Drum brake having a load measurement device
A drum brake having a brake drum, brake shoes, a carrier plate and a load measurement device in the region of an abutment is mountable on a steering knuckle. The abutment has a cylinder in which two pistons are guided, on the outer end faces of which the abutment ends of the brake shoes rest and the inner end faces of which are each supported by a spring on a step in the cylinder. A hollow peg projects from the outside of the cylinder and penetrates an opening in the carrier plate, such that it can be received in a receiving space in the steering knuckle resting on the carrier plate or in a reinforcement element fixed on the steering knuckle.
1. A drum brake comprising:
a brake drum;
two brake shoes, which can be applied to the brake drum, are secured on the brake shoe side of a carrier plate and each have a pressure end and an abutment end;
a spreader device situated between the pressure ends;
an abutment having a cylinder in which two pistons are guided, on the outer end faces of which the abutment ends of the brake shoes rest and the inner end faces of which are each supported by a spring on a step in the cylinder;
a load measurement device situated between the abutment ends wherein, the load measurement device determines the load prevailing at the abutment; and
a hollow peg which projects from the outside of the cylinder and penetrates an opening in the carrier plate, such that it can be received in a receiving space located in one of a steering knuckle resting against the carrier plate and in a reinforcement element fixed on the steering knuckle.
2. The drum brake as claimed in claim 1 , wherein the cylinder has lateral lugs for receiving one of screws and rivets, wherein the one of screws and rivets penetrate the carrier plate to be fixed to the steering knuckle resting against the carrier plate.
3. The drum brake as claimed in claim 1 , further comprising sensors in the peg and elements in the pistons, wherein the elements are sensed by the sensors.
4. The drum brake as claimed in claim 3 , wherein the sensors are accommodated in a sensor housing, which is inserted with an accurate fit into the hollow peg ensuring that the sensors are opposite the elements that can be sensed.
5. The drum brake as claimed in claim 1 , wherein the springs are one of disk springs and spiral disk springs.
6. The drum brake as claimed in claim 1 , wherein the springs are sleeve springs.
7. The drum brake as claimed in claim 1 , wherein the pins project laterally from the pistons, the ends of which pins point toward the peg and which pins carry the elements that can be sensed.
8. The drum brake as claimed in claim 7 , wherein the pins run in a longitudinal slot in an inner step in the cylinder.
9. The drum brake as claimed in claim 8 , wherein the sensors are accommodated in a sensor housing, which is inserted with an accurate fit into the hollow peg, thus ensuring that the sensors are opposite the elements that can be sensed.
10. The drum brake as claimed in claim 8 , wherein the the sensors are AMR sensors, and the elements that can be sensed are magnets.
11. The drum brake as claimed in claim 8 , wherein the sensors are accommodated in a sensor housing, which is inserted with a correct orientation into the hollow peg, thus ensuring that the sensors are opposite the elements that can be sensed.
12. The drum brake as claimed in claim 11 , wherein there is coding on the sensor housing to ensure the correct orientation.
13. The drum brake as claimed in claim 1 , wherein the elements that can be sensed are mounted in or on the lateral surface of the pistons.