A pressure-limited single-plunger booster brake pump

Abstract

A pressure-limited, single-plunger booster brake pump comprises a cylinder body, a plunger assembly, and a valve core. The plunger assembly is provided with an oil inlet control port and an oil outlet control port, the valve core is provided with an oil inlet ring groove and an oil outlet channel, and a booster chamber is provided between the valve core and the plunger assembly. The booster chamber is connected to the right working chamber via the booster port. During braking, the valve core moves rightward, first opening the oil inlet control port and gradually closing the oil outlet control port, causing the plunger assembly to move rightward and boosting the brake cylinder once. The booster port is then opened to boost the brake cylinder a second time. This booster brake pump requires only one foot pedal to complete the entire braking process. In the initial braking phase, only a slight pedal stroke is required to provide stable braking force to the brake cylinder, rapidly decelerating the vehicle and preventing accidents caused by vehicle locking. In the later stages of braking, it can provide sufficient braking force to the brake cylinder, quickly stopping the vehicle while ensuring safety.

Description

Technical Field

[0001] The present invention relates to the field of hydraulic components, in particular to a pressure-limiting single-plunger booster brake pump. Background Art

[0002] Because tractors and some construction vehicles have hydraulic power sources, brake pumps are typically used to drive brake cylinders for braking. Existing brake pumps typically require two-touch braking. When the brake pedal is first pressed, the brake pump piston moves forward, closing the bypass port and building up oil pressure in front of the piston, driving each brake cylinder to apply the brake. When the brake pedal is released, the brake pump piston returns to its original position under the action of oil pressure and a return spring. The oil pressure in each brake cylinder decreases, and excess oil returns to the oil reservoir. This single-touch braking system offers a design trade-off between braking travel and braking force. While it can effectively decelerate the vehicle, it cannot directly lock the wheels. To stop the vehicle quickly, a second braking operation is required. This involves pressing the brake pedal again. Oil from the oil reservoir flows through the compensation port to the front of the piston, further increasing the oil pressure in front of the piston and, in turn, the braking force of each brake cylinder.

[0003] The current problem is that two-foot braking is inconvenient to operate. Especially in emergency situations, drivers often forget to implement two-foot braking, which endangers the safe driving of the vehicle. Summary of the Invention

[0004] In order to overcome the deficiencies in the background technology, the present invention discloses a pressure-limited single-plunger booster brake pump, the purpose of which is to: realize one-foot braking, in the early stage of braking, provide a stable braking force to the brake cylinder, so that the vehicle can quickly decelerate and prevent the vehicle from locking and causing an accident; in the later stage of braking, provide a sufficiently large braking force to the brake cylinder to quickly stop the vehicle.

[0005] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0006] A pressure-limiting single-plunger booster brake pump, comprising:

[0007] a cylinder body having an oil inlet and an oil outlet;

[0008] The plunger assembly is slidably mounted in the cylinder body and divides the cylinder body into a left working chamber and a right working chamber, wherein the right working chamber is communicated with the brake cylinder; the plunger assembly has an oil inlet control port communicated with the oil inlet and an oil outlet control port communicated with the oil outlet;

[0009] The valve core is slidably mounted in the plunger assembly and is provided with an oil inlet ring groove corresponding to the oil inlet control port and an oil outlet channel corresponding to the oil outlet control port. The oil inlet ring groove and the oil outlet channel are connected to the left working chamber. A boost chamber is provided between the valve core and the plunger assembly, and the boost chamber is connected to the right working chamber through the boost port.

[0010] When braking, the valve core moves to the right, first opening the oil inlet control port and gradually closing the oil outlet control port, causing the plunger assembly to move to the right to boost the brake cylinder once; then the boost port is opened to boost the brake cylinder for a second time.

[0011] To further improve the technical solution, the cylinder body is composed of a cylinder liner, a left cylinder head and a right cylinder head, wherein the left cylinder head is floatingly sealed to the left end of the cylinder liner by a fastener and an elastomer, and the cavity formed between the left cylinder head and the plunger is the left working chamber.

