JP7180023B1 - Cooling fluid supply structure - Google Patents

Abstract

A cooling fluid supply structure capable of easily establishing an appropriate cooling fluid supply path according to the shape of a grinding wheel in conjunction with mounting of a tool unit having a grinding wheel on a spindle is provided. A cooling fluid supply structure includes a first supply passage portion (101) that passes through the inside of a spindle housing (4a) and penetrates the wall surface of an engaging recess (30d) at the tip portion thereof, and a tool unit (20) that has a grindstone (22). Engagement in which the co-rotation prevention projection 25 is penetrated through the anti-rotation projection 25 or straddles the co-rotation prevention projection 25 of the tool unit 20 and the casing 24, and the co-rotation prevention projection 25 is engaged with the engagement recess 30d. In this state, the second supply channel portion 102, whose one end side opening communicates with the downstream side opening of the first supply channel portion 101, is provided outside the casing 24 of the tool unit 20, and the one end side opening is the second supply channel portion 102. A third supply channel portion 103 communicates with the downstream opening of the second supply channel portion 102 and has an opening on the other end side located near the surface of the grindstone 22 . [Selection drawing] Fig. 4

Description

TECHNICAL FIELD The present invention relates to a cooling fluid supply structure for supplying a cooling fluid to the surface of a grinding wheel in a machine tool having a spindle to which a tool unit having a grinding wheel is detachable and a spindle housing that rotatably holds the spindle. .

Conventionally, there has been known a tool unit that is detachably attached to the tip of a spindle of a machine tool (see, for example, Patent Document 1). This tool unit includes a rotary output shaft that is integrally rotatably mounted in a tapered hole provided in a spindle, a machining tool that rotates in conjunction with the rotary output shaft, a casing that rotatably supports the rotary output shaft, a casing, and a casing. and a co-rotation prevention protrusion that engages with an engagement recess formed in the tip surface of the spindle housing.

When a grindstone is employed as the machining tool, a cooling fluid supply structure is required to suppress heat generation during grinding. Patent Document 2 discloses an example of a cooling fluid supply structure. This cooling fluid supply structure includes an enclosure that is attached to the casing and surrounds the grindstone, an injection nozzle that is attached to the enclosure and injects coolant into the enclosure, and an injection nozzle that connects the coolant supply device. A coolant line is disclosed. The coolant supplied from the coolant supply device is injected into the enclosure from the injection nozzle through the coolant pipe, and the heat-generating portion of the workpiece (work) is cooled by the injected coolant.

Japanese Patent Application Laid-Open No. 2004-130423 Utility Model Registration No. 3158872

When the cooling fluid supply structure disclosed in Patent Document 2 is adopted, in addition to the operation of mounting the tool unit in the taper hole of the spindle, the operation of connecting the coolant pipe (fluid supply path) to the injection nozzle is required. For this reason, there is a problem that the work time until the coolant supply preparation is completed is long.

In addition, in the cooling fluid supply structure shown in Patent Document 2, regardless of the shape of the grindstone to be used, the position of the enclosure and the position of the injection nozzle are fixed, so the coolant (cooling fluid) is placed at an appropriate position (for example, machining There is a problem that it is not possible to accurately supply to the heat generating part of the object). To solve this problem, the injection nozzle is fixed at the tip of the coolant pipe, and the routing route of the coolant pipe is changed every time the shape of the grindstone used is changed, so that the coolant, which is the cooling fluid, is supplied. It is conceivable to adjust the position. However, in this case, there is a problem that the time required for adjusting the coolant supply position becomes longer, and the setup work time increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is intended to facilitate a suitable cooling fluid supply path according to the shape of the grindstone in conjunction with the operation of mounting a tool unit having a grindstone on the spindle. The object is to provide a cooling fluid supply structure that can be established.

One aspect of the present invention for solving the above problems is
A spindle having a tool mounting hole for mounting a tool unit on a tip surface thereof, and a spindle housing for rotatably holding the spindle, wherein an engagement recess recessed toward the base end is provided at the tip of the spindle housing, The tool unit includes a rotary output shaft fitted into the tool mounting hole, a grinding stone that rotates in conjunction with the rotation of the rotary output shaft, a casing that rotatably holds the rotary output shaft, and a and a fixed co-rotation prevention protrusion, wherein the co-rotation prevention protrusion is engaged with the engaging recess to prevent the casing from co-rotating with rotation of the main shaft. A cooling fluid supply structure for supplying a cooling fluid to the surface of the grindstone,
a first supply passage portion that passes through the interior of the spindle housing and penetrates the wall surface of the engagement recess to supply a cooling fluid toward the interior of the engagement recess;
It is formed through the co-rotation prevention projection, or is penetratingly formed across the co-rotation prevention projection and the casing, and in an engaged state where the co-rotation prevention projection is engaged with the engagement recess, one end a second supply channel portion whose side opening communicates with the downstream opening of the first supply channel portion;
Provided outside the casing, one end side opening communicates with the downstream side opening of the second supply channel portion, and the other end side opening is located near the surface of the grindstone and faces the surface of the grindstone. and a third supply passage portion for supplying cooling fluid.

According to this cooling fluid supply structure, when a tool unit having a grindstone as a working tool is attached to the spindle, a cooling fluid supply path to the surface of the grindstone is automatically established. That is, the cooling fluid supply path is composed of three parts, that is, a first supply path portion, a second supply path portion, and a third supply path portion. The second and third supply channel portions are provided in the tool unit. Here, the first supply channel portion penetrates through the wall surface of the engaging recess provided at the tip of the spindle housing, and the second supply channel portion is formed through the co-rotation prevention protrusion of the tool unit. Alternatively, it is formed so as to extend over the co-rotation prevention projection and the casing. Therefore, when the co-rotation prevention protrusion is engaged with the engagement recess of the spindle housing when the tool unit is attached to the spindle, the downstream opening of the first supply passage and the opening of the one end of the second supply passage are closed. communicates with. Since the second supply channel portion and the third supply channel portion are originally in communication regardless of whether or not the co-rotation prevention protrusion is engaged, as a result, the first to third supply channel portions are connected at once. , a cooling fluid supply path to the grindstone surface is formed.

