Spindle unit, end surface cover, and machine tool

Abstract

To provide a spindle unit, an end surface cover, and a machine tool that can inhibit splash of coolant liquid from entering between a spindle and a spindle housing.SOLUTION: A spindle unit comprises: a spindle; a spindle housing supporting the spindle; a spindle cap 50 fixed to a lower end of the spindle housing; and an end surface cover fixed to a lower end of the spindle. The spindle unit forms a first labyrinth part 91 opening downward. The spindle cap 50 has a first cap groove 91A including a cap inclined surface 62B extending in a direction Y2. The end surface cover has: a first cover labyrinth surface 91B provided on an outer peripheral part on the radially outer side; and a cover inclined surface 82 extending in the direction Y2 from a lower end part of the first cover labyrinth surface 91B and located on a lower side of the cap inclined surface 62B. The first labyrinth part 91 is formed of the first cap groove 91A, the first cover labyrinth surface 91B, and the cover inclined surface 82.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a spindle device, an end face cover, and a machine tool. [Background technology]

[0002] There are machine tools that spray coolant when machining a workpiece, changing tools, etc. The spindle device for a machine tool described in Patent Document 1 includes a spindle and a spindle housing. A tool for cutting the workpiece is attached to the spindle. The spindle housing rotatably supports the spindle. The spindle device for a machine tool has an annular spindle cap fixed to the lower end of the spindle housing, and an annular end cover fixed to the lower end of the spindle. The spindle device for a machine tool forms a labyrinth chamber between the vicinity of the lower end of the spindle cap and the vicinity of the outer circumferential surface of the end cover. The labyrinth chamber prevents splashes of coolant from entering between the spindle and the spindle housing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-76045 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned spindle device for machine tools, when splashes of coolant liquid that have entered the labyrinth chamber are discharged from the labyrinth chamber, the flow of the coolant liquid from the labyrinth chamber in the direction of discharge may be weakened depending on the shape of the labyrinth chamber. At that time, the splashes of coolant liquid may easily enter between the spindle and the spindle housing through the labyrinth chamber. For example, if the splashes of coolant liquid reach a bearing provided between the spindle and the spindle housing, the bearing may be damaged.

[0005] An object of the present invention is to provide a spindle device, an end face cover, and a machine tool that can prevent splashes of coolant liquid from entering between the spindle and the spindle housing. [Means for solving the problem]

[0006] A spindle device according to claim 1 of the present invention includes a spindle having a tool attached to one end thereof, a spindle housing rotatably supporting the spindle, a spindle cap having an annular shape centered on a rotation center of the spindle and fixed to an end of the spindle housing in a one end direction from the other end of the spindle toward the one end, and an end cover having an annular shape centered on the rotation center and fixed to the one end of the spindle, wherein a first labyrinth portion is formed between the spindle cap and the end cover, the first labyrinth portion being a space extending annularly around the rotation center and opening toward the one end direction. has a first cap groove including a first cap inclined surface extending toward the one end direction as it moves toward the radial inside of the spindle cap, the end face cover has a first cover labyrinth surface provided on an outer periphery on the radial outside of the end face cover, and a cover inclined surface extending toward the one end direction from an end of the first cover labyrinth surface in the one end direction as it moves toward the radial inside of the end face cover and is located in the one end direction further than the first cap inclined surface, and the first labyrinth portion is composed of the first cap groove, the first cover labyrinth surface, and the cover inclined surface.

[0007] According to the spindle device of claim 1 of the present invention, when splashes of coolant liquid enter the first labyrinth portion, the splashes of coolant liquid hit the first cap inclined surface and tend to flow along the first cap inclined surface toward the one end portion. After that, the splashes of coolant liquid tend to flow along the cover inclined surface. As the splashes of coolant liquid flow along the cover inclined surface, the flow of the splashes of coolant liquid from the first labyrinth portion toward the one end portion tends to become stronger. This allows the spindle device to suppress the intrusion pressure of the splashes of coolant liquid into the first labyrinth portion. Therefore, the spindle device can suppress the intrusion of the splashes of coolant liquid between the spindle and the spindle housing.

[0008] The spindle device according to claim 2 of the present invention may further include a second labyrinth portion between the spindle cap and the end cover, the second labyrinth portion being a space that extends annularly around the center of rotation and is connected to the first labyrinth portion, the spindle cap has a second cap groove including a second cap inclined surface that extends toward the one end direction as it moves toward the radial inside of the spindle cap, and the end cover has a second cover labyrinth surface adjacent to the radial inside of the end cover relative to the first cover labyrinth surface, and the second labyrinth portion is composed of the second cap groove and the second cover labyrinth surface, and the magnitude of the acute angle formed by the first cap inclined surface with respect to the center of rotation may be smaller than the magnitude of the acute angle formed by the second cap inclined surface with respect to the center of rotation. The spindle device may further strengthen the flow of splashes of coolant from the first labyrinth portion toward the one end direction. Therefore, the spindle device can further prevent splashes of coolant liquid from entering between the spindle and the spindle housing.

