A mechanical double-force brake

Abstract

The present invention provides a mechanical double-force booster brake, comprising a brake base plate, a return spring, two brake shoes and two friction plates; the two brake shoes are arranged opposite to each other, and the two friction plates are respectively fixed on the outsides of the two brake shoes; the return spring gives the two brake shoes an elastic force to retract inward; a force booster mechanism and a force transmission regulator are respectively arranged between the opposite ends of the two brake shoes; the force booster mechanism comprises a driving cam and a support column; the driving cam is located between the two brake shoes and the driving cam is slidably connected to the brake base plate along the movable direction of the brake shoes, and the brake base plate is provided with a movable hole for sliding; the support column is fixed on the brake base plate and is located between the two brake shoes; the two ends of the force transmission regulator are respectively in contact with the ends of the two brake shoes away from the force booster mechanism. The present invention solves the problem of insufficient braking capacity of the existing mechanical brake.

Description

Technical Field

[0001] The present invention relates to the technical field of brakes, and in particular to a drum type mechanical brake. Background Art

[0002] Brakes usually include drum brakes and disc brakes; their principle is that a fixed non-rotating part (brake shoe or brake caliper) presses the part that rotates with the wheel (brake drum or brake disc) with a certain force, thereby forcing the wheel to brake.

[0003] Drum brakes have the characteristics of large braking force, low cost, high reliability and easy maintenance, so they are generally used on the rear wheels of heavy-duty vehicles. Depending on the driving mode, drum brakes are mainly divided into mechanical brakes, hydraulic brakes and pneumatic brakes.

[0004] At present, traditional mechanical brakes are mainly of the leading and trailing shoe type, which mainly include a brake base plate, two friction plates, two brake shoes, a return spring and a drive mechanism; the two brake shoes are respectively hinged on the brake base plate, resulting in the two brake shoes being relatively independent, and one of the brake shoes is affected by the friction force, resulting in a decrease in the braking pressure, so there is a problem of insufficient braking force. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a mechanical dual-force brake, which solves the problem of insufficient braking capacity of the mechanical brake in the prior art.

[0006] According to an embodiment of the present invention, a mechanical double-force booster brake comprises a brake base plate, a return spring, two brake shoes and two friction plates; the two brake shoes are arranged opposite to each other, and the two friction plates are respectively fixed on the outsides of the two brake shoes; the return spring gives the two brake shoes an elastic force to retract inward; a force booster mechanism and a force transmission regulator are respectively arranged between the opposite ends of the two brake shoes;

[0007] The force-increasing mechanism comprises a driving cam and a supporting column; the driving cam and the supporting column are both located between the two brake shoes, and the driving cam is slidably connected to the brake base plate along the movable direction of the brake shoes, and the brake base plate is provided with a movable hole for sliding; the supporting column is fixed to the brake base plate;

[0008] The two ends of the force transmission regulator are respectively in contact with the ends of the two brake shoes away from the force amplification mechanism.

[0009] The technical principle of the present invention is: when braking is required, the driving cam is rotated so that its radially longer part contacts the end of the brake shoe and bears force, and the two brake shoes are pushed toward the inner wall of the brake drum, so that the friction plate contacts and rubs with the brake drum of the automobile to achieve the braking effect; in this process, the force transmission regulator transmits the force-increasing effect of the friction force of the previous brake shoe to the next brake shoe, and at the same time, the driving cam floats and gives way to the direction of the previous brake shoe as needed, and the support column and the driving cam jointly apply pressure to the next brake shoe after the driving cam gives way, so as to prevent the force-increasing effect of the driving cam itself from being affected after the pressure transmission. When stopping braking, the driving cam is rotated again so that the radially shorter part contacts the force plate and bears force, and the brake shoe retracts under the pulling force of the reset spring, and then detaches from the brake drum, and the driving cam is also pushed back to the middle, so as to achieve the effect of releasing the brake.

[0010] Compared with the prior art, the present invention has the following beneficial effects: the present invention realizes the mutual transmission and utilization of the force amplification of the brake shoe through a mechanical structure, achieving the dual force amplification effect of the driving cam and the friction force transmission; compared with the traditional mechanical brake, its braking capacity is greatly enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a front view of the first embodiment of the present invention in cooperation with a brake drum.

