CN112661015B

CN112661015B - Plug-in type hydraulic valve, single-cylinder plug pin type suspension arm hydraulic control system and crane

Info

Publication number: CN112661015B
Application number: CN202011451334.2A
Authority: CN
Inventors: 王雅妮; 王磊; 何伟; 徐清平; 黄珍
Original assignee: Zoomlion Heavy Industry Science and Technology Co Ltd
Current assignee: Zoomlion Heavy Industry Science and Technology Co Ltd
Priority date: 2020-12-09
Filing date: 2020-12-09
Publication date: 2022-11-08
Anticipated expiration: 2040-12-09
Also published as: CN112661015A

Abstract

The invention discloses a plug-in type hydraulic valve which comprises a first one-way valve and a back pressure valve, wherein the first one-way valve takes a first oil cavity as a liquid inlet and a second oil cavity as a liquid outlet, the back pressure valve takes the second oil cavity as a liquid inlet and the first oil cavity as a liquid outlet, and one-way back pressure with a set size can be formed in the second oil cavity. The invention also discloses a single-cylinder bolt type suspension arm hydraulic control system, which comprises a hydraulic pump, a control valve group, a telescopic balance valve, a telescopic oil cylinder, an arm pin electromagnetic reversing valve, a cylinder pin electromagnetic reversing valve and the plug-in type hydraulic valve; the control valve group is connected on the output oil path of the hydraulic pump, the telescopic balance valve and the plug-in type hydraulic valve are installed on the oil path between the control valve group and the telescopic oil cylinder, the telescopic oil cylinder is provided with a central channel connected with the arm pin electromagnetic reversing valve and the cylinder pin electromagnetic reversing valve, and the plug-in type hydraulic valve is installed between the rod cavity and the control valve group, so that the influence of the oil pressure of the central channel on the control precision of the telescopic oil cylinder can be reduced. In addition, the invention also discloses a crane.

Description

Plug-in type hydraulic valve, single-cylinder plug pin type suspension arm hydraulic control system and crane

Technical Field

The invention relates to a crane hydraulic system, in particular to a plug-in hydraulic valve. In addition, the invention also relates to a single-cylinder bolt type suspension arm hydraulic control system and a crane.

Background

The telescopic mechanism of the automobile crane is mainly divided into two types: rope-type and single-cylinder plug-type. The rope row type telescopic mechanism controls the telescopic action of the suspension arm through the extension and retraction of the telescopic oil cylinder, the suspension arm can carry out lifting load at any position in the extension and retraction stroke, and the telescopic oil cylinder bears the load force of the lifting load in the lifting load process. The single-cylinder pin type telescopic mechanism mainly adopts a telescopic oil cylinder to drive the suspension arm to extend out, the suspension arm is fixed at a corresponding position through a pin to be hoisted, the pin is stressed in the hoisting process, and the oil cylinder is not stressed, so that the length of the suspension arm is not changed in the hoisting process.

The single-cylinder bolt type telescopic mechanism usually adopts a hydraulic control system to control the telescopic of the suspension arm and the plugging and unplugging of a bolt, and in an initial state, a cylinder pin in the telescopic mechanism is inserted into a pin hole of a suspension arm cylinder, so that a telescopic oil cylinder can drive the telescopic of the corresponding telescopic suspension arm; the arm pin is inserted into the arm pin hole of the next-stage suspension arm, so that the position of the telescopic suspension arm in the next-stage suspension arm is kept unchanged. When the telescopic boom extends out, the telescopic oil cylinder extends out, and the boom is driven by the cylinder pin to extend out for a certain distance so that the boom pin is in an unstressed state; pulling out the boom pin to enable the telescopic boom to be freely telescopic; the telescopic oil cylinder extends out, and the cylinder pin drives the telescopic suspension arm to extend out to a proper position; and inserting the arm pin into the corresponding arm pin hole on the next-stage suspension arm, so that the telescopic arm is fixed at a new position. When the telescopic boom retracts, the telescopic oil cylinder extends out firstly, and the boom is driven by the cylinder pin to extend out for a certain distance so that the boom pin is in an unstressed state; pulling off the arm pin to enable the telescopic boom to be freely telescopic; the telescopic oil cylinder retracts, and the cylinder pin drives the suspension arm to retract to a proper position; and inserting the arm pin into the corresponding arm pin hole on the next-stage suspension arm, so that the telescopic arm is fixed at a new position. When the upper-stage suspension arm needs to be controlled, the telescopic oil cylinder extends out for a certain distance until the cylinder pin is in an unstressed state; pulling off the cylinder pin to enable the telescopic boom to freely stretch relative to the boom; the telescopic oil cylinder extends out to a proper position of the upper-stage suspension arm; and inserting the cylinder pin into the cylinder pin hole of the upper-stage suspension arm, so that the suspension arm can be driven by the telescopic oil cylinder to be telescopic. When the upper-stage suspension arm needs to be controlled, the telescopic oil cylinder extends out for a certain distance until the cylinder pin is in an unstressed state; pulling off the cylinder pin to enable the telescopic oil cylinder to be freely telescopic relative to the suspension arm; retracting the telescopic oil cylinder to a proper position of the next-stage suspension arm; and inserting the cylinder pin into the cylinder pin hole of the next-stage suspension arm, so that the suspension arm can be driven by the telescopic oil cylinder to be telescopic.

An existing single-cylinder bolt type boom hydraulic control system is shown in fig. 1, hydraulic oil pumped out by a hydraulic pump 1 is conveyed to a telescopic oil cylinder 4 under the control of a control valve group 2, and telescopic motion of the telescopic oil cylinder 4 is driven. The telescopic balance valve 3 is arranged between the control valve group 2 and the telescopic oil cylinder 4, and prevents the suspension arm from retracting too fast under the action of load. Part of hydraulic oil is conveyed to the arm pin electromagnetic reversing valve 51 and the cylinder pin electromagnetic reversing valve 52 through the central channel 42 of the telescopic oil cylinder 4 under the control of the control valve group 2, and the arm pin electromagnetic reversing valve 51 and the cylinder pin electromagnetic reversing valve 52 are controlled to respectively drive and control the arm pin oil cylinder 61 and the cylinder pin oil cylinder 62 to move so as to form the pulling-out action of the cylinder pin and the arm pin.