[0009] In the spindle device according to claim 3 of the present invention, the first cap groove may include a connection surface extending from an end of the first cap inclined surface opposite to the one end direction toward the one end direction. Since the connection surface extends toward the one end direction, the spindle device makes it easy for splashes of coolant liquid that have entered the first labyrinth portion to reach the end of the first cap inclined surface opposite to the one end direction. Therefore, the spindle device can ensure a distance until the splashes of coolant liquid that have entered the first labyrinth portion are discharged from the first labyrinth portion. Therefore, the flow of splashes of coolant liquid from the first labyrinth portion toward the one end direction can be further strengthened. Therefore, the spindle device can further suppress the splashes of coolant liquid from entering between the spindle and the spindle housing.

[0010] In the spindle device according to claim 4 of the present invention, the first cap groove includes a third cap inclined surface extending from an end of the connection surface in the one end direction toward the one end direction while moving toward the radially outer side of the spindle cap, and the end face cover has a cover end surface extending from an end of the cover inclined surface on the radially inner side of the end face cover toward the radially inner side of the end face cover, and the cover end surface may be located in the one end direction relative to an end of the third cap inclined surface located on the radially outer side of the end face cover. The spindle device can ensure a distance until the splash of the coolant liquid that has entered the first labyrinth portion is discharged from the first labyrinth portion. Therefore, the flow of the splash of the coolant liquid from the first labyrinth portion toward the one end direction can be further strengthened. Therefore, the spindle device can further suppress the splash of the coolant liquid from entering between the spindle and the spindle housing.

[0011] The end face cover according to claim 5 of the present invention is an end face cover used for a spindle device including a spindle having one end to which a tool is attached, a spindle housing rotatably supporting the spindle, and a spindle cap having an annular shape centered on a rotation center of the spindle and fixed to an end of the spindle housing in a one end direction from the other end of the spindle toward the one end, the spindle cap having a first cap groove including a first cap inclined surface extending toward the one end direction as it approaches the radial inside of the spindle cap, the end face cover being used for a spindle device including a spindle having an annular shape centered on the rotation center when fixed to the one end of the spindle. The end face cover has a first cover labyrinth surface provided on an outer periphery on the radially outer side of the end face cover, and a cover inclined surface extending from an end of the first cover labyrinth surface in the one end direction toward the radially inner side of the end face cover toward the one end direction and located further toward the one end direction than the first cap inclined surface, and a first labyrinth portion is formed between the spindle cap and the end face cover, which is a space extending in an annular shape centered on the rotation center and opening toward the one end direction, and the first labyrinth portion is composed of the first cap groove, the first cover labyrinth surface, and the cover inclined surface. By using the end face cover in a spindle device, the same effect as that of the spindle device according to claim 1 of the present invention can be achieved.

[0012] A machine tool according to claim 6 of the present invention is a machine tool including a spindle unit and a drive unit for driving the spindle unit, the spindle unit including a spindle having a tool attached to one end thereof, a spindle housing for rotatably supporting the spindle, a spindle cap having an annular shape centered on the center of rotation of the spindle and fixed to an end of the spindle housing in a direction from the other end of the spindle toward the one end thereof, and an end cover having an annular shape centered on the center of rotation and fixed to the one end of the spindle, and a first space extending annularly centered on the center of rotation between the spindle cap and the end cover and opening toward the one end thereof, The spindle cap has a first cap groove including a first cap inclined surface extending toward the one end direction as it moves toward the radial inside of the spindle cap, and the end face cover has a first cover labyrinth surface provided on an outer periphery on the radial outside of the end face cover, and a cover inclined surface extending toward the one end direction from an end of the first cover labyrinth surface in the one end direction as it moves toward the radial inside of the end face cover and located in the one end direction further than the first cap inclined surface, and the first labyrinth portion is composed of the first cap groove, the first cover labyrinth surface, and the cover inclined surface. The machine tool can achieve the same effect as the spindle device according to claim 1 of the present invention. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a perspective view of the machine tool 1 as viewed from above, front left. [Diagram 2] FIG. 2 is an exploded perspective view of the spindle device 3 as viewed from below and front on the right side. [Diagram 3] 2 is a cross-sectional view of the spindle device 3 taken along a plane passing through the center of rotation C and perpendicular to the left-right direction, as viewed from the right. [Figure 4] FIG. 4 is an enlarged view of an area A1 shown in FIG. [Diagram 5] FIG. 5 is an enlarged view of an area A2 shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] A machine tool 1 according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the left / right, front / rear, and up / down directions shown by arrows in the drawings will be used. The left / right, front / rear, and up / down directions of the machine tool 1 are defined as the X-axis, Y-axis, and Z-axis directions of the machine tool 1, respectively.

[0015] The schematic structure of machine tool 1 will be described with reference to Figure 1. Machine tool 1 rotates tool 4 attached to spindle 30 (see Figure 3) and moves tool 4 and workpiece W relatively in the X, Y and Z axis directions to machine workpiece W. Machine tool 1 is a vertical machine tool with spindle 30 extending in the vertical direction.

