JPH026930B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to automotive brake assemblies. More particularly, the present invention relates to pad assemblies and improved brake shoe assemblies for drum brakes, such as those for buses and trucks.

In the past, brake shoes for buses and trucks required that used brake pads be removed from the bus or truck and reattached with asbestos or similar material in order to repair or replace them. The entire brake shoe had to be removed from the brake assembly and sent to a bonding facility for repair. In order to keep buses and trucks in working order, repair shops had to keep all brake shoes in stock. Brake shoes for buses and trucks are heavy parts, and having an inventory of these large heavy parts is difficult due to the cost of the parts themselves, space for inventory, and the difficulty of handling the brake shoe as a whole. It was quite expensive.

Therefore, in order to eliminate the need to keep a large inventory of brake shoes, there is a conventional example of brake pads that have replaceable brake pads, as seen in Japanese Patent Application Laid-Open No. 52-54873. Some shoe shoes have a lining (pad element) attached to the shoe rim via a vibration insulating member, and the rim and lining are coupled and fixed together using rivets.

However, according to this method, since there is no alignment means for aligning the rim and lining, alignment of the rim and lining when driving rivets is troublesome, and since the lining is fixed with rivets, the lining wears out. There is a disadvantage that the replacement work is troublesome when replacing the rivet, and there is also a disadvantage that it is necessary to drill a hole in the lining (pad element) to accept the rivet, which increases the cost of lining processing. When the lining wears out, the entire thickness of the lining cannot be used because the lining extends into the lining area, resulting in poor usage efficiency. Since there are voids), there is a disadvantage that the rate of wear of the lining is large and the efficiency of use is further deteriorated.

In addition, as another conventional example, as shown in Figures 3 to 5 of Utility Model Application No. 51-80582, there is a rectangular plate integrated with the brake shoe and the lining (padded element) (the liner 62 of the present invention). (equivalent) are connected by a bolt and nut connection means.

However, according to this method, since the head of the bolt is submerged within the thickness of the square plate, the thickness of the square plate increases, making it thicker, resulting in an increase in the size of the entire device. As in the case of the first conventional example,
There are disadvantages in that the machining cost increases because of the holes formed in the lining for the bolts to pass through, and the wear rate of the lining increases due to the empty space created by the holes, resulting in poor usage efficiency. Furthermore, since nuts are required in addition to bolts, the number of parts increases and the configuration becomes complicated.

The brake shoe according to the present invention aims to solve the above-mentioned conventional problems, and has a structure that includes: a brake for a drum brake assembly configured to be engaged with and disengaged from the brake drum 16; a plurality of radial through screw holes 6 at various positions thereof.
4 and a wear-resistant pad element 60 adhered to the outer circumferential surface of said liner 62 and covering said outer circumferential surface at least substantially continuously.
0; 60, 62, a table 20 having surfaces on opposite sides, web means 22, 23 fixed to the table on the inner peripheral surface of the table, and a plurality of radii provided on the table. 20, 22, 23, 68 for positioning the brake pad means 10 in a predetermined position with respect to the brake drum 16, the table hole 68 being connected to the liner threaded hole 64; said brake shoe means 12 operably engaged with said brake pad means 10 in positional correspondence;
and alignment means 66 for aligning the brake pad means with the brake shoe means when positioning and fixing the brake pad means 10 on the outer peripheral surface of the table 20 of the brake shoe means 12; and the aligned brake pad means 10. and means 70 for fixing the pad element to the brake shoe means 12, wherein the alignment means 66 is adjacent to the liner threaded hole 64 on the inner circumferential surface of the liner 62 and is adjacent to the liner threaded hole 64 and attached to the pad element. A protruding portion 66 protrudes in a direction opposite to the table hole 60 side, and by inserting and engaging the protruding portion into the table hole 68, the brake pad means 10 is aligned with the brake shoe means 12, and the brake pad means 10 is aligned with the brake shoe means 12. A securing means 70 extends radially outwardly through at least some of the table holes 68 and extends substantially outwardly from the outer circumferential surface of the liner 62 to corresponding liner threaded holes 64 of the brake pad means 10. It is characterized by a plurality of bolts 70 screwed together so as not to protrude.

The invention also allows multiple types of brake pads to be mounted on the same shoe. In order to reduce noise and equalize wear on the brake pads, it is desirable to provide different friction characteristics to the pads in buses and similar vehicles. To balance the braking force of the bus, use an intermediate friction block for the reverse shoe and a low friction shoe for the forward shoe of each brake of the bus, or use an intermediate friction block for the front shaft shoe and a low friction shoe for the rear shaft shoe. It is generally known to use friction blocks. In the present invention, the upper and lower friction blocks on the same shoe can be different to further vary the friction characteristics to modify noise and braking forces, as desired by the particular equipment of the bus or truck.

