GB2313228A

GB2313228A - Knee simulator for vehicle safety testing

Info

Publication number: GB2313228A
Application number: GB9610148A
Authority: GB
Inventors: Barry Simpson; Stephen James Yarrow; Martin Snook
Original assignee: MG Rover Group Ltd
Current assignee: MG Rover Group Ltd
Priority date: 1996-05-15
Filing date: 1996-05-15
Publication date: 1997-11-19
Anticipated expiration: 2016-05-15
Also published as: GB9610148D0; GB2313228B

Abstract

Apparatus for simulating an impact between the knees of a passenger of a vehicle and a part of the vehicle comprises a central support member 10, a pair of knee simulators 24, 26 mounted on the support member 10 by means of a rocker beam 50 such that they are movable in opposite directions relative to each other in the direction of travel, and a position transducer 72 for measuring movement of one of the knee simulators 24 during impact between the apparatus and an object.

Description

Vehicle Safety Testing The present invention relates to the testing of vehicles, and in particular to the testing of the effects of knee impact on the area of a vehicle to the front of a seat.

It is known to test the effect of knee impact, for example on a glove compartment in front of a front passenger seat, by placing a dummy passenger in the vehicle and crashing it under test conditions. However, crashing a vehicle is expensive, so it is desirable to simulate the knee impact using test apparatus. Various forms of test apparatus are known, but they generally do not provide very good simulation of the effects of a crash on both knees of a passenger.

The present invention provides apparatus for simulating the effect of impact between at least one knee of a passenger of a vehicle and a part of the vehicle, the apparatus comprising support means, a pair of knee simulators mounted on the support means such that they are movable relative to each other in a direction of travel, and measuring means for measuring movement of at least one of the knee simulators during impact between the apparatus and an object.

Preferably the knee simulators are constrained such that they can only move in opposite directions to each other, relative to the supporting means. This can be achieved by mounting them on a rocker beam.

The present invention further provides a method of measuring the effects of an impact between at least one of a pair of knee simulators and an object, the method comprising the steps of providing an apparatus according to the invention and an object, producing an impact between at least one of the knee simulators and the object, and measuring movement of at least one of the knee simulators during impact.

Preferred embodiments of the present invention will now be described by way of example only with reference to the accompanying drawing in which: Figure 1 is an isometric view of a test apparatus according to the invention.

Referring to Figure 1, a test apparatus according to the present invention comprises a knee simulator unit 8 comprising a central support member 10 having two upper main guide rod bearings 12, 14 and two lower main guide rod bearings 16, 18 by means of which it is slidably supported on two parallel vertical guide rods 20, 22. The unit B further comprises two knee forms 24, 26 which are mounted on the lower ends of respective vertically extending knee form guide rods 28, 30, which are slidably supported by knee form guide rod bearings 32, 34 mounted on opposite sides of the central support member 10. Each of the knee form guide rod bearings 32, 34 is supported in a housing 36 which comprises a central sleeve portion 38 with upper and lower end plates 40, 42 at its ends. The housing is attached to the central support member 10 by means of studs 44 passing through the end plates 40, 42 and through the central support member, with nuts 46 threaded on the studs to allow adjustment of the position of the knee form guide rod bearings 32, 34 relative to the central support member 10.

The central support member 10 has an aperture 48 through it, and a rocker beam 50 extends through the aperture 48, supported at its centre by a horizontal pin 52 about which it can pivot. The rocker beam 50 comprises a pair of side members 54, 56, which are spaced apart to leave a gap 58 between them, and a pair of end plates 60, 62 each attached to both of the side members. The top end 64 of each of the knee form guide rods 28, 30 extends upwards between the side members 54, 56 of the rocker beam 50, and is pivotably attached to it by means of a pin 66 which extends through the knee form guide rod 28, 30 and has its ends supported in a pair of slots 68, 70 in the side members 54, 56. This arrangement enables the knee form guide rods 28, 30 to slide vertically in their bearings but, as they are attached to the rocker beam 50 on opposite sides of the pivot pin 52, they are constrained such that they can only move simultaneously and in opposite directions relative to the central support member 10.

Holes 71 are provided through the central support member 10 and the rocker beam 50, through which dowels can be inserted to prevent movement of the knee forms 24, 26 relative to the central support member 10.

A displacement transducer 72 is provided to measure the vertical position of one of the knee form guide rods 28 relative to the central support member 10. This comprises a metal rod 74 extending vertically upwards from the lower end plate 42 of the knee form guide rod bearing housing 36, a magnetic ring 76 mounted on a bracket 78 on the rocker beam 50 such that pivoting of the rocker causes it to move along the rod 74, and a sensing device 80 for sensing the position of the magnetic ring 76 along the rod 74.

