JPS5832004Y2 - Digital rotation input type fluid pressure piston position control device - Google Patents

Description

[Detailed Description of the Invention] Conventionally, there have been many linear input means such as analog current-displacement output torque motors and force motors, but there have been no high-precision and inexpensive input means.

On the other hand, in the case of rotational input, it is easy to connect gears, so it is easy to select the resolution by speeding up or decelerating.Also, as a specific manual method, it is possible to use digital type rotational steps with high accuracy in fixed angle increments. Many types are known, including stepper motors, rotary solenoids, and rotary servo actuators.

However, all of the inexpensive and small models have low torque, and it is impossible to obtain a large force even if the rotary motion is directly converted into motion by gear-rack coupling or screw coupling.

Furthermore, when digital input means are used, in the event of a power outage, emergency stop, etc., the return-to-origin (resetting) operation is often troublesome.

The present invention includes a piston that slides in a cylinder hole in a main body, a cylinder chamber with a small area for applying pressure fluid at one end of the piston, and a cylinder chamber with a large area at the other end. A rod is provided on the large-area side, and a nozzle connected to the large-area cylinder chamber is provided at the tip of the rod, and the nozzle is opened and closed by digital rotation input means directly or through an appropriate mechanism, and By guiding the pressure fluid to the large-area cylinder chamber through the throttle, it has a simple structure and does not require high-precision machining, and can also be used with small torque rotation inputs such as stepper motors driven by digital signals. Even when used, the force can be amplified by fluid pressure and converted into linear motion, and the movable parts such as the shaft of the rotation input means are provided with a spring and a mechanical stopper mechanism, making it easy to return to the origin in the event of a power outage or emergency stop. It is an object of the present invention to provide a digital rotary input type hydraulic piston position control device.

Embodiments of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, a piston 3 with both rods is slidably inserted in the cylinder hole 2 provided in the main body 1 in the axial direction, and a mounting screw 4- is attached to the tip of the thick rod on the small piston area side. a and protrude outside the main body 1, and use it as the external rod 4. The other thin rod on the large piston area side is connected to the main body 1.
A drain chamber 10 having a drain hole 10a provided therein.
A nozzle 5C is connected to the eccentric disc 1 at the tip of the internal rod 5, which is connected to the cylinder chamber 7 on the large piston area side through an internal passage 5a and a hole 5b.
The cylindrical surface 11a of No. 1 is opened and closed in accordance with the opening and closing, and the pressure fluid is introduced into the cylinder chamber 6 on the small piston area side through the passage 8, and the pressure fluid is further throttled and transferred through the passage 9 including the piston area 9a on the large area side. Lead to Shinonda room 7.

Next, the connection between the eccentric disk 11 and the stepper motor 15, which is a rotation input means and is driven by a digital signal, will be explained with reference to FIG.

The shaft 12 of the eccentric disk 11 protrudes outside the main body 1 and connects to the joint 13.
It is connected to the shaft 15a of a stepper motor 15 mounted on a support frame 16 fixed to the main body 1, and the joint 13 has a stopper pin 14 projecting downward as shown in FIG. 3, and is fixed to the main body 1. Together with the pins 17 and 18, the operating angle range of the shaft 12 from the rotational angular position θa to 80 is regulated.

Furthermore, if the position of θa is set as the origin, the stopper pin 14 will touch the pin 17 and stop when the stepper motor is de-energized.
A tension spring 22 is provided between the projection 16a and the projection 16a.

With the above configuration, when the stepper motor 15 receives a digital signal and rotates, the shaft 15a and the joint 13
, rotation is transmitted to the shaft 12.

If the shaft 12 now rotates counterclockwise from θa to θb to θC in FIGS. 1 and 3, the eccentric disc 1
1 is attached eccentrically, so the cylindrical surface 1 of the eccentric disk 11
1a moves from Sa to Sb to Sc and approaches the nozzle 5C in FIGS. 1 and 2.

However, as mentioned above, there is an aperture 9a in front of the nozzle 5C.
Since the pressure fluid is supplied through the passage 5a in front of the nozzle 5C as the cylindrical surface 11a approaches the
, the pressure in the hole 5b and the cylinder chamber 7 gradually increases, and the force pushing the piston 3 to the left increases.

On the other hand, pressurized fluid is also introduced into the cylinder chamber 6 and constantly pushes the piston 3 to the right, but since the piston area on the cylinder chamber 7 side is larger than the piston area on the cylinder chamber 6 side, the tip of the nozzle 5C When the gap with the cylindrical surface 11a reaches a value, that is, the gap X in FIG. 2, the forces pushing in the left and right directions are balanced.

Therefore, when the gap becomes smaller than X, the pressure in the cylinder chamber 7 becomes higher and pushes the piston 3 to the left, so the external rod 4 moves to the left with a large force amplified by the fluid pressure, and the gap becomes X. However, the forces in the left and right directions are balanced and stop.

Furthermore, when the shaft 12 rotates clockwise and the value of the clearance X increases, the pressure in the cylinder chamber 7 decreases due to the action of the throttle 9a, so the fluid pressure acting on the cylinder chamber 6 amplifies the piston 3 and external rod 4 to the right. move with great force,
When the gap becomes X, the forces in the left and right directions are balanced and stop.

