Vehicle coupling device

Abstract

To provide a vehicle coupling device that can prevent wheels or the like of a vehicle body and of a vehicle to be towed from digging the soft ground on which the vehicle body runs or digging a hole in the ground so as to rough the ground, when the vehicle body runs on the soft ground or the like while towing the vehicle to be towed.SOLUTION: A vehicle coupling device 3 is constituted of an annular rail 31 in a round shape which surrounds a vehicle body, a coupling arm 66 that extends from a vehicle to be towed and a coupling box 41 into which a tip 67 of the coupling arm 66 is inserted, where in the coupling box 41 are provided first rolling bearings 55 having outer rings 56 that rotate while contacting an outer peripheral surface 33 of the annular rail 31, second rolling bearings 58 having inner rings 60 that rotate while contacting an inner peripheral surface 32 of the annular rail 31, and third rolling bearings 61 having inner rings 63 that rotate while contacting the inner peripheral surface 32 of the annular rail 31.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a vehicle coupling device. [Background technology]

[0002] Farmers who grow crops in fields have a wide range of tasks to perform in the fields. These tasks include spraying fertilizer and pesticides, thinning the crops, and harvesting the ripe crops. For example, if the fertilizer is solid, the farmer must carry the fertilizer to the spraying location. Also, if liquid pesticides or fertilizers are being sprayed, the farmer must carry a tank and sprayer containing the pesticide or fertilizer on his back and go around spraying the pesticide or fertilizer on the field. Furthermore, when harvesting crops, the farmer must place containers for the harvested products in various locations in the field and retrieve the containers when they become heavy with the harvested products. BACKGROUND ART A variety of agricultural work vehicles have been proposed for the purpose of efficiently performing work in fields (see, for example, Non-Patent Document 1).

[0003] The agricultural work vehicle in Non-Patent Document 1 is a so-called four-wheel drive unmanned vehicle that is configured to enable unmanned driving by remote control and can travel freely through fields. This agricultural work vehicle can be equipped with, for example, a chemical tank and a sprayer, and travels through the field while spraying the chemicals contained in the chemical tank with the sprayer. There are also cases where it is desired to have the agricultural work vehicle of Non-Patent Document 1 to tow another vehicle. To meet such demands, a support pole for towing another vehicle is installed on the agricultural work vehicle (see Non-Patent Document 2). In the agricultural work vehicle described in Non-Patent Document 2, the chemical tank and sprayer that were installed on the vehicle were removed to create space, and a support pole was erected in this space, with another vehicle connected to the end of the erected support pole. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Reijiro Kawashima, "The world's first mass-produced unmanned agricultural vehicle has arrived! XAG x Bayer "R150" automates spraying and transportation," [online], AGRI JOURNAL homepage, [searched August 29, 2022], Internet<URL:https: / / agrijournal.jp / material / 62003 / > [Non-patent document 2] XAG Australia Facebook, [online], [Retrieved September 22, 2022], Internet <URL:https: / / www.facebook.com / XAGAustralia / photos / pcb.3169800389961242 / 3169799769961304> Summary of the Invention [Problem to be solved by the invention]

[0005] When a farmer uses the agricultural work vehicle of Non-Patent Document 1 to spray chemicals on a field, he or she may wish to perform other tasks while spraying the chemicals. For example, he or she may wish to remove weeds or thin out crops at the same time as spraying the chemicals. In such cases, the removed weeds or thinned crops cannot be left in the field. Therefore, an empty vehicle is towed behind the agricultural work vehicle of Non-Patent Document 1, and the removed weeds or thinned crops are loaded onto this empty vehicle. When connecting and towing another vehicle (i.e., the towed vehicle) behind an agricultural work vehicle, a flexible rope or chain is used as the connecting means. Alternatively, a hook or the like can also be used as the connecting means.

[0006] Furthermore, when erecting a support pole as in the agricultural work vehicle of Non-Patent Document 2, the chemical tank and sprayer mounted on the agricultural work vehicle must be removed to make space for the erection of the support pole. If this agricultural work vehicle is to be used to spray chemicals, the chemical tank and sprayer must be re-mounted on the towed vehicle towed by the agricultural work vehicle. In this way, when an agricultural work vehicle tows a towed vehicle, as long as the agricultural work vehicle and the towed vehicle are traveling straight in the same direction, the wheels of both the agricultural work vehicle and the towed vehicle will rotate smoothly on the ground of the field. Normally, these wheels will not spin unnecessarily on the ground of the field, and spinning wheels will not dig up the soil of the field.

[0007] Next, consider a case where the agricultural work vehicle changes its direction of travel, and as a result, the towed vehicle being towed by the agricultural work vehicle also changes its direction of travel. Immediately after an agricultural work vehicle changes direction of travel, the towed vehicle's direction of travel is usually not the same as that of the agricultural work vehicle. A force that changes the towed vehicle's direction of travel acts from the agricultural work vehicle to the towed vehicle, with the coupling as the fulcrum. If the field ground is soft or uneven, the force acting between the agricultural work vehicle and the towed vehicle is less likely to be consistent in magnitude and direction. As a result, the towed vehicle is prone to swinging from side to side. When the towed vehicle swings from side to side, the wheels of the towed vehicle slide as if dragging on the field ground, and the soil in the field is dug up by the wheels of the towed vehicle. Furthermore, when the towed vehicle swings from side to side, the towed vehicle may collide with the agricultural work vehicle, causing damage to both the towed vehicle and the agricultural work vehicle.

