Patent Application
20130233584
This application claims priorities from Japanese Patent Application No. 2012-052457 filed Mar. 9, 2012. The entire content of this priority application is incorporated herein by reference.
The invention relates to a power tool and a power tool system, and particularly to a power tool system capable of changing an operation mode of a power tool.
In a screw driving tool or the like that is used at an assembly site such as an automobile plant, specific setting of tightening torque is required, and adjustments of torque setting are required for each tightened part. Thus, a tool capable of setting driving torque as disclosed in Japanese Patent Application Publication No. 2011-31314 is used to set predetermined tightening torque suitable for a tightened part, so that a driving operation is performed.
In the above-described tool, a maximum value, a minimum value, and settable values between the maximum value and the minimum value of tightening torque are set preliminarily. Hence, when an operation requires tightening torque outside this preset range, a tool needs to be provided for each required tightening torque. In view of the foregoing, it is an object of the invention to provide a power tool capable of dealing with a wide range of tightening torque with a single power tool, and to provide a power tool system capable of setting a wide range of tightening torque.
In order to attain the above and other objects, the present invention provides a power tool. The power tool includes a bit mounting unit, a motor, and a control unit. The bit mounting unit is configured to mount thereon a bit. The motor is configured to rotatingly drive the bit. The control unit is configured to control a drive of the motor. The control unit includes a storing unit configured to store a plurality of prescribed values affecting the drive of the motor and a division number by which a range of the plurality of prescribed values is divided. At least one of the range and the division number is arbitrarily settable.
With this configuration, because a range of prescribed values affecting operations of a motor or a division number can be set arbitrarily, a wide range of operations can be performed with a single power tool. Further, because prescribed values affecting operations of the motor can be changed on the power tool itself, changes of the prescribed values or the like become easier.
According to another aspect of the invention, the present invention provides a power tool. The power tool includes a bit mounting unit, a motor, a control unit, a selecting unit, and an external device connecting unit. The bit mounting unit is configured to mount thereon a bit. The motor is configured to rotatingly drive the bit mounting unit. The control unit is configured to control a drive of the motor. The control unit includes a storing unit and a torque determining unit. The torque determining unit is configured to determine the fastening torque. The storing unit is configured to store a plurality of prescribed values having a range for determining a fastening torque and a division number by which the range is divided. The selecting unit is configured to select one of the plurality of prescribed values. The torque determining unit determines the fastening torque based on the selection of the selecting unit. The external device connecting unit is configured to be connected to an external device. The external device includes a changing unit configured to change at least one of the range of the plurality of prescribed values and the division number.
With this configuration, because a division number and a plurality of prescribed values can be changed, a wide range of tightening torque can be obtained with a single power tool. Further, because an external device is required to change the reference value and the like, inadvertent changes of the division number and the like can be suppressed.
According to still another aspect of the invention, the present invention provides a power tool. The power tool includes a bit mounting unit, a motor, a control unit, and a selecting unit. The bit mounting unit is configured to mount thereon a bit. The motor is configured to rotatingly drive the bit mounting unit. The control unit is configured to control a drive of the motor. The control unit includes a storing unit and a torque determining unit . The torque determining unit is configured to determine a fastening torque. The storing unit is configured to store a plurality of prescribed values having a range for determining the fastening torque and a division number by which the range is divided. The selecting unit is configured to select one of a first operation mode and a second operation mode. The selecting unit selects one of the plurality of prescribed values in the first operation mode and the torque determining unit determines the fastening torque based on the selection of the selecting unit. The selecting unit changes at least one of the range of plurality of prescribed values and the division number in the second operation mode.
With this configuration, too, because a division number and a plurality of prescribed values can be changed, a wide range of tightening torque can be obtained with a single power tool. Further, because the division number and the like can be changed on the power tool itself, changes of the reference value and the like become easier.
