A hydraulic brake control valve group for HST drive axle gearbox brake oil cylinder

Abstract

The utility model discloses a hydraulic brake control valve group for HST drive axle gearbox brake oil cylinder, including valve body, four two -position two -way electromagnetic reversing valves are equipped in the valve body, the first oil port, second oil port, third oil port are equipped in the valve body top, and the bottom is equipped with fourth oil port, fifth oil port. Fourth oil port connects system pressure oil and connects the oil inlet of former two reversing valves, and the oil outlet of fourth oil port connects the oil inlet of latter two reversing valves and brake oil cylinder left and right side oil cylinder rodless chamber respectively, fifth oil port connects hydraulic oil tank, and the export connects the oil outlet of latter two reversing valves and second oil port import, and the oil return pipe between second oil port export and brake oil cylinder left and right side oil cylinder rodless chamber is connected. The utility model discloses through independent reversing valve control oil circuit, solves the brake stability problem of traditional slide valve leakage, and can also realize double oil cylinder simultaneous action to complete parking, improves control security and functionality.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic brake control technology, and in particular to a hydraulic brake control valve group for the brake cylinder of an HST drive axle gearbox. Background Technology

[0002] The traditional HST drive axle transmission brake cylinder achieves braking through a three-position four-way solenoid valve with an "H" function. Specifically, the "A" and "B" ports of the "H" function three-position four-way solenoid valve are connected to the brake cylinders (double hydraulic cylinders with spring return; the two cylinders have rod chambers connected in series and directly connected to the oil tank). When the left electromagnet of the three-position four-way solenoid valve is energized, the left piston of the brake cylinder extends (while the right piston is retracted), and the left drive shaft of the transmission stops. When the right drive shaft stops rotating, it continues to rotate, achieving left steering. When the right electromagnet of the three-position four-way solenoid valve is energized, the right piston of the brake cylinder extends, while the left piston retracts under the action of the spring. The right drive shaft of the gearbox stops rotating, while the left drive shaft continues to rotate, achieving right steering. When neither electromagnet of the three-position four-way solenoid valve is energized, both pistons of the brake cylinder retract, and the drive shafts on both sides of the gearbox rotate normally, allowing the vehicle to move straight. The "T" port of the three-position four-way plate-type solenoid directional valve with "H" function is directly connected back to the oil tank. The problem with this control method is: First, the three-position four-way plate electromagnetic directional valve with "H" function is a spool valve. The sealing gap between the spool valve core and the valve body is relatively large. When working, the amount of oil leakage in this gap is significantly larger than that of the spherical seal valve. Moreover, the higher the hydraulic oil pressure, the greater the leakage. This defect is extremely detrimental to the braking stability of the brake cylinder and poses a significant safety hazard. Secondly, the connection between the aforementioned three-position four-way solenoid directional valve and the brake cylinder can only extend the piston of one of the brake cylinders, but cannot extend the pistons of both cylinders simultaneously. That is, this connection method can only achieve vehicle steering, but cannot stop the rotation of both output shafts of the gearbox at the same time and thus bring the vehicle to a stop. Utility Model Content

[0003] To address the aforementioned technical problems, this utility model provides a hydraulic brake control valve assembly for the brake cylinder of an HST drive axle gearbox.

[0004] To achieve the above objectives, the technical solution of this utility model is as follows: A hydraulic brake control valve assembly for the brake cylinder of an HST drive axle transmission includes a valve body. The valve body houses four two-position, two-way solenoid directional valves: a first two-position, two-way solenoid directional valve, a second two-position, two-way solenoid directional valve, a third two-position, two-way solenoid directional valve, and a fourth two-position, two-way solenoid directional valve. The valve body has three ports at the top (first, second, and third ports) and two ports at the bottom (fourth and fifth ports). The inlet of the fourth port is connected to system pressure oil, and the outlet of the fourth port is connected to the inlets of both the first and second two-position solenoid directional valves. The outlet of the first two-position two-way solenoid directional valve is connected to the inlet of the third two-position two-way solenoid directional valve and the rodless chamber of the left cylinder of the brake cylinder, respectively. The outlet of the second two-position two-way solenoid directional valve is connected to the inlet of the fourth two-position two-way solenoid directional valve and the rodless chamber of the right cylinder of the brake cylinder, respectively. The fifth port is connected to the hydraulic oil tank. In the valve body, the fifth port is connected to the outlets of the third two-position two-way solenoid directional valve and the fourth two-position two-way solenoid directional valve, and then connected to the inlet of the second port. The outlet of the second port is connected to the return oil pipe between the rodless chambers of the left and right cylinders of the brake cylinder.

