JP7795078B2 - Tilt angle estimation system, tilt drive mechanism - Google Patents

Description

The present invention relates to a system capable of estimating the opening and closing angle of an openable/closable gate provided on the bed of a cargo vehicle such as a truck, and a gate drive mechanism equipped with a gate angle estimation system.

With the transportation industry accounting for approximately 5% of Japan's GDP, the logistics industry, which accounts for over 60% of the transportation industry's market, is expanding due to environmental changes and is expected to continue to grow significantly in the future. Meanwhile, the logistics industry is seeking to automate truck loading and unloading operations to address the truck driver shortage and improve safety, and a tilt mechanism has been developed that automatically opens and closes the gates (also known as electric gates) installed on the loading platform (see, for example, Patent Document 1).

When automatically opening and closing a tilt lever using motorization, the tilt angle is used as the control state variable for the tilt lever, and it is common to attach an inclination angle sensor to the tilt lever body to obtain tilt angle information.

Japanese Patent Application Laid-Open No. 2019-182376

However, installing a tilt angle sensor on the inward-facing side of the gate body (the side facing the loading space) reduces the cargo loading area (volume), and there is a risk that if cargo comes into contact with the tilt angle sensor, it could be directly damaged or malfunction. On the other hand, installing a tilt angle sensor on the outward-facing side of the gate body (the side facing away from the loading space) could result in the cargo vehicle's width not being able to stay within the regulated limits, leaving room for improvement. Furthermore, if the tilt angle sensor is installed directly on the gate body, it is difficult to secure space for routing the wiring, and there is also the problem that the wiring, which is constantly moved by the opening and closing movement of the gate body, is prone to damage.

The present invention was made in response to these issues, and its primary objective is to provide a system that can estimate the angle of a tilt that opens and closes automatically, without employing a configuration in which an inclination angle sensor is attached to the tilt itself, and a tilt drive mechanism equipped with such tilt angle estimation.

That is, the present invention relates to a tilt angle estimation system that can be applied to a tilt drive mechanism that automatically opens and closes a tilt provided on the bed of a cargo vehicle using the driving force of an actuator. Examples of cargo vehicles with beds include trucks, trailers, and dump trucks. A tilt is also called a gate, and specific examples include a side tilt (side gate) that defines the side of the bed, and a rear tilt (tailgate) that defines the rear of the bed.

The tilt angle estimation system according to the present invention is characterized by comprising a state value detection unit that directly or indirectly detects the state value of a specific part of the tilt drive mechanism that moves in conjunction with the opening and closing operation of the tilt, and a tilt rotation angle estimation unit that estimates the tilt rotation angle based on the detection value of the state value detection unit during the opening and closing operation of the tilt.

In this type of tilt angle estimation system according to the present invention, the state value detection unit detects the state value (e.g., rotation angle) of a specific part of the tilt drive mechanism that moves with the tilt opening/closing operation during the tilt opening/closing operation, and the tilt rotation angle estimation unit estimates the tilt rotation angle based on the detected value. Therefore, by monitoring the state value of the specific part that moves with the tilt opening/closing operation, the tilt rotation angle can be estimated, eliminating the need to install a tilt angle sensor on the tilt. Therefore, compared to an embodiment in which a tilt angle sensor is installed on the tilt, the introduction of the tilt angle estimation system makes it easier to secure wiring space, prevents wiring from being constantly driven by the opening/closing operation of the tilt main body, and reduces the likelihood of damage to the wiring, improving the robustness and reliability of the system. Furthermore, compared to a configuration in which the tilt angle sensor is mounted on the inward-facing surface of the tailgate, the tailgate angle estimation system of the present invention can avoid damage or malfunction of the sensor due to luggage coming into contact with the tilt angle sensor without narrowing the cargo loading area (volume), and compared to a configuration in which the tilt angle sensor is mounted on the outward-facing surface of the tailgate, it can avoid a situation in which the width of the cargo vehicle exceeds the regulated value by the amount of the tilt angle sensor, making it an extremely practical system.

Furthermore , in the tilt angle estimation system of the present invention, the state value detection unit detects as a detection value the rotation angle of a specified part that moves in proportion to the rotation angle of the tilt when the tilt is opened or closed . Therefore , the detection value can be regarded as being equal to or approximately equal to the rotation angle of the tilt, thereby reducing the load during estimation processing in the tilt rotation angle estimation unit.

