CN202707661U - Pilot buffer valve, hydraulic control circuit for buffer and vibration reduction and construction machinery equipment - Google Patents

Abstract

Pilot buffer valve, including parallel first throttle valve (6), first one-way valve (7) and first bypass oil passage (20) and parallel second throttle valve (9), second one-way valve valve (8) and the second bypass oil passage (21), the first bypass oil passage (20) and the second bypass oil passage (21) are provided with devices for controlling the first bypass oil passage and the second bypass oil passage Two hydraulically controlled hydraulic switching elements for switching on and off the bypass oil circuit, the forward port (16) of the first check valve and the forward port (18) of the second check valve are respectively connected with the hydraulically controlled hydraulic switching element The corresponding hydraulic control cavity is connected. In addition, the utility model also provides a shock absorbing hydraulic control circuit and construction machinery equipment. The utility model takes into account the contradiction between reducing the hydraulic shock and improving the operation sensitivity, which can reduce the hydraulic shock when the mechanical working mechanism of the construction machinery equipment is suddenly operated, improve the operation stability of the whole vehicle, and effectively improve the operation comfort and operation efficiency .

Description

Pilot buffer valve, hydraulic control circuit for buffer and vibration reduction and construction machinery equipment

technical field

The utility model relates to a hydraulic valve, in particular to a pilot buffer valve. Further, the utility model relates to a buffer and vibration damping hydraulic control circuit comprising the pilot buffer valve. In addition, the utility model also relates to a construction machinery equipment, such as an excavator, provided with the buffering and damping hydraulic control circuit.

Background technique

Construction machinery, such as excavators, bulldozers, cranes, etc., widely use hydraulic systems to drive related mechanical working mechanisms. When the device starts or stops suddenly, a large hydraulic shock will be generated, which will cause severe vibration of the mechanical working mechanism and make the working stability of the whole machine worse.

For example, as far as excavators are concerned, usually the mechanical working mechanism of the excavator is controlled by manipulating the pilot handle. Skilled operators can operate the mechanical working mechanism smoothly by precisely manipulating the pilot handle, so that the start and stop impact of the mechanical working mechanism is relatively gentle. On the contrary, for unskilled operators, due to the sudden manipulation of the pilot handle, due to the inertia of the mechanical working mechanism, a sudden change in the working state of the mechanical working mechanism will produce a large impact, and the stability of the vehicle will deteriorate, thereby reducing the working performance. , and a strong impact will also reduce the durability of the mechanical working mechanism.

In order to alleviate the above defects, relevant technical measures have been taken in the prior art. The following briefly introduces relevant technical measures for reducing vibration in the prior art by taking an excavator as an example.

Figure 1 and Figure 2 show the damping valve used in the boom lifting control oil circuit of the Hitachi excavator. The damping valve is a slide valve type damping valve, which mainly changes the oil circuit through the movement of the internal valve stem. Flow direction, which mainly plays a role of vibration reduction when the power lifting control handle suddenly changes during the lifting of the boom to lowering the boom. Figure 1 shows the hydraulic schematic diagram of the vibration damping valve when the boom is lifted , Fig. 2 shows the hydraulic schematic diagram of the vibration damping valve that controls the action of the damping valve when the boom is suddenly lowered during the boom lifting process.

As shown in Figure 1, during the boom lifting operation, the low-pressure pilot hydraulic control oil that controls the boom lifting needs to be input to the hydraulic control commutator for controlling the reversing of the boom cylinder (not shown) through the damping valve. In the hydraulic control chamber of the control valve (not shown in the figure), the low-pressure pilot hydraulic control oil is input into the oil port A and acts on the valve stem of the damping valve. When the operation starts, the low-pressure pilot hydraulic control oil passes through the damping valve. The gap C (formed as a throttling oil channel) between the valve stem and the housing flows into the spring cavity of the spring 4. At the same time, the pilot hydraulic control oil flows to the oil port B through the internal oil passage 2 (also formed as a throttling oil passage). As the oil pressure of the pilot hydraulic oil rises, the oil pressure in the spring chamber of the spring 4 rises, pushing the shock absorber The valve stem overcomes the resistance of the spring 1 and moves to the left. Due to the movement of the valve stem, the damping valve switches to the right position, the oil port A communicates with the oil port B, and the oil pressure in the oil port B rises, so that the output pilot fluid The oil control can drive the valve rod in the hydraulic control reversing control valve to move to realize the reversing of the boom cylinder to lift the boom.

If the operator suddenly manipulates the pilot handle (not shown in the figure) to manipulate the pilot valve (not shown in the figure) during the lifting operation of the boom, the hydraulic control reversing control valve of the boom cylinder will suddenly change direction to realize dynamic The arm oil cylinder drives the boom down. At this time, the oil port A is connected with the oil tank through the pilot valve, and the return hydraulic oil from the hydraulic control chamber of the hydraulic control reversing control valve acts on the oil port B; part of the return stroke of the oil port B The hydraulic oil flows into the spring chamber of the spring 3 through the internal oil passage 1, and the other part of the return hydraulic oil flows to the oil port A through the damping valve to flow back to the oil tank, and at the same time, the hydraulic oil in the spring chamber of the spring 4 flows to the oil tank through the internal oil passage. Port A, and flow back to tank through port A. During this process, the hydraulic oil acting in the spring chamber of the spring 3 drives the valve stem of the damping valve to move to the right, so that the valve stem of the damping valve moves to the left position, and the valve stem of the damping valve and the housing The previous gap C is closed, the hydraulic oil in the spring chamber of spring 4 is blocked, the oil pressure in the spring chamber of spring 4 rises and moves the valve stem to the left, the gap C is opened again, and the hydraulic oil flows to port A to flow back to the tank. The valve stem of the damping valve moves back and forth through the above process, so that the return hydraulic oil gradually returns to oil port A, thereby making the valve stem of the hydraulic control valve control valve slowly return.