In the existing single-cylinder bolt type suspension arm hydraulic control system, when the cylinder pin or the arm pin is pulled out, the telescopic oil cylinder needs to extend to ensure that the cylinder pin or the pin shaft is not stressed. At the moment, high-pressure oil is simultaneously filled into a rodless cavity of the telescopic oil cylinder and a central channel of the telescopic oil cylinder, a piston of the telescopic oil cylinder is acted by a high-pressure oil body in the central channel, and the control accuracy of the telescopic oil cylinder by a control system is influenced by the thrust formed by the hydraulic oil in the rodless cavity on the piston.

Disclosure of Invention

The invention aims to solve the technical problem of providing a plug-in type hydraulic valve which can form the one-way flow back pressure of hydraulic oil.

The invention also aims to solve the technical problem of providing a single-cylinder bolt type suspension arm hydraulic control system, and the control precision of a telescopic oil cylinder is high.

The invention further aims to solve the technical problem of providing a crane, wherein the telescopic control of the suspension arm is reliable and convenient.

In order to achieve the above object, a first aspect of the present invention provides a plug-in hydraulic valve, including a first oil chamber and a second oil chamber, further including a first check valve using the first oil chamber as a liquid inlet and using the second oil chamber as a liquid outlet, and a back pressure valve using the second oil chamber as a liquid inlet and using the first oil chamber as a liquid outlet, where the back pressure valve can form a back pressure with a set magnitude in the second oil chamber.

Preferably, the valve body assembly of the cartridge type hydraulic valve and the mounting seat can be mounted in the liquid flow channel of the cartridge parent body through the mounting seat, so that the valve body assembly can divide the liquid flow channel of the cartridge parent body into the first oil cavity and the second oil cavity. Through the preferable technical scheme, the plug-in type hydraulic valve can form the oil cavity of the hydraulic valve by utilizing the liquid flow channel of the plug-in parent body, so that an independently arranged shell and the oil cavity are omitted, the structure of the plug-in type hydraulic valve is simplified, and the plug-in type hydraulic valve can be conveniently matched with other hydraulic valves for use.

Further preferably, the valve body assembly comprises a core rod, a main valve core, a strong spring, a spring seat and a weak spring; one end of the main valve core is provided with a conical flow blocking surface for separating the flow passage of the plug-in mother body, and the other end of the main valve core is arranged in the mounting seat; a valve core oil cavity is arranged in the center of the main valve core, one end of the valve core oil cavity, which is adjacent to the first oil cavity, is provided with a valve core oil port communicated with the first oil cavity, and the valve core oil cavity is communicated with the second oil cavity through a valve core oil hole arranged on the main valve core; the core rod is arranged in the valve core oil cavity, the spring seat is in threaded connection with one end, far away from the first oil cavity, of the core rod, and the strong spring is arranged on the core rod and is positioned between the spring seat and the valve core oil port, so that one end, close to the first oil cavity, of the core rod can block the valve core oil port to form the back pressure valve; the weak spring is arranged between the main valve core and the mounting seat so as to push the main valve core to block the liquid flow channel of the plug-in parent body to form the first one-way valve. In the preferable technical scheme, the main valve core separates the first oil chamber and the second oil chamber under the action of the weak spring, so that hydraulic oil in the second oil chamber cannot directly enter the first oil chamber through the second oil chamber; because the core rod blocks the valve core oil port under the action of the strong spring, hydraulic oil in the first oil cavity acts on the end face of the main valve core, the main valve core is easily pushed to enter the second oil cavity by overcoming the elasticity of the weak spring, and the first check valve with the first oil cavity serving as a liquid inlet and the second oil cavity serving as a liquid outlet is formed. And the hydraulic oil in the second oil cavity can enter the valve core oil cavity through the valve core oil hole and enter the mounting seat through the gap between the main valve core and the spring seat to form pressure on the end face of the core rod. When the oil pressure in the second oil cavity reaches a certain value, the pressure exceeds the elastic force of the strong spring, the core rod is pushed to move to open the valve core oil port, the hydraulic oil enters the first oil cavity through the valve core oil port, certain back pressure is formed in the second oil cavity, and the back pressure valve with the second oil cavity as a liquid inlet and the first oil cavity as a liquid outlet is formed.

The invention provides a single-cylinder bolt type suspension arm hydraulic control system in a second aspect, which comprises a hydraulic pump, a control valve group, a telescopic balance valve, a telescopic oil cylinder, an arm pin electromagnetic reversing valve, a cylinder pin electromagnetic reversing valve and the plug-in type hydraulic valve provided by the first aspect of the invention; the valve unit is connected on the output oil circuit of hydraulic pump, in order to switch and provide the fuel feeding direction of the hydraulic oil of flexible hydro-cylinder, flexible balanced valve and cartridge formula hydrovalve are installed the valve unit with on the connection oil circuit of flexible hydro-cylinder, flexible hydro-cylinder includes no pole chamber, central channel and has the pole chamber, arm round pin electromagnetism switching-over valve and jar round pin electromagnetism switching-over valve with central channel is connected, in order to control the motion of arm round pin hydro-cylinder and jar round pin hydro-cylinder respectively, cartridge formula hydrovalve is installed there is the pole chamber with between the valve unit, in order can to have the pole chamber to provide hydraulic oil, and form backpressure when having the hydraulic oil of pole intracavity to flow back.