All of the above objectives are achieved in one device that is easy to manufacture, has low manufacturing costs, and has lower purchasing and inventory costs.

Referring to FIG. 1, a brake pad 10 of the present invention includes two brake pad means 1 in each of two shoes 12 around a brake assembly 14.
0 is shown attached. Brake assembly 14 includes an outer brake drum 16 within which two brake shoes 12 are disposed with brake pad means 10 extending toward an inner surface 18 of drum 16. Show 12
is table 2 for properly arranging bats 10
The table 20 includes two web portions 22 and 23 welded to the table 20 to form a C-shaped cross section. Each of webs 22 and 23 has two holes (24 and 25 in web 22 and 26 and 2 in web 23).
7). A bar 28 extends from web 22 to web 23 and is located within two holes, one hole in each web. Brake drum 16 located on a vehicle axle 30 includes pins 32 and 34 on opposite sides of axle 30.
Springs 36, 38, 40 and 42 move from bar 28 on brake shoe 12 to respective pin 3.
2 or 34. Spring 36,3
8, 40 and 42 are all tension springs that bias the brake shoe 12 away from the brake drum 16.

At one end of the brake shoes 12, an adjustment assembly 47 maintains the distance between the brake shoes 12. Assembly 47 includes web 22 of each show.
Brake show table 20 between and 23
dowel members 44 and 46 abutting the dowel members 44 and 46. The dowel members 44 and 46 are externally threaded at one end and are connected to a rotating gear adjustment mechanism 5 to effect rotation of the collar 48, either manually or otherwise.
It is combined with a collar 48 provided with internal threads having 0. At the opposite end of the shoe 12 is a conventional hydraulic cylinder 52. Rods 54 and 56 extend from the hydraulic cylinder 52 and actuation of a brake pedal or the like pushes the rods 54 and 56 towards the drum 16 so that the brake pads 10 are pushed against the brake drum 1.
The shoe 12 is pressed toward the drum 16 so as to contact the inner surface of the drum 16. adjustment assembly 47;
Hydraulic brake actuation mechanism 52 and all internal brake actuation assemblies, including springs 36, 38, 40 and 42, are operated by conventional working mechanisms applicable to the brake shoes and brake drums shown and described herein. Exchangeable.

Referring to FIG. 2, an enlarged view of the brake pad 10 and brake shoe 12 of the present invention is shown. Each brake pad 10 includes a pad element 60 integrally bonded to a liner 62. The liner 62 has a plurality of punched and threaded holes 64 throughout the liner;
These holes can be screwed together with suitable bolts. The punching also creates an inwardly extending protruding portion 66 at each location of the hole 64. The brake shoe, on the other hand, has a series of corresponding holes 68 along and through the table 20. The holes 68 have a diameter greater than the width of the protruding portions 66 of the liner 62 to act as seats for the corresponding protruding portions 66.

In this way, the brake pad 10 is assembled by placing the pad 10 on the table 20 of the shoe 12 and placing the pad 10 on the liner 6.
By seating the protruding portion 66 around the screw hole 64 of No. 2 into the hole of table 20,
2. Although a greater number of holes can be provided in the table 20 without any effect on the attachment of the brake pad 10 (or liner 62), a corresponding number of holes on the liner 62 and table 20 can be provided in corresponding positions. It is set in. Thus, the brake shoe table 20 can have holes for locating multiple types of brake pads 10.

Next, a bolt 70 having a locking washer 72
is inserted through hole 68 in table 20 and screwed into hole 64 in pad 10. bolt 70
passes through the hole 64 in the pad 10, but has a length that does not contact or simply adjoin the pad element 60 of the brake pad 10.

Therefore, the configuration of the present invention has the following advantages.

Brake pad 10 and brake shoe 12 are aligned by simply engaging a plurality of protrusions 66 of liner 62 of brake pad 10 into a plurality of radial through holes 68 in table 20 of brake shoe 12, respectively. Since the protruding portions 66 of the liner 62 are formed locally only at locations adjacent to the liner screw holes 64, the protruding portions 66 can be easily molded at the same time as the entire liner shape. Since it can be press-worked, it is extremely easy to manufacture, and the alignment of the protruding portion 66 and the through hole 68 can be done with one touch, which is advantageous.

