Trailer control valve with pressure limiting function, trailer braking system and tractor

Abstract

The utility model relates to a trailer control valve with a pressure limiting function, a trailer braking system and a tractor. The trailer control valve comprises a valve body, a pressure limiting valve, an emergency braking throttle valve and a trailer braking main valve are arranged in the valve body, the valve body is provided with a first port, a second port, a third port, a fourth port, a fifth port and a sixth port, the first port is connected with an inlet of the pressure limiting valve, and an outlet of the pressure limiting valve is connected with an inlet and the second port of the emergency braking throttle valve. An outlet of the emergency braking throttle valve is connected with an inlet of the trailer braking main valve, an outlet of the trailer braking main valve is connected with the sixth port, an air control port and an oil control port of the trailer braking main valve are connected with the third port and the fourth port respectively, and an exhaust port of the trailer braking main valve is connected with the inlet and the fifth port of the trailer braking main valve. The trailer control valve has the advantages that the highest working pressure of an air brake system is controlled by setting the pressure of the pressure limiting valve, the safety coefficient is higher, the mounting space can be reduced by the highly integrated trailer control valve, and standardized arrangement of an air brake pipeline is facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of agricultural machinery and equipment, in particular to a trailer control valve with a pressure limiting function, a trailer brake system and a tractor. Background Art

[0002] As a conventional agricultural machinery, tractors play an indispensable role in agricultural production and road transportation. In road transportation, tractors need to be equipped with air brake systems for trailer braking. As the core component of the air brake system, the trailer control valve has a higher degree of integration, which is more conducive to the layout of the air brake system pipelines while meeting the basic functions. In order to effectively utilize the limited space of the tractor and facilitate the layout of the air brake system pipelines, it is necessary to design a highly integrated trailer control valve.

[0003] In addition, the existing trailer control valve does not have a pressure limiting function, and an additional pressure limiting valve needs to be arranged in the air brake system to control the working pressure of the air brake system, which makes the pipeline layout of the air brake system more difficult.

[0004] Based on this, it is necessary to develop a trailer control valve with a pressure limiting function. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a trailer control valve with a pressure limiting function, a trailer brake system and a tractor, which effectively overcome the defects of the prior art.

[0006] The technical solution of the utility model to solve the above technical problems is as follows:

[0007] A trailer control valve with a pressure limiting function comprises a valve body, wherein the valve body is provided with a pressure limiting valve, an emergency brake throttle valve and a trailer brake main valve, the valve body is provided with a first port, a second port, a third port, a fourth port, a fifth port and a sixth port, the first port is connected to the inlet of the pressure limiting valve, the outlet of the pressure limiting valve is respectively connected to the inlet of the emergency brake throttle valve and the second port, the outlet of the emergency brake throttle valve is connected to the inlet of the trailer brake main valve, the outlet of the trailer brake main valve is connected to the sixth port, the air control port and the oil control port of the trailer brake main valve are respectively connected to the third port and the fourth port, and the exhaust port of the trailer brake main valve is connected to its inlet and the fifth port.

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

[0009] Furthermore, a branch pipeline is externally connected between the second port and the third port, and a first control valve is disposed on the branch pipeline.

[0010] Furthermore, the first control valve is a solenoid valve.

[0011] Furthermore, the valve body is provided with a flow channel connecting the second port and the third port, and a second control valve is provided in the flow channel.

[0012] Furthermore, the second control valve is a solenoid valve.

