WO2014162355A1 - Drum brake - Google Patents

Drum brake Download PDF

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Publication number
WO2014162355A1
WO2014162355A1 PCT/JP2013/002304 JP2013002304W WO2014162355A1 WO 2014162355 A1 WO2014162355 A1 WO 2014162355A1 JP 2013002304 W JP2013002304 W JP 2013002304W WO 2014162355 A1 WO2014162355 A1 WO 2014162355A1
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WO
WIPO (PCT)
Prior art keywords
brake
drum
pair
anchor
leaf spring
Prior art date
Application number
PCT/JP2013/002304
Other languages
French (fr)
Japanese (ja)
Inventor
隼人 駒井
順也 田口
諭 柏村
Original Assignee
株式会社Tbk
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社Tbk filed Critical 株式会社Tbk
Priority to JP2015509598A priority Critical patent/JPWO2014162355A1/en
Priority to CN201380075226.1A priority patent/CN105102841A/en
Priority to PCT/JP2013/002304 priority patent/WO2014162355A1/en
Publication of WO2014162355A1 publication Critical patent/WO2014162355A1/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D51/00—Brakes with outwardly-movable braking members co-operating with the inner surface of a drum or the like
    • F16D51/16—Brakes with outwardly-movable braking members co-operating with the inner surface of a drum or the like shaped as brake-shoes pivoted on a fixed or nearly-fixed axis
    • F16D51/18—Brakes with outwardly-movable braking members co-operating with the inner surface of a drum or the like shaped as brake-shoes pivoted on a fixed or nearly-fixed axis with two brake-shoes
    • F16D51/20—Brakes with outwardly-movable braking members co-operating with the inner surface of a drum or the like shaped as brake-shoes pivoted on a fixed or nearly-fixed axis with two brake-shoes extending in opposite directions from their pivots
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D65/00—Parts or details
    • F16D65/02—Braking members; Mounting thereof
    • F16D65/04—Bands, shoes or pads; Pivots or supporting members therefor
    • F16D65/08—Bands, shoes or pads; Pivots or supporting members therefor for internally-engaging brakes
    • F16D65/09—Pivots or supporting members therefor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2125/00—Components of actuators
    • F16D2125/18—Mechanical mechanisms
    • F16D2125/58—Mechanical mechanisms transmitting linear movement
    • F16D2125/66—Wedges

