Pipeline arrangement structure of a steering hydraulic system for a straddle carrier

Abstract

This invention discloses a pipeline layout structure for a steering hydraulic system of a straddle carrier, including a first-side front wheel steering hydraulic pipeline, a first-side rear wheel steering hydraulic pipeline, a second-side front wheel steering hydraulic pipeline, a second-side rear wheel steering hydraulic pipeline, and front and rear solenoid directional valve assemblies. A driver's cab is located in the middle of the first side of the straddle carrier. The front and rear solenoid directional valve assemblies are respectively located in front of and behind the driver's cab. The front solenoid directional valve assembly controls the steering of the first-side rear wheel via the first-side rear wheel steering hydraulic pipeline, and the rear solenoid directional valve assembly controls the steering of the first-side front wheel via the first-side front wheel steering hydraulic pipeline. Simultaneously, the front and rear solenoid directional valve assemblies control the steering of the second-side front and rear wheels via the second-side front and rear wheel steering hydraulic pipelines, respectively. This invention utilizes the cross-control of the front and rear solenoid directional valve assemblies to improve the synchronicity of steering on both sides of the wheels.

Description

Technical Field

[0001] This invention relates to a hydraulic system pipeline layout structure, and more particularly to a pipeline layout structure for a steering hydraulic system for a straddle carrier. Background Technology

[0002] When straddle carriers are in operation, due to their heavy load and high center of gravity, the vehicle often sways when turning, sometimes moving forward and sometimes backward. This swaying is particularly noticeable when the vehicle is moving, as the vehicle has a certain speed. This swaying can affect the driver's operation. Therefore, to reduce safety hazards and improve the stability of the vehicle during turning maneuvers, ensuring the consistency of the steering of both wheels is a crucial aspect of maintaining stability.

[0003] Unlike other construction machinery, straddle carriers have a more uneven distribution of components. They lack drive shafts or axles, and the driver's cab is located on one side (usually the left), not in the middle. Most major components are situated on the driver's side. Steering cylinders are typically located on either side of the vehicle. Therefore, transferring hydraulic fluid to the other steering cylinder is a significant challenge. Most current solutions involve sending hydraulic lines from the left side through a cable chain to the upper lifting frame, then transferring the fluid from the upper front or rear lifting frame to the right side of the vehicle. Finally, the fluid is transferred from the right lifting frame down to the right-side cable chain and then to the right-side steering cylinder. Consequently, the overall right-side steering cylinder connection pipeline is six to seven times longer than the left-side pipeline, resulting in a slower response time for the right-side cylinder and reduced steering efficiency. Summary of the Invention

[0004] In view of the above-mentioned defects in the prior art, the present invention aims to provide a pipeline layout structure for a steering hydraulic system for a straddle carrier, which solves the problem of asynchronous steering, improves hydraulic transmission efficiency, and optimizes the layout of steering pipelines.

[0005] The technical solution of this invention is as follows: A pipeline layout structure for a steering hydraulic system of a straddle carrier, including a first-side front wheel steering hydraulic pipeline, a first-side rear wheel steering hydraulic pipeline, a second-side front wheel steering hydraulic pipeline, a second-side rear wheel steering hydraulic pipeline, a front electromagnetic directional valve group, and a rear electromagnetic directional valve group. A driver's cab is located in the middle of the first side of the straddle carrier. The front electromagnetic directional valve group and the rear electromagnetic directional valve group are respectively located in front of and behind the driver's cab. The front electromagnetic directional valve group controls the steering of the first and second rear wheels through the first-side rear wheel steering hydraulic pipeline and the second-side rear wheel steering hydraulic pipeline. The rear electromagnetic directional valve group controls the steering of the first and second front wheels through the first-side front wheel steering hydraulic pipeline and the second-side front wheel steering hydraulic pipeline. The first side and the second side are the left and right sides of the straddle carrier, respectively.

