Reach truck

Abstract

The invention relates to a reach truck (1) with a vehicle body (2) and a reach carriage (3) slidably arranged on the vehicle body (2) in the longitudinal direction (L) of the vehicle, on which a lifting mast (7) is arranged, and with a reach measuring device (10) configured to determine a reach and / or a reach position of the reach carriage (3). The reach measuring device (10) has a rotary angle sensor (11) arranged on the vehicle body (2). The rotary angle sensor (11) is connected to the reach carriage (3) by means of a coupling mechanism (12).

Description

[0001] The invention relates to a reach truck with a vehicle body and a push carriage which is arranged on the vehicle body so as to be displaceable in the vehicle longitudinal direction and on which a lifting mast is arranged, and with a push path measuring device which is designed to determine a push path and / or a push position of the push carriage.

[0002] Reach trucks have a reach carriage that can be moved horizontally along the vehicle's longitudinal direction by means of a push drive. It is known to provide a push travel measuring device on the reach truck, with which the push travel and / or push position of the reach carriage can be determined.

[0003] In prior art reach trucks, it is known to provide two inductive sensors as a reach travel measuring device. These sensors are connected to a control unit and interact with a comb. The two sensors are attached to the reach carriage, and the comb is attached to the body of the reach truck. When the reach carriage is moved in the longitudinal direction of the vehicle, the inductive sensors detect the relative movement to the comb. The sensors send a sine / cosine signal to the control unit, which converts this signal into a reach travel and / or a reach position of the reach carriage. In known reach trucks, the inductive sensors are arranged on the reach carriage due to the space constraints.This leads to disadvantages, as a cable connection connecting the sensors arranged on the push carriage to the control unit located in the vehicle body carries out every pushing movement of the push carriage, which increases the risk of cable breakage. In addition, long cables and numerous connectors are required. Another disadvantage is that the change in position of the push carriage is only determined incrementally. Another disadvantage is that errors in the detection cannot be determined and changes in the position of the push carriage cannot be detected when the control unit is switched off. In addition, foreign objects in the measuring section, such as metal packing tape or metal staples, can lead to false detections. Furthermore, mechanical tolerances along the entire measuring section can lead to false detections.

[0004] The present invention is based on the object of providing a reach truck of the type mentioned at the outset which is improved with regard to the disadvantages mentioned.

[0005] This object is achieved according to the invention in that the thrust travel measuring device has a rotation angle sensor which is arranged on the vehicle body, wherein the rotation angle sensor is connected to the thrust carriage by means of a coupling mechanism.

[0006] According to the invention, a rotation angle sensor arranged on the vehicle body and connected to the push carriage by means of a coupling mechanism is used as the sensor of the push carriage travel measuring device, with which the push carriage travel and / or the push position of the push carriage arranged on the vehicle body so as to be displaceable in the vehicle's longitudinal direction is determined. The change in length of the push carriage when the push carriage is displaced on the vehicle body is converted into a rotational movement at the rotation angle sensor by a kinematic connection formed by the coupling mechanism. The sensor measures a corresponding rotation angle or angular change, from which the push carriage travel and / or the push position is determined.

[0007] According to an advantageous embodiment of the invention, the coupling mechanism comprises a rod that is rotationally fixedly connected to the angle of rotation sensor and is connected to the sliding carriage by means of a connecting element. The rod is, in particular, rotationally fixedly connected to a rotatable sensor element of the angle of rotation sensor. With such a coupling mechanism formed from a rod and a connecting element, the change in length of the sliding carriage when the sliding carriage is displaced on the vehicle body can be easily converted into a rotational movement at the angle of rotation sensor.

[0008] According to an advantageous embodiment of the invention, the connecting element is designed as a connecting rod that is pivotally connected to the rod at a first end and pivotally connected to the push carriage at a second end. With such a connecting rod pivotally connected to the rod and pivotally connected to the push carriage, the rod can be easily coupled to the push carriage.

[0009] According to an advantageous embodiment of the invention, the connecting element is designed as a cable that is connected to the rod at a first end and to the push carriage at a second end. With such a cable connected to the rod and the push carriage, the rod can be coupled to the push carriage in a particularly simple manner.

