Normally closed hydraulic power assisting device

Abstract

The utility model provides a normally closed hydraulic power assisting device, and belongs to the technical field of machinery. The problem that an existing brake pump is inconvenient to replace is solved. The normally closed type hydraulic power assisting device comprises a pump body with an oil inlet and an oil return opening, a piston arranged in the pump body and a push rod piston, the piston divides an inner cavity of the pump body into an oil inlet cavity and an oil return cavity, and a concave oil passing hole is formed in one end of the piston. One end of the push rod piston extends into the oil passing hole, the oil passing hole can be communicated with one of the oil inlet cavity and the oil return cavity when the push rod piston axially moves, a concave connecting cavity is formed in the other side of the pump body, the other end, opposite to the push rod piston, of the piston is a connecting end, and an annular sealing piece is arranged in the pump body. The oil return cavity and the connecting cavity are located on the two sides of the sealing piece, the piston and the pump body are always kept sealed through the sealing piece, and the end portion of the connecting end penetrates through the sealing piece and extends into the connecting cavity. The normally closed type hydraulic power assisting device has the advantage of being convenient to replace.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical technology and relates to a normally closed hydraulic power assist device. Background Technology

[0002] With the continuous development of the motor vehicle industry, vehicle usage is constantly increasing, and people's requirements for vehicle comfort and safety are also constantly rising. The clutch and braking system of a vehicle plays a very important role in the process of vehicle use, and the brake pump is a device used to assist in the operation of the vehicle's braking system.

[0003] Existing brake pumps generally include normally open brake pumps and normally closed brake pumps. A normally open brake pump means that when the brake pump is in its default state, that is, when the brake is not applied, its inlet and outlet ports are connected to achieve oil circulation; conversely, a normally closed brake pump means that the inlet and outlet ports of the brake pump are not directly connected.

[0004] A brake pump typically consists of a pump body, a piston housed within the pump body, and a push rod at the outer end for connection with the vehicle pedal. The piston divides the pump body into an inlet chamber and a return chamber. The pump body has an inlet port and a return port that communicate with the inlet chamber and the return chamber, respectively. The piston also has an oil passage that connects the inlet chamber and the return chamber. The inner end of the push rod extends into the oil passage of the pump body.

[0005] However, different usage requirements necessitate different specifications of brake pumps. Since existing brake pumps are all complete integrated structures, if a different brake pump needs to be replaced, all the oil lines connected to it must be blocked and the entire brake pump must be removed for replacement. This not only results in high replacement costs but also inconvenience. Utility Model Content

[0006] The purpose of this invention is to address the aforementioned problems in the existing technology by proposing a normally closed hydraulic power assist device, which solves the problem of inconvenient replacement of existing brake pumps.

[0007] The objective of this utility model can be achieved through the following technical solutions:

[0008] A normally closed hydraulic power steering device includes a pump body with an oil inlet and an oil return port, a piston disposed within the pump body, and a push rod piston extending into the pump body from one side. The piston divides the internal cavity of the pump body into an oil inlet chamber communicating with the oil inlet and a oil return chamber communicating with the oil return port. One end of the piston facing the push rod piston has a recessed oil passage hole that communicates with the oil inlet and oil return chambers. One end of the push rod piston extends into the oil passage hole, and when the push rod piston moves axially, the oil passage hole communicates with one of the oil inlet and oil return chambers. The device is characterized in that the other side of the pump body has a recessed connecting cavity, the other end of the piston relative to the push rod piston is a connecting end, and the pump body is provided with an annular seal. The oil return chamber and the connecting cavity are located on opposite sides of the seal, and the seal maintains a seal between the piston and the pump body at all times. The end of the connecting end passes through the seal and extends into the connecting cavity.

[0009] When installing this normally closed hydraulic power assist device, align the connecting cavity of the pump body with the force input position of the braking system or clutch system, and fix or movably connect the connecting end of the piston to the input component of the braking system or clutch system.

