Anti-lock brake upper pump assembly

Abstract

The invention provides an anti-lock brake upper pump assembly. The anti-lock brake upper pump assembly comprises a pump support, an oil cup, a lining, a push rod, a pressure relief hole and the like. When the push rod moves, the auxiliary oil supply hole and the pressure relief hole are communicated or blocked, the multi-time snub effect is achieved, and wheel locking is avoided. By arranging the communicating oil supply hole, the circulating communicating hole, the pressure retaining valve rod and other structures, the oil flowing path is optimized, the braking response speed is increased, and the oil utilization rate is increased. Meanwhile, the design of a first limiting gasket, a reset spring, teeth and the like is adopted, and the stability and reliability of the braking system are enhanced. The assembly is compact in structure, good in braking effect and suitable for various vehicle braking systems.

Description

Technical Field

[0001] The present invention particularly relates to an anti-lock brake upper pump assembly. Background Art

[0002] The motorcycle handlebars are equipped with a brake pump, which generates pressure through the hydraulic system to push the brake oil to flow, so that the brake pads contact the wheel hub or brake disc to achieve the purpose of deceleration or stopping. The pump is usually composed of a handlebar and an internal piston. When the rider presses the brake handle, the piston pushes the brake oil downward, and the pressure is gradually transmitted to the brake line, so that the brake pads are close to the wheel hub and inhibit the rotation of the wheel hub.

[0003] For example, the Chinese invention patent application document with the publication number of "CN103213571A" discloses a buffer-type brake push rod structure for a vehicle, which is mainly composed of two modules: a brake master cylinder and a brake push rod, wherein the brake push rod is composed of a push rod cylinder, a brake push rod, a brake push rod piston, three groups of springs, and at least three groups of O-rings (equivalent to sealing rings). The brake push rod is designed as a hydraulic cylinder structure, and the interior of the brake push rod is provided with first to fourth stage chambers. The first stage chamber accommodates the first spring and provides elastic buffering. The second stage chamber accommodates the brake push rod piston, the end face is adjacent to the first spring, and an oil channel is arranged axially to allow brake oil to enter. The third stage chamber accommodates the oil valve rod, the end face is adjacent to the brake push rod piston, a flange is arranged at a section of the oil valve rod, and a second spring is arranged between the flange and the brake push rod piston. The fourth stage chamber accommodates a bushing, which is sleeved on the outer edge of the oil valve rod, and the inner edge and the outer edge are respectively provided with a first ring groove and a second ring groove, and a first O-ring and a second O-ring are embedded to prevent brake oil leakage. When the brake pedal is pressed, the brake push rod works as a hydraulic cylinder, allowing brake oil to enter through the oil channel. The oil valve rod generates impedance to the brake oil circuit. After overcoming the impedance, it pushes the push end of the brake master cylinder to realize the braking function.

[0004] However, the buffer type brake push rod structure has the following technical problems: First, when the brake push rod is pushed inward, the oil pressure between the brake master cylinder and the brake push rod will gradually increase. Once the oil pressure reaches a critical point, the brake push rod cannot move forward. Since the brake push rod is designed as a hydraulic cylinder, and its interior contains a multi-stage chamber and spring structure, at this time, the oil will successively push the first spring, brake push rod piston, second spring, oil valve rod, bushing, third spring (according to the attached document of the public document) in the brake push rod. Figure 3 ), thereby increasing the volume between the master brake cylinder and the brake push rod to reduce the oil pressure. This is a pressure-maintaining function and only plays a buffering role. Therefore, the braking function cannot be performed during a single step on the brake in this solution.

[0005] Secondly, the pressure-maintaining function of the brake push rod is also limited, that is, once the "first spring, brake push rod piston, second spring, oil valve stem, bushing, and third spring" are moved to a position where they cannot move anymore, there is still a high probability that the wheels will lock, and safety is poor. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide an anti-lock brake upper pump assembly in view of the deficiencies of the above-mentioned prior art, and to achieve multiple braking effects by setting up several groups of pressure relief holes and auxiliary oil supply holes, thereby avoiding wheel locking and improving the overall safety of the vehicle.

