A brake piston mechanism with a floating pressure relief valve and a brake upper pump thereof

Abstract

A brake piston mechanism with a floating pressure relief valve and a brake upper pump thereof, wherein the piston mechanism includes a piston member having a pressure relief chamber inside, an oil inlet passage and an oil drain hole on the piston member; a first oil seal and a second oil seal, wherein the second oil seal is located in front of the first oil seal, and the effective oil pushing area S2 of the second oil seal is smaller than the effective oil pushing area S1 of the first oil seal; a reset spring, which applies a backward elastic force to the piston member; the oil inlet passage is located between the first oil seal and the second oil seal, and the oil drain hole is located in the rear of the first oil seal; a floating pressure relief valve core, which is movably arranged in the pressure relief chamber; and a pressure relief spring, which abuts between the floating pressure relief valve core and the inner wall of the pressure relief chamber. The present invention adopts a double-piston oil seal structure with different diameters, and realizes a segmented working mode, so that the front section has a relatively large oil seal area, and the rear section has a relatively small oil seal area.

Description

Technical Field

[0001] The invention relates to a brake piston mechanism with a floating pressure relief valve and a brake upper pump thereof. Background Art

[0002] The hydraulic brake upper pump (master cylinder) is one of the key components of the hydraulic brake system. It is usually installed near the handlebars, close to the brake handle. Its main function is to convert the force applied by the rider through the brake handle into hydraulic pressure, thereby initiating the entire braking process. The working principle is: when the rider squeezes the brake handle, the force acts on the piston, and the piston moves forward (towards the brake line) in the cylinder. This movement of the piston compresses the brake fluid in the cylinder, causing the pressure of the brake fluid to increase. Since the hydraulic system is closed, according to Pascal's law, this pressure will be evenly transmitted to the entire hydraulic system, including the connected brake lines and lower pump. Under the action of pressure, the lower pump pushes the brake pads to contact the brake disc (for disc brakes) or brake drum (for drum brakes), generating friction, thereby slowing down or stopping the wheel.

[0003] Piston movement and resistance characteristics: The movement resistance of the upper pump piston also affects the brake feel. The friction between the piston and the cylinder, the elasticity of the seal and other factors determine the resistance of the piston movement. If the resistance of the piston movement is too large, the brake feel will be hard; if the resistance is too small, it may cause unstable handle travel. In addition, the movement of the lower pump piston is equally important. When the pressure is transmitted to the lower pump, the lower pump piston pushes the brake pads to contact the brake disc. The friction characteristics between the brake pads and the brake disc will also be fed back to the brake handle. For example, when the brake pads are worn to a certain extent, the contact area and friction characteristics with the brake disc change, which will cause the brake feel to change, and may make the feel soft or uneven.

[0004] However, the adjustment functions of the hydraulic brake pump in the prior art (such as the adjustment of the piston) need to be operated before use. Once the adjustment is completed and in use, its function and performance will not change. Its braking performance during use is not linear enough, that is, the front section is easy, the rear section resistance becomes significantly larger and a feeling of hitting a wall occurs.

[0005] For an ideal brake upper pump, the front section where the piston is pushed out needs to have a relatively large oil seal area, so that more brake oil can be output to the brake lower pump per unit moving distance, so that the brake pad can be quickly pushed out and contact the brake disc, and the braking effect officially begins to take effect; in the rear section where the piston is pushed out, the brake pad in the brake lower pump is infinitely close to being still (no displacement occurs). According to Pascal's principle (pressure is equal everywhere in a closed liquid, and under the same pressure, the force generated in a small area is smaller), a relatively small oil seal area is required to make the pressure on the piston end smaller (the pressure here is proportional to the oil seal area), so that the user can push the brake handle more easily, reduce the feeling of hitting the wall, and make the feel of the front and rear sections more linear. However, most of the existing brake upper pumps are single-piston (oil seal) structures, so it is impossible to achieve the effect of having a relatively large oil seal area in the front section and a relatively small oil seal area in the rear section.

[0006] In summary, the present application improves the prior art. Summary of the invention

[0007] In order to overcome the above-mentioned deficiencies in the prior art, the present invention provides a brake piston mechanism with a floating pressure relief valve and a brake upper pump thereof.

[0008] The technical solution of the present invention to solve the technical problem is: a brake piston mechanism with a floating pressure relief valve, comprising:

[0009] A piston component having a pressure relief chamber inside thereof, an oil inlet passage and an oil drain hole are provided on the piston component, and the pressure relief chamber is communicated with the outside of the piston component through the oil inlet passage and the oil drain hole respectively;

[0010] A first oil seal, wherein the piston member has a first supporting area, and the first oil seal is disposed in the first supporting area;

[0011] A second oil seal, wherein the piston member has a second supporting area, and the first oil seal is disposed in the second supporting area, wherein the second supporting area is located in front of the first supporting area, and an effective oil pushing area S2 of the second oil seal is smaller than an effective oil pushing area S1 of the first oil seal;

[0012] A return spring, which applies a rearward elastic force to the piston member;

[0013] The oil inlet passage is located between the first oil seal and the second oil seal, and the oil drain hole is located at the rear side of the first oil seal;

[0014] A floating pressure relief valve core is movably disposed in the pressure relief chamber, and the floating pressure relief valve core is located between the oil inlet channel and the oil drain hole;

[0015] The pressure relief spring abuts between the floating pressure relief valve core and the inner wall of the pressure relief chamber. The pressure relief spring acts on the floating pressure relief valve core so that the floating pressure relief valve core has a movement tendency to move forward.

