Motorized or attachable vehicle, frame elements of a main frame of a motorized or attachable vehicle, method for manufacturing a frame of a motorized or attachable vehicle, method for improving a frame of a motorized or attachable vehicle, and method for setting a motorized or attachable vehicle

Abstract

To provide a frame structure with flexibly adaptable variety for various conditions of a vehicle body such as road holding and steering performance or variations of a prime mover in a vehicle with a prime mover such as motorcycle or a vehicle capable of being installed with a prime mover.SOLUTION: A frame 10 of a motorcycle 100 forms a truss structure by a frame element (a connection rod) with an adjustable axial length in a front frame portion 30 of a main frame 20. By adjusting the axial length of a prescribed frame element, a caster angle α is changed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a motor vehicle such as a motorcycle or a vehicle on which a motor vehicle can be attached (mounted), and more particularly to a frame structure for the vehicle. [Background technology]

[0002] The frames of vehicles such as motorcycles, trikes, and reverse trikes are where the engine, suspension, and electrical components are mounted, and also characterize the size and weight balance of the vehicle. In addition, high rigidity and strength are required to maintain stable driving performance, while light weight and flexibility are also required from the perspective of maneuverability such as turning performance. Such frame performance and functions are also required for ATVs (All Terrain Vehicles) such as four-wheeled buggies and other vehicles.

[0003] Motorcycles use a wide variety of frame structures. For example, there are cradle frames that encase the engine, diamond frames / backbone frames that eliminate the downtube of the cradle frame and use part of the engine as a strength member, truss frames with a truss structure for the main frame, twin spar frames, and underbone frames.

[0004] On the other hand, a method for improving the frame structure to suit the user's preferences is known (Patent Document 1). In this method, a part of a ready-made first frame is cut, and a part of a ready-made second frame is cut to match it. The corresponding cut parts of the first and second frames are then joined to unitize the frames. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2003-54471 A Summary of the Invention [Problem to be solved by the invention]

[0006] Not only does it require the strength and flexibility of the body, but it also requires a versatile frame structure that can flexibly adapt to various vehicle conditions, such as the driving and handling performance preferred by users and variations in the prime mover. [Means for solving the problem]

[0007] The motorized vehicle or motor-attachable vehicle of the present invention is directed to a frame structure and configuration (hereinafter simply referred to as a frame), particularly a main frame structure and configuration (hereinafter simply referred to as a main frame), which allows adjustment of running performance, handling performance, etc., or is adaptable to various variations of motors. Here, "motorized vehicle or motor-attachable vehicle" is defined as a vehicle that runs by the power of a motor, or a vehicle that can be equipped with a motor and can run using not only human power but also the assistance of the motor (hereinafter simply referred to as "vehicle" as necessary). For example, it includes vehicles with two wheels, three wheels, or four wheels.

[0008] The frame structure of the present invention can be applied to a variety of motorized vehicles. For example, the frame structure of the present invention can be applied to vehicles with a straddle seat and steering by a rod-shaped steering wheel, or vehicles equipped with either one of them. Conventional motorcycles such as large and small motorbikes and motorized bicycles (mopeds) are included in the motorized vehicles of the present invention.

[0009] In addition, three-wheeled vehicles equipped with two front wheels or two rear wheels with a set wheel spacing, such as trikes and reverse trikes, are also included in the motorized vehicles of the present invention. In this case, both three-wheeled vehicles (special two-wheeled vehicles) that require the body to lean when changing direction and three-wheeled vehicles that do not require the body to lean are included. Furthermore, ATVs such as four-wheeled buggies and vehicles equipped with seats that can seat two people side by side are also included in the vehicles of the present invention.

[0010] On the other hand, the frame structure of the present invention can be applied to various types of vehicles to which a motor can be attached. For example, it can be applied to an electrically assisted bicycle. It can also be applied to trike and reverse trike type bicycles (three-wheeled vehicles) to which an electric motor or the like can be detachably attached, like an electrically assisted bicycle.

[0011] On the other hand, (four-wheeled) vehicles generally called "automobiles" are not included in this invention. For example, large, medium, and semi-medium-sized automobiles under the Road Traffic Act are not included. Furthermore, vehicles that are intended to be driven by human power, such as road cycle-type bicycles, are also not included in this invention.

[0012] The prime mover is not particularly limited in its type, power source, etc. Examples include internal combustion engines such as air-cooled engines, water-cooled engines, and hydrogen engines, electric motors, and hybrids that combine an internal combustion engine and an electric motor.

