JP2020082241A - Electric tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric tool in which a large reaction from a tool body is not transmitted to an operator.
SOLUTION: An electric screwdriver (electric power tool) 100 can be attached with an auxiliary tool 150 for releasing a reaction from a rotation drive unit of an electric screwdriver main body (tool main body) 102. The detection unit 110 detects whether or not the auxiliary tool 150 is attached, and the torque control unit controls the output torque of the rotary drive unit based on the target torque value according to the result. When the auxiliary tool 150 is not attached, the target torque value is limited to the upper limit value for single use or less.
[Selection diagram] Figure 1

Description

The present invention relates to an electric power tool having an auxiliary tool.

Some rotary tools such as electric screwdrivers are capable of varying the output torque according to the work content. With such a rotary tool, a large reaction force is applied to the worker when the output is set to a high torque, which is dangerous. Therefore, when a comparatively large torque is generated, an electric tool that notifies the operator in advance and warns the operator and (Patent Document 1), the instantaneous reaction force generated when the tool is used is transmitted to the operator. There is an electric tool equipped with a shockless stand that can suppress the damage (Patent Document 2).

International Publication No. 2018/088443 JP, 2013-71202, A

If the shockless stand is removed from the rotary tool after the rotary tool set to the high torque is attached to the shockless stand to perform the work, the rotary tool remains set to the high torque. If you work with the rotary tool in this state without using the shockless stand, the reaction that was suppressed by the shockless stand will be transmitted to the worker, and the worker will not be able to hold the rotary tool correctly and the output torque will vary. Occurs, and there is a problem that work cannot be performed with an appropriate tightening torque, or the rotary tool falls apart from the operator's hand in some cases and falls.

In view of the above-mentioned problems of the conventional technique, it is an object of the present invention to provide an electric power tool capable of detecting that a shockless stand is removed from a rotary tool and changing the output torque.

That is, the present invention is
A tool body having a rotation drive part, to which a tool for receiving a reaction generated by the rotation drive part and allowing the reaction to escape from the tool body can be attached,
Detection means for detecting the attachment state of the auxiliary tool to the tool body,
Torque control means for controlling the output torque of the rotation drive unit based on a target torque value,
Equipped with
When the detection means detects that the auxiliary tool is not attached, the torque control means limits the torque target value to a value equal to or lower than the upper limit value during single use, which is lower than the upper limit value during auxiliary tool use. Provide a power tool.

The power tool has an upper limit value of torque that can be output when it is used alone without an auxiliary tool attached, and the auxiliary tool was removed from the tool body to limit the torque target value to the set upper limit value or less when used alone. In this case, a large reaction force is prevented from being transmitted to the worker, the worker cannot hold the power tool correctly, and the output torque varies, or the power tool falls away from the worker's hand in some cases. It becomes possible to prevent the person from getting stuck.

Specifically, the upper limit value for single use can be set to 0 Nm.

By doing so, it is possible to prevent work that is out of the specified specifications.

Preferably, the electric tool is an electric screwdriver for tightening a screw, and the torque control means can set a tightening torque set value for setting a tightening torque of the screw of the electric driver. When the detection means detects that the auxiliary tool is attached, the torque control means can set the torque target value to a preset tightening torque set value.

Preferably, a notification means for notifying the attachment state of the auxiliary tool can be provided.

The present invention also provides an electric power tool system including an electric power tool having the above-described function, and an auxiliary tool that is attached to the tool main body and that receives the reaction from the tool main body to allow the reaction to escape from the electric power tool. The purpose is to

Embodiments of an electric power tool according to the present invention will be described below with reference to the accompanying drawings.

It is an external view of the electric driver which concerns on the 1st Embodiment of this invention. It is a block diagram of the electric screwdriver concerning a 1st embodiment of the present invention. It is an external view of the electric driver which concerns on the 2nd Embodiment of this invention.

As shown in FIG. 1, the electric power tool system 1 according to the first embodiment of the present invention includes an electric screwdriver (electric power tool) 100 and a shockless stand as an auxiliary tool 150. As shown in FIGS. 1 and 2, the electric screwdriver 100 has an electric screwdriver main body (tool main body) 102 having a bit holder 144 rotatably driven by a built-in electric motor 140, and is arranged in the electric screwdriver main body 102. And a control circuit 120. A driver bit 146 appropriately selected according to a screw to be tightened is detachably attached to the bit holder 144. The electric driver main body 102 is further provided with an interface section 130 having an LED display section 132 and a plurality of operation buttons 134. The electric driver 100 includes a start switch for starting the electric motor 140 in the electric driver main body 102. This start switch is turned on by pressing the driver bit 146 attached to the bit holder 144 against the screw, thereby starting the driving of the electric motor 140.

