JP7364509B2 - Wheel drive device, trolley with wheel drive device - Google Patents

Description

The present invention relates to a wheel drive device and a truck equipped with the wheel drive device.

2. Description of the Related Art Wheel drive devices that drive wheels of transportation vehicles and the like are known. The present applicant discloses a wheel drive device in Patent Document 1. This wheel drive device includes a speed reduction mechanism that decelerates the rotation transmitted from the drive source, a rotating body to which the rotation reduced by the speed reduction mechanism is transmitted, and wheels that are integrated with the rotating body.

Japanese Patent Application Publication No. 2018-144778

The wheel drive device of Patent Document 1 has room for improvement from the viewpoint of facilitating the manufacture of the truck.
An object of the present invention has been made in view of such problems, and is to provide a wheel drive device that can easily manufacture a truck.

In order to solve the above problems, a wheel drive device according to an aspect of the present invention is a wheel drive device that can be integrally attached to a vehicle body, and includes a motor and an output shaft for transmitting output rotation to the wheels. and a detection unit for detecting objects existing around the vehicle body.

Note that arbitrary combinations of the above-mentioned components and mutual substitution of the components and expressions of the present invention between methods, systems, etc. are also effective as aspects of the present invention.

According to the present invention, it is possible to provide a wheel drive device that can easily manufacture a truck.

FIG. 1 is a perspective view showing a first example of a truck equipped with a wheel drive device according to a first embodiment. FIG. 2 is a plan view schematically showing the cart of FIG. 1. FIG. FIG. 2 is a plan view schematically showing the configuration of the wheel drive device shown in FIG. 1. FIG. FIG. 2 is a plan view schematically showing a second example of a truck equipped with the wheel drive device of FIG. 1; FIG. 5 is a schematic diagram illustrating an example of control parameters for the truck in FIG. 4;

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on preferred embodiments with reference to the drawings. In the embodiments and modified examples, the same or equivalent components and members are given the same reference numerals, and redundant explanations will be omitted as appropriate. Further, the dimensions of members in each drawing are shown enlarged or reduced as appropriate to facilitate understanding. Further, in each drawing, some members that are not important for explaining the embodiments are omitted.

Also, although ordinal terms such as first, second, etc. are used to describe various components, these terms are used only to distinguish one component from another; The components are not limited by this.

[First embodiment]
Hereinafter, a wheel drive device 10 according to a first embodiment will be described with reference to the drawings. FIG. 1 is a perspective view schematically showing a truck 100 including a wheel drive device 10. As shown in FIG. This figure shows the trolley 100 viewed diagonally from below. FIG. 2 is a plan view schematically showing the trolley 100. The trolley 100 includes a flat car body 80 on which a load is loaded, two wheel drive devices 10 fixed to the lower surface of the car body 80 at a distance from each other in the left and right directions, and wheels to which the output rotation of the wheel drive devices 10 is transmitted. 18. Note that FIG. 2 and the following plan views show the vehicle body 80 seen through. 2 and the following plan views, for convenience, the upper side of the figure is referred to as "front", "front", the lower side of the figure is referred to as "rear", "rear", and the left side of the figure is referred to as "left". The middle right side is called "right". Further, the left-right direction is sometimes referred to as the width direction. Note that the use of the wheel drive device 10 is not limited to trolleys, but can be applied to various vehicles.

Further, the trolley 100 is provided with two casters 82 that are spaced apart from each other in the left and right directions on the lower surface of the vehicle body 80. The trolley 100 can move forward, backward, stop, turn, etc. by controlling the wheel drive device 10 by remote control, tracking control, autonomous control, or the like.

As an example, the trolley 100 may include a battery (not shown) that supplies power to the wheel drive device 10 and an autonomous travel module (not shown) for autonomous travel. This autonomous driving module controls the wheel drive device 10 so that the trolley 100 travels along a predetermined route based on a command from a host system and with reference to own vehicle position information and map information. The autonomous traveling module may be controlled while measuring the distance to surrounding objects, or may be controlled so as to travel along a guidance line.

