JPS62137402A - Rotary actuator - Google Patents

Abstract

PURPOSE:To improve a function of an actuator by providing a stop shaft parallel to a driving shaft, bringing a rack of the stop shaft into engagement with a pinion shaft, and providing a stopper on each of both ends of the stop shaft. CONSTITUTION:A stop shaft 38 is disposed parallel to a driving shaft 31, and a pinion shaft 34 engaged with the driving shaft 31 is engaged with a rack 39 of the stop shaft 38. Stopper heads 29, 30 as a stopper are mounted on both ends of the stop shaft 38. In this arrangement, the stop shaft 38 is brought into contact with the stopper heads 29, 30 to regulate the movement of the driving shaft 31 and backlashes between a pinion 37 and both racks 33, 39 are generated in the opposite directions to each other with respect to the rotating direction of the pinion 37, so that there is no clearance in the turning direction in the pinion shaft 34. Accordingly, a function of an actuator can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotary actuator that obtains an output by converting the reciprocating motion of a rack caused by fluid pressure into rotation of a pinion that meshes with the rack.

[Conventional technology]

A known type of fluid pressure actuator is a rotary actuator that obtains driving force by converting the reciprocating motion of a rack caused by fluid pressure into the rotational motion of a binion that meshes with the rack. Widely used for positioning workpieces, etc.

FIG. 6 is a front view with the left half of a conventional rotary actuator of this type cut away, and FIG. 2 is a plan view with the left half cut away. This will be explained based on this figure. Then, inside the cylinder body 3 whose openings at both ends are closed by the cylinder head 1.2, there are disk-shaped pistons 4 at both ends and two plate-shaped brackets 5 parallel to each other between them. They are connected by split bins and fitted so as to be reciprocally movable, and a rack 6 is held between the two brackets 5 on one side and fixed with rivets. A pinion shaft 7 is rotatably supported in the center of the cylinder body 3 via a bearing 8 perpendicular to the rack 6. A pinion 9 that meshes with the rack 6 is integrally formed on this pinion shaft. It protrudes outside the cylinder body 3. Note that the bracket 5 is provided with a long hole 1o that avoids the pinion shaft 7 during reciprocating movement. A driven member is connected directly or via a connecting member to a swinging member (not shown) fixed to a protrusion of the pinion shaft γ with a key 11, and a boat opening in the cylinder head 1.2 at both ends 12 (one not shown)
is connected to an air source via a switching valve.

With this configuration, when air is supplied to the boat 12 on the cylinder head 1 side, the piston 4 moves to the right in the figure, and the pinion 9, that is, the pinion shaft 7 that meshes with the rack 6 integrated with the piston 4 moves to the right in the figure. Rotate clockwise as shown in Figure 6. Furthermore, when air is supplied to the boat on the cylinder head 2 side, the pinion shaft 7 rotates counterclockwise in FIG. 6. In this case, both rotation end limits of the pinion shaft 7 are regulated by each piston 4 coming into contact with each cylinder head 1.2.

[Problem that the invention seeks to solve]

However, in the conventional rotary actuator configured in this way, both ends of the rotation range are regulated by the ai-t of each piston 4 to each cylinder head 1.2 as described above. Backlash between the rack 6 and the pinio/9 causes play in the pinion shaft 7, causing a problem in that, for example, in the case of a workpiece positioning device, the position of the workpiece becomes unstable.

In addition, if you want to change the rotation range of the cylinder head, as shown in the vertical cross-sectional view in Figure 8, increase the thickness of one cylinder head and screw the adjustment screw 13 into the screw hole. Natsu 1
4, but the adjustment screw 1
In addition to the length of the actuator 3, there was a problem in that a sealing member such as an OIJ ring 15 was required to prevent air leakage from the rotating part, which increased the length of the actuator in the axial direction. .

[Means for solving problems]

In order to solve these problems, the present invention includes a drive shaft that moves in the axial direction using fluid pressure, and a pinion shaft that is orthogonal to the drive shaft and has a pinion that meshes with the rack thereof.
In a rotary actuator that rotates a pinion shaft from the drive shaft side to generate a rotational output, a slidable stop shaft is provided on the opposite side of the drive shaft to the pinion shaft and parallel to the stop shaft, and the rack is connected to the pinion of the pinion shaft. A stopper is provided that engages with the stopper and regulates the forward and backward movement limits of the stop shaft.

