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

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

Cartridge hydraulic valve, single-cylinder bolt-type boom 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 hydraulic control system of a single-cylinder bolt type boom and a crane.

Background technique

The telescopic mechanism of the truck crane is mainly divided into two types: the rope row type and the single cylinder latch type. The rope row type telescopic mechanism controls the expansion and contraction of the boom through the extension and retraction of the telescopic oil cylinder. The boom can be hoisted at any position in the extension and retraction stroke. During the hoisting process, the telescopic oil cylinder bears the weight of the hoisting load. load capacity. The single-cylinder bolt-type telescopic mechanism mainly uses the telescopic oil cylinder to drive the boom to extend, and fix the boom at the corresponding position through the bolt for hoisting. During the hoisting process, the bolt is stressed and the oil cylinder is not stressed, so it can ensure that the hoisting process The boom length does not change.

The single-cylinder bolt-type telescopic mechanism usually uses a hydraulic control system to control the expansion and contraction of the boom and the insertion and removal of the bolt. In the initial state, the cylinder pin of the telescopic mechanism is inserted into the pin hole of the boom cylinder, so that the telescopic cylinder can drive the corresponding telescopic boom. telescopic; the arm pin is inserted into the arm pin hole of the next-level boom, so that the position of the telescopic boom in the next-level boom remains unchanged. When the telescopic boom is stretched out, the telescopic oil cylinder is stretched out, and the cylinder pin drives the boom to extend a certain distance so that the arm pin is in a state of no force; pull out the arm pin, so that the telescopic boom can be stretched freely; Drive the telescopic boom out to a suitable position; insert the boom pin into the corresponding boom pin hole on the next level boom, so that the telescopic boom is fixed at the new position. When the telescopic boom is retracted, the telescopic oil cylinder is stretched out first, and the cylinder pin drives the boom to extend a certain distance so that the arm pin is in an unstressed state; the arm pin is pulled out, so that the telescopic boom can be freely retracted; the telescopic cylinder retracts, and the cylinder The pin drives the boom to retract to a proper position; insert the boom pin into the corresponding boom pin hole on the next level boom, so that the telescopic boom is fixed at a new position. When it is necessary to control the upper-level boom, the telescopic oil cylinder extends a certain distance until the cylinder pin is in a state of no force; unplug the cylinder pin, so that the telescopic boom can freely expand and contract relative to the boom; The proper position of the arm; insert the cylinder pin into the cylinder pin hole of the upper level boom, so that the boom can be stretched and retracted under the drive of the telescopic cylinder. When it is necessary to control the boom of the upper level, the telescopic oil cylinder extends a certain distance until the cylinder pin is in an unstressed state; the cylinder pin is pulled out so that the telescopic oil cylinder can freely expand and contract relative to the boom; the telescopic oil cylinder retracts to the next level of crane. The proper position of the arm; insert the cylinder pin into the cylinder pin hole of the next-level boom, so that the boom can be stretched and retracted under the drive of the telescopic cylinder.

An existing hydraulic control system for a single-cylinder bolt-type boom is shown in Figure 1. The hydraulic oil pumped by the hydraulic pump 1 is delivered to the telescopic cylinder 4 under the control of the control valve group 2 to drive the telescopic movement of the telescopic cylinder 4. The telescopic balance valve 3 is arranged between the control valve group 2 and the telescopic oil cylinder 4 to prevent the boom from retracting too quickly under load. Part of the hydraulic oil is delivered 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 Under the control of the valve 52, the movements of the control arm pin oil cylinder 61 and the cylinder pin oil cylinder 62 are respectively driven to form the pull-out action of the cylinder pin and the arm pin.

In the existing single-cylinder bolt type boom hydraulic control system, when the cylinder pin or arm pin is pulled out, the telescopic oil cylinder needs to extend to ensure that the cylinder pin or pin shaft is not stressed. At this time, the rodless cavity of the telescopic cylinder and the central passage of the telescopic cylinder are filled with high-pressure oil at the same time, and the high-pressure oil in the central passage acts on the piston of the telescopic cylinder, and the hydraulic oil superimposed in the rodless chamber exerts a force on the piston. In terms of thrust, it affects the control accuracy of the control system on the telescopic cylinder.

Contents of the invention

The technical problem to be solved by the present invention is to provide a plug-in hydraulic valve capable of forming a one-way flow back pressure of hydraulic oil.

The technical problem to be solved by the present invention is to provide a single-cylinder bolt-type boom hydraulic control system, and the control precision of the telescopic oil cylinder is high.

The further technical problem to be solved by the present invention is to provide a crane with reliable and convenient telescopic control of the boom.

In order to achieve the above object, the first aspect of the present invention provides a plug-in hydraulic valve, which includes a first oil chamber and a second oil chamber, and uses the first oil chamber as a liquid inlet, and uses the second oil chamber as an inlet. The first one-way valve with the oil chamber as the liquid outlet and the back pressure valve with the second oil chamber as the liquid inlet and the first oil chamber as the liquid outlet, the back pressure valve can be used in the The second oil chamber forms a set back pressure.

Preferably, the valve body assembly and the mounting seat of the cartridge type hydraulic valve of the present invention can be installed in the liquid flow channel of the cartridge body through the mounting seat, so that the valve body assembly can integrate the The liquid flow channel is divided into the first oil chamber and the second oil chamber. Through this preferred technical solution, the cartridge hydraulic valve of the present invention can use the liquid flow channel of the cartridge body to form the oil chamber of the hydraulic valve, thereby omitting the independently provided housing and oil chamber, which simplifies the cartridge hydraulic valve of the present invention. The structure of the hydraulic valve enables the plug-in hydraulic valve of the present invention to be conveniently used in conjunction with other hydraulic valves.

