JP5483004B2 - Machine Tools - Google Patents

Description

  The present invention generally relates to machine tools, and more particularly to a machine tool having a cooling structure for cooling a main shaft.

  With respect to conventional machine tools, for example, Japanese Patent Application Laid-Open No. 2001-179573 has an object of quickly cooling a spindle by supplementing heat from a spindle whose temperature has increased due to the heat generated by a rotor of a spindle head with a built-in motor. A spindle cooling structure is disclosed (Patent Document 1). In the spindle cooling structure disclosed in Patent Document 1, the spindle head has an inner frame in which a motor is incorporated, and an outer frame fitted to the outside of the inner frame. Between the outer frame and the inner frame, there is formed a cooling oil passage composed of vertical and horizontal grooves or spiral grooves through which the cooling oil flows.

  Japanese Utility Model Laid-Open No. 4-47954 discloses a spindle head cooling device for a machine tool for the purpose of effectively preventing thermal deformation of the spindle head housing or the tool spindle (Patent Document 2). In the spindle head cooling device disclosed in Patent Document 2, a drive motor is fixed to a spindle head housing that supports a tool spindle via a motor mounting plate. A cooling oil passage is formed in the motor mounting plate. The cooling oil passage is composed of a plurality of U-shaped passages provided in a rectangular three-side region, and a cooling oil supply passage and a cooling oil discharge passage provided in the remaining one-side region.

JP 2001-179573 A Japanese Utility Model Publication No. 4-47954

  A machine tool basically holds a workpiece or tool in order to process a workpiece by bringing a tool into contact with a rotating workpiece (workpiece) or bringing a rotating tool into contact with a fixed workpiece. A main shaft for rotating them is provided. When the main shaft rotates, heat is generated by driving the motor and rotating the bearing, and this heat generation causes thermal deformation of machine tool parts around the main shaft. Therefore, a structure is adopted in which a coolant channel is formed in a housing member provided so as to surround the main shaft, and the main shaft is forcibly cooled by flowing the coolant through the coolant channel.

  On the other hand, the cooling efficiency of the main shaft correlates with the cross-sectional area of the refrigerant flow path, the positional relationship between the refrigerant flow path and the main shaft, and the like. For example, if there are a position where the cross-sectional area of the refrigerant flow path is large and a small position around the axis of the main shaft, a difference occurs in the flow rate of the refrigerant flowing through each refrigerant flow channel, resulting in variations in the cooling efficiency of the main shaft. In this case, there is a concern that the thermal deformation of the machine tool part is not suppressed or eliminated as intended, and the workpiece machining accuracy is lowered.

  Accordingly, an object of the present invention is to solve the above-described problems and to provide a machine tool capable of improving machining accuracy.

  A machine tool according to one aspect of the present invention includes a main shaft and a housing member provided so as to surround the main shaft. The main shaft holds a workpiece or a tool and rotates by a motor drive. The housing member has a side surface that extends along the rotation axis of the main shaft and has a non-circular cross section when cut by a plane perpendicular to the rotation axis of the main shaft. The housing member is formed with a refrigerant flow path through which the refrigerant flows. When the housing member is cut along a plane perpendicular to the rotation axis of the main shaft, the cooling flow path has a plurality of groove cross-sections that open to the side surfaces and are arranged at intervals. The plurality of groove cross sections include a first groove cross section and a second groove cross section whose depth from the side surface is larger than that of the first groove cross section. The machine tool further includes a block member. The block member is disposed on at least the second groove cross section of the first groove cross section and the second groove cross section, and reduces the area in the groove cross section through which the refrigerant can flow.

  According to the machine tool configured as described above, by disposing the block member in at least the second groove cross-section among the first groove cross-section and the second groove cross-section, the groove cross-sectional area of the first groove cross-section and the second groove cross-section. The difference with the groove cross-sectional area is eliminated or reduced. Thereby, it can suppress that the cooling efficiency of a main axis | shaft varies because the groove depth of a 1st groove cross section differs from the groove depth of a 2nd groove cross section. As a result, it is possible to appropriately control the thermal deformation of the machine tool part accompanying the rotation of the spindle, and improve the machining accuracy.

  Preferably, in the first groove cross section and the second groove cross section, the distance between the opening of the first groove cross section and the rotation axis of the main shaft is greater than the distance between the opening of the second groove cross section and the rotation shaft of the main shaft. Is also arranged to be smaller.

  According to the machine tool configured as described above, in order to eliminate or reduce the difference between the position where the refrigerant flows in the first groove cross section and the position where the refrigerant flows in the second groove cross section, A magnitude relationship is provided between the groove depth of the cross section and the groove depth of the second groove cross section. Furthermore, by disposing or reducing the difference between the groove cross-sectional area of the first groove cross section and the groove cross-sectional area of the second groove cross section by disposing the block member, it is possible to more effectively suppress the cooling efficiency of the main shaft from varying.

  The machine tool further includes a lid member attached to the side surface and closing the opening of the groove cross section. Preferably, the block member is formed integrally with the lid member. According to the machine tool configured as described above, the processing accuracy can be improved with a simple configuration.

  A machine tool according to another aspect of the present invention includes a main shaft and a housing member provided so as to surround the main shaft. The main shaft holds a workpiece or a tool and rotates by a motor drive. The housing member has a side surface that extends along the rotation axis of the main shaft and has a non-circular cross section when cut by a plane perpendicular to the rotation axis of the main shaft. The housing member is formed with a refrigerant flow path through which the refrigerant flows. When the housing member is cut along a plane perpendicular to the rotation axis of the main shaft, the cooling flow path has a plurality of groove cross-sections that open to the side surfaces and are arranged at intervals. The plurality of groove cross sections include a first groove cross section and a second groove cross section whose depth from the side surface is larger than that of the first groove cross section. The first groove cross section and the second groove cross section are such that the distance between the opening of the first groove cross section and the rotation axis of the main shaft is smaller than the distance between the opening of the second groove cross section and the rotation shaft of the main shaft. Placed in. The groove width of the second groove cross section is smaller than the groove width of the first groove cross section.

  According to the machine tool configured as described above, in the first groove section where the distance between the opening of the groove section and the rotation axis of the main shaft is relatively small, the groove depth is set small, In the second groove cross section having a relatively large distance between the main shaft and the rotating shaft, the groove depth is set large. Thereby, the difference between the position where the refrigerant flows in the first groove cross section and the position where the refrigerant flows in the second groove cross section can be eliminated or reduced, and variation in the cooling efficiency of the spindle can be suppressed. Further, the groove width of the first groove cross section having a relatively small groove depth is set large, and the groove width of the second groove cross section having a relatively large groove depth is set small. Thereby, the difference between the groove cross-sectional area of the first groove cross section and the groove cross-sectional area of the second groove cross section can be eliminated or reduced, and variation in the cooling efficiency of the main shaft can be further suppressed. As a result, it is possible to appropriately control the thermal deformation of the machine tool part accompanying the rotation of the spindle, and improve the machining accuracy.

