JP2019119007A - Tool change method and machine tool - Google Patents

Abstract

To prevent intrusion of a coolant into an air flow channel of a MQL (Minimum Quantity Lubrication) holder after its change.SOLUTION: There is provided a tool change method for changing a MQL holder 30 which generates oil mist using high pressure air in the holder, and a coolant holder which uses a coolant during working, and attaching the changed holder to a main spindle device 10 comprising a common flow channel (passage 17a) for high pressure air and the coolant. The method includes: a flow channel cleaning step of letting the high pressure air flow into a common flow channel 17a to clean the inside of the common flow channel 17a, and a tool change step of removing a previously attached tool and attaching the next tool to be attached next. Preferably, the method also includes a determination step of identifying whether the next tool is the MQL holder 30 or the coolant holder and determining that the flow channel cleaning step is performed when the next tool is the MQL holder 30 and that the flow channel cleaning step is not performed when the next tool is the coolant holder.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a tool exchange method and a machine tool.

  In general, a machine tool processes a workpiece while supplying a large amount of oil as a cutting fluid to a processing unit for cooling, lubrication, swarf removal, etc. of a workpiece or a tool. Therefore, there are problems such as large consumption of oil, environmental pollution due to scattering of oil, and disposal processing of used oil. Therefore, in recent years, semi-dry processing has been proposed in which a workpiece is processed while supplying an oil mist generated by mixing oil and high pressure air to a processing unit. In semi-dry processing, the use of oil mist can substantially reduce the amount of oil substantially used.

  However, when the supplied oil mist passes through the spindle and the tool holder and is released through the tool, the oil adheres to the inner wall of the passage inside the spindle, and the oil content in the oil mist actually discharged Was a problem.

  In order to solve this problem, an apparatus has been proposed which supplies oil stored in an oil tank in a tool holder to a fluid passage in the vicinity of a tool and mixes it with high pressure air to generate oil mist (Patent Document 1 See Figure 8 in 1).

Unexamined-Japanese-Patent No. 2000-210836

  By the way, when adopting the above-mentioned tool holder (hereinafter referred to as “MQL (Minimum Quantity Lubrication) holder”) that generates oil mist in the existing machining center, the coolant flow path of the spindle axial center system is used. It will supply high pressure air to the MQL holder. In the tool magazine, if the MQL holder and a tool holder (hereinafter, referred to as "coolant holder") that uses coolant at the time of processing are configured to be exchangeable, both tool holders can be appropriately used. However, the MQL holder has a problem that a problem occurs when the coolant intrudes into the high pressure air flow path.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a tool replacement method and a machine tool that can prevent the entry of coolant into the air flow path of the MQL holder.

  The present invention for solving the above problems uses an MQL holder for producing an oil mist using the high pressure air in the holder and a coolant at the time of processing in a spindle device provided with a dual flow path of high pressure air and coolant. It is a tool change method of replacing and attaching the coolant holder to be carried out. In such a tool changing method, a flow path cleaning step of flowing the high pressure air into the combined flow path to clean the combined flow path, and removing the previously attached tip tool, and then mounting the next And a tool change process of attaching a tool.

  According to the present invention, the coolant remaining in the dual-use flow path can be discharged by flowing high-pressure air into the dual-use flow path before holder replacement, so that the coolant enters the air flow path of the MQL holder after replacement. Can be prevented.

It is a sectional view showing a spindle device of a machine tool concerning an embodiment of the present invention. It is sectional drawing which showed the MQL holder. It is the flowchart which showed the tool exchange method concerning the embodiment of the present invention.

Embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
In addition, in each figure, about the same component and the same component, the same code | symbol is attached | subjected and those duplicate description is abbreviate | omitted suitably. Hereinafter, for convenience of explanation, the side to which the tool T is attached may be referred to as the “tip” side or the “front” side, and the opposite side may be referred to as the “base end” side or the “rear” side.