Definitions

  • the present invention relates to a drum brake that performs braking operation by using friction generated between the brake shoe having a friction material pressed against an inner peripheral surface of a brake drum that rotates together with a wheel.
  • the present invention relates to a drum brake in which one end is attached to an anchor member, and a brake shoe is rocked by swinging a brake shoe around the one end.
  • the drum brake configured as described above is called a leading trailing drum brake and is widely used as a vehicle brake.
  • this leading trailing drum brake there is a form in which one end of a brake shoe is slidably brought into contact with an anchor member, which is called a floating anchor type.
  • Patent Document 1 discloses a floating anchor type drum brake in which one end of a leading shoe 2 and a trailing shoe 3 is elastically brought into contact with an anchor 9 by an anchor spring 10.
  • FIG. 10 also shows a conventional floating anchor type drum brake 500. More specifically, FIG. 10A shows a front view (partially omitted) of the drum brake 500, and FIG. ) Shows bottom views of the drum brake 500, respectively.
  • the drum brake 500 has anchor springs 550 and 550 attached to the front and back sides of the brake shoes 540 and 540, respectively, and one end of the brake shoes 540 and 540 is slidably brought into contact with the anchor pins 526 and 526. It has a configuration to let you.
  • the brake shoes 540, 540 are swung around the anchor pins 526, 526 by the operation of a brake shoe rocking mechanism (not shown) that presses the other end of the brake shoes 540, 540, and the brake drum It is pressed against the inner peripheral surface.
  • the present invention has been made in view of the above problems, and an object of the present invention is to provide a drum brake that can be easily assembled without increasing the number of work steps while suppressing an increase in cost.
  • a drum brake according to the present invention includes a cylindrical brake drum that is connected to a rotating body to be braked and rotates, and a fixed member that is fixed and held (for example, the anchor bracket 2 in the embodiment).
  • a pair of left and right brake shoes that are supported and arranged to face each other along the cylindrical inner peripheral surface of the brake drum, and are attached to the fixing member, and the brake shoes are expanded in response to a brake operation, and the brake drum
  • a brake brake swinging mechanism (for example, the expander 5 in the embodiment) that presses against the inner peripheral surface of the drum brake. It has a contact portion (for example, a pressing surface 41b in the embodiment) that contacts the shoe swinging mechanism from both left and right sides.
  • Each other end has an engaging portion (for example, a sliding surface 41a in the embodiment) that engages with a pair of left and right anchor members (for example, the anchor pin 26 in the embodiment) provided on the fixing member.
  • the engaging portion engages with the anchor member, and the abutting portion abuts the brake shoe swinging mechanism from the left and right so that the pair of left and right brake shoes are along the inner peripheral surface of the brake drum.
  • the brake shoe swinging mechanism pushes the abutting portion away from each other, and swings and expands about the engaging portion engaging the pair of left and right brake shoes with the anchor member.
  • a leaf spring member (for example, a leaf spring 44 in the embodiment) that urges the other ends of the pair of left and right brake shoes in a direction approaching each other straddles the other ends of the pair of left and right brake shoes. It is characterized by being attached.
  • the leaf spring member is formed using an elastically deformable plate material, and is formed in a partial cylindrical shape that connects the other end sides of the pair of left and right brake shoes along the outer peripheral side, and both left and right ends.
  • a locking portion that is locked to the other end of the pair of left and right brake shoes, and the locking portion is in a state in which the leaf spring member is elastically deformed in a direction in which the locking portions are separated from each other.
  • the engagement portion is engaged with the other end side of the pair of left and right brake shoes and urges the other end sides of the pair of left and right brake shoes toward each other by an elastic force generated by the leaf spring member.
  • a configuration that holds the state engaged with the anchor member is preferable.
  • a central portion (for example, the first curved portion 45a in the embodiment) along the outer peripheral direction of the brake shoe is formed to be curved so as to be convex toward the central portion of the brake shoe. It is preferable that the width is formed to be narrower than the width of a portion (for example, the second curved portion 45b in the embodiment) connected from the central portion to the locking portion.
  • the anchor member is formed of a cylindrical member, and the engaging portion is formed of a semicircular recess having substantially the same diameter as the outer periphery of the anchor member.
  • the leaf spring member that urges the other ends of the pair of brake shoes in a direction approaching each other in a state in which the engagement portions of the brake shoes are engaged with the anchor members, respectively. It is configured to be mounted across the other end. For this reason, since the leaf spring member can be attached without reversing the brake shoe, the drum brake can be easily assembled without increasing the number of work steps. Moreover, since the number of parts can be reduced by replacing the two anchor springs in the conventional configuration with one leaf spring member, the manufacturing cost can be reduced and the parts can be easily managed.
  • the leaf spring member is attached to the pair of brake shoes in a state in which the locking portion is elastically deformed in a direction away from each other, and the engaging portion is engaged with the anchor member by the elastic force of the leaf spring member It is preferable to hold the If comprised in this way, the state which the engaging part engaged with the anchor member can be easily hold
  • the leaf spring member is formed to be curved so that the central portion thereof is convex toward the central portion of the brake shoe, and the width of the central portion is narrower than the width of the portion connecting from the central portion to the locking portion.
  • the leaf spring member is formed to be curved so that the central portion thereof is convex toward the central portion of the brake shoe, and the width of the central portion is narrower than the width of the portion connecting from the central portion to the locking portion.
  • FIG. 5 is a cross-sectional view showing a VV portion (expander) in FIG. 1.
  • FIG. 7 is a cross-sectional view (partial side view) showing a VII-VII portion in FIG. 6.
  • FIG. 7 is a cross-sectional view showing a VIII-VIII portion in FIG. 6. It is a figure which shows the modification of an anchor bracket and a brake shoe, Comprising: (a) shows a front view, (b) shows a bottom view, respectively. It is a figure which shows the structure of the conventional drum brake, Comprising: (a) is a front view (a part is abbreviate
  • FIG. 1 is a front view of a floating anchor type drum brake B1 to which the present invention is applied.
  • the entire configuration of the drum brake B1 will be described with reference to FIGS.
  • the following explanation will be given by defining left and right, up and down, and front and rear in the direction of the arrow attached to each figure.
  • the drum brake B ⁇ b> 1 includes an anchor bracket 2 that is fixed to the axle housing 8 of the vehicle body together with the dust cover 6, and a brake drum 31 that is rotatable on the axle 1 together with the axle 1.
  • a drum unit 3 and a brake shoe unit 4 having a pair of left and right brake shoes 40, 40 which are held by the anchor bracket 2 so as to be swingable to the left and right and are respectively disposed along the inner peripheral surface of the brake drum 31;
  • the expander 5 is configured to swing the brake shoes 40, 40 according to the brake operation and press the brake shoes 40 against the inner peripheral surface of the brake drum 31.
  • the drum unit 3 is indicated by a two-dot chain line, and the drum unit 3 is not shown in FIG.
  • the anchor bracket 2 has an axle insertion hole 21 formed at the center and a plurality of bolt insertion holes 22, 22,...
  • a brake shoe support portion 25 having a pair of left and right pin insertion holes 24, 24 penetrating in the front-rear direction in the vicinity of the lower end portion, and the front and rear ends inserted into the pin insertion holes 24, 24 from the brake shoe support portion 25
  • anchor pins 26 and 26 projecting from each other.
  • the anchor bracket 2 is fixed to the axle housing 8 together with the dust cover 6 by using bolts inserted into the respective bolt insertion holes 22.
  • Each anchor pin 26 may be inserted into each pin insertion hole 24 and fixed, or each anchor pin 26 may be inserted into each pin insertion hole 24 and pivoted.
  • the drum unit 3 is mounted on a wheel rim (not shown) on a wheel hub (not shown) rotatably mounted on an axle 1 protruding rearward from the axle insertion hole 21 of the anchor bracket 2 via a bearing (not shown). And the brake drum 31 is coupled. Note that a tire is attached to the wheel rim, and the brake drum 31 and the tire rotate together via a wheel hub.
  • the brake shoe unit 4 is fixed to an outer circumferential surface of the rim portion 42, a semi-disc-shaped web portion 41 extending vertically in an arc shape, a semi-cylindrical rim portion 42 attached to the left and right outer circumferential surfaces of the web portion 41.
  • a pair of brake shoes 40 including a lining 43 is provided.
  • the lining 43 is fixed to the rim portion 42 by caulking of rivets (not shown).
  • Each brake shoe 40 is disposed symmetrically along the inner peripheral surface of the brake drum 31, and the lining 43 is opposed to the inner peripheral surface of the brake drum 31.
  • Sliding surfaces 41a and 41a formed in an arc shape corresponding to the diameter of the anchor pin 26 are formed in a pair of front and rear at the lower end portion of each web portion 41 (see FIG. 2).
  • a pressing surface 41b pressed by the expander 5 is formed on the left and right inner sides.
  • the bottom surface (side surface) of each rim portion 42 is formed with a locking hole 42a to which a leaf spring 44 for slidably contacting each sliding surface 41a to the anchor pin 26 is attached. Has been.
  • FIG. 4 shows a leaf spring 44, which is formed by bending an elastically deformable metal plate.
  • the leaf spring 44 has a base portion 45 formed in a predetermined shape and a pair of left and right engaging portions 46, 46 connected to the left and right ends of the base portion 45. It is formed symmetrically.
  • the base portion 45 is connected to a first curved portion 45a formed to be convex upward and to the left and right ends of the first curved portion 45a. It is comprised from the 2nd bending parts 45b and 45b formed by making it curve so that it may become convex toward the downward direction.
  • Each locking portion 46 is connected to the left and right end portions of the second bending portion 45b and is bent so as to protrude outward in the left and right directions, and the third bending portion 46a. It is comprised from the 4th curved part 46b formed by curving so that it may connect with an upper end part and may become convex toward the left-right inward. As shown in FIG. 4C, since the chamfers 46c and 46c are formed at the front and rear ends of the fourth bending portion 46b, the locking portion 46 is inserted into the locking hole 42a formed in the rim portion 42 of the brake shoe 40. Is easier to insert. Further, as can be seen from FIG.
  • the first curved portion 45a is formed to have a narrower front-rear width than the second curved portions 45b, 45b, and the first curved portion 45b, 45b is the first.
  • the curved portion 45a is more easily elastically deformed.
  • each web portion 41 is opposed to the expander 5, and each sliding surface 41a is inserted into the pin.
  • Brake shoes 40, 40 are arranged so as to face the anchor pin 26 protruding forward and backward from the hole 24.
  • the locking portions 46, 46 of the leaf spring 44 are inserted and locked into the locking holes 42a, 42a of the rim portions 42 from below, and the leaf spring 44 is fixed to the rim portions 42, 42.
  • the leaf spring 44 is attached to the rim portion 42 in a state of being elastically deformed so as to be pushed left and right as indicated by a two-dot chain line in FIG.
  • the leaf spring 44 when the leaf spring 44 is attached to the rim portion 42, the leaf spring 44 tends to be deformed to the original state (not elastically deformed) shown by the solid line in FIG.
  • the left and right inward elastic force acts on the rim portions 42 and 42. Due to this elastic force, the sliding surfaces 41a and 41a are held in a state where they are slidably contacted along the outer peripheral surfaces of the anchor pins 26 and 26.
  • a pair of front and rear return springs 47, 47 are straddled between the upper ends of the web portions 41, 41 of both brake shoes 40, 40. Therefore, the pressing surface 41b of the web portion 41 is pressed against the expander 5 by the urging force of the return spring 47, and when the brake operation is not performed (when the brake is released) as described later, 40 is held at a position that swings inward in the left and right directions.
  • the expander 5 is fixed to the anchor bracket 2 and disposed between the pressing surfaces 41 b and 41 b of both brake shoes 40 and 40.
  • the expander 5 will be described with reference to FIG. 5 showing a cross section of the expander 5.
  • the expander 5 includes a housing 51 that forms a wedge housing 51a at the center and extends to the left and right to form cylinders 51b and 51b that communicate with the wedge housing 51a.
  • the wedge 52, the sleeve assemblies 53 and 53 fitted to the cylinder portions 51b and 51b so as to be slidable to the left and right, and the sleeve assemblies 53 and 53 are screwed to extend outward in the left and right directions of the housing 51. Screw 57, 57.
  • the expander 5 is configured symmetrically, and FIG. 5 shows the state of the expander 5 when the brake is released on the left half and the state of the expander 5 when the brake is operated on the right half.
  • the wedge 52 is formed in a shaft shape, and is attached to the housing 51 so that it can be inserted and removed in the front-rear direction by the operation of a diaphragm (not shown) in the chamber 7 that receives the brake operating air pressure.
  • the wedge 52 is positioned forward by the urging force of the wedge spring 52 a and pulled out from the wedge accommodating portion 51 a when the brake is released.
  • the wedge spring 52a is moved backward in the wedge housing portion 51a against the urging force of the wedge spring 52a and is inserted into the wedge housing portion 51a.
  • the wedge 52 has a wedge-shaped insertion end 52b that is pointed toward the tip, and rollers 52c and 52c are pivotally connected to the left and right sides of the insertion end 52b.
  • the sleeve assembly 53 includes a tappet 54 having an inclined surface 54 a with which the roller 52 c abuts, and a sleeve 55 formed in a cylindrical shape and fitted to the tappet 54.
  • the sleeve 55 is formed with a screw insertion portion extending in the left-right direction, and a screw 57 is inserted and attached to the screw insertion portion. Therefore, the screw 57 is moved to the left and right in the cylinder portion 51b together with the sleeve assembly 53 (the tappet 54 and the sleeve 55).
  • the inclined surface 54a (the tappet 54) is pressed right and left outward by the roller 52c, and the tappet 54, the sleeve 55, and the screw 57 are integrated. Moved left and right.
  • the pressing surface 41 b (web portion 41) is pressed by the screw 57 that moves to the left and right outwards, and both brake shoes 40, 40 against the urging force of the return spring 47 are left and right with the anchor pins 26, 26 as swing centers. Swings outward.
  • the anchor bracket 2 is attached to the axle housing 8 using bolts, and then the expander 5 is attached to the anchor bracket 2.
  • the anchor pins 26, 26 are inserted into the pin insertion holes 24, 24 of the anchor bracket 2, and attached so that the front and rear ends of the anchor pins 26, 26 protrude forward and backward from the brake shoe support portion 25.
  • the brake shoes 40 and 40 are attached to the anchor bracket 2.
  • the brake shoes 40, 40 are arranged so as to surround the ring portion 23, the pressing surface 41 b of each web portion 41 is opposed to the expander 5, and each sliding surface 41 a is opposed to the anchor pin 26.
  • the locking portions 46 and 46 of the leaf spring 44 are inserted into the locking holes 42 a and 42 a of the rim portions 42 from below to be locked, and the leaf spring 44 is attached to the web portion 41.
  • the leaf spring 44 is attached to the rim portion 42 in a state of being elastically deformed so as to be pushed to the left and right, and therefore, the elastic force inwardly on the left and right acts on the rim portions 42 and 42 and the sliding surface.
  • 41a and 41a can be slidably contacted along the outer peripheral surface of the anchor pins 26 and 26. In this manner, the brake shoes 40, 40 are attached to the anchor bracket 2.
  • the drum brake B1 is configured to attach the leaf spring 44 to the bottom surfaces (side surfaces) of the rim portions 42, 42, for example, the leaf spring 44 is mounted on the work table with the rear surface of the drum brake B1 facing the front. 42, 42 can be attached.
  • the drum brake is inverted to attach the rear side anchor springs on the work table. Two steps of placing the leaf spring 44 are not required, and one step of attaching the leaf spring 44 is sufficient. For this reason, assembly work can be simplified and work efficiency can be improved.
  • leaf spring 44 is used in place of the anchor spring in this way, not only during assembly work of the drum brake B1, but also during maintenance of the drum brake B1, such as replacing the brake shoes 40, 40, etc. The effect of simplifying the maintenance work can be obtained. Further, the pair of (two) anchor springs can be replaced with one leaf spring 44 to reduce the number of parts, thereby reducing the manufacturing cost and facilitating parts management.
  • a pair of front and rear return springs 47, 47 are attached between the upper ends of the web portions 41, 41.
  • the return springs 47 and 47 are attached in this way, the pressing surface 41 b of the web portion 41 is pressed against the expander 5 (screw 57) by the urging force of the return spring 47.
  • the leaf spring 44 may be attached after the return springs 47 and 47 are attached.
  • the brake shoes 40, 40 resist the urging force of the return spring 47 to the left and right outwards with the anchor pins 26, 26 as swing centers. It is swung. Accordingly, the linings 43 and 43 are pressed against the inner peripheral surface of the brake drum 31, and the rotation of the brake drum 31 is braked by friction between the linings 43 and 43 and the brake drum 31, and the tire rotates integrally with the brake drum 31. Is braked.
  • the leaf spring 44 is elastically deformed so that each brake shoe 40 is swung and pushed left and right.
  • the leaf spring 44 is elastically deformed so that the first bending portion 45a formed so as to be easily elastically deformed with a narrow width in the base portion 45 is curved upward, so that the rim portions 42, 42 are provided.
  • the web portions 41 and 41 are held slidably along the outer peripheral surface of the anchor pin 26.
  • the operation of the drum brake B1 when the brake operation is released will be described.
  • the brake operation is released, the compressed air in the chamber 7a is discharged according to the release operation, and the insertion end portion 52b is extracted from the wedge housing portion 51a by the urging force of the wedge spring 52a (left side in FIG. 5). See section).
  • the insertion end portion 52b is pulled out in this manner, the brake shoes 40, 40 are swung in the left and right directions around the anchor pins 26, 26 by the urging force of the return spring 47, and the sleeve assembly. 53 and the screw 57 are integrally moved in the cylinder 51b toward the left and right inward.
  • the linings 43 and 43 are separated from the inner peripheral surface of the brake drum 31, and the braking of the tire that rotates integrally with the brake drum 31 is released.
  • the drum brake B2 includes a cam mechanism 150 that swings the brake shoes 40, 40 in accordance with a brake operation.
  • the cam mechanism 150 includes a slack 151 that swings up and down in response to a brake operation, a shaft 152 that is connected to the slack 151 and rotates integrally with the slack 151, and a rear end portion of the shaft 152. And a cam 153 formed integrally therewith.
  • the cam 153 is disposed between the roller pins 141b and 141b of the brake shoes 40 and 40, the arc-shaped left pressing surface 153L abuts on the roller pin 141b of the web portion 41 disposed on the left side, and the arc-shaped right pressing surface 153R. Comes into contact with the roller pin 141b of the web portion 41 disposed on the right side. Further, the leaf spring 44 is attached to the rim portions 42, 42 in the same manner as the drum brake B1 described above. For this reason, also in this drum brake B2, the effect of the structure which attaches the leaf spring 44 mentioned above from the bottom face (side surface) is acquired.
  • the pin 143 may be inserted into the web portions 41 and 41 and the roller 142 in a state where the cylindrical roller 142 is disposed on the pin 143, and the snap rings 144 and 144 may be attached to both ends of the pin 143.
  • the pin 143 is rotatably supported by the web portions 41 and 41, and the roller 142 is rotatably supported by the pin 143.
  • the operation of the drum brake B2 when the brake operation is released will be described.
  • the brake operation is released, the compressed air in the chamber 7b is discharged according to the release operation, and the slack 151 is swung upward by the urging force of the spring immediately below the diaphragm in the chamber 7b.
  • the cam 153 is integrally rotated in the direction opposite to the arrow A.
  • the left pressing surface 153L of the left web portion 41 against the roller pin 141b is weakened
  • the left web portion 41 against the roller pin 141b of the right web portion 41 is weakened.
  • the rightward pressing of the right contact surface 153R is weakened.
  • the brake shoes 40, 40 are swung in the left and right inward directions with the anchor pins 26, 26 as the rocking centers by the urging force of the return spring 47, respectively.
  • the linings 43, 43 are separated from the inner peripheral surface of the brake drum 31, and braking of the tire that rotates integrally with the brake drum 31 is released.
  • the configuration in which the sliding surface 41a formed corresponding to the diameter of the anchor pin 26 is brought into contact with the anchor pin 26 to swing the brake shoe 40 has been described as an example.
  • the portion where the anchor bracket 2 (anchor pin 26) and the brake shoe 40 (web portion 41) abut may have other shapes.
  • a drum brake B3 according to the modification is shown in FIG. 9, and the drum brake B3 will be described below.
  • the same members as those of the above-described drum brake B1 will be denoted by the same reference numerals and the description thereof will be omitted, and a description will be given focusing on a configuration different from the drum brake B1.
  • the drum brake B3 includes a pair of left and right anchor portions 226 and 226 formed in a block shape at the lower end portion of the brake shoe support portion 25.
  • a pair of receiving groove portions 227 and 227 are formed on the side surface of 226 in the front and rear direction.
  • a substantially arc-shaped anchor side contact portion 228 is formed at the bottom of the receiving groove portion 227.
  • a pair of front and rear contact support portions 241 and 241 that are slidably received in the receiving groove portion 227 of the anchor portion 226 are formed at the lower end portion of each web portion 41.
  • a substantially arc-shaped web-side contact portion 241 a is formed at the tip of the contact support portion 241.
  • each brake shoe 40 is swung right and left while maintaining the state in which the web side contact portion 241 a is in contact with the anchor side contact portion 228.
  • the shape of the leaf spring 44 shown in the above embodiment is an example, and is attached to the rim portions 42, 42 so that the sliding surfaces 41a, 41a can be slid along the outer peripheral surfaces of the anchor pins 26, 26. If the function of holding the contacted state is ensured, the leaf spring 44 can be configured in another shape.
  • the present invention can be applied to all floating anchor type drum brakes configured such that one end of the brake shoe 40 is slidably brought into contact with an anchor member.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Braking Arrangements (AREA)

Abstract

A drum brake (B1) comprises a brake drum (31), brake shoes (40) disposed along the inner peripheral surface of the brake drum (31), and an expander (5) that presses the brake shoes (40) against the inner peripheral surface of the brake drum (31). One end of the brake shoes (40) has pressure surfaces (41b) that sandwich and make contact with the expander (5) from both sides of the expander (5), and the other end of the brake shoes has sliding surfaces (41a) that are engaged with anchor pins (26). The brake shoes (40), with the pressure surfaces (41b) being pressed outward in the direction of mutual separation thereof by the expander, are made to expand with a swinging motion centered on the sliding surfaces (41a) so as to press against the inner peripheral surface of the brake drum (31). A leaf spring (44) biases the other ends of the brake shoes (40) in the direction where the ends approach each other in a state where the sliding surfaces (41a) are respectively engaged with the anchor pins (26), and the leaf spring is attached so as to straddle the other ends of the brake shoes (40).

