JP2012002341A - Drum brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drum brake which improves the workability of coupling an end of a brake cable to an other end of a lever member compared to a conventional one, and prevents a loss of a connection pin connecting the other end of the lever member to the end of the brake cable after connecting the end of the brake cable to the other end of the lever member.SOLUTION: By an operator applying a relatively large force to the lever member 56 against an elastic return force of an elastic member 66 so as to elastically deform an elastic projection 66d to expose a coupling hole 56d from first side walls 52c, 52d, the brake cable 58 can be easily coupled while viewing the coupling hole 56d. The coupling hole 56d is not exposed from the first side walls 52c, 52d even if the lever member 56 contacts with the elastic projection 66d by a small force such as vibration when a vehicle travels to be slightly elastically deformed after the coupling, and the resulting elastic return force rotates the other end 56b of the lever member 56 toward a backing plate 16, thereby preventing the loss of the coupling pin 64.

Description

  The present invention relates to a drum brake, and more particularly to a technique for improving workability of a connecting operation for attaching a brake cable to a drum brake spreading device.

  For example, a drum brake spreading device 100 as shown in FIG. 16 is known. In the spreading device 100 shown in FIG. 16, for example, the other end of the lever member 110 rotates in a direction away from the backing plate while the vehicle is running, and the connecting hole 110 a of the lever member 110 is a pair of first members of the main body 120. The other end of the lever member 110 is exposed from the side wall portion 120a so that the connecting pin 140 does not come out of the connecting holes 110a and 130a formed in the other end portion of the lever member 110 and the distal end portion of the brake cable 130, respectively. When the portion rotates in a direction away from the backing plate, the other end of the lever member 110 comes into contact with the first connecting portion 120b of the main body 120 so that the connecting hole 110a is not exposed between the pair of first side wall portions 120a. The rotation range is limited. 16 indicates a state in which the other end portion of the lever member 110 is rotated in a direction away from the backing plate and is in contact with the first connecting portion 120b.

  When connecting the tip end portion of the brake cable 130 to the other end portion of the lever member 110 in the expanding device 100 as described above, the operator moves the other end portion of the lever member 110 closer to the backing plate side by his / her hand. The connecting hole 110a of the lever member 110 is rotated until it is exposed from between the pair of first side wall portions 120a, and the connecting hole 110a of the brake cable 130 is aligned with the connecting hole 110a of the lever member 110. By fitting the connecting pin 140 into the connecting holes 110a and 130a, the tip of the brake cable 130 is connected to the other end of the lever member 110.

JP 2007-071379 A JP 2001-349360 A

  However, in the drum brake as described above, if the tip of the brake cable 130 is connected to the other end of the lever member 110 from a state in which a pair of brake shoes or the like is assembled to the drum brake, the operator The other end of the member 110 is rotated in the direction approaching the backing plate, and the other end of the lever member 110 is close to the backing plate, that is, the connecting hole 110a of the lever member 110 is assembled to the drum brake. Since it is necessary to work in a state where it is hidden from the operator by the parts such as the return spring, the anchor member, the main body 120, etc., the connecting hole 110a of the brake member 130 is aligned with the connecting hole 110a of the lever member 110 and connected. Connecting pin 140 in holes 110a and 130a Work to put fit has been very difficult.

  On the other hand, it is conceivable to attach the tip part of the brake cable 130 having the backing plate penetrated to the other end of the lever member 110 in advance and then assemble the components of the drum brake to the drum brake. If an attempt is made to assemble a drum brake with the brake cable 130 attached thereto, the workability of assembling the drum brake is deteriorated by the brake cable 130.

  Moreover, in order to improve the workability | operativity of the operation | work which connects the front-end | tip part of a brake cable to the other end part of a lever member, the expansion apparatus as described in patent document 1 and patent document 2 is proposed. In this expanding device, the other end portion of the lever member is backed until the connection hole formed in the other end portion of the lever member is exposed from between the pair of first side wall portions of the main body. The lever member is disposed at a position allowing rotation in a direction away from the plate, and the other end of the lever member is rotated in a direction away from the backing plate so that the connecting hole of the lever member is connected to the drum brake. The connecting holes of the brake cable are easily aligned in a state that is not hidden by the parts assembled to the operator and visible to the operator, and the connecting pin is inserted into these connecting holes, and the tip of the brake cable is fitted to the other end of the lever member. This improves the workability of the work of connecting the two.

  In the spreading device as described above, when the other end of the lever member rotates in a direction away from the backing plate after the tip of the brake cable is connected to the other end of the lever member, the other end of the lever member There is a possibility that the connecting hole formed in the part is exposed from the pair of first side wall parts and the connecting pin falls off from the connecting hole. In the expanding device of Patent Document 1, the operator fits the connecting pin into the connecting hole. Backing the other end of the lever member by moving the clip 30 attached to the first connecting portion of the main body to a predetermined position so that the connecting hole of the lever member is not exposed from between the pair of first side wall portions after being inserted. The range of rotation in the direction away from the plate is limited, and the falling of the connecting pin from the connecting hole is prevented. Further, in the expanding device of Patent Document 2, the clip 11 is attached to the main body so as to close the opening of the connecting hole of the lever member and the connecting hole of the brake cable after the operator has fitted the connecting pin into the connecting hole. This prevents the connecting pin from coming off from the connecting hole.

  However, in the expansion device as described above, after the operator connects the tip of the brake cable to the other end of the lever member, the operator is fitted into the connection hole of the lever member and the connection hole of the brake cable. The work of preventing the connection pin from dropping off, for example, the movement of the clip 30 by the worker in Patent Document 1 or the mounting of the clip 11 by the worker in Patent Document 2 is increased. There was a problem that workability of attaching the tip of the brake cable deteriorated.