FIG. 3 is a plan view schematically showing the configuration of the wheel drive device 10. The wheel drive device 10 is configured to be integrally attachable to the vehicle body 80. The wheel drive device 10 mainly includes an output shaft 12, a motor 14, a speed reducer 16, detection units 20, 22, and a casing 50, which are integrally integrated and modularized. Although not limited to, it is assumed that the wheel drive device 10 is manufactured as a module and distributed as a module.

In the wheel drive device 10, all the components described in this embodiment do not need to be modularized, and at least the motor 14, the output shaft 12, and the detection section 20 can be modularized and integrally attached to the vehicle body 80. Good to have. Further, it may be possible to attach the components integrally to the vehicle body as a module, or to attach each component to the vehicle body separately, so that the user can select how to attach them.

Therefore, by attaching the wheel drive device 10 manufactured as a module to a vehicle body of each shape according to each application, a user of the truck can easily manufacture a truck with various specifications. For example, using a single type of wheel drive device 10, it is possible to manufacture carts with a wide range of loads, such as two wheel drive devices for two-wheel drive, four wheels for four-wheel drive, and six wheels for six-wheel drive. Since the wheel drive device 10 is modularized, the number of manufacturing steps can be reduced compared to the case where the wheel drive device is assembled by collecting individual members in the process of manufacturing a truck.

The output shaft 12 transmits the output rotation of the wheel drive device 10 to the wheels 18 . Hereinafter, the direction along the central axis La of the output shaft 12 will be referred to as the "axial direction", and the circumferential direction and radial direction of a circle centered on the central axis La will be referred to as the "circumferential direction" and the "radial direction", respectively. . The output shaft 12 in this example is the output shaft of the reduction gear 16. The reducer 16 reduces the rotation of the motor 14 and outputs it to the output shaft 12 .

The motor 14 functions as a prime mover that rotationally drives the output shaft 12 via a reduction gear 16 . The motor 14 only needs to be capable of driving the output shaft 12, and motors based on various principles can be employed. The motor 14 of this embodiment is a servo motor. In this case, it is preferable because it is small, has a large output, has a relatively long life, and requires almost no maintenance.

The reducer 16 may be of any type as long as it can reduce the input rotation input from the motor 14 and output it to the output shaft 12, such as an eccentric oscillation type reducer, a simple planetary gear device, a flexible mesh gear device, It may also be a simple gear reduction gear. The speed reducer 16 is not limited to a meshing gear device, and may include a belt, chain, pulley, roller, etc.

The casing 50 functions as an outer shell that houses the output shaft 12, the motor 14, the reducer 16, and the detection units 20 and 22. The casing 50 has a mounting portion (not shown) for being fixed to the vehicle body 80. The casing 50 is provided with a bearing (not shown) that rotatably supports the output shaft 12.

The detection units 20 and 22 detect objects existing around the vehicle body 80. Objects to be detected by the detection units 20 and 22 include space division elements such as shelves and walls, other carts, animals such as people, luggage, and other foreign objects (obstacles). The wheel drive device 10 is configured to be able to perform avoidance operations such as decelerating, stopping, reversing, or turning the truck 100 based on the detection information from the detection units 20 and 22.

The detection units 20 and 22 may be any part provided for detecting an object, and may be a sensor for detecting an object, or a mounting part for mounting an object detection sensor such as a connector or a socket. It may be a member that defines a housing space for mounting an object detection sensor, or it may be an input unit into which detection information from a sensor is input. That is, the detection units 20 and 22 may have a structure in which, instead of the sensors themselves, mounting parts for mounting the sensors are provided at the front and rear, respectively, and the sensor is mounted only on the mounting part to be used.

Regarding the wheel drive device, devices with different configurations may be provided for right front, left front, right rear, and left rear depending on the direction of the output shaft and the detection direction of the sensor. In this case, manufacturing, distribution and management become complicated, which is disadvantageous in terms of cost. Therefore, the detection units 20 and 22 of this embodiment include a first detection unit 20 on one side in the front-rear direction with respect to the output shaft 12, and a second detection unit 22 on the other side in the front-rear direction. By providing the first detection section 20 and the second detection section 22, a common wheel drive device 10 can be used for the front wheels and the rear wheels. Further, a common wheel drive device 10 can be used for the left wheel and the right wheel.