[0016] Optionally, the piston member is composed of a first piston and a second piston that are detachable from each other;

[0017] The first support area, the pressure relief chamber and the oil leakage hole are arranged on the first piston;

[0018] The second supporting area and the oil inlet channel are configured on the second piston.

[0019] In some preferred embodiments of the present invention, the front end of the first piston has a first abutting end portion, the middle ring of the first piston is provided with a second abutting end portion, and the first abutting end portion abuts against the second abutting end portion to form a transmission fit;

[0020] The rear end of the second piston has an extending end portion, and the extending end portion at least partially enters into the pressure relief chamber.

[0021] In some more specific embodiments of the present invention, the brake piston mechanism further comprises a piston cylinder sleeve;

[0022] At least part of the first piston is disposed in the piston cylinder sleeve, and a limiting portion is convexly provided on the inner wall of the piston cylinder sleeve, and the limiting portion can abut against the rear end of the first piston to form a limiting stop.

[0023] Furthermore, the first piston has a first accommodating groove therein, the rear end of the floating pressure relief valve core has a second accommodating groove, the rear end of the pressure relief spring extends into the first accommodating groove, and the front end of the pressure relief spring extends into the second accommodating groove.

[0024] Regarding the sealing structure in the present invention, a first sealing ring is sleeved on the outer wall of the first piston, a second sealing ring is sleeved on the outer wall of the floating pressure relief valve core, and a third sealing ring is sleeved on the outer wall of the piston cylinder sleeve.

[0025] Another main technical solution of the present invention is a brake pump, comprising:

[0026] The brake pump body is provided with a piston chamber and an oil storage chamber, the piston chamber and the oil storage chamber are filled with brake oil, and the oil storage chamber is connected with the piston chamber through an oil return hole;

[0027] A brake handle, which is rotatably matched with the brake pump body through a pivot mechanism;

[0028] An oil pipe assembly, which is connected to the brake cylinder body and communicates with the piston chamber;

[0029] The piston chamber is provided with a brake piston mechanism with a floating pressure relief valve as described above, and the brake handle abuts against the rear end of the piston member through a rotating push mechanism to form a transmission fit.

[0030] More specifically, the piston cavity at least has a large diameter cavity section, a small diameter cavity section and a variable diameter cavity section, wherein the large diameter cavity section, the variable diameter cavity section and the small diameter cavity section are sequentially distributed and connected from back to front, and the junction of the large diameter cavity section and the variable diameter cavity section is a first critical point, and the junction of the variable diameter cavity section and the small diameter cavity section is a second critical point;

[0031] The oil return hole is opened on the large diameter cavity section;

[0032] The first oil seal is located in the large diameter cavity section, and the first oil seal forms a sealing fit with the inner wall of the large diameter cavity section when it abuts against the inner wall of the large diameter cavity section;

[0033] The second oil seal moves with the piston member; when the second oil seal is located in the large-diameter cavity section, there is a gap between the second oil seal and the inner wall of the large-diameter cavity section to form a non-sealed fit; when the second oil seal is located in the small-diameter cavity section, the second oil seal abuts against the inner wall of the small-diameter cavity section to form a sealed fit.

[0034] It should be emphasized that when the second oil seal does not abut against the inner wall of the small-diameter cavity section and the first oil seal is located in front of the oil return hole, the user continues to squeeze the brake handle, and the first oil seal pushes the brake oil toward the oil pipe assembly;

[0035] When the second oil seal abuts against the inner wall of the small-diameter cavity section, the user continues to squeeze the brake handle, and the second oil seal pushes the brake oil in front of the second oil seal toward the oil pipe assembly, and the first oil seal pushes the brake oil between the first oil seal and the second oil seal toward the floating pressure relief valve core through the oil inlet channel.

[0036] When the second oil seal is located in the rear part of the variable diameter chamber section, there is a gap between the second oil seal and the inner wall of the variable diameter chamber section to form a non-sealed fit; when the second oil seal is located in the front part of the variable diameter chamber section, the second oil seal abuts against the inner wall of the variable diameter chamber section to form a sealed fit.