[0007] To achieve the above object, the present invention provides the following technical solutions: An anti-lock brake upper pump assembly comprises a pump bracket and an oil cup installed above the pump bracket, a main oil chamber is provided in the pump bracket, a side wall of the main oil chamber is provided with a main oil supply hole that can connect the oil cup with the main oil chamber, and the characteristic is that: a bushing fixedly connected to the pump bracket is provided in the main oil chamber, a piston chamber arranged axially is penetrated in the bushing, a push rod is provided in the piston chamber, an oil return chamber is provided at the inner end of the push rod, an auxiliary oil supply hole communicating with the oil return chamber is penetrated on the side wall of the push rod, a plurality of groups of pressure relief holes arranged in sequence along the axial direction are penetrated on the side wall of the bushing, two ends of the bushing are sealed with the pump bracket, and the middle part is gap-fitted with the pump bracket; when the push rod moves back and forth axially in the piston chamber, the auxiliary oil supply hole moves back and forth along the line connecting the center points of the plurality of groups of pressure relief holes, thereby making the auxiliary oil supply hole and the pressure relief hole conductive or blocked.

[0008] (I) In this technical solution, when the push rod is not in operation, the auxiliary oil supply hole will be connected to a group of pressure relief holes at the end, and the oil in the oil cup will flow into the return oil chamber through the main oil supply hole, the pressure relief hole at the end, and the auxiliary oil supply hole in turn, and fill the main oil chamber. During the braking process, the push rod will move inward, and the oil pressure in the main oil chamber will gradually increase. Whenever the push rod moves to the auxiliary oil supply hole and a group of pressure relief holes, the excessive oil pressure in the main oil chamber and the return oil chamber will squeeze the oil along the auxiliary oil supply hole, the pressure relief hole, and the main oil supply hole to flow back into the oil cup, playing the role of braking. During this period, since the bushing and the pump bracket are clearance-matched, any group of pressure relief holes always maintains communication with the main oil supply hole, but the two ends of the bushing are sealed, and the auxiliary oil supply hole will only be connected to the group of pressure relief holes when it moves to the corresponding group of pressure relief holes, thereby forming a braking effect. By setting up several groups of pressure relief holes, the effect of multiple braking can be achieved. (ii) Compared with the prior art, this solution allows the oil to flow directly back into the oil cup each time the brakes are applied (i.e. when the auxiliary oil supply hole is connected to a set of pressure relief holes), rather than through a structure or space with an extreme deformation such as an extrusion spring. The pressure relief holes can adaptively change the pressure relief amount based on the change in oil pressure in the main oil chamber by using the pressure difference, thereby avoiding locking and improving the overall safety of the vehicle.

[0009] The above-mentioned anti-lock brake upper pump assembly can be further configured as follows: a connecting oil supply hole is penetrated through the side wall of the bushing corresponding to the main oil supply hole, one end of the connecting oil supply hole is connected to the main oil supply hole, and the inner diameter of the connecting oil supply hole is larger than the inner diameter of the pressure relief hole.

[0010] In this technical solution, when the push rod is not working, the auxiliary oil supply hole will be connected to the connecting oil supply hole (this solution no longer uses the pressure relief hole at the end as the oil inlet channel), and the oil in the oil cup will flow into the return oil chamber through the main oil supply hole, the connecting oil supply hole, and the auxiliary oil supply hole in turn, and fill the main oil chamber. The connecting oil inlet hole has a larger inner diameter and a larger oil intake, which can ensure that the main oil chamber is full of oil, shorten the braking response time, reduce the vehicle speed more quickly, and improve driving safety. Because the oil flows more smoothly, the wear of components and heat accumulation caused by poor oil flow are reduced. This helps to extend the service life of the brake system and reduce the degradation of braking performance due to overheating.

[0011] The above-mentioned anti-lock brake upper pump assembly can be further configured as follows: the push rod and the bushing are clearance-fitted, the outer periphery of the push rod close to the inner end of the piston cavity is connected to a first sealing ring, the outer periphery of the push rod close to the outer end of the piston cavity is connected to a second sealing ring, two groups of third sealing rings arranged in sequence along the axial direction of the push rod are provided between the first sealing ring and the second sealing ring, the auxiliary oil supply hole is located between the two groups of third sealing rings, and the side wall of the bushing is also penetrated by a circulation connecting hole, and the circulation connecting hole is distributed between the second sealing ring and the third sealing ring.

