GB2561247A

GB2561247A - Vehicle weighing apparatus

Info

Publication number: GB2561247A
Application number: GB1705688.8A
Authority: GB
Inventors: Lister Martin; Glasspole Julian
Original assignee: Vehicle Weighing Solutions Ltd
Current assignee: Vehicle Weighing Solutions Ltd
Priority date: 2017-04-07
Filing date: 2017-04-07
Publication date: 2018-10-10
Anticipated expiration: 2037-04-07
Also published as: GB2561247B; GB201705688D0

Abstract

A vehicle weighing apparatus comprises an arm having a tube 1 and a plunger, which moves longitudinally within the tube. An inductive proximity sensor 3 is located on the arm via a mounting bracket 7. The plunger includes an indicator arranged to pass across the sensor 3 as the plunger is moved within the tube 4. The plunger may also be tubular and comprise an aperture, the indicator formed from part of the plunger at the tip adjacent to the aperture. The plunger may be mounted in the tube such that the aperture faces the sensor, and may be square or circular in cross section. A further aspect of the disclosure is for a method of weighing the loading of a vehicle, comprising moving a plunger longitudinally within a tube, wherein an indicator of the plunger passes a sensor, and generating and displaying an output indicative of the weight of the load. The apparatus may be mounted between the vehicle chassis and an axle, where the load applied causes compression of the vehicle suspension, and the apparatus can be used to infer the applied load by measuring the amount of compression.

Description

(71) Applicant(s):

Vehicle Weighing Solutions Limited

Unit 5, Southview Park, Marsack Street, Caversham,

Reading, Berkshire, RG4 5AF, United Kingdom (72) Inventor(s):

Martin Lister Julian Glasspole

(51) INT CL:
G01G 19/12 (2006.01)	G01G 19/02 (2006.01)
(56) Documents Cited: GB 1272762 A WO 1986/001888 A1 CN 104006871 A RU 000095607 U1 US 4728922 A	GB 0924276 A CN 203744913 U FR 002598219A1 US 5864295 A US 2792209 A
(58) Field of Search: INT CL B60G, G01G Other: WPI, EPODOC

(74) Agent and/or Address for Service:

Withers & Rogers LLP

More London Riverside, LONDON, SE1 2AU, United Kingdom (54) Title of the Invention: Vehicle weighing apparatus

Abstract Title: Vehicle weighing apparatus and method (57) A vehicle weighing apparatus comprises an arm having a tube 1 and a plunger, which moves longitudinally within the tube. An inductive proximity sensor 3 is located on the arm via a mounting bracket 7. The plunger includes an indicator arranged to pass across the sensor 3 as the plunger is moved within the tube 4. The plunger may also be tubular and comprise an aperture, the indicator formed from part of the plunger at the tip adjacent to the aperture. The plunger may be mounted in the tube such that the aperture faces the sensor, and may be square or circular in cross section. A further aspect of the disclosure is for a method of weighing the loading of a vehicle, comprising moving a plunger longitudinally within a tube, wherein an indicator of the plunger passes a sensor, and generating and displaying an output indicative of the weight of the load. The apparatus may be mounted between the vehicle chassis and an axle, where the load applied causes compression of the vehicle suspension, and the apparatus can be used to infer the applied load by measuring the amount of compression.

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Vehicle Weighing Apparatus

The present application relates to vehicle weighing apparatus.

It is important to ensure that, when loading a vehicle, the weight of the load does not exceed the safe load capacity of that vehicle, and that the load is not distributed in such a way that the vehicle is destabilised. Legislation is in place which makes it an offence to use a vehicle which is overloaded on the roads.

The best way to weigh a vehicle is by use of a weighbridge in which the vehicle is driven over it such that the weight of each axle or each wheel is measured. The measured weights can then be compared with the maximum weight set down in legislation, or set down by the manufacturer of the vehicle, and if the vehicle is overweight, some of the load can be removed. However, a weighbridge is not available every time that a vehicle is loaded, and so there is a danger of a vehicle being overloaded without the vehicle's operator realising it.

In US 2007/029506581, a system is described in which the springs of the vehicle are used to measure the weight of a load. As the weight of the load increases, the springs are deflected, and a distance sensor determines the deflection of the spring. The spring has a known spring rate, and so the weight can be determined by the deflection of the spring. As the weight of the vehicle increases, as determined by the deflection of the spring, air is added to the tyres in order to account for the extra weight. However, little is said about the distance sensor. However, the displacement of a vehicle suspension is typically measured based on the angle of a suspension component relative to the chassis.

The present invention seeks to simplify the measurement of the movement of the suspension, and to produce a much more durable and reliable measurement, thereby permitting the operator of the vehicle to safely load the vehicle.

According to a the present invention, a vehicle weighing apparatus comprises: an arm having a tube and a plunger longitudinally moveable within the tube; and an inductive proximity sensor located on the arm; wherein the tube includes an open end from which the plunger extends, and a sensor mounting bracket; wherein the plunger includes an indicator arranged to pass across the sensor as the plunger is moved within the tube such that its longitudinal position is sensed.