Preferably, the telescopic balance valve comprises a first oil port, a first oil duct, a second oil duct and a second oil port, a two-position two-way valve is arranged between the first oil port and the second oil port, and the two-position two-way valve can switch the position of the valve core under the action of hydraulic oil in the first oil duct, so that a second one-way valve or a damping valve is connected between the first oil port and the second oil port. Through this preferred technical scheme, flexible balanced valve can be through first hydraulic fluid port, second hydraulic fluid port to the rodless chamber fuel feeding of telescopic valve, has the pole chamber fuel feeding to telescopic valve through first oil duct, supplies oil to central channel through the second oil duct. When hydraulic oil enters the rodless cavity through the first oil port and the second oil port, low-pressure oil return is conducted in the rod cavity, the first oil duct is in a low-pressure state, the two-position two-way valve is switched to be in a state where the second check valve is connected, the hydraulic oil can rapidly enter the rodless cavity through the first oil port and the second oil port, and the telescopic oil cylinder is driven to stretch out. When hydraulic oil enters the rod cavity through the first oil duct, the first oil duct is in a high-pressure state, the two-position two-way valve is switched to a state that the damping valve is connected, the hydraulic oil in the non-sensing cavity flows back through the damping valve, and the telescopic oil cylinder retracts. Because the load of the suspension arm is applied to the telescopic oil cylinder, the retraction speed of the telescopic oil cylinder can be increased. The damping valve is connected to the hydraulic oil return passage, so that the return speed of the hydraulic oil can be reduced, the retraction speed of the telescopic oil cylinder is reduced, and the extension speed and the retraction speed of the telescopic oil cylinder are balanced. The switching of the one-way valve and the damping valve is carried out under the pressure control of the first oil duct through the two-position two-way valve, the automatic switching of the one-way valve and the damping valve can be realized, the switching control is simple, and the telescopic oil cylinder can be prevented from retracting under the action of load pressure in the extending process.

Further preferably, the cartridge type hydraulic valve comprises a valve body assembly and a mounting seat, and is inserted into the first oil passage of the telescopic balance valve through the mounting seat to divide the first oil passage into the first oil chamber and the second oil chamber. Through this preferred technical scheme, omitted structures such as cartridge formula hydraulic valve's casing for cartridge formula hydrovalve is in the same place with flexible balanced valve integration, has simplified the structure of valve body, has improved the stability of valve body.

Preferably, the single cylinder bayonet boom hydraulic control system of the present invention further comprises an oil filter assembly connected between the central passage and the arm pin and cylinder pin solenoid directional valves, the oil filter assembly comprising an oil filter and a third one-way valve such that hydraulic oil in the central passage can flow through the oil filter to the arm pin and/or cylinder pin solenoid directional valves and hydraulic oil in the arm pin and/or cylinder pin solenoid directional valves can flow through the third one-way valve to the central passage. In the preferable technical scheme, when the hydraulic oil flows to the arm pin electromagnetic reversing valve and/or the cylinder pin electromagnetic reversing valve from the central channel of the telescopic valve for supplying the oil, because the pressure of the hydraulic oil is higher, impurities in the hydraulic oil can be filtered through the oil filter; when the hydraulic oil flows to the central channel through the arm pin electromagnetic directional valve and/or the cylinder pin electromagnetic directional valve, the pressure of the returned hydraulic oil is lower, and the hydraulic oil can be ensured to smoothly return through the third one-way valve.

The single-cylinder pin type suspension arm hydraulic control system further comprises an arm pin and a cylinder pin, wherein the arm pin and the cylinder pin are respectively installed on two different directions of the side wall of the telescopic oil cylinder, the arm pin can be driven by the arm pin oil cylinder to perform plugging and unplugging actions, and the cylinder pin can be driven by the cylinder pin oil cylinder to perform plugging and unplugging actions. In the preferred technical scheme, the crane jib can be fixed and the extension and retraction of the jib are controlled by the jib pin and the cylinder pin which are arranged on the side wall of the telescopic oil cylinder in two different directions.

Further preferably, the arm pin oil cylinder and the cylinder pin oil cylinder are both spring cylinders, a rod cavity of the arm pin oil cylinder is connected with the arm pin electromagnetic directional valve, and a rod cavity of the cylinder pin oil cylinder is connected with the cylinder pin electromagnetic directional valve. Through the preferred technical scheme, hydraulic oil can be injected into the rod cavities of the arm pin oil cylinder and the cylinder pin oil cylinder to drive the arm pin oil cylinder and the cylinder pin oil cylinder to retract. After the rod cavities of the arm pin oil cylinder and the cylinder pin oil cylinder are unloaded, the arm pin oil cylinder and the cylinder pin oil cylinder can extend out under the action of the spring force in the rodless cavity.

The invention provides a crane comprising the single-cylinder bolt type boom hydraulic control system provided by the second aspect of the invention.

Through the technical scheme, the plug-in type hydraulic valve can form a liquid flow channel in one direction and a back pressure channel for setting pressure in the other direction between the two oil cavities. Two oil cavities are formed by the liquid flow channel of the cartridge parent body, so that the cartridge valve and the parent valve are combined together, the structure is simple, and the stability is higher. The single-cylinder bolt type suspension arm hydraulic control system can form back pressure with a set size in a rod cavity of a telescopic valve through the plug-in type hydraulic valve, and the influence of the pressure in a central channel on the control precision of the telescopic valve is counteracted. The switching structure of the one-way valve and the damping valve in the telescopic balance valve can prevent backflow of hydraulic oil in the rodless cavity in the extending process of the telescopic valve. The arrangement that the plug-in type hydraulic valve is integrated into the telescopic balance valve simplifies the structure and improves the stability of the hydraulic valve. The spring cylinder is used as the arm pin oil cylinder and the cylinder pin oil cylinder, and the oil filter valve assembly is arranged on the oil supply oil path, so that the arm pin oil cylinder and the cylinder pin oil cylinder can be driven smoothly through a single oil supply channel. The crane boom has high control precision and reliable telescopic positioning.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

FIG. 1 is a hydraulic schematic diagram of a prior art single cylinder latch boom hydraulic control system;

FIG. 2 is a schematic diagram of one embodiment of a cartridge hydraulic valve of the present invention;

FIG. 3 is a schematic diagram of an embodiment of a cartridge hydraulic valve of the present invention;

FIG. 4 is a hydraulic schematic diagram of one embodiment of the single cylinder latch boom hydraulic control system of the present invention;

FIG. 5 is a schematic view of a telescopic cylinder according to the present invention;

FIG. 6 is an integrated state schematic diagram of a cartridge type hydraulic valve and a telescopic balance valve of the present invention;

fig. 7 is a schematic diagram of an integrated state structure formed after the cartridge type hydraulic valve is inserted into the telescopic balance valve.

