Safety valve
Technical Field
The invention belongs to the technical field of valves, and particularly relates to a safety valve.
Background
Safety valves are commonly used in industrial control and fluid pipelines, and are used for limiting the highest service pressure in the pipeline to play a role in safety protection. In the prior art, in order to realize the safety protection and unloading functions of the pipeline, a solenoid valve and a safety valve are adopted, whether the pipeline is in unloading state is controlled by electrifying the solenoid valve, and the safety protection function is realized by the safety valve when the solenoid valve is in the unloading state, so that the use cost and the installation complexity are increased, and the whole volume is also increased.
Disclosure of Invention
The invention aims to provide a safety valve which not only can realize an unloading function, but also can realize a safety protection function.
In order to achieve the purpose, the invention provides the following technical scheme:
a safety valve comprises a valve sleeve, wherein a valve hole with an opening at the upper end is arranged in the valve sleeve, a through hole is arranged at the bottom of the valve hole in the valve sleeve, the lower end of the through hole is a P port, a T port communicated with the valve hole is arranged on the side surface of the valve sleeve, a valve core used for controlling the on-off of the through hole is connected in the valve hole in a sliding mode, a magnetic sleeve is fixedly arranged at the opening at the upper end of the valve hole, and a control cavity is formed between the valve core; a flux sleeve through hole penetrating along the axial direction is formed in the flux sleeve, the flux sleeve through hole comprises a sliding hole, a mounting hole and a pilot valve port from top to bottom, the mounting hole is communicated with the T port through a communicating flow channel formed in the flux sleeve and the valve sleeve, a threaded sleeve is fixedly arranged at the upper end of the flux sleeve, and a coil is arranged on the outer circumferential side surface of the flux sleeve between the threaded sleeve and the valve sleeve; the sliding hole is internally and slidably connected with a moving iron, and a pilot valve core matched with the pilot valve port to control the connection and disconnection of the control cavity and the mounting hole is arranged in the mounting hole; a first spring is arranged in the through hole of the magnetic conduction sleeve, one end of the first spring is abutted against the lower end face of the moving iron, and the other end of the first spring is abutted against the pilot valve core, so that the pilot valve core keeps moving downwards to block the trend of the pilot valve port; a first damping hole for communicating the port P with the control cavity is formed in the valve core, and a second damping hole is formed in the pilot valve port; when the coil is powered off, the first spring is in a natural extension state, the valve core is in an opening state under the pressure difference between the port P and the control cavity, and the port P is communicated with the port T; when the coil is electrified, the moving iron moves downwards to compress the first spring, so that the pilot valve core is tightly pressed on the pilot valve port, when the pressure of the P port is lower than the set pressure of the first spring, the valve core is in a closed state, the P port is isolated from the T port and is blocked, when the pressure of the P port is higher than the set pressure of the first spring, the pilot valve core moves upwards to open the pilot valve port, the valve core is in an open state under the pressure difference between the P port and the control cavity, and the P port is communicated with the T port.
In a further technical scheme, an inverted T-shaped limiting sliding groove is formed in the upper end of the moving iron, a regulating rod with the lower end extending into the inverted T-shaped limiting sliding groove is connected with the thread in the threaded sleeve in an internal thread mode, and a convex shoulder connected into the inverted T-shaped limiting sliding groove in a sliding mode is arranged at the lower end of the regulating rod; when the shoulder is close to the threaded sleeve, the coil is electrified, the downward movement distance of the moving iron is short, and when the shoulder is far away from the threaded sleeve, the coil is electrified, and the downward movement distance of the moving iron is long.
In a further technical scheme, a second spring is arranged in the control cavity, one end of the second spring abuts against the magnetic conduction sleeve, and the other end of the second spring abuts against the valve core, so that the valve core keeps a trend of moving downwards to separate the communication between the P port and the T port.
In a further technical scheme, the adjusting rod is in threaded connection with a locking nut above the plug.
In a further technical scheme, the communicating flow channel comprises a first through hole formed in the magnetic sleeve and a second through hole formed in the threaded sleeve, one end of the first through hole is communicated with the mounting hole, the other end of the first through hole is communicated with one end of the second through hole, and the other end of the second through hole is communicated with the T port.
Advantageous effects
Compared with the prior art, the technical scheme of the invention has the following advantages:
the valve core can be in an open state by controlling the coil to lose power, so that the P port is communicated with the T port to complete the unloading function; the valve core can be in a closed state by controlling the coil to be electrified, so that the safety protection function is realized; and the regulation of the set pressure can be conveniently realized by regulating the rod. Compared with the prior art, the invention realizes the functions of two valves through one valve, and has the advantages of compact volume, simple structure and low cost.
Drawings
FIG. 1 is a cross-sectional view of the present invention;
FIG. 2 is a schematic three-dimensional structure of the moving iron of the present invention.