[0008] Furthermore, when a force is applied from the agricultural work vehicle to the towed vehicle, a reaction force is applied from the towed vehicle to the agricultural work vehicle. This reaction force prevents the agricultural work vehicle from moving forward in its forward direction, causing the wheels of the agricultural work vehicle to slip or spin freely on the ground in the field, which can easily lead to digging up the soil in the field. When the wheels of an agricultural work vehicle dig up the soil in a field, holes are dug around the wheels of the agricultural work vehicle, and the wheels of the agricultural work vehicle fall into the hole and spin freely, which makes the hole even larger and prevents the agricultural work vehicle from moving.

[0009] The same thing happens when the wheels of the towed vehicle dig up the soil in a field, digging a hole around the wheels of the towed vehicle, causing the wheels of the towed vehicle to fall into the hole and spin freely, which makes the hole even bigger and prevents the towed vehicle from moving. In particular, the soil in fertile fields is often soft. When an agricultural work vehicle tows a towed vehicle through such a field, there is a risk that the wheels of the agricultural work vehicle and the towed vehicle will dig up the soil and damage the field.

[0010] The present invention was made in consideration of such problems, and aims to provide a vehicle body equipped with a drive mechanism, such as an agricultural work vehicle, that can tow a towed vehicle over the ground such as a field, allowing the vehicle body and the towed vehicle to travel stably and smoothly, To provide a vehicle coupling device capable of preventing a vehicle body and a towed vehicle from colliding with each other and being damaged. Additionally, the present invention aims to provide a vehicle coupling device that can prevent or suppress the wheels of the vehicle body or the towed vehicle from digging up or digging holes in the ground on which they are traveling, thereby damaging the ground, when a vehicle body equipped with a drive mechanism, such as an agricultural work vehicle, travels on the ground such as a field while towing a towed vehicle. Furthermore, the present invention aims to provide a vehicle coupling device that, when a vehicle body equipped with a drive mechanism such as an agricultural work vehicle travels over the ground such as a field while towing a towed vehicle, does not require the installation of a support pole on the vehicle body for towing the towed vehicle, does not require the provision of space on the vehicle body for the installation of the support pole for towing the towed vehicle, and does not require the removal of equipment mounted on the vehicle body to make space for the installation of the support pole for towing the towed vehicle. [Means for solving the problem]

[0011] In order to achieve the above object, a vehicle coupling device according to the present invention has the following configuration. A vehicle coupling device for coupling a vehicle body equipped with a drive mechanism and a towed vehicle to be towed by the vehicle body includes an annular rail attached to surround the vehicle body, a coupling arm extending from the towed vehicle toward the vehicle body, and a coupling box provided at the tip of the coupling arm, the coupling box having first, second, and third rolling bearings, the outer ring of the first rolling bearing rotating along the outer circumferential surface of the annular rail while in contact with the rail, the outer ring of the second rolling bearing rotating along the inner circumferential surface of the annular rail while in contact with the rail, and the outer ring of the third rolling bearing rotating along the inner circumferential surface of the annular rail. The connecting box rotates while making contact with the inner surface of the rail, the connecting box has an opening that opens toward the towed vehicle, the tip of the connecting arm is inserted into the connecting box through the opening, and a support pillar fixed at both the upper and lower ends inside the connecting box passes through a hole at the tip of the connecting arm, and within the connecting box, the hole at the tip of the connecting arm, the first rolling bearing, and the annular rail are positioned in order from the towed vehicle side toward the vehicle body side, and the second rolling bearing and third rolling bearing are positioned closer to the vehicle body side than the annular rail.

[0012] The vehicle body may be, for example, a vehicle intended for agricultural work (i.e., an agricultural work vehicle), a vehicle intended for other work, or a vehicle with no particular work purpose. The drive mechanism of the vehicle body may be, for example, wheels, endless tracks, or a combination of wheels and endless tracks, and the power source that rotates the wheels or endless tracks may be a motor or an engine. The wheels that make up the drive mechanism may be composed of one or more pairs of front wheels and one or more pairs of rear wheels.Also, the wheels that make up the drive mechanism may be composed of one front wheel and one or more pairs of rear wheels.Also, the wheels that make up the drive mechanism may be composed of one or more pairs of front wheels and one rear wheel.

[0013] The endless track that forms the drive mechanism may be composed of a single endless track, or one or more pairs of endless tracks, or may be composed of one endless track on the front side of the vehicle body and one or more pairs of endless tracks on the rear side of the vehicle body, or may be composed of one or more pairs of endless tracks on the front side of the vehicle body and one endless track on the rear side of the vehicle body. The drive mechanism may be composed of one or more front wheels and a rear caterpillar track. In this case, the rear caterpillar track may be a single track, a pair of tracks, or multiple pairs of tracks.

[0014] When the drive mechanism has multiple wheels, the force from the power source may be transmitted independently to each wheel, or may be transmitted only to the front wheels located at the front of the vehicle body, or may be transmitted only to the rear wheels located at the rear of the vehicle body. If the drive mechanism has multiple endless tracks, the force from the power source may be transmitted independently to each endless track, or may be transmitted only to the endless track on the front side of the vehicle body, or may be transmitted only to the endless track on the rear side of the vehicle body.