[0013] A vehicle according to one aspect of the present invention includes a steering shaft tube to which a steering mechanism is attached, and a main frame. Here, the term "main frame" refers to a frame including the steering shaft tube, and can be defined as a part of a vehicle body frame defined according to the form and structure of the vehicle, and as having at least a frame portion connected to the steering shaft tube. There are various ways of connection, and a configuration in which a part of the main frame is connected to or connected with the steering shaft tube is also included. Alternatively, a configuration in which a part of the main frame is connected via a predetermined member (excluding a suspension or a suspension device or a related member that is connected thereto) is also included. The main frame can have a two-dimensional or three-dimensional structure and can be composed of multiple members. For example, the main frame of a motorcycle, trike, reverse trike, etc. can have a three-dimensional or three-dimensional structure. In the above-mentioned main frame configuration, in the present invention, the steering shaft tube is configured (defined) to be included in the main frame. On the other hand, the steering shaft tube can be configured as a separate member from the main frame according to the form of the vehicle.

[0014] The "steering shaft tube" of the present invention may have a variety of configurations depending on the form and structure of the vehicle. For example, in the case of a front fork type steering mechanism used in motorcycles and the like, a part of the main frame is connected to the head pipe. The steering shaft tube may be a single component, or a pair of steering shaft tubes may be formed via an arm or the like. Various variations in steering mechanisms may be employed depending on the form of the vehicle.

[0015] The "main frame" of the present invention can be configured (defined) according to the form of the vehicle (body), the type of vehicle, the frame structure of the entire body, laws, rules, regulations, or the location of the prime mover. In motorcycles, trikes, reverse trikes, etc., the entire frame portion provided between the suspension or suspension device provided on the front wheel side and the rear wheel side along the longitudinal direction of the vehicle, or a part of it, can be configured as the main frame, and in particular, it can be configured as being located on the rear wheel side of the front wheel suspension or suspension device. However, "located on the rear wheel side" can be defined based on the positional relationship with the rear wheel when viewed from the side, and can also be defined from the perspective of the connection order of the parts connected to the front wheel. It is possible to configure a main frame in the same way for other vehicles. In the case of a two-wheeled vehicle, it is possible to configure the main frame as a frame portion connected to the steering shaft tube in accordance with the frame structure of the various variations described above, and it can be configured as a frame portion that constitutes a section spanning the steering shaft tube and the pivot part, or a frame portion provided in a part of that section. For example, in the frame structure of the two-wheeled vehicle described above, the frame portion excluding the seat rail (subframe) at the seating position can be configured as the main frame. In the case of a two-wheeled vehicle such as a scooter, the prime mover is housed in the rear wheel drive (near the swing arm), and the frame portion extending from the steering shaft tube to the vicinity of the rear wheel can be configured as the main frame. On the other hand, a variation in which the frame is substantially configured as the main frame is also included. For vehicles other than a frame two-wheeled vehicle, for example, in the case of an ATV that employs a suspension type (wishbone type) different from the swing arm, the main frame can be configured to match the suspension type. On the other hand, the main frame can be configured (defined) according to the type and location of the prime mover. For example, it can be configured to surround the entire prime mover, or to sandwich part of the prime mover, and it can also be configured as a frame portion that is directly or indirectly connected to the prime mover.In this case, the prime mover may be configured to form a part of the main frame. Furthermore, the main frame may be defined based on a relative positional relationship with the entire vehicle body, and may be configured as a frame part at least partially included in the front side (front wheel side) or upper side (steering side) of the center of the vehicle body, or as a frame part at least partially included in the front side and upper side.

[0016] In the present invention, at least one element that allows the frame alignment to be changed is provided in the frame structure and configuration (hereinafter, it is referred to as a frame element, but it can also be called a frame alignment changeable main frame element). For example, a main frame can be configured by one or more frame elements that allow the frame alignment to be changed and one or more other frame alignments that are not configured to allow the frame alignment to be changed (it can also be called a non-frame alignment changeable main frame element). Here, "frame alignment" is also called frame geometry or frame dimension, and represents the form, structure, connection state with other parts such as a steering shaft tube, distance interval, relative positional relationship, etc. of the main frame that can be changed, reset, or reconstructed. By adjusting the frame alignment, it is possible to set or change the external shape of the vehicle body, weight balance, wheel alignment such as caster angle and trail amount, mounting location of the prime mover, running performance, maneuverability, riding posture, etc. For example, in the case of a two-wheeled vehicle, a trike, or a reverse trike, the frame alignment of the main frame can be changed so that at least the caster angle can be changed.

[0017] The frame element (which allows frame alignment to be changed) in the present invention is configured as a member capable of changing its own alignment by adjusting its own length, modifying its shape or form, changing its mounting position, changing its relative positional relationship with other frame elements or frame parts, etc. Such a function of adjusting its own alignment is configured as a part of the frame that can have the function of adjusting the shape, form, and positional relationship between relative members of the main frame or the entire frame structure. In addition, a frame element selected from a plurality of frame elements with different forms and characteristics such as length for changing the frame alignment, etc., is also included in the frame element that allows frame alignment to be changed. However, all frame elements are defined as being configured as a part that makes the main frame function as a "frame".

