background image

             

(

)

(

)

2

2

2

2

2

1

2

1

.

191

4

32

6

.

35

4

cm

D

D

A

=

×

=

=

π

π

             

 

细长比

4

.

91

3

.

21

25

4

1

5

.

750

4

1

2

2

2

1

2

=

+

=

+

=

d

d

l

k

l

                        

m n

=

=

85 1 85

    根据欧拉公式,液压缸的稳定临界力 P

K

                P

n EJ

l

K

=

π

2

2

     式中符号意义同前,n——末端条件系数; n

=

1

     

工况(I):油缸全伸,P=160000kg 时

                      

P

n EJ

l

K

=

π

2

2

                      

(

)

2

4

4

6

5

.

750

3

.

21

25

64

10

1

.

2

1

×

×

×

×

×

=

π

π

π

                              

kg

2

.

333785

=

                     

  

安全系数

1

.

2

160000

2

.

333785

max

=

=

=

P

P

n

K

K

                 油缸满足压杆稳定性要求。

    工况(II):油缸不全伸(L=700.5cm), P

max

=245000kg 时

                      

P

n EJ

l

K

=

π

2

2

                      

(

)

2

4

4

6

5

.

700

3

.

21

25

64

10

1

.

2

1

×

×

×

×

×

=

π

π

π

                              

kg

2

.

383135

=

                     

  

安全系数

56

.

1

245000

2

.

383135

max

=

=

=

P

P

n

K

K

                 油缸满足压杆稳定性要求。

3、活塞杆强度验算