In particular, the tilt angle estimation system of the present invention includes a connecting member having one end connected to a movable axis that moves with the tilt opening and closing operation and a predetermined area on the other end connected to a predetermined part that is a part that is a target part for state value detection, and is configured so that the connecting member rotates around the movable axis with the tilt opening and closing operation.The state value detection unit detects the rotation angle of the predetermined part that can be identified based on the rotation angle of the movable axis detected at the movable axis as the state value, and the rotation angle of the predetermined part that moves in proportion to the tilt rotation angle when the tilt is opened and closed is used as the detection value, so that the rotation angle of the predetermined part that is a target part for state value detection can be accurately detected.

Furthermore, by configuring the movable shaft to use a potentiometer as a state detection unit and detecting, as a state value, the "rotation angle of a predetermined part" that can be specified based on the rotation angle of the movable shaft detected by the potentiometer, it is possible to accurately detect the rotation angle of the predetermined part, which is the part targeted for state value detection, despite a relatively simple configuration. In this case, if a table that converts the value detected by the potentiometer into a tilt angle is provided and the tilt angle estimation system is configured to estimate the tilt rotation angle using the table, even if the value detected by the potentiometer differs from the actual tilt angle, the tilt angle can be estimated and output as an appropriate angle via the table.

The tilt drive mechanism of the present invention automatically opens and closes a tilt installed on the bed of a cargo vehicle using the driving force of an actuator, and is characterized by being equipped with the tilt angle estimation system described above. Such a tilt drive mechanism provides the same various effects as the tilt angle estimation system described above, and can be easily introduced into work sites where automation of truck loading and unloading operations is desired.

This invention can detect a tilt collision based on the detection value of an acceleration sensor attached to a specific part of the tilt drive mechanism that moves as the tilt opens and closes. This eliminates the need to install a detection system on the entire surface of the tilt. It is possible to provide a tilt collision detection system that can accurately and quickly detect collisions that occur when the tilt opens and closes automatically, while eliminating the need for a large-scale detection system, and a tilt drive mechanism equipped with such a collision detection system.

1 is an overall schematic diagram of a freight vehicle equipped with a swing angle estimation system according to an embodiment of the present invention; FIG. 2 is a diagram showing a tilt drive mechanism according to the embodiment. FIG. 2 is a diagram showing a tilt drive mechanism (excluding a tilt angle estimation system) according to the embodiment. 6A to 6C are diagrams showing a time series of automatic opening and closing processes of the tilt mechanism performed by the tilt drive mechanism according to the embodiment. FIG. 2 is a configuration diagram of a tilt angle estimation system according to the embodiment. 4 is a diagram corresponding to FIG. 3 showing a tilt drive mechanism in which the tilt estimation system according to the embodiment is implemented. FIG. FIG. 6 is a schematic diagram of a tilt drive mechanism as viewed from the direction a in FIG. 5 . 10A and 10B are diagrams showing, in chronological order, the movement of the connecting member when the tilt is automatically opened or closed in the embodiment; FIG. 10 is a diagram (table data) showing the relationship between the angle of the second arm (arm B) (detection value of the potentiometer) and the tilt angle in the embodiment. 10 is a flowchart of a tilt angle estimation process in the embodiment. 5 is a diagram illustrating a schematic arrangement relationship between a long hole of a connecting member and a pin of a second arm in the embodiment. FIG.

One embodiment of the present invention will be described below with reference to the drawings.

The gate collision detection system X according to this embodiment is a system that can detect when the gate A of the loading platform T1 collides with an obstacle while opening or closing, for example, by being installed in a cargo vehicle T (truck) as shown in Figure 1.

Truck T is a large truck (e.g., a 25-ton truck) equipped with a truck body T3 to which tires T2 are attached and a loading platform T1 mounted on this truck body T3. Figures 1(a) and (b) are schematic side and rear views of truck T, respectively.

The bed T1 of the truck T is rotatably attached via hinges T5 to a frame T4 provided around the floor T6 of the cargo space, and is equipped with gates A (specifically, one pair on each side, for a total of four gates A) that openably cover the lower left and right sides of the cargo space, and wings W that openably cover the space above the cargo space. In order to maintain each gate A in an upright, closed state (A1), pillars (not shown) are provided at the left and right middle and end portions of the frame T4.