[0018] Furthermore, the frame elements can be provided detachably so that the frame alignment can be reconstructed, reset, etc. Here, "detachable" means that the frame elements are fastened and fixed with screws, bolts, etc., as opposed to being integrated by welding, etc., and indicates a configuration that allows attachment and detachment so that frame elements of different variations can be replaced, etc.

[0019] The frame element can adjust, reset, or reconstruct the frame alignment so that the steering performance, driving performance, weight balance, and other factors can be changed in addition to the caster angle. For example, when adjusting the position (height) of the steering axle, the frame alignment can be changed or adjusted by adjusting the length of the frame element itself. In addition, the distance between the steering axle and a prime mover such as an engine (for example, the distance between the steering axle and the pivot part in the case of a motorcycle) or the relative positional relationship can be adjusted, allowing the mounting location of the prime mover to be changed or adjusted while taking into consideration the seating posture, mass centralization, and weight balance.

[0020] The frame element can be configured, for example, as a rod-shaped member (hereinafter referred to as a rod-shaped frame element). In this case, the rod-shaped frame element can be not only straight, but also partially or entirely curved or bent. The frame element can also be configured as a member with multiple connecting parts extending in various directions from a central part, such as Y-, X-, H-, or T-shape (hereinafter referred to as a branched frame element). These rod-shaped or branched frame elements may have an alignment function as long as they are configured to change the axial length, the length of the connecting parts, the connecting position (mounting position), and the relative positional relationship with other frame members.

[0021] For example, in the case of a rod-shaped frame element, the axial length may be adjusted near both ends or near the center of the rod-shaped frame element, or between the center and both ends, so that the axial length may be adjusted entirely or partially. In the case of a branched frame element, the axial length of the protruding connecting portion may be adjusted. Alternatively, it is also possible to configure the connecting position (mounting position) of the rod-shaped or branched frame element to be adjustable.

[0022] For example, the rod-shaped frame element can be configured as a connecting rod with spherical sliding bearings (also called pillow balls) attached to both ends. The rod-shaped frame element can be configured as a hollow (pipe-shaped) member or a solid member, and a mechanism for adjusting the axial length can be provided. The mechanism for adjusting the axial length can be either a stepless type such as a screwdriver, or a step type with multiple holes at a predetermined pitch. A hinge-like connecting structure that can rotate around an axis can also be used.

[0023] The number of frame elements included in the main frame and their proportions vary. For example, the main frame can be formed by providing one rod-shaped or branched frame element and combining it with a hinge or the like. Alternatively, it is also possible to provide one, two, or three pairs of rod-shaped frame elements that are symmetrically positioned about the center line of the vehicle body.

[0024] There are various locations where frame elements can be arranged to allow frame alignment to be changed, reconstructed, etc. For example, at least one frame element can be provided to be connected to a steering shaft tube (such as a head pipe) close to the steering axis that determines the caster angle. For example, at least one pair of rod-shaped frame elements or at least one branched frame element can be configured to be connected at least one end of the steering shaft tube. Two pairs of rod-shaped frame elements or two branched frame elements can be connected to both ends of the steering shaft tube, respectively.

[0025] The main frame may be structured with a base portion (herein referred to as an intermediate base) for connecting multiple rod-shaped frame elements to each other. When part of the engine is configured as a strength member (part of the frame), the engine or the like may be mounted on the intermediate base. The base portion may be shaped, for example, as a bracket.

[0026] For example, in a main frame of a motorcycle or the like, an intermediate base is provided between a pivot base including a pivot portion and a steering shaft tube, and a front frame portion provided between the steering shaft tube and the intermediate base can be formed by a plurality of rod-shaped frame elements. In this case, a rear frame portion between the intermediate base and the pivot portion can be formed as an integral frame structure by welding or the like. Alternatively, in a main frame, an intermediate base is provided between a pivot base including a pivot portion and a steering shaft tube, and a rear frame portion provided between the intermediate base and the pivot base can be formed by a plurality of rod-shaped frame elements. In this case, the front frame portion can be formed as an integral frame structure by welding or the like. Furthermore, both the front and rear frame portions may be formed by a plurality of rod-shaped frame elements.

[0027] Considering the strength and rigidity of the main frame, at least a part of the main frame can be made into a truss structure using a plurality of rod-shaped frame elements. In particular, a three-dimensional truss structure can be used. For example, when the front frame portion is made up of a plurality of rod-shaped frame elements, the entire front frame portion can be made into a truss structure.

