CN201461795U

CN201461795U - Drum-type brake

Info

Publication number: CN201461795U
Application number: CN200920122262XU
Authority: CN
Inventors: 郑芳芳; 郑东明
Original assignee: Zhejiang Asia Pacific Mechanical and Electronic Co Ltd
Current assignee: Zhejiang Asia Pacific Mechanical and Electronic Co Ltd
Priority date: 2009-06-10
Filing date: 2009-06-10
Publication date: 2010-05-12
Anticipated expiration: 2019-06-10

Abstract

The utility model discloses a drum-type brake, comprising a braking bottom plate, a prepositional brake shoe, a postpositional brake shoe, a clearance adjustor, a wheel cylinder and an upper return spring, wherein, a shoe rib at one end of the postpositional brake shoe which is connected with wheel cylinder is provided with a waist-shaped hole, meanwhile, a dragging arm pin sequentially passes through a rotating arm, the postpositional brake shoe, and the dragging arm through the waist-shaped hole, and interference fit exists between the dragging arm pin and the dragging arm; the middle of the shoe rib of the postpositional brake shoe is provided with a rotating arm pin, the rotating arm pin sequentially passes through the rotating arm, the postpositional brake shoe and is close to the side of the dragging arm, one end of a pushing plate is connected with the lower end of the prepositional brake shoe through a pushing plate pin, another end of the pushing plate is movably connected with the lower end of the postpositional brake shoe, and the braking bottom plate is provided with a supporting block, the prepositional brake shoe and the postpositional brake shoe respectively support the supporting block from both sides. After adopting the above technical scheme, the brake is a leading trailing shoe brake when the automobile brakes at down slope; and the brake is a servo brake when the automobile brakes at up slope, the braking force is increased, therefore, the drum-type brake more reasonably meet the different braking requirements for automobile at down slope and at up slope.

Description

Drum brake

Technical field

The utility model relates to a kind of automobile drum brake.

Background technique

Service brake and parking braking are the braking system of each automobile indispensability, and consider the requirement of cost, spatial arrangement, Braking efficiency and stability, select the drum brake of attaching Parking structure to be undoubtedly reasonable selection.Service braking sytem is by hydraulic braking, parking braking system is then by pure mechanical device braking, learn that according to the parking braking of automobile upward slope and the force analysis of descending parking braking automobile back axle adhesion when the identical gradient upward slope parking braking is big, because adhesion equates to learn that with braking force automobile is big in identical gradient upward slope parking braking power.

Modal a kind of neck with halting mechanism is from the shoe type drum brake, mainly form by braking bottom board, wheel cylinder, brake drum, brake shoe, slack adjuster and return spring, base plate is installed on the fixed position of axletree, it is fixed, brake shoe, wheel cylinder, return spring are housed above, the rotary torsion when bearing braking.Each drum has a pair of brake shoe, and friction facing is arranged on the brake shoe.Brake drum then is mounted on the wheel hub, is the parts that rotate with wheel, and it is to be made by the cast iron of certain deal, and shape is like drum type.When braking, wheelcylinder piston promotes brake shoe compressing brake drum, and brake drum is rubbed and slows down, and finally forces wheel to stop operating.

Generally have only a wheel cylinder on brake drum, after when braking, wheel cylinder was subjected to fluid power from master cylinder, wheel cylinder two ends piston can push up the hoof end of brake shoe to the left and right simultaneously, and active force equates.But because wheel rotates, it is asymmetric that brake drum acts on the pressure left and right sides of brake shoe, causes reinforcement voluntarily or subtract the effect of power voluntarily.Therefore, in the industry will be voluntarily a side brake shoe of reinforcement be called the neck hoof, a side brake shoe that subtracts power voluntarily is called from hoof, the friction torque of neck hoof is 2～2.5 times from hoof, thereby the degree of wear of two brake shoe friction facings is also just different.

The model utility content

Technical problem to be solved in the utility model provides a kind of drum brake that more reasonably satisfies automobile in the difference requirement of climb and fall parking braking.