[0016] Machine tool 1 comprises a base 2, a table 10, an X-axis feed mechanism 9, a Y-axis feed mechanism 8, a column 5, a spindle unit 3, and a tool changer 17. The base 2 is disposed at the bottom of the machine tool 1, and has a substantially rectangular parallelepiped shape. The table 10 is disposed at the front of the upper surface of the base 2, and extends in a plane in the front-rear and left-right directions. The table 10 holds a workpiece W. The X-axis feed mechanism 9 is disposed below the table 10, and supports the table 10 so that it can move in the X-axis direction. The Y-axis feed mechanism 8 is disposed below the X-axis feed mechanism 9, and supports the table 10 so that it can move in the Y-axis direction via the X-axis feed mechanism 9.

[0017] The column 5 extends upward from the rear of the upper surface of the base 2 and has a rectangular parallelepiped shape. The spindle unit 3 is disposed in front of the column 5 and is supported by the column 5 via a plate 19 so as to be movable up and down in the Z-axis direction. The spindle unit 3 is fitted with a tool 4. The tool 4 is constructed by mounting a tool body 4A to a tool holder 4B. The tool body 4A is a drill or the like. The tool holder 4B has a shape corresponding to a mounting hole 31 described below, and in this embodiment, has a tapered shape that decreases in diameter as it extends upward (see FIG. 3). The tool changer 17 is disposed in front of the spindle unit 3 and is fixed to the column 5 via a plate 18. The tool changer 17 replaces the tool 4 mounted on the spindle unit 3 with another tool (not shown).

[0018] The machine tool 1 drives an X-axis motor and a Y-axis motor (not shown) to move a table 10 in the X-axis and Y-axis directions via an X-axis feed mechanism 9 and a Y-axis feed mechanism 8. The machine tool 1 drives a spindle motor 40 to rotate a tool 4, and drives a Z-axis motor (not shown) to move a spindle device 3 in the Z direction along a column 5. The machine tool 1 moves a workpiece W and the tool 4 on the table 10 relatively, and cuts the workpiece W on the table 10 with the tool 4.

[0019] The detailed structure of the spindle device 3 will be described with reference to Figs. 1 to 4. As shown in Figs. 1 to 3, the spindle device 3 includes a spindle housing 20, a spindle 30, a spindle motor 40, a spindle cap 50, and an end face cover 80. As shown in Fig. 1, the spindle housing 20 extends in the vertical direction and is fixed to a plate 19. As shown in Figs. 2 to 4, the spindle housing 20 has a cylindrical shape and forms a support hole 21. The support hole 21 extends upward from a lower end portion 20A of the spindle housing 20.

[0020] Spindle 30 is disposed in support hole 21 and extends in the vertical direction. As shown in Figs. 2 and 4, a lower end 30A of spindle 30 protrudes downward beyond lower end 20A of spindle housing 20. Spindle 30 includes a step 33. Step 33 is located near lower end 30A of spindle 30 and protrudes radially outward from outer circumferential surface 32 of spindle 30. The outer diameter of step 33 is smaller than the inner diameter of spindle housing 20.

[0021] The spindle 30 has a cylindrical shape and forms a mounting hole 31. The mounting hole 31 extends upward from the lower end 30A of the spindle 30 and has a tapered shape that reduces in diameter toward the top. A tool holder 4B (see FIG. 3) fits into the mounting hole 31. In this state, a clamping mechanism (not shown) for clamping the tool 4 is driven, and the tool 4 is mounted to the lower end 30A of the spindle 30.

[0022] As shown in Figures 3 and 4, the spindle 30 is rotatably supported by the spindle housing 20 via one or more bearings 22. The center of rotation C of the spindle 30 passes through the radial center of the spindle 30 in a plan view and extends in the vertical direction. The number of bearings 22 is not limited to a specific number, but is four in this embodiment. The multiple bearings 22 are each disposed in a support hole 21 and lined up in the vertical direction via a spacer 23.

[0023] The spindle motor 40 is fixed to the upper part of the spindle housing 20. The output shaft 41 of the spindle motor 40 extends downward from the spindle motor 40 and is fixed to the upper end portion 30B of the spindle 30. Therefore, when the spindle motor 40 is driven, the spindle 30 rotates about the center of rotation C.

[0024] As shown in Figs. 2 and 4, the spindle cap 50 includes a first cap 60 and a second cap 70. The first cap 60 and the second cap 70 each have an annular shape. The inner diameter of the first cap 60 and the inner diameter of the second cap 70 are each slightly larger than the outer diameter of the lower end 30A of the spindle 30. The lower end 30A of the spindle 30 is inserted into the first cap 60 and the second cap 70, respectively. The first cap 60 is fixed to the lower end 20A of the spindle housing 20 from below by a plurality of bolts 14. The second cap 70 is fixed to the lower end of the first cap 60 from below by a plurality of bolts 15. Therefore, even if the spindle 30 rotates, the first cap 60 and the second cap 70 do not rotate.

[0025] Spindle cap 50 has an annular shape as a whole, and is fixed to lower end 20A of spindle housing 20. When spindle cap 50 is fixed to lower end 20A of spindle housing 20, the center of spindle cap 50 coincides with center of rotation C of spindle 30 in a plan view.