[0015] When the vehicle body travels on soft ground, such as a fertile field, the drive mechanism of the vehicle body preferably has a pair of left and right wheels at the front and rear of the vehicle body, and is configured so that power from the power source is transmitted to each wheel independently. Alternatively, the drive mechanism of the vehicle body preferably has a pair of left and right endless tracks, and is configured so that power from the power source is transmitted to each endless track independently. By allowing each wheel and each endless track to rotate independently, the vehicle body can easily be oriented in the desired direction on the spot when changing its direction of travel, without having to make unnecessary turns or repeatedly move forward and backward. Furthermore, even on soft ground or sand, the amount of digging up of the ground or sand by the vehicle body's wheels and tracks can be minimized.

[0016] Even if the wheels or tracks of the vehicle body get stuck in a hole in the ground or sand, the vehicle can easily escape from the hole by rotating any wheel or track. The vehicle body may be operated by a person on board, or may be remotely controlled by a wireless or wired remote control. The towed vehicle is not limited to any particular use or type. For example, the towed vehicle may be a vehicle with a bed capable of carrying various objects, a vehicle equipped with a farm tilling mechanism such as a rotating plow, or a vehicle equipped with a tank and spray device for liquid chemicals or the like.

[0017] The towed vehicle may have one wheel, or may have one or more pairs of wheels on either side. The circular rail attached to surround the vehicle body is preferably circular with inner and outer peripheral surfaces that curve smoothly and continuously without bending when the vehicle body is viewed from above.

[0018] When looking down on the vehicle body from above, it is preferable that the center of gravity of the vehicle body and the center of the circular rail coincide. When the vehicle body turns in place to change only its orientation (i.e., its direction of travel), when looking down on the vehicle body from above, only the orientation of the vehicle body changes, while the center of gravity of the vehicle body and the center of the circular rail do not change position, and the circular rail simply rotates around its center. The connecting arm is a member that extends from the towed vehicle and has a hole at its tip. The tip portion of the connecting arm is inserted into the connection box through an opening in the connection box, and a support pillar that passes vertically through the connection box passes vertically through the hole at the tip of the connecting arm. The towed vehicle side portion of the connecting arm extends outward from the opening in the connection box and is connected to the towed vehicle.

[0019] When the vehicle body, circular rail, or connection box sways left and right, or when the towed vehicle sways left and right, the connecting arm inside the connection box rotates around the support post. This rotation of the connecting arm stops when it hits the edge of the opening of the connection box, limiting its rotation. Stopping the rotation of the connecting arm around the support post limits the towed vehicle's large left and right swings, suppressing or preventing collisions between the towed vehicle and the vehicle body, between the towed vehicle and the circular rail, or between the towed vehicle and the connection box, or at least reducing the force of any collisions. As a result, damage to the towed vehicle, vehicle body, circular rail, and connection box is suppressed or prevented.

[0020] In addition, by restricting the rotational movement of the connecting arm inside the connecting box, the towed vehicle is prevented from swinging significantly from side to side, and the wheels of the towed vehicle are prevented from skidding sideways instead of rotating on the ground, which also prevents the wheels of the towed vehicle from digging up the ground or digging holes. The connecting box contains a first rolling bearing, a second rolling bearing, and a third rolling bearing. Each of these bearings has an inner ring, an outer ring, and multiple freely rolling balls (rolling elements) loaded between the inner and outer rings, and is configured so that the outer ring can freely rotate around the inner ring.

[0021] The outer ring of the first rolling bearing can rotate smoothly while contacting the outer circumferential surface of the annular rail, the outer ring of the second rolling bearing can rotate smoothly while contacting the inner circumferential surface of the annular rail, and the outer ring of the third rolling bearing can rotate smoothly while contacting the inner circumferential surface of the annular rail, so the connecting box can move smoothly around and along the annular rail. When the vehicle body changes direction of travel, force is transmitted from the vehicle body via the circular rail to the coupling box, and then from the coupling arm connected to the coupling box to the towed vehicle.

[0022] The force transmitted from the vehicle body to the connecting box causes the outer ring of the first rolling bearing to rotate smoothly while in contact with the outer surface of the annular rail, the outer ring of the second rolling bearing to rotate smoothly while in contact with the inner surface of the annular rail, and the outer ring of the third rolling bearing to rotate smoothly while in contact with the inner surface of the annular rail, and the connecting box to move smoothly along the annular rail. The force energy transmitted from the vehicle body to the coupling box is consumed by the movement of the coupling box along the circular rail. As the coupling box moves along the circular rail, the coupling arm inside the coupling box rotates around the support post. The rotation of the coupling arm is stopped by the edge of the opening in the coupling box, and is limited. As a result, the force energy transmitted from the vehicle body to the towed vehicle is consumed by the movement of the coupling box and the movement of the coupling arm, and is kept small.

[0023] As a result, the rotation of the wheels of the towed vehicle is prevented from being restricted or inhibited by the force transmitted from the vehicle body to the towed vehicle, and the wheels of the towed vehicle are inhibited and prevented from digging up the ground or digging holes in the ground. Furthermore, when the towed vehicle changes direction (i.e., its direction of travel), force is transmitted from the towed vehicle via the connecting arm to the connection box, and then from the connection box via the annular rail to the vehicle body. The force transmitted from the towed vehicle to the connection box causes the connection arm to rotate around the support post inside the connection box. This rotation stops and is limited when it hits the edge of the opening of the connection box. The force transmitted from the connecting arm to the connection box causes the outer ring of the first rolling bearing to rotate smoothly while contacting the outer surface of the annular rail, the outer ring of the second rolling bearing to rotate smoothly while contacting the inner surface of the annular rail, and the outer ring of the third rolling bearing to rotate smoothly while contacting the inner surface of the annular rail, causing the connection box to move smoothly along the annular rail. In response to this movement of the connection box along the annular rail, the connection arm also rotates around the support post inside the connection box. This rotation of the connection arm stops and is limited when it hits the edge of the opening of the connection box. Ultimately, the energy of the force transmitted from the towed vehicle to the vehicle body is consumed by the movement of the connection box and the connection arm, and is kept small.

