CN114506385A

CN114506385A - Steering system and engineering machinery

Info

Publication number: CN114506385A
Application number: CN202210286394.6A
Authority: CN
Inventors: 张广彬
Original assignee: Sany Heavy Equipment Co Ltd
Current assignee: Sany Heavy Equipment Co Ltd
Priority date: 2022-03-23
Filing date: 2022-03-23
Publication date: 2022-05-17
Also published as: WO2023179312A1

Abstract

An embodiment of the present invention provides a steering system and an engineering machine, wherein the steering system includes: an oil tank; the steering gear pump is connected with the oil tank; the priority valve is connected with the steering gear pump; a first steering cylinder; a second steering cylinder; the full hydraulic steering gear is connected with the priority valve and the oil tank, is connected with the first steering oil cylinder through a first liquid path, and is connected with the second steering oil cylinder through a second liquid path; the emergency pump is connected with the oil tank and the priority valve; and the overload protection safety valve is arranged on the first liquid path and/or the second liquid path. According to the technical scheme, the emergency pump is additionally arranged, and when an engine is flamed out due to failure or a steering gear pump fails, the emergency pump can provide an emergency steering function for a steering system, so that the engineering machinery can be smoothly stopped. The steering system has simple structure, convenient maintenance and lower cost. In addition, an overload protection safety valve is additionally arranged between the full hydraulic steering gear and the steering oil cylinder, so that the effect of protecting the steering oil cylinder can be achieved when load impact is overlarge.

Description

Steering system and engineering machinery

Technical Field

The embodiment of the invention relates to the technical field of engineering machinery, in particular to a steering system and engineering machinery.

Background

A steering system of the mining dump truck in the related art adopts a constant pressure pump matched with a steering valve bank and an energy accumulator as a steering power source. The set of power source can release the oil pressure in the energy accumulator to provide the emergency steering capacity for the system under the emergency condition that the engine loses power, but the system has more complex structure and higher cost.

Disclosure of Invention

To solve or improve at least one of the above technical problems, an object of an embodiment of the present invention is to provide a steering system.

Another object of an embodiment of the present invention is to provide a working machine having the above steering system.

To achieve the above object, an embodiment of a first aspect of the present invention provides a steering system including: an oil tank; the steering gear pump is connected with the oil tank; the priority valve is connected with the steering gear pump; a first steering cylinder; a second steering cylinder; the full-hydraulic steering gear is connected with the priority valve, the full-hydraulic steering gear is connected with the oil tank, the full-hydraulic steering gear is connected with the first steering oil cylinder through a first liquid path, and the full-hydraulic steering gear is connected with the second steering oil cylinder through a second liquid path; the emergency pump is connected with the oil tank and the priority valve; and the overload protection safety valve is arranged on the first liquid path and/or the second liquid path.

According to the embodiment of the steering system provided by the invention, the emergency pump is additionally arranged, an energy accumulator in a traditional structure is omitted, and when an engine fails and stalls or a steering gear pump fails, the emergency pump can provide an emergency steering function for the steering system, so that the engineering machinery can be smoothly stopped. The design mode has the advantages that the steering system is simple in structure, convenient to maintain and low in cost. In addition, an overload protection safety valve is additionally arranged between the full-hydraulic steering gear and the steering oil cylinder, so that the effect of protecting the steering oil cylinder can be achieved when the load impact is overlarge, and the damage of the steering oil cylinder caused by the fact that the load pressure is overlarge and exceeds the rated pressure of the steering oil cylinder is avoided.

Specifically, the steering system comprises an oil tank, a steering gear pump, a priority valve, a full hydraulic steering gear, a first steering oil cylinder, a second steering oil cylinder, an emergency pump and an overload protection safety valve. Wherein, the oil tank is used for storing hydraulic fluid. The steering gear pump is connected with the oil tank. Optionally, the oil suction port of the steering gear pump is connected with the oil tank. Gear pumps are rotary pumps that deliver or pressurize fluid by virtue of the change in working volume and movement created between a pump cylinder and a meshing gear. In the gear pump, two gears, a pump body and front and rear covers form two closed spaces. When the gear rotates, the volume of the space on the gear disengagement side is increased from small to large, vacuum is formed, and liquid is sucked; the volume of the space on the gear meshing side is reduced from large to small, and liquid is squeezed into the pipeline. Further, the priority valve is connected to a steering gear pump. Optionally, the port P (i.e., the oil inlet) of the priority valve is connected with the oil outlet of the steering gear pump. Further, a full hydraulic steering gear is connected with the priority valve. Optionally, port P (i.e., the oil inlet) of the full hydraulic diverter is connected to port CF of the priority valve. The T port (namely an oil outlet) of the full hydraulic steering gear is connected with an oil tank. The full hydraulic steering gear is a hydraulic power steering form which is arranged between a steering wheel and a steering control mechanism and does not need to be connected by a connecting rod, and has the advantages of light and flexible control, simple structure, low price, convenient installation and arrangement of the whole machine and the like. Furthermore, the first steering oil cylinder is connected with the full hydraulic steering gear, and the second steering oil cylinder is connected with the full hydraulic steering gear. The full hydraulic steering gear is connected with the first steering oil cylinder through a first liquid path, and the full hydraulic steering gear is connected with the second steering oil cylinder through a second liquid path.