[0026] The end cover 80 has an annular shape. The inner diameter of the end cover 80 is slightly larger than the outer diameter of the lower end 30A of the main shaft 30. Therefore, the lower end 30A of the main shaft 30 is inserted into the end cover 80. The outer diameter of the end cover 80 is slightly smaller than the inner diameter of the second cap 70. The end cover 80 is disposed radially inside the second cap 70. The end cover 80 is fixed to the lower end 30A of the main shaft 30 from below with a plurality of bolts 16. Therefore, when the main shaft 30 rotates, the end cover 80 rotates together with the main shaft 30. When the end cover 80 is fixed to the lower end 30A of the main shaft 30, the center of rotation of the end cover 80 coincides with the center of rotation C of the main shaft 30.

[0027] The detailed structures of the spindle cap 50 and the end cover 80 will be described with reference to Figures 4 and 5. The spindle 30, the spindle cap 50 (first cap 60, second cap 70), and the end cover 80 are each located on a concentric circle centered on the center of rotation C. Therefore, the radial directions of the spindle 30, the spindle cap 50 (first cap 60, second cap 70), and the end cover 80 are the same. Below, each radial direction will be simply referred to as the "radial direction." The radially outward direction is the direction away from the center of rotation C in a plan view, and the radially inward direction is the direction approaching the center of rotation C in a plan view.

[0028] The direction that goes upward as it moves radially outward is referred to as "direction Y1." The opposite direction to direction Y1, i.e., the direction that goes downward as it moves radially inward, is referred to as "direction Y2." The direction that goes downward as it moves radially outward is referred to as "direction Y3." The opposite direction to direction Y3, i.e., the direction that goes upward as it moves radially inward, is referred to as "direction Y4."

[0029] Hereinafter, unless otherwise specified, the shapes of the configurations such as surfaces and spaces refer to the cross-sectional shapes cut by a plane passing through and along the center of rotation C. For example, "the support part 61 has a rectangular shape" means that the cross-sectional shape of the support part 61 cut by a plane passing through and along the center of rotation C is rectangular. The configurations such as surfaces and spaces shown in the cross section extend in a ring shape centered on the center of rotation C. For example, the support part 61 has a rectangular cross section and extends in a ring shape centered on the center of rotation C.

[0030] A direction perpendicular to a certain direction is called "another direction." In a configuration of a surface, an end portion in a direction that moves in a certain direction toward another direction is both an end portion in the certain direction and an end portion in the other direction. For example, an end portion in the direction Y1 of the cap inclined surface 71C is both a radial outer end portion of the cap inclined surface 71C and an upper end portion of the cap inclined surface 71C.

[0031] As shown in FIG. 4, the first cap 60 includes a support portion 61 and a labyrinth forming portion 62. The support portion 61 is located at the upper portion of the first cap 60 and has a rectangular shape. The support portion 61 is fixed to the lower end portion 20A of the spindle housing 20 and supports the bearing 22 from below via the step portion 33. The support portion 61 includes an inner circumferential surface 61A and a bottom surface 61B. The inner circumferential surface 61A is located at the radially inner end portion of the support portion 61 and extends in the vertical direction. The inner circumferential surface 61A forms an air passage 98 between itself and the outer circumferential surface 32 of the spindle 30. The air passage 98 is a space through which compressed air flows, and is connected to a compressor (not shown) via a pipe (not shown). The compressor supplies compressed air to the air passage 98.

[0032] The bottom surface 61B is located at the lower end of the support portion 61 and extends in the radial direction. The bottom surface 61B forms a coolant passage 99 between itself and an upper surface 71A of a labyrinth forming portion 71 described below. The coolant passage 99 is a space through which the coolant flows, and is connected to a coolant supply source (not shown) via piping (not shown). The coolant supply source stores the coolant and supplies the stored coolant to the coolant passage 99.

[0033] As shown in FIG. 5, the labyrinth forming portion 62 is located at the lower part of the radially inner side of the first cap 60 and is connected to the lower part of the radially inner side of the support portion 61. The labyrinth forming portion 62 includes a cap connection surface 62A, a cap inclined surface 62B, a cap connection surface 62C, a cap inclined surface 62D, a cap connection surface 62E, a cap connection surface 62F, and a cap inclined surface 62G. The cap connection surface 62A extends downward from the radially inner end of the bottom surface 61B of the support portion 61. The cap inclined surface 62B extends in the direction Y2 from the lower end of the cap connection surface 62A. The cap inclined surface 62B constitutes a first cap groove 91A together with a cap connection surface 71B and a cap inclined surface 71C described later. The first cap groove 91A has a V-shape that opens downward.

[0034] The acute angle θ1 formed by the cap inclined surface 62B with respect to the rotation center C is smaller than the acute angle θ2 formed by the cap inclined surface 62D (described later) with respect to the rotation center C. The acute angle θ2 is not limited to a specific value, but is 45° in this embodiment. The acute angle θ1 is not limited to a specific value, but is preferably less than 45°, for example, and is 30° in this embodiment.