Description

ドラムブレーキDrum brake
　本発明は、車輪とともに回転するブレーキドラムの内周面に、摩擦材を備えたブレーキシューを押し付けて両者間で生じる摩擦を利用して制動作動するドラムブレーキに関し、さらに詳細には、ブレーキシューの一端がアンカー部材に取り付けられ、この一端を揺動中心としてブレーキシューを揺動させて制動作動するドラムブレーキに関する。 The present invention relates to a drum brake that performs braking operation by using friction generated between the brake shoe having a friction material pressed against an inner peripheral surface of a brake drum that rotates together with a wheel. The present invention relates to a drum brake in which one end is attached to an anchor member, and a brake shoe is rocked by swinging a brake shoe around the one end.
　上記のように構成されるドラムブレーキはリーディングトレーリング式ドラムブレーキと称され、車両用のブレーキとして広く用いられている。このリーディングトレーリング式ドラムブレーキの一形態として、ブレーキシューの一端をアンカー部材に摺動可能に当接させて構成される形態があり、これはフローティングアンカー型と称される。例えば特許文献１には、アンカースプリング１０により、リーディングシュー２およびトレーリングシュー３の一端をアンカー９に弾性的に当接させて構成されるフローティングアンカー型のドラムブレーキが開示されている。 The drum brake configured as described above is called a leading trailing drum brake and is widely used as a vehicle brake. As one form of this leading trailing drum brake, there is a form in which one end of a brake shoe is slidably brought into contact with an anchor member, which is called a floating anchor type. For example, Patent Document 1 discloses a floating anchor type drum brake in which one end of a leading shoe 2 and a trailing shoe 3 is elastically brought into contact with an anchor 9 by an anchor spring 10.
　また、図１０にも、従来構成のフローティングアンカー型のドラムブレーキ５００を示しており、より詳細には、図１０（ａ）にドラムブレーキ５００の正面図（一部省略）を、図１０（ｂ）にドラムブレーキ５００の底面図をそれぞれ示している。このドラムブレーキ５００は、ブレーキシュー５４０，５４０に対して、表側および裏側のそれぞれにアンカースプリング５５０，５５０を取り付けて、アンカーピン５２６，５２６にブレーキシュー５４０，５４０の一端を摺動可能に当接させる構成になっている。このため、ブレーキシュー５４０，５４０の他端を押圧するブレーキシュー揺動機構（図示せず）の作動により、アンカーピン５２６，５２６を揺動中心としてブレーキシュー５４０，５４０が揺動されてブレーキドラムの内周面に押し付けられる。 FIG. 10 also shows a conventional floating anchor type drum brake 500. More specifically, FIG. 10A shows a front view (partially omitted) of the drum brake 500, and FIG. ) Shows bottom views of the drum brake 500, respectively. The drum brake 500 has anchor springs 550 and 550 attached to the front and back sides of the brake shoes 540 and 540, respectively, and one end of the brake shoes 540 and 540 is slidably brought into contact with the anchor pins 526 and 526. It has a configuration to let you. For this reason, the brake shoes 540, 540 are swung around the anchor pins 526, 526 by the operation of a brake shoe rocking mechanism (not shown) that presses the other end of the brake shoes 540, 540, and the brake drum It is pressed against the inner peripheral surface.
特開２００７－６４２６０号公報JP 2007-64260 A
　ところで、図１０に示すドラムブレーキ５００を組み立てる際、一方のアンカースプリング５５０をブレーキシュー５４０，５４０に跨るように取り付けた後で他方のアンカースプリング５５０を取り付けるときに、他方のアンカースプリング５５０を取り付ける部分が表側になるようにブレーキシュー５４０，５４０を反転させて向きを変える工程が必要となる。このため、ブレーキシュー５４０，５４０を反転させて向きを変える工程の分だけ組立作業の工数が増加して、作業が煩雑になるとともに作業効率が低下するという課題があった。また、ドラムブレーキ５００においては、二つのアンカースプリング５５０，５５０が必要で、その分コストが増加するという課題もあった。 By the way, when assembling the drum brake 500 shown in FIG. 10, when attaching the other anchor spring 550 after attaching one anchor spring 550 so as to straddle the brake shoes 540, 540, the part to which the other anchor spring 550 is attached. The step of reversing the brake shoes 540 and 540 and changing the direction is necessary so that is on the front side. For this reason, the man-hour of the assembly work is increased by the process of reversing the brake shoes 540, 540 and changing the direction, and there is a problem that the work becomes complicated and the work efficiency is lowered. Further, the drum brake 500 requires two anchor springs 550 and 550, which increases the cost accordingly.
　本発明は上記のような課題に鑑みてなされたものであり、コストアップを抑えつつ、作業工数を増加させることなく簡単に組み立てることができるドラムブレーキを提供することを目的とする。 The present invention has been made in view of the above problems, and an object of the present invention is to provide a drum brake that can be easily assembled without increasing the number of work steps while suppressing an increase in cost.
　上記目的達成のため、本発明に係るドラムブレーキは、制動対象となる回転体に連結されて回転する円筒状のブレーキドラムと、固定保持された固定部材（例えば、実施形態におけるアンカーブラケット２）に支持され、前記ブレーキドラムの円筒状内周面に沿って対向配設された左右一対のブレーキシューと、前記固定部材に取り付けられ、ブレーキ操作に応じて前記ブレーキシューを拡開させて前記ブレーキドラムの内周面に押し付けるブレーキシュー揺動機構（例えば、実施形態におけるエキスパンダ５）とを有して構成されるドラムブレーキであって、前記左右一対のブレーキシューは、それぞれの一端側に前記ブレーキシュー揺動機構を左右両側から挟んで当接する当接部（例えば、実施形態における押圧面４１ｂ）を有し、それぞれの他端側に前記固定部材に設けられた左右一対のアンカー部材（例えば、実施形態におけるアンカーピン２６）に係合する係合部（例えば、実施形態における摺動面４１ａ）を有し、前記係合部が前記アンカー部材に係合するとともに前記当接部が前記ブレーキシュー揺動機構を左右から挟んで当接して前記左右一対のブレーキシューが前記ブレーキドラムの内周面に沿って対向配置された状態で、前記ブレーキシュー揺動機構により前記当接部を互いに離れる方向に押し出して前記左右一対のブレーキシューを前記アンカー部材と係合した前記係合部を中心として揺動拡開させて前記ブレーキドラムの内周面に押し付けるように構成され、前記左右一対のブレーキシューのそれぞれの前記係合部が前記左右一対のアンカー部材に係合した状態で、前記左右一対のブレーキシューの他端側を互いに近づく方向に付勢するリーフスプリング部材（例えば、実施形態におけるリーフスプリング４４）が、前記左右一対のブレーキシューの他端側に跨がって取り付けられていることを特徴とする。 In order to achieve the above object, a drum brake according to the present invention includes a cylindrical brake drum that is connected to a rotating body to be braked and rotates, and a fixed member that is fixed and held (for example, the anchor bracket 2 in the embodiment). A pair of left and right brake shoes that are supported and arranged to face each other along the cylindrical inner peripheral surface of the brake drum, and are attached to the fixing member, and the brake shoes are expanded in response to a brake operation, and the brake drum A brake brake swinging mechanism (for example, the expander 5 in the embodiment) that presses against the inner peripheral surface of the drum brake. It has a contact portion (for example, a pressing surface 41b in the embodiment) that contacts the shoe swinging mechanism from both left and right sides. Each other end has an engaging portion (for example, a sliding surface 41a in the embodiment) that engages with a pair of left and right anchor members (for example, the anchor pin 26 in the embodiment) provided on the fixing member. The engaging portion engages with the anchor member, and the abutting portion abuts the brake shoe swinging mechanism from the left and right so that the pair of left and right brake shoes are along the inner peripheral surface of the brake drum. In a state of being opposed to each other, the brake shoe swinging mechanism pushes the abutting portion away from each other, and swings and expands about the engaging portion engaging the pair of left and right brake shoes with the anchor member. And is configured to press against the inner peripheral surface of the brake drum, and the engaging portions of the pair of left and right brake shoes are engaged with the pair of left and right anchor members, respectively. In this state, a leaf spring member (for example, a leaf spring 44 in the embodiment) that urges the other ends of the pair of left and right brake shoes in a direction approaching each other straddles the other ends of the pair of left and right brake shoes. It is characterized by being attached.
　上述のドラムブレーキにおいて、前記リーフスプリング部材が弾性変形可能な板材を用いて形成され、前記左右一対のブレーキシューの他端側同士を外周側に沿って繋ぐ部分円筒状に形成されるとともに左右両端部に前記左右一対のブレーキシューの他端側に係止される係止部を有し、前記係止部が互いに離れる方向に前記リーフスプリング部材を弾性変形させた状態で、前記係止部を前記左右一対のブレーキシューの他端側に係止させ、前記リーフスプリング部材が発生する弾性力により前記左右一対のブレーキシューの他端側を互いに近づく方向に付勢して前記係合部が前記アンカー部材に係合した状態を保持する構成が好ましい。 In the above-described drum brake, the leaf spring member is formed using an elastically deformable plate material, and is formed in a partial cylindrical shape that connects the other end sides of the pair of left and right brake shoes along the outer peripheral side, and both left and right ends. A locking portion that is locked to the other end of the pair of left and right brake shoes, and the locking portion is in a state in which the leaf spring member is elastically deformed in a direction in which the locking portions are separated from each other. The engagement portion is engaged with the other end side of the pair of left and right brake shoes and urges the other end sides of the pair of left and right brake shoes toward each other by an elastic force generated by the leaf spring member. A configuration that holds the state engaged with the anchor member is preferable.
　また、両側の前記係止部がそれぞれ前記左右一対のブレーキシューの他端側に係止されて前記リーフスプリング部材が前記左右一対のブレーキシューに跨って取り付けられた状態において、前記リーフスプリング部材における前記ブレーキシューの外周方向に沿った中央部分（例えば、実施形態における第１湾曲部４５ａ）が前記ブレーキシューの中心部に向けて凸となるように湾曲して形成されるとともに、前記中央部分の幅が前記中央部分から前記係止部に繋がる部分（例えば、実施形態における第２湾曲部４５ｂ）の幅よりも狭くなるように形成されたことが好ましい。 Further, in the state in which the engaging portions on both sides are respectively engaged with the other end sides of the pair of left and right brake shoes and the leaf spring member is mounted across the pair of left and right brake shoes, A central portion (for example, the first curved portion 45a in the embodiment) along the outer peripheral direction of the brake shoe is formed to be curved so as to be convex toward the central portion of the brake shoe. It is preferable that the width is formed to be narrower than the width of a portion (for example, the second curved portion 45b in the embodiment) connected from the central portion to the locking portion.
　さらに、前記アンカー部材が円筒状の部材から構成され、前記係合部が前記アンカー部材の外周と略同一径の半円形状の凹部から構成されることが好ましい。 Furthermore, it is preferable that the anchor member is formed of a cylindrical member, and the engaging portion is formed of a semicircular recess having substantially the same diameter as the outer periphery of the anchor member.
　本発明に係るドラムブレーキは、ブレーキシューの係合部がそれぞれアンカー部材に係合した状態で、一対のブレーキシューの他端側を互いに近づく方向に付勢するリーフスプリング部材が一対のブレーキシューの他端側に跨がって取り付けられて構成される。このため、ブレーキシューを反転させることなくリーフスプリング部材を取り付けることができるので、作業工数を増加させることなく簡単にドラムブレーキを組み立てることができる。また、従来構成における二つのアンカースプリングを一つのリーフスプリング部材に置き換えて部品点数を減らすことができるので、製造コストを抑えるとともに部品管理がしやすくなる。 In the drum brake according to the present invention, the leaf spring member that urges the other ends of the pair of brake shoes in a direction approaching each other in a state in which the engagement portions of the brake shoes are engaged with the anchor members, respectively. It is configured to be mounted across the other end. For this reason, since the leaf spring member can be attached without reversing the brake shoe, the drum brake can be easily assembled without increasing the number of work steps. Moreover, since the number of parts can be reduced by replacing the two anchor springs in the conventional configuration with one leaf spring member, the manufacturing cost can be reduced and the parts can be easily managed.
　上述のドラムブレーキにおいて、リーフスプリング部材を係止部が互いに離れる方向に弾性変形させた状態で一対のブレーキシューに取り付けて、リーフスプリング部材の弾性力により係合部がアンカー部材に係合した状態を保持する構成が好ましい。このように構成すれば、リーフスプリング部材を弾性変形させて一対のブレーキシューに取り付けるだけで、簡単に係合部がアンカー部材に係合した状態を保持することができる。 In the above-described drum brake, the leaf spring member is attached to the pair of brake shoes in a state in which the locking portion is elastically deformed in a direction away from each other, and the engaging portion is engaged with the anchor member by the elastic force of the leaf spring member It is preferable to hold the If comprised in this way, the state which the engaging part engaged with the anchor member can be easily hold | maintained only by elastically deforming a leaf spring member and attaching to a pair of brake shoes.
　また、リーフスプリング部材の中央部分がブレーキシューの中心部に向けて凸となるように湾曲して形成されるとともに、この中央部分の幅が中央部分から係止部に繋がる部分の幅よりも狭く形成されたことが好ましい。このため、一対のブレーキシューが揺動されてアンカー部材に沿って係合部が摺動するときに、一対のブレーキシューにおける他端側の変位がリーフスプリング部材の中央部分が弾性変形することによって吸収されるので、ブレーキシューに対するリーフスプリング部材の係止状態を維持することができる。 Further, the leaf spring member is formed to be curved so that the central portion thereof is convex toward the central portion of the brake shoe, and the width of the central portion is narrower than the width of the portion connecting from the central portion to the locking portion. Preferably formed. For this reason, when the pair of brake shoes are swung and the engaging portion slides along the anchor member, the displacement on the other end side of the pair of brake shoes is caused by elastic deformation of the central portion of the leaf spring member. Since it is absorbed, the locked state of the leaf spring member with respect to the brake shoe can be maintained.