Preferably, the plunger is tubular, and includes an aperture in its surface, a part of the tube longitudinally adjacent to the aperture forming the indicator. This arrangement has the benefits of being structurally simple, inexpensive to manufacture and mechanically robust. In the embodiment, the plunger includes a tip, and the indicator is located at the tip. In the preferred embodiment, the sensor has a sensor detection length over which the position of the indicator can be detected, and the aperture has a longitudinal length which is greater or equal in length to the sensor detection length, thereby ensuring that the sensor is able to detect the indicator over the full sensor detection length.

In the embodiment, the plunger is mounted within the tube with the aperture facing the sensor. It is preferred that the tube and the plunger each have a square cross sectional shape which ensures that the plunger can't rotate relative to the tube, which is important to ensure that the indicator faces the sensor. The square shape also provides strength and resistance to bending, although other cross-sectional shapes are possible.

Advantageously, the tube includes a sensor opening in which the sensor mounting bracket supports the sensor.

In the preferred embodiment, the tube includes a tube connector end, and the plunger includes a plunger connector end, the arm being connectable between the sprung body of the vehicle, and the unsprung part of the vehicle.

An embodiment of the present invention will now be described by way of example only with reference to the drawings in which:

Figure 1 is a side view of a tube;

Figure 2 is an end view of the tube of Figure 1;

Figure 3 is a top plan view of a plunger;

Figure 4 is a schematic view of the weighing apparatus of the present invention installed;

Figure 5 is a schematic view of the electrical connections between parts of the apparatus;

Figure 6 is a front view of a display unit; and

Figure 7 is a rear view of the display unit of Figure 6.

The vehicle weighing apparatus is made up of an arm and a sensor which generates a sensor output signal. An interface and display unit convert the sensor output signal so that the weight of the vehicle's load is displayed.

The arm has a tube 1 shown in Figures 1 and 2 and a plunger 2 shown in Figure

3. The sensor 3 is shown in Figures 1 and 2 mounted to the tube 1.

The tube 1 is formed of a tubular body 4 which is a square cross-section tube having outside dimensions 25 mm x 25 mm, and a metal thickness of 2 mm. In this embodiment, the tube is of mild steel. At one end of the tubular body 4 is an open end 11 which is visible in Figure 2. At the opposite end of the tubular body 4 is a tube connector end 5. The tube connector end 5 provides a way of connecting that end of the tubular body 4 to a vehicle.

A length of the top face of the tubular body 4 is removed to form a sensor opening 6. Adjacent to the sensor opening 6 are sensor mounting brackets 7 arranged to contain and support the sensor 3. The sensor mounting brackets 7 include fasteners 9 for securing the sensor 3 to the sensor mounting brackets 7 in such a way that the sensor 3 is supported across the sensor opening 6 but without projecting inside the tubular body 4.

The tubular body 4 also carries a bracket 8 by which the tube 1 may be secured to the chassis of a vehicle. The bracket 8 takes the form of an L-shape in this embodiment, but for other vehicles, will be shaped entirely differently.

The sensor 3 is an inductive proximity sensor which operates as a linear measurement transducer. In this embodiment it is a PepperL and Fuchs sensor PMI80-F90-IU-V1 with a length of 102 mm and a depth of 22 mm. It includes a sensing face 13 having a sensor detection length 12 within the overall length of the sensor of 80 mm. Therefore, it will be understood that the sensor detection length 12 is a little less than the length of the sensor 3 itself. The sensor 3 is able to detect the passage of a metal object across its sensing face 13, and provide a sensor output signal indicative of the position of the metal object from a sensor output port 10. The sensor output signal is a DC signal with a range of 0 to 8V, depending on the position of the metal object. Of course, this specific sensor is one of a number of linear measurement transducers that could be used.

The plunger 2 is formed of a plunger body 21 which is a square cross-section tube having outside dimensions 20 mm x 20 mm, and a metal thickness of 2 mm. In this embodiment, the tube is of mild steel. Figure 3 is a top plan view, so the top face of the plunger body is visible. At one end of the plunger body 21 is a plunger connector end 25 in the form of a captive nut providing a threaded means by which the plunger connector end 25 of the plunger body 21 can be connected to a vehicle. At the opposite end of the plunger body 21 is a tip 26. Towards the tip 26, the top face of the plunger body 21 is removed to leave an aperture 22 defined by an edge 23. A short length of the top face remains between the aperture 22 and the tip 26, which forms an indicator 24, operation of which will become clearer below.

Installation of the apparatus begins with the insertion of the tip 26 of the plunger 2 into the open end 11 of the tube 1 where the plunger 2 is orientated so that the indicator 24 of the plunger 2 faces the sensor opening 6 as it passes through the tubular body 4. This orientation is important, since the indicator 24 is the metal object which will be detected by the sensor 3 as it passes through the sensor detection length 12. If the plunger 2 is inserted into the tube 1 in the wrong orientation, the indicator 24 will not face the sensor opening 6, and the position of the indicator will not be detected by the sensor 3. It should be noted that the use of square cross-section tubing for the tube 1 and the plunger 2 are particularly advantageous in ensuring that, once installed, the plunger 2 cannot rotate with respect to the tube 1. Rotation would cause the indicator 24 to be obscured from the sensor 3.

