JP2015208797A - Tool storage device and machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tool storage device that enables detection of a storage state of a tool without providing each storage part with a sensor, and a machine tool.SOLUTION: A tool storage device of the present invention includes: a storage unit that comprises a plurality of storage parts for housing a tool; a movement unit for moving the storage unit so that the storage part located in an attachment/detachment position where the tool is attached/detached can be replaced; and a tool sensor that has a detection position set to detect the tool housed in the storage part located in the attachment/detachment position.

Description

  The present invention relates to a machine tool.

  Generally, in a machine tool having an automatic tool change function, it is possible to perform machining efficiently and continuously by automatically changing tools when moving from one process to the next. After the tool is changed, it may be required to accurately measure the length of the changed tool before the next processing. Then, the technique which measures the length of the tool after replacement | exchange is also proposed (patent document 1).

JP-A-6-344247

  The tool to be exchanged is stored in a storage unit called a magazine or the like. The storage unit includes a plurality of storage units for storing tools. When a tool is exchanged, if a tool is already in the storage unit, the tool may collide with the tool to be returned and break the tool. As a countermeasure, it is conceivable to provide a sensor for detecting the storage state of the tool in the storage unit. However, providing a sensor for each storage unit increases the size of the storage unit and increases the number of sensors. These are factors that increase costs.

  The present invention provides a tool storage device and a machine tool capable of detecting the storage state of a tool without providing a sensor for each storage unit.

  According to the present invention, a storage unit including a plurality of storage units in which tools are stored, a moving unit that moves the storage unit so that the storage unit located at an attachment / detachment position where a tool is attached / detached, and There is provided a tool storage device comprising: a tool sensor having a detection position set so as to detect the tool stored in the storage unit positioned at an attachment / detachment position.

  According to the present invention, a spindle on which a tool is replaceably mounted, a spindle moving unit for moving the spindle in the axial direction, a storage unit having a plurality of storage units for storing tools, and the spindle In order to detect the moving unit that moves the storage unit so that the storage unit located at the attachment / detachment position where the attachment / detachment of the tool is performed and the tool stored in the storage unit located at the attachment / detachment position are detected. A tool sensor in which a detection position is set; and a processing unit that controls the spindle movement unit, and the processing unit detects the tool sensor when storing the tool mounted on the spindle in the storage unit. Based on the result, it is confirmed whether or not a tool is stored in the storage unit.

  ADVANTAGE OF THE INVENTION According to this invention, the tool storage apparatus and machine tool which can detect the storage state of a tool can be provided, without providing a sensor for every storage part.

Explanatory drawing of the machine tool which concerns on one Embodiment of this invention. (A) is explanatory drawing of a part of machine tool of FIG. 1, (B) is explanatory drawing of a contact-type sensor. (A) And (B) is a figure which shows the example of a detection of the storing state of a tool. (A) And (B) is a figure showing an example of detection of a tip position of a tool.

  Embodiments of the present invention will be described with reference to the drawings. In each figure, an arrow Z indicates a vertical direction, and arrows X and Y indicate horizontal directions orthogonal to each other. FIG. 1 is an explanatory diagram of a machine tool A according to an embodiment of the present invention. FIG. 2A shows the periphery of the processing table 6. The machine tool A is an NC machine tool having an automatic tool change function, and constitutes a vertical machining center.

  The machine tool A includes a main shaft 1. The main shaft 1 has an axial direction Z direction. A tool T is mounted on the spindle 1 so as to be exchangeable. In the case of this embodiment, the tool T is comprised from the tool main body 3 which is a cutter, and the tool holder 2 holding the tool main body 3. FIG. The tool T is rotated using the motor Md as a drive source. The main shaft 1 is supported by a main shaft fixing base 4 and can be moved in the axial direction (Z direction) by the main shaft moving unit 4. The main shaft moving unit 4 includes a motor Mz as a drive source, and includes a transmission mechanism such as a ball screw mechanism to raise and lower the main shaft 1. The amount of movement of the main shaft 1 is detected by the sensor Sz. The sensor Sz is an encoder that detects the amount of rotation of the motor Mz, for example. Based on the detection result of the sensor Sz, the position of the spindle 1 in the Z direction can be calculated.