本発明を適用したドラムブレーキの構成を示す正面図である。It is a front view which shows the structure of the drum brake to which this invention is applied. 図１中におけるＩＩ－ＩＩ部分を示す断面図（一部側面図）である。It is sectional drawing (partial side view) which shows the II-II part in FIG. 上記ドラムブレーキのリーフスプリング近傍を示す底面図である。It is a bottom view which shows the leaf spring vicinity of the said drum brake. リーフスプリングを示す図であって、（ａ）は正面図を、（ｂ）は底面図を、（ｃ）は側面図をそれぞれ示す。It is a figure which shows a leaf spring, Comprising: (a) shows a front view, (b) shows a bottom view, (c) shows a side view. 図１中におけるＶ－Ｖ部分（エキスパンダ）を示す断面図である。FIG. 5 is a cross-sectional view showing a VV portion (expander) in FIG. 1. 本発明を適用した変形例に係るドラムブレーキの構成を示す正面図である。It is a front view which shows the structure of the drum brake which concerns on the modification to which this invention is applied. 図６中におけるＶＩＩ－ＶＩＩ部分を示す断面図（一部側面図）である。FIG. 7 is a cross-sectional view (partial side view) showing a VII-VII portion in FIG. 6. 図６中におけるＶＩＩＩ－ＶＩＩＩ部分を示す断面図である。FIG. 7 is a cross-sectional view showing a VIII-VIII portion in FIG. 6. アンカーブラケットおよびブレーキシューの変形例を示す図であって、（ａ）は正面図を、（ｂ）は底面図をそれぞれ示す。It is a figure which shows the modification of an anchor bracket and a brake shoe, Comprising: (a) shows a front view, (b) shows a bottom view, respectively. 従来のドラムブレーキの構成を示す図であって、（ａ）は正面図（一部省略）を、（ｂ）はアンカースプリング近傍の底面図をそれぞれ示す。It is a figure which shows the structure of the conventional drum brake, Comprising: (a) is a front view (a part is abbreviate | omitted), (b) shows the bottom view of an anchor spring vicinity, respectively.
　以下、本発明の実施形態について図面を参照しながら説明する。図１には本発明を適用したフローティングアンカー型のドラムブレーキＢ１の正面図を示しており、まず、このドラムブレーキＢ１の全体構成について図１～５を参照して説明する。なお、説明の便宜のために、各図に付記する矢印方向で左右、上下および前後を定義して以下の説明を行う。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a floating anchor type drum brake B1 to which the present invention is applied. First, the entire configuration of the drum brake B1 will be described with reference to FIGS. For convenience of explanation, the following explanation will be given by defining left and right, up and down, and front and rear in the direction of the arrow attached to each figure.
　ドラムブレーキＢ１は、図１および図２に示すように、ダストカバー６とともに車体のアクスルハウジング８に固定されるアンカーブラケット２と、車軸１に車軸１とともに回転可能にブレーキドラム３１を設けて構成されるドラムユニット３と、アンカーブラケット２に左右に揺動可能に保持されてそれぞれブレーキドラム３１の内周面に沿って配設される左右一対のブレーキシュー４０，４０を備えたブレーキシューユニット４と、ブレーキ操作に応じてブレーキシュー４０，４０を揺動してブレーキドラム３１の内周面に押し付けるエキスパンダ５とを有して構成される。なお、図１においてはドラムユニット３を２点鎖線で示し、図２においてはドラムユニット３の図示を省略している。 As shown in FIGS. 1 and 2, the drum brake B <b> 1 includes an anchor bracket 2 that is fixed to the axle housing 8 of the vehicle body together with the dust cover 6, and a brake drum 31 that is rotatable on the axle 1 together with the axle 1. A drum unit 3 and a brake shoe unit 4 having a pair of left and right brake shoes 40, 40 which are held by the anchor bracket 2 so as to be swingable to the left and right and are respectively disposed along the inner peripheral surface of the brake drum 31; The expander 5 is configured to swing the brake shoes 40, 40 according to the brake operation and press the brake shoes 40 against the inner peripheral surface of the brake drum 31. In FIG. 1, the drum unit 3 is indicated by a two-dot chain line, and the drum unit 3 is not shown in FIG.
　アンカーブラケット２は、中央部に車軸挿入孔２１が形成されるとともにその周囲に複数のボルト挿入孔２２，２２，…が形成されたリング部２３と、リング部２３の周縁に繋がって下方に延びるとともに下端部近傍において前後に貫通する左右一対のピン挿入孔２４，２４が形成されたブレーキシュー支持部２５と、ピン挿入孔２４，２４に挿入されて前後端部がブレーキシュー支持部２５から前後に突出するアンカーピン２６，２６とを有して構成される。このアンカーブラケット２は、各ボルト挿入孔２２に挿入されたボルトを利用して、ダストカバー６とともにアクスルハウジング８に固定される。なお、各アンカーピン２６を各ピン挿入孔２４に挿入して固定する構成でも良く、または、各アンカーピン２６を各ピン挿入孔２４に挿入して枢結する構成でも良い。 The anchor bracket 2 has an axle insertion hole 21 formed at the center and a plurality of bolt insertion holes 22, 22,... In addition, a brake shoe support portion 25 having a pair of left and right pin insertion holes 24, 24 penetrating in the front-rear direction in the vicinity of the lower end portion, and the front and rear ends inserted into the pin insertion holes 24, 24 from the brake shoe support portion 25 And anchor pins 26 and 26 projecting from each other. The anchor bracket 2 is fixed to the axle housing 8 together with the dust cover 6 by using bolts inserted into the respective bolt insertion holes 22. Each anchor pin 26 may be inserted into each pin insertion hole 24 and fixed, or each anchor pin 26 may be inserted into each pin insertion hole 24 and pivoted.
　ドラムユニット３は、アンカーブラケット２の車軸挿入孔２１から後方に突出する車軸１上にベアリング（図示せず）を介して回転可能に取り付けられたホイールハブ（図示せず）に、ホイールリム（図示せず）を取り付けるとともにブレーキドラム３１を結合して構成されている。なお、ホイールリムにはタイヤが取り付けられており、ブレーキドラム３１とタイヤとがホイールハブを介して一体回転するようになっている。 The drum unit 3 is mounted on a wheel rim (not shown) on a wheel hub (not shown) rotatably mounted on an axle 1 protruding rearward from the axle insertion hole 21 of the anchor bracket 2 via a bearing (not shown). And the brake drum 31 is coupled. Note that a tire is attached to the wheel rim, and the brake drum 31 and the tire rotate together via a wheel hub.
　ブレーキシューユニット４は、弧状に上下に延びる半円板状のウェブ部４１と、ウェブ部４１の左右外周面に取り付けられる半円筒状のリム部４２と、リム部４２の外周面に固定されるライニング４３とからなる一対のブレーキシュー４０を有して構成される。ライニング４３は、リベット（図示せず）のカシメによりリム部４２に固定される。各ブレーキシュー４０は、それぞれブレーキドラム３１の内周面に沿うようにして左右対称に配設され、ライニング４３をブレーキドラム３１の内周面に対向させている。 The brake shoe unit 4 is fixed to an outer circumferential surface of the rim portion 42, a semi-disc-shaped web portion 41 extending vertically in an arc shape, a semi-cylindrical rim portion 42 attached to the left and right outer circumferential surfaces of the web portion 41. A pair of brake shoes 40 including a lining 43 is provided. The lining 43 is fixed to the rim portion 42 by caulking of rivets (not shown). Each brake shoe 40 is disposed symmetrically along the inner peripheral surface of the brake drum 31, and the lining 43 is opposed to the inner peripheral surface of the brake drum 31.
　各ウェブ部４１の下端部には、アンカーピン２６の径に対応させて弧状に形成された摺動面４１ａ，４１ａが前後一対となって形成され（図２参照）、一方上端部には、左右内側にエキスパンダ５により押圧される押圧面４１ｂが形成されている。また、図３に示すように、各リム部４２の底面（側面）には、各摺動面４１ａをアンカーピン２６に摺動可能に当接させるリーフスプリング４４が取り付けられる係止穴４２ａが形成されている。 Sliding surfaces 41a and 41a formed in an arc shape corresponding to the diameter of the anchor pin 26 are formed in a pair of front and rear at the lower end portion of each web portion 41 (see FIG. 2). A pressing surface 41b pressed by the expander 5 is formed on the left and right inner sides. Further, as shown in FIG. 3, the bottom surface (side surface) of each rim portion 42 is formed with a locking hole 42a to which a leaf spring 44 for slidably contacting each sliding surface 41a to the anchor pin 26 is attached. Has been.
　図４にはリーフスプリング４４を示しており、弾性変形可能な金属板材を折曲等して形成されている。リーフスプリング４４は、図４から分かるように、所定の形状に形成されたベース部４５と、このベース部４５の左右端部に繋がった左右一対の係止部４６，４６とを有し、左右対称に形成される。ベース部４５は、図４（ａ）に示すように、上方に向けて凸となるように湾曲させて形成された第１湾曲部４５ａと、この第１湾曲部４５ａの左右端部に繋がって下方に向けて凸となるように湾曲させて形成された第２湾曲部４５ｂ，４５ｂとから構成される。各係止部４６は、第２湾曲部４５ｂの左右端部に繋がって左右外方に向けて凸となるように湾曲させて形成された第３湾曲部４６ａと、この第３湾曲部４６ａの上端部に繋がって左右内方に向けて凸となるように湾曲させて形成された第４湾曲部４６ｂとから構成される。図４（ｃ）に示すように、第４湾曲部４６ｂの前後両端に面取り４６ｃ，４６ｃが形成されているので、ブレーキシュー４０のリム部４２に形成された係止穴４２ａに係止部４６を挿入しやすくなっている。また、図４（ｂ）から分かるように、第２湾曲部４５ｂ，４５ｂに対して第１湾曲部４５ａの方が前後幅が狭く形成されており、第２湾曲部４５ｂ，４５ｂよりも第１湾曲部４５ａの方が弾性変形しやすくなっている。 FIG. 4 shows a leaf spring 44, which is formed by bending an elastically deformable metal plate. As can be seen from FIG. 4, the leaf spring 44 has a base portion 45 formed in a predetermined shape and a pair of left and right engaging portions 46, 46 connected to the left and right ends of the base portion 45. It is formed symmetrically. As shown in FIG. 4A, the base portion 45 is connected to a first curved portion 45a formed to be convex upward and to the left and right ends of the first curved portion 45a. It is comprised from the 2nd bending parts 45b and 45b formed by making it curve so that it may become convex toward the downward direction. Each locking portion 46 is connected to the left and right end portions of the second bending portion 45b and is bent so as to protrude outward in the left and right directions, and the third bending portion 46a. It is comprised from the 4th curved part 46b formed by curving so that it may connect with an upper end part and may become convex toward the left-right inward. As shown in FIG. 4C, since the chamfers 46c and 46c are formed at the front and rear ends of the fourth bending portion 46b, the locking portion 46 is inserted into the locking hole 42a formed in the rim portion 42 of the brake shoe 40. Is easier to insert. Further, as can be seen from FIG. 4B, the first curved portion 45a is formed to have a narrower front-rear width than the second curved portions 45b, 45b, and the first curved portion 45b, 45b is the first. The curved portion 45a is more easily elastically deformed.
　このリーフスプリング４４をリム部４２，４２に取り付ける際には、まず、図１に示すように、各ウェブ部４１の押圧面４１ｂをエキスパンダ５に対向させるとともに、各摺動面４１ａをピン挿入孔２４から前後に突出するアンカーピン２６に対向させるようにブレーキシュー４０，４０を配設する。次に、この状態で、リーフスプリング４４の係止部４６，４６を各リム部４２の係止穴４２ａ，４２ａに下方から挿入して係止させて、リーフスプリング４４をリム部４２，４２に取り付ける。このとき、リーフスプリング４４は、図４（ａ）に２点鎖線で示すように、左右に押し広げられるように弾性変形された状態でリム部４２に取り付けられる。このため、リーフスプリング４４は、リム部４２に取り付けられると、図４（ａ）に実線で示す元の状態（弾性変形していない状態）に変形しようとするので、この元の状態に戻ろうとする左右内方への弾性力がリム部４２，４２に作用する。この弾性力によって、摺動面４１ａ，４１ａがアンカーピン２６，２６の外周面に沿って摺動可能に当接した状態で保持される。 When attaching the leaf spring 44 to the rim portions 42, 42, first, as shown in FIG. 1, the pressing surface 41b of each web portion 41 is opposed to the expander 5, and each sliding surface 41a is inserted into the pin. Brake shoes 40, 40 are arranged so as to face the anchor pin 26 protruding forward and backward from the hole 24. Next, in this state, the locking portions 46, 46 of the leaf spring 44 are inserted and locked into the locking holes 42a, 42a of the rim portions 42 from below, and the leaf spring 44 is fixed to the rim portions 42, 42. Install. At this time, the leaf spring 44 is attached to the rim portion 42 in a state of being elastically deformed so as to be pushed left and right as indicated by a two-dot chain line in FIG. Therefore, when the leaf spring 44 is attached to the rim portion 42, the leaf spring 44 tends to be deformed to the original state (not elastically deformed) shown by the solid line in FIG. The left and right inward elastic force acts on the rim portions 42 and 42. Due to this elastic force, the sliding surfaces 41a and 41a are held in a state where they are slidably contacted along the outer peripheral surfaces of the anchor pins 26 and 26.
　両ブレーキシュー４０，４０のウェブ部４１，４１の上端部間には、前後一対のリターンスプリング４７，４７が跨設されるようになっている。このため、リターンスプリング４７の付勢力により、ウェブ部４１の押圧面４１ｂがエキスパンダ５に押し付けられるとともに、後述するようにブレーキ操作がなされていないとき（ブレーキ解除時）には、ブレーキシュー４０，４０がそれぞれ左右内方に揺動した位置に保持される。 A pair of front and rear return springs 47, 47 are straddled between the upper ends of the web portions 41, 41 of both brake shoes 40, 40. Therefore, the pressing surface 41b of the web portion 41 is pressed against the expander 5 by the urging force of the return spring 47, and when the brake operation is not performed (when the brake is released) as described later, 40 is held at a position that swings inward in the left and right directions.
　エキスパンダ５は、図１に示すように、アンカーブラケット２に固定されて両ブレーキシュー４０，４０の押圧面４１ｂ，４１ｂ間に配設される。このエキスパンダ５について、エキスパンダ５の断面を示した図５を参照しながら説明する。エキスパンダ５は、中央部にウェッジ収容部５１ａを形成するとともに左右に延びてウェッジ収容部５１ａに連通するシリンダ部５１ｂ，５１ｂを形成するハウジング５１と、ウェッジ収容部５１ａに前後に挿抜可能に取り付けられたウェッジ５２と、シリンダ部５１ｂ，５１ｂに左右に摺動可能に嵌挿されたスリーブアセンブリ５３，５３と、スリーブアセンブリ５３，５３と螺合してハウジング５１の左右外方へ延びて設けられたスクリュウ５７，５７とから構成される。また、エキスパンダ５は左右対称に構成されており、図５は左半分にブレーキ解除時におけるエキスパンダ５の状態を、右半分にブレーキ作動時におけるエキスパンダ５の状態をそれぞれ示している。 As shown in FIG. 1, the expander 5 is fixed to the anchor bracket 2 and disposed between the pressing surfaces 41 b and 41 b of both brake shoes 40 and 40. The expander 5 will be described with reference to FIG. 5 showing a cross section of the expander 5. The expander 5 includes a housing 51 that forms a wedge housing 51a at the center and extends to the left and right to form cylinders 51b and 51b that communicate with the wedge housing 51a. The wedge 52, the sleeve assemblies 53 and 53 fitted to the cylinder portions 51b and 51b so as to be slidable to the left and right, and the sleeve assemblies 53 and 53 are screwed to extend outward in the left and right directions of the housing 51. Screw 57, 57. Further, the expander 5 is configured symmetrically, and FIG. 5 shows the state of the expander 5 when the brake is released on the left half and the state of the expander 5 when the brake is operated on the right half.