[0037] The beneficial effects of the present invention are:

[0038] 1. A dual-piston oil seal structure with different diameters is adopted, and a segmented working mode is realized, so that the front section has a relatively large oil seal area, and the rear section has a relatively small oil seal area. Specifically, the first oil seal in the front middle section performs the actual oil pushing work, and the characteristic is that the effective oil pushing area S1 of the first oil seal is larger. When used in hydraulic brakes, the initial oil pushing amount can be larger, and the brake oil quickly fills some tiny gaps and deformation spaces of elastic components, and the braking effect is more quickly achieved; the second oil seal in the middle and rear sections performs the actual oil pushing work, and the characteristic is that the effective oil pushing area S2 of the second oil seal is smaller. According to Pascal's principle (pressure is equal everywhere in a closed liquid, and under the same pressure, the force generated in a small area is smaller), the pressure applied to the second oil seal in the oil circuit is relatively small, so the piston member can be pushed forward with a smaller force, so that the driving force of the piston member will not have too large a gap between the middle and rear sections and the front and middle sections, that is, the overall movement performance will be more linear.

[0039] 2. During the middle and rear stages, the pressure between the first oil seal and the second oil seal can be relieved through the floating pressure relief valve core, so that the oil pushing of the first oil seal has almost no effect on the second oil seal.

[0040] 3. The action point of the front middle section is at the first oil seal, and the action point of the middle and rear section is at the second oil seal, which are variable force arm center points. Correspondingly, when the action point changes, the force resistance and resistance arm will also change. In particular, the middle and rear section has a larger power arm L1 (conventionally, it ends at the first oil seal, and the present invention ends at the second oil seal), and the resistance arm L2 is smaller, so when the user squeezes the brake handle, only a smaller force F1 is needed, so that the user can obtain the same braking effect with less effort. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a structural schematic diagram of the brake upper pump in the present invention.

[0042] Figure 2 It is a schematic diagram of the structural comparison when the brake piston mechanism is gradually pushed forward.

[0043] Figure 3 This is an exploded view of the brake piston mechanism.

[0044] Figure 4 It is a comparative schematic diagram of the first oil seal and the second oil seal.

[0045] Figure 5 It is a vertical sectional view of the brake upper pump (the front middle section where the piston member moves) in the present invention and an enlarged view of its local structure.

[0046] Figure 6 It is a vertical sectional view of the brake upper pump in the fourth embodiment (the second oil seal abuts against the inner wall of the variable diameter cavity section) and an enlarged view of its local structure.

[0047] Figure 7 It is a vertical sectional view of the brake upper pump (the middle and rear section of the movement of the piston member) in the present invention and an enlarged view of its local structure.

[0048] Figure 8 It is a horizontal sectional view of the brake upper pump (the front middle section where the piston member moves) in the present invention and an enlarged view of its local structure.

[0049] Fig. 9 It is a horizontal sectional view of the brake upper pump (the second oil seal abuts against the inner wall of the variable diameter cavity section) in the fourth embodiment and an enlarged view of its local structure.

[0050] Fig.10 It is a horizontal sectional view of the brake upper pump (the middle and rear section of the movement of the piston member) in the present invention and an enlarged view of its local structure.

[0051] In the figure: 1. brake pump body; 11. piston chamber; 111. large diameter chamber section; 112. small diameter chamber section; 113. variable diameter chamber section; 12. oil storage chamber; 13. oil return hole; 14. oil seal chamber; 2. brake handle; 21. pivot mechanism; 22. push-turn mechanism; 3. oil pipe assembly; 4. piston member; 41. first piston; 411. pressure relief chamber; 412. oil leakage hole; 413. first support area; 414. first abutment end ; 415, first accommodating groove; 42, second piston; 421, oil inlet channel; 422, second supporting area; 423, second abutting end; 424, extending end; 43, first oil seal; 44, second oil seal; 45, return spring; 5, floating pressure relief valve core; 51, second accommodating groove; 6, pressure relief spring; 7, piston cylinder sleeve; 71, limiting portion; 81, first sealing ring; 82, second sealing ring; 83, third sealing ring. DETAILED DESCRIPTION

[0052] 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.

[0053] Embodiment 1

[0054] Reference Figures 1 to 10A brake piston mechanism with a floating pressure relief valve comprises: a piston member 4 having a pressure relief chamber 411 inside, an oil inlet channel 421 and an oil drain hole 412 on the piston member 4, the pressure relief chamber 411 being connected to the outside of the piston member 4 through the oil inlet channel 421 and the oil drain hole 412 respectively; brake oil can flow between the inside of the pressure relief chamber 411 and the outside of the pressure relief chamber 411 (generally referring to the piston chamber 11) through the oil inlet channel 421 and the oil drain hole 412, and the flow direction of the brake oil is determined according to the internal and external pressures of the pressure relief chamber 411, and is not specifically limited. A first oil seal 43, the piston member 4 having a first support area 413, the first oil seal 43 is arranged in the first support area 413; a second oil seal 44, the piston member 4 having a second support area 422, the first oil seal 43 is arranged in the second support area 422. When the piston member 4 moves, it drives the first oil seal 43 and the second oil seal 44 to move forward, so that the brake oil is pushed forward through the first oil seal 43 and / or the second oil seal 44 .

