WO2000039543A1

WO2000039543A1 - Device that indicates when the weight of a load reaches a maximum value during loading of a commercial vehicle

Info

Publication number: WO2000039543A1
Application number: PCT/SE1998/002332
Authority: WO
Inventors: Mikael Jacobsson; Anna Westgren
Original assignee: Scania Cv Aktiebolag (Publ)
Priority date: 1998-12-16
Filing date: 1998-12-16
Publication date: 2000-07-06
Also published as: DE19882967T1; BR9815326A; DE19882967B3

Abstract

The invention relates to an arrangement for indicating that a maximum load weight has been reached during the loading of a freight vehicle (1). The arrangement incorporates at least one detection device (11) designed to detect a parameter which varies with the vehicle's weight, a control unit (14) connected to said detection device (11) and designed to determine on the basis of the value of said parameter whether said maximum load weight has been reached, and at least one indicating device (5) designed to be activated by the control unit (14) if said maximum load weight is reached. The indicating devices (5) are arranged on the freight vehicle (1).

Description

Device that indicates when the weight of a load reaches a maximum value during loading of a commercial vehicle

BACKGROUND TO THE INVENTION, AND STATE OF THE ART

The invention relates to an arrangement for indicating that a maximum load weight has been reached during the loading of a freight vehicle according to the preamble to patent claim 1.

A problem during the loading of freight vehicles is knowing when the vehicle has reached its maximum load weight. This may be difficult even for an experienced operator of a mechanical loader. To be able to estimate when maximum load weight has been reached, the operator of the loader has to be acquainted with the maximum load weight of the individual freight vehicle, which may be difficult in that freight vehicles exist in many different versions. Moreover, the operator has to be acquainted with the specific gravity of the various materials carried, which may in itself be difficult in that their weight may vary for a number of reasons, e.g. their moisture content. From the economic point of view it is important to achieve maximum loading of a freight vehicle on each occasion so that as a large a quantity of material as possible can be carried each time. At the same time, the quantity loaded must not exceed a maximum value for the specific freight vehicle, since that might lead to the vehicle becoming a safety hazard by travelling unlawfully in traffic, and to vulnerable parts of the vehicle being so heavily loaded as to break loose or come apart and have to be replaced. An arrangement is known from WO9405981-A1 for indicating when maximum load has been reached as a freight vehicle is loaded by mechanical loader. The freight vehicle incorporates a platfoπn supported by a ram on which pressure sensors are arranged. From the pressure sensors a signal representing the pressure measured is led to a control unit which calculates the load weight on the freight vehicle and sends a signal representing the weight of the load to the loader. The load weight is displayed on a screen in the operator's cab, enabling the operator of the loader to read the freight vehicle's load weight and hence see when maximum load weight has been reached. That indicating arrangement has the disadvantages that the loader operator has to switch his concentration between the loading operation and the screen and that both the freight vehicle and the loader have to be catered for by said load indicating arrangement, which therefore becomes complicated and expensive to install in existing vehicles.

SUMMARY OF THE INVENTION

The object of the present invention is to provide an arrangement for indicating that a maximum load weight has been reached during the loading of a freight vehicle of the kind mentioned in the introduction, which arrangement makes it possible to overcome the disadvantages of the indicating arrangement described above.

This object is achieved according to the invention by the arrangement mentioned in the introduction whereby said indicating device is arranged on the freight vehicle. This configuration of the arrangement means that the operator of the loader can concentrate fully on the loading operation, since the freight vehicle is already within the operator's area of concentration during the loading operation, so he need not turn his head or look away from the continuing operation.

According to a preferred embodiment of the invention, said indicating device is designed to emit a light signal when said maximum load weight has been reached. This is an uncomplicated and effective way of making the operator of the loader aware that the maximum load weight has been reached. To make the operator still more aware that said maximum load weight has been reached, said light signal may also flash. Such an indicating device may incorporate a rotating light unit of the type used, for example, by works machines when travelling in traffic. A further advantage is achieved if said indicating device includes lighting equipment which already exists on the freight vehicle. Using such existing lighting equipment may considerably reduce the cost of equipping vehicles with this type of indicating arrangement. It is further advantageous if said existing lighting equipment on the freight vehicle includes its flasher devices. The result is a flashing beam which is readily perceptible. Moreover, the positioning of such flasher devices on the vehicle is usually such that the flashing beam is perceptible in all directions.

