Clearance-adjustable drum brake

Abstract

The utility model discloses a gap adjusting drum brake which comprises a brake bottom plate and two brake shoe friction plate assemblies which are symmetrically and movably installed on the brake bottom plate, one ends of the two brake shoe friction plate assemblies are connected through a gap adjusting device, and the other ends of the two brake shoe friction plate assemblies are connected through a brake push rod. One end of the brake push rod is connected with the brake zipper through a brake pull rod; the gap adjusting device comprises an adjusting sleeve and an adjusting core which are arranged in a sleeved mode, a ratchet wheel is connected to the adjusting core in a threaded mode, and the end of the adjusting core extends out of the ratchet wheel and then is located in the adjusting sleeve. The gap adjusting device is installed between the two brake shoe friction plate assemblies, the gap between the drum brake and the brake drum is adjusted by adjusting the length of the gap adjusting device, and the braking effect is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of forklift brakes, in particular to a drum brake with clearance adjustment. Background Art

[0002] At present, there are three types of brakes used in forklifts in China, namely wet brakes, disc brakes and drum brakes. Since the drum brake has a simpler structure and lower cost, and when parking, it is generally operated through a mechanical structure, its operating mechanism is relatively simple and its reliability is relatively high. Therefore, forklift brakes are mainly drum brakes.

[0003] The drum brake includes a brake base plate and two brake shoe friction plate assemblies floatingly mounted on the brake base plate. The braking mainly relies on the hand brake handle mechanism on the forklift to pull the two brake shoe friction plate assemblies outward and rub against the brake drum, thereby generating braking force.

[0004] Because the drum brake is a floating shoe type, in which the brake shoe friction pad assembly is installed in a floating manner on the brake base plate, the gap between the brake shoe friction pad assembly and the brake drum is uneven, and the brake shoe friction pad assembly will wear during frequent braking. When the wear is serious, the braking effect will deteriorate. Therefore, it is necessary to adjust the gap between the brake shoe friction pad assembly and the brake drum to improve the braking effect. Summary of the invention

[0005] In order to solve the above problems of the existing drum brake, the utility model provides a drum brake with adjustable clearance.

[0006] The technical solution of the utility model is as follows:

[0007] A drum brake with clearance adjustment comprises a brake base plate and two brake shoe friction plate assemblies symmetrically and movably mounted on the brake base plate, wherein one end of the two brake shoe friction plate assemblies are connected via a clearance adjustment device and the other end are connected via a brake push rod; one end of the brake push rod is connected to a brake zipper via a brake pull rod; the clearance adjustment device comprises a sleeved adjustment sleeve and an adjustment core, a ratchet is threadedly connected to the adjustment core, and the end of the adjustment core is located inside the adjustment sleeve after extending out of the ratchet.

[0008] In a further solution, the middle portion of the brake shoe friction plate assembly is floatingly mounted on the brake base plate through a press-fit seat assembly; the outer ends of the adjustment sleeve and the adjustment core are both provided with a slot connected to the brake shoe friction plate assembly.

[0009] According to a further solution, a tension spring is connected between the two brake shoe friction plate assemblies at one end of the clearance adjustment device, and the outer circle of the tension spring contacts the ratchet to prevent the ratchet from automatically moving.

[0010] In a further solution, the end of the brake rod is connected to a brake shoe friction plate assembly through a pin shaft. When the brake pull lock drives the brake rod to move, the brake push rod is pushed to move with the pin shaft as a fulcrum, thereby driving the two brake shoe friction plate assemblies to move in opposite directions to achieve braking.

[0011] According to a further solution, a spring seat is fixedly provided on the brake base plate at one end of the brake push rod, and the spring seat is connected to the two brake shoe friction plate assemblies through a return spring respectively.

[0012] In a further solution, a gap adjustment hole for rotating the ratchet is provided on the brake base plate at one end of the gap adjustment device.

[0013] In a further solution, one end of the brake push rod is connected to the brake shoe friction plate assembly through a push rod spring.

[0014] The drum brake of the utility model is provided with a gap adjustment device between two brake shoe friction plate assemblies, and the gap between the drum brake and the brake drum is adjusted by adjusting the length of the gap adjustment device, thereby improving the braking effect and the convenience of gap adjustment.

[0015] The gap adjustment device in the utility model has a simple structure and is easy to operate. The ratchet thereon can be rotated in two directions, and when adjusting, it is only necessary to overcome the pressure of the tension spring on the ratchet. A gap adjustment hole is stamped on the brake base plate, and the hole is located directly opposite to the ratchet. The hole is sealed with an elastic rubber plug in a normal state. When the gap needs to be adjusted, after removing the elastic rubber plug, a tool such as a flat-bladed screwdriver is used to extend into the gap adjustment hole and rotate the ratchet to adjust the gap. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the utility model.