[0006] Furthermore, the straddle carrier includes a first side fixing frame, a second side fixing frame, and a lifting frame. The lifting frame is mounted on the first side fixing frame and the second side fixing frame. A first front drag chain and a first rear drag chain are provided between the lifting frame and the first side fixing frame. The first front drag chain and the first rear drag chain are located on the front and rear sides of the driver's cab, respectively. A second drag chain is provided between the lifting frame and the second side fixing frame. The second side rear wheel steering hydraulic line is arranged along the first front drag chain, the front side of the lifting frame, and the second drag chain. The second side front wheel steering hydraulic line is arranged along the first rear drag chain, the rear side of the lifting frame, and the second drag chain.

[0007] Furthermore, the first-side front wheel steering hydraulic line and the first-side rear wheel steering hydraulic line are provided with rigid pipe sections on the first-side mounting bracket, the second-side front wheel steering hydraulic line and the second-side rear wheel steering hydraulic line are provided with rigid pipe sections on the first-side mounting bracket, the second-side mounting bracket and the lifting frame, the second-side rear wheel steering hydraulic line is provided with flexible hose sections on the first front cable chain and the second cable chain, and the second-side front wheel steering hydraulic line is provided with flexible hose sections on the first rear cable chain and the second cable chain.

[0008] Another technical solution of the present invention is: a pipeline layout structure for a steering hydraulic system for a straddle carrier, including a first-side front wheel steering hydraulic pipeline, a first-side rear wheel steering hydraulic pipeline, a second-side front wheel steering hydraulic pipeline, a second-side rear wheel steering hydraulic pipeline, a front solenoid directional valve assembly, and a rear solenoid directional valve assembly. A driver's cab is located in the middle of the first side of the straddle carrier. The front solenoid directional valve assembly and the rear solenoid directional valve assembly are respectively located in front of and behind the driver's cab. The front solenoid directional valve assembly controls the steering of the first-side rear wheel and the second-side front wheel through the first-side rear wheel steering hydraulic pipeline and the second-side front wheel steering hydraulic pipeline. The rear solenoid directional valve assembly controls the steering of the first-side front wheel and the second-side rear wheel through the first-side front wheel steering hydraulic pipeline and the second-side rear wheel steering hydraulic pipeline. The first side and the second side are the left and right sides of the straddle carrier, respectively.

[0009] Furthermore, the straddle carrier includes a first side fixing frame, a second side fixing frame, and a lifting frame. The lifting frame is mounted on the first side fixing frame and the second side fixing frame. A first front drag chain and a first rear drag chain are provided between the lifting frame and the first side fixing frame. The first front drag chain and the first rear drag chain are located on the front and rear sides of the driver's cab, respectively. A second drag chain is provided between the lifting frame and the second side fixing frame. The second side front wheel steering hydraulic line is arranged along the first front drag chain, the front side of the lifting frame, and the second drag chain. The second side rear wheel steering hydraulic line is arranged along the first rear drag chain, the rear side of the lifting frame, and the second drag chain.

[0010] Furthermore, the first-side front wheel steering hydraulic line and the first-side rear wheel steering hydraulic line are provided with rigid pipe sections on the first-side mounting bracket, the second-side front wheel steering hydraulic line and the second-side rear wheel steering hydraulic line are provided with rigid pipe sections on the first-side mounting bracket, the second-side mounting bracket and the lifting frame, the second-side front wheel steering hydraulic line is provided with flexible hose sections on the first front cable chain and the second cable chain, and the second-side rear wheel steering hydraulic line is provided with flexible hose sections on the first rear cable chain and the second cable chain.

[0011] Furthermore, the second cable chain is located in the middle of the second side mounting bracket.

[0012] Furthermore, the front electromagnetic directional valve group and the rear electromagnetic directional valve group each contain two electromagnetic directional valves for controlling the steering of two different wheels, and the P port and T port of the electromagnetic directional valves of the front electromagnetic directional valve group and the rear electromagnetic directional valve group are respectively connected.

