SEAT BRAKE DESIGN METHOD USING SIMULATION

Abstract

Herein lies a caliper brake design method using simulation. The disclosed caliper brake design method, which is a caliper brake design method that uses simulation by CAE analysis when designing a caliper brake to reduce drag torque, includes setting a parameter that determines a clearance between a brake pad and a disc after the brake is released, compressing a pad spring to bring the brake pad into close contact with the disc, releasing the pad spring, pushing a piston inward to bring the brake pad into close contact with the disc, releasing the piston, and obtaining a result of the clearance between the brake pad and the disc.

Description

BACKGROUND1. Field of InterestEmbodiments of the present disclosure relate to a caliper brake configuration method using a simulation, and more particularly, to a caliper brake configuration method for performing configuration of a caliper brake capable of reducing drag torque through a simulation by CAE analysis.2. Description of the Prior ArtGenerally, a vehicle has a braking system for braking. One type of brake system is the saddle brake in which a piston brings a brake pad into contact with a side surface of a disc that rotates together with a vehicle wheel. In the caliper brake, the vehicle is stopped by the frictional force between the disc and the brake pad.The caliper brake again releases the pressure of the piston when the braking of the vehicle ends and travel begins. In this case, the brake lining is separated from the disc. In a conventional caliper brake, however, the distance between brake pad and disc is not sufficiently secured after the braking of a vehicle is ended, so that partial or temporary contact occurs between brake pad and disc during travel. This is referred to as drag torque phenomenon.Drag torque is a problem that affects the performance and durability of a brake system. Accordingly, the designers of caliper brakes have made great efforts to reduce drag torque. Conventionally, the design of a caliper brake to reduce drag torque requires the actual manufacture and testing of a brake, which is very time and costly.Therefore, in the present disclosure, a configuration method is proposed in which a simulation by computer aided engineering (CAE) analysis is used without actually making a brake in the configuration of a caliper brake for reducing drag torque.SUMMARYTherefore, it is an aspect of the present disclosure to provide a configuration method using a simulation by CAE analysis when designing a caliper brake capable of reducing the drag torque.Another aspect of the present disclosure is to provide a configuration method that uses a simulation reflecting actual braking and driving conditions in configuration of a caliper brake that can reduce drag torque.Still another aspect of the present disclosure is to provide a configuration method that can be performed quickly and inexpensively in configuring a caliper brake that can reduce drag torque.According to an aspect of the present disclosure, a caliper brake configuration method using a simulation by CAE analysis when designing a caliper brake to reduce drag torque includes setting a parameter that determines a clearance between a brake pad and a disc after releasing the brake, contracting a pad spring to bring the brake pad into close contact with the disc, releasing the pad spring, pushing a piston inward to bring the brake pad into close contact with the disc, releasing the piston, and obtaining a result for the clearance between the brake pad and the disc.The parameter may include at least one of a length, a width, and a thickness of the pad spring.The pad spring may include a first retraction bracket supporting one side of the brake pad and a second retraction bracket supporting the other side of the brake pad, and the parameter may set a length of the first retraction bracket and a length of the second retraction bracket differently from each other.The parameter may also include at least one of a material of the pad spring, a diameter of the piston, a material of the brake pad, a thickness of the back plate supporting the brake pad, or a thickness or a material of a seam on the back plate.The clearance between the brake pad and the disc may be a distance between a center of an inner circumferential surface of the brake pad and a point on an outer circumferential surface of the disc that meets the center of the inner circumferential surface of the brake pad when the brake pad and the disc are in close contact with each other.When releasing the lining spring, the lining spring must be released until the play between the brake lining and the disc no longer increases.The brake pad may include an inner brake pad and an outer brake pad, and the result of the clearance between the brake pad and the disc may include a result of a clearance between the inner brake pad and the disc and a result of a clearance between the outer brake pad and the disc.BRIEF DESCRIPTION OF THE DRAWINGSThese and / or other aspects of the disclosure will be apparent and more readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings: FIG. 1 is a front view of a caliper brake according to an embodiment of the present disclosure; FIG. 2 is a view showing a pad spring of the caliper brake according to an embodiment of the present disclosure; FIG. 3 is a flowchart sequentially showing detailed steps of a simulation method according to an embodiment of the present disclosure; and FIG. 4 is a diagram showing a change in clearance between a brake pad and a disc according to the detailed steps of the simulation method according to an embodiment of the present disclosure.DETAILED DESCRIPTIONHereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The following embodiment is intended to fully convey the spirit of the present disclosure to a person having ordinary skill in the art of the present disclosure. The present