JP7304217B2 - Cutting fluid supply and recovery device in the spindle of a machine tool - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting fluid supply and recovery device within a spindle of a machine tool such as a machining center.

For example, in machine tools, there is known a through-spindle system in which a cutting fluid circulation hole is provided so as to pass through the spindle and tool holder from the rear of the spindle toward the front end, and the cutting fluid is injected to the work machining area through the cutting fluid circulation hole. It is Machine tools that use the through-spindle cutting fluid supply method stop the cutting fluid supply when the workpiece is not being processed, and supply air to the cutting fluid circulation hole to discharge the cutting fluid remaining in the spindle and tool holder. are doing.

However, for example, when exchanging tools with an automatic tool changer, if the tool holder is removed from the tip of the spindle, the cutting fluid flow hole is separated between the spindle and the tool holder. The cutting fluid remaining in the cutting fluid circulation hole leaks out from the portion. Residual cutting fluid may leak, contaminating the taper surface of the spindle, and degrading tool mounting accuracy.

Therefore, there has been proposed a cutting fluid supply and recovery device for a machine tool, which is provided with a device for sucking the cutting fluid remaining in the cutting fluid flow holes inside the spindle and the tool holder when the workpiece is not machined. For example, in a cutting fluid supply and recovery device for a machine tool disclosed in Patent Document 1 below, a cutting fluid recovery path is provided by branching from a cutting fluid flow path that supplies cutting fluid to a cutting fluid flow hole. The ejector is driven by the cutting fluid supplied from the cutting fluid supply source, and the cutting fluid remaining in the cutting fluid flow holes inside the spindle and the tool holder is sucked and recovered.

As a cutting fluid supply and recovery device for other machine tools that sucks and recovers the cutting fluid remaining in the cutting fluid flow holes inside the spindle and tool holder, for example, Patent Document 2 below discloses a cutting fluid flow passage and a cutting A cutting fluid supply and recovery device for a machine tool, in which an ejector is provided at the branch point of the fluid recovery path and an on-off valve is provided in the middle of the cutting fluid recovery path, and at the branch point of the cutting fluid flow path and the cutting fluid recovery path and a cutting fluid supply and recovery device for a machine tool provided with a ball valve having an ejector function.

Japanese Patent No. 2965468 Japanese Patent No. 3620954

However, the cutting fluid supply and recovery device for a machine tool described in Patent Document 1 needs to circulate the cutting fluid in order to drive the ejector, and it is necessary to constantly drive the cutting fluid pump or provide a new cutting fluid pump. there were. In addition, since the cutting fluid remaining in the cutting fluid circulation hole passes through the branch point from the cutting fluid circulation passage to the cutting fluid recovery passage, pressure loss occurs and the power to suck the cutting fluid is reduced. There was a problem that the recovery could not be sufficiently performed.

In addition, in the cutting fluid supply and recovery device for machine tools described in Patent Document 2, since the cutting fluid is supplied to the cutting fluid flow hole via the ejector, a pressure loss occurs and the cutting fluid is supplied to the workpiece machining area with sufficient pressure. There was a risk that it could not be jetted.

An object of the present invention is to supply cutting fluid from a cutting fluid supply source through a cutting fluid flow passage, which flows through a cutting fluid flow hole formed inside a spindle and a tool holder, and is discharged to a work machining area. When the cutting fluid is discharged to the work machining area during machining, the pressure for discharging the cutting fluid to the work machining area does not decrease, and the cutting fluid circulation hole does not decrease during non-machining. To provide an in-spindle cutting fluid supply and recovery device for a machine tool capable of sucking and recovering cutting fluid without driving a cutting fluid pump when sucking and recovering residual cutting fluid.

This invention consists of the following aspects in order to achieve said objective.

1) The cutting fluid supplied from the cutting fluid supply source through the cutting fluid flow passage flows through the cutting fluid flow holes formed inside the spindle and the tool holder, and is discharged to the work machining area. In machine tools made
A channel switching valve is provided in the middle of the cutting fluid channel,
The flow path switching valve has first to third ports, the first port is connected to the tip of the cutting fluid flow path on the primary side, and the second port is connected to the cutting fluid flow path on the secondary side. The base end of the passage is connected, and the third port is connected to the base end of the cutting fluid recovery passage for collecting the cutting fluid remaining in the cutting fluid flow holes inside the spindle and the tool holder to the cutting fluid supply source. and
An ejector driven by air supplied from an air supply source through the main air flow path is provided in the middle of the cutting fluid recovery path,
During work machining, the cutting fluid is discharged to the work machining area by connecting the first port and the second port of the flow path switching valve, and when not machining the work, the second port and the third port of the flow path switching valve are connected. By connecting the port of the machine tool, supplying air to the ejector, and driving the ejector, the ejector sucks and collects the cutting fluid remaining in the cutting fluid circulation hole inside the spindle and tool holder. Supply recovery device.

