Automotive Technology

To guarantee the highest quality, WPM Leipzig offers you as manufacturer of cars or supplier specifically adapted testing technology.

Measuring and Testing Technology for Suspension Joints

For joint mobility testing – that means for determining the determination of the breakaway movement and moments of resistance and the force-displacement curve in axial or radial direction - WPM offers different measurement equipment. Based on requirements of German automobile manufacturer and in connection with factory requirements of customers, WPM Leipzig has developed and successfully brought to market a range of testing and measuring machines for suspension joints.

 

 

Leak Testing Machine

Application

The leak testing machines fulfils the function of carrying out environmental simulations on suspension joints.

Types

  • Leak testing machine DPM4: to adapt four suspension joints at the same time
  • Leak testing machine DPM6: to adapt six suspension joints at the same time

Features

  • Fully assembled joints are exposed to the influence of different fluids (plain water, salt water, drain water or others) and climates, while tilt and rotation movements are applied with the respective test
  • spray nozzle can be moved in relation to the joint

 

Sealing Bellow Function Test/Leak Test of Housing Cover

Another form of leak testing can be performed with the testing machine for underwater testing SPM.

  • Performing leak tests suspension control arms and joints in liquid medium at temperatures down to -20 °C
  • oscillating rotary motion in two axes for two test specimens
  • pressure test of housing covers for suspension joints with a force loading device

Elasticity Measuring Machine

Application

The elasticity measuring machines EMM are used to measure the elasticity and the spring travel of suspension joints in two loading directions.

Features

  • Movement of the joint pin against the joint housing, first in axial and then in radial direction by means of force-controlled load generators
  • Measuring the relative moment between joint ball and joint housing by means of a sensor, located outside the load chain
  • Specifically designed adaptions for play-free mounting of the suspension joints in the elasticity measuring machine

Options

Device for differential measurements

To increase the measuring accuracy of the measurement of elasticity in axial and radial direction, the installation of a differential measuring device is possible. With this device and the help of displacement sensors attached in axial and radial direction, the relative movement of the suspension housing is determined during the elasticity measurement. This can be removed from the measurement result by the software of the EMM, or it may be used to evaluate the safety (slippage of the joint in the housing).

Free clamping with span/clamping table and second force measuring chain

Optionally, a second force measuring chain can be mounted on the crosshead of the EMM. In conjunction with a special span table, which is mounted within the peg mounting, universal test setups can be realized. This optional load chain is used, for example, for special bodies and/or rare joints for which no adaptations are available, such as rocker lever and bending tests as well as for joint manufacturer typical test setups.

With the second force measuring chain, tensile and compression forces up to 10 kN are possible.

Documentation
Friction Moment Measuring Machine

Friction Moment Measuring Machine

Elasticity and Friction Moment Measuring Machine

Elasticity and Friction Moment Measuring Machine

Friction Moment Measuring Machine

Application

The Friction Moment Measuring Machines of WPM are used to determine the friction torque, occurring when the suspension joint, mounted in a bearing shell, is moved.

Features

  • Depending on the version of the suspension joint, either the friction-induced torque of rotation or the friction-induced torque of turning can be measured
  • For the play-free assemble of the joints into the friction moment measuring machine, special designed adaptations are used.

Options

Electronic Determination of the Stick-Slip-Behavior

For electronic determination of the breakaway torque, the sticking friction and the sliding friction torque of the rotary drive the starting torque of the rotating drive are increased in defined way until the joint breaks loose in the direction of rotation. The rotational speed is regulated to a constant value. The control of the drive reduces the driving torque in defined way until the joint stops by the friction again. The process is repeated.

This method allows determining both, the breakaway torque and the sticking friction torque and its development and the sliding friction moment with its development.

Mechanical Determination of the Stick-Slip-Behavior

With this option, the installation space of the testing machine is expanded to make a stick-slip-measuring on the base of the mechanical determination of stick and sliding friction torques with torsionally soft spring elements possible (additional axis).

Combined Elasticity and Friction Moment Measuring Machine

In addition to the separate measuring machines EMM and RMM as described, the combined Elasticity and Friction Measuring Machine ERMM is also available. Within this measuring machine, all parameters of the single machines RMM and EMM are determined in one clamping and in one automated measuring sequence.

Friction tilt moment test device

Application

The tilt moment test device RPV is designed for manual tests of suspension joints. The load is applied on the test piece by hand. Both friction tilt moments and torque moments from 0 to 50 Nm can be measured.

Features

  • Table device with small required space
  • Maximum clamping diameter 60 mm with a largest free clamping length of 80 mm
    Other diameters can be fixed with exchangeable clamping jaws in the jaw chuck.
  • Operating panel to adjust all settings necessary for the test and to read all test parameters
  • Graphic display of measured values as bar graph display

Joint Wear Testing Rig

Application

The joint wear test rig GVP is designed to carry out wear tests on ball joints and ball arms in the temperature range from -40° C to +100° C. The joint wear test rig has been designed for stress tests on suspension joints with radial and/or axial load.

Features

The following kinds of loads can be realized:

  • Series of service loads: With horizontal force of up to ± 40 kN and with vertical force in the range of -40 kN to 4 kN (40 kN pressure load on the ball)
  • Block programm: With a rotary angle of up to ± 30° (up to 3 Hz) and with a tilt angle of up to ± 17° (up to 10 Hz). Additionally, the customization of the designed position of the suspension to ± 9° is possible.

To control the test rig, the in-house developed devices dynaSax-D2 are applied.  They can control, regulate and supervise the three servo-hydraulic testing cylinders and the servo-pneumatic testing cylinder as well as the temperature chamber.

Slide Bearing Testing Rig

Application

The Slide Bearing Testing Machine GPS 100 is used to examine bearing shells with dynamically highly loaded force impact in combustion engines.

Features

  • Slide bearings loaded with three servo-hydraulic testing cylinders, located in an angular distance of 120°
  • Nominal force of the cylinders: 125 kN with static operation and 100 kN with dynamic loading
  • Controlled by 3-ary high-response servo-valves
  • Stroke of 20 mm at maximum
  • Measuring the force applied to the load ring using transducers mounted at the piston rod