According to further aspect of the invention, the present invention provides a power tool system. The power tool system includes a power tool and an external device. The power tool includes a bit mounting unit, a motor, a control unit, a selecting unit, and an external device connecting unit. The bit mounting unit is configured to mount thereon a bit. The motor is configured to rotatingly drive the bit mounting unit. The control unit is configured to control a drive of the motor. The control unit includes a storing unit and a torque determining unit. The torque determining unit is configured to determine a fastening torque. The storing unit is configured to store a plurality of prescribed values having a range for determining the fastening torque and a division number by which the range is divided. The selecting unit is configured to select one of the plurality of prescribed values. The torque determining unit determines the fastening torque based on the selection of the selecting unit. The external device is configured to connect to the external device connecting unit. The external device includes a changing unit configured to change at least one of the range of the plurality of prescribed values and the division number.
The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings, in which:
Hereinafter, an electronic pulse driver 1 as an example of a power tool according to a first embodiment of the invention and a configuration combined with a PC (personal computer) 10 as an example of an external device will be described while referring to
As shown in
The motor 3 is disposed within the body section 21 such that the longitudinal direction of the body section 21 matches the axial direction of the motor 3. Also, within the body section 21, the hammer section 4 and the anvil section 5 are arranged toward one end side in the axial direction of the motor 3. In the following descriptions, the anvil section 5 side is defined as a front side, the motor 3 side is defined as a rear side, and a direction parallel to the axial direction of the motor 3 is defined as a front-rear direction. Additionally, the body section 21 side is defined as a top side, the handle section 22 side is defined as a bottom side, and a direction in which the handle section 22 extends from the body section 21 is defined as a top-bottom direction. Further, a direction perpendicular to the front-rear direction and to the top-bottom direction is defined as a left-right direction.
The body section 21 has a front portion provided with a metal-made hammer case 23 in which the hammer section 4 and the anvil section 5 are provided. The hammer case 23 has substantially a funnel shape tapering toward the front side. The hammer case 23 has a front-end portion formed with an opening 23a. A metal 23A is provided at an inner surface defining the opening 23a.
The body section 21 is formed with a plurality of inlet ports 21a and outlet ports 21b for introducing external air into the body section 21 and for discharging air to the outside, respectively, with a fan 32 described later. The motor 3 is cooled by the external air.
The handle section 22 extends downward from approximately a center position of the body section 21 in the front-rear direction, and is formed integrally with the body section 21. The battery 24 for supplying the motor 3 and the like with electric power is detachably mounted on the bottom end of the handle section 22. The handle section 22 includes a trigger 25, a switching lever 27, a switch 26 (
The motor 3 is a brushless motor mainly including a rotor 3A having an output shaft section 31 and a stator 3B arranged in confrontation with the rotor 3A. The rotor 3A is provided with a permanent magnet 3C (
The hammer section 4 mainly includes a gear mechanism 41 and a hammer 42, and is disposed at the front side of the motor 3 within the hammer case 23. The gear mechanism 41 includes a planetary gear mechanism 41B having an outer gear 41A. The outer gear 41A is disposed within the hammer case 23 and is fixed to the body section 21. The planetary gear mechanism 41B is disposed within the outer gear 41A so as to meshingly engage the outer gear 41A.
The hammer 42 is defined at the front side of a planetary carrier of the planetary gear mechanism 41B. The hammer 42 includes a first engaging protrusion 42A that protrudes forward and that is disposed at a position shifted from a rotational center of the planetary carrier of the planetary gear mechanism 41B, and a second engaging protrusion (not shown) that is located at a directly opposite position to the first engaging protrusion 42A with respect to the rotational center of the planetary carrier of the planetary gear mechanism 41B.
The anvil section 5 is disposed at the front side of the hammer section 4, and mainly includes an end-bit mounting section 51 and an anvil 52. The end-bit mounting section 51 has a cylindrical shape, and is rotatably supported in opening 23a of the hammer case 23 via the metal 23A. The end-bit mounting section 51 is formed with a bore 51a in the front-rear direction through which a bit (not shown) is detachably inserted. The end-bit mounting section 51 has a front end portion provided with a chuck 51A for holding a bit (not shown). The end-bit mounting section 51 serves as a bit mounting unit of the present invention.
