Work tool

1. A work tool comprising:

a main body to which an attachment device is connectable, the main body comprising:

a drive source;

a work part configured to be driven by the drive source to perform a work;

a handle;

a manipulation part configured to be operated by a user to drive the drive source;

an assisting part configured to assist the work; and

a control circuit configured to perform at least one of:

a control over the drive source; and

a control over the assisting part,

the control circuit being configured to perform:

(a) detecting whether or not the attachment device is connected to the main body; and

(b) changing the at least one of the control over the drive source and the control over the assisting part depending on whether or not the attachment device is connected to the main body;

wherein the control circuit is configured to perform the control over the drive source comprising (d) controlling the drive source, and

wherein the (b) changing comprises (e) changing the (d) controlling, depending on whether or not the attachment device is connected to the main body;

wherein, when the (a) detecting detects that the attachment device is not connected to the main body, the (e) changing sets a maximum rotation speed of the drive source to a first rotation speed, and

wherein, when the (a) detecting detects that the attachment device is connected to the main body, the (e) changing sets the maximum rotation speed of the drive source to a second rotation speed lower than the first rotation speed.

2. The work tool as claimed in claim 1 ,

wherein the (b) changing comprises (c) changing, depending on whether or not the attachment device is connected to the main body, an operation state of the assisting part during the work between an active state and a non-active state.

3. The work tool as claimed in claim 2 , wherein, when the (a) detecting detects that the attachment device is not connected to the main body, the (c) changing sets the operation state of the assisting part during the work to the active state, and

wherein, when the (a) detecting detects that the attachment device is connected to the main body, the (c) changing sets the operation state of the assisting part during the work to the non-active state.

4. The work tool as claimed in claim 3 , wherein the assisting part is a light configured to irradiate light toward a work spot at which the work part performs the work,

wherein the attachment device connected to the main body is positioned between the light and the work spot.

5. The work tool as claimed in claim 1 , wherein the drive source is a motor, wherein the manipulation part is configured to receive user's manual operations including a starting operation to start driving the motor and a stop operation to stop driving the motor wherein, when the manipulation part receives the starting operation,

the control circuit performs the (a) detecting, and

the (d) controlling performs (f) controlling the motor such that a rotational speed of the motor reaches a target rotational speed at a timing when a time period elapses from a timing when the manipulation part receives the starting operation,

wherein, when the (a) detecting detects that the attachment device is not connected to the main body, the (e) changing sets the time period to a first time period, and

wherein, when the (a) detecting detects that the attachment device is connected to the main body, the (e) changing sets the time period to a second time period longer than the first time period.

6. The work tool as claimed in claim 1 , wherein the (d) controlling further performs (g) halting the motor when the manipulation part receives the stop operation, and

wherein the control circuit is configured to further perform (h) stopping the attachment device after the (d) controlling performs the (g) halting.

7. The work tool as claimed in claim 1 , wherein the main body further comprises an acceleration sensor configured to detect an acceleration of the main body, wherein the control circuit is configured to perform the control over the drive source comprising (i) controlling the drive source, and

wherein, when the acceleration detected by the acceleration sensor exceeds an acceleration threshold value, the (i) controlling stops driving the drive source.

8. The work tool as claimed in claim 7 , wherein the (b) changing further comprises (j) changing the acceleration threshold value depending on whether or not the attachment device is connected to the main body.

9. The work tool as claimed in claim 1 , wherein the attachment device comprises:

an attachment-device motor configured to be driven upon receipt of power supply from the main body in a state where the attachment device is connected to the main body; and

a switch switchable between a first state allowing the power supply to the attachment- device motor and a second state interrupting the power supply,

wherein the main body includes a signal line connected to the switch in the state where the attachment device is connected to the main body, and

wherein the (a) detecting is performed by outputting a control signal to the signal line, the control signal being for bringing the switch into the first state.

10. The work tool as claimed in claim 9 , wherein the attachment device further comprises an attachment-device-side resistor, the attachment-device-side resistor being connected to the signal line in the state where the attachment device is connected to the main body,

wherein the signal line includes a main-body-side resistor having one end and another end, the one end being connected to the control circuit the another end being connected to the attachment-device-side resistor in the state where the attachment device is connected to the main body,

wherein the (a) detecting is performed using a divided voltage, the divided voltage being obtained by dividing a voltage of the control signal by the attachment-device-side resistor and the main-body-side resistor.

11. The work tool as claimed in claim 1 , wherein the attachment device is a dust collector configured to generate negative pressure at a work spot at which the work is performed by the work part.

12. The work tool as claimed in claim 1 , wherein the work tool is a drilling tool.

13. A work tool comprising:

a main body to which an attachment device is connectable, the main body comprising:

a drive source;

a work part configured to be driven by the drive source to perform a work;

a handle;

a switch part configured to be operated by a user to drive the drive source; and

a light configured to irradiate light toward a work spot at which the work part performs the work,

a part of the attachment device being positioned between the light and the work spot in a state

where the attachment device is connected to the main body; and

a control circuit configured to perform a control over the light, the control circuit being configured to perform:

(a) detecting whether or not the attachment device is connected to the main body; and

(b) changing the control over the light depending on whether or not the attachment device is connected to the main body,

wherein, when the (a) detecting detects that the attachment device is not connected to the main body, the (b) changing sets an operation state of the light during the work to an active state, and

wherein, when the (a) detecting detects that the attachment device is connected to the main body, the (b) changing sets the operation state of the light during the work to a non-active state.

14. The work tool as claimed in claim 13 , wherein the attachment device comprises an attachment-device-side light configured to irradiate light toward the work spot, and

wherein, when the (a) detecting detects that the attachment device is connected to the main body, the (b) changing sets an operation state of the attachment-device-side light during the work to an active state.

15. The work tool as claimed in claim 13 , wherein the (b) changing is performed in response to a user's operation to the switch part.

16. The work tool as claimed in claim 13 , wherein the main body is further configured to detachably receive a battery configured to supply power to the drive source, and

wherein the light is configured to receive power from the battery attached to the main body.

17. The work tool as claimed in claim 13 , wherein the main body further comprises a main-body-side terminal connectable to the attachment device for supplying power to the attachment device in a state where the attachment device is connected to the main body,

wherein the (a) detecting is performed using the main-body-side terminal.

18. The work tool as claimed in claim 17 , wherein the main-body-side terminal is provided on a front portion of the main body at a position below the light.

19. A work tool comprising:

a main body to which an attachment device is connectable, the main body comprising:

a drive source;

a work part configured to be driven by the drive source to perform a work;

a handle; and

a switch part configured to be operated by a user to drive the drive source; and

a control circuit configured to perform a control over the drive source, the control circuit being configured to perform:

(a) detecting whether or not the attachment device is connected to the main body; and

(b) changing the control over the drive source depending on whether or not the attachment device is connected to the main body;

wherein the drive source is a motor,

wherein the switch part is configured to receive user's manual operations including a starting operation to start driving the motor and a stop operation to stop driving the motor,

wherein, when the switch part receives the starting operation,

the control circuit performs the (a) detecting, and

the (b) changing performs (c) controlling the motor such that a rotational speed of the motor reaches a target rotational speed at a timing when a time period elapses from a timing when the switch part receives the starting operation,

wherein, when the (a) detecting detects that the attachment device is not connected to the main body, the (c) controlling sets the time period to a first time period, and

wherein, when the (a) detecting detects that the attachment device is connected to the main body, the (c) controlling sets the time period to a second time period longer than the first time period.