CN112628101B

CN112628101B - Flow control valve for plunger pump

Info

Publication number: CN112628101B
Application number: CN202011417732.2A
Authority: CN
Inventors: 吴平; 施怀均; 孙泓源; 胡海林; 何东东
Original assignee: Ningbo Hilead Hydraulic Co ltd
Current assignee: Ningbo Hilead Hydraulic Co ltd
Priority date: 2020-12-07
Filing date: 2020-12-07
Publication date: 2022-09-16
Anticipated expiration: 2040-12-07
Also published as: CN112628101A

Abstract

The invention discloses a flow control valve for a plunger pump, which is characterized by comprising a shell and a valve core which are fixedly arranged in a pump cover of the plunger pump, the pressure difference baffle and the elastic adjustable pushing mechanism are arranged in the valve core, an oil liquid cavity is arranged in the valve core, the pressure difference baffle is fixedly arranged on the inner side of the front end of the oil liquid cavity, a first oil through hole is formed in the middle of the front end face of the shell, a second oil through hole is formed in the middle of the pressure difference baffle, at least two third oil through holes are uniformly formed in the circumferential direction of the front portion of the side wall of the valve core, a fourth oil through hole is formed in the rear portion of the side wall of the valve core, a first annular oil through groove with a fifth oil through hole at the bottom of the groove, a second annular oil through groove and a seventh oil through hole with a sixth oil through hole at the bottom of the groove are sequentially formed in the side wall of the shell from front to back, an annular retainer ring is arranged on the outer side of the valve core, and a sealing ring is fixedly and hermetically arranged on the outer side of the valve core between the second annular oil through groove and the seventh oil through hole; the device has the advantages of compact structure, simple and convenient control, easy processing and manufacture and strong pollution resistance.

Description

Flow control valve for plunger pump

Technical Field

The invention relates to a control valve device, in particular to a flow control valve for a plunger pump.

Background

The axial plunger pump is a core element of a hydraulic system, determines whether the whole hydraulic system can reach the integral optimal performance level, has a relatively complex structure and high requirements on materials, machining precision and the like, particularly provides new requirements on energy conservation and environmental protection of the hydraulic system in recent years, needs to upgrade a variable control mode of the plunger pump, improves the output flow control precision and real-time response capability of the hydraulic pump, simultaneously considers indexes such as simplicity, convenience, reliability, energy conservation, noise and the like in operation, and meets the requirements of a hydraulic system matched with high-end hydraulic machinery on the plunger pump.

The conventional variable control mode of the axial plunger pump is constant pressure variable, constant power variable, electric proportional control variable, hydraulic control variable control and the like, wherein the control mode of the output flow stepless variable of the plunger pump can be carried out, a hydraulic system is required to be provided with a corresponding electric proportional controller or a proportional pressure valve to output a control signal to drive a control unit of the plunger pump, and an internal feedback rod of a control valve is connected with a variable mechanism to form a closed-loop force feedback device, or the real-time position of the variable mechanism is detected through an external angle sensor, so that the stepless variable control of the plunger pump can be realized; the added electric proportional control link not only makes the hydraulic system more complex, but also has higher use cost, and because the structure of the proportional valve is complex, the requirement on the cleanliness of working oil is high, the working is easy to be out of control due to oil pollution, and the working reliability of the variable plunger pump is reduced; in some plunger pump control modes, working oil for driving the variable mechanism to act is required to be independent external control oil, so that the overall scheme of the hydraulic system is more complicated.

Disclosure of Invention

The invention aims to provide a flow control valve for a plunger pump, which has the advantages of compact structure, simple and convenient control and easy processing and manufacturing.

