WO2018235809A1

WO2018235809A1 - Actuator and actuator unit

Info

Publication number: WO2018235809A1
Application number: PCT/JP2018/023267
Authority: WO
Inventors: 克也福島; 弘樹丹羽; 正志石井
Original assignee: Thk株式会社
Priority date: 2017-06-23
Filing date: 2018-06-19
Publication date: 2018-12-27
Also published as: JP2019005844A; TW201905346A; JP6918598B2

Abstract

This actuator includes a shaft (10) having a distal end portion (10A) with a hollow hole (11) provided therein, and a shaft housing (50) through which the shaft (10) is slidably inserted. An air tube connecting hole (51) and an internal space (52) which communicates with the air tube connecting hole (51) and surrounds an outer circumferential surface (10a) of the shaft (10) are provided in the shaft housing (50). A through-hole (12) which communicates with the hollow hole (11) is provided in the outer circumferential surface (10a) of the shaft (10) surrounded by the internal space (52).

Description

Actuator and actuator unit

The present invention relates to an actuator and an actuator unit.
Priority is claimed on Japanese Patent Application No. 2017-123427, filed June 23, 2017, the content of which is incorporated herein by reference.

Patent Document 1 below discloses a spindle device configured to supply a coolant to a tool holder at the tip of a spindle as one of the actuators. This spindle device is a spindle device of a shaft core refueling system. In this spindle device, a tool holder is attached to the tip of a spindle rotatably provided on the spindle head. A drawbar is provided on the spindle for clamping and unclamping the tool holder by axial movement. A coolant supply hole capable of supplying coolant to the tool holder is provided in the draw bar. A rotary joint capable of circulating the coolant from the coolant supply device to the coolant supply hole is connected to the rear end of the draw bar. A coolant supply device is connected to the rotary joint via a hose.

JP, 2011-45980, A

When connecting a hose (fluid flow path) to a rotating shaft (spindle) as in the prior art, it is necessary to attach a rotary joint. However, when the rotary joint is attached, a motor with high thrust and torque is required to move the rotary joint as well as the shaft. Also, if the hose connected to the rotary joint is supplied with fluid and the hose becomes hard, shock and resistance may be applied to the shaft, which may affect the operation of the actuator. Furthermore, since the rotary joint has a large number of parts and is fragile, the frequency of maintenance may be high.

The present invention provides an actuator and an actuator unit that can connect a shaft and a fluid flow path without using a rotary joint and has less influence on thrust / torque and operation.

According to the first aspect of the present invention, the actuator has a shaft having a hollow hole at its tip and a housing in which the shaft is slidably inserted. The housing is provided with a fluid channel connection hole and an internal space which is in communication with the fluid channel connection hole and which encloses the outer peripheral surface of the shaft. A communication hole communicating with the hollow hole is provided on the outer peripheral surface of the shaft surrounded by the internal space.

According to the second aspect of the present invention, a power transmission unit for sliding the shaft relative to the housing may be provided on the axis of the shaft. The housing may be disposed closer to the tip of the shaft than the power transmission unit on the axis of the shaft.

According to the third aspect of the present invention, the actuator may further include a linear motion motor for sliding the shaft relative to the housing along the axial direction of the shaft. The internal space may have a length greater than or equal to the stroke of the shaft by the linear motion motor in the axial direction of the shaft.

According to the fourth aspect of the present invention, the housing includes a cylindrical housing main body in which the fluid flow path connection holes are provided in the radial direction, and a pair of lids closing the both end openings of the housing main body. A seal body interposed between the housing body and the pair of lids, and a sliding ring provided on the seal body and slidably supporting the shaft may be included.

According to a fifth aspect of the present invention, in the actuator unit, a plurality of the actuators according to any one of the first to fourth aspects of the present invention are stacked in the direction orthogonal to the axial direction of the shaft A flow path connection hole is provided in a direction perpendicular to the axial direction of the shaft and the stacking direction of the actuator.

According to the above-described actuator and actuator unit, the shaft and the fluid flow path can be connected without using a rotary joint, and the impact on thrust and torque and operation can be reduced.