In the example of FIG. 3, the first detection unit 20 includes sensors 20f, 20d, and 20s that detect objects. The second detection unit 22 includes sensors 22f, 22d, and 22s that detect objects. The sensors 20f and 22f detect objects in the front and back directions of the vehicle body 80, the sensors 20s and 22s detect objects on the sides of the vehicle body 80, and the sensors 20d and 22d detect objects in the diagonal direction of the vehicle body 80. . The detection method of these sensors is not particularly limited as long as they can detect an object, but it is preferable that they are distance sensors that can measure the distance to the object.

In the example of FIG. 3, the first and second detection units 20 and 22 include push sensors 20g and 22g. The push sensors 20g and 22g are sensors that detect contact with an object. The push sensors 20g and 22g may protrude to the front or rear of the vehicle body 80 to directly detect contact with an object, or may be connected to a bumper or the like to indirectly detect contact.

It is desirable that the relative position of the sensor to the output shaft 12 does not change when the same wheel drive device 10 is attached to the front side of the vehicle body 80 and when it is attached to the rear side. Therefore, in this embodiment, the first detection section 20 and the second detection section 22 are arranged symmetrically with respect to the output shaft 12. In this case, even if the front and back are switched, the relative position of the sensor to the output shaft 12 can be kept constant. The first detection section 20 and the second detection section 22 may be line symmetrical with respect to the output shaft 12 in a plan view. Further, the first detection unit 20 and the second detection unit 22 may be rotationally symmetrical with respect to the output shaft 12 twice (when rotated 180 degrees, their positions are swapped) when viewed in the axial direction. . In this case, the height of the sensor can be kept constant even if the front and back are swapped.

It is desirable that a common wheel drive device 10 can be used not only for the front and rear but also for the left and right sides. In the wheel drive device 10 of this embodiment, by providing the first detection section 20 and the second detection section 22, a common wheel drive device 10 can be used for the left and right sides. If the left wheel is shown in FIG. 3, it can be used as a right wheel by rotating the wheel drive device 10 by 180 degrees within the plane of FIG. In this case, the second detection unit 22 is arranged at the front (upper side in FIG. 3). Further, the wheel drive device 10 may be configured to be attachable to the vehicle body 80 even when rotated 180 degrees around the output shaft 12. As an example, this configuration can be realized by arranging the attachment portion of the casing 50 to the vehicle body 80 in two-fold rotational symmetry with respect to the output shaft 12 when viewed in the axial direction.

Further, a common attachment portion may be provided that can be attached to the vehicle body either before or after rotating 180 degrees. In this case, if the wheel drive device 10 is rotated 180 degrees, the front and back will be reversed, so it is sufficient to provide sensors only on one side. Specifically, if the left front wheel is shown in FIG. 3 and does not have the second detection unit 22, when the output shaft 12 is rotated 180 degrees, the first detection unit 20 detects the rear side. It can be used as the left rear wheel. In addition, by rotating it 180 degrees around the output shaft 12 and further rotating it 180 degrees within the plane of FIG. 3, it can be used as a right front wheel. When rotated 180 degrees within the plane of Figure 3, it can be used as the right rear wheel.

The contact sensor 30 will be explained with reference to FIG. In the example of FIG. 2, the trolley 100 is a two-wheel drive vehicle, and is provided with wheel drive devices 10 at two locations, one on the left front portion and one on the right front portion of the vehicle body 80. When the trolley 100 comes into contact with an obstacle, it is desirable that the wheel drive device 10 stop traveling. Therefore, the detection units 20 and 22 of this embodiment include a contact sensor 30 that detects contact with an object. The left and right wheel drive devices 10 are configured to stop running when the contact sensor 30 detects contact of the trolley 100 with an object. In this case, damage upon contact can be reduced.

As shown in FIG. 2, the truck 100 is provided with a bumper 32 to reduce damage caused by contact with objects such as other trucks or shelves. As an example, the bumper 32 is provided on one of the front and rear sides of the vehicle body 80. The contact sensor 30 is provided on the bumper 32, and provides detection information from the contact sensor to the left and right wheel drive devices 10 through the signal cable 30c. In this case, the left and right wheel drive devices 10 can stop their own running based on the detection information of the contact sensor 30 when the bumper 32 comes into contact with an object. As a result, damage to the object and truck 100 can be further reduced. The bumper 32 may be connected to the left and right wheel drive devices 10.

