JPH09112597A - Drum brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drum brake device which realizes a small size and a light weight with the reduction in the number of part items and has constant operating stroke of a brake lever. SOLUTION: A brake drum; a back plate fixed to a car body; a single brake shoe 2 attached movable on the back plate 1; a link 6 pivoted to the back plate 1; a strut member 14 erected between the link 6 and the brake shoe 2; and a brake lever 10 to open between the brake shoe 2 and the link 6 in cooperation with the strut member 14; are provided. A braking force generated by rotating the brake drum in one direction, and friction engaging with the expanded brake shoe 2, is received by the first anchor formed in the revers expanding side direction of the brake shoe 2. A braking force generated by rotating the brake drum in the other direction, and friction engaging with the expanded brake shoe 2 through the link 6, is received by the second anchor through the strut member 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drum brake device having a single brake shoe.

[0002]

2. Description of the Related Art As a conventional drum brake device having a single brake shoe, for example, Japanese Utility Model Publication No. 4-5122.
There is a drum brake device disclosed in Japanese Patent No. 5 and a parking brake device disclosed in Japanese Utility Model Publication No. 5-14016.

[0003]

The above-mentioned conventional device is
Since the adjusting member 30 which is a connecting member and the strut 36 are bridged between the brake shoe and the rotating member, there is a problem that the number of parts is increased and the assembling property is complicated. Further, in the conventional device, since the rotating member is rotated and an input is applied to the brake shoe via the connecting member, a large axial thrust force acts on the connecting member. Moreover, since this connecting member also serves as a shoe gap adjusting member that is screwed, the adjusting action may be abnormal due to the thrust force.
Further, when the screw portion of the shoe gap adjusting member is deformed, adhered, or vibrates while being applied with a thrust force, the screw portion is reversely rotated and the length of the adjusting member is shortened, so that the shoe gap becomes extremely large. There is a problem.

Since the strut member of the above-mentioned conventional device is on the opposite side of the shoe gap adjusting member (connecting member),
If the screw gap of the shoe gap adjusting member is extended to adjust the shoe gap, the gap between the brake shoe and the brake lever around which the strut member is stretched and the rotating member is widened. As a result, the parking brake becomes less effective and the feeling is deteriorated. In addition, the anchor pin 20 of Jpn. Pat. Appln. No. 5-14016 needs to be strong because it receives the braking force of forward and backward movement, and when it is received by the anchor blocks 40 and 42, two anchor blocks are required. There is a problem that the score increases.

[0005]

In order to solve the above problems, in the present invention, a brake drum rotatable in both directions, a back plate fixed to the vehicle body facing the brake drum, and the back plate. A single brake shoe movably attached to the upper side, a link rotatably supporting the intermediate portion to the back plate so as to face the brake shoe, and between one side of each of the link and the brake shoe. A strut member is installed, and a brake lever that cooperates with the strut member to expand between the brake shoe and the link on one side, and the brake drum rotates in one direction. The braking force generated by frictionally engaging the expanded brake shoe is received by the first anchor formed on the other side of the brake shoe, and the brake force is applied. The drum brake device is configured such that the second anchor receives the braking force generated by the child drum rotating in the other direction and frictionally engaging with the brake shoe expanded through the link through the strut member. To do.

Further, according to the present invention, a brake drum rotatable in both directions, a back plate fixed to the vehicle body facing the brake drum, and a single brake shoe movably attached to the back plate. A link having an intermediate portion rotatably supported by the back plate so as to face the brake shoe, and the link and the brake shoe are installed between the respective one sides of the link and expand between the respective one sides of the link and the brake shoe. A brake cylinder having openings on both sides, and a strut member installed between the brake shoe and a link in the vicinity of the brake cylinder, the brake drum rotating in one direction, and the brake shoe expanded by the brake cylinder; The braking force generated by frictional engagement is received by the first anchor formed in the other side direction of the brake shoe,
The brake force generated by the brake drum rotating in the other direction and frictionally engaging with the brake shoe expanded via the link is received by the second anchor via the strut member. Make up.

