A soft pressure relief plunger pump

Abstract

The present invention discloses a soft pressure relief plunger pump, including a housing, a suction valve, a pressure sensor, a control panel and a push valve assembly. A hydraulic cavity and a suction channel are arranged in the housing, a suction port is arranged between the suction channel and the hydraulic cavity to connect the two, a discharge port connected to the hydraulic cavity is arranged on the other side of the housing relative to the suction port, the suction valve is arranged at the suction port, the pressure sensor is connected to the discharge port to measure the system pressure, the pressure sensor is electrically connected to the control panel to transmit pressure information, the push valve assembly is fixed to the housing, and a push rod of the push valve assembly is located at the suction port and acts on the suction valve, and the control panel is controlled and connected to the push valve assembly to extend the push rod, push open the suction valve or retract the push rod. When unloading, the high pressure can be slowly reduced to 0, and the high pressure will not be instantly reduced to 0, thereby avoiding the technical problems of large impact, low safety and life loss caused by high and low pressure high frequency switching.

Description

Technical Field

[0001] The invention relates to the technical field of plunger pumps, and in particular to a soft pressure relief plunger pump. Background Art

[0002] The plunger pump is a positive displacement pump. Figure 1 As shown, the slider 3 in the slide groove 4 is driven to reciprocate by the crankshaft 1 through the connecting rod 2, so that the plunger 5 connected to the slider 3 reciprocates in the working room (hydraulic chamber, not shown in the figure) of the housing 6, so that energy is directly provided to the liquid in the form of pressure energy for liquid transportation. When the plunger 5 is away from the suction and discharge valve, the volume of the working room increases to form a low pressure, and the liquid in the suction channel (liquid supply channel, suction port 10) pushes the suction valve 9 and enters the working room, and the discharge valve 7 is closed due to the liquid pressure in the discharge pipe (discharge port 8, discharge pipeline); when the plunger 5 is transported to the limit position, the suction stroke is completed; when the plunger 5 is close to the suction and discharge valve, the liquid is squeezed and the pressure increases, thereby pushing the discharge valve 7 and pressing it into the discharge pipeline, and the suction valve 9 is closed; when the plunger 5 is transported to the limit position, the discharge stroke is completed.

[0003] When providing power, the existing mining reciprocating plunger pump needs to be used in conjunction with the unloading valve to achieve loading and unloading. The pressure sensor installed at the outlet of the unloading valve detects the system pressure. The control system (PLC board, control board) controls the unloading valve action according to the set loading and unloading pressure to achieve high and low pressure switching. The switching frequency is 20-30 times per minute.

[0004] refer to Figure 2 As shown, the working principle of the unloading valve 200 is: when the output pressure of the pump station system reaches the set opening pressure (high pressure), the solenoid valve is activated, the reversing valve is opened, the liquid flows back to the liquid tank, and the plunger pump 100 is unloaded; when the output pressure of the pump station system drops to the set closing pressure (low pressure), the solenoid valve is activated, the reversing valve is closed, and the plunger pump 100 pressurizes the system. The main function of the unloading valve 200 is to adjust the unloading of the plunger pump 100 through mechanical action to ensure that the required working pressure is not exceeded and the safety of each part in the system is ensured.

[0005] The plunger pump and the unloading valve are used together to control loading and unloading, which is a high-frequency high-low pressure switching loading and unloading method. The pressure is instantly switched from about 375 bar to 0 bar (instantaneous pressure loss, also known as hard pressure relief). The number of loading and unloading times per minute is not less than 20-30 times per minute. The high-frequency switching of high and low pressure has a great impact on hydraulic components such as pumps and valves, as well as the entire system. It is not only unsafe, but also very destructive to the life of the system and components. Summary of the invention

[0006] To this end, the present invention provides a soft pressure relief plunger pump to solve the technical problems in the prior art of large impact, low safety and short service life caused by high-pressure and low-pressure high-frequency switching.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A soft pressure relief plunger pump comprises a shell, a suction valve, a pressure sensor and a control board, wherein a hydraulic chamber and a suction channel are arranged in the shell, a suction port connecting the suction channel and the hydraulic chamber is arranged between the two, a discharge port connected to the hydraulic chamber is arranged on the other side of the shell relative to the suction port, the suction valve is arranged at the suction port, the pressure sensor is connected to the discharge port to measure the system pressure, and the pressure sensor is electrically connected to the control board to transmit pressure information; the soft pressure relief plunger pump also comprises a push valve assembly, the push valve assembly is fixed to the shell and a push rod of the push valve assembly is located at the suction port and acts on the suction valve, and the control board is controlled and connected to the push valve assembly to extend the push rod, push open the suction valve or retract the push rod.

