KR100349536B1 - Adjusting device for drum brake_ - Google Patents

Abstract

The present invention relates to an apparatus for adjusting a brake of a drum brake, and an object thereof is to improve the apparatus for reducing the manufacturing cost, and to prevent unnecessary frictional damage of the lining and to improve braking response.

The apparatus 600 for drum brake according to the present invention includes a first female push rod 610 and a second female push rod 620 via a male push rod 630 having a nut 660 coupled to an outer circumferential surface thereof. ) Is connected, when the lining (310,410) is worn, by using the spiral spring 650 provided in the center of the mail push rod 630 by rotating the nut 660 immediately, the length of the adjuster 600 Is elongated.

Therefore, as soon as the linings 310 and 410 are worn out, the entire length of the adjuster 600 is linearly extended so that the required amount of the wheel cylinder 500 becomes constant so that braking response is not deteriorated. Simple parts have the advantage of reduced manufacturing cost and compactness.

Description

Adjusting device of drum brake

The present invention relates to a drum brake, and more particularly, to an apparatus for assisting brakes that compensates for a gap between linings and linings of drums and inner drum peripheral surfaces during repeated braking.

In general, a brake mounted on a vehicle is a device for decelerating or stopping or maintaining a stopped vehicle. The brake functioning as such functions converts the kinetic energy of the driving into thermal energy by a mechanical friction device and releases the frictional heat into the air to brake the drum. The brake includes a drum hydraulic brake and a disk hydraulic brake.

Drum-type hydraulic brakes obtain a braking force by rubbing the cylindrical drum, which rotates with the wheel instead of the disc, with the lining therein. 1 is a front view showing a general structure of such a conventional drum brake.

As shown in the related art, a conventional drum brake has one end of the drum 10 rotating together with a wheel (not shown) and an anchor block 21 fixed to the back plate 20 so as to be in contact with each other. It consists of a pair of semi-circular brake shoes 30, 40, the wheel cylinder 50, etc. to operate the brake shoes (30, 40) by receiving the braking hydraulic pressure.

The brake shoes 30 and 40 have linings 31 and 41 attached to the outer circumferential surface to exert friction braking force with the inner circumferential surface of the drum 10, which is a forward rotational direction of the drum 10 about the wheel cylinder 50. The one on the side is distinguished by the leading shoe 30 and the one provided on the opposite side as the trailing shoe 40.

The leading shoe 30 and the trailing shoe 40 are coupled to the semicircular rims 32 and 42 to which the linings 31 and 41 are attached and the inner circumferential surface thereof, and one end thereof is supported and supported by the wheel cylinder 50 and the other end thereof. It consists of webs 33 and 43 in contact with the anchor block 21, so that the linings 31 and 41 operate outwardly so as to rub against the inner circumferential surface of the drum 10 during braking.

And both ends of the leading shoe 30 and the trailing shoe 40 is composed of a restoring spring 80, when the braking action is released by the elastic restoring force of the leading shoe 30 and trailing shoe 40 Return to the position of.

The wheel cylinder 50 is interposed between the leading shoe 30 and one end of the trailing shoe 40 webs 33 and 43. Here, a pair of pistons (not shown) which are advanced by braking hydraulic pressure are incorporated. . And between the leading shoe 30 and the trailing shoe 40, the web 33 and 43, the male push rod 61, the female push rod 62 and the lever pwal 63 There is an adjust (60) made of a) and the like, which is extended when the nut 66 screwed to the outer peripheral surface of the mail push rod 61 is rotated.

Accordingly, when the linings 31 and 41 are over-weared by repetitive braking, the gap between the inner peripheral surface of the drum 10 is increased and the role of the linings 31 is further described. .

First, the female push rod 62 has one end coupled to the leading shoe 30 and the web 33, and the other end thereof is formed of a hollow part. The mail push rod 61 is composed of a spiral shaft (not shown) having a male thread on one end of the outer circumferential surface thereof so as to be freely fitted to the hollow portion of the female push rod 62, and the other end thereof includes a trailing shoe 40. It is coupled to the parking brake actuating lever 70 provided on the web 43. The parking brake actuating lever 70 has one end coupled with the trailing shoe 40 and the shaft 71 and the other end is connected with a parking brake lever (not shown) provided next to the driver's seat through a cable (not shown). Braking is mechanically performed.