The technical scheme adopted by the invention for solving the technical problems is as follows: a flow control valve for a plunger pump comprises a shell, a valve core, a pressure difference baffle and an elastic adjustable pushing mechanism, wherein the shell, the valve core, the pressure difference baffle and the elastic adjustable pushing mechanism are fixedly arranged in a pump cover of the plunger pump, the valve core can move back and forth and is arranged in an inner cavity of the shell, the elastic adjustable pushing mechanism is used for elastically pushing the valve core forwards to the inner side of the front end face of the shell according to preset elasticity, an oil liquid cavity is arranged in the valve core, the pressure difference baffle is fixedly arranged on the inner side of the front end of the oil liquid cavity, an oil pressure cavity is formed between the pressure difference baffle and the front end face of the shell, a first oil through hole is formed in the middle of the front end face of the shell, a second oil through hole communicated with the first oil through hole is formed in the middle of the pressure difference baffle, the aperture of the second oil hole is smaller than that of the first oil through hole, and at least two oil holes are uniformly formed in the circumferential direction on the front portion of the side wall of the valve core, which is positioned on the rear side of the pressure difference baffle The rear part of the side wall of the valve core is provided with a fourth oil through hole for communicating the oil cavity with the inner cavity of the shell, the side wall of the shell is sequentially provided with a first annular oil through hole with a fifth oil through hole at the bottom, a second annular oil through hole with a sixth oil through hole at the bottom and a seventh oil through hole communicated with the fourth oil through hole from front to back, the outer side wall of the valve core is naturally positioned at the fifth oil through hole and is provided with an annular check ring, a first plane sealing part is formed between the outer side surface of the annular check ring and the cavity wall of the inner cavity of the shell and is sealed between the third oil through hole and the first annular oil through hole, and a second plane sealing part is formed between the first annular oil through hole and the second annular oil through hole by mutually matching the outer side surface of the valve core and the cavity wall of the inner cavity of the shell, the outer side of the valve core between the second annular oil through groove and the seventh oil through hole is fixedly and hermetically provided with a sealing ring, the first oil through hole is used for communicating with an oil outlet of an oil replenishing pump matched with the plunger pump, the fifth oil through hole is used for communicating with an oil inlet of an electromagnetic reversing valve matched with the plunger pump, the sixth oil through hole is used for communicating with an oil replenishing port inside the plunger pump, and the seventh oil through hole is used for communicating with a leakage oil port of an inner cavity of the plunger pump.

The elastic adjustable pushing mechanism comprises a fine adjustment screw rod, an outer seal head cap, an outer locking nut, a V-shaped hole retainer ring, a first spring seat, a second spring seat, a compression spring, a gasket and an inner locking nut which are arranged between the first spring seat and the second spring seat in a compression mode, a positioning cavity is arranged at the rear portion of the oil liquid cavity in the valve core, a first annular limiting platform with a limiting hole is formed between the positioning cavity and the oil liquid cavity, the V-shaped hole retainer ring, the first spring seat, the compression spring and the second spring seat are sequentially arranged in the positioning cavity from back to front, the gasket is arranged in the limiting hole, a connecting screw hole matched and screwed with the fine adjustment screw rod is arranged at the rear portion of the shell, the rear end of the fine adjustment screw rod extends backwards from the connecting screw hole and is sequentially screwed in the outer locking nut and the outer seal head cap from front to back, a first sealing ring is arranged between the outer head cap and the fine adjustment screw, a second sealing ring is arranged between the outer locking nut and the fine adjustment screw, the front end of the fine adjustment screw sequentially passes through the retaining ring for the V-shaped hole, the first spring seat, the compression spring, the second spring seat and the gasket and extends into the oil cavity, the inner locking nut is screwed at the front end of the fine adjustment screw, a first annular clamping groove is arranged in the positioning cavity, the retaining ring for the V-shaped hole is clamped in the first annular clamping groove, a second annular limiting table is arranged on the fine adjustment screw, the first spring seat is elastically abutted against the second annular limiting table by the rear end of the compression spring, the second spring seat and the gasket are elastically abutted against the inner locking nut by the front end of the compression spring, the maximum outer diameter of the second spring seat is larger than the aperture of the limiting hole. The compression spring is arranged between the first spring seat and the second spring seat in a compression mode, the spring pretightening force of the compression spring is preset through the matching of the inner locking nut and the gasket, when the valve core moves, the first annular limiting table pushes the second spring seat to move, the first spring seat is kept unchanged under the action of the second annular limiting table, the compression spring is compressed to generate reverse thrust elasticity on the valve core, and finally the reverse thrust elasticity is balanced with the pressure difference generated by oil liquid input from the outside at the pressure difference baffle under the combined action of the oil pressure on the annular retainer ring to keep the valve core at a relatively balanced position, when the flow of the oil liquid input from the outside is increased, the pressure difference at the pressure difference baffle is increased to push the valve core to move backwards, the reverse thrust elasticity of the compression spring is correspondingly increased at the moment, the valve core is kept at the relatively balanced position under the combined action of the oil pressure on the annular retainer ring again, and the opening area of the fifth oil hole is increased at the moment, therefore, the oil pressure generated by the oil at the annular retainer ring is correspondingly increased, so that the inclination angle of the swash plate of the plunger pump is increased, and the flow rate of the plunger pump is increased.

