JP4708085B2 - Tire testing equipment - Google Patents

Description

The present invention relates to a tire testing apparatus that ensures the positioning and fixing of a rotating shaft to a rotational position as required under excellent durability. When both the static test and the static test are performed at a certain location without moving the tires across the respective test devices, it is possible to advantageously improve the measurement accuracy of various stiffnesses, etc. by the static test. Propose technology.

In order to fix the rotating shaft to which a tire or the like is mounted at a required rotational position, it has been widely used to fix the rotating shaft with a key, a latch or the like, or to fix it with a brake. .
For example, in Patent Document 1, in order to use a tire dynamic tester as a static tester, a tread of a tire mounted on a rotating shaft on a peripheral surface of a rotationally driven test drum is used for a dynamic test. While the surface is pressed with the required load under the free rotation of its rotating shaft to measure the dynamic performance of the tire, a static pressure tester is attached to a stationary test drum for static testing. It is described that the static performance is measured by pressing a tire with the rotating shaft fixed to the apparatus.
JP 59-70940 A

  By the way, in the place described in Patent Document 1, since the rotating shaft is fixed by the brake in accordance with the static test of the tire, the brake slips during the static test in which a large rotational torque acts on the tire. Therefore, there is a high possibility that the measurement accuracy is lowered. On the other hand, when the braking capability is increased to such a level that no slip occurs, there is a problem that an increase in the apparatus cost cannot be denied.

  In addition, when the rotation shaft is fixed with a single key, latch, etc., the key and the latch itself may be damaged due to the stress concentration caused by the large torque acting on the tire, and hence the rotation shaft. There was a high risk of damage to the hook.

The present invention was made to solve such problems of the prior art, and the object of the invention is to sufficiently remove the possibility of damage to the rotation prevention mechanism, of course, It is an object of the present invention to provide a tire testing apparatus capable of always reliably performing positioning and fixing of a rotating shaft as expected at a low equipment cost.

The rotating shaft fixing device provided in the tire testing apparatus according to the present invention is provided with a plurality of ridges extending in the axial direction on the outer periphery of the end portion of the rotating shaft, for example, at an equal pitch in the circumferential direction thereof. At the same time, a sleeve provided with a plurality of grooves that fits all of the ridges can be reciprocated between a forward position where the grooves fit into the ridges and a reverse position where the fitting is eliminated. And at least a detent mechanism for restricting the rotation of the sleeve in the advanced position, and a sleeve advance / retreat drive mechanism.

  Here, the plurality of ridges provided on the rotating shaft can be a square spline, a ball spline, a serration, etc., and each generated by forming the end portion of the rotating shaft into a polygonal outer contour shape. It can also be a convex corner.

  Preferably, in such a fixed position, a plurality of protrusions that can be formed in the same manner as the previous protrusions, wherein the rotation preventing mechanism is provided on the outer peripheral surface of the sleeve so as to extend in the axial direction thereof. And a cylindrical member connected to the fixed member, each having a groove on the inner peripheral surface thereof that fits all of the protrusions.

Preferably, the forward / backward drive mechanism is composed of a motor and a screw shaft that is rotationally driven by the motor, and a sleeve, for example, an internal thread portion that is provided on an end wall formed at the rear end of the motor and is screwed to the screw shaft. To do.
The forward / backward drive mechanism can be configured by connecting, for example, a cylinder typified by a hydraulic cylinder or an air cylinder to an end wall formed in the sleeve, instead of the above-described one.

  In the tire testing apparatus according to the present invention, the static test unit having a flat surface that presses the tread surface of the test tire can be attached to and detached from the peripheral surface of the rotating drum for dynamic testing. In addition to the arrangement, a rotating shaft fixing device is provided on a rotating shaft on which a test tire is detachably mounted and moved forward and backward with respect to the static test portion.

  Preferably, in this tire testing apparatus, both end portions of the rotating shaft are supported on the frame via spherical bearings, and one end portion of the rotating shaft is perpendicular to each other with respect to the other end portion thereof. Drive means for swinging and displacing in a plane, for example, two types of cylinders are provided.

