Steering brake for crawler tractors

Abstract

The utility model relates to the technical field of tractors, and in particular to a steering brake device for a crawler tractor, comprising a steering wheel joystick, a gearbox and a hydraulic assembly, wherein the gearbox is provided with a main driver's side steering connecting rod, a main driver's side brake connecting rod and a co-driver's side steering connecting rod and a co-driver's side brake connecting rod on the main driver's side and the co-driver's side, respectively, and the hydraulic assembly comprises a first steering oil cylinder, a first brake oil cylinder, a second steering oil cylinder, a second brake oil cylinder and a first hydraulic valve and a second hydraulic valve which are respectively connected with the main driver's side steering connecting rod, the main driver's side brake connecting rod, the co-driver's side steering connecting rod and the co-driver's side brake connecting rod key, wherein the first hydraulic valve is a two-position four-way valve, and the second hydraulic valve is a three-position four-way valve, and the device can realize the vehicle turning around on the spot under the single-side crawler braking state, and can meet the vehicle turning around operation under narrow road conditions.

Description

Technical Field

[0001] The utility model relates to the technical field of tractors, in particular to a steering brake device for a crawler tractor. Background Art

[0002] Crawler tractors are widely used in the agricultural field and can be used for tillage, sowing, fertilization, harvesting, etc. Farm roads are bumpy and uneven. In some narrow mountain roads, it is very difficult for conventional crawler tractors to turn due to their large turning radius.

[0003] Chinese patent CN115013483B discloses a transmission system for an automatic transmission of a tracked vehicle. Paragraphs

[0035] to

[0041] of the specification disclose a hydraulic system configuration scheme, which can realize braking and in-situ steering during normal driving of the vehicle. When the vehicle makes an in-situ steering, the steering radius at this time is the minimum steering radius of the vehicle, which can meet the steering requirements of the vehicle in a narrow mountain road environment. However, the above scheme does not disclose the specific working principle of the hydraulic system when the vehicle is turning and braking, nor does it disclose the specific implementation scheme of the steering brake. Utility Model Content

[0004] Technical purpose: In order to overcome the deficiencies in the prior art, the utility model provides a steering brake device for a crawler tractor.

[0005] Technical solution: To achieve the above-mentioned purpose, the utility model discloses a steering and braking device for a crawler tractor, comprising a steering wheel joystick, a gearbox and a hydraulic assembly, wherein the gearbox is provided with a main driver's side steering connecting rod, a main driver's side brake connecting rod and a co-driver's side steering connecting rod and a co-driver's side brake connecting rod on the main driver's side and the co-driver's side, respectively, and the hydraulic assembly comprises a first steering cylinder, a first brake cylinder, a second steering cylinder, a second brake cylinder and a first hydraulic valve and a second hydraulic valve, which are respectively connected to the main driver's side steering connecting rod, the main driver's side brake connecting rod, the co-driver's side steering connecting rod and the co-driver's side brake connecting rod. The first hydraulic valve is a two-position four-way valve, and the second hydraulic valve is a three-position four-way valve.

[0006] Preferably, the number of the second hydraulic valves is two, and they are symmetrically arranged below the steering wheel joystick.

[0007] Preferably, a pressure valve plate is provided under the steering wheel joystick and turns left or right synchronously therewith. The pressure valve plate includes a pressure valve plate body and a boss located on its outer edge. The pressure valve plate can change the position of the internal valve core of one of the second hydraulic valves during the left or right turn.

[0008] Preferably, the first hydraulic valve is installed close to a brake pedal, and the brake pedal is connected to a push rod, and the valve core of the first hydraulic valve is driven to move by the push rod during the displacement of the brake pedal.

[0009] Preferably, the boss is provided with a first flange and a second flange, the number of the second flanges is two and they are symmetrically arranged on both sides of the first flange, the first flange and the second flange are connected by a first arc transition, and the second flange and the pressure valve disc body are connected by a second arc transition.

[0010] Preferably, the first flange radius value A is greater than the second flange radius value B.

[0011] Preferably, the valve core is provided with three position states in the second hydraulic valve, namely, a first position, a second position and a third position. When the valve core is located at the first position, the valve pressure disc body contacts the end of the valve core. When the valve core is located at the second position, the second flange contacts the end of the valve core. When the valve core is located at the third position, the first flange contacts the end of the valve core.

[0012] Preferably, the hydraulic assembly also includes a priority valve, the first steering cylinder, the first brake cylinder, the second steering cylinder and the second brake cylinder are all single-acting hydraulic cylinders, the first steering cylinder and the second steering cylinder are connected to the LS port of the priority valve through the first pipeline and the second pipeline respectively, and the first pipeline and the second pipeline are respectively provided with a first one-way valve and a second one-way valve.