  The present invention has been made against the background of the above circumstances, and its object is to improve the workability of connecting the tip end portion of the brake cable to the other end portion of the lever member as compared with the prior art. And a drum brake capable of preventing the connecting pin connecting the other end of the lever member and the tip of the brake cable from coming off after the tip of the brake cable is connected to the other end of the lever member. Is to provide.

  To achieve this object, the gist of the invention according to claim 1 is that: (a) a pair of elements that are supported on a backing plate so as to be expandable and whose end portions are biased toward each other by a return spring; A pair of first side wall portions facing each other in a plate shape perpendicular to the backing plate, and a part of side edges of the pair of first side wall portions on the side away from the backing plate A main body having a first connecting portion for connecting the two to each other, and one end portion of the main body disposed between the pair of first side wall portions and at one end portion of the main body by a support shaft parallel to the backing plate. A lever member supported rotatably, and an end portion of the lever member on the support shaft side and the other end portion of the body are inscribed between the one end portions of the pair of brake shoes. Opening device, (c ) A brake cable having a tip connected to the other end of the lever member from the back surface of the backing plate through an insertion hole provided in the backing plate; and (d) a tip of the brake cable and the lever member. And (e) the other end portion of the lever member and the brake, the second end portion of the lever member being connected to the tip end portion and the other end portion of the other end portion. The connecting pin is fitted into the connecting hole at the tip of the cable to connect the other end of the lever member and the tip of the brake cable, and the other end of the lever member is the pair of first A drum brake of a type in which the connection pin is prevented from coming off from the connection hole in a state of being located between the side wall portions; The connecting portion is a direction in which the other end portion of the lever member is separated from the backing plate until a connecting hole formed in the other end portion of the lever member is exposed from between the pair of first side wall portions of the main body. (G) the first connecting portion is pivoted in a direction away from the backing plate at the other end of the lever member. The other end of the lever member approaches the backing plate so that the connecting hole formed in the other end of the lever member is not exposed from between the pair of first side wall portions. The elastic member which urges | biases to the side to perform is provided.

  A gist of the invention according to claim 2 is that, in the invention according to claim 1, (a) the elastic member includes a base end portion having a gripping claw for gripping the first connecting portion of the main body. And an elastically deformable elastic protrusion protruding from the base end portion between the first connecting portion and the lever member, and (b) the elastic protrusion of the elastic member is When the other end of the lever member rotates in a direction away from the backing plate, the lever member comes into contact with and is elastically deformed toward the first connecting portion, whereby the other end of the lever member approaches the backing plate. It is something to be energized.

  Further, the gist of the invention according to claim 3 is that, in the invention according to claim 2, (a) the base end portion is arranged on a surface of the first connecting portion opposite to the backing plate. (B) the gripping claws are respectively extended from the base end portion to the backing plate side surface side of the first connecting portion, and the surface of the first connecting portion on the backing plate side is respectively provided. A pair of gripping claws to be pressed, wherein (c) the pair of gripping claws are disposed adjacent to inner wall surfaces of the pair of first side wall portions, respectively.

  Further, the gist of the invention according to claim 4 is that, in the invention according to claim 2, (a) the elastic projection is formed on both sides of the gripping claw of the base end portion from the first connecting portion and the lever. A pair of elastic protrusions protruding between the pair of members, and (b) the pair of elastic protrusions are respectively disposed adjacent to the inner wall surfaces of the pair of first side wall portions.

  Further, the gist of the invention according to claim 5 is that, in the invention according to claim 4, the tip portions of the pair of elastic projections include a second connecting portion that connects the tip portions to each other. It is in.

  According to the drum brake of the invention according to claim 1, (f) the first connecting portion has a connecting hole formed in the other end portion of the lever member from between the pair of first side wall portions of the main body. The other end of the lever member is disposed in the main body at a position allowing rotation in a direction away from the backing plate until it is exposed, and (g) the lever member includes the lever member The other end portion of the lever member is elastically deformed by contacting the lever member with a rotation in a direction away from the backing plate, and a connecting hole formed in the other end portion of the lever member is formed on the pair of first side wall portions. An elastic member is provided to urge the other end of the lever member toward the side approaching the backing plate so as not to be exposed from the space. Therefore, the lever member is rotated in a direction away from the backing plate until it contacts the elastic member, and a connecting hole formed at the other end of the lever member against the elastic return force of the elastic member is provided. By applying a relatively large force so as to be exposed from the pair of first side wall portions and relatively elastically deforming the elastic member, the other end portion of the lever member is further rotated away from the backing plate. The connecting hole formed at the other end of the lever member is exposed from the pair of first side wall portions, so that the connecting hole of the lever member is connected without being hidden by a part or the like assembled to the drum brake. The tip of the brake cable can be easily connected by visually observing the hole. In addition, after the tip of the brake cable is connected to the other end of the lever member, the other end of the lever member is biased in a direction approaching the backing plate by an elastic return force of the elastic member. The connecting hole formed in the other end portion of the lever member is rotated to a rotation position where it is not exposed from the pair of first side wall portions. Thereafter, when the other end of the lever member is rotated in a direction away from the backing plate by a relatively small force such as vibration during vehicle travel, the elastic member comes into contact with the elastic member. The connecting hole formed in the other end portion is elastically deformed to a relatively small extent so as not to be exposed from between the pair of first side wall portions, and the other end portion of the lever member is backed by the elastic return force of the elastic member. Since the urging is performed in a direction approaching the plate, the connection pin is prevented from coming off from the connection hole. Thereby, the drum brake of the present invention improves the workability of connecting the tip of the brake cable to the other end of the lever member as compared with the conventional one, and the tip of the brake cable is connected to the other end of the lever member. After connecting the other end of the lever member and the tip of the brake cable, the other end of the lever member and the tip of the brake cable are connected without preventing the connecting pin from coming off. It is possible to prevent the connected connecting pin from coming off.

