Parking brake emergency release control system for hydraulically driven agricultural machines

Abstract

This invention relates to the field of parking systems, and particularly to a parking brake emergency release control system for hydraulically driven agricultural machinery. The parking brake emergency release control system of this invention includes a brake piston, a reversing valve, a steering cylinder, a steering gear, and a hydraulic oil tank. The oil port of the brake release chamber of the brake piston is connected to the oil outlet of the reversing valve via a pipeline. The two oil outlets of the steering cylinder are respectively connected to the two oil outlets of the steering gear via oil outlet pipelines. The oil inlet and return port of the steering gear are respectively connected to the hydraulic oil tank via pipelines. A hydraulic oil supply pipeline for supplying oil to the hydraulic brake release chamber is connected between the oil port of the brake piston and any one of the oil outlet pipelines. Advantages: reasonable design, simple principle, convenient operation, cleverly utilizes the vehicle's built-in steering system, eliminating the need for additional pressure oil sources; low design cost, high reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of parking system, in particular to an emergency release control system for parking brake of hydraulic drive agricultural machinery. BACKGROUND

[0002] At present, high-end large agricultural machinery adopts hydrostatic drive, and its braking system includes a parking brake and a running brake system. Among them, the parking brake system belongs to static braking, which can ensure that the vehicle is always in braking state in the off state to prevent the problem of vehicle sliding. When the vehicle is in an unexpected situation such as engine damage and off, emergency towing is needed, and the parking brake needs to be released in advance, otherwise it may cause brake damage.

[0003] At present, there are three ways to release the parking brake: 1. Using external emergency power source, such as using a hand pump to release the parking brake; 2. Adding an accumulator in the circuit to provide emergency oil source for parking brake release; 3. Temporary release of parking brake by mechanical operation. The first and second control methods have more pipelines and high cost, and the third control method is often not easy to operate due to space problems.

[0004] In view of the above factors, a control system with low cost and high reliability is needed for the release function of the parking brake. SUMMARY

[0005] The technical problem to be solved by the present application is to provide an emergency release control system for parking brake of hydraulic drive agricultural machinery, which effectively overcomes the defects of the prior art.

[0006] The technical scheme for solving the above technical problem is as follows:

[0007] An emergency release control system for parking brake of hydraulic drive agricultural machinery, comprising a brake piston, a reversing valve, a steering oil cylinder, a steering gear and a hydraulic oil tank, the oil port of the brake release cavity of the brake piston is connected and communicated with the oil outlet of the reversing valve through a pipeline, the two oil outlets of the steering oil cylinder are respectively connected and communicated with the two oil outlets of the steering gear through the oil outlet pipelines, the oil inlet and the oil return port of the steering gear are respectively connected and communicated with the hydraulic oil tank through the pipelines, and the oil port of the brake release cavity of the brake piston is connected with any one of the oil outlet pipelines for conveying oil to the hydraulic brake release cavity.

[0008] On the basis of the above technical scheme, the present application can also be improved as follows.

[0009] Furthermore, the aforementioned hydraulic oil pipeline includes a main pipeline and a switching valve. The main pipeline is connected between the oil port of the brake release chamber of the brake piston and any one of the aforementioned oil outlet pipelines. The switching valve is located on the main pipeline, and a first check valve is provided on the pipeline section between the switching valve and the aforementioned oil outlet pipeline.

[0010] Furthermore, the aforementioned hydraulic oil supply lines are provided in two pairs, which are respectively connected one-to-one between the oil port of the brake release chamber of the brake piston and the two aforementioned oil outlet lines.

[0011] Furthermore, it also includes a branch line, which is connected between the aforementioned switch valve and another aforementioned oil outlet line, and the branch line is equipped with a second check valve.

[0012] Furthermore, the aforementioned switching valve is a manual valve.

[0013] Furthermore, the aforementioned directional valve is a two-position three-way solenoid valve.

[0014] Furthermore, the oil inlet of the aforementioned reversing valve is connected to an oil inlet pipeline, and a third check valve is provided on the oil inlet pipeline.

[0015] Furthermore, a hydraulic pump is installed on the pipeline connected to the oil inlet of the aforementioned steering gear.

[0016] The advantages of this invention are: reasonable design, simple principle, convenient operation, clever use of the vehicle's own steering system, no need to add a new pressure oil source; low design cost and high reliability. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of an embodiment of the parking brake emergency release control system for hydraulically driven agricultural machinery according to the present invention;

[0018] Figure 2 This is a schematic diagram of another embodiment of the parking brake emergency release control system for hydraulically driven agricultural machinery of the present invention;

[0019] Figure 3 This is a schematic diagram of another embodiment of the parking brake emergency release control system for hydraulically driven agricultural machinery according to the present invention.

