Method for determining number of adjusting teeth of parking braking system of passenger car

Abstract

The invention belongs to the technical field of automobile brake control, and particularly relates to a method for determining the number of adjusting teeth of a parking brake system of a passenger car, which comprises the following steps of: giving a formula for calculating the number of whole teeth lifted by a parking brake operating lever when a force of F is applied to a force application point of the parking brake operating lever, and respectively calculating X values in a forward direction and a backward direction according to the formula, the tooth number of the X values in the forward direction and the backward direction released by one tooth in the corresponding loosening and tightening directions is used as the range of the whole tooth number of the parking brake operating lever in the lifting process; the length adjusting device is suitable for length adjustment of a mechanical parking system with double rear wheel stay wires and an adjusting mechanism in a cab, time is saved, meanwhile, the problem of production takt can be rapidly solved, and the vehicle off-line qualification rate is increased.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile brake control, and in particular relates to a method for determining the number of teeth for adjusting a parking brake system of a passenger car. Background Art

[0002] At present, passenger cars use mechanical parking methods. During the production stage, the production operators will encounter the problem of long adjustment time for the parking system of passenger cars. Therefore, the adjustment of the parking system is related to the assembly rhythm of the whole vehicle. Whether it can meet all working conditions of actual vehicle use requires an adjustment method to be verified in the early development stage, so as to shorten the production time and save production costs.

[0003] At present, due to the fierce competition among automobile companies, in order to reduce costs and seize the market, shortening production hours and saving labor costs are effective methods. Based on this aspect, the method of adjusting the parking brake system is particularly important; all mechanical parking brake systems need to be adjusted to ensure that they work properly; in the past, the adjustment of the parking brake system after installation was usually based on the operator's experience. After the vehicle is assembled, it needs to be adjusted again according to the vehicle test conditions, which is not only time-consuming and labor-intensive but also affects the production rhythm. Summary of the invention

[0004] In order to overcome the above problems, the present invention provides a method for determining the number of adjustment teeth of a passenger car parking brake system, which is suitable for length adjustment of a mechanical parking system with double pull cables for the rear wheels and an adjustment mechanism in the cockpit. It not only saves time but also can quickly solve the production cycle problem and improve the vehicle off-line qualification rate.

[0005] A method for determining the number of teeth for adjusting a parking brake system of a passenger vehicle comprises the following contents:

[0006] Step 1: Calculate the number of teeth X that the parking brake lever is lifted when a force of magnitude F is applied to the application point of the parking brake lever according to the following formula:

[0007] X=[1+(S 拉 +S 后 -L1) / L δ ]

[0008] S 拉 =kF 拉

[0009] F 拉 =F*i / 2*η

[0010] S 后 =f(F 制动器 )

[0011] F 制动器 =F 拉 -f 阻

[0012] L1=2πrθ1 / 360°

[0013] L δ =2πrθ δ / 360°

[0014] in:

[0015] F is the force applied at the application point of the parking brake lever;

[0016] S 拉 is the elastic deformation of the rear tension wire;

[0017] k is the elastic deformation coefficient of the back tension wire;

[0018] F 拉 It is the tension on the rear cable on one side;

[0019] i is the lever ratio of the parking brake lever assembly;

[0020] η is the back-drawing efficiency;

[0021] S 后 is the rear brake swing arm travel;

[0022] F 制动器 is the tension on the rear brake swing arm;

[0023] f 阻 is the internal resistance of the rear brake;

[0024] L1 is the rear wire pulling stroke when the first tooth is lifted;

[0025] r is the rotation radius of the cable in the parking brake lever assembly;

[0026] θ1 is the rotation angle of the first tooth of the ratchet in the parking brake lever assembly;

[0027] Lδ is the wire pulling stroke per tooth;

[0028] θ δ The ratchet wheel in the parking brake lever assembly rotates 1 tooth angle;

[0029] f is S 后 and F 制动器 The functional relationship between

[0030] Step 2: Calculate the X values ​​in the forward direction and the backward direction according to the above formula, and release the X values ​​in the forward direction and the backward direction by 1 tooth in the corresponding loosening and tightening directions as the range of the parking brake lever lifting teeth.

