Patent Description:
Conventionally, there has been known a chassis dynamometer apparatus which carries out a most appropriate centering of each of rotor shafts by adjusting pedestal in order to suppress blurring of each of wheel centers when the rotor shaft of each of load motors is connected with each of load wheels of a vehicle. See a following first reference.

In the case where each of load motors is connected with each of wheel connecting portions, it is necessary to be able to change postures of each of the load motors under consideration of varied postures of each of load wheels during traveling of the vehicle on a path as well as to connect each of the load motors with each of the load wheel connecting portions in conditions that each of the load motors is inclined at the same angles as caster and camber angles of each of the load wheels. For example, it is necessary to consider the postures of the vehicle when the vehicle turns right or left according to operations of a steering wheel. Thus, appropriate changes are required in a performance test of the vehicle so as to be able to realize the same postures of each of the load motors as the ones of each of the load wheels. However, the chassis dynamometer apparatus disclosed in the first reference cannot meet such the requirements as above-mentioned. <CIT> discloses a vehicle brake testing dynamometer comprising a rotatable surface simulation member having an annular cylindrical surface. Friction band means are mounted on the cylindrical surface, and motor means for rotating the surface simulation member. A sub-frame is mounted adjacent the surface simulation member. The sub-frame mounts at least one wheel testing unit wherein the wheel testing unit includes a carriage movable in a radial axis to and from the surface simulation member. The carriage mounts an individual vehicle wheel suspension including a tire, a wheel hub, a brake, and suspension damping means whereby the carriage can move towards and away from the surface simulation member to bring the tire in contact with the friction band means on the surface simulation member and tangentially thereto. Means are provided for varying the position of the carriage, the relative speed of the simulation member, and the application or release of the brakes in order to simulate virtual running and braking conditions of the vehicle wheel suspension. <CIT> discloses a dynamometer inspecting device in which a power absorbing means is used. The dynamometer inspecting device concerned includes a member in coupling or arrangement for coupling with a driving member, for example a driving wheel or hub of a car or the input shaft of a fluid pressure pump in direct coupling or through a joint. <CIT> discloses a method and a device for performing tests on an internal combustion engine or a structure which is associated with the engine by measuring output parameter values on at least one output shaft which is connected to the engine, is distinguished by producing a representation of variations in said output parameter values during operation of the engine, and evaluating the representation for determining an operating parameter value for the engine or the structure. The invention also concerns a dynamometer testing rig.

<CIT> discloses a dynamometer comprising an adaptation unit which is connectable to a load mechanism that applies force to the wheels of a vehicle. The adaptation unit comprises a frictionless plate which has two translatory and rotary degrees of movement.

The present invention was made in the circumstances above-mentioned and has an object to solve such the problems as above-mentioned by providing a chassis dynamometer apparatus which is able to synchronize postures of each of load motors, which is connected with each of load wheel connecting portions of a vehicle and is mounted on a pedestal, with the ones of each of load wheels of a vehicle.

To solve the problems above-mentioned, one of the aspects of the invention provides a chassis dynamometer apparatus in which each of load motors connected with each of load wheel connecting portions of a vehicle is mounted on a pedestal, comprising; provided that a longitudinal direction of a vehicle is an x-axis direction and a width direction of the vehicle is a y-axis direction, the pedestal containing a mounting frame on which each of the load motors is mounted and a base arranged under the mounting frame; a first movable mount(s) slidable in one direction of the x-axis or y-axis direction; a second movable mount slidable in the other direction of the x-axis or y-axis direction; and a spherical joint tiltable and rotatable in an arbitrary direction, wherein the first movable mount(s), the second movable mount, and the spherical joint are connected in series between the mounting frame and the base.

According to one of the aspects of the invention, sliding in the x-axis and y-axis directions of each of the load motors mounted on the pedestal, tilting, and rotation in the arbitrary direction are free by the first movable mount(s), the second movable mount, and the spherical joint which are connected in series between the mounting frame and the base included in the pedestal. This realizes to synchronize postures of each of the load motors with the ones of each of the load wheels of the vehicle.

