JP2018086702A - Tool breakage detection mechanism of machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tool breakage detection mechanism of a machine tool which can perform precise detection by using a laser sensor, and can suppress the generation of cloudiness and contamination accompanied by the adhesion of a mist of a cutting fluid and water vapor on a sensor face.SOLUTION: A tool breakage detection mechanism 6 comprises a cylindrical casing 11 whose one end is opened, and a reflection-type laser sensor 12 arranged in the casing 11. The reflection-type laser sensor 12 detects the presence or absence of the cutting breakage of a tool T by radiating a laser beam to the tool T which is located at the lowest part of a tool magazine 4. A progress direction of the laser beam of the reflection-type laser sensor 12 is inclined to a vertical direction at a prescribed angle.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a tool breakage detection mechanism for a machine tool, and more particularly to a tool breakage detection mechanism suitable for a machine tool having a tool magazine.

  A tool that is provided in a machine tool that includes a spindle, a tool magazine that accommodates the tool, and a tool changer disposed between the spindle and the tool magazine, and detects whether the tool accommodated in the tool magazine is damaged. As a breakage detection mechanism, Patent Document 1 discloses a tool that measures the length of a tool with a contact sensor and determines the presence or absence of breakage.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique for detecting breakage of a tool by arranging an optical sensor so as to correspond to a linear movement region of the tool.

Japanese Patent Laid-Open No. 10-138094 JP 2000-280139 A

  A tool breakage detection mechanism that detects the presence or absence of tool breakage by irradiating a laser is desirable because of its high accuracy, but when using a laser sensor, mist of cutting fluid or water vapor generated during processing The problem that it becomes impossible to detect broken tools due to cloudiness and dirt accompanying the sensor surface arises, and therefore maintenance such as cleaning needs to be performed frequently.

  An object of the present invention is to make it possible to perform accurate detection using a laser sensor, and to suppress the generation of cloudiness and dirt associated with mist or water vapor of the cutting fluid adhering to the sensor surface. The object is to provide a tool breakage detection mechanism of a machine.

  A tool breakage detection mechanism for a machine tool according to the present invention is provided in a machine tool including a main shaft, a tool magazine disposed above the main shaft and containing a tool, and a tool changer disposed between the main shaft and the tool magazine. A tool breakage detection mechanism that is provided and detects the presence or absence of breakage of a tool accommodated in a tool magazine, comprising a cylindrical casing having one end opened, and a reflective laser sensor disposed in the casing. The reflective laser sensor detects the presence or absence of tool breakage by irradiating the tool at the bottom of the tool magazine with a laser, and the laser traveling direction is a predetermined angle with respect to the vertical direction. It is characterized by being inclined.

  According to the tool breakage detection mechanism of the machine tool of the present invention, the cutting fluid mist and water vapor generated during machining soar from below, whereas the laser traveling direction is inclined at a predetermined angle with respect to the vertical direction. Therefore, mist and water vapor hardly reach the sensor surface of the laser, and this can suppress the occurrence of cloudiness and dirt associated with the mist or water vapor of the cutting fluid adhering to the sensor surface. Therefore, the frequency of performing maintenance such as cleaning of the sensor surface can be reduced, and maintainability is improved.

  The opening of the casing may be provided so as to be orthogonal to the laser traveling direction, but is preferably inclined so as to be closer to the vertical direction than the plane orthogonal to the laser traveling direction. .

  In this way, the mist or water vapor of the cutting fluid that rises from below is less likely to reach the sensor surface, and the frequency of maintenance can be further reduced.

  According to the tool breakage detection mechanism of the machine tool of the present invention, it is possible to suppress the occurrence of cloudiness and dirt associated with the mist or water vapor of the cutting fluid adhering to the sensor surface, and perform maintenance such as cleaning of the sensor surface. The frequency can be reduced.

FIG. 1 is a front view showing an embodiment of a tool breakage detection mechanism for a machine tool according to the present invention. FIG. 2 is an enlarged view of a main part of FIG.

  Hereinafter, an embodiment of a tool breakage detection mechanism for a machine tool according to the present invention will be described with reference to FIGS. 1 and 2. In the following description, the vertical and horizontal directions in FIG.

  The machine tool (1) includes a spindle head (2), a spindle (3) supported by the spindle head (2), a tool magazine (4) disposed vertically above the spindle (3), Tool breakage detection mechanism that detects whether the tool change arm (5) placed between the spindle (3) and the tool magazine (4) and the tool (T) housed in the tool magazine (4) are broken ( And 6).

  The spindle head (2) is supported movably in the vertical direction (Y axis) on the front surface of the column (7). The column (7) is relatively movable in three orthogonal axes between a column (not shown) fixed to a bed (not shown) and supported so as to be movable in the left-right direction (X-axis).

  The main shaft (3) has a horizontal axis extending in the front-rear direction (Z-axis), and required machining is performed on the workpiece by the tool (T) attached to the main shaft (3) in an exchangeable manner.

  The tool magazine (4) is vertically supported and supported by the column (7) so as to be rotatable about an axis (4a) parallel to the axis of the main shaft (3). A plurality of tool storage portions (9) are provided at equal intervals in the circumferential direction on the outer peripheral portion of the tool magazine (4). The lowermost one of the plurality of tool storage portions (9) is indicated by reference numeral (9A).