[0010] According to an advantageous embodiment of the invention, the angle of rotation sensor is operatively connected to a control device, in particular an electronic control device, wherein the control device is designed to determine the pushing path and / or the pushing position of the pushing carriage based on the angle of rotation measured by the angle of rotation sensor. In a control device, the pushing path and / or the pushing position of the pushing carriage can be easily determined from the angle of rotation measured by the angle of rotation sensor. The kinematics of the coupling mechanism are preferably known to the control device, so that in this way the control can convert the angle measured by the angle of rotation sensor into a change in length and determine the pushing path and / or the pushing position of the pushing carriage.

[0011] According to an advantageous embodiment of the invention, the coupling mechanism is operatively connected to a spring device. A spring device can be used, particularly when the connecting element is designed as a cable, to keep the cable permanently under tension, ensuring actuation of the angle of rotation sensor during a pushing movement of the sliding carriage.

[0012] According to an advantageous embodiment of the invention, the spring device is designed to actuate the angle of rotation sensor to an error angle. The error angle preferably lies outside the measuring range of the angle of rotation sensor, within which the angle of rotation sensor is actuated during the pushing movement of the sliding carriage. This makes it easy for the angle of rotation sensor to be actuated to the error angle by the spring device in the event of a defect in the coupling device, for example, a break or crack in the rod and / or the connecting element.

[0013] According to an advantageous embodiment of the invention, the control device is designed to output an error message when the error angle is measured. This allows a corresponding error message to be generated easily in the event of a defect in the coupling device.

[0014] According to an advantageous embodiment of the invention, the spring device is designed as a torsion spring arranged coaxially with a rotational axis of the rotation angle sensor. With such a torsion spring, the coupling mechanism can be easily actuated.

[0015] According to an advantageous embodiment of the invention, the angle of rotation sensor is designed as a magnetoresistive sensor. Such a sensor can detect and measure a rotation angle with minimal construction effort and high reliability.

[0016] According to an advantageous embodiment of the invention, the rotary encoder is designed as an optical sensor. With an optical sensor, a rotary angle can be detected and measured with minimal construction effort and high reliability.

[0017] According to an advantageous embodiment of the invention, the rotary encoder is designed as a Hall sensor. A Hall sensor allows a rotation angle to be detected and measured with minimal construction effort and high reliability.

[0018] According to an advantageous embodiment of the invention, the rotary encoder is designed as a potentiometer. A potentiometer allows for detecting and measuring a rotary angle with minimal construction effort and high reliability.

[0019] The invention has a number of advantages.

[0020] According to the invention, the angle sensor is mounted on the vehicle body, eliminating the need to route the angle sensor's cable connection over the sliding carriage, which is a moving part. This saves on intermediate connectors and cable length. Furthermore, the risk of cable breakage due to constantly moving electrical wires is avoided.

[0021] With the rotation angle sensor, an absolute value measurement of the push travel and / or the push position of the push carriage is also possible, since a measured rotation angle always corresponds to a push position of the push carriage.

[0022] Furthermore, the angle sensor is insensitive to interference and foreign bodies, such as metals, do not lead to false detections.

[0023] In conjunction with the spring device, errors or defects in the coupling mechanism can be easily detected.

[0024] In addition, a rotary angle sensor has low manufacturing costs, so that an absolute value measuring system can be provided at low cost with which the push path and / or the push position of the push carriage can be determined.

[0025] Further advantages and details of the invention are explained in more detail with reference to the exemplary embodiments shown in the schematic figures. Figure 1 a reach truck according to the invention in a side view, Figures 2a to 2c schematic plan views of a reach truck according to the invention with the push carriage in different push positions, Figure 3 a rotation angle sensor with a first embodiment of the coupling mechanism and Figure 4 a rotation angle sensor with a second embodiment of the coupling mechanism.

[0026] In the Figure 1 a reach truck 1 according to the invention is shown in a side view.

[0027] The reach truck 1 has a vehicle body 2 on which a push carriage 3 is arranged so as to be displaceable in the horizontal longitudinal direction L of the vehicle by means of a push drive (not shown in detail).