[0024] As a result, the force transmitted from the towed vehicle to the vehicle body is prevented from restricting or inhibiting the rotation of the wheels of the vehicle body, and the wheels of the vehicle body are also inhibited and prevented from digging up the ground or digging holes in the ground. When a force is transmitted from the vehicle body toward the towed vehicle, a reaction force is transmitted from the towed vehicle toward the vehicle body. This reaction force is first transmitted via the connecting arm to the coupling box, and then from the coupling box via the circular rail to the vehicle body. The force transmitted from the towed vehicle to the coupling box causes the coupling arm to rotate around the support post inside the coupling box, but this rotation is stopped and limited when it hits the edge of the opening in the coupling box. Then, the force transmitted from the connecting arm to the coupling box causes the coupling box to move smoothly along the circular rail. Ultimately, the energy of the reaction force transmitted from the towed vehicle to the vehicle body is consumed by the movement of the coupling box and the connecting arm, and is kept small.

[0025] As a result, the reaction force transmitted from the towed vehicle to the vehicle body is prevented from restricting or inhibiting the rotation and other movements of the vehicle body's wheels, and the wheels of the vehicle body are also inhibited and prevented from digging up the ground or digging holes in the ground. In addition, there is no longer a need to erect a support pole on the vehicle body used to tow the towed vehicle, and there is no need to take the trouble of preparing space on the vehicle body for this support pole, and there is no need to remove other equipment from the vehicle body, etc. Furthermore, if equipment removed from the vehicle body needs to be used, there is no need to load the removed equipment onto the towed vehicle and tow it with the vehicle body. [Effects of the Invention]

[0026] The vehicle coupling device of the present invention can prevent the vehicle body and the wheels of the towed vehicle from digging up or digging holes in the ground, which could cause damage to the ground, when the vehicle body tows a towed vehicle and travels, and can also prevent the vehicle body and the towed vehicle from colliding with each other and causing damage. Furthermore, when the vehicle body tows a towed vehicle and travels, there is no need to take the trouble of removing equipment already installed on the vehicle body in order to tow the towed vehicle, and there is no need to install a support pole on the vehicle body for towing the towed vehicle. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 2 is a side view of a vehicle body equipped with a vehicle coupling device and a towed vehicle. [Figure 2] FIG. 2 is a top view of a vehicle body equipped with a vehicle coupling device and a towed vehicle. [Figure 3] FIG. 2 is an enlarged side view of the vehicle coupling device. [Figure 4] FIG. 4 is a cross-sectional view taken along line A-A in FIG. 3. [Figure 5] This is an explanatory diagram (1) of the behavior of the vehicle body and the towed vehicle. [Figure 6] This is an explanatory diagram (2) of the behavior of the vehicle body and the towed vehicle. [Figure 7] This is an explanatory diagram (3) of the behavior of the vehicle body and the towed vehicle. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to these embodiments, and various modifications can be made within the scope of the present invention. Fig. 1 is a side view of a vehicle body 1 equipped with a vehicle coupling device 3 and a towed vehicle 2. Fig. 2 is a top view of the vehicle body 1 equipped with the vehicle coupling device 3 and the towed vehicle 2 viewed from above. Fig. 3 is a side view of the vehicle coupling device 3, and Fig. 4 is a cross-sectional view taken along line A-A in Fig. 3.

[0029] As shown in Figures 1 and 2, the vehicle body 1 has a pair of left and right wheels 13 on the front side 11 and a pair of left and right wheels 14 on the rear side 12, and each of these wheels 13, 14 is configured to be able to rotate independently by force transmitted from a drive source (not shown) mounted on the vehicle body 1. A circular annular rail 31 is attached around the vehicle body 1. In the following description, the imaginary plane including the circle described by the circular rail 31 will be referred to simply as the plane, the direction perpendicular to this plane will be referred to as the up-down direction, and the line segment facing in a direction perpendicular to this plane will be referred to simply as the vertical line.

[0030] The annular rail 31 has an inner peripheral surface 32 that curves smoothly and continuously without bending, and an outer peripheral surface 33 that curves smoothly and continuously without bending. The circular rail 31 is supported on the vehicle body 1 by support arms 34, 35, and 36, which are made up of three round bars. One end of the support arm 34 is connected to the inner circumferential surface 32, and the other end of the support arm 34 is connected to the front surface 11 of the vehicle body 1. One end of the support arm 35 is connected to the inner circumferential surface 32, and the other end of the support arm 35 is connected to one side surface of the vehicle body 1, and one end of the support arm 36 is connected to the inner circumferential surface 32, and the other end of the support arm 36 is connected to the other side surface of the vehicle body 1.

