An impact power tool
By storing the attenuation relationship curve in the control module of the impact power tool, and real-time detection and confirmation of the compensation hit number, the problem of torque drop after long-term use is solved, high precision and control stability are achieved, and cost is reduced.
Patent Information
- Application Number
- CN202211465860.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Priority Date
- 2021-12-18
- Filing Date
- 2022-11-22
- Publication Date
- 2025-02-18
- Estimated Expiration
- 2042-11-22
AI Technical Summary
After long-term use of existing shock power tools, the torque of the impact decreases, resulting in low and unstable tool accuracy and need to be used for detection using expensive torque sensors.
Design an impact power tool, by storing the attenuation relationship curve between the total hit number and the torque value in the control module, detecting the number of effective hits and the actual total hit number in real time, and confirming the compensation hit number based on the attenuation relationship curve, through The motor drive is compensated for a stable torque output.
It realizes high accuracy and stable control of impact power tools, reduces the cost of use, avoids the expensive cost of sensors, and ensures the long-term performance of the tool through real-time compensation.
Smart Images
Figure CN115805568B_ABST
Abstract
Description
[Technical field]
[0001] The invention relates to an electric tool, in particular to an impact electric tool capable of achieving constant torque output. [Background technology]
[0002] Existing impact power tools all have a fixed torque function to ensure that the tool can achieve a fixed torque output. However, most fixed torques require the use of torque sensors for detection, which are usually expensive, resulting in very high usage and maintenance costs for users. Therefore, it is necessary to achieve fixed torque control without using sensors. By setting a predetermined number of strikes to control the motor, the predetermined torque output can be achieved. However, due to long-term use of the tool, the transmission mechanisms such as the striking block, springs, gears, and shafts are worn, resulting in a downward trend in the striking torque, that is, the predetermined torque output cannot be achieved after the predetermined number of strikes. Therefore, the tool has low accuracy and is unstable.
[0003] Therefore, it is necessary to design a high-precision and stable-controlled impact power tool to solve the above problems. [Summary of the invention]
[0004] In view of the deficiencies in the prior art, an object of the present invention is to provide an impact power tool with high precision and stable control.
[0005] The present invention solves the problems of the prior art by adopting the following technical solutions: an impact power tool, comprising: a power supply, a driving module connected to the power supply, and a control module, the driving module being connected to a motor to drive the motor to rotate, the control module comprising a strike detection unit and a controller, the controller comprising a correction parameter generation unit and a compensation confirmation unit connected to the correction parameter generation unit, the strike detection unit being connected to the compensation confirmation unit, and sending a single effective number of strikes and an actual total number of strikes to the compensation confirmation unit, the correction parameter generation unit storing an attenuation relationship curve between the total number of strikes and the torque value, the compensation confirmation unit confirms the compensated number of strikes based on the actual total number of strikes and the attenuation relationship curve, and controls the motor drive to perform compensation.
[0006] A further improvement scheme is: the controller includes a processing module, the strike detection unit includes a sampling resistor connected between the power supply and the driving module and a voltage detection module connected in parallel to both ends of the sampling resistor, the voltage detection module is connected to the processing module, the processing module calculates the working current, and when the working current is not less than a preset current and the duration is not less than a preset time, it is recorded as an effective strike.
[0007] A further improvement is as follows: the single effective number of blows is the effective number of blows of the impact power tool from the start of striking to the end of striking each time it works.
[0008] A further improvement is that the actual total number of blows is the total number of blows of the impact power tool since it was put into use after leaving the factory.
[0009] A further improved solution is: the controller stores a preset torque value and a preset single strike number corresponding to the preset torque value.
[0010] A further improvement is that the compensation confirmation unit is provided with a compensation number of strikes to be compensated within different total strike number intervals.
[0011] A further improved solution is: the compensation confirmation unit confirms the compensation number of strikes based on the actual total number of strikes and the attenuation relationship curve, and the controller drives the motor through the driving module to make the torque value reach the preset torque value.
[0012] Compared with the prior art, the present invention has the following beneficial effects: the impact power tool internally stores the attenuation relationship curve between the total number of blows and the torque value. When working, the single effective number of blows and the actual total number of blows of the detection tool are sent to the compensation confirmation part. The compensation confirmation part confirms the compensated number of blows according to the actual total number of blows and the attenuation relationship curve, and controls the motor drive to make compensation. The compensation is performed in real time with high precision and stable control.
