JP2000110802A - Cylinder position controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the position of a cylinder at high stopping accuracy only by an air source in a place having no hydraulic source and to be used under a high-temperature atmosphere by constituting a drive source of a cylinder of a pneumatic driven hydraulic pump and a selector means of a solenoid valve respectively. SOLUTION: A pneumatic pressure supplied from a Sup.13 is reduced to a prescribed pressure by a pressure reducing valve 14 as necessary. A pneumatic driven hydraulic pump 11 has such a mechanism as stopping the operation at generating a prescribed oil pressure. For example, when a rod 3 of a cylinder 1 is in the completely drawn back state and a command signal of thrusting out the rod 3 for a prescribed stroke is inputted, MV2 and MV4 of solenoid valves 12 for operating the cylinder 1 are opened so that the rod 3 of the cylinder 1 is thrust out. The stroke is fed back to a controller 7 by a feedback sensor 5 and, when it reaches a prescribed stroke, MV2 and MV4 are closed. This constitution can highly precisely control the position of the cylinder at low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder position control device, and more particularly to an inexpensive and highly accurate cylinder position control device.

[0002]

2. Description of the Related Art Conventional cylinder position control devices include:
A cylinder and a driving source of the cylinder, a switching means for switching a moving direction of a piston of the cylinder, a feedback sensor for detecting a position of a piston rod of the cylinder and generating a feedback signal, and a control signal for receiving the feedback signal and controlling the switching means. And a controller that emits.

A conventional cylinder position control device shown in FIG. 3 comprises a cylinder 101, a hydraulic pump 102 for driving the cylinder 101, a servo valve 104 for switching the moving direction of a piston 103 of the cylinder 101, and a rod 105 for the cylinder 101. And the feedback signal 106 is detected.
And a servo controller 109 which receives a feedback signal and issues a control signal 108 for controlling the servo valve 104,
The control signal 108 is amplified by the servo amplifier 110 to control the servo valve 104.

Here, the piston 10 of the cylinder 101 is
Servo valve 10 as switching means for switching the moving direction of
4 is used. In the conventional position control device shown in FIG. 4, a table 201 is screwed into a feed screw 202, and the feed screw 202 is driven by a servomotor 203 via a speed reducer 204. The position of the table 201 is measured by the linear scale 205 or the like, and the position signal 206 is sent to the position control servo amplifier 207. The servo motor 203 is provided with a detector 208 for detecting the speed of the servo motor 203 and supplying a speed signal 209 to the position control servo amplifier 207. Position signal 206 and velocity signal 209 supplied to position control servo amplifier 207
Then, the control signal 210 is sent to the servo motor 203, and the rotation speed of the servo motor 203 is controlled to control the position of the table 201.

Here, a servomotor 203 is used as a drive source of the table 201.

[0006]

The servo valve 1 shown in FIG.
In the position control device using the 04, when performing high-precision position control, the valve allows leakage inside at the time of 0 stroke, the oil always flows, the oil temperature increases, and the hydraulic pump 102 It will be big. The position control device using the servo motor 203 shown in FIG. 4 cannot be used when high output is required. The usable ambient temperature depends on the specifications of the motor and cannot be used in a high-temperature atmosphere.

[0007]

SUMMARY OF THE INVENTION Accordingly, in view of the above circumstances, the present invention has been made to reduce the size of a pump in a cylinder position control and to be able to be used even in a high-temperature atmosphere without consuming oil as much as possible after position determination. The only utilities that the customer needs to provide are the air source and the power supply, which are easier to handle than the hydraulic source. The cylinder and the cylinder are used to obtain high output and eliminate the need for expensive switching means. A driving source, switching means for switching the direction of movement of the piston of the cylinder, a feedback sensor for detecting a rod position of the cylinder and generating a feedback signal, and a controller for receiving a feedback signal and generating a control signal for controlling the switching means. Cylinder position control device,
A cylinder position control device is characterized in that the drive source of the cylinder is a pneumatically driven hydraulic pump and the switching means is an electromagnetic valve.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to specific embodiments shown in FIGS. The present invention relates to a cylinder 1, a driving source of the cylinder 1,
Switching means for switching the moving direction of the piston 2 of the cylinder 1; a feedback sensor 5 for detecting the position of the rod 3 of the cylinder 1 and generating a feedback signal 4; and a control signal 6 for receiving the feedback signal 4 and controlling the switching means.
In the cylinder position control device composed of the controller 7 that generates the pressure, the driving source of the cylinder 1 is constituted by a pneumatically driven hydraulic pump 11 and the switching means is constituted by an electromagnetic valve 12.

FIG. 1 shows a circuit diagram of the present invention. Sup. 1
The air pressure supplied from 3 is reduced to a predetermined constant pressure by a pressure reducing valve 14 as necessary. The pneumatically driven hydraulic pump 11 generates hydraulic pressure by the air pressure. The pneumatically driven hydraulic pump 11 is a pump that generates a predetermined hydraulic pressure due to a difference in the area of the working piston, and has a mechanism that stops operation when the predetermined hydraulic pressure is generated.