[0013] The beneficial effects of the utility model are:

[0014] 1. This device can realize the braking, steering and unilateral steering braking of crawler tractors during normal driving. During unilateral steering braking, the vehicle can turn around on the spot under the unilateral crawler braking state. At this time, the turning radius of the vehicle is the smallest, which can meet the U-turn operation of the vehicle under narrow road conditions.

[0015] 2. The valve cores of the two sets of second hydraulic valves are in contact with the pressure valve disc during steering. The variable arc design of the pressure valve disc can be used to adjust the valve core to different positions, thereby realizing the connection and disconnection of different oil circuits. In addition, the steering wheel only needs to rotate half a circle during U-turn, making the operation more sensitive.

[0016] 3. When the driver turns the steering wheel, the on-off control of the one-way valve can give a priority valve signal to enable the priority valve CF port to supply oil to the first hydraulic valve, thereby realizing the connection of the hydraulic oil circuit in the steering and braking functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0018] Figure 2 This is a front view of the installation position of the second hydraulic valve in the utility model;

[0019] Figure 3 This is a top view of the installation position of the second hydraulic valve in the utility model;

[0020] Figure 4 This is a schematic diagram of the medium-pressure valve disc of the utility model;

[0021] Figure 5 This is a schematic diagram of the valve core in the second hydraulic valve of the utility model being in the first position;

[0022] Figure 6 This is a schematic diagram of the valve core in the second hydraulic valve of the utility model being in the second position;

[0023] Figure 7 This is a schematic diagram of the valve core in the second hydraulic valve of the utility model being in the third position;

[0024] Figure 8 It is a schematic diagram of the pipeline connection of the hydraulic component in the utility model.

[0025] In the figure, 1, the second steering cylinder; 2, the second brake cylinder; 3, the first steering cylinder; 4, the first brake cylinder; 5, the hydraulic assembly; 6, the steering wheel joystick; 7, the second hydraulic valve; 8, the priority valve; 9, the first hydraulic valve; 10, the push rod; 11, the brake pedal; 12, the gearbox; 13, the second hydraulic valve a; 14, the second hydraulic valve b; 15, the pressure valve plate; 16, the first flange; 17, the second flange; 18, the pressure valve plate body; 19, the second hydraulic valve P port; 20, the second hydraulic valve T port; 21, the second hydraulic valve A port; 22, the second hydraulic valve B port; 23, the first channel; 24, the second channel; 25, the valve core; 26, the first arc; 27, the second arc; 28, the third channel; 29, the first one-way valve; 30, the second one-way valve; 31, the oil tank; 32, the boss. DETAILED DESCRIPTION

[0026] The following is combined with Figure 1 To Attachment Figure 8 The principles and features of the present invention are described, and the examples given are only used to explain the present invention, and are not used to limit the scope of the present invention.

[0027] A steering brake device for a crawler tractor, such as Figure 1 — Figure 4As shown, it includes a steering wheel joystick 6, a gearbox 12 and a hydraulic component 5. The gearbox 12 is respectively provided with a main driver's side steering connecting rod, a main driver's side brake connecting rod and a passenger side steering connecting rod, and a passenger side brake connecting rod on the main driver's side and the passenger side. By controlling the main driver's side steering connecting rod, the main driver's side brake connecting rod and the passenger side steering connecting rod, and the passenger side brake connecting rod, the tractor can be turned left and right and braked. This is the prior art in the field and will not be repeated here.

[0028] The hydraulic assembly 5 includes a first steering cylinder 3, a first brake cylinder 4, a second steering cylinder 1, and a second brake cylinder 2 which are respectively connected to the main driver's side steering connecting rod, the main driver's side brake connecting rod, the passenger side steering connecting rod, and the passenger side brake connecting rod to drive them to rotate. The key connection method is a technical means commonly used by people in this field, usually a flat key or a spline connection. The flat key connection method is adopted in this embodiment. The hydraulic assembly 5 also includes a first hydraulic valve 9 and a second hydraulic valve 7. Among them, the first steering cylinder 3, the first brake cylinder 4, the second steering cylinder 1, and the second brake cylinder 2 are all single-acting hydraulic cylinders, and the single-acting hydraulic cylinder has only one oil port. When the hydraulic oil enters the cylinder from the oil port, the cylinder rod extends, and the cylinder rod is reset by a spring.