The anvil 52 is provided integrally with the end-bit mounting section 51 at a position rearward of the end-bit mounting section 51 and within the hammer case 23. The anvil 52 includes a first engaged protrusion 52A and a second engaged protrusion 52B that protrude rearward and that are located at directly opposite positions with respect to the rotational center of the end-bit mounting section 51. When the hammer 42 rotates, the first engaging protrusion 42A and the first engaged protrusion 52A collide with each other and, at the same time, the second engaging protrusion (not shown) and the second engaged protrusion 52B collide with each other, which causes rotational force of the hammer 42 to be transmitted to the anvil 52.
As shown in
The control section 7 is mounted on a board that is disposed at a position adjacent to the battery 24 in the handle section 22. The control section 7 is connected to the battery 24, the trigger 25, the switch 26, the switching lever 27, the inverter circuit board 6, and the display section 26A as shown in
The rotational-position detecting elements 8 are provided at positions opposing permanent magnets 3C of the rotor 3A in the axial direction of the output shaft section 31, and are arranged in a circumferential direction of the rotor 3A with a predetermined interval (for example, an angle of 60 degrees) therebetween.
Next, the configuration of drive control system of the motor 3 will be described while referring to
A gate of each of the switching elements Q1-Q6 of the inverter circuit board 6 is connected to the control-signal outputting circuit 79 of the control section 7, and a drain or a source of each of the switching elements Q1-Q6 is connected to the stator windings U, V, and W of the stator 3B. The six switching elements Q1-Q6 performs switching operations based on switching-element driving signals inputted from the control-signal outputting circuit 79, and supplies to the stator windings U, V, and W the direct-current voltage of the battery 24 applied to the inverter circuit 6 as three-phase (U phase, V phase, and W phase) voltages Vu, Vv, Vw. Specifically, one of the stator windings U, V, and W to be energized, that is, the rotational direction of the rotor 3A is controlled based on output switching signals H1, H2, and H3 inputted to the positive side switching elements Q1, Q2, and Q3 from the control-signal outputting circuit 79. Further, an amount of supplying the stator windings U, V, and W with electric power, that is, the rotational speed of the rotor 3A is controlled based on pulse-width modulation signals (PWM signals) H4, H5, and H6 inputted to the negative side switching elements Q4, Q5, and Q6 from the control-signal outputting circuit 79.
The current detecting circuit 71 detects a value of current supplied to the motor 3 and outputs the detected value to the arithmetic section 78. The switch-operation detecting circuit 72 and the application voltage setting circuit 73 are electrically connected to the trigger 25. The switch-operation detecting circuit 72 detects whether the trigger 25 has been operated and outputs the detection result to the arithmetic section 78. The application-voltage setting circuit 73 outputs a signal based on an operation amount of the trigger 25 to the arithmetic section 78.
The rotational-direction setting circuit 74 is electrically connected to the switching lever 27. Upon detecting a switching operation of the switching lever 27, the rotational-direction setting circuit 74 outputs a signal for switching the rotational direction of the motor 3 to the arithmetic section 78.
The rotor-position detecting circuit 75 is electrically connected to the rotational-position detecting elements 8. The rotor-position detecting circuit 75 detects a rotational position of the rotor 3A based on signals from the rotational-position detecting elements 8, and outputs the detection result to the arithmetic section 78.
The rotational-angle detecting circuit 76 is for detecting an angle of the rotor 3 and for using the detected value when a control based on the rotations A based on a signal from the rotor-position detecting circuit 75 l angle is performed.
The arithmetic section 78 includes a central processing unit (CPU) (not shown) for outputting driving signals based on processing programs and data, an EEPROM 82 (storing unit) that is rewritable for storing data, and a timer (not shown). The CPU serves as a torque determining unit of the present invention. The EEPROM 82 stores the maximum value of tightening torque, the minimum value of tightening torque, the number of steps (division number), and a plurality of prescribed values that is obtained by equally dividing an interval between the maximum value and the minimum value by the number of steps. The number of steps is an integer value. Note that a minimum prescribed value of the prescribed values is the same as the minimum value, and that a maximum prescribed value of the prescribed values is the same as the maximum value. The above-mentioned maximum value, the minimum value, the number of steps, and the plurality of prescribed values are defined collectively as setting values. That is, the EEPROM 82 stores the maximum value of the tightening torque, the minimum value of the tightening torque, the number of steps, and the plurality of prescribed values as torque values calculated by dividing a torque range between the maximum value and the minimum value by the predetermined number. As will be described in greater detail, an operator can calculate the plurality of prescribed values by setting the maximum value and the minimum value each of the tightening torque and subsequently dividing the torque range into the number of steps. For example, assume that the maximum value of the torque is 5 Nm, the minimum value of the torque is 1 Nm, and the number of steps is 5. In this case, the torque range is 1 to 5, the predetermined number is 5, and hence the plurality of prescribed values (Nm) is 1, 2, 3, 4, and 5.