[0020] The attached diagram lists the components represented by each number as follows:

[0021] 1. Brake piston; 2. Directional control valve; 3. Steering cylinder; 4. Steering gear; 5. Hydraulic oil tank; 6. Hydraulic oil supply line; 21. Third check valve; 31. Oil outlet line; 41. Hydraulic pump; 61. Main pipeline; 62. Switch valve; 63. First check valve; 64. Branch pipeline; 65. Second check valve. Detailed Implementation

[0022] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0023] Example: Figure 1 As shown, the parking brake emergency release control system for hydraulically driven agricultural machinery in this embodiment includes a brake piston 1, a reversing valve 2, a steering cylinder 3, a steering gear 4, and a hydraulic oil tank 5. The oil port of the brake release chamber of the brake piston 1 is connected to the oil outlet of the reversing valve 2 via a pipeline. The two oil outlets of the steering cylinder 3 are respectively connected to the two oil outlets of the steering gear 4 via oil outlet pipelines 31. The oil inlet and return port of the steering gear 4 are respectively connected to the hydraulic oil tank 5 via pipelines. A hydraulic oil supply pipeline 6 for supplying oil to the hydraulic brake release chamber is connected between the oil port of the brake release chamber of the brake piston 1 and any one of the oil outlet pipelines 31.

[0024] The working principle is as follows:

[0025] First, with the engine off, the vehicle's hydraulic system is at a standstill. At this time, the hydraulic tank 5 cannot supply pressure oil to the steering gear 4, and the pressure at the inlet of the directional valve 2 (port P in the diagram) will also become zero, thus preventing the parking brake from disengaging. Since the steering gear 4 can convert mechanical energy into pressure energy when the steering wheel is manually turned, it can output a certain amount of pressure, and this pressure is substantial. Therefore, this pressure is introduced into the parking brake system. In actual operation, the directional valve 2 is manually overridden to reverse the direction, keeping the hydraulic oil line 6 unobstructed. Then, both hands grip the steering wheel and turn left or right. At this time, the steering circuit on the corresponding side of the steering gear 4 will generate pressure and quickly transmit it to the brake release chamber of the brake piston 1, pushing the piston of the brake piston 1 to move and engage the brake. During this process, the pressure in the hydraulic oil line 6 will not be transmitted back to the steering system. The entire system is reasonably designed, simple in principle, and easy to operate. It cleverly utilizes the vehicle's built-in steering system without requiring a new pressure oil source; the design cost is low, and the reliability is high.

[0026] In a preferred embodiment, the hydraulic oil pipeline 6 includes a main pipeline 61 and a switching valve 62. The main pipeline 61 is connected between the oil port of the brake release chamber of the brake piston 1 and any one of the oil outlet pipelines 31. The switching valve 62 is provided on the main pipeline 61, and a first check valve 63 is provided on the section of the pipeline between the switching valve 62 and the oil outlet pipeline 31.

[0027] In the above implementation scheme, during actual operation, the reversing valve 2 is manually overridden to reverse the direction, and then the switching valve 62 is manually opened. Then, both hands grip the steering wheel and turn it (taking turning to the left as an example). At this time, the steering circuit on the left side of the steering gear 4 (that is, the circuit where L is located) will generate pressure and quickly transmit it to the brake release chamber of the brake piston 1. The first one-way valve 63 can ensure that the pressure of the parking brake system will not be transmitted to the steering system in the reverse direction. Since the steering system is divided into L side and R side, the output of steering pressure can also be selected from the R side as the output side (specifically determined by which side of the outlet line 31 of the single hydraulic oil line 6 is connected). At this time, it is only necessary to change the direction of steering wheel rotation.

[0028] In this embodiment, the hydraulic oil pipeline 6 can also adopt a "dual-line" layout, specifically including at least the following two structural methods:

[0029] Option 1, such as Figure 2 As shown, the above-mentioned hydraulic oil supply line 6 has two (the two hydraulic oil supply lines 6 are completely independent), and are respectively connected to the oil port of the brake release chamber of the brake piston 1 and the two above-mentioned oil outlet lines 31.

[0030] In the above implementation scheme, two hydraulic oil supply lines 6 are designed. When contact braking is required, one hydraulic oil supply line 6 can be selected to be opened and kept unobstructed (that is, the switch valve 62 of the hydraulic oil supply line 6 is opened) to perform contact braking operation. Of course, in order to improve the pressure build-up efficiency, both the L side and the R side can be selected at the same time (that is, both hydraulic oil supply lines 6 are opened and kept unobstructed at the same time, specifically, the switch valves 62 of the two hydraulic oil supply lines 6 are opened) to perform contact braking operation, and the pressure is transmitted to the parking brake system through the functional logic valve.