The nut 66 is screwed to the spiral shaft (not shown) of the male push rod 61, so that the spiral shaft (not shown) of the male push rod 61 is further directed to the hollow side of the female push rod 62. To prevent abnormal entry, gear teeth are formed at regular intervals on the outer circumferential surface thereof.

Then, the lever pawl 63 for adjusting the nut 66 by using the elastic restoring force of the tension spring 65 when the linings 31 and 41 are worn out is installed. It is configured such that one end is coupled to the leading shoe 30 web 33 under the female push rod 62 by using a roll pin 64, and the other end is engaged with the gear teeth of the nut 66. The tension spring 65 is operated by the pulling force downward.

That is, one end of the tension spring 65 is fixed to the lever pole 63 and the other end is fixed to the lower end of the leading shoe 30, when the lining (31, 41) is in a state of over-wear braking action The lever pole 63 is pulled downward so that the end portion rotates in the direction of arrow A about the roll pin 64.

Accordingly, the end of the lever pole 63 rotates the nut 66 so that the spiral shaft (not shown) of the male push rod 61 comes out of the hollow part slightly, so that the overall length of the adjuster 60 is extended. The distance between the linings 31 and 41 and the inner peripheral surface of the drum 10 is kept constant.

However, the adjuster 60 of the conventional drum brake compensates for the gap with the drum 10 due to wear of the linings 31 and 41 by extending the overall length by using a gear gear formed on the outer circumferential surface of the nut 66. With gear gear, that is, rotation of about 2-3mm, the length of the adjuster 60 is gradually extended so that it does not immediately react to wear of the linings 31 and 41.

That is, it extends with the change width | variety of the one gear of gear gear meshed with the edge part of the lever pole 63. As shown in FIG. Accordingly, since there is a gap change between the linings 31 and 41 and the drum 10 corresponding to one pitch (2-3 mm) of the gear gear, the required amount of the wheel cylinder 50 corresponding to the gap change amount is required. Need to change. This acts as an inconsistent factor in brake responsiveness, which undermines the reliability of the overall braking system.

The present invention is to solve this problem, an object of the present invention is to install a nut that rotates so that the overall length of the adjuster to respond immediately when the wear of the lining using the spiral spring, the amount of wheel cylinder required It is always to maintain a constant to improve the braking responsiveness, to simplify the overall components to reduce the manufacturing cost and to provide a compact device for the drum brake.

1 is a front view showing the overall structure of a conventional drum brake.

2 is a front view showing the overall structure of the drum brake according to the present invention.

3 is an exploded perspective view schematically showing the adjuster according to the present invention.

Figure 4 is a schematic view showing an internal structure and the coupling state of the adjuster device according to the present invention.

5 is a schematic view showing an operating state of the adjuster device according to the present invention during the braking action.

Figure 6 is a schematic diagram showing the operating state of the adjuster device according to the present invention during the braking action in the worn state of the lining.

7 is a schematic view showing a restored state of the adjuster device according to the present invention when the braking action is released.

* Description of the symbols for the main parts of the drawings *

100..Drum 300..Reading 400..Trailing shoe

310.410. Lining 500. Wheel cylinder 600. Adjuster

610 .. 1st mail push rod 620. 2nd mail push rod 630. Mail push rod

640..Disc spring 650.Spiral spring 660.Nut

670. Connecting bar

In order to achieve the above object, the present invention provides a drum that rotates with a wheel, a leading shoe attached to a trailing shoe, a trailing shoe, and a trailing shoe that outwardly operates to exert a braking force by friction with an inner circumferential surface of the drum. When the other end is combined and the braking action is released, both ends are connected between the leading spring and the trailing shoe to restore the leading shoe and trailing shoe, and when the lining wears out, the adjuster device compensates the gap between the inner peripheral surface of the drum and the lining. In the equipped drum brake,

