RU35004U1 - Measuring system - Google Patents

Description

Measuring system

The utility model relates to measuring equipment and can be used in experimental studies of forces on the rear engine support of four-wheel drive and rear-wheel drive cars.

A solution is known in which the sensor cables are connected to the connectors of the measuring system switch via a four-wire system, the deviation of the resistance of the strain gauges from the resistance value of the reference resistor of the measuring device is measured. The measured values at each stage of loading the structure determine the value of the relative deformation (prototype RF patent No. 2196296 IPC G01B7 / 16).

A disadvantage of the known solution is the impossibility of its application for measuring forces on the rear engine mount.

The task is to measure the forces on the engine rear axle support along three mutually perpendicular axes of the Cartesian coordinate system, i.e. along the longitudinal, transverse and vertical axes of the car, as well as measuring the forces on the cross member of the rear engine mount in the vertical direction, arising from the weight of the engine in stationary and transient modes when the car is moving.

This object is achieved by the fact that in the known solution of the measuring system for determining the forces on the structural member, for example, the rear engine mount of four-wheel drive and rear-wheel drive vehicles mounted on a cross-section, containing two-axis force sensors with cables for connecting wires, a longitudinal force sensor, a vertical force sensor, a strain gauge and the recording device, according to the proposed solution, biaxial force sensors are made in the form of bolts and contain two pairs of planar mutually perpendicular x surfaces with strain gauges arranged thereon connected to one of two sensors in a bridge measuring circuit determining the vertical loads and the other bridge measuring circuit determining the shear loads, axial and angular holes.

MPKS01V7 / 16

cylindrical surfaces with diameters greater than or equal to the threaded surface, arc grooves, fixing screws, bushings aligned along the axes with threaded holes of the gearbox cover and rigidly fixed to the plate of the rear support, on which a hole is made for a sleeve having an outer diameter smaller than the diameter of the hole so that the gap between the surfaces of the sleeve and the hole is greater than the bending strain of the elastic elements of the sensors, and the length of the sleeve is greater than the thickness of the support plate to ensure how much between the surfaces of the restriction plate and the surface of the retainer. Moreover, the vertical force sensor having a U-shaped is rigidly fixed in the section of the side walls of the cross member.

Figure 1 - General view of the installation of the measuring system;

Figure 2 - section. AA figure 1;

Fig.Z - retainer restrictive plate Assembly;

Figure 4 is an elastic element of a biaxial force sensor with strain gauges;

5 is a section bB;

6 is a biaxial force sensor assembly with a support for the rear engine mount and with a rear gearbox cover;

7 is a bridge measuring circuit of the strain gauges of the biaxial force sensors;

Fig.Z is a half-bridge measuring diagram of the connections of strain gauges located on the rear suspension support and on the cross member of the rear engine suspension;

Fig.9 is a block diagram of a measuring system.

The measuring system contains two biaxial force sensors 1,2 with cables of connecting wires 3,4, fixing screws 5,6, restrictive plate 7, coupling clamp 8 mounted on the gearbox cover 9, a longitudinal force sensor consisting of a support plate 10 of the rear suspension and strain gauges 11 located on two sides of the support plate below the restrictive plate 7, the sensor of vertical forces 12 U-shaped with

strain gauges 13, rigidly fixed, for example, by welding, to the cross member 14 of the rear support.

The elastic elements of the biaxial force sensors (Fig. 4) are made in the form of bolts with mutually removed perpendicular flats under the strain gages (Fig. 5) T1, T2, TK and T4 located on the sensor 1 and the resistance sensors T5, T6, T7 and T8 on the sensor 2. Near the bolt head, cylindrical surfaces 15 are aligned with the threaded portion 16. The diameters of these cylindrical surfaces are greater than or equal to the outer diameter of the threaded portion of the bolts.

To output the connecting wires through the head of the bolt, the elastic element has a hole 17 in the direction of the longitudinal axis and hole 18 at an angle to this axis. On the heads of the bolts made arc grooves 19 (figure 5) for fixing the sensors in a certain position using screws 5.6. Two-axis sensors 1,2 are included in the guide bushings 20,21, centered on the threaded holes of the gearbox cover 9 and rigidly connected, for example, by welding, to the back support plate 10 (Fig. 6), mounted on the gearbox cover with sensors 1,2.