A further advantageous embodiment of the invention incorporates the means designed to activate the arrangement during the loading of the vehicle. Said means may include a manual arrangement, e.g. a button on the instrument panel of the freight vehicle. Said means may also incorporate automatic activation of the arrangement, which may for example be achieved by the detection device detecting an incipient increase in the load weight while the vehicle is standing still, i.e. while its velocity is zero. The arrangement also includes means designed to deactivate the arrangement upon completion of loading. These means may be manual and, for example, include a button on the instrument panel of the freight vehicle, possibly the same button as for activating the arrangement. These means may also be designed to deactivate the arrangement automatically upon completion of loading, e.g. by detecting movement of the vehicle, i.e. whether its velocity is greater than zero. The arrangement may also be deactivated after a predetermined period of time after maximum load weight is reached, e.g. within the time interval of 5 to 60 seconds.

According to a further embodiment of the invention, said detection device is designed to detect said parameter on at least one wheelshaft of said freight vehicle. Where a wheelshaft incorporates a suspension element, said detection device may advantageously be designed to detect said parameter on that suspension element. If the suspension element consists of a pneumatic suspension arrangement, the detection device may detect the pressure in that pneumatic element, which may take the form of an air bellows. If the suspension element incorporates a leaf spring arrangement, a strain gauge may be arranged on the latter to detect a parameter representing the loading on the leaf spring arrangement. Said detection device may further be designed to detect when the suspension element is compressed to a predetermined extent which corresponds to the vehicle's maximum load. It is also possible to arrange said detection device in such a way that it detects the air pressure in the wheels of a wheelshaft.

According to a further embodiment of the invention, said detection device is designed to detect a parameter on at least two of said freight vehicle's axles, in which case the control unit is designed to determine separately for each axle whether the value of that parameter corresponds to a maximum load weight value for the axle, and to activate specific indicating devices for the respective axles when said maximum load weight value is reached. The front wheelshaft may in this case be associated with forward indicating devices and the rear wheelshaft with rear indicating devices arranged on the vehicle. This also means that the operator of the loader is made aware of whether the load is becoming unevenly distributed on the vehicle. He may then distribute the load with the assistance of the indicating devices on the freight vehicle so as to achieve a desired axle pressure on the respective vehicle axles.

BRIEF DESCRIPTION OF THE DRAWINGS

By way of example, preferred embodiments of the invention are described below with reference to the attached drawings, in which:

Fig. 1 depicts a freight vehicle on which the arrangement according to the invention is applicable. Fig. 2 depicts schematically an embodiment of an indicating arrangement according to the invention in the freight vehicle of

Fig. 1. Fig. 2 depicts schematically an alternative embodiment of an indicating arrangement according to the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

Fig. 1 depicts a freight vehicle 1 with a load receiving unit 2 for accommodating a load 3. The vehicle 1 also incorporates a crane 4 for loading the vehicle 1. The crane 4 may of course be arranged on a separate mechanical loader or the like. The existing flasher devices of the vehicle 1, in reality four in number, are designated in the diagram by reference 5 and constitute indicating devices, described in more detail below, on the vehicle 1 when the vehicle's maximum load is reached. The freight vehicle 1 also incorporates a rear wheelshaft 6 which is fastened to a spring shackle 7 which is attached pivotably to a mounting plate 8 on the chassis of the vehicle 1. Between the spring shackle 7 and the chassis of the vehicle 1, a shock absorber 9 is arranged, as also a pneumatic bellows spring 10.

Fig. 2 depicts a first embodiment of the invention, in which a pressure detecting device 11 is designed to detect the pressure of the bellows spring 10. This pressure constitutes a parameter which is advantageous in the context and varies with the load weight 12 of the vehicle. A signal representing the value of the pressure parameter is led via a line 13 to a control unit 14 which is designed to determine on the basis of the value of this pressure parameter whether the maximum load weight of the vehicle 1 has been reached. If this maximum load weight has been reached, the control unit 14 is designed to activate the flasher devices 5. The latter consequently emit a flashing light signal which clearly indicates to the operator of the crane 4 that the maximum load weight has been reached. The activation of said control unit 14 may be by means 16 which may include a manual activation arrangement, e.g. a button on the vehicle's instrument panel. These means 16 may also incorporate automatic activation of the control unit 14 during loading of the vehicle, e.g. the control unit 14 may be activated by an incipient increase in the pressure in the bellows spring 10 while the velocity of the vehicle 1 is zero. The arrangement also includes means 17 designed to deactivate the arrangement upon completion of loading. These means 17 may include a manual arrangement and, like the means 16, include a button on the instrument panel on the vehicle 1 , possibly the same button, which is placed in two different positions for activation and deactivation. The means 17 may also be designed to deactivate the control unit 14 automatically, e.g. when the vehicle 1 is set in motion, i.e. when its velocity is greater than zero, or be so designed that said activation ceases after a specific time, i.e. so that the flasher devices 5 only flash for a specific period of time after maximum load has been reached. This specific period of time may be selected as desired within the range from 5 to 60 seconds.

