JPH08303631A - Cylinder type valve actuator - Google Patents

Abstract

PURPOSE: To provide an economical cylinder type valve actuator without requiring a large space for arrangement by providing compact accessories of a hydraulic system. CONSTITUTION: A partition wall 6 is arranged inside a casing 5 of a motion converting mechanism 4 which convertes reciprocating motion of a piston rod 6 into rotational motion of an output shaft 3. An oil tank 7 is arranged separately from the motion converting mechanism 4. A filter 8 is arranged between two chambers 7a and 7b of the oil tank 7. A pump 10 for drive oil is arranged inside the oil tank 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic cylinder type valve actuator having a compact hydraulic system.

[0002]

2. Description of the Related Art FIG. 2 is a partial cross-sectional view showing an example of a motion converting device for a conventional scatch-yoke type cylinder valve actuator, in which 21 is an actuator, 22 is a reciprocating motion of a piston rod 23, and an output shaft 24. Is a motion converting mechanism for converting into a rotary motion, and 25 is a cylinder. The pinton rod 23 reciprocates by the action of the cylinder 25, and the pin 26 fixed to the piston rod 23 is fixed to the output shaft 24 by the key 27. The reciprocating motion of the piston rod 23, which is inserted into the slide groove 28a of the scatch yoke 28, is converted into the rotational motion of the output shaft 24 by swinging the scatch yoke 28.

As such a motion converting mechanism, a rack gear is formed on a piston rod, a pinion gear is fixed to an output shaft, and these gears are engaged with each other to convert the reciprocating motion of the piston rod into a rotary motion of the output shaft. Devices designed to do so are also widely used. In both the scatch yoke type and the rack and pinion type described above, the case 29 of the motion converting mechanism has a substantially fan-shaped cross section.

FIG. 3 is a piping diagram showing an example of a hydraulic system when a hydraulic cylinder type actuator is used. This system shows that when the gas pressure in the gas pipeline is excessively lowered due to some abnormality, This hydraulic cylinder type actuator is operated to close the shutoff valve to shut off the flow of the gas pipeline. In FIG. 3, 31 is a gas pipeline, 32 is a shutoff valve,
Reference numeral 33 is a hydraulic cylinder type actuator mounted on the shutoff valve 32.

The pressure in the gas pipeline 31 is transmitted to the pressure sensor 35 through the branch pipe 34, and the gas pipeline 3
When the pressure of 1 is excessively reduced, the electric wire 3 shown by the broken line
The solenoid valve 37 is brought into the state as shown in the figure by the current flowing through the solenoid 6.

Reference numeral 38 is a gas / oil type pressure booster, and the pressure of the gas pipeline 31 or the pressure of a separately installed nitrogen cylinder or the like is applied from the pipe 39 to the gas chamber 38a of the pressure booster 38 to change the hydraulic pressure of the oil chamber 38b. Then, the drive oil is moved upward, and this drive oil is applied to the valve closing pressurizing side 4 of the cylinder 40 of the actuator 33.
0a to close the shutoff valve 32. FIG. 3 shows a state immediately before the valve closing operation starts.

The driving oil in the valve-opening pressurizing side 40b of the cylinder 40 is pushed out by the piston 41 moving leftward in FIG. 3, and sent to the oil tank 42.

After the cause of the excessive decrease in the gas pressure of the gas pipeline 31 is investigated and countermeasures are taken, the shutoff valve 3
2 is opened, the solenoid valve 43 is switched to change the pressure booster 3
8, the pipe 44 from the oil chamber 38b is closed, and the solenoid valve 37
Is switched from the state shown in the figure, and the drive oil in the oil tank 42 is moved to the cylinder 40 by using the manual pump 45 or the electric pump 46.
The pressure is applied to the valve opening pressurizing side 40b. When the shutoff valve 32 is completely opened, the solenoid valve 43 is returned to the state shown in the figure.

[0009]

FIG. 3 shows an example of a hydraulic system in which a hydraulic cylinder type actuator is used as described above. In addition to this, driving oil boosted by a hydraulic pump without using a pressure booster. Various systems are used depending on the application, such as directly feeding the oil to the cylinder or using a pressure accumulator. Normally, however, an oil tank such as the oil tank 42 in FIG. A complicated piping system is formed in the room, which requires a large installation space.