[0031] The S 后 With F 制动器The functional relationship is different in the forward and reverse directions.

[0032] The S 后 With F 制动器 The functional relationships in the forward and reverse directions are obtained from the rear brake performance report.

[0033] The i is obtained by querying the self-test report of the parking brake lever.

[0034] The η is obtained by querying in the rear tension wire test report.

[0035] The k is obtained by querying in the back-pull wire report.

[0036] The f_ 阻 This is the rear brake no-load sliding resistance reported in the rear brake performance report.

[0037] The θ1, θ δ , r are measured from the 3D data of the parking brake lever assembly.

[0038] Beneficial effects of the present invention:

[0039] The present invention can quickly adjust the length of the parking brake system of the whole vehicle during assembly of the whole vehicle, reduce the working hours caused by frequent adjustments, reduce the frequency of parking brake system adjustments, shorten the production cycle, save the production cost of the whole vehicle, and indirectly improve the market competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings used in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without creative work.

[0041] Figure 1 This is the rear brake swing arm tension and travel diagram.

[0042] Figure 2 This is a 3D data diagram of the parking brake lever assembly.

[0043] Figure 3 This is the vehicle parking slope and rear brake swing arm tension diagram. DETAILED DESCRIPTION

[0044] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0045] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0047] In the description of this embodiment, the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0048] Example 1

[0049] A method for determining the number of teeth for adjusting a parking brake system of a passenger vehicle comprises the following contents:

[0050] Step 1: Calculate the number of teeth X that the parking brake lever is lifted when a force of magnitude F is applied to the application point of the parking brake lever according to the following formula:

[0051] X=[1+(S 拉 +S 后 -L1) / L δ ]

[0052] S 拉 =kF 拉

[0053] F 拉 =F*i / 2*η

[0054] S 后 =f(F制动器 )

[0055] F 制动器 =F 拉 -f 阻

[0056] L1=2πrθ1 / 360°

[0057] L δ =2πrθ δ / 360°

[0058] in:

[0059] F is the force applied at the application point of the parking brake lever;

[0060] S 拉 is the elastic deformation of the rear tension wire;

[0061] k is the elastic deformation coefficient of the back tension wire;

[0062] F 拉 It is the tension on the rear cable on one side;

[0063] i is the lever ratio of the parking brake lever assembly;

[0064] η is the back-drawing efficiency;

[0065] S 后 is the rear brake swing arm travel;

[0066] F 制动器 is the tension on the rear brake swing arm;

[0067] f 阻 is the internal resistance of the rear brake;

[0068] L1 is the back-pull wire travel when the first tooth is lifted;

[0069] r is the rotation radius of the cable in the parking brake lever assembly;

[0070] θ1 is the rotation angle of the first tooth of the ratchet in the parking brake lever assembly;

[0071] Lδ is the wire pulling stroke per tooth;

[0072] θ δ The ratchet wheel in the parking brake lever assembly rotates 1 tooth angle; (except the 1st tooth)

[0073] f is S 后 and F 制动器 The functional relationship between

[0074] Step 2: Calculate the X values ​​in the forward direction and the backward direction according to the above formula, and release the X values ​​in the forward direction and the backward direction by 1 tooth in the corresponding loosening and tightening directions as the range of the parking brake lever lifting teeth.

[0075] The S 后 With F 制动器 The functional relationship is different in the forward and reverse directions.

[0076] The S 后 With F 制动器 The functional relationships in the forward and reverse directions are obtained from the rear brake performance report.

[0077] The i is obtained by querying the self-test report of the parking brake lever.

[0078] The η is obtained by querying in the rear tension wire test report.

[0079] The k is obtained by querying in the back-pull wire report.

[0080] The f_ 阻 This is the rear brake no-load sliding resistance reported in the rear brake performance report.

[0081] The θ1, θ δ , r are measured from the 3D data of the parking brake lever assembly.