  The tool change arm (5) delivers the tool (T) between the spindle (3) and the tool magazine (4), and has an axis (5a) extending parallel to the axis of the spindle (3). Yes. The tool change arm (5) has two arm portions (8) that protrude from the shaft (5a) in directions opposite to each other by 180 °. A semicircular concave tool gripping portion (8a) is provided at the tip of each arm portion (8). The tool change arm (5) is attached so as to be rotatable in a vertical plane around the axis (5a) and to be movable back and forth in the axial direction of the axis (5a).

  The tool changing operation using the tool changing arm (5) is performed as follows.

  Two tools (T) to be replaced are held in a forward-facing posture in the main shaft (3) and the tool storage portion (9A) at the lowermost part. With the tool change arm (5) positioned at the backward limit, rotate the tool change arm (5) until the tool gripping part (8a) of both arm parts (8) grips both tools (T). . Then, the tool change arm (5) is advanced. Then, the two tools (T) to be replaced are extracted from the main shaft (3) and the lowermost tool storage portion (9A). When the tool changing arm (5) is turned 180 ° and the tool changing arm (5) is retracted, the two tools (T) to be changed are in the main shaft (3) and the lowermost part in the changed state. Each is held in the tool storage portion (9A).

  As shown in detail in FIG. 2, the tool breakage detection mechanism (6) includes a casing (11) attached to the column (7), and a reflective laser sensor (12) provided in the casing (11). It has.

  The casing (11) has a cylindrical shape with one end closed and the other end opened, and laser irradiation and light reception of the laser sensor (12) are performed through the opening (11a). The laser sensor (12) is disposed in the middle part of the casing (11), and the traveling direction of the laser is made to coincide with the length direction of the casing (11).

  The laser sensor (12) indicates whether the tool (T) is broken by irradiating the tip of the tool (T) stored in the tool storage section (9A) at the bottom of the tool magazine (4) with laser. When the reflected light (O) reaches the light receiving surface with respect to the irradiated light (I) irradiated from the irradiated surface, there is no breakage and the reflected light (O) does not reach the light receiving surface. In this case, it is determined that there is a breakage.

  The casing (11) is not in a vertical arrangement with the opening facing directly below, but in the vertical direction (the axis of the main spindle (3), the axis of the axis (5a) of the tool changer arm (5) and the axis of the tool magazine (4) ( It is inclined at a predetermined angle with respect to the direction connecting the axes of 4a). And the opening (11a) is not perpendicular to the laser traveling direction (length direction of the cylindrical casing (11)), but is in a vertical plane (so as to be perpendicular to the left-right direction). Is formed.

  The inclination angle of the casing (11) is, for example, about 30 ° (an appropriate value between 15 ° and 40 °) with respect to the vertical direction. The opening (11a) is not limited to being in the vertical plane, but may be inclined so as to approach the vertical direction with respect to a plane orthogonal to the laser traveling direction. On the other hand, it may be inclined by about −15 ° to + 15 °.

  In this machine tool (1), the tool magazine (4) is arranged above the main shaft (3), and the mist and water vapor generated during machining on the main shaft (3) are shown by the two-dot chain line in FIG. Soars in the direction indicated by. Therefore, when the laser irradiation direction is directed directly below, the mist and water vapor that have risen are likely to adhere to the sensor surface (irradiation surface and light receiving surface), and clouding and dirt are likely to occur. When cloudy or dirty, it becomes impossible to detect a cut with high accuracy, so maintenance such as frequent cleaning is necessary.

  According to the tool breakage detection mechanism (6) described above, the laser traveling direction is inclined at a predetermined angle with respect to the vertical direction, so that the rising mist and water vapor hardly adhere to the sensor surface. The frequency of performing maintenance such as cleaning of the sensor surface in (12) can be reduced.

  Further, since the opening (11a) of the casing (11) is inclined so as to be perpendicular to or perpendicular to the plane perpendicular to the laser traveling direction, a two-dot chain line in FIG. Mist and water vapor that move in the direction shown are less likely to enter the casing (11) from the opening (11a), and the maintainability is further improved.

  This tool breakage detection mechanism (6) can be attached later to an existing machine tool having a tool magazine. At this time, the tool changer such as the tool magazine (4) and the tool changer arm (5) can be variously changed, and the above also applies to a machine tool having a tool magazine and a tool changer different from those shown in the figure. By applying the tool breakage detection mechanism (6), it is possible to detect the presence or absence of breakage of the tool (T) accommodated in the tool magazine.

(1): Machine tool
(3): Spindle
(4): Tool magazine
(5): Tool change arm (tool changer)
(6): Tool breakage detection mechanism
(7): Column
(11): Casing
(11a): Opening
(12): Laser sensor
(T): Tool
(I): Irradiation light
(O): Reflected light

Claims (2)

A tool that is provided in a machine tool that includes a spindle, a tool magazine that is disposed above the spindle and houses a tool, and a tool changer that is disposed between the spindle and the tool magazine. A tool breakage detection mechanism that detects the presence or absence of breakage,
It has a cylindrical casing with one end open and a reflective laser sensor placed inside the casing. The reflective laser sensor breaks the tool by irradiating the tool at the bottom of the tool magazine with a laser. A tool breakage detection mechanism for a machine tool, wherein the laser traveling direction is inclined at a predetermined angle with respect to the vertical direction.   A tool breakage detection mechanism for a machine tool, wherein the opening of the casing is inclined so as to be closer to a vertical direction than a plane orthogonal to the laser traveling direction.

Images