2) The cutting fluid supply/recovery device for a machine tool according to 1) above, which is branched from the main air flow path and provided with a secondary air flow path for supplying air to a supply destination other than the ejector.

According to the machine tool main spindle cutting fluid supply and recovery device of 1) above, the first port and the second port of the flow path switching valve are communicated during workpiece machining, and the cutting fluid is supplied to the primary side and the secondary side. Since the flow path is communicated, there is no branch point or ejector in the cutting fluid supply path, no pressure loss occurs, and the cutting fluid can be discharged with sufficient pressure to the workpiece machining area. Furthermore, when the workpiece is not processed, the second port and the third port of the flow path switching valve are communicated, and the cutting fluid flow path and the cutting fluid recovery path on the secondary side are communicated, so that the inside of the spindle and the tool holder is Since there is no branching point between the cutting fluid flow hole and the ejector, there is no pressure loss, and the cutting fluid can be sucked and collected. Furthermore, since air is used to drive the ejector, there is no need to drive a cutting fluid pump to drive the ejector, and only the cutting fluid remaining in the cutting fluid flow holes inside the spindle and tool holder can be collected. can be done.

According to the machine tool spindle internal cutting fluid supply/recovery device of 2) above, the air main flow path is branched to provide the air sub flow path, so that when performing work using air such as air blow, Since there is no need to provide such a device, the cost can be reduced.

1 is a schematic diagram of an in-spindle cutting fluid supply and recovery device for a machine tool according to a first embodiment of the present invention; FIG. 2 is a schematic diagram showing a state in which channels are switched by a channel switching valve and an on-off valve shown in FIG. 1; FIG. 3 is a cross-sectional view of the ejector shown in FIGS. 1 and 2; FIG. FIG. 7 is a schematic view of a machine tool internal cutting fluid supply and recovery device according to a second embodiment of the present invention;

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, a machine tool includes a spindle device (1) and an in-spindle cutting fluid supply and recovery device (2) for supplying and recovering cutting fluid to the spindle device (1). there is

The spindle device (1) has a housing (11) having a cylindrical hollow portion. In the hollow part of the housing (11), a spindle (12) having a tapered tool holder mounting hole at its tip is rotatably supported via a bearing (13), and a cutting tool is inserted into the tool holder mounting hole. Attached tool holder (14) is installed. A cutting fluid flow hole (15) is provided inside the spindle (12) and the tool holder (14) in order to discharge the cutting fluid from the tip of the tool toward the work machining area.

The in-spindle cutting fluid supply and recovery device (2) includes a cutting fluid supply source (3) that stores cutting fluid, and a cutting fluid supply source (3) provided between the cutting fluid supply source (3) and the rear end of the spindle device (1). A liquid flow path (4), a flow path switching valve (5) provided in the middle of the cutting fluid flow path (4), and a flow path switching valve (5) and a cutting fluid supply source (3). It comprises a cutting fluid recovery path (6) for recovering the cutting fluid collected, and an ejector (7) provided in the middle of the cutting fluid recovery path (6).

In the cutting fluid flow passage (4), the side connected between the flow switching valve (5) and the cutting fluid supply source (3) is called the primary cutting fluid flow passage (4). The side connected between the switching valve (5) and the spindle device (1) is referred to as a secondary cutting fluid flow passage (4).

The flow path switching valve (5) has a first flow path configuration that allows communication between the primary side cutting fluid flow path (4) and the secondary side cutting fluid flow path (4), and a cutting fluid recovery path ( 6) and the cutting fluid flow passage (4) on the secondary side are switched to one of the second flow passage configurations.

The cutting fluid supply source (3) comprises a cutting fluid tank (31) and a pump (32). A suction port of the pump (32) is connected to the cutting fluid tank (31) through a pipeline. The outflow port of the pump (32) is connected to the base end of the cutting fluid flow passage (4) on the primary side. The cutting fluid sucked by the pump (32) from the cutting fluid tank (31) is supplied to the work machining area through the flow path switching valve (5) as shown in FIG. cutting fluid flow hole (15).

In the cutting fluid recovery path (6), the side connected between the flow path switching valve (5) and the ejector (7) is called the primary side cutting fluid recovery path (6), and the ejector (7). The side connected to the cutting fluid supply source (3) is referred to as a secondary cutting fluid recovery path (6). The tip of the cutting fluid recovery path (6) is connected to a cutting fluid tank (31) so that the recovered cutting fluid is discharged to the cutting fluid tank (31).