It is an appearance perspective view of an actuator unit in an embodiment of the present invention. It is an internal block diagram of the actuator with which the actuator unit shown in FIG. 1 is provided. It is an appearance perspective view of a shaft housing in an embodiment of the present invention. It is a disassembled perspective view of the shaft housing in the embodiment of the present invention. It is a sectional view along an axial direction of a shaft housing in an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments shown below are described by way of example in order to better understand the spirit of the invention, and do not limit the present invention unless otherwise specified. Further, in the drawings used for the following description, for the sake of easy understanding of the features of the present invention, the main parts may be enlarged for convenience, and the dimensional ratio of each component is the same as the actual Not necessarily. Moreover, in order to make the feature of the present invention intelligible, some parts are omitted for convenience.

FIG. 1 is an external perspective view of an actuator unit 100 according to an embodiment of the present invention. FIG. 2 is an internal configuration diagram of the actuator 1 provided in the actuator unit 100 shown in FIG.
As shown in FIG. 1, the actuator unit 100 is configured by laminating a plurality of actuators 1. The actuator 1 has an actuator body 2 for moving the shaft 10, and a cartridge unit 3 for supplying air (fluid) to the shaft 10.

In the following description, an XYZ orthogonal coordinate system may be set, and the positional relationship of each member may be described with reference to this XYZ orthogonal coordinate system. The axial direction in which the shaft 10 extends is taken as the Z-axis direction. The stacking direction of the actuator 1 orthogonal to the axial direction of the shaft 10 is taken as a Y-axis direction. A direction orthogonal to the axial direction of the shaft 10 and the stacking direction of the actuator 1 is taken as an X-axis direction.

The actuator body 2 is, as shown in FIG. 2, a shaft 10, a rotary motor 20 (power transmission unit) for rotating the shaft 10 about its axis O, and an axial direction along the axis O (X axis direction Connected to the lower end surface of the drive unit housing 40 in the Z-axis direction, and the shaft 10 is connected to the linear motor 30 for linear movement, the drive unit housing 40 for accommodating the drive units such as the rotary motor 20 and the linear motor 30 etc. And a shaft housing 50 (housing) slidably inserted.

The shaft 10 extends in the vertical direction (Z-axis direction). The shaft 10 is linearly moved in the vertical direction by the rotary motor 20 and the linear motion motor 30, and is rotated about an axis O extending in the vertical direction. A hollow hole 11 is provided at the tip 10A of the shaft 10. An application device (not shown) such as a tool or a suction pad is attached to the tip end portion 10A of the shaft 10. In the present embodiment, a suction pad (not shown) is attached to the distal end portion 10A of the shaft 10, and a so-called pick and place operation of picking up the work W and placing it at a predetermined place is performed.

The proximal end 10 B side opposite to the distal end 10 A of the shaft 10 is accommodated in the drive unit housing 40. On the proximal end portion 10B side of the shaft 10 accommodated in the drive unit housing 40, for example, a spline groove (not shown) extending in the axial direction is provided. The rotary motor 20 has a spline nut (rotor) (not shown) engaged with the spline groove, and a stator for rotating the spline nut. The stator of the rotary motor 20 is fixed to the drive housing 40. By rotating the spline nut (rotor) engaged with the spline shaft of the shaft 10, the shaft 10 can be rotated about the axis O while allowing axial movement of the shaft 10.

The linear motion motor 30 has a stator 31 fixed to the drive unit housing 40 and a mover 32 moved by the stator 31 in the vertical direction (Z-axis direction). For example, the stator 31 is provided with a plurality of coils (not shown), and the mover 32 is provided with a plurality of permanent magnets (not shown). The coils are arranged at a predetermined pitch along the vertical direction, and a plurality of sets of three coils of U, V, and W phases are provided. In this embodiment, a three-phase armature current is supplied to these U, V, and W phase coils to generate a moving field that moves linearly, and the mover 32 moves linearly with respect to the stator 31. Let

The linear motion motor 30 and the shaft 10 are connected via a linear motion table 33. The linear movement table 33 is guided in the vertical direction (Z-axis direction) by a plurality of linear movement guiding devices 34. The linear motion guide device 34 has a track rail 34 a fixed to the drive housing 40 and a slider block 34 b assembled to the track rail 34 a. The track rail 34a extends in the vertical direction. The slider block 34b is vertically movable along the track rail 34a.