Therefore, it is possible to easily install and remove the cooling fluid supply path in conjunction with the attachment/detachment operation of the tool unit to/from the spindle, thereby shortening the setup work time. In addition, by appropriately setting the wiring route of the third supply flow path for discharging the cooling fluid toward the grindstone in advance according to the shape of the grindstone, the shape of the grindstone can be changed by exchanging the tool unit or the like. Even so, it is possible to establish an appropriate cooling fluid supply path according to the shape of the grindstone. An appropriate cooling fluid supply path according to the shape of the grindstone is defined as, for example, a flow path capable of supplying a cooling fluid to a heat-generating portion of the workpiece (a contact portion of the workpiece with the grindstone). is not limited to, and this definition is appropriately changed according to the usage conditions of the grindstone.

Moreover, since the first supply channel portion is formed inside the spindle housing, there is no need to separately secure a piping space for the cooling fluid, and space efficiency can be improved. Further, the engagement between the co-rotation prevention projection provided on the tool unit and the engaging recess of the spindle housing allows the first supply passage portion on the spindle side and the second supply passage portion on the tool unit side to communicate with each other. As a result, the co-rotation prevention protrusion also serves as a connector for connecting the flow path. Therefore, there is no need to separately provide a connector for connecting the flow path to the tool unit, and there is no need to separately provide an adapter for connection to the tip surface of the spindle housing. Therefore, the number of parts can be reduced and the manufacturing cost can be reduced.

The engaging recess is formed in a mounting member separate from the spindle housing, which is mounted on the tip surface of the spindle housing. It is preferable to comprise a channel and a main shaft external channel formed through the mounting member.

According to this configuration, the engagement recess with which the co-rotation prevention projection engages is formed in the mounting member separate from the spindle housing, so that the co-rotation prevention projection can be removed by, for example, replacing the tool unit. Even if the position changes, it can be dealt with simply by replacing the mounting member with another mounting member having a different position of the engaging recess. Further, by changing the shape of the main shaft external channel formed in the mounting member, the position of the downstream opening of the first supply channel portion can be easily changed. Therefore, even if the position of the second supply flow channel formed in the co-rotation prevention protrusion changes due to the replacement of the tool unit, the first supply flow channel and the second supply flow channel can be replaced simply by exchanging the mounting member. can be easily communicated with each other.

It is preferable that the mounting member is detachably fixed to the tip surface of the spindle housing via a screw that is screwed into a screw hole formed in the tip surface of the spindle housing.

According to this configuration, it is possible to easily replace the mounting member.

It is preferable that the first supply channel portion is a linear channel extending in the axial direction of the main shaft.

According to this configuration, by forming the first supply channel portion in a straight line, it is possible to reduce the channel resistance acting on the cooling fluid in the first supply channel portion. Thereby, the cooling fluid can be vigorously supplied from the first supply channel portion toward the second supply channel portion connected downstream thereof.

Preferably, the second supply channel portion is a linear channel extending in the axial direction of the main shaft in the engaged state.

According to this configuration, by forming the second supply channel portion in a straight line, it is possible to reduce the channel resistance acting on the cooling fluid in the second supply channel portion. Thereby, the cooling fluid can be vigorously supplied from the second supply channel portion toward the third supply channel portion connected downstream thereof.

In the engaged state, the first supply channel portion and the second supply channel portion preferably extend linearly in the axial direction of the main shaft and are arranged coaxially with each other.

According to this configuration, since the first supply channel portion and the second supply channel portion are coaxially arranged, when the cooling fluid flows from the first supply channel portion into the second supply channel portion, of pipeline resistance can be reduced. In addition, since the first supply channel portion and the second supply channel portion cooperate to form one linear fluid supply channel extending in the axial direction of the main shaft, even if the fluid supply channel is bent, In comparison, the pipeline resistance acting on the cooling fluid can be remarkably reduced.

It is preferable that the third supply channel part is formed by a flexible pipe.

According to this configuration, by changing the curved shape of the flexible pipe, it is possible to freely adjust the supply point of the cooling fluid to the grindstone. Therefore, the cooling fluid can be accurately supplied, for example, toward the heat-generating portion of the workpiece.

According to the present invention, the first supply passage portion passes through the interior of the spindle housing and penetrates the wall surface of the engagement recess at the tip portion thereof, and the co-rotation prevention protrusion of the tool unit having the grindstone as a processing tool penetrates. or formed so as to straddle the co-rotation prevention projection of the tool unit and the casing, and in an engaged state in which the co-rotation prevention projection engages the engagement recess, the opening on one end side is the first opening. a second supply channel portion communicating with the downstream opening of the supply channel portion; and a casing provided outside the casing of the tool unit, the opening at one end communicating with the downstream opening of the second supply channel portion. Since the opening on the other end side is provided with the third supply flow path portion positioned near the surface of the grindstone, the tool unit can be appropriately adjusted according to the shape of the grindstone in conjunction with the work of attaching the tool unit to the spindle. cooling fluid supply paths can be easily established. Therefore, it is possible to shorten the setup work time associated with the replacement of the tool unit as much as possible.