[0012] Figure 2 for Figure 1 Axonal view from the back.

[0013] Figure 3 This is a three-dimensional view from one angle of the first force amplification mechanism.

[0014] Figure 4 This is the first three-dimensional view from another angle.

[0015] Figure 5 It is a front view of a third embodiment of the present invention cooperating with a brake drum.

[0016] Figure 6 for Figure 5 Axonometric view from the back.

[0017] Figure 7 This is a three-dimensional view from one angle of the third force amplification mechanism.

[0018] Figure 8 This is a 3D view of the third force amplification mechanism without the drive cylinder.

[0019] In the above drawings: 1. brake drum; 2. brake base plate; 3. brake shoe; 4. friction plate; 5. driving cam; 6. force transmission regulator; 7. force plate; 8. return spring; 9. spring hole; 10. support column; 11. mounting plate; 12. sliding plate; 13. strip groove; 14. strip hole; 15. movable hole; 16. driving cylinder; 17. driving piston; 18. movable plate. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0021] like Figure 1-8 As shown, the embodiment of the present invention proposes a mechanical double-force booster brake, comprising a brake base plate 2, a return spring 8, two brake shoes 3 and two friction plates 4; the two brake shoes 3 are arranged opposite to each other, and the two friction plates 4 are respectively fixed on the outsides of the two brake shoes 3; the return spring 8 gives the two brake shoes 3 an elastic force to retract inward; a force booster mechanism and a force transmission regulator 6 are respectively provided between the opposite ends of the two brake shoes 3;

[0022] The force-increasing mechanism comprises a driving cam 5 and a supporting column 10; the driving cam 5 is located between the two brake shoes 3 and is slidably connected to the brake base plate 2 along the movable direction of the brake shoes 3, and the brake base plate 2 is provided with a movable hole 15 for sliding; the supporting column 10 is fixed on the brake base plate 2 and is located between the two brake shoes 3;

[0023] Both ends of the force transmission regulator 6 are in contact with the ends of the two brake shoes 3 away from the force amplification mechanism respectively.

[0024] In actual configuration, the two brake shoes 3 are provided with force plates 7 on both sides of the driving cam 5, and the force plates 7 are fixed to the ends of the brake shoes 3. The force plates 7 are used to improve the force structure of the ends of the brake shoes 3.

[0025] As described in the above scheme, the working principle of the present invention is as follows: the brake cooperates with the automobile brake drum 1. When braking is required, the driving cam 5 is rotated to make its radially longer part contact with the force plate 7, and the two brake shoes 3 are pushed to the inner wall of the brake drum 1 through the force plate 7, so that the friction plate 4 contacts and rubs with the brake drum 1 to achieve the braking effect; in this process, along the rotation direction of the brake drum 1, starting from the force increasing mechanism, the component force of the friction force received by the front brake shoe 3 is consistent with the driving direction of the driving cam 5, and the friction force increases the pressure of the brake shoe 3 on the brake drum 1, and the friction force plays a "force increasing" role; the component force direction of the friction force received by the rear brake shoe 3 is opposite to the driving direction of the driving cam 5, and the friction force reduces the pressure between the brake shoe 3 and the brake drum 1, and the friction force plays a "force reducing" role. At this time, the force transmission regulator 6 transmits the force increasing effect of the friction force of the front brake shoe 3 to the rear brake shoe 3, and the driving cam 5 gives way to the direction of the front brake shoe 3. The support column 10 applies pressure to the rear brake shoe 3 together with the driving cam 5 after the driving cam 5 gives way, so as to prevent the pressure transmission from affecting the force-increasing effect of the driving cam 5 itself. After the driving cam 5 itself is subjected to lateral pressure, its force-increasing effect on both sides will be reduced. The setting of the support column 10, after the driving cam 5 slides, the support column 10 and the brake shoe 3 are in contact and supported, so as to prevent the rear brake shoe 3 from excessively squeezing the driving cam 5 after the friction force is transmitted. This is the case for both forward and reverse rotations, except that the transmission direction is changed. When the braking stops, the driving cam 5 is rotated again so that its radially shorter part contacts the force plate 7, and the brake shoe 3 retracts under the pulling force of the reset spring 8, and then separates from the brake drum 1, achieving the effect of releasing the brake. In addition to the friction force transmission, the different friction degrees of the two friction plates 4 will also cause the overall offset of the two brake shoes 3. When the friction degrees of the two friction plates 4 are different, the two brake shoes 3 transmit thrust through the force transmission regulator 6, and the force transmission regulator 6 is offset a little distance to the side with a larger friction degree, thereby ensuring that both friction plates 4 can contact the inner wall of the brake drum 1 and ensure the friction effect.

