JP2012137128A - Drum brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drum brake which prevents separation of brake shoes without increasing the number of parts of the drum brake.SOLUTION: A cable guide member 60 is integrally provided with a separation prevention projection 60c projected from the cable guide member 60 to another end of a pair of brake shoes 22 and 24 to prevent the brake shoes 22 and 24 from separating from a backing plate 18. A function of preventing separation of the pair of brake shoes 22 and 24 can be added to the cable guide member 60 by only integrally mounting the separation prevention projection 60c, thereby preventing separation of the pair of brake shoes 22 and 24 without increasing the number of parts of the drum brake 10.

Description

  The present invention relates to a drum brake, and more particularly to a technique for preventing the brake shoe from rising without increasing the number of parts of the drum brake as compared with the conventional one.

  In the drum brake, for example, as shown in Patent Documents 1 and 2, (a) a pair of brake shoes disposed on the backing plate so as to be expandable, and (b) at one end portion of the pair of brake shoes, A brake lever disposed so as to be rotatable around a predetermined mounting shaft; (c) a brake cable having one end connected to the tip of the brake lever; and (d) the brake cable connected to the inside and outside of the backing plate. A through-hole penetrating the backing plate so as to be inserted into (e) when being fixed on the backing plate between the through-hole and the tip of the brake lever and applying a tensile force to the brake cable A cable guide member for supporting the brake cable in a direction parallel to the backing plate by supporting the brake cable. There are things. In the drum brake as described above, when the brake lever is rotated by a predetermined angle by being pulled by the brake cable, the one end portions of the pair of brake shoes are separated, and the brake shoe has a bottomed cylindrical shape. A braking force is generated in the drum brake by being pressed against the inner peripheral surface of the brake drum.

  In the drum brake as described above, it is considered that the other end of the brake shoe is lifted from the backing plate when a relatively high turning force is applied from the brake drum to the brake shoe during braking of the drum brake. .

No. 06-6300 JP 2008-223890 A

  However, in the drum brake as described above, in order to prevent the other end portion of the brake shoe from floating from the backing plate, for example, a component such as the retainer plate 14 like the drum brake of FIG. Is provided on the other end side of the brake shoe, there is a problem that the number of parts of the drum brake increases.

  The present invention has been made in the background of the above circumstances, and its object is to provide a drum brake in which the lifting of the brake shoe is prevented without increasing the number of parts of the drum brake. is there.

  To achieve this object, the gist of the invention according to claim 1 is that: (a) a pair of brake shoes disposed on the backing plate so as to be expandable; and (b) one of the pair of brake shoes. A brake lever rotatably disposed around a predetermined mounting shaft at one end of the brake lever, (c) a brake cable having one end connected to the tip of the brake lever, and (d) the brake cable A through hole that penetrates the backing plate so as to be inserted into and out of the backing plate, and (e) a tensile force applied to the brake cable that is fixed on the backing plate between the through hole and the tip of the brake lever. A cable guide for guiding the brake cable in a direction parallel to the backing plate by supporting the brake cable when (F) The cable guide member protrudes from the cable guide member to the other end side of the pair of brake shoes to lift the pair of brake shoes from the backing plate. The present invention has an integral lifting prevention protrusion for prevention.

  Further, the gist of the invention according to claim 2 is that, in the invention according to claim 1, the rising prevention protrusion of the cable guide member is such that the tip of the rising prevention protrusion is the pair of brake shoes. The other end of the brake shoe projecting from the backing plate at a predetermined interval in the thickness direction of the brake shoe.

  A gist of the invention according to claim 3 is that, in the invention according to claim 1, (a) a shoe gap is provided between the other ends of the pair of brake shoes as the adjusting screw rotates. And (b) the other end of the pair of brake shoes is interposed between the other ends of the pair of brake shoes by the biasing force of a spring stretched between the pair of brake shoes. (C) the lifting prevention protrusion of the cable guide member protrudes so that the tip of the lifting prevention protrusion is located on the opposite side of the backing plate of the gap adjusting device. There is in being.

