A parking brake system for a heavy-duty tractor

Abstract

The utility model discloses a kind of parking brake systems of heavy-duty tractor, specifically relates to tractor brake system technical field, comprising: energy accumulator, oil suction circuit, brake execution module, liquid filling valve, piston rod cylinder assembly and electromagnetic reversing valve;The oil outlet of oil suction circuit is connected with the oil inlet of liquid filling valve, the oil outlet of liquid filling valve is connected with energy accumulator, energy accumulator is connected with the oil inlet of electromagnetic reversing valve, the oil outlet of electromagnetic reversing valve is connected with piston rod cylinder assembly, the movable end of piston rod cylinder assembly is connected with brake execution module;The oil outlet of electromagnetic reversing valve and liquid filling valve is connected with the oil return port of oil suction circuit;Pressure switch assembly is provided on liquid filling valve.The utility model is reset by using spring in piston rod cylinder assembly when heavy-duty tractor is parked and power is off, realizes heavy-duty tractor parking brake, i.

Description

Technical Field

[0001] This utility model relates to the technical field of tractor braking systems, and more specifically, to a parking brake system for a heavy-duty tractor. Background Technology

[0002] Heavy-duty tractor units are known to be core operational equipment in large logistics areas such as ports, shipyards, and steel enterprises. They are mainly used for transferring heavy cargo, with a towing capacity often exceeding 50 tons. The operating environment is complex and safety requirements are extremely high. Currently, the parking brake system commonly used in these vehicles is a mechanical structure. The driver operates the parking brake lever, which transmits braking force to the gearbox or drive axle via a mechanical transmission device, thereby achieving parking braking.

[0003] However, in actual use, the existing braking system relies on the driver's manual operation. If the driver fails to engage the parking brake handle due to negligence after the vehicle is parked, or fails to fully activate the braking mechanism due to insufficient force, the vehicle may roll unexpectedly due to a slope or external force. This poses a serious safety hazard, threatening not only the personal safety of the driver and surrounding workers, but also potentially causing significant property damage and logistical disruption. Therefore, this application proposes a parking brake system for a heavy-duty tractor as a further improvement. Utility Model Content

[0004] In order to overcome the above-mentioned defects of the prior art, the present invention provides a parking brake system for a heavy-duty tractor to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a parking brake system for a heavy-duty tractor, comprising: an accumulator, an oil suction circuit, and a brake execution module; further comprising: a filling valve, a piston rod cylinder assembly, and a solenoid directional valve; The oil outlet of the oil suction circuit is connected to the oil inlet of the filling valve through a pipeline. One oil outlet of the filling valve is connected to the accumulator through a pipeline. The accumulator is connected to one oil inlet of the solenoid directional valve. One oil outlet of the solenoid directional valve is connected to the piston rod cylinder assembly through a pipeline. The movable end of the piston rod cylinder assembly is connected to the brake execution module. The other oil outlet of the electromagnetic reversing valve and the two oil outlets of the filling valve are both connected to the return oil port of the oil suction circuit through pipelines. The filling valve is equipped with a pressure switch assembly for controlling the operation of the directional valve core located inside the filling valve.

[0006] Furthermore, the filling valve is provided with a main oil inlet connected to the oil outlet of the oil suction circuit, a first oil outlet connected to the accumulator, a second oil outlet connected to the oil return port of the oil suction circuit, and a third oil outlet connected to the oil return port of the oil suction circuit. The filling valve is internally equipped with: A normally closed two-position two-way electro-hydraulic directional valve, wherein its valve inlet is connected to the main inlet and its valve outlet is connected to the second outlet; A one-way valve, one end of which is connected to the main oil inlet and the other end of which is connected to the first oil outlet; and... A two-position three-way electro-hydraulic directional valve, wherein its valve inlet is connected to the main inlet and its valve outlet is connected to the third outlet; One valve core of the normally closed two-position two-way electro-hydraulic directional valve is signal-connected to the two valve cores of the two-position three-way electro-hydraulic directional valve. The other valve core of the normally closed two-position two-way electro-hydraulic directional valve is signal-connected to one end of the check valve connected to the main oil inlet. The other valve core of the two-position three-way electro-hydraulic directional valve is signal-connected to one end of the check valve connected to the first oil outlet.