It can be seen from the above description that the Hitachi excavator adopts a damping valve in the boom lifting control oil circuit to prevent the return hydraulic oil from returning too fast, which is mainly through the throttling oil passage (such as the above-mentioned gap C) and the damping valve The pressure difference between the two ends makes the valve stem of the damping valve establish a dynamic balance during the oil return process, thereby preventing the rapid movement of the valve stem of the hydraulic reversing control valve during reversing and causing the rapid closure of the working oil circuit. However, the vibration damping valve of this prior art has a complex structure, and it is difficult to control the throttling flow of the throttling oil passage. At the same time, in order to form a pressure difference to make the valve stem of the damping valve move back and forth, it is necessary to adjust the spring chambers on both sides of the valve stem. Generally speaking, the work of this damping valve is not reliable, and often cannot achieve effective damping performance.

In addition, the Chinese invention patent application CN101619580Y discloses a device for improving the operating comfort of excavators, and Fig. 2 shows the hydraulic schematic diagram of the device. This prior art solution mainly uses a one-way throttle valve to control the oil return flow rate to slow down the moving speed of the main valve core. When the operating handle is suddenly returned, it is reasonable to throttle the return oil. However, after the boom changes from lifting to lowering after buffering, if the operator wants to quickly perform subsequent lowering of the boom to improve work efficiency, at this time the oil return of the hydraulic control chamber of the main hydraulic control reversing control valve Also throttled, which slows down the responsiveness of operations and reduces productivity. That is to say, the technical solution of cushioning through the one-way throttle valve has similar disadvantages to the damping valve on the above-mentioned Hitachi excavator, that is, through the throttle valve (similar to the above-mentioned throttling oil passage). Buffering, the flow rate of the oil return throttle valve needs to be precisely designed. If the oil return throttle oil volume is set too small, the sensitivity of the excavator's vehicle operation will become poor. If the oil return throttle oil volume is set too large, the It may lead to unsatisfactory cushioning effect of hydraulic shock during sudden start and stop, which cannot reasonably take into account the sensitivity of operation and the effectiveness of cushioning. In addition, Chinese utility model patent CN201738368U and the like disclose similar technical solutions, which will not be repeated here.

In view of the above-mentioned defects of the prior art, it is necessary to design a hydraulic device that can be effectively applied to the hydraulic system of construction machinery to buffer the impact.

Utility model content

The first technical problem to be solved by the utility model is to provide a pilot buffer valve, which can be used on the pilot hydraulic control oil circuit of the hydraulic control reversing valve to relatively effectively buffer the sudden start or stop of the hydraulic control reversing valve. Formed hydraulic shock, and has a high response sensitivity.

Furthermore, the technical problem to be solved by the utility model is to provide a buffering and damping hydraulic control circuit, which can be relatively sensitively used for hydraulically controlling the hydraulic control reversing valve, and can relatively effectively buffer The hydraulic shock formed when the hydraulic control reversing valve starts or stops suddenly.

In addition, the technical problem to be solved by the utility model is to provide a kind of engineering machinery equipment, which has good low-impact performance, better working stability, and can improve working efficiency.

In order to solve the above technical problems, the utility model provides a pilot buffer valve, wherein the pilot buffer valve includes a parallel first throttle valve, a first check valve, a first bypass oil passage and a parallel second throttle valve. valve, a second one-way valve, and a second bypass oil passage, the first bypass oil passage and the second bypass oil passage are provided with devices for controlling the first bypass oil passage and the second bypass oil passage The hydraulic control type hydraulic switch element, the forward port of the first check valve and the forward port of the second check valve communicate with the corresponding hydraulic control cavity of the hydraulic control type hydraulic switch element respectively.

Preferably, the hydraulically controlled hydraulic switching element includes a first two-position two-way hydraulic control reversing valve provided on the first bypass oil circuit and a second two-position two-way valve provided on the second bypass oil circuit. through the hydraulic control reversing valve, the hydraulic control chamber of the first two-position two-way hydraulic control reversing valve communicates with the positive port of the second one-way valve, and the second two-position two-way hydraulic control reversing valve The hydraulic control chamber of the valve communicates with the forward port of the first one-way valve.

Optionally, the hydraulically controlled hydraulic switching element includes a three-position four-way hydraulically controlled reversing valve, the left hydraulic control chamber of the three-position four-way hydraulically controlled reversing valve is connected to the positive side of the first one-way valve. port, the right hydraulic control chamber communicates with the forward port of the second check valve, and the first bypass oil passage and Both the second bypass oil passages are disconnected, the first bypass oil passage is disconnected and the second bypass oil passage is turned on in the left position, and the first bypass oil passage is turned on and the second bypass oil passage is turned on in the right position The second bypass oil circuit is disconnected.