The linear movement table 33 is fixed to the slider block 34 b and is movable in the vertical direction together with the slider block 34 b. The linear movement table 33 is coupled to the mover 32 of the linear movement motor 30 via a coupling arm 35. In addition, the linear motion table 33 is coupled to the shaft 10 via the coupling arm 36 (power transmission unit). The connection arm 36 is provided with a bearing (not shown) for rotatably supporting the shaft 10. The base end portion 10B of the shaft 10 is provided with a stopper 37 for preventing the shaft 10 from falling.

As shown in FIG. 1, the drive unit housing 40 has a plate-like rectangular parallelepiped shape extending in the vertical direction. Specifically, in the drive unit housing 40, the dimension in the Z-axis direction is longer than the dimension in the X-axis direction, and the dimension in the X-axis direction is longer than the dimension in the Y-axis direction. That is, the dimension of the drive unit housing 40 in the stacking direction (Y-axis direction) of the actuator 1 is the smallest. A connector 41 including a power supply for driving the rotary motor 20 and the linear motion motor 30, a signal line, and the like is connected to the upper end surface of the drive unit housing 40 in the Z-axis direction. Further, the cartridge housing 60 of the cartridge unit 3 is detachably fixed to the side end surface of the drive unit housing 40 in the X-axis direction.

Similar to the drive unit housing 40, the cartridge housing 60 has a plate-like rectangular parallelepiped shape extending in the vertical direction. Although the dimension of the cartridge housing 60 in the Z-axis direction is shorter than the dimension of the drive unit housing 40 in the Z-axis direction, the dimension in the Z-axis direction is longer than the dimension in the X-axis direction. The axial dimension is longer than the Y-axis dimension. That is, the dimension of the cartridge housing 60 in the stacking direction (Y-axis direction) of the actuator 1 is the smallest. The dimension of the cartridge housing 60 in the Y-axis direction is equal to or less than the dimension of the drive unit housing 40 in the Y-axis direction.

Inside the cartridge housing 60, as shown in FIG. 2, an air control mechanism 61 is accommodated. The air control mechanism 61 has a plurality of solenoid valves (not shown). The air control mechanism 61 controls suction of air from the tip end portion 10A of the shaft 10 through the hollow hole 11, discharge of air for desorption of the work W, vacuum destruction, and the like. The air control mechanism 61 is connected to the air connector 62 provided on the upper end surface of the cartridge housing 60 in the Z-axis direction, and connected to the air tube connector 63 provided on the lower end surface of the cartridge housing 60 in the Z-axis direction. It is done. The air connector 62 is connected to a pump (not shown) for drawing air. The air tube connector 63 is connected to an air tube connection hole 51 (fluid flow path connection hole) provided in the shaft housing 50 via an air tube 64 (fluid flow path).

FIG. 3 is an external perspective view of the shaft housing 50 in the embodiment of the present invention. FIG. 4 is an exploded perspective view of the shaft housing 50 in the embodiment of the present invention. FIG. 5 is an axial sectional view of a shaft housing 50 in an embodiment of the present invention.
As shown in FIGS. 3 and 5, the shaft 10 is slidably inserted in the shaft housing 50. The shaft housing 50 is provided with an air tube connection hole 51 and an internal space 52 communicating with the air tube connection hole 51 and surrounding the outer peripheral surface 10 a of the shaft 10.

The shaft housing 50 has a housing main body 53, a pair of lids 54, a seal 55, and a sliding ring 56, as shown in FIGS. 4 and 5. The housing main body 53 is a cylindrical body provided with the through hole 53a. An air tube connection hole 51 communicates with the through hole 53a in the radial direction. The air tube connection hole 51 is provided at a central portion in the longitudinal direction (Z-axis direction) of the housing main body 53. The air tube connection hole 51 communicates the inside and the outside of the housing main body 53.