Another aspect of the invention provides the chassis dynamometer apparatus, wherein a pair of the first movable mounts disposed at a distance in the x-axis direction are mounted on the base, the second movable mount is connected with the pair of the first movable mounts and bridges the pair of the first movable mounts, and the spherical joint is connected with the second movable mount between the pair of the first movable mounts and protrudes downward from the second movable mount, wherein the spherical joint contains an inner cylinder having a spherical outer face, a collar having a spherical inner face coming into contact with the spherical outer face of the inner cylinder and slidably supporting the inner cylinder inside, and an outer cylinder supporting the collar by fitting the collar inside and being fixed to a lower face of the second movable mount, and wherein a projection protruding downward from the mounting frame is fixed to the inner cylinder by fitting the inner cylinder inside through a window hole opened at the second movable mount.

According to another aspect of the invention, the spherical joint is disposed within a height size of a lower face of the second movable mount bridging the pair of the first movable mounts and a height size of the pedestal is shorten because the spherical joint is connected with the second movable mount at the lower face of the second movable mount between the pair of the first movable mounts.

Another aspect of the invention provides the chassis dynamometer apparatus, wherein each of the load motor contains a case having a peripheral wall, an end wall, a hollow surrounded by the peripheral wall and the end wall, a stator fixed to an inner face of the peripheral wall of the case, and a rotor housed in the hollow of the case, which is rotatably arranged in an inside of the stator in a radial direction and is connectable with each of the load wheel connecting portions of the vehicle, wherein provided an outer side of the width direction of the vehicle is an outer side of the y-axis direction and an inner side of the width direction of the vehicle is an inner side of the y-axis direction, the peripheral wall of the case extends in the y-axis direction, the end wall of the case is arranged at an end of the outer side of the y-axis direction, the case is insertable into a wheel housing of the vehicle from the outer side of the y-axis direction when each of the load motor is provided with the vehicle, and a brake disk and a brake caliper of the vehicle are insertable in an inside of the hollow of the case, wherein the rotor contains a rotor connecting portion connectable with each of the load wheel connecting portions of the vehicle, a rotor frame extending in an outer side of a radial direction of the rotor at a position apart from the brake caliper in a condition that the rotor connecting portion is connected with each of the load wheel connecting portions, a rotor peripheral wall extending in the inner side of the y-axis direction from a connecting portion at an end of the outer side in the radial direction of the rotor frame, and magnets fixed to the rotor peripheral wall, and wherein the brake caliper is inserted into a space positioned at the inner side of the radial direction of the rotor inner wall in a condition that the rotter connecting portion is connected with each of the load wheel connecting portions.

According to another aspect of the invention, a distance in the y-axis direction between the rotor frame and the brake caliper is shortened and therefore a distance in the y-axis direction from the rotor connecting portion to the end wall of the case is also shortened because the brake caliper is inserted into the space of the rotor peripheral wall at the inner side of the radial direction in the condition that the rotor connection portion is connected with each of the load wheel connecting portions. Accordingly, overhanging of the end wall of the case outward from the wheel housing of the vehicle is suppressed in the condition that the rotor connecting portion is connected with each of the load wheel connecting portions. Misdetection of the load motor by various sensors mounted on the vehicle is suppressed and malfunction of the vehicle based on the misdetection is able to be suppressed. Additionally, when the load wheels are turned right and left at a time of the performance test of the vehicle, a distance from each of the load wheel connecting portions to the end wall of the case is shortened and therefore a compact chassis dynamometer apparatus is promoted.