Furthermore, the emergency pump is connected with the oil tank and the priority valve. Optionally, the oil inlet of the emergency pump is connected to the oil tank, and the oil outlet of the emergency pump is connected to the P port (i.e., the oil inlet) of the priority valve. Through additionally arranging the emergency pump, when an engine is flamed out due to failure or the steering gear pump fails, the emergency pump can provide an emergency steering function for a steering system, so that the engineering machinery can be smoothly stopped. In other words, an emergency electric steering system is added on the basis of the prior full hydraulic steering system, the electric emergency steering system provides power assistance through a hydraulic power unit and mainly comprises an emergency motor and an emergency pump, and when an engine is in failure and flameout or a steering gear pump fails, the emergency motor can work by pressing an emergency button switch, so that power of the emergency pump is provided, and a vehicle can be smoothly parked. It should be noted that the emergency motor can not work continuously for more than 30s, and the motor should be turned off in time after the emergency stop is completed, so as to avoid wasting the electric quantity of the storage battery.

Further, the overload protection safety valve is arranged on the first liquid path and/or the second liquid path. Optionally, the overload protection safety valve is connected to a full hydraulic steering gear. The overload protection safety valve is connected with the first steering oil cylinder, and the overload protection safety valve is connected with the second steering oil cylinder. The overload protection safety valve is arranged between the full hydraulic steering gear and the steering oil cylinder. The fluid from the priority valve passes through the full hydraulic steering gear, the protection valve and the steering oil cylinder in sequence. By additionally arranging the overload protection safety valve between the full-hydraulic steering gear and the steering oil cylinder, the effect of protecting the steering oil cylinder can be achieved when the load impact is overlarge, and the damage of the steering oil cylinder caused by the fact that the load pressure is overlarge and exceeds the rated pressure of the steering oil cylinder is avoided.

According to the technical scheme, the emergency pump is additionally arranged, an energy accumulator in a traditional structure is omitted, and when an engine is in failure and flameout or a steering gear pump fails, the emergency pump can provide an emergency steering function for a steering system, so that the engineering machinery can be smoothly stopped. The design mode has the advantages that the steering system is simple in structure, convenient to maintain and low in cost. In addition, an overload protection safety valve is additionally arranged between the full-hydraulic steering gear and the steering oil cylinder, so that the effect of protecting the steering oil cylinder can be achieved when the load impact is overlarge, and the damage of the steering oil cylinder caused by the fact that the load pressure is overlarge and exceeds the rated pressure of the steering oil cylinder is avoided.

In addition, the technical scheme provided by the invention can also have the following additional technical characteristics:

in the technical scheme, the full hydraulic steering gear is provided with a left oil port and a right oil port, and when the full hydraulic steering gear is in a middle position, the left oil port and the right oil port are both in a cut-off state.

In the technical scheme, the first steering oil cylinder is a left steering oil cylinder, and the second steering oil cylinder is a right steering oil cylinder. The first steering oil cylinder is provided with a first rodless cavity and a first rod cavity, the first rodless cavity is provided with an A port of the first steering oil cylinder, and the first rod cavity is provided with a B port of the first steering oil cylinder. The second steering oil cylinder is provided with a second rodless cavity and a second rod cavity, the second rodless cavity is provided with an A port of the second steering oil cylinder, and the second rod cavity is provided with a B port of the second steering oil cylinder. Furthermore, a left oil port (L port) of the full hydraulic steering gear is connected with the port A of the first steering oil cylinder and the port B of the second steering oil cylinder; and a right oil port (R port) of the full hydraulic steering gear is connected with a port B of the first steering oil cylinder and a port A of the second steering oil cylinder. When the full hydraulic steering gear is in the middle position, the left oil port and the right oil port are both in a cut-off state. In other words, the left oil port and the right oil port are both in a cut-off state in the middle position of the steering gear, and the position of the steering wheel cannot be changed after the operator releases the steering wheel.

In the technical scheme, the full-hydraulic steering gear is provided with a first oil inlet and a first oil outlet, when the middle position of the full-hydraulic steering gear is in an open circuit state, the first oil inlet and the first oil outlet are both in a cut-off state, and the fluid pressure of the first oil inlet is greater than that of the first oil outlet.

In the technical scheme, a first oil inlet (port P) of the full hydraulic steering gear is connected with a priority valve, and a first oil outlet (port T) of the full hydraulic steering gear is connected with an oil tank. When the middle position of the pressure steering gear is in an open circuit state, the first oil inlet and the first oil outlet are both in a cut-off state, and the fluid pressure of the first oil inlet is greater than that of the first oil outlet. In other words, the middle position of the steering gear is in an open circuit state (closed core), namely when the steering gear does not work, the hydraulic oil is cut off by the steering gear, and the first oil inlet is a high-pressure port at the moment.

In the above technical scheme, the first steering cylinder has a first rod cavity and a first rodless cavity, the second steering cylinder has a second rod cavity and a second rodless cavity, the first rodless cavity and the second rod cavity are both connected with the left oil port, and the first rod cavity and the second rodless cavity are both connected with the right oil port.