In the rotating shaft fixing device provided in the tire testing apparatus according to the present invention , the rotation preventing fixing of the rotating shaft at a predetermined rotational position is performed by moving the sleeve forward and backward under the action of the sleeve advancing and retracting drive mechanism. Each concave groove on the surface is engaged with each convex groove on the outer periphery of the end portion of the rotating shaft, and on the other hand, the rotational displacement of the sleeve itself is moved under the action of a detent mechanism. By restraining with, it is possible to always carry out reliably with a simple and inexpensive mechanism.

  Also, here, even if a large torque acts directly or indirectly on the rotating shaft, the torque is sufficiently distributed to a plurality of fitting engagement portions of the rotating shaft ridges and the sleeve ridges. Therefore, it is possible to effectively prevent the occurrence of breakage or the like in each hooking portion.

  By the way, when the sleeve is thus fitted to the rotating shaft under the action of the advance / retreat driving mechanism, and when the sleeve is constrained to the fitting position, vibration or the like may be input to the rotating shaft. However, it is possible to sufficiently eliminate the possibility of the sleeve coming out of the rotating shaft.

It is to be noted that the release of the restriction of the rotation shaft by the sleeve can be easily performed by sufficiently moving the sleeve backward by the re-operation of the advance / retreat drive mechanism. In this case, the sleeve is also advanced / retracted. By holding the drive mechanism in the retreat limit position, it is possible to sufficiently prevent the sleeve from being unexpectedly fitted into the rotating shaft.
Therefore, the rotating shaft can freely rotate under this state.

  Here, the anti-rotation mechanism is connected to a plurality of protrusions provided on the outer peripheral surface of the sleeve and a fixed side member, for example, a device frame, a floor surface, etc., and exactly fits all the above protrusions. When configured with a cylindrical member having a groove, it allows the sleeve to advance and retract as required within the cylindrical member, while simplifying the unexpected rotation of the sleeve in the advanced position. Under the inexpensive structure, it is possible to reliably prevent the protrusions and grooves from being damaged.

  In this case, on the tubular member side, not only the advance position of the sleeve but also a groove that fits the sleeve protrusion over the entire advance / retreat stroke thereof can be provided. Even in a retracted posture of the sleeve positioned away from the sleeve, unintentional rotational displacement of the sleeve can be restrained.

Further, when the advance / retreat drive mechanism is constituted by a motor, a screw shaft that is rotationally driven by the motor, and a female screw portion that is formed on the sleeve end wall and is screwed to the screw shaft, for example, a static test on a tire is performed. As done, due to the torque acting on the rotating shaft, the frictional force of the contact surface between the protruding shaft of the rotating shaft and the recessed strip of the sleeve is increased, the protruding strip of the sleeve, and the cylindrical shape Even if the frictional force of the contact surface with the groove of the member becomes large, the sleeve can be easily and smoothly moved backward and displaced under the action of the motor. And the positioning can be reliably held at each of the retreat limit positions.
The same applies to the case where the advance / retreat drive mechanism is configured by connecting, for example, a hydraulic cylinder to the end wall formed on the sleeve.

  Further, in the tire testing apparatus using any of the rotating shaft fixing devices as described above, the static test unit is attached to the peripheral surface of the stationary rotating drum, and the rotating shaft on which the test tire is mounted is attached. Under the action of the above-mentioned fixing device, the rotation shaft, and thus the test tire, is advanced and displaced toward the static test section, and the tread surface of the tire is statically fixed. When performing a static test on a tire by pressing it against the flat surface of the test part with a required force, for example, determining the so-called vertical rigidity of the tire by measuring the load and the amount of deflection at that time In addition, by measuring the lateral force or the longitudinal force and the amount of movement when the at least flat surface portion of the static test portion is displaced in the direction of the central axis of the tire and the circumferential direction of the tread, respectively, Lateral rigidity Further, the torsional rigidity of the tire can be determined by measuring the torque and the torsion angle at this time by oscillating and displacing the rotating shaft in a plane parallel to the flat surface of the test part. Can be sought.

In such a static test on a tire, particularly a measurement test for longitudinal rigidity in which a large torque acts on the rotating shaft, the rotating shaft is surely and firmly secured by the fixing device provided in the tire testing apparatus according to the present invention. Therefore, it is possible to achieve excellent measurement accuracy and to sufficiently eliminate the possibility of breakage of the fixing device.