As an example, the contact sensor 30 includes a tape type switch, and the wheel drive device 10 acquires a detection signal from the contact sensor 30 that is turned off when there is no contact and turned on when there is contact. When the contact sensor 30 detects the contact, the wheel drive device 10 may stop the motor 14, operate an electromagnetic brake (short brake) on the motor 14, or cause the motor 14 to generate reverse rotation torque. The contact sensor 30 is connected in parallel to the left and right wheel drive devices 10, and when contact is detected, can stop both the left and right wheel drive devices 10 from running at the same time. Note that when the contact sensor 30 provided on the bumper 32 is used, the push sensors 20g and 22g provided on the wheel drive device 10 may be omitted, or the push sensors 30 provided on the bumper 32 may be replaced with the push sensors 20g and 22g provided on the bumper 32. may be detected by the push sensors 20g and 22g.

Referring to FIG. 4, a case will be described in which the trolley 100 is a four-wheel drive vehicle. FIG. 4 is a plan view schematically showing a second example of a truck 100 including four wheel drive devices 10. In the example of FIG. 4, the truck 100 is equipped with wheel drive devices 10 at four locations: a left front portion, a right front portion, a left rear portion, and a right rear portion of the vehicle body 80. Further, a set of a bumper 32 and a contact sensor 30 are provided at the front and rear of the vehicle body 80. The front and rear contact sensors 30 are connected in parallel to each of the four wheel drive devices 10 on the front, rear, left and right sides through a signal cable 30j. Therefore, when one of the two front and rear contact sensors 30 detects a contact, the detection information of the contact sensor 30 is provided to each of the four wheel drive devices 10 through the signal cables 30c and 30j. In this case, the four wheel drive devices 10 can simultaneously stop their own running based on the detection information of the contact sensor 30. That is, the trolley 100 stops when contact is detected during forward movement and backward movement.

Note that when the trolley 100 is two-wheel drive, the bumper 32 and the contact sensor 30 may be provided at the front and rear of the vehicle body 80, respectively. Furthermore, when the truck 100 is a four-wheel drive vehicle, the bumper 32 and the contact sensor 30 may be provided at either the front or the rear of the vehicle body 80.

When one wheel drive device 10 detects an object, it may not be possible to avoid the object by operating only that wheel drive device 10, so it is desirable that the other wheel drive devices 10 can operate in coordination. Therefore, from the viewpoint of realizing left and right cooperative operation, it is desirable that the wheel drive device 10 be able to acquire the detection results of the detection units 20 and 22 of the other wheel drive devices 10 mounted on the same truck 100. Therefore, the wheel drive device 10 of this embodiment includes a communication section 44 that communicates detection information from the detection sections 20 and 22 with other wheel drive devices 10. For example, when the detection units 20 and 22 of one wheel drive device 10 detect an object, the left and right wheel drive devices 10 can cooperate to perform an operation to avoid the object.

The communication unit 44 of this embodiment communicates information by wireless communication. The communication unit 44 may communicate information through wired communication.

Even when three or more wheel drive devices 10 are mounted on the same truck 100, each wheel drive device 10 can realize cooperative operation by communicating detection information from the detection units 20 and 22 with each other.

When a plurality of wheel drive devices 10 perform a cooperative operation, a predetermined wheel drive device 10 may be used as a master, and the remaining wheel drive devices 10 may be used as slaves. A cooperative operation can be realized by the master wheel drive device 10 controlling the slave wheel drive devices 10 in a unified manner. Further, apart from the standard configuration of the wheel drive device 10, a coordination control section (not shown) that controls cooperative operation of the plurality of wheel drive devices 10 may be provided.

This cooperative control unit may be provided in each wheel drive device 10, may be provided in a specific wheel drive device 10, may be provided in the trolley 100 separately from the wheel drive device 10, It may be provided outside the trolley 100. Note that when the trolley 100 is provided with a plurality of cooperative control sections, a specific cooperative control section among them may be operated, and the remaining cooperative control sections may be made inactive.