Detailed Description
Referring to fig. 1-2, a safety valve includes a valve housing 1, a valve hole with an open upper end is arranged in the valve housing 1, a through hole is arranged at the bottom of the valve hole in the valve housing 1, a P port is arranged at the lower end of the through hole, a T port communicated with the valve hole is arranged on the side surface of the valve housing, a valve core 2 for controlling the on-off of the through hole is connected in the valve hole in a sliding manner, a magnetic sleeve 4 is fixedly arranged at an opening at the upper end of the valve hole, and a control cavity 1a is formed between the valve core 2 and the magnetic sleeve; a flux sleeve through hole penetrating along the axial direction is formed in the flux sleeve 4, the flux sleeve through hole comprises a sliding hole, a mounting hole and a pilot valve port from top to bottom, the mounting hole is communicated with a T port through a communication flow channel formed in the flux sleeve 4 and the valve sleeve 1, a threaded sleeve 8 is fixedly arranged at the upper end of the flux sleeve 4, and a coil 9 is arranged on the outer circumferential side surface of the flux sleeve 4 between the threaded sleeve 8 and the valve sleeve 1; a moving iron 6 is connected in the sliding hole in a sliding mode, and a pilot valve core 5 which is matched with the pilot valve port to control the connection and disconnection of the control cavity 1a and the mounting hole is arranged in the mounting hole; a first spring 32 is arranged in the through hole of the magnetic conduction sleeve, one end of the first spring 32 is abutted against the lower end face of the moving iron 6, and the other end of the first spring is abutted against the pilot valve core 5, so that the pilot valve core 5 keeps moving downwards to block the trend of the pilot valve port; a first damping hole 21 for communicating the port P with the control cavity 1a is formed in the valve core 2, and a second damping hole 42 is formed in the pilot valve port; when the coil 9 loses power, the first spring 32 is in a natural extension state, the valve core 2 is in an opening state under the pressure difference between the port P and the control cavity 1a, and the port P is communicated with the port T; when the coil 9 is electrified, the moving iron 6 moves downwards to compress the first spring 32, so that the pilot valve core 5 is pressed on the pilot valve port, when the pressure of the port P is lower than the set pressure of the first spring 32, the valve core 2 is in a closed state, the port P is blocked from the port T, when the pressure of the port P is higher than the set pressure of the first spring 32, the pilot valve core 5 moves upwards to open the pilot valve port, the valve core 2 is in an open state under the pressure difference between the port P and the control cavity 1a, and the port P is communicated with the port T.
An inverted T-shaped limiting sliding groove 61 is formed in the upper end of the moving iron 6, an adjusting rod 7 with the lower end extending into the inverted T-shaped limiting sliding groove 61 is connected with the inner thread of the threaded sleeve 8, and a convex shoulder 71 connected into the inverted T-shaped limiting sliding groove in a sliding mode is arranged at the lower end of the adjusting rod 7; when the shoulder 71 is close to the threaded sleeve 8, the coil 9 is electrified, the downward movement distance of the moving iron 6 is short, and when the shoulder 71 is far away from the threaded sleeve 8, the coil 9 is electrified, and the downward movement distance of the moving iron 6 is long.
And a second spring is arranged in the control cavity, one end of the second spring is abutted against the magnetic conduction sleeve, and the other end of the second spring is abutted against the valve core, so that the valve core keeps the trend of moving downwards to separate the communication between the P port and the T port.
And the adjusting rod is in threaded connection with a locking nut above the plug.
The communicating flow channel comprises a first through hole formed in the magnetic sleeve and a second through hole formed in the threaded sleeve, one end of the first through hole is communicated with the mounting hole, the other end of the first through hole is communicated with one end of the second through hole, and the other end of the second through hole is communicated with the T port.
The working principle of the invention is as follows:
the maximum safety pressure of the present invention can be set by adjusting the adjusting lever 7, wherein the distance that the moving iron 6 moves downward is longer the more the adjusting lever 7 is adjusted downward, so that the greater the compression amount of the first spring 32 is, the higher the maximum safety pressure is.
When the coil 9 is not charged, the moving iron 6 is at the uppermost position, so that the first spring 32 is in a natural extension state, the medium at the port P passes through the first damping hole 21 and the control cavity 1a, then pushes the pilot valve core 5 away to enter the mounting hole, and then sequentially passes through the first through-flow hole 41 and the second through-flow hole 101 and then returns to the port T, due to the action of the first damping hole 21, a pressure difference exists between the port P and the control cavity 1a, the pressure difference acts on the valve core 2, the valve core 2 moves upwards to open the through hole, and the port P is communicated with the port T.
When the coil 9 is electrified, under the action of the magnetic field, the moving iron 6 moves downwards to compress the first spring 32 until the upper end face of the shoulder 71 abuts against the step face of the inverted-T-shaped limiting sliding groove 61, and under the acting force of the first spring 32, the pilot valve core 5 is pressed on the pilot valve port. When the pressure of the port P is lower than the set pressure of the first spring 32, the pilot valve core 5 is in a closed state, the valve core 2 is in a closed state under the action force of the second spring 31, and the port P is blocked from the port T. When the pressure of the port P is greater than the set pressure of the first spring 32, the pilot valve core 5 moves upwards to open the pilot valve port, the medium in the control cavity 1a flows into the port T after passing through the pilot valve port, the mounting hole, the first through-flow hole 41 and the second through-flow hole 101, the valve core 2 moves upwards under the action of the pressure difference between the port P and the control cavity 1a, the through-hole is opened, and the medium at the port P flows into the port T to realize overflow, so that the safety protection effect is achieved.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the technical principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.