Emergency steering switching valve

Abstract

The utility model provides an emergency steering switching valve, which belongs to the technical field of automobile steering valves and comprises a switching valve body, a first oil inlet used for being connected with a main steering pump, a second oil inlet used for being connected with an emergency pump and a working port. The first oil inlet is used for feeding oil into the inner cavity of the switching valve body in one direction; the switching valve set comprises a valve element cavity arranged in an inner cavity of the switching valve body, a return cavity communicated with the valve element cavity and a valve element capable of being driven by hydraulic oil to move along the valve element cavity, and the valve element is provided with a pilot hole communicated with the working opening, a pressure hole used for communicating the working opening with the return cavity and an overflowing hole formed in the valve element. According to the emergency steering switching valve, normal work of a vehicle steering system can be guaranteed, the electric emergency pump can intervene in time to guarantee emergency steering when the main steering pump is damaged, and the electric emergency pump can be started to provide steering assistance when a vehicle is dragged in an unpowered state.

Description

Technical Field

[0001] The utility model relates to the technical field of automotive steering valves, and particularly relates to an emergency steering switching valve for a hydraulic emergency steering assist system of various construction machinery vehicles. Background Art

[0002] At present, the emergency steering systems of domestic construction machinery vehicles basically adopt the following scheme: an emergency pump power take-off port is added to the engine. When the output flow of the main pump is insufficient, the switching spool of the emergency steering valve moves and transmits an alarm electrical signal. At the same time, the output flow of the emergency pump is merged into the main oil circuit and supplies oil to the steering gear together with the main pump. However, the above scheme has the following defects: 1. After the vehicle starts, the emergency pump always outputs flow, resulting in a large energy loss; 2. When the engine stops working and the vehicle is towed in a powerless state, emergency steering cannot be achieved; 3. The maximum flow rate of the emergency steering valve is only 80 L / min, resulting in a small flow rate and poor steering control effect of the emergency pump. Summary of the Utility Model

[0003] The utility model provides an emergency steering switching valve, which can ensure the normal operation of the vehicle steering system. It can not only enable the electric emergency pump to intervene in time to ensure emergency steering when the main steering pump is damaged, but also start the electric emergency pump to provide steering assistance when the vehicle is towed in a powerless state.

[0004] To solve the above technical problems, the utility model adopts the following technical solutions:

[0005] An emergency steering switching valve includes a switching valve body, a first oil inlet for connecting with the main steering pump, a second oil inlet for connecting with the emergency pump, and a working port, and further includes:

[0006] A check valve group, which is arranged inside the first oil inlet and is used for unidirectional oil inlet from the first oil inlet into the inner cavity of the switching valve body; and;

[0007] A switching valve group, which includes a spool chamber arranged in the inner cavity of the switching valve body, a return chamber communicated with the spool chamber, and a spool capable of being displaced along the spool chamber under the drive of hydraulic oil. The spool is provided with a pilot hole communicated with the working port, a pressure hole for communicating the working port with the return chamber, and an overflow hole arranged on the spool.

[0008] Preferably, the check valve group includes a check valve installed inside the joint of the first oil inlet.

[0009] Preferably, the switching valve group further includes a limit plug arranged on the outer wall of the switching valve body at the port of the spool chamber and a return spring arranged between the spool and the limit plug.

[0010] Preferably, the emergency steering switching valve further includes an electro-hydraulic signal alarm, which includes a terminal component disposed in the inner cavity of the switching valve body and a terminal disposed on the outer side wall of the switching valve body where the terminal component is located.

[0011] Preferably, the terminal component includes a terminal passing through the valve core chamber and disposed on the switching valve body.

[0012] Preferably, the electro-hydraulic signal alarm further includes an insulating sleeve disposed between the terminal and the inner wall of the switching valve body.

[0013] Preferably, one end of the valve core away from the return spring can be attached to the outer wall of the terminal disposed in the valve core chamber.

[0014] From the above technical solutions, it can be seen that the present utility model has the following beneficial effects:

[0015] 1. In the present utility model, the switching valve body changes the original hydraulic system composed of the main steering pump and the DC motor-driven hydraulic pump in the steering system into a connection mode in parallel with the electric emergency pump. When the main steering pump is working properly, the electric emergency pump does not participate in the work; when the main steering pump fails and the vehicle speed message meets the set requirements, the electric emergency pump starts and supplies oil to the steering system to provide emergency steering assistance, ensuring the safety of the driver. At the same time, it will trigger the electro-hydraulic signal alarm to alarm, prompting the driver that the steering system has a fault and needs to pull over to the side of the road in time to repair the fault; in addition, the electric emergency pump can also be started when the vehicle is in a towed state to supply oil to the steering system and provide steering assistance.