[0029] The first hydraulic valve 9 is a two-position four-way valve, in which P is usually used to represent the pressure oil port, T is used to represent the return oil port, A and B are used to represent the working oil ports respectively. The structure and working principle of the two-position four-way valve are technical knowledge well known to those skilled in the art and will not be described in detail here.

[0030] The second hydraulic valve 7 is a three-position four-way valve, the second hydraulic valve P port of the second hydraulic valve 7 represents the pressure oil port, the second hydraulic valve T port 20 represents the return oil port, the second hydraulic valve A port 21 and the second hydraulic valve B port 22 represent the working oil ports respectively.

[0031] There are two second hydraulic valves 7, which are defined as second hydraulic valve a13 and second hydraulic valve b14 for the convenience of description. The second hydraulic valve a13 and the second hydraulic valve b14 are symmetrically arranged below the steering wheel joystick 6. A valve plate 15 is provided below the steering wheel joystick 6 to rotate synchronously therewith. The valve plate 15 includes a valve plate body 18 and a boss 32 located at its outer edge. The boss 32 is provided with a first flange 16 and a second flange 17. There are two second flanges 17, which are symmetrically arranged on both sides of the first flange 16. The first flange 16 and the second flange 17 are transitionally connected through a first arc 26, and the second flange 17 and the valve plate body 18 are transitionally connected through a second arc 27. The radius value A of the first flange 16 is greater than the radius value B of the second flange 17. In this embodiment, the radius value A is 35 mm, and the radius value B is 31.5 mm.

[0032] When the steering wheel is turned left or right, the steering wheel joystick 6 drives the pressure valve disc 15 to rotate. During the rotation of the pressure valve disc 15, its pressure valve disc body 18, second flange 17, and first flange 16 contact the end of the valve core 25 inside the second hydraulic valve b14 or the second hydraulic valve a13 in sequence, and push the valve core 25 to move, change its position, and realize the communication of different oil ports of the second hydraulic valve b14 or the second hydraulic valve a13. The valve core 25 has three position states in the second hydraulic valve 7, namely the first position, the second position and the third position.

[0033] like Figure 5 As shown, when the valve core 25 is in the first position, the valve disc body 18 contacts the end of the valve core 25, and the second hydraulic valve P port 19 is connected with the second hydraulic valve A port 21 through the first channel 23, and the second hydraulic valve T port 20 is connected with the second hydraulic valve B port 22 through the second channel 24. At this time, the vehicle is in a normal driving state. When braking in this state, the hydraulic oil enters the second hydraulic valve T port 20 and the second hydraulic valve B port 22 into the second brake cylinder 2 and the first brake cylinder 4 to achieve braking.

[0034] like Figure 6 As shown, when the valve core 25 is in the second position, the second flange 17 contacts the end of the valve core 25, and only the second hydraulic valve P port 19 is connected to the second hydraulic valve A port 21 through the first channel 23, and the vehicle is in a steering state.

[0035] like Figure 7 As shown, when the valve core 25 is located in the third position, the first flange 16 contacts the end of the valve core 25. At this time, the second hydraulic valve P port 19 is connected to the second hydraulic valve A port 21 through the first channel 23, and the second hydraulic valve P port 19 is also connected to the second hydraulic valve B port 22 through the third channel 28. At this time, the vehicle is in a single-sided steering braking state, that is, turning around on the spot.

[0036] The first hydraulic valve 9 is installed close to the brake pedal 11 , and the brake pedal 11 is connected to a push rod 10 . During the displacement of the brake pedal 11 , the valve core of the first hydraulic valve 9 is driven to displace by the push rod 10 .

[0037] like Figure 8As shown, the hydraulic assembly 5 also includes a priority valve 8 and a hydraulic pipeline system that connects various components to realize functions. The priority valve 8 is a commonly used component in this field, and its working principle and structure are not repeated here. The first steering cylinder 3 and the second steering cylinder 1 are connected to the LS port of the priority valve 8 through the first pipeline and the second pipeline respectively. The first pipeline and the second pipeline are respectively provided with a first check valve 29 and a second check valve 30. The hydraulic oil return pipeline in the hydraulic assembly 5 is uniformly returned to the oil tank 31. When the driver turns the steering wheel left or right, the first check valve 29 or the second check valve 30 is connected, the LS port receives a signal, and the CF port can supply oil to the first hydraulic valve 9. When the steering wheel does not move, the priority valve 8 supplies oil to other actuators through the EF port.

