Hydraulic power steering gear structure and mounting method thereof

Abstract

The invention discloses a hydraulic power steering gear structure and a mounting method thereof, the structure comprises a hydraulic power steering gear, a transmission shaft and a steering tie rod, the hydraulic power steering gear is connected with a steering wheel through the transmission shaft, the hydraulic power steering gear is connected with the steering tie rod through a steering pull arm, and the steering tie rod is connected with a tire. According to the mounting platform with the positioning rod, the technical problems that the steering performance cannot be met and the assembly efficiency is low due to the fact that the initial posture of a steering pull arm does not have standard positioning during mounting of an existing hydraulic power steering gear, the left steering limit angle and the right steering limit angle are inconsistent, the pressure relief function fails, hydraulic locking cannot be achieved, and the steering performance cannot be met can be solved. The invention discloses a method for positioning the initial position of a standardized steering pull arm, which ensures that the steering angle of the steering pull arm is symmetrical and the pressure relief function and the stop function of the hydraulic power steering gear are normal, improves the assembly efficiency and avoids later debugging.

Description

Technical Field

[0001] This invention belongs to the technical field of vehicle steering systems, and particularly relates to a hydraulic power steering structure and its installation method. Background Technology

[0002] Heavy-duty construction machinery vehicles often choose hydraulic power steering as the power source for auxiliary steering due to its advantages such as easy steering, high load-bearing capacity, stable performance, and wide adaptability. However, the installation process of hydraulic power steering lacks standardized positioning requirements for the initial position and posture of the steering arm, relying heavily on the operator's experience. After the hydraulic power steering is placed on the frame, subsequent components are assembled. This installation method easily leads to deviations in the left and right limit angles of the hydraulic power steering, resulting in inconsistent left and right travel of the internal mechanism. This can cause the pressure relief valve to fail to trigger, resulting in one side failing to release pressure and the other side failing to stop. Furthermore, inconsistent limit angles may cause asymmetrical steering radii, affecting the overall vehicle steering performance and driving safety. Moreover, repeated adjustments and corrections are required during subsequent production, significantly reducing production efficiency and increasing production costs. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a hydraulic power steering system structure and its installation method.

[0004] The present invention is achieved through the following technical solutions.

[0005] The present invention provides a hydraulic power steering structure, including a hydraulic power steering unit, a drive shaft and a steering tie rod. The hydraulic power steering unit is connected to the steering wheel through the drive shaft, and the hydraulic power steering unit is connected to the steering tie rod through a steering arm. The steering tie rod is connected to the tire.

[0006] Preferably, the hydraulic power steering system includes a housing, an input shaft, a rack, and an output shaft gear. The input shaft extends into the housing from one side and is connected to the rack. The rack and the output shaft gear are disposed within the housing. The rack meshes with the output shaft gear, and the output shaft gear is connected to the steering arm.

[0007] Preferably, a first unloading valve core and a second unloading valve core are coaxially arranged at the lower part of the rack, and a connecting hole is provided on the rack, into which the input shaft extends and connects with the rack.

[0008] Preferably, a limiting bolt is provided on the housing.

[0009] Preferably, the input shaft is connected to the housing via an end cover, the input shaft slides through the end cover, and a limiting boss is provided on the end cover.

[0010] Preferably, the housing is provided with mounting holes.

[0011] Preferably, the housing and the rack are interference-fitted.

[0012] Preferably, a cap is provided on one side of the connection hole.

[0013] Preferably, several drive shafts are provided, and adjacent drive shafts are connected by a corner joint.

[0014] A method for installing a hydraulic power steering system includes the following steps: S1: Place the frame on the mounting platform and make one side of the frame easy to attach to the baffle set on the mounting platform; S2: Install the hydraulic power steering system onto the vehicle frame and connect the hydraulic power steering system to the steering wheel by setting up a drive shaft and a steering wheel; S3: Connect the top of the steering arm to the hydraulic power steering unit, connect the bottom of the steering arm to one end of the steering tie rod, and connect the other end of the steering tie rod to the positioning rod attached to the baffle on the mounting platform. At this time, the steering arm forms a 90° angle with the input shaft. S4: After adjusting the tire to a straight-line driving direction, connect it to one end of the steering tie rod, and adjust the length of the steering tie rod until the other end is connected to the bottom of the steering arm.