[0005] Furthermore, the first two-position two-way solenoid directional valve, the second two-position two-way solenoid directional valve, the third two-position two-way solenoid directional valve, and the fourth two-position two-way solenoid directional valve are all threaded cartridge solenoid ball valves.

[0006] Furthermore, the valve body is made of 6061 cast aluminum.

[0007] Furthermore, the first two-position two-way solenoid directional valve and the second two-position two-way solenoid directional valve are two-position two-way solenoid proportional directional valves.

[0008] Compared with the prior art, the beneficial effects of this utility model are: 1. By using four independent two-position two-way solenoid directional valves to control the oil inlet and outlet of the rodless chambers on both sides of the brake cylinder, the limitation of the traditional three-position four-way spool valve, which can only operate on one side, is broken. When the first and second two-position two-way solenoid directional valves are energized simultaneously, pressurized oil can enter the rodless chambers of the left and right cylinders at the same time, causing both pistons to extend simultaneously and actuate the brake levers of the drive shafts on both sides of the gearbox, achieving simultaneous locking of both drive shafts. This solves the problem of not being able to stop the vehicle using the traditional method and expands the function of the control valve group.

[0009] 2. Because the electromagnetic ball valve adopts a spherical sealing structure, compared with the gap sealing of traditional spool valves, the spherical seal has superior sealing performance, and the sealing gap between the valve core and the valve body is extremely small. When the oil is pressurized, the oil leakage is much smaller than that of the spool valve, and it is less affected by pressure changes. This ensures the stability of the pressure in the rodless chamber of the brake cylinder, avoids insufficient braking force or delayed action due to leakage, significantly improves braking stability, and eliminates the safety hazards caused by leakage of traditional spool valves. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the structure of this utility model.

[0011] In the picture: 1. Valve body; 101. First two-position two-way solenoid directional valve; 102. Second two-position two-way solenoid directional valve; 103. Third two-position two-way solenoid directional valve; 104. Fourth two-position two-way solenoid directional valve; 2. Brake cylinder; 201. Left cylinder; 202. Right cylinder; A. First port; Tin. Second port; B. Third port; P. Fourth port; Tout. Fifth port; 8. System pressure oil; 9. Hydraulic oil tank; 10. Return pipe; DT1. Solenoid of the first two-position two-way solenoid directional valve; DT2. Solenoid of the second two-position two-way solenoid directional valve; DT3. Solenoid of the third two-position two-way solenoid directional valve; DT4. Solenoid of the fourth two-position two-way solenoid directional valve. Detailed Implementation

[0012] 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 specific embodiments and accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of this utility model. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of this utility model.

[0013] A hydraulic brake control valve assembly for the brake cylinder of an HST drive axle transmission includes a valve body 1. The valve body 1 houses four two-position two-way solenoid directional valves: a first two-position two-way solenoid directional valve 101, a second two-position two-way solenoid directional valve 102, a third two-position two-way solenoid directional valve 103, and a fourth two-position two-way solenoid directional valve 104. The valve body 1 has three ports at the top: a first port A, a second port Tin, and a third port B. It also has two ports at the bottom: a fourth port P and a fifth port Tout. The inlet of the fourth port P is connected to system pressure oil 8, and the outlet of the fourth port P is connected to the inlets of the first two-position two-way solenoid directional valve 101 and the second two-position two-way solenoid directional valve 102. The outlet of the reversing valve 101 is connected to the inlet of the third two-position two-way solenoid reversing valve 103 and the rodless chamber of the left cylinder 201 of the brake cylinder 2. The outlet of the second two-position two-way solenoid reversing valve 102 is connected to the inlet of the fourth two-position two-way solenoid reversing valve 104 and the rodless chamber of the right cylinder 202 of the brake cylinder 2. The fifth port Tout is connected to the hydraulic oil tank 9. Inside the valve body 1, the fifth port Tout is connected to the outlets of the third two-position two-way solenoid reversing valve 103 and the fourth two-position two-way solenoid reversing valve 104, and then connected to the inlet of the second port Tin. The outlet of the second port Tin is connected to the return pipe 10 between the rodless chamber of the left cylinder 201 and the rodless chamber of the right cylinder 202 of the brake cylinder 2.

