Hydraulic steering structure for construction machine

Abstract

This utility model discloses a hydraulic steering structure for engineering machinery, belonging to the field of steering control technology. It eliminates the problem of vibration and abnormal noise from the steering system being transmitted to the driver's operating end in existing technologies, improving the overall performance of the engineering machinery and the driver's operating comfort. It mainly includes a priority valve and a steering gear. The steering gear is connected to the steering wheel via a steering column. An accumulator module is installed between the priority valve and the steering gear. The accumulator module includes an accumulator and a switching valve, with the switching valve connected to the accumulator via a pipeline. This utility model, through the active absorption of hydraulic pulsations by the accumulator, combined with optimized pipeline layout and mechanical decoupling design, achieves a reduction in steering wheel vibration amplitude and a decrease in the risk of steering column cover resonance.

Description

Technical Field

[0001] This utility model relates to the field of steering control technology, and more specifically, to a hydraulic steering structure for engineering machinery. Background Technology

[0002] The steering system of construction machinery is a crucial component of modern engineering equipment, and its design directly impacts the machine's operational performance. Currently, this system primarily consists of a hydraulic steering gear, a priority valve or flow amplification valve, a steering pump, and piping connections. The hydraulic steering gear, as the core component, is responsible for converting the driver's steering intentions into mechanical actions via the hydraulic system. The steering column and steering wheel are designed with ergonomics in mind to ensure comfort and ease of operation, and are typically integrated into the cab for easy driver control. This integration of systems ensures the flexibility and accuracy of the construction machinery during operation.

[0003] The steering systems of construction machinery face several challenges in design and use, primarily stemming from internal vibrations and flow fluctuations. Currently, the hydraulic steering gear is connected to the cab floor. This connection can cause vibrations to be transmitted from the priority valve or flow amplification valve to the steering gear and steering column, ultimately affecting the interior trim within the cab and generating additional noise and vibration. This negatively impacts the driver's overall operating environment and reduces driving comfort. These issues not only affect driver comfort and ease of operation but also pose a potential threat to the reliability and safety of the construction machinery. Abnormal noises from the hydraulic system may be an early sign of system malfunction and require timely identification and intervention. Utility Model Content

[0004] The purpose of this utility model is to provide a hydraulic steering structure for engineering machinery, so as to eliminate the problem of vibration and abnormal noise of the steering system being transmitted to the driver's operating end in the prior art, thereby improving the overall performance of the engineering machinery and the driver's operating comfort.

[0005] This utility model is achieved through the following technical solution:

[0006] A hydraulic steering structure for engineering machinery includes a priority valve and a steering gear. The steering gear is connected to a steering wheel via a steering column. An accumulator module is disposed between the priority valve and the steering gear. The accumulator module includes an accumulator and a switching valve, and the switching valve is connected to the accumulator via a pipeline.

[0007] Furthermore, the steering gear includes a P port, and the priority valve includes a CF port; an accumulator module is disposed between the P port and the CF port.

[0008] Furthermore, a pressure acquisition module is provided at the CF port, and the switching valve is controlled by the pressure signal acquired by the pressure acquisition module.

[0009] Furthermore, the response time of the switching valve is ≤50ms.

[0010] Furthermore, the energy storage device is equipped with an elastic element.

[0011] Furthermore, the elastic element is an elastic diaphragm.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] This invention achieves reduced steering wheel vibration amplitude and decreased risk of steering column shield resonance by actively absorbing hydraulic pulsations through an accumulator, combined with optimized pipeline layout and mechanical decoupling design; reduced cab noise and high-frequency impact noise elimination rate; and avoids resonance transmission by ensuring that the first-order natural frequency of the steering system avoids the engine idling excitation frequency.

[0014] This invention employs dynamic intervention control of a switching valve to solve the problem of shunting caused by accumulator diversion and to protect the accumulator, preventing damage to the elastic diaphragm under high pressure. Attached Figure Description

[0015] Figure 1 This is a hydraulic schematic diagram of this utility model.

[0016] In the diagram: 1. Priority valve; 2. Switch valve; 3. Accumulator; 4. Steering gear. Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solution of this utility model, the technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Based on the embodiments in this application, other similar embodiments obtained by those skilled in the art without creative effort should all fall within the scope of protection of this application. Furthermore, the directional terms mentioned in the following embodiments, such as "up," "down," "left," and "right," are only for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for illustrative purposes and not for limiting the creation of this utility model.

[0018] The present invention will be further described below with reference to the accompanying drawings.

