CZ2002995A3 - Load monitoring device for foot boards - Google Patents

Abstract

The device has a tread board (1) load detection device connected to vehicle components such as the engine, ignition or gearshift. The load detection device has sensors (20) for detecting movements of the tread board and/or of its holding arrangement (10) in at least two directions. The load detection device has sensors for detecting at least one bending moment and at least one vertical movement.

Description

Device for checking the step load

Technical field

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a device for monitoring the step load on a vehicle by means of a bracket, in particular at the rear of a garbage truck, with a step load detector which is operatively connected to certain vehicle parts. gears.

BACKGROUND OF THE INVENTION

On the back of the garbage trucks there are footrests on which garbage trucks can stand while the truck is moving. However, the garbage truck must not reverse when the operator is standing on the steps. It is known to provide the footrests with sensors which, for example, can be connected to the reverse of the car so that they block its engagement when the footrests are loaded.

DE 41 21 720 A1 discloses a garbage truck in which the steps are provided with contact switches. In order to allow reversing or moving forward at an increased speed, the footrests must be swung into an unusable position. If the steps are not folded out, the pneumatic valve automatically applies the wheel brake or the road blocking device to prevent the vehicle from driving or braking. The pneumatic valve is activated by means of a relay which is first controlled by contact switches fixed to the steps between their support bracket and the tilt or pivot step and, if the relay is not energized, establishes a connection between the return light and the pneumatic valve. The contact switch is intended to be tamper-proof, but not a step. It cannot be ruled out that • • · ·

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4444 44 the operator relieves the step so that the contact switches do not operate when the step is stepped on. This also makes it possible to step on the step, which should not be possible with respect to the said safety device.

DE 39 18 971 C2 discloses a garbage truck with a rotational speed limiting device which is automatically activated by contact when a worker enters a two-track step on contact. For this purpose, proximity switches are provided on the steps, for example, but they can be easily manipulated. In another embodiment, handles are provided which switch the signal when touched. However, even in this case, the garbage collector can prevent the signal from being generated by suitable insulation.

DE-OS 37 29 107 C2 discloses a garbage truck with steps which actuate a contact switch under load, for example a power switch connecting a reversing light and a corresponding relay. This relay causes the motor to stop running when reversing with a stepped load, which can only be started after the step load has been removed.

DE-OS 25 47 959 discloses a load-dependent switching device which is intended in particular for securing movable steps for vehicles.

All known steps for securing the steps can be manipulated so that their intended safety function is disabled and the reversing of the garbage truck is possible even when the operator is standing on the step.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a step load monitoring device which can be detected by the operator even if the step has been greatly relieved by some manipulation.

The object of the solution is that the step load detection device is provided with an apparatus comprising the steps detecting movement of the steps and / or their support in at least two directions.

This solution is based on the fact that the load sensing device must be sensitive not only to movements in one direction, that is to say in the load direction when the operator steps onto the step, but also in at least one other direction, when the stepper safety device was tampered with.

Thus, when the step is handled reliably, for example when it is fixed in the unloaded position, when the operator rises on the step, in each case the step and / or the holding means exert forces which result in bending or partial deformation of the components. Vertical downward movement will be greatly reduced as a result of handling. Instead, there will be an increased generation of bending moments that can be captured by one or more sensors.

Preferably, the load monitoring device is provided with sensors for detecting at least one bending moment and at least one vertical movement. Since only small movements and low forces are associated with such handling, the load detection device must be particularly sensitive.

In order to further improve and achieve better control of the movement of the steps, not only linear but also tilting or rotary movements are preferably detected by the sensors. Optimal control of the steps can be achieved by using sensors to control all six possible release stages, for example by detecting rotational movements of the step. For this purpose, it is not necessary that the step support allows movement in all these directions. By manipulation, the steps of the step can be varied under load, so that not only additional bending forces can occur, but also movements in the vertical or horizontal direction or rotational movements which are predominantly transmitted to the step holding means. Type and • · · ·

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4444 The number of sensors, as well as their location, depends on the design of the step and its mounting.