  A machine tool 1 according to an embodiment of the present invention includes a spindle device 10, a fluid supply device 70, and a tool magazine. The spindle device 10 of the present embodiment is configured to be able to select and attach an MQL holder 30 that generates oil mist using high pressure air in the holder and a coolant holder (not shown) that uses a coolant at the time of processing ing. In FIG. 1, the MQL holder 30 is attached to the tip of the spindle device 10. The spindle device 10 is provided with a combined flow passage of high pressure air and coolant and a holder mounting portion 17b.

  The spindle device 10 includes a cylinder 11 having a cylindrical shape, and a spindle 12 rotatably supported by bearings 13 and 14 inside the cylinder 11. The main shaft 12 is rotated by a built-in motor 15 having a rotor 15a and a stator 15b. An MQL holder 30 or a coolant holder (not shown), to which the tool T is fixed, is removably attached to the tip of the main shaft 12.

  In the inside of the main shaft 12, an axial hole 12a penetrating on the central axis is formed. A tapered hole 12b having a shape complementary to that of the tapered shank portion 36 of the MQL holder 30 is formed at the tip (left side in FIG. 1) of the axial hole 12a.

  The main shaft 12 has a pull rod 17 inserted therein. The distal end portion of the pull rod 17 is configured to be engageable with the pull stud 35 provided at the proximal end portion of the MQL holder 30 via the steel ball 18. A holder mounting portion 17 b is formed at the tip of the pull rod 17. A bracket 19 is fixed to the proximal end of the pull rod 17. A disc spring 20 is mounted between the metal fitting 19 and a locking step 12c formed on the inner peripheral surface of the shaft hole 12a of the main shaft 12 via a retainer member or the like.

  When pull rod 17 is moved to the right in FIG. 1 by the elastic force of disc spring 20, pull stud 35 is pulled in by steel ball 18, and shank portion 36 of MQL holder 30 is pressed against tapered hole 12b of main shaft 12 It is held. On the other hand, when the metal fitting 19 is pushed forward against the elastic force of the disc spring 20, the holding of the pull stud 35 of the MQL holder 30 by the tip of the pull rod 17 and the steel ball 18 is released. The tool T and the MQL holder 30 or the coolant holder are replaced by an automatic tool changer of a tool magazine (not shown).

  The tool magazine comprises a tool holder and an automatic tool changer. The tool holder portion is provided with a plurality of storage locations for tools, and a tool holder provided with a tool is stored in each storage location. In the tool holder, addresses are set at a plurality of storage positions of the tool, and it is grasped which of the MQL holder 30 or the coolant holder is stored at the storage position. Then, whether the next tool to be mounted next is the MQL holder 30 or the coolant holder is identified from the address of the taken out storage position. In addition, identification of a holder is not limited to the said method. For example, the holder may be identified by attaching an IC chip to the holder and reading the information. The automatic tool changer grips a tool holder provided with a tool and conveys it between the storage position and the tip of the spindle 12.

  A passage 17 a is formed on the central axis of the pull rod 17. The proximal end side of the passage 17a is connected to the fluid supply device 70 via the supply pipe 70a. The high pressure air or coolant supplied from the fluid supply device 70 flows through the passage 17a. The passage 17a constitutes a shared flow passage.

  The fluid supply device 70 is configured to be able to selectively supply high pressure air and coolant to the dual purpose flow channel. The fluid supply device 70 includes a high pressure air supply unit 71, a coolant supply unit 72, a switching valve 73, and control means (not shown). The high pressure air supply unit 71 includes a flow path 71a connected to one end of the switching valve 73, a pump 71b that compresses and supplies air, a pressure control valve 71c, and a check valve 71d. The pressure control valve 71c reduces the high pressure air from the pump 71b to a predetermined pressure and flows it. The coolant supply unit 72 includes a flow path 72a connected to the other end of the switching valve 73, a coolant tank 72b, a pump 72c that sucks up and supplies the coolant in the coolant tank 72b, a pressure control valve 72d, and a check valve 72e. Is equipped. The pressure control valve 72 d reduces the coolant from the pump 72 c to a predetermined pressure and flows it. The switching valve 73 has a high pressure air supply position connecting the high pressure air supply unit 71 to the supply pipe 70a extending from the dual purpose flow passage, a coolant supply position connecting the coolant supply unit 72 to the dual purpose flow passage, and supply stoppage stopping the fluid supply Move between the position (the state of FIG. 1). The switching valve 73 is configured of, for example, a solenoid valve.

