Fastening tool and control method therefor

Abstract

A power tool and a control method therefor, which belong to the field of fastening tools. The control method for a power tool comprises: in a starting stage of an electric motor, acquiring a rotational speed value of the electric motor by means of a speed measurement module, and on the basis of the rotational speed value of the electric motor, determining that the electric motor has entered a stable rotational-speed stage; in the stable rotational-speed stage, acquiring a stable rotational speed value of the electric motor, and comparing the stable rotational speed value with a preset rotational speed threshold value stored in a control module to determine a tightening mode of a fastening tool; and on the basis of the tightening mode, selecting a control means matching same to control the operating state of the electric motor. According to the fastening tool and a control method therefor, different control means are selected on the basis of different tightening modes, such that the fastening tool can be shut down promptly after a screw is driven into a wooden board; therefore, problems such as the screw being sunk too deep into the wooden board or penetrating through the wooden board can be avoided, and damage to the screw can also be effectively avoided, thereby enhancing the durability of the screw.

Description

Fastening tool and control method thereof TECHNICAL FIELD

[0001] The present application relates to the field of electric tools, in particular to a fastening tool and a control method thereof. BACKGROUND

[0002] In daily life, when using electric drills or screwdrivers to screw, it is easy to appear that the first screwing is not tightened to the end, or the first screwing is stopped halfway and then continued. Customers need to operate multiple times to tighten, which is usually called "secondary reinforcement".

[0003] In the actual operation of "secondary reinforcement", it is easy to appear that the screw or screw is not stopped in time after being screwed into the wood board, but is excessively sunk into the wood board, or even the wood board is broken. At the same time, the continuous output of the tool on the screw head or screw head is also easy to break the screw head or screw head, and the screw or screw is "difficult to advance and retreat", which greatly reduces the work quality and work efficiency of the customer, and the use experience is very poor. SUMMARY

[0004] Therefore, the embodiments of the present application provide a fastening tool and a control method thereof to solve the technical problems in the background art.

[0005] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0006] In a first aspect, the embodiments of the present application provide a fastening tool, comprising: a shell; a motor located in the shell; a driving module electrically connected with the motor and used to drive the motor to operate; a control module at least electrically connected with the driving module and used to control the motor to operate; a speed detection module used to obtain the speed value of the motor;

[0007] The control module is further configured to: in the starting stage of the motor, obtain the speed value of the motor through the speed detection module, and determine that the motor enters a speed stabilization stage according to the speed value of the motor; obtain the speed stabilization value of the motor in the speed stabilization stage, compare the speed stabilization value with the preset speed threshold value stored in the control module to determine the tightening mode of the fastening tool; select a control means matched with the tightening mode to control the operating state of the motor according to the tightening mode; wherein the tightening mode includes a first tightening mode and a second tightening mode.

[0008] Further, the determination that the motor enters the speed stabilization stage according to the speed value of the motor comprises:

[0009] The control module stores a rotation speed stability ability index threshold value, in a preset time window, a plurality of rotation speed values of the motor are collected by the speed detection module, and then a rotation speed stability ability index value of the motor is calculated according to the plurality of rotation speed values of the motor; when the rotation speed stability ability index value is less than or equal to the rotation speed stability ability index threshold value, it is determined that the motor enters a rotation speed stability stage.

[0010] Or

[0011] The control module stores a rotation speed slope stability threshold value / interval, after the motor is started, a plurality of rotation speed values of the motor are collected by the speed detection module, and then a rotation speed change curve is formed according to the plurality of rotation speed values of the motor by the control module; when the slope of the rotation speed change curve meets the rotation speed slope stability threshold value / interval, it is determined that the motor enters a rotation speed stability stage.

[0012] Further, when the motor enters the rotation speed stability stage, a first rotation speed value of the stage is obtained and taken as the rotation speed stability value, wherein the first rotation speed value is the first rotation speed value detected by the speed detection module when the motor enters the rotation speed stability stage, or the average rotation speed value of the speed detection module within a preset time period after the motor enters the rotation speed stability stage.