In this technical scheme, first steering cylinder includes first cylinder body and first piston rod, and first cylinder body is worn to locate by first piston rod, and first piston rod can remove relative first cylinder body. The piston of the first piston rod divides the interior of the first cylinder into a first rodless chamber and a first rod chamber. The second steering oil cylinder comprises a second cylinder body and a second piston rod, the second cylinder body is penetrated by the second piston rod, and the second piston rod can move relative to the second cylinder body. The piston of the second piston rod divides the interior of the second cylinder into a second rodless chamber and a second rod chamber. And a first rodless cavity of the first steering oil cylinder and a second rodless cavity of the second steering oil cylinder are both connected with a left oil port of the full-hydraulic steering gear. And a first rod cavity of the first steering oil cylinder and a second rodless cavity of the second steering oil cylinder are connected with a right oil port of the full hydraulic steering gear. The piston rod of the first steering cylinder or the second steering cylinder moves by controlling oil feeding and returning of the left oil port and the right oil port so as to achieve the purpose of reversing. Optionally, the first rodless chamber is provided with a port a of the first steering cylinder, and the first rod chamber is provided with a port B of the first steering cylinder. The second steering oil cylinder is provided with a second rodless cavity and a second rod cavity, the second rodless cavity is provided with an A port of the second steering oil cylinder, and the second rod cavity is provided with a B port of the second steering oil cylinder. An L port (namely a left oil port) of the full hydraulic steering gear is connected with an A port of the first steering oil cylinder and a B port of the second steering oil cylinder; and an R port (a right oil port) of the full hydraulic steering gear is connected with a B port of the first steering oil cylinder and an A port of the second steering oil cylinder.

In the technical scheme, the first oil inlet is connected with the priority valve, and the first oil outlet is connected with the oil tank.

In the technical scheme, a first oil inlet (port P) of the full hydraulic steering gear is connected with a CF port of a priority valve, and a first oil outlet (port T) of the full hydraulic steering gear is connected with an oil tank. The hydraulic steering gear is connected with the priority valve and the oil tank to form a hydraulic loop, and hydraulic oil can flow to the hydraulic steering gear through the priority valve and can also flow back to the oil tank through the hydraulic steering gear.

In the above technical scheme, the steering gear pump has a first oil suction port and a second oil outlet, the first oil suction port is connected with the oil tank through a third liquid path, and the second oil outlet is connected with the priority valve through a fourth liquid path.

In the technical scheme, a first oil suction port of the steering gear pump is connected with an oil tank through a third liquid path, and a second oil outlet of the steering gear pump is connected with a P port of the priority valve through a fourth liquid path. By connecting the steering gear pump to the tank and to the priority valve, a hydraulic circuit is formed, the steering gear pump being able to pump hydraulic fluid from the tank to the priority valve, which then distributes the fluid to the full hydraulic steering gear or other modules.

In the above technical solution, the method further comprises: and the stop valve is arranged on the third liquid path.

In this technical solution, the steering system further includes a shutoff valve. Specifically, the stop valve is located the third fluid passage, and the stop valve is located between steering gear pump and the oil tank promptly. The stop valve is also called as a stop valve, has small friction force between sealing surfaces in the opening and closing process, is relatively durable, has small opening height, is easy to manufacture and convenient to maintain, and is suitable for medium and low pressure as well as high pressure. The closing principle of the stop valve is that the sealing surface of the valve clack is tightly attached to the sealing surface of the valve seat by means of the pressure of the valve rod, and the medium is prevented from flowing.

In the above technical solution, the method further comprises: the check valve is arranged on the fourth liquid path; and/or a high-pressure filter arranged on the fourth liquid path.

In this solution, the steering system further comprises a one-way valve. Specifically, the check valve is arranged on the fourth fluid path, namely the check valve is positioned between the steering gear pump and the priority valve. Through setting up the check valve, hydraulic fluid can only be by the steering gear pump flow direction priority valve, and hydraulic fluid can not be by the priority valve flow direction steering gear pump.

Further, the steering system also includes a high pressure filter. Specifically, the high-pressure filter is arranged on the fourth fluid path, namely the high-pressure filter is positioned between the steering gear pump and the priority valve. Through setting up high pressure filter, can play the effect of filtering impurity protection hydraulic system. In addition, the high pressure filter can withstand greater fluid pressures than conventional filters.

It is worth mentioning that the steering system may comprise only one of the check valve and the high pressure filter, and the arrangement is flexible according to actual requirements.

In the above technical scheme, the emergency pump has a second oil suction port and a third oil outlet, the second oil suction port is connected with the oil tank, and the third oil outlet is connected with the priority valve.

In the technical scheme, a second oil suction port of the emergency pump is connected with the oil tank, and a third oil outlet of the emergency pump is connected with a port P of the priority valve. Through being connected emergency pump and oil tank and priority valve, when engine failure stalled or turned to the gear pump and became invalid, emergency pump can provide emergent steering function for a steering system, made engineering machine park smoothly.

In the above technical solution, the method further comprises: and the lifting valve is connected with the priority valve.

In this solution, the steering system further comprises a lift valve. Specifically, the lift valve is connected to the EF port of the priority valve. The hydraulic oil flows to the lifting valve through the priority valve to complete the lifting action.

In the above technical solution, the method further comprises: the lifting pump is provided with a third oil suction port and a fourth oil outlet, the lifting valve is provided with a second oil inlet and a fifth oil outlet, the third oil suction port is connected with the oil tank, the fourth oil outlet is connected with the second oil inlet, and the fifth oil outlet is connected with the oil tank through a fifth liquid path.

In this solution, the steering system further comprises a lift pump. In particular, the lift pump has a third oil suction opening and a fourth oil outlet. The lifting valve is provided with a second oil inlet and a fifth oil outlet. And a third oil suction port of the lifting pump is connected with the oil tank, a fourth oil outlet of the lifting pump is connected with a second oil inlet of the lifting valve, and a fifth oil outlet of the lifting valve is connected with the oil tank through a fifth liquid path. The lift pump is capable of pumping hydraulic oil from the tank to the lift valve.

