JP3502562B2 - Fluid pressure control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pressure control device for controlling pressure by remote control.

[0002]

2. Description of the Related Art A fluid pressure control device (Japanese Patent Laid-Open No. 7-191759) for remotely controlling output pressure using a stepping motor is known. In this conventional fluid pressure control device, a valve body / valve seat that opens and closes a passage that connects an inlet port and an outlet port is arranged, and a feedback chamber and a pilot chamber are partitioned by the first piston, and A second piston biased by a disc spring is arranged at the end. The rotation of the rotating shaft of the stepping motor is
The linear motion of the valve rod is converted by the second coupling, and the valve rod operates the valve to control the inflow to the pilot chamber and the outflow from the feedback chamber.

[0003]

In the conventional fluid pressure control device, there are some components remaining in the case of the handle operation type fluid pressure control device, and the structure is complicated even though the bending stepping motor is used. In the fluid pressure control device of the present invention, the conventional feedback chamber, pilot chamber and piston (diaphragm) are removed, the secondary pressure can be detected by the pressure sensor, and the air supply valve and the exhaust valve are directly controlled by the output of the motor. The challenge is to control.

[0004]

According to the present invention, an air supply valve is provided in a passage that connects an inlet port and an outlet port of a fluid pressure control device body, and a motor is provided at one end of the fluid pressure control device body. The exhaust valve is disposed between the motor and the air supply valve, the rotational movement of the output shaft of the motor is converted into the linear movement of the shaft, and the exhaust valve and the air supply valve are controlled by the output shaft of the motor. In the fluid pressure control device, the abutment portion of the exhaust valve is formed at the tip of the shaft, the stem is connected to the valve body of the air supply valve, and the opening at the tip of the stem and the secondary pressure chamber are formed by the communication passage in the stem. The first configuration is that the exhaust valve is formed by the tip end of the stem and the abutting portion of the shaft end, and the feedback passage that connects the secondary pressure chamber and the pressure sensor is formed. The present invention provides, in a first configuration,
A second configuration is that a feedback port is formed in the fluid pressure control device main body and the feedback passage is connected to the feedback port. According to the present invention, in the first configuration, the pressure sensor is provided in the fluid pressure control device body,
The third configuration is that the feedback passage is communicated with the detection portion of the pressure sensor. In the first to third configurations of the present invention, the coupling member is fixed to the output shaft of the motor, the male screw portion or the female screw portion of the shaft is screwed to the female screw portion or the male screw portion of the coupling member, and the fluid pressure control device main body is provided. The rotation preventing guide is disposed in the shaft, and the rotation of the shaft is prevented by the rotation preventing guide. In the first to fourth configurations of the present invention, the motor is a stepping motor, and the position where the shaft is retracted by a predetermined minute distance from the position where the tip of the stem is in contact with the contact portion of the shaft is the origin. None, the fifth configuration is to control the shaft so as not to move beyond the set distance from the origin and to control the pressure in the secondary pressure chamber so as to follow the target value given through the stepping motor. In the first to fourth configurations of the present invention, the motor is a DC motor or an AC motor,
A sixth configuration is such that the pressure in the secondary pressure chamber is controlled so as to follow a target value given through the motor, and the motor is rotated in the reverse direction when the motor drive current exceeds a predetermined limiter current.

[0005]

1 to 6 show a first embodiment of a fluid pressure control device according to the present invention. As shown in FIG. 1, the fluid pressure control device main body 10 includes a bonnet at both ends of the valve body 11.
It is formed by arranging 12 and the cover 13 and connecting them. A central screw hole 17 is formed on the lower end side (the other end side) of the valve body 11, and a male screw of a cover 13 is screwed into the central screw hole 17, and a space between the valve body 11 and the cover 13 is sealed by an O ring. Has been done. A bottomed guide hole 18 is formed in the central portion on the upper side (inside) of the cover 13, and the valve body 20 of the air supply valve 19 is slidably inserted into the guide hole 18 from the inside. It is sealed with an O-ring between 18 and.

The valve body 11 has an inlet port 23 and an outlet port.
24 is formed, and the air supply valve 19 is disposed in a passage that connects the inlet port 23 and the outlet port 24. The inlet port 23 is communicated with the primary pressure chamber 25, and the outlet port 24 is communicated with the secondary pressure chamber 26, and the annular valve seat of the air supply valve 19 is provided between the primary pressure chamber 25 and the secondary pressure chamber 26. 21 are provided. The valve body 20 has a substantially inverted cup shape, and an annular seal 22 is provided on the outer peripheral portion of the upper surface of the valve body 20.
Is attached, and the annular seal 22 is
Is urged toward the valve seat 21. There is a recess on the bonnet 12 side of the valve body 11, and this recess and the end surface of the bonnet 12 form a recess chamber 30, and the recess chamber 30 and the secondary pressure chamber 26
A partition wall 29 is formed between the partition wall and the side.