[0031] The positions at which the support arms 34, 35, 36 are connected to the inner peripheral surface 32 are equidistant from the lower and upper ends of the inner peripheral surface 32. The vertical width of the circular rail 31 is h1. The bearing arms 34, 35, 36 are parallel to the horizontal plane and have a diameter h2. When the vehicle body 1 is viewed from above, the center point O of the circular rail 31 R is a vertical line L perpendicular to the plane formed by the circle of the circular rail 31 M Above, the vertical line L M Above, the center of gravity G of the vehicle body 1 M is located.

[0032] The towed vehicle 2 has a pair of left and right wheels 23 on the front side 21 and a pair of left and right wheels 24 on the rear side 22, and each wheel 22, 23 is configured to be freely rotatable. The end of a round bar-shaped connecting arm 66 is connected to the front surface 21 of the towed vehicle 2 . Connection box 41 is a roughly rectangular box with openings at the front and rear ends, and has an upper panel 42, a lower panel 43, and two side panels 44. A rear opening 46 of connection box 41 has a mouth-shaped edge 47 surrounded on all four sides by upper panel 42, lower panel 43, and two side panels 44, and a tip 67 of a connection arm 66 is inserted into connection box 41 from rear opening 46.

[0033] The connecting arm 66 has a circular hole 68 at its tip 67. A support pillar 49 made of a round bar is erected at the rear end side within the connecting box 41, and the upper end of the support pillar 49 is fixed to the top plate 42 from the outside of the connecting box 41 with a nut 71, and the lower end of the support pillar 49 is fixed to the bottom plate 43 from the outside of the connecting box 41 with a nut 71. The support pillar 49 passes vertically through the hole 68 at the tip 67 of the connecting arm 66, and the connecting arm 66 is configured to be rotatable around the support pillar 49. The upper plate 42 and the lower plate 43 are parallel to a plane, and the distance between the upper plate 42 and the lower plate 43 is h3.

[0034] The front end opening 45 is sandwiched between an upper plate 42 and a lower plate 43, and a gap 48 having a distance of h3 is formed between the upper plate 42 and the lower plate 43. The longitudinal length of the side panel 44 is shorter than the longitudinal lengths of the upper panel 42 and the lower panel 43, and when the connecting box 41 is viewed from the side, a gap 48 is visible between the upper panel 42 and the lower panel 43 on the front end opening 45 side, and no gap is visible between the upper panel 42 and the lower panel 43 on the rear end opening 46 side. As shown in Figures 3 and 4, within the connecting box 41, there are provided a support 49, a pair of upper and lower first rolling bearings 55, a pair of upper and lower second rolling bearings 58, and a pair of upper and lower third rolling bearings 61.

[0035] The first rolling bearing 55, the second rolling bearing 58, and the third rolling bearing 61 are all conventional ordinary rolling bearings and are all the same size. The first rolling bearing 55 has an outer ring 56 and an inner ring 57, with multiple rolling elements fitted between the outer ring 56 and the inner ring 57, allowing the outer ring 56 to rotate freely around the outside of the inner ring 57. The second rolling bearing 58 has an outer ring 59 and an inner ring 60, with multiple rolling elements fitted between the outer ring 59 and the inner ring 60, allowing the outer ring 59 to rotate freely around the outside of the inner ring 60. The third rolling bearing 61 has an outer ring 62 and an inner ring 63, with multiple rolling elements fitted between the outer ring 62 and the inner ring 63, allowing the outer ring 62 to rotate freely around the outside of the inner ring 63.

[0036] The inner ring 57 of one first rolling bearing 55 is fixed to the upper plate 42 by a nut 71 and a bolt (not shown) inside the connecting box 41, and the inner ring 57 of the other first rolling bearing 55 is fixed to the lower plate 43 by a nut 71 and a bolt (not shown) inside the connecting box 41. The central axes of the inner rings 57 of the pair of first rolling bearings 55 are aligned with each other. The inner ring 60 of one second rolling bearing 58 is fixed to the upper plate 42 by a nut 71 and a bolt (not shown) inside the connecting box 41, and the inner ring 60 of the other second rolling bearing 58 is fixed to the lower plate 43 by a nut 71 and a bolt (not shown) inside the connecting box 41. The central axes of the inner rings 60 of the pair of second rolling bearings 58 are aligned with each other.

[0037] The inner ring 63 of one third rolling bearing 61 is fixed to the upper plate 42 by a nut 71 and a bolt (not shown) inside the connecting box 41, and the inner ring 63 of the other third rolling bearing 61 is fixed to the lower plate 43 by a nut 71 and a bolt (not shown) inside the connecting box 41. The central axes of the inner rings 63 of the pair of third rolling bearings 61 are aligned with each other. Inside the connecting box 41, the hole 68 at the tip 67 of the connecting arm 66 through which the support 49 passes, the first rolling bearing 55, and the annular rail 31 are positioned in order from the towed vehicle 2 side toward the vehicle body 1 side, and the second rolling bearing 58 and the third rolling bearing 61 are positioned closer to the vehicle body 1 side than the annular rail 31.

[0038] The distance between the lower end of the nut 71 that fixes the inner ring 57 of one first rolling bearing 55 to the upper plate 42 and the upper end of the nut 71 that fixes the inner ring 57 of the other first rolling bearing 55 to the lower plate 43 is h4. The distance between the lower end of the nut 71 that fixes the inner ring 60 of one second rolling bearing 58 to the upper plate 42 and the upper end of the nut 71 that fixes the inner ring 60 of the other second rolling bearing 58 to the lower plate 43 is h4. The distance between the lower end of the nut 71 that fixes the inner ring 63 of one third rolling bearing 61 to the upper plate 42 and the upper end of the nut 71 that fixes the inner ring 63 of the other third rolling bearing 61 to the lower plate 43 is h4.