  On the other hand, in the dynamic test of the tire, the static test part is removed from the peripheral surface of the rotating drum, and the rotating shaft is released by the reverse displacement of the sleeve, and then the rotating drum is driven to rotate at the required speed. And, for example, a tire on a rotating shaft, which can be freely rotated, and thus pressing its tread surface against the drum circumference in the required sequence, such a dynamic test can be Of course, it can be performed in a posture in which the central axes of the rotating shaft and the rotating drum are parallel to each other. For example, at least one end of the rotating shaft is swung upward or downward. Also under the condition where the tire is given a slip angle, and at least one end of the rotating shaft is swung in the direction approaching or separating from the rotating drum to give the tire a camber angle. It is possible.

  Here, in the case where driving means for supporting both ends of the rotating shaft on the frame via spherical bearings and displacing one end portion of the rotating shaft with respect to the other end portion is rotated by the driving means. The required swing displacement of the shaft can be performed reliably and easily, and the rotation of the rotating shaft within the frame can be performed sufficiently smoothly under the action of the spherical bearing.

  FIG. 1 is a schematic plan view showing an embodiment of a tire testing apparatus according to the present invention, and FIG. 2 is a side view of the main part of the apparatus.

  In the figure, reference numeral 1 denotes a rotating drum that is rotationally driven by a motor (not shown) during a dynamic test of the tire, and the peripheral surface of the rotating drum 1 is provided with road surface materials, safety walks, and the like as required. You can also

Reference numeral 2 denotes a test tire, and 3 denotes a rotating shaft on which the tire 2 is detachably mounted. Here, both end portions of the rotating shaft 3 are attached to the tip of a carriage 4 formed of a yoke-shaped frame. A spherical bearing 5 is supported for rotation.
The rotating shaft 3 that is rotatable here can also be connected to a rotational driving means (not shown) via, for example, a clutch mechanism, a constant velocity universal joint, etc. Accordingly, a required slip ratio or the like can be imparted between the rotating drum 1 and the test tire 2.

  In the figure, reference numeral 6 denotes a static test section that is attached to and detached from the peripheral surface of the rotating drum 1 as required under the stationary state of the rotating drum 1. The static testing section 6 is in surface contact with the convex curved surface of the rotating drum 1. For example, a base plate 7 that absorbs the protrusions and a flat plate 8 that is reciprocally displaced in the vertical direction indicated by an arrow A in FIG. 2 and the horizontal direction indicated by an arrow B in FIG. In addition, a sensor (not shown) such as a load cell for detecting a force in a predetermined direction acting on the flat plate 8 is provided.

  By the way, the carriage 4 made of a yoke-like frame that supports the rotary shaft 3 is reciprocally displaced on the pair of base rails 9 under the action of the load cylinder 10 as shown in a schematic perspective view in FIG. The carrier 11 can be attached to the carrier 11 so as to be swingable around the central axis. According to such an assembly structure, the tread surface 2a of the tire 2 on the rotating shaft 3 under the action of the load cylinder 10 is provided. Can be pressed against the peripheral surface of the rotating drum 1 or the flat plate 8 of the static test section 6 with a required force. The carriage 4 can be pressed, for example, at one end in a schematic front view in FIG. As shown in FIG. 3, the cylinder 12 attached to the carrier 11 is oscillated and displaced around the central axis 4a provided so as to protrude rearward in the center axis line of the rotating shaft 3. End part For example, the tire 2 on the rotating shaft 3 can be given a slip angle as required by displacing each other in the reverse direction with respect to the center position of the length thereof, and the tire 2 The flat plate 8 can be torsionally displaced around the center position of the tread width.

  Also, here, a cylinder 13 that causes the push-pull displacement of the spherical bearing 5 is disposed inside one of the arm portions 4b of the carriage 4 and the arm portion 4b located on the right side as shown in FIGS. With this cylinder 13, under the action of each spherical bearing 5, for example, ± 5 ° of the rotary shaft 3 is set as a limit (the limit varies depending on the spherical bearing to be used). The camber angle according to the requirement to the tire 2 can be given to the tire 2 by performing the rocking displacement inside.