The ejector (7) is a generally known fluid ejection device, and as shown in FIG. This device has the function of generating a negative pressure by the entrainment action of the ejector (7) and sucking and discharging the second fluid by this negative pressure. , a suction port (7b) through which the second fluid is sucked, and a discharge port (7c) through which the second fluid is discharged together with the first fluid.

An air main flow path (9) extending from an air supply source (8) is connected to the inlet (7a). The inlet (7a) communicates with an ejection nozzle (71) formed in the ejector (7). The ejection nozzle (71) is formed so that the air that has flowed in at a predetermined pressure is ejected toward the discharge port (7c) in the form of a high-speed jet. The suction port (7b) is formed on a side surface closer to the inlet (7a) than the tip of the ejection nozzle (71). An on-off valve (91) is provided in the main air passage (9), and the main air passage (9) is opened or closed by the on-off valve (91).

The flow path switching valve (5) is a solenoid type electromagnetic valve that switches the flow path direction, and has first to third ports (5a), (5b), and (5c).

As shown in FIG. 1, the flow path switching valve (5) is in a state of being excited during work processing, and the first port (5a) and the second port (5b) are connected. and, as shown in FIG. 2, when the workpiece is not processed, the flow switching valve (5) is demagnetized so that the second port (5b) and the third port ( 5c) is in communication with the second channel configuration.

The first port (5a) is connected to the tip of the primary side cutting fluid main flow path (4), and the second port (5b) is connected to the base of the secondary side cutting fluid main flow path (4). The ends are connected, and the base end of the cutting fluid recovery path (6) on the primary side is connected to the third port (5c).

The base end of the cutting fluid flow passage (4) on the primary side is connected to the outlet of the pump (32), and the tip of the cutting fluid flow passage (4) on the secondary side is connected to a rotary joint (not shown). etc. to the rear end of the cutting fluid flow hole (15) of the main shaft (12). The cutting fluid supplied from the cutting fluid supply source (3) flows from the rear end of the cutting fluid flow hole (15) to the tip, and is ejected from the tip of the tool to the work machining area.

The tip of the primary cutting fluid recovery passage (6) connected to the third port (5c) is connected to the suction hole (7b) of the ejector (7).

The pump (32), the flow path switching valve (5), the air supply source (8), and the on-off valve (91) are connected to a control device (not shown), which controls the supply of the cutting fluid and the cutting fluid flow path. switching, air supply and opening/closing of the main air flow path are controlled.

Next, the operation of the in-spindle cutting fluid supply and recovery device (2) for a machine tool according to the first embodiment of the present invention will be described.

First, as shown in FIG. 1, when the machine tool cuts a workpiece, the flow switching valve (5) is energized to communicate the first port (5a) and the second port (5b). It becomes the 1st flow-path form which carries out. As a result, the cutting fluid in the cutting fluid tank (31) is circulated through the cutting fluid flow path (4) and the first and second ports (5a) and (5b) of the flow path switching valve (5) by the pump (32). The coolant is supplied to the cutting fluid flow hole (15) of the main shaft (12) through the main shaft (12). The high-pressure cutting fluid supplied to the cutting fluid flow hole (15) passes through the spindle (12) and the tool holder (14) and is discharged toward the machining area of the workpiece.

When the predetermined machining process is finished, the rotation of the spindle (12) is stopped, and the machine tool starts the tool changing operation.

At this time, the control device stops the supply of cutting fluid by the pump (32) and demagnetizes the flow path switching valve (5) as shown in FIG. 3 ports (5c) communicate with each other to form a second flow path. As a result, the cutting fluid circulation hole (15) of the main shaft (12) is connected to the secondary side cutting fluid circulation passage (4), the second and third ports (5b) and (5c) of the flow path switching valve (5), and It communicates with the suction port (7b) of the ejector (7) through the cutting fluid recovery passage (6) on the primary side.

Further, air is sent from the air supply source (8), and the opening/closing valve (91) is opened by the control device, so that the air flows through the main air flow path (9) to the inlet of the ejector (7). When supplied to (7a), the air is ejected at high speed from the ejection nozzle (71) of the ejector (7) to generate negative pressure, and the pressure at the suction port (7b) becomes lower than the atmospheric pressure. At about the same time, the cutting fluid remaining in the cutting fluid flow holes (15) of the spindle (12) and tool holder (14) is released into the second and third ports (5b) ( 5c), the cutting fluid is sucked from the suction port (7b) into the ejector (7), and the cutting fluid is discharged from the discharge port (7c) of the ejector (7) together with the air supplied to the ejector (7) from the inlet (7a). be done.

