JPH0718083U - Control valve - Google Patents

Abstract

(57) [Abstract] [Purpose] It is an object to pulsate the output air of the main valve and to speed up the off-response of the solenoid valve to operate the solenoid valve with high frequency to make the pilot pressure venous. . In a control valve, a first body, a second body, and a pilot valve body are connected, and communication between a supply port P, an output port A, and an exhaust port R of the first body is switched by a main valve valve body. The feedback pressure of the output port A acts only on one surface of the piston slidably arranged in the second body through the feedback passage, and the pilot pressure acts on the other surface of the piston.
The main valve body is operated by the output member of the piston. When the pilot pressure exceeds the feedback pressure, the supply port P and the output port A communicate with each other, and when the feedback pressure exceeds the pilot pressure, the output port A and the exhaust port R communicate with each other.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a control valve which is used in a circuit for operating an air actuator, an air brake, etc., and maintains the pressure of air flowing into the air actuator, air brake, etc. at a predetermined set pressure.

[0002]

[Prior art]

 The present applicant has previously filed an application for a device for an electric-pneumatic pressure regulator (Japanese Patent Application No. 3-111695). The electro-pneumatic regulator of the above application generates an air pressure proportional to an input electric signal. The solenoid of the 3-port solenoid valve is operated by the input electric signal and the output air pressure of the solenoid valve is controlled by the pressure sensor. Signal is input to the control circuit as a feedback signal. The output air pressure is sent to the pneumatic equipment, and its pressure changes.Therefore, the feedback signal changes according to the change, and the solenoid valve is changed from the control circuit by the magnitude of the electric signal of the pressure sensor and the input electric signal. An electric signal for turning on and off is transmitted, and the solenoid valve frequently turns on and off to set and maintain a desired pressure. Since this electro-pneumatic regulator has been made more compact, the output of the built-in solenoid valve is small, so it cannot be used to operate the air actuator, air brake, etc.

The invention of the present application operates the three-port main valve by the output of the electro-pneumatic regulator of the above-mentioned application so that the flow rate is a desired pressure suitable for operating an air actuator, an air brake, or the like. It is about trying to get air. In that case, the problem is that, firstly, the structure of the main valve does not separate the exhaust chamber and the feedback chamber, but in that case, the pressure at the output port A is discharged to the exhaust port R. When this occurs, dynamic pressure may act on the feedback chamber, causing pulsation in the output air of the main valve. Secondly, if the output of the solenoid valve is sent to the pressure sensor as it is as in the invention of the above-mentioned application, there is a possibility that the output of the solenoid valve may pulsate. Third, as in the invention of the above-mentioned application, the diode connected in parallel to the solenoid of the solenoid valve prevents a large negative voltage when the solenoid valve is turned off, and prevents the transistor etc. Although it does not damage, it has the drawback that the OFF response of the solenoid valve is slow. This electro-pneumatic regulator keeps the set pressure by repeating ON / OFF of the solenoid valve at high frequency.However, due to the delay in the OFF response, the ON / OFF switching frequency decreases and the output There is a drawback that the pulsation of air and the amount of bleed and noise from the exhaust port R increase.

[0004]

[Problems to be solved by the device]

 The present invention solves the above-mentioned drawbacks, in which pulsation does not occur in the output air of the main valve, and the OFF response of the solenoid valve is accelerated to operate the solenoid valve with high frequency to make the pilot pressure venous. This is an issue.

[0005]

[Means for Solving the Problems]

 According to the present invention, in order to achieve the above object, in a control valve, a first body, a second body, and a pilot valve body are connected, and a supply port P, an output port A, and an exhaust port R of the first body are connected. Communication is switched by the main valve valve body, and the feedback pressure of the output port A acts on only one surface of the piston slidably mounted on the second body through only the feedback passage, and the other surface of the piston. Pilot pressure acts on the piston, and the main valve element is operated by the output member of the piston. When the pilot pressure exceeds the feedback pressure, the supply port P and the output port A are communicated, and the feedback pressure is piloted. When the pressure is exceeded, the output port A and the exhaust port R are configured to communicate with each other. Further, in the control valve, the solenoid valve, the control circuit and the pressure sensor are provided in the pilot valve body, the pilot pressure is output from the output port A'of the solenoid valve, and the pilot pressure is throttled from the middle of the pilot passage. It is transmitted to the pressure sensor through the solenoid valve, the control circuit and the pressure sensor are arranged in the pilot valve body, and the varistor is connected in parallel with the solenoid coil of the solenoid valve.