Each of the knee forms 24, 26 is attached to the lower end of its guide rod 28, 30 by means of an angle packer 82 which supports the knee form, a load cell anvil 84 which is attached to the guide rod 28, 30, and a load cell 86 between the angle packer 82 and the load cell. The load cells 86 enable the load on each of the knee forms to be monitored during testing.

The position of the knee simulator unit 8 on the guide rods 20, 22 is measured by a magneto-restrictive transducer (not shown). This, and the displacement transducer 72 and load cells 86 are all connected to a data collection unit (not shown).

In order to test the effects of impact between the knee forms 24, 26 and an object 88, the object 88 is positioned at the bottom of the guide rods 20, 22 and secured in position. The knee simulator unit 8 is lowered until the knee forms 24, 26 are both just in contact with the object 88, and at that point the measurements of the height of the knee simulator unit 8, and the position of the knee form guide rod 28 relative to the central support member 10 are set to zero. The unit 8 is then raised to a predetermined set hight on the guide rods 20, 22 and dropped onto the object.

From the magneto-restrictive transducer the data collection unit can determine when the knee simulator unit 8 has fallen to the zero position, i.e. when the knee forms 24, 26 have just come into contact with the object. It can also determine the speed of the knee simulator unit 8 on impact. From that point on the position of the knee simulator unit 8 relative to the guide rods 20, 22, the position of the knee forms 24, 26 relative to the central support member 10, and the load on each of the knee forms 24, 26 can be measured as a function of time until the knee simulator unit 8 and the knee forms 24, 26 have come to rest.

It will be appreciated that various alterations to the embodiment described above may be made. For example, either or both of the displacement transducers could be replaced by alternatives which are quicker acting or more accurate, such as laser transducers.

Claims

1. Apparatus for simulating an impact between at least one knee of a passenger of a vehicle and a part of the vehicle, the apparatus comprising a knee simulator unit including support means and a pair of knee simulators mounted on the support means such that they are movable relative to each other in a direction of travel, and measuring means for measuring movement of at least one of the knee simulators during impact between the knee simulator unit and an object.

2. Apparatus according to claim 1 wherein the knee simulators are constrained such that they can only move in opposite directions to each other, relative to the supporting means.

3. Apparatus according to claim 1 or claim 2 wherein the knee simulators are connected to each other such that the distance moved by each of them relative to the supporting means is dependent on the distance moved by the other.

4. Apparatus according to claim 3 wherein the knee simulators are connected to each other such that the distance moved by each of them relative to the supporting means is the same.

5. Apparatus according to any one of claims 2 to 4 wherein the knee simulators are connected to each other via a rocker beam.

6. Apparatus according to claim 5 wherein the rocker beam is pivotably mounted on the support means by a pivot, and the knee simulators are attached to the rocker beam on opposite sides of the pivot.

7. Apparatus according to any one of claims 1 to 6 wherein the measuring means is arranged to measure movement of one of the knee simulators relative to the support means.

8. Apparatus according to any one of claims 1 to 7 further comprising guide means for guiding the knee simulator unit towards an object.

9. Apparatus according to claim 9 wherein the guide means is arranged to guide the support means to move in a vertical direction.

10.Apparatus according to any foregoing claim further comprising measuring means for measuring the position of the knee simulator unit relative to the object.

11. Apparatus according to any foregoing claim further comprising load measuring means for measuring the load on at least one of the knee simulators.

12.A method of measuring the effects of an impact between at least one of a pair of knee simulators and an object, the method comprising the steps of providing a knee simulator unit, including support means and a pair of knee simulators mounted on the support means such that they are movable relative to each other in a direction of travel, and an object, producing an impact between the knee simulator unit and the object, and measuring movement of at least one of the knee simulators during impact.

13.A method according to claim 12 wherein the knee simulators are connected to each other such that the distance moved by each of them relative to the supporting means is dependent on the distance moved by the other, and the method includes the step of measuring movement of one of the knee simulators during impact.

l4.A method according to claim 12 or claim 13 further comprising the step of measuring the position of the knee simulator unit relative to the object.

15.A method according to any one of claims 12 to 14 further comprising the step of measuring the load on at least one of the knee simulators.

16.Apparatus substantially as hereinbefore described with reference to the accompanying drawing.

17.A method of measuring the effects of an impact between at least one of a pair of knee simulators and an object substantially as hereinbefore described with reference to the accompanying drawing.