  According to the drum brake of the second aspect of the invention, (a) the elastic member includes a proximal end portion having a gripping claw for gripping the first connecting portion of the main body, and the first end portion from the proximal end portion. An elastically deformable elastic protrusion protruding between the connecting portion and the lever member is integrally provided, and (b) the elastic protrusion of the elastic member has the other end of the lever member at the backing plate. Since the second end of the lever member is urged toward the side closer to the backing plate by abutting and elastically deforming toward the first connecting portion when rotating in a direction away from the By changing the position of the tip of the elastic projection between the first connecting portion and the lever member, a rotation range in a direction in which the other end of the lever member is separated from the backing plate is freely set. thing It can be.

  According to the drum brake of the invention according to claim 3, (a) the base end portion is disposed on a surface of the first connecting portion opposite to the backing plate, and (b) the grip The claws are a pair of gripping claws that are respectively extended from the base end portion to the backing plate side surface side of the first connecting portion and press the backing plate side surface of the first connecting portion, respectively. (c) The pair of gripping claws are disposed adjacent to inner wall surfaces of the pair of first side wall portions. Therefore, when the elastic member removably attached to the first connecting portion of the main body tends to shift toward the first side wall portion due to vibration or the like while the vehicle is running, the pair of gripping claws of the elastic member are The elastic member is prevented from being displaced on the first side wall portion side by contacting the inner wall surface of the first side wall portion.

  According to the drum brake of the invention according to claim 4, (a) the pair of elastic protrusions protrudes between the first connecting portion and the lever member from both sides of the gripping claw of the base end portion. (B) The pair of elastic protrusions are disposed adjacent to the inner wall surfaces of the pair of first side wall portions, respectively. Therefore, when the elastic member detachably attached to the first connecting portion of the main body tends to shift toward the first side wall portion due to vibration or the like while the vehicle is running, the pair of elastic protrusions of the elastic member are The elastic member is prevented from being displaced on the first side wall portion side by contacting the inner wall surface of the first side wall portion.

  According to the drum brake of the invention according to claim 5, since the distal end portions of the pair of elastic protrusions include the second coupling portion that couples the distal end portions to each other, the other end portion of the lever member is When rotating in a direction away from the backing plate, the pair of elastic protrusions come into contact with the second connecting portion, and the force applied to the other end portion of the lever member is suitably applied to the pair of the lever members via the second connecting portion. It can be transmitted to the elastic protrusion.

It is a front view showing a duo servo type drum brake to which the present invention is applied. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1 for explaining the structure of the spreading device shown in FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 2. 3 is a view showing a state where the other end portion of the lever member is rotated in a direction away from the backing plate by, for example, vibration during traveling of the vehicle in the expanding device of FIG. It is a perspective view of the elastic member explaining the elastic member with which the expansion device of Drawing 2 was equipped. FIG. 6 is a VI-VI view of FIG. 5. It is the VII-VII sectional view taken on the line of FIG. It is a figure explaining the operation | work process which connects the front-end | tip part of a brake cable to the other end part of a lever member. It is a figure explaining the operation | work process which connects the front-end | tip part of a brake cable to the other end part of a lever member. It is a figure explaining the operation | work process which connects the front-end | tip part of a brake cable to the other end part of a lever member. It is a figure explaining the operation | work process which connects the front-end | tip part of a brake cable to the other end part of a lever member. It is a figure which shows the elastic member of the other Example of this invention, and respond | corresponds to FIG. It is a figure which shows the elastic member of the other Example of this invention, and respond | corresponds to FIG. It is a figure which shows the elastic member of the other Example of this invention, and respond | corresponds to FIG. It is a figure which shows the elastic member of the other Example of this invention, and respond | corresponds to FIG. It is sectional drawing explaining the expansion apparatus with which the conventional drum brake was equipped.

  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 shows a hat-type disc and a caliper of a duo-servo type drum-in disc brake 12 in which a drum brake for parking brake (hereinafter referred to as a drum brake) 10 according to an embodiment of the present invention is provided at the center. It is a front view. The hat type disk is composed of a disc-shaped outer peripheral portion and a bottomed cylindrical central portion (not shown), and the disc-shaped outer peripheral portion functions as a friction plate of the disc brake, and the bottomed cylindrical central portion Functions as a brake drum. A circle indicated by a one-dot chain line in FIG. 1 indicates the inner peripheral surface 14 of the bottomed cylindrical central portion.

  The drum brake 10 has a substantially disc shape, and includes a backing plate 16 that is integrally fixed to a vehicle body side member such as an axle tube, an axle housing, and a suspension device (not shown), that is, a non-rotating member. . A disk cover 18 is secured to the outer periphery of the backing plate 16 to protect the disk-shaped outer periphery of the hat type disk.

  Further, the drum brake 10 includes a pair of arc-shaped brake shoes 20 and 22 disposed substantially symmetrically so as to be close to and away from each other in a posture in which the convex side is on the outer side of the backing plate 16, and the pair of brake shoes 20 and 22. The expansion device 24 provided at a fixed position between one end portion of the brake shoes 20 and 22, that is, the upper end portion in FIG. 1, and the upper end portion are always urged in a direction approaching each other to contact the expansion device 24. Coil-shaped return spring 26, an anchor member 28 fixed between the upper ends thereof, and the other ends of the pair of brake shoes 20 and 22, that is, the lower ends of FIG. A gap adjusting device 32 that adjusts the shoe gap by changing the overall length along with the rotation of the wheel 30, and is stretched between the lower ends thereof, and the lower ends thereof are mutually connected. An intermediate portion for nipping the gap adjustment device 32 in the longitudinal direction and normally urged in a direction to close is provided with a coiled spring 34.