  The control means controls the operation of the fluid supply device 70. The control means comprises a CPU, and is connected to the fluid supply device 70 and the tool magazine, respectively. The control means receives from the tool magazine a signal indicating whether the next tool is the MQL holder 30 or the coolant holder to control the operation of the fluid supply device 70. In addition, the information of the tip tool attached previously is grasped as information of the next tool at the time of the last exchange. In the present embodiment, when the front tool is the coolant holder and the next tool is the MQL holder 30, the control means causes high-pressure air to flow in the dual-use flow path and the coolant in the dual-use flow path before mounting the next tool. It is configured to flush (perform the cleaning of the shared flow channel). When the next tool is a coolant holder, or when the front tool is the MQL holder 30 and the next tool is also the MQL holder 30, cleaning of the shared flow passage is not performed.

  In the present embodiment, the control means is not limited to the above configuration. For example, the control means may identify only the next tool and decide whether to perform cleaning. Specifically, when the next tool is the MQL holder 30, the control means causes high-pressure air to flow through the alternate channel for a predetermined period of time before mounting the next tool to flush the coolant in the alternate channel to alternate the alternate channel. In the case where the next tool is a coolant holder, the combined flow passage may not be cleaned.

  Furthermore, the control means causes high-pressure air to flow through the dual-use flow path for cleaning for a predetermined time before mounting the next tool each time the holder is replaced without identifying the type of tool. You may configure it.

  As shown in FIG. 2, the MQL holder 30 includes a main body 31, a fixing portion 32 attached to the tip end surface of the main body 31, a nozzle 45 for generating oil mist, and an oil tank 50 for storing oil. Is equipped. The main body 31 is a part that can be attached to and detached from the spindle 12 (see FIG. 1) of the machine tool. The fixing portion 32 is a portion to which the tool T is fixed.

The main body portion 31 is a columnar member in which the support portion 34 on the distal end side and the mounting portion 33 on the proximal end side are formed.
The mounting portion 33 is a portion held by the tapered hole of the main shaft 2. The outer peripheral surface of the mounting portion 33 is formed in a tapered shape that can be in close contact with the tapered hole of the main shaft 12. At the proximal end of the mounting portion 33, a fitting portion 37 held by a tool magazine (see FIG. 1) is formed.
At the center of the mounting portion 33, an air flow passage 38 extends in the axial direction. The air flow passage 38 communicates with the air flow passage (passage 17 a) of the main shaft 12 when the mounting portion 33 is mounted on the main shaft 12.

  The nozzle 45 is provided in the support portion 34. The nozzle 45 mixes oil and air to generate an oil mist, and jets the oil mist toward the tool T attached to the fixed portion 32. The tool T is formed with a through hole that penetrates in the axial direction, and oil mist is supplied from the nozzle 45 to the through hole.

The oil tank 50 is disposed radially outside the support portion 34, and is a cylindrical (annular) case surrounding the support portion 34. In the oil tank 50, an annular internal space 51 surrounding the support portion 34 is formed.
An annular piston 54 is accommodated in the internal space 51 of the oil tank 50. The piston 54 is movable in the inner space 51 in the axial direction of the MQL holder 30.
The internal space 51 is divided into two spaces by the piston 54. In the internal space 51, a storage chamber 55 is formed on one side of the piston 54, and a pressure chamber 56 is formed on the other side of the piston 54. The storage chamber 55 is connected to the nozzle 45 via a flow path in the support portion 34.

  The storage chamber 55 is a space filled with oil. The pressurizing chamber 56 is a space to which high-pressure air is supplied. The pressure of the air in the pressure chamber 56 pushes the piston 54 toward the storage chamber 55, whereby the oil in the storage chamber 55 is pressurized.