  Preferably, the area in the first groove cross section through which the refrigerant can flow is equal to the area in the second groove cross section through which the refrigerant can flow, and the distance between the groove bottom of the first groove cross section and the rotation axis of the main shaft is , Equal to the distance between the groove bottom of the second groove cross section and the rotation axis of the main shaft. According to the machine tool configured as described above, variation in the cooling efficiency of the spindle can be more reliably suppressed.

  As described above, according to the present invention, it is possible to provide a machine tool capable of improving machining accuracy.

It is a perspective view which shows the machine tool in Embodiment 1 of this invention. It is sectional drawing which shows the headstock in FIG. It is sectional drawing which shows the headstock along the III-III line in FIG. FIG. 4 is a perspective view schematically showing an oil flow path formed in the main cylinder in FIG. 3. It is a figure which represents typically the cooling structure of the headstock shown in FIG. It is a block diagram which shows the adjustment mechanism of an oil flow rate. It is a flowchart figure of the process performed by the adjustment mechanism of the oil flow rate in FIG. It is a figure which shows the relationship between the workpiece | work and a tool at the time of seeing from a Z-axis direction. It is a figure which shows the modification of the headstock in FIG. It is a perspective view which shows the 1st modification of the main shaft cylinder in FIG. It is a perspective view which shows the 2nd modification of the main shaft cylinder in FIG. It is sectional drawing which shows the machine tool in Embodiment 3 of this invention. It is a perspective view which shows the side cover provided in the machine tool in FIG. It is a perspective view which shows the 1st modification of the main shaft cylinder in FIG. It is a perspective view which shows the 2nd modification of the main shaft cylinder in FIG. It is a perspective view which shows the side cover attached to the spindle cylinder in FIG. It is sectional drawing which shows the machine tool in Embodiment 5 of this invention.

  Embodiments of the present invention will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are denoted by the same reference numerals.

(Embodiment 1)
FIG. 1 is a perspective view showing a machine tool according to Embodiment 1 of the present invention. With reference to FIG. 1, the overall structure of machine tool 10 in the present embodiment will be described first. The machine tool 10 is a lathe that performs machining by rotating a workpiece and bringing a tool into contact with the workpiece.

  The machine tool 10 includes a bed 160, a headstock 110, a tool rest 120, a transverse feed base 130, a saddle 140, and a tailstock 150 as main components. The machine tool 10 is a two-turret type lathe and has two tool rests 120 (120A, 120B).

  The bed 160 is a basic portion that supports the other components listed above as the main configuration, and is installed on a mounting surface such as a factory. The bed 160 has a mounting surface 162 on which other components are mounted. The bed 160 is formed so that the extending direction of the attachment surface 162 is inclined with respect to the vertical direction. The bed 160 is formed so that the mounting surface 162 faces the worker side during processing. The bed 160 is made of a metal such as cast iron.

  A headstock 110 for rotating the workpiece is attached to the bed 160. The headstock 110 is provided so as to rise upward from the mounting surface 162 of the bed 160. The headstock 110 is disposed at one end of a mounting surface 162 in the Z-axis direction described later. The headstock 110 has a main shaft 21. The main shaft 21 holds a workpiece and rotates around a rotation shaft 101 shown as a virtual line in FIG. The rotation shaft 101 extends in the axial direction indicated by the arrow 202 (Z-axis direction).

  A tailstock 150 is further attached to the bed 160. The tailstock 150 is disposed at the other end of the attachment surface 162 in the Z-axis direction. The tailstock 150 is disposed on an extension line of the rotation shaft 101. That is, the headstock 110 and the tailstock 150 are disposed to face each other on the axis of the rotating shaft 101. The tailstock 150 has a function of supporting the end portion of a work when a long work is mounted on the spindle stock 110.

  A saddle 140 is further attached to the bed 160. The saddle 140 is provided to be slidable in the axial direction (Z-axis direction) indicated by the arrow 202 with respect to the bed 160. The saddle 140 is a component that has a guide surface 141 for slidingly moving the lateral feed stand 130 and slides on the guide surface 161 of the bed 160. The saddle 140 has a function of moving a tool 122 (described later) mounted on the tool post 120 along the Z-axis direction.

  A lateral feed base 130 is attached to the saddle 140. The lateral feed base 130 is provided so as to be slidable relative to the saddle 140 in the axial direction indicated by the arrow 201 (X-axis direction). The lateral feed stand 130 has a function of moving a tool 122 (described later) mounted on the tool post 120 along the X-axis direction. The saddle 140 and the lateral feed base 130 constitute a carriage for causing the tool 122 to perform a feed movement.

  A tool post 120 is attached to the lateral feed base 130. The tool 122 is attached to the tool post 120 via the tool holder 121. The tool post 120 has a function of holding and fixing the tool 122. The tool post 120 has a turret shape, and is formed of a face plate on which a plurality of tools 122 are attached in a radial manner to perform turning indexing.

  In the present embodiment, a saddle 140 and a lateral feed base 130 are provided for each of the tool rests of the tool rest 120A and the tool rest 120B. The tool post 120 </ b> A and the tool post 120 </ b> B are arranged at a distance from each other in the X-axis direction. The tool post 120 </ b> A and the tool post 120 </ b> B are arranged such that the head stock 110 is located between the tool post 120 </ b> B and the tool post 120 </ b> B.

  The bed 160, the saddle 140, and the lateral feed stand 130 are appropriately provided with a feed mechanism, a guide mechanism, a servo motor, and the like for enabling sliding movement of each component along the X-axis and Z-axis directions. Yes.

  The Z-axis that is the movement axis of the saddle 140 extends in the horizontal direction. The Z axis that is the movement axis of the saddle 140 and the X axis that is the movement axis of the lateral feed base 130 are orthogonal to each other. In other words, in the machine tool 10 according to the present embodiment, the machining position of the workpiece by the tool 122 mounted on the tool post 120 is set to X− by combining the linear movement of the saddle 140 and the linear movement of the lateral feed base 130. Move freely in the Z plane.

  In FIG. 1, an axial direction (Y axis) indicated by an arrow 203 is further shown. The Y axis is orthogonal to the Z axis that is the movement axis of the saddle 140 and the X axis that is the movement axis of the lateral feed base 130.

  In addition, the machine tool in this invention is not limited to the said form, You may comprise further having a structure which can be slid to said Y-axis direction component. In this case, the processing position of the workpiece by the tool 122 mounted on the tool post 120 moves three-dimensionally.

  FIG. 2 is a cross-sectional view showing the headstock in FIG. The structure of the head stock 110 will be described in detail with reference to FIGS. 1 and 2. The head stock 110 further includes a main shaft cylinder 41 as a housing member and a support leg 61 as a support member in addition to the main shaft 21. Have.