Fig. 3 depicts a somewhat different embodiment whereby maximum possible use is made of equipment already existing on the vehicle. Such freight vehicles often incorporate a level adjusting system which itself often includes a pressure detecting device for detecting the pressure in, in this case, a pneumatic bellows spring 10. Such a level adjusting system further includes a line 13 for transmitting a signal representing said pressure to a control unit 18 which is part of this level adjusting system. Most such vehicles also incorporate a control unit 19 for activating existing warning flashers 5 via a line 15. The fact that this embodiment uses existing equipment of the vehicle 1 means that an arrangement for indicating that the maximum weight has been reached can be arranged on the freight vehicle easily and at relatively low cost.

The invention is in no way limited to the embodiments indicated in the drawings but may be varied freely within the scopes of the patent claims. For example, the indicating device may be constituted not by the existing flasher devices 5 of the vehicle 1 but by some other existing lighting equipment of the vehicle or by light-emitting indicating devices arranged on the vehicle specifically for the purpose. The indicating devices may also be designed to emit a light signal which may be produced by light-generating devices already existing on the vehicle or applied solely for this purpose.

The invention is of course likewise not limited to vehicles with pneumatic suspension but may be arranged on vehicles with other types of suspension and, broadly, on all types of vehicles where it is possible to detect a parameter which varies with the vehicle's weight.

Maximum load weight here means not only a vehicle's maximum load weight depending on maximum permissible axle loading, it may also mean a settable maximum load weight such as, for example, two tonnes of a material which is to be loaded, in which case this maximum load weight may be set and the control unit may therefore activate the indicating devices when this set load weight is reached.

Load detecting devices may also be arranged on two or more axles, in which case the freight vehicle's front flasher devices 5 may constitute indicating devices for the loading on the vehicle's front axle, while its rear flasher devices 5 constitute indicating devices for the loading on the vehicle's rear axle. This enables the crane operator to achieve optimum load distribution between the axles with the assistance of the respective indicating devices. By further development of the concept of the invention, load detecting devices may be arranged to detect the loading on each wheel, and in the case of a vehicle with four wheels each wheel may be connected to the flasher device 5 situated nearest to it in order to indicate when maximum loading has been reached on the respective wheel.

Claims

Patent claims

1. Arrangement for indicating that a maximum load weight has been reached during the loading of a freight vehicle (1), whereby the arrangement incorporates at least one detection device (11) designed to detect a parameter which varies with the vehicle's weight, a control unit (14) connected to said detection device (11) and designed to determine on the basis of the value of said parameter whether said maximum load weight has been reached, and at least one indicating device (5) designed to be activated by the control unit (14) if said maximum load weight is reached, characterised in that said indicating device (5) is arranged on the freight vehicle (1).

2. Arrangement according to claim 1, characterised in that said indicating device (5) is designed to emit a light signal when said maximum load weight has been reached.

3. Arrangement according to claim 2, characterised in that said light signal includes a flashing beam.

4. Arrangement according to claim 2 or 3, characterised in that said indicating device (5) includes lighting equipment already existing on the freight vehicle (1).

5. Arrangement according to claim 4, characterised in that said existing lighting equipment includes the freight vehicle's flasher devices (5).

6. Arrangement according to any one of the foregoing claims, characterised in that it incorporates means (16) designed to activate the arrangement during loading of the vehicle.

7. Arrangement according to either of claims 5 or 6, characterised in that it incorporates means (17) designed to deactivate the arrangement upon completion of loading.

8. Arrangement according to any one of the foregoing claims, characterised in that said detection device is designed to detect said parameter on at least one wheelshaft (6) of said freight vehicle (1).

9. Arrangement according to claim 8, characterised in that said wheelshaft (6) incorporates at least one suspension element (10) and said detection device (11) is designed to detect said parameter on that suspension element (10).

10. Arrangement according to claim 8 or 9, characterised in that said detection device (11) is designed to detect a parameter on at least two of said freight vehicle's axles and the control unit (14) is designed to determine separately for each axle whether the value of this parameter corresponds to a maximum load weight value for the axle, and the control unit (14) is designed to activate specific indicating devices (5) for the respective axles when said maximum load weight value is reached.