A plurality of bolts 70 are inserted from the brake shoe 12 side into the plurality of radial through holes 68 of the table 20 of the brake shoe, and are further inserted outward from the outer peripheral surface of the liner 62 into the liner threaded holes 64. (In other words, since the bolts 70 are screwed together so as not to substantially protrude into the area of the pad element 60, the bolts 70 are screwed into the pad element 60.
There is no need to process receiving holes, etc., which reduces processing costs, and
The thickness of the liner 62 may be relatively thin enough to ensure the screwing length of the bolt 70, and there is an advantage that the thickness of the brake pad 10 can be reduced and the entire device can be miniaturized.

As mentioned above, since the bolt 70 does not enter the area of the pad element 60, when the pad element 60 wears out, the entire thickness of the element can be used, improving the efficiency of use. There is no need to process bolt receiving holes in the pad element 60, and there are no empty spaces in the element, so when the element wears out, the wear rate can be reduced due to the absence of the empty space, and the pad element 60 This has the advantage of improving usage efficiency.

As described above, since the bolt 70 is screwed into the threaded hole 64 of the liner 62 and connected, there is no need for a connecting nut or the like, which has the advantage of reducing the number of parts and simplifying the configuration.

Furthermore, the present invention also has the following advantages.

That is, a used pad 10 with a strong metal liner 62 can be reused by bonding a new asbestos or other wear-resistant surface.

A plurality of pads 10 can be attached to the brake shoe 12 as shown in FIGS. 1, 2, and 3. Thus, different pads may be placed on the same brake shoe 12 depending on which pad is most forward on the shoe with respect to the forward direction of wheel motion, or other considerations where different wear characteristics are desired. Can provide wear characteristics. However, it is now preferred to provide pads with identical or at least substantially identical wear characteristics on the same brake shoe.

Thus, there have been disclosed in the above description and drawings illustrative embodiments of the invention that fully and effectively accomplish the objectives of the invention. It will be apparent, however, that changes may be made in the details of the apparatus without departing from the scope of the invention as described above and as indicated in the claims.

[Brief explanation of drawings]

1 is a side view of the brake pad of the invention in a representative example of its use; FIG. 2 is a side view of one brake shoe of FIG. 1; FIG. 3 is a side view of the brake shoe and brake pad of FIG. and FIG. 4 is an enlarged side sectional view of the assembly of FIG. 2. 10... Brake pad, 12... Brake shoe, 16... Brake drum, 20... Table, 22, 23... Web, 62... Liner,
64...screw hole, 68...hole, 70...bolt.

Claims (1)

Claims: 1. A brake shoe for a drum brake assembly configured to engage and disengage from a brake drum 16, the brake shoe having a plurality of radially through threaded holes 6 at various locations thereof.
4 and a wear-resistant pad element 60 adhered to the outer circumferential surface of said liner 62 and covering said outer circumferential surface at least substantially continuously.
0; 60, 62, a table 20 having surfaces on opposite sides, web means 22, 23 fixed to the table on the inner peripheral surface of the table, and a plurality of radii provided on the table. 20, 22, 23, 68 for positioning the brake pad means 10 in a predetermined position with respect to the brake drum 16, the table hole 68 being connected to the liner threaded hole 64; said brake shoe means 12 operably engaged with said brake pad means 10 in positional correspondence;
and alignment means 66 for aligning the brake pad means with the brake shoe means when positioning and fixing the brake pad means 10 on the outer peripheral surface of the table 20 of the brake shoe means 12; and the aligned brake pad means 10. and means 70 for fixing the pad element to the brake shoe means 12, wherein the alignment means 66 is adjacent to the liner threaded hole 64 on the inner circumferential surface of the liner 62 and is adjacent to the liner threaded hole 64 and attached to the pad element. A protruding portion 66 protrudes in a direction opposite to the table hole 60 side, and by inserting and engaging the protruding portion into the table hole 68, the brake pad means 10 is aligned with the brake shoe means 12, and the brake pad means 10 is aligned with the brake shoe means 12. A securing means 70 extends radially outwardly through at least some of the table holes 68 and extends substantially outwardly from the outer circumferential surface of the liner 62 to corresponding liner threaded holes 64 of the brake pad means 10. A brake shoe characterized by comprising a plurality of bolts 70 screwed together so as not to protrude. 2. The brake shoe according to claim 1, wherein the brake pad means 10 comprises a plurality of brake pad elements 60. 3. The brake shoe of claim 2, wherein the plurality of pad elements 60 all have at least substantially the same wear characteristics. 4. The brake shoe according to claim 2, wherein the plurality of pad elements 60 have different wear characteristics from each other.