The arithmetic section 78 generates the output switching signals H1, H2, and H3 based on signals from the rotational-direction setting circuit 74 and the rotor-position detecting circuit 75, and generates the pulse-width modulation signals (PWM signals) H4, H5, and H6 based on signals from the application-voltage setting circuit 73, and outputs the generated signals to the control-signal outputting circuit 79. Note that the PWM signals may be outputted to the positive side switching elements Q1, Q2, and Q3, and the output switching signals may be outputted to the negative side switching elements Q4, Q5, and Q6.
The arithmetic section 78 is connected to the above-described switch 26. Based on an operation of the switch 26, one of the plurality of prescribed values stored in the EEPROM 82 is determined The arithmetic section 78 is connected to the display circuit section 80 receiving the signal therefrom. The display circuit section 80 is electrically connected to the display section 26A. The display circuit section 80 controls the display section 26A (the seven-segment display section 26B) based on the signal from the arithmetic section 78.
The PC 10 is a known personal computer and, as shown in
The operation-mode setting window 11 includes a connect button 11A, a set-value display area 11B, a setting-value input area 11C, a setting-value display area 11D, a read-in button 11E, a message display area 11F, a transmit button 11G, and an exit button 11H. The operation-mode setting window 11 is for setting the setting values such as the maximum value, the minimum value, and the number of steps, and for calculating the plurality of the prescribed values. The connect button 11A is clicked after the PC 10 is connected to the electronic pulse driver 1 via the cable 10A, and then the electronic pulse driver 1 is recognized on the PC 10. The set-value display area 11B displays setting values that are currently stored in the EEPROM 82 in the electronic pulse driver 1. The setting-value input area 11C is an area for inputting setting values that are newly rewritten. The setting-value display area 11D is an area for displaying step numbers and newly set setting values corresponding to the step numbers. The read-in button 11E is clicked after new setting values are inputted in the setting-value input area 11C, and then the inputted values are recognized as setting values. The message display area 11F displays a request to an operator or the like with respect to various conditions of the operation-mode setting window 11. When the transmit button 11G is clicked, values displayed in the setting-value display area 11D are transmitted to the electronic pulse driver 1 and then are stored in the EEPROM 82. When the exit button 11H is clicked, the operation-mode setting window 11 is closed and then the application software is ended.
A process of setting an operation mode in the electronic pulse driver 1 and the PC 10 will be described while referring to the flowchart in
In S04, the operator inputs a maximum value in the setting-value input area 11C. Next, in S05, the operator inputs a minimum value in the setting-value input area 11C. Next, in S06, the operator inputs the number of steps for obtaining prescribed values in the setting-value input area 11C. The maximum value and the minimum value can be set between 10 to 1 Nm and be set at one decimal place. The number of steps is 10 steps at maximum. In S07, when the read-in button 11E is clicked, the PC 10 determines whether the setting values inputted in the setting-value input area 11C can be displayed in the setting-value display area 11D (that is, whether the setting values inputted in the setting-value input area 11C can be set). Specifically, if a maximum value larger than the settable maximum value, i.e., 10, is inputted as shown in
If it is determined that the values can be displayed (the values can be set) (S07: Yes), the routine proceeds to S09 and the PC 10 displays, in the setting-value display area 11D, the step number (1, 2, . . . , 5 in the present embodiment) and torque values (prescribe values) corresponding to each of the step number. In
An operation of changing set torque values (a maximum value of 3.0 Nm, a minimum value of 1.0 Nm, the number of steps of 5) using the electronic pulse driver 1 will be described below. Note that, as shown in
Every time the switch 26 is pressed short, the step number increases by one, and can be changed from the minimum number of 1 to the maximum number of 5 as shown in the left side of
Accordingly, the operator presses the switch 26 short until a desired step number (torque value) is displayed. A desired setting value is displayed, and the setting value is stored in the EEPROM 82. As a method of storing the setting value, the setting value can be stored automatically if the switch 26 is not operated for a predetermined time or longer after the desired value is displayed, or the setting value can be stored by performing a predetermined operation with the switch 26. With the above-described operations, the operator can set a desired torque value. Note that, when the tightening operation is completed and the battery 24 is detached temporarily, and the like, the setting values may be reset, or the existing setting values may be retained.