　ウェッジ５２は、シャフト状に形成されており、ブレーキ作動空気圧を受けるチャンバ７内のダイヤフラム（図示せず）の作動によりハウジング５１に対して前後に挿抜可能に取り付けられている。これにより、ウェッジ５２は、ブレーキ解除時には図５左側部分に示すように、ウェッジスプリング５２ａの付勢力により前方に位置してウェッジ収容部５１ａに対して抜出された状態とされ、ブレーキ作動時には図５右側部分に示すように、ウェッジスプリング５２ａの付勢力に抗してウェッジ収容部５１ａ内を後方に移動してウェッジ収容部５１ａに対して挿入された状態とされる。ウェッジ５２の先端部には、先端に向かって尖る楔状の挿入端部５２ｂが形成されており、この挿入端部５２ｂの左右両側面にローラ５２ｃ，５２ｃが枢結されている。 The wedge 52 is formed in a shaft shape, and is attached to the housing 51 so that it can be inserted and removed in the front-rear direction by the operation of a diaphragm (not shown) in the chamber 7 that receives the brake operating air pressure. As a result, as shown in the left part of FIG. 5, the wedge 52 is positioned forward by the urging force of the wedge spring 52 a and pulled out from the wedge accommodating portion 51 a when the brake is released. 5 As shown in the right side portion, the wedge spring 52a is moved backward in the wedge housing portion 51a against the urging force of the wedge spring 52a and is inserted into the wedge housing portion 51a. The wedge 52 has a wedge-shaped insertion end 52b that is pointed toward the tip, and rollers 52c and 52c are pivotally connected to the left and right sides of the insertion end 52b.
　スリーブアセンブリ５３は、ローラ５２ｃが当接する傾斜面５４ａを有するタペット５４と、円筒状に形成されてタペット５４に嵌合されたスリーブ５５とから構成される。スリーブ５５には、左右に延びるスクリュウ挿入部が形成されており、このスクリュウ挿入部にスクリュウ５７が挿入されて取り付けられる。よって、スクリュウ５７は、スリーブアセンブリ５３（タペット５４およびスリーブ５５）と一体となってシリンダ部５１ｂ内を左右に移動される。 The sleeve assembly 53 includes a tappet 54 having an inclined surface 54 a with which the roller 52 c abuts, and a sleeve 55 formed in a cylindrical shape and fitted to the tappet 54. The sleeve 55 is formed with a screw insertion portion extending in the left-right direction, and a screw 57 is inserted and attached to the screw insertion portion. Therefore, the screw 57 is moved to the left and right in the cylinder portion 51b together with the sleeve assembly 53 (the tappet 54 and the sleeve 55).
　ブレーキ操作がされてウェッジ５２がウェッジ収容部５１ａ内に挿入されると、ローラ５２ｃによって傾斜面５４ａ（タペット５４）が左右外方に押圧されて、タペット５４、スリーブ５５およびスクリュウ５７が一体となって左右外方に移動される。この左右外方に移動するスクリュウ５７によって押圧面４１ｂ（ウェブ部４１）が押圧され、リターンスプリング４７の付勢力に抗して両ブレーキシュー４０，４０がアンカーピン２６，２６を揺動中心として左右外方に揺動される。一方、ブレーキ操作が解除されてウェッジ５２がウェッジ収容部５１ａから抜出されると、傾斜面５４ａ（タペット５４）に対するローラ５２ｃの左右外方への押圧が解除される。そうすると、リターンスプリング４７の付勢力によって、両ブレーキシュー４０，４０がアンカーピン２６，２６を揺動中心として左右内方に揺動されて、タペット５４、スリーブ５５およびスクリュウ５７が一体となって左右内方に移動される。 When the brake operation is performed and the wedge 52 is inserted into the wedge accommodating portion 51a, the inclined surface 54a (the tappet 54) is pressed right and left outward by the roller 52c, and the tappet 54, the sleeve 55, and the screw 57 are integrated. Moved left and right. The pressing surface 41 b (web portion 41) is pressed by the screw 57 that moves to the left and right outwards, and both brake shoes 40, 40 against the urging force of the return spring 47 are left and right with the anchor pins 26, 26 as swing centers. Swings outward. On the other hand, when the brake operation is released and the wedge 52 is pulled out from the wedge housing portion 51a, the right and left outward pressing of the roller 52c against the inclined surface 54a (the tappet 54) is released. Then, the urging force of the return spring 47 causes the brake shoes 40, 40 to swing left and right inward with the anchor pins 26, 26 as the swing center, and the tappet 54, sleeve 55, and screw 57 are integrated into the left and right. Moved inward.
　以上、ドラムブレーキＢ１の全体構成について説明した。次に、ドラムブレーキＢ１を組み立てて、アクスルハウジング８に取り付けるときの組立手順の一例について説明する。 The overall configuration of the drum brake B1 has been described above. Next, an example of an assembly procedure when the drum brake B1 is assembled and attached to the axle housing 8 will be described.
　まず、ボルトを用いてアクスルハウジング８にアンカーブラケット２を取り付けた後、アンカーブラケット２にエキスパンダ５を取り付ける。次に、アンカーブラケット２のピン挿入孔２４，２４にアンカーピン２６，２６を挿入して、アンカーピン２６，２６の前後端部がブレーキシュー支持部２５から前後に突出するように取り付ける。 First, the anchor bracket 2 is attached to the axle housing 8 using bolts, and then the expander 5 is attached to the anchor bracket 2. Next, the anchor pins 26, 26 are inserted into the pin insertion holes 24, 24 of the anchor bracket 2, and attached so that the front and rear ends of the anchor pins 26, 26 protrude forward and backward from the brake shoe support portion 25.
　続いて、アンカーブラケット２にブレーキシュー４０，４０を取り付ける。このとき、各ブレーキシュー４０，４０をリング部２３を囲むように配置し、各ウェブ部４１の押圧面４１ｂをエキスパンダ５に対向させるとともに、各摺動面４１ａをアンカーピン２６に対向させる。この状態で、リーフスプリング４４の係止部４６，４６を各リム部４２の係止穴４２ａ，４２ａに下方から挿入して係止させて、リーフスプリング４４をウェブ部４１に取り付ける。上述したように、リーフスプリング４４は、左右に押し広げられるように弾性変形された状態でリム部４２に取り付けられるので、左右内側への弾性力がリム部４２，４２に作用し、摺動面４１ａ，４１ａをアンカーピン２６，２６の外周面に沿って摺動可能に当接させることができる。このようにして、アンカーブラケット２にブレーキシュー４０，４０を取り付ける。 Subsequently, the brake shoes 40 and 40 are attached to the anchor bracket 2. At this time, the brake shoes 40, 40 are arranged so as to surround the ring portion 23, the pressing surface 41 b of each web portion 41 is opposed to the expander 5, and each sliding surface 41 a is opposed to the anchor pin 26. In this state, the locking portions 46 and 46 of the leaf spring 44 are inserted into the locking holes 42 a and 42 a of the rim portions 42 from below to be locked, and the leaf spring 44 is attached to the web portion 41. As described above, the leaf spring 44 is attached to the rim portion 42 in a state of being elastically deformed so as to be pushed to the left and right, and therefore, the elastic force inwardly on the left and right acts on the rim portions 42 and 42 and the sliding surface. 41a and 41a can be slidably contacted along the outer peripheral surface of the anchor pins 26 and 26. In this manner, the brake shoes 40, 40 are attached to the anchor bracket 2.
　ドラムブレーキＢ１は、リーフスプリング４４をリム部４２，４２の底面（側面）に取り付ける構成なので、例えばドラムブレーキＢ１の後面を表に向けて作業台上に載置したまま、リーフスプリング４４をリム部４２，４２に取り付けることができる。このため、例えばウェブ部の前後両面にそれぞれアンカースプリングを取り付ける従来構成のように、前面側のアンカースプリングを取り付けた後で、後面側のアンカースプリングを取り付けるためにドラムブレーキを反転させて作業台上に載置させるという２つの工程を必要とせず、リーフスプリング４４を取り付けるという一つの工程で良い。このため、組立作業を簡単にして作業効率を向上させることができる。なお、このようにアンカースプリングに代えてリーフスプリング４４を用いる構成にすれば、ドラムブレーキＢ１の組立作業時のみならず、ブレーキシュー４０，４０を交換する等のドラムブレーキＢ１のメンテナンス時においても、メンテナンス作業が簡単になるという効果が得られる。また、一対（二つ）のアンカースプリングを一つのリーフスプリング４４に置き換えて部品点数を減らすこともでき、これにより製造コストを低減できるとともに部品管理がしやすくなる。 Since the drum brake B1 is configured to attach the leaf spring 44 to the bottom surfaces (side surfaces) of the rim portions 42, 42, for example, the leaf spring 44 is mounted on the work table with the rear surface of the drum brake B1 facing the front. 42, 42 can be attached. For this reason, for example, as in the conventional configuration in which anchor springs are attached to both the front and rear surfaces of the web part, after attaching the front side anchor springs, the drum brake is inverted to attach the rear side anchor springs on the work table. Two steps of placing the leaf spring 44 are not required, and one step of attaching the leaf spring 44 is sufficient. For this reason, assembly work can be simplified and work efficiency can be improved. If the leaf spring 44 is used in place of the anchor spring in this way, not only during assembly work of the drum brake B1, but also during maintenance of the drum brake B1, such as replacing the brake shoes 40, 40, etc. The effect of simplifying the maintenance work can be obtained. Further, the pair of (two) anchor springs can be replaced with one leaf spring 44 to reduce the number of parts, thereby reducing the manufacturing cost and facilitating parts management.
　続いて、ウェブ部４１，４１の上端部間に、前後一対のリターンスプリング４７，４７を取り付ける。このようにリターンスプリング４７，４７を取り付けると，リターンスプリング４７の付勢力により、ウェブ部４１の押圧面４１ｂがエキスパンダ５（スクリュウ５７）に押し付けられる。なお、ここでは、リーフスプリング４４を取り付けた後でリターンスプリング４７，４７を取り付ける手順を説明したが、リターンスプリング４７，４７を取り付けた後でリーフスプリング４４を取り付けるようにしても良い。 Subsequently, a pair of front and rear return springs 47, 47 are attached between the upper ends of the web portions 41, 41. When the return springs 47 and 47 are attached in this way, the pressing surface 41 b of the web portion 41 is pressed against the expander 5 (screw 57) by the urging force of the return spring 47. Although the procedure for attaching the return springs 47 and 47 after attaching the leaf spring 44 has been described here, the leaf spring 44 may be attached after the return springs 47 and 47 are attached.
　続いて、アンカーブラケット２の各ボルト挿入孔２２にボルトを挿入してアクスルハウジング８に締結し、エキスパンダ５、ダストカバー６およびブレーキシュー４０，４０が取り付けられたアンカーブラケット２をアクスルハウジング８に固定する。次に、車軸１にホイールハブを取り付けた後、このホイールハブにブレーキドラム３１を取り付けて、ブレーキドラム３１の内周面をブレーキシュー４０，４０（ライニング４３，４３）に対向させる。以上のようにして、ドラムブレーキＢ１が組み立てられる。 Subsequently, a bolt is inserted into each bolt insertion hole 22 of the anchor bracket 2 and fastened to the axle housing 8. The anchor bracket 2 to which the expander 5, dust cover 6 and brake shoes 40, 40 are attached is attached to the axle housing 8. Fix it. Next, after the wheel hub is attached to the axle 1, the brake drum 31 is attached to the wheel hub, and the inner peripheral surface of the brake drum 31 is opposed to the brake shoes 40, 40 (linings 43, 43). The drum brake B1 is assembled as described above.
　以上、リーフスプリング４４の組立手順について説明した。次に、このようにして組み立てられるドラムブレーキＢ１の作動について説明する。 The assembly procedure of the leaf spring 44 has been described above. Next, the operation of the drum brake B1 assembled in this way will be described.
　まず、ブレーキ操作がされた場合のドラムブレーキＢ１の作動について説明する。ブレーキ操作がされると、そのブレーキ操作に応じてチャンバ７ａ内に圧縮空気が供給され、チャンバ７ａ内のダイヤフラムの作動によりウェッジスプリング５２ａの付勢力に抗して挿入端部５２ｂがウェッジ収容部５１ａ内に挿入される（図５右側部分を参照）。この挿入端部５２ｂの挿入動により、ローラ５２ｃ，５２ｃによって傾斜面５４ａ，５４ａ（タペット５４，５４）が左右外方に向けて押圧され、タペット５４、スリーブ５５およびスクリュウ５７が一体となってシリンダ部５１ｂ内をそれぞれ左右外方に向けて移動される。このときのスクリュウ５７，５７の左右外方への張出作動により、ブレーキシュー４０，４０は、リターンスプリング４７の付勢力に抗してアンカーピン２６，２６を揺動中心としてそれぞれ左右外方に揺動される。これにより、ライニング４３，４３がブレーキドラム３１の内周面に押し付けられ、ライニング４３，４３とブレーキドラム３１との間の摩擦によりブレーキドラム３１の回転が制動され、ブレーキドラム３１と一体回転するタイヤが制動される。 First, the operation of the drum brake B1 when the brake is operated will be described. When the brake is operated, compressed air is supplied into the chamber 7a according to the brake operation, and the insertion end 52b is resisted against the urging force of the wedge spring 52a by the operation of the diaphragm in the chamber 7a. (See right part of FIG. 5). By the insertion movement of the insertion end 52b, the inclined surfaces 54a and 54a (the tappets 54 and 54) are pressed toward the left and right by the rollers 52c and 52c, and the tappet 54, the sleeve 55 and the screw 57 are integrated into the cylinder. The part 51b is moved outward in the left and right directions. As a result of the screw 57, 57 extending outwardly to the left and right at this time, the brake shoes 40, 40 resist the urging force of the return spring 47 to the left and right outwards with the anchor pins 26, 26 as swing centers. It is swung. Accordingly, the linings 43 and 43 are pressed against the inner peripheral surface of the brake drum 31, and the rotation of the brake drum 31 is braked by friction between the linings 43 and 43 and the brake drum 31, and the tire rotates integrally with the brake drum 31. Is braked.
　このように、ブレーキ操作がされて各ブレーキシュー４０が左右外方に向けて揺動されると、リーフスプリング４４は各ブレーキシュー４０の揺動じて左右に押し広げられるように弾性変形される。このとき、リーフスプリング４４は、ベース部４５のうちで幅が狭く弾性変形しやすいように形成された第１湾曲部４５ａが上方に向けて湾曲するように弾性変形するので、リム部４２，４２に対する取付状態が維持されて、ウェブ部４１，４１がアンカーピン２６の外周面に沿って摺動可能に保持される。 Thus, when the brake operation is performed and each brake shoe 40 is swung toward the left and right outwards, the leaf spring 44 is elastically deformed so that each brake shoe 40 is swung and pushed left and right. At this time, the leaf spring 44 is elastically deformed so that the first bending portion 45a formed so as to be easily elastically deformed with a narrow width in the base portion 45 is curved upward, so that the rim portions 42, 42 are provided. The web portions 41 and 41 are held slidably along the outer peripheral surface of the anchor pin 26.
