CN110745181A

CN110745181A - Hydraulic power steering gear

Info

Publication number: CN110745181A
Application number: CN201810819185.7A
Authority: CN
Inventors: 王涛
Original assignee: Bosch Automotive Steering Jinan Co Ltd
Current assignee: Bosch Automotive Steering Jinan Co Ltd
Priority date: 2018-07-24
Filing date: 2018-07-24
Publication date: 2020-02-04

Abstract

The present application provides a hydraulic power steering gear. Wherein the locking portion of the first limit member is located in an operable position from outside the housing, the locking portion being movable by operation of the locking portion between a locked condition and a released condition in which the first trigger portion is movable relative to the housing in a direction parallel to the axis within the hydraulic chamber. A sliding part penetrating through the piston is provided with a pressure relief channel communicated with the first cavity and the second cavity, a first valve is installed in the pressure relief channel, and the first valve controls fluid communication between the pressure relief channel and the first cavity. When the piston moves towards the direction of reducing the first cavity, the first valve can be pushed by the second trigger part to be opened if the first valve contacts the second trigger part. The steering gear is simple in structure and low in cost.

Description

Hydraulic power steering gear

Technical Field

The present application relates to a steering device for a vehicle, and more particularly to a hydraulic power steering machine.

Background

In a hydraulic power steering machine, when the steering stroke reaches a limit, the hydraulic power needs to be bled off to avoid damaging the machine. After the steering machine is installed on the transport vehicle, the limit of the steering stroke needs to be adjustable within a certain range so as to adapt to the flexible application requirement of the transport vehicle. However, the steering gear that provides the function of adjusting the steering stroke limit is complicated in structure and high in cost.

Therefore, there is a need to provide an improved technical solution to overcome the technical problems in the prior art.

Disclosure of Invention

The main technical problem that this application will be solved is that current steering gear structure is complicated, problem with high costs.

In order to solve the above technical problem, the present application provides a hydraulic power steering apparatus including:

a housing in which a hydraulic chamber is disposed;

a worm rotatably mounted to the housing about an axis and including a first spiral portion located in the hydraulic chamber;

a first stopper mounted to the housing and including a locking portion and a first trigger portion, the locking portion being located at an operable position from outside the housing, the locking portion being movable by operation of the locking portion between a locked state in which the first trigger portion is movable relative to the housing in a direction parallel to the axis within the hydraulic chamber and a released state in which the locking portion fixes the first trigger portion relative to the housing; and

the piston comprises a second spiral part and a sliding part, the first spiral part is meshed with the second spiral part, the sliding part can be movably arranged in the hydraulic cavity along the direction parallel to the axis and separates the hydraulic cavity into a first cavity and a second cavity, a pressure relief channel communicated with the first cavity and the second cavity is arranged through the sliding part, and a first valve is arranged in the pressure relief channel and controls fluid communication between the pressure relief channel and the first cavity;

when the piston moves in a direction of contracting the first chamber, the first valve can be pushed to open by the second trigger if the first valve touches the second trigger.

According to the technical scheme of this application, realize turning to the regulatory function of stroke limit with simple part, turn to quick-witted simple structure, it is with low costs.

Drawings

The present application will be more fully understood from the detailed description given below with reference to the accompanying drawings, in which like reference numerals refer to like elements in the figures. Wherein:

FIG. 1 shows a schematic view of an embodiment of a hydraulic power steering engine;

FIG. 2 shows a partially enlarged schematic view of the limit adjustment mechanism of the steering engine of FIG. 1;

FIG. 3 is an enlarged partial view taken along line A-A of FIG. 2; and

FIG. 4 shows a partially enlarged schematic view of a limit adjustment mechanism of another embodiment of a steering engine.