disclosure is not limited to the exemplary embodiment shown here, but can also be realized in other forms. In the drawings, the illustration of parts unrelated to the description may be omitted to clarify the present invention, and the size of the components is easily exaggerated for better understanding.FIG. 1 is a front view illustrating a caliper brake according to an embodiment of the present disclosure, and FIG. 2 is a view illustrating a pad spring of the caliper brake according to an embodiment of the present disclosure.Referring now to FIGS. 1 and 2, a general caliper brake including an embodiment of the present disclosure is shown including a disc 200, back plates 500, a brake pad 100, a piston 300, and pad springs 400.The disk 200 is a circular plate fixed to a wheel hub. The disc 200 rotates together with a rotating wheel and decelerates a vehicle by converting the kinetic energy of the vehicle into heat by friction with the brake pad 100.The back plates 500 are arranged in pairs in a lateral direction of the disc 200. The brake pad 100 may be fixed to the back plates 500, and may include a layer of an iron material and a layer of a rubber material.The brake pad 100 contacts the disc 200 and generates a braking force by direct friction. The brake pad 100 is located on both sides of the disc 200 and in particular includes an inner brake pad 110 proximate the piston 300 and an outer brake pad 120 located on the opposite side of the inner brake pad 110.The piston 300 serves to press the brake pad 100 against the disc 200. The piston 300 is formed in a cylindrical shape and brings the brake pad 100 into close contact with the disc 200 by pressurizing.The pad springs 400 are provided in a pair to elastically support the pair of back plates 500 on a support (not shown). Specifically, the pad springs 400 include a first retraction bracket 410 that directly contacts and supports one side of the back plates 500 and a second retraction bracket 420 that directly contracts and supports the other side of the back plates 500.In addition, the caliper brake may include a caliper housing 700 that determines the appearance of the caliper brake, a seal 600 provided between the caliper housing 700 and the piston 300 and for sealing, the carrier (not shown) on which the back plates 500 are seated, and the like. A detailed configuration of the caliper brake is known in the art, so a detailed description will be omitted.When braking a vehicle, the piston 300 presses the back plates 500 or the brake pad 100 to rub the brake pad 100 on the disc 200, and when the vehicle travels again after braking, the piston 300 releases the pressure to separate the brake pad 100 from the disc 200. However, in the conventional caliper brake, the distance between the brake pad 100 and the disc 200 is not sufficiently secured even after the completion of the braking operation of a vehicle, so that partial or temporary contact occurs between the brake pad 100 and the disc 200 during running.This phenomenon is referred to as drag torque, and since the drag torque affects the performance and durability of a brake system, designers of brakes are striving to reduce drag torque greatly. However, a conventional caliper brake for reducing drag torque is very time and costly to manufacture and test a brake.Accordingly, the present disclosure solves the conventional problem by a method capable of designing a caliper brake for reducing drag torque by using a simulation by CAE analysis in designing the caliper brake.CAE is the abbreviation for computer-aided engineering and means engineering design and analysis using computers. CAE allows for a faster and more economical design and analysis than existing experimental methods. CAE uses a computer to provide a simulation for the design of a product and is particularly simple for optimum design by adjusting various variables of the product.FIG. 3 is a flowchart sequentially showing detailed steps of a simulation method according to an embodiment of the present disclosure.Referring to FIG. 3, a simulation according to an embodiment of the present disclosure includes, when the simulation begins ( 10), setting a parameter ( 20), contracting the pad spring 400 ( 30), releasing the pad spring 400 ( 40), pressing the piston 300 ( 50), releasing the piston 300 ( 60), and finally deriving ( 70) a result of a clearance between the brake pad 100 and the disc 200, and then the simulation ( 80) ends. In this case, the simulation is not carried out separately in each step, but rather each step takes place as a single CAE analysis.CAE analysis uses optimization tools of various solvers (Abaqus, Nastran, Optistruct, Optimus, and Ansys). In this case, a desired result value can be derived by setting corresponding parameters and a permissible range of a parameter value for configurations of the caliper brake.In setting the parameter (20), a parameter that determines a clearance between the brake pad 100 and the disc 200 after the brake is released is set. Accordingly, a simulation can be performed that corresponds to the actual braking and driving conditions.The parameter may include at least one of a length, a width, and a thickness of the pad spring 400. The pad spring 400 is an important parameter that determines the distance between the brake pad 100 and the disc 200.The length of the pad spring 400 set as a parameter may be shorter than the actual length of the pad spring 400. In general, the distance between the brake pad 100 and the disc 200 should be 0.12 mm in the brake un-braked state, and in the simulation by CAE analysis, optimum design is possible only when a retraction bracket of the pad spring 400 is set shorter than an actual retraction bracket of the pad spring 400.In the pad spring 400 length set as a parameter, a length of the first retracting bracket 410 and a length of the second retracting bracket 420 of the pad spring 400 may be set differently. In