Apparatus and method for detecting failure in holding tool of machine tool

Patent metadata

Field	Value
Publication number	US-12172256-B2
Application number	US-202218046512-A
Country	US
Kind code	B2
Filing date	Oct 14, 2022
Priority date	Nov 2, 2021
Publication date	Dec 24, 2024
Grant date	Dec 24, 2024

Abstract

Provided is an apparatus for detecting a failure in holding a tool of a machine tool that includes, in each of a plurality of tool holding mechanisms in a tool magazine, a locking member provided to have different self-displacement positions for a case where a tool is held at a proper held position between tool gripping portions of a pair of holding arms and a case where the tool is held with deviation from the proper held position, and that detects a holding failure state of the tool in the tool holding mechanism by detecting the position of a detection target portion that moves integrally with the locking member with a predetermined detector provided in the machine tool. The apparatus makes it possible to effectively prevent a risk of a breakdown of and damage to the machine tool.

First claim

What is claimed is:

1. An apparatus for detecting a failure in holding a tool of a machine tool including a tool magazine that holds a plurality of tools in an attachable/detachable manner, and configured to use one tool of the plurality of tools by selectively and exchangeably attaching the one tool to a machining spindle, the apparatus comprising:
a plurality of tool holding mechanisms configured to hold the tools and provided to the tool magazine,
wherein each of the tool holding mechanisms includes
a pair of holding arms that extend from one end side to an other end side and include tool gripping portions provided on the one end side to grip the tool,
a pair of supports that are provided at intermediate points of the pair of holding arms in an extending direction,
an urging member that is provided between the pair of holding arms at a location adjacent to the other end side of the holding arms and urges the tool gripping portions in a tool gripping direction via the supports,
a locking member that is interposed between the pair of holding arms and provided at a location closer to the other end side than a location where the urging member is provided, and is movable between a locking position where the locking member causes the pair of holding arms to continue gripping the tool with the tool gripping portions and a release position where the locking member allows displacement to cause the pair of holding arms to discontinue gripping the tool with the tool gripping portions, and
a detection target portion, which moves integrally with the locking member, a position of which is detected by a predetermined detector, and
wherein the pair of holding arms inhibit return of the locking member to the locking position in a case where the position of the tool held by the tool gripping portions has deviated from a proper held position.

2. The apparatus for detecting a failure in holding a tool of a machine tool according to claim 1 ,
wherein the detector is fixed to a predetermined portion of the machine tool, and functions as a single detector that is common to the detection target portion of each of the plurality of tool holding mechanisms.

3. The apparatus for detecting a failure in holding a tool of a machine tool according to claim 1 ,
wherein each of the tool gripping portions of the pair of holding arms has a gripping curved surface corresponding to an outer peripheral surface of a cylindrical portion of the tool or a tool holding body integrated with the tool.

4. The apparatus for detecting a failure in holding a tool of a machine tool according to claim 1 ,
wherein the machine tool operates under control of a predetermined controller, and the controller monitors a detection output from the detector, and in a case where the detection output indicating return of the locking member to the locking position is not received within a predetermined period of time following issuance of a control command to return the locking member to the locking position after causing the locking member to move to the release position, the controller issues an output indicating determination of a failure in holding the tool for the tool.

5. A method for detecting a failure in holding a tool of a machine tool including a tool magazine that holds a plurality of tools in an attachable/detachable manner, and configured to use one tool of the plurality of tools by selectively and exchangeably attaching the one tool to a machining spindle, the tool magazine including a plurality of tool holding mechanisms that hold the tools, each of the tool holding mechanisms including a pair of holding arms that extend from one end side to an other end side and include tool gripping portions provided on the one end side to grip the tool, a pair of supports that are provided at intermediate points of the pair of holding arms in an extending direction, an urging member that is provided between the pair of holding arms at a location adjacent to the other end side of the holding arms and urges the tool gripping portions in a tool gripping direction via the supports, and a locking member that is interposed between the pair of holding arms and provided at a location closer to the other end than a location where the urging member is provided, and is movable between a locking position where the locking member causes the pair of holding arms to continue gripping the tool with the tool gripping portions and a release position where the locking member allows displacement to cause the pair of holding arms to discontinue gripping the tool with the tool gripping portions, the method comprising:
a positioning step of causing one of the tool gripping mechanisms in the tool magazine to move to a position where the tool gripping mechanism faces one tool;
a locking release step of causing the locking member to retract from the locking position to the release position;
a gripping step of causing the one tool to advance into a gap between the tool gripping portions of the pair of holding arms;
a returning step of causing the locking member to return to the locking position; and
a determination step of determining a failure in holding the tool in a case where a detection output from a detector indicating return of the locking member to the locking position is not issued within a predetermined period of time following a start of the returning step.

6. The method for detecting a failure in holding a tool of a machine tool according to claim 5 ,
wherein in the determination step, detection of the position of the locking member is performed using the detector that functions as a single detector common to the plurality of tool holding mechanisms.

7. The method for detecting a failure in holding a tool of a machine tool according to claim 5 ,
wherein in the determination step, detection of the position of the locking member is performed using a non-contact-type detector.

8. The method for detecting a failure in holding a tool of a machine tool according to claim 7 , wherein a magnetic sensor is used as the non-contact-type detector.

Assignees

• Honda Motor Co Ltd

Inventors

• Nagaoka Shuma
• Yuzuri Yuki
• Tanaka Toshiyuki

Classifications

• B23Q3/15706

  a single tool being inserted in a spindle directly from a storage device, i.e. without using transfer devices (B23Q3/15786 takes precedence) · CPC title

• B23Q3/15506

  the tool being inserted in a tool holder directly from a storage device (without transfer device) · CPC title

• B23Q3/15539

  Plural magazines, e.g. involving tool transfer from one magazine to another (involving manual operation B23Q3/15533) · CPC title

• B23Q2003/15527

  the storage device including means to latch tools · CPC title

• B23Q3/15553 Primary

  Tensioning devices or tool holders, e.g. grippers (driving working-spindles and adjusting or stopping them in a predetermined angular position B23Q5/20; securing milling cutters to the driving spindle in a given angular position B23C5/26) · CPC title