[0013] The advantages of this invention compared to the prior art are:

[0014] This system employs a front solenoid directional valve assembly to control the rear wheel steering on the same side as the solenoid directional valve assembly, and a rear solenoid directional valve assembly to control the front wheel steering on the same side. The hydraulic lines from the solenoid directional valve assemblies to the wheels on their respective sides are lengthened, while the length of the hydraulic lines connecting the other wheels remains largely unchanged. This reduces the difference in line length from the directional valves to the cylinders on both sides, thereby reducing the difference in steering response speed between the left and right wheels and preventing the problem of the left wheel steering too quickly and the right wheel steering too slowly. Compared to electric servo steering, this pipeline layout still uses the original hydraulic drive method, with two sets of solenoid directional valve assemblies as the core components. The total length of the hydraulic lines remains largely unchanged, without significantly increasing costs. It improves steering efficiency, reduces steering response time, and also facilitates initial modifications and subsequent maintenance. By adopting a cross-control method, where one set of electromagnetic directional valves controls the first front wheel and the second rear wheel, and another set of electromagnetic directional valves controls the second front wheel and the first rear wheel, tire wear caused by unreasonable steering angles that may result from one set of electromagnetic directional valves simultaneously controlling one side of the steering cylinder or one set of electromagnetic directional valves simultaneously controlling the steering of two front wheels can be avoided. Attached Figure Description

[0015] Figure 1 A schematic diagram of the pipeline layout of the steering hydraulic system for straddle carriers (left front view).

[0016] Figure 2 A schematic diagram of the pipeline layout of the steering hydraulic system for straddle carriers (top left view).

[0017] Figure 3This is a hydraulic schematic diagram of the front and rear solenoid directional valve groups. Detailed Implementation

[0018] The present invention will be further described below with reference to embodiments, but these are not intended to limit the scope of the invention.

[0019] Please combine Figures 1 to 3 As shown, the pipeline layout of the steering hydraulic system for the straddle carrier in this embodiment is as follows: it is arranged on the straddle carrier, which includes a first side fixing frame 1, a second side fixing frame 2, and a lifting frame 3. In this embodiment, the left side is defined as the first side, and the right side is defined as the second side.

[0020] The first side mounting bracket 1 includes a left longitudinal beam 101, with a left front wheel bracket 102 rotatably connected to its front end. The left front wheel bracket 102 is used to mount the left front wheel. A left front wheel steering hydraulic cylinder 10 is connected to the left front wheel bracket 102. The action of the left front wheel steering hydraulic cylinder 10 causes the left front wheel bracket 102 to rotate, thereby steering the left front wheel. Similarly, a left rear wheel bracket 103 is rotatably connected to the front end of the left longitudinal beam 101, with the left rear wheel bracket 103 used to mount the left rear wheel. A left rear wheel steering hydraulic cylinder 11 is connected to the left rear wheel bracket 103. The action of the left rear wheel steering hydraulic cylinder 11 causes the left rear wheel bracket 103 to rotate, thereby steering the left rear wheel.

[0021] The second side fixing frame 2 includes a right longitudinal beam 201. The front and rear ends of the right longitudinal beam 201 are rotatably connected to the right front wheel bracket 202 and the right rear wheel bracket 203, respectively. The right front wheel steering hydraulic cylinder 12 and the right rear wheel steering hydraulic cylinder 13 drive the right front wheel bracket 202 and the right rear wheel bracket 203 to rotate, thereby driving the right front wheel and the right rear wheel to steer.

[0022] The lifting frame 3 includes a left front column 301, a left rear column 302, a right front column 303, and a right rear column 304. A left upper longitudinal beam 305 and a left lower longitudinal beam 306 connect the left front column 301 and the left rear column 302; a right upper longitudinal beam 307 and a right lower longitudinal beam 308 connect the right front column 303 and the right rear column 304; a front crossbeam 309 connects the upper parts of the left front column 301 and the right front column 303; and a rear crossbeam 310 connects the upper parts of the left rear column 302 and the right rear column 304, thus forming a rectangular frame structure. The bottom ends of the left front column 301 and the left rear column 302 are fixed to the front and rear ends of the first side fixing frame 1, respectively; and the bottom ends of the right front column 303 and the right rear column 304 are fixed to the front and rear ends of the second side fixing frame 2, respectively.