Detailed Description

Referring to fig. 1 to 3, a hydraulic power steering apparatus 100 according to an embodiment of the present invention includes a housing 1 having a hydraulic chamber 10. The worm 2 is mounted rotatably about an axis X to the housing 1 and comprises a first helical portion 20 located in the hydraulic chamber 10. The piston 5 includes a second screw portion 50 and a sliding portion 52. The first spiral portion 20 has an outer spiral formed on the outer peripheral surface of the worm 2, the second spiral portion 50 has an inner spiral formed on the inner peripheral surface of a through hole (not numbered) axially penetrating the piston 5, and the first spiral portion 20 is engaged with the second spiral portion 50. For example, the first helical portion 20 directly engages the second helical portion 50. Alternatively, if necessary, engagement by a ball (not shown) may be employed. The first helical portion 20 meshes with the second helical portion 50, thereby converting the rotary motion of the worm 2 about the axis X into the linear motion of the piston 5 in the direction parallel to the axis X. The sliding portion 52 is slidably and sealingly engaged with the hydraulic chamber 10, is movably mounted in the hydraulic chamber 10 in a direction parallel to the axis X, and separates the hydraulic chamber 10 into the first chamber 11 and the second chamber 12. When power assistance for steering in the first direction is needed, high-pressure liquid is filled in the first cavity 11, so that the pressure of the liquid in the first cavity 11 is greater than that of the liquid in the second cavity 12, the piston 2 is driven to move in the direction of narrowing the second cavity 12 and enlarging the first cavity 11, the moving piston 2 drives the angle shaft 6 to rotate in the first direction, and the angle shaft 6 outputs steering torque. When power assistance for steering in a second direction opposite to the first direction is required, high-pressure liquid is filled in the second chamber 12, so that the pressure of the liquid in the second chamber 12 is greater than that of the liquid in the first chamber 11, the piston 2 is driven to move in the direction of contracting the first chamber 11 and increasing the second chamber 12, the moving piston 2 drives the angle shaft 6 to rotate in the second direction, and the angle shaft 6 outputs steering torque.

A relief passage 14 communicating the first chamber 11 and the second chamber 12 is provided through the sliding portion 52. A first valve 16 and a second valve 18 are installed in the pressure relief passage 14. A first valve 16 controls the fluid communication between the pressure relief channel 14 and the first chamber 11. A second valve 18 controls fluid communication between the pressure relief passage 14 and the second chamber 12. The first valve 16 is a one-way valve that prevents the fluid from flowing from the pressure release passage 14 to the first chamber 11 and conducts in the opposite direction. Second valve 18 is a one-way valve that prevents fluid flow from pressure relief passage 14 to second chamber 12 and conducts in the opposite direction.

The length of the sliding portion 52 in the direction parallel to the axis X is much smaller than the entire length of the piston 5, and the length of the pressure relief passage 14 extending through the sliding portion 52 is not more than 50% and not less than 20 mm of the entire length of the piston 5. For example, the pressure relief channel 14 has a length corresponding to 10%, 15%, 20%, 30% or 34% of the overall length of the piston 5. The length of the pressure relief channel 14 is much smaller than the overall length of the piston 5, so that the installation of the first valve 16 and the second valve 18 in the pressure relief channel 14 can be designed as one piece. For example, the first valve 16 and the second valve 18 have an integrated pipe-shaped valve housing 15, and the valve housing 15 is installed in the relief passage 14, so that the first valve 16 and the second valve 18 are integrally installed in the relief passage 14. When the pressure is relieved, fluid communication in the pressure relief channel 14 is realized through the middle of the pipe-shaped valve housing 15. Therefore, the first valve 16 and the second valve 18 can adopt the standard valve products on the market, and the cost is low.

A first stopper 3 is mounted to the left middle of the housing 1 shown in fig. 1, and a second stopper 4 is mounted to the lower side of the housing 1. The first limit element 3 comprises a first trigger part 30 and a locking part 32. The locking portion 32 is located at a position operable from outside the housing 1, and the locking portion 32 can be moved between the locked state and the released state by operating the locking portion 32. In the released state, the first triggering part 30 is movable relative to the housing 1 in a direction parallel to the axis X within the hydraulic chamber 10.