Various parts and mechanisms are arranged below the floor T6 of the luggage compartment and the underframe T4. Therefore, the free space below the floor T6 of the luggage compartment and the underframe T4 is quite narrow, and the tilt drive mechanism Y of this embodiment, shown in Figures 2 and 3, is arranged in this narrow space. Figure 2 shows a schematic diagram of the tilt drive mechanism Y and its peripheral devices (hardware), including the power supply that drives the tilt drive mechanism Y. Figure 3 is a simplified schematic diagram of the hardware surrounding the tilt drive mechanism Y, extracted from Figure 2.

In this embodiment, a number of gate drive mechanisms Y corresponding to the number of gates A (four in this embodiment) are provided on the floor T6 of the cargo space and in the open space below the underframe T4, and each gate A can be automatically opened and closed individually by each gate drive mechanism Y. The gate drive mechanisms Y automate the opening and closing of the gates A, which can be a significant burden for workers, and even if the driver of the truck T is an elderly person, female, or other weak person, the gates A can be opened and closed easily.

As shown in Figures 2 and 3, the tilt drive mechanism Y includes a bracket 1 that supports the tilt A. The bracket 1 is fixed to the tilt A at a position higher than the tilt rotation axis (hinge T5) of the tilt A when the tilt A is in the closed state (A1) and rotates integrally with the tilt A around the tilt rotation axis T5 when the tilt A opens or closes. As shown in Figure 3, the tilt drive mechanism Y includes a first arm 2 whose tip (upper end) is pivotally attached to the bracket 1, a second arm 4 whose tip (upper end) is pivotally attached to the base end (lower end) of the first arm 2 in the space below the frame T4 provided around the floor T6 of the luggage compartment, an actuator 5 that is positioned in a recumbent position (sideways) in the space below the frame T4, a third arm 7 whose one end is pivotally attached to the tip of the actuator 5 and that swings around a fixed axis 6 in response to the forward and backward movement of the actuator 5, and a connecting arm 8 that connects the third arm 7 to the second arm 4. The tilt drive mechanism Y is equipped with a link mechanism L made up of multiple arms like this, and by operating the link mechanism L with the actuator 5, the tilt A can be automatically opened and closed.

The actuator 5 includes a rod that can be moved back and forth by the rotational force of a drive motor (e.g., a DC motor) shown in Figure 2, with the tip of the rod pivotally attached to an appropriate location on the third arm 7 (see Figure 3). Note that motors other than DC motors, such as AC motors and servo motors, can also be used as the drive motor. The third arm 7 swings about the fixed axis 6 as the rod moves back and forth. The second arm 4, which is connected to the third arm 7 via the connecting arm 8, rotates as the third arm 7 swings. Therefore, when the tilt A is in the closed state (A1), which is the upright position at +90 degrees as shown in Figures 2 and 3, driving the actuator 5 to move the rod forward in the positive direction causes the third arm 7, connecting arm 8, and second arm 4 to move in unison. As the second arm 4 rotates, the first arm 2 moves downward while remaining in the upright position, gradually changing the tilt A from the closed state (A1) to the open state (A2), which is the upright position at -90 degrees. Figure 4 shows a schematic diagram of how the angle of the tilt A changes in response to the movement of the tilt drive mechanism Y, from +90 degrees (closed state, Figure 4(a)), +45 degrees (Figure 4(b)), 0 degrees (horizontal state, Figure 4(c)), -45 degrees (Figure 4(d)), to -90 degrees (open state, Figure 4(e)). The bracket 1 moves and rotates around the rotation axis (hinge) that connects it to the first arm 2 in unison with the opening and closing movement of the tilt A. The actuator 5 can be configured, for example, so that a motor operated by a 24 volt voltage moves a rod back and forth, and can also include a load retention mechanism that can retain the load applied to the rod even when the motor rotation is stopped.

Tilt drive mechanism Y automatically opens and closes tilt A using the driving force of a motor. Specifically, when a higher-level controller (control unit C) receives a drive command (such as "Open tilt A" or "Close tilt A," which is equivalent to the open/close command shown in Figure 2) based on an operator (such as a truck driver) inputting the drive command via an input device such as an appropriate button, switch, or touch panel, the control unit C generates an angle command to set tilt A to the desired angle, performs position control using this angle command and the actual tilt angle, and generates a speed command that determines how to move the motor (the distance that actuator 5 should move forward or backward). Next, control unit C controls the motor speed by adjusting the speed command, generates a current command, and performs current control using the current command and the motor current (the current actually input to the motor) to drive the motor. As a result, the rod of tilt drive mechanism Y moves forward or backward using the driving force of the motor, automatically opening and closing tilt A. As shown in Figure 2, it is also possible to configure a tilt drive mechanism Y that includes an auxiliary power spring mechanism 51 that applies auxiliary power around the actuator 5, and an acceleration gear section G.