[0035] The cap connection surface 62C extends upward from the end of the cap inclined surface 62B in the direction Y2. The cap inclined surface 62D extends in the direction Y2 from the upper end of the cap connection surface 62C and is located radially inward from the cap inclined surface 62B. The cap connection surface 62C and the cap inclined surface 62D form a second cap groove 92A. The second cap groove 92A has a V-shape that opens downward. The second cap groove 92A is located radially inward from the first cap groove 91A and is adjacent to the first cap groove 91A.

[0036] The cap connection surface 62E extends upward from the end of the cap inclined surface 62D in the direction Y2. The cap connection surface 62F extends radially inward from the upper end of the cap connection surface 62E. The cap inclined surface 62G extends in the direction Y2 from the radial inner end of the cap connection surface 62F and is located radially inward from the cap inclined surface 62D. The end of the cap inclined surface 62G in the direction Y2 connects to the lower end of the inner circumferential surface 61A of the support portion 61. The cap connection surface 62E, the cap connection surface 62F, and the cap inclined surface 62G form a third cap groove 93A. The third cap groove 93A has a U-shape that opens downward. The third cap groove 93A is located radially inward from the second cap groove 92A and is adjacent to the second cap groove 92A.

[0037] The second cap 70 includes a labyrinth forming portion 71 and a nozzle forming portion 72. The labyrinth forming portion 71 is located on the upper portion of the second cap 70 and includes an upper surface 71A, a cap connecting surface 71B, and a cap inclined surface 71C. The upper surface 71A is located approximately on the same plane as the bottom surface 61B of the support portion 61 and extends in the radial direction. The upper surface 71A forms a coolant passage 99 between the bottom surface 61B and the upper surface 71A.

[0038] The cap connection surface 71B is located on approximately the same plane as the cap connection surface 62A and extends downward from the radial inner end of the upper surface 71A. The lower end of the cap connection surface 71B is located below the end of the cap inclined surface 62B in the direction Y1 and above the end of the cap inclined surface 62B in the direction Y2. In the first cap groove 91A, a portion of the cap connection surface 71B below the end of the cap inclined surface 62B in the direction Y1 extends downward from the end of the cap inclined surface 62B in the direction Y1. The cap inclined surface 71C extends in the direction Y3 from the lower end of the cap connection surface 71B.

[0039] The nozzle forming portion 72 is connected to a lower end of the labyrinth forming portion 71 and includes a nozzle surface 72A. The nozzle surface 72A extends further in the direction Y3 from the end of the cap inclined surface 71C in the direction Y3. The acute angle θ3 formed by the nozzle surface 72A with respect to the rotation center C is not limited to a specific angle, but in this embodiment, it is larger than the acute angle θ4 formed by the cap inclined surface 71C with respect to the rotation center C.

[0040] The nozzle surface 72A forms a plurality of nozzles 721. Each of the plurality of nozzles 721 is an opening and is connected to a coolant passage 99. Each of the plurality of nozzles 721 sprays coolant liquid supplied from a coolant supply source through the coolant passage 99 radially inward (see arrow F1). When the sprayed coolant liquid hits the tool 4, the tool 4 is cleaned.

[0041] The end face cover 80 includes a labyrinth forming portion 81, a cover inclined surface 82, and a cover end face 83. The labyrinth forming portion 81 is disposed on the outer peripheral portion of the end face cover 80 in the radial direction, and faces the labyrinth forming portions 62 and 71. The outer peripheral portion of the end face cover 80 in the radial direction is a portion of the end face cover 80 that constitutes the outer peripheral surface of the end face cover 80, and in this embodiment, refers to a portion that is radially outward from the hole provided in the end face cover 80 through which the bolt 16 passes. The labyrinth forming portion 81 includes a cover inclined surface 81A, a cover connecting surface 81B, a cover connecting surface 81C, a cover inclined surface 81D, a cover connecting surface 81E, a cover inclined surface 81F, and a cover connecting surface 81G.

[0042] The cover inclined surface 81A is located below the cap inclined surface 62G and extends in the direction Y1 from the radially inner end of the labyrinth forming portion 81. The cover connecting surface 81B extends radially outward from the end of the cover inclined surface 81A in the direction Y1. The cover inclined surface 81A and the cover connecting surface 81B form a third cover labyrinth surface 93B. The third cover labyrinth surface 93B is located radially inward from a second cover labyrinth surface 92B described below and is adjacent to the second cover labyrinth surface 92B.

[0043] The cover connection surface 81C extends downward from the radial outer end of the cover connection surface 81B. The cover inclined surface 81D extends in the direction Y3 from the lower end of the cover connection surface 81C. The cover connection surface 81C and the cover inclined surface 81D form a second cover labyrinth surface 92B. The second cover labyrinth surface 92B is located radially inward of a first cover labyrinth surface 91B described below and is adjacent to the first cover labyrinth surface 91B.