For solving the problems of the technologies described above, the utility model adopts following technological scheme: drum brake, comprise braking bottom board, preposition brake shoe, rearmounted brake shoe, slack adjuster, wheel cylinder and last return spring, described preposition brake shoe, rearmounted brake shoe is connected with two end in contact of described slack adjuster respectively, also comprise pivoted arm, torque arm and push pedal, the tendons of beef, mutton or pork that connect an end of wheel cylinder on the described rearmounted brake shoe are provided with a waist shaped hole, pass pivoted arm successively by this Kong Youyi torque arm pin, rearmounted brake shoe, torque arm, this torque arm pin and described torque arm interference fit, the center fixed of the described rearmounted brake shoe tendons of beef, mutton or pork has the pivoted arm pin, this pivoted arm pin passes pivoted arm successively, rearmounted brake shoe and near a side of described torque arm, described push pedal one end is connected with described preposition brake shoe lower end by the push pedal pin, the described push pedal the other end and described rearmounted brake shoe lower end flexibly connect, one support block is arranged on the described braking bottom board, described preposition brake shoe, rearmounted brake shoe props up this support block respectively from both sides, described slack adjuster two ends have preposition slot and rearmounted slot, the tendons of beef, mutton or pork of described preposition brake shoe insert in the described preposition slot and with the bottom of this preposition slot and contact, and the tendons of beef, mutton or pork of described rearmounted brake shoe and torque arm insert in the described rearmounted slot in the lump.

Described pivoted arm lower end is provided with a concaved circular cambered surface, the connecting end of described push pedal and pivoted arm have one with the corresponding convex arc surface of this concaved circular cambered surface, arc surface had both made pivoted arm or push pedal be delivered to thrust on another part, can do rolling motion again.

Be connected with the tension spring between described pivoted arm lower end and the described push pedal pin, so that being connected between push pedal and the pivoted arm is more stable.

The lower end of described preposition brake shoe and rearmounted brake shoe is connected by following return spring, when the break brake off, makes the brake shoe return.

The tendons of beef, mutton or pork of described rearmounted brake shoe place the position in the described rearmounted slot to have slot.

Described torque arm places the position in the described rearmounted slot to have slot.

The utility model is owing to adopted technique scheme, and automobile is when the descending parking braking, and rearmounted brake shoe sense of rotation is opposite with the sense of rotation of brake drum, and preposition brake shoe sense of rotation is identical with the sense of rotation of brake drum, and this moment, break was for leading from shoe type; And when the upward slope parking braking, be self-boosting type, increased parking braking power, because the Braking efficiency of self-boosting type is bigger from the Braking efficiency of shoe type than neck, so this drum brake has more reasonably satisfied the different requirements of automobile in the climb and fall parking braking.

Description of drawings

Below in conjunction with accompanying drawing the utility model is further described.

Fig. 1 is an embodiment's of the utility model drum brake a structural representation.

Fig. 2 is the structural representation of this embodiment intermediate gap regulator.

Fig. 3 is the connection diagram of this embodiment intermediate gap regulator and preposition brake shoe, rearmounted brake shoe, torque arm.

Fig. 4 is the structural representation of torque arm among this embodiment.

Fig. 5 is the structural representation of the rearmounted brake shoe tendons of beef, mutton or pork among this embodiment.

Fig. 6 is the force analysis sketch of the utility model drum brake when the descending parking braking.

Embodiment

Figure 1 shows that an embodiment of the utility model drum brake, comprise braking bottom board 1, preposition brake shoe 2, rearmounted brake shoe 3, slack adjuster 4, wheel cylinder 5 and last return spring 6, described preposition brake shoe 2, rearmounted brake shoe 3 is connected with two end in contact of described slack adjuster 4 respectively, also comprise pivoted arm 7, torque arm 8 and push pedal 9, the tendons of beef, mutton or pork that connect an end of wheel cylinder 5 on the described rearmounted brake shoe 3 are provided with a waist shaped hole 31, pass pivoted arm 7 successively by this Kong Youyi torque arm pin 80, rearmounted brake shoe 3, torque arm 8, this torque arm pin 80 and described torque arm 8 interference fit, the center fixed of described rearmounted brake shoe 3 tendons of beef, mutton or pork has pivoted arm pin 70, this pivoted arm pin 70 passes pivoted arm 7 successively, rearmounted brake shoe 3 and near a side of described torque arm 8, described push pedal 9 one ends are connected with described preposition brake shoe 2 lower ends by push pedal pin 90, described push pedal 9 the other ends and described rearmounted brake shoe 3 lower ends flexibly connect, one support block 11 is arranged, described preposition brake shoe 2 on the described braking bottom board 1, rearmounted brake shoe 3 props up this support block 11 respectively from both sides.