  Each of the pair of brake shoes 20 and 22 is formed as a flat plate substantially parallel to the plate surface of the backing plate 16, and the shoe webs 36 and 38 are curved in an arc shape in the front view shown in FIG. The belt-like shoe rims 40 and 42 are integrally fixed so that the cross-section is substantially T-shaped along the outer peripheral side edge of the circular arc shape, and an adhesive is attached to the outer peripheral surfaces of the shoe rims 40 and 42. And linings 44 and 46 made of friction materials fixed integrally with each other. The pair of brake shoes 20 and 22 are pressed against the backing plate 16 by being pressed toward the backing plate 16 by shoe hold-down devices 48 and 50 disposed on the shoe web 36 and the shoe web 38, respectively. It is held so that it can move in the relative direction.

  As shown in FIG. 2, the spreading device 24 includes a main body 52 and a lever member 56 in which one end portion 56 a is rotatably supported on one end portion 52 a of the main body 52 by a support shaft 54 substantially parallel to the backing plate 16. The one end portion 56a of the lever member 56 and the other end portion 52b of the main body 52 are inscribed between the one end portions of the pair of brake shoes 20 and 22. The other end portion 56b of the lever member 56 is connected to the tip end portion of the brake cable 58, and the other end portion 56b of the lever member 56 is pulled by pulling the tip end portion of the brake cable 58 toward the backing plate 16 side. Rotates around the support shaft 54 in the direction of arrow F1.

  As shown in FIG. 2, the fixing portion 28 a of the anchor member 28 is not shown together with the backing plate 16 on the surface 16 a of the backing plate 16 between the one end portions of the pair of brake shoes 20, 22. The expansion device 24 is integrally fixed to a vehicle body side member such as a housing or a suspension device, and is supported in contact with the heads 60a of the pair of bolts 60. As shown in FIG. 2, the fixing portion 28 a of the anchor member 28, the backing plate 16, and the axle 62 are provided with insertion holes 28 b, 16 b, 62 a for inserting the distal end portion of the brake cable 58.

  As shown in FIGS. 2 and 3, the lever member 56 is constituted by a single metal plate, and one end portion 56 a of the lever member 56 is engaged with the shoe web 38 of the brake shoe 22. A recess 56c is provided. As shown in FIGS. 2 and 3, the distal end portion of the brake cable 58 has a pair of plate-like second side wall portions 58 a and 58 b that face each other across the other end portion 56 b of the lever member 56, and A pair of second side wall portions 58a, 58b and a connecting portion 58c for connecting the tip of the brake cable 58 are provided, and the pair of second side wall portions 58a, 58b and the other end portion 56b of the lever member 56 are provided. Are provided with connecting holes 58d, 58e, and 56d into which substantially cylindrical connecting pins 64 for connecting the distal end of the brake cable 58 and the other end 56b of the lever member 56 are fitted. As shown in FIG. 3, the distance A between the inner wall surfaces of the pair of second side wall portions 58a and 58b in the brake cable 58 is set to a length longer than the thickness dimension B of the other end portion 56b of the lever member 56. The other end portion 56b of the lever member 56 passes between the pair of second side wall portions 58a and 58b of the brake cable 58.

  As shown in FIGS. 2 and 3, the main body 52 has a pair of first side wall portions 52 c and 52 d that are formed in a plate shape substantially perpendicular to the backing plate 16 and are separated from both sides of the lever member 56 and substantially parallel to each other. The pair of first side wall portions 52c, 52d is constituted by a flat plate-like first connecting portion 52e that connects the side edges on the side away from the backing plate 16 to each other. The pair of first side wall portions 52c and 52d is provided with an engaging recess 52f that engages with the shoe web 36 of the brake shoe 20 at the other end portion 52b. As shown in FIG. 3, the dimension C in the longitudinal direction of the connecting pin 64 is shorter than the distance D between the inner wall surfaces 52g and 52h of the pair of first side wall portions 52c and 52d, and the pair of second side wall portions 58a and 58b. The length is set longer than the width dimension E, and when the connecting pin 64 is fitted in the connecting holes 58d, 58e, 56d, the connecting pin 64 is one of the pair of first side wall portions 52c, 52d, for example, the first The size of the gap F between the first side wall parts 52c, 52d and the second side wall parts 58a, 58b is such that the connecting pin 64 does not come out of the connecting hole 58d of the second side wall part 58a even if it contacts the first side wall part 52d. Is set.

  As shown in FIGS. 2 and 4, when the other end portion 56 b of the lever member 56 is rotated in a direction away from the backing plate 16, for example, due to vibration during traveling of the vehicle, The lever member 56 is elastically deformed by coming into contact with the lever member 56 so that the connecting hole 56d formed in the other end portion 56b of the lever member 56 is not exposed between the pair of first side wall portions 52c and 52d of the main body 52. An elastic member 66 that urges the other end portion 56 b of the member 56 toward the side approaching the backing plate 16 is provided. Further, when the elastic member 66 is not attached to the first connecting portion 52e of the main body 52, the other end portion 56b of the lever member 56 rotates in a direction away from the backing plate 16 and comes into contact with the first connecting portion 52e. Then, the first connecting portion 52e is disposed in the main body 52 so that the connecting hole 56d formed in the other end portion 56b of the lever member 56 is exposed from between the pair of first side wall portions 52c, 52d of the main body 52. .

  As shown in FIGS. 4 and 5, the elastic member 66 is made of an elastic steel material such as spring steel. The elastic member 66 holds the first connecting portion 52 e of the main body 52. A flat base end portion 66b having a pair of gripping claws 66a, and an elastic deformation in which the front end portion 66c protrudes between the first connecting portion 52e and the lever member 56 from the central portion at the front end portion of the base end portion 66b. A possible elastic protrusion 66d is integrally provided.