Here, for the static test of the test tire 2, the fixing device provided in the tire test apparatus according to the present invention, which is provided on one shaft end portion side of the rotating shaft 3, is, for example, a cross section shown in FIG. In this fixing device, one small-diameter end portion of the rotary shaft 3 is provided on its peripheral surface with a plurality of ridges 14 extending in the axial direction, for example, in the circumferential direction. And a sleeve 17 having a plurality of recesses 16 that fit exactly with the respective protrusions 14 of the shaft portion 15 on the outer peripheral side of the spline shaft portion 15. 6 is reciprocated between the forward limit position shown in the upper half of FIG. 6 where the concave and convex strips 16 and 14 are completely fitted to each other, and the backward limit position shown in the lower half of FIG. 6 where the fitting is eliminated. It is arranged to be movable.

Also, here, the outer periphery of the sleeve 17 extends in the axial direction of the sleeve 17 and is connected to a plurality of protrusions 18 provided at equal intervals in the circumferential direction and to the fixed member, A rotation preventing mechanism 21 comprising a cylindrical member 20 provided with a plurality of grooves 19 that exactly fit with the protrusion 18 is provided, and at least the recess 16 of the sleeve 17 is caused to be splined by the rotation preventing mechanism 21. The sleeve 17 is reliably prevented from rotating under the condition of being fitted to the ridge 14 of the portion 15.

  Further, the motor 24 is attached to the outer side of the end wall 22a of the housing 22 that protrudes from the tubular member 20 to the rear side with a length that does not interfere with the sleeve 17, via the speed reducer 23, and A screw shaft 25 that is rotationally driven by a motor 24 is provided in the housing, and the screw shaft 25 is screwed into a female screw portion 26 provided on a rear end wall 17 a formed on the sleeve 17, thereby moving the sleeve 17 forward and backward. 27 is constructed.

  In the rotating shaft fixing device configured as described above, the sleeve 17 is retracted to the retreat limit position by the operation of the advance / retreat drive mechanism 27 and held there, whereby the rotating shaft 3 is moved to the sleeve 17. When fully released from the restraint by the anti-rotation mechanism 21, the free rotation of the rotary shaft 3 is ensured. Therefore, the test tire 2 mounted on the rotary shaft 3 under the rotational drive of the rotary drum 1. The required dynamic test for can be performed.

  On the other hand, the static test of the test tire 2 is performed by attaching the static test unit 6 to the circumferential surface of the rotating drum 1 while the rotating drum 1 is stopped, and fixing the rotating shaft 3 by the fixing device. You can prepare to start it by doing it in the required order.

  In this case, the rotation of the rotating shaft 3 is fixed by displacing the sleeve 17 to the advanced limit position by the re-operation of the advance / retreat driving mechanism 27 and holding the sleeve 17 there, and the spline shaft portion 15 of the rotating shaft 3 is rotated. Under the action of the stop mechanism 21, it can be carried out by engaging with the tubular member 20 via the sleeve 17 that just fits into it, and according to this, it is input to the rotary shaft 3 during the static test of the tire. Even if the torque to be increased, it is possible to reliably prevent the rotational displacement of the rotating shaft 3 due to the slip, and to sufficiently prevent the breakage of each fitting engagement portion and the like.

By the way, the static test of the test tire 2 in the state where the rotating shaft 3 is fixed in this manner, for example, measurement of various stiffnesses can be performed as described above.
That is, the vertical rigidity of the test tire 2 is determined by pressing the tread surface 2a of the tire 2 on the rotating shaft 3 against the flat plate 8 of the static test unit 6 by the action of the load cylinder 10 and the load at that time. Further, the lateral stiffness of the tire 2 can be obtained by measuring the flat plate 8 when the tire tread surface 2a is pressed against the flat plate 8. As shown by arrow B in FIG. 1, the lateral force and the amount of movement when the tire 2 is reciprocated in the center axis direction, that is, the left-right direction, and the longitudinal rigidity is determined by measuring the flat plate 8. 2 can be obtained by measuring the longitudinal force and the amount of movement when reciprocating in the vertical direction as indicated by an arrow A in FIG.

  The torsional rigidity of the test tire 2 is such that the carriage 4 is swung around its central axis under the action of the cylinder 12 under the pressure of the tread surface 2a against the flat plate 8, and the arm portions 4b It can be obtained by measuring the torque and the torsion angle when they are displaced in the opposite directions.