[0028] It is possible to provide a vehicle setting method as another aspect of the present invention. That is, it is possible to provide a setting method for adjusting frame alignment by adjusting the alignment of at least one frame element. As described above, the "setting" here includes resetting and reconstructing the frame alignment that enables adjustment and change of the above-mentioned running performance, maneuverability, weight balance of the vehicle body, and the like. It also includes addition, replacement, and change of frame elements. For example, alignment adjustment can be performed to change at least one of the caster angle and the position of the steering shaft tube. In the case of a two-wheeled vehicle, alignment adjustment can be performed to change the distance between the steering shaft tube and the pivot part, or the relative positional relationship between them. In this case, it is sufficient to perform alignment adjustment for the frame element whose alignment can be changed as described above. Alternatively, setting can be performed by selecting and attaching a frame element according to the desired alignment from among multiple frame elements. In addition, a method of resetting or changing the frame alignment by selecting a desired frame element from multiple frame elements having different lengths, etc., is also included in the setting method of the present invention.

[0029] On the other hand, the present invention can provide the above-mentioned frame element constituting the main frame (the definition of the main frame is as described above). That is, the frame element, which is another aspect of the present invention, is provided with connecting parts at both ends (for example, spherical plain bearing parts) and can be aligned near both ends or at the center near both ends. For example, in the case of a rod-shaped or branched frame element, the alignment can be achieved by a structure that allows the length to be adjusted continuously, such as by a screwdriver, or by a structure that allows the length to be adjusted in stages by a combination of pitch holes.

[0030] Furthermore, the present invention can provide a method for manufacturing a vehicle frame using a frame element. That is, in another aspect of the present invention, a method for manufacturing (assembling) a frame includes configuring at least a part of a main frame with at least one frame element that allows frame alignment to be changed, adjusting the alignment of at least one frame element to obtain a desired frame alignment, and then assembling the main frame. For example, a rod-shaped frame element with an adjustable axial length or a branched frame element can be installed. In addition, when a detachable frame element is applied as described above, the manufacturing method of the present invention also includes selecting and attaching a rod-shaped frame element having a desired axial length from a plurality of rod-shaped frame elements having different axial lengths.

[0031] Similarly, the present invention can provide a method for improving a vehicle frame using a frame element. That is, in another aspect of the present invention, a frame improvement method involves removing a part of a frame portion from an existing main frame by cutting or the like, and replacing it with at least one frame element that allows the frame alignment to be changed so as to obtain a desired frame alignment. For example, a rod-shaped frame element with an adjustable axial length or a branched frame element can be installed instead. Also, the above-mentioned detachable frame element can be applied. For example, a rod-shaped frame element having a desired axial length can be selected from a plurality of rod-shaped frame elements having different axial lengths, and attached in place of the removed part. The frame improvement method of the present invention includes an improvement method for changing the type or form of a vehicle by including a frame element (that allows the frame alignment to be changed) in an existing frame. For example, an improvement method for changing a normal motorcycle into a trike or reverse trike with two rear wheels or two front wheels is also included.

[0032] The configuration of the present invention described above can make it possible to reuse vehicles that have become unridable due to political or administrative decisions such as the manufacturer ending parts supply or exhaust gas regulations, or that have become unnecessary due to reasons such as unprofitability in the market, by reconstructing the frame, or to provide new, valuable vehicles, which can lead the way toward realizing a sustainable approach to vehicles. Effect of the Invention

[0033] According to the present invention, it is possible to provide a versatile frame structure that can be flexibly adapted to various vehicle conditions, such as the driving performance and handling performance preferred by users, or variations in engines. [Brief description of the drawings]

[0034] [Figure 1] 1 is a schematic side view of a motorcycle according to a first embodiment. [Diagram 2] FIG. 2 is a schematic perspective view of a frame. [Diagram 3] FIG. 11 is a schematic perspective view of a frame of a motorcycle according to a second embodiment. [Figure 4] FIG. 11 is a schematic plan view of a frame of a motorcycle according to a third embodiment, viewed from one side. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Hereinafter, a motorcycle according to the present embodiment will be described with reference to the drawings.

[0036] 1 is a schematic side view of a motorcycle according to a first embodiment. Motorcycle 100 is provided with a frame 10 that constitutes the vehicle body framework between a front wheel 110 and a rear wheel 120, and is equipped with a main frame 20 and a seat rail 60 that serves as a subframe. A swing arm 80 that supports the rear wheel 120 and functions as a suspension device is attached to a pivot portion 70 of frame 10.

[0037] Here, a front fork type steering mechanism is applied as the steering mechanism 130. A stem shaft (steering rotation shaft) is inserted into a head pipe 140, and the front wheel 110 is steered in response to an operation on a steering wheel 150.

[0038] Fig. 2 is a schematic perspective view of the frame 10. As shown in Fig. 2, the frame 10 here has a frame structure without a down tube, and as described above, includes the main frame 20 and seat rails 60. An engine (not shown) is mounted to engine mount 55 of a base portion 50 (hereinafter referred to as pivot base) provided with a pivot portion 70.