In the present invention, a brake drum rotatable in both directions, a back plate fixed to the vehicle body facing the brake drum, and a single brake shoe movably attached to the back plate. , A link having an intermediate portion rotatably supported by the back plate so as to face the brake shoe, and a link provided between one side of each of the link and the brake shoe, and one side opening for expanding the brake shoe. A brake cylinder, the brake drum rotates in one direction, and a braking force generated by frictionally engaging the brake shoe expanded by the brake cylinder or the brake lever is generated in the other side direction of the brake shoe. Done first
The brake drum rotates in the other direction while being received by the anchor, and the braking force generated by frictionally engaging with the brake shoe expanded by the brake lever through the link is generated by the second anchor through the strut member. Configure the drum brake device so that it is received by.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In the figure, reference numeral 1 denotes a back plate fixed to the vehicle body, and a brake drum (not shown) fixed to an axle (not shown) so as to face the inner side of the back plate 1 is positioned so as to be rotatable in both directions. Reference numeral 2 denotes a single brake shoe movably provided with respect to the back plate 1 and facing the inner peripheral surface of the brake drum, 2a denotes a web thereof, 2b denotes a rim, 2c denotes a lining, and a web 2a. The rim 2b has a T-shaped cross section.

The brake shoe 2 has a hole 2d (see FIG. 3) formed in the middle of the web 2a, and a shoe hold pin 3 penetrating the back plate 1 penetrates the hole 2d, and a plate is formed on the protruding portion thereof. A spring-shaped shoe hold spring 4 is engaged to elastically hold the brake shoe 2 movably on the back plate 1. Reference numeral 1a in FIG. 3 denotes a ledge projecting from three points on the back plate 1, and supports the rim 2b of the brake shoe 2.

The back plate 1 on the opposite side of the brake shoe 2
In addition, a semi-circular link 6 having an intermediate portion pivotally supported by a support shaft 5
1, the lower end of the link 6 in FIG. 1 is bent to the back plate 1 side by about 90 degrees as shown in FIG. 4, and the lower end 2e of the web 2a of the brake shoe 2 is supported by the bent piece 6a. Then, the back plate 1 is formed with the protrusion 1b that supports the inner surface of the bent piece 6a of the link 6 as a first anchor. The arm 6b projecting from the link 6 in FIGS. 1 and 5 is engaged with the web 2a of the brake shoe 2 to prevent the brake shoe 2 from rising.
Reference numeral 7 denotes a shoe return spring that extends over the lower portion of the brake shoe 2 and the link 6 in FIG. As another embodiment in which the support shaft 5 is not used, the link may be rotatably supported by engaging the projection or the recess formed on the back plate with the recess or the projection formed on the link. .

Between the brake shoes 2 and the upper ends of the links 6 in FIG. 1, a brake cylinder 8 of a double-sided opening type is fixed to the back plate 1 with fixing bolts (not shown) or the like. Reference numerals 8a and 8b denote pistons provided on both sides of the brake cylinder 8. The piston 8a engages with the upper end of the web 2a of the brake shoe 2, and the piston 8b engages with the upper end of the link 6. Reference numeral 8c is a spring inserted between the pistons 8a and 8b, 8d (see FIG. 6) is an input port of the cylinder 8, and 8e is an air bleed screw for removing air from the cylinder 8.

A lever pin 9 pivotally supports the upper end of the brake lever 10 on the upper end of the link 6. Reference numeral 9a is a U retainer fitted in the lever pin 9. Further, as shown in FIGS. 1 and 2, a plate-like quadrant 12 is superposed on the brake shoe 2 side of the plate-like strut 11, and the quadrant 12 can be rotated with respect to the strut 11 by a quadrant pin 13. To form a strut member 14, and the neck portion 12a of the quadrant 12 is formed in the web 2a of the brake shoe 2 through the window hole 2
The quadrant spring 15 is bridged between the quadrant pin 13 and the strut 11 by engaging with f. 12b
(See FIG. 2) is a stopper portion of the quadrant 12.

As shown in FIG. 2, a step portion 11a and a side projection 11b are formed on the link 6 side of the strut 11, and the side edge of the brake lever 10 connected to the link 6 is engaged with the step portion 11a. At the same time, the hole 6c provided in the link 6 (see FIG.
(See) and the lateral projection 11b of the strut 11 are bridged with the anti-rattle spring 16. Strut 11
The step portion 11c (see FIG. 2) is formed on the back plate 1 side of the back plate 1, and the protrusion 1c engaging with the step portion 11c is formed on the back plate 1 as the second anchor. Also, a window hole 11 is formed in the middle of the strut 11.
d is provided, and a projecting piece 8f that is inserted into the window hole 11d is provided so as to project from the cylinder 8, and the strut 11 is prevented from rising by the engagement between the projecting piece 8f and the window hole 11d. The spring load of the quadrant spring 15 is smaller than that of the anti-rattle spring 16.

Further, as shown in FIG. 2, the step portion 11c and the second
The gap with the anchor 1c is set to L ₁ , and the window hole 11d and the protruding piece 8
Let L _{2 be the} gap on the left side of FIG. 2 from f and L ₁ > L
_{If the number is 2} , the protruding piece 8f of the cylinder 8 can be used as the second anchor. 1 of the brake shoe 2 and the link 6
Shoe return spring 17 is bridged between the upper parts of.