The adjuster,

One end is coupled to the leading shoe and the other end of the first female push rod formed in the insertion hole to a predetermined depth, the other end of the first female push rod axially spaced apart a predetermined distance and the end is coupled to the trailing shoe One end portion is coupled to the insertion hole of the first female push rod axially spaced in the axial direction so as to connect the second female push rod, the second female push rod and the first female push rod and the other end The male push rod and the spiral shaft of the male push rod, which are composed of shafts and fitted with one end of the second female push rod, are gradually pulled out from one end of the second female push rod, and the drum and The screw is screwed to the spiral shaft to compensate the separation gap of the screw, and one end is fixed on the center of the mail push rod to rotate the nut, and the other end is wound to surround it. Spiral springs weaker than the elastic force of the restoring spring, and the connecting bar with one end coupled to the other end of the spiral spring axially so that the nut rotates simultaneously when the spiral spring is loosened, and the other end is fixedly coupled to the outer circumferential surface of the nut. It is characterized by including.

Hereinafter, one preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings. Figure 2 is a front view showing the overall structure of the drum brake according to the present invention, Figures 3 and 4 are combined cross-sectional view showing an exploded perspective view and the internal structure of the adjuster according to the present invention.

The drum brake according to the present invention is configured such that the cylindrical drum 100 rotates together with a wheel (not shown), as shown in the drawing, and outwardly acts on the edge of the back plate 200. A pair of brake shoes 300 and 400 with linings 310 and 410 attached to friction with the inner circumferential surface of the wheels, and a wheel cylinder 500 with a pair of pistons (not shown) to operate the brake shoes 300 and 400 under braking hydraulic pressure. It is large.

The brake shoes 300 and 400 are configured such that one end thereof is supported by the anchor block 210 and the other end thereof is in contact with the wheel cylinder 500, and that the side of the drum 100 in the forward rotation direction is the leading shoe 300, and the opposite direction thereof. The side is distinguished by the trailing shoe 400.

The leading shoe 300 and the trailing shoe 400 have a “T” shape in cross section, and are coupled to the inner circumferential surface of the rim 320 and the inner circumferential surface of the rim 320 by the linings 310 and 410 attached to the outer circumferential surface thereof. One end is supported by the anchor block 210 and the other end is formed of plate-shaped webs 330 and 430 contacting the front end of a piston (not shown) built in the wheel cylinder 500.

On the other hand, when the linings 310 and 410 are excessively worn due to the continuous braking action, the distance from the inner peripheral surface of the drum 100 increases, so that the adjusting device 600 always compensates for this and maintains a constant interval with the leading shoe 300. It is interposed between the trailing shoe 400, which in addition to the function of compensating the gap between the lining (310, 410) and the drum 100, the leading shoe 300 and the trailing shoe 400 is operated outwards and parking braking action This is done, the detailed structure of which is as follows.

The adjuster 600 according to the present invention includes a first female push rod 610 and a second female push rod 620, each end of which is supported by the leading shoe 300 and the trailing shoe 400. To connect them and the nut 660 is rotatably coupled to the outer circumferential surface of the male push rod 630 configured at the end, the nut 660 immediately rotates in one direction when the linings 310 and 410 wear. It consists of a large spiral spring 650 and the like.

One end of the first female push rod 610 is supported by the web 330 of the leading shoe 300, the insertion hole 613 is formed to have a predetermined depth in the other end 612 do. One end 631 of the mail push rod 630 made of a rod is inserted into the insertion hole 613 to be coupled to the left and right sliding, the other end 632 of the outer peripheral surface so that the nut 660 is engaged It consists of a spiral shaft machined with male threads.

In addition, the second female push rod 620 is coupled to one end 621 of the spiral shaft 632 of the male push rod 630 so as to be freely fitted, and the other end 622 is a trailing shoe 400. It is coupled to the operating lever 700 coupled to the shaft 710.

On the other hand, since the side surface portion of the nut 660 screwed to the outer circumferential surface of the spiral shaft 6322 is in close contact with the one end portion 621 of the second female push rod 620, this causes the nut 660 to rotate in the direction of arrow A. Then, the spiral shaft 632 slightly out of the one end portion 621 of the second female push rod 620, the length of the overall adjuster 600 is increased, its operation structure is as follows.

