RU2483287C2 - Bench to test elements of front suspension of passenger cars - Google Patents

Abstract

FIELD: test equipment.

SUBSTANCE: bench for testing of elements of front suspension in passenger cars comprises a stand, an electric motor, a control unit, a rotary cam, a cross lever, a spring, a hydraulic drive with a horizontal hydraulic cylinder, a guide element with the possibility to rotate the cylinder relative to the stem, a flow control valve and a vertical hydraulic cylinder.

EFFECT: simplified design, reduced time of testing and dimensions, maximum approximation of tests to actual conditions of operation.

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Description

The invention relates to testing equipment and can be used for accelerated testing of ball joints of the front suspension of cars, as well as other elements of the front suspension (silent blocks, bushings and stabilizer struts) with minor upgrades, for durability with simulated operational loads and movements.

In the automotive industry, various kinds of stands are widely used for testing suspension elements (shock absorbers, springs, bushings, ball joints, brake systems, elastic couplings, etc.) or for testing the suspension as a whole.

From US patent No. 3580059, IPC G01M 13/04, publ. 05/25/71, a device for testing ball joints is known, which creates a rotational-vibrational motion of the inner ring of the ball bearing relative to its outer ring.

The disadvantage of this device for testing ball bearings is the limited ability to simulate operational loads.

The next one is a test bench for steering link joints, containing a bed, a gear motor with two output shafts, connecting levers, a loading mechanism for the tested joints (see USSR AS No. 1182315 A, G01M 17/06, publ. 1985) .

The disadvantage is that this stand does not allow to expand the range of dynamic loads and simulate loads characteristic of the actual operating conditions of the ball joint of the front suspension of the car.

There is a well-known accelerated test bench for running gears of wheeled vehicles, coatings (see RF patent No.20180806 IPC G01M 17/00, publ. 1994). The disadvantage is that on this stand for the transmission of dynamic loads eccentrics are used, which imitate the unevenness of the soil to a greater extent than the actual loads caused by the unevenness of the road.

A known bench for testing ball joints (see RF patent No. 2263889, IPC G01M 13/00, publ. 2005). The disadvantage of this stand is that it requires the presence of a pneumatic line with a pressure of 5-8 atm, as well as the complexity of the design.

The closest in technical essence and the achieved technical result is a test bench for ball joints, containing a bed, an electric motor mounted on it, an automatic control unit, upper and lower wishbones, a mechanism for loading the ball joints. The loading mechanism is made in the form of series-connected gearboxes, a bridge, a crank mechanism, which is connected to the ball joints through the steering knuckles, upper and lower wishbones and hydraulic systems (see RF patent No. 2308011, IPC G01M 7/06, G01M 17 / 04; F16C 11/06, published in 2007).

The disadvantages of this stand are the complexity of its design, bulkiness, high cost.

The technical problem to which the invention is directed is to simplify and reduce the cost of design, maximize the approximation of tests to actual operating conditions and reduce test time, reduce the size of the stand and expand its technical capabilities.

This is achieved by the fact that the test bench for the elements of the front suspension, comprising a bed, an electric motor, a control unit, a knuckle, a wishbone, a spring, a hydraulic actuator with a horizontal hydraulic cylinder, according to the invention contains a guide element with the ability to rotate the cylinder relative to the rod, a flow control valve and vertical hydraulic cylinder.

The invention is illustrated by drawings, where figure 1 shows the mechanical part of the stand for testing elements of the front suspension of cars, side view, figure 2 is a top view, figure 3 is the hydraulic part of the stand.

The stand contains a vertical hydraulic cylinder 1, a spherical bearing 2, a horizontal hydraulic cylinder 3, a knuckle 4, a lower spring support 5, a spring 6, an upper spring support 7, a base 8, an upper frame 9, a nut for the upper fastening of the guide element 10, a thrust washer 11, an upper the support of the guide element 12, the side frame 13, the nut of the rod of the guide element 14, the thrust bearing 15, the protective cover 16, the rod 17, the cylinder 18, the lever 19, the mounting of the lever 20, the cross member 21. The hydraulic part of the stand (figure 2) contains a pump 23 , clutch 24, electric motor 25, pressure gauge 26, The valve flow controller 27, controller 28, hydraulic line 29, switch 30, power supply 31 and hydraulic valves 32, 33, safety valve 34, a filter 35, working fluid 36, hydraulic reservoir 37 and a frame 38.