Preferably, the pilot buffer valve is formed as an integral compound valve, and the valve body of the integral compound valve is formed with a first connection port communicated with the reverse port of the first one-way valve, and connected with the second port of the one-way valve. A second connection port communicated with the reverse port of the one-way valve, a third connection port communicated with the forward port of the first one-way valve, and a fourth connection port communicated with the forward port of the second one-way valve port.

On the basis of the above-mentioned technical solution of the pilot buffer valve, the utility model provides a buffering and damping hydraulic control circuit, wherein the buffering and damping hydraulic control circuit includes the pilot buffer valve described in any of the above technical solutions, the pilot buffer The valve is connected to the pilot hydraulic control oil circuit of the main hydraulic control reversing valve, and the main hydraulic control reversing valve is connected to the control oil circuit of the hydraulic actuator for reversing control, wherein the first check valve of the pilot buffer valve The reverse port of the second check valve communicates with the hydraulic control cavity on one side of the main hydraulic control reversing valve, the reverse port of the second check valve communicates with the other side hydraulic control cavity of the main hydraulic control reversing valve, and the The forward port of the first one-way valve and the forward port of the second one-way valve are connected to the pilot hydraulic control oil supply oil circuit and the pilot hydraulic control oil return oil circuit via the pilot valve.

Typically, the hydraulic actuator is a hydraulic cylinder or a hydraulic motor, the main hydraulic control valve is a hydraulically controlled three-position four-way valve, and the main hydraulic control valve is connected to the telescopic valve of the hydraulic cylinder. Commutation control is performed on the control oil circuit or the forward and reverse control oil circuit of the hydraulic motor.

Specifically, the pilot valve is a reversing valve, and the pilot valve can be switched such that the forward port of the first check valve is selectively connected to the pilot hydraulic control oil supply circuit or the pilot hydraulic control oil return circuit. The oil circuit is connected, and the forward port of the first one-way valve is selectively communicated with the pilot hydraulic control oil return circuit or the pilot hydraulic control oil supply circuit.

Preferably, the pilot valve includes a first pilot valve and a second pilot valve in the form of a two-position three-way reversing valve, the pilot hydraulic control oil supply circuit includes a pilot hydraulic control oil supply pump, and the pilot hydraulic control oil return oil The oil circuit includes an oil tank, wherein the forward port of the first check valve communicates with the working oil port of the first pilot valve, and the forward oil port of the second check valve communicates with the working oil port of the second pilot valve. The working oil port is connected, the output port of the pilot hydraulic oil supply pump is respectively connected with the oil inlet port of the first pilot valve and the oil inlet port of the second pilot valve, and the oil return port of the first pilot valve is connected with the oil inlet port of the second pilot valve. The oil return ports of the two pilot valves communicate with the oil tank respectively.

In addition, the present utility model also provides construction machinery equipment, wherein the hydraulic system of the construction machinery equipment includes the damping and vibration damping hydraulic control circuit described in any one of the above technical solutions.

Specifically, the construction machinery equipment is an excavator.

It can be seen from the above technical solutions that the design of the pilot operated buffer valve of the present utility model is different from the traditional one-way throttle valve. The traditional one-way throttle valve is added on one side or both sides of the pilot hydraulic control oil circuit. It is difficult to solve the contradiction between control sensitivity and impact reduction. The pilot buffer valve of the utility model adopts a mutual control mode. When the pilot valve starts suddenly, it first throttles through the corresponding throttle valve to achieve the purpose of buffering. When the spool of the main hydraulic control reversing valve moves through the initial After buffering, the oil pressure gradually increases to the predetermined value of the pilot hydraulic control oil to make the hydraulic control hydraulic switch element open, so that the corresponding hydraulic control chamber of the hydraulic control reversing valve returns oil quickly, ensuring the moving speed of the spool , taking into account the contradiction between reducing hydraulic shock and improving operational sensitivity. Therefore, the pilot buffer valve and its buffering and damping hydraulic control circuit of the utility model can reduce the hydraulic shock when the mechanical working mechanism of the construction machinery equipment (such as an excavator) suddenly operates, improve the stability of the vehicle operation, and effectively improve the operating comfort. and operating efficiency; at the same time, due to the reduction of impact, the service life of the mechanical working mechanism of construction machinery and related hydraulic components can be improved. The engineering mechanical equipment of the utility model has the pilot buffer valve of the utility model, so it also has the above-mentioned advantages.

Other features and advantages of the present utility model will be described in detail in the following specific embodiments.

Description of drawings

The following drawings are used to provide a further understanding of the utility model, and constitute a part of the description, which are used together with the following specific embodiments to explain the utility model, but the scope of protection of the utility model is not limited to the following accompanying drawings and specific implementation methods. In the attached picture:

Fig. 1 is a hydraulic schematic diagram of the operation of the damping valve on the Hitachi excavator when the boom is lifted in the prior art.

Fig. 2 is a hydraulic schematic diagram of the operation of the vibration damping valve of the Hitachi excavator shown in Fig. 1 when the boom is suddenly lowered during the boom lifting operation.

Fig. 3 is a hydraulic schematic diagram of a device for improving the operating comfort of an excavator disclosed in the Chinese invention patent application CN101619580Y.

Fig. 4 is a schematic hydraulic diagram of a pilot buffer valve according to a specific embodiment of the present invention.