FIG. 7 is a cross-sectional view of the main part showing another configuration example of the advance / retreat drive mechanism 27 of the sleeve 17.
The advancing / retracting drive mechanism 27 shown here has a cylinder 28 that can be a hydraulic or air cylinder, for example, instead of the speed reducer 23 and the motor 24 described above, attached to the outside of the end wall 22a of the housing 22, and its rod. The leading end portion of 29 is connected to a boss 30 provided on the sleeve rear end wall 17a, and according to this advance / retreat drive mechanism 27, under a simpler structure than the advance / retreat drive configuration described above, The sleeve 17 can be moved forward and backward more quickly.

The embodiment of the present invention has been described above based on the drawings. For example, when it is necessary to relatively change the initial contact position of the tire tread surface 2a with the flat plate 8, FIG. As shown by arrows A and B, the flat plate 8 that is driven and displaced in directions orthogonal to each other is displaced by a required amount in a required direction, and the operation origin of the flat plate 8 is as expected. It can be easily accommodated by adjusting the position.
Further, the change in the circumferential position of the tire tread surface 2a that is in contact with the flat plate 8 is necessary, for example, on the tread surface 2a of the tire 2 mounted on the rotation shaft 3 before the rotation shaft 3 is positioned and fixed. Accordingly, the rubber belt, rubber crawler, roller, and the like that are displaced up and down according to the above and brought into contact with each other are brought into contact with each other, and the tire 2 can be rotated and displaced together with the rotary shaft 3 over a predetermined angular range.

It is an approximate line top view showing an embodiment of a tire testing device. It is a principal part side view of FIG. It is a rough-line perspective view which shows the assembly | attachment structure of a carriage. It is an approximate line front view which illustrates an attachment mode of a carriage rocking cylinder. It is a top view which shows embodiment of a fixing device as a cross section. It is a principal part enlarged view which shows the effect | action of a sleeve. It is principal part sectional drawing which shows the other structural example of the advancing / retreating drive mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating drum 2 Test tire 2a Tread surface 3 Rotating shaft 4 Carriage 4a Center shaft 4b Arm part 5 Spherical bearing 6 Static test part 7 Base plate 8 Flat plate 9 Base rail 10 Load cylinder 11 Carrier 12, 13 Cylinder 14 Projection 15 Spline Shaft portion 16 Concave strip 17 Sleeve 17a Rear end wall 18 Projection 19 Strip groove 20 Cylindrical member 21 Non-rotating mechanism 22 Housing 22a End wall 23 Reducer 24 Motor 25 Screw shaft 26 Female thread member 27 Advance / retreat drive mechanism 28 Cylinder 29 Rod 30 Boss A Up / down direction B Left / right direction

Claims (5)

A static test section having a flat surface that presses the tread surface of the test tire is detachably disposed on the peripheral surface of the stationary rotating drum, and the test tire is detachably mounted and statically mounted. A tire testing device in which a fixing device is provided on a rotating shaft that is advanced and retracted relative to a test unit,
The fixing device is provided with a plurality of ridges extending in the axial direction on the outer periphery of the end portion of the rotating shaft, and a sleeve provided with a plurality of ridges that exactly fit the ridges. The sleeve is disposed so as to be able to reciprocate between a forward position where the strip fits the convex strip and a retracted position where the fit is eliminated, and at least a rotation prevention mechanism is provided to restrain the rotation of the sleeve in the forward position, and the sleeve A tire testing device provided with a forward / backward drive mechanism. A cylinder having a plurality of protrusions provided on the outer peripheral surface of the sleeve extending in the axial direction of the sleeve, and a groove that is connected to the fixed side member and fits exactly to the protrusions. The tire testing device according to claim 1, wherein the tire testing device is configured with a member. Wherein the forward and backward driving mechanism, motor and a screw shaft that is rotated by it, provided at the end wall which is formed in the sleeve, to claim 1 or 2 comprising constituted by a female screw portion to be screwed to the screw shaft Tire testing equipment . The tire test apparatus according to claim 1 or 2, wherein the advance / retreat drive mechanism is configured by connecting a cylinder to an end wall formed in a sleeve. Driving means for supporting both end portions of the rotating shaft on the frame through spherical bearings and displacing one end portion of the rotating shaft in two planes perpendicular to each other with respect to the other end portion thereof. The tire testing apparatus according to any one of claims 1 to 4, which is provided.

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