[0039] In the main frame 20, a plurality of rod-shaped members (hereinafter referred to as rod-shaped frame elements or simply frame elements) are connected or joined to one another from the head pipe 140 to the vicinity of the pivot portion 70. A pair of bracket-shaped base portions (hereinafter referred to as intermediate bases) 80 that enable the rod-shaped frame elements to be connected to one another are provided near the middle between the head pipe 140 and the pivot base 50. Here, the main frame 20 includes the head pipe 140, and also includes a front frame portion 30 extending from the intermediate base 80 to the head pipe 140 side, and a rear frame portion 40 extending from the intermediate base 80 to the pivot base 50 side.

[0040] The front frame portion 30 has a truss structure in which a plurality of frame elements are connected. Specifically, bar-shaped frame elements 32A, 32B, frame elements 34A, 34B, and frame elements 36A, 36B are provided in pairs, each of which is positioned approximately symmetrically with respect to a line (center line) extending from the steering axis C to the front wheels 110 and the rear wheels 120. In addition, a pair of frame elements 38A, 38B are connected to the pair of intermediate bases 80 so as to intersect with each other.

[0041] Each frame element of the front frame portion 30 is constituted by a connecting rod whose axial length is adjustable. Here, a spherical plain bearing (also called a pillow ball) is attached to the rod end, and the connecting rod is constituted by an adjustable axial length. Various well-known techniques can be adopted as a mechanism for adjusting the axial length. Here, screwed parts with different threading directions are formed near both ends of the connecting rod, and the axial length can be adjusted by turning a screw into one of the screwed parts. Also, each frame element is attached to the head pipe 140 and the intermediate base 80 by screwing a screw (not shown) into an opening (see 144P, for example) formed in the spherical plain bearing at both ends and tightening it with a nut from the opposite side.

[0042] The pair of frame elements 32A, 32B are attached to brackets 142A, 142B provided near the upper end of the head pipe 140. On the other hand, the pair of frame elements 34A, 34B are attached to brackets 144A, 144B provided near the lower end of the head pipe 140.

[0043] Each pair of frame elements 32A, 32B, frame elements 34A, 34B, and frame elements 36A, 36B extend from the head pipe 140 toward the intermediate base 80 in a direction in which the included angle widens (in an eight-shape), and the other end is attached to the intermediate base 80.

[0044] The frame elements 32A and 34A extend in substantially the same direction so as to face each other, and are connected to the upper end 80A and the lower end 80C of the intermediate base 80. Similarly, the frame elements 32B and 34B extend in substantially the same direction so as to face each other, and are connected to the upper end 80B and the lower end 80D of the intermediate base 80.

[0045] Meanwhile, the pair of frame elements 36A, 36B are connected to upper ends 80A, 80B of the intermediate base 80. Therefore, in the front frame portion 30, a triangular connection structure is formed between the frame elements 32A, 34A, 36A and the frame elements 32B, 34B, 36B, and a triangular connection structure is also formed between the frame elements 34A, 38B, 36B and the frame elements 36A, 38A, 34B, forming a three-dimensional truss structure overall. In other words, unlike a road cycle or other bicycle, which forms a triangular truss structure on a plane along the wheels, this is a three-dimensional truss structure formed by a plurality of triangles.

[0046] The rear frame portion 40 has an integral structure in which a plurality of rod-shaped frame elements are joined together by welding or the like. The seat rail 60, like the front frame portion 30, includes frame elements 62A, 62B whose axial length is adjustable, and is connected to the rear frame portion 40 and the pivot base 50.

[0047] In this embodiment, the axial length of each frame element constituting the front frame portion 30 can be adjusted, and the frame alignment of the main frame 20 can be changed by adjusting the length. The caster angle α can be changed by changing the frame alignment. The caster angle α changes the amount of trail, which affects the running stability and handling performance.

[0048] Specifically, a smaller caster angle α makes it easier to change direction when operating the steering wheel 150. Conversely, a larger caster angle α increases straight-line stability but increases resistance to the operation of the steering wheel 150, making it difficult to change direction quickly. In this way, differences in caster angle α affect the riding performance and maneuverability of the motorcycle 10.

[0049] By configuring each frame element constituting the front frame portion 30 of the main frame 20 to be adjustable in axial length, it becomes possible to finely change and adjust the caster angle α according to the riding conditions and the user's preferences. For example, the caster angle α can be set to be small for riding on a circuit. Alternatively, the caster angle α can be set to be large for long-distance travel (touring) to improve straight-line stability.

[0050] The caster angle α is adjusted by removing the screws and nuts attached to both ends of each frame element. Then, the pair of frame elements 32A and 32B are adjusted in length so that the axial length is increased, for example, at the end side close to the head pipe 140. Accordingly, the axial length of the pair of frame elements 34A and 34B is shortened, and the length of the pair of frame elements 36A and 36B is also finely adjusted. Then, the frame elements are again fixed with screws and nuts to connect between the head pipe 140 and the intermediate base 80. This reduces the caster angle α. The caster angle α can also be changed to be smaller by adjusting the axial length of other frame elements. It is also possible to change the caster angle to be larger.