[0055] It is worth mentioning that, referring to Figures 5 to 10 , the second support position 422 is located in front of the first support position 413, and the effective oil pushing area S2 of the second oil seal 44 is smaller than the effective oil pushing area S1 of the first oil seal 43. When working, the first oil seal 43 and the second oil seal 44 can realize different oil pushing functions according to different working conditions (associated with the distance the piston member 4 moves forward). For example, in the front and middle sections of the movement of the piston member 4, the first oil seal 43 realizes the sealing structure, so the first oil seal 43 moves forward to work and plays an actual oil pushing function. At this time, the second oil seal 44 moves forward at the same time but does not realize the sealing structure, so the second oil seal 44 does not play an actual oil pushing function; in the middle and rear sections of the movement of the piston member 4, although the first oil seal 43 and the second oil seal 44 realize the sealing structure at the same time, the second oil seal 44 is in front, so the second oil seal 44 moves forward to work and plays an actual oil pushing function, and the first oil seal 43 does not play an actual oil pushing function.

[0056] The return spring 45 in the brake piston mechanism applies a rearward elastic force to the piston member 4 so that the piston member 4 always has a movement tendency of returning to the rear.

[0057] It should be particularly emphasized that the oil inlet channel 421 is located between the first oil seal 43 and the second oil seal 44, and the oil drain hole 412 is located on the rear side of the first oil seal 43; the floating pressure relief valve core 5 is movably arranged in the pressure relief chamber 411, and the floating pressure relief valve core 5 is located between the oil inlet channel 421 and the oil drain hole 412; the pressure relief spring 6 is abutted between the floating pressure relief valve core 5 and the inner wall of the pressure relief chamber 411, and the pressure relief spring 6 acts on the floating pressure relief valve core 5 so that the floating pressure relief valve core 5 has a movement tendency to move forward. As mentioned above, in the middle and rear sections of the movement of the piston member 4, the first oil seal 43 and the second oil seal 44 simultaneously realize the sealing structure, and the oil seal chamber 14 is formed between the first oil seal 43 and the second oil seal 44, and during the forward movement of the piston member 4, the effective oil pushing area S1 of the first oil seal 43 is greater than the effective oil pushing area S2 of the second oil seal 44, which will cause the pressure in the oil seal chamber 14 to increase rapidly (in principle, the more forward movement, the more brake oil in the oil seal chamber 14). At this time, the brake oil in the oil seal chamber 14 enters the pressure relief chamber 411 through the oil inlet channel 421 after being pressurized, and transmits the pressure to the floating pressure relief valve core 5. The floating pressure relief valve core 5 retreats under pressure (the pressure is greater than the force of the pressure relief spring 6) and makes a part of the space of the pressure relief chamber 411. The brake oil overflowing from the oil seal chamber 14 enters the pressure relief chamber 411, so that the oil pressure in the oil seal chamber 14 is restored to a normal level, ensuring that the piston member 4 can be used normally in the future. On the other hand, during the retreat of the floating pressure relief valve core 5, the brake oil originally existing in the pressure relief chamber 411 (referring to the brake oil behind the floating pressure relief valve core 5) is discharged to the outside of the pressure relief chamber 411 through the oil drain hole 412, thereby ensuring the front and rear balance of the floating pressure relief valve core 5.

[0058] In general, the hydraulic brake with a conventional piston structure has a softer feel in the front part of the brake: when the hydraulic brake is just started, the brake handle 2 or pedal will have a relatively soft stroke. This is because in the hydraulic brake system, the brake oil needs to fill some tiny gaps and deformation space of the elastic components first. At the same time, the braking force gradually increases: as the brake handle 2 continues to be squeezed, the braking force begins to gradually increase. This is because the brake oil is transmitted to the brake caliper through the hydraulic pipeline under pressure, pushing the caliper piston to squeeze the brake disc. In the front part, the increase in braking force is relatively gentle, and it is roughly linear with the stroke of the handle or pedal.

[0059] The brake feels harder in the rear section: When the brake handle 2 or the pedal is squeezed to a certain extent, the feel will become noticeably harder. This is because at this time, the components in the brake system have almost no extra elastic deformation space, and the contact pressure between the piston and the brake disc is also increasing. At the same time, the pressure in the hydraulic system rises sharply, and the brake oil has very little compressibility, and transmits pressure almost like a solid. At the same time, according to Pascal's principle, the braking force rises rapidly: the increase in braking force in the rear section is more significant than that in the front section. Because at this time, the clamping force of the brake caliper on the brake disc increases nonlinearly, it can cause a large deceleration of the vehicle in a short period of time.

[0060] In summary, the unique function of the present invention is that it adopts a dual-piston oil seal structure with different diameters and realizes a segmented working mode. The details are as follows:

[0061] The first oil seal 43 in the front middle section performs the actual oil pushing work, and its characteristic is that the effective oil pushing area S1 of the first oil seal 44 is larger. When used in hydraulic brakes, the initial oil pushing amount can be larger, and the brake oil quickly fills some tiny gaps and deformation space of elastic components, thereby achieving a more rapid braking effect; the second oil seal 44 in the middle and rear section performs the actual oil pushing work, and its characteristic is that the effective oil pushing area S2 of the second oil seal 44 is smaller. According to Pascal's principle (the pressure is equal everywhere in a closed liquid, and under the same pressure, the force generated in a place with a smaller area is smaller), the pressure applied to the second oil seal 44 in the oil circuit is relatively small, and therefore the piston member 4 can be pushed forward with a smaller force, so that the pushing force of the piston member 4 will not have too large a gap between the middle and rear section and the front and middle section, that is, the overall movement performance will be more linear.