1 is a schematic side view showing a machine tool provided with a coolant supply structure (an example of a cooling fluid supply structure) according to an embodiment of the invention; FIG. FIG. 4 is a partial cross-sectional view of the spindle head horizontally cut along its axis; FIG. 3 is an external perspective view showing a tool unit equipped with a grindstone; FIG. 4 is a partial cross-sectional view horizontally cutting the spindle head to which the tool unit is attached along its axis; FIG. 5 is an enlarged view showing an enlarged V portion of FIG. 4; (a) is a side view of the mounting member, and (b) is a front view of the mounting member as seen from the engaging recess side. It is an explanatory view for explaining a mounting member concerning other embodiments. It is an explanatory view for explaining the composition of the 2nd supply channel part concerning other embodiments.

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

<<Embodiment>>
FIG. 1 is a right side view showing a machine tool 1 having a coolant supply structure (an example of a cooling fluid supply structure) according to the embodiment. This machine tool 1 is a horizontal machining center, and includes a bed 2, a column 3, a spindle head 4, a spindle 5, a table 6, and the like. The machine tool 1 is entirely covered with a splash guard 7 that constitutes its appearance. Note that FIG. 1 showing the entire machine tool 1 shows only the essential parts, which are the main constituent elements of the machine tool 1 .

The bed 2 as a whole is formed in a substantially T-shape in plan view, and the table 6 is arranged on the bed 2 and guided by a guide rail (not shown) in the longitudinal direction of the bed 2, that is, in a horizontal direction. It is provided to move in the indicated Z-axis direction. A workpiece W (only shown in FIG. 1) to be processed is set on the table 6 with a pallet P therebetween.

The column 3 is arranged on the bed 2 and guided by a guide rail 8 so as to move in the X-axis direction (perpendicular to the plane of FIG. 1) perpendicular to the Z-axis. A spindle head 4 is supported on the column 3 . The spindle head 4 has a spindle housing 4a (see FIG. 2). A main shaft 5 is rotatably held in the main shaft housing 4 a via a bearing 11 . A machining tool K is detachably attached to the spindle 5 via a tool holder or as part of a tool unit 20 (see FIG. 3), which will be described later. In the following, unless otherwise specified, the latter case where the machining tool K is mounted on the spindle 5 as a part of the tool unit 20 will be described.

A spindle head 4 is held by the column 3 so as to be movable in the Y-axis direction perpendicular to the X-axis and the Z-axis. Thus, the spindle head 4 moves within the X-Y plane.

The column 3 is driven to feed in the X-axis direction by an X-axis feed mechanism (not shown), the spindle head 4 is driven to feed in the Y-axis direction by a Y-axis feed mechanism (not shown), and the table 6 is driven to feed in the Z-axis direction. It is driven to feed in the Z-axis direction by a feed mechanism (not shown). These X-axis feed mechanism, Y-axis feed mechanism, and Z-axis feed mechanism are configured by, for example, a combination of a ball screw and a motor. Each feed mechanism, the main shaft 5 and a main shaft motor (not shown) for driving the main shaft 5 function as a machining mechanism section 9 .

The machining mechanism 9 changes the relative positions of the machining tool K mounted on the spindle 5 and the workpiece W set on the table 6 under the control of the control device 50 (see FIG. 2) to change the workpiece W. is processed into the desired shape. The control device 50 is a computer having a CPU, a ROM and a RAM, and controls the operation of the machining mechanism section 9 based on an NC program stored in a hard disk or the like.

The machine tool 1 further includes a coolant supply device 10 (see FIG. 2) that supplies a coolant liquid into the machining area for purposes such as cooling and lubrication of the machining site and discharging chips.

The coolant supply device 10 sucks the coolant liquid stored in the storage tank with a supply pump (not shown), and supplies the sucked coolant liquid to the machining portion of the workpiece W. As shown in FIG. After being supplied, the coolant liquid is collected in the storage tank through a return pipe connected to the bottom of the bed 2 . The coolant supply device 10 is operated and controlled by the control device 50 .

[Details of spindle structure]
As shown in FIG. 2, the spindle housing 4a is composed of a substantially cylindrical housing main body portion 4b and a front end cover portion 4c that covers the front end side of the housing main body portion 4b. The front end cover portion 4c has a spigot portion and is attached to the front end portion of the housing main body portion 4b from the outside in the axial direction.

A through hole 4e is formed in the spindle housing 4a. The through-hole 4e is positioned radially outward of the bearing 11 in the spindle housing 4a and extends parallel to the axis of the spindle 5 across the housing body 4b and the tip cover 4c. One end of the through-hole 4e is connected to the coolant supply device 10 via an electromagnetic valve 51, and the other end opens to the tip surface of the spindle housing 4a. The solenoid valve 51 is driven to open and close by the control device 50 . When the electromagnetic valve 51 is excited and driven in the opening direction, the coolant liquid is supplied from the coolant supply device 10 into the through hole 4e. An O-ring groove 4f is formed so as to surround the through hole 4e in the contact surface of the housing main body 4b with the tip cover portion 4c, and an O-ring 35 is fitted in the O-ring groove 4f.

The main shaft 5 is arranged radially inside the housing body portion 4b and the tip cover portion 4c. The main shaft 5 is rotatably supported by a bearing 11 fitted on the inner peripheral surface of the housing main body 4b. Two bearings 11 are arranged on each of the distal end side and the proximal end side of the housing body portion 4b. In FIG. 2, the drawing is simplified and only two bearings 11 on the tip side are shown. The number and arrangement of the bearings 11 are not limited to this. Moreover, the type of the bearing 11 is not limited to rolling bearings, and may be slide bearings, for example.

The spindle 5 has a tool mounting hole 5a in which a tool unit 20 (see FIG. 3) is mounted, and a through hole 5b in which a collet 12 for holding the tool unit 20 to the spindle 5 is accommodated.