[0007] Furthermore, the pressure switch assembly includes: a normally open pressure switch for controlling the operation of the valve core of the normally closed two-position two-way electro-hydraulic directional valve and a normally closed pressure switch for controlling the operation of the valve core of the other directional valve of the normally closed two-position two-way electro-hydraulic directional valve. The filling valve is provided with a first pressure test port connected to a normally open pressure switch and a second pressure test port connected to a normally closed pressure switch. Both the first pressure test port and the second pressure test port are connected to one end of the first oil outlet of the one-way valve.

[0008] Furthermore, the electromagnetic directional valve is a two-position three-way electromagnetic directional valve, and the working position of its valve core changes in response to the start and stop state of the heavy-duty tractor. The electromagnetic reversing valve is provided with an inlet, a first outlet, and a second outlet. The accumulator is connected to the liquid inlet, the first liquid outlet is connected to the piston rod cylinder assembly through a pipeline, and the second liquid outlet, the second oil outlet, and the third oil outlet are all connected to the oil return port of the oil suction circuit through pipelines.

[0009] Furthermore, the piston rod cylinder assembly is configured as: a single-acting spring-return type single piston rod cylinder; The piston rod cylinder assembly includes: a spring, a piston rod, and a cylinder body; The first liquid outlet is connected to the cylinder body through a pipeline. The piston rod slides and extends inside the cylinder body, and the piston rod is connected to the inner wall of the cylinder body through a spring. The end of the piston rod away from the cylinder body is connected to the braking execution module.

[0010] Furthermore, the braking execution module includes a parking brake and a brake cable, wherein the end of the piston rod away from the cylinder is fixedly connected to the parking brake via the brake cable.

[0011] Furthermore, the oil suction circuit includes: a hydraulic oil tank, an oil suction filter, and a hydraulic oil pump; the inlet of the oil suction filter is connected to the outlet of the hydraulic oil tank, the outlet of the oil suction filter is connected to the inlet of the hydraulic oil pump, and the outlet of the hydraulic oil pump is connected to the main oil inlet of the filling valve. The second liquid outlet, the second oil outlet, and the third oil outlet are all connected to the return oil port of the hydraulic oil tank via pipelines.