[0009] Furthermore, the push valve assembly is a pneumatic assembly, an electric assembly or a hydraulic assembly.

[0010] Furthermore, the pneumatic component includes a cylinder body, a piston, a piston rod, a push rod, a spring, an air nozzle, a compressed gas pipeline and a solenoid valve, wherein the cylinder body is provided with a piston rod chamber, a piston chamber and a spring chamber which are connected in sequence, wherein one end of the piston rod chamber away from the piston chamber is connected to the outside, the piston is slidably and sealedly arranged in the piston chamber, one end of the piston rod is fixed to the piston, and the other end is slidably and sealedly arranged in the piston rod chamber and exposed from the cylinder body, one end of the push rod is connected to the exposed end of the piston rod, the spring is pre-compressedly arranged in the spring chamber, one end of the spring is abutted against a side of the piston away from the piston rod chamber, the air nozzle is fixed outside the cylinder body, the air nozzle is connected to the piston chamber and the connecting port is located on the side of the piston chamber close to the piston rod chamber, the air nozzle is connected to the compressed gas pipeline, the solenoid valve is serially connected to the compressed gas pipeline, and the control board is electrically connected to the solenoid valve.

[0011] Furthermore, the cylinder body is divided into an upper cylinder body and a lower cylinder body, and the upper cylinder body and the lower cylinder body are detachably connected by threads and the connection is sealed.

[0012] Furthermore, the pneumatic component also includes a spring seat, an adjusting screw and a first anti-loosening nut. The spring seat is movably arranged in the spring cavity and is located at and abuts against the end of the spring away from the piston. The end of the spring cavity away from the piston cavity is provided with a threaded through hole connected to the outside world. The adjusting screw is screwed into the threaded through hole and the screwed-in end abuts against the side of the spring seat away from the spring. The first anti-loosening nut is located outside the cylinder body and is tightened on the adjusting screw.

[0013] Furthermore, the pneumatic component also includes a second anti-loosening nut, a countersunk hole is provided at the end of the piston rod away from the piston, the countersunk hole is provided with an internal thread, and an external thread is provided at the end of the push rod away from the suction port. The push rod is connected to the piston rod through threads, and the second anti-loosening nut is located outside the cylinder body and is tightened on the external thread of the push rod.

[0014] Furthermore, the shell is provided with a mounting hole opposite to the suction port and connected to the suction channel, the end of the cylinder body provided with the piston rod chamber is detachably sealed and fixed at the mounting hole, and the end of the push rod away from the piston rod passes through the mounting hole, the suction channel and the suction port in sequence and then acts on the suction valve.

[0015] Furthermore, the soft pressure relief plunger pump also includes a drain valve, and the drain valve is arranged at the drain port.

[0016] Furthermore, a plurality of hydraulic chambers are provided in the shell, each of the hydraulic chambers is connected to the liquid suction channel through a liquid suction port, a liquid suction valve is provided at each liquid suction port, and a plurality of push valve assemblies are provided outside the shell, the plurality of push valve assemblies are arranged in one-to-one correspondence with the plurality of liquid suction valves, and each of the push valve assemblies is controlled by the control panel.

[0017] The present invention has the following advantages:

[0018] The soft pressure relief plunger pump of the present invention is an improvement on the existing technology, removing the original unloading valve and adding a push valve assembly, which is still controlled by the original control panel. When the pressure value measured by the sensor reaches the loading and unloading pressure, the control panel controls the action of the push valve assembly, specifically as follows: when the pressure reaches the predetermined high pressure, the push rod is pushed out to push open the suction valve corresponding to the suction stroke, at which time the hydraulic chamber corresponding to the suction stroke cannot form a closed space, so in the subsequent discharge stroke, the liquid cannot be pressed into the high-pressure side (discharge port, discharge pipe), but the sucked liquid is pressed into the low-pressure side (suction port, suction channel), so that the loading to the high-pressure side is stopped and the unloading is completed. Multiple plungers complete the above actions one by one under the drive of the crankshaft (in the discharge stroke, the push rod cannot push open the suction valve, so the above actions are completed one by one), and the pressure will not switch from high pressure to low pressure instantly (hard pressure relief in the background technology), but will slowly unload from high pressure to low pressure to complete the soft pressure relief. Therefore, the problems of high impact, low safety and damaged life are effectively avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0020] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantial technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0021] Figure 1 It is a working principle diagram of the plunger pump in the background technology of the present invention.