[0013] Further, when the rotation speed stability value is greater than the preset rotation speed threshold value, the initial tightening mode is entered, and when the rotation speed stability value is less than or equal to the preset rotation speed threshold value, the re-tightening mode is entered.

[0014] Further, the control means at least includes a first running control means and a second running control means, in the initial tightening mode, the first running control means is adopted, which includes: the control module obtains the real-time rotation speed value of the motor, and calculates the speed difference value between the real-time rotation speed value of the motor and the rotation speed stability value; when the speed difference value is greater than or equal to the preset speed difference value threshold value stored in the control module, the control module controls the motor to stop running.

[0015] In the re-tightening mode, the second running control means is adopted, which includes: the control module obtains the working current value of the motor when the motor is running; when the working current value is greater than the preset current threshold value stored in the control module, the control module controls the motor to stop running.

[0016] Further, the rotation speed stability threshold value includes a rotation speed average threshold value corresponding to the rotation speed average value, a rotation speed square difference threshold value corresponding to the rotation speed square difference value, and a rotation speed square root threshold value corresponding to the rotation speed square root value.

[0017] In a second aspect, the embodiments of the present application further provide a control method of a fastening tool, comprising:

[0018] A preset rotating speed threshold value is stored in the control module;

[0019] In the motor starting stage, the rotating speed value of the motor is acquired by the speed detection module;

[0020] The rotating speed value of the motor is determined to determine that the motor enters the rotating speed stable stage;

[0021] The rotating speed stable value of the motor is acquired in the rotating speed stable stage, and the size of the rotating speed stable value and the preset rotating speed threshold value is compared to determine the tightening mode of the fastening tool, wherein the tightening mode comprises a first-time tightening mode and a second-time tightening mode;

[0022] According to the tightening mode, a control means matched with the tightening mode is selected to control the operating state of the motor.

[0023] Further, the determination of the rotating speed value of the motor to determine that the motor enters the rotating speed stable stage comprises:

[0024] The rotating speed stable threshold value is stored in the control module, in a preset time window, a plurality of rotating speed values of the motor are acquired by the speed detection module, and then the rotating speed stable capability index value of the motor is calculated according to the plurality of rotating speed values of the motor, when the rotating speed stable capability index value is less than or equal to the rotating speed stable capability index threshold value, it is determined that the motor enters the rotating speed stable stage;

[0025] Or

[0026] The rotating speed slope stable threshold value / interval is stored in the control module, after the motor is started, a plurality of rotating speed values of the motor are acquired by the speed detection module, and then the rotating speed change curve is formed according to the plurality of rotating speed values of the motor by the control module, when the slope of the rotating speed change curve meets the rotating speed slope stable threshold value / interval, it is determined that the motor enters the rotating speed stable stage.

[0027] Further, when the motor enters the rotating speed stable stage, the first rotating speed value in this stage is acquired and taken as the rotating speed stable value, wherein the first rotating speed value is the first rotating speed value detected by the speed detection module when the motor enters the rotating speed stable stage, or the rotating speed average value of a preset time period after the motor enters the rotating speed stable stage.

[0028] Further, when the rotating speed stable value is greater than the preset rotating speed threshold value, the first-time tightening mode is entered, and when the rotating speed stable value is less than or equal to the preset rotating speed threshold value, the second-time tightening mode is entered.

[0029] Further, the control means at least includes a first operation control means and a second operation control means, in the initial tightening mode, the first operation control means is adopted, which includes: the control module acquires the real-time rotating speed value of the motor, and calculates the speed difference value between the real-time rotating speed value of the motor and the rotating speed stable value, when the speed difference value is greater than or equal to the preset speed difference value threshold stored in the control module, the control module controls the motor to stop running;

[0030] In the re-tightening mode, the second operation control means is adopted, which includes: the control module acquires the working current value of the motor when the motor is running, when the working current value is greater than the preset current threshold stored in the control module, the control module controls the motor to stop running.