[0017] Figure 2 This is a schematic diagram of the structure of the gap adjustment device of the utility model.

[0018] In the figure:

[0019] Brake zipper 1, tension spring 2, press-fit seat assembly 3, push rod spring 4, brake push rod 5, return spring 6, brake pull rod 7, brake shoe friction plate assembly 8, pin shaft 9, brake base plate 10, gap adjustment hole 11; gap adjustment device 12, adjustment sleeve 1201, ratchet 1202, adjustment core 1203, slot 1204, spring seat 13. DETAILED DESCRIPTION

[0020] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] See also Figure 1-2 This embodiment provides a drum brake with clearance adjustment, including a brake base plate 10 and two brake shoe friction pad assemblies 8 symmetrically and movably mounted on the brake base plate 10. Specifically, the middle part of the brake shoe friction pad assembly 8 is floatingly mounted on the brake base plate 10 through a press-fit seat assembly 3; when braking, the two brake shoe friction pad assemblies 8 can move in opposite directions and contact with the brake inner circle of the brake drum to achieve braking. The two brake shoe friction pad assemblies 8 have the same structure, and are not distinguished between left and right.

[0022] One end of the two brake shoe friction plate assemblies 8 is connected via a gap adjustment device 12, and the other end is connected via a brake push rod 5; one end of the brake push rod 5 is connected to the brake zipper 1 via a brake pull rod 7, and the brake pull rod 7 and the brake zipper 1 are detachably connected;

[0023] The clearance adjustment device 12 includes a sleeved adjustment sleeve 1201 and an adjustment core 1203, wherein the adjustment core 1203 is threadedly connected with a ratchet 1202, and the end of the adjustment core 1203 extends out of the ratchet 1202 and is located inside the adjustment sleeve 1201. The outer ends of the adjustment sleeve 1201 and the adjustment core 1203 are both provided with a slot 1204 connected to the brake shoe friction plate assembly 8.

[0024] The adjusting sleeve 1201 has an inner hole, the inner ring of the ratchet 1202 has an inner thread, and the outer circumference of the adjusting core 1203 has an outer thread. After the adjusting core 1203 is threadedly connected with the ratchet 1202, its end extends out of the ratchet 1202 and is located inside the adjusting sleeve 1201, and the ratchet 1202 contacts the end of the adjusting sleeve 1201. After the adjusting sleeve 1201, the ratchet 1202 and the adjusting core 1203 are assembled into a whole, they are installed between the two brake shoe friction plate assemblies 8.

[0025] When the brake shoe friction plate assembly 8 is worn and affects the parking brake, manual clearance adjustment is required, that is, the ratchet wheel 1202 is rotated to drive the adjustment core 1203 connected thereto to extend or shorten, further pushing the lower ends of the two brake shoe friction plate assemblies 8 closer or farther away, thus achieving the clearance adjustment.

[0026] In order to enhance the smoothness of the movement of the brake shoe friction plate assembly, a tension spring 2 is also connected between the two brake shoe friction plate assemblies 8 located at one end of the gap adjustment device 12. When the ratchet 1202 is rotated, the resistance of the tension spring 2 must be overcome before rotation in two directions can be achieved. The outer circle of the tension spring 2 contacts the ratchet 1202 to prevent the ratchet 1202 from automatically turning without external force.

[0027] One end of the brake rod 7 is connected to a brake shoe friction plate assembly 8 through a pin shaft 9, so that the brake rod 7 can rotate around the pin shaft 9, that is, the brake rod 7 rotates relative to the brake shoe friction plate assembly 8; the other end of the brake rod 7 is detachably connected to the brake zipper 1, and the brake rod 7 near the end of the pin shaft 9 is also connected to the brake push rod 5. When the brake zipper 1 drives the brake rod 7 to move, the pin shaft 9 is used as a fulcrum to push the brake push rod 5 to move, thereby driving the two brake shoe friction plate assemblies 8 to move in opposite directions to achieve braking.

[0028] A spring seat 13 is fixedly arranged on the brake base plate 10 at one end of the brake push rod 5, and the spring seat 13 is connected to the two brake shoe friction plate assemblies 8 through a return spring 6. The function of the return spring 6 is to return the two brake shoe friction plate assemblies 8 in time when the brake is not in use. One end of the brake push rod 5 is connected to the brake shoe friction plate assembly 8 through a push rod spring 4, and the function of the push rod spring 4 is also to return.