The electric driver 100 further includes a torque sensor 142 for detecting the output torque of the electric motor 140. Further, the control circuit 120 has an arithmetic unit 124 for performing various arithmetic processes and a memory 126 for storing data such as setting parameters. The setting parameter can be changed by the operation button 134 of the interface unit 130 or a sequencer (not shown) connected by wire communication to the electric driver main body 102. The communication connection can be a wireless connection or a wired connection, and it is also possible to change the setting parameters by connecting a remote controller or a computer instead of the sequencer. The setting parameter may include items such as a tightening torque setting value that is a value of the screw tightening torque, a rotation speed, a rotation time, and the like as necessary.

The control circuit 120 includes a torque control unit 122 for changing the setting of the tightening torque of the screw. Specifically, the torque control unit 122 controls the torque of the electric motor 140 by appropriately controlling the electric power supplied to the electric motor 140 based on the magnitude of the torque detected by the torque sensor 142. The control circuit 120 determines the torque target value based on the preset tightening torque setting value, and the torque control means 122 controls the tightening torque applied to the screw to be the torque target value. However, the tightening torque applied to the screw may be temporarily higher than the torque target value due to the influence of the inertial force of the electric motor 140 and the like. It is preferable to set the torque target value in consideration of such influence.

The electric screwdriver 100 may be configured to be able to automatically change the set value when it becomes necessary to change the magnitude of the tightening torque. Setting parameters used in each process in a series of work including a plurality of tightening processes can be stored in advance in the memory 126, and the arithmetic unit 124 can move to the next process at the end of each process. The setting parameters used in the step (1) are read from the memory 126, and the setting of the electric driver 100 is automatically changed. For example, assuming that the first step is a tightening operation for the same four screws and the second step is a tightening operation for two screws different from the screw in the first step, the four screws in the first step The electric screwdriver 100 is driven under the first setting parameter at the time of tightening, and when the first step is completed, the calculation unit 124 changes the setting to the second setting parameter for the second step. In the second step, the electric screwdriver 100 is driven based on the setting (second setting parameter) until the tightening of the two screws is completed. After that, similarly, the setting parameters are automatically changed to the setting parameters for the next step each time each step is completed.

The electric screwdriver 100 further includes a hall sensor (detection state) that detects a mounting state of the auxiliary tool 150 that receives the reaction generated by the rotation driving unit including the electric motor 140, the bit holder 144, the driver bit 146, and the like and escapes the reaction from the electric driver main body 102. Means) 110. The hall sensor 110 detects that the auxiliary tool 150 is attached and sends a detection signal to the control circuit 120. The control circuit 120 monitors the detection signal and determines the attachment state of the auxiliary tool 150.

The torque control means 122 of the control circuit 120 is adapted to change the torque target value in accordance with the detected state of the auxiliary tool 150. For example, when the hall sensor 110 detects the state where the auxiliary tool 150 is attached to the electric driver main body 102, the control circuit 120 determines that the auxiliary tool 150 is attached to the electric driver main body 102, and the torque control means. Reference numeral 122 sets the torque set value when using the auxiliary tool stored in the setting parameter as the torque target value. The torque setting value when using the assisting device can be set only at a value equal to or lower than a predetermined upper limit value when using the assisting device. When the hall sensor 110 cannot detect the state in which the auxiliary tool 150 is attached to the tool body 102, the control circuit 120 determines that the auxiliary tool 150 is not attached to the electric driver main body 102, and the torque control unit 122 sets the setting parameter. Set the torque setting value for single use stored in to the target torque value. The torque set value for single use can be set only at a value equal to or lower than the predetermined upper limit value for single use. The upper limit value when using the assisting tool is the maximum output setting value of the electric driver 100 in the present invention, and the upper limit value when using the assisting tool is a value smaller than the upper limit value when using the assisting tool. The upper limit value for single use is set to a value that does not cause recoil that affects work even if the auxiliary tool 150 is not attached.

The lower limit value of the settable range of the torque set value when using the auxiliary tool is 0 Nm. This value can be arbitrarily changed and is preferably not more than the upper limit value when used alone.

As described above, the torque setting value for single use is set to a value not more than the upper limit value for single use. If the torque setting value when using the assistive device is less than or equal to the upper limit value during single use, the torque setting value during single use is preferably the same value as the torque setting value when using the auxiliary device, but is not limited to this. It is not something that will be done.

When the hall sensor 110 detects the state in which the auxiliary tool 150 is not attached and the auxiliary tool 150 is attached, the torque setting unit 122 of the control circuit 120 uses the auxiliary tool whose torque target value is set in advance. Torque setting value (tightening torque setting value).

By setting the torque target value to 0 Nm, the driving of the electric driver 100 can be stopped. For example, by setting the torque set value for single use stored in the setting parameter in advance to 0 Nm, the auxiliary tool 150 can be used during the screw tightening work using the auxiliary tool 150. When the auxiliary tool 150 comes off, the torque control means 122 switches the tightening torque set value set as the target torque value from the torque set value when the auxiliary tool is used to the torque set value when the auxiliary tool is used independently. The drive of the rotary drive unit of the electric driver body 102 is stopped. By doing so, it is possible to prevent the work from deviating from the specifications set for each process.