[0031] The tightening tool and the control method thereof provided by the embodiment of the present application include: a shell; a motor located in the shell; a driving module electrically connected with the motor and used to drive the motor to run; a control module at least electrically connected with the driving module and used to control the motor to run; a speed detection module used to acquire the rotating speed value of the motor; the control module is further configured to: in the starting stage of the motor, acquire the rotating speed value of the motor through the speed detection module, and determine that the motor enters a rotating speed stable stage according to the rotating speed value of the motor; acquire the rotating speed stable value of the motor in the rotating speed stable stage, and compare the rotating speed stable value with a preset rotating speed threshold stored in the control module to determine the tightening mode in which the tightening tool is located, wherein the tightening mode includes an initial tightening mode and a re-tightening mode; and select a control means matched with the tightening mode to control the running state of the motor according to the tightening mode. Therefore, the tightening tool and the control method thereof of the embodiment of the present application can select different control means according to different tightening modes, can stop the motor in time after the screw or the bolt is driven into the wood board, can avoid the problems that the screw or the bolt is excessively sunk into the wood board or the wood board is broken, can effectively avoid the damage of the screw or the bolt, can improve the durability of the screw or the bolt, and can further improve the work quality and the work efficiency of the customer, so that the customer has a good experience and the use requirement of the customer is met.

[0032] Additional aspects and advantages of the present application will be made apparent by the following description. BRIEF DESCRIPTION OF DRAWINGS

[0033] The accompanying drawings, which are included to provide a further understanding of the present application and are incorporated in and constitute a part of this application, illustrate embodiments of the present application and serve to explain the principles of the present application, and do not limit the present application in any manner. In the drawings:

[0034] Fig. 1 is a module block diagram of a control method of a fastening tool according to an embodiment of the present application;

[0035] Fig. 2 is a flowchart of a control method of a fastening tool according to an embodiment of the present application;

[0036] Fig. 3 is a logic diagram of a control method of a fastening tool according to an embodiment of the present application.

[0037] Fig. 4 is a current waveform diagram of a fastening tool in a first tightening mode and a second tightening mode according to an embodiment of the present application.

[0038] Fig. 5 is a rotational speed waveform diagram of a fastening tool in a first tightening mode and a second tightening mode according to an embodiment of the present application.

[0039] Fig. 6 is a schematic diagram of a fastening tool according to an embodiment of the present application.

[0040] Reference signs: 1, housing; 2, motor; 3, driving module; 4, control module; 5, speed detection module; 6, power module; 7, torque setting module; 10, fastening tool. DETAILED DESCRIPTION

[0041] The exemplary embodiments of the present application will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the application but there can be many variations to the embodiments and they should not be thought of in a limiting sense. Rather, these embodiments are provided so that this present application will be thorough and complete, and will fully convey the scope of the application to those skilled in the art. Like reference numerals refer to like elements throughout.

[0042] In the following description, numerous specific details are given to provide a thorough understanding of the application. However, it will be apparent that the application can be practiced without one or more of the specific details. In other instances, well-known structures are not shown in detail in order not to obscure the application. As such, the sole purpose of the description is to enable the person skilled in the art to practice the application. Although combinations of the features of the dependent claims can cause departures from the spirit of the application in a scope not specifically set forth below, embodiments of the application encompass such apparent variations.

[0043] For a thorough understanding of the present application, reference should be made to the following detailed description together with the accompanying drawings wherein: there is shown by way of illustration of the preferred embodiments a number of specific details, and there is no intention to limit the scope of the application as defined by the appended claims inasmuch as the detailed description is not exhaustive of every possible embodiment and numerous embodiments not specifically described are contemplated as falling within the scope of the present application. Moreover, some of the particular details provided herein are by way of example and for purposes of illustration only inasmuch as, unless otherwise specifically stated in the appended claims, various embodiments of the application are not limited in scope to any one particular feature, aspect, structure, function or characteristic described herein.