[0012] To further improve the technical solution, the fastener is a high-pressure-limiting adjustment nut threaded on the left end of the cylinder sleeve, the elastic body is a butterfly spring, and the butterfly spring is located between the high-pressure-limiting adjustment nut and the left cylinder cover.

[0013] To further improve the technical solution, the plunger assembly includes a main plunger, a return spring and a sliding plunger, and the sliding plunger can slide on the main plunger; the boost port is provided on the main plunger, and under the action of the oil pressure in the right working chamber, the sliding plunger can overcome the thrust of the return spring and move to the left, opening the boost port, so that the boost chamber is connected with the right working chamber.

[0014] To further improve the technical solution, a floating slide rod, a valve core spring and a seal are arranged in the boost chamber, wherein the floating slide rod is connected to the right end of the valve core, and the seal is arranged in the through hole of the main plunger; when braking, the valve core moves to the right, and the floating slide rod cooperates with the seal to form a closed boost chamber.

[0015] To further improve the technical solution, a boost oil replenishment port is provided on the main plunger, and the boost oil replenishment port is connected to the oil outlet of the cylinder body through the boost oil replenishment port; when braking, the valve core moves to the right to close the boost oil replenishment port.

[0016] To further improve the technical solution, the sealing member is a Y-shaped sealing ring.

[0017] To further improve the technical solution, the plunger assembly is provided with an annular groove-shaped oil inlet chamber and an oil outlet chamber, the oil inlet control port is connected to the oil inlet through the oil inlet chamber, and the oil outlet control port is connected to the oil outlet through the oil outlet chamber.

[0018] To further improve the technical solution, a one-way valve is installed in the oil inlet.

[0019] Due to the adoption of the above technical solution, compared with the background technology, the present invention has the following beneficial effects:

[0020] This booster brake pump only requires one foot press to complete the entire braking process. In the initial braking phase, a light press of the pump provides a stable braking force to the brake cylinder, rapidly decelerating the vehicle and preventing accidents caused by vehicle locking. In the later stages of braking, the booster brake pump can provide sufficient braking force to the brake cylinder, quickly stopping the vehicle while ensuring safety.

[0021] Compared with the two-foot brake of the existing brake pump, the booster brake pump is easy to operate, can avoid the occurrence of braking accidents in emergency situations, and ensure driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Shown is a schematic structural diagram of the cylinder body.

[0023] Figure 2 Shown is a schematic structural diagram of the plunger assembly.

[0024] Figure 3 Shown is a schematic structural diagram of the valve core.

[0025] Figure 4 Shown is a schematic diagram of the structure when the boost port is open.

[0026] Figure 5 Shown is a schematic structural diagram of the booster brake pump in its initial state.

[0027] Figure 6 Shown is a schematic structural diagram of the booster brake pump in a primary boost state.

[0028] Figure 7 Shown is a schematic structural diagram of the booster brake pump in the secondary boost state.

[0029] In the picture:

[0030] 100, cylinder body;

[0031] 101. Cylinder liner; 102. Left cylinder head; 103. Right cylinder head; 104. High-pressure limit adjustment nut; 105. Belleville spring; 106. Oil inlet; 107. Oil outlet; 108. Check valve; 109. Left working chamber; 110. Right working chamber.

[0032] 200, plunger assembly;

[0033] 201, main plunger; 202, sliding plunger; 203, return spring; 204, adjusting nut; 205, oil inlet chamber; 206, oil outlet chamber; 207, oil inlet control port; 208, oil outlet control port; 209, boost oil replenishment port; 210, boost port; 211, through hole; 212, Y-shaped sealing ring; 213, plunger spring;

[0034] 300, valve core;

[0035] 301, oil inlet ring groove; 302, oil outlet channel; 303, floating slide; 304, valve core spring; 305, limit plate; 306, boost chamber; 307, flow gap;

[0036] 400. Brake cylinder. Implementation Method

[0037] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. It should be noted that in the description of the present invention, the terms "front", "rear", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation of the present invention. It should also be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" 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, an indirect connection through an intermediate medium, or a communication between two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0038] A pressure-limiting single-plunger booster brake pump mainly comprises a cylinder body 100, a plunger assembly 200 and a valve core 300, and its structure and function are described in detail below.

