WO2023128979A1

WO2023128979A1 - An electro-hydraulic steering circuit for vehicles

Info

Publication number: WO2023128979A1
Application number: PCT/TR2022/050972
Authority: WO
Inventors: Gokay UYMAZ; Samet NAK
Original assignee: Hema Endustri Anonim Sirketi
Priority date: 2021-12-28
Filing date: 2022-09-12
Publication date: 2023-07-06

Abstract

The present invention relates to a steering circuit (1) for providing guidance of vehicles during driving and which has at least one primary control line (2) which enables guidance by means of physical contact of the user to the steering, and at least one secondary control line (4) which enables guiding of vehicle autonomously and which keeps a steering (22) at a free position. The novelty of the present invention is that in order to provide passage of the steering (22), which is at free position while the vehicle is being guided in autonomous control state, to vehicle guidance by means of physical contact of the user; the subject matter steering circuit (1 ) comprises at least one discharge line (5) which has at least one discharge valve (40) configured to be connected to both said primary control line (2) and to said secondary control line (4) and to be able to manage the steering cylinders (50).

Description

AN ELECTRO-HYDRAULIC STEERING CIRCUIT FOR VEHICLES

TECHNICAL FIELD

The present invention relates to a steering circuit for providing guidance of vehicles during driving and which has at least one primary control line which enables guidance by means of physical contact of the user to the steering, and at least one secondary control line which enables guiding of vehicle autonomously and which keeps a steering at a free position.

PRIOR ART

In vehicles, there are auxiliary systems for providing rotation of the steering by the driver with little effort. These systems essentially operate with the rationale of transfer of a force, which is additional to the rotation force for the steering, to the guidance system by the driver. Today, hydraulically supported and electrically supported systems are frequently used. Besides these two systems, there is also electro-hydraulic steering which operates both electrically and hydraulically supported manner.

Electro-hydraulic steering is particularly preferred in heavy vehicles where the axle load is high. Here, an electrical motor which has hydraulic circuit is provided. Electrically supported systems enable autonomous movement of the steering by means of a signal control. This signal can be produced for usage with the purpose of safety or comfort. Servo motor controlled hydraulic circuits are also known in the present art. In such systems, in case of signal stopping, instant control is not allowed and serious results can occur.

The application no US5511457A known in the literature describes a steering control system. Accordingly, in an embodiment described in the application, an electrically controlled device mechanically operates the manual steering control valve for guiding the machine.

As a result, because of the abovementioned problems, an improvement is required in the related technical field. BRIEF DESCRIPTION OF THE INVENTION

The present invention relates to a steering circuit, for eliminating the abovementioned disadvantages and for bringing new advantages to the related technical field.

An object of the present invention is to provide a steering circuit where the steering cylinders are in free form when in free position.

In order to realize the abovementioned objects and the objects which are to be deducted from the detailed description below, the present invention is a steering circuit for providing guidance of vehicles during driving and which has at least one primary control line which enables guidance by means of physical contact of the user to the steering, and at least one secondary control line which enables guiding of vehicle autonomously and which keeps a steering at a free position. Accordingly, the improvement is that in order to provide passage of the steering, which is at free position while the vehicle is being guided in autonomous control state, to vehicle guidance by means of physical contact of the user; the subject matter steering circuit comprises at least one discharge line which has at least one discharge valve configured to be connected to both said primary control line and to said secondary control line and to be able to manage the steering cylinders.

In a possible embodiment of the present invention, said discharge line comprises at least one check valve for allowing passage of the fluid only towards said discharge valve. Thus, the discharge valve changes position without returning of the fluid from the blind part of the discharge valve. The fluid pushes the discharge valve through the blind part thereof and turns the tank from the open position to the closed position. Thus, guidance can be obtained for the wheels from the steering cylinder.

In another possible embodiment of the present invention, the discharge line comprises one each check valves for each flow path. Thus, unidirectional passage of the fluid is provided for each flow path which exists in the discharge line. Thus, position change can be provided for the fluid discharge valve both in right and left guidance.

BRIEF DESCRIPTION OF THE FIGURES

In Figure 1 , a representative schematic view of the subject matter steering circuit is given. DETAILED DESCRIPTION OF THE INVENTION

In this detailed description, the subject matter is explained with references to examples without forming any restrictive effect only in order to make the subject more understandable.