Further preferably, the valve body assembly includes 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 choke for separating the liquid flow channel of the inserted mother On the surface, the other end of the main valve core is installed in the installation seat; the center of the main valve core is provided with a valve core oil chamber, and the end of the valve core oil chamber adjacent to the first oil chamber is provided with a The spool oil port communicated with the first oil cavity, and the spool oil cavity communicates with the second oil cavity through the spool oil hole provided on the main spool; the core rod is installed on the In the valve core oil chamber, the spring seat is threadedly connected to the end of the core rod away from the first oil chamber, and the strong spring is installed on the core rod and is between the spring seat and the valve core oil chamber. Between the ports, so that the end of the core rod adjacent to the first oil chamber can block the oil port of the spool to form the back pressure valve; the weak spring is installed between the main spool and the installation Between the seats, the main valve core can be pushed to block the liquid flow channel of the cartridge body to form the first one-way valve. In this preferred technical solution, the main valve core isolates the first oil chamber and the second oil chamber under the action of the weak spring, so that the hydraulic oil in the second oil chamber cannot directly enter the first oil chamber through the second oil chamber; The core rod blocks the oil port of the valve core under the action of the strong spring, and the hydraulic oil in the first oil chamber acts on the end face of the main valve core, easily overcoming the elastic force of the weak spring to push the main valve core into the second oil chamber, A first one-way valve is formed in which the first oil chamber is the liquid inlet and the second oil chamber is the liquid outlet. The hydraulic oil in the second oil chamber can enter the valve core oil chamber through the valve core oil hole, and enter the mounting seat through the gap between the main valve core and the spring seat, forming pressure on the end face of the core rod. When the oil pressure in the second oil chamber reaches a certain value, the pressure will exceed the elastic force of the strong spring, push the core rod to move and open the oil port of the valve core, the hydraulic oil enters the first oil chamber through the oil port of the valve core, and A certain back pressure is formed in the second oil chamber, forming a back pressure valve with the second oil chamber as the liquid inlet and the first oil chamber as the liquid outlet.

The second aspect of the present invention provides a hydraulic control system for a single-cylinder bolt-type boom, including a hydraulic pump, a control valve group, a telescopic balance valve, a telescopic oil cylinder, an electromagnetic reversing valve for arm pins, an electromagnetic reversing valve for cylinder pins and the first hydraulic control system of the present invention. On the one hand, the cartridge hydraulic valve is provided; the control valve group is connected to the output oil circuit of the hydraulic pump, so as to be able to switch the oil supply direction of the hydraulic oil provided to the telescopic cylinder, and the telescopic balance valve and The plug-in hydraulic valve is installed on the connecting oil circuit between the control valve group and the telescopic oil cylinder. The telescopic oil cylinder includes a rodless cavity, a central channel and a rod cavity. The arm pin electromagnetic reversing valve and the cylinder pin electromagnetic The reversing valve is connected with the central channel to control the movement of the arm pin oil cylinder and the cylinder pin oil cylinder respectively, and the plug-in hydraulic valve is installed between the rod chamber and the control valve group to be able to Hydraulic oil is supplied to the rod cavity, and a back pressure is formed when the hydraulic oil in the rod cavity returns.

Preferably, the telescopic balance valve includes a first oil port, a first oil passage, a second oil passage and a second oil port, and a two-position two-way connection is provided between the first oil port and the second oil port The two-position two-way valve can switch the position of the spool under the action of the hydraulic oil in the first oil passage, so that the connection between the first oil port and the second oil port is a second one-way valve or damper valve. Through this preferred technical solution, the telescopic balance valve can supply oil to the rodless chamber of the telescopic valve through the first oil port and the second oil port, supply oil to the rod chamber of the telescopic valve through the first oil passage, and supply oil to the rod chamber of the telescopic valve through the second oil passage. Supply oil to the center channel. When the hydraulic oil enters the rodless chamber through the first oil port and the second oil port, the rod chamber returns oil at low pressure, the first oil passage is in a low pressure state, and the two-position two-way valve is switched to the state where the second one-way valve is connected , the hydraulic oil can quickly enter the rodless chamber through the first oil port and the second oil port, and drive the telescopic oil cylinder to extend. When the hydraulic oil enters the rod chamber through the first oil passage, the first oil passage is in a high-pressure state, the two-position two-way valve is switched to the state where the damping valve is connected, the hydraulic oil in the non-sensing chamber flows back through the damping valve, and the telescopic cylinder retract. As the boom load is applied to the telescoping cylinder, it will increase the retraction speed of the telescoping cylinder. Connecting the damping valve to the hydraulic oil return passage can slow down the return speed of the hydraulic oil and slow down the retraction speed of the telescopic oil cylinder, so that the extension speed and the retraction speed of the telescopic oil cylinder are balanced. The one-way valve and the damping valve are switched under the pressure control of the first oil passage through the two-position two-way valve, which can realize the automatic switching of the one-way valve and the damping valve, the switching control is simple, and it can prevent the telescopic cylinder from being extended. Retracts under load pressure.

