Nghiên cứu khảo sát một số thông số làm việc của hệ thống phanh dăn động khí nén lắp trên xe tải sản xuất lắp ráp tại việt nam

T6MTAT De tien tdi muc tieu ngi dia hod theo chiin lUdc xdy diing vd phdt trien ngdnh Cong nghiep 0 to cua Chinh phu, viic tUng biidc ldm chd cdng nghe trong qud trinh thiet ke, che tao

NGHIEN Cl]rU-TRAO Ddi

NGHIEN Ctru KHAO SAT MOT S6 THONG S6 LAM VI$C CUA HE TH6NG PHANH DAN DONG KHI NEN LAP TREN XE TAI SAN XUAT LAP RAP TAI VIET NAM

A STUDY ON EFFECTS OF STRUCTURAL PARAMETERS

OF THE PNEUMATIC BRAKE SYSTEM ON TRUCKS MADE IN VIETNAM

ThS Trdn Van Quylt', TS Dfldng Ngoc Khdnh^

'Trfldng Dai hpc Sfl pham Ky thu^t Hflng Yin

^Trfldng Dai hpc Bdch Khoa Ha Ndi

T6MTAT

De tien tdi muc tieu ngi dia hod theo chiin lUdc xdy diing vd phdt trien ngdnh Cong nghiep 0 to cua Chinh phu, viic tUng biidc ldm chd cdng nghe trong qud trinh thiet ke, che tao vd tien tdi xdy diing ddy chuyin sdn xudt cdc cum vd he thong tren 6 to Id viec ldm rdt cdn thiet Bdi bdo ndy, tien hdnh mo phong he thong phanh ddn dong khi nen trin 6 td tdi diictc sdn xudt, lap rdp tqi Viit Nam Sau dd, md hinh md phdng dUdc sii dung di khdo sdt dnh hudng cua mgt so thong so ket cdu tdi khd ndng ldm viec cda hi thSng Tii do, dUa ra cdc thong so kit cdu toi Uu, phu hdp vdi he thong phanh ddn dgng khi nen trang bi tren xe tdi Ddy co the coi Id mdt bUdc quan trgng trong qud trinh tinh todn thiet ke vd tien tdi che tao he thong phanh ddn dgng khi nen cho cdc xe tdi dUOc sdn xudt, lap rdp tqi Viit Nam

Tfl khoa: Mo phong phanh khi nen, xe tdi 8 tdn

ABSTRACT

In order to achieve localization goal according to automobile industry development strategy ofthe government, gradually build concrete steps of owning technology in the design and manufacture process,

as well as approach building automobile parts and systems production line In this paper, performance of air brake system in trucks manufactured and assembled in Vietnam And then, the simulation model will

be used to investigate the effect of some vehicle structures specifications to air brake system performance Thus, the optimal structures specifications were proposed to appropriate for truck air brake system This

is an important step in the analysis and design process, as well as toward manufacture for large trucks are manufactured and assembled in Vietnam

Keywords: Simulation, the pneumatic brake, large tucs of 8 tanes

NGHIEN CLJfU - TRAO D O I

l.DATVANDE

Hien nay, trin hau hit cdc xe tdi deu sfl

dung he thdng phanh dan ddng khi nen va he

thdng phanh ddng vai trd rat quan trpng ddi vdi

an toan chuyen ddng cua d td Theo thdng kl,

edc vu tai nan xay ra do he thdng phanh la 52,2

- 74,4% [6] Vi v^y, viec nang eao chat Ifldng cua

he thdng phanh khi nen lap tren d td tai la rat can

thiet

Trfldc kia khdng cd sfl ho trd cua may tinh

thi viec thiet ke cac he thdng trin d td ndi chung va

he thdng phanh khi nen ndi rieng gap nhilu khd

khan Qua trinh thiet ke phai trai qua nhieu giai

doan thiet ke thfl, thi nghiem do dae nhieu mdi

rut ra dflpc cac thdng sd kit cau phu hdp vdi yeu

cau vd tilu chuan dat ra Ngay nay, vdi sfl hd trd

cfla cac phan mem chuyen dung, viec md phdng

cac he thdng tren d td trong qua trinh thiet ke trd

nin ddn gian hdn va dat kit qua vdi dp chinh xac

cao

2 M 6 PHONG HE THONG PHANH KHi N £ N

Dl nghien cflu ddng lflc hpc efla he thdng

phanh can phai thilt lap dfldc cac phfldng trinh

md ta qua trinh lam viec cua nd Tuy nhien, do bdn chdt vat ly efla cac hien tfldng xay ra trong