In the above technical solution, the method further comprises: and the oil return filter element is arranged on the fifth liquid path.

In the technical scheme, the steering system further comprises an oil return filter element. Specifically, the oil return filter core is arranged on the fifth liquid path, namely the oil return filter core is arranged between the lifting valve and the oil tank. Through setting up the oil return filter core, can play the effect of filtering impurity protection hydraulic system.

In the above technical solution, the method further comprises: and the lifting cylinder is connected with the lifting valve.

In this solution, the steering system further comprises a lifting cylinder. Specifically, the lift cylinder is connected to a lift valve. The hydraulic oil flows to the lifting cylinder from the lifting valve, and a piston rod of the lifting cylinder moves to complete the lifting action of the hydraulic system.

In the technical scheme, the priority valve is provided with a third oil inlet, a sixth oil outlet and a seventh oil outlet, the steering gear pump and the emergency pump are connected with the third oil inlet, the sixth oil outlet is connected with the full-hydraulic steering device, and the seventh oil outlet is used for being connected with the lifting valve.

In the technical scheme, a third oil inlet (P port) of the priority valve is connected with an oil outlet of the steering gear pump, and the third oil inlet of the priority valve is connected with an oil outlet of the emergency pump. And a sixth oil outlet (CF port) of the priority valve is connected with a P port of the full hydraulic steering gear, and a seventh oil outlet (EF port) of the priority valve is connected with the lifting valve. Hydraulic fluid can flow to the priority valve through a steering gear pump or an emergency pump, and hydraulic fluid can also flow to a full hydraulic steering gear or a lifting valve through the priority valve.

In the above technical solution, the method further comprises: and the three-way valve is provided with a first port, a second port and a third port, the first port is connected with the seventh oil outlet, the second port is connected with the lifting valve, and the third port is connected with the oil tank.

In this solution, the steering system further includes a three-way valve. Specifically, the three-way valve has a first port, a second port, and a third port. The first port of the three-way valve is connected with the seventh oil outlet (EF port) of the priority valve, the second port of the three-way valve is connected with the lifting valve, and the third port of the three-way valve is connected with the oil tank. The EF port of the priority valve is communicated with the first port of the three-way valve, hydraulic oil flowing out of the EF port can be converged with hydraulic oil pressed out by the lifting pump when the cargo compartment is lifted, the flow of the hydraulic oil during lifting is increased, and the lifting speed of the cargo compartment is increased.

An embodiment of the second aspect of the present invention provides a construction machine, including: an operating device; in the steering system of any of the above embodiments, the full hydraulic steering gear of the steering system is connected to the operating device.

According to an embodiment of the work machine according to the invention, the work machine comprises an operating device and a steering system as in any of the embodiments described above. Specifically, a full hydraulic steering gear of the steering system is connected with the operating device. It is worth mentioning that the engineering machine may be an engineering vehicle, such as a mining dump truck or the like. Of course, the work machine may also be another type of equipment.

The construction machine includes any one of the steering systems in the first aspect, so that the beneficial effects of any one of the embodiments are achieved, and are not described herein again.

Additional aspects and advantages of embodiments of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

FIG. 1 shows a schematic view of a steering system according to an embodiment of the invention;

FIG. 2 shows a schematic diagram of a steering gear pump according to one embodiment of the present invention;

FIG. 3 shows a schematic view of a priority valve according to an embodiment of the invention;

FIG. 4 shows a schematic of a full hydraulic steering gear according to one embodiment of the present invention;

FIG. 5 shows a schematic diagram of an emergency pump according to an embodiment of the invention;

FIG. 6 illustrates a schematic diagram of the connection of a lift pump, lift valves and lift cylinders according to one embodiment of the present invention;

FIG. 7 shows a schematic diagram of a three-way valve according to one embodiment of the invention;

FIG. 8 is a schematic diagram illustrating the connection of a full hydraulic steering gear to a first steering cylinder and a second steering cylinder according to one embodiment of the present invention;

fig. 9 shows a schematic view of a working machine according to an embodiment of the invention.

Wherein, the correspondence between the reference numbers and the part names in fig. 1 to 9 is:

100: a steering system; 110: an oil tank; 120: a steering gear pump; 121: a first oil suction port; 122: a second oil outlet; 130: a priority valve; 131: a third oil inlet; 132: a sixth oil outlet; 133: a seventh oil outlet; 140: a full hydraulic steering gear; 141: a left oil port; 142: a right oil port; 143: a first oil inlet; 144: a first oil outlet; 151: a first steering cylinder; 152: a first rod chamber; 153: a first rod-less chamber; 154: a second steering cylinder; 155: a second rod chamber; 156: a second rodless cavity; 160: an emergency pump; 161: a second oil suction port; 162: a third oil outlet; 171: an overload protection safety valve; 172: a stop valve; 173: a one-way valve; 174: a high pressure filter; 175: an oil return filter element; 176: a third fluid path; 177: a fourth fluid path; 178: a fifth fluid path; 1791: a first fluid path; 1792: a second fluid path; 181: a lift valve; 182: a second oil inlet; 183: a fifth oil outlet; 184: a lift pump; 185: a third oil suction port; 186: a fourth oil outlet; 187: a lifting cylinder; 190: a three-way valve; 191: a first port; 192: a second port; 193: a third port; 200: an engineering machine; 210: and an operating device.