　次に、ブレーキ操作が解除された場合のドラムブレーキＢ１の作動について説明する。ブレーキ操作が解除されると、その解除操作に応じてチャンバ７ａ内の圧縮空気が排出され、ウェッジスプリング５２ａの付勢力によりウェッジ収容部５１ａに対して挿入端部５２ｂが抜出される（図５左側部分を参照）。このように挿入端部５２ｂが抜出されると、リターンスプリング４７の付勢力により、ブレーキシュー４０，４０がアンカーピン２６，２６を揺動中心としてそれぞれ左右内方に揺動されるとともに、スリーブアセンブリ５３およびスクリュウ５７が一体となってシリンダ部５１ｂ内をそれぞれ左右内方に向けて移動される。これにより、ライニング４３，４３がブレーキドラム３１の内周面から離間されて、ブレーキドラム３１と一体回転するタイヤの制動が解除される。 Next, the operation of the drum brake B1 when the brake operation is released will be described. When the brake operation is released, the compressed air in the chamber 7a is discharged according to the release operation, and the insertion end portion 52b is extracted from the wedge housing portion 51a by the urging force of the wedge spring 52a (left side in FIG. 5). See section). When the insertion end portion 52b is pulled out in this manner, the brake shoes 40, 40 are swung in the left and right directions around the anchor pins 26, 26 by the urging force of the return spring 47, and the sleeve assembly. 53 and the screw 57 are integrally moved in the cylinder 51b toward the left and right inward. As a result, the linings 43 and 43 are separated from the inner peripheral surface of the brake drum 31, and the braking of the tire that rotates integrally with the brake drum 31 is released.
　以上ここまでは、エキスパンダ５によりブレーキシュー４０，４０をそれぞれ揺動させて制動作動を行うドラムブレーキＢ１に本発明を適用した例について説明した。以下においては、本発明を、カムによりブレーキシューをそれぞれ揺動させて制動作動を行うドラムブレーキＢ２に適用した例について説明する。まず、このドラムブレーキＢ２の全体構成について、図６および図７を参照しながら説明する。なお、以下においては、ドラムブレーキＢ１と同一部材には同一番号を付してその説明を省略し、ドラムブレーキＢ１とは異なる構成を中心に説明する。 So far, the example in which the present invention is applied to the drum brake B1 that performs the braking operation by swinging the brake shoes 40, 40 by the expander 5 has been described. In the following, an example in which the present invention is applied to a drum brake B2 that performs braking operation by swinging brake shoes by cams will be described. First, the overall configuration of the drum brake B2 will be described with reference to FIGS. In the following description, the same members as those of the drum brake B1 are denoted by the same reference numerals, and the description thereof is omitted. The description will focus on a configuration different from the drum brake B1.
　図６に示すように、ドラムブレーキＢ２においては、弧状に形成された各ウェブ部４１の上端部に、ローラとピンとが一体形成されたローラピン１４１ｂが回転可能に取り付けられている。また、ドラムブレーキＢ２は、ブレーキ操作に応じてブレーキシュー４０，４０を揺動させるカム機構１５０を備える。カム機構１５０は、図７に示すように、ブレーキ操作に応じて上下に揺動されるスラック１５１と、スラック１５１に連結されてスラック１５１と一体に回転するシャフト１５２と、シャフト１５２の後端部に一体形成されたカム１５３とから構成される。カム１５３は、両ブレーキシュー４０，４０のローラピン１４１ｂ，１４１ｂ間に配設され、弧状の左押圧面１５３Ｌが左側に配設されたウェブ部４１のローラピン１４１ｂに当接し、弧状の右押圧面１５３Ｒが右側に配設されたウェブ部４１のローラピン１４１ｂに当接する。また、リーフスプリング４４は、上述したドラムブレーキＢ１と同様にリム部４２，４２に取り付けられている。このため、このドラムブレーキＢ２においても、上述したリーフスプリング４４を底面（側面）から取り付ける構成の効果が得られる。 As shown in FIG. 6, in the drum brake B2, a roller pin 141b in which a roller and a pin are integrally formed is rotatably attached to an upper end portion of each web portion 41 formed in an arc shape. The drum brake B2 includes a cam mechanism 150 that swings the brake shoes 40, 40 in accordance with a brake operation. As shown in FIG. 7, the cam mechanism 150 includes a slack 151 that swings up and down in response to a brake operation, a shaft 152 that is connected to the slack 151 and rotates integrally with the slack 151, and a rear end portion of the shaft 152. And a cam 153 formed integrally therewith. The cam 153 is disposed between the roller pins 141b and 141b of the brake shoes 40 and 40, the arc-shaped left pressing surface 153L abuts on the roller pin 141b of the web portion 41 disposed on the left side, and the arc-shaped right pressing surface 153R. Comes into contact with the roller pin 141b of the web portion 41 disposed on the right side. Further, the leaf spring 44 is attached to the rim portions 42, 42 in the same manner as the drum brake B1 described above. For this reason, also in this drum brake B2, the effect of the structure which attaches the leaf spring 44 mentioned above from the bottom face (side surface) is acquired.
　なお、図８（ａ）に示すように、ウェブ部４１の上端部にローラピン１４１ｂを回転可能に当接させた構成に代えて、図８（ｂ）に示すように、ウェブ部４１，４１間に円筒状のローラ１４２を配置した状態で、ウェブ部４１，４１およびローラ１４２にピン１４３を挿通させ、このピン１４３の両端部にスナップリング１４４，１４４を取り付ける構成でも良い。図８（ｂ）の構成においては、ピン１４３がウェブ部４１，４１に回転可能に支持されるとともに、ローラ１４２がピン１４３に回転可能に支持される。 As shown in FIG. 8A, instead of the configuration in which the roller pin 141b is rotatably contacted with the upper end portion of the web portion 41, as shown in FIG. The pin 143 may be inserted into the web portions 41 and 41 and the roller 142 in a state where the cylindrical roller 142 is disposed on the pin 143, and the snap rings 144 and 144 may be attached to both ends of the pin 143. In the configuration of FIG. 8B, the pin 143 is rotatably supported by the web portions 41 and 41, and the roller 142 is rotatably supported by the pin 143.
　次に、ドラムブレーキＢ２の作動について説明する。まず、ブレーキ操作がされた場合のドラムブレーキＢ２の作動について説明する。ブレーキ操作がされると、そのブレーキ操作に応じてチャンバ７ｂ内に圧縮空気が供給され、チャンバ７ｂ内のダイアフラムの作動によりダイアフラムに繋がるロッド部７ｃとスラック１５１との枢結部を介してスラック１５１が下方に揺動され、これによりシャフト１５２およびカム１５３が一体に矢印Ａ（図６参照）の方向に回転される。カム１５３が矢印Ａの方向に回転されると、左押圧面１５３Ｌにより左側のウェブ部４１のローラピン１４１ｂが左側に押圧されるとともに、右押圧面１５３Ｒにより右側のウェブ部４１のローラピン１４１ｂが右側に押圧される。これにより、ブレーキシュー４０，４０は、リターンスプリング４７の付勢力に抗してアンカーピン２６，２６を揺動中心としてそれぞれ左右外方に揺動される。これにより、ライニング４３，４３がブレーキドラム３１の内周面に押し付けられ、ブレーキドラム３１と一体回転するタイヤが制動される。 Next, the operation of the drum brake B2 will be described. First, the operation of the drum brake B2 when the brake operation is performed will be described. When a brake operation is performed, compressed air is supplied into the chamber 7b according to the brake operation, and the slack 151 is connected via a pivot portion between the rod portion 7c and the slack 151 connected to the diaphragm by the operation of the diaphragm in the chamber 7b. Is pivoted downward, whereby the shaft 152 and the cam 153 are integrally rotated in the direction of arrow A (see FIG. 6). When the cam 153 is rotated in the direction of arrow A, the roller pin 141b of the left web portion 41 is pressed to the left by the left pressing surface 153L, and the roller pin 141b of the right web portion 41 is moved to the right by the right pressing surface 153R. Pressed. As a result, the brake shoes 40, 40 are swung outwardly left and right around the anchor pins 26, 26 against the urging force of the return spring 47. Thereby, the linings 43 and 43 are pressed against the inner peripheral surface of the brake drum 31, and the tire that rotates integrally with the brake drum 31 is braked.
　次に、ブレーキ操作が解除された場合のドラムブレーキＢ２の作動について説明する。ブレーキ操作が解除されると、その解除操作に応じてチャンバ７ｂ内の圧縮空気が排出され、チャンバ７ｂ内のダイアフラム直下にあるスプリングの付勢力によりスラック１５１が上方に揺動され、これによりシャフト１５２およびカム１５３が一体に矢印Ａとは反対の方向に回転される。カム１５３が矢印Ａとは反対方向に回転されると、左側のウェブ部４１のローラピン１４１ｂに対する左当接面１５３Ｌの左方への押圧が弱められ、また、右側のウェブ部４１のローラピン１４１ｂに対する右当接面１５３Ｒの右方への押圧が弱められる。これにより、ブレーキシュー４０，４０は、リターンスプリング４７の付勢力によってアンカーピン２６，２６を揺動中心としてそれぞれ左右内方に揺動される。このようにして、ライニング４３，４３がブレーキドラム３１の内周面から離間されて、ブレーキドラム３１と一体回転するタイヤの制動が解除される。 Next, the operation of the drum brake B2 when the brake operation is released will be described. When the brake operation is released, the compressed air in the chamber 7b is discharged according to the release operation, and the slack 151 is swung upward by the urging force of the spring immediately below the diaphragm in the chamber 7b. The cam 153 is integrally rotated in the direction opposite to the arrow A. When the cam 153 is rotated in the direction opposite to the arrow A, the left pressing surface 153L of the left web portion 41 against the roller pin 141b is weakened, and the left web portion 41 against the roller pin 141b of the right web portion 41 is weakened. The rightward pressing of the right contact surface 153R is weakened. As a result, the brake shoes 40, 40 are swung in the left and right inward directions with the anchor pins 26, 26 as the rocking centers by the urging force of the return spring 47, respectively. In this way, the linings 43, 43 are separated from the inner peripheral surface of the brake drum 31, and braking of the tire that rotates integrally with the brake drum 31 is released.
　上述の実施形態においては、アンカーピン２６に対してこのアンカーピン２６の径に対応させて形成された摺動面４１ａを当接させて、ブレーキシュー４０を揺動させる構成を例示して説明したが、アンカーブラケット２（アンカーピン２６）とブレーキシュー４０（ウェブ部４１）とが当接する部分は他の形状でも良い。その変形例に係るドラムブレーキＢ３を図９に示しており、このドラムブレーキＢ３について以下に説明する。なお、以下においては、上述したドラムブレーキＢ１と同一部材には同一番号を付してその説明を省略し、ドラムブレーキＢ１とは異なる構成を中心に説明する。 In the above-described embodiment, the configuration in which the sliding surface 41a formed corresponding to the diameter of the anchor pin 26 is brought into contact with the anchor pin 26 to swing the brake shoe 40 has been described as an example. However, the portion where the anchor bracket 2 (anchor pin 26) and the brake shoe 40 (web portion 41) abut may have other shapes. A drum brake B3 according to the modification is shown in FIG. 9, and the drum brake B3 will be described below. In the following, the same members as those of the above-described drum brake B1 will be denoted by the same reference numerals and the description thereof will be omitted, and a description will be given focusing on a configuration different from the drum brake B1.
　ドラムブレーキＢ３は、図９（ａ）および図９（ｂ）に示すように、ブレーキシュー支持部２５の下端部にブロック状に形成された左右一対のアンカー部２２６，２２６を備え、各アンカー部２２６の側面に受容溝部２２７，２２７が前後一対となって形成されている。この受容溝部２２７の底部には、略円弧状のアンカー側当接部２２８が形成されている。一方、各ウェブ部４１の下端部には、アンカー部２２６の受容溝部２２７に摺動可能に受容される当接支持部２４１，２４１が前後一対となって形成されている。この当接支持部２４１の先端部には、略円弧状のウェブ側当接部２４１ａが形成されている。このドラムブレーキＢ３は、各ウェブ部４１の当接支持部２４１，２４１を各アンカー部２２６の受容溝部２２７，２２７に対して左右から挿入し、その状態でリーフスプリング４４の係止部４６，４６を各リム部４２の係止穴４２ａ，４２ａに下方から挿入して係止させて、リーフスプリング４４をリム部４２，４２に取り付けて構成される。このようにしてリーフスプリング４４が取り付けられると、アンカー側当接部２２８にウェブ側当接部２４１ａが弾性的に当接された状態に保持される。このため、各ブレーキシュー４０は、アンカー側当接部２２８にウェブ側当接部２４１ａが当接された状態を維持しつつ左右に揺動される。 As shown in FIGS. 9A and 9B, the drum brake B3 includes a pair of left and right anchor portions 226 and 226 formed in a block shape at the lower end portion of the brake shoe support portion 25. A pair of receiving groove portions 227 and 227 are formed on the side surface of 226 in the front and rear direction. A substantially arc-shaped anchor side contact portion 228 is formed at the bottom of the receiving groove portion 227. On the other hand, a pair of front and rear contact support portions 241 and 241 that are slidably received in the receiving groove portion 227 of the anchor portion 226 are formed at the lower end portion of each web portion 41. A substantially arc-shaped web-side contact portion 241 a is formed at the tip of the contact support portion 241. In this drum brake B3, the contact support portions 241 and 241 of each web portion 41 are inserted from the left and right into the receiving groove portions 227 and 227 of each anchor portion 226, and in this state, the locking portions 46 and 46 of the leaf spring 44 are inserted. Is inserted into the locking holes 42a, 42a of the rim portions 42 from below and locked, and the leaf spring 44 is attached to the rim portions 42, 42. When the leaf spring 44 is attached in this way, the web-side contact portion 241a is held in an elastically contacted state with the anchor-side contact portion 228. For this reason, each brake shoe 40 is swung right and left while maintaining the state in which the web side contact portion 241 a is in contact with the anchor side contact portion 228.
　上述の実施形態に示したリーフスプリング４４の形状は一例であって、リム部４２，４２に取り付けられて摺動面４１ａ，４１ａをアンカーピン２６，２６の外周面に沿って摺動可能に当接させた状態に保持するという機能が確保されれば、リーフスプリング４４を他の形状により構成することも可能である。 The shape of the leaf spring 44 shown in the above embodiment is an example, and is attached to the rim portions 42, 42 so that the sliding surfaces 41a, 41a can be slid along the outer peripheral surfaces of the anchor pins 26, 26. If the function of holding the contacted state is ensured, the leaf spring 44 can be configured in another shape.
　本発明は、ブレーキシュー４０の一端をアンカー部材に摺動可能に当接させて構成されるフローティングアンカー型のドラムブレーキ全般に適用可能である。 The present invention can be applied to all floating anchor type drum brakes configured such that one end of the brake shoe 40 is slidably brought into contact with an anchor member.
Ｂ１　　ドラムブレーキ
２　　　アンカーブラケット（固定部材）
５　　　エキスパンダ（ブレーキシュー揺動機構）
２６　　アンカーピン（アンカー部材）
３１　　ブレーキドラム
４０　　ブレーキシュー
４１ａ　摺動面（係合部）
４１ｂ　押圧面（当接部）
４４　　リーフスプリング（リーフスプリング部材）
４５ａ　第１湾曲部（中央部分）
４５ｂ　第２湾曲部（係止部に繋がる部分）
４６　　係止部 B1 Drum brake 2 Anchor bracket (fixing member)
5 Expander (brake shoe swing mechanism)
26 Anchor pin (anchor member)
31 Brake drum 40 Brake shoe 41a Sliding surface (engagement part)
41b Press surface (contact part)
44 Leaf spring (leaf spring member)
45a 1st bending part (central part)
45b 2nd bending part (part connected to the locking part)
46 Locking part