The pair of lids 54 closes the openings at both ends of the housing body 53 to form an internal space 52. An annular stepped groove 53 b having a diameter larger than that of the through hole 53 a is provided at both end openings of the housing main body 53. On the other hand, the lid 54 is provided with an annular fitting protrusion 54b that fits in the stepped groove 53b. A through hole 54a through which the shaft 10 is inserted is provided at a central portion of the lid 54 so as to penetrate the fitting protrusion 54b. The pair of lids 54 is fitted to the openings at both ends of the housing main body 53 by the fitting projections 54 b and is fixed to the housing main body 53 by bolts or the like (not shown).

The seal body 55 is interposed between the housing body 53 and the pair of lids 54, and seals the gap between the two in an airtight manner. The seal body 55 of the present embodiment is an annular O-ring. The seal body 55 is disposed in the stepped groove 53 b of the housing main body 53, and is squeezed in the axial direction (Z-axis direction) by the fitting projection 54 b of the lid 54. A sliding ring 56 is provided on the inner diameter side of the seal body 55. The sliding ring 56 slidably supports the shaft 10. The sliding ring 56 is pressed against the outer peripheral surface 10 a of the shaft 10 by the seal body 55 being crushed in the axial direction. Thus, air leakage from the gap between the outer peripheral surface 10 a of the shaft 10 and the sliding ring 56 is suppressed.

As shown in FIG. 5, a communication hole 12 communicating with the hollow hole 11 is provided on the outer peripheral surface 10 a of the shaft 10 surrounded by the internal space 52 of the shaft housing 50. The communication holes 12 of the present embodiment pass through the shaft 10 in the cross direction in the radial direction, and four open in the outer peripheral surface 10 a of the shaft 10. The number of the communication holes 12 may be one. The hollow hole 11 does not penetrate the shaft 10 in the axial direction, but extends in the axial direction from the tip end portion 10A of the shaft 10 to a position where the communication hole 12 is provided. Thus, the hollow hole 11 communicates with the internal space 52 through the communication hole 12 and further communicates with the air tube connection hole 51 through the internal space 52.

The internal space 52 of the shaft housing 50 is a cylindrical space one size larger than the outer diameter of the shaft 10. That is, in the internal space 52 of the housing main body 53, a gap is formed between the through hole 53 a of the housing main body 53 and the outer peripheral surface 10 a of the shaft 10. The internal space 52 has a length L equal to or greater than the stroke S of the shaft 10 by the linear motion motor 30 (see FIG. 2) in the axial direction of the shaft 10. That is, in the entire range of the stroke S of the shaft 10, the communication hole 12 and the internal space 52 communicate with each other. The stroke S of the shaft 10 can be set by a stopper (not shown) provided inside the drive unit housing 40.

As shown in FIG. 2, the shaft housing 50 having the above configuration is disposed closer to the tip end portion 10A of the shaft 10 (closer to the work W) than the drive transmission portion provided on the axis O of the shaft 10. The drive transmission portion transmits a force to slide the shaft 10 relative to the shaft housing 50 to the shaft 10. In the present embodiment, the rotary motor 20 and the connection arm 36 correspond to a drive transmission unit. The shaft housing 50 is attached to the drive housing 40 such that the air tube connection hole 51 extends in the X-axis direction orthogonal to the axial direction of the shaft 10 and the stacking direction of the actuators. That is, the air tube connection hole 51 is opened in the same direction as the mounting and demounting direction of the cartridge portion 3 and is arranged in the direction that does not interfere with the stacking direction of the actuator 1 shown in FIG. Thereby, the connection between the air tube 64 and the air tube connection hole 51 is facilitated.

In the actuator 1 configured as described above, when the work W shown in FIG. 2 is picked up, the air control mechanism 61 is driven. The air control mechanism 61 opens a solenoid valve in communication with the pump and pulls the air in the internal space 52 of the shaft housing 50 through the air tube 64 to generate a negative pressure in the hollow hole 11 provided in the shaft 10 . Here, the shaft housing 50 is provided with an air tube connection hole 51 to which the air tube 64 is connected, and an internal space 52 which communicates with the air tube connection hole 51 and surrounds the outer peripheral surface 10 a of the shaft 10. . A communication hole 12 communicating with the hollow hole 11 is provided on the outer peripheral surface 10 a of the shaft 10 surrounded by the internal space 52.