[0044] Embodiment:

[0045] In combination with Figs. 1, 2 and 6, the present embodiment provides a fastening tool and a control method thereof. On one hand, the fastening tool comprises:

[0046] A housing 1, in which a motor 2 is accommodated;

[0047] A driving module 3, which is electrically connected with the motor 2 and used to drive the motor 2 to run, wherein the driving module is an inverter, generally adopting an inverter circuit of "two-phase conduction three-phase six states", and the motor 2 generally adopts a brushless motor;

[0048] A control module 4, which is at least electrically connected with the driving module 3 and used to control the motor 2 to run;

[0049] A speed detection module 5, which is used to obtain a rotating speed value of the motor 2;

[0050] A power module 6, which is used to supply power to a control circuit inside the electric tool 10;

[0051] A torque setting module 7, which is used to receive a torque gear instruction input by a user to set an upper limit value of a rotating torque output by the electric tool 10, wherein the torque setting module 7 adopts a common torque cup structure;

[0052] On the other hand, the control method comprises:

[0053] Step S1: obtaining a rotating speed value of the motor 2 in a starting stage of the motor 2 through the speed detection module 5;

[0054] Step S2: determining that the motor 2 enters a rotating speed stable stage according to the rotating speed value of the motor 2;

[0055] Step S3: obtaining a rotating speed stable value of the motor 2 in the rotating speed stable stage;

[0056] Step S4: determining a tightening mode of the tightening tool 10 by comparing the rotating speed stable value with a preset rotating speed threshold value stored in the control module 4, wherein the tightening mode comprises a first-time tightening mode and a re-tightening mode;

[0057] Step S5: selecting a control means matched with the tightening mode to control a running state of the motor 2 according to the tightening mode.

[0058] In step S1, the rotating speed value of the motor 2 is obtained in the starting stage of the motor 2 through the speed detection module 5, wherein the rotating speed value of the motor 2 is detected in the starting stage of the motor 2, so as to facilitate subsequent determination of the tightening mode of the tool, such as the first-time tightening mode and the re-tightening mode.

[0059] In step S2, the motor 2 enters the speed stabilization stage according to the speed value of the motor 2, wherein first, the control module 4 stores a speed stabilization capability index threshold value, a plurality of speed values of the motor 2 are collected in a preset time window through the speed detection module 5, and then the speed stabilization capability index value of the motor 2 is calculated according to the plurality of speed values of the motor, and when the speed stabilization capability index value is less than or equal to the speed stabilization capability index threshold value, it is determined that the motor 2 enters the speed stabilization stage, wherein the speed stabilization capability index threshold value is set by referring to the industry standard ISO5393 in the prior art, and the following is a simple description of determining the performance of the torque tool according to the industry standard ISO5393:

[0060] In the ISO5393 specification, when Cm>1.67 and Cmk>1.33, it means that the performance of the tool meets the standard, and it is a good tool, wherein Cm=(USL-LSL) / 6σ, Cmk=Min((USL-Xbar) / 3σ,(Xbar-LSL) / 3σ), wherein USL is the upper limit of the process torque, LSL is the lower limit of the process torque, Xbar is the average value of the test data of the torque detector, σ is the standard deviation of the test data of the torque detector, Cm and Cmk are equipment capability indexes, Cm reflects the dispersion of the tool and the relationship between the upper and lower limits of the process torque, and is the proportional relationship between the process torque and 6σ, Cmk not only considers the relationship between the dispersion and the process torque, but also considers the actual average value, and the actual production average value and the process set value are concentrated together without deviation, otherwise the deviation will also affect the unqualified rate of actual production.

[0061] Therefore, the present application refers to the above test method, determines the dispersion of the tool speed value by detecting the values of Cm and Cmk, and determines when the tool speed reaches a stable state, wherein the speed stabilization capability index value includes Cm and Cmk, and the speed stabilization capability index threshold values are 1.67 and 1.33 respectively, and as an optimization, the present application can select any one of Cm and Cmk as the speed stabilization capability index value, and of course, both can also be selected.