[0039] The relationship of formula (1) holds between the above-mentioned h1 and h3, and the relationship of formula (2) holds between the above-mentioned h2 and h4. h1 <h3 ···(1) h2 <h4 ···(2) On the side of the front-end opening 45 inside the connecting box 41, a portion of the annular rail 31 is sandwiched in a gap 48 between the upper plate 42 and the lower plate 43. Within the gap 48, the inner circumferential surface 32 of the annular rail 31 contacts the outer ring 59 of one second rolling bearing 58, and also contacts the outer ring 59 of the other second rolling bearing 58. Similarly, within the gap 48, the inner circumferential surface 32 contacts the outer ring 62 of one third rolling bearing 61, and also contacts the outer ring 62 of the other third rolling bearing 61. Furthermore, within the gap 48, the outer circumferential surface 33 of the annular rail 31 contacts the outer ring 56 of one first rolling bearing 55, and also contacts the outer ring 56 of the other first rolling bearing 55.

[0040] The circular rail 31, the connection box 41, and the connection arm 66 constitute the vehicle coupling device 3.

[0041] Next, the operation will be described. For example, let us assume that the vehicle body 1 equipped with the vehicle coupling device 3 and the towed vehicle 2 are initially stationary on flat ground 90 in a field with soft, fertile soil, with the front surface 11 of the vehicle body 1 facing north, the rear surface 12 of the vehicle body 1 facing south, the front surface 21 of the towed vehicle 2 facing north, and the rear surface 22 of the towed vehicle 2 facing south (see Figure 2). At this time, the center of gravity G of the vehicle body 1 M A vertical line L passing through M is the center point O of the circular rail 31 R passes through the vertical line L M The intersection point of the line and the ground 90 is point O M1 Vertical line L S is the center of gravity G of the towed vehicle 2 S It passes through the vertical line L S The intersection point of the line and the ground 90 is point O S1 Point O M1 , support arm 34, connecting box, connecting arm 66 and point O S1 are located on a straight line running north-south.

[0042] First, a case where the vehicle body 1 moves straight north will be described. As the vehicle body 1 moves north, the support arm 34 and the center of gravity G M , center point O R, the connecting box 41, the connecting arm 66, the connected vehicle 2, and the center of gravity G S They move north together in a single straight north-south line. While the vehicle body 1 is traveling north, there may be some unevenness on the ground surface 90, causing the traveling direction of the vehicle body 1 to deviate slightly from the north direction, preventing it from traveling straight north. When the traveling direction of the vehicle body 1 deviates slightly from the north direction, the direction in which the front face 11 of the vehicle body 1 faces changes slightly from the north direction. When the direction in which the front face 11 of the vehicle body 1 faces changes slightly, the center of gravity G M As the vehicle body 1 turns, the circular rail 31 turns slightly around the center point O. R Rotate slightly around the center.

[0043] Since the relationship between equations (1) and (2) is established, when the annular rail 31 rotates, the annular rail 31 and the support arms 34, 35, and 36 do not come into contact with the upper plate 42, the lower plate 43, the nut 71 that secures the inner ring 60 of the second rolling bearing 58 to the upper plate 42, the nut 71 that secures the inner ring 60 of the second rolling bearing 58 to the lower plate 43, the nut 71 that secures the inner ring 63 of the third rolling bearing 61 to the upper plate 42, and the nut 71 that secures the inner ring 63 of the third rolling bearing 61 to the lower plate 43.

[0044] When the circular rail 31 rotates slightly, the outer peripheral surface 33 of the circular rail 31 rotates smoothly within the connection box 41 while contacting the outer ring 56 of the first rolling bearing 55, while the inner peripheral surface 32 of the circular rail 31 rotates smoothly while contacting the outer ring 59 of the second rolling bearing 58 and the outer ring 62 of the third rolling bearing 61. The force energy acting from the vehicle body 1 on the connection box 41 is consumed in the smooth movement of the connection box 41 along the circular rail 31. As a result, the direction of movement of the connection box 41, which moves north together with the vehicle body 1 and circular rail 31, is hardly affected by the force acting on the connection box 41 from the vehicle body 1 and remains almost entirely northward, and the towed vehicle 2 connected to the connection box 41 via the connection arm 66 also moves northward almost entirely unchanged. In other words, even if the ground surface 90 is slightly uneven and the direction of travel of the vehicle body 1 sways slightly left and right, this has almost no effect on the movement of the towed vehicle 2.

[0045] Furthermore, since each wheel 13, 14 of the vehicle body 1 rotates independently by the force from the driving source, even if the wheels 13, 14 fall into and get stuck in an uneven surface of the ground 90, they can easily get out of the uneven surface, and the wheels 13, 14 are prevented and suppressed from unnecessarily digging up the ground 90. If the direction of travel of the vehicle body 1 deviates slightly from the north direction due to slight unevenness in the ground surface 90, a force will act from the vehicle body 1 on the towed vehicle 2, but the energy of this force will be wasted in allowing the connection box 41 to move smoothly along the circular rail 31. As a result, the connection box 41, connection arm 66, and towed vehicle 2 can continue to move north (i.e., continue traveling north).