In other words, since the part to the left of the nozzle 5a is a device that follows the eccentric disk 11 by force amplification by fluid pressure while maintaining the gap between it and the cylindrical surface 11a of the eccentric disk 11 at X, the eccentric disk 11 is accurately moved by the stepper motor 15. If the external rod 4 is moved, there is no need to turn it with a large torque, and the position of the external rod 4 can be determined digitally with force and accuracy while maintaining the gap X using the force amplification follow-up device.

In addition, in the event of a power outage or emergency stop, the stepper motor 15
When the excitation is released, the stopper pin 14 comes into contact with the pin 17 and stops due to the action of the spring 22, so that it can automatically return to the origin.

As mentioned above, it has a simple structure and does not require parts that require high-precision machining. Furthermore, it uses a small digital rotation input means with low torque to perform accurate linear positioning with a large force, and can be used in the event of a power outage or emergency stop. It is also possible to provide a Digimol rotation input type fluid pressure piston position control device that can automatically return to the origin.

In addition, in the above example, the stepper motor shaft 15a and the shaft 12
Alternatively, the shaft 21 is directly connected, but it goes without saying that the resolution can be freely selected by speeding up or decelerating by gear coupling or the like.

Furthermore, although it is easy to control and generally keep the area on both sides of the piston 3, that is, the ratio of the cross-sectional areas in the direction perpendicular to the axis between the cylinder chamber 7 and the cylinder chamber 6 to 2:1, this ratio is not necessarily 2:1.
: Operation is possible even if it is not 1.

Furthermore, if a spool valve function is added between the cylinder hole 2 and the piston 3, it can also be used as a hydraulic control valve.

As for returning to the origin, as briefly described above, returning to the origin with a positioning device using general digital input means requires a separate detection mechanism such as an encoder, which is troublesome.

Similarly, in the event of a power outage or emergency stop, the return-to-origin operation is often troublesome.

In this case, the spring and mechanical stopper mechanism can be used to easily and automatically return to the origin, but in reality, we will take an example where a 4-phase stepper motor with 1.8° steps is used as the rotation input means. and 4 coils A, B, C
, D in order, one rotation of 360° can be obtained in 200 steps.

Therefore, if the excitation coil in the return-to-origin state is A, the A coil will be in an excitation state at as many as 50 points during one rotation.

Therefore, the method of the present invention uses a spring and a stopper to mechanically return the stepper motor to the original home return position when the A coil is energized, and if the A coil is energized later, the stepper motor can be easily returned to the original home position. It has the advantage of being able to

Although the origin position has been explained as θa in Figures 1 and 3, it is of course possible to use the same position at θC, but it is also possible to balance the forces of the two springs at an intermediate position such as θb. By aligning them, it is possible to return to the origin.

Also, if a pressure accumulator is included in the fluid pressure system, pressure fluid will remain for a while after a power outage, so if the stepper motor shaft 15a and the eccentric disk 11 return to their original positions, the dimensions of the tip of the nozzle 5C mentioned above can be adjusted. Piston 3 returns to the origin while maintaining X.

If it is a fluid pressure system without a pressure accumulator, the pressure fluid will disappear immediately after a power outage, and the piston alone will not be able to return to its home position. If the piston 3 is inserted, the piston 3 can be returned to its origin.

[Brief explanation of the drawing]

FIG. 1 is an explanatory longitudinal cross-sectional view of one embodiment of the present invention f'iJ;
FIG. 2 is a partial sectional explanatory view taken along line ll--ll in FIG. 1, and FIG. 3 is an explanatory sectional view taken along the line III--II in FIG. 1...Body, 3...Piston, 4...
...External rod dome 5...Internal rod, 5C
...Nozzle, 6,7...Cylinder chamber, 9a...Aperture, 10...Drain chamber,
11... Eccentric disk, 11 a... Cylindrical surface, 12, 15 a, 21... Axis, 13...
...Joint, 14... Stopper pin, 15.
・・・・・・Stepper motor, 17.18・・・・・・
Pin, 20...rod, 20a...rack, 20b...end face, 21a...pinion, 22...spring.

Claims (1)

[Scope of utility model registration request] A piston that slides in a cylinder hole in the main body is provided, a small-area cylinder chamber for applying pressure fluid is provided at one end of the piston, a large-area cylinder chamber is provided at the other end, and the large-area side of the piston is provided. A rod is provided in the main body to protrude into a drain chamber provided with a drain hole in the main body, and a nozzle is provided at the tip of the rod that communicates with the cylinder chamber on the larger area side of the piston, and the pressurized fluid is passed through the throttle to the drain chamber. The piston is positioned by causing the nozzle to follow the outer cylindrical surface of an eccentric disk rotated by a stepper motor driven by a digital input signal guided into the cylinder chamber on the large area side, and the digital rotation means is returned to its original position. 1. A digital rotation input type fluid pressure piston position control device, characterized in that it has an origin return mechanism provided with a directional spring.