[0028] A driver's cab 5 is arranged on the vehicle body 2. Also arranged on the vehicle body 2 is a battery pack 6, which supplies all drives of the reach truck 1 with electrical energy.

[0029] A lifting mast 7 is arranged on the push carriage 3, on which a load-handling device 8, for example a load fork having two forks, is arranged so as to be able to be raised and lowered.

[0030] In the Figure 1 the reach truck 1 is shown with a push carriage 3 pushed back.

[0031] The reach truck 1 has a Figures 2a to 4shown in more detail, which is designed to determine a thrust path and / or a thrust position of the thrust carriage 3.

[0032] In the Figure 2a The reach truck 1 is shown with a forward-extended push carriage 3. In the Figure 2c The reach truck 1 is shown with a push carriage 3 pushed back. Figure 2b shows the reach truck 1 in an intermediate position of the reach carriage 3.

[0033] The thrust measuring device 10 has - as shown in the Figures 2a to 4 shown in more detail - a rotation angle sensor 11, which is arranged and fastened to the vehicle body 2. The rotation angle sensor 11 is connected to the push carriage 3 by means of a coupling mechanism 12.

[0034] The coupling mechanism 12 has a rod 15 which is non-rotatably connected to the rotation angle sensor 11 and which is connected to the sliding carriage 3 by means of a connecting element 16.

[0035] The rod 15 is preferably non-rotatably connected to a rotatable sensor element of the rotation angle sensor 11. The rotatable sensor element is preferably arranged to rotate about a vertical axis of rotation D. The rod 15 is arranged radially on the rotation angle sensor 11.

[0036] In the Figure 3A first embodiment of the coupling mechanism 12 is shown, in which the connecting element 16 is designed as a connecting rod 20. The connecting rod 20 is pivotally connected to the rod 15 at a first end 20a and pivotally connected to the sliding carriage 3 at a second end 20b. For the pivotal connection to the rod 15 and / or the sliding carriage 3, a respective pivot device G1, G2 can be provided, which preferably has a vertical axis of rotation. The coupling mechanism 12 of the Figure 3 It thus consists of two rods 15, 20, which are connected to one another by means of the articulated connection G1 and thus by means of a rotation axis, wherein the rod 15 is rotationally fixed to the rotation angle sensor 11 and the connecting rod 20 is articulatedly coupled to the sliding carriage 3. The sliding path of the sliding carriage 3 can be converted into an angular change of up to 180° on the rotation angle sensor 11 using the coupling mechanism 12.

[0037] In the Figure 4a second embodiment of the coupling mechanism 12 is shown, in which the connecting element 16 is designed as a cable 21 which is connected to the rod 15 at a first end 21a and to the push carriage 3 at a second end 21b.

[0038] The kinematic connection of the angle of rotation sensor 11 to the sliding carriage 3, formed by the coupling mechanism 12, thus consists of the rod 15, which is non-rotatably connected to the angle of rotation sensor 11 and actuates the angle of rotation sensor 11. The connecting element 16 connected to the sliding carriage 3 is articulated on the other side of the rod 15.

[0039] According to the Figure 4 The coupling mechanism 12 is operatively connected to a spring device 25. In the illustrated embodiment, the spring device 25 is designed as a torsion spring 26, which is arranged coaxially to the rotation axis D of the rotation angle sensor 11 and is connected to the rod 15.

[0040] In the embodiment of the Figure 4 the spring device 25 ensures that the connecting element 16 designed as a cable 21 is always taut.

[0041] During normal operation of the reach truck 1, the rotation angle sensor 11 is operated with a rotation angle within a measuring range MB.

[0042] The spring device 25 is designed to actuate the angle of rotation sensor to an error angle FW. The error angle FW lies outside the angle of rotation range of the measuring range MB of the angle of rotation sensor 11.

[0043] The angle of rotation sensor 11 is operatively connected to a control device 30, for example, an electronic control device. The control device 30 is designed to determine the pushing path and / or the pushing position of the pushing carriage 3 based on the angle of rotation measured by the angle of rotation sensor 11.

[0044] Furthermore, the control device 30 is designed to output an error message when the error angle FW is measured.