  The main shaft 21 is provided as a rotating body that rotates around the rotation shaft 101, and is configured by combining a plurality of components including the main shaft body 22 and the rotor 23. The main spindle body 22 has a shape extending in a cylindrical shape along the axial direction of the rotary shaft 101. The main spindle body 22 is rotatably supported by a bearing 26 and a bearing 27. A chuck 111 (see FIG. 1) for holding a workpiece is mounted on the main spindle body 22. The chuck 111 is disposed at the end of the main spindle body 22 in the axial direction of the rotary shaft 101. The rotor 23 has a cylindrical shape and is fitted on the outer periphery of the main spindle body 22.

  The bearing 26 is disposed on the front end side of the main shaft 21 to which the chuck 111 is mounted, and the bearing 27 is disposed on the rear end side of the main shaft 21 opposite to the side on which the chuck 111 is mounted. A bearing 26 is disposed between the chuck 111 and the rotor 23 in the axial direction of the rotary shaft 101. In the axial direction of the rotating shaft 101, the bearing 27 is disposed on the opposite side of the bearing 26 with respect to the rotor 23.

  The main shaft cylinder 41 is provided so as to surround the main shaft 21 from the outer periphery thereof. The main cylinder 41 has a cylindrical shape extending in the axial direction of the rotary shaft 101 in a state of being arranged on the outer periphery of the main spindle 21. A stator 46 is fixed to the inner periphery of the main shaft cylinder 41. The stator 46 is disposed on the outer periphery of the rotor 23. A small gap is provided between the stator 46 and the rotor 23 so as to extend in the circumferential direction about the rotation shaft 101. The rotor 23 and the stator 46 are combined to constitute a motor for rotating the main shaft 21.

  In the present embodiment, the case where the head stock 110 is a built-in type in which the motor is built inside the main shaft cylinder 41 has been described. However, the present invention is not limited to this, and the main head stock 110 includes the main shaft cylinder 41. A type in which a motor is externally attached and the output of the motor is transmitted to the main shaft 21 via a gear may be used.

  The support legs 61 are provided to support the spindle cylinder 41 on the bed 160. The spindle cylinder 41 is attached to the bed 160 via support legs 61. More specifically, the support leg 61 is fixed on the mounting surface 162 of the bed 160. The support leg 61 has a column shape extending upward from the mounting surface 162. The spindle cylinder 41 is fixed to the tip of the extending support leg 61. The spindle cylinder 41 and the support legs 61 are made of a metal such as cast iron.

  3 is a cross-sectional view showing the headstock along the line III-III in FIG. With reference to FIGS. 1 to 3, the main cylinder 41 has a side surface 42. The side surface 42 extends along the rotation axis 101. The side surface 42 extends in a direction parallel to the rotation shaft 101. The side surface 42 is a plane that is not orthogonal to the rotation axis 101. When the main cylinder 41 is cut by a plane orthogonal to the rotation shaft 101, the side surface 42 has a non-circular cross section. In the present embodiment, when the main shaft cylinder 41 is cut by a plane orthogonal to the rotation shaft 101, the side surface 42 has a substantially rectangular cross section.

  In the main shaft cylinder 41 having such a configuration, the side surface 42 includes a plurality of side surfaces 42A, 42B, 42C, and 42D. The side surfaces 42 </ b> A, 42 </ b> B, 42 </ b> C, 42 </ b> D are arranged side by side in the circumferential direction around the rotation shaft 101 in the order given. The side surfaces 42A to 42D are formed such that the side surfaces adjacent to each other are orthogonal to each other. The side surfaces 42 </ b> A to 42 </ b> D constitute four surfaces having a substantially rectangular cross section that the side surface 42 has. When the regions 111A, 111B, 111C, and 111D are defined around the rotation shaft 101, the side surfaces 42A, 42B, 42C, and 42D are arranged in the regions 111A, 111B, 111C, and 111D, respectively.

  FIG. 4 is a perspective view schematically showing an oil passage formed in the main cylinder in FIG. With reference to FIGS. 2 to 4, an oil passage 31 for circulating cooling oil is formed in the main shaft cylinder 41.

  In the machine tool 10 according to the present embodiment, the oil flow path 31 includes oil flow paths 31A, 31B, 31C, and 31D. The oil flow paths 31A, 31B, 31C, 31D are formed in the regions 111A, 111B, 111C, 111D, respectively. The oil flow paths 31A to 31D extend independently of each other. In other words, the oil flow paths 31 </ b> A to 31 </ b> D are not connected to each other in the main shaft cylinder 41.

  The oil flow path 31 is formed on the outer periphery of the main shaft 21. The oil flow path 31 is formed at a position overlapping the rotor 23, the stator 46, and the bearing 26 in the axial direction of the rotating shaft 101 (see FIG. 2).

  The oil flow path 31 extends in a linear shape and is formed in a range that extends in a plane on the side surface 42. The oil flow path 31 is formed on the side surface 42 so as to change the linearly extending direction for each predetermined section. The oil flow path 31 extends in a zigzag shape. The oil channel 31 includes a channel portion 33 as a first channel portion extending along the axial direction of the rotating shaft 101 and a channel as a second channel portion extending along a direction orthogonal to the channel portion 33. Part 34. The oil flow path 31 extends while meandering so that the flow path portions 33 and the flow path portions 34 are alternately arranged. In the present embodiment, each of the oil flow paths 31A to 31D is formed such that the total length of the flow path portion 33 is larger than the total length of the flow path portion 34 on each of the side surfaces 42A to 42D. .

  When the main shaft cylinder 41 is cut along a plane orthogonal to the rotation shaft 101, the oil passage 31 has a plurality of groove cross sections 36 (see FIG. 3). The plurality of groove cross-sections 36 open to the side surface 42 and are arranged at intervals. The oil passages 31A, 31B, 31C, and 31D are formed by groove sections 36 that open to the side surfaces 42A, 42B, 42C, and 42D, respectively. The plurality of groove cross sections 36 are cross sections in the flow path portion 33 of the oil flow path 31.

  The machine tool 10 further includes a side lid 52 as a lid member. The side lid 52 has a flat plate shape. The side lid 52 is attached to the main shaft cylinder 41 so as to close the opening of the groove cross section 36. In order to prevent oil leakage from the oil flow path 31, a seal member (not shown) is interposed between the side lid 52 and the side surface 42.

  In the present embodiment, the case where the side surface 42 has a substantially rectangular cross section when the main cylinder 41 is cut by a plane orthogonal to the rotation shaft 101 has been described. It may have a polygonal cross section.

  FIG. 5 is a diagram schematically showing the cooling structure of the headstock shown in FIG. Referring to FIG. 5, machine tool 10 in the present embodiment includes an oil cooler 66 for cooling oil, an oil tank 67 for storing oil, and oil supply channels 73A, 73B, 73C, 73D, an oil discharge passage 75, flow rate adjusting valves 71A, 71B, 71C, 71D, and temperature sensors 51A, 51B, 51C, 51D.