[0082] Example 2

[0083] By using 100N force to lift the number of teeth of the parking brake lever assembly at the parking brake lever application point, you can quickly determine whether the entire parking system adjustment is completed. This method only calculates the number of teeth lifted by the parking brake; 100N force is suitable for the operator's hand force control range, and 100N can achieve the effective number of teeth lifted (over the first tooth), and force measuring tools that meet the range are easy to find and inexpensive;

[0084] Taking the E131 model as an example, the number of adjustment teeth of the parking brake system of the whole vehicle is calculated according to this method, and the rationality is verified.

[0085] 1. Calculate the number of teeth that the parking brake lever is lifted based on the force F = 100N applied at the parking brake lever application point:

[0086] 1. Apply a force of F = 100N to the application point of the parking brake lever, and the elastic deformation of the rear cable S 拉 The calculation process is as follows:

[0087] F 拉_100 =F*i / 2*η=250.8N

[0088] S 拉_100 =kF拉_100 ≈0.38mm

[0089] Where: i = 5.7 (query and obtain in the self-test report of the parking brake lever), η = 88% (query and obtain in the rear cable test report), k = 1.5 mm / KN (query and obtain in the rear cable report);

[0090] 2. Apply a force of F = 100N to the application point of the parking brake lever. The rear brake arm travel S 后 The calculation process is as follows:

[0091] f_ 阻 =13.5N (no-load sliding resistance of rear brake in the report)

[0092] F 制动器_100 =F 拉_100 -f 阻 =250.8N-13.5N=237.3N

[0093] Where S is obtained from the rear brake performance report 后 =f(F 制动器 ) functional relationship; and the movement trend has two directions, one forward and one backward, which need to be analyzed separately, among which:

[0094] Direction: S 后 =f(F 制动器 ) The functional relationship is S 后_100前 =0.009F 制动器 _ 100前 +5.0675, so S 后_100前 ≈7.20mm;

[0095] Backward direction: S 后 =f(F 制动器 )The functional relationship is S 后_100后 =0.0076F 制动器_100后 +6.1909, so S 后_100后 ≈7.99mm;

[0096] 3. Calculate L1 and Lδ based on the parking brake lever assembly data. The process is as follows:

[0097] The parking brake lever assembly has 15 teeth on the gear plate, and the effective number of teeth on the lever is 14. Figure 2 The measured values ​​of θ1 = 8.36° and θ δ =2.87°, r=32.1mm, so:

[0098] L1=2πrθ1 / 360°=4.69mm

[0099] L δ =2πrθ δ / 360°=1.61mm;

[0100] 4. Substitute the formula to calculate the number of teeth X that are lifted when the parking brake lever is applied with F = 100N:

[0101] Forward direction: X = [1 + (S 拉_100 +S 后_100前 -L1) / L δ ]=3

[0102] Backward direction: X = [1 + (S 拉 +S 后_100后 -L1) / L δ =4

[0103] The tolerance and clearance of the parking brake system are calculated to be 0.38mm in total, which is less than 1 tooth. Taking into account the adjustment time during production and other issues, the number of teeth is increased by 1 tooth in the loosening and tightening direction. That is, when adjusting, F=100N corresponds to 2 to 5 teeth of the parking brake lever being lifted, which is reasonable.

[0104] 2. Verify the rationality of the design that the number of teeth on the parking brake lever lifted when the adjustment force F=100N is set to 2 to 5.

[0105] 1. Verification content: Press F = 100N force to lift the parking brake lever and adjust it by 2 teeth. Put the parking brake lever flat and the vehicle will not drag:

[0106] (1) Forward direction: Parking brake lever applied F = 100N, rear brake arm travel S 后_100前 The parking brake lever is lifted by 2 teeth, and the cable travel is L2 = L1 + (2-1) * L δ =6.30mm

[0107] L2<S 后_100前 (6.30mm-7.20mm=-0.90mm)

[0108] Press F = 100N to lift the parking brake lever and adjust it by 2 teeth. After the parking brake lever is flat, the rear brake swing arm will move 0.90mm from Figure 1 It can be seen that the idle travel of the rear brake in the forward direction is 5.07mm, so moving 0.90mm will not cause drag (as long as L2-S 后_100前 The value can be less than this empty stroke);

[0109] Press F = 100N force to lift the parking brake lever 5 teeth adjustment, the cable travel is L5 = L1 + (5-1) * Lδ = 11.13mm, L5 > S 后_100前, which means that the rear brake swing arm will not move, and there will be no drag;

[0110] (2) Reverse direction: parking brake lever applied F = 100N, rear brake arm travel S 后_100后 The parking brake lever is lifted by 2 teeth, and the cable travel is L2 = 6.30 mm.