  The machine tool A includes a movable stage 6. On the movable stage 6, a storage unit 5, a processing table 10, and a contact sensor 9 are mounted. In FIG. 1, the machining table 10 is not shown, and the contact sensor 9 is not shown in FIG.

  The storage unit 5 is a magazine in which the tool T is stored. The storage unit 5 constitutes a tool storage device together with a moving unit 8 and a tool sensor 7 which will be described later. In the present embodiment, the tool storage device is integrally incorporated in the machine tool A, but the tool storage device can be configured as a single device.

  The storage unit 5 includes a plurality of storage units # 1 to # 5 (indicated as storage unit #n if not distinguished). Here, the number of storage units is five as an example. The plurality of storage units # 1 to # 5 are arranged in the X direction.

  Each storage unit #n stores one tool T. Each storage unit #n has an opening in the upper part, and removal and storage of the tool T are performed in the vertical direction through this opening.

  A workpiece (not shown) to be machined is held on the machining table 10, and the machining is performed by the tool T attached to the spindle 1. The processing table 10 is located on the front side with respect to the storage unit 5.

  The contact sensor 9 is a sensor for detecting the tip position of the tool T mounted on the main shaft 1. The contact sensor 9 detects the position of the tip by contacting the tip of the tool T mounted on the main shaft 1. FIG. 2B is an explanatory diagram thereof. The contact sensor 9 is a pressure sensor, for example, and has a pressure-sensitive portion on the upper surface thereof. As shown in FIG. 2B, the spindle 1 is lowered on the contact sensor 9 and the contact sensor 9 is pressed with the tool T. The contact sensor 9 detects this press. Since the position of the upper surface of the contact sensor 9 is known by design, the tip position of the tool T in the Z direction relative to the position of the spindle 1 in the Z direction can be calculated. The tip position of the tool T is necessary for control when machining the workpiece.

  Referring to FIGS. 1 and 2A again, the machine tool A includes a moving unit 8. The moving unit 8 moves the movable stage 6 in the X direction and the Y direction. The moving unit 8 includes a motor Mx as a drive source, and includes a transmission mechanism such as a ball screw mechanism, for example, to move the movable stage 6 in the X direction. The amount of movement of the movable stage 6 in the X direction is detected by the sensor Sx. The sensor Sx is an encoder that detects the amount of rotation of the motor Mx, for example. The moving unit 8 also includes a motor My as a drive source, and includes a transmission mechanism such as a ball screw mechanism to move the movable stage 6 in the Y direction. The amount of movement of the movable stage 6 in the Y direction is detected by the sensor Sy. The sensor Sy is an encoder that detects the amount of rotation of the motor My, for example.

  When a machining operation is performed on the workpiece on the machining table 10, the movable stage 6 is moved by the moving unit 8 so that the workpiece is positioned below the spindle 1. When the tool T is attached to or detached from the main shaft 1, the movable stage 6 is moved by the moving unit 8 so that the storage unit 5 is positioned on the attachment / detachment position P. The attachment / detachment position P is a position below the main shaft 1. When the movable stage 6 is moved in the X direction, the storage unit #n located at the attachment / detachment position P is switched.

  The machine tool A includes a tool sensor 7. As shown in FIG. 2 (A), the tool sensor 7 is fixed to the main body portion of the machine tool A or the like via a support member 7a, and the position thereof does not move. The detection position of the tool sensor 7 is set so as to detect the tool T stored in the storage unit #n positioned at the attachment / detachment position P. Therefore, when the storage unit #n located at the attachment / detachment position P is switched, the storage unit #n to be detected is replaced. The detection position can be set, for example, on the axis of the main shaft 1.

  In the case of this embodiment, the tool sensor 7 is an optical sensor, and includes a light emitting element and a light receiving element. In the light emitting element, the light irradiation direction is set to the attachment / detachment position P, and the light receiving element is arranged to receive the reflected light. FIGS. 3A and 3B are diagrams illustrating an example of detection of the storage state of the tool T by the tool sensor 7.