[0012] There is a clearance fit between the push rod and the bushing, and the oil in the oil cup flows into the gap between the push rod and the bushing along the main oil supply hole, the gap between the bushing and the pump bracket, the circulation connecting hole or the pressure relief hole. Due to the position distribution of the first sealing ring, the second sealing ring, and the two sets of third sealing rings, the oil will not enter the main oil chamber and the return oil chamber at will. During the reciprocating movement of the push rod, only when the auxiliary oil supply hole is connected with the connecting oil supply hole or the pressure relief hole, the oil in the main oil chamber and the return oil chamber will flow back to the oil cup, or flow from the oil cup to the main oil chamber and the return oil chamber. At the same time, the setting of the circulation connecting hole allows the oil to circulate in the gap between the bushing and the pump bracket, and the gap between the push rod and the bushing, which not only helps to balance the oil pressure of each part, but also can timely discharge or replenish the excess oil to the required position during the reciprocating movement of the push rod, thereby improving the utilization rate of the oil and the response speed of the braking system.

[0013] The above-mentioned anti-lock brake upper pump assembly can be further configured as follows: a pressure-maintaining valve stem is provided in the oil return chamber, one end of the pressure-maintaining valve stem is linked to a pressure-maintaining spring, the end of the pressure-maintaining spring away from the pressure-maintaining valve stem is in contact with the inner end of the oil return chamber, the inner wall of the oil return chamber is provided with a limit retaining ring protruding toward the center line of the oil return chamber, the outer periphery of the end of the pressure-maintaining valve stem away from the pressure-maintaining spring is connected to a pressure-maintaining rubber ring, the outer diameter of the pressure-maintaining rubber ring is larger than the inner diameter of the limit retaining ring and the outer diameter of the pressure-maintaining rubber ring is smaller than the inner diameter of the oil return chamber, and the auxiliary oil supply holes are distributed on the inner end side wall of the oil return chamber.

[0014] During the braking process, the push rod will move inward, and the oil pressure in the main oil chamber will gradually increase. The oil in the main oil chamber will squeeze the pressure-maintaining valve stem, and the pressure-maintaining valve stem will squeeze the pressure-maintaining spring. As long as the pressure-maintaining rubber ring does not hold up the limit retaining ring, the oil can still flow along the main oil chamber, the return oil chamber, and the auxiliary oil supply hole. Whenever the push rod moves to the auxiliary oil supply hole and a group of pressure relief holes are connected, the excessive oil pressure in the main oil chamber and the return oil chamber will squeeze the oil back to the oil cup along the auxiliary oil supply hole, the pressure relief hole, and the main oil supply hole, which plays a role in braking. When the oil pressure increases to the point where the pressure-maintaining valve stem moves to the point where the pressure-maintaining rubber ring holds up the limit retaining ring, the oil will no longer flow back. Continue to push the push rod, and the pressure-maintaining rubber ring will pass through the limit retaining ring under greater pressure, and the oil can keep flowing at this time. When the braking stops, the pressure-maintaining spring pushes the pressure-maintaining valve stem to reset, and the pressure-maintaining rubber ring also follows the pressure-maintaining valve stem through the limit retaining ring and returns to the initial position. In summary, by designing the pressure-maintaining valve stem, limit retaining ring, pressure-maintaining rubber ring and other structures, the necessary oil pressure is maintained while preventing the wheel from locking due to excessive oil pressure, thereby enhancing the pressure-maintaining function of the brake system. The purpose of the outer diameter of the pressure-maintaining rubber ring being larger than the inner diameter of the limit retaining ring and the outer diameter of the pressure-maintaining rubber ring being smaller than the inner diameter of the oil return chamber is that as long as the pressure-maintaining rubber ring does not press against the limit retaining ring, the oil can flow.

[0015] The above-mentioned anti-lock brake upper pump assembly can be further configured as follows: a first mounting ring groove is provided at the open end of the oil return chamber, a first limiting washer is fixed in the first mounting ring groove, and a plurality of groups of spaced-apart stoppers are provided on the inner periphery of the first limiting washer.

[0016] When braking is stopped and the pressure-maintaining spring pushes the pressure-maintaining valve stem to reset, the block on the first limit retaining ring limits the pressure-maintaining valve stem to avoid excessive reset, thereby ensuring that the "pressure-maintaining" function is stably implemented.

