IP Library Granted Patent US 10,886,764
Granted Patent B2
US 10,886,764 · App. 15/536,946 · Granted Jan 5, 2021

Power tool

Inventors: Yoshikazu Kawano (Hitachinaka, JP); Kazuhiko Funabashi (Hitachinaka, JP); Toshiaki Koizumi (Hitachinaka, JP); Hironori Mashiko (Hitachinaka, JP)
Assignee: Koki Holdings Co., Ltd.
H02J7/0063B25F5/00B25F5/02H01M10/486H01M10/48H01M2220/30H02J7/0029H02J7/00036H02J2007/0067
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Quick Facts
Patent No.
US 10,886,764
App. No.
15/536,946
Granted
Jan 5, 2021
Kind
B2
Abstract

A power tool includes: a battery connecting part to which one of a first battery pack and a second battery pack having capacity smaller than that of the first battery pack is detachably attachable; a motor driven by electric power supplied from the battery pack; current detection means configured to detect a discharge current flowing from the battery pack to the motor; cut-off controlling means configured to cut off the discharge current when the discharge current becomes equal to or larger than a current threshold; and battery type discrimination means configured to discriminate the battery pack connected to the battery connecting part. The current threshold when the second battery pack is connected to the battery connecting part is lower than that when the first battery pack is connected to the battery connecting part.

Claims (19)

1. A power tool comprising:

a battery connecting part to which a battery pack is detachably attachable;

a motor driven by electric power supplied from the battery pack; and

a controller configured to:

detect a discharge current which flows from the battery pack to the motor;

when a specific condition on the discharge current is met, cut off the discharge current; and

discriminate a battery type of the battery pack connected to the battery connecting part,

wherein the specific condition is changed in accordance with the battery type of the battery pack

wherein the specific condition is met when a state where the discharge current is equal to or larger than an overcurrent threshold continues for a specific time period,

wherein when the discharge current is equal to a first current value which is equal to or larger than the overcurrent threshold, the specific time period is a first time period, and

wherein when the discharge current is equal to a second current value which is larger than the first current value, the specific time period is a second time period which is shorter than the first time period.

2. The power tool according to claim 1 , wherein the controller is further configured to:

detect a battery temperature of the battery pack, and

when the battery temperature is equal to or higher than a temperature threshold, cut off the discharge current regardless of whether the specific condition is met.

3. The power tool according claim 1 , further comprising an accommodation case accommodating the controller,

wherein the controller is configured to be connected to the battery pack through a lead wire, and

wherein the accommodation case has a rib portion holding the lead wire.

4. The power tool according to claim 1 , wherein the controller is further configured to cut off the discharge current when a discharge stop signal is outputted from the battery pack connected to the battery connecting part.

5. The power tool according to claim 1 , wherein the overcurrent threshold differs depending on a capacity of the battery pack.

Assignments (2)
CHANGE OF NAME Recorded Jul 26, 2018
From: HITACHI KOKI KABUSHIKI KAISHA
To: KOKI HOLDINGS CO., LTD.
Reel/Frame 047270/0107 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 16, 2017
From: KAWANO, YOSHIKAZU; FUNABASHI, KAZUHIKO; KOIZUMI, TOSHIAKI; MASHIKO, HIRONORI
To: HITACHI KOKI CO., LTD.
Reel/Frame 042733/0190 →
Priority Claims (1)
JP 2014-256730 · Dec 18, 2014 · national
Continuity (1)
Related Publication 20180048173A1 · Feb 15, 2018
Cited By (4)
US 12,206,353 US 12,551,072 US 12,620,828 US 12,633,486