  In the case of the example of FIG. 3A, the storage unit # 3 is located at the attachment / detachment position P. A tool T is stored in the storage unit # 3. Light from the tool sensor 7 is reflected by the tool T and received by the tool sensor 7. Thus, when the tool sensor 7 receives reflected light, it can be determined that the tool T exists in the storage unit # 3. In the case of the example of FIG. 3B, the storage unit # 4 is located at the attachment / detachment position P. The tool T is not stored in the storage unit # 4. Since there is no tool T that reflects light from the tool sensor 7, the reflected light is not confirmed by the tool sensor 7, or the amount of received light is smaller than when the tool T is present. For this reason, it can be determined that the tool T does not exist in the storage unit # 4.

  Returning to FIG. 1, the machine tool A includes a processing unit 100. The processing unit 100 includes a processing unit 101 such as a CPU, a storage unit 102 such as a RAM, a ROM, and a hard disk, and an interface unit 103 that interfaces an external device and the processing unit 101. The processing unit 100 is a control unit that controls the machine tool A, and is also an arithmetic unit that performs various calculations.

  The processing unit 101 executes a program stored in the storage unit 102 and controls the machine tool A. For example, drive control of the motor Md is performed. Further, drive control of a tool changer (not shown) provided at the end of the spindle 1 is performed. Further, the motor Mz is driven based on the detection result of the sensor Sz, and movement control and position control of the main shaft 1 are performed. Further, the motor Mx is driven based on the detection result of the sensor Sx, or the motor My is driven based on the detection result of the sensor Sy to perform movement control and position control of the movable table 6.

  As an example of control, control when the tool T mounted on the spindle 1 is stored in the storage unit #n will be described. First, the moving unit 8 is controlled so that the storage unit #n where the tool T is stored is located at the attachment / detachment position P. Next, the detection result of the tool sensor 7 is acquired, and it is determined whether another tool is stored in the storage unit #n that stores the tool T based on the detection result. When it is determined that another tool is not stored, that is, when it is determined that the storage unit #n is empty, the spindle 1 is lowered by the spindle moving unit 4 and the tool attached to the spindle 1 T is inserted into the storage unit #n at the attachment / detachment position P. Then, the tool T is separated from the main shaft 1. The separated tool T is stored in the storage unit #n.

  When it is determined that another tool is stored, the tool T attached to the spindle 1 interferes with another tool. Therefore, error processing such as canceling storage and selecting another storage unit #n or issuing a warning is performed.

  In the case of the present embodiment, the detection position of the tool sensor 7 is set so as to detect the tool T stored in the storage unit #n located at the attachment / detachment position P, and the storage located at the attachment / detachment position P. By replacing the part #n with the moving unit 8, one tool sensor 7 can also be used for detecting the presence of the tool T in all the storage parts # 1 to # 5. Therefore, the storage state of the tool can be detected without providing a sensor for each storage unit #n.

  Next, as another example of control, control for calculating the tip position of the tool T when the tool T stored in the storage unit #n is mounted on the spindle 1 and taken out from the storage unit #n will be described. In the present embodiment, the tip position of the tool T can be detected by the contact sensor 9, but the tip position can also be detected by using the tool sensor 7.

  First, the moving unit 8 is controlled so that the storage unit #n for storing the tool T to be mounted is positioned at the attachment / detachment position P. The spindle 1 is lowered by the spindle moving unit 4 and the tool T is mounted on the spindle 1.

  Next, the spindle 1 is raised by the spindle moving unit 4, and the tool T attached to the spindle 1 is taken out from the storage unit #n. At that time, the detection result of the tool sensor 7 is constantly monitored as shown in FIG. In the middle of taking out the tool T, the tool T is detected by the tool sensor 7. When the tool T is completely removed from the storage unit #n, the tool T is not detected as shown in FIG. When the detection result of the tool sensor 7 changes from “with tool T” to “without tool T”, the tip of the tool T has passed the detection position of the tool sensor 7. Therefore, the tip position of the tool T in the Z direction relative to the position of the main spindle 1 in the Z direction can be calculated from the position in the Z direction of the main spindle 1 at that time. In the present embodiment, the tool sensor 7 can be used for detecting the tip position of the tool T as described above.

  The tip position detection accuracy of the tool T by the tool sensor 7 may be inferior to the tip position detection accuracy of the tool T by the non-contact sensor 9. When performing precise machining, more accurate information on the tip position of the tool T is required. Therefore, the tip position of the tool T is detected using the non-contact sensor 9.