The tilt drive mechanism Y in this embodiment is equipped with a tilt angle estimation system X that estimates the opening and closing angle of the tilt A.

As shown in FIG. 5, the tilt angle estimation system X estimates the angle of tilt A by detecting the movement of the arm (in this embodiment, second arm 4) that moves the same or approximately the same as or similar to the opening/closing angle of tilt A, among the arms (first arm 2, second arm 4, third arm 7, connecting arm 8) of the tilt drive mechanism Y that move in conjunction with the opening and closing movement of tilt A. As shown in FIGS. 5 and 6, the tilt angle estimation system X includes a state value detection unit X1 that directly or indirectly detects the state value (rotation angle) of second arm 4 (corresponding to the "predetermined part" in this invention), which is a predetermined part of the tilt drive mechanism Y that moves in conjunction with the opening and closing movement of tilt A (at a rotation angle that is the same or approximately the same as that of tilt A), and a tilt rotation angle estimation unit X2 that estimates the rotation angle of tilt A based on the detection value of the state value detection unit X1 during the opening and closing movement of tilt A.

As shown in Figures 5 to 7 (Figure 7 is a schematic view from direction a in Figure 5), the tilt angle estimation system X according to this embodiment includes a connecting member X3, one end of which is connected to a movable shaft 3 that moves in conjunction with the opening and closing movement of the tilt, and a predetermined region on the other end of which is connected to the second arm 4. The connecting member X3 is, for example, a flat plate body, and has an elongated hole X31 extending longitudinally in a predetermined region on the other end of which the pin 41 of the second arm 4 is accommodated in the elongated hole X31. In this embodiment, one end of the connecting member X3 is connected to the movable shaft 3, and the connecting member X3 is configured to rotate. Figure 8 schematically shows the connecting member X3, which rotates as the tilt A angle changes from +90 degrees (closed state, Figure 8(a)), to 0 degrees (horizontal state, Figure 8(c)), to -90 degrees (open state, Figure 8(e)). As shown in the figure, the rotational movement of the connecting member X3 is synchronized with the movement of the pin 41 of the second arm 4 housed in the elongated hole X31. Therefore, unless the second arm 4 moves, the connecting member X3 does not move (it remains in that position). However, when the second arm 4 moves, the pin 41 of the second arm 4 moves within the elongated hole X31, and as a result, the connecting member X3 rotates around the movable shaft 3. At this time, the pin 41 of the second arm 4 moves in proportion to the angle of tilt A.

In this embodiment, a potentiometer P is attached coaxially with the movable shaft 3 and is configured to rotate in synchronization with the movement of the pin 41 of the second arm 4. With this configuration, the rotation angle of the movable shaft 3 is detected by the potentiometer P and converted into an electrical signal, making it possible to detect the control state quantity (state value) of the second arm 4, i.e., the rotation angle of the second arm 4. In other words, in this embodiment, the potentiometer P is used to configure the above-mentioned state value detection unit X1.

The value detected by potentiometer P corresponds or nearly corresponds to the rotation angle of second arm 4, but differs from the actual angle of tilt A. Therefore, the tilt angle estimation system X of this embodiment includes a table X4 that converts the value detected by potentiometer P into a tilt angle (see Figure 6), and is configured to estimate the rotation angle of tilt A using this table X4. Figure 9 shows a graph of the relationship between the detected angle of potentiometer P (the arm B angle in Figure 9 is synonymous with the angle of second arm 4) and the actual opening/closing angle of tilt A (the tilt angle in Figure 9), observed when a tilt drive mechanism Y equipped with the tilt angle estimation system X of this embodiment is applied to a freight vehicle. The tilt rotation angle estimation unit X2 estimates the opening/closing angle of tilt A from the detected value (rotation angle) of potentiometer P using table X4. In this embodiment, data based on the graph shown in Figure 9 is used in table X4. In other words, Figure 9 is table data. The relationship between the detected angle of the potentiometer P on table X4 and the actual opening and closing angle of the tilt A may be set based on theoretical values.