[0013] Further, the emergency brake throttle valve is a pneumatic throttle valve, which includes a throttle valve body, a columnar valve cavity is provided in the throttle valve body, a matching columnar valve core is provided in the valve cavity, a first annular cavity is provided on the inner wall at one end of the valve cavity, an air inlet connected to the first annular cavity is provided on the side wall of the valve cavity, a second annular cavity is provided on the inner wall at the other end of the valve cavity, an exhaust port connected to the second annular cavity is provided on the side wall of the valve cavity, a throttling annular cavity is provided on the outer surface of the valve core along its axial direction, a first pressure cavity is defined between one end of the valve core and one end of the valve core, a first control port connected to the first pressure cavity is provided at one end of the valve cavity, a second pressure cavity is defined between the other end of the valve cavity and the other end of the valve core, a first elastic member is connected between the other end of the valve core and the bottom wall of the second pressure cavity, and the second pressure cavity is connected to the exhaust port of the valve cavity.

[0014] Furthermore, the first elastic member is a spring.

[0015] Furthermore, the third port is connected to the first control port, and the second control port is connected to an outlet of the emergency brake throttle valve.

[0016] The beneficial effects of the utility model are: the structural design is simple and reasonable, the maximum pressure of the gas entering the trailer control main valve is controlled by setting the pressure limiting valve, so as to control the maximum working pressure of the air brake system, and the safety factor is higher. At the same time, the highly integrated trailer control valve can reduce the installation space, and all air brake pipelines can be planned in a coordinated manner, which is conducive to the standardized layout of the air brake pipelines.

[0017] A trailer brake system with a pressure limiting function is also provided, comprising a trailer control valve with a pressure limiting function, wherein the first port is connected to an air source, the fifth port is connected to an air inlet of an emergency relay valve, the air outlet of the emergency relay valve is connected to an air tank, the sixth port is connected to an air control port of the emergency relay valve, the third port is connected to a service brake oil circuit, and the air tank is connected to a brake air circuit inlet of the emergency relay valve.

[0018] A tractor is also provided that includes a trailer brake system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a trailer control valve with a pressure limiting function of the utility model;

[0020] Figure 2It is a structural schematic diagram of an emergency relay valve involved in the trailer control valve with pressure limiting function of the utility model.

[0021] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0022] 1. Pressure limiting valve; 2. Emergency brake throttle valve; 3. Trailer brake main valve. DETAILED DESCRIPTION

[0023] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0024] Example 1

[0025] like Figure 1 As shown, the trailer control valve with pressure limiting function of this embodiment includes a valve body, in which a pressure limiting valve 1, an emergency brake throttle valve 2 and a trailer brake main valve 3 are provided, and the valve body is provided with a first port (port A), a second port (port B), a third port (port C), a fourth port (port D), a fifth port (port F) and a sixth port (port E), the first port is connected to the inlet of the pressure limiting valve 1, the outlet of the pressure limiting valve 1 is respectively connected to the inlet of the emergency brake throttle valve 2 and the second port, the outlet of the emergency brake throttle valve 2 is connected to the inlet of the trailer brake main valve 3, the outlet of the trailer brake main valve 3 is connected to the sixth port, the air control port and the oil control port of the trailer brake main valve 3 are respectively connected to the third port and the fourth port, and the exhaust port of the trailer brake main valve 3 is connected to its inlet and the fifth port.

[0026] During operation, the gas from the air source (tractor air source) enters the trailer control valve through the first port (port A) of the trailer control valve, and the pressure limiting valve 1 is connected to the first port of the trailer control valve. The pressure limiting valve 1 controls the working pressure of the air brake system. After passing through the pressure limiting valve 1, the gas is divided into two paths, one path enters the emergency brake throttle valve 2, and the other path is connected to the second port (port B) of the trailer control valve. After passing through the emergency brake throttle valve 2, the gas enters the trailer brake main valve 3. The trailer brake main valve 3 has a total of 5 working ports, among which the air control port is the pre-brake port, connected to the third port (port C), and the oil control port is connected to the tractor's service brake oil through the fourth port (port D). The outlet of the trailer brake main valve 3 is connected to the air control port of the emergency relay valve through the sixth port (port E), and the exhaust port of the trailer brake main valve 3 is connected to the air inlet of the emergency relay valve through the fifth port (port F) to provide an air source for the trailer. The specific working principle is as follows:

[0027] The pressure limiting valve 1 controls the maximum working pressure of the air brake system;

[0028] The second port of the trailer control valve is connected in series with the third port (port C) of the trailer control valve, and a control valve (solenoid valve) is arranged on the series line. When the brake pedal is pressed, the solenoid valve works to connect the second port of the trailer control valve with the third port of the trailer control valve, and the gas enters the air control port of the trailer brake main valve 3, so that the outlet gas of the trailer control valve has a certain pressure, and the trailer is pre-braked;

[0029] When the brake pedal is fully depressed, the brake hydraulic oil in the oil control port of the trailer control valve acts on the valve cavity of the trailer brake main valve 3, pushing the valve core of the trailer brake main valve 3 to move, so that the gas pressure of the sixth port of the trailer brake valve reaches the pressure value set by the pressure limiting valve 1 and brakes the trailer;

[0030] When the air pipe connected to the outlet of the trailer control valve is broken or leaking, the brake pedal is pressed at this time, the valve core of the trailer brake main valve 3 moves, and the outlet loses pressure. At this time, the valve core of the emergency brake throttle valve 2 will move under the push of the pressurized gas, thereby throttling the gas entering the trailer brake main valve 3, thereby causing the gas pressure at the exhaust port of the trailer control valve to decrease. When the gas pressure at the fifth port drops to a certain value, the emergency relay valve connected to the fifth port plays a braking role to brake the trailer.

[0031] In this embodiment, the second port and the third port include the following two connection modes:

[0032] 1) Connected outside the valve body, specifically: a branch line is externally connected between the second port and the third port, and a first control valve is arranged on the branch line.

[0033] Wherein, the first control valve is a solenoid valve.

[0034] 2) Connected within the valve body, specifically: the valve body is provided with a flow channel connecting the second port and the third port, and a second control valve is provided in the flow channel.

[0035] Wherein, the second control valve is a solenoid valve.

[0036] In this embodiment, the emergency brake throttle valve 2 adopts a pneumatic throttle valve of an adapted model in the prior art, and two cavities are formed at the two ends of the valve core of the pneumatic throttle valve, one cavity is connected to a control port, and a spring member is arranged in the other cavity, and the other cavity is connected to the exhaust port of the emergency brake throttle valve 2, wherein the third port is connected to the first control port, and the second control port is connected to the outlet of the emergency brake throttle valve 2. Under normal circumstances, the exhaust port diverts a part of the gas into the other cavity, and the valve core maintains the position of the non-throttling state. When braking is required, the gas diverted through the third port enters the control port, breaking the pressure balance at both ends of the valve core, causing the valve core to move and switch to the throttling state, and then the valve core maintains the current position balance; when the air pipe connected to the sixth port of the trailer control valve is broken or leaking, the exhaust port pressure gradually decreases, and the gas pressure of the sixth port (F port) of the trailer control valve decreases. When the gas pressure of the F port decreases to a certain value, the emergency relay valve (air control port) connected to the F port of the trailer control valve plays a braking role to brake the trailer.

[0037] Example 2

[0038] The trailer brake system with pressure limiting function of this embodiment comprises the trailer control valve with pressure limiting function in embodiment 1, wherein the first port is connected to an air source (tractor air source), the fifth port is connected to an air inlet of an emergency relay valve, the air outlet of the emergency relay valve is connected to an air tank (trailer air tank), and the sixth port is connected to an emergency relay valve (such as Figure 2 The air control port as shown), the third port is connected to the service brake oil circuit, and the gas tank is connected to the brake air circuit inlet of the emergency relay valve.