  The gist of the invention according to claim 4 is that, in the invention according to any one of claims 1 to 3, the cable guide member is formed by pressing from a single plate-like member. A fixed plate-shaped fixing portion fixed to the backing plate; a plate-shaped wall portion bent in a direction away from the backing plate from the fixed plate-shaped fixing portion; and a tip portion of the plate-shaped wall portion Are bent to the other end side of the pair of brake shoes, and a part of the plate-like wall portion is cut and bent so as to protrude to the opposite side of the lifting prevention protrusion. The cable support portion for supporting the cable is provided integrally.

  According to the drum brake of the first aspect of the present invention, the cable guide member protrudes from the cable guide member to the other end side of the pair of brake shoes to lift the pair of brake shoes from the backing plate. Since the lifting prevention protrusion is integrally provided to prevent the cable guide member, the function of blocking the lifting of the pair of brake shoes can be added to the cable guide member simply by providing the lifting prevention protrusion integrally. Brake shoe lift is prevented without increasing the number of parts. In addition, by preventing the brake shoe from lifting, interference noise between the brake shoe and the backing plate can be prevented, and the strength of the brake shoe can be reduced when the brake shoe is pressed against the brake drum while being lifted. Can be prevented.

  According to the drum brake of the second aspect of the present invention, the lifting prevention protrusion of the cable guide member has the tip of the lifting prevention protrusion opposite to the backing plate at the other end of the pair of brake shoes. The pair of brake shoes protrudes from the backing plate so as to be located at a predetermined interval in the thickness direction of the brake shoe on the side, so that the pair of brake shoes is opposite to the backing plate of the brake shoe. The other end on the side abuts against the tip of the lifting prevention protrusion, and the pair of brake shoes are prevented from lifting.

  According to the drum brake of the invention according to claim 3, a gap adjusting device is provided between the other ends of the pair of brake shoes to adjust the shoe gap as the adjusting screw rotates. The other end portion of the brake shoe is connected via the gap adjusting device by the biasing force of a spring stretched between the other end portions of the pair of brake shoes, and the lifting prevention protrusion of the cable guide member Is formed so that the tip of the lifting prevention projection is located on the opposite side of the backing plate of the gap adjusting device, so that when the pair of brake shoes try to lift from the backing plate, The gap adjusting device comes into contact with the tip of the lifting prevention protrusion, and the pair of brake shoes are prevented from lifting.

  According to the drum brake of the invention according to claim 4, the cable guide member is formed by pressing from a single plate-like member, and has a longitudinal plate-like fixing portion fixed to the backing plate. A plate-like wall portion bent in a direction away from the backing plate from the longitudinal plate-like fixed portion, and the levitating portion in which a tip portion of the plate-like wall portion is bent toward the other end side of the pair of brake shoes Since a part of the plate-like wall part is cut and bent, a cable supporting part that protrudes to the opposite side of the lifting prevention protrusion and supports the brake cable is integrally provided. The cable guide member is formed from a single plate-like member, and the number of parts of the drum brake can be suitably reduced.

  Here, it is preferable that the ends of the pair of brake shoes on the anchor member side be lifted by, for example, a spring, but the drum brake of the present invention has a ledge on the shoe gap adjusting device side of the pair of brake shoes. It can be set as the structure which suppresses the floating of the edge part of the surface vicinity. Thus, the lift of the pair of brake shoes can be reliably prevented, and the brake shoes are stably pressed against the brake drum to generate a stable braking force.