For example, when autonomously traveling from one point to another in a warehouse along a curved path between shelves, the trolley takes into account the difference between the inner and outer wheels and uses a track that does not come into contact with the shelves (hereinafter referred to as a "compatible track"). '') and run on the appropriate trajectory. For example, the wheel drive device 10 determines a turning radius, a turning start position, a turning end position, a turning speed, etc. by itself in order to travel around a bend on a suitable track.

Even if the bogies are equipped with the same wheel drive device 10, the compatible trajectory differs depending on parameters such as the size of the bogie, the diameter of the wheels, the tread width of the wheels, and the wheel base (hereinafter referred to as "control parameters"). In other words, when a truck user manufactures a truck using the wheel drive device 10, the user of the truck is required to change the control program of the wheel drive device 10 according to the control parameters. This modification work required advanced knowledge and skills, and was also complicated.

Therefore, the wheel drive device 10 of this embodiment includes a control unit 40 that receives control parameters input by the user and controls the wheels 18. In this case, the wheel drive device 10 receives the control parameters, automatically determines a suitable trajectory, and can travel on the determined suitable trajectory.

FIG. 5 is an explanatory diagram illustrating an example of control parameters for the trolley 100. In this figure, a circumscribed quadrangle circumscribing the trolley 100 is shown by a broken line. The circumscribed rectangle may be set to include a protrusion of the cart 100, etc. There are no restrictions on control parameters. The control parameters of this embodiment include the width W1 of the circumscribed rectangle, the distance W2 between the centers of the left and right wheels 18 in the width direction, the longitudinal length L1 of the circumscribed rectangle, the distance L2 between the centers of the front and rear wheels 18 in the longitudinal direction, and the wheels 18. It includes an outer diameter Dw of 18. In this example, the distance L2 is equal to the distance between the centers of the respective output shafts, and the distance W2 is equal to the distance between the centers of the respective ground contact areas of the left and right wheels 18 in the width direction.

Although there is no limit to the means for accepting control parameters, for example, a reception unit that accepts control parameters may be provided. The control parameter reception unit may be provided in each wheel drive device 10, may be provided in a specific wheel drive device 10, or may be provided in the trolley 100 separately from the wheel drive device 10. , may be provided outside the trolley 100.

In this embodiment, a control parameter reception unit is provided in a so-called tablet-type external information terminal 60. The external information terminal 60 includes a touch panel 60p that receives user operations, and a terminal communication section 60c that communicates the received results with the communication section 44 of the wheel drive device 10. The external information terminal 60 may be a desktop information terminal. Further, the external information terminal 60 may communicate with the trolley 100 or the wheel drive device 10 via an information network such as the Internet. The external information terminal 60 may receive control parameters in the form of a question.

In the system described above, it is desirable to be able to fine-tune the adaptive trajectory automatically determined by the wheel drive 10 based on control parameters. Therefore, the wheel drive device 10 of this embodiment includes a trajectory correction unit 46 that receives correction information input by the user and corrects the suitable trajectory. The trajectory correction unit 46 generates a corrected suitable trajectory based on the received correction information. The wheel drive device 10 travels based on the modified trajectory. Modification information may be received, communicated, and processed by similar means and methods as control parameters.

The features of this embodiment configured as above will be explained. With the wheel drive device 10, a user of the bogie can easily manufacture desired bogies with various specifications by attaching the wheel drive device 10 to a vehicle body of each shape according to each application. Since the wheel drive device 10 can be used both front and rear, and right and left, it is advantageous in terms of manufacturing, distribution, and management costs. Since the contact sensor 30 is included, the operation can be quickly stopped upon contact with an object, thereby reducing contact damage. Control parameters can be easily set, and even users without advanced knowledge or skills can easily use it.

[Second embodiment]
Next, a truck 100 according to a second embodiment will be explained. The bogie 100 of the present embodiment is a bogie equipped with a wheel drive device 10, which is integrally attached to the vehicle body 80 and has a motor 14 and a motor for transmitting output rotation to the wheels 18. The bogie 100 has an output shaft 12 and detection units 20 and 22 for detecting objects existing around the vehicle body 80, and the bogie 100 receives control parameters input by the user and controls the wheels 18. A control section 40 is provided.

