Double-piston brake upper pump with stopping function

Abstract

A double-piston upper brake pump with a locking function comprises a brake pump body, a piston cavity and an oil storage cavity which are communicated with each other are formed in the brake pump body; a brake handle; the piston oil pushing assembly comprises a small-diameter piston push rod, a large-diameter piston push sleeve, a large-diameter piston oil seal, a small-diameter piston oil seal, a reset elastic piece and a power-assisted elastic piece; a stop mechanism is arranged in the piston cavity; the large-diameter piston push sleeve is in contactable connection fit with the stop mechanism, so that the stop mechanism acts on the large-diameter piston push sleeve to limit forward movement of the large-diameter piston push sleeve; and a movable gap exists between the small-diameter piston push rod and the stop mechanism, so that the small-diameter piston push rod can freely pass through the stop mechanism. The piston oil seal is provided with the large-diameter piston oil seal and the small-diameter piston oil seal which are different in size, and different oil pushing effects can be achieved through the large-diameter piston oil seal and the small-diameter piston oil seal; the braking device is provided with the stop mechanism, the stop mechanism only acts on the large-diameter piston push sleeve, the pressure relief phenomenon in a short time is eliminated, and the situation that braking fails suddenly in the short time is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to the product technical field of oil pressure brake especially a double piston brake upper pump with stop function. BACKGROUND

[0002] The bicycle brake upper pump (also known as brake master cylinder or brake handle assembly) is one of the core components of the hydraulic brake system, mainly responsible for converting the pressing force of the rider's hand into the pressure of the hydraulic oil, thereby driving the brake caliper to clamp the disc, achieving the braking effect.

[0003] The ideal bicycle brake upper pump needs a larger size piston oil seal to play a role in the early stage of oil pushing, so that the brake upper pump quickly delivers brake oil to the brake lower pump, and then pushes the brake pad out of the brake lower pump and quickly contacts the brake disc, and the brake starts to take effect; in the middle and late stages of oil pushing, a smaller size piston oil seal is needed to play a role, at this time, a static pressure environment (Pascal principle) is formed between the piston oil seal and the brake lower pump, at this time, the smaller size piston oil seal compared with the larger size piston oil seal, in the case of exerting the same brake force, the smaller pressure caused by the reaction force is more likely to pinch and maintain, so that the user has a better brake feel.

[0004] Prior art example 1, refer to patent document CN118545202A, discloses a double cylinder piston oil pressure upper pump and oil pressure disc brake. The double cylinder piston oil pressure upper pump is used with a bicycle frame handlebar pipe, including an upper pump body, one end of the upper pump body is movably connected with a brake handle piece, a double cylinder oil cavity is formed on one side of the upper pump body close to the brake handle piece; the double cylinder oil cavity includes a first oil cylinder cavity and a second oil cylinder cavity which are coaxially connected and have decreasing inner diameters, a double cylinder piston piece is movably assembled in the double cylinder oil cavity, and a piston rod is movably assembled at the first end of the double cylinder piston piece, the other end of the piston rod extends out of the oil cylinder cavity and is fixedly assembled at the lower end of the brake handle piece to drive the oil liquid to input the oil outlet with a large braking force ratio when the brake handle piece is slightly angularly moved. The present application divides the angular movement stroke of the brake into two stages, in the first stage, when the brake handle piece is slightly angularly moved, the small stroke can eliminate the preset gap between the brake pad and the disc; in the second stage, the brake handle piece is further pinched to obtain the strong braking effect when the brake handle piece is slightly angularly moved.

[0005] The prior art example 2, refer to patent document ZL202520084516.2, discloses a brake upper pump with double oil seals and lateral pressure relief, comprising a brake pump body provided with a piston cavity and an oil storage cavity in communication with each other; a brake handle in rotational cooperation with the brake pump body, the brake handle being in transmission cooperation with a piston mechanism; an oil pipe assembly in communication with the piston cavity; the piston mechanism comprising a piston body, a first oil seal and a second oil seal, wherein the second oil seal is located at the front side of the first oil seal, and the effective oil pushing area S1 of the second oil seal is smaller than that of the first oil seal; a return spring acting on the piston body; a pressure relief valve mechanism installed in a pressure relief cavity of the brake pump body; the piston cavity has at least a large-diameter cavity section, a small-diameter cavity section and a variable-diameter cavity section, and the pressure relief cavity is in communication with the variable-diameter cavity section through a pressure relief channel. The double-piston oil seal structure with large and small diameters is adopted to realize the effect that the front section has a relatively large oil seal area and the rear section has a relatively small oil seal area, and the overall brake performance will be more linear.

[0006] Both the technical example 1 and the technical example 2 have large and small piston oil seals, and the working sequence meets the ideal bicycle brake upper pump in the foregoing. However, both the two technical solutions have the same defects, specifically: in the front, middle and rear sections of the pinched brake handle, the large-size piston oil seal and the small-size piston oil seal are always moved forward synchronously. Therefore, there is an intersection point for the actually working piston oil seal, that is, in the moving process after the large-size piston oil seal switches to the small-size piston oil seal, the space between the large-size piston oil seal and the small-size piston oil seal changes, at this time, the large-size piston oil seal is still assisting the brake oil between the large-size piston oil seal and the small-size piston oil seal. In order to prevent this part of brake oil from interfering with the use of the small-size piston oil seal, the pressure relief structure is applied in the example 1 and the example 2, which is used to offset and relieve the brake oil pressure between the large-size piston oil seal and the small-size piston oil seal. However, since the space between the large-size piston oil seal and the small-size piston oil seal changes constantly, the brake oil pressure also changes constantly, and the effect of the pressure relief structure cannot be completely uniform and stable, so obvious pressure relief (pressure drop) phenomenon will occur in a short time, which will be completely relieved, and further cause the brake to suddenly fail in a short time, which has very serious safety hazards. SUMMARY

[0007] In order to overcome the above-mentioned deficiencies of the prior art, the utility model provides a double-piston brake upper pump with a stop function.