[0044] The cover connection surface 81E extends downward from the end of the cover inclined surface 81D in the direction Y3. The cover inclined surface 81F extends in the direction Y3 from the lower end of the cover connection surface 81E. The acute angle θ5 formed by the cover inclined surface 81F with respect to the rotation center C is not limited to a specific value, but in this embodiment, it is smaller than the acute angle θ6 formed by the cover inclined surface 81D with respect to the rotation center C. The cover connection surface 81G extends downward from the end of the cover inclined surface 81F in the direction Y3. The cover connection surface 81E, the cover inclined surface 81F, and the cover connection surface 81G constitute the first cover labyrinth surface 91B.

[0045] The cover inclined surface 82 extends in the direction Y2 from the lower end of the cover connection surface 81G and is located lower than the cap inclined surface 62B. The cover inclined surface 82 extends in the direction Y1 from the radial outer end of a cover end surface 83 (described later). The acute angle θ7 formed by the cover inclined surface 82 with respect to the rotation center C is not limited to a specific angle, but is 45° in this embodiment and is larger than the acute angle θ1 formed by the cap inclined surface 62B with respect to the rotation center C.

[0046] The cover end surface 83 extends radially inward from the end of the cover inclined surface 82 in the direction Y2. The cover end surface 83 faces downward and is located at the lower end of the end surface cover 83. In FIG. 5, the position of the end of the cover inclined surface 82 in the direction Y1 is indicated as position P2, and the position of the end of the cover inclined surface 82 in the direction Y2 is indicated as position P3 in the vertical direction. Position P3 coincides with the vertical position of the cover end surface 83. FIG. 5 indicates the position of the end of the cap inclined surface 71C of the labyrinth forming portion 71 in the direction Y3 as position P1. Position P2 is located above position P1. Position P3 is located below position P1.

[0047] According to the above configuration, the spindle device 3 forms a first labyrinth portion 91, a second labyrinth portion 92, and a third labyrinth portion 93 between the spindle cap 50 and the end face cover 80. The first labyrinth portion 91 is a space surrounded by the first cap groove 91A, the first cover labyrinth surface 91B, and the cover inclined surface 82. The first labyrinth portion 91 opens downward. The second labyrinth portion 92 is a space surrounded by the second cap groove 92A and the second cover labyrinth surface 92B, and is located radially inward from the first labyrinth portion 91. The second labyrinth portion 92 is connected to the first labyrinth portion 91 in the radial direction through a gap between the cap connection surface 62C and the cover connection surface 81E.

[0048] The third labyrinth portion 93 is a space surrounded by the third cap groove 93A and the third cover labyrinth surface 93B, and is located radially inward of the second labyrinth portion 92. The third labyrinth portion 93 is connected to the second labyrinth portion 92 through a gap between the cap connection surface 62E and the cover connection surface 81C in the radial direction. The third labyrinth portion 93 is connected to the air passage 98 through a gap between the outer peripheral surface 32 of the spindle 30 and the inner peripheral surface 61A of the support portion 61 in the radial direction.

[0049] When the coolant liquid ejected from the multiple nozzles 721 hits the tool 4, the coolant liquid splashes. At that time, the splashed coolant liquid passes through the first labyrinth portion 91, the second labyrinth portion 92, and the third labyrinth portion 93 in this order, and may penetrate between the spindle 30 and the spindle housing 20 and reach the multiple bearings 22. The compressed air supplied by the compressor through the air passage 98 flows through the third labyrinth portion 93, the second labyrinth portion 92, and the first labyrinth portion 91 in this order, and is ejected downward from the first labyrinth portion 91 (see arrow F2). Therefore, the compressed air supplied by the compressor functions as an air seal to prevent splashed coolant liquid from penetrating between the spindle 30 and the spindle housing 20.

[0050] The spindle device 3 described above can achieve the following main effects by using the end face cover 80. The machine tool 1 can achieve the same effects. The following effects are examples of the effects achieved by the above embodiment.

[0051] If the cover inclined surface 82 does not exist and the surface extends radially inward from the lower end of the cover connection surface 81G, the flow of the splash of the coolant liquid that has entered the first labyrinth portion 91 in the first labyrinth portion 91 is likely to be disturbed. According to the above embodiment, the first labyrinth portion 91 is composed of the first cap groove 91A, the first cover labyrinth surface 91B, and the cover inclined surface 82. Therefore, when the splash of the coolant liquid enters the first labyrinth portion 91, the splash of the coolant liquid hits the cap inclined surface 62B in the first cap groove 91A and tends to flow downward along the cap inclined surface 62B (see arrow F3). After that, the splash of the coolant liquid tends to flow along the cover inclined surface 82. This suppresses the flow of the splash of the coolant liquid in the first labyrinth portion 91 from being disturbed. Therefore, the flow of the splash of the coolant liquid downward from the first labyrinth portion 91 tends to be strong. Therefore, by using the end face cover 80, the spindle device 3 can suppress the intrusion pressure of splashes of coolant liquid into the first labyrinth portion 91. Therefore, the spindle device 3 can suppress the intrusion of splashes of coolant liquid between the spindle 30 and the spindle housing 20. Therefore, the spindle device 3 can suppress the amount of compressed air supplied from the compressor functioning as an air seal, thereby suppressing the environmental load.