he thdng ddn ddng khi nen rdt phflc tap Cho t6i nay, vile md phdng mdt each hoan toan chinh xac Id khdng the thflc hien dUde, dac bilt la cac qua trinh qua dd Do vay, ngUdi ta thfldng sil dung cdc phfldng phap md phdng gdn dflng de gidi quyet bai toan nay Hien nay, cd kha nhieu phfldng phap md phdng cdc he thdng khi nen va ndi chung chung deu cd flu nhfldc dMm rieng Mdt trong eac phfldng phap md phdng pho biln hiln nay la phUdng phap rad phdng tap trung cua Metliuk Ban chat cfla phUdng phdp ndy la difa trin nguyen tac: i) Thi tich khi tat ca cac phan

tfl eua he thdng (van, dfldng dng, ca cau ch£p

hanh, ) dfldc coi la tap trung t^i mdt dung tich

va sflc can cfla cdc phan tfl nay tap trung t^ mfit tilt lflu; ii) Lflu Ifldng di qua cac diem nut trlnscf

dd md phdng dfldc tinh theo quy tac tinh dong diln di qua dilm nut

Hiln nay, nhilu xe tai dang dfldc san xu&

va lap rdp t ^ Viet Nam Mpt trong sd do la lo?i

xe tai 8 tdn sfl dung phanh ddn ddng khi nen hai ddng ddc l^p nhfl tren hinh 1

^€31

=G:

P max

II Mf

m

II It

J P max

^ ^ P „ n x

c:C^DiiiJ^^2t^l^

i^i^Cxlh

a, Ddn dgng phanh cdu trUdc b, Ddn ddng phanh cdu sau

V: dung tich nut thie i (i = 1,2 14); fi: he so lUu lUdng;

f tiit diin cda tiit lUu; P : dp sudt binh chiia khi nen;

Hinh 1 Sd do md phong hi thong ddn ddng phanh khi nen

NGHIEN CUTU - TRAO eOl

Ddi vdi h i thdng phanh khi nen cd n h i l u Tfl hinh 2, ta nhdn thdy ed ba thdng sd thdng sd lam viec, va cdc thdng s6 ldm viec chu chinh can dfldc nghien cflu va khao sat: Van gia yeu dfldc t h i h i l n t r i n hinh 2 tdc, tilt dien cac dng dan khi va tilt d i l n cdc bdu

phanh Xet d i n sfl dnh hfldng cua ba thdng sd nay tdi thdi gian c h ^ tae dyng eua he thdng va quang dfldng phanh He phfldng trinh vi phdn

md ta d i n ddng phanh dfldc md td d t r i n cd dang nhfl sau:

TrgdghipDi 1 Cblti«u 4Utlh|tt

ISnh 2 Sd do cdc thong s6 ldm viic cda hi thong

phanh khi nin

H^ phfldng trinh vi phan md ta ddn dpng phanh eau trfldc:

^ *»'(-"/},/'

fv,+Fy ^ F'

dy _F dp^

dl~ C dt

He phl^Oi^ trinh vi plian mo ta dan dpng phanh cau sau:

Pt -Pu

p- - Pll

Bp.-p,,

dy _F dpf

(1)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(10)

(11)

(12)

(13)

(14)

NGHIEN CIJlU - TRAO D O I

Quang ditdng phanh diicfc tinh theo coi^

thijCc sau:

dt' GS, J(K,P,*JG*C^^A/V'

Trong do:

A,B: Xdc dinh bdng thUc nghiem, doi vdi he

thong khi nen tren 6 to ta co: A= 0,654; B =1.13;

V*; van toe gidi han: v' = •\lkRT (~330m/s:van tdc

truyin song trong khdng khi); k =1.4; F: Dien tich

tiet dien cda piston; Y- Khodng dich chuyen cUa

piston; C: do cdng quy doi; C^: He so cdn khong

khi (0,8 -i- 0,9) vdi xe tdi; p: Mat do khong khi; v:

Vdn toe cua xe; A- Diin tich cdn chinh dien; K: He

sd phu thudc vdo cdc thong so kit cdu cda cd cdu

phanh; p: Ap sudt cdp vdo bdu phanh; G: Trong

liiOng khdng tdi cua xe; S: Qudng dUdng di dUdc

E H

cita 6 td trong khi phanh; V: Van toe chuyen ddng cua xe; S: He'so ki den dnh hiidng ciia cdc kha liidng quay khi phanh

Sfl dung edng cy Matlab-Simulink ni6 phdng dan ddng phanh eau trUdc, cau sau dflOc

md ta bdi edc he phfldng trinh d tren Sd dd khffi

md phdng dfldc trinh bay trin hinh 3 vd hinh 4

3 KET QUA M 6 P H 6 N G VA PHU'ONG AN Ll^A CHON KET c X u *

* Khao sdt sU dnh hUdng cua van gia tdc

De khao sdt vai trd efla van gia tdc troi^ ddn ddng phanh ta xet hai trfldng hdp: i), cau sau khdng ldp van gia tdc; ii) eau sau cd lap van gia tde Ket qua md phdng dUde thi hiln trin hmh 5

- < « ]

[E>-Hinh 3 Sd dd khSi md phong ddn ddng phanh edu trUdc

Hinh 4 Sd do khSi mo phong ddn ddng phanh cdu sau

NGHIEN CUfU-TRAODdi

[ 4- /^P ^ ^ c 6 vangia toe

^^^khong CO van gja toe

-a, Ap sudt d hdu phanh trUde; b, Ap sudt d bdu phanh sau;

ISnh 5 Ap sudt tqi cdc bdu phanh xet din dnh hudng van gia toe

Theo TCVN 6822 : 2001 v l thdi gian eh^m tae dyng eua he thdng phanh khi nen, tai thdi diem

t = 0,6s thi dp suat tai bau phanh P phdi dat t r i n 90% gid tri P (trin cac xe h i l n nay P^^ phd biln la 7N/m^)

Tfl hinh 5-a ta thdy dp sudt bdu phanh eau trfldc dat tilu chuan v l thdi gian cham tdc dung (tai

t = 0,6s thi P = 95,7% P^^) Hinh 5-b chp thdy dp suat bdu phanh cdu sau ed sfl khdc bilt rd ret trong hai trUdng hdp cd va khdng cd van gia tdc TrUdng hdp cd lap van gia tdc thi dp suat bau phanh cau sau tang nhanh hdn so vdi trUdng hdp khdng lap van gia tde va dat tieu chuan ve thdi gian cham tac dimg (t^i t = 0,6s thi P = 94,28%P^^) TrUdng hdp khdng lap van gia tdc thi h i thdng khdng d^it tilu chuan

ve thdi gian eh$m tdc dyng (tai t = 0,6s thi P = 81,42% P ^ )

* Khdo sdt sU dnh hiidng cua thdng so tiet diin cdc ong ddn khi nen

Bdng 1 Dudng kinh cdc doan 6ng ddn khi nen (chgn theo tiiu ehudn cda nhd sdn xudt)

Cac niit

Diidng ldnh Dl (mm)

D\ldng ldnh D2 (mm)

Dil6ng kinh D3 (mm)

2

10

12

14

3,4

6

8

10

6

10

12

14

8

10

12

14

9,12

10

12

14

10,11,13,14

6

8

10

De khao sat vai trd cua dfldng kinh dng ddn trong dan ddng phanh, ta thay ddi kich thflde dfldng dng nhfl bdng 1 Kit qud md phdng dfldc the hien t r i n hinh 6

„X10'

13

0 O i 04 0,6 08 1

Tluii]ian(si

a, Ap sudt bdu phanh trUdc;

1,4 16

'0 0.2 0 4 0 ^

D2 r •

^ ^ ^ D l

0 8 1 i : 1 4 16 Thoiqianist

6, Ap sudt bdu phanh sau;

