Bosch GDX 180-LI - Инструкция по эксплуатации - Страница 17

English | 

17

Removing

Pull the locking sleeve 

(2)

 forward and remove the applica-

tion tool.

Operation

Method of Operation

The tool holder 

(1)

 (with the application tool) is driven by an

electric motor via a gear and impact mechanism.
The working procedure is divided into two phases: 

Screwing in

 and 

tightening

 (impact mechanism in action).

The impact mechanism is activated as soon as the screwed
connection runs tight and load is therefore put on the motor.
The impact mechanism then converts the power of the mo-
tor to steady rotary impacts. When loosening screws or nuts,
the process is reversed.

Starting Operation

Set the rotational direction (see figure C)

The rotational direction switch 

(5)

 is used to change the ro-

tational direction of the power tool. However, this is not pos-
sible while the on/off switch 

(6)

 is being pressed.

Right rotation:

 To drive in screws and tighten nuts, press

the rotational direction switch 

(5)

 through to the left stop.

Left Rotation:

 To loosen and unscrew screws and nuts,

press the rotational direction switch 

(5)

 through to the right

stop.

Switching on/off

To 

start

 the power tool, press and hold the on/off switch

(6)

.

The lamp 

(7)

 lights up when the on/off switch 

(6)

 is lightly or

fully pressed, meaning that the work area is illuminated in
poor lighting conditions.
To 

switch off

 the power tool, release the on/off switch 

(6)

.

Adjusting the speed

You can adjust the speed of the power tool when it is on by
pressing in the on/off switch 

(6)

 to varying extents.

A light pressure on the on/off switch 

(6)

 results in a low rota-

tional speed. Increased pressure on the switch causes an in-
crease in speed.

Practical advice

u

Only apply the power tool to the screw/nut when the
tool is switched off.

 Rotating tool inserts can slip off.

The torque depends on the impact duration. The maximum
achieved torque results from the sum of all individual
torques achieved through impact. Maximum torque is
achieved after an impact duration of 6–10 seconds. After
this duration, the tightening torque increases only minimally.
The impact duration is to be determined for each required
tightening torque. The tightening torque actually achieved
should always be checked with a torque wrench.

Screw applications with hard, spring-loaded or soft seats

When the achieved torques in an impact series are measured
during a test and transferred onto a diagram, the result is the
curve of a torque characteristic. The height of the curve cor-
responds to the maximum achievable torque, and the steep-
ness indicates the duration in which this is achieved.

A torque characteristic depends on the following factors:
– Strength properties of the screws/nuts
– Type of backing (washer, disc spring, seal)
– Strength properties of the material being screwed/bolted

together

– Lubrication conditions at the screw/bolt connection

Consequently, the following applies in each case:
– A 

hard seat

 is used for metal-to-metal screw applications

that use washers. After a relatively short impact duration,
the maximum torque is achieved (steep characteristic
curve). An unnecessarily long impact duration only
causes damage to the machine.

– A 

spring-loaded seat

 is used for metal-to-metal screw

applications that use spring washers, disc springs, studs
or screws/nuts with conical seats. It is also called a
spring-loaded seat when extensions are used.

– A 

soft seat

 is used for screw applications of e.g. metal on

wood or screw applications that use lead washers or fibre
washers as backing.

For a spring-loaded seat, as well as for a soft seat, the max-
imum tightening torque is lower than for a hard seat. A much
longer impact duration is also required.

Guide values for maximum screw tightening torques

Figures given in Nm; calculated from the tensional cross-section; utilization of the yield point: 90% (with friction coefficient
µ

total

 = 0.12). As a control measure, always check the tightening torque with a torque wrench.

Property Classes
according to
DIN 267

Standard Screws/Bolts

High-strength Bolts

3.6

4.6

5.6

4.8

6.6

5.8

6.8

6.9

8.8

10.9

12.9

M6

2.71

3.61

4.52

4.8

5.42

6.02

7.22

8.13

9.7

13.6

16.2

M8

6.57

8.7

11

11.6

13.1

14.6

17.5

19.7

23

33

39

M10

13

17.5

22

23

26

29

35

39

47

65

78

M12

22.6

30

37.6

40

45

50

60

67

80

113

135

M14

36

48

60

65

72

79

95

107

130

180

215

M16

55

73

92

98

110

122

147

165

196

275

330

Bosch Power Tools

1 609 92A 7X2 | (21.02.2023)