[0012] The technical effects and advantages of this utility model are as follows: Compared with existing technologies, by setting up an electromagnetic directional valve, when the heavy-duty tractor is parked and powered off, the spring in the piston rod cylinder assembly resets, realizing the parking brake of the heavy-duty tractor. This automatically engages the parking brake, avoiding the risk of vehicle rollover due to the driver forgetting to engage the handbrake. By setting up a filling valve in conjunction with a pressure switch assembly, the accumulator can be automatically filled, thus facilitating the supply of hydraulic oil to the electromagnetic directional valve. This utility model makes minor modifications to the original service braking system of the heavy-duty tractor, namely adding a filling valve, a piston rod cylinder assembly, and an electromagnetic directional valve, to achieve automatic parking function. The modification cost is low, and the cost-effectiveness is high. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0014] The attached figures are labeled as follows: 10. Accumulator; 20. Oil suction circuit; 21. Hydraulic oil tank; 22. Oil suction filter; 23. Hydraulic oil pump; 30. Braking actuator module; 31. Parking brake; 32. Brake cable; 40. Filling valve; 41. Normally closed 2-position 2-way electro-hydraulic directional valve; 411. Directional valve spool; 412. Directional valve spool; H. Valve inlet; I. Valve outlet; 42. Check valve; 43. 2-position 3-way electro-hydraulic directional valve; P. Main inlet; A. First outlet; C. Second outlet; D. Third outlet; B1. First pressure test port; B2. Second pressure test port; 50. Piston rod cylinder assembly; 51. Spring; 52. Piston rod; 53. Cylinder body; 60. Solenoid directional valve; 61. Directional valve core; E. Inlet; F. First outlet; G. Second outlet; 70. Pressure switch assembly; 71. Normally open pressure switch; 72. Normally closed pressure switch; 80. Service brake piping system. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0016] As attached Figure 1 The parking brake system of a heavy-duty tractor shown includes: an accumulator 10, an oil suction circuit 20 and a brake actuation module 30 connected to a service brake pipeline system 80; it also includes: a filling valve 40, a piston rod cylinder assembly 50 and a solenoid directional valve 60; The oil outlet of the oil suction circuit 20 is connected to the oil inlet of the filling valve 40 through a pipeline. One oil outlet of the filling valve 40 is connected to the accumulator 10 through a pipeline. The accumulator 10 is connected to one oil inlet of the solenoid directional valve 60. One oil outlet of the solenoid directional valve 60 is connected to the piston rod cylinder assembly 50 through a pipeline. The movable end of the piston rod cylinder assembly 50 is connected to the brake execution module 30. The other oil outlet of the electromagnetic reversing valve 60 and the two oil outlets of the filling valve 40 are both connected to the return oil port of the suction circuit 20 through pipelines. The filling valve 40 is equipped with a pressure switch assembly 70 for controlling the operation of the directional valve core located inside the filling valve 40. The pressure switch assembly 70 switches the oil circuit according to the amount of hydraulic oil stored inside the accumulator 10. For example, when the stored pressure of the accumulator 10 is lower than the system's set lower limit pressure, the filling valve 40 starts to fill the accumulator 10 with liquid. When the pressure of the accumulator 10 reaches the upper limit pressure again, the hydraulic oil circuit inside the filling valve 40 is switched, and the oil flows back from the outlet to the suction circuit 20. The check valve 42 maintains the pressure of the hydraulic oil in the accumulator 10.

[0017] In a preferred embodiment, as shown in the appendix Figure 1 As shown, the filling valve 40 is provided with a main oil inlet P connected to the oil outlet of the oil suction circuit 20, a first oil outlet A connected to the accumulator 10, a second oil outlet C connected to the oil return port of the oil suction circuit 20, and a third oil outlet D connected to the oil return port of the oil suction circuit 20. The filling valve 40 has the following internal features: The normally closed two-position two-way electro-hydraulic directional valve 41 has its valve inlet H connected to the main inlet P and its valve outlet I connected to the second outlet C. One-way valve 42, one end of which is connected to the main oil inlet P, and the other end of which is connected to the first oil outlet A; and, The two-position three-way electro-hydraulic directional valve 43 has its valve inlet connected to the main inlet P and its valve outlet connected to the third outlet D. One valve core of the normally closed two-position two-way electro-hydraulic directional valve 41 is signal-connected to the two valve cores of the two-position three-way electro-hydraulic directional valve 43. The other valve core of the normally closed two-position two-way electro-hydraulic directional valve 41 is signal-connected to one end of the check valve 42 connected to the main oil inlet P. The other valve core of the two-position three-way electro-hydraulic directional valve 43 is signal-connected to one end of the check valve 42 connected to the first oil outlet A.

[0018] In a preferred embodiment, as shown in the appendix Figure 1 As shown, the pressure switch assembly 70 includes: a normally open pressure switch 71 for controlling the operation of the valve core of the normally closed two-position two-way electro-hydraulic directional valve 41, and a normally closed pressure switch 72 for controlling the operation of the valve core of another directional valve of the normally closed two-position two-way electro-hydraulic directional valve 41. The filling valve 40 is provided with a first pressure test port B1 connected to a normally open pressure switch 71 and a second pressure test port B2 connected to a normally closed pressure switch 72; Both the first pressure testing port B1 and the second pressure testing port B2 are connected to one end of the first oil outlet A of the one-way valve 42.