[0038] The working principle of this device is that when the crawler tractor turns during normal driving, the driver starts to turn the steering wheel. In this embodiment, taking the left steering wheel as an example, the first one-way valve 29 is connected, and the pressure signal is transmitted to the LS port of the priority valve 8. The hydraulic oil is supplied to the second hydraulic valve P port 19 of the second hydraulic valve b14 through the CF port. At this time, the second flange 17 contacts the valve core 25 of the second hydraulic valve b14 and pushes its position to the second position. The second hydraulic valve P port 19 is connected with the second hydraulic valve A port 21 through the first channel 23. The hydraulic oil enters the first steering cylinder 3 through the second hydraulic valve A port, and the cylinder rod of the first steering cylinder 3 extends, and the vehicle starts to turn left. When the driver continues to turn the steering wheel to the left, the first flange 16 contacts the end of the valve core 25. At this time, the second hydraulic valve P port 19 is connected to the second hydraulic valve A port 21 through the first channel 23, and the second hydraulic valve P port 19 is also connected to the second hydraulic valve B port 22 through the third channel 28. At this time, the hydraulic oil enters the first steering cylinder 3 and the first brake cylinder 4, and the cylinder rods of the first steering cylinder 3 and the first brake cylinder 4 are both in an extended state. At this time, the left track of the vehicle is in an in-situ steering and braking state, that is, an in-situ U-turn state. At this time, the vehicle's turning radius is the smallest, and steering and U-turning can be achieved in a narrow mountain road environment.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A steering brake device for a crawler tractor, comprising a steering wheel lever (6), a gearbox (12) and a hydraulic assembly (5), wherein the gearbox (12) is provided with a main driver's side steering connecting rod, a main driver's side brake connecting rod and a co-driver's side steering connecting rod and a co-driver's side brake connecting rod on the main driver's side and the co-driver's side, respectively, and characterized in that: The hydraulic assembly (5) comprises a first steering cylinder (3), a first brake cylinder (4), a second steering cylinder (1), a second brake cylinder (2), a first hydraulic valve (9) and a second hydraulic valve (7) which are respectively connected to the main driver's side steering connecting rod, the main driver's side brake connecting rod, the passenger side steering connecting rod and the passenger side brake connecting rod. The first hydraulic valve (9) is a two-position four-way valve, and the second hydraulic valve (7) is a three-position four-way valve.

2. The steering brake device for a crawler tractor according to claim 1, characterized in that: The number of the second hydraulic valves (7) is two, and they are symmetrically arranged below the steering wheel joystick (6).

3. The steering brake device for a crawler tractor according to claim 2, characterized in that: A pressure valve disc (15) is provided below the steering wheel joystick (6) and is synchronously turned left or right therewith. The pressure valve disc (15) comprises a pressure valve disc body (18) and a boss (32) located at the outer edge thereof. The pressure valve disc (15) can change the position of a valve core (25) inside one of the second hydraulic valves (7) during the process of turning left or right.

4. The steering brake device for a crawler tractor according to claim 1, characterized in that: The first hydraulic valve (9) is installed close to a brake pedal (11), and the brake pedal (11) is connected to a push rod (10). During the displacement of the brake pedal (11), the push rod (10) drives the valve core of the first hydraulic valve (9) to move.

5. The steering brake device for a crawler tractor according to claim 3, characterized in that: The boss (32) is provided with a first flange (16) and a second flange (17). The number of the second flanges (17) is two and they are symmetrically arranged on both sides of the first flange (16). The first flange (16) and the second flange (17) are transitionally connected via a first circular arc (26), and the second flange (17) and the valve plate body (18) are transitionally connected via a second circular arc (27).

6. The steering brake device for a crawler tractor according to claim 5, characterized in that: The radius value A of the first flange (16) is greater than the radius value B of the second flange (17).

7. The steering brake device for a crawler tractor according to claim 6, characterized in that: The valve core (25) is provided with three position states in the second hydraulic valve (7), namely, a first position, a second position and a third position. When the valve core (25) is located at the first position, the valve plate body (18) contacts the end of the valve core (25); when the valve core (25) is located at the second position, the second flange (17) contacts the end of the valve core (25); when the valve core (25) is located at the third position, the first flange (16) contacts the end of the valve core (25).

8. The steering brake device for a crawler tractor according to claim 1, characterized in that: The hydraulic assembly (5) further comprises a priority valve (8); the first steering cylinder (3), the first brake cylinder (4), the second steering cylinder (1) and the second brake cylinder (2) are all single-acting hydraulic cylinders; the first steering cylinder (3) and the second steering cylinder (1) are respectively connected to the LS port of the priority valve (8) via a first pipeline and a second pipeline; the first pipeline and the second pipeline are respectively provided with a first non-return valve (29) and a second non-return valve (30).

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