Hinh 6 Ap sudt tqi cdc bdu phanh xit den dnh hUdng cua tiet diin 6ng

NGHIEN cflu - TRAO Ddi

Til hinh 6 va hinh 7 ta thay trong ba

trddng hop dddng kinh ong dan, tif ket qua d6

thi cho thay trddng hdp dddng kinh ong (D^) la

phu hdp vdi cac tieu chuan v^ thdi gian cham tac

dung (tai t = Q,6s thi P = 9 0 % P „ J , quang dddng

phanh (S^„ < 20m vdi van tdc v = 60km/h

-TCVN 6822:2001 v^ danh gia h i t a qua quang

dddng phanh)

phanh trong dan dpng phanh, ta thay ddi kich thddc dddng kinh bau phanh n h d bang 2 Ket qui

md phdng dddc the hien tren hinh 9

Td hinh 8 va hinh 9, trong ba trUdng h(lp thay ddi dddng kinh ban phanh cho thJy trddng; hdp dddng kinh ban phanh (D^) la phu hdp vdi

cac tilu c h u i n ve thdi gian ch^m tac di,mg vi hiSu

q u i quang dddng phanh

0 2 0 4 0,6 0.8 1 1,2 1.4 1.« Thoi 9an (s>

cl, Ap sudt bdu phanh tnidc; Hinh 7 Hi$u qud qudng dudng phanh xet den hUdng

cua tiet dien

Hinh 8 HiSu qud qudng dudng phanh xet den dnh

hudng cua tiet dien bdu phanh

* Khao sdt stf anh hiidng cua ihdng so tiet di&n

cdc hdu phanh

Bdng 2 Dudng kinh cdc bdu phanh (chon theo tiiu

chudn cua nhd sdn xudt)

b, Ap sudt bdu phanh sau; ;-Hinh 9 Ap sudt tai cdc bdu phanh xet den anh hUdng

cua tiet dien bdu phanh

V^y td ket qua nghien cdu ta rut ra cac

thdng sd k i t cau tdi du ddi vdi dan ddng phanh khi nen tren xe tai 8 tan n h d sau:

Bdng 3 Thdng sS kit cdu

Cac bSu phanh

Dddng kinh Dl (mm)

Dddng kinh D2 (mm)

Dddng kinh 03 (mm)

Trddc

120

140

160

Sau

140

160

180

Cic nut Dif ilng kinh ong

d i n khi n^n (mm)

C h i l u dai 1 (m) Cac bau phanh Diiirng kinh bau phanh (mm)

2

12

3,5 Tnfdc

140

3,4

8

1,5 Sau

160

6

12

5

8

12

1,1

9,12

12

1,5

10,11,13,14

S

1,5

i

De khao sat vai trd cua dfldng kinh bdu

NGHIEN CUTU - TRAO B6\

4 KET LUAN

Md hinh tinh toan va khao sat da nghiin cflu dfldc sfl anh hfldng cfla edc ylu td dau vao (van gia t d c tiet d i | n dng va tilt diln bau phanh) d i n thdi gian chdm tdc dung va h i l u qua qudng dudng

phanh de tfl dd dfla ra phfldng an phu hdp

Kit qua dfla ra thdng sd ky thudt cho h i thdng phanh khi nen tren xe 8 tan la phfl hdp vdi thflc t l vd ed tinh khd thi cao

Tdi flu trong qud trinh thilt k l tinh todn Vdi each tilp can nay, hodn todn cd the dp dung cho cdc loai xe tai khdc sfl dvmg phanh khi nen Tfl dd tien tdi ndi dia hda v l thilt ke, san xuat vd ldp rap

he thdng phanh ddn ddng khi nen t r i n xe tai tgi Vilt Nam •

Ngay nhdn bai: 10/6/2013

Ngay phan biln: 15/7/2013

Ngfldi phan biln: TS Nguyin Chi Tinh, Khoa Cd diln, Trfldng Dai hpe Md - Dai chat

Tai li^u tham khao:

[ 1] Nguyen HQu Can, Dfl Qu6c Thinh, Pham Minh Thai, Nguyen Van Tai, Le Thi Vang, Ly thuyit d to mdy kio,

NXB Khoa hpc Ky thuat Ha Npi, 2000

[2] Nguyen Khac Trai, CO sd thiit kid td, NXB Giao thong Van tdi Ha Ngi, 2004

[3] Nguyin Trpng Hoan,'Dgng lUc hgc cdc hi thong thuy khi tren d to, Trfldng Dai hpc Bach Khoa Ha Npi, 2007 [4] Tran Van Nghia, Tin hgc dng dung trong thUt ke Cd khi, NXB Giao due

[5] Robert Bosch Gmbh, Automotive Brake Systems, 1995

[6] www.doko.vn