[0022] Figure 2 It is a control principle diagram when the plunger pump and the unloading valve in the background technology of the present invention are used in combination;

[0023] Figure 3 A schematic diagram of the partial structure of a soft pressure relief plunger pump provided in an embodiment of the present invention;

[0024] Figure 4 A schematic structural diagram of a push valve assembly (pneumatic assembly) of a soft pressure relief plunger pump provided in an embodiment of the present invention;

[0025] Figure 5A control schematic diagram (gas circuit control) of a soft pressure relief plunger pump provided in an embodiment of the present invention.

[0026] In the figure: 100-plunger pump, 1-crankshaft, 2-connecting rod, 3-slider, 4-slide, 5-plunger, 6-housing, 7-discharge valve, 8-discharge port, 9-suction valve, 10-suction port, 11-flange cover, 12-push valve assembly, 13-upper cylinder body, 14-lower cylinder body, 15-piston, 16-piston rod, 17-push rod, 18-second anti-loosening nut, 19-spring, 20-spring seat, 21-adjusting screw, 22-first anti-loosening nut, 23-first O-type sealing seal, 24-second O-type sealing ring, 25-third O-type sealing ring, 26-compressed gas pipeline, 27-solenoid valve, 28-gas source.

[0027] 200-Unloading valve. DETAILED DESCRIPTION

[0028] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The terms such as "upper", "lower", "left", "right", "middle", etc. cited in this specification are only for the convenience of description and are not intended to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships should be regarded as within the scope of implementation of the present invention without substantially changing the technical content.

[0030] The present embodiment provides a soft pressure relief plunger pump, which is an improvement on the technology of the existing plunger pump. The original unloading valve is removed, and the original pressure sensor and control system (hereinafter referred to as the control board) are used. A push valve assembly is added. The push valve assembly is controlled by the control board. During the suction stroke, the push rod of the push valve assembly pushes open the corresponding suction valve, so that the hydraulic cavity cannot be closed, so that liquid cannot be pressed into the high-pressure side during the discharge stroke, but the liquid is pressed back to the low-pressure side. The above actions are performed one by one during multiple discharge strokes, thereby completing soft pressure relief.

[0031] like Figure 3As shown, the soft pressure relief plunger 5 pump includes a housing 6, a plunger 5, a suction valve 9, a discharge valve 7, a pressure sensor (not shown in the figure), a control board (not shown) and a push valve assembly 12. The housing 6, the plunger 5, the suction valve 9, the discharge valve 7, the pressure sensor and the control board are all existing, and the structure, position and connection relationship of each are also existing, for example: a hydraulic chamber and a suction channel are arranged in the housing 6; the upper end of the hydraulic chamber is open and closed by a flange cover 11; the suction channel is arranged horizontally below the hydraulic chamber, and the two are connected through the suction port; opposite to the suction port, the other side of the housing 6 is provided with a discharge port connected to the hydraulic chamber, and the discharge ports of each hydraulic chamber are connected to the discharge pipe; the plunger 5 reciprocates under the action of the crankshaft, thereby changing the size of the hydraulic chamber; the suction valve 9 is arranged at the suction port; the discharge valve 7 is arranged at the discharge port; the pressure sensor is connected to the discharge port, generally arranged in the discharge pipe, to measure the system pressure; the pressure sensor is electrically connected to the control board to transmit pressure information. The push valve assembly 12 is fixed to the housing 6 and the push rod 17 of the push valve assembly 12 is located at the suction port and interacts with the suction valve 9. The control panel is connected to the push valve assembly 12 to extend the push rod 17, push open the suction valve 9, or retract the push rod 17. During loading, the control panel controls the push rod 17 to retract. At this time, the suction valve 9 works as before, and the plunger 5 pump completes normal loading; during unloading, the control panel controls the push rod 17 to extend. At this time, the suction valve 9 cannot be closed, so that the hydraulic chamber cannot be closed. During the discharge stroke, the liquid cannot be pressed into the high-pressure side, but is pressed back to the low-pressure side. The plunger 5 pump supplies liquid to the external actuator. If it is not loaded, the pressure will decrease. When multiple discharge strokes perform the above actions one by one, the system pressure slowly drops from high pressure to achieve soft pressure relief.

[0032] The push valve assembly 12 is an electric assembly, a hydraulic assembly or a pneumatic assembly. The electric assembly can be an electric telescopic rod of a linear motor type. The hydraulic assembly can be a telescopic rod based on hydraulic pressure. In this embodiment, a pneumatic assembly is preferably used.