[0031] Option 2: The two hydraulic oil supply lines share six parts, as detailed below:

[0032] like Figure 3 As shown, the hydraulic oil pipeline 6 includes a main pipeline 61 and a switching valve 62. The main pipeline 61 is connected between the oil port of the brake release chamber of the brake piston 1 and any one of the oil outlet pipelines 31. The switching valve 62 is provided on the main pipeline 61. A first check valve 63 is provided on the section of the pipeline between the switching valve 62 and the oil outlet pipeline 31. The pipeline also includes a branch pipeline 64, which is connected between the switching valve 62 and another oil outlet pipeline 31. A second check valve 65 is provided on the branch pipeline 64.

[0033] In the above-mentioned Scheme 2, the two hydraulic oil supply lines 6 share a single switch valve 62 and main pipeline 61. At the oil outlet end of the switch valve 62, two branch lines 64 are connected to the two oil outlet lines 31 respectively. Other braking operations are the same as those in Scheme 1 and the single-line method, and will not be described in detail here.

[0034] In this embodiment, the aforementioned switching valve 62 is a manual valve, which can be manually operated and controlled during use. The specific model can be reasonably selected according to the actual use requirements, and will not be elaborated here.

[0035] In this embodiment, the aforementioned reversing valve 2 is a conventional two-position three-way solenoid valve, with its inlet and outlet ports connected to the inlet and outlet pipelines respectively, and one of its two outlet ports connected to the oil port of the brake release chamber of the brake piston 1 via a pipeline.

[0036] In a preferred embodiment, the oil inlet of the aforementioned reversing valve 2 is connected to an oil inlet pipeline, and a third check valve 21 is provided on the oil inlet pipeline.

[0037] In the above implementation scheme, during actual operation, the reversing valve 2 is manually overridden to reverse the direction, and then the switch valve 62 of the hydraulic oil supply line 6 is manually opened. Then, both hands grip the steering wheel and turn it to the left or right. At this time, the L or R side steering circuit will generate pressure and quickly transmit it to the brake release chamber of the brake piston 1. The first check valve 63 can ensure that the pressure of the parking brake system will not be transmitted to the steering system in the reverse direction, and the third check valve 21 can ensure that the pressurized oil will not be directly released to the hydraulic oil tank 5.

[0038] In this embodiment, a hydraulic pump 41 is provided on the pipeline connected to the oil inlet of the steering gear 4.

[0039] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0041] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0042] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0043] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0044] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A parking brake emergency release control system for hydraulically driven agricultural machinery, characterized in that: The system includes a brake piston (1), a reversing valve (2), a steering cylinder (3), a steering gear (4), and a hydraulic oil tank (5). The oil port of the brake release chamber of the brake piston (1) is connected to the oil outlet of the reversing valve (2) through a pipeline. The two oil outlets of the steering cylinder (3) are respectively connected to the two oil outlets of the steering gear (4) through an oil outlet pipeline (31). The oil inlet and return port of the steering gear (4) are respectively connected to the hydraulic oil tank (5) through pipelines. A hydraulic oil supply pipeline (6) for supplying oil to the brake release chamber of the brake piston (1) is connected between the oil port of the brake release chamber of the brake piston (1) and any one of the oil outlet pipelines (31). The hydraulic oil pipeline (6) includes a main pipeline (61) and a switching valve (62). The main pipeline (61) is connected between the oil port of the brake release chamber of the brake piston (1) and any one of the oil outlet pipelines (31). The switching valve (62) is located on the main pipeline (61). A first check valve (63) is provided on the pipe section between the switching valve (62) and the oil outlet pipeline (31). The hydraulic oil supply line (6) has two lines, which are respectively connected to the oil port of the brake release chamber of the brake piston (1) and the two oil outlet lines (31).

2. The parking brake emergency release control system for hydraulically driven agricultural machinery according to claim 1, characterized in that: The hydraulic oil supply line (6) includes a branch line (64), which is connected between the switch valve (62) and another oil outlet line (31), and the branch line (64) is provided with a second check valve (65).

3. The parking brake emergency release control system for hydraulically driven agricultural machinery according to claim 1, characterized in that: The switching valve (62) is a manual valve.

4. The parking brake emergency release control system for hydraulically driven agricultural machinery according to claim 1, characterized in that: The reversing valve (2) is a two-position three-way solenoid valve.

5. A parking brake emergency release control system for hydraulically driven agricultural machinery according to claim 1, characterized in that: The oil inlet of the reversing valve (2) is connected to an oil inlet pipeline, and a third check valve (21) is provided on the oil inlet pipeline.

6. The parking brake emergency release control system for hydraulically driven agricultural machinery according to claim 1, characterized in that: A hydraulic pump (41) is installed on the pipeline connected to the oil inlet of the steering gear (4).

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