As shown in FIGS. 1 and 3, a large diameter portion 31A and a medium diameter portion are formed in the partition wall 29 at a position between the secondary pressure chamber 26 and the recess chamber 30.
An insertion hole 31 composed of 31B and a small diameter portion 31C is formed, and the stem 33 is inserted into the insertion hole 31. The O-ring 32 attached to the medium diameter portion 31B seals between the stem 33 and the insertion hole 31, and the retaining metal fitting 34 attached to the large diameter portion 31A prevents the O-ring 32 from coming out. The base end (lower end) of the stem 33 is fitted into the fitting hole in the upper portion of the valve body 20, and the fitting portion is not sealed. A communication passage 37 is formed in the stem 33, and the communication passage 37 communicates the opening at the tip (upper end) of the stem 33 with the opening on the side surface of the stem 33, and the opening on the side surface of the stem 33 faces the secondary pressure chamber 26. is doing.

The bonnet 12 has a large diameter portion 39A and a medium diameter portion 39B.
And a stepped through hole 39 having a small diameter portion 39C is formed, and the opening of the small diameter portion 39C faces the recess chamber 30. A motor 14 is disposed on the upper end (one end) of the fluid pressure control device body 10, and the motor 14 is mounted on a plate 15 by bolts 60.
The plate 15 is arranged at one end of the bonnet 12 and is fixed to the bonnet 12 by bolts 61. The head of the bolt 60 is located inside the large diameter portion 39A, and the output shaft 41 of the motor 14 passes through the opening 40 of the plate 15 and protrudes inside the large diameter portion 39A and the middle diameter portion 39B. A connecting member 42 is arranged inside the large-diameter portion 39A and the medium-diameter portion 39B at a predetermined interval, and one portion (upper portion) of the connecting member 42 is attached to the output shaft 41 of the motor 14 and fixed by screws. Has been done.

A female screw portion 43 having an opening at the other end is formed in the lower portion (the other portion) of the connecting member 42, and a male screw portion 45 at the base end portion of the shaft 44 is screwed into the female screw portion 43, and the tip of the shaft 44 is screwed. The section has a hexagonal cross section to prevent galling. A male screw is formed on the connecting member 42, and the shaft 44
A female screw portion may be formed on the connecting member 42 and the shaft 44 so as to be screwed together. A rotation stopping guide 47 is disposed in the vicinity of the opening of the small diameter portion 39C of the insertion hole 39, and the hexagonal cross section of the tip end portion of the shaft 44 slides on the inner peripheral surface of the rotation stopping guide 47.
The rotation of the shaft 44 is prevented. Therefore, the connecting member
The rotation motion of the output shaft 41 of the motor 14 is converted into the linear motion (vertical motion) of the shaft 44 by the shaft 42 and the shaft 44. When viewed from the direction of the output shaft 41 of the motor 14, the motor 14 is rotated clockwise.
When the shaft 14 rotates, the shaft 44 linearly moves in the extension (down) direction, and when the motor 14 is rotated in the reverse direction, the shaft 44 linearly moves in the backward (up) direction.

A truncated frustoconical contact portion 46 is formed at the center of the tip of the shaft 44, and an exhaust valve 48 is formed by the contact portion 46 of the shaft 44 and the tip of the stem 33. Exhaust valve 48
The air exhausted therethrough passes through the exhaust holes 36 formed in the valve body 11 and is exhausted from the recess chamber 30 to the outside. Figure 1
When the shaft 44 is extended in the
The contact portion 46 of 44 contacts the tip of the stem 33 to close the exhaust valve 48. When the shaft 44 extends further, the stem 33 descends,
The valve body 20 is lowered against the elastic force of the spring 27, the air supply valve 19 is opened, and compressed air flows from the primary pressure chamber 25 to the secondary pressure chamber 26. When the shaft 44 is retracted, the stem 33 springs.
Energized by 27 and rising, closing the intake valve 19 and then the exhaust valve
48 is opened, and the air in the secondary pressure chamber 26 allows the communication passage 37 in the stem 33,
It is discharged through the recessed chamber 30 and the exhaust hole 36.