[0062] The following is an example of detecting the speed value of the motor 2 and the values of Cm and Cmk in the initial tightening mode and the re-tightening mode when the electric tool is working: the control module 4 continuously samples 10 data, and sets a rolling filter window, 5 data is a group (window filtering), the average speed value Vbar and the standard deviation S of each group are calculated through an algorithm, and then the values of Cm and Cmk are further calculated, and when Cm>1.67 and Cmk>1.33 are obtained, it is judged that the speed enters a stable state.

[0063] From the experimental data, it can be seen that, in both the initial tightening mode and the re-tightening mode, when the speed stability capability index value Cm>1.67 and / or Cmk>1.33, the motor 2 enters the speed stability stage.

[0064] In addition, in step S2, the speed slope stability threshold / interval is stored in the control module 4. After the motor 2 is started, a plurality of motor 2 speed values are collected by the speed detection module 5, and then the control module 4 forms a speed change curve according to the plurality of motor speed values. When the slope of the speed change curve meets the speed slope stability threshold / interval, it is determined that the motor enters the speed stability stage. As shown in FIG. 5, after the motor 2 is started, the speed gradually increases, and the slope k of the speed change curve changes constantly from large to small until it changes to 0, i.e., at T1, the motor enters the speed stability stage. As an optimized scheme, when the slope k of the speed change curve fluctuates between the interval [-0.1, 0.1] and lasts for a certain period of time, it is determined that the motor enters the speed stability stage. Therefore, when the slope k of the speed change curve is less than or equal to 0, or the slope k of the speed change curve fluctuates between the interval [-0.1, 0.1] and lasts for a certain period of time, it is determined that the motor 2 enters the speed stability stage. The speed slope stability threshold is not limited to 0, and the interval is not limited to [-0.1, 0.1].

[0065] It is worth noting that the determination of the above-mentioned speed stability stage is one of the important links of the present application. In actual operation, due to the difference in the hardness of the workpiece material or the difference in the type of fastener (such as a screw or a bolt), the time when the motor enters the speed stability stage is different. For example, in the initial tightening mode, when the drill just screws the front end of the screw into the wood, the motor starts to enter the speed stability stage, and the speed is relatively stable at this time. With the passage of time, the speed of the motor 2 gradually decreases, especially when the screw is seated, the speed drops sharply to zero. In the re-tightening mode, it is generally considered that the motor enters the speed stability stage when the drill speed is the highest. The reason is that when the screw is initially tightened, it is not completely tightened, i.e., the seating is not in place. When the tool is started again for the second tightening, the screw will rotate by a certain angle again. From the beginning of the screw rotation to the screw rotating by the certain angle, this stage is called the speed stability stage.

[0066] In step S3, the speed stabilization value of the motor 2 is obtained in the speed stabilization stage, wherein the speed stabilization value is the first speed value when the motor 2 enters the speed stabilization stage, i.e. the first speed value detected when the motor 2 enters the speed stabilization stage; of course, the speed stabilization value is not necessarily the first speed value detected when the motor 2 enters the speed stabilization stage, but can also be the average speed value in a certain preset time period, or the maximum speed value in a certain group of speed data or speed data in a certain period of time.

[0067] In step S4, the tightening mode of the tightening tool 10 is determined by comparing the speed stabilization value with the preset speed threshold value stored in the control module 4, wherein the tightening mode includes the initial tightening mode and the re-tightening mode, and the re-tightening mode generally refers to the secondary reinforcement tightening mode, but is not limited to the secondary reinforcement tightening mode, and can also be the tertiary or quaternary reinforcement tightening mode; when the speed stabilization value (i.e. the first speed value) is greater than the preset speed threshold value, the initial tightening mode is entered; when the speed stabilization value is less than or equal to the preset speed threshold value, the re-tightening mode is entered.

[0068] It is worth noting that the preset speed threshold value is pre-stored in the control module 4, and the preset speed threshold value is less than the speed stabilization value in the initial tightening mode and greater than the speed stabilization value in the re-tightening mode; the specific value of the preset speed threshold value can be determined by testing and verifying multiple experimental data; at the same time, the preset speed threshold value can have multiple groups, and each group of preset speed threshold values corresponds to the current working condition, including the set torque value, the size and model of the screw or bolt, and the material of the working surface. Under normal circumstances, the customer will first adjust the torque position of the electric tool 10 through the torque setting module 7, and then match the corresponding preset speed threshold value by manually selecting the working condition or automatically identifying the working condition in the control module 4 under the torque position.