[0111] L2<S 后_100后 (6.30mm-7.99mm=-1.69mm)

[0112] Press F = 100N to lift the parking brake lever and adjust it by 2 teeth. When the parking brake lever is flat, the rear brake swing arm will move 1.69mm. Figure 1 It can be seen that the rear brake idle travel in the reverse direction is 6.19mm, so moving 1.69mm will not cause drag;

[0113] Press F = 100N force to lift the parking brake lever 5-tooth adjustment, the cable travel is 11.13mm,

[0114] L5>S 后_100后 , which means that the rear brake swing arm will not move and there will be no drag in the reverse direction;

[0115] 2. Verification content: After lifting 5 teeth at F=100N, the number of teeth when stationary at a 20% slope can meet the national standard requirements;

[0116] From the vehicle parking slope and rear brake arm tension diagram in the rear brake report, Figure 3 Find out the tension F on the brake arm when the slope is 20% 制动器 and the functional relationship of the stationary slope γ, that is, F 制动器 =f(γ)Forward direction: F 制动器_20％前 =18.144γ+5.4895(γ=20)≈368.37(N)

[0117] S 后_20％前 =0.009*F 制动器_20％前 +5.0675≈8.38(mm), F 拉_20％前 =F 制动器_20％前 + f 阻 =381.87N, S 拉_20％前 =kF 拉_20％前 =0.57mm; calculate the change in the back wire travel and calculate the number of teeth added ΔS 20％前 =(S 后_20％前+ S 拉_20％前 )-(S 后_100前 +S 拉_100)=(8.38mm+0.57mm)-(7.20mm+0.38mm)=1.37mm.

[0118] The change in the rear cable travel is less than 1 tooth (L δ =1.61mm) stroke, calculated by adding 1 tooth, then according to F=100N, lift the parking brake lever 5 teeth to adjust the parking teeth in the forward direction of a 20% slope to 6 teeth;

[0119] Backward direction: F 制动器 _ 20％后 =27.723γ-63.001 (γ is explained before)≈491.46(N)

[0120] S 后 _ 20％后 =0.0076*F 制动器 _ 20％后 +6.1909≈9.93(mm)

[0121] F 拉_20％后 =F 制动器 _ 20％后 + f 阻 =504.96N(f_ 阻 =13.5N, as explained above)

[0122] S 拉 _ 20％后 =0.76mm (k=1.5mm / KN, as explained above)

[0123] ΔS 20％后 =(S 后 _ 20％后+ S 拉 _ 20％后 )-(S 后_100后 +S 拉 _ 100 )=(9.93+0.76)-(7.99+0.38)=2.32(mm)

[0124] The change in the rear cable travel is less than 2 teeth (L δ =1.61mm) stroke, calculated by adding 2 teeth, then according to F=100N, lift the parking brake lever 5 teeth to adjust the parking teeth number for the 20% slope backward direction to 7 teeth;

[0125] According to 7.3.2 of the national standard GB728, parking on a 20% slope must be completed within two-thirds of the teeth; the parking mechanism has a total of 14 effective teeth, and parking must be completed within 9 teeth; after pressing F=100N and lifting the parking brake lever 5 teeth to adjust the parking position on a 20% slope, the number of parking teeth in both the forward and reverse directions meets the national standard requirements.