A lower fitting hole 50 opening to the recessed chamber 30 is formed in the partition wall 29 at a position adjacent to the insertion hole 31.
50 is communicated with the secondary pressure chamber 26 via the small diameter hole 55. An upper fitting hole 51 is formed at the lower end of the bonnet 12 at a position facing the lower fitting hole 50, and the upper fitting hole 51 is opened in the recess chamber 30. The lower end and the upper end of the communication member 52 are fitted into the lower fitting hole 50 and the upper fitting hole 51, respectively, and the inner surface of the lower fitting hole 50 and the upper fitting hole 51 and the outer surface of the communication member 52 are connected to each other. The space is sealed by an O-ring. The bonnet 12 is formed with a feedback port 54 opening on its side surface, and the feedback port 54 has an upper fitting hole 51 through a communication passage 53.
Of the communication member 52, and further communicates with the secondary pressure chamber 26 through the internal passage of the communication member 52 and the small diameter hole 55.

FIG. 2 shows a system using the fluid pressure control device body 10 of the present invention. The fluid pressure control device body 10 is equipped with a stepping motor 66. Compressed air from the air pressure source 57 flows into the inlet port 23 and output air is discharged from the outlet port 24. Secondary pressure is feedback port
The pressure sensor 63 is transmitted from 54 to the pressure sensor 63 through piping, and the output of the pressure sensor 63 is transmitted to the controller 64 through wiring. Target pressure and pressure sensor by controller 64
The pressure of the feedback value from 63 is compared, and the pressure difference is transmitted to the driver 65 as a pulse signal. The driver 65 converts the pulse signal into signals for the four conductors of red, yellow, blue, and white in FIG. 4B, and the signals are transmitted from the driver 65 to the stepping motor 66 through these conductors. The relationship between the terminals of the stepping motor 66 and the conductors and the relationship between the input signal and the steps are as shown in FIGS. 4 (a) and 4 (b).

FIG. 5 shows a first modification of the embodiment of the fluid pressure control device of the present invention. In the modification of FIG. 5, in FIG.
The same components as those of the above are denoted by the same reference numerals as those in FIG. 1, and the description of the common parts will be omitted. In FIG. 5, a storage chamber 68 for the pressure sensor 63 is formed at the position of the feedback port 54 in FIGS. 1 and 2, and a cover 69 is arranged at the opening of the storage chamber 68.
A mounting hole 70 that connects the lower end of the storage chamber 68 and the upper end of the upper fitting hole 51 is formed, and the tubular portion (pressure detection unit) 63A of the pressure sensor 63 is inserted from the storage chamber 68 into the mounting hole 70. There is. The inner surface of the mounting hole 70 and the cylindrical portion 63A are sealed by an O-ring, and the output of the pressure sensor 63 is a wiring that penetrates the cover 69.
Transmitted by 71. Other configurations in FIG. 5 are similar to those in FIG.

FIG. 6 is a flow chart showing the operation (function) of the system of FIG. 2, and the operation of the system will be described with reference to this flow chart. When a switch (not shown) is turned on, the operation of the system starts, and it is determined in step S1 whether or not the secondary pressure is output. When it is determined in step S1 that the secondary pressure is being output, in step S2 the shaft 44 is retracted to raise the stem 33, and the intake valve 19 is closed by a set distance, and then step S1 is performed. Return. When it is determined in step S1 that the secondary pressure is not output (secondary pressure is zero),
Go to step S3.

In step S3, it is again determined whether or not the secondary pressure is output. When it is determined that the secondary pressure is not output (secondary pressure is zero), the shaft 44 is advanced in step S4. Lower the stem 33 to release the air supply valve 19
Is moved by a set distance in the opening direction, and the process returns to step S3. When it is determined in step S3 that the secondary pressure is being output, in step S5 the origin position of the step motor 66 (a predetermined small distance from the position where the contact portion of the shaft 44 contacts the tip of the stem 33 (eg, 0.1 mm) present position) is set. Next, in step S6, the allowable pressure is set, and in step S7, the limiter position in the stem descending direction and the stem ascending direction is set. By setting the limiter position, the distance that can be moved from the origin position to the stem descending direction and the stem ascending direction is determined, and unless the limiter position is exceeded, the shaft 44 and the connecting member 42 mechanically collide with the inside of the bonnet 12 and cannot operate. It is possible to prevent occurrence of trouble (step-out) peculiar to the stepping motor.

The target pressure (target value) input to the controller is read in step S8, and the secondary pressure transmitted from the pressure sensor 63 is read in step S9. Step S
At 10, it is determined whether the pressure difference between the target pressure and the secondary pressure is within the allowable pressure range. If it is determined that the pressure difference is within the allowable pressure range, the process returns to step S8. When it is determined in step S10 that the pressure difference is not within the allowable pressure range, it is determined in step S11 whether [target pressure-secondary pressure] <0, and [target pressure-secondary pressure] < If it is determined to be 0, the drive angle and the rotation direction of the motor 66 (the rising direction of the stem) in order to reduce the secondary pressure in step S15.
Is calculated and the calculation result is stored in the memory A of the controller.

