JPH065853U - Tool breakage detection device - Google Patents

Abstract

(57) [Abstract] [Purpose] An NC machine tool equipped with an automatic tool changer is capable of detecting tool damage reliably and at high speed without loss of machining time. [Structure] Tool 10 stored in tool magazine 20
Is taken out to a predetermined position E other than the machining area, and the tool length is measured at the taken-out position E using the optical sensor 3 and the time measuring means 2. The measured tool length is compared with the regular length of the tool stored in advance in the storage means 4, and if they do not match, it is determined that the tool is broken, and the alarm means 7 issues an alarm.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a tool breakage detection device for an NC machine tool having a tool magazine, and relates to a tool breakage detection device for detecting tool breakage in a tool magazine without impairing smooth machining processing.

[0002]

[Prior art]

 Conventionally, in order to detect the broken state of the tool used in NC machine tools, the tool length is detected with the tool set on the spindle, and if the tool length does not match the regular length, the tip end is detected. A tool breakage detection device has been proposed, which is configured to judge that the tool is in a broken state such as a chipped part. For example, in Japanese Unexamined Patent Publication (Kokai) No. 54-5282, a measuring element is brought into contact with a tool attached to a spindle, and position information of the measuring element is generated as an electric signal at the time of contact with a tool. The tool breakage is detected by electrically detecting the length from the reference position to the tool tip position.

[0003]

[Problems to be solved by the device]

 As described above, the conventional tool breakage detecting device measures the tool length by bringing the probe into contact with the tool set on the spindle of the NC machine tool to obtain an electric signal. By the way, in recent years, multiple tools have been stored in a tool magazine, and suitable tools are automatically replaced according to the contents of the machining program and attached to the spindle to speed up machining processing. ATC (Automatic Tool Changer) Is widely used in NC machine tools. The NC machine tool attached to the ATC is characterized by high-speed machining.

However, the above-described conventional tool breakage detection device detects the tool breakage by directly contacting the probe attached to the tool attached to the spindle, and therefore, when the tool breakage is detected, the machining operation of the NC machine tool is performed. Had to be stopped, which was a major factor in hindering high-speed processing. In the NC machine tool attached to ATC, this must be detected every time the tool is changed, so this problem becomes particularly apparent. In addition, the stylus for detecting tool damage is installed near the spindle in the machining area, limits the movement range of the spindle (tool), and measures chips and cutting oil generated during machining. It adhered to the child and caused a malfunction.

Therefore, an object of the present invention is to provide a tool breakage detection device which reliably and quickly detects breakage of a tool while maintaining high-speed machining without loss of machining time.

[0006]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, a tool breakage detecting device according to the present invention is an NC machine tool having an automatic tool changing device, and a tool which is taken out from a tool magazine and positioned at a predetermined position is provided with a light emitting part and a light receiving part. A positioning actuator that moves an optical sensor sandwiching the tool at the predetermined position from a reference position on one end side of the tool toward the other end side, and a light reception signal obtained from a light receiving unit of the optical sensor. The tool length measuring means for measuring the length corresponding information of the tool based on the timing, the storage means for storing the normal length corresponding information of the tool stored in advance in the tool magazine, and the tool length measuring means. Comparison means for comparing the obtained length correspondence information with the normal length correspondence information of the tool read from the storage means, and the comparison means for detecting a mismatch Constructed and a alarm means for indicating that the tool is damaged when.

[0007]

[Action]

 In the present invention, not the tool attached to the spindle, but the tool stored in the ATC magazine is taken out to a predetermined position other than the machining area, and the tool length is measured at the taken-out position using an optical sensor, The broken state is detected by comparing with the tool length. As a result, high-speed machining is possible without interrupting the machining process of NC machine tools, and the machining area is not restricted.

[0008]

【Example】

 Next, the present invention will be described with reference to the drawings. FIG. 1 is a configuration block diagram showing an embodiment of a tool breakage detecting device according to the present invention, and FIG. 2 is a flow chart showing its operation processing procedure. 3 is a perspective view of a main part when the present invention is applied to an NC machine tool attached to an ATC, and FIG. 4 is a view for explaining a tool breakage detection principle according to this embodiment. This embodiment does not directly detect the damage of the tool attached to the spindle, but detects the damage state of the tool stored in the tool magazine of the TC, and when the damage is detected, the damage is detected. Allows the tool to be removed from the tool magazine and replaced with a working tool. This damage detection and replacement is performed in the tool magazine and has no influence on the machining movement operation of the tool mounted on the spindle in the machining area.

Referring to FIG. 3, a tool breakage detection device is provided on the same frame 23 as the tool magazine 20. A plurality of pots 12 are accommodated in the tool magazine 20 so that they can circulate freely as shown by arrow A. Although not shown in the drawing, tools are fitted into the pots 12, respectively. The tool for which damage is to be detected is indexed at a predetermined position D and then moved to a measurement position E by a pot shifter (not shown). The length of the tool 10 is measured by surrounding the tool 10 positioned at the measurement position E and linearly moving the sensor arm 25 provided with the light emitting portion 21 and the light receiving portion 22 of the optical sensor by the positioning actuator 24. To do. This measurement principle will be described later. The tool 10 for which damage has been detected in this way is returned from the measurement position E to the predetermined indexing position D by the pot shifter, and the tool magazine 20 can be circulated.