[0069] The following is an example of storing different working condition corresponding preset speed threshold values in the control module 4:

[0070] As can be seen from the above, the customer can appropriately select the corresponding preset speed threshold value according to the set torque value, the size and model of the screw or bolt, and the material of the working surface, wherein the preset speed threshold value can be manually selected or automatically adapted in the control module 4; if the first manual selection, the torque adjustment device, the size and model selection button of the screw or bolt, and the material selection button of the working surface can be provided on the tool housing; if the second automatic adaptation, the control module 4 can determine the working condition (such as the size of the torque value, the hardness of the material of the working surface, and the size and model of the screw or bolt) by real-time detection of the current value, and then match the corresponding preset speed threshold value according to the current working condition.

[0071] In step S5, a control means matched with the tightening mode is selected to control the running state of the motor 2, wherein the control means at least includes a first running control means and a second running control means. In the primary tightening mode, the first running control means is adopted, which includes: the control module 4 acquires the real-time rotating speed value of the motor 2, and calculates the speed difference value between the real-time rotating speed value of the motor and the rotating speed stable value. When the speed difference value is greater than or equal to the preset speed difference value threshold value stored in the control module, the control module 4 controls the motor 2 to stop. The following is an example of the first running control means in the primary tightening mode of the tool:

[0072] In combination with FIG. 3, it is assumed that the working condition selects the torque gear 1.0 N·m, and the hard material / φ6.0 mm*50 mm screw. In combination with the above table, the preset rotating speed threshold value V1 is 1100 rpm, and the preset speed difference value threshold value AV0 is 200 rpm. The specific control method is: after starting the motor 2, the rotating speed rapidly rises. When it is detected that the motor 2 enters the rotating speed stable stage, the first rotating speed value of the motor 2 in the rotating speed stable stage is set as the rotating speed stable value V0. It is assumed that the rotating speed stable value V0 is 1500 rpm, that is, the rotating speed stable value V0 is greater than the preset rotating speed threshold value V1, and it is determined that the primary tightening mode is entered. The control module 4 continues to detect the real-time rotating speed value Vt of the motor 2. When the real-time rotating speed value Vt of the motor 2 decreases to 1300 rpm, that is, the speed difference value AV between the rotating speed stable value V0 and the real-time rotating speed value Vt of the motor 2 is equal to 200 rpm, the control module 4 controls the motor 2 to stop.

[0073] In the secondary tightening mode, the second running control means is adopted, which includes: the control module 4 acquires the working current value of the motor 2 when the motor 2 runs. When the working current value is greater than the preset current threshold value stored in the control module and reaches a certain time, the control module 4 controls the motor 2 to stop.

[0074] The following is an example of the second running control means in the secondary tightening mode of the tool:

[0075] In combination with FIG. 3, it is assumed that the working condition selection torque gear selection is 1.0 N·m, the hard material / φ6.0 mm*50 mm screw, in combination with the above table, the preset speed threshold V1 is 1100 rpm, and the preset current threshold is 10 A. The specific control method is as follows: after starting the motor 2, the speed rapidly rises, and when it is detected that the motor 2 enters the speed stable stage, the first speed value of the motor 2 in the speed stable stage is set as the speed stable value V0. It is assumed that the speed stable value V0 is 600 rpm, that is, the speed stable value V0 is less than the preset speed threshold V1, and it is determined to enter the re-tightening mode. Then, the control module 4 obtains the working current value It of the motor 2 in real time. When it is detected that the working current value It is greater than the preset current threshold I1 and the duration reaches 60 ms, the control module 4 controls the motor 2 to stop. The duration can be the total time length (as shown in Table 1 below) that is continuously greater than the preset current threshold I1, or the total time length (as shown in Table 2 below) accumulated by a timer in an accumulation or subtraction manner. The current sampling time is 1 ms / time, so the sampling number N is at least 60 times (that is, count = 60) when the duration reaches 60 ms. It is worth noting that, in combination with FIG. 4, the preset current threshold I1 is the working current value in the speed stable stage in the initial tightening mode. Under normal circumstances, the working current value I2 in the speed stable stage in the re-tightening mode is necessarily greater than the working current value I1 in the speed stable stage in the initial tightening mode.