[0045] The invention is not limited to the embodiments shown in the figures. The spring device 25 of the Figure 4 can also be used with a coupling mechanism 12 of the Figure 3 be provided.

[0046] In the Figures 3, 4 the rod 15 is straight. In the Figure 3 The connecting rod 20 is straight. The rod 15 and / or the connecting rod 20 can alternatively also be curved. The curvature of the rod 15 and / or the connecting rod 20 is preferably designed such that a change in length at one end of the thrust path of the thrust carriage 3 (sensor angle -0°) corresponds to an equal change in angle in the middle of the thrust path of the thrust carriage 3 (sensor angle -90°) and at the second end of the thrust path of the thrust carriage 3 (sensor angle -180°).

[0047] The invention works as follows: If the push carriage 3 is displaced in the vehicle longitudinal direction L by means of the push drive, the change in length of the push carriage 3 when displacing the push carriage 3 on the vehicle body 2 with the kinematic connection formed by the coupling mechanism 12 is converted into a rotational movement at the rotation angle sensor 11, which measures a corresponding angle of rotation or an angular change, from which the push path and / or the push position of the push carriage 3 is determined in the control device 30.

[0048] If a defect occurs in the coupling device 12, for example a break or tear in the connecting element 16 designed as a cable 21 or connecting rod 20 and / or a defect in the articulated connection G1 or G2, the rod 15 of the coupling device 12 is pulled by the spring device 25 into the error angle FW, whereby the control device 30 can output an error message.

Claims

1. Reach truck (1) with a vehicle body (2) and a push carriage (3) which is arranged on the vehicle body (2) so as to be displaceable in the vehicle longitudinal direction (L), on which a lifting mast (7) is arranged, and with a push path measuring device (10) which is designed to determine a push path and / or a push position of the push carriage (3), characterized in that the thrust travel measuring device (10) has a rotation angle sensor (11) which is arranged on the vehicle body (2), wherein the rotation angle sensor (11) is connected to the thrust carriage (3) by means of a coupling mechanism (12).

2. Reach truck according to claim 1, characterized in that the coupling mechanism (12) has a rod (15) which is connected in a rotationally fixed manner to the rotation angle sensor (11) and which is connected to the sliding carriage (3) by means of a connecting element (16).

3. Reach truck according to claim 2, characterized in thatthe connecting element (16) is designed as a connecting rod (20) which is articulated to the rod (15) at a first end (20a) and articulated to the sliding carriage (3) at a second end (20b).

4. Reach truck according to claim 2, characterized in that the connecting element (16) is designed as a cable (21) which is connected to the rod (15) at a first end (21a) and to the sliding carriage (3) at a second end (21b).

5. Reach truck according to one of claims 1 to 4, characterized in that the angle of rotation sensor (11) is operatively connected to a control device (30), in particular an electronic control device, wherein the control device (30) is designed to determine the pushing path and / or the pushing position of the pushing carriage (3) on the basis of the angle of rotation measured by the angle of rotation sensor (11).

6. Reach truck according to one of claims 1 to 5, characterized in thatthe coupling mechanism (12) is operatively connected to a spring device (25).

7. Reach truck according to claim 6, characterized in that the spring device (25) is designed to actuate the rotation angle sensor into an error angle (FW).

8. Reach truck according to claim 7, characterized in that the control device (30) is designed to output an error message when the error angle (FW) is measured.

9. Reach truck according to one of claims 6 to 8, characterized in that the spring device (25) is designed as a torsion spring (26) which is arranged coaxially to a rotation axis (D) of the rotation angle sensor (11).

10. Reach truck according to one of claims 1 to 9, characterized in that the angle of rotation sensor (11) is designed as a magnetoresistive sensor.

11. Reach truck according to one of claims 1 to 9, characterized in that the rotary angle sensor (11) is designed as an optical sensor.

12. Reach truck according to one of claims 1 to 9, characterized in that the rotary angle sensor (11) is designed as a Hall sensor.

13. Reach truck according to one of claims 1 to 9, characterized in that the rotary angle sensor (11) is designed as a potentiometer.

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