spindle device

Abstract

Provided is a spindle device capable of suppressing expansion of the outer shape of a housing in the radial direction of a shaft. A spindle device (10) of one embodiment has a tubular member (42) fixed to a housing (14) into which a shaft (12) is inserted and extending outward from an end surface (14F) of the housing (14) on the other end side of the shaft (12) in the axial direction of the shaft (12). The spindle device (10) includes a holding portion (72) provided on the end surface (14F) of the housing (14) on the outer side than the outer peripheral surface of the tubular member (42), extending in the axial direction of the shaft (12), and used for holding a wire-like member (70) passing through the inside of the housing (14), and a cutout portion (74) formed in the outer peripheral surface of the tubular member (42). At least a part of the holding portion (72) is disposed on the inner side of the cutout portion (74).

Description

TECHNICAL FIELD

[0001] The present application relates to a spindle device of a machine tool. BACKGROUND

[0002] A spindle device is used in a machine tool, which has a shaft, a housing through which the shaft is inserted, and a bearing that rotatably supports the shaft to the housing. The spindle device sometimes has a mechanism that can replace a tool depending on the type of the machine tool or the like.

[0003] A spindle device (automatic tool changer) is disclosed in Japanese Patent Application Publication No. 2018-001323, which has a shaft (spindle), a housing (housing main body) through which the shaft is inserted, and a bearing (front bearing, rear bearing) that rotatably supports the shaft to the housing. The spindle device has a tubular member (cylinder), a slider (loosening piston), and a clamping portion (collet) as a mechanism that can replace a tool.

[0004] The tubular member is fixed to the housing and extends outward from an end surface of the housing on the other end side of the shaft in the axial direction of the shaft. The slider slides in the tube of the tubular member in the axial direction of the shaft. The clamping portion selectively performs clamping and loosening of a tool inserted through a through-hole that penetrates the shaft in the axial direction of the shaft depending on the sliding of the slider.

[0005] In the spindle device of Japanese Patent Application Publication No. 2018-001323, a motor for rotating the spindle is provided inside the housing, so a cable for supplying power to the motor needs to pass through the inside of the housing. In the case where the cable passes through the inside of the housing, there is a tendency to adopt a cable joint in the field of machine tools (for example, refer to Japanese Patent Application Publication No. 2016-111783). SUMMARY

[0006] However, in the housing of Japanese Patent Application Publication No. 2018-001323 described above, in the case where the cable passes from the side where the tubular member is fixed, it is necessary to provide the cable joint at a position that is outward of the outer peripheral surface of the tubular member. Therefore, there is a tendency for the outer shape of the housing to expand in the radial direction of the shaft.

[0007] Therefore, an object of the present application is to provide a spindle device that can suppress expansion of the outer shape of the housing in the radial direction of the shaft.

[0008] A spindle device according to an embodiment of the present application includes:

[0009] a shaft;

[0010] a housing through which the shaft is inserted;

[0011] a bearing that rotatably supports the shaft to the housing;

[0012] a tubular member fixed to the housing and extending outward in the axial direction of the shaft from an end surface of the housing on the other end side of the shaft;

[0013] a slider that slides in the axial direction of the shaft within the tube of the tubular member; and

[0014] a clamping portion that selectively performs clamping and release of a tool inserted through a through-hole of the shaft in the axial direction of the shaft in accordance with the sliding of the slider,

[0015] The spindle device has:

[0016] a holding portion provided at an end surface of the housing on an outer side than the outer peripheral surface of the tubular member, extending in the axial direction of the shaft, and used for holding a wire-like member that passes through the inside of the housing; and

[0017] a cutout portion formed at the outer peripheral surface of the tubular member,

[0018] at least a part of the holding portion is disposed on the inner side of the cutout portion.

[0019] According to the present application, since at least a part of the holding portion is disposed on the inner side of the cutout portion, the expansion of the outer shape of the housing in the radial direction of the shaft can be suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a cross-sectional view showing the spindle device of the present embodiment.

[0021] Figure 2 is a cross-sectional view showing the drive portion side of Figure 1 .

[0022] Figure 3 is a perspective view showing the drive portion side of Figure 1 . DETAILED DESCRIPTION

[0023] Hereinafter, the present application will be described in detail with reference to preferred embodiments, with reference to the accompanying drawings.