Fig. 5 is a schematic hydraulic diagram of the pilot buffer valve in another specific embodiment of the present invention.

Fig. 6 is a hydraulic principle diagram of the buffer and vibration damping hydraulic control circuit formed by adopting the pilot buffer valve of the embodiment shown in Fig. 4 .

Fig. 7 is a hydraulic principle diagram of the buffer and vibration damping hydraulic control circuit formed by adopting the pilot buffer valve of the embodiment shown in Fig. 5 .

Explanation of reference signs:

1 main oil pump; 2 pilot hydraulic control oil supply pump;

3 first pilot valve; 4 second pilot valve;

5 fuel tank; 6 first throttle valve;

7 the first one-way valve; 8 the second one-way valve;

9 second throttle valve; 10 main hydraulic control reversing valve;

11 Boom oil cylinder; 12 Pilot buffer valve;

13 The first two-position two-way hydraulic control reversing valve; 14 The second two-position two-way hydraulic control reversing valve;

15 three-position four-way hydraulic control reversing valve; 16 positive port of the first one-way valve;

17 the reverse port of the first one-way valve; 18 the forward port of the second one-way valve;

19 The reverse port of the second one-way valve; 20 The first bypass oil circuit;

21 The second bypass oil circuit; 22 The working oil port of the first pilot valve;

23 The oil inlet port of the first pilot valve; 24 The oil return port of the first pilot valve;

25 The working oil port of the second pilot valve; 26 The oil inlet port of the second pilot valve;

27 Oil return port of the second pilot valve; A first connection port;

B the second connection port; C the third connection port;

D The fourth connection port.

Detailed ways

The specific embodiments of the present utility model 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 utility model, and the protection scope of the present utility model is not limited to the following Detailed ways.

Below firstly the specific implementation of the pilot buffer valve of the present invention. What needs to be explained here is that the pilot buffer valve of the present utility model belongs to hydraulic components, and Fig. 4 and Fig. 5 show only the hydraulic schematic diagrams of the pilot buffer valves in two embodiments of the present utility model, but obviously, the utility model In terms of mechanical structure, the pilot buffer valve can be formed by connecting the various valves shown in the figure through pipelines, or it can share the valve body to form an integral compound valve. Correspondingly, the connection ports A, B, C, and D marked in Fig. 4 and Fig. 5 are only marked for convenience of description, and such connection ports are generally formed on the mechanical entity structure of the buffer pilot valve of the present utility model When it is an integral compound valve, it is the corresponding oil port, but in the case where the pilot buffer valve of the present invention is connected by the various valves shown in the figure through pipelines, these connection ports may not exist in the physical structure. Instead, it represents only certain points on the corresponding pipeline.

Referring to Fig. 4 and Fig. 5, the pilot buffer valve 12 of the present invention includes a parallel first throttle valve 6, a first check valve 7, a first bypass oil passage 20 and a parallel second throttle valve 9 , the second one-way valve 8 and the second bypass oil passage 21, the first bypass oil passage 20 and the second bypass oil passage 21 are provided with a device for selectively controlling the first bypass oil passage 20 and the second bypass oil passage The bypass oil circuit 21 is a hydraulically controlled hydraulic switching element, the forward port 16 of the first check valve 7 and the forward port 18 of the second check valve 8 are respectively connected to the hydraulically controlled hydraulic switch element. The corresponding hydraulic control chamber is connected to drive the hydraulic control switch element to switch to make the second bypass The oil passage 21 is conducted, and when the oil pressure of the positive port 18 of the second check valve 8 is equal to or greater than a second predetermined value, the hydraulic control type hydraulic switch element is driven to switch to make the first bypass The oil circuit 20 is turned on.

For those skilled in the art, since the hydraulic control type hydraulic switch element generally has a return spring, by selecting or adjusting the return spring, the above-mentioned first predetermined value or the second predetermined value can be changed, thereby changing the hydraulic control type hydraulic switch. The opening oil pressure of the component. Therefore, within the scope of the above-mentioned technical concept of the present utility model, the above-mentioned first predetermined value and second predetermined value of the oil pressure may be equal or unequal. In addition, for the one-way valve, as known to those skilled in the art, the one-way valve has the functions of forward conduction and reverse cut-off. When hydraulic oil with a predetermined oil pressure is input from its forward port, the one-way valve will On the contrary, if the hydraulic oil is input from the reverse port, no matter how high the oil pressure is, it cannot be conducted.

Inspired by the above-mentioned technical concept of the present utility model, those skilled in the art can think of many kinds of hydraulic control hydraulic components capable of realizing the above-mentioned driving on-off hydraulic relationship. Typically, as shown in FIG. 4, the hydraulically controlled hydraulic switching element includes a first two-position two-way hydraulic control reversing valve 13 arranged on the first bypass oil passage 20 and a second bypass oil passage The second two-position two-way hydraulic control reversing valve 14 on the 21. Wherein, the hydraulic control cavity of the first two-position two-way hydraulic control reversing valve 13 communicates with the positive port 18 of the second check valve 8, and the hydraulic control cavity of the second two-position two-way hydraulic control reversing valve 14 It communicates with the forward port 16 of the first one-way valve 7 .