[0062] Therefore, refer to Figure 5 , Figure 8 In the middle front section, the floating pressure relief valve core 5 moves forward together with the piston member 4, that is, the floating pressure relief valve core 5 remains stationary relative to the piston member 4. Figure 7 , Fig.10 In the middle and rear stages, the pressure between the first oil seal 43 and the second oil seal 44 can be relieved through the floating pressure relief valve core 5, so that the oil pushing of the first oil seal 43 has almost no effect on the second oil seal 44. The floating pressure relief valve core 5 is under pressure, that is, the floating pressure relief valve core 5 moves backward relative to the piston member 4, and the distance between the floating pressure relief valve core 5 and the first oil seal 43 and / or the second oil seal 44 increases.

[0063] Embodiment 2

[0064] Based on the structure of the first embodiment, this embodiment provides a more preferred structural solution for some structures, specifically:

[0065] 1. Reference Figure 2 to Figure 4The piston component 4 is composed of a first piston 41 and a second piston 42 which are detachable from each other; the first support area 413, the pressure relief chamber 411 and the oil drain hole 412 are arranged on the first piston 41; the second support area 422 and the oil inlet channel 421 are arranged on the second piston 42. The structural scheme of the split piston and rear assembly (the first piston 41 and the second piston 42) is adopted. On the one hand, it is easier to process and manufacture, and reduces production costs; on the other hand, it is convenient to provide a larger operating space for the assembly of parts such as the floating pressure relief valve core 5 and the pressure relief spring 6, reduce the difficulty of the assembly process, and improve production efficiency. Of course, the structure of the split piston and rear assembly is only a preferred scheme, and the piston component 4 can also adopt an integrated structure, which is not specifically limited here.

[0066] In some preferred embodiments of the present invention, the front end of the first piston 41 has a first abutting end 414, and the middle part of the first piston 41 is ringed with a second abutting end 423, and the first abutting end 414 and the second abutting end 423 abut against each other and form a transmission fit. By setting the two abutting ends, the front end of the first piston 41 and the second piston 42 can form a larger contact area, thereby ensuring a more stable force transmission effect. On the other hand, the rear end of the second piston 42 has an insertion end 424, and the insertion end 424 at least partially enters into the pressure relief chamber 411, playing a certain limiting and guiding role, so as to prevent the second piston 42 from being displaced in a non-front-rear direction relative to the first piston 41.

[0067] 2. Reference Figure 3 , 5 ~ Fig.10 The brake piston mechanism further comprises a piston sleeve 7; wherein the first piston 41 is at least partially disposed in the piston sleeve 7, and a position limiting portion 71 is convexly provided on the inner wall of the piston sleeve 7, and the position limiting portion 71 can abut against the rear end of the first piston 41 and form a position limiting stop. The arrangement of the piston sleeve 7 mainly plays the role of supporting, position limiting protection, and motion guiding the piston member 4.

[0068] Preferably, in order to restrict the deformation process of the pressure relief spring 6 and prevent the pressure relief spring 6 from being in an unnecessary deformation state, the adopted structural solution is: the first piston 41 has a first accommodating groove 415, the rear end of the floating pressure relief valve core 5 has a second accommodating groove 51, the rear end of the pressure relief spring 6 extends into the first accommodating groove 415, and the front end of the pressure relief spring 6 extends into the second accommodating groove 51. Through the provision of the first accommodating groove 415 and the second accommodating groove 51, effective limit is formed for the two ends of the pressure relief spring 6, so that the pressure relief spring 6 can be used more stably in conjunction with the floating pressure relief valve core 5.

[0069] 3. Sealing structure: refer to Figure 3 , 5 ~ Fig.10 , a first sealing ring 81 is sleeved on the outer wall of the first piston 41, so that a sealing fit is formed between the outer wall of the first piston 41 and the inner wall of the piston cylinder sleeve 7; a second sealing ring 82 is sleeved on the outer wall of the floating pressure relief valve core 5, so that a sealing fit is formed between the outer wall of the floating pressure relief valve core 5 and the inner wall of the pressure relief chamber 411; a third sealing ring 83 is sleeved on the outer wall of the piston cylinder sleeve 7, so that a sealing fit is formed between the outer wall of the piston cylinder sleeve 7 and the inner wall of the piston chamber 11. By setting multiple sealing rings, the gaps between related parts are filled to ensure a good sealing fit, prevent oil leakage, and stabilize the internal pressure.