Description of the reference numerals

1. 2 control valve group of hydraulic pump

3. Telescopic balance valve 31 second one-way valve

32. Damping valve 4 telescopic oil cylinder

41. Rodless cavity 42 center channel

43. Electromagnetic reversing valve with rod cavity 51 arm pin

52. 61 arm pin oil cylinder of cylinder pin electromagnetic reversing valve

62. Oil filter assembly of cylinder pin oil cylinder 7

71. Oil filter 72 third check valve

81. Arm pin 82 cylinder pin

9. Plug-in type hydraulic valve 91 main valve element

92. Core rod 921 valve core oil chamber

922. Valve core oil port 923 valve core oil hole

93. Strong spring 94 spring seat

95. Weak spring 96 mounting base

901. First one-way valve 902 back pressure valve

A first oil port A and B first oil cavity

C second oil duct D second oil port

E second oil chamber

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

The terms "first", "second", "third", are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, and therefore the features defined "first", "second", "third", may explicitly or implicitly include one or more of the features described.

In the description of the present invention, it should be noted that, unless otherwise explicitly stated or limited, the terms "mounted," "disposed," and "connected" are to be construed broadly, and for example, the term "connected" may be a fixed connection, a detachable connection, or an integral connection; either directly or indirectly through intervening media, either internally or in any combination thereof. The specific meanings of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.

In the drawings of the present invention, the two-dot chain line represents a hydraulic member, the solid line represents a working oil path, and the broken line represents a control oil path.

An embodiment of the cartridge hydraulic valve 9 of the present invention, as shown in fig. 2 and 3, includes a first oil chamber B and a second oil chamber E, a first check valve 901 formed between the first oil chamber B and the second oil chamber E and having the first oil chamber B as a liquid inlet and the second oil chamber E as a liquid outlet, and a back pressure valve 902 having the second oil chamber E as a liquid inlet and the first oil chamber B as a liquid outlet. Thus, when the hydraulic oil flows from the first oil chamber B to the second oil chamber E, the hydraulic oil passes through the first check valve 901, which has a smaller resistance; when the hydraulic oil flows from the second oil chamber E to the first oil chamber B, the hydraulic oil cannot pass through the first check valve 901, but only passes through the back pressure valve 902, and the passing resistance of the back pressure valve 902 causes the hydraulic oil to form a certain amount of back pressure in the second oil chamber E. The magnitude of this back pressure is determined by the passing resistance of the back pressure valve 902, and the setting characteristic of the back pressure valve 902 can determine the resistance when the hydraulic oil passes, that is, the magnitude of the hydraulic oil return back pressure in the second oil chamber E.

In some embodiments of the cartridge type hydraulic valve 9 of the present invention, as shown in fig. 2 and 7, the cartridge type hydraulic valve 9 of the present invention includes a valve body assembly and a mounting seat 96, and can be mounted in a flow passage of a cartridge main body through the mounting seat 96, the flow passage of the cartridge main body is divided into two parts by the valve body assembly, and the flow passages of the cartridge main body form a first oil chamber B and a second oil chamber E of the cartridge type hydraulic valve 9 of the present invention, respectively. Thus, the plug-in type hydraulic valve 9 forms a shell and an inlet and outlet cavity by means of the liquid flow channel and the wall structure of the plug-in type mother body, the structure of the plug-in type hydraulic valve 9 is simplified, the plug-in type hydraulic valve 9 is integrated in the plug-in type mother body, and the stability of the plug-in type structure is improved.