Referring to <FIG>, one of the embodiments of a chassis dynamometer apparatus <NUM> is explained. A longitudinal direction of a vehicle is an x-axis direction and a width direction of the vehicle is a y-axis direction in the following explanations. The chassis dynamometer apparatus <NUM> contains a load motor <NUM> connectable with a load wheel connecting portion of the vehicle, and a pedestal <NUM> on which the load motor <NUM> is mounted. The pedestal <NUM> contains a mounting frame <NUM> on which the load motor <NUM> is mounted, and a base <NUM> arranged at a position lower than that of the mounting frame <NUM>. The mounting frame <NUM> is a longitudinal member in the x-axis direction and has a concave portion 31a which has a concave inner peripheral face and is possible to be put on an outer peripheral face of a lower portion of the load motor <NUM>, and a flange <NUM>1b disposed at both ends of one and the other sides of the x-axis direction, which extends outward in the x-axis direction from the concave portion 31a. The mounting frame <NUM> also has a projection 31c protruding downward. A connecting frame <NUM> is provided with the load motor <NUM> and has a flange 21a which is able to overlap with the flange 31b of the mounting frame <NUM>. When the outer face of the lower portion of the load motor <NUM> is put on the inner face of the concave portion 31a, the flanges 31b and 21a of the mounting frame <NUM> and the connecting frame <NUM> are overlapped and the load motor <NUM> is fastened to the mounting frame <NUM> at the connecting frame <NUM> in such the overlapped condition as above-mentioned.

In the embodiment, the base <NUM> is divided into a first base 32a and a second base 32b and the first base 32a and the second base 32b are disposed at a distance in the x-axis direction. The base <NUM> is not necessarily divided as such and may be integrated. A first movable mount <NUM> slidable in the x-axis direction and a second movable mount <NUM> slidable in the y-axis direction, and a spherical joint are connected in series between the mounting frame <NUM> and the base <NUM>. Specifically, two longitudinal rails <NUM> extending in the x-axis direction are fixed to one and the other side portions in the y-axis direction of each of the first base 32a and the second base 32b. Each of sliders <NUM> slidable in a longitudinal direction is arranged on each of the rails <NUM>. A pair of the first movable mount <NUM> are arranged at a distance in the x-axis direction. Each of the first movable mount <NUM> is arranged by bridging four rails <NUM> in total fixed to each of the first base 32a and the second base 32b and is also fixed to the four sliders <NUM> in total. Therefore, each of the first movable mount <NUM> is slidable in the x-axis direction with regard to the first base 32a and the second base 32b. A stopper <NUM> is raised on each of one end portion of the x-axis direction of the first base 32a and the other stopper <NUM> is raised on the other end portion of the x-axis direction of the second base 32b. The stopper <NUM> raised on the first base 32a forms a sliding limit of one of the first movable mounts <NUM> in one side of the x-axis direction and the stopper <NUM> raised on the second base 32b forms a sliding limit of the other of the first movable mounts <NUM> in the other side of the x-axis-direction.

Additionally, in the embodiment, four longitudinal rails <NUM> extending in the y-axis direction are arranged abreast in the x-axis direction and are fixed to each of the first movable mounts <NUM>. One of the sliders <NUM> is slidable arranged on each of the rails <NUM> in the direction of each of the rails <NUM>. The second movable mount <NUM> is fixed to the eight sliders <NUM> in total and bridges the pair of the first movable mounts <NUM>. In this manner, the second movable mount <NUM> is connected with the first movable mounts <NUM> and is slidable in the y-axis direction with regard to the first movable mounts <NUM>. A same member is adaptable to the rails <NUM> and <NUM>, and this is applicable to sliders <NUM> and <NUM>. Arbitral structures of the member above-mentioned are adaptable. On the other hand, a window hole <NUM> pierces the second movable mount <NUM> at a position corresponding to a projection 31c of the mounting frame <NUM>.