It is advantageous if the sensors are arranged on or in the step support. The most sensitive location is the area of the bracket adjacent to the point of attachment to the vehicle.

The sensors are preferably designed as strain gauges that react even to a small elongation of the component on which they are mounted. The arrangement of the strain gauges on the step support must be selected so that it can detect directions in which the step can move, be loaded or deformed.

It is advantageous if four strain gauges are arranged in one sensor, the device containing them being referred to herein as an apparatus. This sensor apparatus can also advantageously be arranged on the side of the step support.

Advantageously, the device containing the sensors together with the strain gauges can also be integrated into the known Wheatstone bridge circuit, in order to detect even small variations in resistance in strain gauges. Wheatstone bridge can be designed as half or full bridge depending on whether two or four strain gauges are connected to it. The advantage of a full bridge is that temperature compensation can also be performed, so that misinterpretation with respect to the step load is avoided.

In another embodiment, electrical pressure switches are provided, and it is advantageous if, in particular, a pressure switch for each direction of movement to be received is mounted on the footrest, in particular.

The step load monitoring device is preferably provided with a control device which is connected both to the sensors and to the vehicle parts so that the vehicle can respond to the detected step load. This can be done, for example, by activating an acoustic or optical signaling device in the driver's cab. For example, the control device may affect the driving speed or the •

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9999 forward or reverse operation of the vehicle to avoid endangering the operator standing on the step. Which vehicle components are connected to the control device depends on the operator's requirement. Thus, the control device can also be connected to the refuse compression device in the collection box and / or to the refuse collection device. Preferably, when the step is loaded, the compression device is stopped or switched off and / or the device is moved to a safe position before stopping operation. A safe position for a garbage truck is, for example, a height that allows the vehicle to be further driven, which is a position for further safe driving.

The control device is also preferably sized for receiving and processing vehicle data. For example, the measuring signals can evaluate the vehicle speed. Due to the high sensitivity of the sensors, for example, it may happen that, when the footboard is unloaded, when driving quickly over a pothole on the road, a downward force is applied for a short time, which could act to slow down the speed. For example, depending on the vehicle parameters, it may be expedient to provide windows on the device in which the sensor signals are evaluated or not evaluated.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention are illustrated in the drawings and described in greater detail below. Fig. 1 is a rear view of the rear of a garbage truck with two downwardly folded steps; Fig. 2a-c is a perspective, side and top view of the sensor step according to the first embodiment; Figs. 3a-d. the sensor step according to the second embodiment shown in perspective, side and top views, as well as its suspension in a somewhat enlarged representation, and Figure 4 is a schematic diagram of the step load monitoring device.

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DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, the rear portion of the garbage truck 40 is shown in perspective, with a garbage disposal opening 41 therein. A tilting step 1, 2 is provided on the side frame 42 of the vehicle 40 and is connected to the frame 42 by means of the step holder 10.

In FIG. 2a, such a step 1 is also shown in perspective with the respective holders 10 and 17. The step 1 is mostly designed as an L-shaped body, which is pivotably mounted on the horizontal axis 16 of the step 1 holder 10. 2a and 2b tilt upwards to the rest position.

The step 1 is fixed to the vehicle by means of brackets (not shown), the brackets forming a right-angled leg of the step 1 bracket 10 and the mounting plate 17.

The bracket arm 10 is mounted on the vehicle by the mounting plate 17 so that the step 1 load is shown as bending force on the step 1 bracket arm 1. When the step F 1 acts on the step 1, bending moments occur on the bracket arm 10 leading to side 11 of the arm support material 10 of the step 1.

In the illustrated embodiment, an opening 18 is provided in the side 12 for the apparatus 20 comprising the sensors. The apparatus 20 consists of a cylindrical base body on which four strain gauges 21a-d are arranged. These strain gauges 21a-d are arranged in pairs with respect to each other, each strain gauge being arranged such that it forms an angle of 45 ° with respect to the vertical. As a result, both vertical and horizontal forces are absorbed by the strain gauges 21a-d. The arrangement in pairs has the advantage that the strain gauges can be compensated for one another, thus avoiding errors.