With this configuration, because setting values can be changed, a wide range of tightening torque can be obtained with the electronic pulse driver 1. Further, because PC 10 is required to change the setting values and the like, inadvertent changes of the setting values and the like can be suppressed.
Next, a second embodiment of the invention will be described while referring to
Steps of setting an operation mode with the electronic pulse driver 101 will be described while referring to the flowchart of the arithmetic section 78 in
In this state, the CPU proceeds to S101, and first starts the setting of a minimum value. The above-described long press for 3 seconds or longer starts the setting mode and, at the same time, as shown in
Subsequently, the CPU proceeds to S106 and starts the setting of a maximum value. After the switch 26 is pressed long for 1 second or longer at the step of determining the minimum value (S103), as shown in
Subsequently, the CPU proceeds to S111 and starts the setting of the number of steps. After the switch 26 is pressed long for 1 second or longer at the step of determining the maximum value (S108), as shown in
Next, the CPU proceeds to S116 and performs a review of the setting values. After the switch 26 is pressed long for 1 second or longer at the step of determining the number of steps (S113), a setting-value review mode is started. Specifically, as shown in
Because the setting range of tightening torque can be changed in both of the first embodiment and the second embodiment, a wide range of tightening torque can be dealt with by a single power tool. In particular, in the first embodiment, setting of an electronic pulse driver which is an example of a power tool is performed with a PC which is an example of an external device. Thus, an unintentional change of the setting values by an operator can be suppressed. Further, because an external device is not required in the second embodiment, the setting values can be changed easily and, when necessary, the setting values can be changed easily.
With this configuration, because a range of prescribed values affecting operations of the motor or the number of steps can be set arbitrarily, a wide range of operations can be performed with a single power tool. Further, prescribed values affecting operations of the motor can be changed on the power tool itself, facilitating changes of the prescribed values or the like.
With this configuration, because a maximum value, a minimum value and a plurality of prescribed values can be changed, a wide range of tightening torque can be obtained with a single power tool. Further, because the setting values and the like can be changed on the power tool itself, changes of the setting values and the like become easier.
While the power tool and the operation-mode change system of the power tool according to the invention have been described in detail with reference to the above aspects thereof, it would be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the claims.
For example, in the second embodiment, because settings are performed only with the power tool, there is a possibility that settings cannot be performed well when the remaining amount of the battery is low. Thus, it may be so configured that a battery remaining-amount detecting circuit is provided in the control section for detecting the remaining amount of the battery, and that settings are prohibited based on a detection result of the battery remaining-amount detecting circuit
Further, in the above-described embodiment, a PC which is a general-purpose product is described as an example of an external device. However, the external device is not limited to a PC, but may be a special device for changing the operation mode and the setting values. Further, in the second embodiment, both of the manipulation mode and the change mode are implemented with the switch 26. However, the method is not limited to this, but a special operating section may be provided for each of the manipulation mode and the change mode.
Further, in the above-described embodiment, an electronic pulse driver is described as an example of a power tool. However, the power tool is not limited to this, but may be a tool that rotates an end bit with a motor, for example, a driver drill.
Further, the use is applicable for various works such as tightening of distribution boards, assembling of electronic appliances, assembling of automobiles, and the like.
Further, the power tool of the second embodiment may be configured to be connectable to an external device like the first embodiment. With this configuration, an operation mode can be changed with each of the power tool itself and the external device.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-052457 | Mar 2012 | JP | national |