[0039] like Figure 1 As shown, the cylinder body 100 is composed of a cylinder liner 101 , a left cylinder head 102 and a right cylinder head 103 . An oil inlet 106 and an oil outlet 107 are provided on the cylinder liner 101 , and a one-way valve 108 is provided in the oil inlet 106 .

[0040] Unlike existing cylinder block structures, the left cylinder head 102 is floatingly sealed to the left end of the cylinder liner 101 via a fastener and an elastic member. In this embodiment, the fastener is a high-pressure adjustment nut 104 threaded onto the left end of the cylinder liner 101, and the elastic member is a butterfly spring 105. The butterfly spring 105 is located between the high-pressure adjustment nut 104 and the left cylinder head 102. By tightening or loosening the high-pressure adjustment nut 104, the thrust exerted by the butterfly spring 105 on the left cylinder head 102 can be adjusted. If the oil pressure within the cylinder block 100 is less than the thrust of the butterfly spring 105, the left cylinder head 102 will not move. If the oil pressure within the cylinder block 100 is greater than the thrust of the butterfly spring 105, the left cylinder head 102 will move leftward, thereby increasing the internal cylinder volume and reducing the internal oil pressure. This design significantly reduces the internal oil pressure within the cylinder block 100, preventing damage to the cylinder block 100 or internal components caused by high oil pressure. It is worth noting that this structure is also suitable for installation on the right cylinder head 103.

[0041] like Figure 2 As shown, the plunger assembly 200 is slidably installed in the cylinder body 100, and a plunger spring 213 is provided between the plunger assembly 200 and the right cylinder head 103. The cavity formed between the left cylinder head 102 and the plunger assembly 200 is the left working chamber 109, and the cavity formed between the right cylinder head 103 and the plunger assembly 200 is the right working chamber 110. Figure 5 、 Figure 6 and Figure 7 The right working chamber 110 is connected to the two brake cylinders 400 through a pipeline, and is used to provide the oil pressure required for braking to the two brake cylinders 400.

[0042] The plunger assembly 200 is primarily composed of a main plunger 201, a return spring 203, and a sliding plunger 202. The sliding plunger 202 is capable of sliding on the main plunger 201. The main plunger 201 is provided with an oil inlet control port 207, which communicates with the oil inlet 106, and an oil outlet control port 208, which communicates with the oil outlet 107. Since the main plunger 201 is capable of sliding within the cylinder body 100, an annular groove-shaped oil inlet chamber 205 and an oil outlet chamber 206 are provided on the plunger assembly 200 to maintain communication. The oil inlet control port 207 communicates with the oil inlet 106 via the oil inlet chamber 205, and the oil outlet control port 208 communicates with the oil outlet 107 via the oil outlet chamber 206.

[0043] A boost port 210 is also provided on the main plunger 201. Under the action of the oil pressure in the right working chamber 110, the sliding plunger 202 can overcome the thrust of the return spring 203 and move leftward, opening the boost port 210 and connecting the boost chamber 306 with the right working chamber 110. To adjust the opening pressure of the boost port 210, an adjusting nut 204 is threaded onto the main plunger 201. By tightening or loosening the adjusting nut 204, the thrust of the return spring 203 on the sliding plunger 202 can be adjusted. The boost port 210 can only be opened after the oil pressure in the right working chamber 110 increases to a certain level, allowing the hydraulic oil in the boost chamber 306 to enter the right working chamber 110.