[0076] The fastening tool and the control method thereof provided in the embodiments of the present application comprise: a shell 1; a motor 2 located in the shell 1; a driving module 3 electrically connected with the motor 2 and used to drive the motor 2 to operate; a control module 4 at least electrically connected with the driving module 3 and used to control the motor 2 to operate; and a speed detection module 5 used to obtain the speed value of the motor 2. The control module 4 is further configured to: in a motor starting stage, obtain the speed value of the motor 2 through the speed detection module 5, and determine that the motor 2 enters a speed stable stage according to the speed value of the motor 2; obtain the speed stable value of the motor 2 in the speed stable stage, compare the speed stable value with a preset speed threshold stored in the control module 4, to determine the tightening mode of the fastening tool 10, wherein the tightening mode comprises an initial tightening mode and a re-tightening mode; and select a control means matched with the tightening mode to control the operating state of the motor 2. Therefore, the fastening tool and the control method thereof in the embodiments of the present application select different control means according to different tightening modes, can stop the screw or the screw from being driven into the wood board in time, can avoid the problems that the screw or the screw is excessively sunk into the wood board or the wood board is punched, can effectively avoid the damage of the screw or the screw, can improve the durability of the screw or the screw, and can further improve the work quality and the work efficiency of the customer, so that the customer has a good experience and the use requirement of the customer is met.

[0077] The fastening tool can be a screwdriver machine, an electric drill, a screwdriver, etc., and can be an AC tool directly plugged in for use or a DC tool configured with a battery pack for use.

[0078] It should be understood that the above description and the accompanying drawings are only examples of the embodiments of the present application and do not limit the present application. The advantages of the present application have been fully and effectively achieved. The functions and principles of the present application have been shown and described in the embodiments, and the embodiments of the present application can be modified or changed in any way without departing from the principles.

Claims

1. A fastening tool, comprising: a housing; a motor located in the housing; a driving module electrically connected with the motor and used to drive the motor to operate; a control module electrically connected with at least the driving module and used to control the motor to operate; a speed detection module used to obtain a rotating speed value of the motor; characterized in that: the control module is further configured to: in a starting stage of the motor, obtain the rotating speed value of the motor through the speed detection module, and determine that the motor enters a rotating speed stable stage according to the rotating speed value of the motor; obtain a rotating speed stable value of the motor in the rotating speed stable stage, and determine a tightening mode in which the fastening tool is located by comparing the rotating speed stable value with a preset rotating speed threshold value stored in the control module; select a control means matched with the tightening mode to control an operating state of the motor according to the tightening mode; wherein the tightening mode comprises a first tightening mode and a second tightening mode.

2. The fastening tool of claim 1, wherein the determination that the motor enters the rotating speed stable stage according to the rotating speed value of the motor comprises: the control module stores a rotating speed stability index threshold value, in a preset time window, a plurality of rotating speed values of the motor are collected through the speed detection module, and then a rotating speed stability index value of the motor is calculated according to the plurality of rotating speed values of the motor, when the rotating speed stability index value is less than or equal to the rotating speed stability index threshold value, it is determined that the motor enters the rotating speed stable stage; or the control module stores a rotating speed slope stability threshold value / interval, after the motor is started, a plurality of rotating speed values of the motor are collected through the speed detection module, and then a rotating speed change curve is formed according to the plurality of rotating speed values of the motor through the control module, when a slope of the rotating speed change curve meets the rotating speed slope stability threshold value / interval, it is determined that the motor enters the rotating speed stable stage.