As shown in Figure 4, described pivoted arm 7 lower ends are provided with a concaved circular cambered surface 71, the connecting end of described push pedal 9 and pivoted arm 7 have one with these concaved circular cambered surface 71 corresponding convex arc surface.

Be connected with tension spring 91 between described pivoted arm 7 lower ends and the described push pedal pin 90.

The lower end of described preposition brake shoe 2 and rearmounted brake shoe 3 is connected by following return spring 12, when the break brake off, makes the brake shoe return.

As shown in Figures 2 and 3, described slack adjuster 4 two ends have preposition slot 41 and rearmounted slot 42, the tendons of beef, mutton or pork of described preposition brake shoe 2 insert in the described preposition slot 41 and with the bottom of this preposition slot 41 and contact, the tendons of beef, mutton or pork of described rearmounted brake shoe 3 and torque arm 8 insert in the described rearmounted slot 42 in the lump. and as shown in Figure 4 and Figure 5, the tendons of beef, mutton or pork of described rearmounted brake shoe 3 place the positions in the described rearmounted slot 42 to have slot 32. described torque arm 8 to place the positions in the described rearmounted slot 42 to have slot 82.

Do not have when stressed in torque arm 8, have only the tendons of beef, mutton or pork of rearmounted brake shoe 3 to contact with the bottom of rearmounted slot 42, and torque arm 8 sides do not contact with rearmounted slot 42 bottoms, when torque arm 8 is stressed at A point place, 8 of torque arm are rotated around torque arm pin 80, torque arm 8 sides contact with the bottom of rearmounted slot 42 when forwarding several angle to, when being rotated further, torque arm 8 after having overcome the power of last return spring 6 is pushed slack adjuster 4 open, this moment, the tendons of beef, mutton or pork face of rearmounted brake shoe 3 no longer contacted with the bottom of rearmounted slot 42, but the tendons of beef, mutton or pork face of preposition brake shoe 2 contacts with the bottom of the preposition slot 41 of slack adjuster 4 left ends all the time.

Described torque arm 8 is installed in the tendons of beef, mutton or pork below of rearmounted brake shoe 3, pivoted arm 7 is installed in the tendons of beef, mutton or pork top of rearmounted brake shoe 3, when torque arm 8 is stressed, to pass to pivoted arm 7 to power by torque arm pin 80, pivoted arm 7 is passed to rearmounted brake shoe 3 to power by pivoted arm pin 70 again and is made the support block 11 on the moving base plate of its coiling open braking.Parking braking is to be rotated and then promoted slack adjuster by torque arm to make the strong point on the moving base plate of two brake shoe coilings open to be attached to drum to be gone up to realize braking.

Automobile is when the descending parking braking, as can be seen from Figure 6, when the driver applies power to parking control, parking brake cable just is subjected to tension, and pulling force is delivered to torque arm 8, break is subjected to an input power F at the A of torque arm 8 point place, because the hole of torque arm pin 80 is installed on the rearmounted brake shoe 3 is a waist shaped hole, this makes torque arm pin 80 that certain space be arranged in waist shaped hole, and power F is delivered to rearmounted brake shoe 3 by pivoted arm 7 and pivoted arm pin 70, produces power F1 in corresponding pivoted arm pin 70 positions, and F1 makes rearmounted brake shoe 3 open around the O2 point, rearmounted brake shoe 3 sense of rotation are opposite with the sense of rotation of brake drum, so be from hoof; And preposition brake shoe 2 is subjected to that torque arm 8 imposes on the thrust of slack adjuster 4 and support block 11 on the moving base plate of coiling opens, meanwhile, the power F at the A point place of torque arm 8 is delivered to H point place's generation power F3 of preposition brake shoe 2 by slack adjuster 4, so just make preposition brake shoe 2 open around the O1 point, its sense of rotation is identical with the sense of rotation of brake drum, so be the neck hoof, promptly this moment, break was for leading from shoe type.