[0015] The beneficial effects of this invention are as follows: This invention solves the technical problems of inconsistent left and right steering limit angles, failure of pressure relief function, and inability to hydraulically stop the steering in existing hydraulic power steering systems due to the lack of standard positioning of the initial posture of the steering arm. This results in unsatisfactory steering performance and low assembly efficiency. The invention provides a method for standardizing the initial positioning of the steering arm using an installation platform with a positioning rod, ensuring symmetrical steering angles of the steering arm, normal pressure relief and stopping functions of the hydraulic power steering system, and improving assembly efficiency. It also avoids the need for later debugging in the installation of hydraulic power steering systems. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the hydraulic power steering system of the present invention; Figure 2 This is a schematic diagram of the structure of the hydraulic power steering system connected to the steering tie rod of the present invention; Figure 3 This is a schematic diagram of the installation structure of the hydraulic power steering system of the present invention; Figure 4 This is a schematic diagram of the installation structure of the hydraulic power steering system of the present invention; Figure 5 This is a schematic diagram of the steering arm in the vertical state of the present invention; Figure 6 This is a schematic diagram of the tilt state of the steering arm of the present invention; In the diagram: 1-Hydraulic power steering gear, 2-Drive shaft, 3-Steering tie rod, 4-Steering wheel, 5-Steering arm, 6-Tire, 7-Housing, 71-Mounting hole, 8-Input shaft, 9-Rack, 91-Connecting hole, 92-Cap, 10-Output shaft gear, 11-First unloading valve core, 12-Second unloading valve core, 13-Limit bolt, 14-End cover, 15-Angle switch, 16-Frame, 17-Mounting platform, 18-Baffle, 19-Positioning rod, 20-Steering front tie rod, 21-Limit boss. Detailed Implementation

[0017] The technical solution of the present invention is further described below, but the scope of protection is not limited to what is described.

[0018] The function of hydraulic stop and pressure relief in hydraulic power steering system 1: The hydraulic stop function of the hydraulic power steering 1 is that when the steering wheel is turned to the maximum steering angle position (mechanical limit of the vehicle steering mechanism), if the operator continues to maintain the steering operation, the pressure of the steering hydraulic system including the hydraulic power steering 1 will rise to the safe pressure setting value, the hydraulic system overflows and heats up, and the hydraulic power steering 1 applies the maximum steering force to the vehicle steering mechanism.

[0019] To prevent the vehicle steering mechanism from bearing excessive steering force at mechanically limited positions and to prevent the oil temperature of the steering hydraulic system from becoming too high due to overflow, a hydraulic stop and unloading function is designed into the structure. When the above working state occurs, the first unloading valve core 11 or the second unloading valve core 12 opens to bypass and release the high pressure in the housing 7 of the hydraulic power steering unit 1, that is, to release the pressure into the channel between the first unloading valve core 11 and the second unloading valve core 12, so as to reduce the steering force output by the power hydraulic power steering unit 1, reduce the steering force acting on the steering mechanism and the heat generation of the hydraulic system.

[0020] Adjustment methods for hydraulic stop and pressure relief of hydraulic power steering system 1: When the steering tire 6 reaches its maximum turning angle (minimum turning radius) for the first time, the self-adjusting first unloading valve core 11 or second unloading valve core 12 is blocked by the limiting bolt 7 or end cap 14, causing the unloading valve core to open and unload. Simultaneously, the first unloading valve core 11 or second unloading valve core 12 pushes the rack 9 to the corresponding position and fixes it, causing the output shaft gear 10 to rotate; at this time, the hydraulic power steering 1 emits a throttling sound, and the hydraulic stop adjustment is complete. The first unloading valve core 11 and second unloading valve core 12 on both the left and right sides are adjusted in this manner.