As an optional modification, the above-mentioned hydraulically controlled hydraulic switch element may also include a three-position four-way hydraulically controlled reversing valve 15, obviously, the three-position four-way hydraulically controlled reversing valve 15 has four oil ports, The first bypass oil passage 20 and the second bypass oil passage 21 are disconnected in the middle, so that the two connection ends of the disconnected position of the first bypass oil passage 20 and the two connected ends of the disconnected position of the second bypass oil passage 21 The connecting ends can be respectively connected to the four oil ports of the three-position four-way hydraulic control reversing valve. The internal oil passage and valve stem form of the three-position four-way hydraulic control reversing valve are various for those skilled in the art, so I will not repeat them here, as long as the following working conditions can be realized, that is, the three-position four-way hydraulic control When the spool of the reversing valve 15 is in the neutral position, both the first bypass oil passage 20 and the second bypass oil passage 21 are closed, and the left hydraulic control chamber of the three-position four-way hydraulic control reversing valve 15 is in contact with the The forward port 16 of the first one-way valve 7 communicates to drive the spool to switch to the left position when the oil pressure of the forward port 16 of the first one-way valve 7 is equal to or greater than the first predetermined value. The first bypass oil passage 20 is cut off and the second bypass oil passage 21 is turned on. The right hydraulic control cavity of the three-position four-way hydraulic control reversing valve is connected to the positive port 18 of the second check valve 8. When the oil pressure of the positive port 18 of the second check valve is equal to or greater than the second predetermined value, the valve core is driven to switch to the right position to make the first bypass oil passage 20 conduct , The second bypass oil passage 21 is closed.

In addition, as far as the two typical implementations shown in Fig. 4 and Fig. 5 are concerned, Fig. 4 adopts the first two-position two-way hydraulically controlled reversing valve 13 and the second two-position two-way reversing valve 14 to realize, which can facilitate Set different opening pressures accordingly. For example, the opening oil pressure of the first two-position two-way hydraulic control reversing valve 13 (that is, the opening oil pressure when the boom is lifted) is set to 0.6MPa, and the second two-position two-way reversing The opening oil pressure of the valve 14 (that is, the opening oil pressure when the boom is lowered) can be set to 1MPa; compared with the replacement scheme 15 of the three-position four-way reversing valve 15 shown in Figure 5, it can better adapt to the specific requirements of different actions , and the two two-position two-way hydraulic control reversing valves 13, 14 can be selected as standard cartridge valves, which is simpler and more versatile.

Of course, the above-mentioned hydraulic control type hydraulic switch element is not limited to the two typical implementation forms shown in Fig. 4 and Fig. 5. For those skilled in the field of hydraulic pressure, under the inspiration of the technical concept of the present utility model, many simple modifications can be conceived Form to realize the above-mentioned work driving relationship, these simple modifications all belong to the protection scope of the present utility model.

In addition, as mentioned above, the pilot buffer valve of the present invention can be formed in the form of an integral compound valve. In this case, the valve body of the integral compound valve is formed with a reverse port with the first one-way valve 7. The first connection port A communicating with 17, the second connection port B communicating with the reverse port 19 of the second one-way valve 8, the third connection port C communicating with the forward port 16 of the first one-way valve 7, and the third connection port C communicating with The forward port 18 of the second one-way valve 8 communicates with the fourth connection port D.

The specific implementation of the shock absorbing hydraulic control circuit of the present invention will be described below with reference to FIG. 6 and FIG. 7 .

The cushioning and damping hydraulic control circuit of the utility model includes the pilot buffer valve 12 of the above-mentioned technical solution, the pilot buffer valve 12 is connected to the pilot hydraulic control oil circuit of the main hydraulic control reversing valve 10, and the main hydraulic control reversing valve 10 is connected to On the control oil circuit of the hydraulic actuator to perform reversing control, wherein the reverse port 17 of the first check valve 7 of the pilot buffer valve 12 communicates with the hydraulic control chamber on one side of the main hydraulic control reversing valve 10 , the reverse port 19 of the second one-way valve 8 communicates with the other side of the main hydraulic control reversing valve, and the forward port 16 of the first one-way valve 7 and the second one-way valve 8 The forward port 18 is connected to the pilot hydraulic control oil supply oil circuit and the pilot hydraulic control oil return oil circuit through the pilot valve.