  As shown in FIGS. 5 and 6, the pair of gripping claws 66a of the elastic member 66 are extended from the base end portion 66b of the elastic member 66 and bent so that the tip end faces the base end portion 66b. Since the distance G between the distal end portion of the pair of gripping claws 66a and the flat base end portion 66b is smaller than the thickness H of the first connecting portion 52e of the main body 52, the base end portion 66b of the elastic member 66 is the first. When the connecting portion 52e is disposed on the surface 52i opposite to the backing plate 16, the tip of the pair of gripping claws 66a causes the backing plate 16 side surface 52j of the first connecting portion 52e to be elastically restored. The first connecting portion 52e is pressed by the pair of gripping claws 66a and the base end portion 66b, and the elastic member 66 is attached to the first connecting portion 52e of the main body 52. In FIG. 6, a solid line gripping claw 66 a indicates a state before the elastic member 66 is attached to the first connecting portion 52 e of the main body 52, and a one-dot chain line gripping claw 66 a indicates that the elastic member 66 is the first of the main body 52. The state attached to the 1 connection part 52e is shown.

  As shown in FIG. 7, the pair of gripping claws 66a of the elastic member 66 are formed on the inner wall surfaces 52g and 52h of the pair of first side wall portions 52c and 52d of the main body 52 from both sides of the elastic protrusion 66d at the distal end portion of the base end portion 66b. The width I of the pair of gripping claws 66a is slightly smaller than the distance D between the inner wall surfaces 52g and 52h of the pair of first side wall portions 52c and 52d.

  FIG. 4 shows a state in which the other end portion 56b of the lever member 56 is rotated in a direction away from the backing plate 16 due to, for example, vibration during traveling of the vehicle and is in contact with the elastic protrusion 66d of the elastic member 66. . According to FIG. 4, when the lever member 56 comes into contact with the tip portion 66c of the elastic projection 66d, the tip portion 66c of the elastic projection 66d is elastically deformed toward the first connecting portion 52e and the elastic restoring force of the elastic projection 66d. Thus, the other end portion 56b of the lever member 56 is urged toward the backing plate 16 side.

  In the elastic projection 66d of the elastic member 66, the position of the distal end portion 66c of the elastic projection 66d between the first connecting portion 52e and the lever member 56 is determined by the lever member 56 by a relatively small force such as vibration during vehicle travel. Is in contact with the tip 66c of the elastic projection 66d, and the connecting hole 56d formed in the other end 56b of the lever member 56 has a pair of second ends of the main body 52 even if the tip 66c is elastically deformed toward the first connecting portion 52e. It is set by experiment or the like so as not to be exposed from between the one side wall portions 52c and 52d. Further, the elastic protrusion 66d is formed when the operator rotates the other end 56b of the lever member 56 toward the side away from the backing plate 16 with a force larger than a relatively small force such as vibration during the traveling of the vehicle. The tip end portion 66c of the lever member 56 is elastically deformed toward the first connecting portion 52e, and the connecting hole 56d formed in the other end portion 56b of the lever member 56 is exposed from between the pair of first side wall portions 52c, 52d of the main body 52. In this way, it is designed by experiment.

  FIGS. 8 to 11 are diagrams for explaining an operation process for connecting the distal end portion of the brake cable 58 to the other end portion 56 b of the lever member 56. Hereinafter, an operation process for connecting the tip end portion of the brake cable 58 to the other end portion 56b of the lever member 56 will be described.

  First, as shown in FIG. 8, the operator attaches an elastic member 66 to the first connecting portion 52 e of the main body 52, and the lever member of the expanding device 24 is inscribed between one end portions of the pair of brake shoes 20 and 22. 56 is rotated in the direction away from the backing plate 16 around the support shaft 54, that is, in the direction of the arrow F2, and the lever member 56 is brought into contact with the tip 66c of the elastic projection 66d. Then, as shown in FIG. 9, the operator connects the connecting hole 56 d formed in the other end portion 56 b of the lever member 56 against the elastic restoring force of the elastic protrusion 66 d to the pair of first side wall portions 52 c, The tip 66c of the elastic projection 66d is elastically deformed toward the first connecting portion 52e by applying a relatively large force so as to be exposed from between 52d, and the connecting hole 56d is formed as a pair of first side wall portions 52c, 52d of the main body 52. Expose between.

  Next, the operator looks at the connecting hole 56d of the lever member 56 exposed from between the pair of first side wall portions 52c and 52d as shown in FIG. As shown in FIG. 10, the connecting hole 56d of the lever member 56 and the connecting holes 58d and 58e of the pair of second side wall portions 58a and 58b are visually observed to move the connecting holes 56d, 58d and 58e. Adjust.

  Finally, as shown in FIG. 11, the operator inserts the connecting pin 64 into the connecting holes 56 d, 58 d, 58 e, and the tip of the brake cable 58 is connected to the other end 56 b of the lever member 56. When the operator releases his / her hand from the state in which the tip end of the brake cable 58 is connected to the other end 56b of the lever member 56, the other end 56b of the lever member 56 is formed by the elastic return force of the elastic projection 66d. The connecting hole 56d is rotated in the direction approaching the backing plate 16 from the pair of first side wall portions 52c and 52d to a rotating position where it is not exposed, and then the length of the brake cable 58 is adjusted on the vehicle body side. This completes the work.

  When the expansion device 24 configured as described above receives an operation force in a pulling direction from a parking brake lever (not shown) via a brake cable 58 connected to the other end portion 56 b of the lever member 56. The other end portion 56b of the lever member 56 rotates around the support shaft 54 toward the backing plate 16 so that the distance between the engaging recess 52f and the engaging recess 56c of the spreading device 24 is increased, and the pair of brake shoes 20, 22 expands.

  Further, for example, as shown in FIG. 4, the spreading device 24 rotates in a direction in which the other end portion 56 b of the lever member 56 is separated from the backing plate 16 by a relatively small force such as vibration during the running of the vehicle. When it moves and abuts against the tip 66c of the elastic projection 66d, the tip 66c of the elastic projection 66d has a connecting hole 56d formed in the other end 56b of the lever member 56, and a pair of first side walls 52c, 52d. It is relatively small so as not to be exposed from the space, and is elastically deformed toward the first connecting portion 52e, and the other end portion 56b of the lever member 56 is urged toward the backing plate 16 by the elastic return force of the elastic protrusion 66d. .