In step S16, when the motor is driven according to the motor driving calculation value stored in the memory A, whether the position (current position + movement distance) after a predetermined short time exceeds the limiter position in the stem rising direction. The decision is made. If it is determined in step S16 that the limiter position is not exceeded, the motor is driven in accordance with the motor drive calculation value stored in the memory A in step S18, and step S18 is performed.
8 (returning from step S18 to step S8 is the same below). If it is determined in step S16 that the limiter position is exceeded, the limiter position is written in the memory A in step S17, and the calculated value stored in the memory A is erased in step S15 (the calculated value in the memory A is the limiter position information). In step S18, step S18
The motor is driven according to the limiter position data written in the memory A at 17.

In step S11, [target pressure-secondary pressure]
When it is determined that it is not <0, the drive angle and the rotation direction of the motor 66 (the descending direction of the stem) are calculated in order to increase the secondary pressure in step S12, and the calculation result is stored in the memory A of the controller. To do. In step S13,
When the motor is driven according to the motor drive calculation value stored in the memory A, the position (current position + current position +
It is determined whether or not the moving distance) exceeds the limiter position in the stem descending direction. When it is determined in step S13 that the limiter position is not exceeded, the motor is driven according to the motor drive calculation value stored in the memory A in step S18. If it is determined in step S13 that the limiter position is exceeded, the limiter position is written (rewritten) in memory A in step S14, and in step S18 the motor is driven according to the limiter position data written in memory A in step S14. To do.

In FIG. 6, a stepping motor is used as a motor for cost reduction, and a position detecting sensor for detecting the positions of the shaft 44 and the connecting member 42 is not provided. Therefore, the position of the motor and the limiter are detected by calculation. However, it goes without saying that similar driving can be performed using a position detection sensor.

FIG. 7 shows a second flowchart of the embodiment of the fluid pressure control system of the invention. The second embodiment uses a DC motor or an AC motor as a motor, and the configuration of the second fluid pressure control device body of the second embodiment is the same as that of the first fluid pressure control device body 10 of the first embodiment. Therefore, the other description of the configuration is omitted.

The operation of the second embodiment system will be described with reference to the flowchart of FIG. When the switch (not shown) is turned on, the operation of the system starts, the target pressure is read in step S1, and the pressure sensor is read in step S2.
Read the secondary pressure input from 63. In step S3, it is determined whether or not the pressure difference between the target pressure and the secondary pressure is within the allowable range. If it is determined that the pressure difference is within the allowable range, the process returns to step S1. When it is determined in step S3 that the pressure difference is not within the allowable range, it is determined in step S4 whether [target pressure-secondary pressure] <0 and [target pressure-secondary pressure] <0. If it is determined that the driving angle and the rotation direction of the motor (the rising direction of the stem) are calculated in step S8, the calculation result is stored in the memory A of the controller.

In step S9, it is judged whether or not the motor drive current is larger than the limiter current. If it is judged that the motor drive current is larger than the limiter current, the motor is rotated by a predetermined set angle in step S10. Then, the process returns to step S9. When it is determined in step S9 that the motor drive current is not larger than the limiter current, the process returns to step S1. Since the motor drive current is controlled in the second embodiment, the limiter value is set by the current, and when the motor drive current does not exceed the limiter current, an excessive rotational force is generated at the stroke end or the like. There is no such thing.

In step S4, [target pressure-secondary pressure] <
When it is determined that the value is not 0, the drive angle and the rotation direction of the motor (the downward direction of the stem) are calculated in order to increase the secondary pressure in step S5, and the calculation result is stored in the memory A of the controller. In step S6, it is determined whether or not the motor drive current is larger than the limiter current. If it is determined that the motor drive current is larger than the limiter current, the motor is reversed by a predetermined set angle in step S7, Return to step S6. When it is determined in step S6 that the motor drive current is not larger than the limiter current, the process returns to step S1.