1 is a front view showing a DIO servo type drum brake of one embodiment to which the present invention is applied. It is an enlarged view explaining the cable guide member of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is a figure which shows the cable guide member of another Example, and is a figure corresponding to FIG. 2 of the above-mentioned Example. It is a figure which shows the cable guide member of another Example, and is a figure corresponding to FIG. 3 of the above-mentioned Example.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

  FIG. 1 is a front view of a duo-servo type drum-in disc brake 12 with a drum brake 10 according to an embodiment of the present invention provided at the center thereof with a hat-type disc and calipers removed. The hat-type disc is composed of a disc-shaped outer peripheral portion and a bottomed cylindrical central portion not shown in the drawing, and the disc-shaped outer peripheral portion functions as a friction plate for the disc brake, and has a bottomed cylindrical central portion. The part functions as a brake drum 14. The brake drum 14 is represented by two concentric circles indicated by a one-dot chain line in FIG. 1, and the circle on the center side of the drum brake 10 of the two circles indicates the inner peripheral surface 16 of the brake drum 14. ing.

  The drum brake 10 has a substantially disk shape, and includes a backing plate 18 that is integrally fixed to a vehicle body side member, that is, a non-rotating member such as an axle tube, an axle housing, and a suspension device (not shown). . A disc cover 20 is secured to the outer periphery of the backing plate 18 to protect the disc-like outer periphery of the hat type disc.

  Also, the drum brake 10 includes a pair of arc-shaped brake shoes 22 and 24 disposed substantially symmetrically so as to be close to and away from each other in a posture in which the convex side is outward on the left and right outer peripheral portions of the backing plate 18, A substantially columnar anchor member 26 provided in a fixed position between one end of the pair of brake shoes 22, 24, that is, the upper end of FIG. 1, and the anchor member 26 and one end of the pair of brake shoes 22, 24 A pair of return springs 28, 28 that are stretched between the pair of brake shoes 22, 24 and constantly bias one end portions of the pair of brake shoes 22, 24 toward each other, and the upper ends of the pair of brake shoes 22, 24. Rotation of the adjusting screw 32a is interposed between the long plate-like strut 30 and the other end of the pair of brake shoes 22, 24, that is, the lower end of FIG. Along with this, the gap adjusting device 32 that adjusts the shoe gap by changing the total length and the other end of the pair of brake shoes 22 and 24 are stretched between them, and the lower ends thereof are always urged toward each other. An intermediate portion for clamping the gap adjusting device 32 in the longitudinal direction is provided with a coiled spring 34.

  At the tip of the anchor member 26, one end of the pair of brake shoes 22, 24 is larger than the diameter R of the cylindrical contact portion 26 a of the anchor member 26, which is contacted by the urging force of the pair of return springs 28, 28. A lifting prevention portion 26b having a diameter is provided, and is positioned at a predetermined interval in the thickness direction of the brake shoes 22 and 24 on the side opposite to the backing plate 18 at one end of the pair of brake shoes 22 and 24. .

  Each of the pair of brake shoes 22 and 24 has a flat plate shape substantially parallel to the flat flat plate portion 18a located on the inner peripheral portion of the backing plate 18, and is entirely curved in an arc shape in the front view shown in FIG. The shoe webs 38, 40 are integrally fixed to the shoe webs 38, 40 so that the cross-sections are substantially T-shaped along the outer peripheral side edges of the shoe webs 38, 40 having the arc shape. Band-like shoe rims 42, 44, and ledge surfaces 42a that are in sliding contact with the backing plate 16 at both ends and the center of the shoe rims 42, 44 on the arcuate side edges of the shoe rims 42, 44 on the backing plate 16 side. The ledge portions 42b and 44b that are bent so as to protrude toward the inner peripheral side of the backing plate 16 and the outer peripheral surfaces of the shoe rims 42 and 44 are in contact with each other. Are constituted respectively by a lining 46 made of a friction material is integrally fixed at such agents. Further, as shown in FIG. 1, the ledge portions 42 b and 44 b of the shoe rims 42 and 44 are arranged at both ends of the shoe rims 42 and 44 on the arcuate side edge opposite to the backing plate 16 side of the shoe rims 42 and 44. It is provided in the center.