The strain gauges 21a-d are connected to the Wheatstone bridge for evaluating the detected elongations. 2a to 2c is a stepboard movable vertically both upwards and downwards and possibly in torsion, and these movements may occur both in the elongation changes or in the bending moments of the arm of the footboard holder 10.

Fig. 3a shows another embodiment which differs from the embodiment according to Figs. 2a to 2c in that, instead of the strain gauges, pressure switches 30, 31 are arranged in the region of the mounting plate 17 and that the support arm of the holder 10 is displaceable vertically. Other fastening means such as stops and the like are not shown in the figure for the sake of clarity.

The pressure switch 30 is arranged vertically and with the tip of its sensor rests on the lower side 13 of the support arm 10, so that it is controlled by the load in the vertical direction. To this end, the arm of the step support 10 with at least two free steps in the direction of torques and transverse forces is movably mounted in the joint 19, as shown in Fig. 3d. The bending elements of the support arm of the holder 10 are monitored by a pressure switch 31 which is arranged horizontally and abuts the rear side 14 of the support arm 10 of the step 1.

FIG. 4 schematically illustrates the entire device showing the connection of the step load monitoring device to the vehicle components.

Both steps 1, 2 are connected to a battery, preferably to a battery 7 of the vehicle. Through the electrical connection lines 8 and 9, both steps 1 and 2 are connected to a control device 3 which processes the data supplied by the sensors and converts them into signals for the respective parts of the vehicle. For this purpose, the control device 3 is connected to the gearbox 6 and to the motor 5 by means of the guides 50, 51 and 52. These lines 50, 51 and 52 are also designed so that by means of the vehicle parts, ie the motor 5 and the gearbox 6 devices 3, which can thus be taken into account when evaluating the sensor signals. In the embodiment shown here, an indicating device 4 is also connected, which is installed in the driver's cab and thus transmits to him the load information of step 1 or step 1, 2.

Claims (12)

PATENT CLAIMS 1. Device for checking the step load on a vehicle by means of a holder, in particular at the rear of a garbage truck, with a step load detector which is operatively connected to certain parts of the vehicle, such as an engine, ignition or gear shifting device 2. A method according to claim 1, characterized in that the load detecting device (20) comprises sensors for detecting the movement of the step (1, 2) and / or their holders (10, 17) in at least two directions. A step load monitoring device according to claim 1, characterized in that the load detection device comprises sensors for detecting at least one bending moment and at least one vertical movement. A step load monitoring device according to claim 1 or 2, characterized in that the load detection device comprises sensors for detecting at least one linear and at least one rotary motion. A step load monitoring device according to any one of claims 1 to 3, characterized in that the load detection device comprises sensors for detecting vertical or horizontal movements. Step load monitoring device according to one of Claims 1 to 4, characterized in that the sensors are arranged on the step support (10). »* ·· * · -9 ·· ·· 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 · · · · · · A tread load monitoring device according to claim 5, characterized in that the sensor or sensors are arranged adjacent to the mounting point of the brackets (10) on the vehicle. A step load monitoring device according to any one of claims 1 to 6, characterized in that the sensors are strain gauges (21 a-d). A step load monitoring device according to claim 7, characterized in that the strain gauges (21 a-d) are mounted in a common apparatus (20). A step load monitoring device according to claim 7 or 8, characterized in that the device (20) is integrated in a Wheatstone bridge circuit. A step load monitoring device according to claim 8 or 9, characterized in that the device (20) is arranged in a side (12) of the step holder (10). Step load monitoring device according to one of Claims 1 to 6, characterized in that the sensors are electric pressure switches (30, 31). A step load monitoring device according to any one of claims 1 to 8, characterized in that the load detection device comprises 3 »·» ·· -104 4 4 5 4 4 4 4 4 4 4 4 4 4444 * 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 5 4 4 4 4 4 4 4 4 4 4 44 44 4444 a control device (3) which is connected both to the sensors and to the vehicle components.