For those skilled in the art, the pilot valve of the main hydraulic control reversing valve is well known, and it is generally in the form of a reversing valve, which is manipulated by a pilot control handle. There are various types of specific reversing valves, as long as it can be realized The following normal working state is sufficient, that is, the positive port 16 of the first check valve 7 is selectively connected to the pilot hydraulic control oil supply oil circuit or the pilot hydraulic control oil return oil circuit through the switching of the pilot valve. and the forward port 16 of the first one-way valve 7 communicates with the pilot pilot oil return oil circuit or the pilot pilot oil control oil supply oil circuit. For example, as shown in Figure 6 and Figure 7, the pilot valve includes a first pilot valve 3 and a second pilot valve 4 in the form of a two-position three-way reversing valve, and the pilot hydraulic control oil supply circuit includes a pilot hydraulic control oil The oil supply pump 2, the pilot hydraulic control oil return oil circuit includes the oil tank 5, wherein the positive port 16 of the first check valve 7 communicates with the working oil port 22 of the first pilot valve 3, and the positive port of the second check valve 8 The oil port 19 communicates with the working oil port 25 of the second pilot valve 4, and the output port of the pilot oil control oil supply pump 2 is connected with the oil inlet 23 of the first pilot valve 3 and the oil inlet 26 of the second pilot valve respectively. (Obviously, the input port of the pilot hydraulic control oil supply pump 2 communicates with the oil tank to pump hydraulic oil), and the oil return port 24 of the first pilot valve 3 and the oil return port 27 of the second pilot valve are respectively connected to the oil tank 5 connected. In this way, obviously, by operating the first pilot valve 3, the positive port 16 of the first check valve 7 can be selectively communicated with the pilot hydraulic control oil supply pump 2 or the oil tank 5, and by operating the second pilot valve 4, it can be The forward oil port 19 of the second one-way valve 8 is selectively communicated with the pilot hydraulic oil supply pump 2 or the oil tank 5 . Of course, the pilot valve is not limited to the above-mentioned form including the first pilot valve 3 and the second pilot valve 4, for example, the above-mentioned first pilot valve 3 and the second pilot valve 4 can also be integrated into a Y-type three-position four-way reversing valve That is, the left position of the three-position four-way reversing valve makes the forward port 16 of the first check valve 7 communicate with the pilot hydraulic oil supply pump 2, and the forward oil port 19 of the second check valve 8 communicates with the fuel tank. 5 communication; when the neutral position makes the forward port 16 of the first check valve 7 and the forward oil port 19 of the second check valve 8 communicate with the oil tank 5; when the right position makes the forward port 16 of the first check valve 7 The port 16 communicates with the oil tank 5 , and the forward oil port 19 of the second check valve 8 communicates with the pilot hydraulic oil supply pump 2 . The simple variants of the pilot valve are obvious to those skilled in the art, and all of them belong to the protection scope of the present utility model.

In addition, within the scope of the above-mentioned basic technical concepts of the buffering and damping hydraulic control circuit of the present invention, for the technology in the hydraulic field, the hydraulic actuators in the hydraulic system of construction machinery are typically hydraulic cylinders or hydraulic motors, and the main The hydraulically controlled reversing valve 10 is generally a hydraulically controlled three-position, four-way reversing valve, and the main hydraulically controlled reversing valve 10 is connected to the telescopic control oil circuit of the hydraulic cylinder to realize the telescopic control of the hydraulic cylinder through reversing control, or It is connected to the forward and reverse control oil circuit of the hydraulic motor to realize the forward and reverse control of the hydraulic motor through commutation control. For example, as shown in Fig. 6 or Fig. 7, the telescopic control oil circuit of the hydraulic cylinder is known, and the rod chamber and the rodless chamber of the hydraulic cylinder are respectively connected to the two working oils of the main hydraulic control reversing valve 10 through pipelines. The oil inlet port of the main hydraulic control reversing valve 10 is connected to the output port of the main oil pump 1 through a pipeline, and the oil return port is connected to the oil tank 5 through a pipeline. The control oil circuits of hydraulic cylinders or hydraulic motors are well known and will not be repeated here. Typically, the hydraulic cylinder shown in FIG. 6 and FIG. 7 can be used as the boom cylinder 11 of the excavator, and the boom cylinder 11 is used to drive the boom of the excavator. Certainly not limited thereto, the hydraulic cylinder shown in Figure 6 and Figure 7 can also be used as a luffing cylinder of a hydraulic crane, or a folding driving cylinder between adjacent boom sections of the jib of a concrete pump truck, for example, in addition, in Fig. The hydraulic cylinders shown in Figure 6 and Figure 7 can be simply replaced by a hydraulic motor, and the working oil circuits connected to the rod cavity and the rodless cavity of the hydraulic cylinder are respectively connected to the two working oil ports of the hydraulic motor. The control oil circuit form of this hydraulic cylinder or hydraulic motor is similar.

On the basis of the technical solution of the buffering and damping hydraulic control circuit of the utility model, the utility model also provides a kind of engineering machinery equipment, the hydraulic system of the engineering machinery equipment includes the buffering and vibration damping hydraulic control circuit of the above technical solution of the utility model . Typically, the construction machinery equipment may be an excavator.

In order to help those skilled in the art understand the advantages of the utility model, the following describes how the pilot buffer valve of the utility model and its buffer and vibration damping hydraulic control circuit improve the operating comfort and performance of the excavator with reference to Figure 6 and take an excavator as an example. Job stability, and improved responsiveness and operational flexibility. Among them, the hydraulic cylinder shown in Fig. 6 is the boom cylinder 11 used to drive the boom of the excavator, and the telescopic control oil circuit of the boom cylinder 11 is provided with a main hydraulic control reversing valve 10, this hydraulic actuator (such as hydraulic cylinder or hydraulic motor) to set the main hydraulic control reversing valve on the control oil circuit is commonly used in construction machinery, such as excavator arm, slewing mechanism, hydraulic crane slewing table, luffing cylinder, etc., so this The utility model pilot buffer valve and its buffer and vibration damping hydraulic control circuit are not limited to the hydraulic drive system of the boom of the excavator.