[0033] refer to Figure 3 As shown, the lower part of the housing 6 is provided with five mounting holes, which correspond to the five suction ports of the five hydraulic chambers respectively; each mounting hole is connected to the suction channel, and then connected to the suction port; there are also five pneumatic components, all of which are arranged at the bottom of the housing 6, and the cylinder body is fixed to the housing 6 by bolts, and the cylinder body and the housing 6 are sealed by the first O-ring 23; the top of the cylinder body of each pneumatic component extends into the corresponding mounting hole. The cylinder body is divided into an upper cylinder body 13 and a lower cylinder body 14, and the upper cylinder body 13 and the lower cylinder body 14 are detachably connected by threads and the connection is sealed.

[0034] like Figure 4 and 5As shown, the pneumatic assembly includes a cylinder body, a piston 15, a piston rod 16, a push rod 17, a second anti-loosening nut 18, a spring 19, a spring seat 20, an adjusting screw 21, a first anti-loosening nut 22, a gas nozzle (not shown in the figure), a compressed gas pipeline 26 and a solenoid valve 27. The cylinder body is provided with a piston rod chamber, a piston chamber and a spring 19 chamber which are arranged and connected from top to bottom. The upper end of the piston rod chamber is connected to the outside of the cylinder body. The function of the piston rod chamber is to allow the piston rod 16 to pass through and to seal with the piston rod 16 through the second O-ring 24. It does not necessarily have a large length (height) size; in this embodiment, it has a large length because the cylinder body corresponding to the piston rod chamber needs to extend into the mounting hole of the housing 6. The piston 15 is slidably arranged in the piston chamber, and the two are sealed by the third O-ring 25. The lower end of the piston rod 16 is fixed to the piston 15, and the upper end is slidably and sealed in the piston rod chamber and exposed from the top of the cylinder body; because the push rod 17 is used to push the suction valve 9, the piston rod 16 does not need to be too long. The piston 15 and the piston rod 16 can be connected by threads or by an integrated structure (such as welding or casting). The lower end of the push rod 17 is provided with an external thread, and the upper end of the piston rod 16 is provided with a countersunk hole, and the countersunk hole is provided with an internal thread. The lower end of the push rod 17 is first screwed with the second anti-loosening nut 18 and then screwed with the internal thread of the upper end of the piston rod 16. The stability of the connection between the push rod 17 and the piston rod 16 is ensured by tightening the second anti-loosening nut 18; the end of the push rod 17 passes through the mounting hole, the liquid suction channel and the liquid suction port in sequence and then acts on the liquid suction valve 9. The spring 19 is pre-compressed and arranged in the spring 19 cavity, and the upper end of the spring 19 abuts against the lower side of the piston 15. The spring seat 20 is movably arranged in the spring 19 cavity, and is located below and abuts against the spring 19. The lower end of the cylinder body is provided with a threaded through hole connecting the outside and the spring 19 cavity. The adjusting screw 21 is first screwed on the second anti-loosening nut 18 and then screwed on the threaded through hole. The upper end of the adjusting screw 21 is against the lower side of the spring seat 20. By rotating the adjusting screw 21, the height of the spring seat 20 can be adjusted, thereby adjusting the pre-pressure of the spring 19, that is, adjusting the force of pushing open the suction valve 9. By tightening the first anti-loosening nut 22, the relative position of the adjusting screw 21 and the cylinder body can be fixed, and then the height of the spring seat 20 can be fixed. The air nozzle is fixed outside the cylinder body, and the air nozzle is connected to the piston cavity and the connecting port is located at the upper position of the piston cavity. In this way, when the compressed gas is ventilated, the compressed gas can force the piston 15 to move downward, thereby retracting the push rod 17, releasing the restriction on the suction valve 9, and no longer pushing open the suction valve 9. At this time, the suction valve 9 can work normally as before. One end of the compressed gas pipeline 26 is connected to the air nozzle, and the other end is connected to the gas source 28. The solenoid valve 27 is connected in series to the compressed gas pipeline 26, and the control panel is electrically connected to the solenoid valve 27; generally, the solenoid valve 27 is installed in a pneumatic control box, which is also provided with a pressure regulating valve, a pressure gauge, etc. connected in series to the compressed gas pipeline 26.

[0035] The plunger pump supplies liquid to the external actuator, the solenoid valve opens, and the compressed gas in the gas source enters the piston chamber in the cylinder through the compressed gas pipeline. When the piston is subjected to a large enough force, it overcomes the elastic force of the spring and moves downward, driving the push rod to retract. At this time, the suction valve works normally, and the plunger pump outputs the pressure required by the actuator; when the pressure sensor detects that the pressure reaches the set value, the control board cuts off the power to the solenoid valve, the gas in the piston chamber is discharged, and the push rod extends under the action of the spring to push open the suction valve (only the suction valve corresponding to the suction stroke can be pushed open), and the suction stroke of the plunger pump proceeds normally; in the discharge stroke, because the suction valve is pushed open, the hydraulic chamber cannot form a closed space, so the liquid is not pressed into the high-pressure side in the discharge stroke, but flows back to the low-pressure side, stopping loading the actuator, thereby completing the unloading. The five plungers complete the above actions one by one under the rotation of the crankshaft to achieve the purpose of unloading. During unloading, the suction valve in the discharge stroke cannot be pushed open and has partial loading capacity. Therefore, the pressure does not drop from high pressure to 0 instantly, and there is no problem of large impact, low safety and damaged life in hard pressure relief.