  The pair of brake shoes 22, 24 are pressed against the backing plate 18 by being pressed toward the backing plate 18 by shoe hold-down devices 50, 52 disposed on the shoe web 38 and the shoe web 40, respectively. It is held so as to be movable in the direction of expansion.

  As shown in FIG. 1, one brake shoe 22 is provided with a flat brake lever 56 in an overlapped state, and one end portion of the brake shoe 22 and a base end portion 56 a of the brake lever 56 are arranged. The mounting shaft 54 is connected around the mounting shaft 54 so as to be relatively rotatable. A portion of the base end portion 56a of the brake lever 56 that is close to the mounting shaft 54 is engaged with a notch surface 30a cut out at the end portion of the strut 30 on the brake shoe 22 side together with the shoe web 38. . In addition, a tensile force generated by operating a brake operation device (not shown) such as a parking brake pedal or a parking brake operation lever is transmitted to the front end portion 56b of the brake lever 56 at the front end portion 56b of the brake lever 56. The brake cable 58 is connected.

  As shown in FIGS. 1 and 2, the backing plate 18 includes a through hole 18 b that penetrates the outer periphery of the backing plate 18 so that the brake cable 58 is inserted into and out of the backing plate 18, and the backing plate 18. The brake cable 58 is fixed to the backing plate 18 between the through hole 18b of the brake lever 56 and the tip end portion 56b of the brake lever 56, and the brake cable 58 is supported by the brake cable 58 when a tensile force is applied from the brake operating device. A cable guide member 60 for guiding the cable 58 in a direction substantially parallel to the flat plate portion 18a of the backing plate 18 is provided.

  The through hole 18b of the backing plate 18 is fitted in the through hole 18b and is attached to the backing plate 18 with the brake cable 58 inserted into and out of the backing plate 18, for example, an elastically deformable synthetic rubber or the like not shown. A coil spring 62 compressed in the longitudinal direction is disposed around the brake cable 58 between the cable mounting member and the tip 56b of the brake lever 56. ing. For this reason, the front end portion 56 b of the brake lever 56 is always biased by the biasing force of the coil spring 62 in the direction opposite to the pulling direction in which the brake cable 58 is pulled when the drum brake 10 is braked.

  As shown in FIGS. 2 and 3, the cable guide member 60 is fixed to the flat plate portion 18 a of the backing plate 18 between the through hole 18 b of the backing plate 18 and the tip end portion 56 b of the brake lever 56 by, for example, welding. A long plate-like fixed portion 60a, a plate-like plate-like wall portion 60b that is bent substantially perpendicularly from the long-plate-like fixed portion 60a and away from the backing plate 18, and a tip of the plate-like wall portion 60b. A plate-like lifting prevention protrusion 60c that is bent substantially perpendicularly to the plate-like wall portion 60b on the other end side of the pair of brake shoes 22, 24, and a part of the plate-like wall portion 60b is a brake. In order to support the cable 58, a lifting prevention projection 60c and a cable support portion 60d which is cut and bent so as to protrude to the opposite side, that is, the brake cable 58 side, are provided. Tough 60a, plate-shaped wall portion 60b, uplift preventing protrusions 60c, the cable guide member 60 having a cable support portion 60d are those which are integrally formed by pressing from a sheet of metal plate.

  As shown in FIG. 3, the lifting prevention protrusion 60 c of the cable guide member 60 is such that the leading end of the lifting prevention protrusion 60 c is the backing of the other end of the shoe webs 38 and 40 of the pair of brake shoes 22 and 24. On the opposite side of the plate 18, the brake shoes 22 and 24 are provided so as to be positioned at a predetermined interval in the thickness direction of the shoe webs 38 and 40 of the brake shoes 22 and 24. Further, a notch 60e is provided at the tip of the lifting prevention protrusion 60c, and the brake drum 14 is brought into contact with the inner peripheral surface 16 of the brake drum 14 by the notch 60e when the drum brake 10 is braked, for example. When the other ends of the pair of brake shoes 22 and 24 are moved in the circumferential direction, the adjustment screw 32a of the gap adjusting device 32 connected to the other ends of the pair of brake shoes 22 and 24 and the lifting prevention protrusion Interference with the part 60c is prevented.