[0126] 3. Verify that after the parking brake lever is lifted up with F=100N and adjusted by 5 teeth, the rear cable can still meet the national standard when the number of teeth is permanently extended and parked on a 20% slope;

[0127] Permanent elongation L of the cable assembly after durability in the test report 耐 1.70mm, corresponding displacement increased by 1.70mm

[0128] Forward direction: ΔS 20％前耐 =ΔS 20％前 +L 耐 =1.37mm+1.70mm=3.07(mm)

[0129] The change in the rear cable travel is less than 2 teeth (L δ =1.61mm) stroke, calculated by adding 2 teeth, then according to F = 100N, lift the parking brake lever 5 teeth to adjust the rear cable endurance elongation after parking in the forward direction of 20% slope, the number of parking teeth is 7 teeth, which meets the national standard requirements;

[0130] Backward direction: ΔS 20％后耐 =ΔS 20％后 +L 耐 =2.32+1.70=4.02(mm)

[0131] The change in the rear cable travel is less than 3 teeth (L δ =1.61mm) stroke, calculated by adding 3 teeth, then according to F=100N, lift the parking brake lever 5 teeth to adjust the rear cable endurance elongation after parking on a 20% slope backward direction, the number of parking teeth is 8 teeth, that is, 8 teeth in the backward direction, which meets the national standard requirements;

[0132] It has been verified that the vehicle parking system fully meets the vehicle performance requirements after being adjusted to 2 to 5 teeth at F=100N.

[0133] According to the inventive method, the parking brake system of the vehicle is adjusted to meet the performance of the whole vehicle and the national standard requirements.

[0134] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the protection scope of the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention. These simple variations all belong to the protection scope of the present invention.

[0135] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0136] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for determining the number of teeth for adjusting the parking brake system of a passenger car, characterized in that: It includes the following: Step 1: Calculate the number of teeth X that the parking brake lever is lifted when a force of magnitude F is applied to the application point of the parking brake lever according to the following formula: X=[1+(S 拉 +S 后 -L1) / L δ ] S 拉 =kF 拉 F 拉 =F*i / 2*η S 后 =f(F 制动器 ) F 制动器 =F 拉 -f 阻 L1=2πrθ1 / 360° L δ =2πrθ δ / 360° in: F is the force applied at the application point of the parking brake lever; S 拉 is the elastic deformation of the rear tension wire; k is the elastic deformation coefficient of the back tension wire; F 拉 It is the tension on the rear cable on one side; i is the lever ratio of the parking brake lever assembly; η is the back-drawing efficiency; S 后 is the rear brake swing arm travel; F 制动器 is the tension on the rear brake swing arm; f 阻 is the internal resistance of the rear brake; L1 is the rear wire pulling stroke when the first tooth is lifted; r is the rotation radius of the cable in the parking brake lever assembly; θ1 is the rotation angle of the first tooth of the ratchet in the parking brake lever assembly; Lδ is the wire pulling stroke per tooth; θ δ The ratchet wheel in the parking brake lever assembly rotates 1 tooth angle; f is S 后 and F 制动器 The functional relationship between Step 2: Calculate the X values ​​in the forward direction and the backward direction according to the above formula, and release the X values ​​in the forward direction and the backward direction by 1 tooth in the corresponding loosening and tightening directions as the range of the parking brake lever lifting teeth.

2. A method for determining the number of teeth for adjusting the parking brake system of a passenger vehicle according to claim 1, characterized in that: The S 后 With F 制动器 The functional relationship is different in the forward and reverse directions.

3. The method for determining the number of teeth for adjusting the parking brake system of a passenger vehicle according to claim 1, characterized in that: The S 后 With F 制动器 The functional relationships in the forward and reverse directions are obtained from the rear brake performance report.

4. A method for determining the number of teeth for adjusting the parking brake system of a passenger vehicle according to claim 1, characterized in that: The i is obtained by querying the self-test report of the parking brake lever.

5. The method for determining the number of teeth for adjusting the parking brake system of a passenger vehicle according to claim 1, characterized in that: The η is obtained by querying in the rear tension wire test report.

6. A method for determining the number of teeth for adjusting the parking brake system of a passenger vehicle according to claim 1, characterized in that: The k is obtained by querying in the back-pull wire report.

7. A method for determining the number of teeth for adjusting the parking brake system of a passenger vehicle according to claim 1, characterized in that: The f_ 阻 This is the rear brake no-load sliding resistance reported in the rear brake performance report.

8. The method for determining the number of teeth for adjusting the parking brake system of a passenger vehicle according to claim 1, characterized in that: The θ1, θ δ , r are measured from the 3D data of the parking brake lever assembly.

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