Further, in the embodiment, the spherical joint <NUM> is connected with the second movable mount <NUM> so as to protrude downward from the second movable mount <NUM> between the pair of the first movable mounts <NUM>. Specifically, the spherical joint <NUM> contains an inner cylinder <NUM> having an outer spherical face, a collar <NUM> having a spherical inner surface coming into contact with the spherical outer surface of the inner cylinder <NUM> and slidably supporting the inner cylinder <NUM> in the collar <NUM>, and an outer cylinder <NUM> supporting the collar <NUM> by fitting the collar <NUM> in the outer cylinder <NUM>. Since the inner cylinder <NUM> is slidable in the collar <NUM> supported by the outer cylinder <NUM> in an arbitrary direction, the spherical joint <NUM> is tiltable and rotatable in an arbitrary direction. On the other hand, the outer cylinder <NUM> is fixed to a lower face of the second movable mount <NUM> and is positioned at an outside of a circumferential edge of the window whole <NUM>. The projection 31c of the mounting frame <NUM> is engaged with an inside of the inner cylinder <NUM> through the window hole <NUM>. A clearance d may be formed between the lower face of the mounting frame <NUM> and an upper face of the second movable mount <NUM> in a condition that the projection 31c is engaged with an inside of the inner cylinder <NUM>. Although the clearance d is not particularly necessary in the case where both the lower face of the mounting frame <NUM> and the upper face of the second movable mount <NUM> are slidably curved, in the case of a planar second movable mount <NUM>, there is a feasibility that the upper face of the second movable mount <NUM> comes into contact with the lower face of the mounting frame <NUM> and the contact of the upper face of the second movable mount <NUM> to the lower face of the mounting frame <NUM> may deteriorate tilting and rotation and lead to abrasion of both the lower face of the mounting frame <NUM> and the upper face of the second movable mount <NUM> during tilting or rotation of the mounting frame <NUM> by the spherical joint <NUM>. The clearance d is advantageous to suppresses such the drawback as above-mentioned. The clearance d may be gradually increased at one and the other side of the x-axis direction or in y-axis direction as a boundary of the spherical joint <NUM>.

As above-mentioned, in the embodiment, slides of the load motor <NUM> mounted on the pedestal <NUM> in the x-axis and y-axis directions, and tilting and rotation of the load motor <NUM> are possible and therefore postures of the load motor <NUM> are synchronized with the ones of load wheels of the vehicle by the first movable mounts <NUM>, the second movable mount <NUM>, and the spherical joint <NUM> which are connected in series between the mounting frame <NUM> and the base <NUM> of the pedestal <NUM>. For example, as shown in <FIG>, the postures of the load motor <NUM> is synchronized with the ones of the load wheels under conditions that the vehicle turns right and left according to rotational operations of a steering wheel. Further, as shown in <FIG> and <FIG>, the load motors <NUM> are connected with the load wheel connecting portions of the vehicle in a condition that the load motors <NUM> are inclined at the same angles as caster and camper angles of the load wheels. Additionally, in the embodiment, since the spherical joint <NUM> is connected with the lower face of the second movable mount <NUM> between the pair of the first movable mounts <NUM>, the spherical joint <NUM> is arranged within a height size from the lower face of the second movable mount <NUM> bridging the pair of the first movable mounts <NUM> to the upper face of the base <NUM> and therefore a height size of the pedestal <NUM> is shortened.

Referring to <FIG>, an embodiment of the load motor <NUM> is explained. The load motor <NUM> is attachable to each of load wheel connecting portions provided with an end of an axle of the vehicle. The load wheel connecting portion A contains a break disk A<NUM> and a wheel hub and is varied by structures of various vehicle suspensions. The load motor <NUM> contains a case <NUM>, a stator <NUM>, and a rotor <NUM>.

With regard to the load motor <NUM>, a radial direction is "r", an outer side and an inner side of the radial direction is "o" and "i", respectively, in the following explanations. Also, an outer side and an inner side of the y-axis direction which is a width direction of the vehicle is "o" and "i", respectively. The case <NUM> has a peripheral wall 111a, an end wall 111b, and a hollow 111c surrounded by the peripheral wall 111a and the end wall 111b. The peripheral wall 111a has a cylinder-like shape extending in the y-axis. The end wall 111b is fastened to an outer side end of the y-axis direction of the peripheral 111a. The stator <NUM> is fixed to an inner face of the peripheral wall 111a of the case <NUM>. A coil is wound around the stator <NUM> and supplies an electric power from the chassis dynamometer apparatus <NUM> shown in <FIG>. The case <NUM> is insertable to a wheel housing from the outer side o of the y-axis direction when the load motor <NUM> is provided with the vehicle, and when inserting the case <NUM>, the brake disk A<NUM> and a brake caliper A<NUM> contained the load wheel connecting portion A of the vehicle are inserted in the hollow 111c.