[0008] The technical scheme for solving the technical problems of the utility model is: a double-piston brake upper pump with a stop function, comprising:

[0009] The brake pump body is provided with a piston cavity and an oil storage cavity which are communicated with each other, the piston cavity is provided with a movable piston oil pushing assembly, and the front end of the piston cavity is connected with an oil pipe assembly;

[0010] The brake handle is rotatably connected with the brake pump body through a pivot mechanism, and the brake handle is in transmission connection with the piston oil pushing assembly through a push rod assembly.

[0011] The piston oil pushing assembly comprises a small-diameter piston push rod and a large-diameter piston push sleeve, the large-diameter piston push sleeve is sleeved on the small-diameter piston push rod and is in clearance fit, the large-diameter piston push sleeve is provided with a large-diameter piston oil seal, the small-diameter piston push rod is provided with a small-diameter piston oil seal, a reset elastic member is arranged between the small-diameter piston push rod and the inner wall of the piston cavity, and a boosting elastic member is arranged between the rear end of the small-diameter piston push rod and the rear end of the large-diameter piston push sleeve.

[0012] The radial dimension of the large-diameter piston oil seal is greater than that of the small-diameter piston oil seal.

[0013] The piston cavity is provided with a stop mechanism.

[0014] The large-diameter piston push sleeve is in contactable connection with the stop mechanism, so that the stop mechanism acts on the large-diameter piston push sleeve to limit the forward movement of the large-diameter piston push sleeve.

[0015] The small-diameter piston push rod and the stop mechanism have an activity gap, so that the small-diameter piston push rod can freely pass through the stop mechanism.

[0016] In some embodiments of the utility model, the stop mechanism is a first limiting step which is protruded on the inner wall of the piston cavity, the radial dimension of the large-diameter piston oil seal is greater than the inner diameter dimension of the first limiting step, and the inner diameter dimension of the first limiting step is greater than the radial dimension of the small-diameter piston oil seal.

[0017] In some embodiments of the utility model, the first limiting step divides the piston cavity into a first equal-diameter section and a second equal-diameter section, the large-diameter piston oil seal is in contact with the inner wall of the first equal-diameter section and forms a sealing fit, and the small-diameter piston oil seal can be in contact with the inner wall of the second equal-diameter section and forms a sealing fit.

[0018] In some embodiments of the utility model, the oil storage cavity is communicated with the piston cavity through an oil supplementing hole and an oil return hole, and the oil supplementing hole is located behind the oil return hole.

[0019] In the first stage of pinching the brake, the large-diameter piston oil seal is located between the oil supplementing hole and the oil return hole, and the small-diameter piston push rod and the large-diameter piston push sleeve move forward together.

[0020] The second stage of the user pinching the brake, the large-diameter piston oil seal is located in front of the oil return hole, and the large-diameter piston push sleeve has not contacted the stop mechanism, and the small-diameter piston push rod and the large-diameter piston push sleeve move forward together.

[0021] The third stage of the user pinching the brake, the large-diameter piston oil seal is located in front of the oil return hole, and the large-diameter piston push sleeve contacts the stop mechanism and stops advancing, and the small-diameter piston push rod continues to advance.

[0022] In some embodiments of the utility model, the large-diameter piston push sleeve is provided with a containing cavity, and the small-diameter piston oil seal can retract into the containing cavity or / and extend out of the containing cavity.

[0023] In the first stage and the second stage of the user pinching the brake handle, the small-diameter piston oil seal retracts into the containing cavity, and the small-diameter piston oil seal contacts the inner wall of the containing cavity and forms a sealing fit.

[0024] In the third stage of the user pinching the brake handle, the small-diameter piston oil seal extends out of the containing cavity.

[0025] In some embodiments of the utility model, the large-diameter piston push sleeve is provided with a through hole distributed in the front-rear direction, and the small-diameter piston push rod at least partially penetrates the through hole.

[0026] A first flow channel groove is formed on the inner wall of the through hole, and a piston cavity at the rear of the large-diameter piston push sleeve is communicated with the containing cavity through the first flow channel groove.

[0027] A second flow channel groove is formed on the outer wall of the large-diameter piston push sleeve, and in the first stage and the second stage of the user pinching the brake handle, the first constant-diameter section is communicated with the second constant-diameter section through the second flow channel groove.

[0028] In some embodiments of the utility model, the inner diameter size of the containing cavity is equal to the inner diameter size of the second constant-diameter section.

[0029] In some embodiments of the utility model, the opening of the containing cavity is provided with a circular arc chamfer portion.