  The oil passage 31 formed in the main shaft cylinder 41, the oil cooler 66, and the oil tank 67 are connected to each other by the oil supply passages 73A to 73D and the oil discharge passage 75. The oil cooler 66 has a function of cooling the oil whose temperature has been increased by cooling the headstock 110.

  More specifically, one end of an oil flow path 31A extending in a zigzag shape on the side surface 42A and the oil cooler 66 are connected by an oil supply flow path 73A. An oil discharge passage 75 connects between the other end of the oil passage 31 </ b> A extending in a zigzag shape on the side surface 42 </ b> A and the oil tank 67. Similarly, one end of the oil passage 31B and the oil cooler 66 are connected by an oil supply passage 73B, and the other end of the oil passage 31B and the oil tank 67 are connected to the oil discharge passage. 75 is connected. The one end of the oil passage 31C and the oil cooler 66 are connected by an oil supply passage 73C, and the other end of the oil passage 31C and the oil tank 67 are connected by an oil discharge passage 75. Has been. The oil flow path 73D is connected between one end of the oil flow path 31D and the oil cooler 66, and the oil discharge flow path 75 is connected between the other end of the oil flow path 31D and the oil tank 67. Has been.

  With such a configuration, the oil supplied to the oil passages 31A, 31B, 31C, and 31D through the oil supply passages 73A, 73B, 73C, and 73D, The headstock 110 is cooled by performing heat exchange. The oil whose temperature has been increased by heat exchange is collected in the oil tank 67 through the oil discharge passage 75. The oil is pumped up by a pump (not shown), cooled by the oil cooler 66, and then supplied again to the oil flow paths 31A, 31B, 31C, 31D.

  Since the temperature of the oil gradually increases while flowing through the oil flow path 31, there is a difference in the temperature of the oil between the upstream side and the downstream side of each of the oil flow paths 31A to 31D. On the other hand, in the present embodiment, as shown in FIG. 4, the total length of the flow path portion 33 on each of the side surfaces 42 </ b> A to 42 </ b> D is zigzag so as to be larger than the total length of the flow path portion 33. Is formed. According to such a configuration, the oil flow path 31 reciprocates many times in the axial direction of the rotation shaft 101 of the main shaft 21, so that the oil temperature difference that occurs between the upstream side and the downstream side of the oil flow path 31. Can have a small influence on the thermal deformation of the main shaft 21 in the axial direction of the rotating shaft 101. Thereby, it can suppress that the main axis | shaft 21 deform | transforms so that it may curve in the axial direction of the rotating shaft 101. FIG.

  The cooling structure of the headstock 110 provided in the machine tool 10 adjusts the oil flow rate supplied to the oil flow paths 31A to 31D for each flow path in order to achieve the purpose of finally improving the machining accuracy of the workpiece. Provide mechanism. Hereinafter, the oil flow rate adjusting mechanism will be described.

  Flow rate adjusting valves 71A, 71B, 71C, and 71D as adjusting units are provided on the paths of the oil supplying channels 73A, 73B, 73C, and 73D, respectively. The flow rate adjusting valves 71A, 71B, 71C, 71D are provided as variable flow rate valves capable of adjusting the flow rate of oil flowing through the oil flow paths 31A, 31B, 31C, 31D, respectively.

  The temperature sensors 51 </ b> A to 51 </ b> D are provided at a plurality of locations of the spindle cylinder 41. The temperature sensors 51 </ b> A to 51 </ b> D are embedded in the metal that forms the spindle cylinder 41. In the present embodiment, the temperature sensors 51 </ b> A, 51 </ b> B, 51 </ b> C, 51 </ b> D are embedded in four locations of the main cylinder 41 located between the side surfaces 42 </ b> A, 42 </ b> B, 42 </ b> C, 42 </ b> D and the main shaft 21. The temperature sensors 51A to 51D have a function of detecting the temperature of the spindle cylinder 41 at the position where each sensor is provided.

  In addition, the position which provides temperature sensor 51A-51D is not limited to the said location. For example, the temperature sensors 51 </ b> A to 51 </ b> D may be joined to the surface of the main shaft cylinder 41. The temperature sensors 51A to 51D may be provided at positions between adjacent oil flow paths (for example, corner portions of the main cylinder 41 between the oil flow paths 31A and 31B). In the present embodiment, the number of oil flow paths 31 and the number of temperature sensors match, but they do not necessarily have to match.

  FIG. 6 is a block diagram showing an oil flow rate adjusting mechanism. FIG. 7 is a flowchart of processing executed by the oil flow rate adjusting mechanism in FIG.

  Referring to FIGS. 6 and 7, machine tool 10 further includes a control unit 76. The controller 76 is electrically connected to the temperature sensors 51A to 51D and the flow rate adjusting valves 71A to 71D so that temperature data can be input and output and commands related to the valve opening can be input and output.

The processing flow for adjusting the oil flow rate will be described. First, the temperature sensors 51A to 51D detect the temperatures (t ₁ , t ₂ , t ₃ , t ₄ ) of the spindle cylinder 41 at the positions where the sensors are provided ( S101). The temperature sensors 51 </ b> A to 51 </ b> D output the detected temperature data of the spindle cylinder 41 to the control unit 76.

Based on the temperature data received from the temperature sensors 51A to 51D, the control unit 76 determines the oil flow rates (A ₁ , A ₂ , A ₃ , A ₄ ) to be circulated through the oil flow paths 31A to 31D ( S102). At this time, the oil flow rate (A ₁ , A ₂ , A ₃ , A ₄ ) is determined so that the rotation center of the main shaft 21 does not change due to thermal deformation caused by heat generation during rotation of the main shaft 21. In order to make it possible to determine such an oil flow rate, a calculation formula “A ₁ , A ₂ , A ₃ , A ₄ == the temperature (t ₁ , t ₂ , t ₃ , t ₄ ) of the spindle cylinder 41 as a variable = f (t ₁ , t ₂ , t ₃ , t ₄ ) ”is given to the control unit 76 in advance. This calculation formula shows the rotation center of the main shaft 21 while varying the temperature (t ₁ , t ₂ , t ₃ , t ₄ ) and the oil flow rate (A ₁ , A ₂ , A ₃ , A ₄ ) of the main shaft cylinder 41. Is obtained by sampling the combination of the temperature of the spindle cylinder 41 and the oil flow rate at which the position of the center of rotation of the spindle 21 does not change. The control unit 76 calculates a valve opening for realizing the determined oil flow rate, and outputs this to each of the flow rate adjusting valves 71A to 71D.

  Each of the flow rate adjusting valves 71A to 71D operates in accordance with the input valve opening (S103). As a result, a predetermined amount of oil flows through each of the oil flow paths 31A to 31D.