Referring to Fig. 6, since the technical solution of the present utility model has been introduced in detail above, only a brief description is given in relation to Fig. 6 here, as shown in Fig. The pilot valve 3 (as the boom lowering pilot valve) is connected to the second pilot valve 4 (as the boom lifting pilot valve); the first and second pilot valves 3 and 4 are respectively connected to the pilot buffer valve 12, and the pilot buffer valve 12 They are respectively connected to the hydraulic control chambers on both sides of the main hydraulic control reversing valve 10 , and the main oil pump 1 and the oil tank 5 are connected to the boom cylinder 11 via the main hydraulic control reversing valve 10 to form the telescopic control oil circuit of the boom cylinder 11 .

As shown in Figure 6, during the sudden opening process of the first pilot valve 3, the pilot hydraulic control oil flows from the first pilot valve 3 through the third connection port C, through the first one-way valve 7, the first connection port A to the main pilot control valve. The hydraulic control chamber on the right side of the reversing valve 10 pushes the spool of the main hydraulic control reversing valve 10 to move to the left, and the hydraulic oil in the hydraulic control chamber on the left side of the main hydraulic control reversing valve 10 passes through the second connection port B Through the second throttle valve 9, the fourth connection port D flows to the second pilot valve 4 and returns to the oil tank 5. Since the return oil is throttled by the second throttle valve 9, the spool of the main hydraulic control reversing valve 10 Move slowly, the high-pressure hydraulic oil flowing out of the main oil pump 1 is slowly opened by the main valve core, and slowly flows into the rod chamber of the boom cylinder 11, so that the boom is slowly lowered. Since the pilot hydraulic control oil passing through the first one-way valve 7 acts on the hydraulic control cavity of the second two-position two-way hydraulic control reversing valve 14 at the same time, as the opening of the first pilot valve 3 gradually increases and the main hydraulic control changes As the movement resistance of the spool of the valve 10 increases (spring resistance), the oil pressure of the pilot hydraulic control oil gradually increases. When the opening pressure of the second two-position two-way hydraulic control reversing valve 14 is reached, the second two-position two-way The hydraulic control reversing valve 14 is opened. At this time, the hydraulic oil in the hydraulic control cavity on the left side of the main hydraulic control valve 10 returns oil directly through the second two-position two-way hydraulic control valve 14, and no longer passes through the second throttle valve 9, so that the main hydraulic control The spool of the reversing valve 10 performs rapid movement and reversing after the initial buffer slow movement, so that it can respond more quickly to the control signal of the first pilot valve 3 under the boom, thereby improving the sensitivity of the operation.

When the first pilot valve 3 returns suddenly during the operation of lowering the boom to stop the lowering of the boom, the spool in the main hydraulic control reversing valve 10 slides to the right under the action of the return spring on the left, and the main The hydraulic oil in the hydraulic control chamber on the right side of the hydraulic control reversing valve 10 flows through the first throttle valve 6 to the first pilot valve 3 and back to the oil tank 5. Since the return oil is throttled, the main hydraulic control reversing The moving speed of the spool of the valve 10 is stable, the hydraulic shock of the system is significantly reduced, and the stability of the vehicle during operation is improved.

The working principle when the boom lifting pilot valve 4 suddenly starts and stops is the same as above, and will not be repeated.

It can be seen from the above description that the design of the pilot-operated buffer valve 12 of the present utility model is different from the traditional one-way throttle valve. The traditional one-way throttle valve is added on one side or both sides of the pilot hydraulic control oil circuit. It is difficult to solve the contradiction between control sensitivity and impact reduction. The pilot buffer valve 12 of the utility model adopts a mutual control mode. When the pilot valve starts suddenly, it first throttles through the corresponding throttle valve to achieve the purpose of buffering. When the valve core of the main hydraulic control reversing valve 10 moves through the initial After the reversing buffer, the oil pressure gradually increases to the predetermined value of the pilot hydraulic control oil to make the hydraulic control hydraulic switch element open, so that the corresponding hydraulic control chamber of the hydraulic control reversing valve 10 can quickly return oil, ensuring the valve core The speed of movement takes into account the contradiction between reducing hydraulic shock and improving operational sensitivity. Therefore, the pilot buffer valve and its buffering and damping hydraulic control circuit of the utility model can reduce the hydraulic shock when the mechanical working mechanism of the construction machinery equipment (such as an excavator) suddenly operates, improve the stability of the vehicle operation, and effectively improve the operating comfort. and operating efficiency; at the same time, due to the reduction of impact, the service life of the mechanical working mechanism of construction machinery and related hydraulic components can be improved.

The preferred embodiment of the utility model has been described in detail above in conjunction with the accompanying drawings, but the utility model is not limited to the specific details of the above-mentioned embodiment, and within the scope of the technical concept of the utility model, the technical solution of the utility model can be carried out in many ways. These simple modifications all belong to the protection scope of the present utility model.

In addition, it should be noted that the various specific technical features described in the above specific implementation manners may be combined in any suitable manner if there is no contradiction. In order to avoid unnecessary repetition, the utility model will not further describe various possible combinations.

In addition, any combination of various implementations of the present invention can also be made, as long as they do not violate the idea of the present invention, they should also be regarded as the disclosed content of the present invention.

Claims (10)

1. guide's trimmer valve, it is characterized in that, this guide's trimmer valve comprises first throttle valve (6) in parallel, the first one-way valve (7) and the first bleed off circuit (20) and the second throttle valve (9) in parallel, the second one-way valve (8) and the second bleed off circuit (21), be provided with the hyraulic controlled type hydraulic switch element for this first bleed off circuit of control and the second bleed off circuit break-make on described the first bleed off circuit (20) and the second bleed off circuit (21), the forward port (16) of described the first one-way valve and the forward port (18) of the second one-way valve are communicated with the corresponding liquid controling cavity of described hyraulic controlled type hydraulic switch element respectively.