[0019] Specifically, the normally open pressure switch 71 is connected to the first pressure measuring port B1, thereby controlling the operation of the directional valve core 411 inside the normally closed two-position two-way electro-hydraulic directional valve 41 by switching the normally open pressure switch 71 on and off; the normally closed pressure switch 72 is connected to the second pressure measuring port B2, thereby controlling the operation of the directional valve core 412 inside the normally closed two-position two-way electro-hydraulic directional valve 41 by switching the normally closed pressure switch 72 on and off. In a preferred embodiment, as shown in the appendix Figure 1 As shown, the solenoid directional valve 60 is a two-position three-way solenoid directional valve 60, and the working position of its directional valve core 61 changes in response to the start and stop state of the heavy tractor. The electromagnetic reversing valve 60 is provided with an inlet E, a first outlet F, and a second outlet G. The accumulator 10 is connected to the inlet E, the first outlet F is connected to the piston rod cylinder assembly 50 through a pipeline, and the second outlet G, the second oil outlet C and the third oil outlet D are all connected to the return oil port of the oil suction circuit 20 through pipelines.

[0020] In a preferred embodiment, as shown in the appendix Figure 1 As shown, the piston rod cylinder assembly 50 is configured as a single-acting spring-return type single piston rod cylinder; The piston rod cylinder assembly 50 includes: a spring 51, a piston rod 52, and a cylinder body 53; The first outlet F is connected to the cylinder 53 through a pipeline. The piston rod 52 slides inside the cylinder 53 and is connected to the inner wall of the cylinder 53 through a spring 51. The end of the piston rod 52 away from the cylinder 53 is connected to the brake actuator module 30.

[0021] In a preferred embodiment, as shown in the appendix Figure 1 As shown, the braking execution module 30 includes a parking brake 31 and a brake cable 32. The end of the piston rod 52 away from the cylinder 53 is fixedly connected to the parking brake 31 through the brake cable 32.

[0022] In a preferred embodiment, as shown in the appendix Figure 1 As shown, the oil suction circuit 20 includes: a hydraulic oil tank 21, an oil suction filter 22, and a hydraulic oil pump 23; the inlet of the oil suction filter 22 is connected to the outlet of the hydraulic oil tank 21, the outlet of the oil suction filter 22 is connected to the inlet of the hydraulic oil pump 23, and the outlet of the hydraulic oil pump 23 is connected to the main oil inlet P of the filling valve 40. The second liquid outlet G, the second oil outlet C, and the third oil outlet D are all connected to the return oil port of the hydraulic oil tank 21 via pipelines.

[0023] Working principle of this utility model: When the heavy-duty tractor is started for the first time, the hydraulic oil pump 23 works: it draws hydraulic oil from the hydraulic oil tank 21 and filters it through the suction filter 22 before entering the filling valve 40. At this time, the valve inlet H and valve outlet I of the normally closed two-position two-way electro-hydraulic directional valve 41 in the filling valve 40 are disconnected. At this time, the filling valve 40 prioritizes filling the accumulator 10. When the pressure in the accumulator 10 reaches the upper limit pressure, the normally closed pressure switch 72 is opened, that is, the normally closed pressure switch 72 controls the valve core 412 of the normally closed two-position two-way electro-hydraulic directional valve 41 to work, connecting the valve inlet H and valve outlet I of the normally closed two-position two-way electro-hydraulic directional valve 41. Thus, the hydraulic oil flows from the valve inlet H to the valve outlet I, and is discharged through the second outlet C back to the hydraulic oil tank 21. The check valve 42 maintains the pressure of the hydraulic oil in the accumulator 10.