In Figure 1 , a representative schematic view of the subject matter steering circuit (1) is given. Accordingly, said steering circuit (1) is a guiding unit circuit in order to be provided in vehicles. In a possible embodiment of the invention, the steering circuit (1 ) describes a steering system in order to be provided in automobiles or in heavy commercial vehicles. Accordingly, the steering circuit (1) enables control of the steering both manually and electrically.

A fluid is circulated between steering circuit (1) elements. Said fluid is hydraulic oil. The fluid is enclosed within at least one tank (70). Said tank (70) is associated with at least one pump (60). Said pump (60) provides reaching of the fluid to the steering circuit (1 ) elements. Accordingly, the pump (60) pressurizes the fluid which exists in the tank (70) and provides circulation thereof in the steering circuit (1).

The steering circuit (1) comprises at least one safety valve (80). Said safety valve (80) is associated with the output line of the pump (60). The safety valve (80) is associated with the tank (70). Thus, the safety valve (60) prevents the steering circuit (1) from being damaged due to high pressure.

The steering circuit (1) comprises at least one steering (22). Said steering (22) provides the guidance to be managed by a person. The steering circuit comprises at least one steering arm (21). Said steering arm (21 ) provides steering by means of the movement received from the steering (22). The steering arm (21 ) is connected to at least one steering valve (20). Said steering valve (20) provides controlling of oil passage for providing support to the movements of the steering arm (21). The steering circuit (1 ) comprises at least one steering cylinder (50). Said steering cylinder (50) is the part where steering support is provided by means of the pressure of oil. Accordingly, the steering cylinder (50) has the ability to guide the vehicle wheels (not shown in the figures) to the right or to the left. The steering circuit (1 ) comprises at least one primary control line. Said primary control line (2) essentially provides the fluid to be transferred to the steering valve (20).

The steering circuit (1) comprises at least one proportional valve (30). Said proportional valve (30) is connected to at least one solenoid (31). There are one each solenoids (31) at the two ends of the proportional valve (30). Said solenoid (31) provides the position of the proportional valve (30) to be changed. Thus, the proportional valve (30) is controllable by means of electrical signals. The proportional valve (30) guides the fluid to the tank (70) at the position shown in Figure 1. When signal comes to one of the solenoids (31 ), the proportional valve (30) is changing position. When signal comes to one of the solenoids (31), the proportional valve (30) guides the fluid to at least one secondary control line (4). Said secondary control line (4) comprises two flow paths for right and left guidance. The secondary control line (4) is connected to the steering cylinder (50). Thus, the proportional valve (30) provides controlling of the fluid, transferred to the steering cylinder (50), by means of electrical signals.

The steering circuit (1) comprises at least one discharge line (5). Said discharge line (5) comprises two flow paths for right and left guidance. The discharge line (5) is associated with at least one discharge valve (40). While said discharge valve (40) is at the position which exists in Figure 1 , it guides the fluid to the tank (70). Thus, while the steering is at free position, the discharge line (5) provides sending of the fluid to the tank (70). Said free position defines the state where there is no intervention to the steering (22) by a person. When guidance is transferred to the steering cylinder (50), the discharge valve (40) passes to the closed position. Thus, transfer of the fluid to the tank (70) is interrupted for providing guidance.

The discharge line (5) comprises at least one check valve (41). Said check valve (41) is provided such that there is one check valve (41) for each flow path which exists in the discharge line (5). The check valve (41) allows passage of the fluid only towards the discharge valve (40). Thus, the check valve (41) provides non-returning of the fluid from the blind part of the discharge valve (40) when guidance is applied to the steering. Thus, the check valve (41 ) enables pushing of the discharge valve (40) by means of fluid and enables position change when the steering is guided. While the discharge valve (40) is at the position which exists in Figure 1 , the discharge valve (40) transfers the fluid to the tank (70). When the fluid pushes the discharge valve (40) through the blind part thereof, the blind part blocks the connection of the flow paths to the tank (70). Thus, guidance can be obtained for the wheels from the steering cylinder (50).

The steering circuit (1) comprises at least one passage line (3). Said passage line (3) is essentially the line which interconnects manual control and electrical signal control of steering to each other. Besides, the passage line (3) provides the pressured fluid to be transferred from the pump (60) to the proportional valve (30). The steering circuit (1) comprises at least one priority valve (10). Said priority valve (10) provides transfer of the fluid to the pilot line (6) and to the passage line (3).