The rotor <NUM> is housed in the hollow 111c of the case 111and is rotatably arranged at the inner side i of the radial direction r of the stator <NUM>. The rotor <NUM> contains a rotor frame <NUM> a, a rotor peripheral wall 113b, magnets 113c, and a shaft member 113d. The rotor frame 113a extends in the outer side o of the radial direction r. An inside end of the radial direction r of the rotor frame 113a is bent to the outer side o of the y-axis direction and has a projection 113a<NUM> protruding to the outer side o of the radial direction r. A plurality of pin holes 114a in each of which a pin <NUM> is insertable are opened at a portion of the inner side i of the y-axis direction of an inner end of the rotor frame 113a in the radial direction r. A torque sensor <NUM> is arranged at the rotor frame 113a. The rotor peripheral wall 113b is connected with an outer side end of the rotor frame 113a in the radial direction r and has a cylindrical shape extending from a connecting portion of the rotor peripheral wall <NUM> with an outer side end of the rotor frame 113a to the inner side i in the y-axis direction. The magnets 113c are disposed at the rotor peripheral wall 113c with a prescribed interval in a peripheral direction of the rotor peripheral wall 113b. An outer face of each of the magnets 113c in the radial direction r is apart from an inner end face of the stator <NUM> in the radial direction r at a prescribed gap g. A cylinder shaft 113a<NUM> protrudes to the outer side o of the y-axis direction and is disposed at a middle portion between an inner end and an outer end of the rotor frame 113a in the radial direction r. The cylinder shaft 113a<NUM> is integrated with the rotor frame 113a.

The shaft member 113d is separated from the rotor frame 113a. The shaft member 113d has a rotor connecting portion 113d<NUM> at an inner side i of the y-axis direction and the rotor frame 113a is connected with the shaft member 113d at an inner side end of the rotor frame 113a in the radial direction r. Specifically, the shaft member 113d is a member extending in the y-axis direction and contains a columnar rotor frame fixing portion 113d<NUM> and a cylindrical rotor frame fixing and positioning portion <NUM>13ds. Thread grooves are provided around an outer face of a portion from an outer side end to a middle portion of the rotor frame fixing portion 113d<NUM> in the y-axis direction. An inner end of the rotor frame fixing portion 113d<NUM> in the y-axis direction is bent to the outer side o of the radial direction r and the rotor frame fixing and positioning portion 113d<NUM> is formed by bending the rotor frame fixing portion 113dz to an inner side i of the y-axis direction. A plurality of pins <NUM> protruding in the outer side o of the y-axis direction are concentrically embedded in the rotor frame fixing and positioning portion 113d<NUM> at a prescribed distance. The rotor connecting portion 113d<NUM> is formed by bending an inner side end of the rotor frame fixing and positioning portion 113d<NUM> in the y-axis direction. A plurality of inserting holes <NUM> piercing the rotor connecting portion 113d<NUM> are opened at the rotor connecting portion 113d<NUM>. The inserting holes <NUM> are concentrically disposed at a prescribed distance. Each of the insertion holes <NUM> is also opposed to each of a plurality of thread holes (not shown) opened at the load wheel connecting portion A containing the brake disk A<NUM> in the y-axis direction with a relationship of one by one. Accordingly, the shaft member 113d is connected with the load wheel connecting portion A by inserting a bolt from each of inserting holes <NUM> and by screwing the bolt with the thread holes as above-mentioned.