[0070] Embodiment 3

[0071] Another main technical solution of the present invention is a brake pump, referring to Figure 1 , 5 ~ Fig.10 , including: a brake pump body 1, which is provided with a piston chamber 11 and an oil storage chamber 12, wherein the piston chamber 11 and the oil storage chamber 12 are filled with brake oil, and the oil storage chamber 12 is connected with the piston chamber 11 through an oil return hole 13; a brake handle 2, which is rotationally matched with the brake pump body 1 through a pivot mechanism 21; an oil pipe assembly 3, which is connected to the brake pump body 1 and is connected with the piston chamber 11, and the oil pipe assembly 3 can extend to the brake lower pump; the piston chamber 11 is provided with a brake piston mechanism with a floating pressure relief valve as described above, and the brake handle 2 is abutted against the rear end of the piston member 4 through a push-turn mechanism 22 to form a transmission match.

[0072] When the user squeezes the brake handle 2, the brake handle 2 rotates around the pivot mechanism 21, and the front end of the brake handle 2 transmits the force of the user's squeezing operation to the piston member 4 through the push-turn mechanism 22, so that the piston member 4 moves forward along the piston cavity 11. When the user releases the brake handle 2, the piston member 4 automatically resets backward under the action of the reset spring 45 and the oil pressure.

[0073] It should be noted that when the first oil seal 43 moves in the space between the initial position and the oil return hole 13, the forward movement of the first oil seal 43 will push the brake oil from the piston chamber 11 into the oil storage chamber 12 through the oil return hole 13 (that is, the brake oil does not flow to the brake pump), so the brakes do not work in this process, and this section is also called the idle travel section.

[0074] In this embodiment, a brake piston mechanism with a floating pressure relief valve is applied to the brake upper pump, which has a brand-new set of lever arm action mechanism of the brake upper pump. The basic concept of lever arm: In the context of the brake handle 2, the lever arm refers to the vertical distance from the rotation axis (fulcrum) to the line of action of the force. The formula of the lever arm is F1*L1=F2*L2. For the brake handle 2, it rotates around a fixed point, and this fixed point is the fulcrum. When you hold the brake handle 2 and apply force, the length of the lever arm will affect the amount of force required to be applied. Among them, when the power arm (brake handle 2 lever arm) is longer, when the resistance and resistance arm are constant, the required power (the force you apply to the brake handle 2) is smaller. This is the principle of saving effort.

[0075] In the prior art, the piston member 4 and the piston oil seal in the brake upper pump are of a single quantity, and the working mechanism is also very simple, that is, after the brake handle 2 is squeezed, the piston member 4 is pushed out a certain distance, and the piston oil seal also moves forward the same distance, so the lever arm action mechanism is simple.

[0076] In the present invention, the front middle section action point is at the first oil seal 43, and the middle and rear section action point is at the second oil seal 44, which are variable force arm center points. Correspondingly, when the action point changes, the force resistance and resistance arm will also change. In particular, the middle and rear section has a larger power arm L1 (conventionally, it ends at the first oil seal 43, and the present invention ends at the second oil seal 44), and the resistance arm L2 is smaller, so that when the user squeezes the brake handle 2, only a smaller force F1 is needed, so that the user can obtain the same braking effect with less effort.

[0077] In order to cooperate with the first oil seal 43 and the second oil seal 44, a more specific solution for the oil storage chamber 12 is as follows: Fig.10The piston chamber 11 at least comprises a large diameter chamber section 111, a small diameter chamber section 112 and a variable diameter chamber section 113, wherein the large diameter chamber section 111, the variable diameter chamber section 113 and the small diameter chamber section 112 are sequentially distributed and connected from the back to the front, and the junction of the large diameter chamber section 111 and the variable diameter chamber section 113 is a first critical point, and the junction of the variable diameter chamber section 113 and the small diameter chamber section 112 is a second critical point; the oil return hole 13 is opened on the large diameter chamber section 111; the first oil The seal 43 is located in the large diameter cavity section 111, and the first oil seal 43 forms a sealing fit when it abuts against the inner wall of the large diameter cavity section 111; the second oil seal 44 moves with the piston member 4; when the second oil seal 44 is located in the large diameter cavity section 111, there is a gap between the second oil seal 44 and the inner wall of the large diameter cavity section 111 to form a non-sealed fit; when the second oil seal 44 is located in the small diameter cavity section 112, the second oil seal 44 abuts against the inner wall of the small diameter cavity section 112 and forms a sealing fit. It is worth mentioning that when the second oil seal 44 is located in the large diameter cavity section 111 or the variable diameter cavity section 113, there is a gap between the second oil seal 44 and the inner wall of the piston cavity 11 (large diameter cavity section 111 or variable diameter cavity section 113), so the second oil seal 44 does not play a sealing effect, nor can it play an effective oil pushing role.

[0078] The front middle section mentioned in Example 1 (the first oil seal 43 performs the actual oil pushing work) corresponds to the first oil seal 43 (located in front of the oil return hole 13) and the inner wall of the large diameter cavity section 111 when they are against each other to form a sealing fit, and there is a gap between the second oil seal 44 and the inner wall of the piston cavity 11 (the large diameter cavity section 111 or the variable diameter cavity section 113).