When the elongated hole X31 of the connecting member X3 is set as an oval-shaped elongated hole X31 with arc-shaped outer edges at both ends, as shown schematically in Figure 11, when the tilt A angle is +90 degrees (closed state, Figure 8(a)), the pin 41 is set to abut near one end of one of the two straight line portions X31b, X31c extending in the longitudinal direction without abutting the arc-shaped portion X31a at one end of the elongated hole X31 (see Figure 11(a)). When the tilt A angle is -90 degrees (open state, Figure 8(e)), the pin 41 is set to abut near the other end of the other straight line portion X31c of the two straight line portions X31b, X31c extending in the longitudinal direction without abutting the arc-shaped portion X31d at the other end of the elongated hole X31 (see Figure 11(b)). This makes it possible to suppress external forces other than the rotational torque transmitted to the potentiometer P during the opening and closing operation of the tilt angle A when estimating the tilt angle, thereby improving the accuracy of estimating the tilt angle. In this case, the condition is that the distance between the two linear portions X31b, 31c extending in the longitudinal direction that make up the outer edge of the elongated hole X31 is greater than the diameter of the pin 41. In other words, it is essential that the pin 41 is positioned with some play within the elongated hole X31.

The overall control of the tilt angle estimation system X according to this embodiment is managed by the control unit C, and the opening/closing angle of the tilt A estimated by the tilt rotation angle estimation unit X2 is used as the actual opening/closing angle of the tilt A for feedback control of the motor-driven tilt drive mechanism Y. Note that if the tilt angle estimated by the tilt rotation angle estimation unit X2 is accurate enough that feedback control is not necessary, it may be used for open-loop control, etc. The control unit C may be a higher-level control unit (higher-level controller) than the tilt angle estimation system X or the tilt drive mechanism Y, or it may be a control unit dedicated to the tilt angle estimation system X. The control unit C is composed of a normal microprocessor equipped with a CPU, memory, and interface. The programs required for processing are stored in advance in the memory, and the CPU sequentially retrieves and executes the necessary programs to achieve the desired functions in cooperation with peripheral hardware resources.

The process steps for estimating the rotation angle of tilt A using the tilt angle estimation system X according to this embodiment, which has the above configuration, are as follows:

First, when the control unit C receives an operator's input, it drives the tilt drive mechanism Y based on a drive command corresponding to the received input information (such as a command to "open tilt A" or "close tilt A") to switch tilt A from the closed state (A1) to the open state (A2) or from the open state (A2) to the closed state (A1). During this automatic tilt opening/closing process, the tilt angle estimation system X detects the state value of the second arm 4, i.e., the rotation angle of the second arm 4, using the state value detection unit X1 that uses the potentiometer P (state value detection step S1, see Figure 10), and estimates the rotation angle of tilt A based on the detected state value and table X4 (tilt rotation angle estimation step S2). If the opening/closing operation of tilt A is still ongoing, the process returns to state value detection step S1 and repeats the above-described process.

After the above processing, for example, the control unit C can be configured to detect a collision of tilt A based on the estimated tilt angle. Specifically, the control unit C can be configured to compare the angle of tilt A estimated by the tilt angle estimation process (actual tilt angle) with the angle command sent to the motor that drives the tilt drive mechanism Y, and determine that tilt A has collided if the actual tilt angle differs from the angle command by more than a predetermined reference value. If it is determined that tilt A has collided, executing appropriate post-collision processing (such as stopping the motor, moving tilt A in the opposite direction to the rotation direction at the time of collision detection, issuing a warning sound, or displaying a warning on a monitor in the cab) will greatly contribute to improved safety. Note that the opening and closing operation of the tilt A by the tilt drive mechanism Y is not limited to switching the tilt A from the closed state (A1) to the open state (A2) or from the open state (A2) to the closed state (A1), but also includes switching from the closed state (A1) or open state (A2) to any tilt angle (any angle in the range of -89 degrees to +89 degrees), switching from any tilt angle to the closed state (A1) or open state (A2), and switching between any tilt angles.