7 to 16 show another embodiment of the present invention, in which the same reference numerals as those used in the drawings denote the same elements. FIG. 7 shows a modified example of the portion shown in FIG. 4, in which the end portion 2g of the shoe web 2a is bent and engaged with the first anchor 1b, and the link 6 is flat. Further, FIG. 8 shows a brake cylinder 18 of one side opening type fixed to the back plate 1 instead of the brake cylinder 8 of both side opening type shown in FIG.
18b is a spring. This is arranged so that the piston 18a contacts the upper end of the brake shoe 2.

FIG. 9 shows a modified example of the portion shown in FIG. 2, which is an example in which the present invention is applied to a cross-pull type brake lever. Reference numeral 19 is a cable bracket for fixing the outer part of the control cable for pulling the brake lever and receiving a reaction force, which is fixed to the back plate 1 by welding, rivets, bolting or the like. A brake lever 20 is pivotally supported by a lever pin 21 on the right end of the strut 11 in the drawing. 22 is a push nut type retainer,
Reference numeral 23 is an opening 1d through which the brake lever 20 penetrates the back plate 1.
Rubber boots 24 are provided to seal the periphery of the lever, 24 is a lever stopper fixed to the back plate 1 by welding, rivets, bolting, etc. 25 is a span between the protrusion 24a of the lever stopper 24 and the brake lever 20. It is a lever return spring. The second anchor 1c is
The back plate 1 is projected in a stepped manner. Instead of the projection 1c, a convex portion is formed on the vehicle body side member, or a pin or a bolt is attached so that the strut 11 directly abuts. Good.

10 and 11 show a modification of the lower part of FIG. 1, in which a hole 6d is provided in the lower part of the link 6, and an anchor pin 26 loosely fitted in the hole 6d is fixed to the back plate 1. And used as the first anchor. A flange portion 26a is formed on the anchor pin 26 to prevent the link 6 from rising. Reference numeral 6e denotes an arm extending from the link 6 so that the web 2a of the brake shoe 2 is sandwiched between the arm 6e and the back plate 1. Also, θ in FIG.
Is an anchor angle. This anchor angle is an angle at which the brake shoe 2 abuts the vertical line L. Normally, when the anchor angle θ becomes large, the braking effect decreases, and the maximum surface pressure position in the lining circumferential direction is the anchor. Move closer to the input side. It also has the purpose of preventing dragging on the anchor side.

FIG. 12 shows a modification of the portion corresponding to FIG. 3, in which the diaphragm shape of the back plate 1 is symmetrical, and FIG. 3 shows the surface of the ledge 1 a of the back plate 1. While the rim 2b of the brake shoe 2 is supported, this FIG.
Then, the web 2a of the brake shoe 2 is supported by the surface of the ledge 1e of the back plate 1.

13 and 14 show a modification of the pivotal support portion of the link 6, in which a stepped support shaft 27 is caulked and fixed to the projection of the back plate 1 as shown in FIG. , A large-diameter hole 2 through which the collar portion 27a of the support shaft 27 can be inserted into the link 6
8a and the small-diameter slot 28b are connected to each other to form the dulmar hole 28. The large-diameter hole 28a of the dulmer hole 28 is inserted into the support shaft 27, and then the link 6 is displaced to the end of the slot 28b. The support shaft 27 is positioned. The purpose is to improve the assemblability of links.

FIGS. 15 and 16 show another pivotal support means of the link 6, in which a stepped support shaft 29 as shown in FIG. 29
The link 6 is fitted to the shaft portion 29a of the above, and the push nut type retainer 30 is fitted and fixed to the protruding portion of the shaft portion 29a.

The strut member 14 of the above embodiment (see FIG.
2, 8 and 9) are quadrants 1 on struts 11.
It is a one-shot type automatic gap adjustment mechanism that engages 2 (see Jpn. Pat. Appln. KOKAI No. 2-18837). This is an incremental type in which the adjusting teeth of the push rod using a screw member is rotated by the claw of the adjusting lever. It does not matter whether it is a mold or a type in which the push rod is manually adjusted. The point is that a mechanism is installed between the brake shoe 2 and the link 6 in the vicinity of the brake cylinders 8 and 18, and the diameter of the brake shoe 2 is expanded to correct the wear of the brake shoe 2. The action of the stopper portion 12b of the quadrant 12 is achieved by engaging the stopper portion 12b with the edge of the web 2a of the brake shoe 2 even when a strong braking reaction force is applied during backward movement and the neck portion 12a of the quadrant 12 is broken. The lifting of the brake shoe 2 can be prevented.