Detailed Description

In order that the above objects, features and advantages of the embodiments of the present invention can be more clearly understood, embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and detailed description. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application, however, embodiments of the present invention may be practiced in other ways than those described herein, and therefore the scope of the present application is not limited to the specific embodiments disclosed below.

Turning now to fig. 1-9, a steering system 100 and a work machine 200 provided in accordance with some embodiments of the present invention are described.

Example one

As shown in fig. 1, a steering system 100 according to an embodiment of the present invention includes a fuel tank 110, a steering gear pump 120, a priority valve 130, a full hydraulic steering gear 140, a first steering cylinder 151, a second steering cylinder 154, an emergency pump 160, and an overload protection safety valve 171. The oil tank 110 is used to store hydraulic oil. The steering gear pump 120 is connected to the oil tank 110. Optionally, an oil suction port of the steering gear pump 120 is connected to the oil tank 110. Gear pumps are rotary pumps that deliver or pressurize fluid by virtue of the change in working volume and movement created between a pump cylinder and a meshing gear. In the gear pump, two gears, a pump body and front and rear covers form two closed spaces. When the gear rotates, the volume of the space on the gear disengagement side is increased from small to large, vacuum is formed, and liquid is sucked; the volume of the space on the gear meshing side is reduced from large to small, and liquid is squeezed into the pipeline. Further, a priority valve 130 is connected to the steering gear pump 120. Optionally, port P (i.e., oil inlet) of the priority valve 130 is connected to an oil outlet of the steering gear pump 120. Further, a full hydraulic diverter 140 is connected to the priority valve 130. Optionally, port P (i.e., the oil inlet) of the full hydraulic diverter 140 is connected to port CF of the priority valve 130. The port T (i.e., the oil outlet) of the full hydraulic steering gear 140 is connected to the oil tank 110. The full hydraulic steering gear 140 is a hydraulic power steering form between a steering wheel and a steering control mechanism without connecting rods, and has the advantages of light and flexible control, simple structure, low price, convenient installation and arrangement of the whole machine and the like. Further, the first steering cylinder 151 is connected to the full hydraulic steering gear 140, and the second steering cylinder 154 is connected to the full hydraulic steering gear 140. The full hydraulic steering gear 140 is connected to the first steering cylinder 151 via a first fluid path 1791, and the full hydraulic steering gear 140 is connected to the second steering cylinder 154 via a second fluid path 1792.

Further, an emergency pump 160 is connected to the oil tank 110, and the emergency pump 160 is connected to the priority valve 130. Alternatively, the oil suction port of the emergency pump 160 is connected to the oil tank 110, and the oil outlet of the emergency pump 160 is connected to the P port (i.e., the oil inlet) of the priority valve 130. By adding the emergency pump 160, when the engine fails and stalls or the steering gear pump 120 fails, the emergency pump 160 can provide an emergency steering function for the steering system 100, so that the construction machine 200 can be smoothly parked. In other words, the electric emergency steering system 100 is added on the basis of the prior full hydraulic steering system 100, the electric emergency steering system 100 provides power assistance through a hydraulic power unit and mainly comprises an emergency motor and an emergency pump 160, when an engine fails and stalls or the steering gear pump 120 fails, the emergency motor can work by pressing an emergency button switch, and power of the emergency pump 160 is provided, so that a vehicle can smoothly stop. It should be noted that the emergency motor can not work continuously for more than 30s, and the motor should be turned off in time after the emergency stop is completed, so as to avoid wasting the electric quantity of the storage battery.

Further, an overload protection safety valve 171 is provided in the first fluid passage 1791 and/or the second fluid passage 1792. Optionally, an overload protection relief valve 171 is connected to the full hydraulic diverter 140. The overload protection safety valve 171 is connected to the first steering cylinder 151, and the overload protection safety valve 171 is connected to the second steering cylinder 154. The overload protection safety valve 171 is provided between the full hydraulic steering gear 140 and the steering cylinder. The fluid from the priority valve 130 passes through the full hydraulic diverter 140, the protection valve, and the steering cylinder in sequence. By additionally arranging the overload protection safety valve 171 between the full-hydraulic steering gear 140 and the steering oil cylinder, the effect of protecting the steering oil cylinder can be achieved when the load impact is overlarge, and the damage of the steering oil cylinder caused by the fact that the load pressure is overlarge and exceeds the rated pressure of the steering oil cylinder is avoided.

In the mining dump truck in the related art, a steering system 100 adopts a constant pressure pump matched with a steering valve bank and an energy accumulator as a steering power source. The power source can release the oil pressure in the energy accumulator to provide the emergency steering capacity for the system under the emergency condition that the engine loses power, but the system has more complex structure and higher cost.

In the technical scheme defined by the invention, the emergency pump 160 is additionally arranged, an energy accumulator in the traditional structure is omitted, and when the engine is in failure and is flamed out or the steering gear pump 120 fails, the emergency pump 160 can provide an emergency steering function for the steering system 100, so that the engineering machinery 200 is smoothly stopped. With this design, the steering system 100 is simple, easy to maintain and low in cost. In addition, an overload protection safety valve 171 is additionally arranged between the full-hydraulic steering gear 140 and the steering oil cylinder, so that the effect of protecting the steering oil cylinder can be achieved when the load impact is overlarge, and the damage of the steering oil cylinder caused by the fact that the load pressure is overlarge and exceeds the rated pressure of the steering oil cylinder is avoided.