Brief Description of the Drawings
[0013] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings:
[0014] Figure 1 is a structural diagram of the impact power tool of the present invention;
[0015] Figure 2 is a control circuit diagram of the impact power tool of the present invention;
[0016] Figure 3 is a working current diagram of the impact power tool of the present invention;
[0017] Figure 4 It is a curve diagram of the total number of blows and torque value of the impact power tool of the present invention.
[0018] Meaning of the reference numerals in the figures:
[0019] 100, impact power tool 1, housing 11, motor 12, planet carrier 13, active impact block 14, driven impact block 15, spring 2, battery 3, drive module 4, impact detection unit 41, voltage detection module 5, controller 51, correction parameter generation unit 52, compensation confirmation unit 53,
[0020] Management Module [Specific implementation method]
[0021] The present invention is further described in detail below in conjunction with the accompanying drawings and implementation modes.
[0022] See also Figure 1 As shown, the present invention relates to an impact power tool 100, which is an impact wrench. The impact power tool 100 includes a housing 1, a motor 11 accommodated in the housing 1, and a rotary impact mechanism driven by the motor 11. A battery 2 is installed on the housing 1 to supply power to the motor 11. The impact power tool 100 applies a rotational force and an impact force to an output shaft to intermittently transmit the rotational impact force to a front-end tool such as a driving drill bit to tighten screws or bolts. The rotary impact mechanism includes a planetary carrier 12 driven by the motor 11, an active impact block 13 sleeved on the planetary carrier 12, and a driven impact block 14 matched with the active impact block 13. A spring 15 is installed between the active impact block 13 and the planetary carrier 12, and one end of the spring 15 abuts against the planetary carrier 12, and the other end abuts against the active impact block 13. During the initial tightening action, the protrusion of the active impact block 13 abuts against the protrusion of the driven impact block 14 and is driven to rotate by the motor 11; when approaching the tightening state or a large load is loaded on the front end tool, the active impact block 13 moves back and forth under the action of the spring 15 and intermittently drives the driven impact block 14 to rotate, realizing the striking movement and further tightening the screws or bolts.
[0023] After the impact power tool 100 leaves the factory, the torque value generated by its rotating impact mechanism is determined, which is determined by the size of the impact block, spring 15, gears and other transmission mechanisms, and the preset number of single strikes can be set to achieve the output of the preset torque value. However, due to long-term use, the impact block, spring 15, gears and the like will wear out, resulting in the failure to achieve the output of the preset torque value after the preset number of single strikes. Therefore, it is necessary to compensate for the number of single strikes in the state of long-term use. Figure 2 As shown, it is a control circuit diagram of an impact power tool 100 according to the present invention. The impact power tool 100 also includes a driving module 3 and a control module connected to the power supply. The driving module 3 is connected to the motor 11 to drive the motor 11 to rotate. The control module includes a strike detection unit 4 and a controller 5. The controller 5 includes a correction parameter generation unit 51 and a compensation confirmation unit 52 connected to the correction parameter generation unit 51. The strike detection unit 4 is connected to the compensation confirmation unit 52, and the single effective strike number and the actual total strike number are sent to the compensation confirmation unit 52. The correction parameter generation unit 51 stores an attenuation relationship curve between the total strike number and the torque value. The compensation confirmation unit 52 confirms the compensation strike number according to the actual total strike number and the attenuation relationship curve, and controls the motor 11 to drive for compensation.
[0024] The controller 5 is a microprocessor, including a processing module 53, a memory for storing processing programs, control data and temporary storage data, and a timer. The strike detection unit 4 includes a sampling resistor R connected between the power supply and the driving module 3 and a voltage detection module 41 connected in parallel to both ends of the sampling resistor R. The voltage detection module 41 is connected to the processing module 53. The processing module 53 calculates the working current. The memory stores a preset current and a preset time value. When the processing module 53 determines that the working current is not less than the preset current and the duration is not less than the preset time, it is recorded as an effective strike. In this embodiment, if Figure 3 As shown, the preset current is I1, time t1 to t2 is one effective operation, time t3 to t4 is one effective operation, the memory stores a single effective number of strikes and an actual total number of strikes, the single effective number of strikes is the effective number of strikes of the impact power tool 100 from the start of striking to the end of striking during each operation, and the actual total number of strikes is the total number of strikes of the impact power tool 100 since it was used since leaving the factory.