[0006]

[Action]

 When the main valve body is operated by the output member of the piston and the pilot pressure exceeds the feedback pressure, the supply port P and the output port A are communicated, and the air is supplied from the supply port P through the output port A. To be done. When the feedback pressure exceeds the pilot pressure, the output port A and the exhaust port R are communicated with each other, and the air is discharged to the atmosphere through the output port A, the exhaust port R, and the like. In this way, the pressure at output port A is maintained at pilot pressure. The pilot pressure also passes through the throttle and is detected by the pressure sensor and fed back.

[0007]

【Example】

 FIG. 1 is a partial cross-sectional view showing the overall construction of the control valve of the first embodiment of the present invention. The second body 4 is placed on the upper surface of the first body 3 to become the main valve 1, and the pilot valve 2 with the pilot valve body 5 is placed on the upper surface of the second body 4, which are not shown in the drawings. -Fixed by nuts. In the bottom view of the first body 3, a stepped hole is formed vertically in the central part, the upper small diameter part of the stepped hole serves as the primary pressure chamber 6, and the lower large diameter part of the stepped hole is the first part. The lower surface of the body 3 is opened. The retainer 10 is fitted to the large diameter portion of the lower portion, and the retainer 10 is prevented from slipping out by the split pin. A disk-shaped portion is formed in the lower portion of the retainer 10, an annular seal is fitted in an annular groove on the outer periphery of the disk-shaped portion, and the lower large-diameter portion is sealed. A tubular portion 11 is formed on the upper portion of the retainer 10, and an annular seal is fitted in an annular groove on the outer periphery of the tubular portion 11 to provide a seal between the outer periphery of the tubular portion 11 and the inner periphery of the lower large diameter portion. To be done. An exhaust port R, a supply port P and an output port A are opened in order from one side of the first body 3 (right side in FIG. 1), and the other side (first side in FIG. 1) of the first body 3 is opened. The gauge port G and the external supply port 27 are opened sequentially from the bottom. An annular groove is formed on the outer periphery of the lower end of the tubular portion 11, a plurality of lateral holes are formed to connect the annular groove and the inside of the tubular portion 11, and the annular groove is connected to the exhaust port R.

A secondary pressure chamber 7 is formed above the primary pressure chamber 6 via a main passage 12, and the secondary pressure chamber 7 is communicated with the output port A via a passage 13. An exhaust chamber 8 is formed in the upper part of the secondary pressure chamber 7 through a central hole, and the upper wall surface of the exhaust chamber 8 is the lower surface of the second body 4. The exhaust chamber 8 is communicated with the secondary pressure chamber 7 and the output port A via a passage 13, and is communicated with the gauge port G via a passage 14. The hollow main valve valve body 9 is inserted into the primary pressure chamber 6 and the secondary pressure chamber 7, and the annular portion 15 at the upper part of the main valve valve body 9 is at the center between the secondary pressure chamber 7 and the exhaust chamber 8. It is slidably fitted in the hole. The outer periphery of the lower portion of the main valve body 9 is slidably fitted to the inner peripheral surface of the cylindrical portion 11 of the retainer 10, and an annular groove is formed on the outer periphery of the lower portion of the main valve body 9. Is fitted with an annular seal, and the annular seal seals between the inner peripheral surface of the cylindrical portion 11 and the outer periphery of the lower portion of the main valve body 9. A collar 16 is integrally formed on the outer periphery of the central portion of the main valve body 9 in the axial direction, and an annular valve seat 17 made of a flexible material is fixed to the upper surface of the collar 16. An annular groove is formed on the upper surface of the cylindrical portion 11 of the retainer 10, and a guide spring 18 is interposed between the annular groove and the lower surface of the collar 16. A valve seat 19 is formed at the lower end of the outer wall of the main passage 12, and when the annular valve seat 17 comes into contact with the valve seat 19, the communication between the primary pressure chamber 6 and the secondary pressure chamber 7 is cut off.