[0036] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A soft pressure relief plunger pump, comprising a housing, a suction valve, a pressure sensor and a control board, wherein a hydraulic chamber and a suction channel are provided in the housing, a suction port communicating with the hydraulic chamber is provided between the suction channel and the hydraulic chamber, a discharge port communicating with the hydraulic chamber is provided on the other side of the housing opposite to the suction port, the suction valve is arranged at the suction port, the pressure sensor is connected to the discharge port to measure the system pressure, and the pressure sensor is electrically connected to the control board to transmit pressure information, characterized in that: The soft relief plunger pump further comprises a push valve assembly, the push valve assembly is fixed to the housing, a push rod of the push valve assembly is located at the suction port and acts on the suction valve, and the control panel is connected to the push valve assembly to control the push rod to extend, push open the suction valve or retract the push rod; The push valve assembly is a pneumatic assembly; The pneumatic assembly includes a cylinder body, a piston, a piston rod, a push rod, a spring, an air nozzle, a compressed gas pipeline and a solenoid valve, wherein the cylinder body is provided with a piston rod chamber, a piston chamber and a spring chamber which are connected in sequence, wherein one end of the piston rod chamber away from the piston chamber is connected to the outside, the piston is slidably and sealedly arranged in the piston chamber, one end of the piston rod is fixed to the piston, and the other end is slidably and sealedly arranged in the piston rod chamber and exposed from the cylinder body, one end of the push rod is connected to the exposed end of the piston rod, the spring is pre-compressedly arranged in the spring chamber, one end of the spring is against a side of the piston away from the piston rod chamber, the air nozzle is fixed to the cylinder body, the air nozzle is connected to the piston chamber and the connecting port is located on the side of the piston chamber close to the piston rod chamber, the air nozzle is connected to the compressed gas pipeline, the solenoid valve is serially connected to the compressed gas pipeline, and the control board is electrically connected to the solenoid valve; The pneumatic assembly further comprises a spring seat, an adjusting screw and a first anti-loosening nut, wherein the spring seat is movably arranged in the spring cavity and is located at and abuts against an end of the spring away from the piston, an end of the spring cavity away from the piston cavity is provided with a threaded through hole communicating with the outside, the adjusting screw is screwed into the threaded through hole and the screwed-in end abuts against a side of the spring seat away from the spring, and the first anti-loosening nut is located outside the cylinder body and is screwed onto the adjusting screw; The pneumatic assembly also includes a second anti-loosening nut, a countersunk hole is provided at one end of the piston rod away from the piston, the countersunk hole is provided with an internal thread, an external thread is provided at one end of the push rod away from the suction port, the push rod is connected to the piston rod by threads, and the second anti-loosening nut is located outside the cylinder body and is screwed onto the external thread of the push rod.

2. The soft pressure relief plunger pump according to claim 1, characterized in that: The cylinder body is divided into an upper cylinder body and a lower cylinder body, and the upper cylinder body and the lower cylinder body are detachably connected through threads and the connection is sealed.

3. The soft pressure relief plunger pump according to claim 1, characterized in that: The shell is provided with a mounting hole opposite to the suction port and connected to the suction channel, the end of the cylinder body provided with the piston rod chamber is detachably sealed and fixed at the mounting hole, and the end of the push rod away from the piston rod passes through the mounting hole, the suction channel and the suction port in sequence to act on the suction valve.

4. The soft pressure relief plunger pump according to claim 1, characterized in that: The soft pressure relief plunger pump further comprises a liquid discharge valve, which is arranged at the liquid discharge port.

5. The soft pressure relief plunger pump according to any one of claims 1 to 4, characterized in that: A plurality of hydraulic chambers are provided in the shell, each of which is connected to the liquid suction channel through a liquid suction port, and a liquid suction valve is provided at each liquid suction port. A plurality of push valve assemblies are provided outside the shell, and the plurality of push valve assemblies are arranged in one-to-one correspondence with the plurality of liquid suction valves, and each of the push valve assemblies is controlled by the control panel.

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