[0010] When not braking, the position of the push rod piston blocks the oil passage from the oil inlet chamber and connects the oil passage from the oil return chamber, allowing oil in the oil passage to drain to the oil return port and reducing the resistance to the push rod piston's inward movement. During braking, the push rod piston moves into the pump body, blocking the oil passage from the oil return chamber, stopping oil leakage, and connecting the oil passage from the oil inlet chamber. This allows oil entering from the oil inlet to enter the oil passage, providing hydraulic assistance for the piston's movement. This pushes the piston towards the connecting chamber, extending the connecting end towards the connecting chamber, thus moving the input components in the braking or clutch system and driving the braking or clutch system to perform the corresponding operations. After operation, the push rod piston and piston can return to their original positions.

[0011] In this normally closed hydraulic power steering device, the seal is different from the one-way seal of the piston cup. Instead, it keeps the piston and pump body sealed at all times. This blocks the oil passage between the connecting chamber and the return oil chamber, making them independent of each other. That is, there is no oil in the connecting chamber, which allows this normally closed hydraulic power steering device to be mechanically connected to the braking system or clutch system as a hydraulic power steering component. Even if the normally closed hydraulic power steering device needs to be replaced, there is no need to consider the oil passage interruption or sealing at the connection point, making replacement more convenient.

[0012] In the aforementioned normally closed hydraulic power assist device, the pump body has an inwardly protruding, annular shoulder. The connecting cavity and the return oil cavity are located on opposite sides of the shoulder, respectively. The connecting end passes through the shoulder, and the seal is fixed to the inner circumference of the shoulder. The shoulder design reduces the diameter, facilitating the insertion of the connecting end and ensuring proper sealing.

[0013] In the aforementioned normally closed hydraulic power assist device, the shoulder has an annular protrusion at one end facing the return oil chamber. An annular groove is formed between the outer side of the protrusion and the inner wall of the pump body. A return spring, sleeved on the outside of the piston, is also installed inside the return oil chamber. One end of the return spring abuts against the bottom of the groove, and the other end abuts against the piston. The annular protrusion at one end of the shoulder serves two purposes: extending the axial length of the shoulder and improving the stability of the guide and seal at the connection end; and forming a groove on the outer side of the protrusion to limit the movement of one end of the return spring.

[0014] In the normally closed hydraulic power steering device described above, the number of seals is at least two and they are distributed along the axial direction of the shoulder. Multiple seals provide multiple seals, improving the sealing effect and facilitating connection at the joint.

[0015] In the aforementioned normally closed hydraulic power steering device, there is a connection gap between the outer side of the connecting end and the sidewall of the connecting cavity, and the end face of the connecting end is an arc-shaped surface. The presence of the connection gap allows the braking system or clutch system to be partially embedded in the pump body and connected to the connecting end, making the overall structure more compact and the connection more stable.

[0016] In the aforementioned normally closed hydraulic power assist device, the piston is provided with a side hole 1 communicating with the oil return chamber and a side hole 2 communicating with the oil inlet chamber through the side wall of the oil passage. The outer side of one end of the push rod piston has a protruding annular sealing part 1 and a sealing part 2. The sealing part 1 and the sealing part 2 are spaced apart, and their outer sides abut against the side wall of the oil passage to form a seal. An ejector spring is also provided between the push rod piston and the piston. The push rod piston can move out of the pump body under the elastic force of the ejector spring, so that the sealing part 1 and the sealing part 2 are located on both sides of the side hole 2 and the sealing part 1 is located between the side hole 1 and the side hole 2. When the push rod piston moves into the pump body against the elastic force of the ejector spring until it abuts against the piston, the sealing part 1 and the sealing part 2 are located on both sides of the side hole 1 and the sealing part 2 is located between the side hole 1 and the side hole 2. The positional relationship between the sealing part 1, sealing part 2, side hole 1, and side hole 2 mentioned here refers to their relative positional relationship in the axial direction of the push rod piston. In the default state, the push rod piston moves outward under the elastic force of the ejection spring, and sealing part 1 and sealing part 2 form a seal with the oil passage sidewalls on both sides of side hole 2, blocking the communication between side hole 2 and oil passage. Thus, the oil inlet and oil passage are not connected. At the same time, sealing part 1 is located between side hole 1 and side hole 2, that is, side hole 1 is not blocked, allowing side hole 1 to connect the return oil chamber and oil passage for oil drainage. Conversely, when the push rod piston moves inward, side hole 1 is blocked, and side hole 2 connects the oil inlet chamber and oil passage, initiating oil intake braking.