Referring to FIG. 4, in the present embodiment, breakage of the tool 10 is detected by optically measuring the tool length. The tool 10 is held firmly in a pot 12 within a tool magazine 20 as shown. To measure the tool length, first of all, at a reference position F, which is the starting portion of the taper portion 11 of the tool 10, for example, a fiber light emitting portion 21 and a light receiving portion 22 provided on the opposite portion with the tool 10 sandwiched therebetween are provided. After positioning the optical sensor, light reception from the light emitting unit 21 is started and the time counter is activated to move the sensor toward the tip of the tool 10 at a constant speed. Until the sensor pair passes over the tip of the tool 10, the light from the light emitting section 21 is not blocked by the tool 10 and does not reach the light receiving section 22, but when the sensor pair moves to the tip (position G), the light receiving section 22 is reached. The received light signal appears from. The time counter is stopped by this light reception signal, and the tool length (that is, the movement distance from F to G of the sensor) can be calculated based on the count value of the time counter at that time. Here, the normal length of each tool is measured in advance, and the calculated tool length and the normal length are compared. If they match, it is determined to be normal, and if they do not match, it is determined to be damaged. The above tool length is calculated by converting the time information into distance information, but when the sensor is moved at a constant speed, the regular tool length is also expressed as time information and comparison is made based on the time information. It is also possible to detect tool breakage. In FIG. 4, the position H is the final position of sensor movement at the stroke end of the sensor and corresponds to a distance position slightly longer than the maximum length of the tools stored in the magazine.

Referring to FIGS. 1 and 2, first, after the measurement tool is taken out to the measurement position outside the machining area (step S 1), the positioning actuator 1 is used to detect the sensor 3 (light receiving portion 21 and light receiving portion 22 in FIG. 4). (Comprising) is positioned at the reference position F (step S2), and measurement of the time measuring means 2 is started. Next, the positioning actuator 1 moves the sensor 3 from the reference position F toward the position H, and the time measurement is continued (step S3). When the tool tip portion G is detected by the sensor 3, the time measurement of the time measurement means 2 is ended (step S4), and the measurement time is sent to the calculation means 5. As described above, the calculation means 5 calculates the tool length from the measurement time (step S5) and supplies it to the comparison means 6. The storage unit 4 stores the normal length information of each tool stored in the tool magazine in association with the tool number, and the normal length of the tool currently detected as being damaged is read out and compared. It is supplied to the means 6. The comparing means 6 compares the tool length from the calculating means 5 with the regular tool length from the storing means 4, and if they match, it is judged that there is no damage. If they do not match, the tool is damaged. If it is determined that the tool is replaced, a command to replace the tool of the same type is sent to the alarm means 7 to notify the alarm (step S7).

[0012]

[Effect of device]

 As described above, the tool damage detection device according to the present invention detects the damage state by optically measuring the tool length of the tool stored in the tool magazine of the ATC, not the tool attached to the spindle. Therefore, not only the machining process of the NC machine tool is not interrupted but high-speed machining is possible, and the damage detection device does not limit the machining area. Further, since the detection device is not in the processing area, it is possible to eliminate problems such as a breakdown of the detection device due to chips and cutting oil.

[Brief description of drawings]

FIG. 1 is a configuration block diagram showing an embodiment of a tool breakage detection device according to the present invention.

FIG. 2 is a flow chart showing an operation processing procedure in the embodiment of FIG.

FIG. 3 is a perspective view showing a simplified main configuration of a tool magazine unit to which the present invention is applied.

FIG. 4 is an explanatory view of a tool length measuring unit of an embodiment of a tool breakage detecting device according to the present invention.

[Explanation of symbols]

1, 24 Positioning actuator 2 Time measuring means 3 Sensor 4 Storage means 5 Calculation means 6 Comparison means 7 Alarm means 10 Tool 11 Tapered part 12 Pot 21 Light emitting part 22 Light receiving part 23 ATC
Frame 25 sensor arm

Claims (2)

[Scope of utility model registration request] 1. An NC machine tool having an automatic tool changer, which is provided by sandwiching a tool, which is composed of a light emitting part and a light receiving part, at a predetermined position with respect to a tool taken out from a tool magazine and positioned at a predetermined position. Positioning actuator that moves the optical sensor from the reference position on one end side of the tool toward the other end side, and measures the length correspondence information of the tool based on the timing of the light reception signal obtained from the light receiving unit of the light sensor. Tool length measuring means, storage means for storing the regular length correspondence information of the tools stored in advance in the tool magazine, length correspondence information obtained by the tool length measuring means, and read from the storage means. Comparing means for comparing the regular length correspondence information of the tool and an alarm hand indicating that the tool is damaged when the comparing means detects a mismatch. When, tool breakage detection apparatus characterized in that it comprises an. 2. The tool breakage detection device according to claim 1, wherein the length correspondence information is time information.