Example two

As shown in fig. 4, the full hydraulic steering gear 140 has a left oil port 141 and a right oil port 142, and when the full hydraulic steering gear 140 is at the neutral position, both the left oil port 141 and the right oil port 142 are in the blocking state. A left oil port 141 (port L) of the full hydraulic steering gear 140 is connected with a port A of the first steering oil cylinder 151 and a port B of the second steering oil cylinder 154; the right port 142(R port) of the full hydraulic steering gear 140 is connected to the B port of the first steering cylinder 151 and the a port of the second steering cylinder 154. When the full hydraulic steering gear 140 is in the middle position, both the left oil port 141 and the right oil port 142 are in the cut-off state. In other words, the left oil port and the right oil port are both in a cut-off state in the middle position of the steering gear, and the position of the steering wheel cannot be changed after the operator releases the steering wheel.

Further, as shown in fig. 4, the full hydraulic steering gear 140 has a first oil inlet 143 and a first oil outlet 144, when the middle position of the full hydraulic steering gear 140 is in an off state, both the first oil inlet 143 and the first oil outlet 144 are in an off state, and the fluid pressure of the first oil inlet 143 is greater than the fluid pressure of the first oil outlet 144. A first oil inlet 143 (port P) of the full hydraulic steering gear 140 is connected to the priority valve 130, and a first oil outlet 144 (port T) of the full hydraulic steering gear 140 is connected to the oil tank 110. The middle position of the steering gear is in an open circuit state (closed core), namely when the steering gear does not work, the hydraulic oil is cut off by the steering gear, and the first oil inlet 143 is a high-pressure port at the moment.

Further, as shown in fig. 4 and 8, the first steering cylinder 151 includes a first cylinder body and a first piston rod, the first piston rod is disposed through the first cylinder body, and the first piston rod can move relative to the first cylinder body. The piston of the first piston rod partitions the interior of the first cylinder into a first rodless chamber 153 and a first rod chamber 152. The second steering cylinder 154 includes a second cylinder body and a second piston rod, the second piston rod is inserted into the second cylinder body, and the second piston rod can move relative to the second cylinder body. The piston of the second piston rod divides the interior of the second cylinder into a second rodless chamber 156 and a second rod chamber 155. The first rodless chamber 153 of the first steering cylinder 151 and the second rodless chamber 155 of the second steering cylinder 154 are both connected to the left port 141 of the full hydraulic steering gear 140. The first rod chamber 152 of the first steering cylinder 151 and the second rod-less chamber 156 of the second steering cylinder 154 are connected to the right port 142 of the full hydraulic steering gear 140. By controlling the oil feeding and returning of the left oil port 141 and the right oil port 142, the piston rod of the first steering cylinder or the second steering cylinder moves to achieve the purpose of reversing. Alternatively, the first rod chamber 153 is provided with the port a of the first steering cylinder 151, and the first rod chamber 152 is provided with the port B of the first steering cylinder 151. The second steering cylinder 154 has a second rodless chamber 156 and a second rod chamber 155, the second rodless chamber 156 being provided with port a of the second steering cylinder 154, and the second rod chamber 155 being provided with port B of the second steering cylinder 154. An L port (namely, a left oil port 141) of the full hydraulic steering gear 140 is connected with an A port of the first steering oil cylinder 151 and a B port of the second steering oil cylinder 154; the R port (right port 142) of the full hydraulic steering gear 140 is connected to the B port of the first steering cylinder 151 and the a port of the second steering cylinder 154.

Further, a first oil inlet 143 (port P) of the full hydraulic steering gear 140 is connected to the CF port of the priority valve 130, and a first oil outlet 144 (port T) of the full hydraulic steering gear 140 is connected to the oil tank 110. By connecting the full hydraulic diverter 140 to the priority valve 130 and the tank 110 to form a hydraulic circuit, hydraulic fluid can flow through the priority valve 130 to the full hydraulic diverter 140 or can flow back through the full hydraulic diverter 140 to the tank 110.

EXAMPLE III

As shown in fig. 2, the steering gear pump 120 has a first oil suction port 121 and a second oil discharge port 122. The first oil inlet 121 of the steering gear pump 120 is connected to the oil tank 110 through a third fluid passage 176, and the second oil outlet 122 of the steering gear pump 120 is connected to the port P of the priority valve 130 through a fourth fluid passage 177. By connecting the steering gear pump 120 to the tank 110 and the priority valve 130, forming a hydraulic circuit, the steering gear pump 120 is able to pump hydraulic oil from the tank 110 to the priority valve 130, which then distributes the oil to the full hydraulic steering gear 140 or other module.

Further, as shown in fig. 1 and 2, the steering system 100 also includes a shut-off valve 172. Specifically, the shutoff valve 172 is provided in the third fluid passage 176, that is, the shutoff valve 172 is located between the steering gear pump 120 and the oil tank 110. The stop valve 172 is also called a stop valve, and has the advantages of small friction force between sealing surfaces in the opening and closing process, durability, small opening height, easy manufacture, convenient maintenance, suitability for medium and low pressure, and suitability for high pressure. The closing principle of the stop valve 172 is that the valve flap sealing surface and the valve seat sealing surface are tightly attached to each other by the pressure of the valve rod, and the medium is prevented from flowing through the valve flap sealing surface and the valve seat sealing surface.