[0017] In the aforementioned normally closed hydraulic power steering device, a recessed axial hole is provided at one end of the push rod piston, and a radial hole communicating with the axial hole is provided through the side of the push rod piston. The opening of the radial hole is located on the outer side of the push rod piston, opposite to the side hole one. The axial hole and the radial hole allow the oil flowing into the side hole two to be sent to the oil passage hole during braking. After braking, the oil in the axial hole and the radial hole can be discharged into the return oil chamber through the side hole two together with the oil in the oil passage hole.

[0018] Compared with existing technologies, in this normally closed hydraulic power steering device, the seal is different from the one-way seal of the piston cup. Instead, it keeps the piston and pump body in a sealed state at all times. This blocks the oil passage between the connecting chamber and the return oil chamber, making them independent of each other. That is, there is no oil in the connecting chamber, which allows this normally closed hydraulic power steering device to be mechanically connected to the braking system or clutch system as a hydraulic power steering component. Even if the normally closed hydraulic power steering device needs to be replaced, there is no need to consider the oil passage interruption and sealing issues at the connection point, making replacement more convenient. Attached Figure Description

[0019] Figure 1 This is a cross-sectional structural schematic diagram of this normally closed hydraulic power assist device.

[0020] In the diagram, 1. Pump body; 1a. Oil inlet; 1b. Oil return port; 1c. Oil inlet chamber; 1d. Oil return chamber; 1e. Connecting chamber; 1f. Shoulder; 1g. Protrusion; 1h. Groove; 2. Piston; 2a. Oil passage hole; 2b. Connecting end; 2c. Side hole one; 2d. Side hole two; 3. Push rod piston; 3a. Sealing part one; 3b. Sealing part two; 3c. Axial hole; 3d. Radial hole; 4. Seal; 5. Return spring; 6. Ejection spring. Detailed Implementation

[0021] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0022] like Figure 1 As shown, this normally closed hydraulic power assist device includes a pump body 1 with an oil inlet 1a and an oil return port 1b on the side, a piston 2 disposed in the pump body 1, and a push rod piston 3 that passes through the pump body 1 from one side. The piston 2 divides the inner cavity of the pump body 1 into an oil inlet chamber 1c that communicates with the oil inlet 1a and an oil return chamber 1d that communicates with the oil return port 1b.

[0023] The piston 2 has a recessed oil passage hole 2a at one end facing the push rod piston 3. The piston 2 has a side hole 2c that communicates with the oil return chamber 1d and a side hole 2d that communicates with the oil inlet chamber 1c at the side wall of the oil passage hole 2a. When the push rod piston 3 extends into the oil passage hole 2a and moves axially, the oil passage hole 2a can be connected to one of the oil inlet chamber 1c and the oil return chamber 1d.

[0024] Specifically, the outer side of one end of the push rod piston 3 has two annular protrusions, a first sealing part 3a and a second sealing part 3b. The first sealing part 3a and the second sealing part 3b are spaced apart, and their outer sides abut against the side wall of the oil passage hole 2a to form a seal. A push-out spring 6 is also provided between the push rod piston 3 and the piston 2. One end of the push-out spring 6 abuts against the bottom of the oil passage hole 2a, and the other end abuts against the push rod piston 3. Here, in the axial direction of the push rod piston 3, the distance between the sealing part 3a and the sealing part 3b is approximately the same as the distance between the side hole 2c and the side hole 2d. The push rod piston 3 can move outward from the pump body 1 under the elastic force of the ejector spring 6, so that the sealing part 3a and the sealing part 3b are located on both sides of the side hole 2d and the sealing part 3a is located between the side hole 2c and the side hole 2d. When the push rod piston 3 moves into the pump body 1 against the piston 2, the sealing part 3a and the sealing part 3b are located on both sides of the side hole 2c and the sealing part 3b is located between the side hole 2c and the side hole 2d.