[0024] [EMBODIMENT]

[0025] Use Figure 1 The spindle device 10 of the present embodiment will be described. The spindle device 10 has a shaft 12, a housing 14, and a bearing 16.

[0026] The shaft 12 becomes the center of rotation. The shaft 12 is rotated by power of a motor 18 provided inside the housing 14. The motor 18 has a stator 22 installed to the inner peripheral side of the housing 14 and a rotor 24 inserted through the stator 22 and fixed to the outer peripheral surface of the shaft 12. A through-hole 12H is formed in the shaft 12, which penetrates from one end surface (front surface) to the other end surface (rear surface) of the shaft 12 in the extending direction (axial direction) of the shaft 12.

[0027] The housing 14 is a box having a hole through which the shaft 12 is inserted. The housing 14 is divided into a plurality of housing parts 14A, 14B, 14C, 14D, 14E, and is formed by assembling the housing parts 14A, 14B, 14C, 14D, 14E, respectively. A rotation sensor 26 that detects the rotational speed of the shaft 12 is provided to the inner peripheral surface of the housing 14 (housing part 14D). The rotation sensor 26 detects the rotational speed of the shaft 12 based on a rotation detection gear 28 provided to the outer peripheral surface of the shaft 12.

[0028] The bearing 16 rotatably supports the shaft 12 to the housing 14. The inner ring of the bearing 16 is fixed to the outer peripheral surface of the shaft 12, and the outer ring of the bearing 16 is fixed to the inner peripheral surface of the housing 14. The bearing 16 can also have a first bearing 16A that supports one end side (front side) of the shaft 12 and a second bearing 16B that supports the other end side (rear side) of the shaft 12. In the case where the bearing 16 has the first bearing 16A and the second bearing 16B, the number of the first bearing 16A and the second bearing 16B can be one or a plurality. In addition, in the case where the bearing 16 has the first bearing 16A and the second bearing 16B, the first bearing 16A and the second bearing 16B can be provided to the housing 14 or the shaft 12. Figure 1 In the present embodiment, the bearing 16 having two first bearings 16A and one second bearing 16B is exemplified.

[0029] In the present embodiment, the spindle device 10 has a driving portion 40 and a clamping portion 60 as a mechanism capable of replacing the tool 30.

[0030] The clamping portion 60 selectively performs clamping and releasing of the tool 30 inserted into the through-hole 12H of the shaft 12 in the axial direction of the shaft 12 in accordance with the driving of the driving portion 40. The clamping portion 60 has a pressure receiving rod 62, a chuck 64, and a force applying portion 66.

[0031] The pressure receiving rod 62 is a rod pressed from the driving portion 40, and is slidably provided to the other end (rear end) side of the shaft 12. An engaging portion 62X is formed at the end portion of the pressure receiving rod 62 exposed from the through-hole 12H of the shaft 12. The engaging portion 62X is brought into contact with the other end surface (rear end surface) of the shaft 12, thereby suppressing the entire pressure receiving rod 62 from being inserted into the through-hole 12H of the shaft 12.

[0032] The chuck 64 is arranged in the through-hole 12H of the shaft 12. The end portion of the chuck 64 on the other end (rear end) side of the shaft 12 is attached to the end portion of the pressure receiving lever 62 on the opposite side from the end portion of the pressure receiving lever 62 exposed from the through-hole 12H of the shaft 12. When the pressure receiving lever 62 is not pressed from the driving section 40, the end portion of the chuck 64 on the one end (front end) side of the shaft 12 clamps the pull pin 30A of the tool 30 inserted through the through-hole 12H from the one end surface (front surface) of the shaft 12. On the other hand, when the pressure receiving lever 62 is pressed from the driving section 40, the end portion of the chuck 64 on the one end (front end) side of the shaft 12 releases the pull pin 30A of the tool 30.

[0033] The urging section 66 is arranged in the through-hole 12H of the shaft 12 and urges the pressure receiving lever 62 from the one end (front end) side to the other end (rear end) side of the shaft 12. The urging section 66 is a spring material such as a coil spring or a disc spring and is arranged in a compressed state between the inner peripheral surface of the shaft 12 and the end surface of the pressure receiving lever 62 on the opposite side from the end surface of the pressure receiving lever 62 exposed from the through-hole 12H of the shaft 12.