[0030] In some embodiments of the utility model, the rear end portion of the large-diameter piston push sleeve is provided with a limiting groove, the rear portion of the small-diameter piston push rod is provided with a limiting convex, the front end of the power-assisted elastic member extends into the limiting groove, and the rear end of the power-assisted elastic member is sleeved on the limiting convex.

[0031] In some embodiments of the utility model, the rear portion of the small-diameter piston push rod is provided with a detachable transmission joint, and the limiting convex is formed on the front end portion of the transmission joint.

[0032] The rear end of the transmission joint has a transmission groove, and the push rod assembly extends into the transmission groove, so that the push rod assembly forms a transmission fit with the small-diameter piston push rod through the transmission joint.

[0033] A sealing ring is sleeved on the outer wall of the transmission joint, and the sealing ring is in contact with the inner wall of the piston cavity, so that the outer wall of the transmission joint and the inner wall of the piston cavity form a sealing fit.

[0034] The beneficial effects of the utility model lie in: having large-diameter piston oil seals and small-diameter piston oil seals with different sizes, which can realize different oil pushing functions; having a stop mechanism, which only acts on the large-diameter piston push sleeve (equivalent to acting on the large-diameter piston oil seal), and cannot limit the movement of the small-diameter piston push rod (equivalent to acting on the small-diameter piston oil seal). On the one hand, the large-diameter piston oil seal and the small-diameter piston oil seal cooperate to obtain the functions of a large oil pushing amount and a larger oil pushing cross-sectional area in the early stage and a small oil pushing amount and a smaller oil pushing cross-sectional area in the later stage in different stages of pinching the brake handle, that is, the large-diameter piston oil seal can help the brake to push out the brake pad in the pump quickly in the early stage, the pressure received by the large-diameter piston oil seal is smaller in the later stage in the static pressure environment, the user feels more soft and linear, and the wall collision feeling is eliminated, so that the ideal bicycle brake pump is realized to meet the demand of the change of the brake oil pushing amount. On the other hand, the pressure relief (pressure drop) phenomenon in a short time is completely eliminated, the sudden brake failure in a short time is avoided, the brake is ensured to be normally used, the brake safety is greatly improved, and the life safety and health safety of the user are ensured. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a structural exploded view of the utility model.

[0036] Figure 2 is a radial size comparison schematic view of the large-diameter piston oil seal and the small-diameter piston oil seal.

[0037] Figure 3 is a front side structure schematic view of the large-diameter piston push sleeve.

[0038] Figure 4 is a rear side structure schematic view of the large-diameter piston push sleeve.

[0039] Figure 5 is an assembly schematic view of the small-diameter piston push rod and the small-diameter piston oil seal.

[0040] Figure 6 is an exploded view of the structure of the small-diameter piston push rod and the small-diameter piston oil seal.

[0041] Figure 7 is a whole structure comparison schematic view in each stage when the user pinches the brake handle.

[0042] Figure 8Fig. 1 is a schematic view of a piston oil pushing assembly in different stages when a user pinches a brake handle.

[0043] Figure 9 Fig. 2 is a schematic view of a structure sectional view and a partial enlarged view of the brake handle in a first stage.

[0044] Figure 10 Fig. 3 is a schematic view of a structure sectional view and a partial enlarged view of the brake handle in a second stage.

[0045] Figure 11 Fig. 4 is a schematic view of a structure sectional view and a partial enlarged view of a switching node of the brake handle in a second stage and a third stage.

[0046] Figure 12 Fig. 5 is a schematic view of a structure sectional view and a partial enlarged view of the brake handle in a third stage.

[0047] In the figure: 1, brake pump body; 11, piston cavity; 111, first constant diameter section; 112, second constant diameter section; 114, first limiting step; 115, second limiting step; 12, oil storage cavity; 13, oil return hole; 14, oil supplement hole; 2, piston oil pushing assembly; 21, small-diameter piston pushing rod; 215, transmission joint; 2151, transmission groove; 2152, limiting convex; 2153, sealing ring; 22, large-diameter piston pushing sleeve; 221, limiting groove; 222, accommodating cavity; 223, circular arc chamfer part; 224, through hole; 225, first flow channel groove; 226, cavity; 227, second flow channel groove; 23, small-diameter piston oil seal; 24, large-diameter piston oil seal; 25, reset elastic element; 26, booster elastic element; 3, brake handle; 31, pivoting mechanism; 32, pushing rod assembly; 3a, initial stage; 3b, first stage; 3c, second stage; 3d, third stage; 4, oil pipe assembly. DETAILED DESCRIPTION

[0048] The utility model will be further explained in connection with the drawings and specific embodiments. It should be explained that the embodiment is only the specific elaboration of the utility model, and the purpose is to let the person skilled in the art better understand the technical scheme of the utility model, and should not be regarded as the limitation of the utility model.

[0049] In the description of the utility model, it should be explained that the orientation or position relationship indicated by terms such as 'center', 'upper', 'lower', 'left', 'right','vertical', 'horizontal', 'inner', 'outer' and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as the limitation of the utility model.

[0050] In the description of the utility model, it is necessary to explain that, unless there is definite stipulation and limitation, if the term "installation", "connection", "connection" appears, it should be understood in a broad sense, for example, it can be fixed connection, also can be detachable connection, or integrally connected;It can be mechanical connection, or electrical connection;It can be direct connection, or indirectly connected through intermediate medium, it can be the communication inside two elements.For the person skilled in the art, the specific meaning of the above-mentioned terms in the utility model can be understood according to the specific circumstances.