[0019] Example 1: A hydraulic steering structure for engineering machinery, such as... Figure 1As shown, the system includes a priority valve 1 and a steering gear 4. The steering gear 4 is connected to a steering wheel via a steering column. An accumulator module is located between the priority valve 1 and the steering gear 4. The accumulator module includes an accumulator 3 and a switching valve 2, with the switching valve 2 connected to the accumulator 3. The volume matching of the accumulator 3 is calculated based on the maximum flow rate (Qmax) of the hydraulic system, and the size of the accumulator 3 is selected. The pre-charge nitrogen pressure is set through calculation and actual testing. The natural frequency of the accumulator 3 is determined through computational fluid dynamics (CFD) simulation to ensure it covers the main excitation frequency band and has an attenuation rate ≥15dB.

[0020] Example 2: A hydraulic steering structure for engineering machinery, comprising a steering gear 4 including a P port and a priority valve 1 including a CF port; an accumulator 3 module is installed between the P port and the CF port. A pressure acquisition module is provided at the CF port, and the switching valve 2 is controlled by the pressure signal acquired by the pressure acquisition module to ensure that the steering force is transmitted without delay. The response time of the switching valve 2 is ≤50ms.

[0021] The accumulator 3 contains an elastic element; the elastic element is an elastic diaphragm, and the preset threshold of the switching valve is obtained through actual experiments and matched with the elastic diaphragm. Through its elastic element, and further selected from the elastic diaphragm or airbag, it absorbs the high-frequency pressure pulsations generated by the hydraulic pump. The volume and pre-charge pressure of the accumulator 3 need to be precisely matched with the system flow characteristics, especially for residual hydraulic excitation in the non-working state of the steering system. Optimal parameters are determined through fluid dynamics simulation, which can reduce cab noise. Other aspects are the same as in Example 1.

[0022] Steering activation interruption: When steering begins, a signal is fed back to priority valve 1 through the LS port of steering gear 4. Priority valve 1 controls the closing of switching valve 2, cutting off the connection between accumulator 3 and the main oil circuit, ensuring that steering force transmission is smooth. When the oil pressure at the CF port of priority valve 1 exceeds the set value, switching valve 2 is immediately closed to disconnect accumulator 3, preventing the elastic diaphragm from rupturing.

[0023] Steering intervention interruption: The switching valve 2 is closed by the oil pressure at the CF port of priority valve 1, with a response time of ≤50ms, to avoid steering force lag caused by the shunting of accumulator 3 and to ensure the linearity of steering force transmission.

[0024] This invention, through the combination of mechanical structure optimization and intelligent control, reduces steering wheel vibration amplitude while ensuring steering response, keeps system pressure fluctuation within the expected range, and improves NVH performance and energy utilization.

[0025] When the steering gear 4 is not in operation, residual pressure pulsations generated by the hydraulic pump still exist between the CF port of the priority valve 1 and the P port of the steering gear 4. These pulsations are transmitted through pipelines to mechanical components such as the steering column cover, causing resonance and noise. The introduction of the accumulator 3 is based on the Helmholtz resonance principle. It converts the pressure fluctuation energy into elastic potential energy through the deformation of the elastic diaphragm, temporarily storing it and achieving peak smoothing and valley filling of pressure. The volume and pre-charge pressure of the accumulator 3 need to be precisely matched with the system flow characteristics to form a low-impedance path in a specific frequency band, thereby preferentially absorbing the excitation energy of the target frequency band.

[0026] The present invention has been described in detail above. The above description is only a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of this application should still fall within the scope of the present invention.

Claims

1. A hydraulic steering structure for engineering machinery, comprising a priority valve (1) and a steering gear (4), characterized in that: The steering gear (4) includes a P port, and the priority valve (1) includes a CF port; an accumulator module is provided between the P port and the CF port; the accumulator module includes an accumulator (3) and a switching valve (2), and the switching valve (2) is connected to the accumulator (3).

2. The hydraulic steering structure for engineering machinery according to claim 1, characterized in that: The CF port is equipped with a pressure acquisition module, and the switching valve (2) is controlled by the pressure signal acquired by the pressure acquisition module.

3. The hydraulic steering structure for engineering machinery according to claim 2, characterized in that: The response time of the switching valve (2) is ≤50ms.

4. The hydraulic steering structure for engineering machinery according to claim 1, characterized in that: The energy storage device (3) is equipped with an elastic element.

5. The hydraulic steering structure for engineering machinery according to claim 4, characterized in that: The elastic element is an elastic diaphragm.

6. The hydraulic steering structure for engineering machinery according to claim 1, characterized in that: The steering gear (4) is connected to the steering wheel via the steering column.

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