[0034] The driving section 40 drives the chucking section 60 in a manner of clamping the pull pin 30A of the tool 30 inserted through the through-hole 12H from the one end surface (front surface) of the shaft 12 and releasing the clamped pull pin 30A. Here, a Figure 2 The driving section 40 will be described.

[0035] The driving section 40 is fixed to the housing 14 and has a tubular member 42 extending outward from the end surface 14F of the housing 14 on the other end side (rear side) of the shaft 12 in the axial direction of the shaft 12. Inside the tubular member 42, a slider 44 and a support member 46 supporting the slider 44 in a manner that the slider 44 can slide inside the tube of the tubular member 42 in the axial direction of the shaft 12 are arranged.

[0036] The slider 44 is formed in a bar shape extending in the axial direction of the shaft 12. The end portion of the slider 44 on the shaft 12 side is opposed to the end portion of the pressure receiving lever 62 exposed from the through-hole 12H of the shaft 12 with a space therebetween. A protrusion 44X is arranged on the slider 44 between both ends of the slider 44 in the direction in which the slider 44 extends. The protrusion 44X has an outer diameter larger than that of the portion of the slider 44 other than the protrusion 44X and protrudes outward from the portion.

[0037] The support member 46 is formed in a cylindrical shape with a hole into which the slider 44 is inserted. The support member 46 can also be divided into a plurality of parts, and formed in a cylindrical shape by assembling the parts. A first locking portion 46X and a second locking portion 46Y that lock the protrusion 44X of the slider 44 are formed on the inner circumferential surface of the support member 46. The first locking portion 46X is located on the side farther from the end surface 14F of the housing 14, and the second locking portion 46Y is located on the side closer to the end surface 14F of the housing 14. The protrusion 44X of the slider 44 is disposed between the first locking portion 46X and the second locking portion 46Y. The slider 44 slides in the axial direction of the shaft 12 between a first position where the protrusion 44X is in contact with the first locking portion 46X and a second position where the protrusion 44X is in contact with the second locking portion 46Y.

[0038] The support member 46 can be fixed to the housing 14, or can be configured to be movable in the axial direction of the shaft 12. In the present embodiment, the support member 46 is configured to be movable. In the case where the support member 46 is configured to be movable, a protrusion 46Z that extends from the end portion on the side of the end surface 14F of the housing 14 toward the inside is provided on the support member 46, and a locking portion 12X that locks the protrusion 46Z is formed on the other end portion of the shaft 12 that is exposed from the housing 14. The locking portion 12X can also be a flange of the shaft 12 that extends in the radial direction of the shaft 12. The support member 46 moves in the axial direction of the shaft 12 between a position where the protrusion 46Z is in contact with the locking portion 12X of the shaft 12 and a position where the protrusion 46Z is in contact with the end surface 14F of the housing 14.

[0039] In the case where the support member 46 is configured to be movable, the support member 46 is urged toward the end surface 14F of the housing 14 by an urging portion 48. The urging portion 48 is a spring material such as a coil spring or a disc spring, and is disposed in a compressed state between a cover portion 50 that closes the opening of the tubular member 42 on the side opposite to the end surface 14F of the housing 14 and the support member 46.

[0040] Three seal members 52 are disposed at intervals in the axial direction of the shaft 12 between the slider 44 and the support member 46, and a first hydraulic chamber 54 and a second hydraulic chamber 56 are formed between the seal members 52. High-pressure oil is supplied to the first hydraulic chamber 54 when the clamping portion 60 is released, and high-pressure oil is supplied to the second hydraulic chamber 56 when the clamping portion 60 is clamped.

[0041] In the case where high-pressure oil is supplied to the first hydraulic chamber 54, the support member 46 moves in a second direction opposite to the first direction toward the end surface 14F of the housing 14, and stops at a position where the protrusion 46Z of the support member 46 is in contact with the locking portion 12X of the shaft 12. In this case, the slider 44 is pressed against the pressure receiving rod 62 by sliding in the first direction, and stops at the second position where the protrusion 44X is in contact with the second locking portion 46Y. Thus, the released state of the clamping portion 60 is maintained.