This embodiment has similar features to the first embodiment.

The above description is based on the embodiments of the present invention. Those skilled in the art will understand that these embodiments are illustrative and that various modifications and changes are possible and within the scope of the claims of the present invention. It is about to be done. Accordingly, the description and drawings herein are to be regarded in an illustrative rather than a restrictive sense.

Modifications will be described below. In the drawings and description of the modified example, the same reference numerals are given to the same or equivalent components and members as in the embodiment. Explanation that overlaps with the embodiment will be omitted as appropriate, and configurations that are different from the embodiment will be mainly explained.

In the description of the first embodiment, an example was shown in which the trolley 100 has a function of traveling along a predetermined route based on a command. It may also have a tracking function.

In the description of the first embodiment, an example is shown in which the bumper 32 and the contact sensor 30 are provided at the front or rear of the vehicle body 80, but the bumper 32 and the contact sensor 30 may also be provided at the side of the vehicle body 80. good. In this case, the trolley 100 can be stopped even when there is a side contact.

In the description of the first embodiment, an example was shown in which the wheel drive device 10 includes the reducer 16, but it is not essential to include the reducer 16, and the output shaft 12 may be driven at the same speed as the motor shaft. Alternatively, it may be directly driven by the motor 14.

In the description of the first embodiment, an example was shown in which the wheel drive device 10 is modularized without the wheels 18, but the wheel drive device 10 with the wheels 18 attached may be modularized. That is, a module of the wheel drive device 10 having the wheels 18 may be manufactured and distributed.

In the description of the first embodiment, an example was shown in which the wheel drive device 10 includes a sensor that detects an object, but the wheel drive device 10 includes various types of sensors such as an acceleration sensor and a gyro sensor in addition to the object detection sensor. It may be installed.

Each of the above-described modifications has the same functions and effects as the first embodiment.

Any combination of the above-described embodiments and modifications are also useful as embodiments of the present invention. A new embodiment resulting from the combination has the effects of each of the combined embodiments and modifications.

10 wheel drive device, 12 output shaft, 14 motor, 16 speed reducer, 18 wheel, 20 first detection unit, 20d, 20f sensor, 20s sensor, 22 second detection unit, 30 contact sensor, 32 bumper, 40 control unit, 44 communication department, 80 car body, 100 trolley.

Claims (10)

A wheel drive device that can be integrally attached to a vehicle body,
comprising a motor, an output shaft for transmitting output rotation to the wheels, and a detection section for detecting objects existing around the vehicle body ,
The wheel drive device is characterized in that the detection section includes a first detection section on one side in the longitudinal direction with respect to the output shaft, and a second detection section on the other side in the longitudinal direction. The wheel drive device according to claim 1, further comprising a speed reducer that reduces rotation of the motor. The wheel drive device according to claim 1 or 2, wherein the detection unit includes a sensor that detects an object. The wheel drive device according to any one of claims 1 to 3, wherein the first detection section and the second detection section are arranged symmetrically with respect to the output shaft. The wheel drive device according to any one of claims 1 to 4 , wherein the wheel drive device can be attached to the vehicle body even when the wheel drive device is rotated 180 degrees around the output shaft. A wheel drive device that can be integrally attached to a vehicle body,
comprising a motor, an output shaft for transmitting output rotation to the wheels, and a detection section for detecting objects existing around the vehicle body,
The wheel drive device, wherein the detection unit includes a contact sensor that detects contact with an object. The wheel drive device according to claim 6 , wherein the contact sensor detects contact between a bumper provided on the vehicle body and an object. The wheel drive device according to any one of claims 1 to 7 , further comprising a communication unit that communicates detection information of the detection unit with another wheel drive device. The wheel drive device according to any one of claims 1 to 8 , further comprising a control section that receives control parameters input by a user and controls the wheels. A truck equipped with the wheel drive device according to claim 1 or claim 6 ,
The present truck is a truck equipped with a wheel drive device, characterized in that the truck includes a control section that receives control parameters input by a user and controls the wheels.

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