According to this configuration, as shown in FIG. 2, even when the shaft 10 rotates around the axis O, the communication between the internal space 52 and the communication hole 12 is maintained. For this reason, negative pressure can be generated in the hollow hole 11 provided at the tip end portion 10A of the shaft 10, and the workpiece W can be picked up. As described above, according to the present embodiment, the air tube 64 can be connected to the rotating shaft 10 to generate a negative pressure without using a rotary joint. This eliminates the need to select the rotary motor 20 having a large torque in order to move the rotary joint. Further, since it is not necessary to use a rotary joint having a large number of parts, the frequency of maintenance of the actuator 1 can be reduced.

Further, in the present embodiment, as shown in FIG. 5, the internal space 52 of the shaft housing 50 has a length L equal to or greater than the stroke S of the shaft 10 by the linear motor 30 (see FIG. 2) in the axial direction of the shaft 10. have. According to this configuration, as shown in FIG. 2, even when the shaft 10 moves in the axial direction, the communication between the internal space 52 and the communication hole 12 is maintained. Thereby, negative pressure can be generated in the hollow hole 11 provided at the tip end portion 10A of the shaft 10. Further, since the shaft housing 50 is fixed to the drive housing 40, the connection state with the air tube 64 does not change. For this reason, for example, even if the air is discharged or vacuum destroyed from the hollow hole 11 in order to desorb the picked-up work W, the influence can be prevented from being transmitted to the shaft 10.

Assuming that the hollow hole 11 is provided to penetrate the shaft 10 in the axial direction and the air tube 64 is connected to the base end portion 10B, if the hardness of the air tube 64 changes due to the air supply and discharge of air. The hardness of the air tube 64 is the resistance in the axial direction of the shaft 10. Therefore, when the linear motion motor 30 with a small thrust is used, the hardness of the air tube 64 may make it impossible for the mover 32 to return to the origin. On the other hand, according to the present embodiment, even if the hardness of the air tube 64 changes, the influence is not transmitted to the shaft 10. For this reason, it is not necessary to select the linear motion motor 30 having a large thrust, and it becomes possible to transport the small and lightweight work W at high speed.

Further, as shown in FIG. 2, the shaft housing 50 is disposed closer to the tip 10 A of the shaft 10 than the power transmission unit (the rotary motor 20 and the connection arm 36) on the axis O of the shaft 10. According to this configuration, the tact time for picking and placing the work W can be shortened. That is, as described above, in the configuration in which the hollow hole 11 is provided to penetrate the shaft 10 in the axial direction and the air tube 64 is connected to the base end 10B, it is necessary to draw air over the entire length of the shaft 10 Although, according to the present embodiment, air may be drawn from the tip end portion 10A of the shaft 10 to the communication hole 12, and the distance to the air control mechanism 61 is also shortened, so that negative pressure can be generated quickly. .

Further, as shown in FIG. 4, the shaft housing 50 is configured of a cylindrical housing main body 53, a pair of two bodies 54, and a seal body 55. The pair of lids 54 is attached so as to close the openings at both ends of the housing body 53. The seal body 55 is sandwiched between the housing body 53 and the pair of lids 54. The sealing body 55 is provided with a sliding ring 56. The sliding ring 56 slidably supports the shaft 10.
As described above, by sandwiching the seal body 55 between the housing main body 53 and the pair of lids 54, assembly becomes easy. Further, for example, it is not necessary to process an annular groove for disposing the seal body 55 in the through hole 53 a of the housing main body 53. When an annular groove is machined in the through hole 53a of the housing main body 53, machining is difficult and dimensional control becomes difficult. On the other hand, according to the present embodiment, the stepped groove 53b is processed in the opening at both ends of the housing main body 53, and the groove for arranging the seal body 55 is formed using the lid 54. Therefore, the processing is easy and accurate. Allows dimensional control. As a result, the management of the crush margin of the seal body 55 is facilitated, and the management of the sliding resistance to the shaft 10 by the sliding ring 56 is facilitated.