In accordance with the detection state of the hall sensor 110, the control circuit 120 drives the LED display unit 132 and the buzzer 136 of the interface unit 130 as a notification unit, so that the worker can be notified of the attachment state of the auxiliary tool 150. .. The notification means is appropriately selected from various forms depending on the type and presence of the control circuit 120.

As shown in FIG. 3, the electric power tool system 2 according to the second embodiment of the present invention includes an electric screwdriver (electric power tool) 200 and a pistol grip as an auxiliary tool 250. The electric power tool 200 in the second embodiment is the same as the electric power tool 100 in the first embodiment, and therefore its explanation is omitted.

In the electric tool system according to the third embodiment of the present invention, the state in which the auxiliary tool is attached cannot be detected from the state in which the detection means detects that the auxiliary tool is attached to the electric driver main body, and the control circuit is electrically driven. When it is determined that the driver main body is not equipped with the auxiliary tool, the torque control means requires an operator's operation when changing the setting of the torque target value. Specifically, when the control circuit determines that the auxiliary tool is not attached to the electric driver body, the notification means notifies the worker of the attachment state of the auxiliary tool, and at the same time, the control circuit puts the electric driver in the standby state. The electric motor of the electric driver cannot be rotationally driven. When the operator operates the interface section of the electric driver in the standby state and removes the auxiliary tool to allow the torque target value to become the torque set value for single use, the torque control means sets the setting. Set the torque setting value stored in the parameter for single use as the target torque value. If the operator refuses to set the torque target value to the torque setting for single use, that is, if the auxiliary tool is detached and it is permitted to use the torque setting value for using the auxiliary tool, The torque control means sets the torque set value when the auxiliary tool is used, which is stored in the setting parameter, to the torque target value.

The electric screwdriver has been described above as an embodiment of the electric power tool of the present invention, but the present invention is not limited to this, and various modifications as described below are possible.

In the above embodiment, the detection of the auxiliary tool 150 is performed by the hall sensor 110, but it can also be realized by a photoelectric sensor or an electrical contact. As with the Hall sensor, a photoelectric sensor and electrical contacts are provided so that the auxiliary tool can be detected, and a detection signal is sent to the control circuit for detection.

In the above-described embodiment, the tightening torque control performed by the torque control unit 122 is performed by electrical control by controlling the electric power supplied to the electric motor 140. It may be realized by mechanical control by changing the setting. In a mechanical clutch mechanism, one of the two clutch plates is normally biased by a spring toward the other clutch plate, and the power transmission between the clutch plates is released by the screwing operation. It is like this. Therefore, the magnitude of the clutch operation starting torque, that is, the torque target value can be changed by adjusting the biasing force of the spring. When such a clutch mechanism is adopted, the torque control means acquires the current torque target value based on a signal from a sensor that directly or indirectly detects the biasing force of the spring, or By providing a mechanism for changing the biasing force of the spring based on an external signal, the torque control means transmits a signal related to the torque target value to the clutch mechanism to change the clutch operation start torque of the clutch mechanism. The torque target value can be changed.

The present invention can be applied not only to an electric screwdriver but also to an electric tool such as an electric drill.

Electric screwdriver (electric power tool) 100; Electric screwdriver main body (tool main body) 102; Hall sensor 110; Control circuit 120; Torque control means 122; Arithmetic unit 124; Memory 126; Interface unit 130; LED display unit 132; Operation button 134; Buzzer 136; Electric Motor 140; Torque Sensor 142; Bit Holder 144; Driver Bit 146; Auxiliary Tool 150; Electric Driver (Electric Tool) 200; Auxiliary Tool 250;

Claims (5)

A tool body having a rotation drive part, to which a tool for receiving a reaction generated by the rotation drive part and allowing the reaction to escape from the tool body can be attached,
Detection means for detecting the attachment state of the auxiliary tool to the tool body,
Torque control means for controlling the output torque of the rotation drive unit based on a target torque value,
Equipped with
When the detection means detects that the auxiliary tool is not attached, the torque control means limits the torque target value to a value equal to or lower than the upper limit value during single use, which is lower than the upper limit value during auxiliary tool use. Power tools that are. The power tool according to claim 1, wherein the upper limit value when used alone is 0 Nm. The electric power tool is an electric screwdriver for tightening a screw, and a tightening torque set value for setting a screw tightening torque of the electric screwdriver can be set in the torque control means. The electric power tool according to claim 1 or 2, wherein the torque target value is set as a preset tightening torque set value when the detecting means detects that the auxiliary tool is attached. The electric power tool according to any one of claims 1 to 3, further comprising a notification unit that notifies a mounting state of the auxiliary tool. An electric power tool system comprising: the electric power tool according to any one of claims 1 to 4; and an auxiliary tool that is attached to the tool main body and that receives the reaction from the tool main body to allow the reaction to escape from the electric power tool. ..

Images