First, in order to rotate the nut 660 in the direction of arrow A, a spiral spring 650 is mounted at the center of the mail push rod 630. The spiral spring 650 made of a plate shape is wound around the outer circumferential surface of the mail push rod 630 by being firmly fixed to the outer circumferential surface of the mail push rod 630 using the fixing rod 633. The fixed rod 633 is fixed to the support part 634 to be described later to extend in the axial direction on the outer circumferential surface of the male push rod 630, and the spiral spring 650 is fitted to be firmly installed. The other end of the spiral spring 650 is connected to the outer circumferential surface of the nut 660 using a connection bar 670 extending to have a predetermined length.

That is, one end 671 of the connecting bar 670 is coupled to the other end 652 of the spiral spring 650 so as to be free from side to side, and the other end 672 is fixed to the outer circumferential surface of the nut 660. To this end, the other end of the spiral spring 650 is bent in the shape of the letter "c" is formed with a coupling portion 652 is formed in the receiving space 653 therein, one end portion 671 of the connecting bar 670 Is slidably coupled to the receiving space 653 of the coupling portion 652. Therefore, when the spiral spring 650 is released in the arrow A direction by the elastic force, the nut 660 connected through the connecting bar 670 is rotated in the arrow A direction.

And the mail between the other end 612 and the spiral spring 650 of the first female push rod 610 to prevent the loosening action of the spiral spring 650, except when the lining (310, 410) is worn On the outer circumferential surface of the push rod 630, a pair of disk springs 640 are interposed as elastic members which bias them in opposite directions. A support portion 634 protruding in the circumferential direction is formed on the outer circumferential surface of the mail push rod 630 for installation of the disk spring 640. In addition, the disc spring 640 has a through hole 641 formed in the center thereof and is inserted through one end 631 of the mail push rod 630, so that the other end portion 612 of the first female push rod 610 is fixed. Is interposed between the support and the support 634.

The elastic region of the disk spring 640, that is, the width of the disk spring 640 is kept constant so that the gap G between the bottom of the insertion hole 613 and one end 631 of the male push rod 630 is constant. 5, G, which is the difference between the width in the compressed state where the load is applied to both end portions of the disc spring 640 and the width when the load is removed, is a predetermined width (an embodiment of the present invention). Is about 3 mm). As a result, the width of the pair of disk springs 640 in the compressed state is reduced by about 3 mm rather than the width of the non-external force. The gap of 3 mm is the maximum value at which the leading shoe 300 and trailing shoe 400 are operated outward during normal braking operation, and the overall length of the adjuster 600 can be freely changed.

In addition, of the disk spring 640, spiral spring 650, and restoring spring 800 for restoring the leading shoe 300 and trailing shoe 400, the elastic force of the rest spring is the strongest and then the disk The spring 640 and the spiral spring 650 are configured in this order. Therefore, when the braking action is released, since the leading shoe 300 and the trailing shoe 400 are restored by the elastic restoring force of the restoring spring 800, the disc spring 640 is pressed and the nut 660 side end and the second end are simultaneously. One end 621 of the female push rod 620 is in close contact with the spiral spring 650 to prevent loosening.

On the other hand, a pair of flat washers 680 are provided at both end portions of the spiral spring 650, which are fitted into the mail push rod 630 to surround both end portions of the spiral spring 650 and are coupled to each other. Prevent warping.

Next, the braking action of the drum brake according to the present invention configured as described above will be described.

First, before the driver presses the brake pedal (not shown), the disk spring 640 is maintained in the maximum compressed state by the elastic force of the restoring spring 800. When the driver presses the brake pedal (not shown) in this state, The braking hydraulic pressure generated in the master cylinder (not shown) is transferred to the wheel cylinder 500 so that the piston (not shown) is advanced. Therefore, since the leading shoe 300 and the trailing shoe 400 operate outwardly about the anchor block 210, the braking force is generated by friction with the inner circumferential surface of the drum 100 on which the linings 310 and 410 rotate.

In addition, when the leading shoe 300 and the trailing shoe 400 are pushed out due to the braking action, one end 611 of the first female push rod 610 and the other end of the second female push rod 620 Since the external force applied to the 622 is removed, as shown in FIG. 5, the adjuster device escapes from the insertion hole 613 of the first female push rod 610 by the expansion force of the disk spring 640. The overall length of 600 is stretched. At this time, the length D1 ′ of the adjuster device during the braking action extends longer than the length D1 of the initial state, and its elongation length is 3 mm or less.