Further preferably, the plug-in hydraulic valve includes 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, dividing the first oil passage into all Describe the first oil chamber and the second oil chamber. Through this preferred technical solution, structures such as the shell of the plug-in hydraulic valve are omitted, so that the plug-in hydraulic valve and the telescopic balance valve are integrated together, the structure of the valve body is simplified, and the stability of the valve body is improved.

Preferably, the hydraulic control system of the single-cylinder bolt type boom of the present invention further includes an oil filter assembly, the oil filter assembly is connected to the arm pin electromagnetic reversing valve and the cylinder pin electromagnetic reversing valve in the central channel. In between, the oil filter assembly includes an oil filter and a third check valve, so that the hydraulic oil in the central passage can flow to the arm pin solenoid reversing valve and/or the cylinder pin solenoid through the oil filter. The reversing valve, and the hydraulic oil in the arm pin electromagnetic reversing valve and/or the cylinder pin electromagnetic reversing valve can flow to the central passage through the third one-way valve. In this preferred technical solution, when the hydraulic oil flows from the central channel of the expansion valve to the arm pin electromagnetic reversing valve and/or the cylinder pin electromagnetic reversing valve, due to the high pressure of the hydraulic oil, it can be filtered out by the oil filter. Impurities in the hydraulic oil; when the hydraulic oil flows from the arm pin electromagnetic reversing valve and/or the cylinder pin electromagnetic reversing valve to the center passage, the pressure of the returning hydraulic oil is low, and the hydraulic oil can be guaranteed to flow smoothly through the third check valve. reflow.

Specifically, the single-cylinder bolt type boom hydraulic control system of the present invention further includes an arm pin and a cylinder pin, and the arm pin and the cylinder pin are respectively installed in two different directions on the side wall of the telescopic oil cylinder, and the arm pin The plugging action can be performed under the drive of the arm pin oil cylinder, and the plugging action of the cylinder pin can be performed under the drive of the cylinder pin oil cylinder. In this preferred technical solution, the boom of the crane can be fixed and the expansion and contraction of the boom can be controlled through the arm pin and the cylinder pin installed in two different directions on the side wall of the telescopic oil cylinder.

Further preferably, both the arm pin oil cylinder and the cylinder pin oil cylinder are spring cylinders, the rod chamber of the arm pin oil cylinder is connected with the arm pin electromagnetic reversing valve, the rod chamber of the cylinder pin oil cylinder is connected to the The cylinder pin electromagnetic reversing valve is connected. Through this preferred technical solution, hydraulic oil can be injected into the rod cavity of the arm pin oil cylinder and the cylinder pin oil cylinder to drive the retraction of the arm pin oil cylinder and the cylinder pin oil cylinder. After the rod cavity of the arm pin oil cylinder and the cylinder pin oil cylinder is unloaded, the arm pin oil cylinder and the cylinder pin oil cylinder can stretch out under the elastic force of the spring in the rodless cavity.

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

Through the above technical solution, the cartridge hydraulic valve of the present invention can form a liquid flow channel in one direction and a back pressure channel in another direction to set the pressure between the two oil chambers. The two oil chambers formed by inserting the liquid flow channel of the mother body make the cartridge valve and the mother valve combined together, with simple structure and higher stability. The hydraulic control system of the single-cylinder bolt-type boom of the present invention can form a back pressure of a set size in the rod cavity of the telescopic valve through the plug-in hydraulic valve of the present invention, and offset the impact of the pressure in the central channel on the control accuracy of the telescopic valve. influences. The switching structure of the one-way valve and the damping valve in the telescopic balance valve can prevent the backflow of hydraulic oil in the rodless chamber during the stretching process of the telescopic valve. The arrangement of integrating the plug-in hydraulic valve of the present invention into the telescopic balance valve simplifies the structure and improves the stability of the hydraulic valve. The setting of using the spring cylinder as the arm pin cylinder and the cylinder pin cylinder and setting the oil filter valve assembly on its oil supply line enables the arm pin cylinder and the cylinder pin cylinder to be driven smoothly through a single oil supply passage. The crane arm of the invention has high control precision and reliable telescopic positioning.

Other features and advantages of the present invention will be described in detail in the detailed description that follows.

Description of drawings

Fig. 1 is a kind of hydraulic principle diagram of existing single-cylinder bolt type boom hydraulic control system;

Fig. 2 is a principle schematic diagram of an embodiment of the cartridge type hydraulic valve of the present invention;

Fig. 3 is a schematic structural view of an embodiment of the cartridge hydraulic valve of the present invention;

Fig. 4 is a hydraulic schematic diagram of an embodiment of the single-cylinder bolt-type boom hydraulic control system of the present invention;

Fig. 5 is a schematic structural view of a telescopic oil cylinder in the present invention;

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

Fig. 7 is a schematic structural diagram of an integrated state formed after the plug-in hydraulic valve of the present invention is plugged into the telescopic balance valve.

Explanation of reference signs

1 Hydraulic pump 2 Control valve group

3 Telescopic balance valve 31 Second check valve

32 Damper valve 4 Telescopic cylinder

41 Rodless cavity 42 Center channel

43 Rod cavity 51 Arm pin solenoid directional valve

52 Cylinder pin electromagnetic reversing valve 61 Arm pin oil cylinder

62 cylinder pin cylinder 7 oil filter assembly

71 Oil filter 72 Third check valve

81 Arm pin 82 Cylinder pin

9 Cartridge hydraulic valve 91 Main spool

92 Core rod 921 Spool oil chamber

922 Spool port 923 Spool port

93 strong spring 94 spring seat

95 Weak spring 96 Mounting seat

901 First check valve 902 Back pressure valve

A First oil port B First oil chamber

C Second oil passage D Second oil port

E Second oil chamber

Detailed ways

Specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

The terms "first", "second", and "third" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, the term " The features of "first", "second" and "third" may explicitly or implicitly include one or more of said features.