As above-mentioned, a fixing position of the rotor frame 113a is spontaneously decided by fitting the projection 113a<NUM> on the rotor frame fixing portion 113d<NUM> and inserting pins <NUM> into the pin holes 114a in a condition that the shaft member 113d is connected with the load wheel connecting portion A. When a nut <NUM> is screwed from the outer side end of the rotor frame fixing portion 113dz to inner side i in the y-axis direction, the projection 113a<NUM> is fastened between the nut <NUM> and the rotor frame fixing and positioning portion 113d<NUM> and the rotor frame 113a is connected with the shaft member 113d at an inner side end of the rotor frame 113a in the radial direction r. As a result, the rotor <NUM> is rotatable together with the load wheel connecting portion A. In this condition, the brake caliper A<NUM> is inserted into a space 111c<NUM> positioned at the inner side i of the radial direction r of the rotor peripheral wall 113b in the hollow 111c of the case <NUM> and the rotor frame 113a extends in the outer side o of the radial direction r at an outer side position apart from the break caliper A<NUM>. Accordingly, a distance in the y-axis direction from the rotor connecting portion 113d<NUM> to the end wall 111b of the case <NUM> is shorten and overhanging of the end wall 111b of the case <NUM> outward from the wheel housing of the vehicle is suppressed in the condition that the rotor connecting portion 113d<NUM> is connected with the load wheel connecting portion A of the vehicle. Therefore, misdetection of the load motor <NUM> by various sensors mounted on the vehicle is suppressed and malfunction of the vehicle based on the misdetection is able to be suppressed. A highly reliable vehicle performance test is realized. A compact size of the chassis dynamometer apparatus <NUM> is promoted by the short distance from the load wheel connecting portion A to the end wall 111b of the case <NUM> when the load wheels are tuned right and left at a time of the vehicle performance test.

A rotational supporting portion 111b<NUM> is disposed at a center of the end wall 111b in the load motor <NUM>. A corresponding portion of the end wall 111b to the rotational supporting portion 111b<NUM> is bent to the outer side o of the y-axis direction and a cylindrical body 111b<NUM> is formed. Bearings <NUM> in an inner ring rotation manner are arranged to an inner face of the body 111b<NUM>. The cylinder shaft 113a<NUM> of the rotor frame 113a protrudes to the outer side o of the y-axis direction at the body 111b<NUM> and the bearings <NUM> are interposed between the cylinder shaft 113a<NUM> and the body 111b<NUM>. A portion between the inner side end of the rotor frame 113a and the cylinder shaft 113a<NUM> is hollow and a rotation sensor <NUM> containing a magnetic pickup and a sensor gear is housed in a space 111b<NUM>. An inner portion of the rotational supporting portion 111b<NUM> is concealed by a cover <NUM> fixed to the rotational supporting portion 111b<NUM> from the outer side o of the y-axis direction. A whole or only some portion opposed to the nut <NUM> of the cover <NUM> may be detachable.

As above-mentioned, the load motor <NUM> is connected with the load motor connecting portion A in place of the load wheel at a time of the vehicle performance test. The load motor <NUM> is able to be connected with each of two front wheels in a front wheel drive vehicle, each of two rear wheels in a rear wheel drive vehicle, or each of four wheels in all wheel drive vehicle.

Claim 1:
A chassis dynamometer apparatus (<NUM>) comprising,
- a load motor (<NUM>) connectable with a load wheel connecting portion (A) of a vehicle; and
- a pedestal (<NUM>) on which the load motor (<NUM>) is mounted,
wherein a longitudinal direction of the vehicle is a x-axis direction and a width direction of the vehicle is a y-axis direction, the pedestal (<NUM>) contains:
- a mounting frame (<NUM>) on which the load motor (<NUM>) is mounted and a base (<NUM>) arranged under the mounting frame (<NUM>);
- a first movable mount(s) (<NUM>) slidable in one direction of the x-axis or y-axis direction;
- a second movable mount (<NUM>) slidable in the other direction of the x-axis or y-axis direction; and
- a spherical joint (<NUM>) tiltable and rotatable in an arbitrary direction,
wherein the first movable mount(s) (<NUM>), the second movable mount (<NUM>), and the spherical joint (<NUM>) are connected in series between the mounting frame (<NUM>) and the base (<NUM>).