[0025] In this embodiment, the piston 2 consists of two parts, namely, part one and part two. Part one has a recessed hole at the end facing the push rod piston 3. Part two is cylindrical, and both parts one and two have retaining edges to prevent them from separating. The recessed hole of part one and the inner hole of part two together form an oil passage hole 2a. An annular retaining ring is fixed on the inner side of the end of part two away from part one to prevent the push rod piston 3 from falling out. A recessed axial hole 3c is opened at one end of the push rod piston 3, and a through hole 3c is opened on the side of the push rod piston 3. The radial hole 3d is connected to the push rod piston 3, and the orifice of the radial hole 3d is located on the other side of the side hole 2d relative to the side hole 2c. Both the sealing part 1 3a and the sealing part 2 3b include a convex ring and a sealing ring. The outer side of the two convex rings is provided with a recessed annular sealing groove. The sealing ring is correspondingly set in the two sealing grooves and extends out of the sealing grooves and abuts against the side wall of the oil passage hole 2a to form a seal. A cylindrical cylinder liner is fixed on the pump body 1 for the push rod piston 3 to pass through. The outer end of the push rod piston 3 passes through the cylinder liner and out of the pump body 1.

[0026] The pump body 1 has a recessed connecting cavity 1e on the other side. The piston 2 is connected to the other end of the push rod piston 3 as a connecting end 2b. A ring-shaped sealing element 4 is provided between the outer side of the connecting end 2b and the inner wall of the pump body 1. The sealing element 4 keeps the piston 2 and the pump body 1 sealed at all times. The end of the connecting end 2b passes through the sealing element 4 and extends into the connecting cavity 1e.

[0027] In this embodiment, the pump body 1 has an inwardly protruding annular shoulder 1f, the connecting cavity 1e and the oil return cavity 1d are located on both sides of the shoulder 1f, the connecting end 2b passes through the inner hole of the shoulder 1f, and the sealing member 4 is disposed between the inner side of the shoulder 1f and the outer side of the connecting end 2b. Here, the shoulder 1f has a protruding annular protrusion 1g at one end facing the return oil chamber 1d. The inner wall of the protrusion 1g is flush with the inner wall of the shoulder 1f. An annular groove 1h is formed between the outer side of the protrusion 1g and the inner wall of the pump body 1. A return spring 5 is also provided in the return oil chamber 1d, which is sleeved on the outside of the piston 2. One end of the return spring 5 abuts against the bottom of the groove 1h, and the other end abuts against the piston 2. The number of the above-mentioned sealing elements 4 is at least two and they are distributed along the axial direction of the shoulder 1f. At least two sealing elements 4 are respectively fixed in several grooves 1h in the inner wall of the shoulder 1f. There is a connection gap between the outer side of the connecting end 2b and the side wall of the connecting cavity 1e. The end face of the connecting end 2b is an arc-shaped surface.

[0028] When installing this normally closed hydraulic power assist device, the connecting cavity 1e of the pump body 1 should be aligned with the force input position of the braking system or clutch system, and the connecting end 2b of the piston 2 should be fixedly or movably connected to the input component of the braking system or clutch system.

[0029] When not braked, the push rod piston 3 moves outward under the elastic force of the ejection spring 6. The sealing part 3a and the sealing part 3b are located on both sides of the side hole 2d, blocking the oil passage 2a from the oil inlet chamber 1c. This allows the oil passage 2a to be connected to the oil return chamber 1d through the side hole 2c, so that the oil in the oil passage 2a, the axial hole 3c and the radial hole 3d can be discharged to the oil return port 1b, reducing the resistance to the inward movement of the push rod piston 3.

[0030] During braking, the outer end of the push rod piston 3 is subjected to the stepping force applied by the user, moving into the pump body 1 until the inner end of the push rod piston 3 abuts against the piston 2. The sealing part 3a and the sealing part 3b move to both sides of the side hole 2c, blocking the oil passage 2a from the oil return chamber 1d, stopping the oil leakage. The side hole 2d is then released, allowing the oil passage 2a to connect with the oil inlet chamber 1c through the side hole 2d. This allows the oil entering from the oil inlet 1a to pass through the side hole 2d, the radial hole 3d, and the axial hole 3c in sequence into the oil passage 2a, providing hydraulic assistance for the movement of the piston 2. This pushes the piston 2 towards the connecting chamber 1e, that is, the connecting end 2b extends towards the connecting chamber 1e, to push the input component in the braking system or clutch system to move, thereby driving the braking system or clutch system to perform the corresponding work.