[0051] Embodiment one

[0052] Refer to Figures 1-12 A double-piston brake upper pump with stop function, comprising: a brake pump body 1, which is provided with a piston cavity 11 and an oil storage cavity 12 that are in communication with each other, a movable piston oil pushing assembly 2 is arranged in the piston cavity 11, and an oil pipe assembly 4 is connected to the front end of the piston cavity 11;A brake handle 3 is rotatably connected to the brake pump body 1 through a pivoting mechanism 31, and the brake handle 3 is in transmission cooperation with the piston oil pushing assembly 2 through a push rod assembly 32;The piston oil pushing assembly 2 comprises a small-diameter piston push rod 21 and a large-diameter piston push sleeve 22, the large-diameter piston push sleeve 22 is sleeved on the small-diameter piston push rod 21 and forms a clearance fit, so that the small-diameter piston push rod 21 and the large-diameter piston push sleeve 22 are not in a fixed connection relationship, and therefore the small-diameter piston push rod 21 can move relative to the large-diameter piston push sleeve 22.

[0053] A large-diameter piston oil seal 24 is arranged on the large-diameter piston push sleeve 22, and a small-diameter piston oil seal 23 is arranged on the small-diameter piston push rod 21, so that the large-diameter piston oil seal 24 moves synchronously with the large-diameter piston push sleeve 22, and the small-diameter piston oil seal 23 moves synchronously with the small-diameter piston push rod 21.

[0054] A reset elastic member 25 is arranged between the small-diameter piston push rod 21 and the inner wall of the piston cavity 11, so that the small-diameter piston push rod 21 always has a backward movement trend.Once the user releases the brake handle 3, the reset elastic member 25 will be released in the absence of external force, so that the reset elastic member 25 (which may also be combined with the oil pressure of the brake oil) applies a reset elastic force to the small-diameter piston push rod 21, so that the small-diameter piston push rod 21 is reset backward, and the large-diameter piston push sleeve 22, the push rod assembly 32 and other components are also reset.

[0055] A power-assisted elastic member 26 is arranged between the rear end of the small-diameter piston push rod 21 and the rear end of the large-diameter piston push sleeve 22; the power-assisted elastic member 26 works in such a way that the push rod assembly 32 directly drives the small-diameter piston push rod 21 to move forward, and the small-diameter piston push rod 21 applies a forward thrust to the power-assisted elastic member 26 and drives the rear end of the power-assisted elastic member 26 to move forward, so that the power-assisted elastic member 26 is compressed and releases a larger elastic thrust forward, and the elastic thrust is applied to the large-diameter piston push sleeve 22, so that the large-diameter piston push sleeve 22 can also overcome the resistance and realize forward displacement.

[0056] The radial dimension of the large-diameter piston oil seal 24 is greater than the radial dimension of the small-diameter piston oil seal 23; the piston cavity 11 is provided with a stop mechanism; the large-diameter piston push sleeve 22 is in contact with the stop mechanism, so that the stop mechanism acts on the large-diameter piston push sleeve 22 to limit the forward movement of the large-diameter piston push sleeve 22; and the small-diameter piston push rod 21 has a clearance with the stop mechanism, so that the small-diameter piston push rod 21 can freely pass through the stop mechanism.

[0057] Preferably, the stop mechanism is a first limiting step 114 protruding on the inner wall of the piston cavity 11, the radial dimension of the large-diameter piston oil seal 24 is greater than the inner diameter dimension of the first limiting step 114, and the inner diameter dimension of the first limiting step 114 is greater than the radial dimension of the small-diameter piston oil seal 23. The first limiting step 114 is a switching node of the push oil amount function, that is, when the front end of the large-diameter piston push sleeve 22 is not in contact with the first limiting step 114, the large-diameter piston oil seal 24 and the small-diameter piston oil seal 23 push oil forward together, so that a greater push oil amount is obtained under the condition of the same amplitude of pinching the brake handle 3, and the actual working push oil cross-sectional area of the piston push oil assembly 2 is larger; when the front end of the large-diameter piston push sleeve 22 is in contact with the first limiting step 114, a physical limit is formed, and thereafter when the brake handle 3 is pinched, the large-diameter piston push sleeve 22 and the large-diameter piston oil seal 24 will no longer move forward, so that the small-diameter piston oil seal 23 pushes oil forward alone, so that a smaller push oil amount is obtained under the condition of the same amplitude of pinching the brake handle 3, and the actual working push oil cross-sectional area of the piston push oil assembly 2 is smaller.

[0058] It should be emphasized that the purpose of the stop mechanism is to limit the large-diameter piston oil seal 24 from continuing to advance after the large-diameter piston oil seal 24 advances a certain distance. Therefore, the first limiting step 114 is only a preferred way, and the stop mechanism can also be other structural ways, which are not specially limited here.

[0059] The above is the basic structure scheme of the utility model, and the same as technical examples 1 and 2 is that large-diameter piston oil seals 24 and small-diameter piston oil seals 23 with different sizes are provided, and different oil pushing effects can be achieved; the feature of the utility model distinguished from technical examples 1 and 2 is that the stop mechanism only acts on the large-diameter piston push sleeve 22 (here, it is equivalent to acting on the large-diameter piston oil seal 24), and the stop mechanism cannot limit the movement of the small-diameter piston push rod 21 (here, it is equivalent to acting on the small-diameter piston oil seal 23).