[0024] The accumulator 10 is connected to the inlet E of the electromagnetic steering valve 60. When the vehicle is powered on, the inlet E of the electromagnetic steering valve 60 is connected to the first outlet F. The hydraulic oil eventually enters the cylinder 53 of the piston rod cylinder assembly 50. Under the action of the oil pressure, the piston rod 52 of the piston rod cylinder assembly 50 is pushed to move and compress the spring 51, changing the brake cable 32 from a taut to a slack state, thus releasing the parking brake. At this time, the spring 51 is in a compressed state.

[0025] If the heavy-duty tractor is stopped and powered off, the directional valve core 61 of the electromagnetic steering valve 60 is de-energized and disconnected. At this time, the inlet E of the electromagnetic steering valve 60 is disconnected from the first outlet F, while the first outlet F is connected to the second outlet G. At this time, the hydraulic oil pressure in the piston rod cylinder assembly 50 decreases. Then, under the action of the oil pressure, the spring 51 resets and pushes the piston rod 52 to move, squeezing the hydraulic oil in the cylinder 53 back to the hydraulic oil tank 21. The piston rod 52 drives the brake cable 32 to be stressed, tightening the parking brake 21 and realizing the parking brake of the heavy-duty tractor.

[0026] When the heavy-duty tractor starts working again, the reversing valve core 61 of the electromagnetic steering valve 60 is energized. At this time, the inlet E of the electromagnetic steering valve 60 is connected to the first outlet F, and the first outlet F is disconnected from the second outlet G. The accumulator 10 provides energy to the piston rod cylinder assembly 50, pushing the piston rod 52 to move and realize the release of the parking brake. When the storage pressure of the accumulator 10 is lower than the system's set lower limit pressure, the normally closed pressure switch 72 closes, while the normally open pressure switch 71 operates, controlling the valve core 411 of the normally closed two-position two-way electro-hydraulic directional valve 41 to operate, disconnecting the valve inlet H from the valve outlet I of the normally closed two-position two-way electro-hydraulic directional valve 41. The charging valve 40 then begins to charge the accumulator 10. When the pressure of the accumulator 10 reaches the upper limit pressure again, the normally closed pressure switch 72 opens, controlling the valve core 412 of the normally closed two-position two-way electro-hydraulic directional valve 41 to operate, connecting the valve inlet H and the valve outlet I of the normally closed two-position two-way electro-hydraulic directional valve 41. The hydraulic oil flows from the valve inlet H to the valve outlet I, and is discharged through the second outlet C back to the hydraulic oil tank 21. The check valve 42 maintains the pressure of the hydraulic oil in the accumulator 10.

[0027] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0028] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A parking brake system for a heavy-duty tractor, comprising: An accumulator (10), an oil suction circuit (20), and a brake actuation module (30) connected to a service brake pipeline system; characterized in that it further includes: a filling valve (40), a piston rod cylinder assembly (50), and a solenoid directional valve (60). The oil outlet of the oil suction circuit (20) is connected to the oil inlet of the filling valve (40) through a pipeline. One oil outlet of the filling valve (40) is connected to the accumulator (10) through a pipeline. The accumulator (10) is connected to one oil inlet of the solenoid directional valve (60). One oil outlet of the solenoid directional valve (60) is connected to the piston rod cylinder assembly (50) through a pipeline. The movable end of the piston rod cylinder assembly (50) is connected to the brake execution module (30). The other oil outlet of the electromagnetic reversing valve (60) and the two oil outlets of the filling valve (40) are connected to the return oil port of the oil suction circuit (20) through pipelines; The filling valve (40) is provided with a pressure switch assembly (70) for controlling the operation of the directional valve core located inside the filling valve (40).