  If the rotation center of the spindle 21 is kept at a fixed position during processing as described above, the oil required for each flow path of the oil flow paths 31A to 31D due to the distortion of the shape of the headstock 110 or the like. The flow rates are different from each other. Further, while the three side surfaces 42A, 42C, and 42D of the spindle cylinder 41 face the surrounding environment, the side surface 42B is connected to the bed 160 via the support legs 61, so that the headstock 110 is The heat radiation property is low toward three sides of the side surfaces 42A, 42C, and 42D and increases toward one of the side surfaces 42b. This also causes the oil flow rates required for each of the oil flow paths 31A to 31D to be different from each other.

  On the other hand, in machine tool 10 in the present embodiment, oil flow paths 31A to 31D that are independent from each other are formed on each side face 42A to 42D, and further supplied to these oil flow paths 31A to 31D. Flow rate adjustment valves 71A to 71D are provided that individually change the oil flow rate.

  In the present embodiment, the adjustment of the oil flow rate is used as means for properly cooling the spindle cylinder 41 for each of the regions 111A to 111D, but the present invention is not limited to this. For example, the cooling efficiency of the spindle cylinder 41 in each of the regions 111A to 111D may be made variable by providing a difference in the temperature of the oil supplied to the oil passages 31A to 31D. In this case, the temperature of the oil supplied to the oil flow paths 31A to 31D is adjusted by mixing the oil recovered by the oil tank 67 with the oil cooled by the oil cooler 66 in FIG. May be.

On the other hand, depending on the state of heat generation during rotation of the main shaft 21, it may be difficult to hold the rotation center of the main shaft 21 at a fixed position. In this case, in the flow indicated by S102 in FIG. 7, the control unit 76 determines the oil flow rates (A ₁ , A ₂ , A ₃ , A ₄ so that the rotation center of the main shaft 21 is displaced along the Y-axis direction. ). The reason will be described below.

  FIG. 8 is a diagram showing the relationship between the workpiece and the tool when viewed from the Z-axis direction. Referring to FIG. 8, in the drawing, a cylindrical workpiece 123 that rotates about the rotation shaft 101 and a tool 122 that cuts the workpiece 123 (as an example, mounted on the tool post 120 </ b> B in FIG. 1). Stuff).

  During machining, the tool 122 moves along the X-axis direction indicated by the arrow 201 and contacts the outer peripheral surface of the workpiece 123. In this case, for example, if the rotation shaft 101 is displaced in a direction parallel to the X axis indicated by the arrow 211 due to thermal deformation accompanying heat generation during rotation of the main shaft 21, a machining position 81 where the workpiece 123 and the tool 122 come into contact with each other. Is displaced in the cutting direction of the tool 122 as indicated by an arrow 213. For this reason, the influence which the displacement of the rotating shaft 101 has on the machining accuracy of the workpiece 123 is increased. On the other hand, when the rotary shaft 101 is displaced in a direction parallel to the Y axis indicated by the arrow 212 due to thermal deformation caused by heat generated when the main shaft 21 rotates, the machining position 81 where the workpiece 123 and the tool 122 contact each other is indicated by an arrow. The workpiece 123 is displaced in the tangential direction of the outer peripheral surface of the work 123. In this case, the displacement in the cutting direction is small, and the influence of the displacement of the rotating shaft 101 on the machining accuracy of the workpiece 123 is small. As a result, even when the center of rotation of the main shaft 21 is displaced due to thermal deformation accompanying the rotation of the main shaft 21, it is possible to suppress a decrease in machining accuracy as much as possible.

  FIG. 9 is a view showing a modification of the headstock in FIG. Referring to FIG. 9, in the present modification, support leg 61 has leg portion 62 and leg portion 63. The leg portion 62 and the leg portion 63 extend in a columnar shape between the bed 160 and the main shaft cylinder 41. The leg part 62 and the leg part 63 are branched from the spindle cylinder 41 side, and are connected to different positions of the bed 160. The leg portion 62 has a leg length H1 that is the length between the bed 160 and the spindle cylinder 41, and the leg portion 63 has a leg length H2 that is larger than H1.

  In this modification, temperature sensors 51E and 51F are provided on the spindle cylinder 41 in place of the temperature sensors 51A to 51D in FIG. The temperature sensor 51E is disposed between the oil passage 31A and the oil passage 31B (the corner between the side surface 42A and the side surface 42B), and the temperature sensor 51F is provided between the oil passage 31B and the oil passage 31C. It is arrange | positioned between (the corner | angular part between the side surface 42B and the side surface 42C).

  In the headstock 110 having such a configuration, it is assumed that the control unit 76 determines the oil flow rate so that the rotation center of the main shaft 21 is displaced along the Y-axis direction. In this modification, since the leg part 62 has the leg length H1 and the leg part 63 has the leg length H2 larger than H1, the leg part 62 and the leg part 63 reach the same temperature by heat transfer from the spindle cylinder 41. When the temperature rises, the extension amount of the leg portion 63 becomes larger than the extension amount of the leg portion 62 after the thermal deformation. For this reason, for example, when 8 ° C. is detected by the temperature sensor 51E and 10 ° C. is detected by the temperature sensor 51F, the oil flow rate supplied to the oil passage 31A is decreased and supplied to the oil passage 31C. Increase the oil flow rate. Thereby, the temperature in the temperature sensor 51E is set to 10 ° C., the temperature in the temperature sensor 51F is set to 8 ° C., and the difference in the amount of thermal deformation caused by the leg lengths of the leg portion 62 and the leg portion 63 is cancelled.

  The structure of the machine tool 10 according to the first embodiment of the present invention described above will be described collectively. The machine tool 10 according to the present embodiment includes a main shaft 21 and a main shaft cylinder 41 as a housing member. The main shaft 21 holds a work as a work or a tool, and rotates by driving a motor. The spindle cylinder 41 is provided so as to surround the spindle 21. The main cylinder 41 is formed with oil passages 31A to 31D as a plurality of refrigerant passages through which oil as a refrigerant flows. The oil flow paths 31A to 31D are arranged in a plurality of regions 111A to 111D arranged in the circumferential direction around the rotation shaft 101 of the main shaft 21, and are formed independently of each other.

  According to the machine tool 10 according to the first embodiment of the present invention configured as described above, the oil flow paths 31A to 31D that are independent from each other are formed on the respective side surfaces 42A to 42D of the spindle cylinder 41. As a result, it is possible to set conditions for circulating oil for each oil flow path, and it is possible to appropriately control the thermal deformation of the headstock 110 due to heat generation during rotation of the main shaft 21. As a result, machining accuracy can be improved.

  In the present embodiment, the case where the machine tool in the present invention is a lathe has been described. However, the present invention can also be applied to a machining center. The present invention can also be applied to a multi-tasking machine such as a lathe having a tool spindle or a machining center having a rotary table.

(Embodiment 2)
In the present embodiment, various modifications of the spindle cylinder 41 provided in the machine tool 10 according to the first embodiment will be described.