[0026] In one embodiment, Figure 1-4As shown, the force-increasing mechanism further includes a mounting plate 11 and a sliding plate 12. The mounting plate 11 is fixed on the brake base plate 2, the sliding plate 12 is slidably connected to the mounting plate 11, the driving cam 5 is rotatably connected to the sliding plate 12, and the mounting plate 11 is provided with a strip groove 13 for the sliding plate 12 to slide and a strip hole 14 for the driving cam 5 shaft to slide, and the strip hole 14 is arranged corresponding to the movable hole 15. The strip groove 13 is provided for the sliding plate 12 to slide, so as to ensure the stability of the overall sliding; the driving cam 5 needs to be connected to the transmission structure, so it needs to pass through the brake base plate 2 and extend out of the brake base plate 2, so the strip hole 14 is reserved for it to move, and the width of the strip groove 13 is equal to the width of the sliding plate 12, so as to ensure the stability of the sliding. The sliding plate 12 also prevents the driving cam 5 from moving axially; the strip hole 14 and the movable hole 15 jointly limit the moving path of the driving cam 5. The width of the strip hole 14 can be equal to the diameter of the rotating connecting part of the driving cam 5 to ensure the stability of the movement of the driving cam 5. The strip hole 14 is within the coverage of the movable hole 15; or the movable hole 15 has the same diameter as the rotating part of the driving cam 5; the movable hole 15 is within the coverage of the strip hole 14, or the movable hole 15 and the strip hole 14 can both be strip hole-shaped and their contours completely overlap. In conjunction with the setting of the mounting plate 11, the strength of the connecting position of the driving cam 5 is guaranteed, and it is convenient to process them separately. The moving range of the driving cam 5 does not need to be very large, and it is sufficient to allow the support column 10 to be stressed; it can move in a direction perpendicular to the force plate 7 when not braked, or it can move in an arc range centered on the center of the brake bottom plate 2. Of course, the shape of the strip groove 13 must be changed accordingly.

[0027] Furthermore, the force plate 7 is fixed at the end of the brake shoe 3 in a direction perpendicular to the brake shoe 3 and is provided with a reinforcing plate on the side away from the driving cam 5. The force plate 7 ensures that the driving cam 5 has a sufficient contact force bearing area with the brake shoe 3, improving the force bearing condition. The reinforcing plate is generally perpendicular to the force plate 7, which provides support for the force plate 7 and ensures the force strength of the end of the brake shoe 3.

[0028] Furthermore, the cross section of the driving cam 5 between the two force-bearing plates 7 is in the shape of a strip hole. The difference in width and length ensures the driving distance, and the side surface of the radially longer part of the driving cam 5 is an arc surface to ensure smoothness during driving, and the two side surfaces with opposite widths are flat to ensure stable force when not braking; the driving cam 5 should not be too thin, and should have a certain thickness to ensure strength. The part of the driving cam 5 outside the two force-bearing plates 7 is generally cylindrical, which is convenient for rotation connection and transmission connection.

[0029] In another embodiment, the force-increasing mechanism further includes two clamping plates, which cover both ends of the movable hole 15 and are provided with rotation holes for the drive cam 5 to be rotatably connected, and the drive cam 5 passes through the movable hole 15 and the two rotation holes in a direction perpendicular to the brake base plate 2. The two clamping plates limit the axial movement of the drive cam 5, and then limit the movement path of the drive cam 5 by using the opening shape.

[0030] In another embodiment, if Figure 5-8 As shown, the force-enhancing mechanism also includes a driving cylinder 16 and a driving piston 17. The two ends of the driving cylinder 16 are respectively opposite to the ends of the two brake shoes 3, and are slidably connected to the brake base plate 2 along its own axial direction; one end of the two driving pistons 17 are slidably connected in the driving cylinder 16, and the other ends extend from the two ends of the driving cylinder 16 and contact with the ends of the two brake shoes 3; the driving cam 5 extends into the driving cylinder 16 along a direction perpendicular to the brake base plate 2 and is rotatably connected between the two driving pistons 17.