the caliper brake, an asymmetric pressure distribution is formed on the brake pad 100 after braking. Accordingly, in the simulation by CAE analysis, the lengths of the first retracting bracket 410 and the second retracting bracket 420 may be set to be different from each other to reflect an actual state after braking.The parameters may also include at least one of the material of the pad spring 400, the diameter of the piston 300, the material of the brake pad 100, the thickness of the back plate 500 supporting the brake pad 100, the thickness or material of a seam on the back plate 500, or a material property (modulus of elasticity, modulus of elasticity, or the like) of the individual components. In this way, the parameters can be set differently in order to carry out the simulation by means of an extremely reliable CAE analysis.The allowable range of the parameter value may be appropriately selected in consideration of the time required for deriving a simulation result. For example, no simulation result is derived or a lot of time is required when an allowable range for the thickness of the pad spring 400 selected as a parameter is an error of 5%, while the simulation result value can be rapidly derived when the allowable range is an error of 10%.Contraction ( 30) of the pad spring 400 and release ( 40) of the pad spring 400 are a numerical approximation method for stably performing the simulation in the CAE analysis and obtaining a better convergence value. Accordingly, the above two steps are steps for the simulation, not steps performed in an actual caliper brake.FIG. 4 is a diagram showing a change in the clearance between the brake pad 100 and the disc 200 according to the detailed steps of the simulation method according to an embodiment of the present disclosure.Referring to FIG. 4, the steps corresponding to the step times in the simulation according to an embodiment of the present disclosure and a change in the clearance between the brake pad 100 and the disc 200 may be identified in the steps.As shown in FIG. 4, there are two results for the clearance between the brake pad 100 and the disc 200. That is, one is a dotted line having a positive value and the other is a solid line having a negative value. This is because a pair of brake pads 100 are provided on both sides of the disc 200. Accordingly, one of the dashed or solid lines results from the clearance between the inner brake pad 110 and the disc 200, and the other from the clearance between the outer brake pad 120 and the disc 200.The contraction (30) of the pad spring 400 lies between the step times 0 and 1 in the graph of FIG. 4 At this time, the brake pad 100 contacts the disc 200 and the back plates 500 are attached.The release (40) of the pad spring 400 lies between step times 1 and 2 in the graph of Figure 4 at which time the back plates 500 are free to move and the brake pad 100 gradually moves away from the disc 200. In this case, sufficient time is to be provided for releasing contraction until the clearance between the brake pad 100 and the disc 200 no longer increases.The clearance between the brake pad 100 and the disc 200 is based on a distance between the center of an inner circumferential surface of the brake pad 100 and a point on an outer circumferential surface of the disc 200 that abuts the center of the inner circumferential surface of the brake pad 100 when the brake pad 100 and the disc 200 are in close contact with each other.The pressing (50) of the piston 300 takes place between the step times 2 and 3 in the diagram of FIG. 4. At this time, the piston 300 moves forward and presses the back plates 500 inward to bring the brake pad 100 into close contact with the disc 200.The release (60) of the piston 300 lies between the step times 3 and 4 in the diagram of FIG. 4 At this time, the piston 300 moves backward and the brake pad 100 is separated from the disc 200 after a certain time.In deriving (70) the result, a result of the clearance between the brake pad 100 and the disc 200 is obtained. The simulation according to an embodiment of the present disclosure has a target clearance of 0.12 mm for the clearance between the brake pad 100 and the disc 200. If the result is less than 0.12 mm, the caliper brake can be re-designed by adjusting the value of a parameter.However, the present disclosure is not limited to 0.12 mm for the target clearance between the brake pad 100 and the disc 200, and may include various settings depending on the type of the caliper brake.The simulation ends after it is determined from the result of the clearance between the brake pad 100 and the disc 200 (80) whether the brake is to be completed or re-designed.As is apparent from the above description, the caliper brake configuration method capable of reducing the drag torque according to an embodiment of the present disclosure can use a simulation using a computer, particularly, can rapidly and inexpensively configure a caliper brake by performing the simulation not separately but by a single CAE analysis, and can design the caliper brake by the simulation by reflecting the actual braking and running conditions with each feature of the brake configurations set as a parameter.An embodiment of the present disclosure may provide a configuration method that uses a simulation by CAE analysis to configure a caliper brake capable of reducing drag torque.An embodiment of the present disclosure may provide a configuration method that uses a simulation reflecting actual braking and driving conditions in configuration of a caliper brake that can reduce drag torque.An embodiment of the present disclosure may provide a configuration method that can be performed quickly and inexpensively in designing a caliper brake that can reduce drag torque.While a few embodiments of the present disclosure have been illustrated and described, it will be understood by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.

