Brake master cylinder

A brake master cylinder of the invention is to dispose a main oil cylinder and an oil storing space on a handlebar base. In addition, a sleeve engaged with the main oil cylinder is disposed in the oil storing space. The one end of the oil storing space has a fastening seat passed by a draw bar linked to the brake handlebar, and a positioning sheath of the fastening seat is utilized to engage with the sleeve. A leakage prevention component is disposed between the fastening seat and the handlebar base. A bushing integrally extended from the leakage prevention component is utilized to encapsulate the positioning sheath of the fastening seat and the sleeve. Accordingly, the brake master cylinder having convenient assembly and better sealing effect for hydraulic oil is obtained.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a hydraulic braking device, and more particularly to a brake master cylinder that is conveniently assembled and having better sealing effect for hydraulic oil.

2. Description of the Related Art

A hydraulic brake apparatus utilized in a motorcycle or a bicycle can be taken as one of hydraulic equipment that is in widespread use. A brake master cylinder driven by a brake handlebar is disposed to a handgrip place of the hydraulic brake apparatus. In addition, a braking caliper is disposed to wheels through a hydraulic pipe. When a rider presses the brake handlebar, a piston relatively disposed in a main oil cylinder of the brake master cylinder is driven by the brake handlebar to go forward. Hydraulic oil within the main oil cylinder is pushed into a sub-oil cylinder of the braking caliper to allow a brake pad of the sub-oil cylinder to move toward the brake disc. The brake pad is in contact with the brake disc of the hub to further brake the wheels.

When the rider releases the brake handlebar, the piston in the main oil cylinder or the brake pad at the sub-oil cylinder can back off under the effect of the spring, and the brake handlebar can return to a predetermined angle.

Moreover, after performing braking motion for several times, the brake pad may be worn away (the brake pad is thinned). The reciprocation stroke of the piston must be relatively increased to achieve a desired braking effect. To avoid the brake handlebar from completely reciprocating due to the foregoing factors and to avoid influencing the braking force, an oil pot (or an oil cup) is further disposed to a normal brake master cylinder, and an oil-return hole connected to the oil pot is disposed to a reciprocation stroke place for the piston of the main oil cylinder.

With the state of completely backing the piston off, hydraulic oil within the oil pot is automatically filled into a hydraulic pipe in front of the piston through the oil-return hole. The brake handlebar may not return to a predetermined angle due to the abrasion of the brake pad, and the desired braking effect can be retained.

However, the conventional brake master cylinder usually disposes the oil pot at a radial position of the main oil cylinder of the handlebar base and must dispose a leakage prevention structure at the oil pot and a conjunction channel between the piston and the brake handlebar respectively to prevent hydraulic oil from being leaked. Consequently, it does not only influence the beauty of the brake master cylinder, but also increases the difficulty of assembling the brake master cylinder. Moreover, the sealing effect of hydraulic oil is relatively not good enough.

Therefore, no matter the brake master cylinder applied to the motorcycle or the bicycle has the function of automatically filling hydraulic oil or not, the reliability of the brake master cylinder can be greatly improved if the assembly convenience of the brake master cylinder and the sealing effect for hydraulic oil are actively improved and increased.

SUMMARY OF THE INVENTION

In view of the shortcomings of the prior art, the inventor(s) of the present invention based on years of experience in the related industry to conduct extensive researches and experiments, and finally developed a brake master cylinder that is conveniently assembled and having better sealing effect for hydraulic oil.

To achieve an objective, the brake master cylinder of the invention is to integrally dispose a main oil cylinder and an oil storing space at a handlebar base for installing a brake handlebar. The oil storing space is disposed to an axial position of the main oil cylinder of the handlebar base. One end of the handlebar base is provided with an oil outlet, which relatively corresponds to the main oil cylinder, connected to a hydraulic pipe. One end of the handlebar base is provided with an installation hole corresponding to the oil storing space. In addition, a piston capable of being driven by the brake handlebar is disposed in the main oil cylinder.

The characteristic of the invention is that a sleeve engaged with the main oil cylinder is disposed in the oil storing space of the handlebar base. One end of the piston, which relatively stretches into the main oil cylinder, has a first rubber ring. One end of the piston, which relatively stretches into the sleeve, is provided with a second rubber ring. A fastening seat is disposed at the installation hole of the handlebar base. The fastening seat has a positioning sheath stretching into the oil storing space to engage with the sleeve. In addition, a draw bar passes through a central place of the positioning sheath to link the piston and the brake handlebar. A leakage prevention component is disposed between the fastening seat and the handlebar base.

While in assembly, a channel formed by the installation hole is utilized to sequentially and respectively place the piston, the sleeve and the leakage prevention component into the main oil cylinder and the oil storing space of the handlebar base. Finally, the fastening seat passed by the draw bar is installed to the installation hole of the handlebar base to quickly complete the assembly of the brake master cylinder. More specifically, under the effect of the leakage prevention component, hydraulic oil can be prevented from being leaked through the installation hole and the engaging place between the sleeve and the positioning sheath. Further, hydraulic oil can be prevented from being leaked through the place passed by the draw bar under the effect of the second rubber ring so as to generate better sealing effect for hydraulic oil.

The detail structure of each component in the invention is further depicted.

A bushing for encapsulating the positioning sheath of the fastening seat and the sleeve is integrally extended from the leakage prevention component. An inner flange is disposed to a tail of the bushing. A circular groove for fastening the inner flange is circularly disposed to a periphery of the sleeve.

Under structural forms of integrally extending the bushing for encapsulating the positioning sheath of the fastening seat and the sleeve from the leakage prevention component, disposing the inner flange at the tail of the bushing and circularly disposing the circular groove for fastening the inner flange at the periphery of the sleeve, a stage for plugging the sleeve and the bushing is formed at an engaging place between the main oil cylinder and the oil storing space of the handlebar base to enhance the joint effect between the sleeve and the bushing.

In addition, an external flange clamped between the installation hole and the fastening seat is disposed in front of the leakage prevention component of the invention to ensure the sealing effect between the fastening seat and the installation hole.

While implementing the invention, the handlebar base has at least one first oil-return hole, which is connected to the oil storing space, disposed to a reciprocation place for the first rubber ring in the main oil cylinder so that hydraulic oil within the oil storing space is automatically filled in the hydraulic pipe in front of the first rubber ring through the first oil-return hole under state of allowing the piston to completely fall back. The brake handlebar may not return to a predetermined angle due to the abrasion of the brake pad, and the braking effect can be retained.

While implementing the invention, at least one second oil-return hole connected to the oil storing space is disposed on the sleeve to allow hydraulic oil entering into the sleeve through the second oil-return hole, thereby increasing the lubricating effect between the piston and the sleeve.

Of course, the handlebar base has the first oil-return hole, which is connected to the oil storing space, disposed to a reciprocation place for the first rubber ring in the main oil cylinder, and the second oil-return hole connected the oil storing space is disposed to the sleeve.

While implementing the invention, a spring is disposed to a position between the main oil cylinder and the piston of the handlebar base to generate an active force of restoring the piston. When a rider releases the brake handlebar, the piston steps back, and the brake handlebar linked to the piston is allowed to return to a predetermined angle.

The handlebar base has the first oil-return hole, which is connected to the oil storing space, disposed to the reciprocation place for the first rubber ring in the main oil cylinder and the spring disposed to the position between the main oil cylinder and the piston.

Under the structural form of disposing the second oil-return hole, which is connected to the oil storing space, on the sleeve, the spring is disposed at the position between the main oil cylinder and the piston of the handlebar base.

Similarly, under structural forms of disposing the first oil-return hole, which is connected to the oil storing space, at the reciprocation place for the first rubber ring in the main oil cylinder of the handlebar base and disposing the second oil-return hole, which is connected to the oil storing space, on the sleeve, the spring is further disposed to the place between the main oil cylinder and the piston of the handlebar base.

While implementing the invention, the first rubber ring can be a bowl rubber ring, and the bowl opening of the first rubber ring is arranged toward the oil outlet to relatively speed up the piston to step back. Further, when the piston moves forward, the contact effect between the first rubber ring and the main oil cylinder is relatively increased as well.

While implementing the invention, the first rubber ring can also be a circular rubber ring. The handlebar base further has an oil-return section, in which an inner diameter is relatively larger than an external diameter of the first rubber ring, formed at a position of relatively disposing the first oil-return hole of the main oil cylinder to relatively speed up the first rubber ring passing through the first oil-return hole.

While implementing the invention, the second rubber ring can be a circular rubber ring that is mainly utilized to prevent hydraulic oil from being leaked through the passing place between the piston and the sleeve and to steady the motion of the piston.

While implementing the invention, the piston is provided with a necking section between the first rubber ring and the second rubber ring to contain hydraulic oil, thereby increasing the lubricating effect with respect to the reciprocation motion of the piston.

While implementing the invention, one end of the piston has a ball seat that is relatively toward the fastening seat. The draw bar has a ball end fit to the ball seat. Accordingly, with the steering effect between the ball end and the ball seat, the draw bar can swing by incorporating the brake handlebar.

While implementing the invention, the draw bar is pivotally connected to the brake handlebar through the rotary shaft so that the draw bar can rotate relative to the brake handlebar in accordance with the changed angle of the brake handlebar, thereby exactly linking the brake handlebar and the piston.

Under the structural form of allowing the draw bar to pivotally connect the brake handlebar through the rotary shaft, a thread section is further disposed to the bar body of the draw bar. The rotary shaft has a thread hole threaded to the thread section of the draw bar so that the angle of the brake handlebar can be regulated by rotating the draw bar.

Of course, under the structural forms of disposing the ball seat, which is relatively toward the fastening seat, at one end of the piston and disposing the ball end, which is fit to the ball seat, at the draw bar, the draw bar can also be pivotally connected to the brake handlebar through the rotary shaft.

Under structural forms of disposing the ball seat, which is relatively toward the fastening seat, at one end of the piston and disposing the ball end, which is fit to the ball seat, at the draw bar and allowing the draw bar to pivotally connect the brake handlebar through the rotary shaft, the thread section is further disposed to the bar body of the draw bar, and the rotary shaft is provided with the thread hole threaded to the thread section of the draw bar.

A rod body that is toward the brake handlebar is extended from one end of the piston. The rod body can replace the draw bar, and the brake handlebar has a ball end that is in contact with the rod body. When the brake handlebar swings, the ball end is utilized to push the rod body to perform the reciprocation motion together with the spring to achieve the foregoing motion as well.

By comparing with the conventional brake master cylinder, the brake master cylinder of the invention does not only have beauty, but also improves the assembly convenience and increases the sealing effect for hydraulic oil under the condition of whether there is the function of automatically filling hydraulic oil, thereby greatly improving the reliability of the brake master cylinder.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The foregoing and other technical characteristics of the present invention will become apparent with the detailed description of the preferred embodiments and the illustration of the related drawings.

With reference toFIG. 1for a cross-sectional drawing of an axial structure of a brake master cylinder in accordance with a first embodiment of the invention is depicted. The brake master cylinder of the invention is to integrally dispose a main oil cylinder11and an oil storing space12at a handlebar base10for installing a brake handlebar70. The oil storing space12is disposed to an axial position of the main oil cylinder11of the handlebar base10. One end of the handlebar base10is provided with an oil outlet13, which relatively corresponds to the main oil cylinder11, connected to a hydraulic pipe (not shown in the figure). One end of the handlebar base10is provided with an installation hole14corresponding to the oil storing space12. In addition, a piston capable of being driven by the brake handlebar70is disposed in the main oil cylinder11.

A sleeve30engaged with the main oil cylinder11is disposed in the oil storing space12of the handlebar base10. One end of the piston20, which relatively stretches into the main oil cylinder11, has a first rubber ring21. One end of the piston20, which relatively stretches into the sleeve30, is provided with a second rubber ring22. A fastening seat40is disposed at the installation hole14of the handlebar base10. The fastening seat40has a positioning sheath41stretching into the oil storing space12to engage with the sleeve30. In addition, a draw bar50passes through a central place of the positioning sheath41to link the piston20and the brake handlebar70.

A leakage prevention component60is disposed between the fastening seat40and the handlebar base10. A bushing61for encapsulating the positioning sheath41of the fastening seat40and the sleeve30is integrally extended from the leakage prevention component60. The leakage prevention component60is mainly utilized to seal the joint place between the fastening seat40and the handlebar base10and encapsulates the joint place between the positioning sheath41of the fastening seat40and the sleeve30to prevent hydraulic oil inside the oil storing space12from being leaked through the joint place between the positioning sheath41of the fastening seat40and the sleeve30.

While assembling the brake master cylinder of the invention, a channel formed by the installation hole14is utilized to sequentially and respectively place the piston20, the sleeve30and the leakage prevention component60into the main oil cylinder11and the oil storing space12of the handlebar base10. Finally, the fastening seat40passed by the draw bar50is installed to the installation hole14of the handlebar base10to quickly complete the assembly of the brake master cylinder. More specifically, under multiple effect of the leakage prevention component60, hydraulic oil can be prevented from being leaked through the installation hole14and the engaging place between the sleeve30and the positioning sheath41. Further, hydraulic oil can be prevented from being leaked through the place passed by the draw bar50under the effect of the second rubber ring22so as to generate better sealing effect for hydraulic oil.

The related structure, functional restriction and generated efficacy of each component in the embodiment of the invention are further depicted.

Under the structural form of integrally extending the bushing61for encapsulating the positioning sheath41of the fastening seat40and the sleeve30from the leakage prevention component60, an inner flange62is disposed to a tail of the bushing61. A circular groove31for fastening the inner flange62is circularly disposed to a periphery of the sleeve30. Moreover, a stage15for plugging the sleeve30and the bushing61is formed at an engaging place between the main oil cylinder11and the oil storing space12of the handlebar base10so as to enhance the joint effect between the sleeve30and the bushing61.

In addition, an external flange63clamped between the installation hole14and the fastening seat40is disposed in front of the leakage prevention component60to ensure the sealing effect between the fastening seat40and the installation hole14.

While implementing the invention, the handlebar base10has at least one first oil-return hole16, which is connected to the oil storing space12, disposed to a reciprocation place for the first rubber ring21in the main oil cylinder11so that hydraulic oil within the oil storing space12is automatically filled in the hydraulic pipe in front of the first rubber ring21through the first oil-return hole16under state of allowing the piston to completely fall back.

While implementing the invention, at least one second oil-return hole32connected to the oil storing space12is disposed on the sleeve30to allow hydraulic oil entering into the sleeve30through the second oil-return hole32, thereby increasing the lubricating effect between the piston20and the sleeve30.

Of course, the handlebar base has the first oil-return hole16, which is connected to the oil storing space12, disposed to a reciprocation place for the first rubber ring21in the main oil cylinder11, and the second oil-return hole32connected the oil storing space12is disposed to the sleeve30to automatically fill hydraulic oil into the hydraulic pipe in front of the first rubber ring21and to increase the lubricating effect between the piston20and the sleeve30.

While implementing the invention, a spring17is disposed to a position between the main oil cylinder11and the piston20of the handlebar base10to generate an active force of restoring the piston20. When a rider releases the brake handlebar, the piston20steps back, and the brake handlebar70linked to the piston20returns to a predetermined angle.

The handlebar base10has the first oil-return hole16, which is connected to the oil storing space12, disposed to the reciprocation place for the first rubber ring21in the main oil cylinder11and the spring17disposed to the position between the main oil cylinder11and the piston20. Alternatively, under the structural form of disposing the second oil-return hole32, which is connected to the oil storing space12, on the sleeve30, the spring17is disposed at the position between the main oil cylinder11and the piston20of the handlebar base10.

Similarly, under structural forms of disposing the first oil-return hole16, which is connected to the oil storing space12, at the reciprocation place for the first rubber ring21in the main oil cylinder11of the handlebar base10and disposing the second oil-return hole32, which is connected to the oil storing space, on the sleeve30, the spring17is further disposed to the place between the main oil cylinder11and the piston20of the handlebar base10.

In the embodiment shown inFIG. 1, the first rubber ring21can be a bowl rubber ring, and the bowl opening of the first rubber ring21is arranged toward the oil outlet13to relatively speed up the piston20to step back. Further, when the piston20moves forward, the contact effect between the first rubber ring21and the main oil cylinder11is relatively increased as well.

Moreover, with reference toFIG. 2for a cross-sectional drawing of a structure in accordance with a second embodiment of the invention, the first rubber ring21can also be a circular rubber ring. The handlebar base10further has an oil-return section18, in which an inner diameter is relatively larger than an external diameter of the first rubber ring21, formed at a position of relatively disposing the first oil-return hole16of the main oil cylinder11to relatively speed up the first rubber ring21passing through the first oil-return hole16, thereby increasing the braking sensitivity.

Under the structural forms of two different embodiments shown inFIG. 1andFIG. 2, the second rubber ring22can be a circular rubber ring that is mainly utilized to prevent hydraulic oil from being leaked through the passing place between the piston20and the sleeve and to steady the motion of the piston20.

The piston20is provided with a necking section23between the first rubber ring21and the second rubber ring22to contain hydraulic oil, thereby increasing the lubricating effect with respect to the reciprocation motion of the piston20.

While implementing the invention, one end of the piston20has a ball seat24that is relatively toward the fastening seat40. The draw bar50has a ball end51fit to the ball seat24. Accordingly, with the steering effect between the ball end51and the ball seat24, the draw bar50can swing by incorporating the brake handlebar70.

The draw bar is pivotally connected to the brake handlebar through a rotary shaft80so that the draw bar50can rotate relative to the brake handlebar70in accordance with the changed angle of the brake handlebar70, thereby exactly linking the brake handlebar70and the piston20.

Under the structural form of allowing the draw bar50to pivotally connect the brake handlebar70through the rotary shaft80, a thread section52is further disposed to the bar body of the draw bar50. The rotary shaft80has a thread hole81threaded to the thread section52of the draw bar50so that the angle of the brake handlebar70can be regulated by rotating the draw bar50.

Of course, under the structural forms of disposing the ball seat24, which is relatively toward the fastening seat40, at one end of the piston20and disposing the ball end51, which is fit to the ball seat24, at the draw bar50, the draw bar50can also be pivotally connected to the brake handlebar70through the rotary shaft80.

Under structural forms of disposing the ball seat20, which is relatively toward the fastening seat40, at one end of the piston20and disposing the ball end51, which is fit to the ball seat24, at the draw bar50and allowing the draw bar50to pivotally connect the brake handlebar20through the rotary shaft80, the thread section52is further disposed to the bar body of the draw bar50, and the rotary shaft80has the thread hole81threaded to the thread section52of the draw bar50.

According to the embodiment shown inFIG. 3, a rod body25that is toward the brake handlebar70is extended from one end of the piston20. The rod body can replace the draw bar50, and the brake handlebar70has a ball end71that is in contact with the rod body25. When the brake handlebar70swings, the ball end71is utilized to push the rod body25to perform the reciprocation motion together with the spring17to achieve the foregoing motion as well.

By comparing with the conventional brake master cylinder, the brake master cylinder of the invention does not only have beauty, but also improves the assembly convenience and increases the sealing effect for hydraulic oil under the condition of whether there is the function of automatically filling hydraulic oil, thereby greatly improving the reliability of the brake master cylinder.

The brake master cylinder provided by the invention improves over the prior art and complies with patent application requirements, and thus is duly filed for patent application. While the invention has been described by device of specific embodiments, numerous modifications and variations could be made thereto by those generally skilled in the art without departing from the scope and spirit of the invention set forth in the claims.