Installation of the apparatus would further include the attachment of suitable connectors to the plunger connector end 25 and the tube connector end 5. Those connectors can then be attached to the vehicle, one to the sprung part of the vehicle, and the other to the unsprung part of the vehicle. Then the sensor output port can be connected to data cabling in order to feed the sensor output signal of the sensor to suitable processing apparatus which is described below.

Figure 4 shows the apparatus installed on a vehicle using suitable connectors.

Figure 5 shows the way in which the sensor 3 is connected to other components within the vehicle weighing apparatus. In this embodiment, the apparatus includes one sensor at the front of the vehicle, and another at the rear. The front sensor 51 and the rear sensor 52 are connected via cabling to an interface 53. The interface 53 supplies power to the front and rear sensors 51, 52, and receives the sensor output signals, which are analogue signals, from each of those sensors.

The interface 53 has a power supply input 54 and 2 channel connections via cabling to a display unit 55.

The interface 53 includes an interface board with an analogue-to-digital converter which converts the analogue sensor output signals which are in the range 0 to 10 V to a digital signal which is conveyed to the display unit 55.

The display unit is shown in figures 6 and 7. Figure 6 shows the front of the display unit 55 and figure 7 shows the rear. From figure 7, the 2 data signal inputs 56 are shown which receive the millivolts signals from the interface 53. It also includes a power input 57, and in this case a power output port 58 for supplying power to the interface 53. A printer port 59 is also included.

The front view of the display unit 55 includes a display 60 and keyboard 61 for controlling the display. The display unit 55 also includes an amplifier which converts the input signal to a voltage level which can be displayed on the display 60. The keyboard 61 permits data entry. In this embodiment, the system has been calibrated to display the load from two separate sensors corresponding to the front of the vehicle and the rear of the vehicle, with a total gross vehicle weight indication as a percentage of the maximum permitted gross weight.

Once the apparatus is installed, calibration is required. With the vehicle empty, the indicator 24 of the plunger 2 will be positioned at a certain point along the sensor detection length 12 of the tube 1. Using the keyboard 61, the system can be zeroed. Then a load of a known weight can be placed in the vehicle. This will cause the springs of the vehicle to be compressed, and the plunger 2 will move within the tube 1. This will cause the indicator 24 to move within the sensor deflection length 12 so as to change the output signal from the sensor output port

10. The keyboard 61 can again be used to notify the display unit 55 of the addition of the known load so that it is able to create a calibration profile for the vehicle. For example, if the maximum load for a vehicle is 1000 kg, and the known load is 500 kg, the calibration profile will present the known weight as 50% of the total gross vehicle weight.

After calibration, heavier weights will be indicated with a higher percentage of the maximum gross weight, and lighter weights will be indicated with a lower percentage of the maximum gross weight.

Various modifications could be made to this embodiment while still falling within the scope of the claims of this application. In this embodiment, there is a front and a rear sensor. This could be modified to include a single sensor. Alternatively, a sensor could be installed for each of the four wheels of the vehicle.

Claims

1. Vehicle weighing apparatus comprising:

an arm having a tube and a plunger longitudinally moveable within the tube; and an inductive proximity sensor located on the arm;

wherein the tube includes an open end from which the plunger extends, and a sensor mounting bracket;

wherein the plunger includes an indicator arranged to pass across the sensor as the plunger is moved within the tube such that its longitudinal position is sensed.

2. The vehicle weighing apparatus of claim 1, wherein the plunger is tubular, and includes an aperture in its surface, a part of the tube longitudinally adjacent to the aperture forming the indicator.

3. The vehicle weighing apparatus of claim 2, wherein the plunger includes a tip, and the indicator is located at the tip.

4. The vehicle weighing apparatus of claim 2 or 3, wherein the sensor has a sensor detection length over which the position of the indicator can be detected, and the aperture has a longitudinal length which is greater or equal in length to the sensor detection length.

5. The vehicle weighing apparatus according to any one of claims 2 to 4, wherein the plunger is mounted within the tube with the aperture facing the sensor.

6. The vehicle weighing apparatus according to any one of the preceding claims, wherein the tube and the plunger each have a square cross sectional shape.

7. The vehicle weighing apparatus according to any one of the preceding claims, wherein the tube includes a sensor opening in which the sensor mounting bracket supports the sensor.

8. The vehicle weighing apparatus of any one of the preceding claims, wherein the tube includes a tube connector end, and the plunger includes a plunger connector end, the arm being connectable between the sprung body of the vehicle, and the unsprung part of the vehicle.

9. A method of weighing the loading of a vehicle comprising:

a. moving a plunger longitudinally within a tube by adding load to the vehicle, wherein an indicator of the plunger passes across a sensor;

b. generating a sensor output signal indicative of the position of the

10. A method according to claim 9 further comprising converting the sensor

15 output signal from analogue to digital before it is displayed.

Mr Michael Collett

7 September 2017

10 indicator; and

c. displaying an indication of the weight of the load on a display device.