In the description of the present invention, it should be noted that, unless otherwise specified and limited, the terms "installation", "setting", and "connection" should be understood in a broad sense, for example, the term "connection" can be a fixed connection, or It can be a detachable connection or an integrated connection; it can be a direct connection or an indirect connection through an intermediary; it can be the internal communication of two elements or the interaction relationship between two elements. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In addition, in the drawings of the present invention, double-dot dash lines represent hydraulic components, solid lines represent working oil passages, and dotted lines represent control oil passages.

An embodiment of the cartridge type hydraulic valve 9 of the present invention, as shown in Figure 2 and Figure 3, includes a first oil chamber B and a second oil chamber E, and is formed in the first oil chamber B and the second oil chamber Between E, the first one-way valve 901 with the first oil chamber B as the liquid inlet and the second oil chamber E as the liquid outlet, and the second oil chamber E as the liquid inlet and the first oil chamber B is the back pressure valve 902 of the liquid outlet. In this way, when the hydraulic oil flows from the first oil chamber B to the second oil chamber E, the hydraulic oil passes through the first one-way valve 901 with less 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 one-way valve 901, but can only pass through the back pressure valve 902, and the passage resistance of the back pressure valve 902 makes the hydraulic oil form a certain amount of back pressure in the second oil chamber E. The size of the back pressure is determined by the passage resistance of the back pressure valve 902. The setting characteristics of the back pressure valve 902 can determine the resistance when the hydraulic oil passes through, and also can determine the back pressure of the hydraulic oil in the second oil chamber E.

In some embodiments of the cartridge type hydraulic valve 9 of the present invention, as shown in FIGS. In the liquid flow passage of the inserting mother body, the liquid flow passage of the inserting mother body is divided into two parts by the valve body assembly, and the liquid flow passages of the two parts of the inserting mother body respectively form the first part of the cartridge type hydraulic valve 9 of the present invention. Oil chamber B and the second oil chamber E. In this way, the plug-in hydraulic valve 9 of the present invention forms its own housing and inlet and outlet cavity by means of the liquid flow channel of the plug-in mother body and its wall structure, which simplifies the structure of the plug-in hydraulic valve 9 and makes the plug-in The type hydraulic valve 9 is integrated in the inside of the cartridge body, which improves the stability of the cartridge structure.

As a specific embodiment of the cartridge hydraulic valve 9 of the present invention, as shown in FIG. 3 , the valve body assembly includes 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 spool 91 is provided with a conical choke surface, and through the conical choke surface, it is in contact with the step of the liquid flow channel of the inserting matrix, separating the liquid flow channel of the inserting matrix into 91 ends of the main spool. The first oil chamber B on the top and the second oil chamber E on the side of the main valve core 91. The other end of the main valve core 91 is installed in the installation seat 96 and can slide in the installation seat 96 . The center of the main spool 91 is provided with a spool oil chamber 921, and one end of the main spool 91 where the conical flow blocking surface is located is provided with a spool oil port 922, which is connected to the first oil chamber B and the spool oil. Between chambers 921. The side wall of the main valve core 91 is provided with a valve core oil hole 923 , and the valve core oil chamber 921 communicates with the second oil chamber E through the valve core oil hole 923 . The core rod 92 is installed in the valve core oil chamber 921 through the valve core oil port 922, and the end of the core rod 92 away from the first oil chamber B is provided with a thread, and the strong spring seat 94 is screwed on the thread at the end of the core rod 92, The strong spring 93 installed on the core rod 92 and located between the spring seat 94 and the spool oil port 922 is compressed. One end of the core rod 92 located in the first oil chamber B is provided with an end cap, and the elastic force of the strong spring 93 presses the end cap at the end of the core rod 92 against the valve core oil port 922 to block the valve core oil port 922 . The weak spring 95 is installed at the end of the main valve core 91 , between the main valve core 91 and the installation seat 96 . The weak spring 95 can form the driving force of the main valve core 91 to the direction of the first oil chamber B, so that the conical flow blocking surface at the other end of the main valve core 91 blocks the liquid between the first oil chamber B and the second oil chamber E. flow channel. In this way, 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 ends of the core rod 92 and the main valve core 91, and it is easy to overcome the weak spring 95. The small elastic force pushes the whole valve body assembly to move into the mounting seat 96, opens the liquid flow channel 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 . And 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 valve core oil chamber 921 through the valve core oil hole 923, and then passes through the main valve core. The gap between 91 and spring seat 94 enters the mounting seat 96 to form pressure on the end of the main valve core 91, and together with the weak spring, the conical flow blocking surface of the main valve core 91 is pressed against the first oil chamber B and the second oil chamber B. On the step of the liquid flow channel between the two oil chambers E, the liquid flow channel between the first oil chamber B and the second oil chamber E is blocked, forming a second oil chamber B between the first oil chamber B and the second oil chamber E A one-way valve 901. 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, after the hydraulic oil in the second oil chamber E enters the mounting seat 96 , it will also form pressure on the end surface of the core rod 92 . 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 will exceed the elastic force of the strong spring 93, pushing the core rod 92 to move toward the first oil chamber B, and the end cover of the core rod 92 will A flow port is formed between the spool oil port 922 , and the hydraulic oil in the second oil chamber E enters the first oil chamber B through the spool oil hole 923 , the spool oil chamber 921 and the spool oil port 922 . As the hydraulic oil in the second oil chamber E flows out, the pressure in the second oil chamber E drops, and the pressure acting on the end face of the core rod 92 located in the mounting seat 96 drops, and the core rod 92 under the elastic force of the strong spring 93 Under the action, it moves toward the mounting seat 96, and the flow opening between the end cover of the core rod 92 and the valve core oil port 922 is reduced, so that the pressure in the second oil chamber E is maintained at a value compatible with the elastic force of the strong spring 93. Horizontally, a back pressure valve 902 between the second oil chamber E and the first oil chamber B is formed. Turning the spring seat 94 can adjust the position of the spring seat 94 at the end of the core rod 92, thereby adjusting the elastic force of the strong spring 93, and also adjusting the back pressure formed by the back pressure valve 902 in the second oil chamber E. size.