As described above, in the case of using the hydraulic cylinder type actuator, a complicated hydraulic system is required, a large number of auxiliary devices and complicated piping for connecting them are required, and a large space is required for these. There is a problem in that the oil tank requires a large space, especially the oil tank. The present invention was developed to solve the above problems, and an object thereof is to make a hydraulic system compact and reduce the system cost.

[0011]

In order to solve the above object, the present invention provides a motion converting mechanism for converting reciprocating motion of a piston rod into rotary motion of an output shaft in a casing, and a part of the casing. Alternatively, a configuration is adopted in which the whole is an oil tank for driving the cylinder.

In this case, a partition is provided in the casing to provide an oil tank separated from the motion conversion mechanism, or a partition is provided in the casing to form an oil tank. A structure in which they communicate with each other is preferable. In addition, a cylinder drive oil pump is stored in the oil tank, or a filter is provided between the two oil tanks, and the oil tank is equipped with accessories such as a pressure gauge, oil level gauge, and relief valve. It is better to install it directly.

[0013]

The function of the cylinder type valve actuator of the present invention is as follows.
Part or all of the casing of the motion conversion mechanism that converts the reciprocating motion of the piston rod into the rotary motion of the output shaft,
Since it is also used as an oil tank for the cylinder drive oil, there is no need to provide a separate oil tank and no extra space is required. In particular, the motion conversion mechanism of the scatch-yoke type or rack and pinion type cylinder valve actuator has a fan-shaped cross section, so make the shape too large by making it almost square or round. Instead, it can serve as an oil tank reasonably.

In this case, if a partition wall is provided in the casing and separated from the piston rod and scatch yoke or the rack and pinion motion conversion mechanism, an independent oil tank is formed, but the oil tank moves without the partition wall. There may be a conversion mechanism. Further, if the partition wall is provided with a communication hole, it is also possible to similarly configure the motion conversion mechanism to exist in the oil tank.

Since the scatch-yoke type and rack-and-pinion type cylinder valve actuators have a substantially fan-shaped cross section, it is easy to provide two oil tanks on both sides of the fan-shaped actuator. It is easy to provide a filter between them, and in this case, it is not necessary to provide a filter separately.

Further, it is easy to directly install accessories such as a pressure gauge, an oil level gauge and a relief valve in an oil tank also provided as a casing. Particularly, when a cylinder driving pump is directly installed, It can be omitted and contributes to further compactness.

The motion conversion mechanism of this valve actuator is naturally equipped with a cylinder, and an oil tank is attached to this cylinder, which is integrated with a relatively large accessory of the hydraulic system. By arranging the parts around this, the hydraulic system can be made compact and the cost can be reduced.

[0018]

Embodiments of the cylinder type valve actuator according to the present invention will be described below in detail with reference to the drawings. FIG.
FIG. 1 is a partial cross-sectional view showing an embodiment of a cylinder type valve actuator, in which 1 is an actuator body, 2 is a reciprocating piston rod provided in the actuator body 1, and 3 is a ball valve. Alternatively, it is an output shaft that is connected to the stem of a valve body (not shown) of a valve such as a butterfly valve, and the output shaft 3 is a shaft that converts the reciprocating motion of the piston rod 2 and rotates. Reference numeral 4 denotes a motion converting mechanism for converting reciprocating motion into rotary motion. In this example, a scatch yoke type is used, but the present invention is not limited to this, and a rack and pinion type or other method may be used.

Reference numeral 5 is a casing for accommodating the motion converting mechanism 4, 6 is a partition wall, and one or both of the fan-shaped corners accommodating the motion converting mechanism 4 has an oil tank 7 for casing 5.
It is integrated with. The oil tank 7 is provided with two chambers 7a and 7b as in this example, and a filter 8 is interposed between the two chambers. As shown by a chain line in FIG. 1, a partition wall 6 may be provided in the casing 5 and a communication hole 6a may be provided in the partition wall 6 to communicate with the inside of the casing 5. In the figure, 9 is a cylinder, 10 is a pump for cylinder drive oil, 11 is a pin, 12 is a scatch yoke, and 13 is a key.