A cylinder chamber is formed in the center of the upper half of the second body 4, and the cylinder chamber is opened on the upper surface of the second body 4, and this opening is closed by the lower surface of the pilot valve body 5. The piston 20 is slidably fitted in the cylinder chamber, and an annular groove is formed on the outer peripheral surface of the piston 20, and an annular seal fitted in the annular groove separates the cylinder chamber wall from the outer peripheral surface of the piston 20. The space is sealed. A feedback chamber 22 is provided between the lower partition wall 23 of the second body 4 and the lower surface of the piston 20, and the lower surface of the pilot valve body 5 (including a central concave portion. Between the upper surface of the piston 20 and the upper surface of the piston 20. The piston rod 21 is slidably inserted into the central hole of the partition wall 23, and the upper end of the piston rod 21 is fitted into the central hole of the piston 20 and fixed by caulking or the like. The lower end of the piston rod 21 is inside the exhaust chamber 8, and a disc-shaped contact member 25 is integrally formed at the lower end of the piston rod 21, and the periphery of the contact member 25 is covered with an elastic sheet. In order to reduce the size of the second body 4 in the vertical direction, a recess having a diameter larger than that of the contact member 25 is formed in the center of the lower surface of the partition 23, and a protrusion is formed in the center of the upper surface of the partition 23. A recess having a diameter larger than that of the protrusion is formed in the center of the lower surface of the piston 20. A space between the piston rod 21 and the central hole of the partition wall 23 is sealed by an annular seal provided in a recess at the center of the partition wall 23. The feedback chamber 22 is in communication with the supply port A via a feedback passage 26, and the pilot chamber 24 is in communication with an output port A'of a solenoid valve 30 described later via a pilot passage 29.

As clearly shown in FIGS. 1 and 2, an electromagnetic valve 30, a control circuit (control device) 31, and a pressure sensor (static converter) 32 are arranged in the pilot valve 2. Air is supplied from the supply port P of the first body 3 to the supply port P ′ of the solenoid valve 30 through the internal supply passage 33 of the first body 3 and the second body 4 and the supply passage 34 of the pilot valve body 5. Alternatively, it is supplied from the external supply port 27 of the second body 4 to the supply port P ′ of the solenoid valve 30 through the external supply passage 35 and the supply passage 34. The output port A ′ of the solenoid valve 30 communicates with the pilot chamber 24 of the second body 4 via the pilot passage 29 as described above, and the pilot passage 29 communicates with the input port of the pressure sensor 32 via the pilot branch passage 28. To be done. A throttle 36 is arranged in the pilot branch passage 28 to prevent pulsation of air flowing through the pilot passage 29 from being input to the pressure sensor 32. The output terminal of the pressure sensor 32 is connected to the control circuit 31, the input electric signal is input from the input terminal of the control circuit 31, and the control circuit 31 generates an electromagnetic signal depending on the magnitude of the electric signal of the pressure sensor and the input electric signal. Transmits an on / off electrical signal to the solenoid of valve 30.

FIG. 3 is a circuit configuration diagram of the control circuit 31, which is an electric circuit of the control circuit 31 of FIG. The input signal (voltage) is input to the input signal circuit (composed of R16, R27) and sent to the comparison circuit (composed of IC2, R15, R26). The air pressure output from the output port A'of the solenoid valve 30 is converted into an electric signal (voltage) by the pressure sensor 32 (S1) of the pressure sensor circuit (composed of pressure sensors S1, R21 to R24, R3). It The pressure sensor signal output from the pressure sensor circuit is adjusted by a zero adjustment circuit (composed of IC2, R11 to R14 and VR2) and a gain adjustment circuit (composed of two IC1, R5 to R9 and VR3). It is amplified by a differential amplifier circuit (composed of IC1, R10 and C4) and input to the comparison circuit. The input signal and the pressure sensor signal are compared in the comparison circuit, and an ON / OFF signal is output to the solenoid valve 30 via the output circuit (constituted by Q1, R17, R18 and varistor ZNR1) depending on the magnitude of the comparison. According to this output circuit, since the varistor is connected in parallel with the solenoid coil, the off response of the solenoid valve 30 is accelerated, and the solenoid valve 30 can be turned on and off at high frequency. It should be noted that the solenoid valve 30 and the power supply circuit (composed of C2, C3) of each IC and the power supply circuit of the pressure sensor circuit (composed of IC1, C1, IC3, R1, R2, R19, R20) are provided. There is.