The casing include main valve seat and valve seat cover, valve seat cover spiro union set up the front end of main valve seat, main valve seat with the inside of valve seat cover constitute jointly the casing inner chamber, first logical oilhole sets up the middle part of the preceding terminal surface of valve seat cover, the tank bottom is provided with fifth logical oilhole first annular logical oil groove and tank bottom be provided with the sixth logical oilhole second annular logical oil groove set up backward in the past in proper order the lateral wall of valve seat cover on, seventh logical oilhole set up the lateral wall of main valve seat on, the lateral wall of main valve seat be provided with be used for with the pump cover screw hole cooperation spiro union of plunger pump connecting thread and be used for with the pump cover screw hole the sealed third sealing washer of conical surface cooperation. The front end of the main valve seat is provided with external threads which are connected with internal threads at the rear end of the valve seat sleeve to form a whole in a locking way, the connecting threads at the middle position of the main valve body are fixedly connected with a pump cover threaded hole of the plunger pump, and a third sealing ring is matched with the conical surface of the pump cover threaded hole to realize the sealing between the main valve body and the pump cover, so that the oil leakage is prevented, and the processing and the assembly are convenient.

The front end inboard of oil liquid chamber set gradually second annular draw-in groove and third annular spacing platform after to in the past, second annular draw-in groove internal fixation card be equipped with the check ring for hole, pressure differential baffle chucking set up the check ring for hole with the third annular spacing platform between, the hole aperture of check ring for hole be greater than the aperture of second through hole, the pore wall of second through hole for the annular inclined plane that reduces in proper order in the past to back aperture. The pressure difference baffle is tightly clamped between the hole retainer ring and the third annular limiting table, when external oil flows into the oil pressure cavity, pressure is generated on the pressure difference baffle, the pressure difference baffle pushes the third annular limiting table backwards, and the valve core is pushed to start moving backwards until the pressure is greater than preset elasticity, so that the first plane sealing part is opened, and the oil flows into the fifth oil through hole from the third oil through hole; the pore wall of the second oil through hole is an annular inclined plane with the sequentially reduced pore diameter from front to back, so that the oil liquid entering the oil liquid cavity flows stably, and the pause and the contusion during the flow rate adjustment of the plunger pump are reduced.

Compared with the prior art, the invention has the advantages that when an external servo motor or a diesel engine is started to drive the connected transmission shaft to rotate, the plunger pump and the matched oil replenishing pump start to work simultaneously, when the oil replenishing pump outputs oil with certain pressure and flow to enter the oil cavity in the valve core through the first oil through hole, because the aperture of the second oil through hole is smaller than that of the first oil through hole, pressure difference can be generated on two sides of the pressure difference baffle plate, the larger the flow output by the oil replenishing pump is, the larger the generated pressure difference is, the pressure difference overcomes the spring force of the compression spring to push the valve core to move backwards, at the moment, the fifth oil through hole which is originally in the positive covering position is gradually opened, the control oil pressure at the fifth oil through hole is increased from the zero pressure at the initial stage until the preset elastic force of the elastic adjustable thrusting mechanism is reached, and at the moment, the oil pressure acts on the annular baffle ring at the fifth oil through hole, the hydraulic control device has the advantages that a forward reverse thrust PA is generated, the valve core is located at a relative balance position at the moment, the pressure of oil liquid is stable and controllable, the oil liquid with the stable pressure flows into an oil inlet of an electromagnetic reversing valve matched with the plunger pump through an internal working flow passage and enters a variable mechanism of the plunger pump through a working oil port of the electromagnetic reversing valve, the angle of a plunger pump swash plate can be controlled, and the effect of stepless regulation of the flow rate of the plunger pump is achieved; after the structural size of the flow control valve is determined, the range of PA can be adjusted by changing the size of the second oil through hole or changing the preset elastic force, so that the adjustable range of the flow of the plunger pump is limited; the oil path structure and the oil replenishing pump in the plunger pump are both conventional structures corresponding to the flow control valve.