A partition wall 6 is provided in the casing 5 of the motion converting mechanism 4 for converting the reciprocating motion of the piston rod 2 to which the piston (not shown) of the cylinder 9 is fixed to the rotary motion of the output shaft 3 to convert the motion. An oil tank 7 is provided separately from the mechanism 4, and the oil tank 7 is composed of two chambers 7a and 7b. A filter 8 is mounted between the two chambers 7a and 7b, and a cylinder driving oil pump 10 is provided. Oil tank 7 (7b
Side).

In the motion converting mechanism 4 in the embodiment shown in FIG. 1, the pin 11 fixed to the piston rod 2 is inserted into the slide groove 12a of the scatch yoke 12 fixed to the output shaft 3 using the key 13. The reciprocating motion of the piston rod 2 causes the scatch yoke 12 to oscillate and the output shaft 3
It is converted into the rotational movement of.

As described above, in the actuator body 1 of the cylinder type valve, since a part of the casing 5 of the motion converting mechanism 4 is also used as the oil tank 7 for the cylinder driving oil, it is not necessary to provide a separate oil tank. , Can be configured compactly.

In particular, in the scatch-yoke type actuator body 1, since the motion converting mechanism 4 has a substantially fan-shaped cross section, its outer shape is made too large by making it substantially rectangular as shown in the drawing. Without the need for the oil tank 7. Furthermore, two chambers 7a and 7b are easily provided on both sides of the fan shape.
It is easy to provide a filter between 7b, and it is not necessary to provide a separate filter in this way.

Further, when the pump 10 for driving oil is housed in the casing 5, the piping is partially omitted, which is very useful for making the hydraulic system compact. Further, since the motion converting mechanism 4 of the actuator body 1 is provided with the cylinder 9 and the oil tank 7 is provided side by side with this, by arranging other related accessories around this, the entire hydraulic system is provided. It can be made compact and cost can be reduced.

Further, in addition to the above-mentioned embodiment, the conventional FIG.
A structure similar to that shown in FIG. 3 is provided, and a motion converting mechanism 4 for converting the reciprocating motion of the piston rod 2 into the rotary motion of the output shaft 3 is provided in the casing 5, and all of the inside of the casing 5 having the motion converting mechanism 4 incorporated therein. Even if it is configured to be an oil tank for driving a cylinder, the same operational effects as those of the above example are exhibited.

[0026]

As described above, according to the cylinder type valve actuator of the present invention, by providing the oil tank in the casing of the motion converting mechanism, the hydraulic system can be formed compactly and a wide space is required for installation. An economical actuator can be provided without the need.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an embodiment of a cylinder type valve actuator of the present invention.

FIG. 2 is a partial cross-sectional view showing an example of a conventional scatch-yoke type cylinder valve actuator.

FIG. 3 is a piping diagram showing an example of a hydraulic system when a hydraulic cylinder type actuator is used.

[Explanation of symbols]

 1 Actuator Main Body 2 Piston Rod 3 Output Shaft 4 Motion Conversion Mechanism 5 Casing 6 Partition 6a Communication Hole 7 Oil Tank 8 Filter 10 Pump

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sadayuki Nakanishi Kits Osaka Branch 1-32-11 Shinmachi, Nishi-ku, Osaka-shi, Osaka (72) Inventor Yoshiharu Sato Nagasaka-cho, Kitakoma-gun, Yamanashi 2040 Kamakajojo Kitz Nagasaka Plant (72) Inventor Akio Fukunaga 2040 Nagasaka, Nagasaka-cho, Kitakoma-gun, Yamanashi Kitz Nagasaka Plant

Claims (5)

[Claims] 1. A motion conversion mechanism for converting reciprocating motion of a piston rod into rotational motion of an output shaft is provided in a casing.
A cylinder type valve actuator, wherein a part or all of this casing is an oil tank for driving a cylinder. 2. The cylinder type valve actuator according to claim 1, wherein a partition is provided in the casing, and an oil tank is provided separately from the motion converting mechanism. 3. The cylinder type valve actuator according to claim 1, wherein a partition wall is provided in the casing to form an oil tank, and a communication hole is provided in the partition wall to communicate the inside of the casing. 4. The cylinder type valve actuator according to claim 1, wherein the cylinder driving oil pump is housed in an oil tank. 5. The cylinder type valve actuator according to claim 1, wherein the oil tank has two chambers and a filter is provided between the two chambers.