[0044] like Figure 3 As shown, the valve core 300 is slidably mounted within the plunger assembly 200. The valve core 300 is provided with an oil inlet annular groove 301 corresponding to the oil inlet control port 207 and an oil outlet channel 302 corresponding to the oil outlet control port 208. The oil inlet annular groove 301 and the oil outlet channel 302 communicate with the left working chamber 109. A limit plate 305 is also provided on the valve core 300 to limit the travel of the valve core 300. The left end of the valve core 300 extends outward from the left cylinder head 102 for connection to the brake pedal. During braking, the valve core 300 moves rightward, opening the oil inlet control port 207, allowing hydraulic oil from the oil inlet port 106 to enter the left working chamber 109. Simultaneously, the oil outlet control port 208 is gradually closed, building up oil pressure within the left working chamber 109. This oil pressure propels the plunger assembly 200 rightward, boosting the pressure in the brake cylinder 400.

[0045] like Figure 4 As shown, a boost chamber 306 is provided between the valve core 300 and the plunger assembly 200, and the boost chamber 306 is connected to the right working chamber 110 through an openable boost port 210. Specifically, a floating slide 303, a valve core spring 304 and a seal are provided in the boost chamber 306. In this embodiment, the seal is a Y-type sealing ring 212. The floating slide 303 is connected to the right end of the valve core 300, and the Y-type sealing ring 212 is provided in the through hole 211 of the main plunger 201. A plug is provided between the floating slide 303 and the valve core 300, and the plug is used to isolate the connection between the boost chamber 306 and the oil outlet channel 302. A boost oil replenishment port 209 is provided on the main plunger 201, and the boost chamber 306 is connected to the oil outlet 107 of the cylinder body 100 through the boost oil replenishment port 209. During braking, valve core 300 moves rightward, first closing boost oil replenishment port 209. Then, floating slide 303 inserts into and engages with Y-ring 212, forming a closed boost chamber 306. When boost port 210 opens, the hydraulic oil in boost chamber 306 enters right working chamber 110, providing a secondary boost to brake cylinder 400.

[0046] Description of working process:

[0047] Figure 5 The figure shows the structure of the booster brake pump in the initial state. Figure 5 It can be seen that the plunger assembly 200 is located at the left end of the cylinder body 100 under the action of the plunger spring 213, and the oil inlet control port 207 is now closed by the valve core 300. For the left working chamber 109, the left working chamber 109 is connected to the oil outlet 107 through the oil outlet channel 302, the oil outlet control port 208, and the oil outlet chamber 206. For the right working chamber 110, the right working chamber 110 is connected to the oil outlet 107 through the through hole 211, the boost chamber 306, the boost oil replenishment port 209, and the oil outlet chamber 206. It can be seen that the left working chamber 109 and the right working chamber 110 are respectively connected to the oil outlet 107. There is no oil pressure in the left working chamber 109 and the right working chamber 110, the plunger assembly 200 cannot move, and the brake cylinder 400 does not generate braking force.

[0048] Figure 6 The figure shows the structure of the booster brake pump in the primary boost state. Figure 6 As can be seen, lightly pressing the brake pedal causes valve core 300 to move a small distance to the right. At this point, oil inlet control port 207 gradually opens, while oil outlet control port 208 gradually closes. Hydraulic oil from oil inlet port 106 enters left working chamber 109 through oil inlet control port 207, building up oil pressure within left working chamber 109, which propels plunger assembly 200 to the right. Simultaneously, valve core 300 closes pressurized oil replenishment port 209, and floating slide 303 inserts into Y-shaped sealing ring 212, forming a seal. Pressurized chamber 306 remains closed, and pressure begins to build as valve core 300 moves rightward.

[0049] As the plunger assembly 200 begins to move rightward, the effective area of ​​the left working chamber 109 increases dramatically. At this point, a small pedaling force applied to the valve core 300 generates a large oil pressure in the right working chamber 110, thereby boosting the brake cylinder 400. Clearly, the boosting effect of the plunger assembly 200 amplifies the pedaling force, resulting in a higher brake oil pressure in the brake cylinder 400.