[0031] The rotation of the driving cam 5 drives the driving piston 17 to move in the driving cylinder 16 and then drives the two brake shoes 3 to move toward the brake drum 1. When the driving cam 5 needs to give way to the left and right, the driving cam 5 moves to both sides with the driving cylinder 16 and the driving piston 17 as a whole.

[0032] Furthermore, the force-increasing mechanism further includes a movable plate 18, the movable plate 18 and the driving cylinder 16 are respectively located on both sides of the brake base plate 2, the driving cylinder 16 protrudes toward the movable plate 18 on the side close to the brake base plate 2 and passes through the strip hole 14 to be fixed to the movable plate 18, the length of the strip hole 14 is greater than the length of the protruding portion of the driving cylinder 16, and the movable plate 18 and the driving cylinder 16 cannot pass through the strip hole 14. Usually, in order to ensure the stability of sliding, the width of the protruding portion and the strip hole 14 are the same.

[0033] Furthermore, the force transmission regulator 6 includes an adjustment sleeve and two adjustment rods. One end of the two adjustment rods extends into the adjustment sleeve and matches with the adjustment sleeve thread. The two adjustment rod threads are driven in opposite directions. The other ends are respectively in contact with the ends of the two brake shoes 3 to bear force. The adjustment sleeve is also provided with a transmission gear. The adjustment rod is provided with a notch for the ends of the brake shoes 3 to be embedded. A screw structure is formed between the adjustment rod and the adjustment sleeve. After the friction between the two friction plates 4 reaches a certain level, the adjustment length of the driving cam 5 may be slightly insufficient. If the friction plates 4 are replaced and not fully utilized, the adjustment rod can be extended by rotating the transmission gear to increase the overall length of the force transmission regulator 6, thereby adjusting the initial position of the brake shoes 3 before the driving cam 5 is adjusted, so that they are closer to the inner wall of the brake drum 1, ensuring that the friction plates 4 can smoothly contact the inner wall of the brake drum 1 when the driving cam 5 is rotated for adjustment.

[0034] Furthermore, the support column 10 is elastically connected to the two brake shoes 3 through two symmetrically arranged return springs 8. The two brake shoes 3 are symmetrically provided with spring holes 9 on both sides of the support column 10. One end of the return spring 8 is fixed on the support column 10, and the other end is fixed at the spring hole 9 or other positions that can give the spring hole 9 a pulling force toward the support column 10. The two return springs 8 are symmetrically arranged. When resetting, the driving cam 5 is acted upon by the two return springs 8 to return to the middle position. The support column 10 not only provides supporting pressure to the brake shoe 3 when the driving cam 5 is offset, but also serves as a fulcrum when the whole is reset.

[0035] Furthermore, the support column 10 is located outside the driving cam 5, and the ends of the two brake shoes 3 extend to the outside of the driving cam 5 and are provided with grooves that cooperate with the support column 10. The cooperation between the groove and the support column 10 plays a guiding role during resetting, further ensuring the accuracy of resetting the brake shoe 3 and the driving cam 5; at the same time, it also increases the force area between the support column 10 and the brake shoe 3 when the driving cam 5 deviates.

[0036] Furthermore, the two brake shoes 3 are also provided with spring holes 9 at the positions near the two ends of the force transmission regulator 6, and the two spring holes 9 are also elastically connected by a return spring 8. The return spring 8 cooperates with the notch of the adjustment rod to ensure that the brake shoe 3 and the force transmission regulator 6 are always in contact and thus stable, and does not limit the angle change between the brake shoe 3 and the force transmission regulator 6 in the plane; thus, the angle change of the brake shoe 3 can be more flexibly adapted.