As an embodiment of the cartridge type hydraulic valve 9 of the present invention, as shown in fig. 3, the valve body assembly includes a core rod 92, a main valve 91, a strong spring 93, a spring seat 94, and a weak spring 95. One end of the main valve element 91 is provided with a conical flow blocking surface, and the conical flow blocking surface is contacted with a flow passage step of the plug parent body to divide the flow passage of the plug parent body into a first oil chamber B positioned at the end part of the main valve element 91 and a second oil chamber E positioned at one side of the main valve element 91. The other end of main spool 91 is mounted in mount 96 and is slidable in mount 96. A valve core oil cavity 921 is arranged in the center of the main valve core 91, a valve core oil port 922 is arranged at one end of the conical flow blocking surface of the main valve core 91, and the valve core oil port 922 is communicated between the first oil cavity B and the valve core oil cavity 921. A spool oil hole 923 is provided in a side wall of the main spool 91, and the spool oil chamber 921 and the second oil chamber E are communicated through the spool oil hole 923. The core rod 92 is installed in the core oil chamber 921 through the core oil port 922, a thread is provided at one end of the core rod 92 away from the first oil chamber B, and the strong spring seat 94 is screwed on the thread at the end of the core rod 92, compressing the strong spring 93 installed on the core rod 92 and located between the spring seat 94 and the core oil port 922. An end cover is arranged at one end of the core rod 92 in the first oil cavity B, and the end cover at the end of the core rod 92 is pressed on the valve core oil port 922 by the elastic force of the strong spring 93 to block the valve core oil port 922. Weak spring 95 is mounted on the end of main spool 91 between main spool 91 and mount 96. Weak spring 95 may provide a pushing force of main spool 91 toward first oil chamber B, such that a conical flow-blocking surface at the other end of main spool 91 blocks a flow passage between first oil chamber B and second oil chamber E. Thus, when the pressure of the hydraulic oil in the first oil chamber B is higher than the pressure in the second oil chamber E, the pressure of the hydraulic oil acts on the core rod 92 and the end of the main valve core 91, and it is easy to overcome the small elastic force of the weak spring 95, and push the valve body assembly to move integrally into the mounting seat 96, and open the fluid passage between the first oil chamber B and the second oil chamber E, and the hydraulic oil can enter the second oil chamber E from the first oil chamber B. When the pressure of the hydraulic oil in the second oil chamber E is higher than the pressure in the first oil chamber B, the hydraulic oil in the second oil chamber E enters the spool oil chamber 921 through the spool oil hole 923, and then enters the mount 96 through the gap between the main spool 91 and the spring seat 94, forming a pressure on the end of the main spool 91, pressing the tapered flow blocking surface of the main spool 91 against the step of the flow passage between the first oil chamber B and the second oil chamber E together with the weak spring, blocking the flow passage between the first oil chamber B and the second oil chamber E, and forming the first check valve 901 between the first oil chamber B and the second oil chamber E. In addition, when the pressure of the hydraulic oil in the second oil chamber E is higher than the pressure in the first oil chamber B, the hydraulic oil in the second oil chamber E also presses the end surface of the core rod 92 after entering the mounting seat 96. When the pressure in the second oil chamber E is large enough, the pressure of the hydraulic oil on the end surface of the core rod 92 exceeds the elastic force of the strong spring 93, the core rod 92 is pushed to move towards the first oil chamber B, a through-flow opening is formed between the end cover of the core rod 92 and the valve core oil port 922, and the hydraulic oil in the second oil chamber E enters the first oil chamber B through the valve core oil hole 923, the valve core oil chamber 921 and the valve core oil port 922. With the outflow of the hydraulic oil in the second oil chamber E, the pressure in the second oil chamber E decreases, the pressure acting on the end surface of the core rod 92 in the mounting seat 96 decreases, the core rod 92 moves toward the mounting seat 96 under the elastic force of the strong spring 93, the through-flow opening between the end cover of the core rod 92 and the valve core oil port 922 decreases, the pressure in the second oil chamber E is maintained at a level suitable for the elastic force of the strong spring 93, and the back pressure valve 902 between the second oil chamber E and the first oil chamber B is formed. By rotating the spring seat 94, the position of the spring seat 94 at the end of the core rod 92 can be adjusted, and the magnitude of the elastic force of the strong spring 93, and thus the magnitude of the back pressure formed in the second oil chamber E by the back pressure valve 902, can be adjusted.

One embodiment of the single-cylinder pin type boom hydraulic control system of the invention is shown in fig. 4, and comprises a hydraulic pump 1, a control valve group 2, a telescopic balance valve 3, a telescopic oil cylinder 4, an arm pin electromagnetic directional valve 51, a cylinder pin electromagnetic directional valve 52 and a plug-in type hydraulic valve 9 of any embodiment of the invention. The hydraulic pump 1 pumps hydraulic oil from a tank under the driving of an engine to provide a hydraulic driving force for system operation. The control valve group 2 is connected to an output oil path of the hydraulic pump 1, and is capable of switching an oil supply direction of hydraulic oil supplied to the telescopic cylinder 4 by an operation of the control valve group 2 and controlling supply of hydraulic oil to an oil path connected to the arm pin electromagnetic directional valve 51 and the cylinder pin electromagnetic directional valve 52. The telescopic cylinder 4 comprises a rodless chamber 41, a central passage 42 and a rod chamber 43. The hydraulic oil from the control valve group 2 enters the central channel 42 through the connecting oil path, and is connected to the arm pin electromagnetic directional valve 51 and the cylinder pin electromagnetic directional valve 52 through the connecting oil path via the central channel 42, so that the arm pin oil cylinder 61 can be driven to move under the control of the arm pin electromagnetic directional valve 51, and the cylinder pin oil cylinder 62 can be driven to move under the control of the cylinder pin electromagnetic directional valve 52. The flexible balanced valve 3 and the cartridge formula hydrovalve 9 are installed on the oil circuit of being connected of valve unit 2 and telescopic cylinder 4, wherein, the cartridge formula hydrovalve 9 is installed and is being had between pole chamber 43 and the valve unit 2, first oil pocket B is connected with valve unit 2, second oil pocket E is connected with having pole chamber 43, hydraulic oil can get into through first check valve 901 has pole chamber 43, drive telescopic cylinder 4 withdrawal, and when hydraulic oil was from having pole chamber 43 to flow back, must pass through back pressure valve 902, form the back pressure of setting for the size in having pole intracavity 43.

The cylinder body part of the telescopic cylinder 4 used for a general single-cylinder pin type boom is shown in fig. 5, the cylinder diameter of the telescopic cylinder 4 is D1, the rod diameter is D2, the diameter of the central channel 42 is D3, the area of the rodless cavity 41 is S1, the area of the rod cavity 43 is S2, and the area of the central channel 42 is S3. The central passage 42 is an oil passage formed between the piston rod and the bottom of the telescopic cylinder 4, and the oil passage is correspondingly lengthened and shortened along with the extension and retraction of the telescopic cylinder 4. When the telescopic oil cylinder 4 with the cylinder body structure is used in the existing single-cylinder bolt type boom hydraulic control system shown in fig. 1, if the boom pin 81 and the cylinder pin 82 need to retract, the telescopic oil cylinder 4 needs to extend to ensure that the action pin shaft is in an unstressed state. At this time, hydraulic oil needs to be injected into the rodless cavity 41 of the telescopic cylinder 4 to drive the telescopic cylinder 4 to extend, and hydraulic oil needs to be injected into the central passage 42 to drive the arm pins 81 and the cylinder pins 82 to retract. The pressure of the hydraulic oil in the rodless cavity 41 is a high oil pressure P1, the pressure of the hydraulic oil in the central passage 42 is a high oil pressure P2, the pressure P2 in the central passage 42 is determined by a load and is generally a constant value, the pressure of the hydraulic oil in the rod cavity 43 is P3, at this time, the hydraulic oil in the rod cavity 43 is in a direct backflow state, and the pressure P3 is a small oil return back pressure, and the magnitude of the pressure can be ignored. At this time, the force borne by the piston of the telescopic oil cylinder 4 is P1 × S1+ P2 × S3, the force-bearing direction of the piston is the cylinder extension direction, and:

P1×S1+P2×S3＝m1×g+m1×a (1)

in the formula: m1 is the mass of the telescopic oil cylinder 4, a is the load acceleration, and g is the gravity acceleration.