[0025] The attenuation relationship curve is a characteristic curve generated by the experimental test of the impact power tool 100 before leaving the factory. The total number of blows is the total number of times the impact power tool 100 can strike. According to the attenuation relationship curve, the compensation confirmation unit 52 is provided with the compensation number of blows to be compensated in different total number of blows intervals. The controller 5 drives the motor 11 through the driving module 3 to make the torque value reach the preset torque value. The compensation number of blows is positively correlated with the total number of blows, that is, the larger the total number of blows, the larger the compensation number of blows. Please refer to Figure 4As shown, it is a curve diagram of the total number of blows and the torque value of the impact power tool 100 in this embodiment, wherein the curve a is an attenuation curve of the total number of blows and the torque value, and the curve b is the preset torque value, the preset torque value is 280 N.m, and the corresponding preset single blow number is 50 times, that is, a single blow of 50 times can achieve a force output of 280 N.m, and the total blow number interval is set to 10W times. Since the attenuation of the impact power tool 100 shows a rapid downward trend, when the actual total blow number is 10W to 20W, the single effective blow number is 10W. The number of single effective blows is increased by 10 times on the basis of 50 times. When the actual total number of blows is 20W to 30W, the number of single effective blows is increased by 20 times on the basis of 50 times. When the actual total number of blows is 30W to 40W, the number of single effective blows is increased by 30 times on the basis of 50 times. When the actual total number of blows is 40W to 50W, the number of single effective blows is increased by 50 times on the basis of 50 times. When the actual total number of blows exceeds 50W, the number of single effective blows is increased by 100 times on the basis of 50 times. The more the actual total number of blows, the more compensation times. Of course, different models of impact power tools have different attenuation relationship curves, and the number of compensation times in different intervals is also different. By setting the attenuation relationship curve and the number of compensation blows before leaving the factory, it can be effectively compensated after long-term use to achieve constant torque output, simple control and low cost.
[0026] The impact power tool 100 of the present invention internally stores an attenuation relationship curve between the total number of blows and the torque value. When working, the single effective number of blows and the actual total number of blows of the detection tool are sent to the compensation confirmation unit 52. The compensation confirmation unit 52 confirms the compensated number of blows based on the actual total number of blows and the attenuation relationship curve, and controls the motor 11 to drive for compensation. The compensation is performed in real time with high precision and stable control.
[0027] The present invention is not limited to the above specific embodiments. A person skilled in the art can easily understand that there are many other alternatives to the impact power tool of the present invention without departing from the principle and scope of the present invention. The protection scope of the present invention shall be subject to the content of the claims.
Claims
1. An impact power tool comprising: A power supply, a driving module and a control module connected to the power supply, wherein the driving module is connected to a motor to drive the motor to rotate; characterized in that: the control module includes a strike detection unit and a controller, the controller includes a correction parameter generation unit and a compensation confirmation unit connected to the correction parameter generation unit, the strike detection unit is connected to the compensation confirmation unit, and sends a single effective strike number and an actual total strike number to the compensation confirmation unit, the correction parameter generation unit stores an attenuation relationship curve between the total strike number and the torque value, the compensation confirmation unit confirms the compensation strike number according to the actual total strike number and the attenuation relationship curve, and controls the motor drive to compensate; wherein the compensation confirmation unit is provided with a compensation strike number to be compensated within different total strike number intervals; The controller drives the motor through the driving module so that the torque value reaches the preset torque value; the attenuation relationship curve is a characteristic curve generated by experimental testing of the impact power tool before leaving the factory; wherein, the controller stores a preset torque value and a preset single number of strikes corresponding to the preset torque value; the single effective number of strikes is the effective number of strikes of the impact power tool from the start of striking to the end of striking during each operation. When the working current is not less than the preset current and the duration is not less than the preset time, it is recorded as an effective strike; the actual total number of strikes is the total number of strikes of the impact power tool since it was used after leaving the factory; the total number of strikes is the total number of strikes that the impact power tool can perform.
2. The impact power tool according to claim 1, characterized in that: The controller includes a processing module, the strike detection unit includes a sampling resistor connected between the power supply and the driving module and a voltage detection module connected in parallel to both ends of the sampling resistor, the voltage detection module is connected to the processing module, and the processing module calculates the working current.