[0042] On the other hand, in a case where high-pressure oil is supplied to the second hydraulic chamber 56, the support member 46 moves toward the first direction and stops at a position where the protrusion 46Z of the support member 46 contacts the end surface 14F of the housing 14. In this case, the slider 44 slides toward the second direction and stops at the first position where the protrusion 44X contacts the first locking portion 46X. Thus, the clamped state of the clamping portion 60 is maintained. In addition, the slider 44 is urged toward the second direction by the urging portion 66 via the pressure-receiving rod 62 of the clamping portion 60, and thus even if the supply of high-pressure oil to the second hydraulic chamber 56 is stopped, the slider 44 continues to stop at the first position.

[0043] In addition, in the spindle device 10 of the present embodiment, the linear member 70 penetrates the housing 14. As the linear member 70, a cable or the like can be given. The linear member 70 can be a member that causes fluid to flow or a member that supplies a driving current. The number of the linear member 70 can be one or a plurality.

[0044] In a case where the linear member 70 is a member that causes fluid to flow, the linear member 70 has a flow path for causing fluid to flow. As the fluid, for example, lubricating oil for the bearing 16 or compressed air for sealing the gap between the shaft 12 and the housing 14 can be given. In a case where the linear member 70 supplies a driving current, the linear member 70 has an electric wire for supplying a driving current. The electric wire is connected to, for example, the motor 18 or the rotation sensor 26. In a case where a temperature sensor that detects the temperature of the motor 18 is provided, the electric wire can be connected to the temperature sensor.

[0045] In the present embodiment, the linear member 70 that supplies a driving current to the motor 18 and the linear member 70 that supplies a driving current to the rotation sensor 26 penetrate the housing 14. Figure 3 is a perspective view of the driving portion 40 side. Figure 1 In Figure 3 , the linear member 70 is omitted.

[0046] The end surface 14F of the housing 14 on the outside of the outer peripheral surface of the tubular member 42 is provided with a holding portion 72 for holding the linear member 70. The number of the holding portion 72 can be one or a plurality. In addition, the number of the holding portion 72 can be the same as or different from the number of the linear member 70 that penetrates the housing 14. That is, the holding portion 72 can be provided to the end surface 14F of the housing 14 in a state where the linear member 70 is not held.

[0047] The holding portion 72 extends along the axial direction of the shaft 12 and has an insertion hole through which the wire-like member 70 is inserted. The insertion hole of the holding portion 72 is connected to a communication hole of the housing 14 that is open at the end surface 14F of the housing 14. The communication hole of the housing 14 is a hole that penetrates the housing 14 and communicates the inside and outside of the housing 14. The holding portion 72 holds the wire-like member 70 inserted in the insertion hole along the axial direction of the shaft 12 and seals the gap between the wire-like member 70 and the housing 14.

[0048] A cutout portion 74 is formed on the outer peripheral surface of the tubular member 42. The cutout portion 74 is formed by cutting the outer peripheral surface of the end portion of the tubular member 42 on the end surface 14F side of the housing 14. The cutout portion 74 can be formed at a plurality of positions spaced apart in the circumferential direction of the tubular member 42, or can be formed on the entire circumference of the tubular member 42. In addition, in the embodiment shown in Figure 3 , a case in which the cutout portion 74 is formed at a plurality of positions spaced apart in the circumferential direction of the tubular member 42 is shown.

[0049] At least a portion of the holding portion 72 is disposed inside the cutout portion 74. Thus, in the present embodiment, the expansion of the outer shape of the housing 14 in the radial direction of the shaft 12 can be suppressed. In addition, in the embodiment shown in Figures 1 to 3 , a case in which the entire holding portion 72 is disposed inside the cutout portion 74 is shown. In the case where the entire holding portion 72 is disposed inside the cutout portion 74, the expansion of the outer shape of the housing 14 in the radial direction of the shaft 12 can be further suppressed compared to the case where a portion of the holding portion 72 is disposed inside the cutout portion 74.

[0050] Further, in the case where a plurality of holding portions 72 are provided on the end surface 14F of the housing 14, at least a portion of each of the plurality of holding portions 72 is disposed inside the cutout portion 74. In the case where a plurality of cutout portions 74 are formed at a plurality of positions spaced apart in the circumferential direction of the tubular member 42, or are formed on the entire circumference of the tubular member 42, the number of holding portions 72 disposed inside the cutout portion 74 can be increased compared to the case where one cutout portion 74 is formed on a portion of the circumference of the tubular member 42.