Strain gages T1, TZ, T5, T7 from two axial sensors 1,2 located on the planes of elastic elements installed horizontally are connected to one bridge measuring circuit, i.e. in one measuring channel, for measuring vertical loads, and strain gauges T2, T4, T6, TV, located on the vertical planes of the elastic elements, are connected to another bridge measuring circuit to measure horizontal loads acting in the direction of the transverse axis of the car.

On the plate 10, a hole is made for the sleeve 22 (Fig. 2). This sleeve has an outer diameter smaller than the diameter of the hole so that the gap between the sleeve and the plate 10 along the cylindrical surface of the hole is greater than the elastic bending strain of the sensors 1,2. Between the parallel planes 23.24 of the retainer 8 (FIG. 3), the level difference is made in the form of a step 25 (FIG. 2). The height of the sleeve 22 and the height of the ledge 25 is greater than the thickness of the plate 10 by an amount that provides free sliding of the plate 10

between the surface of the restrictive platinum 7 and the surface 23 of the retainer 8 with three bolts 26 tightened that secure the restrictive plate. An arc coupler 27 is attached to the base of the latch 8 with two bolts 28 and nuts 29.

To exclude frictional forces between the surfaces of the gearbox cover 9 (Fig. 6) and the support plate 10, a gap is established between the bolt head and the flat surface of the sleeve 20, no larger than the pitch of the threaded part of the biaxial sensor.

In order to exclude the influence of transverse forces on the deformation of the elastic element of the sensor 12, the fastening of the cross member 14 to the body 30, carried out with the help of bolts 31.32 and nuts 33.34, is weakened by the nut 33, so that the cross member can move along the gap between the edges of its hole and the cylindrical surface of the bolt 31.

The strain gauges 11 located on the plate 10 of the back support, as well as the strain gauges 13 located on the elastic element of the vertical force sensor 12, are connected in half-bridge circuit (Fig. 8) for measuring bending deformations.

Before installing the force sensors on the vehicle, they are calibrated along the X, y, Z axes. After determining the calibration coefficients, the force sensors and the restriction plate 7 (Fig. 1), fixed with the latch 8 (Fig. 3), are installed on the gearbox cover of the test vehicle for measuring static and dynamic loads acting on the rear engine support 10 in the direction of the axes X, Y, 7, and loads acting on the cross member of the rear support 14 in the vertical direction.

When vertical or lateral loads are transmitted from the engine to the rear support via sensors 1,2, bending deformation occurs along the Z or Y axes in the elastic elements of these sensors. Bending deformation of the elastic elements of these sensors from longitudinal forces (along the X axis) when the support plate 10 is deformed, the restriction plate 7 located above the strain gages 11, which perceives and

transforming into an electrical signal the deformation of the support plate under longitudinal loads.

When measuring on a car, a strain gauge 35 connected to force sensors and a recording device 36, for example, a computer, are used.

The tests carried out confirmed the high reliability and performance of the measuring system.

Claims (2)

1. A measuring system for determining the forces on the rear engine support of four-wheel drive and rear-wheel drive vehicles mounted on a cross-section, comprising two-axis force sensors with cables for connecting wires, a longitudinal force sensor, a vertical force sensor, a strain gauge and a recording device, characterized in that the two-axis force sensors are made in the form of bolts and contain two pairs of flat mutually perpendicular surfaces with strain gauges located on them, connected from two sensors to one bridge measuring scheme for determining vertical loads and in another bridge measuring scheme for determining lateral loads, axial and angular holes, cylindrical surfaces with diameters greater than or equal to the threaded surface, arc grooves, fixing screws, bushings, aligned axially with threaded holes of the gearbox cover and rigidly mounted on the plate of the rear support, on which a hole is made for a sleeve having an outer diameter less than the diameter of the specified hole so that the gap between the surface styami bushings and the holes was greater than the bending deformation of the elastic elements of the sensors, and the sleeve length is greater than the thickness of the support plate. 2. The measuring system according to claim 1, characterized in that the vertical force sensor having a U-shape is rigidly fixed in the section of the side walls of the cross member.