In the support portion 34, a first branch flow path 39 and a second branch flow path 40 branched from the air flow path 38 in the mounting portion 33 are formed.
The first branch channel 39 is a channel from the air channel 38 to the pressurizing chamber 56. The first branch 39 is provided with a first regulator 39 a.
The second branch flow path 40 is a flow path from the air flow path 38 to the nozzle 45. A second regulator 40 a is provided in the second branch flow channel 40.

  An injection port 60 for supplying oil to the storage chamber 55 of the oil tank 50 is provided on the outer peripheral surface of the oil tank 50. The injection port 60 is in communication with the storage chamber 55 via the flow passage in the support portion 34.

  Next, a tool replacement method for replacing the MQL holder 30 and the coolant holder in the machine tool 1 configured as described above will be described with reference to FIG. The tool replacement method includes the determination step, the flow path cleaning step, and the tool replacement step.

  The determination step is a step of determining whether or not to perform channel cleaning based on the type of holder to be replaced. In the determination step, the tool magazine identifies whether the next tool is the MQL holder 30 or the coolant holder, and the control means performs channel cleaning when the next tool is the MQL holder, and the next tool is the coolant When it is a holder, it is determined that the flow path cleaning process is not performed. In this embodiment, the determination is performed in more detail, and the channel cleaning process is performed when the front tool is the coolant holder and the next tool is the MQL holder, and the next tool is the coolant holder, and the front tool When the MQL holder is the next tool is the MQL holder, it is determined that the flow path cleaning is not to be performed.

  The determination step corresponds to STEP 1 and STEP 2 in FIG. In the determination step, first, from the holder information received from the tool magazine, the control means determines whether or not the next tool is the MQL holder (STEP 1). Here, if the next tool is the MQL holder, the process proceeds to the determination of whether or not the front tool is the coolant holder (STEP 2). When the next step is not the MQL holder (in the case of the coolant holder), the coolant is made to flow through the alternate flow path at the time of the next processing, so there is no need to perform the flow path cleaning. Therefore, in this case, the process proceeds to the tool replacement step (STEP 4).

  In STEP 2, it is determined from the holder information accumulated by the control means whether the leading tool is the MQL holder or the coolant holder. If the front tool is a coolant holder, since the coolant remains in the dual purpose flow path, the flow proceeds to the flow path cleaning step (STEP 3) in order to remove the coolant. When the front end tool is not the coolant holder (in the case of the MQL holder), since the coolant does not remain in the dual purpose flow path, it is not necessary to perform the flow path cleaning. Therefore, in this case, the process proceeds to the tool replacement step (STEP 4).

  The flow path cleaning step is a step of flowing high pressure air into the dual purpose flow path to clean the dual purpose flow path (STEP 3 in FIG. 3). In the flow path cleaning process, high pressure air is flowed into the dual flow path for a predetermined time before the next tool is attached, and the coolant in the dual flow path is flushed. The time and pressure for flowing high pressure air are appropriately set according to the length of the dual purpose flow path and the viscosity of the coolant.

  The tool changing step is a step of changing the holder on which the tool is fixed. In the tool change process, the tool magazine automatic tool changer is used to remove the previously mounted tip tool and attach the next tool to be mounted next. In this embodiment, after performing channel cleaning, the front tool is removed and the next tool is attached, but the present invention is not limited to this. After removal of the front tool, channel cleaning may be performed, and then the next tool may be attached.

  According to the machine tool 1 and the tool replacement method described above, it is possible to remove and wash the coolant remaining inside by flowing high pressure air in the dual purpose flow path. Then, the coolant in the air flow path of the MQL holder 30 (the air flow path 38, the first branch flow path 39, and the second branch flow path 40) is cleaned by cleaning the shared flow path before the MQL holder 30 is attached. Can prevent the infiltration of This can reduce the occurrence of a failure of the MQL holder 30.