Claims

A caliper brake configuration method using a simulation by CAE analysis in the configuration of a caliper brake to reduce drag torque, the method comprising: setting a parameter that determines play between a brake pad (100) and a disc (200) after releasing the brake; contracting a pad spring (400) to bring the brake pad (100) into close contact with the disc (200); releasing the pad spring (400); pushing a piston (300) inward to bring the brake pad (100) into close contact with the disc (200); releasing the piston (300); and obtaining a result of the play between the brake pad (100) and the disc (200).The saddle brake configuration method of claim 1, wherein the parameter comprises at least one of a length, a width, and a thickness of the pad spring (400).The parking brake configuration method according to claim 2, wherein the pad spring (400) includes a first retraction bracket (410) supporting one side of the brake pad (100) and a second retraction bracket (420) supporting the other side of the brake pad (100), and the parameter sets a length of the first retraction bracket and a length of the second retraction bracket differently.The caliper brake configuration method according to claim 2 or 3, wherein the parameter further comprises at least one of: a material of the pad spring (400), a diameter of the piston (300), a material of the brake pad (100), a thickness of a back plate (500) supporting the brake pad (100), or a thickness or a material of a seam provided on the back plate (500).The caliper brake configuration method according to any one of claims 1 to 4, wherein the clearance between the brake pad (100) and the disc (200) is a distance between a center of an inner circumferential surface of the brake pad (100) and a point on an outer circumferential surface of the disc (200) that meets the center of the inner circumferential surface of the brake pad (100) when the brake pad (100) and the disc (200) are in close contact with each other.The saddle brake configuration method according to any one of claims 1 to 5, wherein, when the lining spring (400) is released, the lining spring (400) is released until the clearance between the brake lining (100) and the disc (200) no longer increases.The saddle brake configuration method according to any one of claims 1 to 6, wherein the brake pad (100) has an inner brake pad (110) and an outer brake pad (120), and the result of the clearance between the brake pad (100) and the disc (200) comprises a result of a clearance between the inner brake pad (110) and the disc (200) and a result of a clearance between the outer brake pad (120) and the disc (200).

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