After the cutting fluid remaining in the cutting fluid flow holes (15) of the spindle (12) and the tool holder (14) is removed by continuously sucking the cutting fluid for a predetermined time, air is supplied by the control device of the machine tool. The supply of air from the source (8) is stopped, and the on-off valve (91) is closed. When the supply of air is stopped, air is no longer supplied to the inlet (7a) of the ejector (7), so the ejector (7) also stops sucking the cutting fluid.

Cutting fluid leaks from the cutting fluid circulation hole (15) when the tool holder (14) is removed from the spindle (12) while cutting fluid remains in the cutting fluid circulation hole (15), or when the tool is replaced. Therefore, after the cutting fluid is removed from the cutting fluid circulation hole (15), the cutting fluid will not leak even if the tool holder (14) is removed or the tool is replaced.

On the other hand, as shown in FIG. 4, in the machine tool spindle cutting fluid supply and recovery device according to the second embodiment, the air main flow path (9) branches to supply air to a supply destination other than the ejector (7). An air sub-channel (10) is provided for this purpose, and the tip of the air sub-channel (10) extends to an air supply destination (not shown). It is preferable that the main air flow path (9) branches between the on-off valve (91) and the ejector (7). Since the configuration other than the above configuration is the same as that of the first embodiment shown in FIGS. 1 and 2, the same components as those in FIGS.

For example, an air blower having an air nozzle provided in the work machining area is one of the destinations of the air supplied by the air sub-flow path (10). When the secondary air flow path (10) is connected to the air blow device, the cutting fluid remaining in the cutting fluid flow holes (15) of the spindle (12) and tool holder (14) is ejected from the ejector (14) when the workpiece is not machined. At the same time as suctioning by 7), air is jetted toward the work processing area from the air nozzle to scatter and remove foreign matter such as chips and cutting fluid remaining in the work processing area, and to remove moisture adhering to the work. It can be used for various purposes, such as drying by blowing off and evaporating, and cooling to lower the temperature of the work that has been heated during the processing process.

Furthermore, an air flow path switching valve is provided at the branch point of the main air flow path (9) and the sub air flow path (10), and when air is circulated, the flow path, ejector (7), is supplied only to the ejector (7). ), and a flow path that supplies air to both the ejector (7) and the air supply destination other than the ejector (7). Alternatively, the supply of air to the ejector (7) and to other air supply destinations than the ejector (7) may be independently controlled. Furthermore, an air flow path switching valve may be provided with a function of blocking air flow in both the main air flow path (9) and the secondary air flow path (10), instead of the on-off valve (91).

(2)...Spindle cutting fluid supply and recovery device (3)...Cutting fluid supply source (4)...Cutting fluid flow path (5)...Flow path switching valve (5a)...Second 1st port (5b)... second port (5c)... third port (6)... cutting fluid recovery path (7)... ejector (7a)... inflow port (7b ) Suction port (7b) Discharge port (8) Air supply source (9) Main air flow path (10) Secondary air flow path (12) Main shaft ( 14)...Tool holder (15)...Cutting fluid flow hole

Claims (2)

The cutting fluid supplied from the cutting fluid supply source through the cutting fluid flow passage flows through the cutting fluid flow holes formed inside the spindle and the tool holder, and is discharged to the work machining area. In machine tools,
A channel switching valve is provided in the middle of the cutting fluid channel,
The flow path switching valve has first to third ports, the first port is connected to the tip of the cutting fluid flow path on the primary side, and the second port is connected to the cutting fluid flow path on the secondary side. The base end of the passage is connected, and the third port is connected to the base end of the cutting fluid recovery passage for collecting the cutting fluid remaining in the cutting fluid flow holes inside the spindle and the tool holder to the cutting fluid supply source. and
An ejector driven by air supplied from an air supply source through the main air flow path is provided in the middle of the cutting fluid recovery path, and a branch is provided between the ejector and the cutting fluid supply source in the cutting fluid recovery path. not
When machining a workpiece, the cutting fluid is discharged to the workpiece machining area by connecting the first port and the second port of the flow path switching valve, and when not machining the workpiece, the second port and the third port of the flow path switching valve are connected. By connecting the port of the machine tool, supplying air to the ejector, and driving the ejector, the ejector sucks and collects the cutting fluid remaining in the cutting fluid circulation hole inside the spindle and tool holder. Supply recovery device. A valve for opening and closing the main air passage is provided in the middle of the main air passage. 2. The in-spindle cutting fluid supply and recovery device for a machine tool according to claim 1, wherein a flow path is provided.

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