The second stopper 4 includes a second trigger 40 and an operating portion 42, the operating portion 42 is attached to the housing 1 at a position operable from outside the housing 1, and the second trigger 40 is movable in the hydraulic chamber 10 in a direction parallel to the axis X by operating the operating portion 42. Also mounted in the pressure relief passage 14 is a second valve 18, the second valve 18 controlling fluid communication between the pressure relief passage 14 and the second chamber 12. The first valve 16 has a first port 160, and a first spool 162 is mounted on the first port 160. The second valve 18 has a second port 180, and a second spool 182 is mounted on the second port 180. An elastically pre-compressed valve spring 19 is installed between the first spool 162 and the second spool 182. The valve spring 19 elastically pushes the spherical first valve element 162 to seal the first valve element 162 to the first port 160, and the valve spring 19 elastically pushes the spherical second valve element 182 to seal the second valve element 182 to the second port 180.

The locking portion 32 is screwed to the housing 1, and the locking portion 32 can be advanced and retracted in the direction perpendicular to the axis X with respect to the housing 1 by screwing the locking portion 32. The first trigger 30 is subjected to a conservative force toward the first valve 16. For example, when the first trigger 30 is mounted above the first valve 16, the conservative force is gravity, and when the steering stroke limit needs to be adjusted, the locking portion 32 is twisted from the locked state to the released state, the first trigger 30 is subjected to gravity and automatically moves downward to be close to the first valve 16. When the required steering stroke limit is adjusted, the first trigger 30 naturally comes to rest on the first valve 16 at the steering stroke limit position. The locking portion 32 is then twisted from the released state to the locked state to lock the first trigger 30, thereby completing the adjustment of the first trigger 30. Those skilled in the art will appreciate that the conservative force experienced by the first trigger 30 drives the first trigger 30 toward the first valve 16 as long as at least a portion of the force is directed toward the first valve 16, or as long as the conservative force experienced by the first trigger 30 has a component directed toward the first valve 16, without requiring that the conservative force experienced by the first trigger 30 be absolutely precise toward the first valve 16.

Referring to fig. 4, in another embodiment, the conservative force acting on the first trigger 30 toward the first valve 16 is an elastic force. Here, since the elastic member 34 is provided and the elastic member 34 is elastically mounted between the housing 1 and the first trigger 30 in a compressed and pre-deformed manner, the elastic member 34 applies an elastic force to the first trigger 30 toward the first valve 16.

The first trigger part 30 has a first thimble portion 31, the first thimble portion 31 is smaller than the first valve port 160, and the first thimble portion 31 can access the first valve spool 162 through the first valve port 160. In the locked state, the locking portion 32 fixes the first trigger 30 with respect to the housing 1, and when the piston 5 moves in a direction to reduce the first chamber 11, if the first valve 16 touches the first trigger 30, it can be pushed by the first trigger 30 to be opened.

The second trigger part 40 has a second thimble portion 41, the second thimble portion 41 is smaller than the second valve port 180, and the second thimble portion 41 can reach the second valve spool 182 through the second valve port 180. When the piston 5 moves in a direction to reduce the second chamber 12, the second valve 18 can be pushed to open by the second trigger 40 if it touches the second trigger 40.

According to the technical scheme of the application, the function of adjusting the steering stroke limit is realized by simple components, and the steering engine 100 is simple in structure and low in cost.

The above detailed description is merely illustrative of the present application and is not intended to be limiting of the present application. In the present application, relative terms such as left and right, up and down, and front and back are used to describe relative positional relationships, and are not intended to limit absolute positions. Various changes and modifications can be made by one skilled in the art without departing from the scope of the present application, and all equivalent technical solutions also belong to the scope of the present application, and the protection scope of the present application should be defined by the claims.