Obtainable from formula (1):

P1＝(m1×g+m1×a-P2×S3)/S1 (2)

p2, S1 and S3 are all fixed values, and under the condition of the same load m1 Xg and a certain load acceleration a, the pressure P1 in the rodless cavity 41 is influenced by the pressure P2 in the central channel 42 in the process of extending the telescopic oil cylinder 4. This affects the control accuracy of the telescopic cylinder 4.

In the single-cylinder pin type boom hydraulic control system of the present invention, the use of the plug-in hydraulic valve 9 makes the hydraulic oil in the rod chamber 43 flow back through the back pressure valve 902, and sets the value PR3 of the back pressure valve 902, so that PR3= P2 × S3/S2, and the hydraulic oil in the rod chamber 43 can generate the back pressure PR3= P2 × S3/S2.

At this time, when the extension of the telescopic cylinder 4 and the retraction of the cylinder pin and the jib pin are performed simultaneously, the force applied to the piston of the telescopic cylinder 4 is:

P1×S1+P2×S3-PR3×S2

＝P1×S1+P2×S3-(P2×S3/S2)×S2

＝P1×S1

the direction of force of the piston is the extending direction of the oil cylinder, and the piston is provided with:

P1×S1＝m1×g+m1×a (3)

from formula (3):

P1＝(m1×g+m1×a)/S1 (4)

as can be seen from the formula (4), under the condition of the same load m1 Xg and a certain load acceleration a, the pressure P1 in the rodless cavity (41) is constant in the extending process of the telescopic oil cylinder (4), and is not influenced by the pressure P2 in the central passage 42, so that the control precision of the telescopic oil cylinder (4) in the extending process is improved.

In some embodiments of the single cylinder pin boom hydraulic control system of the present invention, as shown in fig. 6 and 7, the telescopic balance valve 3 comprises a first oil port a, a first oil passage, a second oil passage C and a second oil port D. A two-position two-way valve is arranged between the first oil port a and the second oil port D, and when a valve core of the two-position two-way valve is located at different positions, the first oil port a and the second oil port D of the telescopic balance valve 3 are respectively connected to form a second check valve 31 or a damping valve 32. As shown in fig. 4, hydraulic oil can be rapidly injected into the rodless cavity 41 of the telescopic cylinder 4 through the second check valve 31, so as to drive the telescopic cylinder 4 to extend out against the load pressure; through the damping valve 32, the speed of the hydraulic oil backflow in the rodless cavity 41 can be slowed down, the retraction speed of the telescopic oil cylinder 4 under the combined action of hydraulic driving and load pressure is prevented from being too high, and the telescopic speed of the telescopic oil cylinder 4 is balanced. The valve core position of the two-position two-way valve can be switched under the action of hydraulic oil in the first oil duct, and the first channel is set as an oil supply channel of the rod cavity 43, so that when the hydraulic oil is injected into the rod cavity 43, the hydraulic oil in the rodless cavity 41 flows back, at the moment, the pressure in the first channel is higher, the two-position two-way valve is switched to the position where the damping valve 32 is connected, and the speed of the hydraulic oil flowing back in the rodless cavity 41 is reduced; when the hydraulic oil is injected into the rodless cavity 41, the hydraulic oil in the rod cavity 43 flows back, at this time, the pressure in the first passage is low, the two-position two-way valve is switched to the position where the second check valve 31 is connected, and the hydraulic oil is rapidly injected into the rodless cavity 41 through the second check valve 31. The valve position switching of the two-position two-way valve is automatically carried out.

As one embodiment of the single cylinder latch boom hydraulic control system of the present invention, as shown in fig. 6 and 7, the cartridge hydraulic valve 9 includes a valve body assembly and a mounting seat 96. The plug-in type hydraulic valve 9 is plugged in the first oil channel of the telescopic balance valve 3 through a mounting seat 96. The valve body assembly divides the first oil passage into a first oil chamber B and a second oil chamber E, so that the first oil chamber B and the second oil chamber E of the plug-in hydraulic valve 9 can be formed by means of the first oil passage of the telescopic balance valve 3, an independent shell does not need to be arranged for the plug-in hydraulic valve 9 to form the first oil chamber B and the second oil chamber E, and the structure of the plug-in hydraulic valve 9 is simplified. In addition, the plug-in mounting structure integrates the plug-in mounting type hydraulic valve 9 into the first oil duct of the telescopic balance valve 3, the plug-in mounting type hydraulic valve 9 is prevented from being influenced by external factors, and the stability of the integrated structure is higher.