  FIG. 10 is a perspective view showing a first modification of the spindle cylinder in FIG. With reference to FIG. 10, the oil flow path 31 includes a flow path portion 33 extending along the axial direction of the rotation shaft 101 and a flow path portion 34 extending along a direction orthogonal to the flow path portion 33. The flow path portions 33 and the flow path portions 34 extend while meandering so as to be alternately arranged. In this modification, each of the oil flow paths 31 </ b> A to 31 </ b> D is formed such that the total length of the flow path portion 34 is larger than the total length of the flow path portion 33 on each of the side surfaces 42 </ b> A to 42 </ b> D.

  In the machine tool having such a configuration, oil is preferably supplied from the front of the main shaft to the oil passage 31 and discharged from the rear of the main shaft. In this case, since oil with a low temperature flows in front of the main shaft, seizure of the bearing 26 (see FIG. 2) disposed in front of the main shaft can be prevented more reliably.

  FIG. 11 is a perspective view showing a second modification of the main barrel in FIG. Referring to FIG. 11, in this modification, the oil flow path 31 is divided into regions 86, 87, 88 aligned in the axial direction of the rotation shaft 101 in addition to the regions 111 </ b> A to 111 </ b> D in FIG. 3 aligned in the circumferential direction. Has been formed. That is, the oil flow path 31 is composed of twelve oil flow paths that are formed independently of each other. According to such a configuration, the condition for supplying oil to the oil flow path 31 is further set for each of the regions 86 to 88 aligned in the axial direction of the rotating shaft 101. Thereby, it can prevent that the main axis | shaft 21 deform | transforms so that it may curve in the axial direction of the rotating shaft 101. FIG. As a result, machining accuracy can be improved.

  According to the machine tool in the second embodiment of the present invention configured as described above, the effects described in the first embodiment can be obtained in the same manner.

(Embodiment 3)
FIG. 12 is a cross-sectional view showing a machine tool according to Embodiment 3 of the present invention. The machine tool in the present embodiment has basically the same structure as that of the machine tool 10 in the first embodiment. Hereinafter, the description of the overlapping structure will not be repeated.

  Referring to FIG. 12, when the main shaft cylinder 41 is cut along a plane orthogonal to the rotation shaft 101, the oil flow path 31 has a plurality of groove cross sections 36. The plurality of groove cross sections 36 are cross sections of the oil flow path 31 in the flow path portion 33 in FIG. 4. The plurality of groove cross sections 36 are arranged at intervals from each other. In the drawing, a plurality of groove cross sections 36 opened on the side surface 42A of the main shaft cylinder 41 are shown. Since the plurality of groove sections 36 have the same structure on the side surfaces 42A to 42D, the structure of the plurality of groove sections 36 that typically open to the side surface 42A will be described below.

  The plurality of groove cross sections 36 includes two groove cross sections 36p, two groove cross sections 36q, and two groove cross sections 36r. The two groove cross sections 36p are disposed adjacent to each other. The two groove cross sections 36q are disposed on both sides of the groove cross section 36p, respectively, and the two groove cross sections 36r are disposed on both sides of the groove cross section 36q. The groove cross section 36p, the groove cross section 36q, and the groove cross section 36r are arranged so as to be arranged from the center portion of the side surface 42A toward the end portion in the order given.

  As already described, in the present embodiment, when the main shaft cylinder 41 is cut by a plane orthogonal to the rotation shaft 101, the side surface 42 has a substantially rectangular cross section. For this reason, the distance between the side surface 42A and the rotating shaft 101 increases from the center of the side surface 42A toward the end. The length L2 between the opening of the groove cross section 36q and the rotating shaft 101 on the side surface 42A is larger than the length L1 between the opening of the groove cross section 36p and the rotating shaft 101. The length L3 between the opening of the groove cross section 36r and the rotating shaft 101 on the side surface 42A is larger than the length L2 between the opening of the groove cross section 36q and the rotating shaft 101.

  When the length of the side surface 42A and the groove cross section 36 to the groove bottom is referred to as the groove depth, the groove cross section 36p has a groove depth H1. The groove cross section 36q has a groove depth H2 larger than the groove depth H1. The groove cross section 36r further has a groove depth H3 that is greater than the groove depth H2. The length L4 between the groove bottom of the groove cross section 36p and the rotary shaft 101, the length L5 between the groove bottom of the groove cross section 36q and the rotary shaft 101, the groove bottom of the groove cross section 36r and the rotary shaft 101 The length L6 between them is equal to each other. That is, the groove cross-sections 36p, 36q, and 36r are formed such that the groove bottoms of the respective groove cross-sections are aligned in the circumferential direction around the rotation shaft 101.

  In the cross section shown in FIG. 12, when the length of the groove cross section 36 in the direction perpendicular to the groove depth direction is referred to as the groove width, each of the groove cross sections 36p, 36q, 36r has a constant groove width. The groove cross sections 36p, 36q, 36r have the same groove width.

  FIG. 13 is a perspective view showing a side lid provided on the machine tool in FIG. Referring to FIGS. 12 and 13, machine tool 90 in the present embodiment has in-groove block 56 as a block member. The in-groove block 56 is disposed in the groove cross section 36q and the groove cross section 36r having a groove depth larger than the groove cross section 36p. In the present embodiment, the in-groove block 56 is not disposed on the groove cross section 36p. When the in-groove block 56 arranged in the groove cross section 36q is referred to as an in-groove block 56Q, and the in-groove block 56 arranged in the groove cross section 36r is referred to as an in-groove block 56R, the in-groove block 56Q is within the groove cross section 36q. The area in which oil can flow (hereinafter also referred to as an oil flow path area) is arranged to be small, and the in-groove block 56R is arranged to reduce the oil flow area in the groove cross section 36r.

  The in-groove block 56Q disposed in the groove cross section 36q having a relatively small groove depth has a height h2, and the in-groove block 56R disposed in the groove cross section 36r having a relatively large groove depth is , Having a height h3 greater than the height h2. By arranging the in-groove block 56Q and the in-groove block 56R in the groove cross section 36q and the groove cross section 36r, respectively, the oil flow area S1 of the groove cross section 36p, the oil flow area S2 of the groove cross section 36q, and the groove cross section 36r Are equal to each other. That is, the flow velocity of oil flowing through the groove cross section 36p, the flow velocity of oil flowing through the groove cross section 36q, and the flow velocity of oil flowing through the groove cross section 36r are equal to each other.

  According to such a configuration, by disposing the in-groove block 56 in the groove cross section 36, the groove cross sections 36 p, 36 q, 36 r having equal oil flow path areas have a main shaft having a circular cross section around the rotation shaft 101. It is formed around the main shaft 21 with an equal positional relationship with respect to the shaft 21. Thereby, the cooling efficiency of the main shaft cylinder 41 is caused by the difference in the oil flow path area between the plurality of groove cross sections 36 and the difference in the positional relationship between the main shaft 21 and each groove cross section 36, with the rotation shaft 101 as the center. It is possible to prevent variation in the circumferential direction.