2. guide's trimmer valve according to claim 1, it is characterized in that, described hyraulic controlled type hydraulic switch element comprises and is arranged on the first two-position two-way hydraulic control selector valve (13) on described the first bleed off circuit (20) and the second two-position two-way hydraulic control selector valve (14) on described the second bleed off circuit (21) is set, the liquid controling cavity of described the first two-position two-way hydraulic control selector valve (13) is communicated with the forward port (18) of described the second one-way valve (8), and the liquid controling cavity of described the second two-position two-way hydraulic control selector valve (14) is communicated with the forward port (16) of described the first one-way valve (7).

3. guide's trimmer valve according to claim 1, it is characterized in that, described hyraulic controlled type hydraulic switch element comprises a 3-position 4-way pilot operated directional control valve (15), the left side liquid controling cavity of this 3-position 4-way pilot operated directional control valve (15) is communicated with the forward port (16) of described the first one-way valve (7), the right side liquid controling cavity is communicated with the forward port (18) of described the second one-way valve (8), described the first bleed off circuit (20) and the second bleed off circuit (21) all disconnected when the spool of described 3-position 4-way pilot operated directional control valve (15) was in meta, be in left described the first bleed off circuit in position (20) and disconnect and described the second bleed off circuit (21) conducting, described the first bleed off circuit (20) conducting and the second bleed off circuit (21) disconnect when being in right position.

4. each described guide's trimmer valve in 3 according to claim 1, it is characterized in that, described guide's trimmer valve forms the integrated type combination valve, be formed with the first connecting port (A) that is communicated with the reverse port (17) of described the first one-way valve (7) on the valve body of this integrated type combination valve, the second connecting end (B) that is communicated with the reverse port (19) of described the second one-way valve (8), the 3rd connecting port (C) that is communicated with the forward port (16) of described the first one-way valve (7) and the 4th connecting end (D) that is communicated with the forward port (18) of described the second one-way valve (8).

5. buffer shock-absorbing hydraulic control circuit, it is characterized in that, this buffer shock-absorbing hydraulic control circuit comprises according to claim 1 each described guide's trimmer valve (12) in 4, this guide's trimmer valve (12) is connected on guide's hydraulic control oil circuit of main pilot operated directional control valve (10), described main pilot operated directional control valve (10) is connected on the oil circuit control of hydraulic actuator with the control that commutates, the reverse port (17) of first one-way valve (7) of wherein said guide's trimmer valve (12) is communicated with a side liquid controling cavity of described main pilot operated directional control valve (10), the reverse port (19) of the second one-way valve (8) is communicated with the opposite side liquid controling cavity of this main pilot operated directional control valve, and the forward port (18) of the forward port (16) of described the first one-way valve and the second one-way valve is connected in guide's hydraulic control oil oil feeding line and guide's hydraulic control oil oil return circuit via pilot valve.

6. buffer shock-absorbing hydraulic control circuit according to claim 5, it is characterized in that, described hydraulic actuator is oil hydraulic cylinder or oil hydraulic motor, described main pilot operated directional control valve (10) is the hyraulic controlled type three position four-way directional control valve, this main pilot operated directional control valve (10) be connected on the extension and contraction control oil circuit of described oil hydraulic cylinder or on the clockwise and anticlockwise oil circuit control of described oil hydraulic motor with the control that commutates.

7. buffer shock-absorbing hydraulic control circuit according to claim 5, it is characterized in that, described pilot valve is selector valve, described pilot valve can switch so that the forward port (16) of described the first one-way valve (7) optionally is communicated with described guide's hydraulic control oil oil feeding line or guide's hydraulic control oil oil return circuit is communicated with, and so that the forward port (16) of described the first one-way valve (7) optionally be communicated with described guide's hydraulic control oil oil return circuit or the oily oil feeding line of guide's hydraulic control.

8. buffer shock-absorbing hydraulic control circuit according to claim 7, it is characterized in that, described pilot valve comprises the first pilot valve (3) and second pilot valve (4) of two position three way directional control valve form, described guide's hydraulic control oil oil feeding line comprises guide's hydraulic control oil oil feed pump (2), described guide's hydraulic control oil oil return circuit comprises fuel tank (5), the forward port (16) of wherein said the first one-way valve (7) is communicated with the actuator port (22) of described the first pilot valve (3), the forward hydraulic fluid port (19) of described the second one-way valve (8) is communicated with the actuator port (25) of described the second pilot valve (4), the delivery outlet of described guide's hydraulic control oil oil feed pump (2) is communicated with the filler opening (23) of described the first pilot valve and the filler opening (26) of the second pilot valve (4) respectively, and the return opening (27) of the return opening of this first pilot valve (24) and the second pilot valve is communicated with described fuel tank (5) respectively.

9. engineering mechanical device is characterized in that, comprises in the hydraulic system of this project machinery according to each described buffer shock-absorbing hydraulic control circuit in 5 to 8 in the claim.

10. engineering mechanical device according to claim 9 is characterized in that, described engineering mechanical device is excavator.

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