[0039] It should be noted that: Figure 2In the figure, a1 is the brake air circuit inlet of the emergency relay valve, a7 is the brake air circuit outlet, a2 is the inlet connected to the upper ring cavity of the outer core a6, a2 is connected to the sixth port (F port) of the trailer control valve, a3 is the air control port, G is the piston pusher (used to push the inner valve core a4 downward), and a5 is the valve port. During conventional braking, the sixth port (E port) is connected to a3, the fifth port (F port) is connected to a7, the piston pusher G is pushed downward to block the flow channel of the inner valve core a4, and continues to push the inner valve core a4 downward (and block the internal flow channel of the valve core a4) to open the a5 valve port, the outer valve core a6 maintains a balanced position due to the lower spring H and the air pressure of the upper ring cavity, and the brake air circuit (a1--a7) remains unobstructed. In the braking state, when the air pipe connected to the outlet of the trailer control valve is broken or leaks, the air pressure of a3 decreases (pressure loss), the piston pusher does not move (moves away from the inner valve core a4), and at the same time, the pressure of a2 decreases, the position balance of the outer core a6 is broken, and the outer core a6 is pushed upward by the gas entering from a1. During the pushing process, the inner core a4 moves upward and contacts G to limit the position. When the outer core a6 continues to move upward, the inner core a4 no longer moves upward, and the valve port a5 is opened. The brake gas enters between the inner and outer cores through the holes on the side walls of a1 and the outer core a6, and then passes through the a5 valve port to a7, and the brake air path (a1--a7) remains unobstructed.

[0040] It should be additionally explained that: in this embodiment, the trailer brake main valve 3 belongs to the existing technology, and specifically adopts a dual-pipe trailer brake valve of a suitable model on the market.

[0041] Example 3

[0042] The tractor of this embodiment includes the trailer braking system of the second embodiment.

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0044] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0045] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0047] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0048] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A trailer control valve with pressure limiting function, characterized in that: The invention comprises a valve body, wherein a pressure limiting valve (1), an emergency brake throttle valve (2) and a trailer brake main valve (3) are arranged in the valve body, and the valve body is provided with a first port, a second port, a third port, a fourth port, a fifth port and a sixth port, wherein the first port is connected to the inlet of the pressure limiting valve (1), the outlet of the pressure limiting valve (1) is respectively connected to the inlet of the emergency brake throttle valve (2) and the second port, the outlet of the emergency brake throttle valve (2) is connected to the inlet of the trailer brake main valve (3), the outlet of the trailer brake main valve (3) is connected to the sixth port, the air control port and the oil control port of the trailer brake main valve (3) are respectively connected to the third port and the fourth port, and the exhaust port of the trailer brake main valve (3) is connected to its inlet and the fifth port.

2. A trailer control valve with pressure limiting function according to claim 1, characterized in that: A branch line is externally connected between the second port and the third port, and a first control valve is disposed on the branch line.

3. A trailer control valve with pressure limiting function according to claim 2, characterized in that: The first control valve is a solenoid valve.

4. The trailer control valve with pressure limiting function according to claim 1, characterized in that: The valve body is provided with a flow channel connecting the second port and the third port, and a second control valve is provided in the flow channel.

5. The trailer control valve with pressure limiting function according to claim 4, characterized in that: The second control valve is a solenoid valve.

6. The trailer control valve with pressure limiting function according to claim 1, characterized in that: The emergency brake throttle valve (2) is a pneumatic throttle valve.

7. The trailer control valve with pressure limiting function according to claim 6, characterized in that: The third port is connected to the control port of the emergency brake throttle valve (2).

8. A trailer braking system with a pressure limiting function, characterized in that: It comprises a trailer control valve with a pressure limiting function as described in any one of claims 1 to 7, wherein the first port is connected to an air source, the fifth port is connected to an air inlet of an emergency relay valve, the air outlet of the emergency relay valve is connected to an air tank, the sixth port is connected to an air control port of the emergency relay valve, the third port is connected to a service brake oil circuit, and the air tank is connected to a brake air circuit inlet of the emergency relay valve.

9. A tractor, characterized in that: Comprising the trailer braking system of claim 8.

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