A first aspect of the present invention is a brake drum rotatable in both directions, a back plate 1 fixed to a vehicle body facing the brake drum, and a single unit movably attached to the back plate 1. Brake shoe 2 and a link 6 facing the brake shoe 2 and having an intermediate portion rotatably supported on the back plate 1 by a support shaft 5, and the link 6 and the brake shoe 2
Strut member 14 installed between the respective one side of
And the brake lever 10 that cooperates with the strut member 14 to expand between the brake shoe 2 and the link 6 on one side, so that the brake drum rotates in the direction of arrow X in FIG. The braking force generated by frictionally engaging the brake shoe 2 expanded by the brake lever 10 is received by the first anchor 1b formed in the other side direction of the brake shoe 2, and the brake drum 2 is moved in the other direction. The second anchor 1c receives, through the strut member 14, the braking force generated by rotating (in the direction of the arrow Y in FIG. 1) and frictionally engaging with the brake shoe 2 expanded through the link 6. be able to.

A second aspect of the present invention is a brake drum rotatable in both directions, a back plate 1 fixed to the vehicle body so as to face the brake drum, and a single movably mounted on the back plate 1. Brake shoe 2 and a link 6 facing the brake shoe 2 and having an intermediate portion rotatably supported on the back plate 1 by a support shaft 5, and the link 6 and the brake shoe 2
And a brake cylinder 8 having two openings which are opened between the brake shoes 2 and the link 6 in the vicinity of the brake cylinder 8, and the strut member 14 is installed in the vicinity of the brake cylinder 8. And the brake drum rotates in the direction of arrow X in FIG.
The braking force generated by frictionally engaging the brake shoe 2 expanded by the brake cylinder 8 is received by the first anchor 1b formed in the other side direction of the brake shoe 2, and the brake drum moves in the other direction ( The second anchor 1c receives, through the strut member 14, a braking force generated by frictional engagement with the brake shoe 2 expanded through the link 6 by rotating in the Y direction of FIG. 1). You can

A third aspect of the present invention is a brake drum rotatable in both directions, a back plate 1 fixed to the vehicle body so as to face the brake drum, and a single movably mounted on the back plate 1. Brake shoe 2 and a link 6 facing the brake shoe 2 and having an intermediate portion pivotally supported on the back plate 1 by a support shaft 5 and the link 6 and the brake shoe 2.
And a brake cylinder 18 having a one-sided opening for expanding the brake shoe 2, the brake drum rotates in the direction of arrow X in FIG. Lever 1
The braking force generated by frictionally engaging the brake shoe 2 expanded by 0 is received by the first anchor 1b formed on the other side of the brake shoe 2, and the brake drum moves in the other direction (see FIG. 1). Rotate in the Y direction)
The braking force generated by frictionally engaging the brake shoe 2 expanded by the brake lever 10 through the link 6 is generated by the second anchor 1c through the strut member 14.
You can catch it.

[0025]

Since the device of the present invention is constructed as described above, the following effects can be obtained. (1) The adjusting member that is a connecting member between the brake shoe 2 and the link 6 that is the rotating member is not necessary. (2) Since the strut member 14 which is the gap adjusting mechanism is on the expansion side of the brake shoe 2, the brake lever 10
The operating stroke of is constant. Also brake shoe 2
The wear is corrected by the gap adjusting mechanism, so the stroke does not increase. (3) Since the strut member 14 that is the gap adjusting mechanism is used as a member that transmits the braking reaction force of the brake shoe 2 to the second anchor 1c, the number of parts can be reduced. or,
It is easy to assemble the brake.

(4) Link the lower end of the brake shoe 2 to the link 6
By sandwiching it with the arm 6b extended from the back plate 1 and the back plate 1, it is possible to prevent the brake shoe 2 from rising. Further, if the protruding piece 8f extending from the brake cylinder 8 is inserted into the window hole 11d formed in the strut 11, the lifting of the brake shoe 2 can be prevented through the strut 11. (5) If the brake shoe 2 is attached with an anchor angle θ (see FIG. 10), it is easy to optimize the behavior (centering) and effectiveness of the shoe. Anchor angle cannot be attached to a normal duo servo type drum brake. (6) The present invention is applicable not only to the forward pull type but also to the cross pull type as shown in FIG.

[Brief description of the drawings]

FIG. 1 is a front view showing a partial cross-section of a device of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a sectional view taken along line CC of FIG.