[0016] 2. In the present utility model, the valve core adopts a spool structure. When the main steering pump is working, the hydraulic oil output by the main steering pump flows through the one-way valve group through the first oil inlet and enters the interior of the switching valve body, and the hydraulic oil flows to the working port through the pilot hole on the valve core; when the emergency pump intervenes in the work, the hydraulic oil generates a pressure difference at both ends of the valve core through the pilot hole on the valve core, pushing the valve core to move and connecting the valve core flow hole to pass a larger flow rate and supply oil to the steering system; therefore, this switching valve body structure realizes the switching of different working conditions through the movement of the valve core in the inner cavity of the valve body. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is the front view of the present utility model;

[0018] Figure 2 is the side view of the present utility model;

[0019] Figure 3 is the sectional structure diagram of the present utility model.

[0020] In the figure: 10, switching valve body; 20, first oil inlet; 21, first oil inlet joint; 30, second oil inlet; 40, working port; 510, check valve; 610, spool chamber; 620, return chamber; 630, spool; 631, pilot hole; 632, pressure hole; 633, flow hole; 640, limit plug; 650, return spring; 711, terminal; 720, terminal block; 730, insulating sleeve. Detailed implementation mode

[0021] The following is a detailed description of a preferred implementation mode of the present utility model in conjunction with the accompanying drawings.

[0022] To achieve the above object, the embodiments of the present utility model adopt the following technical solutions: Refer to Figure 1 , Figure 2 , Figure 3, An emergency steering switching valve, comprising a switching valve body 10, a first oil inlet 20, a second oil inlet 30 and a working port 40. The first oil inlet is arranged at one axial end of the switching valve body and is used to connect with the main steering pump. The second oil inlet 30 is arranged on the side wall of the switching valve body and is used to connect with the emergency pump. The working port 40 is also arranged on the side wall of the switching valve body 10 and is used to output hydraulic power outward to control the action of the vehicle steering system. Further, the emergency steering switching valve further comprises a check valve group and a switching valve group. Specifically, the check valve group is arranged inside the first oil inlet 20 and is used to supply oil to the inner cavity of the switching valve body 10 unidirectionally from the first oil inlet 20. That is, when the main steering pump is working, hydraulic oil can be conveyed into the switching valve body through the first oil inlet 20. The switching valve group comprises a spool chamber 610, a return chamber 620 and a spool 630. The spool chamber 610 is arranged in the inner cavity of the switching valve body, and the return chamber 620 is also arranged in the inner cavity of the switching valve body and is communicated with the spool chamber. The spool 630 is arranged in the spool chamber 610 and can be driven by hydraulic oil to displace along the spool chamber. Further, a pilot hole 631 communicating with the working port 40, a pressure hole 632 for communicating the working port with the return chamber 620 and a flow-through hole 633 arranged on the spool are provided on the spool. During operation, the hydraulic oil output by the main steering pump flows through the first oil inlet and the check valve group into the inside of the switching valve body, and the hydraulic oil flows to the working port through the pilot hole on the spool, realizing the effect of the main steering pump hydraulically driving the vehicle steering system. When the main steering pump fails and the vehicle speed message meets the set requirements, the electric emergency pump starts and supplies oil to the steering system to improve the emergency steering assistance. Specifically, the hydraulic oil flows through the pilot hole on the spool and generates a pressure difference at both ends of the spool, pushing the spool to move in the spool chamber and making the flow-through hole communicate with the working port, so as to supply oil to the steering system with a larger flow rate and an increased flow area to ensure the safety of the driver. In the present utility model, when the main steering pump is working properly, the electric emergency pump does not participate in the work, which can greatly reduce the energy loss of the emergency pump; when the main steering pump fails and the vehicle speed message meets the set requirements, the electric emergency pump starts and supplies oil to the steering system to provide emergency steering assistance to ensure the safety of the driver; in addition, the electric emergency pump can also be started when the vehicle is in a towed state to supply oil to the steering system and provide steering assistance.

[0023] Further, the check valve group comprises a check valve 510 installed inside the interface of the first oil inlet 20. The check valve is a tubular check valve and is embedded inside the first oil inlet joint 21. The check valve is to prevent the electric emergency pump from participating in the work when the main steering pump does not work or is damaged, and its flow output reaches the main steering pump, resulting in the failure of the internal seal and the hydraulic oil leaking into the engine or the transmission to cause losses.

[0024] As a preferred technical solution of this embodiment, the switching valve group further includes a limit plug 640 and a return spring 650. The limit plug 640 is arranged on the outer wall of the switching valve body at the port of the spool chamber. This limit plug serves to block the port of the spool chamber, thereby improving the sealing performance of the switching valve body. The return spring 650 is arranged between the spool 630 and the limit plug. When the spool moves along the spool chamber, the return spring can be compressed, and the presence of the return spring enables the reset of the spool.