The tool mounting hole 5a is open on the distal end surface of the main shaft 5 and tapers in diameter from the distal end side of the main shaft 5 toward the proximal end side. When mounting the tool unit 20 on the spindle 5, the shank 21a of the tool unit 20 is fitted into the tool mounting hole 5a. In this example, the operation of attaching and detaching the tool unit 20 to and from the tool attachment hole 5a is automatically performed by an ATC (Automatic Tool Changer) device mounted on the machine tool 1, but the present invention is not limited to this. can be done manually.

The through hole 5b extends in the axial direction coaxially with the main shaft 5 and communicates with the base end of the tool mounting hole 5a. The collet 12 is accommodated in the through hole 5 b so as to be movable in the axial direction of the main shaft 5 . The collet 12 is connected to a drawbar mechanism (not shown). When the collet 12 is moved to the proximal end side of the main shaft 5 by the draw bar mechanism, the collet 12 is closed, and the pull stud 21g of the tool unit 20 is gripped by the collet 12, and the pull stud 21g is moved to the proximal end side of the main shaft 5. drawn into. As a result, the shank 21 a of the tool unit 20 is firmly fitted into the tool mounting hole 5 a and the tool unit 20 is fixed to the spindle 5 . When removing the tool unit 20 from the spindle 5 , the drawbar mechanism moves the collet 12 to the tip side of the spindle 5 . As a result, the collet 12 is opened and the grip of the shank 21a by the collet 12 is released, making it possible to pull out the tool unit 20 from the tool mounting hole 5a.

FIG. 3 is a perspective view showing an example of the tool unit 20 attached to the spindle 5, and FIG. 4 is a longitudinal sectional view showing the tool unit 20 attached to the spindle 5. As shown in FIG. In FIGS. 3 and 4, the work W is omitted. In the following description, the distal end side and proximal end side of the tool unit 20 in the axial direction are defined as the unit front side and the unit rear side, respectively.

This tool unit 20 has a grindstone 22 as a processing tool K. As shown in FIG. 3 and 4 show an example in which the grindstone 22 is disc-shaped, but the shape of the grindstone 22 is not limited to this, and may be, for example, conical. When the tool unit 20 is attached to the spindle 5, a cooling flow path (see the white arrow in FIG. 4) is formed for supplying cooling coolant to the grindstone 22. As shown in FIG. This cooling channel is composed of a first supply channel portion 101 , a second supply channel portion 102 and a third supply channel portion 103 . Details of each of the supply channel portions 101 to 103 will be described later.

The tool unit 20 includes a rotation output shaft 21, the grindstone 22 fixed to the tip of the rotation output shaft 21, a pair of bearings 23 rotatably supporting the rotation output shaft 21, and a pair of bearings 23 inside. and a co-rotation prevention pin 25 connected to the casing 24 .

The pair of bearings 23 are spaced apart in the axial direction of the rotation output shaft 21 . A spacer 26 is arranged between the pair of bearings 23 to regulate the gap therebetween. The number and arrangement of the bearings 23 are not limited to this. Moreover, the type of the bearing 23 is not limited to a rolling bearing, and may be, for example, a sliding bearing.

The rotation output shaft 21 is connected to a tapered shank 21a that can be fitted into the tool mounting hole 5a of the main shaft 5, and a flange portion 21b that is interposed at the tip of the shank 21a. A shaft main body portion 21c, a nut engaging shaft portion 21d to which a nut 27 for fixing the pair of bearings 23 is screwed, and a grindstone 22 are attached to the tip end side of the nut engaging shaft portion 21d. and a tip screw portion 21f connected to the tip of the tool attachment shaft 21e. A nut 28 for fixing the grindstone 22 is screwed to the tip screw portion 21f.

A pull stud 21g which is detachably held by the collet 12 is connected to the base end of the shank 21a. Although various standards are prepared for the shape of the shank 21a, the BBT standard is adopted in the example of FIG. The standard of the shank 21a is not limited to the BBT standard, and other standards such as the BT standard and the HSK standard may be adopted.

The flange portion 21b has a groove portion 21h having a substantially V-shaped cross section extending over the entire circumference of the outer peripheral surface. The groove portion 21h is used when the tool unit 20 is automatically changed by the ATC device. Specifically, when the tool unit 20 is automatically replaced, the tool unit 20 is held by the ATC arm by engaging the claw portion of the ATC arm with the groove portion 21h.

The casing 24 includes a cylindrical bearing housing cylinder portion 24a for housing the pair of bearings 23, a front end cover portion 24b attached to one end side of the bearing housing cylinder portion 24a in the axial direction, and a bearing housing cylinder portion 24a. and a pin holding portion 24c that holds the co-rotation prevention pin 25 and a connecting portion 24d that connects the pin holding portion 24c and the bearing housing cylindrical portion 24a. there is

The pin holding portion 24c has a substantially cylindrical shape in appearance. The pin holding portion 24c has a guide hole 24e for slidably guiding the co-rotation prevention pin 25, as shown in FIG. The axis of the guide hole 24e extends parallel to the axis of the rotation output shaft 21, and the distance between the two axes is the distance between the axis of the main shaft 5 and the through hole 4e (see FIG. 4) formed in the main shaft housing 4a. Equal to the separation distance from the axis. The guide hole 24e is a blind hole that opens toward the rear of the unit. The co-rotation prevention pin 25 is inserted into the guide hole 24e so that a portion of the distal end thereof protrudes toward the rear side of the unit. The co-rotation prevention pin 25 is guided by a guide hole 24e so as to move back and forth in its axial direction. The edge of the tip of the co-rotation prevention pin 25 is chamfered at approximately 45 degrees.