The plunger pump and the matched oil replenishing pump are coaxially driven mechanisms, the oil replenishing pump is a fixed-displacement hydraulic pump, the output flow is in direct proportion to the rotating speed of a servo motor or a diesel engine, the input rotating speed change is converted into the output flow change of the oil replenishing pump, the output flow of the oil replenishing pump is further converted into a pressure value of the position of an annular retainer ring through the flow control valve, and the pressure value is connected with a variable mechanism of the plunger pump, so that a simple, convenient and reliable stepless variable hydraulic control system of the plunger pump is formed.

Drawings

FIG. 1 is a cross-sectional view of the overall structure of the present invention;

fig. 2 is a partial structural sectional view of the present invention.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

A flow control valve for a plunger pump comprises a shell fixedly arranged in a pump cover of the plunger pump, a valve core 1, a differential pressure baffle 2 and an elastic adjustable pushing mechanism, wherein the shell comprises a main valve seat 3 and a valve seat sleeve 4, the valve seat sleeve 4 is screwed and arranged at the front end of the main valve seat 3, the outer side wall of the main valve seat 3 is provided with a connecting thread 31 which is matched and screwed with a pump cover threaded hole of the plunger pump and a third sealing ring 32 which is matched and sealed with a conical surface of the pump cover threaded hole, the valve core 1 can move back and forth and is arranged in a shell inner cavity 5 which is jointly formed by the main valve seat 3 and the valve seat sleeve 4, the elastic adjustable pushing mechanism is used for elastically pushing the valve core 1 forwards to the inner side of the front end surface of the valve seat sleeve 4 according to preset elasticity, an oil liquid cavity 11 is arranged in the valve core 1, the differential pressure baffle 2 is fixedly arranged at the inner side of the front end of the oil liquid cavity 11, and an oil pressure cavity 21 is formed between the differential pressure baffle 2 and the front end surface of the valve seat sleeve 4, a first oil through hole 41 is formed in the middle of the front end face of the valve seat sleeve 4, a second oil through hole 22 communicated with the first oil through hole 41 is formed in the middle of the differential pressure baffle 2, the aperture of the second oil through hole 22 is smaller than that of the first oil through hole 41, two third oil through holes 12 are uniformly formed in the front portion of the side wall of the valve core 1 and located on the rear side of the differential pressure baffle 2 in the circumferential direction, a fourth oil through hole 13 for communicating an oil liquid cavity 11 with an inner cavity 5 of the housing is formed in the rear portion of the side wall of the valve core 1, a first annular oil through groove 43 with a fifth oil through hole 42 at the groove bottom and a second annular oil through groove 45 with a sixth oil through hole 44 at the groove bottom are sequentially formed in the front portion to the rear portion of the side wall of the valve seat sleeve 4, a seventh oil through hole 33 communicated with the fourth oil through hole 13 is formed in the side wall of the main valve core 3, an annular retainer ring 14 is located at the fifth oil through hole 42 in the natural state of the outer side wall of the valve core 1, a first plane sealing portion 15 is formed between the outer side wall of the annular retainer 14 and the chamber wall of the housing inner cavity 5 and is sealed with the third oil through hole Between the oil hole 12 and the first annular oil through groove 43, the outer side surface of the valve core 1 between the first annular oil through groove 43 and the second annular oil through groove 45 and the cavity wall of the inner cavity 5 of the shell are mutually matched to form a second plane sealing part 16, the outer side of the valve core 1 between the second annular oil through groove 45 and the seventh oil through hole 33 is fixedly and hermetically provided with a sealing ring 17, the first oil through hole 41 is used for being communicated with an oil outlet of an oil supplementing pump matched with the plunger pump, the fifth oil through hole 42 is used for being communicated with an oil inlet of an electromagnetic reversing valve matched with the plunger pump, the sixth oil through hole 44 is used for being communicated with an oil supplementing hole in the plunger pump, and the seventh oil through hole 33 is used for being communicated with a leakage oil hole in the inner cavity of the plunger pump;