As described above, according to the tilt angle estimation system X of this embodiment, when the tilt A opens or closes, the state value detection unit X1 detects the rotation angle, which is the state value of the second arm 4 of the tilt drive mechanism Y that moves in conjunction with the opening or closing movement of the tilt A, and the tilt rotation angle estimation unit X2 estimates the rotation angle of the tilt A based on the detected value. Therefore, by monitoring the rotation angle, which is the state value of the second arm 4 that moves in conjunction with the opening or closing movement of the tilt A, the rotation angle of the tilt A can be estimated, eliminating the need to provide a tilt angle sensor on the tilt A. Therefore, according to the tilt angle estimation system X of this embodiment, compared to an embodiment in which a tilt angle sensor is provided on the tilt A, the introduction of the tilt angle estimation system X simplifies wiring, preventing the wiring from being constantly driven by the opening or closing movement of the tilt A and reducing the likelihood of damage to the wiring, thereby improving the robustness and, ultimately, reliability of the system. Furthermore, the swing-up angle estimation system X according to this embodiment has the advantage of not interfering with the cargo loading area (not reducing the volume) compared to a configuration in which an inclination angle sensor is mounted on the inward surface of the swing-up A, and the advantage of being able to keep the width of the cargo vehicle T within regulated values compared to a configuration in which an inclination angle sensor is mounted on the outward surface of the swing-up A, making it an extremely useful system.

In particular, in the tilt angle estimation system X according to this embodiment, the state value detection unit X1 detects, as a state value, the rotation angle of the second arm 4 of the link mechanism L, which moves in proportion to the rotation angle of the tilt A when the tilt A is opened or closed. This state value can be considered to be movement that is equal to, substantially equal to, or approximates the actual rotation angle of the tilt A, thereby reducing the load on the tilt rotation angle estimation unit X2 during estimation processing and contributing to improved estimation processing speed.

Furthermore, the tilt angle estimation system X according to this embodiment includes a connecting member X3, one end of which is connected to the movable shaft 3, which moves in conjunction with the opening and closing movement of the tilt A, and a predetermined region on the other end of which is connected to the second arm 4, which is a part targeted for state value detection. The connecting member X3 is configured to rotate around the movable shaft 3 in conjunction with the opening and closing movement of the tilt A, and is configured to detect, as a state value, the "rotation angle of the second arm 4," which can be determined based on the rotation angle of the movable shaft 3 detected by a potentiometer P provided on the movable shaft 3. Therefore, despite the relatively simple configuration, the rotation angle of the second arm 4, which is a part targeted for state value detection, can be accurately detected. This also avoids the high costs associated with introducing a system.

In addition, the tilt angle estimation system X according to this embodiment is equipped with a table X4 that converts the value detected by the potentiometer P into a tilt angle, and is configured to estimate the rotation angle of the tilt A using this table X4. Therefore, even if the value detected by the potentiometer P differs from the actual tilt angle, the appropriate tilt angle can be estimated and output via the table X4.

Although the above describes an embodiment of the present invention, the present invention is not limited to the configuration of the above embodiment. For example, in the above embodiment, the rotation angle of tilt A is estimated by monitoring the rotation angle, which is the state value of second arm 4 that moves in conjunction with the opening and closing movement of tilt A, but the present invention is not limited to this. For example, the tilt angle estimation system of the present invention can also be realized by using other parts that make up the tilt drive mechanism, such as an arbitrary arm selected from the multiple arms that make up the link mechanism, an axis that connects the arms (an axis that moves in conjunction with the opening and closing movement of tilt), or a bracket of the tilt drive mechanism as the "predetermined part (part for which state value detection is targeted)" in the present invention.

In particular, it is preferable to configure the tilt angle to be estimated by detecting the operation of a component part of the tilt drive mechanism that moves in the same way (or moves similarly) to the tilt in response to the opening and closing of the tilt as the "state value of a specified part (part subject to state value detection)" in this invention.

Furthermore, when using a connecting member, instead of connecting one end of the connecting member to a movable shaft (movable shaft 3 in the above embodiment) that moves with the opening and closing of the tilt among the shafts that make up the tilt drive mechanism, it may be connected to a dedicated movable shaft (a movable shaft that does not make up the tilt drive mechanism) or a fixed shaft (a shaft that does not move with the opening and closing of the tilt). Furthermore, instead of accommodating a pin of an arm in a slot formed in a predetermined area on the other end of the connecting member, it may also accommodate an axis (movable shaft) that connects parts that make up the tilt drive mechanism and moves with the opening and closing of the tilt. Furthermore, depending on the rotation angle range of the connecting member associated with the opening and closing of the tilt, a notch (slit) that opens to the other end rather than a slot may be formed on the other end of the connecting member, and a pin (protrusion) or movable shaft may be accommodated in the notch. In this case, the applicable condition is that the pin or movable shaft will not fall out of the notch regardless of the rotation angle of the connecting member during the opening and closing of the tilt.