The operation of the first embodiment of the present invention will be described. Air flows from the supply port P into the primary pressure chamber 6, and also flows through the internal supply passage 33 and the supply passage 34 to the supply port P ′ of the solenoid valve 30. When the input electric signal of zero air pressure is input to the control circuit 31 and the off signal is input to the solenoid valve 30 from the control circuit 31 and the solenoid valve 30 is stopped at the position I, the output port A'of the solenoid valve 30 is input. And the exhaust port R ', the pilot chamber 24 communicates with the atmosphere through the pilot passage 29, the output port A'of the solenoid valve 30, the exhaust port R', and the like. Since the elastic force of the guide spring 18 and the air pressure are applied to the lower surface of the collar 16 of the main valve body 9, the annular valve seat 17 of the main valve body 9 contacts the valve seat 19 and the primary pressure chamber 6 and The communication with the secondary pressure chamber 7 is cut off. Since the contact member 25 is separated from the upper end of the main valve body 9, the output port A has the passage 13, the exhaust chamber 8, the inner hole 37 of the main valve body 9, the lateral hole of the retainer 10, the annular groove, and the exhaust. It communicates with the atmosphere through the port R and the like. The abutment member 25 remains separated from the upper end of the main valve body 9, but when air of a predetermined pressure is present in the secondary pressure chamber 7, the exhaust chamber 8 and the feedback chamber 22, the pilot chamber This is because the piston 20, the piston rod 21, and the abutment member 25 have moved to the upper position and are left as they are when the air in 24 is discharged to the atmosphere. A spring may be arranged between the lower surface of the piston 20 and the upper surface of the partition wall 23 in order to surely move the contact member 25 upward when the electromagnetic valve 30 is at the position I. As described above, when the solenoid valve 30 is stopped at the position I, the main valve body 9 is at the position shown in FIG. 1, the primary pressure chamber 6 and the secondary pressure chamber 7 are shut off, and the output Port A is in communication with the atmosphere.

When an input electric signal corresponding to a desired air pressure is input to the control circuit 31 and an ON signal is input from the control circuit 31 to the solenoid valve 30, the solenoid valve 30 is switched to the position II and air is supplied. It flows from the supply port P ′ to the output port A ′ and the pilot passage 29 into the pilot chamber 24. The piston 20 and the contact member 25 move downward due to the air pressure in the pilot chamber 24, the lower surface of the contact member 25 contacts the upper end of the main valve body 9, and the lower surface of the contact member 25 and the main valve valve. The upper end of the body 9 is closed, and the communication between the exhaust chamber 8 and the inner hole 37 of the main valve body 9 is cut off. Then, the contact member 25 and the main valve body 9 move further downward against the force of the air acting on the lower surface of the collar 16 and the elastic force of the guide spring 18, and the valve seat 19 and the annular valve. A gap is created by separating from the sheet 17, and air is supplied from the primary pressure chamber 6 through the secondary pressure chamber 7, the passage 13 and the output port A to the actuator and the like through this gap. The air pressure in the output port A is transmitted to the feedback chamber 22 through the feedback passage 26, and the piston 20, the contact member 25, and the main valve body 9 are returned upward.

The pressure in the pilot passage 29 / pilot chamber 24 gradually rises, the pressure in the pilot passage 29 is transmitted to the pressure sensor 32 through the pilot branch passage 28 / throttle 36, and the air pressure is detected by the pressure sensor 32. It is converted into an electric signal and input to the control circuit 31 as a feedback signal. The air pressure is transmitted from the middle of the pilot passage 29 to the pressure sensor 32 via the pilot branch passage 28, so that the feedback operation is fast, and because it is transmitted via the throttle 36, it is not affected by the pulsation and the pilot chamber 24 Accurately sense the pressure inside. When the pressure sensor 32 detects that the pressure in the pilot chamber 24 exceeds the set pressure, the feedback signal exceeds the input electric signal, the control circuit 31 returns the solenoid valve 30 to the position I, and the pressure sensor When 32 detects that the pressure in the pilot chamber 24 is below the set pressure, the feedback signal falls below the input electrical signal and the control circuit 31 switches the solenoid valve 30 to position II, which By repeating the above with high frequency, the pressure in the pilot chamber 24 is maintained at the set pressure.