[0017] The above-mentioned anti-lock brake upper pump assembly can be further configured as follows: a return spring is provided in the main oil chamber, one end of the return spring is in contact with the pump bracket, a limiting step is provided on the outer periphery of the inner end of the push rod, and the other end of the return spring is in contact with the limiting step.

[0018] When braking stops, the return spring can help the push rod to return to its original position faster, thus speeding up the braking response and improving safety performance.

[0019] The above-mentioned anti-lock brake upper pump assembly can be further configured as follows: a tooth is provided on the outer periphery of the end of the bushing away from the main oil chamber, and the tooth is inclined toward the side away from the main oil chamber; a second mounting ring groove is provided on the pump bracket corresponding to the end of the bushing, and a second limit retaining ring is fixed in the second mounting ring groove, and the inner diameter of the second limit retaining ring is smaller than the outer diameter of the bushing.

[0020] By adopting the above technical solution, the teeth are arranged obliquely to avoid the bushing from moving when the push rod is reset, thereby improving the connection reliability between the bushing and the pump bracket. The second limit ring is used to position the bushing for installation.

[0021] The present invention is further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is an exploded schematic diagram of an embodiment of the present invention; Figure 2 It is a partial schematic cross-sectional view of an embodiment of the present invention; Figure 3 It is an exploded schematic diagram of a push rod and a bushing according to an embodiment of the present invention; Figure 4 It is a schematic diagram of the assembly of the push rod and the bushing according to an embodiment of the present invention; Figure 5 It is a cross-sectional schematic diagram of the push rod and bushing after assembly according to an embodiment of the present invention.

[0023] Reference numerals: pump bracket 1, main oil chamber 1a, main oil supply hole 1b; oil cup 2; bushing 3, piston chamber 3a, pressure relief hole 3b, connecting oil supply hole 3c, circulation connecting hole 3d, tooth 3e; push rod 4, oil return chamber 4a, auxiliary oil supply hole 4b, limit retaining ring 4c, limit step 4d, second limit washer 4f; first sealing ring 5, second sealing ring 6, third sealing ring 7, pressure maintaining valve stem 8, pressure maintaining spring 9, pressure maintaining rubber ring 10, first limit washer 11, block 12, return spring 13. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] like Figures 1 to 5 The anti-lock brake upper pump assembly shown includes a pump bracket 1 and an oil cup 2 installed above the pump bracket 1. The pump bracket 1 is provided with a main oil chamber 1a, and the side wall of the main oil chamber 1a is provided with a main oil supply hole 1b that can connect the oil cup 2 with the main oil chamber 1a. The main oil chamber 1a is provided with a bushing 3 fixedly connected to the pump bracket 1, and the bushing 3 is penetrated with a piston chamber 3a arranged in the axial direction, and a push rod 4 is provided in the piston chamber 3a. The inner end of the push rod 4 is provided with an oil return chamber 4a, and the side wall of the push rod 4 is penetrated with an auxiliary oil supply hole 4b connected with the oil return chamber 4a. The side wall of the bushing 3 is penetrated with 4 groups of pressure relief holes 3b arranged in sequence along the axial direction, and the two ends of the bushing 3 are sealed with the pump bracket 1, and the middle part is clearance-matched with the pump bracket 1. The side wall of the bushing 3 is penetrated with a connecting oil supply hole 3c corresponding to the main oil supply hole 1b, and one end of the connecting oil supply hole 3c is connected with the main oil supply hole 1b. The inner diameter of the connecting oil supply hole 3c is larger than the inner diameter of the pressure relief hole 3b, and the oil intake is larger, which can ensure that the main oil chamber 1a is full of oil, shorten the braking response time, reduce the vehicle speed more quickly, and improve driving safety.

[0026] When the push rod 4 is not in operation, the auxiliary oil supply hole 4b is connected to the connecting oil supply hole 3c, and the oil in the oil cup 2 flows into the return oil chamber 4a through the main oil supply hole 1b, the connecting oil supply hole 3c, and the auxiliary oil supply hole 4b in sequence, and fills the main oil chamber 1a. When the push rod 4 moves axially in the piston chamber 3a, the auxiliary oil supply hole 4b moves back and forth along the center point connection line of the four groups of pressure relief holes 3b, thereby connecting or blocking the auxiliary oil supply hole 4b with the pressure relief hole 3b.