The present invention also includes a configuration in which the value detected by the potentiometer is not provided with a table for converting the value into a tilt angle, and the value detected by the potentiometer is directly estimated as the tilt rotation angle.

In addition, the state value detection unit may use a sensor that directly detects the rotation angle of the part for which state values are to be detected, rather than using a potentiometer.

The present invention also includes a configuration in which the amount of forward and backward movement of the actuator is detected by a state value detection unit as a state value for a specific part of the tilt drive mechanism that moves in conjunction with the opening and closing movement of the tilt, and the tilt rotation angle estimation unit estimates the tilt rotation angle based on that detected value.

Specific examples of the tilt drive mechanism are not limited to the tilt drive mechanism Y described above; the tilt angle estimation system of the present invention can be applied to any mechanism that automatically opens and closes the tilt using the driving force of an actuator. The tilt angle estimation system may be a system included in the tilt drive mechanism, or it may be a system that is mechanically or electrically separated from the tilt drive mechanism.

Cargo vehicles on which the tilt angle estimation system of the present invention alone, or a tilt drive equipped with the tilt angle estimation system, can be implemented are not limited to trucks (classified according to load capacity: small trucks (2-ton and 3-ton trucks), medium-sized trucks (4-ton trucks), large trucks (10-ton trucks), and light trucks), but can also be implemented in cargo vehicles such as trailers and dump trucks.

In the above-described embodiment, the side gates (lateral gates) that define the sides of the loading platform are used as an example of the gates, but collision detection can also be performed when the rear gates that define the rear of the loading platform are opened or closed. Note that gates are also called gates (side gates, back gates).

In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention.

A...Aori T...Cargo vehicle (truck)
T1...Platform P...Potentiometer X...Tilt angle estimation system X1...State value detection unit X2...Tilt rotation angle estimation unit X3...Connecting member X4...Table Y...Tilt drive mechanism

Claims (4)

A tilt angle estimation system applicable to a tilt drive mechanism that automatically opens and closes a tilt provided on the bed of a freight vehicle using an actuator,
a state value detection unit that directly or indirectly detects a state value of a predetermined part of the tilt drive mechanism that moves in accordance with the opening and closing operation of the tilt;
a tilt rotation angle estimating unit that estimates a rotation angle of the tilt based on a detection value of the state value detecting unit during an opening or closing operation of the tilt ;
a connecting member having one end connected to a movable shaft that moves in accordance with the opening and closing operation of the tilt, and a predetermined region on the other end connected to the predetermined part ,
The connecting member is configured to rotate around the movable shaft in accordance with the opening and closing operation of the tilt.
a potentiometer is provided on the movable shaft;
a state value detection unit that detects, as the state value, a rotation angle of the predetermined part that can be specified based on the rotation angle of the movable shaft detected by the potentiometer, and detects, as the detection value, a rotation angle of the predetermined part that moves in proportion to the rotation angle of the tilt when the tilt is opened or closed . 2. The tilt angle estimation system according to claim 1 , further comprising a table for converting a value detected by the potentiometer into a tilt angle, and configured to estimate the tilt rotation angle using the table. A tilt angle estimation system applicable to a tilt drive mechanism that automatically opens and closes a tilt provided on the bed of a freight vehicle using an actuator,
a state value detection unit that directly or indirectly detects a state value of a predetermined part of the tilt drive mechanism that moves in accordance with the opening and closing operation of the tilt;
a tilt rotation angle estimating unit that estimates a rotation angle of the tilt based on a detection value of the state value detecting unit during an opening or closing operation of the tilt ;
a connecting member having one end connected to a movable shaft that moves in accordance with the opening and closing operation of the tilt, and a predetermined region on the other end connected to the predetermined part ,
The connecting member is configured to rotate around the movable shaft in accordance with the opening and closing operation of the tilt.
a state value detection unit that detects, as the state value, a rotation angle of the predetermined part that can be identified based on a rotation angle of the movable shaft detected in the movable shaft, and sets, as the detected value, a rotation angle of the predetermined part that moves in proportion to the rotation angle of the tilt when the tilt is opened or closed. A gate drive mechanism that automatically opens and closes a gate provided on a cargo vehicle bed by an actuator,
A tilt drive mechanism comprising the tilt angle estimation system according to any one of claims 1 to 3 .