[0014] The first two-position two-way solenoid directional valve 101, the second two-position two-way solenoid directional valve 102, the third two-position two-way solenoid directional valve 103, and the fourth two-position two-way solenoid directional valve 104 are all threaded cartridge solenoid ball valves.

[0015] The valve body 1 is made of 6061 cast aluminum, and its outer surface is treated with a natural color anodizing process.

[0016] The working process of this embodiment is as follows: Left turn of the vehicle: When the vehicle needs to turn left, the solenoid DT1 of the first two-position two-way solenoid directional valve is energized. The pressurized oil enters the first two-position two-way solenoid directional valve 101 through the fourth oil port P, and then enters the rodless chamber of the left cylinder 201 of the brake cylinder 2 through its oil outlet. The piston rod of the left cylinder 201 extends and moves the brake lever of the left drive shaft on the corresponding gearbox. The brake lever drives the brake pads inside the gearbox to fit tightly with the gear of the left drive shaft, locking the left drive shaft. At this time, the right drive shaft of the gearbox continues to rotate normally, and the vehicle turns left. Left turn disengagement: After the vehicle completes a left turn, the solenoid DT1 of the first two-position two-way solenoid directional valve is de-energized, while the solenoid DT3 of the third two-position two-way solenoid directional valve is energized. The pressure oil in the rodless chamber of the left cylinder 201 of brake cylinder 2 flows back to the hydraulic oil tank 9 through the third two-position two-way solenoid directional valve 103 and the fifth oil port Tout. At the same time, the spring in the rod chamber of the left cylinder 201 of brake cylinder 2 resets the piston, and the brake pads of the left drive shaft in the gearbox disengage from the gears of the left drive shaft, thus disengaging the left turn. Right turn of the vehicle: When the vehicle needs to turn right, the solenoid DT2 of the second two-position two-way solenoid directional valve is energized. The pressurized oil enters the second two-position two-way solenoid directional valve 102 through the fourth oil port P, and then enters the rodless chamber of the right cylinder 202 of the brake cylinder 2 through its oil outlet. The piston rod of the right cylinder 202 extends and actuates the brake lever of the right drive shaft on the gearbox. The brake lever drives the brake pads inside the gearbox to fit tightly with the gear of the right drive shaft, locking the right drive shaft. At this time, the left drive shaft of the gearbox continues to rotate normally, and the vehicle turns right. Right turn disengagement: After the vehicle completes a right turn, the solenoid DT2 of the second two-position two-way solenoid directional valve is de-energized, while the solenoid DT4 of the fourth two-position two-way solenoid directional valve is energized. The pressure oil in the rodless chamber of the right cylinder 202 of brake cylinder 2 flows back to the hydraulic oil tank 9 through the fourth two-position two-way solenoid directional valve 104 and the fifth oil port Tout. At the same time, the spring in the rod chamber of the right cylinder 202 of brake cylinder 2 resets the piston, and the brake pads of the right drive shaft in the gearbox disengage from the right drive shaft gear, thus disengaging the right turn. Vehicle Braking: When the vehicle body needs to brake, the electromagnets DT1 and DT2 of the first two-position two-way solenoid valve 101 and the second two-position two-way solenoid valve 102 are simultaneously energized. The pressurized oil enters the first and second two-position two-way solenoid valves 101 and 102 through the fourth oil port P, and then simultaneously enters the rodless chambers of the left cylinder 201 and the right cylinder 202 of the brake cylinder 2. The piston rods of the two cylinders extend and respectively actuate the brake levers of the left and right drive shafts on the gearbox. The two brake levers respectively drive the left and right brake pads inside the gearbox to engage tightly with the gears of the left and right drive shafts, locking the left and right drive shafts and stopping the drive wheels on both sides of the vehicle body, thus achieving braking of the vehicle body. Vehicle brake release: When the vehicle body needs to move again while in a braking state, the electromagnets DT1 and DT2 of the first and second two-position two-way solenoid directional valves 101 and 102 are simultaneously de-energized, while the electromagnets DT3 and DT4 of the third and fourth two-position two-way solenoid directional valves 103 and 104 are simultaneously energized. The hydraulic oil in the rodless chambers of the left cylinder 201 and the right cylinder 202 of the brake cylinder 2 flows back to the hydraulic oil tank 9 through the third two-position two-way solenoid directional valve 103, the fourth two-position two-way solenoid directional valve 104, and the fifth oil port Tout, respectively. The piston rods of the two cylinders are reset by the return springs in their respective rod chambers. The left and right brake pads inside the gearbox disengage from the gears of the left and right drive shafts, the brakes on the left and right drive shafts of the gearbox are released, and the vehicle body moves.