the elastic adjustable pushing mechanism comprises a fine adjustment screw 61, an outer seal head cap 62, an outer locking nut 63, a retaining ring 64 for a V-shaped hole, a first spring seat 65, a second spring seat 66, a compression spring 67 arranged between the first spring seat 65 and the second spring seat 66 in a compression mode, a gasket 68 and an inner locking nut 69, a positioning cavity 18 is arranged at the rear portion of the oil liquid cavity 11 in the valve core 1, a first annular limiting platform 19 with a limiting hole 191 is formed between the positioning cavity 18 and the oil liquid cavity 11, the retaining ring 64 for the V-shaped hole, the first spring seat 65, the compression spring 67 and the second spring seat 66 are sequentially arranged in the positioning cavity 18 from back to front, the gasket 68 is arranged in the limiting hole 191, a connecting screw hole 34 matched and screwed with the fine adjustment screw 61 is arranged at the rear portion of the main valve seat 3, the rear end of the fine adjustment screw 61 extends out from the connecting screw hole 34 and is sequentially screwed in the outer locking nut 63 and the outer seal head cap 62 from front to back, a first sealing ring 71 is arranged between the outer head cap 62 and the fine adjustment screw 61, a second sealing ring 72 is arranged between the outer locking nut 63 and the fine adjustment screw 61, the front end of the fine adjustment screw 61 sequentially passes through the V-shaped hole retainer ring 64, the first spring seat 65, the compression spring 67, the second spring seat 66 and the gasket 68 forwards and extends into the oil liquid cavity 11, the inner locking nut 69 is screwed on the front end of the fine adjustment screw 61, a first annular clamping groove 181 is arranged in the positioning cavity 18, the V-shaped hole retainer ring 64 is clamped in the first annular clamping groove 181, a second annular limiting table 611 is arranged on the fine adjustment screw 61, the first spring seat 65 is elastically abutted to the second annular limiting table 611 by the rear end of the compression spring 67, the second spring seat 66 and the gasket 68 are elastically abutted to the inner locking nut 69 by the front end of the compression spring 67, and the maximum outer diameter of the second spring seat 66 is larger than the aperture of the limiting hole 191;

the inner side of the front end of the oil liquid cavity 11 is sequentially provided with a second annular clamping groove 23 and a third annular limiting table 24 from front to back, a hole check ring 25 is fixedly clamped in the second annular clamping groove 23, the pressure difference baffle 2 is tightly clamped between the hole check ring 25 and the third annular limiting table 24, the hole diameter of an inner hole of the hole check ring 25 is larger than that of the second oil through hole 22, and the hole wall of the second oil through hole 22 is an annular inclined surface with the hole diameter gradually reduced from front to back.

Example two: the rest of the embodiment is the same as the first embodiment, and the difference is that four third oil through holes 12 are uniformly formed in the front portion of the side wall of the valve core 1 at the rear side of the differential pressure baffle 2 in the circumferential direction.