[0021] The principle behind the hydraulic stop and pressure relief failure of hydraulic power steering gear 1: When the steering arm 5 is not in the vertically downward position, such as Figure 6As shown, the swing angles on both sides are inconsistent. When the steering tire 6 turns to its maximum left and right steering angle, one side of the hydraulic power steering system can achieve hydraulic stop and pressure relief; the other side cannot achieve hydraulic stop. The reason for this is that when one side is at its maximum steering angle, the unloading valve core on that side cannot contact the limit bolt 7 or end cap 14 and open the valve core to unload. In other words, the steering arm 5 is not in the vertical direction, resulting in inconsistent left and right travel of the steering arm 5. On the side with excessive travel, under the condition of meeting the steering radius, the unloading valve core on that side may not have reached the initial unloading position, resulting in the inability to unload on that side.

[0022] For example, during assembly, only the tire 6 is positioned in the straight-line travel direction, while the steering arm 5 is not in the vertical direction, but deviates to the left by a large angle. In this state, the steering arm 5 is actually pre-positioned to the left by a steering angle relative to the center position of the rack 9, causing the distance between the unloading valve cores at both ends of the rack 9 and the limiting bolts 7 or the limiting steps 21 on the end cap 14 to be unequal, L1 < L0 < L2. Figure 5-6 As shown.

[0023] Example: like Figures 1 to 4 As shown, a hydraulic power steering structure includes a hydraulic power steering unit 1, a drive shaft 2, and a steering tie rod 3. The hydraulic power steering unit 1 is connected to a steering wheel 4 via the drive shaft 2, and the hydraulic power steering unit 1 is connected to the steering tie rod 3 via a steering arm 5. The steering tie rod 3 is connected to a tire 6.

[0024] The hydraulic power steering 1 includes a housing 7, an input shaft 8, a rack 9, and an output shaft gear 10. The input shaft 8 extends into the housing 7 from one side and is connected to the rack 9. The rack 9 and the output shaft gear 10 are disposed inside the housing 7. The rack 9 meshes with the output shaft gear 10, and the output shaft gear 10 is connected to the steering arm 5.

[0025] The rack 9 is coaxially provided with a first unloading valve core 11 and a second unloading valve core 12 at its lower part. The rack 9 is provided with a connecting hole 91, and the input shaft 8 extends into the connecting hole 91 to connect with the rack 9.

[0026] The housing 7 is provided with a limiting bolt 13, which is threadedly connected to the housing 7. The length of the limiting bolt 13 extending into the inner cavity of the housing 7 can be adjusted by rotating the limiting bolt 13. When the second unloading valve core 12 moves with the rack 9 and touches the limiting bolt 13, the second unloading valve core 12 is squeezed, which can open the second unloading valve core 12 to bypass pressure relief and reduce the steering force output by the power hydraulic power steering gear 1.

[0027] The input shaft 8 is connected to the housing 7 through the end cover 14. The input shaft 8 slides through the end cover 14. A limiting boss 21 is provided on the end cover 14. When the first unloading valve core 11 moves with the rack 9 and touches the limiting boss 21, the first unloading valve core 11 is squeezed, which can open the first unloading valve core 11 to bypass pressure relief, thereby reducing the steering force output by the power hydraulic power steering gear 1.

[0028] The housing 7 is provided with a mounting hole 71, and the end cap 14 is disposed in the mounting hole 71.

[0029] The housing 7 is interference-fitted with the rack 9, allowing the rack 9 to slide within the housing 7 under hydraulic pressure.

[0030] A cover 92 is provided on one side of the connection hole 91 to limit the depth of the input shaft 8 extending into the connection hole 91.

[0031] Three drive shafts 2 are provided, and adjacent drive shafts 2 are connected by an angler 15, which is used to feed back the rotation angle of the steering wheel 4 to the hydraulic power steering unit 1.