Therefore, the expansion of the adjuster 600 is stopped before the disk spring 640 is fully extended, and the nut 660 side end and the one end 621 of the second female push rod 620 are in close contact with each other. By maintaining the rotation of the nut 660 by the elastic force of the spiral spring 650 is not made.

That is, the overall length D1 ′ of the adjusting device 600 is slightly extended during the braking operation of the linings 310 and 410 not worn, but the rotation of the nut 660 does not occur because the length of the adjuster 600 is slightly extended. Do not. This action is performed because the force in the axial direction due to the loosening force of the spiral spring 650 is smaller than the expanding force of the disk spring 640.

When the braking action is released, the leading shoe 300 and the trailing shoe 400 are restored to their original positions by the elastic force of the restoring spring 800. At the same time, the disc spring 640 is pressed to end the mail push rod 630. By inserting the portion 631 into the insertion hole 613 again, the adjuster 600 also returns to its initial state.

On the other hand, when the linings 310 and 410 gradually wear out due to the repeated braking action, the outward working width of the leading shoe 300 and the trailing shoe 400 is increased. In this case, the nut 660 immediately moves in the direction of the arrow A. As the entire length of the adjuster 600 is extended to rotate, the gap between the linings 310 and 410 and the inner circumferential surface of the drum 100 is always kept constant.

That is, when the wear of the lining (310, 410) occurs, the operating width of the leading shoe 300 and the trailing shoe 400 is increased, the mail push rod (from the insertion hole 613 of the first female push rod 610) By slightly exiting one end 631 of 630, the disk spring 640 extends by a sufficiently free distance, and the expansion force is no longer reached. In this case, the spiral spring 650 is released by the elastic force to rotate the nut 660 in the direction of arrow A. Therefore, as shown in FIG. 6, the spiral shaft 632 of the male push rod 630 is pulled out of one end 621 of the second female push rod 620, whereby the expansion force of the disk spring 640 is increased. The other end 612 and the support 634 of the first female push rod 610 is affected. At the same time, since the elastic force of the spiral spring 650 is smaller than the expansion force of the disk spring 640, the distance between the bottom of the insertion hole 613 and the one end 631 of the male push rod 630 is maintained at the predetermined width G again. And no further nut 660 rotation occurs. At this time, one end 671 of the connecting bar 670 is slidably coupled in the axial direction through the coupling portion 652 provided at the end of the spiral spring 650, according to the rotation of the nut 660 Even though the vertical gap between the nut 660 and the spiral spring 650 increases, one end 671 of the connection bar 670 gradually exits and the elastic force of the spiral spring 650 is continuously provided through the connection bar 670. 660). In addition, the pair of flat washers 680 supporting the both ends of the spiral spring 650 to prevent twisting of the spiral spring 650 during operation or non-operation.

And when the driver releases the brake pedal (not shown) and the braking action is released, the leading shoe 300 and the trailing shoe 400 are restored by the elastic restoring force of the restoring spring 800, and as shown in FIG. Likewise, the load is applied to both ends of the adjuster 600 again, and the disc spring 640 is pressed again to contact the bottom of the insertion hole 613 and one end 631 of the male push rod 630.

At this time, the nut 660 is rotated due to the wear of the linings 31 and 410 so that the other end portion 632 of the male push rod 630 is slightly removed from the one end portion 621 of the second female push rod 620. In this state, the length D1 ″ of the overall adjuster 600 is kept longer than the initial state, so that the gap between the linings 310 and 410 and the inner peripheral surface of the drum 100 is kept constant.

Therefore, as soon as the wear of the linings 310 and 410 occurs, the length of the adjuster 600 is immediately extended to compensate for the gap between the linings 310 and 410 and the inner circumferential surface of the drum 100, thereby lining 310 and 410 during the next braking action. Distance between the wheel cylinder 500 and the piston (not shown) for contacting the inner circumferential surface of the drum 100 is equal to the distance before wear of the linings 310 and 410. Therefore, even if the drum brake is used for a long time, the same braking response can be felt as in the initial state, and the reliability of the overall braking device is improved. In addition, since the components for rotating the nut 660 are simply made of a spiral spring 650, a connecting bar 670, a disk spring 640, etc., manufacturing cost is also reduced.