[0052] According to the above embodiment, the acute angle θ1 formed by the cap inclined surface 62B with respect to the rotation center C is smaller than the acute angle θ2 formed by the cap inclined surface 62D with respect to the rotation center C. Therefore, the spindle device 3 can further strengthen the flow of the coolant liquid downward from the first labyrinth portion 91. Therefore, the spindle device 3 can further prevent splashes of the coolant liquid from entering between the spindle 30 and the spindle housing 20.

[0053] According to the above embodiment, the first cap groove 91A includes the cap connection surface 71B. Since the cap connection surface 71B extends downward, the spindle device 3 makes it easy for splashes of coolant liquid that have entered the first labyrinth portion 91 to reach the upper end of the cap inclined surface 62B. Therefore, the spindle device 3 can ensure a distance from which the splashes of coolant liquid that have entered the first labyrinth portion 91 are discharged from the first labyrinth portion 91. Therefore, the flow of the splashes of coolant liquid downward from the first labyrinth portion 91 can be further strengthened. Therefore, the spindle device 3 can further suppress the splashes of coolant liquid from entering between the spindle 30 and the spindle housing 20.

[0054] According to the above embodiment, the cover end surface 83 (position P3) is located below the end (position P1) of the cap inclined surface 71C in the direction Y3. That is, the cover end surface 83 is located at a position relatively far from the spindle 30 in the vertical direction (axial direction of the spindle 30). Therefore, the spindle device 3 can ensure a distance until the splashes of the coolant liquid that have entered the first labyrinth portion 91 are discharged from the first labyrinth portion 91. Therefore, the flow of the splashes of the coolant liquid downward from the first labyrinth portion 91 can be further strengthened. Therefore, the spindle device 3 can further suppress the splashes of the coolant liquid from entering between the spindle 30 and the spindle housing 20.

[0055] In the above embodiment, the downward direction of the machine tool 1 corresponds to the "one end direction" of the present invention. The cap inclined surface 62B corresponds to the "first cap inclined surface" of the present invention. The cover inclined surface 82 corresponds to the "cover inclined surface" of the present invention. The cap inclined surface 62D corresponds to the "second cap inclined surface" of the present invention. The acute angle θ1 corresponds to the "acute angle formed by the first cap inclined surface with respect to the center of rotation" of the present invention. The acute angle θ2 corresponds to the "acute angle formed by the second cap inclined surface with respect to the center of rotation" of the present invention. The cap connection surface 71B corresponds to the "cap connection surface" of the present invention. The cap inclined surface 71C corresponds to the "third cap inclined surface" of the present invention.

[0056] The present invention may be modified from the above embodiment. For example, the spindle device 3 may be disposed in a position rotated by 90° so that the spindle 30 extends horizontally (for example, in the front-to-rear direction). That is, the machine tool 1 may be a horizontal machine tool in which the spindle 30 extends horizontally (for example, in the front-to-rear direction). The drive axes of the machine tool 1 are not limited to three axes, the X, Y and Z axes, and may be one, two, or four or more axes.

[0057] In the above embodiment, the magnitude of acute angle θ1 may be the same as the magnitude of acute angle θ2. The magnitude of acute angle θ3 may be the same as the magnitude of acute angle θ4. The magnitude of acute angle θ5 may be the same as the magnitude of acute angle θ6. The magnitude of acute angle θ7 may be the same as the magnitude of acute angle θ1.

[0058] In the above embodiment, the spindle device 3 may omit one or both of the second labyrinth portion 92 and the third labyrinth portion 93, or another labyrinth portion may be further formed radially inward from the third labyrinth portion 93.

[0059] The shapes of the first labyrinth portion 91, the second labyrinth portion 92, and the third labyrinth portion 93 are not limited to those in the above embodiment. For example, in the first labyrinth portion 91, the lower end of the cap connection surface 71B may be located at the same position as the end of the cap inclined surface 62B in the direction Y1 in the vertical direction, or may be located above the end of the cap inclined surface 62B in the direction Y1. Furthermore, in the first labyrinth portion 91, the first cap groove 91A may be U-shaped and open downward. That is, the first cap groove 91A may further include a connection surface extending in the radial direction between the end of the cap inclined surface 62B in the direction Y1 and the upper end of the cap connection surface 71B.

[0060] In the above embodiment, the first cap 60 and the second cap 70 are formed as separate bodies. In contrast, the first cap 60 and the second cap 70 may be integrally molded. The second cap 70 may be fixed to the spindle housing 20. The method of fixing the first cap 60 and the second cap 70, the method of fixing the first cap 60 and the spindle housing 20, and the method of fixing the end face cover 80 and the spindle 30 are not limited to fixing with bolts. For example, a screw may be formed on each of the cap connection surface 62A and the cap connection surface 71B.