Automobile is when the upward slope parking braking, and the sense of rotation of brake drum and aforementioned automobile are opposite when the descending parking braking, and the motion of rearmounted brake shoe 3 is identical during with down hill braking, and rearmounted brake shoe 3 sense of rotation are identical with the brake drum sense of rotation, therefore are the neck hoof; And it is consistent with the friction torque direction to be subjected to the moment that thrust F2 that pivoted arm 7 imposes on push pedal 9 produces on the preposition brake shoe 2, therefore the point of contact H point of preposition brake shoe 2 on slack adjuster 4 opens, its sense of rotation is identical with the brake drum sense of rotation, therefore also be the neck hoof, when break is realized braking, preposition brake shoe rotates around the strong point, forwarding several angle brake shoe exterior arc surface (being the friction plate exterior arc surface) to is adjacent to brake drum, because brake shoe is subjected to the indirectly-acting of torque arm input power, make the friction plate exterior arc surface produce pressure, and brake drum rotates, and then produces frictional force.Frictional force on the preposition brake shoe 2 through slack adjuster 4 affact in the torque arm 8 and indirect transfer to rearmounted brake shoe 3, brake efficiency is increased, promptly this moment, break was a self-boosting type.

Therefore this drum brake is that service brake is to lead from the hoof structure, and it is that self-boosting type, descending are the drum brake of neck from shoe type that parking braking is gone up a slope.Because the Braking efficiency of self-boosting type is bigger from the Braking efficiency of shoe type than neck, so this drum brake has more reasonably satisfied the different requirements of automobile in the climb and fall parking braking.

Claims

1. drum brake, comprise braking bottom board (1), preposition brake shoe (2), rearmounted brake shoe (3), slack adjuster (4), wheel cylinder (5) and last return spring (6), described preposition brake shoe (2), rearmounted brake shoe (3) is connected with two end in contact of described slack adjuster (4) respectively, it is characterized in that: also comprise pivoted arm (7), torque arm (8) and push pedal (9), the tendons of beef, mutton or pork that described rearmounted brake shoe (3) is gone up an end that connects wheel cylinder (5) are provided with a waist shaped hole (31), pass pivoted arm (7) successively by this Kong Youyi torque arm pin (80), rearmounted brake shoe (3), torque arm (8), this torque arm pin (80) and described torque arm (8) interference fit, the center fixed of described rearmounted brake shoe (3) tendons of beef, mutton or pork has pivoted arm pin (70), this pivoted arm pin (70) passes pivoted arm (7) successively, rearmounted brake shoe (3) and near a side of described torque arm (8), described push pedal (9) one ends are connected with described preposition brake shoe (2) lower end by push pedal pin (90), described push pedal (9) the other end and described rearmounted brake shoe (3) lower end flexibly connect, one support block (11) is arranged on the described braking bottom board (1), described preposition brake shoe (2), rearmounted brake shoe (3) props up this support block (11) respectively from both sides, described slack adjuster (4) two ends have preposition slot (41) and rearmounted slot (42), the tendons of beef, mutton or pork of described preposition brake shoe (2) insert in the described preposition slot (41) and with the bottom of this preposition slot (41) and contact, and the tendons of beef, mutton or pork of described rearmounted brake shoe (3) and torque arm (8) insert in the described rearmounted slot (42) in the lump.

2. according to the described drum brake of claim 1, it is characterized in that: described pivoted arm (7) lower end is provided with a concaved circular cambered surface (71), the connecting end of described push pedal (9) and pivoted arm (7) have one with the corresponding convex arc surface of this concaved circular cambered surface (71).

3. according to the described drum brake of claim 1, it is characterized in that: be connected with tension spring (91) between described pivoted arm (7) lower end and the described push pedal pin (90).

4. according to the described drum brake of claim 1, it is characterized in that: the lower end of described preposition brake shoe (2) and rearmounted brake shoe (3) is connected by following return spring (12).

5. according to the described drum brake of claim 1, it is characterized in that: the tendons of beef, mutton or pork of described rearmounted brake shoe (3) place the position in the described rearmounted slot (42) to have slot (32).

6. according to the described drum brake of claim 1, it is characterized in that: described torque arm (8) places the position in the described rearmounted slot (42) to have slot (82).