3. The fastening tool of claim 2, wherein when the motor enters the rotating speed stable stage, a first rotating speed value in this stage is obtained and taken as the rotating speed stable value, wherein the first rotating speed value is a first rotating speed value detected by the speed detection module when the motor enters the rotating speed stable stage, or an average rotating speed value of the speed detection module in a preset time period after the motor enters the rotating speed stable stage.

4. The fastening tool of claim 3, wherein when the rotating speed stable value is greater than the preset rotating speed threshold value, the first tightening mode is entered, and when the rotating speed stable value is less than or equal to the preset rotating speed threshold value, the second tightening mode is entered.

5. The fastening tool of claim 1 wherein, the control means at least comprises a first operating control means and a second operating control means, in the first tightening mode, the first operating control means is adopted, which comprises: the control module obtains a real-time rotating speed value of the motor, and calculates a speed difference value between the real-time rotating speed value of the motor and the rotating speed stable value, when the speed difference value is greater than or equal to a preset speed difference value threshold value stored in the control module, the control module controls the motor to stop. In the second tightening mode, a second operation control means is adopted, which comprises: the control module acquires the working current value of the motor during operation, and when the working current value is greater than the preset current threshold value stored in the control module, the control module controls the motor to stop.

6. A control method of the fastening tool according to any one of claims 1 to 5, characterized by, Comprise: A preset rotating speed threshold value is stored in the control module; In the motor starting stage, the rotating speed value of the motor is acquired through the speed detection module; According to the rotating speed value of the motor, it is determined that the motor enters the rotating speed stable stage; In the rotating speed stable stage, the rotating speed stable value of the motor is acquired, and by comparing the rotating speed stable value with the preset rotating speed threshold value, the tightening mode of the tightening tool is determined, wherein the tightening mode comprises a first tightening mode and a second tightening mode; According to the tightening mode, a control means matched with the tightening mode is selected to control the operation state of the motor.

7. The control method according to claim 6, characterized by According to the rotating speed value of the motor, it is determined that the motor enters the rotating speed stable stage, which comprises: The control module stores a rotating speed stability index threshold value, and in a preset time window, a plurality of rotating speed values of the motor are collected through the speed detection module, and then the rotating speed stability index value of the motor is calculated according to the plurality of rotating speed values of the motor, and when the rotating speed stability index value is less than or equal to the rotating speed stability index threshold value, it is determined that the motor enters the rotating speed stable stage; Or The control module stores a rotating speed slope stability threshold value / interval, and after the motor starts, a plurality of rotating speed values of the motor are collected through the speed detection module, and then a rotating speed change curve is formed according to the plurality of rotating speed values of the motor through the control module, and when the slope of the rotating speed change curve meets the rotating speed slope stability threshold value / interval, it is determined that the motor enters the rotating speed stable stage.

8. The control method according to claim 7, characterized by, When the motor enters the rotating speed stable stage, a first rotating speed value in this stage is acquired and taken as the rotating speed stable value, wherein the first rotating speed value is the first rotating speed value detected by the speed detection module when the motor enters the rotating speed stable stage, or the rotating speed average value of the speed detection module within a preset time period after the motor enters the rotating speed stable stage.

9. The control method according to claim 8, characterized by, When the rotating speed stable value is greater than the preset rotating speed threshold value, the first tightening mode is entered, and when the rotating speed stable value is less than or equal to the preset rotating speed threshold value, the second tightening mode is entered.

10. The control method according to claim 6, characterized by, The control means at least comprises a first operation control means and a second operation control means, in the first tightening mode, the first operation control means is adopted, which comprises: the control module acquires the real-time rotating speed value of the motor, and calculates the speed difference value between the real-time rotating speed value of the motor and the rotating speed stable value, and when the speed difference value is greater than or equal to the preset speed difference value threshold value stored in the control module, the control module controls the motor to stop; In the second tightening mode, the second operation control means is adopted, which comprises: the control module acquires the working current value of the motor during operation, and when the working current value is greater than the preset current threshold value stored in the control module, the control module controls the motor to stop.

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