[0061] In the above embodiment, the coolant is sprayed from the nozzle 721. However, the coolant may be sprayed from a spraying device separate from the spindle device 3. The cover end surface 83 may be located at the same position as the end of the cap inclined surface 71C in the direction Y3 in the vertical direction or higher than the end of the cap inclined surface 71C in the direction Y3. [Explanation of symbols]

[0062] 1: Machine tool 3: Spindle device 4:Tools 20: Spindle housing 30: Spindle 50: Spindle cap 62B: Cap inclined surface 62D: Cap inclined surface 71B: Cap connection surface 71C: Cap inclined surface 80: End cover 82: Cover inclined surface 83: Cover end face 91: First Labyrinth 91A: First cap groove 91B: First cover labyrinth surface 92: Second Labyrinth 92A: Second cap groove 92B: Second cover labyrinth surface

Claims

1. a spindle having a tool attached to one end thereof; a spindle housing that rotatably supports the spindle; a spindle cap having an annular shape centered on the rotation center of the spindle and fixed to an end of the spindle housing in a direction from the other end of the spindle toward the one end; an end cover having an annular shape centered on the rotation center and fixed to the one end of the main shaft; Equipped with In a spindle device, a first labyrinth portion is formed between the spindle cap and the end face cover, the first labyrinth portion being a space that extends annularly around the rotation center and opens toward the one end, the spindle cap has a first cap groove including a first cap inclined surface extending toward the one end direction as it moves toward the radial inside of the spindle cap, The end cover is A first cover labyrinth surface provided on an outer circumferential portion of the end face cover in the radial direction; a cover inclined surface extending from an end of the first cover labyrinth surface in the one end direction toward the radially inner side of the end face cover toward the one end direction and positioned in the one end direction relative to the first cap inclined surface, A spindle device characterized in that the first labyrinth portion is composed of the first cap groove, the first cover labyrinth surface, and the cover inclined surface.

2. a second labyrinth portion is formed between the spindle cap and the end face cover, the second labyrinth portion being a space that extends annularly about the rotation center and is connected to the first labyrinth portion, the second labyrinth portion being located radially inward of the spindle relative to the first labyrinth portion; the spindle cap has a second cap groove including a second cap inclined surface extending toward the one end direction while moving toward the radial inside of the spindle cap at a position radially inside of the first cap inclined surface, the end face cover has a second cover labyrinth surface adjacent to the first cover labyrinth surface on a radially inner side of the end face cover, The second labyrinth portion is constituted by the second cap groove and the second cover labyrinth surface, The magnitude of the acute angle formed by the first cap inclined surface with respect to the rotation center is smaller than the magnitude of the acute angle formed by the second cap inclined surface with respect to the rotation center.

2. The spindle device according to claim 1 .

3. The first cap groove includes a cap connection surface extending toward the one end from an end of the first cap inclined surface opposite to the one end.

3. The spindle device according to claim 1 or 2.

4. the first cap groove includes a third cap inclined surface extending from an end of the cap connection surface in the one end direction toward the radially outer side of the spindle cap toward the one end direction, The end face cover has a cover end surface extending radially inward from an end portion of the cover inclined surface on the radially inner side of the end face cover, The cover end surface is located toward the one end surface side of the end surface cover, further toward the one end surface side than an end portion of the third cap inclined surface located radially outward of the end surface cover.

4. The spindle device according to claim 3.

5. a spindle having a tool attached to one end thereof; a spindle housing that rotatably supports the spindle; a spindle cap having an annular shape centered on a rotation center of the spindle and fixed to an end of the spindle housing in a one end direction from the other end of the spindle toward the one end, the spindle cap having a first cap groove including a first cap inclined surface extending toward the one end direction as it moves toward the radial inside of the spindle cap; An end face cover for use in a spindle device comprising: The end face cover is fixed to the one end of the spindle, having an annular shape centered on the rotation center, A first cover labyrinth surface provided on an outer circumferential portion of the end face cover in the radial direction; a cover inclined surface extending from an end of the first cover labyrinth surface in the one end direction toward the radially inner side of the end face cover toward the one end direction and positioned in the one end direction relative to the first cap inclined surface, a first labyrinth portion is formed between the spindle cap and the end face cover, the first labyrinth portion being a space that extends annularly around the rotation center and opens toward the one end portion; The first labyrinth portion is composed of the first cap groove, the first cover labyrinth surface, and the cover inclined surface. An end cover characterized by:

6. A spindle device; a drive unit that drives the spindle device; In a machine tool equipped with The spindle device is a spindle having a tool attached to one end thereof; a spindle housing that rotatably supports the spindle; a spindle cap having an annular shape centered on the rotation center of the spindle and fixed to an end of the spindle housing in a direction from the other end of the spindle toward the one end; an end cover having an annular shape centered on the rotation center and fixed to the one end of the main shaft; Equipped with a first labyrinth portion is formed between the spindle cap and the end face cover, the first labyrinth portion being a space that extends annularly around the rotation center and opens toward the one end portion; the spindle cap has a first cap groove including a first cap inclined surface extending toward the one end direction as it moves toward the radial inside of the spindle cap, The end cover is A first cover labyrinth surface provided on an outer circumferential portion of the end face cover in the radial direction; a cover inclined surface extending from an end of the first cover labyrinth surface in the one end direction toward the radially inner side of the end face cover toward the one end direction and positioned in the one end direction relative to the first cap inclined surface, The first labyrinth portion is composed of the first cap groove, the first cover labyrinth surface, and the cover inclined surface. A machine tool characterized by:

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