  Further, as shown in FIG. 3, an arc-shaped support surface 60f is formed on the cable support portion 60d of the cable guide member 60, and the brake cable 58 is applied to the brake cable 58 on the brake surface 58f. When a tensile force is applied from the device, the brake cable 58 from the support surface 60f of the cable support portion 60d to the tip portion 56b of the brake lever 56 is substantially parallel to the parallel portion 18a of the backing plate 18. The height H of the support surface 60f of the cable support portion 60d from the backing plate 18 is set.

  In the drum brake 10 configured as described above, when the brake operating device is operated and a tensile force is applied to the brake cable 58 and the brake lever 56 is rotated, the brake shoe 24 is pushed by the strut 30 and the brake is applied. The shoe 22 is pushed by the mounting shaft 54, and the linings 46 and 48 of the pair of brake shoes 22 and 24 are pushed by the inner peripheral surface 16 of the brake drum 14, and a braking force is generated in the drum brake 10. Further, for example, when the drum brake 10 is braked, a relatively high revolving force is applied from the brake drum 14 to the pair of brake shoes 22, 24, and the other ends of the pair of brake shoes 22, 24 are lifted from the backing plate 18. When trying to do so, lifting of the other ends of the pair of brake shoes 22, 24 is prevented by the lifting prevention protrusions 60 c provided integrally with the cable guide member 60.

  According to the drum brake 10 of the present embodiment, the cable guide member 60 protrudes from the cable guide member 60 to the other end side of the pair of brake shoes 22 and 24 and from the backing plate 18 of the pair of brake shoes 22 and 24. Since the lifting prevention protrusion 60c that prevents the lifting of the brake shoe is integrally provided, the cable guide member 60 has a function of preventing the lifting of the other ends of the pair of brake shoes 22 and 24. Therefore, the brake shoes 22 and 24 are prevented from being lifted without increasing the number of parts of the drum brake 10. In addition, by preventing the brake shoes 22 and 24 from lifting, the interference sound between the brake shoes 22 and 24 and the backing plate 16 is prevented, and when the brake shoes 22 and 24 are pressed against the brake drum 14 while being lifted. The strength reduction of the brake shoes 22 and 24 can be prevented.

  Further, according to the drum brake 10 of the present embodiment, the lifting prevention protrusion 60c of the cable guide member 60 has the shoe webs 38 and 40 of the pair of brake shoes 22 and 24 at the tip of the lifting prevention protrusion 60c. The pair of brake shoes 22 are disposed so as to be located at a predetermined interval in the thickness direction of the shoe webs 38, 40 of the brake shoes 22, 24 on the opposite side of the backing plate 18 at the other end of the brake shoes 22, 24. , 24 is lifted from the backing plate 18, the other end of the brake shoes 22, 24 opposite to the backing plate 18 against the shoe webs 38, 40 abuts against the tip of the lifting preventing projection 60 c. The pair of brake shoes 22 and 24 are prevented from lifting.

  Moreover, according to the drum brake 10 of the present embodiment, the cable guide member 60 is formed by pressing from a single metal plate, and has a longitudinal plate-like fixing portion 60 a fixed to the backing plate 18. The plate-like wall portion 60b bent in a direction away from the backing plate 18 from the long plate-like fixing portion 60a, and the tip end portion of the plate-like wall portion 60b are on the other end side of the pair of brake shoes 22 and 24. And a cable support portion 60d that supports the brake cable 58 by projecting to the opposite side of the lift prevention projection 60c when a part of the plate-like wall portion 60b is cut and bent. Since they are integrally provided, the cable guide member 60 is formed from a single metal plate, and the number of parts of the drum brake 10 can be suitably reduced.