  According to the drum brake 10 of the present embodiment, the first connecting portion 52e of the main body 52 has a connecting hole 56d formed in the other end portion 56b of the lever member 56 with the pair of first side wall portions 52c and 52d. The other end portion 56b of the lever member 56 is disposed in the main body 52 at a position allowing rotation in a direction away from the backing plate 16 until the lever member 56 is exposed from between the first and second connecting portions 52e. The other end portion 56b of the 56 is elastically deformed by contacting the lever member 56 with the rotation in the direction away from the backing plate 16, and the connecting hole 56d formed in the other end portion 56b of the lever member 56 has a pair of The elastic protrusion 66 of the elastic member 66 that urges the other end portion 56b of the lever member 56 toward the side approaching the backing plate 16 so as not to be exposed from between the first side wall portions 52c and 52d. It is provided. Therefore, the lever member 56 is rotated in the direction away from the backing plate 16 until it abuts against the elastic protrusion 66d of the elastic member 66, and the lever member 56 resists the elastic return force of the elastic protrusion 66d of the elastic member 66. The operator applies a relatively large force so that the coupling hole 56d formed in the other end portion 56b is exposed from the pair of first side wall portions 52c and 52d, and the elastic protrusion 66d of the elastic member 66 is elastically deformed. By doing so, the other end portion 56b of the lever member 56 is further rotated in a direction away from the backing plate 16, and the connecting hole 56d formed in the other end portion 56b of the lever member 56 is a pair of first side wall portions 52c, 52d, the connecting hole 56d of the lever member 56 is not hidden by the parts assembled to the drum brake 10 or the like. Tip of readily brake cable 58 views the d is ligated. Further, after the distal end portion of the brake cable 58 is connected to the other end portion 56 b of the lever member 56, the other end portion 56 b of the lever member 56 approaches the backing plate 16 by the elastic return force of the elastic protrusion 66 d of the elastic member 66. The connecting hole 56d formed in the other end portion 56b of the lever member 56 that is biased in the direction is rotated from the pair of first side wall portions 52c and 52d to a rotation position that is not exposed. Thereafter, when the other end portion 56b of the lever member 56 is rotated in a direction away from the backing plate 16 by a relatively small force such as vibration during traveling of the vehicle and comes into contact with the elastic protrusion 66d of the elastic member 66, the elastic member The elastic projection 66d of 66 is elastically deformed to a relatively small extent so that the connecting hole 56d formed in the other end portion 56b of the lever member 56 is not exposed between the pair of first side wall portions 52c, 52d, and the elastic member 66 The other end portion 56b of the lever member 56 is urged toward the backing plate 16 by the elastic restoring force of the elastic protrusion 66d, so that the connection pin 64 is prevented from coming off from the connection holes 56d, 58d, 58e. Thereby, the drum brake 10 of the present embodiment improves the workability of connecting the tip end portion of the brake cable 58 to the other end portion 56b of the lever member 56 as compared with the conventional one, and the other end portion of the lever member 56. After connecting the distal end portion of the brake cable 58 to 56b, the lever member 56 is not operated to prevent the connecting pin 64 connecting the other end portion 56b of the lever member 56 and the distal end portion of the brake cable 58 from coming off. This prevents the connecting pin 64 that connects the other end 56b and the tip of the brake cable 58 from coming off.

  Further, according to the drum brake 10 of the present embodiment, the elastic member 66 includes a base end portion 66b having a pair of gripping claws 66a for gripping the first connection portion 52e of the main body 52, and a base end portion 66b through the base end portion 66b. An elastically deformable elastic projection 66d protruding between the one connecting portion 52e and the lever member 56 is integrally provided, and the other end 56b of the lever member 56 is backed by the elastic projection 66d of the elastic member 66. When it rotates in a direction away from the plate 16, it abuts and elastically deforms toward the first connecting portion 52 e, thereby biasing the other end portion 56 b of the lever member 56 toward the side closer to the backing plate 16. Therefore, by changing the position of the tip end portion 66c of the elastic protrusion 66d between the first connecting portion 52e and the lever member 56, the other end portion 56b of the lever member 56 is moved. The rotational range of the direction away from Tsu King plate 16 can be freely set.

  Further, according to the drum brake 10 of the present embodiment, the base end portion 66b of the elastic member 66 is disposed on the surface 52i on the opposite side of the backing plate 16 of the first connecting portion 52e, and the gripping claws 66a. Are extended from the base end portion 66b to the backing plate 16 side surface 52j side of the first connecting portion 52e to press the backing plate 16 side surface 52j of the first connecting portion 52e, respectively. The pair of gripping claws 66a is disposed adjacent to the inner wall surfaces 52g and 52h of the pair of first side wall portions 52c and 52d, respectively. Therefore, when the elastic member 66 detachably attached to the first connecting portion 52e of the main body 52 tries to shift to, for example, the one 52c side of the pair of first side wall portions 52c and 52d due to vibration during traveling of the vehicle, the elastic member 66. The gripping claws 66a abut against the inner wall surface 52g of the first side wall portion 52c, thereby preventing the elastic member 66 from being displaced on the first side wall portion 52c side. Further, when the elastic member 66 tries to shift to the first side wall portion 52d side, the gripping claws 66a of the elastic member 66 abut against the inner wall surface 52h of the first side wall portion 52d and the elastic member 66 on the first side wall portion 52d side. Misalignment is prevented.

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

  The drum brake of the present embodiment is substantially the same as the drum brake 10 of the first embodiment except that it includes an elastic member 68 different from the elastic member 66 of the first embodiment, and FIGS. 12 to 15 illustrate the elastic member 68. This corresponds to FIGS. 4, 5, 6, and 7 of the first embodiment.