When the air pressure of the output port A exceeds the set pressure, the piston 20 rises against the pilot pressure in the pilot chamber 24, and the lower surface of the contact member 25 separates from the upper end of the main valve body 9. A gap is created between the two, and air is discharged from the supply port A to the atmosphere through the passage 13, the exhaust chamber 8, the inner hole 37 of the main valve body 9, the exhaust port R, and the like. When the air pressure at the output port A falls below the set pressure, the piston 20 is lowered by the pilot pressure in the pilot chamber 24, and the lower surface of the contact member 25 and the upper end of the main valve body 9 are blocked, The exhaust chamber 8 and the inner hole 37 of the main valve valve body 9 are shut off, and the main valve valve body 9 further resists the force of the air acting on the lower surface of the collar 16 and the elastic force of the guide spring 18. When moving downward, the valve seat 19 and the annular valve seat 17 are separated from each other to form a gap, and air passes through the gap from the primary pressure chamber 6 to the secondary pressure chamber 7, the passage 13, and the output port A to the actuator. Is supplied to By repeating such operations, the pressure at the output port A is maintained at the set pressure. The feedback chamber 22 is communicated with the output port A through the feedback passage 26, and static pressure acts on the feedback chamber 22 (not affected by the dynamic pressure of the exhaust chamber 8), so that the piston 20 vibrates. No pulsation does not occur at output port A.

FIG. 5 is a partial sectional view showing the overall construction of the control valve of the second embodiment of the present invention. An output port A is opened on one side surface (right side surface in FIG. 5) of the first body 3, and an exhaust port R, a supply port P, and a supply port P are sequentially formed on the other side surface (left side surface in FIG. 5) of the first body 3 from the bottom. The external supply port 27 is opened. Since the gauge port G is not opened, the passage 14 communicating with the gauge port G is not formed. The internal supply passage 33 is arranged on the other side surface, and the rest of the configuration is the same as that of the first embodiment of FIG. 1, and the same reference numerals as those in FIG. 1 are attached to FIG. 5 and the description thereof is omitted. The operation of the second embodiment of the present invention is the same as that of the first embodiment.

[0017]

[Effect of device]

 In the present invention, the feedback pressure of the output port A acts on one surface of the piston slidably arranged in the second body, and the pilot pressure acts on the other surface of the piston. Becomes static pressure, and pulsation does not occur in the air at output port A. Further, the pilot pressure is output from the output port A'of the solenoid valve, and the pilot pressure is transmitted from the middle of the pilot passage through the throttle to the pressure sensor, so that the feedback operation is fast and there is no pulsation effect. Furthermore, since the solenoid valve and control circuit are installed in the pilot valve body and the varistor is connected in parallel with the solenoid coil of the solenoid valve, the OFF response of the solenoid valve is accelerated to operate the solenoid valve with high frequency. The pressure is venated, and thus the main valve output pressure is also venated.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an overall configuration of a control valve according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a configuration of a pilot valve of the control valve of the present invention.

FIG. 3 is a circuit configuration diagram of a control circuit of the control valve of the present invention.

FIG. 4 is an electric circuit diagram of a control circuit of the control valve of the present invention.

FIG. 5 is a partial cross-sectional view showing the overall construction of the control valve of the second embodiment of the present invention.

[Explanation of symbols]

 3 1st body 4 2nd body 5 Pilot valve body 9 Main valve valve body 20 Piston 21 Piston rod 22 Feedback chamber 24 Pilot chamber 29 Pilot passage 30 Solenoid valve 32 Pressure sensor 36 Throttle

Claims (3)

[Scope of utility model registration request] 1. A first body, a second body, and a pilot valve body are connected, and communication between a supply port P, an output port A, and an exhaust port R of the first body is switched by a main valve valve body. The feedback pressure of the output port A acts only on one surface of the piston slidably arranged on the body through the feedback passage, and the pilot pressure acts on the other surface of the piston, and the output member of the piston When the main valve element is operated and the pilot pressure exceeds the feedback pressure, the supply port P and the output port A are communicated, and when the feedback pressure exceeds the pilot pressure, the output port A and the exhaust port R are communicated. Control valve. 2. A solenoid valve, a control circuit, and a pressure sensor are arranged in a pilot valve body, a pilot pressure is output from an output port A'of the solenoid valve, and the pilot pressure passes through a throttle from a midway of the pilot passage and a pressure sensor. The control valve according to claim 1, which is transmitted to the control valve. 3. The control valve according to claim 1, wherein a solenoid valve, a control circuit, and a pressure sensor are arranged in a pilot valve body, and a varistor is connected in parallel with a solenoid coil of the solenoid valve.