[0029] A clearance adjustment hole 11 for rotating the ratchet 1202 is provided on the brake base plate 10 at one end of the clearance adjustment device 12. The clearance adjustment hole 11 is located opposite to the ratchet 1202 and is blocked with an elastic rubber plug when no clearance adjustment is performed; when clearance adjustment is required, the elastic rubber plug is removed to perform clearance adjustment. In addition, when a drum brake fails, the clearance adjustment hole 11 can be used to observe whether the internal parts of the brake are damaged without disassembling the brake and the brake drum.

[0030] The drum brake of the utility model is installed in cooperation with the brake drum. When parking brake operation is required, the brake handle mechanism on the forklift pulls the brake zipper 1, and the brake zipper 1 drives the brake pull rod 7 connected thereto. The brake pull rod 7 uses the pin shaft 9 installed on the brake shoe friction plate assembly 8 as a fulcrum to push the brake push rod 5 connected to the brake pull rod 7. The brake push rod 5 first pushes the upper part of one brake shoe friction plate assembly 8 to move outward, and at the same time, due to the connection of the gap adjustment device, it further pushes the lower part of the other brake shoe friction assembly 8 to move outward; when the outer circle of the brake shoe friction assembly 8 contacts the inner circle of the brake drum, a braking force is generated to achieve parking brake. After the braking action stops, the brake shoe friction assembly 8 returns to its original position under the action of the tension spring 2, the return spring 6, etc.

[0031] Because the brake shoe friction plate assembly 8 is floating relative to the brake base plate 10, the outer cylindrical surface of the brake shoe friction plate 8 will be worn. When the wear affects the parking brake, manual clearance adjustment is required. When the clearance is adjusted, a tool such as a flat-bladed screwdriver is inserted into the clearance adjustment hole 11 to rotate the ratchet 1202. The rotation of the ratchet 1202 will drive the adjustment core 1203 connected thereto to extend or shorten, further pushing the lower end of the brake shoe friction plate assembly 8 closer or farther away, thereby achieving the adjustment of the clearance between the brake drum and the brake drum.

[0032] Although this specification is described according to implementation modes, not every implementation mode includes only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0033] Therefore, the above description is only a preferred embodiment of the present application and is not intended to limit the scope of implementation of the present application; that is, all equivalent changes made according to the scope of the claims of the present application are within the protection scope of the claims of the present application.

Claims

1. A drum brake with clearance adjustment, comprising a brake base plate (10) and two brake shoe friction plate assemblies (8) symmetrically and movably mounted on the brake base plate (10), characterized in that: One end of the two brake shoe friction plate assemblies (8) is connected via a gap adjustment device (12), and the other end is connected via a brake push rod (5); one end of the brake push rod (5) is connected to the brake zipper (1) via a brake pull rod (7); the gap adjustment device (12) comprises a sleeved adjustment sleeve (1201) and an adjustment core (1203); a ratchet (1202) is threadedly connected to the adjustment core (1203); an end of the adjustment core (1203) extends out of the ratchet (1202) and is located inside the adjustment sleeve (1201).

2. A drum brake with clearance adjustment according to claim 1, characterized in that: The middle part of the brake shoe friction plate assembly (8) is floatingly mounted on the brake base plate (10) through a press-fit seat assembly (3); the outer ends of the adjustment sleeve (1201) and the adjustment core (1203) are both provided with a clamping groove (1204) connected to the brake shoe friction plate assembly (8).

3. A clearance-adjustable drum brake according to claim 1, characterized in that: A tension spring (2) is also connected between the two brake shoe friction plate assemblies (8) located at one end of the gap adjustment device (12), and the outer circle of the tension spring (2) is in contact with the ratchet (1202) to prevent the ratchet (1202) from automatically moving.

4. A clearance-adjustable drum brake according to claim 1, characterized in that: The end of the brake rod (7) is connected to a brake shoe friction plate assembly (8) via a pin shaft (9). When the brake zipper (1) drives the brake rod (7) to move, the pin shaft (9) is used as a fulcrum to push the brake push rod (5) to move, thereby driving the two brake shoe friction plate assemblies (8) to move in opposite directions to achieve braking.

5. The clearance-adjustable drum brake according to claim 1, characterized in that: A spring seat (13) is fixedly arranged on a brake base plate (10) at one end of a brake push rod (5), and the spring seat (13) is connected to two brake shoe friction plate assemblies (8) via a return spring (6) respectively.

6. A clearance-adjustable drum brake according to claim 1, characterized in that: A clearance adjustment hole (11) for rotating the ratchet wheel (1202) is provided on the brake base plate (10) located at one end of the clearance adjustment device (12).

7. The clearance-adjustable drum brake according to claim 1, characterized in that: One end of the brake push rod (5) is connected to the brake shoe friction plate assembly (8) via a push rod spring (4).

Images