[0023] Generally, the driver's cab (not shown in the figure) is located on the left side. Therefore, a driver's cab floor plate 104 is also provided in the middle of the first side fixing frame 1 to house the driver's cab. The lifting frame 3 will be raised and lowered as needed. At the same time, more control devices (including electrical components and hydraulic components) are concentrated on the side where the driver's cab is located. In order to ensure reliable connection of pipeline cables, a first front drag chain 105 and a first rear drag chain 106 are provided between the lower left longitudinal beam 306 of the lifting frame 3 and the left longitudinal beam 101 of the first side fixing frame 1. The first front drag chain 105 and the first rear drag chain 106 are located in front of and behind the driver's cab, respectively. A second drag chain 204 is provided between the lower right longitudinal beam 308 of the lifting frame 3 and the right longitudinal beam 201 of the second side fixing frame 2.

[0024] The steering of the four wheels on the straddle carrier is controlled by the front solenoid directional valve assembly 4 and the rear solenoid directional valve assembly 5. The front solenoid directional valve assembly 4 is located at the front of the driver's cab, and the rear solenoid directional valve assembly 5 is located at the rear of the driver's cab, both fixedly mounted on the first side mounting bracket 1. Each of the front and rear solenoid directional valve assemblies includes two solenoid directional valves. The P and T ports of all solenoid directional valves are connected, allowing simultaneous oil inlet and outlet; the TX and LS ports are also connected, thus reducing the number of hydraulic hoses with the same function.

[0025] In this embodiment, the two solenoid directional valves of the front solenoid directional valve assembly 4 are used to control the steering of the left rear wheel (first side rear wheel) and the right front wheel (second side front wheel), respectively. The two solenoid directional valves of the rear solenoid directional valve assembly 5 are used to control the steering of the left front wheel (first side front wheel) and the right rear wheel (second side rear wheel), respectively. The front solenoid directional valve assembly 4 is connected to the left rear wheel steering hydraulic cylinder 11 through the first side rear wheel steering hydraulic line 6, and to the right front wheel steering hydraulic cylinder 12 through the second side front wheel steering hydraulic line 8.

[0026] The first rear wheel steering hydraulic line 6 starts from the front solenoid directional valve assembly 4, runs rearward along the driver's cab floor 104, and connects to the left rear wheel steering hydraulic cylinder 11. The first front wheel steering hydraulic line 7 starts from the rear solenoid directional valve assembly 5, runs forward along the driver's cab floor 104, and connects to the left front wheel steering hydraulic cylinder 10. The first rear wheel steering hydraulic line 6 and the first front wheel steering hydraulic line 7 can be set as rigid pipe sections on the driver's cab floor 104 for neatness and easy maintenance.

[0027] The second-side front wheel steering hydraulic line 8 originates from the front solenoid directional valve assembly 4, enters the first front cable chain 105 along the left longitudinal beam 101, and sequentially enters the second cable chain 204 along the lower left longitudinal beam 306, left front pillar 301, front crossbeam 309, right front pillar 303, and lower right longitudinal beam 308 of the lifting frame 3. It then connects forward along the right longitudinal beam 201 to the right front wheel steering hydraulic cylinder 12. The second-side rear wheel steering hydraulic line 9 originates from the rear solenoid directional valve assembly 5, enters the first rear cable chain 106 along the left longitudinal beam 101, and sequentially enters the second cable chain 204 along the lower left longitudinal beam 306, left rear pillar 302, rear crossbeam 310, right rear pillar 304, and lower right longitudinal beam 308 of the lifting frame 3. It then connects backward along the right longitudinal beam 201 to the right rear wheel steering hydraulic cylinder 13. The long, straight sections of the second-side front wheel steering hydraulic line 8 and the second-side rear wheel steering hydraulic line 9 on the first-side fixing frame 1, the second-side fixing frame 2, and the lifting frame 3 are arranged as rigid pipe sections. The second-side front wheel steering hydraulic line 8 is arranged as a flexible hose section on the first front cable chain 105 and the second cable chain 204, and the second-side rear wheel steering hydraulic line 9 is arranged as a flexible hose section on the first rear cable chain 106 and the second cable chain 204. The combination of flexible hose sections and rigid pipe sections ensures the reliability and ease of maintenance of the hydraulic lines.