[Effect]

When the drive shaft is moved back and forth using fluid pressure, the pinion shaft, which is equipped with a pinion that engages with the rack of the drive shaft, rotates, producing rotational output. At this time, the stop shaft slides due to the engagement between the pinion and the rack, and by coming into contact with the stopper, the end of rotation of the pinion shaft is regulated, and the backlash between the pinion and both racks at this time is Since they occur in opposite directions to the rotational direction, there is no play in the rotational direction of the pinion shaft.

〔Example〕

1 to 3 show an embodiment of the rotary actuator according to the present invention, FIG. 1 is a longitudinal sectional view thereof, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. FIG. 2 is an enlarged cross-sectional view of a rack and pinion shown to explain backlash.

In the figure, the low reactor actuator 20 is equipped with a cubic body 21, and this body 21 is defined by a partition wall 22 in the center and has drive cylinders 2 parallel to each other.
3 and a stop cylinder 24, and a bushing 25 is fitted into the drive cylinder 23. Further, a bushing 26 that is divided into two parts in the axial direction is fitted into the stop cylinder 24. The openings at both ends of the drive cylinder 230 are closed by cylinder heads 27 and 28, and between these cylinder heads 27 and 28 and both ends of the bushing 25, a QIJ ring 29- is interposed as a sealing material. has been done. 27a and 28m are cylinder heads 27.
A plug is screwed into the boat, which is connected to an air source as a pressure fluid source via a switching valve, and when the switching valve is switched, the boat is connected to the air source as a pressure fluid source (27).
The configuration is such that the share is sent to either of a and 28a. Stopper heads 29 and 30 are formed in a cylindrical shape with a bottom and close the openings at both ends of the stop cylinder 24, respectively. Furthermore, 31 is a drive shaft which is housed in the inner hole of the frisch 25, and at both ends thereof,
Piston 32 slidably fits into the inner hole of bush 25
are integrally formed 9, and the partition wall portion 22 of the drive shaft 31
A rack 33 is provided on the side.

A pinion shaft 34 with a flange is supported via a bearing 35 and fixed with a NAND 36 in a shaft hole provided in the center of the partition wall 22 which is the center of the body 21. , the rack 33 and the engaging gear 37 are integrally formed. A driven member (not shown) is connected to the collar of the pinion shaft 34. On the other hand, a stop shaft 38 is slidably fitted into the bush 26 of the stop cylinder 24, and a pinion 38 is fitted onto the stop shaft 38.
A rank 39 meshing with 7 is provided. For example, when pressurized air is introduced from the port 27a in the illustrated state, the drive shaft 31 moves downward while sliding the piston 32, the pinion shaft 34 rotates counterclockwise, and the stonf shaft 38 moves upward. However, at the rotation limit of the pinion shaft 34, the drive shaft 31. Stop axis 3
A length of 8 is set. -Also, even when the stop shaft 3B contacts the lower stop head 3° as shown, the upper end of the piston 32 does not contact the cylinder head 2T.

The operation of the rotary actuator 20 configured as above will be explained. When pressurized air is supplied from the boat 27 in the illustrated state, the piston 32 is pushed and the drive shaft 31 integrated therewith moves downward, and the pinion shaft integrated with the pinion 3γ that meshes with the rack 33 of the drive shaft 31 34 rotates counterclockwise in the figure, the driven member connected to the collar of the pinion shaft 34 makes a predetermined movement. pinion shaft 3
4, the stop shaft 38 integrated with the rank 39 that engages with the υ pinion 37 moves upward, and its upper end abuts against the stop head 29, thereby restricting the rotation limit of the pinion shaft 34, and the driven member The movement of stops at a predetermined position. The meshing state between the ranks 33 and 39 and the pinion 37 in this case will be explained based on FIG. Since the piston 32 is not in contact with the cylinder head 28 and the drive shaft 31 is biased toward the cylinder head 28 by air pressure, the pinion 37 is biased by rotational force by the rack 33 and rotated by the rack 39. Bank crash B,,B,
occur on opposite sides of the teeth with respect to the direction of rotation of the 3rd and 0th rotations. Therefore, the pinion shaft 34 is stable with no play in either the forward or reverse direction, and the stopped position of the driven member connected to the pinion shaft 34 is stable. Then, when air is introduced from the boat: Zaa side, the drive @ 31 and the stop shaft 3B move to the illustrated position, and the pinion shaft 34 rotates clockwise in the figure.