In some embodiments of the single cylinder latch boom hydraulic control system of the present invention, as shown in fig. 4, the single cylinder latch boom hydraulic control system of the present invention further comprises an oil filter assembly 7. The oil filter assembly 7 is connected to the oil path between the central passage 42 and the arm pin electromagnetic directional valve 51 and the cylinder pin electromagnetic directional valve 52, and hydraulic oil flowing between the central passage 42 and the arm pin oil cylinder 61 and the cylinder pin oil cylinder 62 is required to pass through the oil filter assembly 7. The oil filter assembly 7 includes an oil filter 71 and a third check valve 72, and the oil filter assembly 7 is provided so that the hydraulic oil of higher pressure output from the central passage 42 flows to the arm-pin electromagnetic directional valve 51 and/or the cylinder-pin electromagnetic directional valve 52 through the oil filter 71 therein to be able to filter out foreign particles in the hydraulic oil. And the hydraulic oil with a small pressure that flows back from the arm pin electromagnetic directional valve 51 and/or the cylinder pin electromagnetic directional valve 52 flows to the central passage 42 through the third check valve 72, so that smooth flow of the hydraulic oil can be ensured.

In some embodiments of the single cylinder latch boom hydraulic control system of the present invention, as shown in FIG. 5, the single cylinder latch boom hydraulic control system of the present invention further comprises an arm pin 81 and a cylinder pin 82. The arm pin 81 and the cylinder pin 82 are respectively installed in two different directions on the side wall of the telescopic cylinder 4. The arm pin 81 is driven by the arm pin cylinder 61 to perform an insertion and extraction operation, and the arm pin 81 is inserted into or extracted from the arm pin hole of the next-stage boom. The cylinder pin 82 is driven by the cylinder pin cylinder 62 to perform an inserting and extracting operation, and the cylinder pin 82 is inserted into or extracted from a cylinder pin hole in the boom.

As a specific embodiment of the single cylinder pin type boom hydraulic control system of the present invention, as shown in fig. 4, the arm pin cylinder 61 and the cylinder pin cylinder 62 are both spring cylinders. When hydraulic oil enters the rod cavity of the arm pin oil cylinder 61 from the central channel 42 under the control of the arm pin electromagnetic directional valve 51, the hydraulic oil pushes the piston of the arm pin oil cylinder 61 to move and compresses the spring in the rodless cavity of the arm pin oil cylinder 61, and the arm pin oil cylinder 61 retracts to drive the arm pin 81 to be pulled out of the arm pin hole. After the hydraulic oil in the central passage 42 is unloaded, the spring in the rodless cavity of the arm pin cylinder 61 rebounds, the hydraulic oil in the rod cavity flows back through the central passage 42, and the arm pin cylinder 61 extends out to drive the arm pin 81 to be inserted into the arm pin hole. The rod chamber of the cylinder pin cylinder 62 is connected to the cylinder pin solenoid directional valve 52 and when hydraulic oil enters the rod chamber of the cylinder pin cylinder 62 from the center passage 42 under the control of the cylinder pin solenoid directional valve 52, the hydraulic oil pushes the piston of the cylinder pin cylinder 62 to move and compress the spring in the rod-less chamber of the cylinder pin cylinder 62, the cylinder pin cylinder 62 retracts, and the cylinder pin 82 is pulled out of the cylinder pin bore. When the hydraulic oil in the central passage 42 is unloaded, the spring in the rodless cavity of the cylinder pin cylinder 62 rebounds, the hydraulic oil in the rod cavity flows back through the central passage 42, the cylinder pin cylinder 62 extends out, and the cylinder pin 81 is driven to be inserted into the cylinder pin hole.

The operation of the telescopic cylinder 4 of the present invention will be described with reference to the embodiment shown in fig. 4 as an example:

the extending process of the telescopic oil cylinder 4 is as follows: the engine drives the hydraulic pump 1 to operate and output high-pressure hydraulic oil, the solenoid valve Y1B in the control valve group 2 is electrified, the main valve rod is reversed, and the high-pressure hydraulic oil passes through the main valve rod, is output through a port B1 of the control valve group 2 after flow compensation, and flows back through a port A1 of the control valve group 2. Because the oil port A1 is connected with the first oil duct of the telescopic balance valve 3, and the first oil duct is in a low-pressure state, the second check valve 31 of the telescopic balance valve 3 is in an access state, and the high-pressure hydraulic oil output from the port B1 enters the rodless cavity 41 of the telescopic oil cylinder 4 through the second check valve 31 to drive the telescopic oil cylinder 4 to extend out. The hydraulic oil in the rod chamber 43 of the telescopic cylinder 4 flows to the first oil chamber B through the back pressure valve 902 via the second oil chamber E of the plug-in hydraulic valve 9, and a back pressure with a set magnitude is formed in the rod chamber 43, so as to reduce the influence of the pressure of the hydraulic oil in the central passage 42 on the extension speed of the telescopic cylinder 4. The hydraulic oil in the first oil cavity B flows back to the oil tank through the control valve group 2.

The retracting process of the telescopic oil cylinder 4 is as follows: the engine drives the hydraulic pump 1 to operate and output high-pressure hydraulic oil, the solenoid valve Y1a in the control valve group 2 is electrified, the main valve rod is reversed, the high-pressure hydraulic oil passes through the main valve rod and is output through the port A1 of the control valve group 2 after flow compensation, and the port A1 is connected with the first oil duct of the telescopic balance valve 3, so that the first oil duct is in a high-pressure state, and the damping valve 32 of the telescopic balance valve 3 is in an access state. The high-pressure hydraulic oil enters the first oil chamber B of the first oil passage, flows to the second oil chamber E through the first check valve 901, enters the rod chamber 43 of the telescopic cylinder 4, and drives the telescopic cylinder 4 to retract. The hydraulic oil in the rodless cavity 41 of the telescopic oil cylinder 4 enters the second oil port D of the telescopic balance valve 3, passes through the damping valve 32, enters the port B1 of the control valve group 2 through the first oil port A, and flows back to the oil tank. The damping valve 32 slows down the return speed of the hydraulic oil so that the extension and retraction speeds of the telescopic cylinder 4 are balanced.

In the crane, the single-cylinder bolt type boom hydraulic control system provided by any embodiment of the invention is used, so that the beneficial effects of the single-cylinder bolt type boom hydraulic control system provided by the invention are also achieved.