[0051] As described above, each frame element is connected at both slidable ends. Therefore, even if there is a positional deviation or offset between the head pipe 140 and the intermediate base 80 due to the axial length adjustment, the head pipe 140 and the intermediate base 80 can be easily connected, and problems such as position adjustment of the intermediate base 80 caused by the length adjustment can be prevented. Since the length of the frame element connected to the head pipe 140 is adjusted, fine adjustment of the caster angle α is not complicated and is easy. On the other hand, since the caster angle α is adjusted by the two pairs of frame elements 34A, 34B and frame elements 36A, 36B, it is easy to appropriately adjust the caster angle α even for motorcycles 10 whose center of gravity position, vehicle balance, etc. differ depending on the model.

[0052] On the other hand, in the axial length adjustment mechanism of each frame element, each frame element functions as a reinforcing member that applies tension. Since the front frame portion 30 has a truss structure, sufficient frame strength and rigidity can be maintained. On the other hand, in the rear frame portion 40 of the main frame 30, a plurality of rod-shaped frame elements are integrally joined by welding or the like. Since the frame strength and rigidity of the rear frame portion 40 close to the engine mounting location are sufficiently maintained, the rigidity and strength can be maintained even when the vehicle balance changes by changing the caster angle α. In this embodiment, the thickness of each frame element is approximately the same, but the rod size (thickness) of the pair of frame elements 32A, 32B and the frame elements 34A, 34B may be made larger than that of the pair of frame elements 36A, 36B to further increase the rigidity.

[0053] On the other hand, since the frame elements 62A, 62B of the seat rail 60 can be adjusted in length along the axial direction, it is also possible to adjust the length of the frame elements 62A, 62B after changing the caster angle α, so that the seating posture before the change does not change.

[0054] Next, a motorcycle according to a second embodiment will be described with reference to Fig. 3. In the second embodiment, the rear frame portion is formed of a frame element whose length is adjustable.

[0055] 3 is a schematic perspective view of a frame of a motorcycle according to the second embodiment. In a rear frame portion 40' of a main frame 20', a pair of frame elements 42A, 42B and a pair of frame elements 44A, 44B extend along both sides of the vehicle body between an intermediate base 80 and a pivot base 50. The frame elements 42A, 44A and the frame elements 42B, 44B extend opposite to each other.

[0056] The pair of frame elements 46A, 46B connect lower ends 80'B, 80'D of the intermediate base 80' to upper ends 50A, 50C of the connecting portion of the pivot base 50. In addition, the pair of frame elements 48A, 48B connect the connecting portion of the intermediate base 80' and the pivot base 50 so as to cross each other. And the frame element 49 connects between the pair of intermediate bases 80'. Here, the intermediate base 80' is configured to also function as an engine mounting member.

[0057] Such a frame structure of the rear frame portion 40' makes it possible to change the frame alignment of the main frame 20 and change the caster angle α by adjusting the axial lengths of some or all of the frame elements not only in the front frame portion 30 but also in the rear frame portion 40'. Meanwhile, since the rear frame portion 40' has a three-dimensional truss structure, sufficient frame strength and rigidity can be maintained.

[0058] In addition, because the intermediate base 80' is configured as an engine mount member, it is possible to change the caster angle α while adjusting the engine mount position at the rear frame portion 40'. This makes it possible to maintain the center of gravity position and vehicle balance in the state before the caster angle was changed while changing the caster angle α. Note that, even in the first embodiment, the intermediate base 80 can be configured as a member for mounting the engine.

[0059] Next, a motorcycle according to a third embodiment will be described with reference to Fig. 4. In the third embodiment, the caster angle is adjusted by one frame element.

[0060] FIG. 4 is a schematic plan view of the frame of the motorcycle according to the third embodiment as viewed from one side. The main frame 20" is not configured as a front frame portion and a rear frame portion as in the first and second embodiments, but configures most of the engine (not shown) as part of the frame (strength member). The pivot portion 70" is provided in the rear portion of the engine.

[0061] The main frame 20" has a frame structure that is symmetrical with respect to a center line along the wheels 110, 120, and a rod-shaped frame element 122 that extends along the center line and connects to a curved frame element 123 is provided at the upper end of the head pipe 140. The frame element 122 is configured as a connecting rod whose axial length is adjustable, similar to the first and second embodiments.

[0062] The frame element 124 attached to the lower end of the head pipe 140 is forked into two (Y-shaped) parts halfway (only one branched part is shown in FIG. 4). The curved frame element 123 branches into two parts halfway from the connection part with the frame element 122 toward the connection part 126, and the ends are connected to the frame element 124 (only one branched part is shown in FIG. 4), and are symmetrical with respect to the center line. The connection part 126 between the branched frame element 124 and the curved frame element 123 has a hinge structure that can rotate about an axis, and is connected to a part of the main frame 20". One end of the branched frame element 124 and the curved frame element 123 is connected to the main body of a prime mover such as an engine.