Claims

1. A flow control valve for a plunger pump is characterized by comprising a shell, a valve core, a pressure difference baffle and an elastic adjustable pushing mechanism, wherein the shell, the valve core, the pressure difference baffle and the elastic adjustable pushing mechanism are fixedly arranged in a pump cover of the plunger pump, the valve core can be arranged in an inner cavity of the shell in a back-and-forth movement mode, the elastic adjustable pushing mechanism is used for elastically pushing the valve core forwards to the inner side of the front end face of the shell according to preset elasticity, an oil liquid cavity is arranged in the valve core, the pressure difference baffle is fixedly arranged on the inner side of the front end of the oil liquid cavity, an oil pressure cavity is formed between the pressure difference baffle and the front end face of the shell, a first oil through hole is formed in the middle of the front end face of the shell, a second oil through hole communicated with the first oil through hole is formed in the middle of the pressure difference baffle, and the aperture of the second oil hole is smaller than that of the first oil hole, the front part of the side wall of the valve core is positioned at the rear side of the differential pressure baffle plate and is circumferentially and evenly provided with at least two third oil through holes, the rear part of the side wall of the valve core is provided with a fourth oil through hole used for communicating the oil cavity with the inner cavity of the shell, the side wall of the shell is sequentially provided with a first annular oil through hole with a fifth oil through hole at the bottom, a second annular oil through hole with a sixth oil through hole at the bottom and a seventh oil through hole communicated with the fourth oil through hole at the bottom, the outer side wall of the valve core is positioned at the fifth oil through hole under the natural state and is provided with an annular check ring, a first plane sealing part is formed between the outer side surface of the annular check ring and the cavity wall of the inner cavity of the shell, the outer side surface of the valve core is positioned between the first annular oil through hole and the second annular oil through hole, and the cavity wall of the inner cavity of the shell are mutually sealed A second plane sealing part is formed by matching, a sealing ferrule is fixedly and hermetically arranged at the outer side of the valve core between the second annular oil through groove and the seventh oil through hole, the first oil through hole is used for being communicated with an oil outlet of an oil supplementing pump matched with the plunger pump, the fifth oil through hole is used for being communicated with an oil inlet of an electromagnetic reversing valve matched with the plunger pump, the sixth oil through hole is used for being communicated with an oil supplementing port in the plunger pump, the seventh oil through hole is used for being communicated with an oil leakage port in an inner cavity of the plunger pump, the elastic adjustable thrusting mechanism comprises a fine adjusting screw rod, an outer sealing head cap, an outer locking nut, a retaining ring for a V-shaped hole, a first spring seat, a second spring seat, a compression spring, a gasket and an inner locking nut which are arranged between the first spring seat and the second spring seat in a compression manner, and a positioning cavity is arranged at the rear part of the oil liquid cavity in the valve core, the positioning cavity and the oil cavity between form the first annular spacing platform that has spacing hole, V type hole with retaining ring first spring holder compression spring and second spring holder from the back to setting gradually before the positioning cavity in, the packing ring set up spacing downthehole, the rear portion of casing be provided with the connection screw of fine setting screw cooperation spiro union, the rear end of fine setting screw follow the connection screw stretch out backward and from the past to the back in proper order the spiro union in outer lock nut and outer seal head cap in, outer seal head cap with the fine setting screw between be provided with first sealing washer, outer lock nut with the fine setting screw between be provided with the second sealing washer, the front end of fine setting screw pass forward in proper order V type hole with retaining ring, the packing ring for V type hole, The first spring seat, the compression spring, the second spring seat and the gasket extend into the oil cavity, the inner locking nut is in threaded connection with the front end of the fine adjustment screw rod, a first annular clamping groove is formed in the positioning cavity, the V-shaped hole retainer ring is clamped in the first annular clamping groove, a second annular limiting table is arranged on the fine adjustment screw rod, the rear end of the compression spring elastically abuts against the first spring seat on the second annular limiting table, the front end of the compression spring elastically abuts against the second spring seat and the gasket on the inner locking nut, the maximum outer diameter of the second spring seat is larger than the aperture of the limiting hole, the shell comprises a main valve seat and a valve seat sleeve, and the valve seat sleeve is in threaded connection with the front end of the main valve seat, the main valve seat with the inside of valve seat cover constitute jointly the casing inner chamber, first logical oilhole sets up the middle part of the preceding terminal surface of valve seat cover, the tank bottom is provided with fifth logical oilhole first annular oil groove and tank bottom be provided with sixth logical oilhole the second annular oil groove set up backward in the past in proper order the lateral wall of valve seat cover on, seventh logical oilhole set up the lateral wall of main valve seat on, the lateral wall of main valve seat be provided with be used for with the pump cover screw hole cooperation spiro union of plunger pump connecting thread and be used for with the sealed third sealing washer of pump cover screw hole's conical surface cooperation.

2. The flow control valve for the plunger pump according to claim 1, wherein a second annular groove and a third annular stop are sequentially formed in the front end inner side of the oil chamber from front to back, a hole check ring is fixedly clamped in the second annular groove, the differential pressure baffle is tightly clamped between the hole check ring and the third annular stop, the hole diameter of the hole check ring is larger than that of the second oil passage hole, and the hole wall of the second oil passage hole is an annular inclined surface with a diameter gradually decreasing from front to back.