  Further, according to the drum brake 10 of this embodiment, the ends of the pair of brake shoes on the anchor member side are conventionally lifted by, for example, springs, but the drum brake 10 of this embodiment has a pair of brake shoes. It can be set as the structure which suppresses the floating of the edge part of 22 and 24 vicinity of the clearance adjustment apparatus 32 side ledge surfaces 42a and 44a vicinity. As a result, the pair of brake shoes 22 and 24 can be more reliably prevented from rising, and the brake shoes 22 and 24 are stably pressed against the brake drum 14 to generate a stable braking force.

  Next, another embodiment of the present invention will be described. In the following description of the embodiments, portions common to the above-described embodiments are denoted by the same reference numerals and description thereof is omitted.

  The drum brake of this embodiment is substantially the same as the drum brake 10 of the first embodiment except that the cable guide member 64 is different from the cable guide member 60 of the first embodiment. FIGS. 64 corresponds to FIG. 2 and FIG. 3 of the first embodiment.

  As shown in FIGS. 4 and 5, the cable guide member 64 includes a longitudinal plate-like fixing portion 64 a similar to the longitudinal plate-like fixing portion 60 a of the first embodiment, and a plate-like wall portion 60 b of the first embodiment. A similar plate-like wall portion 64b and a plate-like levitation in which the tip portion of the plate-like wall portion 64b is bent substantially perpendicular to the plate-like wall portion 64b on the other end side of the pair of brake shoes 22 and 24. And a cable support portion 64d similar to the cable support portion 60d of the first embodiment. The fixing portion 64a, the plate-like wall portion 64b, the lifting prevention protrusion portion 64c, and the cable support portion are provided. The cable guide member 64 having 64d is integrally formed by pressing from a single metal plate.

  As shown in FIG. 4, the lifting prevention protrusion 64 c of the cable guide member 64 is provided so that the tip of the lifting prevention protrusion 64 c is located on the opposite side of the backing plate 18 of the gap adjusting device 32. Is. Further, a notch 64e is provided at the tip of the lifting prevention protrusion 64c, and the brake drum 14 is brought into contact with the inner peripheral surface 16 of the brake drum 14 by the notch 64e when the drum brake 10 is braked, for example. When the other ends of the pair of brake shoes 22 and 24 are moved in the circumferential direction, the adjustment screw 32a of the gap adjusting device 32 connected to the other ends of the pair of brake shoes 22 and 24 and the lifting prevention protrusion Interference with the portion 64c is prevented.

  As shown in FIG. 5, an arcuate support surface 64f is formed on the cable support 64d of the cable guide member 64, and the height H of the support surface 64f of the cable support 64d from the backing plate 18 is set to be high. It is set to be the same as the height H of the support surface 60f of the cable support portion 60d of the first embodiment.

  According to the drum brake 10 of the present embodiment, the gap adjusting device 32 that adjusts the shoe gap with the rotation of the adjusting wheel 32a is disposed between the other ends of the pair of brake shoes 22 and 24. The other ends of the brake shoes 22, 24 are connected via a gap adjusting device 32 by a biasing force of a spring 34 stretched between the other ends of the pair of brake shoes 22, 24. The lift preventing projection 64c of the member 64 is provided so that the tip of the lift preventing projection 64c is located on the opposite side of the backing plate 18 of the gap adjusting device 32, and therefore, the pair of brake shoes 22 is provided. , 24 is lifted from the backing plate 18, the gap adjusting device 32 comes into contact with the tip of the lifting preventing projection 64c and a pair of brake shoes. 2, 24 of the lift is prevented.

  As mentioned above, although the Example of this invention was described based on drawing, this invention is applied also in another aspect.