Claims (4)

  1. 　制動対象となる回転体に連結されて回転する円筒状のブレーキドラムと、
    　固定保持された固定部材に支持され、前記ブレーキドラムの円筒状内周面に沿って対向配設された左右一対のブレーキシューと、
    　前記固定部材に取り付けられ、ブレーキ操作に応じて前記ブレーキシューを拡開させて前記ブレーキドラムの内周面に押し付けるブレーキシュー揺動機構とを有して構成されるドラムブレーキであって、
    　前記左右一対のブレーキシューは、それぞれの一端側に前記ブレーキシュー揺動機構を左右両側から挟んで当接する当接部を有し、それぞれの他端側に前記固定部材に設けられた左右一対のアンカー部材に係合する係合部を有し、前記係合部が前記アンカー部材に係合するとともに前記当接部が前記ブレーキシュー揺動機構を左右から挟んで当接して前記左右一対のブレーキシューが前記ブレーキドラムの内周面に沿って対向配置された状態で、前記ブレーキシュー揺動機構により前記当接部を互いに離れる方向に押し出して前記左右一対のブレーキシューを前記アンカー部材と係合した前記係合部を中心として揺動拡開させて前記ブレーキドラムの内周面に押し付けるように構成され、
    　前記左右一対のブレーキシューのそれぞれの前記係合部が前記左右一対のアンカー部材に係合した状態で、前記左右一対のブレーキシューの他端側を互いに近づく方向に付勢するリーフスプリング部材が、前記左右一対のブレーキシューの他端側に跨がって取り付けられていることを特徴とするドラムブレーキ。     A cylindrical brake drum connected to a rotating body to be braked and rotating;
    A pair of left and right brake shoes supported by a fixed and held fixing member and arranged to face each other along the cylindrical inner peripheral surface of the brake drum;
    A drum brake configured to include a brake shoe swinging mechanism that is attached to the fixing member and expands the brake shoe according to a brake operation and presses the brake shoe against an inner peripheral surface of the brake drum;
    Each of the pair of left and right brake shoes has an abutting portion that abuts the brake shoe swinging mechanism from both left and right sides at one end side, and a pair of left and right provided on the fixing member at each other end side. An engaging portion that engages with the anchor member; the engaging portion engages with the anchor member; and the abutting portion abuts the brake shoe swinging mechanism from the left and right to contact the pair of left and right brakes With the shoe disposed opposite to the inner peripheral surface of the brake drum, the brake shoe swinging mechanism pushes the contact portion away from each other to engage the pair of left and right brake shoes with the anchor member. Configured to swing and expand around the engaging portion and press against the inner peripheral surface of the brake drum,
    A leaf spring member that urges the other ends of the pair of left and right brake shoes in a direction approaching each other in a state in which the engagement portions of the pair of left and right brake shoes are engaged with the pair of left and right anchor members, A drum brake characterized by being mounted across the other end of the pair of left and right brake shoes.
  2. 　前記リーフスプリング部材が弾性変形可能な板材を用いて形成され、前記左右一対のブレーキシューの他端側同士を外周側に沿って繋ぐ部分円筒状に形成されるとともに左右両端部に前記左右一対のブレーキシューの他端側に係止される係止部を有し、
    　前記係止部が互いに離れる方向に前記リーフスプリング部材を弾性変形させた状態で、前記係止部を前記左右一対のブレーキシューの他端側に係止させ、前記リーフスプリング部材が発生する弾性力により前記左右一対のブレーキシューの他端側を互いに近づく方向に付勢して前記係合部が前記アンカー部材に係合した状態を保持することを特徴とする請求項１に記載のドラムブレーキ。     The leaf spring member is formed using a plate material that is elastically deformable, and is formed in a partial cylindrical shape that connects the other ends of the pair of left and right brake shoes along the outer peripheral side. Having a locking portion locked to the other end of the brake shoe,
    In a state where the leaf spring member is elastically deformed in a direction in which the locking portions are separated from each other, the locking portion is locked to the other end side of the pair of left and right brake shoes, and the elastic force generated by the leaf spring member 2. The drum brake according to claim 1, wherein the engagement portion is engaged with the anchor member by urging the other ends of the pair of left and right brake shoes toward each other.
  3. 　両側の前記係止部がそれぞれ前記左右一対のブレーキシューの他端側に係止されて前記リーフスプリング部材が前記左右一対のブレーキシューに跨って取り付けられた状態において、前記リーフスプリング部材における前記ブレーキシューの外周方向に沿った中央部分が前記ブレーキシューの中心部に向けて凸となるように湾曲して形成されるとともに、前記中央部分の幅が前記中央部分から前記係止部に繋がる部分の幅よりも狭くなるように形成されたことを特徴とする請求項１もしくは２に記載のドラムブレーキ。 The brakes in the leaf spring member in a state where the engaging portions on both sides are respectively engaged with the other end sides of the pair of left and right brake shoes and the leaf spring member is mounted across the pair of left and right brake shoes. A central portion along the outer peripheral direction of the shoe is formed to be curved so as to protrude toward the central portion of the brake shoe, and the width of the central portion is a portion of the portion connecting from the central portion to the locking portion. The drum brake according to claim 1, wherein the drum brake is formed to be narrower than a width.
  4. 　前記アンカー部材が円筒状の部材から構成され、前記係合部が前記アンカー部材の外周と略同一径の半円形状の凹部から構成されることを特徴とする請求項１～３のいずれかに記載のドラムブレーキ。 4. The anchor member according to claim 1, wherein the anchor member is formed of a cylindrical member, and the engaging portion is formed of a semicircular recess having substantially the same diameter as the outer periphery of the anchor member. Drum brake as described.
PCT/JP2013/002304 2013-04-03 2013-04-03 Drum brake WO2014162355A1 (en)