[0050] It is worth noting that as the valve core 300 moves rightward, the plunger assembly 200 also moves rightward with the valve core 300. At this point, the relative distance between the valve core 300 and the plunger assembly 200 is not fixed, but rather in a state of dynamic equilibrium. When the oil inlet control port 207 is opened too wide and the oil outlet control port 208 is opened too narrowly, the oil pressure in the left working chamber 109 exceeds the oil pressure in the right working chamber 110. The plunger assembly 200 moves rightward relative to the valve core 300, tending to reduce the oil inlet control port 207 and increase the oil outlet control port 208, thereby reducing the pressure differential across the plunger assembly 200. Conversely, when the opening of oil inlet control port 207 is too small and the opening of oil outlet control port 208 is too large, the oil pressure in the left working chamber 109 is lower than the oil pressure in the right working chamber 110. The plunger assembly 200 moves leftward relative to the valve core 300, tending to increase the pressure of the oil inlet control port 207 and decrease the pressure of the oil outlet control port 208, thereby reducing the pressure difference across the plunger assembly 200. This dynamic balance prevents sudden rightward movement of the valve core 300 due to sudden application of the brake pedal, which could lead to a sharp increase in the oil pressure in the brake cylinder 400 and directly lock the wheel, resulting in a braking accident.

[0051] It is also worth noting that before a certain oil pressure is formed in the right working chamber 110 , no matter how the brake pedal is depressed, the sliding plunger 202 will block the boost port 210 to prevent the hydraulic oil in the boost chamber 306 from entering the right working chamber 110 and pressurizing the right working chamber 110 .

[0052] Figure 7 The diagram shows the structure of the booster brake pump in the secondary boost state. Figure 7 As can be seen, as the valve core 300 continues to move rightward, the oil outlet control port 208 is completely closed by the valve core 300, the dynamic equilibrium is broken, and the plunger assembly 200 tends to move rightward, but the movement is very limited, and the oil pressure in the right working chamber 110 begins to increase. When the oil pressure in the right working chamber 110 increases to a certain level, the sliding plunger 202 overcomes the thrust of the return spring 203 and moves leftward, opening the boost port 210 and connecting the boost chamber 306 with the right working chamber 110.

[0053] Reference Figure 4After the sliding plunger 202 moves to the left, the boost port 210 is connected to the right working chamber 110 through the flow gap 307, and the hydraulic oil in the boost chamber 306 enters the right working chamber 110, performing secondary boosting on the right working chamber 110. According to the principle of communicating vessels, applying a small force on a small-area piston can generate a large force on a large-area piston. During the movement of the valve core 300 to the right, the valve core 300 applies a small thrust to the boost chamber 306 (which can be regarded as a cylinder with a small effective area). After the boost chamber 306 is connected to the right working chamber 110, it can generate an amplified thrust in the right working chamber 110 (which can be regarded as a cylinder with a large effective area), thereby causing the brake cylinder 400 to be secondary boosted.

[0054] It's worth noting that the boost port 210 opens only after a certain level of oil pressure has been established in the right working chamber 110. Before this level of oil pressure is established in the right working chamber 110, the vehicle has already been decelerated to a certain extent by the brake cylinders 400, significantly reducing its speed. Opening the boost port 210 at this point in time to provide a secondary boost to the brake cylinders 400 further increases the braking force of each brake cylinder 400, bringing the vehicle to a rapid stop while ensuring safety.

[0055] It's also worth noting that as the oil pressure in the right working chamber 110 increases, the oil pressure in the left working chamber 109 also increases, transmitted through the plunger assembly 200. To prevent damage to the cylinder block 100 and the hydraulic components, the left cylinder head 102, overcoming the thrust of the disc spring 105, moves leftward, increasing the cylinder volume and reducing the oil pressure within the cylinder. This prevents damage to the cylinder block 100 or the components within the cylinder from being caused by high oil pressure.

[0056] When the vehicle stops, the valve core 300 is released, and the valve core 300 moves to the left under the action of the valve core spring 304, the oil inlet control port 207 is closed, and the oil outlet control port 208 is opened. At the same time, the floating slide 303 is separated from the Y-shaped sealing ring 212, the boost oil replenishment port 209 is opened, and the left working chamber 109, the right working chamber 110 and the boost chamber 306 are connected to the oil outlet 107 respectively to release the pressure. The plunger assembly 200 moves to the left under the action of the plunger spring 213, and the plunger assembly 200 and the valve core 300 return to the Figure 5 The initial position shown in .