[0079] The middle and rear section mentioned in Example 1 (the second oil seal 44 performs the actual oil pushing work) corresponds to the first oil seal 43 (located in front of the oil return hole 13) abutting against the inner wall of the large-diameter cavity section 111 to form a sealing fit, and the second oil seal 44 abuts against the inner wall of the small-diameter cavity section 112 to form a sealing fit.

[0080] Embodiment 4

[0081] Based on the structure of the third embodiment, optionally, referring to Figure 6 , Fig. 9When the second oil seal 44 does not abut against the inner wall of the small-diameter cavity section 112 and the first oil seal 43 is located in front of the oil return hole 13, the user continues to squeeze the brake handle 2, and the first oil seal 43 pushes the brake oil toward the oil pipe assembly 3; when the second oil seal 44 abuts against the inner wall of the small-diameter cavity section 112, the user continues to squeeze the brake handle 2, and the second oil seal 44 pushes the brake oil in front of the second oil seal 44 toward the oil pipe assembly 3, and the first oil seal 43 pushes the brake oil between the first oil seal 43 and the second oil seal 44 toward the floating pressure relief valve core 5 through the oil inlet channel 421. When the second oil seal 44 is located in the rear part of the variable-diameter cavity section 113, there is a gap between the second oil seal 44 and the inner wall of the variable-diameter cavity section 113 to form a non-sealed fit; when the second oil seal 44 is located in the front part of the variable-diameter cavity section 113, the second oil seal 44 abuts against the inner wall of the variable-diameter cavity section 113 and forms a sealed fit. In order to play an actual sealing role, the first oil seal 43 and the second oil seal 44 are larger in size than the corresponding sections in the piston cavity 11. For example, the diameter of the large diameter cavity section 111 is 11.5 mm, and the diameter of the first oil seal 43 is 12 mm; the diameter of the small diameter cavity section 112 is 9 mm, and the diameter of the second oil seal 44 is 9.7 mm; the diameter of the variable diameter cavity section 113 is between 9 mm and 11.5 mm, so when the second oil seal 44 moves to the second half of the variable diameter cavity section 113, the second oil seal 44 and the inner wall of the variable diameter cavity section 113 are against each other and form a sealing fit, that is, the second oil seal 44 starts to play an actual oil pushing work in advance.

[0082] In the third embodiment, it is also mentioned that the working mechanism of the lever arm changes once, specifically when the oil seal that actually pushes oil is switched from the first oil seal 43 to the second oil seal 44. In this embodiment, the working mechanism of the lever arm changes multiple times. The first time is when the oil seal that actually pushes oil is switched from the first oil seal 43 to the second oil seal 44, and the second oil seal 44 is still in the variable diameter cavity section 113. After that, it needs to change continuously when moving from the variable diameter cavity section 113 to the small diameter cavity section 112, and stabilize to another working mechanism after completely entering the small diameter cavity section 112. The difference between this embodiment and the third embodiment is that, according to the Pascal principle (F2=P*S), since the S (due to the diameter of the second oil seal 44 that actually works constantly changes and gradually shrinks from 9.7mm to 9mm) generated by the second oil seal 44 in the variable diameter cavity section 113 and the small diameter cavity section 112 is constantly changing, therefore, the force F2 is constantly changing. According to the formula of the lever arm F1*L1=F2*L2, when F2 changes, F1 will also change continuously under the condition that the working conditions of L1 and L2 remain unchanged, that is, in the middle and rear section (when the second oil seal 44 performs the actual oil pushing work), the force applied by the user to squeeze the brake handle 2 is under the same working condition, and F1 gradually decreases.

[0083] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment according to the technical essence of the invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A brake piston mechanism with a floating pressure relief valve, characterized in that: Included are: A piston component (4) having a pressure relief chamber (411) therein, an oil inlet passage (421) and an oil leakage hole (412) are provided on the piston component (4), and the pressure relief chamber (411) is communicated with the outside of the piston component (4) through the oil inlet passage (421) and the oil leakage hole (412) respectively; A first oil seal (43), wherein the piston member (4) has a first supporting area (413), and the first oil seal (43) is arranged in the first supporting area (413); A second oil seal (44), wherein the piston member (4) has a second supporting area (422), and the first oil seal (43) is arranged in the second supporting area (422), wherein the second supporting area (422) is located in front of the first supporting area (413), and an effective oil pushing area S2 of the second oil seal (44) is smaller than an effective oil pushing area S1 of the first oil seal (43); a return spring (45) which applies a rearward elastic force to the piston member (4); The oil inlet passage (421) is located between the first oil seal (43) and the second oil seal (44), and the oil drain hole (412) is located at the rear side of the first oil seal (43); A floating pressure relief valve core (5) is movably disposed in the pressure relief chamber (411), and the floating pressure relief valve core (5) is located between the oil inlet channel (421) and the oil drain hole (412); A pressure relief spring (6) is abutted between the floating pressure relief valve core (5) and the inner wall of the pressure relief chamber (411), and the pressure relief spring (6) acts on the floating pressure relief valve core (5) so that the floating pressure relief valve core (5) has a movement tendency to move forward.