[0024]

According to the fluid pressure control device of the present invention, the rotational movement of the motor is converted into the linear movement of the shaft, the abutment portion of the exhaust valve is formed at the tip of the shaft, and the stem of the valve body of the intake valve is formed. The opening at the tip of the stem and the secondary pressure chamber communicate with each other through the communication passage in the stem, and the exhaust valve is formed by the contact portion between the tip of the stem and the tip of the shaft, and the secondary pressure chamber and the pressure sensor. A feedback passage is formed to communicate with and. By doing so, the feedback chamber, pilot chamber and piston (diaphragm) of the conventional example
The secondary pressure can be detected by the pressure sensor, and the intake valve and the exhaust valve can be directly controlled by the output of the motor. Therefore, the structure is simple, the cost can be reduced, and the structure is simple, so that the efficiency is high. In the present invention, the motor is a stepping motor, and the position where the shaft is retracted by a predetermined minute distance from the position where the tip of the stem is in contact with the contact portion of the shaft is the origin, and the shaft is the set distance from the origin. Since the control is performed so as not to move beyond, the position detection sensor is not necessary, and the stepping motor is less expensive than the DC motor or the like, so that the cost of the fluid pressure control device can be further reduced.

[Brief description of drawings]

FIG. 1 (a) is a first longitudinal sectional view of a first embodiment of a fluid pressure control device of the present invention, and FIG. 1 (b) is a plan view of FIG. 1 (a).

FIG. 2 is a system diagram using the first embodiment of the present invention.

FIG. 3 is an enlarged view of a portion A of FIG.

FIG. 4 (a) is a diagram showing connection of a stepping motor, and FIG. 4 (b) is a diagram showing a relationship between an input signal of the stepping motor and rotation.

FIG. 5 is a vertical cross-sectional view of a first modified example of the embodiment of the fluid pressure control device of the present invention.

FIG. 6 is a flowchart of a first system according to an embodiment of the present invention.

FIG. 7 is a flowchart of a second system according to the embodiment of the present invention.

[Explanation of symbols]

10 Fluid pressure controller body 14 motor 19 Air supply valve 23 entrance port 24 exit port 26 Secondary pressure chamber 33 stems 37 passage 41 Output shaft 42 Connecting member 44 shaft 46 abutment 47 Non-rotating guide 48 exhaust valve 54 Feedback Port 63 Pressure sensor 66 stepper motor

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuhiro Fujiwara, Kinawadai, Taniwahara-mura, Tsukuba-gun, Ibaraki 4-2-2 SMC Tsukuba Technology Center (72) Inventor Shigeru Komoritani Kinawadai, Taniwa-mura, Tsukuba-gun, Ibaraki 4 -2-2 SMC Corp. Tsukuba Technology Center (56) Reference JP-A-7-191759 (JP, A) JP-A-3-127210 (JP, A) Actual development Sho-48-89022 (JP, U ) Actual Kaihei 2-98280 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G05D 16/20

Claims (6)

(57) [Claims] 1. A supply valve is provided in a passage that connects an inlet port and an outlet port of a fluid pressure control device main body, and a motor is provided at one end of the fluid pressure control device main body. In the fluid pressure control device in which the exhaust valve is disposed at a position between the two, the rotational movement of the output shaft of the motor is converted into the linear movement of the shaft, and the exhaust valve and the air supply valve are controlled by the output shaft of the motor. The exhaust valve abutment portion is formed at the tip of the stem, the stem is connected to the valve body of the air supply valve, and the communication passage in the stem connects the opening at the tip of the stem and the secondary pressure chamber,
A fluid pressure control device, wherein an exhaust valve is formed by a tip portion of a stem and a contact portion of a tip of a shaft, and a feedback passage is formed to connect a secondary pressure chamber and a pressure sensor. 2. The fluid pressure control device according to claim 1, wherein a feedback port is formed in the fluid pressure control device body, and the feedback passage is connected to the feedback port. 3. The fluid pressure control device according to claim 1, wherein a pressure sensor is arranged in the fluid pressure control device main body, and the feedback passage communicates with a detection portion of the pressure sensor. 4. A connecting member is fixed to the output shaft of the motor,
The male screw part or the female screw part of the shaft is screwed to the female screw part or the male screw part of the connecting member, and the rotation preventing guide is arranged in the fluid pressure control device main body, and the shaft rotation is prevented by the rotation preventing guide. The fluid pressure control device according to claim 1. 5. The stepping motor is used as the motor, and the position where the shaft is retracted by a predetermined minute distance from the position where the tip of the stem is in contact with the contact part of the shaft is the origin, and the shaft is the set distance from the origin. 2. The pressure in the secondary pressure chamber is controlled so as not to move beyond the range and to follow the target value given through the stepping motor.
5. The fluid pressure control device as described in any one of 4 to 4. 6. The motor is a DC motor or an AC motor, the pressure of the secondary pressure chamber is controlled so as to follow a target value given through the motor, and when the motor drive current exceeds a predetermined limiter current, the motor is controlled. The fluid pressure control device according to claim 1, wherein the fluid pressure control device is configured to rotate in reverse.