  For example, in the present embodiment, a duo-servo type drum brake is applied to the drum brake 10, but a leading trailing type drum brake or the like may be applied to the drum brake of the present invention. Note that the other ends of the pair of brake shoes 22 and 24 are not supported at all by other members as in the above-described duo-servo type drum brake, and the other ends of the pair of brake shoes 22 and 24 are the backing plate 18. The effect is increased when it is applied to an object that tends to float up. In other words, the leading trailing drum brake has a pair of brake shoes that are stretched between the other ends of the pair of brake shoes on an anchor member that is fixed to the backing plate between the other ends. Since the springs are in contact with each other by the urging force of the springs, the other ends of the pair of brake shoes are relatively difficult to lift. In addition, when the present invention is applied to a leading trailing drum brake, the other end of the pair of brake shoes is attached to the tip of the anchor member fixed between the other ends of the pair of brake shoes. Since there is no need to provide a flat plate-like lifting prevention plate that prevents lifting, the number of parts of the drum brake can be reduced.

  In this embodiment, the gap adjusting device is provided at the other end of the pair of brake shoes, but the gap adjusting device is not necessarily provided, and the pair of brake shoes does not have a function of adjusting the shoe gap. A connecting member that connects the other end portions of the two may be provided.

  Although not illustrated one by one, the present invention can be implemented in variously modified and improved modes based on the knowledge of those skilled in the art.

10: drum brake 18: backing plate 18b: through holes 22, 24: pair of brake shoes 32: gap adjusting device 32a: adjusting screw 34: spring 54: mounting shaft 56: brake lever 56b: tip 58: brake cable 60, 64: Cable guide member 60a, 64a: Fixed part 60b, 64b: Plate-like wall part 60c, 64c: Lifting prevention protrusion 60d, 64d: Cable support part

Claims (4)

A pair of brake shoes disposed on the backing plate so as to be expandable; a brake lever disposed on one end of the pair of brake shoes so as to be rotatable about a predetermined mounting shaft; A brake cable having one end connected to the tip, a through hole that penetrates the backing plate so that the brake cable is inserted into and out of the backing plate, and a space between the through hole and the tip of the brake lever A drum brake comprising: a cable guide member that is fixed on the backing plate and guides the brake cable in a direction parallel to the backing plate by supporting the brake cable when a tensile force is applied to the brake cable. Because
The cable guide member is integrally provided with a lifting prevention protrusion that protrudes from the cable guide member toward the other end of the pair of brake shoes and prevents the pair of brake shoes from lifting from the backing plate. A drum brake characterized by that.   The cable guide member's lifting prevention protrusion has a predetermined distance in the thickness direction of the brake shoe between the tip of the lifting prevention protrusion and the other end of the pair of brake shoes opposite to the backing plate. 2. The drum brake according to claim 1, wherein the drum brake is provided so as to be spaced apart. Between the other ends of the pair of brake shoes, a gap adjusting device is provided for adjusting the shoe gap as the adjusting screw rotates.
The other ends of the pair of brake shoes are connected via the gap adjusting device by a biasing force of a spring stretched between the other ends of the pair of brake shoes,
2. The drum brake according to claim 1, wherein the rising prevention protrusion of the cable guide member protrudes so that a tip of the rising prevention protrusion is positioned on an opposite side of the backing plate of the gap adjusting device.   The cable guide member is formed by pressing from a single plate-like member, and is provided with a longitudinal plate-like fixing portion fixed to the backing plate, and from the longitudinal plate-like fixing portion from the backing plate. A plate-like wall portion bent in a separating direction, the lift-preventing protrusion portion where the tip end portion of the plate-like wall portion is bent toward the other end side of the pair of brake shoes, and one of the plate-like wall portions The drum brake according to any one of claims 1 to 3, wherein a cable support portion that protrudes to the opposite side of the lifting prevention protrusion and supports the brake cable is integrally provided by cutting and bending the portion.

Images