As described in detail above, in the drum brake adjuster according to the present invention, the first female push rod and the second female push rod are connected to each other via a male push rod having a nut coupled to an outer circumferential surface thereof. When worn, the length of the adjuster is extended by immediately rotating the nut using a spiral spring provided at the center of the male push rod.

Therefore, as soon as the abrasion of lining occurs, the overall length of the adjuster is linearly stretched so that the required amount of wheel cylinder becomes constant, so that the braking response is not lowered. The components are simple and the manufacturing cost is reduced and compact. There is an advantage to be made.

Claims (5)

The drum 100 rotating together with the wheel, and the leading shoe 300 and trailing shoe 400 with the lining 310 and 410 attached outward to friction with the inner circumferential surface of the drum 100 to exert a braking force. When one end is coupled to 300 and the other end is coupled to the trailing shoe 400 to release the braking action, a restoring spring 800 for restoring the leading shoe 300 and the trailing shoe 400 and the leading shoe ( Both ends between the 300 and the trailing shoe 400 is coupled to the drum having an adjuster 600 to compensate for the gap between the inner peripheral surface of the drum 100 and the lining (310,410) when the wear of the lining (310,410) In the brake, The adjuster 600, One end 611 is coupled to the leading shoe 300 and the first female push rod 610, the first female push rod (610) having an insertion hole 613 formed at a predetermined depth in the other end 612 ( The second end portion 612 and the other end portion 612 of the axial direction spaced apart and the second female push rod 620 is coupled to the trailing shoe 400, the second female push rod 620 and One end 631 is coupled to the insertion hole 613 of the first female push rod 610 so as to be spaced apart by a predetermined interval in the axial direction so as to connect the first female push rod 610, and the other end is a helix. Is formed by the shaft 632, the mail push rod 630, the spiral shaft 632 of the mail push rod 630 is inserted into the one end portion 621 of the second female push rod 620 to be freely coupled The gap between the drum 100 and the drum 100 is compensated according to the wear of the linings 310 and 410 gradually exiting from one end 621 of the second female push rod 620. The nut 660 is screwed to the spiral shaft 632 to rotate, the one end 651 is fixed on the center of the mail push rod 630 to rotate the nut 660 and the other end 652. Is wound to wrap it, but the plate-shaped spiral spring 650 weaker than the elastic force of the restoring spring 800, one end 671 so that the nut 660 is rotated at the same time when the spiral spring 650 loosening action A drum comprising a connecting bar 670 coupled to the end of the spiral spring 650 and the other end 652 so as to be axially spaced and the other end 672 fixedly coupled to the outer circumferential surface of the nut 660. Brake adjuster. The method of claim 1, The outer peripheral portion of the mail push rod 630 is installed between the other end portion 612 of the first push rod rod 610 and the side end of the spiral spring 650, the elastic region is kept constant so that its elastic force when a braking action occurs The side of the nut 660 is in close contact with one end 621 of the second female push rod 620 by preventing the rotation of the nut 660 by one end and one end of the first female push rod 610. It characterized in that it comprises an elastic member 640 which is in close contact with the leading shoe 300 and the trailing shoe 400, the part 611 and the other end 622 of the second female push rod 620, respectively. Adjusting device for drum brake. The method of claim 2, The elastic member 640 is weaker than the elastic restoring force of the restoring spring 800 and stronger than the spiral sparing 650 so that the deformation is removed during the braking action, and when the braking action is released, the restoring force of the restoring spring 800 is compressed. The drum brake of the drum brake, characterized in that the through-hole (641) is formed in the center so that the mail push rod (630) through. The method of claim 1, One end portion 671 of the connecting bar 670 is coupled to the end of the other end of the spiral spring 650 is coupled to be bent so that the receiving space 653 is formed therein so that the connecting bar 670 is slidable An apparatus for adjusting a drum brake, wherein a part 652 is provided. The method of claim 4, wherein The mail push rod 630 is provided with a pair of flat washers 680 supporting both ends of the spiral spring 650 to prevent the spiral spring 650 from twisting. Device.