[0046] Therefore, even if a force is applied from the vehicle body 1 to the towed vehicle 2, this force does not hinder the rotation of the wheels 23, 24 of the towed vehicle 2, and the wheels 23, 24 of the towed vehicle 2 will not dig up or create holes in the ground 90. Furthermore, even if the vehicle body 1 sways slightly left and right in the direction of travel, the rotation of the connecting arm 66 about the support post 49 inside the connection box 41 is limited between the edges 47 of the rear end opening 46 of the connection box 41. In other words, even if the connecting arm 66 tries to rotate widely, the connecting arm 66 will hit the edge 47 and stop its rotation. Because the rotation of the connecting arm 66 is limited, the swaying movement of the towed vehicle 2 connected to the connecting arm 66 is limited, and the towed vehicle 2 will not collide with the vehicle body 1 or the circular rail 31. This prevents or inhibits the wheels 23, 24 of the coupled vehicle 2 from skidding on the ground surface 90 and digging up or creating holes in the ground surface 90.

[0047] A case will be described where a vehicle body 1 traveling north turns left and travels west. The vehicle body 1, which had been traveling north, stops temporarily. At this point, the front 11 of the stopped vehicle body 1 faces north, the rear 12 of the vehicle body 1 faces south, the front 21 of the towed vehicle 2 faces north, and the rear 22 of the towed vehicle 2 faces south (see Figure 2). The center of gravity G of the vehicle body 1 M A vertical line L passing through M is the center point O of the circular rail 31 R passes through the vertical line L M The intersection point of the line and the ground 90 is point O M1 Vertical line L S is the center of gravity G of the towed vehicle 2 S It passes through the vertical line L S The intersection point of the line and the ground 90 is point O S1 Looking down from above, point O M1 , the support arm 34, the connecting box 41, the connecting arm 66 and the point O S1 are located on a straight line running north-south.

[0048] Next, the vehicle body 1 is aligned with the vertical line L M When the vehicle body 1 turns on the spot to change direction, the circular rail 31 turns together with the vehicle body 1. When viewed from above, the circular rail 31 itself does not appear to be turning, but the support arms 34, 35, and 36 turn together with the vehicle body 1 along the vertical line L. M The wheels 13, 14 of the vehicle body 1 rotate independently by the force from the driving source, causing the vehicle body 1 to turn. Each wheel 13, 14 moves little by little from the vertical line L on the ground 90. M The wheels 13 and 14 move by rotating around the center of gravity, and do not continue to rotate and stay at exactly the same position on the ground 90. Therefore, the wheels 13 and 14 are prevented and suppressed from unnecessarily digging up the ground 90.

[0049] Next, the vehicle body 1, with its front face 11 facing west, moves westward (see FIG. 6). The center of gravity G of the vehicle body 1 moving westward M A vertical line L passing through M The intersection point with the ground 90 is point O M2The center of gravity G of the towed vehicle 2, which was towed by the main vehicle 1 traveling westward, is S A vertical line L passing through S The intersection point of the line and the ground 90 is point O S2 Point O M1 and point O M2 The distance L1 between these points is the distance traveled by the westward-moving vehicle body 1. When the vehicle body 1 moves westward by the distance L1, the circular rail 31 also moves westward by the distance L1 together with the vehicle body 1.

[0050] When the circular rail 31 moves westward by a distance L1, the connection box 41 moves along the circular rail 31 in accordance with the movement of the circular rail 31. At this time, when the movement of the connection box 41 is viewed from above, the connection box 41 moves in a direction perpendicular to the center point O. R 49, sliding counterclockwise around the center of the connecting box 41 and changing its position. As the connecting box 41 moves, the connecting arm 66 inside the connecting box 41 rotates around the support post 49. As the connecting arm 66 rotates, its middle section hits the edge 47 of the rear end opening 46, and the rotation of the connecting arm 66 stops. As the connecting box 41 moves and the connecting arm 66 rotates, the towed vehicle 2 connected to the connecting arm 66 is pulled and moves, and the direction in which the front face 21 of the towed vehicle 2 faces changes from north to approximately northwest.

[0051] Next, the vehicle body 1 further travels a distance L2 westward (see FIG. 7). Together with the vehicle body 1, the circular rail 31 also moves a distance L2 westward. As the circular rail 31 further travels westward, the connection box 41 slides along the circular rail 31, and eventually the connection box 41 moves toward the rear surface 12 of the vehicle body 1. When the connection box 41 moves toward the rear surface 12 of the vehicle body 1, the center of gravity G of the vehicle body 1 M A vertical line L passing through M The intersection point with the ground 90 is point O M3 and the center of gravity G of the towed vehicle 2 S A vertical line L passing through S The intersection point of the line and the ground 90 is point O S3 is. While the connection box 41 moves along the circular rail 31, the connection arm 66 rotates around the support post 49. The rotation of this connection arm 66 is limited when the connection arm 66 comes into contact with the edge 47 of the rear end opening 46 of the connection box 41. By limiting the rotation of the connection arm 66, the movement of the connected vehicle 2 connected to the connection arm 66 is also limited. As a result, the connected vehicle 2 and the main vehicle 1 are prevented from colliding with each other. Then, as the connection box 41 moves along the circular rail 31, the connected vehicle 2 faces its front face 21 west. The main vehicle 1 can then travel straight westward, pulling the connected vehicle 2 along.