[0025] As a preferred technical solution of this embodiment, when a fault occurs in the steering system, in order to prompt the driver, the emergency steering switching valve further includes an electro-hydraulic signal alarm. Specifically, this electro-hydraulic signal alarm includes a terminal block assembly and a terminal 720. The terminal block assembly is arranged in the inner cavity of the switching valve body 10, and the terminal 720 is arranged on the side wall of the terminal block assembly outside the switching valve body. The terminal is the connection point for the electro-hydraulic signal alarm to output an electrical signal. Further, the terminal block assembly includes a terminal 711 passing through the spool chamber and arranged on the switching valve body 10. During use, the spool and the spool chamber adopt a small clearance fit. Under the action of the return spring force, the spool can be in close contact with the terminal, and when the spool contacts the terminal, the electro-hydraulic signal alarm is turned on.

[0026] When a fault occurs in the main steering pump and the vehicle speed message meets the set requirements, the electric emergency pump starts and supplies oil to the steering system to provide emergency steering assistance, ensuring the safety of the driver. At the same time, it will trigger the electro-hydraulic signal alarm to alarm, prompting the driver that a fault has occurred in the steering system and that they need to pull over to the side of the road in time to repair the fault.

[0027] It should be noted that the switching valve body only starts to work when the flow rate of the first oil inlet decreases, the spool contacts the terminal, the electro-hydraulic signal alarm is turned on, and after judging in combination with the vehicle speed message of the whole vehicle. At this time, the flow rate of the first oil inlet passes through the spool and then converges with the flow rate of the second oil inlet and passes through the working port.

[0028] Further, in order to improve the insulation performance of the terminal 711, the electro-hydraulic signal alarm further includes an insulating sleeve 730 arranged between the terminal 711 and the inner wall of the switching valve body 10. This insulating sleeve is made of aluminum alloy and undergoes surface hard anodizing treatment. Compared with the original polytetrafluoroethylene parts, the voltage withstand performance can be effectively improved.

[0029] During use, the hydraulic oil output by the main steering pump enters the interior of the emergency switching valve body 10 through the first oil inlet 20 and flows through the one-way valve 510. The hydraulic oil flows to the working port 40 through the pilot hole 631 on the spool 630. The pressure hole 632 on the spool communicates the working port with the return cavity 620. Since there is no relative flow of the oil, the pressures at both ends of the pressure hole are the same, and a pressure difference is generated at the front end of the pilot hole of the spool and at both ends of the return cavity, pushing the spool to move. When the flow-through hole 633 on the spool is connected to the oil outlet cavity, the flow area is increased, allowing a larger flow rate. The spool is in close contact with the terminal 711 under the action of the return spring 650. The spool and the inner cavity of the switching valve body 10 are in a small-clearance fit. When the flow rate through the pilot hole of the spool decreases and the thrust generated by the pressure difference at the front end of the pilot hole of the spool and at both ends of the return cavity is not sufficient to balance the spring force of the return spring, the spool contacts the terminal, and the electro-hydraulic signal alarm is turned on.

[0030] The above-described embodiments are merely descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. An emergency steering switching valve, comprising a switching valve body (10), a first oil inlet (20) for connecting to a main steering pump, a second oil inlet (30) for connecting to an emergency pump, and a working port (40), characterized in that: Also includes: a one-way valve group, the one-way valve group being arranged inside the first oil inlet (20) and used for one-way oil intake from the first oil inlet (20) to the inner cavity of the switching valve body (10); and; A switching valve group, the switching valve group comprising a valve core chamber (610) arranged in the inner cavity of a switching valve body, a return chamber (620) connected to the valve core chamber, and a valve core (630) that can be driven by hydraulic oil to move along the valve core chamber, wherein the valve core is provided with a pilot hole (631) connected to a working port (40), a pressure hole (632) for connecting the working port and the return chamber (620), and a flow hole (633) arranged on the valve core.

2. The emergency steering switching valve according to claim 1, characterized in that: The one-way valve assembly comprises a one-way valve (510) installed inside the interface of the first oil inlet (20).

3. The emergency steering switching valve according to claim 1, characterized in that: The switching valve assembly further comprises a limit screw plug (640) arranged on the outer wall of the switching valve body at the port of the valve core chamber and a return spring (650) arranged between the valve core (630) and the limit screw plug.

4. The emergency steering switching valve according to claim 1, characterized in that: The emergency steering switching valve further comprises an electro-hydraulic signal alarm, which comprises a terminal assembly arranged in the inner cavity of the switching valve body (10) and a terminal (720) arranged on the outer side wall of the switching valve body where the terminal assembly is located.

5. The emergency steering switching valve according to claim 4, characterized in that: The terminal assembly comprises a terminal (711) which passes through the valve core chamber and is arranged on the switching valve body (10).

6. The emergency steering switching valve according to claim 4, characterized in that: The electro-hydraulic signal alarm further comprises an insulating sleeve (730) arranged between the terminal post (711) and the inner wall of the switching valve body (10).

7. The emergency steering switching valve according to claim 5, characterized in that: One end of the valve core (630) away from the return spring (650) can be in contact with the outer wall of the terminal (711) placed in the valve core chamber.

Images