[0027] The push rod 4 and the bushing 3 are clearance-matched. The outer periphery of the push rod 4 near the inner end of the piston chamber 3a is connected with a first sealing ring 5, and the outer periphery of the push rod 4 near the outer end of the piston chamber 3a is connected with a second sealing ring 6. Two groups of third sealing rings 7 arranged in sequence along the axial direction of the push rod 4 are provided between the first sealing ring 5 and the second sealing ring 6. The auxiliary oil supply hole 4b is located between the two groups of third sealing rings 7. The side wall of the bushing 3 is also penetrated by a circulation communication hole 3d, which is distributed between the second sealing ring 6 and the third sealing ring 7. The push rod 4 and the bushing 3 are clearance-matched. The oil in the oil cup 2 flows into the gap between the push rod 4 and the bushing 3 along the main oil supply hole 1b, the gap between the bushing 3 and the pump bracket 1, the circulation communication hole 3d or the pressure relief hole 3b. Due to the position distribution of the first sealing ring 5, the second sealing ring 6, and the two groups of third sealing rings 7, the oil will not enter the main oil chamber 1a and the return oil chamber 4a at will. During the reciprocating movement of the push rod 4, only when the auxiliary oil supply hole 4b is connected with the connecting oil supply hole 3c or the pressure relief hole 3b, the oil in the main oil chamber 1a and the oil return chamber 4a will flow back to the oil cup 2, or flow from the oil cup 2 to the main oil chamber 1a and the oil return chamber 4a. At the same time, the setting of the circulating connecting hole 3d allows the oil to circulate in the gap between the bushing 3 and the pump bracket 1, and the gap between the push rod 4 and the bushing 3, which not only helps to balance the oil pressure of each part, but also can timely discharge or replenish the excess oil to the required position during the reciprocating movement of the push rod 4, thereby improving the utilization rate of the oil and the response speed of the brake system.

[0028] A pressure-maintaining valve stem 8 is provided in the oil return chamber 4a, and a pressure-maintaining spring 9 is linked to one end of the pressure-maintaining valve stem 8. The end of the pressure-maintaining spring 9 away from the pressure-maintaining valve stem 8 is in contact with the inner end of the oil return chamber 4a. A limit retaining ring 4c protruding toward the center line of the oil return chamber 4a is provided on the inner wall of the oil return chamber 4a. A pressure-maintaining rubber ring 10 is connected to the outer periphery of the end of the pressure-maintaining valve stem 8 away from the pressure-maintaining spring 9. The outer diameter of the pressure-maintaining rubber ring 10 is larger than the inner diameter of the limit retaining ring 4c and the outer diameter of the pressure-maintaining rubber ring 10 is smaller than the inner diameter of the oil return chamber 4a. The auxiliary oil supply holes 4b are distributed on the inner end side wall of the oil return chamber 4a. A first mounting ring groove is provided at the open end of the oil return chamber 4a, and a first limit washer 11 is fixed in the first mounting ring groove. A plurality of groups of spaced-apart stoppers 12 are provided on the inner periphery of the first limit washer 11.

[0029] During the braking process, the push rod 4 will move inward, and the oil pressure in the main oil chamber 1a will gradually increase. The oil in the main oil chamber 1a will squeeze the pressure-maintaining valve stem 8, and the pressure-maintaining valve stem 8 will squeeze the pressure-maintaining spring 9. As long as the pressure-maintaining rubber ring 10 does not hold the limit retaining ring 4c, the oil can still flow along the main oil chamber 1a, the return oil chamber 4a, and the auxiliary oil supply hole 4b. Whenever the push rod 4 moves to the auxiliary oil supply hole 4b and connects with a group of pressure relief holes 3b, the excessive oil pressure in the main oil chamber 1a and the return oil chamber 4a will squeeze the oil along the auxiliary oil supply hole 4b, the pressure relief hole 3b, and the main oil supply hole 1b to flow back into the oil cup 2, playing the role of braking. When the oil pressure increases to the point where the pressure-maintaining valve stem 8 moves to the point where the pressure-maintaining rubber ring 10 holds the limit retaining ring 4c, the oil will no longer flow back. Continue to push the push rod 4, and the pressure-maintaining rubber ring 10 will pass through the limit retaining ring 4c under a larger pressure, and the oil can keep flowing at this time. When braking stops, the pressure-maintaining spring 9 pushes the pressure-maintaining valve stem 8 to reset, and the pressure-maintaining rubber ring 10 also follows the pressure-maintaining valve stem 8 through the limit retaining ring 4c to return to the initial position. In summary, by designing structures such as the pressure-maintaining valve stem 8, the limit retaining ring 4c, and the pressure-maintaining rubber ring 10, while maintaining the necessary oil pressure, the wheel locking caused by excessive oil pressure is prevented, and the pressure-maintaining function of the braking system is enhanced. The purpose of the outer diameter of the pressure-maintaining rubber ring 10 being larger than the inner diameter of the limit retaining ring 4c and the outer diameter of the pressure-maintaining rubber ring 10 being smaller than the inner diameter of the oil return chamber 4a is that as long as the pressure-maintaining rubber ring 10 does not support the limit retaining ring 4c, the oil can flow. When braking stops, the pressure-maintaining spring 9 pushes the pressure-maintaining valve stem 8 to reset, and the block 12 on the first limit washer 4c limits the pressure-maintaining valve stem 8 to avoid excessive reset, ensuring that the "pressure-maintaining" function is stably implemented.