  As shown in FIG. 12, when the other end portion 56 b of the lever member 56 is rotated in a direction away from the backing plate 16 due to, for example, vibration during traveling of the vehicle, the first connecting portion 52 e of the main body 52 rotates. Of the lever member 56 so that the connecting hole 56d formed in the other end portion 56b of the lever member 56 is not exposed from between the pair of first side wall portions 52c, 52d of the main body 52. An elastic member 68 that urges the other end portion 56 b toward the side approaching the backing plate 16 is provided.

  As shown in FIGS. 13 and 14, the elastic member 68 is made of an elastic steel material such as spring steel. The elastic member 68 holds the first connecting portion 52 e of the main body 52. A flat base end portion 68b having a gripping claw 68a, and a front end portion between the first connecting portion 52e and the lever member 56 from both sides of the gripping claw 68a provided at the central portion of the front end portion of the base end portion 66b. A pair of elastically deformable elastic projections 68d protruding from 68c and a second connecting portion 68e for connecting the tip portions 68c of the pair of elastic protrusions 68d to each other are integrally provided.

  As shown in FIGS. 13 and 14, the grip claw 68a of the elastic member 68 is extended from the base end portion 68b of the elastic member 68 and bent so that the tip end faces the base end portion 68b. Since the distance J between the distal end portion of 68a and the flat base end portion 68b is smaller than the thickness H of the first connecting portion 52e of the main body 52, the base end portion 68b of the elastic member 68 is the first connecting portion 52e. When disposed on the surface 52i opposite to the backing plate 16, the tip end portion of the gripping claw 68a presses the surface 52j of the first connecting portion 52e on the backing plate 16 side by the elastic restoring force, thereby first connecting. The elastic member 68 is attached to the first connecting portion 52e of the main body 52 by the portion 52e being pinched by the gripping claws 68a and the base end portion 68b. In FIG. 14, a solid-line gripping claw 68 a indicates a state before the elastic member 68 is attached to the first connecting portion 52 e of the main body 52, and a dashed-dotted gripping claw 68 a indicates that the elastic member 68 is the first of the main body 52. The state attached to the 1 connection part 52e is shown.

  As shown in FIG. 15, the pair of elastic protrusions 68d of the elastic member 68 are formed on the inner wall surfaces 52g and 52h of the pair of first side wall portions 52c and 52d of the main body 52 from both sides of the gripping claw 68a at the distal end portion of the base end portion 68b. The width dimension K of the pair of elastic protrusions 68d is slightly smaller than the distance D between the inner wall surfaces 52g and 52h of the pair of first side wall portions 52c and 52d.

  In FIG. 12, for example, the other end portion 56b of the lever member 56 rotates in a direction away from the backing plate 16 due to vibration or the like when the vehicle travels, and comes into contact with the second connecting portion 68e of the elastic protrusion 68d of the elastic member 68. It shows the state. According to FIG. 12, when the lever member 56 contacts the second connecting portion 68e of the elastic protrusion 68d, the second connecting portion 68e of the elastic protrusion 68d is elastically deformed toward the first connecting portion 52e and the pair of elastic members 68e. The other end portion 56b of the lever member 56 is urged toward the backing plate 16 by the elastic restoring force of the protrusion 68d.

  In the pair of elastic projections 68d of the elastic member 68, the position of the tip end portion 68c of the pair of elastic projections 68d between the first connecting portion 52e and the lever member 56, that is, the position of the second connecting portion 68e is vibration during vehicle travel. The other end of the lever member 56 even if the lever member 56 abuts against the second connecting portion 68e of the pair of elastic protrusions 68d and the second connecting portion 68e is elastically deformed toward the first connecting portion 52e by a relatively small force such as The connection hole 56d formed in the portion 56b is set by experiment or the like so as not to be exposed from between the pair of first side wall portions 52c and 52d of the main body 52. Further, the pair of elastic protrusions 68d are paired when the operator rotates the other end portion 56b of the lever member 56 toward the side away from the backing plate 16 with a force larger than a relatively small force such as vibration during vehicle travel. The second connecting portion 68e of the elastic projection 68d is elastically deformed toward the first connecting portion 52e, and the connecting hole 56d formed in the other end portion 56b of the lever member 56 has a pair of first side wall portions 52c, It is designed by experiment etc. so that it may be exposed from between 52d.

  Therefore, the lever member 56 is rotated in the direction away from the backing plate 16 until it abuts on the second connecting portion 68e, and the lever member 56 is resisted against the elastic restoring force of the pair of elastic protrusions 68d of the elastic member 68. The pair of elastic protrusions 68d of the elastic member 68 is relatively large by an operator applying a relatively large force so that the connecting hole 56d formed in the other end portion 56b of the other end portion 56b is exposed from the pair of first side wall portions 52c and 52d. Since the connecting hole 56d formed in the other end portion 56b of the lever member 56 is exposed from the pair of first side wall portions 52c and 52d by elastically deforming the lever member 56, the connecting hole 56d of the lever member 56 is assembled to the drum brake 10. The tip of the brake cable 58 can be easily connected by visually observing the connecting hole 56d without being hidden by the parts and the like. After the distal end portion of the brake cable 58 is connected to the other end portion 56 b of the lever member 56, the other end portion 56 b of the lever member 56 approaches the backing plate 16 by the elastic return force of the pair of elastic protrusions 68 d of the elastic member 68. The connecting hole 56d formed in the other end portion 56b of the lever member 56 that is biased in the direction is rotated from the pair of first side wall portions 52c and 52d to a rotation position that is not exposed.

  Thereafter, the other end portion 56b of the lever member 56 is rotated in a direction away from the backing plate 16 by a relatively small force such as vibration during traveling of the vehicle and abuts on the second connecting portion 68e of the elastic member 68. The pair of elastic projections 68d of the elastic member 68 are elastically deformed relatively small so that the connecting hole 56d formed in the other end portion 56b of the lever member 56 is not exposed between the pair of first side wall portions 52c and 52d. At the same time, the elastic restoring force of the pair of elastic protrusions 68d of the elastic member 68 urges the other end portion 56b of the lever member 56 in the direction approaching the backing plate 16, so that the connection holes 56d, 58d, 58e of the connection pin 64 Omission is prevented.