[0037] It is worth noting that, at present, the force transmission regulator 6 is used in hydraulic brakes, and can also achieve a good force-increasing effect. However, the power system cost of hydraulic brakes is relatively high; the most important thing is that hydraulic brakes have high requirements for the reliability of the manufacturing and supporting of their brake systems; each link must be reliable, and it is not applicable to models with immature supporting equipment and low cost budgets, such as tricycles. Every year, safety accidents occur due to failure of the hydraulic power system, such as oil leakage in the hydraulic system causing the friction plate 4 to lose its braking ability. Some companies in the industry have also tried to directly use the force transmission adjustment column in mechanical brakes, but they all failed to achieve the expected braking effect.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A mechanical double-force brake, comprising a brake base plate, a return spring, two brake shoes and two friction plates; the two brake shoes are arranged opposite to each other, and the two friction plates are respectively fixed on the outsides of the two brake shoes; the return spring gives the two brake shoes an elastic force to retract inward; characterized in that: A force amplification mechanism and a force transmission regulator are respectively provided between the opposite ends of the two brake shoes; The force-increasing mechanism comprises a driving cam and a supporting column; the driving cam is located between the two brake shoes and is slidably connected to the brake base plate along the movable direction of the brake shoes, and the brake base plate is provided with a movable hole for sliding; the supporting column is fixed to the brake base plate and is located between the two brake shoes; The two ends of the force transmission regulator are respectively in contact with the ends of the two brake shoes away from the force amplification mechanism; The force-increasing mechanism further comprises a mounting plate and a sliding plate, wherein the mounting plate is fixed to the brake bottom plate, the sliding plate is slidably connected to the mounting plate, the driving cam is rotatably connected to the sliding plate, the mounting plate is provided with a strip groove for the sliding plate to slide and a strip hole for the rotating shaft of the driving cam to slide, and the strip hole is arranged corresponding to the movable hole; The two brake shoes are provided with force plates on both sides of the driving cam, and the force plates are fixed to the ends of the brake shoes; the partial cross section of the driving cam between the two force plates is in the shape of a strip hole.

2. The mechanical dual-force brake according to claim 1, characterized in that: The force-bearing plate is fixed to the end of the brake shoe in a direction perpendicular to the brake shoe and a reinforcing plate is provided on the side away from the driving cam.

3. The mechanical dual-force brake according to claim 1, characterized in that: The force amplification mechanism also includes two clamping plates, which cover the two ends of the movable hole and are provided with rotating holes for the driving cam to be rotatably connected. The driving cam passes through the movable hole and the two rotating holes in a direction perpendicular to the brake base plate.

4. The mechanical dual-force brake according to claim 1, characterized in that: The force amplification mechanism also includes a driving cylinder and a driving piston. The two ends of the driving cylinder are respectively opposite to the ends of the two brake shoes and are slidably connected to the brake base plate along its own axial direction; one end of the two driving pistons is slidably connected in the driving cylinder; the other ends extend from the two ends of the driving cylinder respectively and contact the ends of the two brake shoes; the driving cam extends into the driving cylinder in a direction perpendicular to the brake base plate and is rotatably connected between the two driving pistons.

5. The mechanical dual-force brake according to claim 4, characterized in that: The force-enhancing mechanism also includes a movable plate, and the movable plate and the driving cylinder are respectively located on both sides of the brake base plate. The side of the driving cylinder close to the brake base plate protrudes toward the movable plate and passes through the strip hole to be fixed to the movable plate. The length of the strip hole is greater than the length of the protruding part of the driving cylinder, and the movable plate and the driving cylinder cannot pass through the strip hole.

6. The mechanical dual-force brake according to any one of claims 1 to 5, characterized in that: The support column is elastically connected to the two brake shoes through two symmetrically arranged return springs; the support column is located on the outside of the driving cam, and the ends of the two brake shoes extend to the outside of the driving cam and are provided with grooves that cooperate with the support column.

7. The mechanical dual-force brake according to any one of claims 1 to 5, characterized in that: The force transmission regulator includes an adjusting sleeve and two adjusting rods, one end of the two adjusting rods respectively extends into the adjusting sleeve and cooperates with the adjusting sleeve thread, and the driving directions of the two adjusting rod threads are opposite; the other ends are respectively in contact with the ends of the two brake shoes to receive force; a transmission gear is also provided on the outside of the adjusting sleeve, and a groove is provided on the adjusting rod for the ends of the brake shoes to be embedded.

8. The mechanical dual-force brake according to claim 7, characterized in that: The two brake shoes are also elastically connected by a return spring at positions close to the two ends of the force transmission regulator.

Images