2. The parking brake system for a heavy-duty tractor according to claim 1, characterized in that: The filling valve (40) is provided with a main oil inlet (P) connected to the oil outlet of the oil suction circuit (20), a first oil outlet (A) connected to the accumulator (10), a second oil outlet (C) connected to the oil return port of the oil suction circuit (20), and a third oil outlet (D) connected to the oil return port of the oil suction circuit (20). The filling valve (40) is internally equipped with: A normally closed two-position two-way electro-hydraulic directional valve (41) has its valve inlet connected to the main inlet (P) and its valve outlet connected to the second outlet (C). A one-way valve (42), one end of which is connected to the main oil inlet (P), and the other end of which is connected to the first oil outlet (A); and, A two-position three-way electro-hydraulic directional valve (43) has its valve inlet connected to the main inlet (P) and its valve outlet connected to the third outlet (D). One valve core of the normally closed two-position two-way electro-hydraulic directional valve (41) is signal-connected to the two valve cores of the two-position three-way electro-hydraulic directional valve (43). The other valve core of the normally closed two-position two-way electro-hydraulic directional valve (41) is signal-connected to one end of the check valve (42) connected to the main oil inlet (P). The other valve core of the two-position three-way electro-hydraulic directional valve (43) is signal-connected to one end of the check valve (42) connected to the first oil outlet (A).

3. The parking brake system for a heavy-duty tractor according to claim 2, characterized in that: The pressure switch assembly (70) includes: a normally open pressure switch (71) for controlling the operation of the valve core of the normally closed two-position two-way electro-hydraulic directional valve (41) and a normally closed pressure switch (72) for controlling the operation of the valve core of the other directional valve of the normally closed two-position two-way electro-hydraulic directional valve (41). The filling valve (40) is provided with a first pressure test port (B1) connected to a normally open pressure switch (71) and a second pressure test port (B2) connected to a normally closed pressure switch (72). The first pressure test port (B1) and the second pressure test port (B2) are both connected to one end of the first oil outlet (A) of the one-way valve (42).

4. The parking brake system for a heavy-duty tractor according to claim 2, characterized in that: The solenoid directional valve (60) is a two-position three-way solenoid directional valve (60), and the working position of its directional valve core changes in response to the start and stop state of the heavy tractor. The electromagnetic reversing valve (60) is provided with an inlet (E), a first outlet (F), and a second outlet (G); The accumulator (10) is connected to the inlet (E), the first outlet (F) is connected to the piston rod cylinder assembly (50) through a pipeline, and the second outlet (G), the second oil outlet (C) and the third oil outlet (D) are all connected to the return oil port of the oil suction circuit (20) through pipelines.

5. The parking brake system for a heavy-duty tractor according to claim 4, characterized in that: The piston rod cylinder assembly (50) is configured as: a single-acting spring-return type single piston rod cylinder; The piston rod cylinder assembly (50) includes: a spring (51), a piston rod (52), and a cylinder body (53); The first outlet (F) is connected to the cylinder (53) through a pipeline. The piston rod (52) slides inside the cylinder (53) and is connected to the inner wall of the cylinder (53) through a spring (51). The end of the piston rod (52) away from the cylinder (53) is connected to the brake actuator module (30).

6. The parking brake system for a heavy-duty tractor according to claim 5, characterized in that: The braking execution module (30) includes a parking brake (31) and a brake cable (32). The end of the piston rod (52) away from the cylinder (53) is fixedly connected to the parking brake (31) through the brake cable (32).

7. The parking brake system for a heavy-duty tractor according to claim 4, characterized in that: The oil suction circuit (20) includes: a hydraulic oil tank (21), an oil suction filter (22), and a hydraulic oil pump (23); the inlet of the oil suction filter (22) is connected to the outlet of the hydraulic oil tank (21), the outlet of the oil suction filter (22) is connected to the inlet of the hydraulic oil pump (23), and the outlet of the hydraulic oil pump (23) is connected to the main oil inlet (P) of the filling valve (40); The second liquid outlet (G), the second oil outlet (C), and the third oil outlet (D) are all connected to the return oil port of the hydraulic oil tank (21) through pipelines.

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