[0063] With such a configuration of the main frame 20" (including the head pipe 140), it is possible to change and adjust the frame alignment and to change the caster angle α. Also, because the connection structure for the head pipe 140 uses both a bearing rod end and a connection by welding, even if the frame size of the main frame 20" is small relative to the engine, it is possible to change the caster angle α while sufficiently maintaining strength and rigidity. Furthermore, it is also possible to adjust the height H of the head pipe 140, and it is also possible to change the distance between the pivot portion 70" and the head pipe 140, i.e., the relative positional relationship between them. By making the connection portion between the branched frame element 124 and the head pipe 140 rotatable about an axis, it is also possible to adjust the height (position) of the head pipe 140 while maintaining the caster angle. Therefore, settings can be made to adjust any one of the caster angle, the position of the head pipe, or the distance (relative positional relationship) between the head pipe and the pivot portion.

[0064] Since the main frame 20" is premised on configuring most of the engine as a strength member, it can be applied to next-generation motorcycles. In other words, in order to combat climate change and achieve the goals of the SDGs, shifting the prime mover from a conventional internal combustion engine to an electric motor such as a motor is also an urgent issue for motorcycles. Even if the prime mover is to be shifted to a motor or the like, it is easy to replace the existing internal combustion engine with a motor as it is by simply adjusting the mounting part, and there is no need to separately manufacture or improve a new dedicated frame for the electric motor. In other words, it is possible to mount the prime mover regardless of the variations in the prime mover, and to create a frame structure that has a versatile and flexible platform function while realizing the riding performance and handling performance preferred by the user.

[0065] In addition, the frame elements 122 may be configured as a pair, as in the frame elements 32A and 32B shown in the first embodiment, and the curved frame 123 may be configured as a pair of curved frames, and may be configured to be connected to each other. In addition, it is also possible to adjust the axial length of the curved frame 123 by making it possible to adjust the length of the mounting portion of the rod end of the curved frame 123, and it is also possible to configure without providing a hinge structure. Furthermore, as in the first and second embodiments, a pivot base may be provided on the rear seat (subframe) side, and a rear frame portion, a branched frame element 124, and one end of the curved frame element 123 may be connected. In addition, as in the first and second embodiments, the branched frame element 124 and the curved frame element 123 may be configured to be connected to a bracket-shaped intermediate base, or a frame structure may be configured to be connected to a branched frame element such as an X-shaped, H-shaped, or T-shaped. The rod-shaped and branched frame elements are not limited to being pipe-shaped (hollow), and may be configured of solid members. The connecting portions at both ends of the frame element are not limited to a connecting structure in which a screw hole is provided in the spherical plain bearing portion, but may be provided with connecting portions formed with male threads, for example.

[0066] Although the motorcycles equipped with the frames shown in the first to third embodiments have been described above, it is also possible to improve existing motorcycles to have the frame structures shown in the first to third embodiments.

[0067] For example, it is possible to form a frame structure as in the third embodiment by joining the head pipe 140 to the frame element 124 and cutting the frame portion, as in the case of the frame element 124, and forming a frame structure as in the third embodiment. Alternatively, it is possible to improve a front frame portion, which is integrated by welding or the like in the same manner as the rear frame portion, in a frame structure similar to that of the first embodiment, to a configuration in which a plurality of frame elements whose axial length is adjustable are connected, as in the first embodiment.

[0068] It is also possible to manufacture (assemble) the frames shown in the first to third embodiments. For example, as shown in the second embodiment, a main frame having a desired caster angle can be manufactured by preparing a plurality of frame elements (connecting rods) whose axial length can be adjusted, connecting the frame elements to the intermediate base and pivot base, and fixing them with the above-mentioned screws and nuts. Note that, instead of preparing a plurality of connecting rods whose axial length can be adjusted, a plurality of frame elements (connecting rods) whose axial length can be adjusted, each having a different length, may be prepared in advance, and an appropriate frame element may be selected according to a determined caster angle and connected and fixed. The connecting structure is not limited to a structure in which the axial length can be continuously adjusted in a stepless manner, as with a screwdriver. Alternatively, it is possible to configure a rod-shaped or branched frame element whose length can be adjusted in a stepwise manner by providing a large number of pins (holes) arranged at a predetermined interval in the connecting portion and selectively fixing the pins. Also, in the first to third embodiments, the main frame is configured to be connected to a single head pipe 140, but it is also possible to provide a pair of head pipes via a rod or arm. This makes it possible to change the motorcycles shown in the first to third embodiments to vehicles of a reverse-strike type. Specifically, a frame structure can be created in which the main frame is connected to a pair of steering hubs via rods, arms, etc., to create a two-front wheel structure. In this case, the above-mentioned setting is possible by applying the above-mentioned frame elements.