  In particular, in the present embodiment, when the next tool is a coolant holder, unnecessary flow path cleaning is not performed, so time loss can be eliminated and processing efficiency can be enhanced. Furthermore, even when the next tool is the MQL holder 30, when the front tool is the MQL holder 30, the coolant does not remain in the dual-use flow path. Even in such a case, time loss can be further reduced by not performing channel cleaning, and therefore processing efficiency can be further enhanced.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to the structure described in the said embodiment. The present invention can appropriately change the configuration without departing from the scope of the present invention, including appropriately combining or selecting the configurations described in the embodiments. Moreover, it is possible to add, delete, and replace a part of the configuration of the embodiment.

  For example, in the embodiment described above, although it is determined in the determination step whether the next tool is the MQL holder, it is determined whether the leading tool is the MQL holder or the coolant holder, but this is limited to this It is not something to be done. Only whether the next tool is the MQL holder may be determined to determine whether or not to perform the channel cleaning. Specifically, in the determination step, if the next tool is the MQL holder, the flow path cleaning step is performed, and if the next tool is the coolant holder, it is determined that the flow path cleaning step is not performed. Good. In addition, the channel cleaning may be always performed each time the holder is replaced without identifying the holder of the next tool (without performing the determination step). Even in this case, since the channel cleaning is always performed when using the MQL holder, no problem occurs in the MQL holder.

  In the embodiment, the control means controls the operation of the fluid supply device 70 according to the next tool recognized in the tool magazine, but the invention is not limited to this. An operator may read the next tool recognized in the tool magazine, and the operator may manually press and operate the high pressure air and coolant supply switches provided in the fluid supply device.

1 machine tool 10 spindle device 17a passage (shared flow passage)
17b Holder mounting portion 30 MQL holder 70 Fluid supply device 71 High pressure air supply portion 72 Coolant supply portion 73 Switching valve T Tool

Claims (7)

Tool replacement by replacing the MQL holder that generates oil mist using the high pressure air in the holder and the coolant holder that uses the coolant at the time of processing to the spindle device provided with the combined flow path of high pressure air and coolant Method,
A flow path cleaning step of flowing the high pressure air into the combined flow path to clean the combined flow path;
A tool changing step of removing a previously attached tip tool and attaching a next tool to be attached next. When the next tool is identified as either the MQL holder or the coolant holder, and the channel cleaning process is performed when the next tool is the MQL holder, and the next tool is the coolant holder The tool replacement method according to claim 1, further comprising a determination step of determining that the flow path cleaning step is not to be performed. While identifying whether the next tool is the MQL holder or the coolant holder, the flow path cleaning process is performed when the front tool is the coolant holder and the next tool is the MQL holder, and The method further includes a determination step of determining that the flow path cleaning step is not to be performed when the next tool is the coolant holder or the front tool is the MQL holder and the next tool is the MQL holder. The tool exchange method according to claim 1, characterized in that A machine tool comprising: a spindle device having a dual flow path of high pressure air and coolant and a holder mounting portion; and a fluid supply device capable of selectively supplying the high pressure air and the coolant to the dual flow path.
The holder attachment portion can select and attach an MQL holder that generates oil mist using the high-pressure air in the holder and a coolant holder that uses the coolant at the time of processing,
A machine tool characterized in that the high-pressure air is made to flow and the dual-use flow path is flushed before holder replacement in the holder mounting portion. It further comprises a tool magazine for selecting and replacing the MQL holder and the coolant holder,
The machine tool according to claim 4, wherein the tool magazine can identify whether the holder to be replaced is the MQL holder or the coolant holder. The fluid supply device includes control means for controlling the supply of the high pressure air and the coolant.
The control means is configured to cause the high pressure air to flow through the shared flow path before the mounting of the next tool, when the next tool to be mounted next is an MQL holder. Machine tool described. The fluid supply device includes control means for controlling the supply of the high pressure air and the coolant.
The control means causes the high-pressure air to flow through the shared flow path before the installation of the next tool when the first tool attached first is the coolant holder and the next tool attached next is the MQL holder. When the next tool is the coolant holder or when the front tool is the MQL holder and the next tool is the MQL holder, the high pressure air is not allowed to flow into the shared flow path before the installation of the next tool The machine tool according to claim 5, characterized in that:

Images