FIG. 4 is a longitudinal sectional view of a rotary actuator as another embodiment of the present invention, and members having the same configuration as those in FIG. In the rotary actuator 20A of this embodiment, an adjustment screw 40 is screwed into a screw hole provided in the stop head 29, 30, and is fixed with a Nand 41 at the adjustment position.

By doing this, the movement of the stop shaft 38 is regulated by coming into contact with the adjustment screw 40, and this regulated position is
It can be freely adjusted by rotating the adjustment screw 40. In this case, since no air is introduced into the stop cylinder 24, a sealing member is not required, and since the adjustment screw 40 is not coaxial with the driving cylinder 23, the entire length of the actuator is not very long even if an adjustment mechanism is provided. It never becomes.

Further, FIG. 5 is a longitudinal cross-sectional view of a rotary actuator as another embodiment of the present invention, and members having the same configuration as those in FIG. A shock absorber 42 is provided in the low reactuator 20B in this embodiment. That is, one end opening of the stop cylinder 24 is covered with a cover 43.
A cylindrical absorber cylinder 44 is connected and fixed, and a piping 4 having a throttle valve 45 is installed inside the cylinder.
6, pressure oil 47 is introduced. Also, a piston 49 at the tip of the condo 4B integrally formed with the stop shaft 38
is slidably fitted into the absorber cylinder 44. By doing this, the impact caused by the sudden stop of the stop shaft 3B at the end of rotation of the pinion shaft 34 is alleviated by the shock absorber 42, so that the pinion shaft 34
The driven member connected to stops slowly.

〔Effect of the invention〕

As is clear from the above description, the present invention includes a drive shaft that moves in the axial direction using fluid pressure, and a pinion shaft that is orthogonal to the drive shaft and has a pinion that meshes with the rank of the drive shaft. In a rotary actuator that rotates a pinion shaft from the side to generate rotational output, a slidable stop shaft is provided on the opposite side of the drive shaft to the pinion shaft and parallel to the drive shaft, and the rack is engaged with the pinion of the pinion shaft. By providing a stopper that restricts the movement of the stop shaft, when the drive shaft is moved by fluid pressure and the pinion shaft is rotated, the stop shaft moves in the opposite direction to the drive shaft and comes into contact with the stopper. The rotation limit of the pinion shaft is regulated, but if the movement of the drive shaft is not restricted by the stopper at this time, the teeth of the rack on the drive shaft side will push the teeth of the pinion, and the teeth of the pinion will press the teeth of the pinion on the stop shaft side. By pressing the teeth, bank lash does not occur, so the rotation end position of the pinion shaft is stabilized, and the stopped position of the driven member connected to the pinion shaft is stabilized, improving the function as an actuator. . In addition, by providing a stop mechanism for regulating the rotation limit of the pinion shaft outside the driving fluid pressure cylinder, even if the stop mechanism is provided with a rotation limit adjustment mechanism, no sealing member is required. Since this adjustment mechanism does not protrude further in the axial direction than the hydraulic cylinder, the overall length of the actuator can be reduced.

[Brief explanation of drawings]

1 to 5 show an embodiment of the low reactor according to the present invention, FIG. 1 is a longitudinal sectional view thereof, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. 3 is a pinio/rank 4 and 5 are longitudinal sectional views of a rotary actuator as other embodiments of the present invention, respectively. The figures show a conventional rotary actuator, Fig. 6 is a front view with the left half cut away, Fig. 7 is a plan view with the left half cut away, and Fig. 8 is a rotary actuator with an adjustment screw. FIG. 3 is a front view showing a main part cut away. 20.2OA, 20B @...Rotary actuator, 27&, 27b--Φm boat, 29.30--
・Stop head, 31... Drive shaft, 33° 39.
@e@Rack, 348... Pinion shaft, 37-...
Pinion, 38...stop shaft, Bled! ...
・Backlash.

Claims (1)

[Claims] A rack of a drive shaft and a pinion of a pinion shaft perpendicular to the drive shaft are engaged with each other, and the drive shaft is moved forward and backward in the axial direction using fluid pressure, thereby rotating the pinion shaft and producing a rotational output on the pinion shaft. In the rotary actuator, a stop shaft is provided which is located on the opposite side of the drive shaft to the pinion shaft and can move forward and backward parallel to the drive shaft, and a rack provided on the stop shaft and a pinion of the pinion shaft are engaged with each other. A rotary actuator characterized in that a stopper is provided for moving the stop shaft back and forth in a direction opposite to the drive shaft and for regulating the limits of the forward and backward movement of the stop shaft.