Inside the co-rotation prevention pin 25, a small diameter hole 25a and a large diameter hole 25c connected to the small diameter hole 25a via a stepped surface 25b are formed through the pin axial direction. The small-diameter hole 25a opens to a distal end face 25g (end face on the projecting side) of the co-rotation prevention pin 25, and the large-diameter hole 25c opens to a base end face 25f of the co-rotation prevention pin 25. As shown in FIG. A compression coil spring 34 is arranged in a compressed state between the step surface 25b and the inner end surface 24i of the guide hole 24e. The co-rotation prevention pin 25 is biased toward the rear side of the unit by the compression coil spring 34 .

As shown in FIG. 5, the space inside the co-rotation prevention pin 25 and the space on the hole bottom side of the base end surface 25f of the co-rotation prevention pin 25 in the guide hole 24e are used for cooling during grinding as will be described later. filled with coolant. The co-rotation prevention pin 25 has a surface dimension set so that it advances toward the rear side of the unit by the pressure of the coolant liquid. That is, when the area of the step surface 25b of the co-rotation prevention pin 25 is A1, the area of the base end surface 25f is A2, and the area of the tip surface 25g is A3, the relationship A1+A2>A3 is satisfied. According to this, the thrust toward the unit rear side, which is generated by the coolant pressure acting on the step surface 25b and the base end surface 25f of the co-rotation pin, is caused by the coolant pressure acting on the tip end surface 25g of the co-rotation prevention pin 25. Overcome the forward thrust of the unit that is produced. Therefore, the co-rotation prevention pin 25 can be firmly brought into close contact with the engaging recess 30d of the mounting member 30 located on the rear side of the unit, thereby preventing leakage of the coolant liquid.

An O-ring groove 25d is formed in a surface portion of the outer peripheral surface of the co-rotation prevention pin 25 that fits into the guide hole 24e. An O-ring 33 is fitted in the O-ring groove 25d.

A through hole 24f is formed in a guide end wall 24j of the pin holding portion 24c, which forms the inner end face 24i of the guide hole 24e. The through hole 24 f is formed coaxially with the small diameter hole 25 a and the large diameter hole 25 c of the co-rotation prevention pin 25 . The through hole 24f has a small hole portion 24m that opens to the inner end surface 24i of the guide hole 24e, and a female screw portion for pipe connection is formed on the inner peripheral surface of the through hole 24f located on the front side of the unit from the small hole portion 24m. and a screw hole portion 24n. One end of a flexible pipe 36, which will be described later, is screwed into the screw hole portion 24n.

A protruding plate 25e is formed on the outer peripheral surface of the co-rotation prevention pin 25 so as to protrude toward the center of rotation of the tool unit 20 (toward the cylindrical bearing housing portion 24a). The co-rotation prevention pin 25 is guided in a direction parallel to the axis of the guide hole 24e by a retaining pin 29 passing through the projecting plate 25e. The retainer pin 29 is fixed by screwing a screw portion at its tip into a screw hole 24k formed in the rear side surface of the unit of the connecting portion 24d. When the head of the retaining pin 29 comes into contact with the protruding plate 25e, the amount of movement of the co-rotation preventing pin 25 toward the rear side of the unit is restricted, and the co-rotating preventing pin 25 is prevented from slipping out of the guide hole 24e. ing.

When the tool unit 20 is attached to the spindle 5, the co-rotation prevention pin 25 is engaged with the engagement recess 30d of the mounting member 30 fixed to the spindle housing 4a. By this engagement, the casing 24 of the tool unit 20 is connected to the spindle housing 4a, which is a stationary member, via the anti-corotation pin 25 and the mounting member 30. As shown in FIG. This prevents the casing 24 from co-rotating when the main shaft 5 rotates. Thus, the co-rotation prevention pin 25 functions as a co-rotation prevention protrusion.

As shown in FIG. 3, when the tool unit 20 is not attached to the main shaft 5, the tip of the protruding plate 25e connected to the outer peripheral surface of the co-rotation prevention pin 25 is attached to the flange portion 21b of the rotation output shaft 21. It is engaged with the formed engagement groove 21i. The engagement groove 21i is located on the outer peripheral portion of the flange portion 21b and is open to the radially outer side of the flange portion 21b and to the front side of the unit. Then, the tip of the protruding plate 25e is engaged with the engagement groove 21i of the rotation output shaft 21, so that the casing 24 is prevented from rotating with respect to the rotation output shaft 21. As shown in FIG. Therefore, it is possible to prevent the casing 24 from rotating unnecessarily with respect to the rotation output shaft 21 when the tool unit 20 is accommodated in the tool magazine of the ATC device, for example.

On the other hand, when the tool unit 20 is attached to the spindle 5 as shown in FIG. 4, the co-rotation prevention pin 25 is engaged with the engaging recess 30d of the mounting member 30 and the contact from the engaging recess 30d is prevented. Receiving the reaction force, it slightly moves to the unit front side (right side in FIG. 4) while resisting the biasing force of the compression coil spring 34 . As a result, the distal end of the protruding plate 25e connected to the co-rotation prevention pin 25 moves to the outside of the engagement groove 21i of the rotation output shaft 21, canceling the anti-rotation function of the protruding plate 25e. As a result, the rotation output shaft 21 can rotate independently of the casing 24 while being supported by the casing 24 .

[Configuration of mounting member]
As shown in FIGS. 5 and 6, the mounting member 30 has a bracket portion 30a forming a mounting seat surface, and a cylindrical boss portion 30b projecting from the side surface of the bracket portion 30a opposite to the mounting seat surface side. is doing.

The mounting member 30 has an engaging recess 30d that opens to the end surface of the cylindrical boss portion 30b, and a communication hole 30g that is connected to the engaging recess 30d and opens to the mounting seat surface. The communication hole 30g is formed so as to communicate the through hole 4e of the spindle housing 4a and the engaging recess 30d in a state where the mounting member 30 is attached to the tip surface of the spindle housing 4a.