For example, in the state where the rod 3 of the cylinder 1 is completely retracted, when a command signal from the rod 3 corresponding to a certain stroke is input, a solenoid valve 12 for operating the cylinder 1 (shown in FIG. MV2 and MV4 of the two-way valve are opened, and the rod 2 of the cylinder 1 comes out. The stroke is fed back to the controller 7 by the feedback sensor 5. When a predetermined stroke (within the allowable value set by the controller 7) is reached,
MV2 and MV4 are closed.

If the stroke at the time when the cylinder 1 stops is within the allowable range, the hydraulic pressure is sealed in the cylinder 1, and the pneumatically driven hydraulic pump 11 also stops with the predetermined hydraulic pressure generated. If the stroke at the time when the cylinder 1 stops exceeds the allowable value, the MV1 and MV3 of the solenoid valve 12 for operating the cylinder 1 are opened (if the stroke is excessive) or the MV2 and MV4 are opened (the stroke is Is repeated until the stroke is determined to a predetermined allowable value.

Reference numeral 15 denotes a tank. Next, FIG. 2 shows a flowchart of the present invention. First, the set value St of the rod 3 is read by the controller 7. Next, the stroke S of the rod 3 is read. The stroke set value St and the stroke S are compared.

When the stroke set value St> stroke S, the out solenoid valve MV2 of the rod 3 is turned on, that is, electricity is supplied to the solenoid of the solenoid valve MV2, and the in solenoid valve MV4 of the rod 3 is turned on, ie, , Solenoid valve MV
4 to energize the solenoid. MV2 and MV4 are turned on, MV1 and MV3 are turned off, and the rod 3 comes out.

On the other hand, when the stroke set value St <stroke S, the out solenoid valve MV2 of the rod 3 is turned off.
F, that is, the electricity to the solenoid of the solenoid valve MV2 is cut off, and the in-use solenoid valve MV4 of the rod 3 is turned off, that is, the solenoid electricity of the solenoid valve MV4 is cut off. MV2
And MV4 are OFF, MV1 and MV3 are ON, and the rod 3 enters.

When the stroke set value St = stroke S, the out solenoid valve MV2 of the rod 3 is turned off, that is, the electricity to the solenoids of the solenoid valves MV2 and MV4 is cut off, and the in solenoid valve MV1 of the rod 3 is shut off. MV3 is OF
F, that is, shut off the electricity to the solenoids of the solenoid valves MV1 and MV3. MV2, MV4 and MV1, MV3
Both are turned off, and the rod 3 stops.

In this embodiment, an example in which four two-way valves are used as the electromagnetic valves has been described, but the present invention is not limited to this. One or two solenoid valves, a large solenoid valve, or a small solenoid valve may be used.

[0017]

According to the present invention, as described above, a cylinder,
A drive source for the cylinder, switching means for switching the direction of movement of the piston of the cylinder, a feedback sensor for detecting a rod position of the cylinder and issuing a feedback signal, and a controller for receiving a feedback signal and issuing a control signal for controlling the switching means. In the cylinder position control device, the cylinder drive source is a pneumatically driven hydraulic pump and the switching means is an electromagnetic valve. It is possible.

The present invention can be used in a high-temperature atmosphere by using a pneumatically driven hydraulic pump as a drive source without using a servomotor. Furthermore, the present invention is inexpensive by using a pneumatically driven hydraulic pump as the driving source of the cylinder and an electromagnetic valve as the switching means. Furthermore, the present invention can provide a position control device with high stopping accuracy even if an inexpensive pneumatically driven hydraulic pump or solenoid valve is used.

Further, according to the present invention, it is possible to provide a position control device with low utility consumption.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a cylinder position control device of the present invention.

FIG. 2 is a flowchart of the cylinder position control device of the present invention.

FIG. 3 is a circuit diagram of a conventional cylinder position control device.

FIG. 4 is a schematic view of another conventional cylinder position control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cylinder 2 ... Piston 3 ... Rod 4 ... Feedback signal 5 ... Feedback sensor 6 ... Control signal 7 ... Controller 11 ... Pneumatic drive hydraulic pump 12 ... Solenoid valve 13 ... Sup. 14 ... pressure reducing valve 15 ... tank

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masashi Mizutani 4-97, Ueda-Higashi-cho, Nishinomiya-shi, Hyogo Konan Electric F-term (reference) 3H001 AA01 AB01 AC03 AD04 AE11 AE23 5H303 BB01 BB06 BB11 DD08 MM02

Claims (1)

[Claims] 1. A cylinder, a driving source for the cylinder, a switching means for switching a moving direction of a piston of the cylinder, a feedback sensor for detecting a rod position of the cylinder and generating a feedback signal, and the switching means for receiving the feedback signal. A cylinder position control device comprising a controller for issuing a control signal for controlling, wherein a driving source of the cylinder is constituted by a pneumatically driven hydraulic pump and a switching means is constituted by an electromagnetic valve.