Thus, according to the above-described embodiment, the actuator 1 has the shaft 10 provided with the hollow hole 11 at the tip end portion 10A, and the shaft housing 50 in which the shaft 10 is slidably inserted. The shaft housing 50 is provided with an air tube connection hole 51 and an internal space 52 communicating with the air tube connection hole 51 and surrounding the outer peripheral surface 10 a of the shaft 10. A communication hole 12 communicating with the hollow hole 11 is provided on the outer peripheral surface 10 a of the shaft 10 surrounded by the internal space 52. By adopting this configuration, the air tube 64 can be connected to the shaft 10 without using a rotary joint, and the actuator 1 and the actuator unit 100 with less influence on the thrust / torque and operation can be obtained.

As mentioned above, although the suitable embodiment of the present invention was described referring to drawings, the present invention is not limited to the above-mentioned embodiment. The shapes, combinations, and the like of the constituent members shown in the above-described embodiment are merely examples, and various changes can be made based on design requirements and the like without departing from the spirit of the present invention.

For example, in the above embodiment, the configuration in which the actuator 1 includes the rotary motor 20 and the linear motion motor 30 is exemplified. However, the actuator 1 may be configured to include only the rotary motor 20. It may be the composition which has only.
For example, when the actuator 1 is configured to have only the rotary motor 20, the length L of the internal space 52 shown in FIG. 5 may be shortened to a length (area) that can face the communication hole 12.

In the above embodiment, although the configuration in which the rotation motor 20 rotates the shaft 10 via the spline nut is illustrated, for example, the rotation motor 20 may be configured to rotate the shaft 10 via the belt and the pulley. . In this case, a pulley fixed to the shaft 10 is a power transmission unit.

Further, for example, in the above embodiment, the present invention is applied to the actuator 1 that picks and places the work W. For example, other pneumatic actuators or a spindle device that supplies liquid as a fluid as in the prior art The present invention can be applied to the like.

DESCRIPTION OF SYMBOLS 1 actuator 10 shaft 10a outer peripheral surface 10A front-end | tip part 10B base end part 11 hollow hole 12 communicating hole 20 rotation motor 30 direct-acting motor 36 connection arm (power transmission part)
50 shaft housing (housing)
51 Air tube connection hole (fluid flow path connection hole)
52 Internal space 53 Housing body 54 Lid 55 Seal body 56 Sliding ring 64 Air tube (fluid flow path)
100 Actuator unit L Length O Axis line S Stroke W Work

Claims

A shaft provided with a hollow at the tip,
And a housing in which the shaft is slidably inserted.
The housing is provided with a fluid flow passage connection hole, and an internal space in communication with the fluid flow passage connection hole and surrounding an outer peripheral surface of the shaft.
A communication hole communicating with the hollow hole is provided on an outer peripheral surface of the shaft surrounded by the internal space.
A power transmission unit for sliding the shaft relative to the housing is provided on an axis of the shaft,
The actuator according to claim 1, wherein the housing is disposed closer to a tip of the shaft than the power transmission unit on an axis of the shaft.
A linear motion motor for sliding the shaft relative to the housing along the axial direction of the shaft;
The actuator according to claim 1, wherein the inner space has a length equal to or greater than a stroke of the shaft by the linear motion motor in an axial direction of the shaft.
The housing is
A cylindrical housing body in which the fluid channel connection holes are provided in the radial direction;
A pair of lids closing the openings at both ends of the housing body;
A sealing body interposed between the housing body and the pair of lids;
The actuator according to any one of claims 1 to 3, further comprising: a sliding ring provided on the seal body and slidably supporting the shaft.
A plurality of actuators according to any one of claims 1 to 4 are stacked in a direction orthogonal to the axial direction of the shaft,
An actuator unit, wherein the fluid channel connection hole is provided in a direction orthogonal to the axial direction of the shaft and the stacking direction of the actuators.