[0052] While the vehicle body 1 travels westward a distance of L1+L2, each wheel 13, 14 of the vehicle body 1 moves on the ground 90 and does not continue to rotate at the same position on the ground 90, and these wheels 13, 14 are prevented and suppressed from unnecessarily digging up the ground 90. Furthermore, while the main vehicle 1 travels westward a distance of L1+L2, the coupled vehicle 2 is pulled by the main vehicle 1 via the coupling box 41 and the coupling arm 66, and moves in an arc on the ground 90. The arc drawn by the movement of the coupled vehicle 2 begins at point O S1 Starting from point O S2 passes through point O S3 While the coupled vehicle 2 moves in this arc, the wheels 23, 23 of the coupled vehicle 2 continue to move on the ground 90, and do not continue to rotate while remaining in the same position on the ground 90. Therefore, the wheels 23, 23 are prevented and suppressed from unnecessarily digging up the ground 90.

[0053] Furthermore, while the main vehicle 1 travels westward a distance of L1 + L2, a force acts from the main vehicle 1 to the coupling box 41 via the circular rail 31, and then from the coupling box 41 to the coupled vehicle 2 via the coupling arm 66. At the same time, a reaction force acts from the coupled vehicle 2 to the coupling box 41 via the coupling arm 66, and then from the coupling box 41 to the main vehicle 1 via the circular rail 31. The energy of these forces is dissipated and consumed in the smooth movement of the coupling box 41 along the circular rail 31. Therefore, the force acting between the main vehicle 1 and the coupled vehicle 2 prevents and suppresses the wheels 13, 14 of the main vehicle 1 and the wheels 23, 23 of the coupled vehicle 2 from unnecessarily digging up the ground 90.

[0054] Furthermore, even if the connecting box 41 moves along the circular rail 31 and this movement causes the connecting arm 66 to rotate about the support post 49, the rotation of the connecting arm 66 is suppressed and limited as the connecting arm 66 hits the edge 47. Therefore, the towed vehicle 2 connected to the connecting arm 66 is suppressed and limited from swinging left and right, and the towed vehicle 2 is suppressed and prevented from hitting the vehicle body 1 or the circular rail 31, preventing damage to the towed vehicle 2, vehicle body 1, or the circular rail 31. Furthermore, since it is sufficient to attach the circular rail 31 so as to surround the vehicle body 1, there is no need to take the trouble of removing the devices and equipment mounted on the vehicle body 1 in order to use the vehicle body 1 to pull the coupled vehicle 2, and when using the removed devices and equipment, there is no need to reinstall them on the coupled vehicle 2. [Industrial Applicability]

[0055] The vehicle coupling device as described above is useful in industries that manufacture and supply vehicle coupling devices that couple a vehicle body to a towed vehicle to be towed by the vehicle body. [Explanation of symbols]

[0056] 1 Vehicle body 11 Front 12 Rear 13, 14 wheels 2 Towed vehicle 21 Front 22 Rear 23, 24 wheels 3 Vehicle coupling device 31 Circular Rail 32 Inner surface 33 Outer surface 34, 35, 36 Support arm 41 Connection box 42 Top plate 43 Bottom plate 44 Side plate 45 Front end opening 46 Rear end opening 47 En 48 Gap 49 Post 55 First rolling bearing 56 Outer ring of first rolling bearing 57 Inner ring of first rolling bearing 58 Second Rolling Bearing 59 Outer ring of second rolling bearing 60 Inner ring of second rolling bearing 61 Third Rolling Bearing 62 Outer ring of third rolling bearing 63 Inner ring of third rolling bearing 66 Connecting Arm 67 Tip of connecting arm 68 Hole 71 Nut 90 ground h1 Vertical width of circular rail h2 diameter of bearing arm h3 Distance between the top and bottom plates O R Center point of circular rail G M Center of gravity of the vehicle body G S Center of gravity of coupled vehicle L M A vertical line passing through the center of gravity of the vehicle body and the center point of the circular rail L S A vertical line passing through the center of gravity of the towed vehicle O M , OM1 , O M2 , O M3 The intersection of the vertical line passing through the center of gravity of the vehicle body and the ground O S , O S1 , O S2 , O S3 The intersection of a vertical line passing through the center of gravity of the towed vehicle and the ground

Claims

[Claim 1] A vehicle coupling device that couples a vehicle body equipped with a drive mechanism to a towed vehicle towed by the vehicle body, The towed vehicle has an annular rail attached to the vehicle body so as to surround it, a connecting arm extending from the towed vehicle toward the vehicle body, and a connecting box provided at the tip end of the connecting arm. The connecting box has first, second, and third rolling bearings, the outer ring of the first rolling bearing rotates while contacting the outer peripheral surface of the annular rail, the outer ring of the second rolling bearing rotates while contacting the inner peripheral surface of the annular rail, and the outer ring of the third rolling bearing rotates while contacting the inner peripheral surface of the annular rail, The connection box has an opening that opens toward the towed vehicle, The tip of the connecting arm is inserted into the connecting box through the opening, A support pillar fixed at both the top and bottom ends inside the connecting box passes through the hole at the tip of the connecting arm, A vehicle coupling device characterized in that within the coupling box, the hole at the tip of the coupling arm, the first rolling bearing, and the annular rail are positioned in order from the towed vehicle side toward the vehicle body side, and the second rolling bearing and the third rolling bearing are positioned closer to the vehicle body side than the annular rail.

Images