  For example, assuming that all of the plurality of groove cross sections 36 have a groove depth H1, in this case, the distance between the main shaft 21 and the oil flow path 31 is increased at the position where the groove cross section 36r is formed. For this reason, heat from the main shaft 21 side toward the outer peripheral direction cannot immediately exchange heat with the oil flowing through the groove cross section 36r, and thermal interference occurs at the boundary positions of the adjacent regions 111A to 111D in FIG. The occurrence of such thermal interference is a matter that is not determined as a phenomenon, and becomes a factor that complicates the control of thermal deformation of the head stock 110. On the other hand, in the machine tool 90 according to the present embodiment, the head stock 110 can be evenly cooled in the circumferential direction around the rotation shaft 101 in each of the regions 111A to 111D. Thereby, the thermal deformation of the headstock 110 can be controlled easily and appropriately through the setting of the oil flow rate supplied to the oil flow paths 31A to 31D.

  Further, in the present embodiment, the oil flow path 36 is formed in a groove shape that opens to the side surface 42. With such a configuration, the oil flow path 36 can be easily formed by forming the groove shape at the same time when the main shaft cylinder 41 is cast. Thereby, the manufacturing process of the spindle cylinder 41 can be simplified and the productivity can be improved.

  Furthermore, in this embodiment, the in-groove block 56 is formed integrally with the side lid 52. According to such a configuration, the number of parts required for the headstock 110 can be reduced. Further, since the in-groove block 56 is disposed on the groove cross section 36 simultaneously with the attachment of the side lid 52, the workability at the time of assembling the headstock 110 can be improved.

  The structure of the machine tool 90 according to the third embodiment of the present invention described above will be described together. The machine tool 90 according to the present embodiment is a main shaft 21 and a main shaft as a housing member provided so as to surround the main shaft 21. A cylinder 41. The main shaft 21 holds a work as a work or a tool, and rotates by driving a motor. The main cylinder 41 has a side surface 42 that extends along the rotation shaft 101 of the main shaft 21 and has a non-circular cross section when cut by a plane orthogonal to the rotation shaft 101 of the main shaft 21. An oil passage 31 through which oil as a refrigerant flows is formed in the main cylinder 41. When the main shaft cylinder 41 is cut by a plane orthogonal to the rotation shaft 101 of the main shaft 21, the oil flow path 31 is open to the side surface 42 and is arranged with a plurality of groove cross sections 36 (36p, 36q, 36p, 36q,. 36r).

  The plurality of groove cross sections 36 include a groove cross section 36p as a first groove cross section and a groove cross section 36q as a second groove cross section whose depth from the side surface 42 is larger than the groove cross section 36p. The machine tool 90 further includes an in-groove block 56 as a block member. The in-groove block 56 is disposed in at least the groove cross section 36q as the second groove cross section of the first groove cross section and the second groove cross section, and reduces the area in the groove cross section 36 through which oil can flow.

  Alternatively, the plurality of groove cross sections 36 include a groove cross section 36q as a first groove cross section and a groove cross section 36r as a second groove cross section whose depth from the side surface 42 is larger than the groove cross section 36q. The machine tool 90 further includes an in-groove block 56 as a block member. The in-groove block 56 is disposed in at least the groove cross section 36q and the groove cross section 36r as the second groove cross section of the first groove cross section and the second groove cross section, and reduces the area in the groove cross section 36 through which the coolant can flow.

  According to the machine tool 90 according to the third embodiment of the present invention configured as described above, by cooling the headstock 110 evenly in the circumferential direction around the rotation shaft 101 in each of the regions 111A to 111D. The thermal deformation of the headstock 110 can be easily and appropriately controlled. As a result, machining accuracy can be improved.

  In the present embodiment, the machine tool 90 in which the oil flow paths 31A to 31D independent from each other are formed on each side surface of the main barrel 41 has been described. However, in the present invention, the oil flows formed independently from each other are described. The road is not an essential configuration. That is, the oil flow paths 31A to 31D may be formed to communicate with each other.

(Embodiment 4)
As shown in FIG. 4, the oil flow path 31 includes a flow path portion 33 that extends along the axial direction of the rotation shaft 101 and a flow path portion 34 that extends along a direction orthogonal to the flow path portion 33. ing. In the present embodiment, a structure for obtaining the same oil passage area as the passage portion 33 in the passage portion 34 will be described. Note that the description of the same structure as that of the machine tool 90 in Embodiment 3 will not be repeated.

  FIG. 14 is a perspective view showing a first modification of the spindle cylinder in FIG. In FIG. 14 and FIG. 15 to be described later, a flow path portion 34 that connects the groove cross section 36q and the groove cross section 36r of the flow path portion 33 is typically shown.

  Referring to FIG. 14, in this modification, the flow path portion 33 has a groove width B1, and the flow path portion 34 has a groove width B2 smaller than B1. In a state where the side cover 52 in FIG. 13 is attached to the main shaft cylinder 41 in FIG. 14, the oil flow path area of the groove cross sections 36p to 36r in the flow path portion 33 and the oil flow path area in the flow path portion 34 are as follows. , Become equal to each other. That is, the flow rate of oil flowing through the groove sections 36p to 36r of the flow path portion 33 and the flow rate of oil flowing through the flow path portion 34 are equal to each other.

  FIG. 15 is a perspective view showing a second modification of the main cylinder in FIG. FIG. 16 is a perspective view showing a side cover attached to the spindle cylinder in FIG.

  Referring to FIGS. 15 and 16, the groove bottom of the flow path portion 34 has a groove bottom of a groove section 36 r having a relatively large groove depth and a groove of a groove section 36 q having a relatively small groove depth. Inclined so as to connect the bottom to each other. In this modification, an in-groove block 57 is further arranged in the flow path portion 34. The in-groove block 57 is formed so as to be inclined at the same angle as the groove bottom of the channel portion 34 between the in-groove block 56Q and the in-groove block 56R in a state of being disposed in the channel portion 34.

  In a state where the side lid 52 is attached to the main shaft cylinder 41, the oil flow path area of the groove cross sections 36p to 36r in the flow path portion 33 and the oil flow path area in the flow path portion 34 are equal to each other. That is, the flow rate of oil flowing through the groove sections 36p to 36r of the flow path portion 33 and the flow rate of oil flowing through the flow path portion 34 are equal to each other.

  According to these modified examples, by making the oil flow path area of the groove cross-sections 36p to 36r in the flow path portion 33 equal to the oil flow path area in the flow path portion 34, the variation in cooling efficiency is more effectively achieved. Can be suppressed.

  According to the machine tool according to the fourth embodiment of the present invention configured as described above, the effects described in the third embodiment can be obtained similarly.

(Embodiment 5)
FIG. 17 is a cross-sectional view showing a machine tool according to Embodiment 5 of the present invention. The machine tool in the present embodiment has basically the same structure as that of the machine tool 90 in the third embodiment. Hereinafter, the description of the overlapping structure will not be repeated.