The engagement concave portion 30d is composed of a cylindrical hole portion 30e coaxial with the cylindrical boss portion 30b and a tapered hole portion 30f connected to the cylindrical hole portion 30e and having a smaller diameter toward the mounting seat surface. The cylindrical hole portion 30 e is formed so as to fit on the outer peripheral surface of the co-rotation prevention pin 25 . The tapered hole portion 30f is formed so as to fit into the chamfered portion on the tip side of the co-rotation prevention pin 25. As shown in FIG.

An O-ring groove 30h is formed in the mounting seat surface of the mounting member 30 so as to surround the communicating hole 30g. An O-ring 32 is fitted in the O-ring groove 30h.

A pair of mounting holes 30c are formed through the bracket portion 30a in the thickness direction. The pair of mounting holes 30c are arranged symmetrically across the cylindrical boss portion 30b when viewed in the bracket thickness direction. The mounting member 30 is fixed to the front end surface of the spindle housing 4a by bolts 31 passing through the respective mounting holes 30c. A threaded hole 4d into which the bolt 31 is screwed is formed in the tip surface of the spindle housing 4a. An existing screw hole formed in the tip surface of the spindle housing 4a can be used for the screw hole 4d. When the attachment member 30 is fixed to the tip end surface of the spindle housing 4a, the through hole 4e formed in the spindle housing 4a communicates with the engaging recess 30d through the communication hole 30g of the attachment member 30. As shown in FIG.

[Coolant supply structure]
Next, a coolant supply structure for supplying a coolant liquid, which is a cooling fluid, to the surface of the grindstone 22 will be described. In addition, the white arrow shown in each figure schematically shows the flow of the coolant liquid.

This coolant supply structure includes a first supply channel portion 101, a second supply channel portion 102, and a third supply channel portion 103, as shown in FIG.

As shown in FIG. 4, the first supply channel portion 101 is composed of a through hole 4e formed in the spindle housing 4a and a communication hole 30g formed in the mounting member 30. As shown in FIG. The through hole 4e corresponds to the main shaft internal channel, and the communication hole 30g corresponds to the main shaft external channel.

As shown in FIGS. 4 and 5, the second supply channel portion 102 extends through the co-rotation prevention pin 25 of the tool unit 20 and the guide end wall 24j of the casing 24. As shown in FIG. Specifically, the second supply channel portion 102 is composed of a small-diameter hole 25a and a large-diameter hole 25c formed inside the co-rotation prevention pin 25, and a through hole 24f formed in the guide end wall 24j. ing. The small-diameter hole 25a, the large-diameter hole 25c, and the through hole 24f are linearly arranged coaxially with each other along the axial direction of the main shaft 5. As shown in FIG. That is, the second supply channel portion 102 is a linear channel extending parallel to the axial direction of the main shaft 5 . The opening on one end side of the second supply channel portion 102 communicates with the downstream opening of the first supply channel portion 101 (that is, the downstream opening of the communication hole 30g). An opening on the other end side of the second supply channel portion 102 communicates with a third supply channel portion 103 to be described later.

As shown in FIG. 4, the third supply channel portion 103 is composed of a channel in the flexible pipe 36 connected to the through hole 24f and a channel in the diverging nozzle 37 connected to the tip of the flexible pipe 36. It is configured. The flexible pipe 36 extends toward the front side of the unit from the through hole 24f, bends radially outward along the side surface of the grindstone 22, and then bends toward the front side of the unit to a position close to the outer peripheral surface of the grindstone 22. extended. A diverging nozzle 37 is connected to the end of the flexible pipe 36 on the grindstone 22 side. The diverging nozzle 37 is a flat nozzle whose flow path width becomes wider toward the downstream side, and is arranged so that the discharge opening is positioned near the surface of the grindstone 22 . Specifically, the divergent nozzle 37 is arranged such that its outlet faces the outer circumferential surface of the grindstone with a predetermined gap therebetween. Here, the predetermined interval is set within a range in which the coolant can be supplied toward the heat-generating portion of the work W (the contact portion of the work W with the grindstone 22). In this example, the discharge port of the divergent nozzle 37 faces the outer peripheral surface of the grindstone 22, but is not limited to this. They may be offset without facing each other.

In the machine tool 1 configured as described above, when the tool unit 20 is not attached to the main spindle 5, the first supply channel portion 101 opens near the tip of the main spindle 5 as shown in FIG. However, it does not function as a coolant supply path. On the other hand, as shown in FIG. 4 , when the tool unit 20 is attached to the spindle 5 , the co-rotation prevention pin 25 is engaged with the engagement recess 30 d of the mounting member 30 . When the co-rotation prevention pin 25 is engaged with the engaging recess 30d, the downstream opening of the first supply channel portion 101 (the downstream opening of the communication hole 30g of the mounting member 30) and the upstream side of the second supply channel portion 102 are opened. side opening (the upstream side opening of the small-diameter hole 25a of the co-rotation prevention pin 25). Since the second supply channel portion 102 and the third supply channel portion 103 are originally provided in the tool unit 20 and communicate with each other, the three supply channel portions 101 to 103 are connected at once, and the coolant supply device A coolant supply flow path (flow path indicated by an outline arrow in FIG. 4) is formed from 10 to near the surface of the grindstone 22 .

During grinding by the grindstone 22, the solenoid valve 51 is excited and driven in the opening direction under the control of the control device 50, and the coolant liquid discharged from the coolant supply device 10 flows into the first supply channel portion 101. After that, it is supplied to a heat-generating part of the work W (a contact part of the work W with the grindstone 22 ) via the second supply flow path part 102 and the third supply flow path part 103 provided in the tool unit 20 .