[0028] from Figure 1 and Figure 2 As can be seen, in this embodiment, the length difference between the first rear wheel steering hydraulic line 6 and the second front wheel steering hydraulic line 8, which are connected from the front solenoid directional valve assembly 4 to the left rear wheel and the right front wheel respectively, is small. Similarly, the length difference between the first front wheel steering hydraulic line 7 and the second rear wheel steering hydraulic line 9, which are connected from the rear solenoid directional valve assembly 5 to the left front wheel and the right rear wheel respectively, is also small. This reduces the difference in steering response speed between the left and right tires, avoiding the problem of the left wheel steering too quickly and the right wheel steering too slowly. Furthermore, since the front solenoid directional valve assembly 4 controls the steering of the left rear wheel and the right front wheel, while the rear solenoid directional valve assembly 5 controls the steering of the left front wheel and the right rear wheel, this cross-control method can prevent tire wear caused by unreasonable steering angles.

[0029] It should also be noted that, since the second cable chain 204 is located in the middle of the second side of the second fixed frame 2 and the lifting frame 3, the distance from the front electromagnetic directional valve assembly 4 to the second cable chain 204 is approximately the same as the distance from the rear electromagnetic directional valve assembly 5 to the second cable chain 204, and the distance from the second cable chain 204 to the right front wheel steering cylinder is approximately the same as the distance from the second cable chain 204 to the right rear wheel steering cylinder. Therefore, in some embodiments, the front electromagnetic directional valve assembly 4 can also control the first and second rear wheels via the first rear wheel steering hydraulic line 6 and the second rear wheel steering hydraulic line 9, and the rear electromagnetic directional valve assembly 5 can also control the first and second front wheels via the first front wheel steering hydraulic line 7 and the second front wheel steering hydraulic line 8. This also reduces the difference in steering response speed between the left and right tires, avoiding the problem of the left wheel steering too fast and the right wheel steering response being slow.

Claims

1. A pipeline layout structure for a steering hydraulic system for a straddle carrier, characterized in that, The vehicle includes a first-side front wheel steering hydraulic line, a first-side rear wheel steering hydraulic line, a second-side front wheel steering hydraulic line, a second-side rear wheel steering hydraulic line, a front solenoid directional valve assembly, and a rear solenoid directional valve assembly. A driver's cab is located in the middle of the first side of the straddle carrier. The front solenoid directional valve assembly and the rear solenoid directional valve assembly are respectively located in front of and behind the driver's cab. The front solenoid directional valve assembly controls the steering of the first and second rear wheels via the first-side rear wheel steering hydraulic line and the second-side rear wheel steering hydraulic line. The rear solenoid directional valve assembly controls the steering of the first and second front wheels via the first-side front wheel steering hydraulic line and the second-side front wheel steering hydraulic line. The first side and the second side are the left and right sides of the straddle carrier, respectively. The straddle carrier includes a first side mounting frame, a second side mounting frame, and a lifting frame. The lifting frame is mounted on the first and second side mounting frames. A first front cable chain and a first rear cable chain are provided between the lifting frame and the first side mounting frame. The first front cable chain and the first rear cable chain are located at the front and rear sides of the driver's cab, respectively. A second cable chain is provided between the lifting frame and the second side mounting frame. The second side rear wheel steering hydraulic line is arranged along the first front cable chain, the front side of the lifting frame, and the second cable chain. The second side front wheel steering hydraulic line is arranged along the first rear cable chain. The cable chain, the rear side of the lifting frame, and the second cable chain are arranged such that the first side front wheel steering hydraulic line and the first side rear wheel steering hydraulic line are provided with rigid pipe sections on the first side fixed frame, the second side front wheel steering hydraulic line and the second side rear wheel steering hydraulic line are provided with rigid pipe sections on the first side fixed frame, the second side fixed frame, and the lifting frame, the second side rear wheel steering hydraulic line is arranged as a flexible hose section on the first front cable chain and the second cable chain, and the second side front wheel steering hydraulic line is arranged as a flexible hose section on the first rear cable chain and the second cable chain.