According to the above mentioned explanations, the steering circuit (1 ) provides controlling of the guidance unit of a vehicle by means of both steering arm (21 ) and electrical signals. The fluid pressurized by the pump (60) reaches the priority valve (10). In accordance with the position which exists in Figure 1 , the priority valve (10) guides the fluid to the primary control line (2). The primary control line (2) guides the fluid to the steering valve (20). Here, if there is no intervention to the steering arm (21) by a person, the fluid is guided to at least one pilot line (6). Said pilot line (6) provides transfer of fluid to the priority valve (10) for position change. Here, the fluid pushes the priority valve (10) and changes its position. As the position changes in the priority valve (10), the fluid is guided to the passage line (3). The fluid is transferred through the passage line (3) to the proportional valve (30). While the proportional valve (30) is at the position which exists in Figure 1 , it transfers the fluid to the tank (70) through the passage line (3). Thus, when there is no intervention to the steering circuit (1), the system is open to the tank (70) and is in free form.

When steering is realized as the steering arm (21 ) is rotated by a person, the steering valve (20) changes its position which exists in Figure 1. When the steering arm (21 ) is rotated, the steering valve (20) which it is connected is also pushed and changes position. Thus, passage of the fluid to the steering cylinder (50) is provided. The steering valve (20) sends the fluid to one side of the steering cylinder (50) in accordance with the rotation direction of the steering arm. The fluid which exists on the other side of the steering cylinder (50) is guided from the steering valve (20) to the tank (70). Thus, the steering cylinder (50) provides guidance to the wheels to which it is connected. Thus, steering of the vehicle can be manually controlled.

In electrical control of steering of the vehicle, the electrical signal activates the solenoid (31 ). The solenoid (31) changes the position of the proportional valve (30) to which it is connected. When electricity is transferred to the solenoid (31 ) which is next to the proportional valve

(30), the solenoid (31) pushes the proportional valve (30). When electricity is transferred to the solenoid (31) which is at the other side of the proportional valve (30), the solenoid (31) pushes the proportional valve (30) at the opposite direction. Thus, the proportional valve (30) transfers fluid to one side of the steering shaft (50) as electricity is transferred to the solenoid

(31) which is at one of the two sides. The fluid which exists at the other side of the steering cylinder (50) is guided from the proportional valve (30) to the tank (70). Thus, the steering cylinder (50) provides guidance to the wheels to which it is connected. Thus, steering of the vehicle is controlled by means of electricity. By means of this, the vehicle is guided autonomously.

The steering circuit (1) provides the steering cylinders (50) to be in free-state by means of the discharge valve (40) thereof. The check valves (41) of the discharge line (5) allow fluid passage only to the discharge valve (40) and enable changing of position of the discharge valve (40) by means of fluid pressure. Thus, the check valves (41) prevent returning of the fluid from the blind part of the discharge valve (40). The protection scope of the present invention is set forth in the annexed claims and cannot be restricted to the illustrative disclosures given above, under the detailed description. It is because a person skilled in the relevant art can obviously produce similar embodiments under the light of the foregoing disclosures, without departing from the main principles of the present invention.

REFERENCE NUMBERS

1 Steering circuit

2 Primary control line

3 Passage line

4 Secondary control line

5 Discharge line

6 Pilot line

10 Priority valve

20 Steering valve

21 Steering arm

22 Steering

30 Proportional valve

31 Solenoid

40 Discharge valve

41 Check valve

50 Steering cylinder

60 Pump

70 Tank

80 Safety valve

Claims

CLAIMS The present invention is a steering circuit (1 ) for providing guidance of vehicles during driving and which has at least one primary control line (2) which enables guidance by means of physical contact of the user to the steering, and at least one secondary control line (4) which enables guiding of vehicle autonomously and which keeps a steering (22) at a free position, wherein in order to provide passage of the steering (22), which is at free position while the vehicle is being guided in autonomous control state, to vehicle guidance by means of physical contact of the user; the subject matter steering circuit (1 ) comprises at least one discharge line (5) which has at least one discharge valve (40) configured to be connected to both said primary control line (2) and to said secondary control line (4) and to be able to manage the steering cylinders (50). The steering circuit (1) according to claim 1 , wherein said discharge line (5) comprises at least one check valve (41 ) for allowing passage of the fluid only towards said discharge valve (40). The steering circuit (1 ) according to claim 1 , wherein the discharge line (5) comprises one each check valves (41 ) for each flow path.

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