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JP2015509598A JPWO2014162355A1 (en) 2013-04-03 2013-04-03 Drum brake
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DE102019207664B3 (en) * 2019-05-24 2020-04-23 Continental Teves Ag & Co. Ohg drum brake

Citations (7)

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JPS62181729U (en) * 1986-05-12 1987-11-18
JPH0296044U (en) * 1989-01-19 1990-07-31
JPH0322139U (en) * 1989-07-13 1991-03-06
JPH0579427U (en) * 1992-03-27 1993-10-29 株式会社ソキア Card holding device
JPH0777231A (en) * 1991-04-08 1995-03-20 Toyota Motor Corp Fiber reinforced plastic leaf spring
JPH10110757A (en) * 1996-10-08 1998-04-28 Nisshinbo Ind Inc Drum brake device
JP2001020979A (en) * 1999-07-06 2001-01-23 Nisshinbo Ind Inc Drum brake system

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2233002Y (en) * 1995-08-03 1996-08-14 北京新利奥汽车技术发展公司 Automotive drum-like self-adjusting brake for rear-wheel

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Publication number Priority date Publication date Assignee Title
JPS62181729U (en) * 1986-05-12 1987-11-18
JPH0296044U (en) * 1989-01-19 1990-07-31
JPH0322139U (en) * 1989-07-13 1991-03-06
JPH0777231A (en) * 1991-04-08 1995-03-20 Toyota Motor Corp Fiber reinforced plastic leaf spring
JPH0579427U (en) * 1992-03-27 1993-10-29 株式会社ソキア Card holding device
JPH10110757A (en) * 1996-10-08 1998-04-28 Nisshinbo Ind Inc Drum brake device
JP2001020979A (en) * 1999-07-06 2001-01-23 Nisshinbo Ind Inc Drum brake system

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