Claims

1. Hydraulic power steering machine (100), characterized in that it comprises:

a housing (1) in which a hydraulic chamber (10) is arranged;

a worm (2) rotatably mounted to the housing (1) about an axis and comprising a first helical portion (20) located in the hydraulic chamber (10);

a first limit element (3) mounted to the housing (1) and comprising a first trigger portion (30) and a locking portion (32), the locking portion (32) being located in an operable position from outside the housing (1), the locking portion (32) being movable by operation of the locking portion (32) between a locked condition in which the first trigger portion (30) is movable within the hydraulic chamber (10) relative to the housing (1) in a direction parallel to the axis and a released condition in which the locking portion (32) fixes the first trigger portion (30) relative to the housing (1); and

a piston (5) including a second screw portion (50) and a sliding portion (52), the first screw portion (20) being engaged with the second screw portion (50), the sliding portion (52) being movably installed in the hydraulic chamber (10) in a direction parallel to the axis and separating the hydraulic chamber (10) into a first chamber (11) and a second chamber (12), a pressure relief passage (14) communicating the first chamber (11) and the second chamber (12) being provided through the sliding portion (52), a first valve (16) being installed in the pressure relief passage (14), the first valve (16) controlling fluid communication between the pressure relief passage (14) and the first chamber (11);

when the piston (5) moves in a direction to reduce the first chamber (11), the first valve (16) can be pushed open by the first trigger (30) if it touches the first trigger (30).

2. The hydraulic power steering machine (100) according to claim 1, further comprising a second limiter (4), the second limiter (4) comprising a second trigger portion (40) and an operating portion (42), the operating portion (42) being mounted on the housing (1) at a position operable from outside the housing (1), the second trigger portion (40) being drivable to move in a direction parallel to the axis within the hydraulic chamber (10) by operating the operating portion (42); a second valve (18) is also mounted in the pressure relief channel (14), the second valve (18) controlling fluid communication between the pressure relief channel (14) and the second chamber (12), and the second valve (18) can be pushed open by the second trigger (40) if it touches the second trigger (40) when the piston (5) moves in a direction to reduce the second chamber (12).

3. The hydraulic power steering (100) according to claim 1, wherein the first valve (16) is a one-way valve that prevents fluid flow from the pressure relief passage (14) in the direction of the first chamber (11) and is reverse-conducting.

4. The hydraulic power steering engine (100) of claim 2, wherein the second valve (18) is a one-way valve that prevents fluid flow from the pressure relief passage (14) to the second chamber (12) and is reverse-conducting.

5. The hydraulic power steering (100) of claim 2, wherein the first valve (16) and the second valve (18) have an integral valve housing (15), the valve housing (15) being mounted in the pressure relief channel (14).

6. The hydraulic power steering machine (100) according to claim 1, wherein the first trigger (30) is subjected to a conservative force towards the first valve (16).

7. The hydraulic power steering machine (100) according to claim 1, further comprising an elastic member (34), the elastic member (34) being elastically pre-deformed mounted between the housing (1) and the first trigger portion (30) to apply an elastic force to the first trigger portion (30) toward the first valve (16).

8. The hydraulic power steering (100) according to claim 1, wherein the pressure relief channel (14) has a length in a direction parallel to the axis that is not more than 50% and not less than 20 mm of the overall length of the piston (5).

9. The hydraulic power steering machine (100) according to claim 1, wherein the lock portion (32) is screw-engaged with the housing (1) so as to be able to advance and retreat the lock portion (32) in the direction perpendicular to the axis line with respect to the housing (1) by screwing the lock portion (32).

10. The hydraulic power steering engine (100) of claim 2, wherein the first trigger (30) has a first needle portion (31), the first valve (16) has a first valve port (160), a first spool (162) is mounted on the first valve port (160), and the first needle portion (31) is accessible to the first spool (162) through the first valve port (160); the second trigger part (40) is provided with a second thimble part (41), the second valve (18) is provided with a second valve port (180), a second valve core (182) is installed on the second valve port (180), and the second thimble part (41) can access the second valve core (182) through the second valve port (180); an elastically pre-compressed valve spring (19) is mounted between the first spool (162) and the second spool (182).