Further, as shown in fig. 1, the steering system 100 further includes a check valve 173. Specifically, check valve 173 is provided in fourth fluid passage 177, i.e., check valve 173 is located between steering gear pump 120 and priority valve 130. By providing the check valve 173, hydraulic oil can only flow from the steering gear pump 120 to the priority valve 130, and hydraulic oil cannot flow from the priority valve 130 to the steering gear pump 120.

Further, as shown in FIG. 1, the steering system 100 also includes a high pressure filter 174. Specifically, the high-pressure filter 174 is provided in the fourth fluid passage 177, that is, the high-pressure filter 174 is located between the steering gear pump 120 and the priority valve 130. By providing the high pressure filter 174, it is possible to function as a filter for impurities to protect the hydraulic system. In addition, the high pressure filter 174 can withstand greater fluid pressures than conventional filters.

It is worth noting that the steering system 100 may include only one of the check valve 173 and the high pressure filter 174, which may be flexibly configured according to actual requirements.

Further, as shown in fig. 5, the emergency pump 160 has a second oil suction port 161 and a third oil outlet port 162. The second suction port 161 of the emergency pump 160 is connected to the oil tank 110, and the third oil outlet 162 of the emergency pump 160 is connected to the P port of the priority valve 130. By connecting the emergency pump 160 with the oil tank 110 and the priority valve 130, the emergency pump 160 can provide an emergency steering function to the steering system 100 when the engine fails to operate or the steering gear pump 120 fails, so that the construction machine 200 can be smoothly parked.

Example four

As shown in fig. 1 and 6, the steering system 100 also includes a lift valve 181. Specifically, the lift valve 181 is connected to the EF port of the priority valve 130. Hydraulic oil flows through the priority valve 130 to the lift valve 181 to complete the lifting action.

Further, as shown in fig. 1 and 6, the steering system 100 further includes a lift pump 184. Specifically, the lift pump 184 has a third oil suction port 185 and a fourth oil discharge port 186. The lift valve 181 has a second oil inlet 182 and a fifth oil outlet 183. The third oil intake port 185 of the lift pump 184 is connected to the oil tank 110, the fourth oil outlet 186 of the lift pump 184 is connected to the second oil intake port 182 of the lift valve 181, and the fifth oil outlet 183 of the lift valve 181 is connected to the oil tank 110 through the fifth fluid passage 178. The lift pump 184 is capable of pumping hydraulic oil from the tank 110 to the lift valve 181.

Further, as shown in fig. 1, the steering system 100 also includes an oil return filter element 175. Specifically, the oil return filter element 175 is disposed in the fifth fluid path 178, i.e., the oil return filter element 175 is located between the lift valve 181 and the oil tank 110. By providing the oil return filter element 175, the function of protecting the hydraulic system by filtering impurities can be achieved.

Further, as shown in fig. 1 and 6, the steering system 100 further includes a lifting cylinder 187. Specifically, the lift cylinder 187 is connected to the lift valve 181. Hydraulic oil flows from the lift valve 181 to the lift cylinder 187, and the piston rod of the lift cylinder 187 moves to complete the lifting operation of the hydraulic system.

EXAMPLE five

As shown in fig. 3, the priority valve 130 has a third oil inlet 131, a sixth oil outlet 132, and a seventh oil outlet 133. The third oil inlet 131 (port P) of the priority valve 130 is connected to the oil outlet of the steering gear pump 120, and the third oil inlet 131 of the priority valve 130 is connected to the oil outlet of the emergency pump 160. The sixth outlet port 132(CF port) of the priority valve 130 is connected to the port P of the full hydraulic steering gear 140, and the seventh outlet port 133(EF port) of the priority valve 130 is connected to the lift valve 181. Hydraulic oil can flow through the steering gear pump 120 or the emergency pump 160 to the priority valve 130, and hydraulic oil can also flow through the priority valve 130 to the full hydraulic steering gear 140 or the lift valve 181.

Further, as shown in fig. 7, the steering system 100 further includes a three-way valve 190. Specifically, the three-way valve 190 has a first port 191, a second port 192, and a third port 193. The first port 191 of the three-way valve 190 is connected to the seventh oil outlet 133(EF port) of the priority valve 130, the second port 192 of the three-way valve 190 is connected to the lift valve 181, and the third port 193 of the three-way valve 190 is connected to the oil tank 110. The EF port of the priority valve 130 is communicated with the first port 191 of the three-way valve 190, so that the hydraulic oil flowing out of the EF port can be converged with the hydraulic oil pressed out by the lifting pump 184 when the cargo compartment is lifted, the flow of the hydraulic oil during lifting is increased, and the lifting speed of the cargo compartment is increased.

EXAMPLE six

As shown in fig. 9, a working machine 200 according to an embodiment of the present invention includes a steering device 210 and the steering system 100 of any of the above embodiments. Specifically, the fully hydraulic steering gear 140 of the steering system 100 is coupled to a steering device 210. It is worth mentioning that the work machine 200 may be a work vehicle, such as a mining dump truck or the like. Of course, the work machine 200 may also be other types of equipment.