[0031] After the work is completed, the push rod piston 3 and piston 2 can be reset under the elastic force of the ejection spring 6 and the return spring 5.

[0032] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A normally closed hydraulic power assist device, comprising a pump body (1) having an oil inlet (1a) and an oil return port (1b), a piston (2) disposed within the pump body (1), and a push rod piston (3) extending into the pump body (1) from one side of the pump body (1), wherein the piston (2) divides the inner cavity of the pump body (1) into an oil inlet chamber (1c) communicating with the oil inlet (1a) and an oil return chamber (1d) communicating with the oil return port (1b), wherein one end of the piston (2) facing the push rod piston (3) has a recessed oil passage hole (2a) that can communicate with the oil inlet chamber (1c) and the oil return chamber (1d), and one end of the push rod piston (3) extends into the oil passage hole (2a) and, when the push rod piston (3) moves axially, the oil passage hole (2a) can communicate with one of the oil inlet chamber (1c) and the oil return chamber (1d), characterized in that, The pump body (1) has a recessed connecting cavity (1e) on the other side. The piston (2) is connected at the other end relative to the push rod piston (3) (2b). The pump body (1) is provided with a ring-shaped seal (4). The oil return cavity (1d) and the connecting cavity (1e) are located on both sides of the seal (4) and the seal (4) keeps the piston (2) and the pump body (1) sealed at all times. The end of the connecting cavity (2b) passes through the seal (4) and extends into the connecting cavity (1e).

2. The normally closed hydraulic power assist device according to claim 1, characterized in that, The pump body (1) has an inwardly protruding annular shoulder (1f), the connecting cavity (1e) and the oil return cavity (1d) are located on both sides of the shoulder (1f), the connecting end (2b) passes through the shoulder (1f), and the sealing element (4) is fixed to the inner circumference of the shoulder (1f).

3. The normally closed hydraulic power assist device according to claim 2, characterized in that, The shoulder (1f) has a protruding annular protrusion (1g) at one end facing the oil return chamber (1d). An annular groove (1h) is formed between the outer side of the protrusion (1g) and the inner wall of the pump body (1). A return spring (5) is also provided in the oil return chamber (1d) and sleeved on the outside of the piston (2). One end of the return spring (5) abuts against the bottom of the groove (1h) and the other end abuts against the piston (2).

4. The normally closed hydraulic power assist device according to claim 3, characterized in that, The number of the seals (4) is at least two and they are distributed along the axial direction of the shoulder (1f).

5. The normally closed hydraulic power assist device according to any one of claims 1 to 4, characterized in that, There is a connection gap between the outer side of the connecting end (2b) and the side wall of the connecting cavity (1e), and the end face of the connecting end (2b) is an arc-shaped surface.

6. The normally closed hydraulic power assist device according to any one of claims 1 to 4, characterized in that, The piston (2) is provided with a side hole (2c) communicating with the oil return chamber (1d) and a side hole (2d) communicating with the oil inlet chamber (1c) through the side wall of the oil passage (2a). The outer side of one end of the push rod piston (3) has a sealing part (3a) and a sealing part (3b) that are both annular protrusions. The sealing part (3a) and the sealing part (3b) are spaced apart and their outer sides abut against the side wall of the oil passage (2a) to form a seal. A push rod piston (3) and the piston (2) are also provided with a push spring (6). The piston (3) can move outward from the pump body (1) under the elastic force of the ejector spring (6), so that the sealing part one (3a) and the sealing part two (3b) are located on both sides of the side hole two (2d) and the sealing part one (3a) is located between the side hole one (2c) and the side hole two (2d). When the push rod piston (3) moves into the pump body (1) against the elastic force of the ejector spring (6) and abuts against the piston (2), the sealing part one (3a) and the sealing part two (3b) are located on both sides of the side hole one (2c) and the sealing part two (3b) is located between the side hole one (2c) and the side hole two (2d).

7. The normally closed hydraulic power assist device according to claim 6, characterized in that, The end of the push rod piston (3) has a recessed axial hole (3c), and the side of the push rod piston (3) has a radial hole (3d) that communicates with the axial hole (3c). The radial hole (3d) is located on the other side of the side hole (2d) relative to the side hole (2c) on the outer side surface of the push rod piston (3).

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