[0069] In the first to third embodiments, the frame structure of a motorcycle has been described, but the above-mentioned frame elements can also be applied to the main frame of three-wheeled vehicles such as reverse trikes and ATVs such as four-wheeled buggies, and setting, manufacturing (assembly) and improvement can also be performed. That is, in order to change and adjust wheel alignment such as caster angle and trail amount, weight balance of the vehicle body including the location of the prime mover, running performance, maneuverability, riding posture, etc., a part of the main frame that is connected to the head pipe or a steering shaft pipe equivalent thereto can be configured with the above-mentioned frame elements, and setting and assembly can be performed.

[0070] In this case, a frame alignment that can adjust its own alignment can be installed according to the desired alignment, or a specific frame element (e.g., one with a compatible axial length) can be selected from multiple frame elements and set or assembled. Furthermore, it is also possible to cut a part of an existing main frame and install the above-mentioned frame element instead. The frame element is configured as a detachable member, making it possible to adjust its own alignment or select and install a frame element. However, within the range where the frame alignment can be adjusted, a part of the frame element may be configured as one piece with the main frame by welding or the like.

[0071] Such setting, assembly, and improvement may be performed according to the characteristics of the vehicle. Frame alignment can be adjusted to match the characteristics of the form of the vehicle, such as a vehicle that does not include a pivot part (such as a wishbone-type ATV) or a two-wheeled vehicle that does not have an intermediate base. For example, it is possible to adjust the frame alignment based on the location of the engine, electric motor, or other prime mover, and change the running performance, handling performance, riding posture, weight balance of the vehicle, and the like. Alternatively, it is also possible to adjust the frame alignment based on the riding posture. The above-mentioned frame elements can be configured as members that enable frame alignment to be adjusted, reset, or reconstructed, and also enable strength reinforcement, etc. [Explanation of symbols]

[0072] 10 Frames 20. Mainframe 30 Front frame part 32A, 32B Frame elements (connecting rods) 40 Rear frame part 60 Seat rail (subframe) 100 Motorcycles 140 Head pipe (steering shaft pipe) 150 Steering

Claims

1. a steering shaft tube to which a steering mechanism is attached; a main frame having a frame portion connected to at least the steering shaft pipe, the main frame including the steering shaft pipe; A motorized or mountable vehicle, characterized in that at least a portion of the main frame is formed into a truss structure by a plurality of frame elements, each of which is axially adjustable in length and capable of changing frame alignment.

2. The steering mechanism is a steering mechanism in which a trail changes in accordance with a change in caster angle, 2. The vehicle according to claim 1, wherein at least one of said plurality of frame elements is connected to said steering shaft tube and is capable of changing wheel alignment.

3. 2. The vehicle of claim 1, wherein each of said plurality of frame elements is axially variable in length at an end thereof.

4. Further comprising a pivot portion, 2. The vehicle according to claim 1, wherein an intermediate base is provided in the main frame between a pivot base including the pivot portion and the steering shaft tube, and at least a portion of a front frame portion provided between the steering shaft tube and the intermediate base is formed into a truss structure by the plurality of frame elements.

5. a steering shaft tube to which a steering mechanism is attached; a main frame including the steering shaft pipe and having at least a frame portion connected to the steering shaft pipe; A pivot portion. A vehicle with a motor or capable of being attached to a motor, characterized in that an intermediate base that is attached to or can be attached to a motor is provided in the main frame between a pivot base including the pivot portion and the steering shaft tube, and at least one frame element that is connected to the intermediate base and can change frame alignment is provided in a rear frame portion provided between the intermediate base and the pivot base.

6. Further comprising a pivot portion, an intermediate base is provided between the pivot base including the pivot portion and the steering shaft tube in the main frame; 2. The vehicle according to claim 1, wherein at least a portion of a rear frame portion provided between said intermediate base and said pivot base is formed into a truss structure by said plurality of frame elements.

7. A method for setting a motorized or mountable vehicle according to any one of claims 1 to 6, comprising the steps of: A method of setting up a vehicle, comprising adjusting a frame alignment by adjusting an alignment for at least one frame element of the plurality of frame elements.

8. At least a portion of the main frame is formed into a truss structure by a plurality of frame elements each of which is axially adjustable in length and capable of changing frame alignment; A method for manufacturing a frame for a motor vehicle or a vehicle mountable thereto, comprising the steps of: adjusting the alignment of said plurality of frame elements to a desired frame alignment; and then assembling said main frame.

9. A part of the frame is taken out of the ready-made main frame, A method for improving a frame of a motorized or mountable vehicle, comprising replacing the frame structure with one that includes a portion that is formed into a truss structure by a plurality of frame elements, each of which is adjustable in axial length and capable of changing frame alignment.

10. A method for setting up a motorized or mountable vehicle as claimed in claim 5, comprising the steps of: and adjusting said at least one frame element for alignment to adjust frame alignment.

Images