According to the embodiment of the steering system and the engineering machinery, the emergency pump is additionally arranged, an energy accumulator in a traditional structure is omitted, and when an engine fails and is flamed out or a steering gear pump fails, the emergency pump can provide an emergency steering function for the steering system, so that the engineering machinery can be smoothly stopped. The design mode has the advantages that the steering system is simple in structure, convenient to maintain and low in cost. In addition, an overload protection safety valve is additionally arranged between the full-hydraulic steering gear and the steering oil cylinder, so that the effect of protecting the steering oil cylinder can be achieved when the load impact is overlarge, and the damage of the steering oil cylinder caused by the fact that the load pressure is overlarge and exceeds the rated pressure of the steering oil cylinder is avoided.

In the present invention, the terms "first", "second", and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the term "plurality" means two or more unless expressly limited otherwise. The terms "mounted," "connected," "fixed," and the like are to be construed broadly, and for example, "connected" may be a fixed connection, a removable connection, or an integral connection; "coupled" may be direct or indirect through an intermediary. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "left", "right", "front", "rear", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the referred device or unit must have a specific direction, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

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

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A steering system (100), comprising:

a fuel tank (110);

a steering gear pump (120) connected to the oil tank (110);

a priority valve (130) connected to the steering gear pump (120);

a first steering cylinder (151);

a second steering cylinder (154);

the full hydraulic steering gear (140) is connected with the priority valve (130), the full hydraulic steering gear (140) is connected with the oil tank (110), the full hydraulic steering gear (140) is connected with the first steering oil cylinder (151) through a first liquid path (1791), and the full hydraulic steering gear (140) is connected with the second steering oil cylinder (154) through a second liquid path (1792);

an emergency pump (160) connected to the oil tank (110), the emergency pump (160) being connected to the priority valve (130);

and an overload protection safety valve (171) provided in the first fluid path (1791) and/or the second fluid path (1792).

2. The steering system (100) according to claim 1, wherein the full hydraulic steering gear (140) has a left oil port (141) and a right oil port (142), and when the full hydraulic steering gear (140) is in a neutral position, the left oil port (141) and the right oil port (142) are both in a cut-off state.

3. The steering system (100) according to claim 1, wherein the full hydraulic steering gear (140) has a first oil inlet (143) and a first oil outlet (144), when the middle position of the full hydraulic steering gear (140) is in an off state, the first oil inlet (143) and the first oil outlet (144) are both in a cut-off state, and the fluid pressure of the first oil inlet (143) is greater than the fluid pressure of the first oil outlet (144).

4. The steering system (100) of claim 2, wherein the first steering cylinder (151) has a first rod chamber (152) and a first rodless chamber (153), the second steering cylinder (154) has a second rod chamber (155) and a second rodless chamber (156), the first rodless chamber (153) and the second rod chamber (155) are both connected to the left oil port (141), and the first rod chamber (152) and the second rodless chamber (156) are both connected to the right oil port (142).

5. The steering system (100) according to claim 3, wherein said first oil inlet (143) is connected with said priority valve (130) and said first oil outlet (144) is connected with said oil tank (110).

6. The steering system (100) according to any one of claims 1 to 5, wherein the steering gear pump (120) has a first oil suction port (121) and a second oil discharge port (122), the first oil suction port (121) being connected to the oil tank (110) through a third fluid passage (176), the second oil discharge port (122) being connected to the priority valve (130) through a fourth fluid passage (177).

7. The steering system (100) of claim 6, further comprising:

and a shut valve (172) provided in the third liquid path (176).

8. The steering system (100) of claim 6, further comprising:

a check valve (173) provided in the fourth fluid passage (177); and/or

And a high-pressure filter (174) provided in the fourth fluid passage (177).

9. Steering system (100) according to any one of claims 1 to 5, characterized in that said emergency pump (160) has a second oil suction opening (161) and a third oil outlet (162), said second oil suction opening (161) being connected with said oil tank (110) and said third oil outlet (162) being connected with said priority valve (130).

10. The steering system (100) according to any one of claims 1 to 5, further comprising:

and a lift valve (181) connected to the priority valve (130).

11. The steering system (100) of claim 10, further comprising:

the lifting pump (184) is provided with a third oil suction port (185) and a fourth oil outlet (186), the lifting valve (181) is provided with a second oil inlet (182) and a fifth oil outlet (183), the third oil suction port (185) is connected with the oil tank (110), the fourth oil outlet (186) is connected with the second oil inlet (182), and the fifth oil outlet (183) is connected with the oil tank (110) through a fifth liquid path (178).

12. The steering system (100) of claim 11, further comprising:

and an oil return filter element (175) provided in the fifth fluid passage (178).

13. The steering system (100) of claim 10, further comprising:

and a lifting cylinder (187) connected to the lifting valve (181).

14. The steering system (100) according to any one of claims 1 to 5, wherein the priority valve (130) has a third oil inlet (131), a sixth oil outlet (132) and a seventh oil outlet (133), the steering gear pump (120) and the emergency pump (160) are both connected with the third oil inlet (131), the sixth oil outlet (132) is connected with the full hydraulic steering gear (140), and the seventh oil outlet (133) is used for being connected with a lifting valve (181).

15. The steering system (100) of claim 14, further comprising:

and the three-way valve (190) is provided with a first port (191), a second port (192) and a third port (193), the first port (191) is connected with the seventh oil outlet (133), the second port (192) is connected with the lifting valve (181), and the third port (193) is connected with the oil tank (110).

16. A work machine (200), comprising:

a manipulation device (210);

the steering system (100) of any one of claims 1 to 15, a fully hydraulic steering gear (140) of the steering system (100) being connected to the steering device (210).