  Referring to FIG. 17, in the machine tool 95 in the present embodiment, the length L2 between the opening of the groove cross section 36q in the side surface 42A and the rotation shaft 101 is similar to the machine tool 90 in the third embodiment. It becomes larger than the length L1 between the opening of the groove cross section 36p and the rotating shaft 101. The length L3 between the opening of the groove cross section 36r and the rotating shaft 101 on the side surface 42A is larger than the length L2 between the opening of the groove cross section 36q and the rotating shaft 101. Further, the groove cross section 36p has a groove depth H1. The groove cross section 36q has a groove depth H2 larger than the groove depth H1. The groove cross section 36r further has a groove depth H3 that is greater than the groove depth H2. Further, the length L4 between the groove bottom of the groove cross section 36p and the rotary shaft 101, the length L5 between the groove bottom of the groove cross section 36q and the rotary shaft 101, the groove bottom of the groove cross section 36r and the rotary shaft 101. Are equal to each other in length L6.

  On the other hand, the groove cross section 36p, the groove cross section 36q, and the groove cross section 36r have different groove widths. More specifically, the groove cross section 36p has a groove width B1. The groove cross section 36q has a groove width B2 larger than the groove width B1. The groove cross section 36r has a groove width B3 that is larger than the groove width B2. The oil passage area S1 of the groove section 36p, the oil passage area S2 of the groove section 36q, and the oil passage area S3 of the groove section 36r are equal to each other. That is, the flow velocity of oil flowing through the groove cross section 36p, the flow velocity of oil flowing through the groove cross section 36q, and the flow velocity of oil flowing through the groove cross section 36r are equal to each other.

  With such a configuration, groove cross-sections 36p, 36q, and 36r having an equal oil passage area are formed around the main shaft 21 at an equal distance from the rotation shaft 101. As a result, the cooling efficiency of the main shaft cylinder 41 varies in the circumferential direction around the rotation shaft 101 due to the difference in the oil passage area between the plurality of groove cross sections 36 and the difference in the distance from the rotation shaft 101. Can be prevented.

  The structure of the machine tool 95 according to the fifth embodiment of the present invention described above will be described together. The machine tool 95 according to the present embodiment serves as the main shaft 21 and a housing member provided so as to surround the main shaft 21. A main cylinder 41 is provided. The main shaft 21 holds a work as a work or a tool, and rotates by driving a motor. The main cylinder 41 has a side surface 42 that extends along the rotation shaft 101 of the main shaft 21 and has a non-circular cross section when cut by a plane orthogonal to the rotation shaft 101 of the main shaft 21. The main cylinder 41 is formed with an oil passage 31 as a refrigerant passage through which oil as a refrigerant flows. When the main shaft cylinder 41 is cut by a plane orthogonal to the rotation shaft 101 of the main shaft 21, the oil flow path 31 is open to the side surface 42 and is arranged with a plurality of groove cross sections 36 (36p, 36q, 36p, 36q,. 36r).

  The plurality of groove cross sections 36 include a groove cross section 36p as a first groove cross section, and a groove cross section 36q having a depth from the side surface 42 larger than the groove cross section 36p. In the groove cross section 36p and the groove cross section 36q, the distance L1 between the opening of the groove cross section 36p and the rotation shaft 101 of the main shaft 21 is smaller than the distance L2 between the opening of the groove cross section 36q and the rotation shaft 101 of the main shaft 21. It is arranged to become. The groove width B2 of the groove cross section 36q is smaller than the groove width B1 of the groove cross section 36p.

  Alternatively, the plurality of groove cross-sections 36 include a groove cross-section 36q as a first groove cross-section and a groove cross-section 36r whose depth from the side surface 42 is larger than the groove cross-section 36q. In the groove cross section 36q and the groove cross section 36r, the distance L2 between the opening of the groove cross section 36q and the rotation shaft 101 of the main shaft 21 is smaller than the distance L3 between the opening of the groove cross section 36r and the rotation shaft 101 of the main shaft 21. It is arranged to become. The groove width B3 of the groove cross section 36r is smaller than the groove width B2 of the groove cross section 36q.

  According to the machine tool 95 according to the fifth embodiment of the present invention configured as described above, the effects described in the third embodiment can be obtained similarly.

  In addition, you may comprise a new machine tool combining the various structures of the machine tool in Embodiment 1-5 demonstrated above suitably.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention is mainly applied to machine tools such as a lathe and a machining center.

  10, 90, 95 Machine tool, 21 spindle, 22 spindle body, 23 rotor, 26, 27 bearing, 31, 31A, 31B, 31C, 31D oil passage, 33, 34 passage portion, 36, 36p, 36q, 36r Groove cross section, 41 Main cylinder, 42, 42A, 42B, 42C, 42D Side, 46 Stator, 51A, 51B, 51C, 51D, 51E, 51F Temperature sensor, 52 Side lid, 56, 56Q, 56R, 57 Block in groove, 61 support legs, 62, 63 legs, 66 oil cooler, 67 oil tank, 71A, 71B, 71C, 71D flow regulating valve, 73A, 73B, 73C, 73D oil supply flow path, 75 oil discharge flow path, 76 Control unit, 81 machining position, 86, 87, 88, 111A, 111B, 111C, 111D area, 1 DESCRIPTION OF SYMBOLS 1 Rotating shaft, 110 Headstock, 115 Chuck, 120, 120A, 120B Tool post, 121 Tool holder, 122 Tool, 123 Workpiece, 130 Horizontal feed stand, 140 Saddle, 141 Guide surface, 150 Tailstock, 160 Bed, 161 Guide surface, 162 Mounting surface.

Claims (4)

A spindle that holds the workpiece or tool and rotates by motor drive;
A refrigerant flow path is formed that has a side surface that extends along the rotation axis of the main shaft and has a non-circular cross section when cut by a plane orthogonal to the rotation axis of the main shaft. A housing member provided so as to surround,
When the housing member is cut by a plane perpendicular to the rotation axis of the main shaft, the cooling flow path has a plurality of groove cross-sections that are open at the side surfaces and arranged at intervals from each other,
The plurality of groove cross sections include a first groove cross section and a second groove cross section whose depth from the side surface is larger than the first groove cross section.
A machine tool, comprising: a block member that is arranged in at least the second groove cross section of the first groove cross section and the second groove cross section and reduces an area in the groove cross section through which the refrigerant can flow.   The first groove cross section and the second groove cross section are such that the distance between the opening of the first groove cross section and the rotation axis of the main shaft is between the opening of the second groove cross section and the rotation shaft of the main shaft. The machine tool according to claim 1, wherein the machine tool is arranged to be smaller than the distance. A lid member attached to the side surface and closing the opening of the groove cross section;
The machine tool according to claim 1, wherein the block member is formed integrally with the lid member. The area in the first groove cross section through which the refrigerant can flow is equal to the area in the second groove cross section through which the refrigerant can flow, and the distance between the groove bottom of the first groove cross section and the rotation axis of the main shaft is the equal to the distance between the groove bottom of the second groove section and the rotation axis of the spindle, the machine tool according to any one of claims 1 to 3.

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