[0032] A method for installing a hydraulic power steering system includes the following steps: S1: Place the frame 16 on the mounting platform 17 and make one side of the frame 16 easy to attach to the baffle 18 provided on the mounting platform 17 to fix the position of the frame 16. S2: Install the hydraulic power steering unit 1 onto the frame 16, and connect the hydraulic power steering unit 1 to the steering wheel 4 by setting the drive shaft 2 and the cornering device 15; S3: Connect the top of the steering arm 5 to the hydraulic power steering unit 1, connect the bottom of the steering arm 5 to one end of the steering tie rod 3, and connect the other end of the steering tie rod 3 to the positioning rod 19 set on the mounting platform 17 and attached to the baffle 18. At this time, the steering arm 5 and the input shaft 8 form a 90° angle. S4: After adjusting the tire 6 to the straight-line driving direction, connect it to one end of the steering tie rod 20, and adjust the length of the steering tie rod 20 until the other end is connected to the bottom of the steering arm 5.

[0033] After installation using the above method, the initial position of the steering arm 5 was calibrated, ensuring the symmetry of the left and right swing angles of the steering arm 5. This ensures that the hydraulic power steering unit 1 can unload and brake after the left and right swing angles reach the set angles, reducing the need for re-adjustment after the tires 6 are installed, and ensuring steering performance and safety.

Claims

1. A hydraulic power steering gear structure, characterized by: The hydraulic power steering gear (1), the transmission shaft (2) and the steering tie rod (3), the hydraulic power steering gear (1) is connected with the steering wheel (4) through the transmission shaft (2), the hydraulic power steering gear (1) is connected with the steering tie rod (3) through the steering drag link (5), and the steering tie rod (3) is connected with the tire (6).

2. A hydraulic power steering gear structure as claimed in claim 1, wherein: The hydraulic power steering gear (1) includes a housing (7), an input shaft (8), a rack (9) and an output shaft gear (10), the input shaft (8) extends into the housing (7) from one side of the housing (7) and is connected with the rack (9), the rack (9) and the output shaft gear (10) are arranged in the housing (7), the rack (9) is engaged with the output shaft gear (10), and the output shaft gear (10) is connected with the steering drag link (5).

3. A hydraulic power steering gear structure as claimed in claim 2, wherein: The first unloading valve core (11) and the second unloading valve core (12) are coaxially arranged at the lower part of the rack (9), and the connecting hole (91) is arranged on the upper part of the rack (9), the input shaft (8) extends into the connecting hole (91) and is connected with the rack (9).

4. A hydraulic power steering gear structure as claimed in claim 2, wherein: The limiting bolt (13) is arranged on the housing (7).

5. A hydraulic power steering gear structure as claimed in claim 2, wherein: The input shaft (8) is connected with the housing (7) through the end cover (14), the input shaft (8) is slidingly connected through the end cover (14), and the limiting boss (21) is arranged on the end cover (14).

6. A hydraulic power steering gear structure and its mounting method as set forth in claim 2, wherein: The mounting hole (71) is arranged on the housing (7).

7. A hydraulic power steering gear structure and its mounting method as set forth in claim 2, wherein: The housing (7) is in interference fit with the rack (9).

8. A hydraulic power steering gear structure as claimed in claim 3, wherein: The connecting hole (91) is provided with a cover (92) on one side.

9. A hydraulic power steering gear structure as claimed in claim 1, wherein: The transmission shaft (2) is provided with a plurality of transmission shafts (2), and adjacent transmission shafts (2) are connected through the corner gear (15).

10. A method of installing a hydraulic power steering arrangement as claimed in any one of claims 1 to 9, characterised in that, The following steps are included: S1: placing the vehicle frame (16) on the mounting platform (17), and making one side of the vehicle frame (16) close to the baffle (18) arranged on the mounting platform (17); S2: installing the hydraulic power steering gear (1) on the vehicle frame (16), and connecting the hydraulic power steering gear (1) with the steering wheel (4) through the transmission shaft (2) and the corner gear (15); S3: connecting the top of the steering drag link (5) with the hydraulic power steering gear (1), connecting the bottom of the steering drag link (5) with one end of the steering tie rod (3), and connecting the other end of the steering tie rod (3) with the positioning rod (19) arranged on the baffle (18) of the mounting platform (17), at this time, the steering drag link (5) and the input shaft (8) form a 90° angle; S4: connecting one end of the tire (6) with the steering front pull rod (20) after adjusting the tire (6) to a straight walking direction state, and adjusting the length of the steering front pull rod (20) to connect the other end with the bottom of the steering drag link (5).

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