An embodiment of the hydraulic control system of the single-cylinder bolt type boom of the present invention is shown in Figure 4, including a hydraulic pump 1, a control valve group 2, a telescopic balance valve 3, a telescopic oil cylinder 4, an arm pin electromagnetic reversing valve 51, a cylinder pin Electromagnetic reversing valve 52 and the cartridge hydraulic valve 9 of any embodiment of the present invention. Driven by the engine, the hydraulic pump 1 pumps out hydraulic oil from the oil tank to provide the hydraulic driving force for the system to work. The control valve group 2 is connected to the output oil circuit of the hydraulic pump 1. The oil supply direction of the hydraulic oil supplied to the telescopic cylinder 4 can be switched through the action of the control valve group 2, and the electromagnetic reversing valve 51 connected to the arm pin and the cylinder pin can be controlled. The supply of hydraulic oil in the oil circuit of the electromagnetic reversing valve 52. The telescopic oil cylinder 4 includes a rodless cavity 41 , a central channel 42 and a rod cavity 43 . The hydraulic oil from the control valve group 2 enters the central channel 42 through the connecting oil circuit, and is connected to the arm pin electromagnetic reversing valve 51 and the cylinder pin electromagnetic reversing valve 52 through the central channel 42 through the connecting oil circuit, which can be used in the arm pin electromagnetic reversing valve. The arm pin oil cylinder 61 is driven to move under the control of the reversing valve 51 , and the cylinder pin oil cylinder 62 is driven to move under the control of the cylinder pin electromagnetic reversing valve 52 . The telescopic balance valve 3 and the plug-in hydraulic valve 9 are installed on the connecting oil circuit between the control valve group 2 and the telescopic oil cylinder 4, wherein the plug-in hydraulic valve 9 is installed between the rod cavity 43 and the control valve group 2, the first The oil chamber B is connected with the control valve group 2, the second oil chamber E is connected with the rod chamber 43, the hydraulic oil can enter the rod chamber 43 through the first one-way valve 901, and drives the telescopic cylinder 4 to retract, while the hydraulic oil When returning from the rod cavity 43 , it must pass through the back pressure valve 902 to form a set back pressure in the rod cavity 43 .

Usually, the structure of the telescopic oil cylinder 4 cylinder part used by the single-cylinder bolt type boom is shown in Figure 5. The bore diameter of the telescopic oil cylinder 4 is D1, the rod diameter is D2, the diameter of the central channel 42 is D3, and the diameter of the rodless cavity 41 is D3. The area is S1, the area of the rod chamber 43 is S2, and the area of the central channel 42 is S3. The central channel 42 is an oil passage formed between the connecting piston rod and the cylinder bottom of the telescopic oil cylinder 4. As the telescopic oil cylinder 4 stretches and retracts, the oil passage will be elongated and shortened accordingly. When the telescopic oil cylinder 4 of this cylinder body structure is used in the existing single-cylinder bolt type boom hydraulic control system as shown in Figure 1, if the arm pin 81 and the cylinder pin 82 need to retract, the telescopic oil cylinder 4 needs to be retracted. Carrying out the action of extending ensures that the action pin 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 also needs to be injected into the central channel 42 to drive the retraction of the arm pin 81 and the cylinder pin 82 . The pressure of the hydraulic oil in the rodless chamber 41 is the high oil pressure P1, the pressure of the hydraulic oil in the center passage 42 is the high oil pressure P2, and the pressure P2 in the center passage 42 is determined by the load, usually a constant value, and the rod chamber 43 The pressure of the hydraulic oil inside is P3. At this time, the hydraulic oil in the rod cavity 43 is in a state of direct return, and the pressure P3 is a very small oil return back pressure, which can be ignored. At this time, the force on the piston of telescopic cylinder 4 is P1×S1+P2×S3, and the force direction of the piston is the extending direction of the oil cylinder, 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.

From formula (1) can get:

P1=(m1×g+m1×a-P2×S3)/S1 (2)

P2, S1 and S3 are all fixed values. Under the same load m1×g and a certain load acceleration a, the pressure P1 in the rodless chamber 41 will be affected by the pressure P2 in the central channel 42 during the stretching process of the telescopic cylinder 4 Impact. This has just influenced the control accuracy of telescopic oil cylinder 4.