[0030] A return spring 13 is provided in the main oil chamber 1a, one end of which is in contact with the pump bracket 1, and a limit step 4d is provided on the inner periphery of the push rod 4, and the other end of the return spring 13 is in contact with the limit step 4d. When braking stops, the return spring 13 can help the push rod 4 to reset faster, speed up the braking response speed, and improve safety performance.

[0031] The outer periphery of the end of the bushing 3 away from the main oil chamber 1a is provided with teeth 3e, and the teeth 3e are inclined toward the side away from the main oil chamber 1a. The pump bracket 1 is provided with a second mounting ring groove corresponding to the end of the bushing 3, and a second limiting washer 4f is fixed in the second mounting ring groove. The inner diameter of the second limiting washer 4f is smaller than the outer diameter of the bushing 3. The teeth 3e are inclined to prevent the bushing 3 from moving when the push rod 4 is reset, thereby improving the connection reliability between the bushing 3 and the pump bracket 1. The second limiting washer 4f is used to install and position the bushing 3.

[0032] Working principle of this embodiment: When the push rod 4 is not in working state, the auxiliary oil supply hole 4b will be connected with the connecting oil supply hole 3c, and the oil in the oil cup 2 will flow into the return oil chamber 4a through the main oil supply hole 1b, the connecting oil supply hole 3c, and the auxiliary oil supply hole 4b in sequence, and fill the main oil chamber 1a.

[0033] During the braking process, the push rod 4 will move inward, and the oil pressure in the main oil chamber 1a will gradually increase. The oil in the main oil chamber 1a will squeeze the pressure-maintaining valve stem 8, and the pressure-maintaining valve stem 8 will squeeze the pressure-maintaining spring 9. As long as the pressure-maintaining rubber ring 10 does not support the limit retaining ring 4c, the oil can still flow along the main oil chamber 1a, the return oil chamber 4a, and the auxiliary oil supply hole 4b.

[0034] Whenever the push rod 4 moves to the auxiliary oil supply hole 4b and connects with a group of pressure relief holes 3b, the excessive oil pressure in the main oil chamber 1a and the return oil chamber 4a will squeeze the oil along the auxiliary oil supply hole 4b, the pressure relief hole 3b, and the main oil supply hole 1b to flow back into the oil cup 2, which plays a role of braking. During this period, since the bushing 3 and the pump bracket 1 are clearance-matched, any group of pressure relief holes 3b always maintains communication with the main oil supply hole 1b, but the two ends of the bushing 3 are sealed, and the auxiliary oil supply hole 4b will only be connected with the group of pressure relief holes 3b when it moves to the corresponding group of pressure relief holes 3b, thereby forming a braking effect. By setting a plurality of groups of pressure relief holes 3b, the effect of multiple braking can be achieved.

[0035] During the movement of the push rod 4, if the oil pressure increases to the point where the pressure-maintaining valve stem 8 moves to the point where the pressure-maintaining rubber ring 10 presses against the stop ring 4c, the oil will no longer flow back. If the push rod 4 is pushed further, the pressure-maintaining rubber ring 10 will pass through the stop ring 4c under a greater pressure, and the oil can keep flowing. When the brake is stopped, the pressure-maintaining spring 9 pushes the pressure-maintaining valve stem 8 to return to its original position, and the pressure-maintaining rubber ring 10 also follows the pressure-maintaining valve stem 8 through the stop ring 4c to return to its original position.