In the description of the present invention, reference to the description of the terms "one embodiment," "some embodiments," "a specific embodiment," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In the present disclosure, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, numerous simple modifications can be made to the technical solution of the invention, including combinations of the individual specific technical features in any suitable way. The invention is not described in detail in order to avoid unnecessary repetition. Such simple modifications and combinations should be considered within the scope of the present disclosure as well.

Claims

1. A plug-in type hydraulic valve (9) comprises a first oil cavity (B) and a second oil cavity (E), and is characterized by further comprising a first one-way valve (901) taking the first oil cavity (B) as a liquid inlet and the second oil cavity (E) as a liquid outlet, a back pressure valve (902) taking the second oil cavity (E) as a liquid inlet and the first oil cavity (B) as a liquid outlet, a valve body assembly and a mounting seat (96), wherein the back pressure valve (902) can form back pressure with a set size in the second oil cavity (E); the valve body assembly can be installed in a liquid flow channel of the insertion parent body through the installation seat (96) so that the valve body assembly can divide the liquid flow channel of the insertion parent body into the first oil chamber (B) and the second oil chamber (E); the valve body assembly comprises a core rod (92), a main valve core (91), a strong spring (93), a spring seat (94) and a weak spring (95); one end of the main valve core (91) is provided with a conical flow blocking surface for separating the flow channel of the plug parent body, and the other end of the main valve core (91) is installed in the installation seat (96); a valve core oil cavity (921) is arranged in the center of the main valve core (91), one end, adjacent to the first oil cavity (B), of the valve core oil cavity (921) is provided with a valve core oil port (922) communicated with the first oil cavity (B), and the valve core oil cavity (921) is communicated with the second oil cavity (E) through a valve core oil hole (923) formed in the main valve core (91); the core rod (92) is installed in the valve core oil cavity (921), the spring seat (94) is in threaded connection with one end, far away from the first oil cavity (B), of the core rod (92), and the strong spring (93) is installed on the core rod (92) and located between the spring seat (94) and the valve core oil port (922), so that one end, close to the first oil cavity (B), of the core rod (92) can block the valve core oil port (922) to form the back pressure valve (902); the weak spring (95) is installed between the main valve core (91) and the installation seat (96) to push the main valve core (91) to block the liquid flow passage of the plug parent body, so as to form the first one-way valve (901).

2. A single-cylinder bolt type boom hydraulic control system is characterized by comprising a hydraulic pump (1), a control valve group (2), a telescopic balance valve (3), a telescopic oil cylinder (4), a boom pin electromagnetic directional valve (51), a cylinder pin electromagnetic directional valve (52) and the plug-in hydraulic valve (9) as claimed in claim 1; control valve group (2) are connected on the output oil circuit of hydraulic pump (1), in order to switch the confession offer the fuel feeding direction of the hydraulic oil of telescopic cylinder (4), install flexible balanced valve (3) and cartridge formula hydrovalve (9) control valve group (2) with on the connection oil circuit of telescopic cylinder (4), telescopic cylinder (4) are including no pole chamber (41), center channel (42) and have pole chamber (43), arm round pin electromagnetic directional valve (51) and cylinder round pin electromagnetic directional valve (52) with center channel (42) are connected to can control the motion of arm round pin hydro-cylinder (61) and cylinder round pin hydro-cylinder (62) respectively, cartridge formula hydrovalve (9) are installed there be pole chamber (43) with between control valve group (2), in order can to have pole chamber (43) to provide hydraulic oil, and form the backpressure when having the hydraulic oil backward flow in pole chamber (43).

3. The single cylinder pin type boom hydraulic control system of claim 2, wherein the telescopic balance valve (3) comprises a first oil port (a), a first oil passage, a second oil passage (C) and a second oil port (D), a two-position two-way valve is arranged between the first oil port (a) and the second oil port (D), and the two-position two-way valve can switch the position of a valve core under the action of hydraulic oil in the first oil passage, so that the connection between the first oil port (a) and the second oil port (D) is a second check valve (31) or a damping valve (32).

4. The single cylinder plug boom hydraulic control system of claim 3, characterized in that the plug-in hydraulic valve (9), comprising a valve body assembly and a mounting seat (96), is plugged into the first oil channel of the telescopic balance valve (3) through the mounting seat (96), dividing the first oil channel into the first oil chamber (B) and the second oil chamber (E).

5. The single cylinder latch boom hydraulic control system according to any of claims 2-4, further comprising an oil filter assembly (7), said oil filter assembly (7) being connected between said central channel (42) and said arm pin solenoid directional valve (51) and cylinder pin solenoid directional valve (52), said oil filter assembly (7) comprising an oil filter (71) and a third one-way valve (72) such that hydraulic oil in said central channel (42) can flow through oil filter (71) to said arm pin solenoid directional valve (51) and/or cylinder pin solenoid directional valve (52) and hydraulic oil in said arm pin solenoid directional valve (51) and/or cylinder pin solenoid directional valve (52) can flow through said third one-way valve (72) to said central channel (42).

6. The single-cylinder pin-type boom hydraulic control system according to any one of claims 2 to 4, characterized by further comprising an arm pin (81) and a cylinder pin (82), wherein the arm pin (81) and the cylinder pin (82) are respectively installed on two different directions of the side wall of the telescopic cylinder (4), the arm pin (81) can perform a plugging action under the driving of the arm pin cylinder (61), and the cylinder pin (82) can perform a plugging action under the driving of the cylinder pin cylinder (62).

7. The single cylinder pin boom hydraulic control system of claim 6, wherein the boom cylinder (61) and the cylinder pin cylinder (62) are spring cylinders, the rod cavity of the boom cylinder (61) is connected to the boom solenoid directional valve (51), and the rod cavity of the cylinder pin cylinder (62) is connected to the cylinder pin solenoid directional valve (52).

8. A crane comprising a single cylinder pinboom hydraulic control system of any one of claims 2 to 7.