[0057] As can be seen from the above, this booster brake pump only requires one foot pedal to complete the entire braking process. In the initial braking phase, only a slight pedal stroke is needed to provide stable braking force to the brake cylinder, rapidly decelerating the vehicle and preventing accidents caused by vehicle locking. In the later stages of braking, the booster brake pump can provide sufficient braking force to the brake cylinder, quickly stopping the vehicle while ensuring safety. Compared to the two-foot braking method of existing brake pumps, this booster brake pump is easier to operate and can prevent braking accidents in emergency situations.

[0058] Parts not described in detail are prior art. 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 variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A pressure-limited single-plunger booster brake pump, characterized by: include: a cylinder body having an oil inlet and an oil outlet; The plunger assembly is slidably mounted within the cylinder body and divides the cylinder body into a left working chamber and a right working chamber, wherein the right working chamber is connected to the brake cylinder; the plunger assembly has an oil inlet control port connected to the oil inlet and an oil outlet control port connected to the oil outlet; the plunger assembly includes a main plunger, a return spring, and a sliding plunger. The sliding plunger can slide on the main plunger and is provided with a boost port on the main plunger; The valve core is slidably mounted in the plunger assembly and is provided with an oil inlet ring groove corresponding to the oil inlet control port and an oil outlet channel corresponding to the oil outlet control port. The oil inlet ring groove and the oil outlet channel are connected to the left working chamber. A boost chamber is provided between the valve core and the plunger assembly, and the boost chamber is connected to the right working chamber through the boost port. When braking, the valve core moves to the right, first opening the oil inlet control port and gradually closing the oil outlet control port, causing the plunger assembly to move to the right and boosting the brake cylinder once; as the valve core continues to move to the right, the oil pressure in the right working chamber begins to increase. Under the action of the oil pressure in the right working chamber, the sliding plunger overcomes the thrust of the return spring and moves to the left, thereby opening the boost port and boosting the brake cylinder for a second time.

2. A pressure-limiting single-plunger booster brake pump according to claim 1, characterized in that: The cylinder body is composed of a cylinder liner, a left cylinder head and a right cylinder head, wherein the left cylinder head is floatingly sealed to the left end of the cylinder liner through a fastener and an elastomer, and the cavity formed between the left cylinder head and the plunger assembly is the left working chamber.

3. The pressure-limiting single-plunger booster brake pump according to claim 2, characterized in that: The fastener is a high-pressure-limiting adjustment nut threaded on the left end of the cylinder sleeve, and the elastic body is a butterfly spring located between the high-pressure-limiting adjustment nut and the left cylinder cover.

4. A pressure-limiting single-plunger booster brake pump as claimed in claim 1, characterized in that: A floating slide rod, a valve core spring and a seal are provided in the boost chamber, wherein the floating slide rod is connected to the right end of the valve core and the seal is provided in the through hole of the main plunger; when braking, the valve core moves to the right, and the floating slide rod cooperates with the seal to form a closed boost chamber.

5. The pressure-limiting single-plunger booster brake pump according to claim 4, characterized in that: A boost oil replenishing port is provided on the main plunger, and the boost oil replenishing port is connected to the oil outlet of the cylinder body through the boost oil replenishing port; when braking, the valve core moves to the right to close the boost oil replenishing port.

6. The pressure-limiting single-plunger booster brake pump according to claim 4, characterized in that: The sealing member is a Y-shaped sealing ring.

7. The pressure-limiting single-plunger booster brake pump according to claim 1, characterized in that: The plunger assembly is provided with an annular groove-shaped oil inlet cavity and an oil outlet cavity. The oil inlet control port is communicated with the oil inlet through the oil inlet cavity, and the oil outlet control port is communicated with the oil outlet through the oil outlet cavity.

8. The pressure-limiting single-plunger booster brake pump according to claim 1, characterized in that: A one-way valve is installed in the oil inlet.

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