JPH0218845Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a rotary actuator, particularly a rotary actuator that obtains swing torque to a shaft body through a pinion meshed with a rack that is reciprocated by fluid pressure. Regarding Eta.

[Background Art] Generally, as an actuator for position control of machine tools and various automatic equipment, there is a so-called rotary actuator that extracts fluid pressure energy such as compressed air as swing torque of a shaft body or the like.

However, in a rotary actuator with the above structure, fluctuations in the external load driven by the oscillating shaft and the compressed air pressure that drives the rack that rotates the shaft via the pinion, etc. The inventor of the present invention has discovered that, due to this, there is a drawback that the angular velocity of the shaft body through which the swinging torque is output becomes unstable.

[Object of the invention] An object of the invention is to provide a rotary actuator that can obtain a swinging torque with a constant angular velocity.

Another object of the present invention is to provide a rotary actuator that can arbitrarily adjust the swing angle of a shaft body that outputs swing torque.

Still another object of the present invention is to provide a rotary actuator that can simplify assembly work.

[Summary of the invention] The present invention provides a feed rate control mechanism that can control the moving speed of a rack to a predetermined value by applying a predetermined load to the rack that is reciprocated by fluid pressure. By installing this, the angular velocity of the swinging torque of the shaft obtained by the reciprocating movement of the rack via the pinion becomes constant.

[Example] FIG. 1 is a cross-sectional view of a rotary actuator that is an example of the present invention, and FIG.
FIG. 2 is a sectional view of a portion indicated by a line in the figure.

A cylinder 2 and a cylinder 3 having parallel axes in the same plane are formed inside the main body 1, and a pinion 4 and a pinion 4 extend perpendicularly to the plane and pass through the boundary between the cylinders 2 and 3.
A main shaft 5 is provided coaxially and integrally with the main shaft 5.

One end of the main shaft 5 is projected to the outside of the main body 1,
Further, the main shaft 5 is rotatably supported by a bearing metal 6 and a bearing metal 7 fitted to the main body 1 at a position where a pinion 4 integrally formed with the main shaft 5 is sandwiched therebetween.

The bearing metals 6 and 7 are configured to be held in the main body 1 by a bearing presser 8 and a bearing presser 9 that are fitted into the main body 1.

The teeth of the pinion 4 are exposed inside the cylinders 2 and 3, and linearly arranged teeth are carved on the side surface of a cylindrical member that is slidably accommodated in the axial direction of the cylinders 2 and 3. The racks 14 and 15 are meshed with each other.

A piston part 16 and a piston part 17 are arranged at the same ends of the racks 14 and 15, and between the piston parts 16 and 17 and a cylinder cover 18 that closes one end of the cylinders 2 and 3, fluid chambers A and Each fluid chamber B is configured.

The racks 14 and 15 are then activated by alternately applying fluid pressure such as compressed air through pressure ports 19 and 20 that are formed through the cylinder cover 18 and communicated with the fluid chambers A and B, respectively. The shafts are reciprocated in opposite directions, and a predetermined swing torque is generated on the main shaft 5 via a pinion 4 meshed with racks 14 and 15.

An O-ring 21 and an O-ring 22 are respectively attached to the portions where the cylinder cover 18 and the cylinders 2 and 3 are in close contact with each other, so that the fluid chambers A and B are kept airtight.

On the outer periphery of the piston parts 16 and 17, a piston part packing 23 and a piston part packing 2 are provided.
4 is provided, and the sliding portions between the piston portions 16 and 17 and the cylinders 2 and 3 are configured to be kept airtight.

Furthermore, a dustproof cover 25 is provided at the other end of the cylinders 2 and 3 formed in the main body 1 to prevent dust from entering into the cylinders 2 and 3 from the outside.

In this case, the dustproof cover 25 provided at the ends of the cylinders 2 and 3 includes a feed rate control mechanism H1 and a feed rate control mechanism H1 in which a threaded part 26 and a threaded part 27 are formed over almost the entire length of the outer periphery of the main body. A mechanism H2 is screwed onto each of the cylinders 2 and 3 so as to be positioned substantially coaxially therewith.

The feed speed control mechanisms H1 and H2 may have any structure, such as the one disclosed in Japanese Utility Model Application Publication No. 57-122337 filed by the present applicant.

The rods 28 and 29, which are provided in the feed rate control mechanisms H1 and H2 and protrude axially into the cylinders 2 and 3, are always pressed against the cylinder 2 by a biasing force such as a spring (not shown).
and racks 14 and 1 housed inside 3
Rack 1
4 and 15 are moved by fluid pressure in the direction toward the dustproof cover 25, that is, in the direction in which the rods 28 and 29 are pushed into the feed rate control mechanisms H1 and H2, respectively, the movement of the racks 14 and 15 is prevented. The structure is such that a constant load is generated over the entire length of the stroke.

In addition, when screwing the feed rate control mechanisms H1 and H2 into the dustproof cover 25, the amount of screwing is adjusted, and the rack 14 is adjusted so that the rods 28 and 29 are fully pushed into the feed rate control mechanisms H1 and H2. By setting the abutment positions for the racks 14 and 15 at desired positions, the stroke range of the racks 14 and 15, that is, the swing angle of the main shaft 5, can be arbitrarily set.