2. The brake piston mechanism with a floating pressure relief valve according to claim 1, characterized in that: The piston component (4) is composed of a first piston (41) and a second piston (42) which are detachable from each other; The first supporting area (413), the pressure relief chamber (411) and the oil leakage hole (412) are arranged on the first piston (41); The second supporting area (422) and the oil inlet channel (421) are arranged on the second piston (42).

3. The brake piston mechanism with a floating pressure relief valve according to claim 2, characterized in that: The front end of the first piston (41) has a first abutting end (414), the middle ring of the first piston (41) is provided with a second abutting end (423), and the first abutting end (414) and the second abutting end (423) abut against each other to form a transmission fit; The rear end of the second piston (42) has an extending end (424), and the extending end (424) at least partially enters into the pressure relief chamber (411).

4. The brake piston mechanism with a floating pressure relief valve according to claim 2, characterized in that: The brake piston mechanism also includes a piston cylinder sleeve (7); The first piston (41) is at least partially disposed in the piston cylinder sleeve (7), and a limiting portion (71) is protruding from the inner wall of the piston cylinder sleeve (7), and the limiting portion (71) can abut against the rear end of the first piston (41) to form a limiting stop.

5. The brake piston mechanism with a floating pressure relief valve according to claim 4, characterized in that: The first piston (41) has a first accommodating groove (415) therein, the rear end of the floating pressure relief valve core (5) has a second accommodating groove (51), the rear end of the pressure relief spring (6) extends into the first accommodating groove (415), and the front end of the pressure relief spring (6) extends into the second accommodating groove (51).

6. The brake piston mechanism with a floating pressure relief valve according to claim 4, characterized in that: A first sealing ring (81) is sleeved on the outer wall of the first piston (41), a second sealing ring (82) is sleeved on the outer wall of the floating pressure relief valve core (5), and a third sealing ring (83) is sleeved on the outer wall of the piston cylinder sleeve (7).

7. A brake pump, comprising: A brake pump body (1) is provided with a piston chamber (11) and an oil storage chamber (12), wherein the piston chamber (11) and the oil storage chamber (12) are filled with brake oil, and the oil storage chamber (12) is connected to the piston chamber (11) through an oil return hole (13); A brake handle (2) which is rotatably matched with the brake pump body (1) via a pivot mechanism (21); An oil pipe assembly (3) connected to the brake cylinder body (1) and communicating with the piston chamber (11); Features: The piston chamber (11) is provided with a brake piston mechanism with a floating pressure relief valve as described in any one of claims 1 to 5, and the brake handle (2) abuts against the rear end of the piston member (4) through a push-turn mechanism (22) to form a transmission fit.

8. The brake pump according to claim 7, characterized in that: The piston chamber (11) at least comprises a large diameter chamber section (111), a small diameter chamber section (112) and a variable diameter chamber section (113), wherein the large diameter chamber section (111), the variable diameter chamber section (113) and the small diameter chamber section (112) are sequentially distributed and connected from the back to the front, and the junction between the large diameter chamber section (111) and the variable diameter chamber section (113) is a first critical point, and the junction between the variable diameter chamber section (113) and the small diameter chamber section (112) is a second critical point; The oil return hole (13) is provided on the large diameter cavity section (111); The first oil seal (43) is located in the large-diameter cavity section (111), and a sealing fit is formed when the first oil seal (43) abuts against the inner wall of the large-diameter cavity section (111); The second oil seal (44) moves following the piston member (4); when the second oil seal (44) is located in the large-diameter cavity section (111), a gap exists between the second oil seal (44) and the inner wall of the large-diameter cavity section (111) to form a non-sealed fit; when the second oil seal (44) is located in the small-diameter cavity section (112), the second oil seal (44) abuts against the inner wall of the small-diameter cavity section (112) to form a sealed fit.

9. The brake pump according to claim 8, characterized in that: When the second oil seal (44) does not abut against the inner wall of the small-diameter cavity section (112) and the first oil seal (43) is located in front of the oil return hole (13), the user continues to squeeze the brake handle (2), and the first oil seal (43) pushes the brake oil toward the oil pipe assembly (3); When the second oil seal (44) abuts against the inner wall of the small-diameter cavity section (112), the user continues to squeeze the brake handle (2), and the second oil seal (44) pushes the brake oil in front of the second oil seal (44) toward the oil pipe assembly (3), and the first oil seal (43) pushes the brake oil between the first oil seal (43) and the second oil seal (44) toward the floating pressure relief valve core (5) through the oil inlet channel (421).

10. The brake pump according to claim 8, characterized in that: When the second oil seal (44) is located at the rear part of the variable diameter chamber section (113), a gap exists between the second oil seal (44) and the inner wall of the variable diameter chamber section (113) to form a non-sealed fit; when the second oil seal (44) is located at the front part of the variable diameter chamber section (113), the second oil seal (44) abuts against the inner wall of the variable diameter chamber section (113) to form a sealed fit.

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