  However, the detection of the tip position of the tool T by the tool sensor 7 can be used to control the moving speed of the spindle 1 when the tip position of the tool T is detected using the non-contact sensor 9. When the tip position of the tool T is detected by the non-contact sensor 9, the tip of the tool T may be damaged by the impact when the tool T comes into contact with the non-contact sensor 9 when the descending speed of the spindle 1 is fast. . If the lowering speed of the main shaft 1 is slowed in order to avoid breakage, the time required for detecting the tip position becomes longer.

  Therefore, the descending speed of the spindle 1 is relatively increased until just before the tool T comes into contact with the non-contact sensor 9, and thereafter is relatively decreased. The position where the speed is changed uses the detection result of the tip position of the tool T by the tool sensor 7. By detecting the tip position of the tool T by the tool sensor 7, the position in the Z direction of the main shaft 1 at which the tip of the tool T abuts against the non-contact sensor 9 can be almost calculated. Therefore, it is only necessary to decelerate the descent speed with the position of the effort as the speed change position.

  In order to prevent damage even when the amount of protrusion of the tool body 3 is minimum, when the tip position is measured, the tip position detection is performed by using the tip position detection result of the tool T by the tool sensor 7. The time required for can be shortened as follows.

  Assume that the actual protrusion amount of the tool body 3 is L, the minimum protrusion amount of the tool body 3 is Lmin, and the protrusion amount of the tool body 3 based on detection of the tip position of the tool T by the tool sensor 7 is Lα. The maximum descending speed of the spindle 1 is Fmax, and the descending speed at which the tool body 3 can contact the non-contact sensor 9 without breakage is F.

When the tip position of the tool T is detected by the non-contact sensor 9 with the descending speed F, at least the time required is t0.
t0 = (L−Lmin) / F
It is. When at least the time required for detecting the tip position of the tool T by the non-contact sensor 9 by changing the descending speed using the protrusion amount Lα is t1,
t1 = (Lα−Lmin) / Fmax + (Lα−L) / F
It is. The measurement time can be shortened by the difference: (2L−Lα−Lmin) / F− (Lα−Lmin) / Fmax. Moreover, the use of the tool sensor 7 eliminates the need for additional sensors.

Claims (5)

A storage unit having a plurality of storage units for storing tools;
A moving unit that moves the storage unit so that the storage unit located at the attachment / detachment position where the attachment / detachment of the tool is performed is replaced;
A tool sensor in which a detection position is set so as to detect the tool stored in the storage unit positioned at the attachment / detachment position;
A tool storage device. The tool storage device according to claim 1,
The tool further includes a processing unit that calculates a tip position of the tool based on a detection result of the tool sensor when the tool is taken out from the storage unit.
A tool storage device. A spindle on which tools can be exchanged, and
A spindle moving unit for moving the spindle in the axial direction;
A storage unit having a plurality of storage units for storing tools;
A moving unit that moves the storage unit so that the storage unit located at an attachment / detachment position where the attachment / detachment of the tool to / from the spindle is performed;
A tool sensor in which a detection position is set so as to detect the tool stored in the storage unit positioned at the attachment / detachment position;
A processing unit for controlling the spindle moving unit,
The processing unit is
When storing the tool mounted on the spindle in the storage unit, based on the detection result of the tool sensor, confirm whether or not the tool is stored in the storage unit,
A machine tool characterized by that. The machine tool according to claim 3,
The processing unit is
The tip position of the tool is calculated based on the detection result of the tool sensor when the tool mounted on the spindle is taken out from the storage unit by moving the spindle by the spindle moving unit.
A machine tool characterized by that. The machine tool according to claim 4,
A contact sensor that abuts the tip of a tool mounted on the spindle;
The control means includes
The spindle is moved by the spindle moving unit so that the tool attached to the spindle contacts the contact sensor, and the tip of the tool is determined based on the detection result of the contact sensor at that time. Calculate the position,
The control means includes
When the spindle movement unit moves the spindle so that a tool attached to the spindle comes into contact with the contact sensor, the movement speed of the spindle is calculated based on the detection result of the tool sensor. Changing based on the tip position of the tool,
A machine tool characterized by that.

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