[0017] Example 2 The difference between this embodiment and Embodiment 1 is that the first two-position two-way solenoid directional valve 101 and the second two-position two-way solenoid directional valve 102 are two-position two-way solenoid proportional directional valves.

[0018] During the operation of this embodiment, when performing left turn, right turn, or braking operations, the valve core opening can be controlled by adjusting the current signal input to the first and second two-position two-way electromagnetic proportional directional valves 101 and 102, thereby adjusting the pressure oil flow rate entering the rodless chamber of the brake cylinder 2, so that the piston extension speed changes smoothly, ensuring smoother control of vehicle braking or steering. It can also be used to control the brake cylinder of the HST drive axle gearbox.

[0019] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A hydraulic brake control valve assembly for the brake cylinder of an HST drive axle transmission, characterized in that, The system includes a valve body (1) and a hydraulic oil tank (9). The valve body (1) is equipped with four two-position two-way solenoid directional valves, namely a first two-position two-way solenoid directional valve (101), a second two-position two-way solenoid directional valve (102), a third two-position two-way solenoid directional valve (103), and a fourth two-position two-way solenoid directional valve (104). The top of the valve body (1) has three oil ports, namely a first oil port (A), a second oil port (Tin), and a third oil port (B), and the bottom has two oil ports, namely a fourth oil port (P) and a fifth oil port (Tout). The inlet of the fourth oil port (P) is connected to the system pressure oil (8), and the outlet of the fourth oil port (P) is connected to the oil inlet of the first two-position two-way solenoid directional valve (101) and the second two-position two-way solenoid directional valve (102), respectively. The outlet of the first two-position two-way solenoid directional valve (101) is connected to the oil outlet of the second two-position two-way solenoid directional valve (104). The oil inlet of the third two-position two-way solenoid directional valve (103) and the rodless chamber of the left cylinder (201) of the brake cylinder (2) are respectively connected. The oil outlet of the second two-position two-way solenoid directional valve (102) is respectively connected to the oil inlet of the fourth two-position two-way solenoid directional valve (104) and the rodless chamber of the right cylinder (202) of the brake cylinder (2). The fifth oil port (Tout) is connected to the hydraulic oil tank (9). In the valve body (1), the fifth oil port (Tout) is connected to the oil outlet of the third two-position two-way solenoid directional valve (103) and the fourth two-position two-way solenoid directional valve (104) and then connected to the inlet of the second oil port (Tin). The outlet of the second oil port (Tin) is connected to the return oil pipe (10) between the rodless chamber of the left cylinder (201) and the rodless chamber of the right cylinder (202) of the brake cylinder (2).

2. The hydraulic brake control valve assembly for the brake cylinder of an HST drive axle gearbox according to claim 1, characterized in that, The first two-position two-way solenoid directional valve (101), the second two-position two-way solenoid directional valve (102), the third two-position two-way solenoid directional valve (103), and the fourth two-position two-way solenoid directional valve (104) are all threaded cartridge solenoid ball valves.

3. A hydraulic brake control valve assembly for the brake cylinder of an HST drive axle gearbox according to claim 2, characterized in that, The valve body (1) is made of 6061 cast aluminum.

4. A hydraulic brake control valve assembly for the brake cylinder of an HST drive axle gearbox according to claim 1, characterized in that, The first two-position two-way solenoid directional valve (101) and the second two-position two-way solenoid directional valve (102) are two-position two-way solenoid proportional directional valves.

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