In the single-cylinder bolt 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 return through the back pressure valve 902, and the return flow of the back pressure valve 902 is set. The value PR3 of the back pressure is such that PR3=P2×S3/S2, so that the hydraulic oil in the rod cavity 43 can generate a return back pressure of PR3=P2×S3/S2.

At this time, when the extension of the telescopic oil cylinder 4 and the retraction of the cylinder pin and the arm pin are carried out simultaneously, the force on the piston of the telescopic oil cylinder 4 is:

P1×S1+P2×S3-PR3×S2

=P1×S1+P2×S3-(P2×S3/S2)×S2

=P1×S1

The force direction of the piston is the extension direction of the oil cylinder, and there are:

P1×S1=m1×g+m1×a (3)

From formula (3) can get:

P1=(m1×g+m1×a)/S1 (4)

It can be seen from formula (4) that under the same load m1×g and a certain load acceleration a, the pressure P1 in the rodless chamber (41) is constant during the stretching process of the telescopic cylinder (4), and is no longer affected by the central passage 42 The influence of the internal pressure P2 improves the control accuracy of the telescopic oil cylinder 4 in the telescopic process.

In some embodiments of the hydraulic control system of the single-cylinder bolt type boom of the present invention, as shown in Fig. 6 and Fig. 7, the telescopic balance valve 3 includes a first oil port A, a first oil passage, a second oil passage C and The second oil port D. Wherein, a two-position two-way valve is arranged between the first oil port A and the second oil port D, and when the spool of the two-position two-way valve is in a different position, the first oil port A of the telescopic balance valve 3 The second check valve 31 or the damping valve 32 are respectively connected with the second oil port D. As shown in Figure 4, through the second one-way valve 31, the hydraulic oil can be quickly injected into the rodless cavity 41 of the telescopic cylinder 4, and the telescopic cylinder 4 is driven to overcome the load pressure and stretch out; The return speed of the hydraulic oil in the cavity 41 prevents the retraction speed of the telescopic cylinder 4 from being too fast under the joint action of hydraulic drive and load pressure, so that the telescopic cylinder 4 has a relatively balanced telescopic speed. The position of the spool of the two-position two-way valve can be switched under the action of the hydraulic oil in the first oil passage, and the first passage is set as the oil supply passage of the rod chamber 43, so that when the hydraulic oil is injected into the rod chamber 43, The hydraulic oil in the rodless chamber 41 flows back. At this time, the pressure in the first channel is relatively high. Switch the two-position two-way valve to the position where the damping valve 32 is connected to slow down the return speed of the hydraulic oil in the rodless chamber 41. ; When hydraulic oil is injected into the rodless chamber 41, the hydraulic oil in the rod chamber 43 will flow back. In position, the hydraulic oil is quickly injected into the rodless chamber 41 through the second one-way valve 31 . The valve position switching of the 2/2-way valve can be carried out automatically.

As a specific embodiment of the hydraulic control system of the single-cylinder bolt type boom of the present invention, as shown in FIGS. 6 and 7 , the cartridge hydraulic valve 9 includes a valve body assembly and a mounting seat 96 . The plug-in hydraulic valve 9 is plugged into the first oil passage of the telescopic balance valve 3 through the mounting seat 96 . The valve body assembly divides the first oil passage into the first oil chamber B and the 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 use the telescopic balance valve 3 The first oil passage is formed instead of providing a separate housing for the cartridge hydraulic valve 9 to form the first oil chamber B and the second oil chamber E, which simplifies the structure of the cartridge hydraulic valve 9 . In addition, the plug-in structure integrates the plug-in hydraulic valve 9 into the first oil passage of the telescopic balance valve 3, which avoids the impact of external factors on the plug-in hydraulic valve 9, and the stability of the integrated structure is higher.

In some embodiments of the hydraulic control system of the single-cylinder bolt-type boom of the present invention, as shown in FIG. 4 , the hydraulic control system of the single-cylinder bolt-type boom of the present invention further includes an oil filter assembly 7 . The oil filter assembly 7 is connected on the oil path between the central passage 42 and the arm pin electromagnetic reversing valve 51 and the cylinder pin electromagnetic reversing valve 52, and the oil flowing between the central passage 42 and the arm pin oil cylinder 61 and the cylinder pin oil cylinder 62 All hydraulic oil needs to pass through the oil filter assembly 7. The oil filter assembly 7 includes an oil filter 71 and a third one-way valve 72. The oil filter assembly 7 is arranged so that the hydraulic oil with higher pressure output from the central channel 42 flows to the arm pin electromagnetic switch through the oil filter 71 therein. The directional valve 51 and/or the cylinder pin electromagnetic directional valve 52 can filter out the impurity particles in the hydraulic oil. The hydraulic oil with lower pressure flowing back from the arm pin electromagnetic reversing valve 51 and/or the cylinder pin electromagnetic reversing valve 52 flows to the central channel 42 through the third check valve 72 to ensure the smooth return of the hydraulic oil.

In some embodiments of the single-cylinder bolt type boom hydraulic control system of the present invention, as shown in FIG. 5 , the single-cylinder bolt type boom hydraulic control system of the present invention further includes an arm pin 81 and a cylinder pin 82 . The arm pin 81 and the cylinder pin 82 are respectively installed on two different directions of the side wall of the telescopic oil cylinder 4 . The arm pin 81 is driven by the arm pin oil cylinder 61 to perform a plugging action, and the arm pin 81 is inserted into the arm pin hole of the next-stage boom, or pulled out from the arm pin hole of the next-stage boom. The cylinder pin 82 is driven by the cylinder pin oil cylinder 62 to perform a plugging action, and the cylinder pin 82 is inserted into the cylinder pin hole on the boom, or pulled out from the cylinder pin hole on the boom.