2. The pipeline layout structure of the steering hydraulic system for straddle carriers according to claim 1, characterized in that, The second cable chain is located in the middle of the second side mounting bracket.

3. The pipeline layout structure of the steering hydraulic system for straddle carriers according to claim 1, characterized in that, The front solenoid directional valve group and the rear solenoid directional valve group each contain two solenoid directional valves for controlling the steering of two different wheels, and the P port and T port of the solenoid directional valves of the front solenoid directional valve group and the rear solenoid directional valve group are respectively connected.

4. A pipeline layout structure for a steering hydraulic system for a straddle carrier, characterized in that, The vehicle includes a first-side front wheel steering hydraulic line, a first-side rear wheel steering hydraulic line, a second-side front wheel steering hydraulic line, a second-side rear wheel steering hydraulic line, a front solenoid directional valve assembly, and a rear solenoid directional valve assembly. A driver's cab is located in the middle of the first side of the straddle carrier. The front solenoid directional valve assembly and the rear solenoid directional valve assembly are respectively located in front of and behind the driver's cab. The front solenoid directional valve assembly controls the steering of the first-side rear wheel and the second-side front wheel steering hydraulic line through the first-side rear wheel steering hydraulic line and the second-side front wheel steering hydraulic line. The rear solenoid directional valve assembly controls the steering of the first-side front wheel and the second-side rear wheel steering hydraulic line through the first-side front wheel steering hydraulic line and the second-side rear wheel steering hydraulic line. The first side and the second side are the left and right sides of the straddle carrier, respectively. The straddle carrier includes a first side mounting frame, a second side mounting frame, and a lifting frame. The lifting frame is mounted on the first and second side mounting frames. A first front cable chain and a first rear cable chain are provided between the lifting frame and the first side mounting frame. The first front cable chain and the first rear cable chain are located at the front and rear sides of the driver's cab, respectively. A second cable chain is provided between the lifting frame and the second side mounting frame. The second side front wheel steering hydraulic line is arranged along the first front cable chain, the front side of the lifting frame, and the second cable chain. The second side rear wheel steering hydraulic line is arranged along the first rear cable chain. The cable chain, the rear side of the lifting frame, and the second cable chain are arranged such that the first side front wheel steering hydraulic line and the first side rear wheel steering hydraulic line are provided with rigid pipe sections on the first side fixed frame, the second side front wheel steering hydraulic line and the second side rear wheel steering hydraulic line are provided with rigid pipe sections on the first side fixed frame, the second side fixed frame, and the lifting frame, the second side front wheel steering hydraulic line is arranged as a flexible hose section on the first front cable chain and the second cable chain, and the second side rear wheel steering hydraulic line is arranged as a flexible hose section on the first rear cable chain and the second cable chain.

5. The pipeline layout structure of the steering hydraulic system for straddle carriers according to claim 4, characterized in that, The second cable chain is located in the middle of the second side mounting bracket.

6. The pipeline layout structure of the steering hydraulic system for straddle carriers according to claim 4, characterized in that, The front solenoid directional valve group and the rear solenoid directional valve group each contain two solenoid directional valves for controlling the steering of two different wheels, and the P port and T port of the solenoid directional valves of the front solenoid directional valve group and the rear solenoid directional valve group are respectively connected.

Images