[0036] In summary, this embodiment not only has the pressure-maintaining function, but also can realize multiple braking operations, and has high safety performance.

Claims

1. An anti-lock brake upper pump assembly, comprising a pump bracket and an oil cup installed above the pump bracket, wherein a main oil chamber is provided in the pump bracket, and a main oil supply hole is provided on the side wall of the main oil chamber for connecting the oil cup with the main oil chamber, characterized in that: The main oil chamber is provided with a bushing fixedly connected to the pump bracket, the bushing is penetrated by a piston chamber arranged axially, the piston chamber is provided with a push rod, the inner end of the push rod is provided with an oil return chamber, the side wall of the push rod is penetrated by an auxiliary oil supply hole connected to the oil return chamber, the side wall of the bushing is penetrated by a plurality of groups of pressure relief holes arranged in sequence along the axial direction, the two ends of the bushing are sealed with the pump bracket, and the middle part is clearance-fitted with the pump bracket; when the push rod moves back and forth axially in the piston chamber, the auxiliary oil supply hole moves back and forth along the line connecting the center points of the plurality of groups of pressure relief holes, thereby making the auxiliary oil supply hole and the pressure relief hole conductive or blocked.

2. The anti-lock brake upper pump assembly according to claim 1, characterized in that: A connecting oil supply hole is penetrated through the side wall of the bushing corresponding to the main oil supply hole, one end of the connecting oil supply hole is connected to the main oil supply hole, and the inner diameter of the connecting oil supply hole is larger than the inner diameter of the pressure relief hole.

3. The anti-lock brake upper pump assembly according to claim 2, characterized in that: The push rod and the bushing are clearance-fitted, the outer periphery of the push rod near the inner end of the piston cavity is connected to a first sealing ring, the outer periphery of the push rod near the outer end of the piston cavity is connected to a second sealing ring, two groups of third sealing rings arranged in sequence along the axial direction of the push rod are provided between the first sealing ring and the second sealing ring, the auxiliary oil supply hole is located between the two groups of third sealing rings, the side wall of the bushing is also penetrated by a circulation connecting hole, and the circulation connecting hole is distributed between the second sealing ring and the third sealing ring.

4. The anti-lock brake upper pump assembly according to any one of claims 1 to 3, characterized in that: A pressure-maintaining valve stem is provided in the oil return chamber, one end of the pressure-maintaining valve stem is linked with a pressure-maintaining spring, the end of the pressure-maintaining spring away from the pressure-maintaining valve stem is in contact with the inner end of the oil return chamber, the inner wall of the oil return chamber is provided with a limit retaining ring protruding toward the center line of the oil return chamber, the outer periphery of the end of the pressure-maintaining valve stem away from the pressure-maintaining spring is connected with a pressure-maintaining rubber ring, the outer diameter of the pressure-maintaining rubber ring is larger than the inner diameter of the limit retaining ring and the outer diameter of the pressure-maintaining rubber ring is smaller than the inner diameter of the oil return chamber, and the auxiliary oil supply holes are distributed on the inner end side wall of the oil return chamber.

5. The anti-lock brake upper pump assembly according to claim 4, characterized in that: The open end of the oil return cavity is provided with a first mounting ring groove, a first limiting washer is fixed in the first mounting ring groove, and a plurality of groups of stoppers arranged at intervals are provided on the inner periphery of the first limiting washer.

6. The anti-lock brake upper pump assembly according to claim 5, characterized in that: A return spring is arranged in the main oil chamber, one end of the return spring is connected in abutment with the pump bracket, a limiting step is arranged on the outer periphery of the inner end of the push rod, and the other end of the return spring is connected in abutment with the limiting step.

7. The anti-lock brake upper pump assembly according to any one of claims 1 to 3, characterized in that: The outer periphery of the end of the bushing away from the main oil chamber is provided with teeth, and the teeth are inclined toward the side away from the main oil chamber. A second mounting ring groove is provided on the pump bracket corresponding to the end of the bushing, and a second limit retaining ring is fixed in the second mounting ring groove, and the inner diameter of the second limit retaining ring is smaller than the outer diameter of the bushing.

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