[0060] The utility model can achieve the following functions: on the one hand, the large-diameter piston oil seal 24 and the small-diameter piston oil seal 23 cooperate to obtain the functions of a large oil pushing amount and a larger oil pushing cross-sectional area in the early stage and a small oil pushing amount and a smaller oil pushing cross-sectional area in the later stage in different stages of pinching the brake handle 3, that is, the large-diameter piston oil seal 24 can help the brake pad to be quickly pushed out in the brake pump in the early stage, the pressure received by the large-diameter piston oil seal 24 is smaller in the static pressure environment in the later stage, the user feels more soft and linear, and the wall collision feeling is eliminated, so that the ideal bicycle brake pump can meet the demand of the change of the brake oil pushing amount. On the other hand, when the small-diameter piston oil seal 23 starts to work, the position of the large-diameter piston push sleeve 22 and the large-diameter piston oil seal 24 remains static, so the space between the large-diameter piston oil seal 24 and the first limiting step 114 remains unchanged, and the large-diameter piston oil seal 24 will not push oil forward, so the pressure relief mechanism is not needed to relieve pressure in this stage, the pressure relief (pressure drop) phenomenon in a short time is completely eliminated, the sudden brake failure in a short time is avoided, the brake is normally used, the brake safety is greatly improved, and the life safety of the user is ensured.

[0061] In short, a very important improvement of the utility model is that in technical examples 1 and 2, the pressure borne by the piston push rod assembly 32 (or the pressure fed back to the user) is first increased, suddenly reduced (because of pressure relief), and then increased during the process that the user pinches the brake handle 3, so there is a risk of instability, pressure drop and brake failure; in the scheme of the utility model, the pressure borne by the piston push rod assembly 32 (or the pressure fed back to the user) is continuously increased during the process that the user pinches the brake handle 3, so a stable, reliable and safe brake function is provided.

[0062] Preferably, the first limiting step 114 separates the piston cavity 11 into a first constant diameter section 111 and a second constant diameter section 112, the large-diameter piston oil seal 24 is in contact with the inner wall of the first constant diameter section 111 and forms a sealing fit, and the small-diameter piston oil seal 23 can be in contact with the inner wall of the second constant diameter section 112 and forms a sealing fit. It is emphasized here that the first constant diameter section 111 maintains the same inner diameter in the front-rear direction, and the second constant diameter section 112 maintains the same inner diameter in the front-rear direction. The consistent inner diameter size can make the large-diameter piston oil seal 24 or / and the small-diameter piston oil seal 23 more stable when pushing oil forward.

[0063] More preferably, the first constant diameter section 111 further has a second limiting step 115, and the second limiting step 115 is located rearward of the first limiting step 114. When the large-diameter piston push sleeve 22 contacts the first limiting step 114, the large-diameter piston oil seal 24 contacts the second limiting step 115, reducing the impact of internal pressure on the large-diameter piston oil seal 24 and making its form more stable. Therefore, the first limiting step 114 and the second limiting step 115 in the embodiment respectively provide limiting effects, especially during the process of the small-diameter piston push rod 21 moving forward alone relative to the large-diameter piston push sleeve 22, which can make the large-diameter piston oil seal 24 and the large-diameter piston push rod each maintain a stable stationary state.

[0064] In the specific embodiment of the utility model, the oil storage cavity 12 is communicated with the piston cavity 11 through the oil supplement hole 14 and the oil return hole 13, and the oil supplement hole 14 is located rearward of the oil return hole 13; when the user pinches the brake handle 3, the brake oil in the oil storage cavity 12 is supplemented to the piston cavity 11 rearward of the large-diameter piston oil seal 24 through the oil supplement hole 14 to maintain the oil pressure balance on the front and rear sides of the large-diameter piston oil seal 24. The conditions of the user pinching the brake handle 3 in each stage are explained as follows:

[0065] Referring to Figure 9 , the first stage 3b of the user pinching the brake, the large-diameter piston oil seal 24 is located between the oil supplement hole 14 and the oil return hole 13, so that when the piston push oil assembly 2 moves forward, the small-diameter piston push rod 21 and the large-diameter piston push sleeve 22 advance together, so that the large-diameter piston oil seal 24 delivers the brake oil in the piston cavity 11 to the oil storage cavity 12 through the oil return hole 13; this stage is usually called as an empty stroke stage, that is, in this stage, although the piston push rod assembly 32 advances forward, the large-diameter piston oil seal 24 or / and the small-diameter piston oil seal 23 does not form a closed environment with the brake lower pump, and no static pressure is generated, so the brake pad is not pushed out, the brake pad does not contact the brake disc, and thus no brake effect is generated.

[0066] Referring to Figures 10-11, the second stage 3c of the user pinching the brake, the large-diameter piston oil seal 24 is located in front of the oil return hole 13, and the large-diameter piston push sleeve 22 has not yet contacted the stop mechanism, the small-diameter piston push rod 21 and the large-diameter piston push sleeve 22 move forward together, so that the large-diameter piston oil seal 24 and the small-diameter piston oil seal 23 together deliver the brake oil in the piston cavity 11 to the brake lower pump through the oil pipe assembly 4; at this stage, the large-diameter piston oil seal 24 and the small-diameter piston oil seal 23 act simultaneously and form a sealed environment with the brake lower pump, mainly to achieve the action of the brake pad pushing out, once the brake pad contacts the brake disc, the brake effect begins to occur, but the braking force in this stage is generally smaller.

[0067] In the above case, it is worth mentioning that when the user pinches the brake handle 3 at the first stage 3b and the second stage 3c, the boost force exerted by the boost elastic member 26 to the large-diameter piston push sleeve 22 in the forward direction is greater than the return force exerted by the brake oil to the large-diameter piston push sleeve 22 in the backward direction, so as to realize the effect of the forward movement of the large-diameter piston push sleeve 22. It should be noted that the basic performance of the boost elastic member 26, such as wire diameter, number of turns, free length, material, etc., can be customized according to actual needs, and is not specially limited here.

[0068] Referring to Figures 11-12 , the third stage 3d of the user pinching the brake, the large-diameter piston oil seal 24 is located in front of the oil return hole 13, and the large-diameter piston push sleeve 22 contacts the stop mechanism and stops advancing, the small-diameter piston push rod 21 continues to advance, so that the small-diameter piston oil seal 23 delivers the brake oil in the piston cavity 11 to the brake lower pump through the oil pipe assembly 4; at this stage, the small-diameter piston oil seal 23 forms a sealed environment with the brake lower pump, so the small-diameter piston oil seal 23 alone plays a role in pushing oil, and in essence, in this stage, since the brake pad has contacted the brake disc, it is difficult to continue to move, the brake oil is a liquid and is difficult to be compressed, so the displacement of the small-diameter piston oil seal 23 is relatively small. It is suitable for Pascal's principle (in an incompressible and static fluid, the pressure change applied to a certain part of the closed fluid will be transmitted to all parts of the fluid and the container wall without change), satisfying the formula F1 / A1=F2 / A2=P, A1 refers to the effective boost area of the brake upper pump with the brake oil, A2 refers to the effective contact area of the brake upper pump with the brake oil, so the smaller the effective boost area, the smaller the pressure and pressure that the brake upper pump bears. Since the effective boost area of the small-diameter piston oil seal 23 will be smaller than that of the large-diameter piston oil seal 24, the pressure and pressure that the piston push rod assembly 32 bears in this stage will be smaller, so the force fed back to the brake handle 3 will be smaller, that is, the user will operate more easily, and the feeling of pinching the brake handle 3 will be softer and more linear, greatly reducing the feeling of hitting the wall. On the other hand, it can also be understood that when the user pinches the brake handle 3 at this stage, the same force is applied, and the force acting on the brake lower pump is greater, so a stronger brake braking force will be obtained.

[0069] In addition, the brake further has an initial stage 3a, which refers to a stage when the user does not pinch the brake and / or a stage after the brake is automatically reset after being released.

[0070] With reference to Figure 2 In the present disclosure, the effective oil pushing area (radial dimension) of the large-diameter piston oil seal 24 is greater than that of the small-diameter piston oil seal 23. The advancing distance of the piston oil pushing assembly 2 when the brake handle 3 is in the first stage 3b is less than that when the brake handle 3 is in the second stage 3c, and the advancing distance of the piston oil pushing assembly 2 when the brake handle 3 is in the second stage 3c is less than that when the brake handle 3 is in the third stage 3d.

[0071] Embodiment Two

[0072] In some embodiments of the present utility model, with reference to Figure 3 , Figures 9-12 The large-diameter piston pushing sleeve 22 is provided with a containing cavity 222, and the small-diameter piston oil seal 23 can be retracted into the containing cavity 222 or / and extended out of the containing cavity 222. In the first stage 3b and the second stage 3c of pinching the brake handle 3, the small-diameter piston oil seal 23 is retracted into the containing cavity 222, and the small-diameter piston oil seal 23 is in contact with the inner wall of the containing cavity 222 and forms a sealing fit. In the third stage 3d of pinching the brake handle 3, the small-diameter piston oil seal 23 extends out of the containing cavity 222. The containing cavity 222 can accommodate the small-diameter piston oil seal 23 in the first stage 3b and the second stage 3c, making its movement and form more stable and reliable.

[0073] Preferably, the opening of the containing cavity 222 is provided with a circular arc chamfer 223, so that when the small-diameter piston oil seal 23 is retracted into the containing cavity 222, the small-diameter piston oil seal 23 is in contact with the circular arc chamfer 223, achieving smooth transition and protection to prevent the small-diameter piston oil seal 23 from being scratched and damaged by sharp edges, resulting in sealing failure.

[0074] Another preferred arrangement in the present embodiment is that the inner diameter of the containing cavity 222 is equal to the inner diameter of the second constant-diameter section 112, so that the small-diameter piston oil seal 23 can move in and out of the containing cavity 222 more smoothly, and the small-diameter piston oil seal 23 can always maintain a stable posture.

[0075] Embodiment Three

[0076] In the third stage 3d of the user pinching the brake handle 3 during the forward and backward movement of the piston oil pushing assembly 2, the large-diameter piston oil seal 24 remains stationary and the small-diameter piston oil seal 23 alone realizes the forward oil pushing function. In this stage, as the small-diameter piston oil seal 23 advances, a cavity 226 is formed between the small-diameter piston oil seal 23 and the accommodating cavity 222 and gradually increases. If brake oil is not supplemented into the cavity 226, a certain pressure difference will be generated on the front and back sides of the small-diameter piston oil seal 23, causing the small-diameter piston oil seal 23 to have a backward movement trend. The user needs to exert greater operating force to push the small-diameter piston oil seal 23 forward, resulting in a decrease in brake braking force under the same operating force.

[0077] To eliminate the above-mentioned defects and achieve local oil pressure balance during movement, the preferred solution is as follows: Figure 3 、 Figure 4 、 Figures 9-12 The large-diameter piston pushing sleeve 22 has a through hole 224 distributed in the front and back directions, and the small-diameter piston pushing rod 21 at least partially passes through the through hole 224.

[0078] A first flow channel groove 225 is formed on the inner wall of the through hole 224, and the piston cavity 11 at the rear of the large-diameter piston pushing sleeve 22 is in communication with the accommodating cavity 222 through the first flow channel groove 225. Once the small-diameter piston oil seal 23 moves alone relative to the large-diameter piston pushing sleeve 22, the brake oil in the piston cavity 11 at the rear of the large-diameter piston pushing sleeve 22 can be supplemented into the cavity 226 of the accommodating cavity 222 through the first flow channel groove 225 to eliminate the cavity 226 and play a role in balancing the pressure, thereby obtaining greater brake braking force under the same operating force. It needs to be supplemented that after the brake oil in the piston cavity 11 at the rear of the large-diameter piston pushing sleeve 22 is supplemented into the accommodating cavity 222, the brake oil in the oil storage cavity 12 is supplemented into the piston cavity 11 at the rear of the large-diameter piston pushing sleeve 22 through the oil supplementing hole 14 to maintain the internal pressure balance.

[0079] On the other hand, a second flow channel groove 227 is formed on the outer wall of the large-diameter piston pushing sleeve 22. In the first stage 3b and the second stage 3c of the user pinching the brake handle 3, the first equal-diameter section 111 is in communication with the second equal-diameter section 112 through the second flow channel groove 227, realizing the forward oil pushing function of the large-diameter piston oil seal 24. In the third stage 3d of the user pinching the brake handle 3, the large-diameter piston oil seal 24 remains stationary, so theoretically the large-diameter piston oil seal 24 maintains local pressure balance of the brake oil between the second flow channel groove 227 and the first limiting step 114.

[0080] Embodiment Four

[0081] Since the boosting elastic member 26 needs to repeatedly realize the contraction and expansion action during use, if the position is skewed, the boosting function will be unstable or even invalid. In order to eliminate the defect, in some embodiments of the utility model, the structure scheme adopted is: referring to Figure 4 , Figure 6 , Figures 8-12 , the rear end of the large-diameter piston push sleeve 22 is provided with a limiting groove 221, the rear of the small-diameter piston push rod 21 is provided with a limiting convex 2152, the front end of the boosting elastic member 26 extends into the limiting groove 221, and the rear end of the boosting elastic member 26 is sleeved on the limiting convex 2152. Through the setting of the limiting groove 221 and the limiting convex 2152, the two ends of the boosting elastic member 26 are effectively limited, so that the boosting elastic member 26 can work continuously in a stable posture.

[0082] Referring to Figures 5-6 , preferably, the rear of the small-diameter piston push rod 21 is provided with a detachable transmission joint 215, and the limiting convex 2152 is formed on the front end of the transmission joint 215; the transmission joint 215 is detachable, so as to facilitate the installation and adjustment of the boosting elastic member 26. Further, the rear end of the transmission joint 215 is provided with a transmission groove 2151, the push rod assembly 32 extends into the transmission groove 2151, so that the push rod assembly 32 is in transmission cooperation with the small-diameter piston push rod 21 through the transmission joint 215; the outer wall of the transmission joint 215 is sleeved with a sealing ring 2153, and the sealing ring 2153 is in contact with the inner wall of the piston cavity 11, so as to form a sealing cooperation between the outer wall of the transmission joint 215 and the inner wall of the piston cavity 11.

[0083] It is worth noting that other technical schemes of the utility model belong to the prior art, and therefore will not be described in detail.

[0084] The above is only the preferred embodiment of the utility model, and it should be pointed out that for ordinary skilled persons in the technical field, some improvements and refinements can be made without departing from the concept of the utility model, and these improvements and refinements should also be regarded as the protection range of the utility model.

Claims

1. A double-piston brake upper pump with stop function, comprising: a brake pump body (1) having a piston cavity (11) and an oil storage cavity (12) in communication with each other, the piston cavity (11) being provided with a movable piston oil pushing assembly (2), and the front end of the piston cavity (11) being connected with an oil pipe assembly (4); a brake handle (3) being rotatably connected with the brake pump body (1) through a pivot mechanism (31), and the brake handle (3) being drivingly connected with the piston oil pushing assembly (2) through a push rod assembly (32); the piston oil pushing assembly (2) comprising a small-diameter piston push rod (21) and a large-diameter piston push sleeve (22), the large-diameter piston push sleeve (22) being sleeved on the small-diameter piston push rod (21) and being in clearance fit, the large-diameter piston push sleeve (22) being provided with a large-diameter piston oil seal (24), the small-diameter piston push rod (21) being provided with a small-diameter piston oil seal (23), a reset elastic member (25) being arranged between the small-diameter piston push rod (21) and the inner wall of the piston cavity (11), and a boosting elastic member (26) being arranged between the rear end of the small-diameter piston push rod (21) and the rear end of the large-diameter piston push sleeve (22); the radial dimension of the large-diameter piston oil seal (24) being greater than the radial dimension of the small-diameter piston oil seal (23); characterized in that the piston cavity (11) being provided with a stop mechanism; the large-diameter piston push sleeve (22) being in contactable connection with the stop mechanism, so that the stop mechanism acts on the large-diameter piston push sleeve (22) to limit the forward movement of the large-diameter piston push sleeve (22); there being a clearance between the small-diameter piston push rod (21) and the stop mechanism, so that the small-diameter piston push rod (21) can freely pass through the stop mechanism.

2. The dual piston brake apply pump with a detent function according to claim 1, characterized in that: the stop mechanism being a first limiting step (114) protruding on the inner wall of the piston cavity (11), the radial dimension of the large-diameter piston oil seal (24) being greater than the inner diameter dimension of the first limiting step (114), and the inner diameter dimension of the first limiting step (114) being greater than the radial dimension of the small-diameter piston oil seal (23).

3. The dual piston brake apply pump with a detent function according to claim 2, characterized in that: the first limiting step (114) dividing the piston cavity (11) into a first constant-diameter section (111) and a second constant-diameter section (112), the large-diameter piston oil seal (24) being in contact with and in sealing fit with the inner wall of the first constant-diameter section (111), and the small-diameter piston oil seal (23) being capable of being in contact with and in sealing fit with the inner wall of the second constant-diameter section (112).

4. The dual piston brake apply pump with a detent function according to claim 1, characterized in that: the oil storage cavity (12) being in communication with the piston cavity (11) through a replenishing hole (14) and a return hole (13), and the replenishing hole (14) being located rearward of the return hole (13); in a first stage (3b) of user pinch braking, the large-diameter piston oil seal (24) is located between the replenishing hole (14) and the return hole (13), and the small-diameter piston push rod (21) and the large-diameter piston push sleeve (22) move forward together. The second stage (3c) of the user pinching the brake handle, the large-diameter piston oil seal (24) is located in front of the oil return hole (13), and the large-diameter piston push sleeve (22) has not contacted the stop mechanism, and the small-diameter piston push rod (21) and the large-diameter piston push sleeve (22) move forward together; The third stage (3d) of the user pinching the brake handle, the large-diameter piston oil seal (24) is located in front of the oil return hole (13), and the large-diameter piston push sleeve (22) contacts the stop mechanism and stops advancing, and the small-diameter piston push rod (21) continues to advance.

5. The dual piston brake apply pump with a detent function according to claim 4, characterized in that: The large-diameter piston push sleeve (22) is provided with a containing cavity (222), and the small-diameter piston oil seal (23) can be retracted into the containing cavity (222) or / and extended out of the containing cavity (222); In the first stage (3b) and the second stage (3c) of the user pinching the brake handle (3), the small-diameter piston oil seal (23) is retracted into the containing cavity (222), and the small-diameter piston oil seal (23) is in contact with the inner wall of the containing cavity (222) and forms a sealing fit; In the third stage (3d) of the user pinching the brake handle (3), the small-diameter piston oil seal (23) extends out of the containing cavity (222).

6. The dual piston brake apply pump with a detent function according to claim 3, characterized in that: The large-diameter piston push sleeve (22) has a through hole (224) distributed in the front-rear direction, and the small-diameter piston push rod (21) at least partially penetrates the through hole (224); A first flow channel (225) is formed on the inner wall of the through hole (224), and the piston cavity (11) behind the large-diameter piston push sleeve (22) is in communication with the containing cavity (222) through the first flow channel (225); A second flow channel (227) is formed on the outer wall of the large-diameter piston push sleeve (22); in the first stage (3b) and the second stage (3c) of the user pinching the brake handle (3), the first equal-diameter section (111) is in communication with the second equal-diameter section (112) through the second flow channel (227).

7. The dual piston brake apply pump with a detent function according to claim 6, characterized in that: The inner diameter of the containing cavity (222) is equal to the inner diameter of the second equal-diameter section (112).

8. The dual piston brake apply pump with a detent function according to claim 6, characterized in that: The opening of the containing cavity (222) has a circular arc chamfer (223).

9. The dual piston brake apply pump with a detent function according to claim 3, characterized in that: The rear end of the large-diameter piston push sleeve (22) is provided with a limiting groove (221), the rear part of the small-diameter piston push rod (21) has a limiting convex (2152), the front end of the power-assisted elastic member (26) extends into the limiting groove (221), and the rear end of the power-assisted elastic member (26) is sleeved on the limiting convex (2152).

10. The dual piston brake apply pump with a detent function according to claim 9, characterized in that: The rear part of the small-diameter piston push rod (21) has a detachable transmission joint (215), and the limiting convex (2152) is formed on the front end of the transmission joint (215); The rear end of the transmission joint (215) has a transmission groove (2151), and the push rod assembly (32) extends into the transmission groove (2151), so that the push rod assembly (32) is in transmission fit with the small-diameter piston push rod (21) through the transmission joint (215); The outer wall of the transmission joint (215) is sleeved with a sealing ring (2153), which is in contact with the inner wall of the piston cavity (11) to form a sealed fit between the outer wall of the transmission joint (215) and the inner wall of the piston cavity (11).

Images