In addition, in a machining operation in which a normal tool holder without the co-rotation prevention pin 25 is mounted on the spindle 5, the control device 50 recognizes this based on the analysis contents of the NC program and moves the solenoid valve 51 in the closing direction. Excitation drive. Therefore, during normal machining operations that do not require the co-rotation prevention pin 25, the coolant liquid is not unnecessarily jetted from the tip of the first supply channel portion 101. FIG.

[Action and effect of the present embodiment]
As described above, according to the coolant supply structure of this embodiment, the first supply passage portion 101 that passes through the interior of the spindle housing 4a and penetrates the wall surface of the engagement recess 30d at the tip portion thereof, and the tool unit 20 The co-rotation prevention pin 25 and the casing 24 are penetratingly formed, and when the co-rotation prevention pin 25 is engaged with the engagement recess 30d, the opening on the one end side of the first supply channel portion 101 A second supply channel portion 102 communicating with a downstream opening, and a second supply channel portion 102 provided outside the casing 24 of the tool unit 20, one end side opening communicating with the downstream opening of the second supply channel portion 102 and the other opening. Since the opening on the end side is provided with the third supply channel portion 103 positioned near the surface of the grindstone 22, the coolant is supplied to the grindstone 22 in conjunction with the operation of attaching and detaching the tool unit 20 to and from the spindle 5. Installation and removal of roads can be easily performed. Therefore, it is possible to shorten the setup work time associated with the replacement of the tool unit 20 as much as possible. Further, by appropriately setting the wiring path of the third supply flow path portion 103 for discharging the coolant liquid toward the grindstone 22 in advance according to the shape of the grindstone 22, the grindstone 22 can be easily displaced by exchanging the tool unit 20 or the like. Even if the shape of the grindstone 22 is changed, it is possible to establish an appropriate coolant supply path according to the shape of the grindstone 22 .

Moreover, since most of the first supply channel portion 101 is formed inside the spindle housing 4a, there is no need to separately secure a space for pipes for the coolant liquid, and space efficiency can be improved. Further, the first supply channel portion 101 on the spindle 5 side and the second supply channel portion 102 on the tool unit 20 side are connected by the engagement between the co-rotation prevention pin 25 provided on the tool unit 20 and the engagement recess 30d. are communicated with each other, and the co-rotation prevention pin 25 also serves as a connector for connecting the flow path. Therefore, it is possible to standardize the parts and reduce the cost.

The engaging recess 30d is formed in a mounting member 30 which is separate from the spindle housing 4a and which is mounted on the tip surface of the spindle housing 4a. It is composed of a through hole 4e formed as a spindle internal flow path and a communication hole 30g formed through the mounting member 30 and serving as a spindle external flow path.

According to this, the engaging recess 30d with which the co-rotation prevention pin 25 engages is formed in the mounting member 30 which is separate from the spindle housing 4a, so that co-rotation can be prevented by exchanging the tool unit 20, for example. Even if the position of the pin 25 changes, it can be dealt with simply by changing the shapes of the engaging recess 30d and the communication hole 30g formed in the mounting member 30 (see FIG. 7 described later).

The mounting member 30 is detachably fixed to the tip end face of the spindle housing 4a by means of a bolt 31 screwed into a screw hole 4d formed in the tip face of the spindle housing 4a.

According to this, the replacement work of the mounting member 30 can be easily performed. As the screw hole 4d, an existing screw hole formed in the tip surface of the spindle housing 4a can be used.

The first supply channel portion 101 is a linear channel extending in the axial direction of the main shaft 5 .

According to this configuration, the line resistance in the first supply channel portion 101 can be reduced by forming the first supply channel portion 101 in a straight line. Thereby, the coolant liquid can be vigorously supplied from the first supply channel portion 101 toward the second supply channel portion 102 connected downstream thereof.

The second supply channel portion 102 is formed to extend linearly in the axial direction of the main shaft 5 when the co-rotation prevention pin 25 is engaged with the engagement recess 30 d of the mounting member 30 .

According to this configuration, by forming the second supply channel portion 102 in a straight line, the channel resistance in the second supply channel portion 102 can be reduced. Thereby, the coolant liquid can be vigorously supplied from the second supply channel portion 102 toward the third supply channel portion 103 connected downstream thereof.

The first supply channel portion 101 and the second supply channel portion 102 extend linearly in the axial direction of the main shaft 5 when the co-rotation prevention pin 25 is engaged with the engagement recess 30d of the mounting member 30. are arranged coaxially with each other.

According to this, since the first supply channel portion 101 and the second supply channel portion 102 are coaxially arranged, the coolant flows from the first supply channel portion 101 into the second supply channel portion 102. It is possible to reduce the pipeline resistance when In addition, since the first supply channel portion 101 and the second supply channel portion 102 cooperate to form one linear fluid supply channel, the channel resistance acting on the coolant can be reduced as much as possible. can do.

Also, the third supply channel portion 103 is formed by a flexible pipe 36 .

According to this, by changing the curved shape of the flexible pipe 36, the supply point of the coolant liquid to the grindstone 22 can be freely adjusted. Therefore, the coolant liquid can be accurately supplied to the heat-generating portion of the work W, and the cooling efficiency can be improved.

<<Other embodiments>>
In the above-described embodiment, the tool unit 20 is configured such that the axis of the spindle 5 and the axis of the grindstone 22 are oriented in the same direction. may intersect at a predetermined angle (for example, 90°). In this case, a gear mechanism may be added in the casing 24 for crossing the rotation axis.

In the above embodiment, the cooling fluid for cooling the grinding wheel 22 is the coolant liquid, but it is not limited to this. The cooling fluid may be, for example, cooling air, inert gas, or the like.

