be clearly known, the Pwm output duty cycle of the motor 8 is adjusted, and finally the motor 8 is basically in the fast approach to the locked state, so that the output torque of the motor 8 can greatly improve the control precision of the wrench.

[0050] The communication board assembly comprises a main controller two, the main controller two is connected with the main controller one through a serial communication module, a display screen is arranged at the output end of the main controller two, a 1.3-inch display screen is selected, and the display screen is used for displaying related contents; the main controller two is connected with a server through a WIFI module, and the main controller two is connected with a matching host computer software through a USB interface; the final tightening torque result of the wrench is sent to the server or the matching host computer software, and the display screen in the electronic assembly 1 can display the current wrench state, the output torque, the running direction of the wrench and the running state of the motor 8.

[0051] The communication board assembly is connected with a 128Mb Flash storage module for storing data, and is responsible for storing motor 8 running parameter related data, wrench current calibration data and wrench tightening result data. The host computer software can check the tightening result data of the wrench through the USB line connected with the USB interface of the wrench.

[0052] The input end of the main controller two is connected with a key, so that the target torque of the display screen in the above-mentioned electronic assembly 5 can be adjusted, the output torque of the wrench can be changed, and the working efficiency of workers can be improved.

[0053] The handle 7 is provided with a lithium battery 6 at the bottom, the lithium battery 6 provides electric energy for the wrench through a power management module, and the power management module provides various power requirements for the electronic assembly (communication board assembly, servo controller, start-stop and reversing assembly and display screen).

Claims

1. A current-fed variable speed cordless electric wrench comprising a handle (7), characterized in that: The handle (7) is sequentially provided with a clutch assembly (3), a gear assembly (2) and a counterforce arm (1) at one end, and is fixed with a shell (4) at the other end, and the shell (4) is provided with an electronic assembly (5) therein. The clutch assembly (3) comprises a third-stage gear assembly (32), a fourth-stage gear assembly (33) and a double clutch structure (36) which are sequentially and drivingly connected in a clutch housing (37), the double clutch structure (36) is provided with a clutch seat (34) and a clutch sleeve (38) at the two outer sides, respectively, three steel balls (35) are arranged in the clamping groove (39) in the clutch seat (34), and a circular groove (310) is arranged on the outer side of the clutch seat (34). In the high-speed output state, the vertical moment received by the clutch assembly (3) is less than the critical value, and the fourth-stage gear assembly (33) does not participate in the torque transmission. In the low-speed state, the vertical moment received by the clutch assembly (3) is greater than the critical value, and the fourth-stage gear assembly (33) participates in the torque transmission.

2. A current-fed variable speed cordless electrically powered wrench as defined in claim 1, wherein: The fourth-stage gear assembly (33) is fixedly connected with the clutch assembly (3) through a screw, and a deep groove ball bearing is assembled on the input end of the clutch assembly (3). In the high-speed output state, the three steel balls (35) are in the clamping groove (39), the clutch sleeve (38) is provided with a spring which presses the electronic assembly (5) tightly, so that the three steel balls (35) cannot be lifted, and the fourth-stage gear assembly (33) does not participate in the transmission and has no torque amplification effect. In the low-speed state, the three steel balls (35) leave the clamping groove (39) and enter the circular groove (310), the fourth-stage gear assembly (33) participates in the torque transmission, and the output speed is reduced.

3. A current-fed variable speed cordless electrically powered wrench as defined in claim 1, wherein: The handle (7) is internally provided with a motor (8), the output shaft of the motor (8) is sequentially connected with a first-stage gear assembly (9) and a second-stage gear assembly (10), and the second-stage gear assembly (10) is fixedly connected with a third-stage center gear (31) of the third-stage gear assembly (32).

4. A current-fed variable speed cordless electrically powered wrench as defined in claim 1, wherein: The gear assembly (2) comprises a fifth-stage gear assembly (22) and a sixth-stage gear assembly (23) which are sequentially arranged in a housing (21), and a fifth-stage center gear (24) of the fifth-stage gear assembly (22) is drivingly connected with the double clutch structure (36).

5. A current-fed variable speed cordless electrically powered wrench as defined in claim 4, wherein: The sixth-stage gear assembly (23) is connected with an output shaft (25) at the end away from the fifth-stage gear assembly (22), the counterforce arm (1) is arranged on the side of the housing (21) away from the clutch assembly (3), and the counterforce arm (1) is sleeved on the outer side of the output shaft (25).

6. A current-fed variable speed cordless electrically powered wrench as defined in claim 3, wherein: The counterforce arm (1) is provided with a reversing switch (11) for controlling the rotating direction of the motor (8), and the handle (7) is further provided with a start-stop switch (12) for providing a starting signal and a running signal for the motor (8).

7. A current-fed variable speed cordless electrically powered wrench as defined in claim 3, wherein: The electronic assembly (5) comprises a servo controller and a communication board assembly. The servo controller is internally provided with a main controller I, and the output end of the main controller I is connected with a motor driving module for driving control of the motor (8). The motor (8) is connected with a speed reducer, which is used for amplifying the power provided by the motor (8) to meet the final output torque requirement, and the speed reducer is provided with an angle module for controlling the output angle, and the angle module is installed directly below the second-stage gear assembly (10). An input end of the main controller is connected with a current sampling module, which is used for collecting the phase current flowing through the motor (8), so as to improve the output torque accuracy.

8. A current-fed variable speed cordless electrically powered wrench as defined in claim 7, wherein: The communication board assembly comprises a main controller two, which is connected with the main controller one through a serial communication module, and the output end of the main controller two is provided with a display screen, which is used for displaying relevant contents. The main controller two is connected with a server through a WIFI module, and the main controller two is connected with a matching host computer software through a USB interface, and finally the tightening torque result is sent to the server or the host computer software. The communication board assembly is connected with a storage module for storing data, and the input end of the main controller two is connected with a key.

9. A current-fed variable speed cordless electrically powered wrench as defined in claim 1 wherein: The handle (7) is provided with a lithium battery (6) at the bottom, and the lithium battery (6) provides power for the wrench through a power management module.

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