Further, a locking nut 30 and a locking nut 31 are screwed into threaded portions 26 and 27 formed on the outer periphery of the feed rate control mechanisms H1 and H2, respectively.
is screwed onto the dustproof cover 25 so that it is in a predetermined position, and then tightened so as to come into contact with the dustproof cover 25, thereby preventing vibrations caused by, for example, the operation of the rotary actuator. This prevents the feed speed control mechanisms H1 and H2 from being in a floating state with respect to the dustproof cover 25.

The operation of this embodiment will be explained below.

First, the main body 1 of the rotary actuator is attached to a predetermined device, and the pressure ports 19 and 20 are connected to a predetermined air pressure source (not shown) via a predetermined control valve mechanism (not shown). .

Next, the control valve mechanism controls the pressure port 19.
Compressed air pressure is applied alternately to the fluid chambers A and B of the cylinders 2 and 3 through the cylinders 20 and 20, and the racks 14 and 15 are reciprocated in opposite directions. A predetermined swing torque is generated at the main shaft 5, and a predetermined external load connected to the main shaft 5 is driven to perform a predetermined work.

In this case, pressure port 1 is installed inside fluid chambers A and B.
The main shaft 5 is driven by compressed air pressure applied through 9 and 20, and the pinion 4 is engaged with the main shaft 5.
The racks 14 and 15 are moved axially inside the cylinders 2 and 3 toward the end where the dustproof cover 25 is attached while rotating in a predetermined direction. Speed control mechanism H1,
Rack 14,1 so that it is pushed into the inside of H2.
Since a constant load is applied over the entire length of the stroke from the rods 28, 29, which are displaced together with the shaft 5, the speed of movement of the racks 14, 15, due to, for example, fluctuations in the external load connected to the main shaft 5, That is, the rack 14,1 is connected via the pinion 4.
This prevents the angular velocity of the main shaft 5 that is oscillated by the main shaft 5 from becoming unstable, and it is possible to obtain a swinging torque of a constant angular velocity on the main shaft 5 in any direction of rotation.

Note that the present invention is not limited to the above-mentioned embodiments; for example, the fluid for operating the rotary actuator is not limited to compressed air, but may also be a gas other than pressurized air or a liquid such as oil. Also good.

[Effects] (1) A predetermined load is applied to the rack that is reciprocated by a rotary actuator that generates rocking torque on the shaft body through a pinion meshed with the rack that is reciprocated by fluid pressure. A feed rate control mechanism is installed to control the moving speed of the rack to a predetermined value over the entire length of the stroke by controlling the moving speed of the rack to a predetermined value over the entire length of the stroke. The angular velocity of the shaft, which is oscillated by the rack via the pinion, can be controlled to be almost constant over the entire length. Therefore, it is possible to obtain a swinging torque at a constant angular velocity on the shaft.

(2) By appropriately setting the screwing position of each of the plurality of feed rate control mechanisms screwed onto the dustproof cover with respect to the dustproof cover and changing the contact position with respect to each of the plurality of racks meshing with the pinion, The swinging angle of the shaft body through which the swinging torque is output can be adjusted as desired.

(3) By simply screwing the feed rate control mechanism from the outside onto the dust-proof cover that closes one end of multiple cylinders, the feed rate control mechanism stabilizes the angular velocity during the swinging displacement of the spindle, making assembly work easier. can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a rotary actuator that is an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the portion indicated by the line - in FIG. 1... Body, 2, 3... Cylinder, 4... Pinion, 5... Main shaft (shaft body), 6, 7... Bearing metal, 8, 9... Bearing holder, 14, 15... Rack, 16 , 17... Piston part, 18... Cylinder cover, 19, 20... Pressure port, 21, 2
2... O-ring, 23, 24... Piston seal, 25... Dust-proof cover, 26, 27... Threaded part, 28, 29... Rod, 30, 31... Locking nut, H1, H2... feed rate control mechanism,
A, B...Fluid chamber.

Claims (1)

[Claims for Utility Model Registration] (1) A pinion engaged with a shaft body, a plurality of cylinders provided in parallel with this pinion in between, and a device housed in each cylinder and exposed to a part of the cylinder. a plurality of racks that individually mesh with the pinions, a plurality of pistons each disposed at the same end of the plurality of racks, and a plurality of pistons that close one end of the plurality of cylinders, and a plurality of A cylinder cover that forms a fluid chamber, and a hole bored in the cylinder cover,
A pressure port that communicates with each of the plurality of fluid chambers, a dustproof cover that closes the other end side of the plurality of cylinders, and a dustproof cover that is screwed onto a position facing each of the plurality of cylinders, and a A rotary actuator comprising a plurality of feed rate control mechanisms each having a rod protruding into the cylinder, each of which applies a braking force. (2) A threaded portion is carved on the outer periphery of the feed rate control mechanism over almost the entire length, and by changing the screwing position of the feed rate control mechanism, the regulating position of the stroke end of the rack can be varied. A rotary actuator according to claim 1, characterized in that the rotary actuator is made of: