CN103921885B - Hydraulic brake master cylinder - Google Patents

Abstract

The invention discloses an oil pressure brake master cylinder.A movable sleeve is rotated through an exposed outer convex ring, so that one end of the movable sleeve, which is far away from the outer convex ring, can be far away from or can prop against a first inner flange, and the position of one of two flow through holes is adjusted, so that the pressure of oil and air in a main oil cylinder cannot influence the use of braking; furthermore, two elastic sheets of the inner connecting piece are plugged in the inner conical part, an outer convex ring between two ends of the inner connecting piece is propped against the third inner flange adjacent to the fifth inner threaded part, and the two elastic sheets are extruded by the inner conical part to fixedly penetrate through the second end plug, the second piston and the first piston to one end of a brake cable at the two elastic sheets to form a middle pull structure; the first piston is moved through the brake line to adjust the oil pressure, and the position of the master cylinder can be adjusted according to the requirement of a user.

Description

Hydraulic brake master cylinder

technical field

The present invention relates to the related field of a bicycle, in particular to a hydraulic brake master cylinder.

Background technique

The hydraulic brake device used by bicycles should be regarded as one of the most commonly used hydraulic devices. It is mainly equipped with a brake master cylinder driven by the brake handle at the handshake, and is connected to the brake cylinder opposite to the wheel through a hydraulic pipeline. When the rider presses the brake handle, the handle drives a piston in the master cylinder of the brake master cylinder to move forward, pushing the hydraulic oil in the master cylinder into the auxiliary cylinder of the brake caliper, so that the auxiliary The brake pad at the oil cylinder advances towards the direction of the brake disc, and the brake pad is used to contact the brake disc on the wheel hub, thereby generating a detent action on the wheel.

However, the brake master cylinder must be installed adjacent to the brake handle, and there is no flexibility to adjust the position; and after the assembly is completed, the two 0.5mm holes cannot be adjusted, which is very inconvenient.

Based on the above problems, the inventor has proposed a hydraulic brake master cylinder to overcome the defects of the prior art.

Contents of the invention

The technical problem mainly solved by the present invention is to provide a hydraulic brake master cylinder, which can avoid that the brake master cylinder must be adjacent to the position of the brake handle, and there is no flexibility to adjust the position, and after the assembly is completed, the two 0.5mm holes cannot be adjusted. the inconvenience caused.

In order to solve the above problems, the technical solution adopted by the present invention is to provide a hydraulic brake master cylinder, which at least includes:

A main body has a main oil cylinder, the two ends of the main oil cylinder are respectively provided with a first internal thread part and a second internal thread part, the main oil cylinder has a first internal flange and a second internal flange, the first internal thread an internal flange adjacent to the first internally threaded portion, and a second internal flange adjacent to the second internally threaded portion;

A movable sleeve is installed in the main oil cylinder of the main body, and one end of the movable sleeve protrudes radially outwards with an outer convex ring, and the outer convex ring is exposed outside the main oil cylinder, adjacent to the outer convex ring There is a first external thread part on the outer surface of the outer ring, and a fourth internal thread part is provided on the inner surface adjacent to the outer convex ring. The first external thread part is rotatably adjustable with the first internal thread part of the master oil cylinder. Connecting, the fourth internal thread part is screwed and combined with a fourth external thread part of a first end plug, and the movable sleeve has two opposite flow holes, located between the two ends of the movable sleeve;

A first piston has a large-diameter section and a small-diameter section connected to each other, the large-diameter section is passed through the movable sleeve, the small-diameter section is exposed outside the movable sleeve, and the large-diameter section and the small-diameter section the junction of the segments abuts against the first end plug; and

A second piston, one end of which is plugged into the end of the large-diameter section of the first piston away from the small-diameter section, and the other end is plugged into the second inner flange of the master cylinder and adjacent to the second internal thread part, and a second external thread part of a second end plug is rotatably screwed to the second internal thread part of the master oil cylinder, and abuts against an end of the second piston adjacent to the second internal thread part ;

Wherein, an elastic component is sleeved outside the second piston, and the two ends of the elastic component are respectively pressed against the large-diameter section of the first piston and the first inner flange of the master cylinder; through the exposed The outer convex ring rotates the movable sleeve, so that the end of the movable sleeve away from the outer convex ring can be away from or against the first inner flange, thereby adjusting the position of one of the two flow holes.

Wherein, the movable sleeve has a concave ring groove adjacent to the first external thread portion and a portion far away from the first external thread portion, and each of the concave ring grooves is respectively provided with an O-ring sleeve.

Wherein, the two ends of the large-diameter section of the first piston respectively have a recessed ring groove, and each of the recessed ring grooves is respectively provided with a V-shaped ring.

Wherein, the end of the small-diameter section of the first piston away from the large-diameter section is provided with a fifth external thread portion, and the inner surface of the small-diameter section has the fifth external thread portion in a tapered shape that gradually increases outward. Inner tapered part, a fifth internal thread part of an outer sleeve is screwed to the fifth external thread part, and a third flange is arranged in the end of the outer sleeve away from the fifth internal thread part, and an inner The two elastic pieces of the connecting piece are plugged in the inner tapered part, and an outer convex ring between the two ends of the inner connecting piece is pressed against the third inner flange adjacent to the fifth internal thread part, and the two elastic pieces are supported by the The extrusion of the inner tapered portion fixes one end of a brake line passing through the second end plug, the second piston, and the first piston to the two elastic pieces.

A hydraulic brake master cylinder at least includes:

A main body has a main oil cylinder and an auxiliary oil cylinder connected to each other. The two ends of the main oil cylinder are respectively provided with a first internal thread part and a second internal thread part. The end of the auxiliary oil cylinder adjacent to the first internal thread part is provided with a The third internal thread part, the third internal thread part is screwed and combined with a third external thread part of an end cap, the main oil cylinder has a first internal flange and a second internal flange, the first internal flange The rim is adjacent to the first internally threaded portion, and the second internal flange is adjacent to the second internally threaded portion;

A movable sleeve is installed in the main oil cylinder of the main body, and one end of the movable sleeve protrudes radially outwards with an outer convex ring, and the outer convex ring is exposed outside the main oil cylinder, adjacent to the outer convex ring There is a first external thread part on the outer surface of the outer ring, and a fourth internal thread part is provided on the inner surface adjacent to the outer convex ring. The first external thread part is rotatably adjustable with the first internal thread part of the master oil cylinder. Connecting, the fourth internal thread part is screwed and combined with a fourth external thread part of a first end plug, and the movable sleeve has two opposite flow holes, located between the two ends of the movable sleeve;

A first piston has a large-diameter section and a small-diameter section connected to each other, the large-diameter section is passed through the movable sleeve, the small-diameter section is exposed outside the movable sleeve, and the large-diameter section and the small-diameter section the junction of the segments abuts against the first end plug; and

A second piston, one end of which is plugged into the end of the large-diameter section of the first piston away from the small-diameter section, and the other end is plugged into the second inner flange of the master cylinder and adjacent to the second internal thread part, and a second external thread part of a second end plug is rotatably screwed to the second internal thread part of the main oil cylinder, and abuts against an end of the second piston adjacent to the second internal thread part;

Wherein, an elastic component is sleeved outside the second piston, and the two ends of the elastic component are respectively pressed against the large-diameter section of the first piston and the first inner flange of the master cylinder; through the exposed The outer convex ring rotates the movable sleeve, so that the end of the movable sleeve away from the outer convex ring can be away from or against the first inner flange, thereby adjusting the position of one of the two flow holes to be aligned The communication place between the main oil cylinder and the auxiliary oil cylinder.

Wherein, the end of the small-diameter section of the first piston away from the large-diameter section is provided with a fifth external thread portion, and the inner surface of the small-diameter section has the fifth external thread portion in a tapered shape that gradually increases outward. Inner tapered part, a fifth internal thread part of an outer sleeve is screwed to the fifth external thread part, and a third flange is arranged in the end of the outer sleeve far away from the fifth internal thread, and an internal connection The two elastic pieces of the piece are plugged in the inner tapered part, and an outer convex ring between the two ends of the inner connecting piece is pressed against the third inner flange adjacent to the fifth internal thread part, and the two elastic pieces are supported by the inner Extrusion of the tapered portion fixes one end of a brake line passing through the second end plug, the second piston, and the first piston to the two elastic pieces.

Beneficial effects of the present invention: With the above-mentioned structure, the movable sleeve is rotated through the exposed outer convex ring, so that the end of the movable sleeve away from the outer convex ring can be far away from or against the first inner flange, and thereby adjusted The position of one of the two flow holes can be aligned with the connection between the main oil cylinder and the auxiliary oil cylinder, so that the pressure of the oil fluid and air in the main oil cylinder will not affect the use of the brake. The hydraulic brake master cylinder of the present invention can be arranged at any position of the bicycle, such as any position of the vehicle frame, any position of the handlebar or any position of the front fork; To press the brake master cylinder, the color of the outer cover can be the same as that of the frame, handlebar or front fork to achieve the hidden effect.

Description of drawings

Fig. 1 is an exploded schematic view of a first embodiment of a hydraulic brake master cylinder of the present invention.

FIG. 2 is a schematic view of the appearance of the first embodiment of the hydraulic brake master cylinder of the present invention.

FIG. 3 is a schematic cross-sectional view of the first embodiment of the hydraulic brake master cylinder of the present invention.

Fig. 4 is an exploded schematic diagram of a second embodiment of the hydraulic brake master cylinder of the present invention.

FIG. 5 is a schematic view of the appearance of the second embodiment of the hydraulic brake master cylinder of the present invention.

FIG. 6 is a schematic cross-sectional view of the second embodiment of the hydraulic brake master cylinder of the present invention.

Fig. 7 is a schematic diagram of the present invention where the hydraulic brake master cylinder is installed anywhere on the frame of the bicycle.

Fig. 8 is a schematic diagram of the hydraulic brake master cylinder of the present invention arranged at the handlebar of the bicycle.

Fig. 9 is a schematic diagram of the hydraulic brake master cylinder of the present invention arranged at the front fork of the bicycle.

Description of main symbols

1 hydraulic brake master cylinder; 2 main body; 21 main oil cylinder; 211 first internal thread part; 212 second internal thread part; 213 first internal flange; 214 second internal flange; 22 auxiliary oil cylinder; 221 third internal 23 end cap; 231 third external thread; 3 movable sleeve; 31 external convex ring; 32 first external thread; 33 fourth internal thread; 34 circulation hole; 35 circulation hole; 36 concave ring groove ; 37 O-ring; 4 first piston; 41 large-diameter section; 42 small-diameter section; 43 concave ring groove; 44V-shaped ring; 45 fifth external thread part; 6 first end plug; 61 fourth external thread part; 7 second end plug; 71 second external thread part; 8 outer sleeve; 81 fifth internal thread part; 82 third flange; 9 internal connection piece; 91 Shrapnel; 92 outer convex ring; 10 brake line; 100 frame; 200 handle; 300 front fork; 400 jacket cover.

detailed description

Please also refer to FIG. 1 to FIG. 3 , the hydraulic brake master cylinder 1 of this embodiment may include a body 2 , a movable sleeve 3 , a first piston 4 and a second piston 5 .

The main body 2 has a main oil cylinder 21. The two ends of the main oil cylinder are respectively provided with a first internal thread part 211 and a second internal thread part 212. The main oil cylinder 21 has a first internal flange 213 and a second internal flange 214 , the first internal flange 213 is adjacent to the first internal thread portion 211 , and the second internal flange 214 is adjacent to the second internal thread portion 212 .

The movable sleeve 3 is installed in the main oil cylinder 21 of the main body 2, and one end of the movable sleeve 3 protrudes radially outwards with an outer convex ring 31, and the outer convex ring 31 is exposed outside the main oil cylinder 21, adjacent to the outer convex ring 31 The outer surface at the place is provided with a first external thread portion 32, and the inner surface adjacent to the outer convex ring 31 is provided with a fourth internal thread portion 33, the first external thread portion 32 and the first internal thread portion 211 of the master cylinder 21 are rotatable Adjustably connected, the adjustment stroke can be about 1mm, the fourth internal threaded part 33 is screwed and combined with a fourth external threaded part 61 of a first end plug 6, and the movable sleeve 3 has two flow holes ( Such as 0.5mm hole) 34,35, are positioned between the two ends of movable sleeve 3.

Wherein, the movable sleeve 3 has a concave ring groove 36 adjacent to the first external thread portion 32 and away from the first external thread portion 32 respectively, and each concave ring groove 36 is respectively provided with an O-ring 37 sleeved therein.

The first piston 4 has a large-diameter section 41 and a small-diameter section 42 connected to each other. The large-diameter section 41 is worn in the movable sleeve 3, and the small-diameter section 42 is exposed outside the movable sleeve 3. The large-diameter section 41 and the small-diameter The junction of the segments 42 abuts against the first end plug 6 .

Wherein, two ends of the large-diameter section 41 of the first piston 4 respectively have a recessed ring groove 43 , and each recessed ring groove 43 is respectively provided with a V-shaped ring 44 to be sleeved therein.

One end of the second piston 5 is plugged in the end of the large-diameter section 41 of the first piston 4 away from the small-diameter section 42, and the other end of the second piston 5 is plugged in the second inner flange 214 of the master cylinder 21 and adjacent to the first piston 4. Two internal threaded parts 212, and a second external threaded part 71 of a second end plug 7 is screwed with the second internal threaded part 212 of the master oil cylinder 21 in a rotatable and adjustable manner, and abuts against the second piston 5 adjacent to the second One end of the internal thread portion 212 .

Wherein, an elastic component 50 is sheathed outside the second piston 5 , and two ends of the elastic component 50 are pressed against the large-diameter section 41 of the first piston 4 and the first inner flange 213 of the master cylinder 21 respectively.

With the above-mentioned structure, the movable sleeve 3 is rotated through the exposed outer convex ring 31, so that the end of the movable sleeve 3 away from the outer convex ring 31 can be away from or against the first inner flange 213, thereby adjusting the two The position of one of the flow holes 34, 35 makes the pressure of oil and air in the main oil cylinder 21 not affect the use of the brake.

Furthermore, the end of the small-diameter section 42 of the first piston 4 away from the large-diameter section 41 is provided with a fifth external threaded portion 45, and the inner surface of the small-diameter section 42 with the fifth external threaded portion 45 is tapered outwardly. An inner tapered portion 46, a fifth inner threaded portion 81 of an outer sleeve 8 is screwed to the fifth outer threaded portion 45, and an end of the outer sleeve 8 away from the fifth inner threaded portion 81 is provided with a third The flange 82, the two elastic pieces 91 of an inner connecting piece 9 are plugged in the inner tapered part 46, and an outer convex ring 92 between the two ends of the inner connecting piece 9 abuts against the third inner flange 82 adjacent to the fifth inner flange 82. At the threaded portion 81, the second elastic piece 91 is squeezed by the inner tapered portion 46 to fix one end of a brake line 10 passing through the second end plug 7, the second piston 5, and the first piston 4 to the second elastic piece 91. , forming a center pull structure; thereby the first piston 4 is moved through the brake line 10 to adjust the oil pressure, and the position of the brake master cylinder can be adjusted according to the needs of the user.

Please also refer to FIG. 4 to FIG. 6 , the hydraulic brake master cylinder 1 of this embodiment may include a body 2 , a movable sleeve 3 , a first piston 4 and a second piston 5 .

The main body 2 has a main oil cylinder 21 and an auxiliary oil cylinder 22 connected to each other. The two ends of the main oil cylinder 21 are respectively provided with a first internal thread part 211 and a second internal thread part 212. The auxiliary oil cylinder 22 is adjacent to the first internal thread part 211. One end is provided with a third internal thread portion 221, and the third internal thread portion 221 is screwed together with a third external thread portion 231 of an end cover 23. The main oil cylinder 21 has a first internal flange 213 and a second internal protrusion The first internal flange 213 is adjacent to the first internal thread portion 211 , and the second internal flange 214 is adjacent to the second internal thread portion 212 .

The movable sleeve 3 is installed in the main oil cylinder 21 of the main body 2, and one end of the movable sleeve 3 protrudes radially outwards with an outer convex ring 31, and the outer convex ring 31 is exposed outside the main oil cylinder 21, adjacent to the outer convex ring 31 The outer surface at the place is provided with a first external thread portion 32, and the inner surface adjacent to the outer convex ring 31 is provided with a fourth internal thread portion 33, the first external thread portion 32 and the first internal thread portion 211 of the master cylinder 21 are rotatable Adjustably connected, the adjustment stroke can be about 1mm, the fourth internal threaded part 33 is screwed and combined with a fourth external threaded part 61 of a first end plug 6, and the movable sleeve 3 has two flow holes ( Such as 0.5mm hole) 34,35, are positioned between the two ends of movable sleeve 3.

Wherein, the movable sleeve 3 has a recessed ring groove 36 adjacent to the first external threaded portion 32 and away from the first external threaded portion 32 respectively, and each recessed ring groove 36 is respectively provided with an O-ring 37 sleeved therein.

The first piston 4 has a large-diameter section 41 and a small-diameter section 42 connected to each other. The large-diameter section 41 is worn in the movable sleeve 3, and the small-diameter section 42 is exposed outside the movable sleeve 3. The large-diameter section 41 and the small-diameter The junction of the segments 42 abuts against the first end plug 6 .

Wherein, two ends of the large-diameter section 41 of the first piston 4 respectively have a recessed ring groove 43 , and each recessed ring groove 43 is respectively provided with a V-shaped ring 44 to be sleeved therein.

One end of the second piston 5 is plugged in the end of the large-diameter section 41 of the first piston 4 away from the small-diameter section 42, and the other end of the second piston 5 is plugged in the second inner flange 214 of the master cylinder 21 and adjacent to the first piston 4. Two internal threaded parts 212, and a second external threaded part 71 of a second end plug 7 is screwed with the second internal threaded part 212 of the master oil cylinder 21 in a rotatable and adjustable manner, and abuts against the second piston 5 adjacent to the second One end of the internal thread portion 212 .

Wherein, an elastic component 50 is sheathed outside the second piston 5 , and two ends of the elastic component 50 are pressed against the large-diameter section 41 of the first piston 4 and the first inner flange 213 of the master cylinder 21 respectively.

With the above-mentioned structure, the movable sleeve 3 is rotated through the exposed outer convex ring 31, so that the end of the movable sleeve 3 away from the outer convex ring 31 can be away from or against the first inner flange 213, thereby adjusting the two The position of one of the flow holes 34, 35 can be aligned with the connection between the main oil cylinder 21 and the auxiliary oil cylinder 22, so that the oil and air pressure in the main oil cylinder 21 will not affect the use of the brake.

Moreover, the brake line 10 , the master cylinder 21 , the first piston 4 and the second piston 5 can be arranged coaxially.

Furthermore, the end of the small-diameter section 42 of the first piston 4 away from the large-diameter section 41 is provided with a fifth external threaded portion 45, and the inner surface of the small-diameter section 42 with the fifth external threaded portion 45 is tapered outwardly. An inner tapered portion 46, a fifth inner threaded portion 81 of an outer sleeve 8 is screwed to the fifth outer threaded portion 45, and an end of the outer sleeve 8 away from the fifth inner threaded portion 81 is provided with a third The flange 82, the two elastic pieces 91 of an inner connecting piece 9 are plugged in the inner tapered part 46, and an outer convex ring 92 between the two ends of the inner connecting piece 9 abuts against the third inner flange 82 adjacent to the fifth inner flange 82. At the threaded portion 81, the second elastic piece 91 is squeezed by the inner tapered portion 46 to fix one end of a brake line 10 passing through the second end plug 7, the second piston 5, and the first piston 4 to the second elastic piece 91. , forming a center pull structure; thereby the first piston 4 is moved through the brake line 10 to adjust the oil pressure, and the position of the brake master cylinder can be adjusted according to the needs of the user.

In addition, please refer to FIG. 7 to FIG. 9, the hydraulic brake master cylinder 1 of the present invention can be arranged at any position of the bicycle, such as any position of the vehicle frame 100 (as shown in FIG. 7 ), any position of the handlebar 200 (such as 8) or any place (as shown in FIG. 9 ) of the front fork 300; meanwhile, a detachable overcoat cover 400 can cover the hydraulic brake master cylinder 1, and the color of the overcoat cover 400 can be matched with that of the vehicle. The frame 100, the handle 200 or the front fork 300 are the same to achieve the effect of concealment.

The above is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related technologies fields, are all included in the scope of patent protection of the present invention in the same way.

Claims (6)

1. A hydraulic brake master cylinder, characterized in that it at least includes: A main body has a main oil cylinder, the two ends of the main oil cylinder are respectively provided with a first internal thread part and a second internal thread part, the main oil cylinder has a first internal flange and a second internal flange, the first internal thread an internal flange adjacent to the first internally threaded portion, the second internal flange adjacent to the second internally threaded portion; A movable sleeve is installed in the main oil cylinder of the main body, and one end of the movable sleeve protrudes radially outwards with an outer convex ring, and the outer convex ring is exposed outside the main oil cylinder, adjacent to the outer convex ring There is a first external thread part on the outer surface of the outer ring, and a fourth internal thread part is provided on the inner surface adjacent to the outer convex ring. The first external thread part is rotatably adjustable with the first internal thread part of the master oil cylinder. Connecting, the fourth internal thread part is screwed and combined with a fourth external thread part of a first end plug, and the movable sleeve has two opposite flow holes, located between the two ends of the movable sleeve; A first piston has a large-diameter section and a small-diameter section connected to each other, the large-diameter section is passed through the movable sleeve, the small-diameter section is exposed outside the movable sleeve, and the large-diameter section and the small-diameter section the junction of the segments abuts against the first end plug; and A second piston, one end of which is plugged into the end of the large-diameter section of the first piston away from the small-diameter section, and the other end is plugged into the second inner flange of the master cylinder and adjacent to the second internal thread part, and a second external thread part of a second end plug is rotatably screwed to the second internal thread part of the master oil cylinder, and abuts against an end of the second piston adjacent to the second internal thread part ; Wherein, an elastic component is sleeved outside the second piston, and the two ends of the elastic component are respectively pressed against the large-diameter section of the first piston and the first inner flange of the master cylinder; through the exposed The outer convex ring rotates the movable sleeve, so that the end of the movable sleeve away from the outer convex ring can be away from or against the first inner flange, thereby adjusting the position of one of the two flow holes. 2. The hydraulic brake master cylinder according to claim 1, wherein the movable sleeve has a concave ring groove adjacent to the first external thread portion and a portion far away from the first external thread portion, and each of the concave ring grooves is The ring grooves are respectively provided for an O-ring to be sleeved. 3. The hydraulic brake master cylinder according to claim 1, wherein the two ends of the large-diameter section of the first piston respectively have a concave ring groove, and each of the concave ring grooves is respectively provided with a V-shaped ring. . 4. The hydraulic brake master cylinder according to claim 1, characterized in that, the end of the small-diameter section of the first piston away from the large-diameter section is provided with a fifth external thread portion, and the small-diameter section has the fifth The inner surface of the external threaded portion is an internal tapered portion that tapers toward the outside, and a fifth internal threaded portion of an outer sleeve is screwed to the fifth external threaded portion, and the outer sleeve is far away from the One end of the fifth internal thread part is provided with a third flange, and the two elastic pieces of an internal connecting piece are plugged in the internal tapered part, and an external convex ring between the two ends of the internal connecting piece is pressed against the third flange. The flange is adjacent to the fifth internal threaded portion, and the two elastic pieces are pressed by the inner tapered portion to fix one of the two elastic pieces passing through the second end plug, the second piston, and the first piston to the two elastic pieces. end of the brake cable. 5. A hydraulic brake master cylinder, characterized in that it at least includes: A main body has a main oil cylinder and an auxiliary oil cylinder connected to each other. The two ends of the main oil cylinder are respectively provided with a first internal thread part and a second internal thread part. The end of the auxiliary oil cylinder adjacent to the first internal thread part is provided with a The third internal thread part, the third internal thread part is screwed and combined with a third external thread part of an end cap, the main oil cylinder has a first internal flange and a second internal flange, the first internal flange The rim is adjacent to the first internally threaded portion, and the second internal flange is adjacent to the second internally threaded portion; A movable sleeve is installed in the main oil cylinder of the main body, and one end of the movable sleeve protrudes radially outwards with an outer convex ring, and the outer convex ring is exposed outside the main oil cylinder, adjacent to the outer convex ring There is a first external thread part on the outer surface of the outer ring, and a fourth internal thread part is provided on the inner surface adjacent to the outer convex ring. The first external thread part is rotatably adjustable with the first internal thread part of the master oil cylinder. Connecting, the fourth internal thread part is screwed and combined with a fourth external thread part of a first end plug, and the movable sleeve has two opposite flow holes, located between the two ends of the movable sleeve; A first piston has a large-diameter section and a small-diameter section connected to each other, the large-diameter section is passed through the movable sleeve, the small-diameter section is exposed outside the movable sleeve, and the large-diameter section and the small-diameter section the junction of the segments abuts against the first end plug; and A second piston, one end of which is plugged into the end of the large-diameter section of the first piston away from the small-diameter section, and the other end is plugged into the second inner flange of the master cylinder and adjacent to the second internal thread part, and a second external thread part of a second end plug is rotatably screwed to the second internal thread part of the main oil cylinder, and abuts against an end of the second piston adjacent to the second internal thread part; Wherein, an elastic component is sleeved outside the second piston, and the two ends of the elastic component are respectively pressed against the large-diameter section of the first piston and the first inner flange of the master cylinder; through the exposed The outer convex ring rotates the movable sleeve, so that the end of the movable sleeve away from the outer convex ring can be away from or against the first inner flange, thereby adjusting the position of one of the two flow holes to be aligned The communication place between the main oil cylinder and the auxiliary oil cylinder. 6. The hydraulic brake master cylinder according to claim 5, characterized in that, the end of the small-diameter section of the first piston away from the large-diameter section is provided with a fifth external thread portion, and the small-diameter section has the fifth The inner surface of the external threaded portion is an internal tapered portion that tapers toward the outside, and a fifth internal threaded portion of an outer sleeve is screwed to the fifth external threaded portion, and the outer sleeve is far away from the One end of the fifth internal thread is provided with a third flange, and the two elastic plugs of an inner connecting piece are arranged in the inner tapered part, and an outer convex ring between two ends of the inner connecting piece is pressed against the third flange. Edge adjacent to the fifth internal thread portion, the two elastic pieces are pressed by the inner tapered portion to fix a brake that passes through the second end plug, the second piston, and the first piston to the two elastic pieces. end of the line.