FIG. 5 is a sectional view taken along line DD of FIG. 1;

FIG. 6 is a sectional view taken along the line EE of FIG. 1;

FIG. 7 is a modification diagram of FIG. 4.

FIG. 8 is a modified example of a brake cylinder.

FIG. 9 is a diagram showing a modification of the portion of FIG.

FIG. 10 is a modification view of the lower portion of FIG.

11 is a sectional view taken along line GG of FIG.

12 is a modification diagram of FIG. 3. FIG.

FIG. 13 is a partial front view showing a modification of the pivotal support portion of the link.

14 is a plan sectional view of FIG.

FIG. 15 is a partial front view showing another modification of the pivot portion of the link.

16 is a plan sectional view of FIG.

[Explanation of Codes] 1 Back plate 1a Ledge 1b First anchor (projection) 1c Second anchor (projection) 1d Opening 1e Ledge 2 Brake shoe 2a Web 2b Rim 2c Lining 2d Hole 2e Bottom edge 2f Window hole 2g Edge 3 shoe hold pin 4 shoe hold spring 5 support shaft 6 link 6a bent piece 6b arm 6c hole 6d hole 6e arm 7 shoe return spring 8 both side opening type brake cylinder 8a, 8b piston 8c spring 8d input port 8e air lead screw 8f protrusion One side 9 Lever pin 9a U retainer 10 Brake lever 11 Strut 11a Step part 11b Side protrusion 11c Step part 11d Window hole 12 Quadrant 12a Neck part 12b Stopper part 13 Quadrant pin 14 Strut member 15 Quadrants Pulling 16 Anti-rattle spring L ₁ and L ₂ Gap 17 Shoe return spring 18 One side open type brake cylinder 18a Piston 18b Spring 19 Cable bracket 20 Brake lever 21 Lever pin 22 Retainer 23 Rubber boot 24 Reverser top 24a Projection piece 25 Lever return spring 26 Anchor pin (first anchor) 26a Collar part θ Anchor angle 27 Support shaft 27a Collar part 28 Dharma hole 28a Large diameter hole 28b Groove hole 29 Support shaft 29a Shaft part 30 Retainer

Front Page Continuation (72) Inventor Yasushi Kobayashi 5-14-25 Toyota, Minami-ku, Aichi Prefecture Nagoya City Nisshin Spinning Co., Ltd. Nagoya Factory

Claims (3)

[Claims] 1. A brake drum rotatable in both directions,
A back plate fixed to the vehicle body facing the brake drum, a single brake shoe movably attached on the back plate, and an intermediate portion rotatable to the back plate facing the brake shoe. A link pivotally supported on the link shoe, a strut member installed between one side of the link and the brake shoe, and a brake that cooperates with the strut member to expand between the brake shoe and the link on one side thereof. A first anchor having a lever, wherein the brake drum rotates in one direction, and a braking force generated by frictionally engaging with a brake shoe expanded by the brake lever is formed in the other side direction of the brake shoe. The brake drum rotates in the other direction and the braking force generated by frictionally engaging with the brake shoe expanded through the link is generated by the brake. A drum brake device characterized by being received by a second anchor via a trat member. 2. A brake drum rotatable in both directions,
A back plate fixed to the vehicle body facing the brake drum, a single brake shoe movably attached on the back plate, and an intermediate portion rotatable to the back plate facing the brake shoe. A link that is pivotally supported on the brake shoe, and a brake cylinder that is installed between the links and one side of the brake shoe, and that opens between both sides of the brake cylinder.
The brake shoe is provided in the vicinity of the brake cylinder and a strut member provided between the links, and the brake drum rotates in one direction and frictionally engages with the brake shoe expanded by the brake cylinder. The braking force is received by the first anchor formed on the other side of the brake shoe, and the brake drum is rotated in the other direction to generate frictional engagement with the brake shoe expanded through the link. Braking force
A drum brake device characterized in that it is received by a second anchor via the strut member. 3. A brake drum rotatable in both directions,
A back plate fixed to the vehicle body facing the brake drum, a single brake shoe movably attached on the back plate, and an intermediate portion rotatable to the back plate facing the brake shoe. And a brake cylinder that is installed between one side of each of the link and the brake shoe and that has one side opening that expands the brake shoe.The brake drum rotates in one direction, and the brake A braking force generated by frictionally engaging a brake shoe expanded by a cylinder or a brake lever is received by a first anchor formed on the other side of the brake shoe, and the brake drum rotates in the other direction. A braking force generated by frictionally engaging the brake shoe expanded by the brake lever via the link is generated by the first strut member via the strut member. A drum brake device characterized by being received by two anchors.