  According to the drum brake of this embodiment, the elastic protrusion 68d of the elastic member 68 protrudes between the first connecting portion 52e and the lever member 56 from both sides of the gripping claw 68a at the distal end portion of the base end portion 68b. The pair of elastic protrusions 68d are disposed adjacent to the inner wall surfaces 52g and 52h of the pair of first side wall portions 52c and 52d of the main body 52, respectively. Therefore, when the elastic member 68 detachably attached to the first connecting portion 52e of the main body 52 tries to shift to, for example, the one 52c side of the pair of first side wall portions 52c and 52d due to vibration during traveling of the vehicle, the elastic member The 68 elastic projections 68d abut against the inner wall surface 52g of the first side wall 52c, thereby preventing the elastic member 68 from being displaced on the first side wall 52c side. Further, when the elastic member 68 tries to shift to the first side wall 52d side, the elastic protrusion 68d of the elastic member 68 abuts on the inner wall surface 52h of the first side wall 52d and the elastic member 68 on the first side wall 52d side. Deviation is prevented.

  Further, according to the drum brake of the present embodiment, the distal end portions 68c of the pair of elastic protrusions 68d include the second coupling portion 68e that couples the distal end portions 68c to each other. When 56b rotates in the direction away from the backing plate 16, it abuts against the second connecting portion 68e of the pair of elastic projections 68d, and the force applied to the other end portion 56b of the lever member 56 is passed through the second connecting portion 68e. Preferably, it can be transmitted to the pair of elastic protrusions 68d.

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

  For example, in the drum brake 10 of this embodiment, the elastic member 66 is detachably attached to the first connecting portion 52e of the main body 52 by the gripping claws 66a. The first connecting portion 52e need not be removably attached using the gripping claws 66a, but the flat base end portion 66b of the elastic member 66 may be directly attached to the first connecting portion 52e of the main body 52 by, for example, welding. .

  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 16: backing plate 16b: insertion holes 20, 22: pair of brake shoes 24: expansion device 26: return spring 52: main body 52a: one end 52b: other end 52c, 52d: a pair of first side walls Portion 52e: first connecting portion 52g, 52h: inner wall surface 52i: surface 52j opposite to the backing plate of the first connecting portion: surface 54j of the first connecting portion on the backing plate side: support shaft 56: lever member 56a: One end 56b: The other end 56d: Connection hole 58: Brake cable 58d, 58e: Connection hole 64: Connection pin 66, 68: Elastic member 66a, 68a: Holding claw 66b, 68b: Base end 66d, 68d: Elastic protrusion 68e: 2nd connection part

Claims (5)

A pair of brake shoes supported on the backing plate so as to be expandable and biased in a direction in which one ends thereof approach each other by a return spring;
A first connection that connects a pair of first side wall portions facing each other in a plate shape perpendicular to the backing plate and a part of the side edges of the pair of first side wall portions on the side away from the backing plate. And a lever disposed between the pair of first side wall portions of the main body and rotatably supported at one end portion of the main body by a support shaft parallel to the backing plate. A spreading device in which one end of the lever member on the side of the support shaft and the other end of the main body are inscribed between one end of the pair of brake shoes;
A brake cable having a tip connected to the other end of the lever member from the back surface of the backing plate through an insertion hole provided in the backing plate;
In order to mutually connect the tip end portion of the brake cable and the other end portion of the lever member, a longitudinal connection pin fitted in a connection hole formed in the tip end portion and the other end portion, respectively,
The connecting pin is fitted into a connecting hole in the other end of the lever member and the tip of the brake cable to connect the other end of the lever member and the tip of the brake cable, and the lever member A drum brake of a type in which the connecting pin is prevented from coming off from the connecting hole in a state where the other end portion of the connecting pin is positioned between the pair of first side wall portions,
The other end of the lever member is separated from the backing plate until a connection hole formed in the other end of the lever member is exposed from between the pair of first side wall portions of the main body. Disposed in the main body at a position allowing rotation in a separating direction;
The first connecting portion is elastically deformed by contacting the lever member with rotation of the other end portion of the lever member in a direction away from the backing plate, and is formed at the other end portion of the lever member. A drum brake, comprising: an elastic member that urges the other end of the lever member toward the side closer to the backing plate so that the connecting hole is not exposed from between the pair of first side wall portions. . The elastic member includes a base end portion having a gripping claw for gripping the first connecting portion of the main body, and is elastically deformable protruding from the base end portion between the first connecting portion and the lever member. With an elastic protrusion,
The elastic protrusion of the elastic member abuts when the other end portion of the lever member rotates in a direction away from the backing plate and is elastically deformed toward the first connecting portion side, whereby the other end of the lever member is 2. The drum brake according to claim 1, wherein the portion is urged toward the side approaching the backing plate. The base end portion is disposed on a surface of the first connecting portion opposite to the backing plate,
The gripping claws are a pair of gripping claws that are respectively extended from the base end portion toward the backing plate side surface of the first connecting portion and press the backing plate side surface of the first connecting portion. And
The drum brake according to claim 2, wherein the pair of gripping claws are arranged adjacent to inner wall surfaces of the pair of first side wall portions. The elastic protrusions are a pair of elastic protrusions that protrude between the first connecting part and the lever member from both sides of the gripping claw of the base end part,
The drum brake according to claim 2, wherein the pair of elastic protrusions are disposed adjacent to inner wall surfaces of the pair of first side wall portions.   The drum brake according to claim 4, wherein the distal end portions of the pair of elastic protrusions include a second coupling portion that couples the distal end portions to each other.

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