[0051] INVENTION

[0052] The following description can be understood as the invention according to the above-described embodiments.

[0053] The present application is a spindle device (10) having: a shaft (12); a housing (14) through which the shaft (12) is inserted; a bearing (16) that rotatably supports the shaft (12) to the housing (14); a tubular member (42) that is fixed to the housing (14) and extends outward from an end surface (14F) of the housing (14) on the other end side of the shaft (12) in the axial direction of the shaft (12); a slider (44) that slides within a tube of the tubular member (42) in the axial direction of the shaft (12); and a clamping portion (60) that selectively performs clamping and releasing of a tool (30) inserted through a through-hole (12H) that penetrates the shaft (12) in the axial direction of the shaft (12) in accordance with the sliding of the slider (44). The spindle device (10) is provided with: a holding portion (72) that is provided to the end surface (14F) of the housing (14) on the outer side than the outer peripheral surface of the tubular member (42), extends in the axial direction of the shaft (12), and is used for holding a wire-like member (70) that passes through the inside of the housing (14); and a cutout portion (74) that is formed in the outer peripheral surface of the tubular member (42). At least a part of the holding portion (72) is disposed on the inner side of the cutout portion (74).

[0054] According to the spindle device (10) of the present application, since at least a part of the holding portion (72) is disposed on the inner side of the cutout portion (74), it is possible to suppress the expansion of the outer shape of the housing (14) in the radial direction of the shaft (12).

[0055] The holding portion (72) as a whole can also be disposed on the inner side of the cutout portion (74). Thereby, compared to the case where a part of the holding portion (72) is disposed on the inner side of the cutout portion (74), it is possible to further suppress the expansion of the outer shape of the housing (14) in the radial direction of the shaft (12).

[0056] The cutout portion (74) can also be formed in a plurality spaced apart in the circumferential direction of the tubular member (42). Thereby, compared to the case where 1 is formed in a part of the circumferential direction of the tubular member (42), it is possible to increase the number of the holding portions (72) disposed on the inner side of the cutout portion (74).

[0057] The wire-like member (70) can also be a member that flows a fluid. Thereby, it is possible to flow a fluid into the inside of the housing (14), or flow the flowed-in fluid to the outside of the housing (14).

[0058] The wire-like member (70) can also be a member that supplies a drive current. Thereby, it is possible to drive an electronic component such as a motor (18) provided in the inside of the housing (14).

[0059] The linear member (70) is connected to at least one of the motor (18) provided inside the housing (14), a rotation sensor (26) that detects the rotation speed of the motor (18), and a temperature sensor that detects the temperature of the motor (18). Thus, the motor (18), the rotation sensor (26), or the temperature sensor to which the linear member (70) is connected can be driven.

Claims

1. A spindle device, comprising: a shaft (12); a housing (14) through which the shaft is inserted; a bearing (16) that rotatably supports the shaft to the housing; a tubular member (42) fixed to the housing, extending outward from an end surface (14F) of the housing on the other end side of the shaft in the axial direction of the shaft; a slide block (44) that slides in the tube of the tubular member in the axial direction of the shaft; and a clamping portion (60) that selectively performs clamping and releasing of a tool (30) inserted into a through hole (12H) that penetrates the shaft in the axial direction of the shaft in accordance with the sliding of the slide block, characterized in that the spindle device (10) comprises: a holding portion (72) for holding a wire member (70) disposed outside the tubular member and not passing through the inside of the tubular member but passing through the inside of the housing; and a cutout portion (74) formed by thinning a portion of the tubular member.

2. The spindle device according to claim 1, characterized in that the entirety of the holding portion is disposed inside the cutout portion.

3. The spindle device according to claim 1 or 2, characterized in that a plurality of the cutout portions are formed at intervals in the circumferential direction of the tubular member.

4. The spindle device according to claim 1 or 2, characterized in that the wire member is a member that flows a fluid.

5. The spindle device according to claim 1 or 2, characterized in that the wire member is a member that supplies a drive current.

6. The spindle device according to claim 5, characterized in that the wire member is connected to at least one of a motor (18) provided inside the housing, a rotation sensor (26) that detects the rotational speed of the motor, and a temperature sensor that detects the temperature of the motor. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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