As a specific embodiment of the single-cylinder bolt-type boom hydraulic control system of the present invention, as shown in FIG. 4 , both the arm pin oil cylinder 61 and the cylinder pin oil cylinder 62 are spring cylinders. The rod chamber of the arm pin oil cylinder 61 is connected with the arm pin electromagnetic reversing valve 51. When the hydraulic oil enters the rod chamber of the arm pin oil cylinder 61 from the central channel 42 under the control of the arm pin electromagnetic reversing valve 51, the hydraulic oil Push the piston of the arm pin oil cylinder 61 to move, and compress the spring in the rodless chamber of the arm pin oil cylinder 61, and the arm pin oil cylinder 61 retracts, driving the arm pin 81 to be pulled out from the arm pin hole. When the hydraulic oil in the central passage 42 is unloaded, the spring in the rodless chamber of the arm pin cylinder 61 rebounds, and the hydraulic oil in the rod chamber flows back through the central passage 42, and the arm pin cylinder 61 stretches out, driving the arm pin 81 to insert Arm pin hole. The rod chamber of cylinder pin oil cylinder 62 is connected with cylinder pin electromagnetic reversing valve 52, when the hydraulic oil enters the rod chamber of cylinder pin oil cylinder 62 from central channel 42 under the control of cylinder pin electromagnetic reversing valve 52, the hydraulic oil Push the piston of the cylinder pin oil cylinder 62 to move, and compress the spring in the rodless chamber of the cylinder pin oil cylinder 62, the cylinder pin oil cylinder 62 retracts, and drives the cylinder pin 82 to be pulled out from the cylinder pin hole. When the hydraulic oil in the central channel 42 is unloaded, the spring in the rodless cavity of the cylinder pin cylinder 62 rebounds, and the hydraulic oil in the rod cavity flows back through the central channel 42, and the cylinder pin cylinder 62 stretches out, driving the cylinder pin 81 to insert in the cylinder pin hole.

Take the embodiment shown in Figure 4 as an example below to illustrate the action process of the telescopic oil cylinder 4 of the present invention:

The stretching process of the telescopic cylinder 4 is as follows: the engine drives the hydraulic pump 1 to output high-pressure hydraulic oil, the solenoid valve Y1b in the control valve group 2 is energized, the main valve stem changes direction, the high-pressure hydraulic oil passes through the main valve stem, and after flow compensation Output through port B1 of control valve group 2, and return through port A1 of control valve group 2. Since the A1 oil port is connected to the first oil passage of the telescopic balance valve 3, the first oil passage is in a low-pressure state, so that the second check valve 31 of the telescopic balance valve 3 is in the connected state, and the high-pressure hydraulic oil output from the B1 port passes through The second one-way valve 31 enters the rodless cavity 41 of the telescopic oil cylinder 4 to drive the telescopic oil cylinder 4 to extend. The hydraulic oil in the rod chamber 43 of the telescopic cylinder 4 flows through the second oil chamber E of the plug-in hydraulic valve 9 to the first oil chamber B through the back pressure valve 902, forming a set back pressure in the rod chamber 43, To reduce the influence of the pressure of the hydraulic oil in the central channel 42 on the extension speed of the telescopic oil cylinder 4 . The hydraulic oil in the first oil chamber B flows back into the oil tank through the control valve group 2 .

The retraction process of the telescopic cylinder 4 is as follows: the engine drives the hydraulic pump 1 to output high-pressure hydraulic oil, the solenoid valve Y1a in the control valve group 2 is energized, the main valve stem changes direction, the high-pressure hydraulic oil passes through the main valve stem, and after flow compensation By controlling the output of the A1 port of the valve group 2, since the A1 port is connected to the first oil passage of the telescopic balance valve 3, the first oil passage is in a high pressure state, so that the damping valve 32 of the telescopic balance valve 3 is in the connected state. High-pressure hydraulic oil enters the first oil chamber B of the first oil passage, flows through the first check valve 901 to the second oil chamber E, 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 cylinder 4 enters the second oil port D of the telescopic balance valve 3, passes through the damping valve 32, enters the B1 port of the control valve group 2 through the first oil port A, and flows back into the oil tank. The damping valve 32 slows down the return flow speed of the hydraulic oil, so that the extension and retraction speeds of the telescopic oil cylinder 4 are balanced.

In the crane of the present invention, the single-cylinder bolt-type boom hydraulic control system of any embodiment of the present invention is used, so it also has the beneficial effects of the single-cylinder bolt-type boom hydraulic control system of the present invention.

In the description of the present invention, reference to the terms "one embodiment," "some embodiments," "a particular embodiment," etc., means that a specific feature, structure, material, or characteristic is described in connection with the embodiment or example. Included in at least one embodiment or example of the invention. In the present invention, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific 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, however, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, including combinations of specific technical features in any suitable manner. In order to avoid unnecessary repetition, various possible combinations are not further described in the present invention. However, these simple modifications and combinations should also be regarded as the content disclosed by the present invention, and all belong to the protection scope of the present invention.