In the above embodiment, an example in which the through hole 4e formed in the spindle housing 4a and the co-rotation prevention pin 25 of the tool unit 20 are coaxially positioned has been described. The axis of the pin 25 may be offset radially outward (lower in FIG. 7) of the spindle housing 4a with respect to the axis of the through hole 4e. In this case, by shifting the position of the communication hole 30g formed in the mounting member 30 in the direction to absorb this offset, that is, inwardly in the radial direction of the spindle housing 4a (upper side in FIG. 6), it rotates together with the through hole 4e. The small-diameter hole 25a in the prevention pin 25 communicates with the small-diameter hole 25a through the communication hole 30g. Therefore, it is possible to obtain the same effects as those of the above-described embodiment.

In the above-described embodiment, the second supply channel portion 102 is formed so as to extend over the co-rotation prevention pin 25 and the guide end wall 24j of the casing 24, but is not limited to this. As shown in FIG. 8, only the co-rotation prevention pin 25 may be penetrated. In the example of FIG. 8, the co-rotation prevention pin 25 is fixed to the casing 24, the flexible pipe 36 is connected to the co-rotation prevention pin 25 from the radial outside (side), and the small diameter hole in the co-rotation prevention pin 25 25a and the channel in the flexible pipe 36 are in communication.

In the above-described embodiment, the first supply channel portion 101 can also be used for a tool unit having a cutting tool such as a drill as the working tool K. In this case, the coolant supplied to the first supply channel portion 101 passes through the channel in the casing and the channel formed inside the rotary output shaft by a well-known method such as a center-through method or a side-through method. It is supplied to the tip of the working tool K. In this way, the first supply channel portion 101 is shared between the tool unit adopting the center-through method or the side-through method and the tool unit 20 of the above-described embodiment having the grindstone 22, thereby simplifying the coolant supply structure. cost can be reduced.

In the above-described embodiment, the co-rotation prevention pin 25 is configured as a separate member from the casing 24 , but is not limited to this, and may be integrally formed with the casing 24 .

In the above-described embodiment, the engaging recess 30d is formed in the mounting member 30 which is separate from the spindle housing 4a. good too.

In the above-described embodiment, the flexible pipe 36 is used to form the third supply channel portion 103, but it is not always necessary to use the flexible pipe 36, and a fixed pipe having a fixed shape may be used. may Moreover, the divergent nozzle 37 may be abolished.

In the above embodiment, the machine tool 1 is a horizontal machining center, but it is not limited to this, and may be a vertical machining center or multitasking machine, for example.

It should be noted that the above description of the embodiment is illustrative in all respects and is not restrictive. Modifications and modifications are possible for those skilled in the art. The scope of the invention is indicated by the claims rather than the above-described embodiments. Furthermore, the scope of the present invention includes modifications from the embodiments within the scope of claims and equivalents.

1 machine tool 4a spindle housing 4d screw hole 5 spindle 5a tool mounting hole 20 tool unit 21 rotation output shaft 22 grindstone 24 casing 25 co-rotation prevention pin (co-rotation prevention protrusion)
30 Mounting member 30d Engaging concave portion 36 Flexible pipe 101 First supply channel portion 102 Second supply channel portion 103 Third supply channel portion

Claims (7)

A main shaft having a tool mounting hole for mounting a tool unit on its distal end surface, and a non-rotating main shaft housing for rotatably holding the main shaft. An engagement recess recessed toward the base end is formed at the distal end of the main shaft housing. The tool unit includes a rotation output shaft fitted into the tool mounting hole, a grindstone rotating in conjunction with the rotation of the rotation output shaft, a casing rotatably holding the rotation output shaft, a co-rotation prevention projection fixed to the casing, and the co-rotation prevention projection is engaged with the engaging recess to prevent co-rotation of the casing accompanying rotation of the main shaft. A cooling fluid supply structure for supplying a cooling fluid to the surface of the grindstone in a machine tool,
a first supply passage portion that passes through the interior of the spindle housing and penetrates the wall surface of the engagement recess to supply a cooling fluid toward the interior of the engagement recess;
It is formed through the co-rotation prevention projection, or is penetratingly formed across the co-rotation prevention projection and the casing, and in an engaged state where the co-rotation prevention projection is engaged with the engagement recess, one end a second supply channel portion whose side opening communicates with the downstream opening of the first supply channel portion;
Provided outside the casing, one end side opening communicates with the downstream side opening of the second supply channel portion, and the other end side opening is located near the surface of the grindstone and faces the surface of the grindstone. A cooling fluid supply structure, comprising: a third supply channel portion for supplying the cooling fluid to the cooling fluid supply structure. The engaging recess is formed in a mounting member separate from the spindle housing and mounted on the tip surface of the spindle housing,
2. A cooling fluid supply according to claim 1, wherein said first supply passage portion comprises a spindle inner passage formed in said spindle housing and a spindle outer passage formed through said mounting member. structure. 3. The cooling fluid supply structure according to claim 2, wherein the mounting member is detachably fixed to the tip end face of the spindle housing via a screw that is screwed into a screw hole formed in the tip face of the spindle housing. . 4. The cooling fluid supply structure according to claim 1, wherein the first supply channel portion is a linear channel extending in the axial direction of the main shaft. 5. The cooling fluid supply according to any one of claims 1 to 4, wherein the second supply channel portion is a linear channel extending in the axial direction of the main shaft in the engaged state. structure. 2. The first supply channel portion and the second supply channel portion, in the engaged state, extend linearly in the axial direction of the main shaft and are arranged coaxially with each other. 6. The cooling fluid supply structure according to any one of 1 to 5. 7. The cooling fluid supply structure according to any one of claims 1 to 6, wherein the third supply channel portion is formed by a flexible pipe.

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