The stand works as follows.

Oil from the hydraulic tank is sucked in by a pump, which is driven by an electric motor through an elastic coupling. Further, from the pump, oil under pressure is supplied to the flow regulator, which divides the oil flow into two flows of different flow rates.

One stream with a large oil flow rate is supplied to the hydraulic distributor 33, which acts on the vertical hydraulic cylinder, providing upward movement of the lever, ball bearing, steering knuckle and guide element, the downward movement is provided by the spring. The guide element moves relative to the fixed rod. The operation of the vertical hydraulic cylinder simulates the loads that occur in the front suspension of the car when overcoming road bumps, acceleration, braking, turning. The second stream with a lower oil flow rate is supplied to the distributor 32, which controls the horizontal double-acting hydraulic cylinder acting on the knuckle, which rotates together with the cylinder relative to the fixed rod and relative to the lever in the ball joint. The spring rotates with the cylinder in the pillow block bearing. The operation of the horizontal hydraulic cylinder simulates the loads that occur in the front suspension of the car during a turn, as well as the turn itself. The cylinder is filled with grease to facilitate the movement of the stem. A protective cover is used to seal the lubricant. Different oil consumption for hydraulic cylinders ensures their operation with different frequencies. The system also includes a manometer to control the oil pressure in the hydraulic system, a safety valve to relieve pressure at a critical increase, and a filter to separate contaminants, water, and other generated by the drain line from the oil into the hydraulic tank during stand operation. The guide element is attached to the upper frame through the support 12 and the support bearing 15, which provides rotation of the rack and ball joint. The guide element provides vertical movement S of the rack with a lever and is a rod 17 that moves in the cylinder 18. Two hydraulic cylinders are used as a source of movement. The main hydraulic cylinder 1 acts on the lower lever 19 and provides movement in a vertical plane, the additional hydraulic cylinder 3 acts on the knuckle 4 and allows you to simulate the lateral load on the suspension and rotation of the wheel V.

The hydraulic part of the stand provides:

- cyclic loading of the ball joint in a vertical plane in the range of 3000-5000 N (compression stroke), with a frequency of 2 Hz, while the ball joint is under a constant vertical load of 400 kg The stroke of the suspension arm 19 is 30-40 mm, the angle α is 15-20 degrees;

- cyclic loading of the ball joint in the horizontal plane (lateral loading) with a force sufficient to rotate the fist 4 by an angle of 40-50 degrees with a frequency of up to 30 cycles per min. The stroke of the hydraulic cylinder is 150-200 mm;

- the test of one ball joint occurs at 1 million test cycles.

The cycle is the movement of the lever from the bottom point (rebound) to the top point (compression) and return to the bottom point, i.e. angle 2α.

Start and stop of the stand are carried out manually.

Tests include monitoring the number of cycles.

EFFECT: due to the exclusion of part of the working elements, it was possible to increase the vibration frequency of the suspension and, accordingly, accelerate testing, while simplifying the design. Simulation of real conditions is achieved through the use of a modernized front suspension of a car as the basis. The loads acting on the ball joint and its kinematics of movement are as close as possible to the actual operating conditions.

Thus, the stand provides an imitation of the wear of the ball joint of the front suspension of a passenger car in accelerated mode. This is achieved by maintaining the kinematics of the suspension on the stand during its operation corresponding to the kinematics of the suspension on a car with a full mass moving along the cobblestone surface at a speed of 30-40 km / h.

Claims (1)

A test bench for elements of the front suspension of passenger cars, comprising a bed, an electric motor, a control unit, a knuckle, a wishbone, a spring, a hydraulic actuator with a horizontal hydraulic cylinder, characterized in that it contains a guiding element with the ability to rotate the cylinder relative to the rod, a flow control valve and vertical hydraulic cylinder.

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