Claims (8)

1. A plug-in hydraulic valve (9), comprising a first oil chamber (B) and a second oil chamber (E), characterized in that it also includes a fluid inlet with the first oil chamber (B) , the first one-way valve (901) with the second oil chamber (E) as the liquid outlet, the second oil chamber (E) as the liquid inlet, and the first oil chamber (B) It is the back pressure valve (902) of the liquid outlet, the valve body assembly and the mounting seat (96), and the back pressure valve (902) can form a set size back pressure in the second oil chamber (E); the The valve body assembly can be installed in the liquid flow passage of the inserting mother body through the mounting seat (96), so that the valve body assembly can separate the liquid flow passage of the inserting mother body into the first oil chamber ( B) and the second oil chamber (E); the valve body assembly includes a core rod (92), a main valve core (91), a strong spring (93), a spring seat (94) and a weak spring (95); the One end of the main spool (91) is provided with a tapered flow blocking surface for separating the liquid flow channel of the inserted mother body, and the other end of the main spool (91) is installed in the mounting seat (96); The center of the main spool (91) is provided with a spool oil cavity (921), and one end of the spool oil cavity (921) adjacent to the first oil cavity (B) is provided with a ) connected to the spool oil port (922), and the spool oil chamber (921) is connected to the second oil chamber (E ) communicated; the core rod (92) is installed in the valve core oil chamber (921), and the spring seat (94) is threaded on the core rod (92) away from the first oil chamber (B) The strong spring (93) is installed on the core rod (92) and is between the spring seat (94) and the valve core oil port (922), so that the core rod (92) ) adjacent to the first oil chamber (B) can block the spool oil port (922) to form the back pressure valve (902); the weak spring (95) is installed on the main spool ( 91) and the installation seat (96), to be able to push the main valve core (91) to block the liquid flow channel of the cartridge body, forming the first one-way valve (901). 2. A single-cylinder pin-type boom hydraulic control system, characterized in that it includes a hydraulic pump (1), a control valve group (2), a telescopic balance valve (3), a telescopic oil cylinder (4), an electromagnetic reversing arm pin valve (51), cylinder pin electromagnetic reversing valve (52) and the plug-in hydraulic valve (9) according to claim 1; the control valve group (2) is connected to the output of the hydraulic pump (1) On the oil circuit, the oil supply direction of the hydraulic oil provided to the telescopic oil cylinder (4) can be switched, and the telescopic balance valve (3) and the plug-in hydraulic valve (9) are installed on the control valve group (2) On the oil circuit connected to the telescopic oil cylinder (4), the telescopic oil cylinder (4) includes a rodless chamber (41), a central channel (42) and a rod chamber (43), and the arm pin electromagnetic reversing valve ( 51) and the cylinder pin electromagnetic reversing valve (52) are connected with the central channel (42) to control the movement of the arm pin oil cylinder (61) and the cylinder pin oil cylinder (62) respectively, and the cartridge type hydraulic valve (9) Installed between the rod chamber (43) and the control valve group (2), so as to provide hydraulic oil to the rod chamber (43) and form the rod chamber (43) The back pressure when the hydraulic oil in the backflow. 3. The hydraulic control system of the single-cylinder bolt type boom according to claim 2, characterized in that, the telescopic balance valve (3) comprises a first oil port (A), a first oil passage, a second oil passage ( C) and the 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 The position of the spool is switched under the action of the hydraulic oil in the first oil passage, so that the connection between the first oil port (A) and the second oil port (D) is the second check valve (31) or damping valve (32). 4. The hydraulic control system of the single-cylinder bolt type boom according to claim 3, characterized in that, the plug-in hydraulic valve (9) includes a valve body assembly and a mounting seat (96), and is installed through the The seat (96) is inserted into the first oil passage of the telescopic balance valve (3), and divides the first oil passage into the first oil chamber (B) and the second oil chamber (E). 5. The hydraulic control system of the single-cylinder bolt-type boom according to any one of claims 2 to 4, characterized in that it further comprises an oil filter assembly (7), and the oil filter assembly (7) is connected to Between the central channel (42) and the arm pin electromagnetic reversing valve (51) and cylinder pin electromagnetic reversing valve (52), the oil filter assembly (7) includes an oil filter (71) and a second Three one-way valves (72), so that the hydraulic oil in the central channel (42) can flow to the arm pin electromagnetic reversing valve (51) and/or the cylinder pin electromagnetic reversing valve through the oil filter (71) (52), and the hydraulic oil in the arm pin electromagnetic reversing valve (51) and/or the cylinder pin electromagnetic reversing valve (52) can flow to the central channel ( 42). 6. The single-cylinder bolt type boom hydraulic control system according to any one of claims 2 to 4, further comprising 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 oil cylinder (4), and the arm pin (81) can perform plugging and unplugging actions driven by the arm pin oil cylinder (61), The cylinder pin (82) can be inserted and pulled out under the drive of the cylinder pin oil cylinder (62). 7. The hydraulic control system of the single-cylinder bolt type boom according to claim 6, characterized in that, the arm pin oil cylinder (61) and the cylinder pin oil cylinder (62) are both spring cylinders, and the arm pin oil cylinder (61 ) is connected with the arm pin electromagnetic reversing valve (51), and the rod chamber of the cylinder pin oil cylinder (62) is connected with the cylinder pin electromagnetic reversing valve (52). 8. A crane, characterized in that it comprises the hydraulic control system for the single-cylinder bolt type boom as claimed in any one of claims 2 to 7.

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