JP4888832B2 - Wet road surface testing machine - Google Patents

Description

  The present invention relates to a wet road surface testing machine for forming a water film on a simulated road surface having a surface condition equivalent to that of a paved road, for example, and measuring the characteristics of a tire on the simulated road surface on which the water film is formed. .

  Generally, this type of wet road surface testing machine is provided so as to be in contact with a support device that rotatably supports a test object such as a tire and an outer peripheral surface of the test object supported by the support device from below. And a cylindrical simulated road surface member, forming a water film on the inner peripheral surface of the simulated road surface member, bringing the outer peripheral surface of the test object into contact with the inner peripheral surface of the simulated road surface member, and further rotating the simulated road surface member By this, what measured the characteristic of the test subject on a wet road surface is known (for example, refer to patent documents 1).

In addition, as another wet road surface testing machine, a support device that rotatably supports a test object such as a tire, and a circle provided so as to come into contact with the outer peripheral surface of the test object supported by the support device from below. A plate-like simulated road surface member and a water film forming device capable of forming a water film on the upper surface of the simulated road surface member are provided, and the outer peripheral surface of the test object is brought into contact with an arbitrary radial position on the upper surface of the simulated road surface member. Further, it is known that the characteristics of the test object on the wet road surface are measured by rotating the simulated road surface member and further forming a water film on the upper surface of the simulated road surface member by the water film forming apparatus ( For example, see Patent Document 2.)
JP-A-11-326142 JP 2006-208095 A

  By the way, the former wet road surface testing machine does not have means for adjusting the thickness of the water film formed on the inner peripheral surface of the simulated road surface member, so the relationship between the thickness of the water film and the characteristics of the test object is shown. It cannot be measured.

  In the latter wet road surface testing machine, a gap of a predetermined size is formed between a plurality of spray nozzles that discharge water toward a predetermined radial range of the upper surface of the simulated road surface member and the upper surface of the simulated road surface member. And a water film thickness adjusting member that adjusts the thickness of the water film discharged from each spray nozzle and formed on the simulated road surface by the gap. The thickness of the membrane is adjusted, and the relationship between the thickness of the water membrane and the characteristics of the test object is measured.

  However, the thickness of the water film after passing through the gap between the upper surface of the simulated road surface member and the water film thickness adjusting member varies depending on the rotational speed of the simulated road surface member, the surface condition of the simulated road surface member, etc. There is a problem that the size of the water film does not always correspond to the thickness of the water film, and the relationship between the thickness of the water film and the characteristics of the test object cannot be measured accurately.

  The present invention has been made in view of the above problems, and an object thereof is to provide a wet road surface testing machine capable of accurately measuring the relationship between the water film thickness and the characteristics of the test object. It is in.

In order to achieve the above object, the present invention provides a wet road surface testing machine for measuring characteristics on a wet road surface of a test object having a rubber outer peripheral surface, and a support device for rotatably supporting the test object; A pseudo road surface that is provided so as to come into contact with the outer peripheral surface of the test object supported by the support device from below, and that forms a water film on the pseudo road surface. The test object supported by the apparatus and the support device is in contact with the simulated road surface, and the simulated road surface is moving in a predetermined direction with respect to the test object, and the pseudo road surface before the test object is contacted. Irradiates infrared rays and receives infrared rays reflected by the simulated road surface, and detects the thickness of the water film formed on the simulated road surface based on the absorbance of the received infrared rays at a predetermined wavelength or a predetermined wavelength band. Rumizumaku a thickness detecting device, to the water film forming apparatus, a water supply device for supplying water to the simulated road surface, is formed capable of placing a gap any size between the simulated road surface, A gap forming member capable of adjusting the water film thickness on the pseudo road surface by the size of the gap is provided .

As a result, the test object is rotatably supported by the support device, the simulated road surface comes into contact with the outer peripheral surface of the test object supported by the support device from below, and the water film forming device is placed on the simulated road surface. The test object rolls on the simulated road surface on which the water film is formed because the simulated road surface moves in a predetermined direction with respect to the test object while the test object is in contact with the simulated road surface. A state can be formed. In addition, in a state where the test object is rolling on the pseudo road surface on which the water film is formed, the infrared ray is irradiated toward the pseudo road surface before contacting the test object and the infrared ray reflected by the pseudo road surface is received, Since the thickness of the water film formed on the simulated road surface is detected based on the absorbance of the received infrared light at a predetermined wavelength or a predetermined wavelength band, the water film thickness on the simulated road surface before contacting the test object is determined. It can be measured without contact, and the relationship between the water film thickness and the characteristics of the test object is accurately measured. Furthermore, the water film forming device is provided with a water supply device for supplying water on the simulated road surface and a gap forming member capable of forming a gap of any size between the simulated road surface. The water film thickness can be adjusted by changing the amount of water supplied from the apparatus onto the simulated road surface, and the water film thickness can also be adjusted by changing the size of the gap formed by the gap forming member.

According to the present invention, since the relationship between the water film thickness and the characteristics of the test object can be accurately measured, the characteristics corresponding to the water film thickness of the test object can be measured in detail. . In addition, the water film thickness can be adjusted by changing the amount of water supplied from the water supply device onto the simulated road surface, and the water film thickness can be adjusted by changing the size of the gap formed by the gap forming member. Therefore, it is possible to easily adjust the water film thickness.

  1 to 8 show a first embodiment of the present invention. FIG. 1 is a front view of a wet road surface testing machine, FIG. 2 is a plan view of the wet road surface testing machine, and FIG. 3 is a line AA in FIG. FIG. 4 is a graph showing the absorption state of infrared rays received by the water film thickness detector, FIG. 5 is a graph showing the relationship between absorbance and water film thickness, and FIG. 6 is a block diagram of a wet road surface testing machine. FIG. 7, FIG. 7 and FIG. 8 are flowcharts showing the operation of the control unit.

  In this wet road surface testing machine, a support device 10 that rotatably supports a tire TA as an object to be tested, and a pseudo road surface 20a that contacts the outer peripheral surface of the tire TA supported by the support device 10 from below are formed on the upper surface. The disc-shaped member 20, the water film forming device 30 capable of forming a water film on the simulated road surface 20 a on the upper surface of the disk-shaped member 20, and the water film thickness capable of detecting the thickness of the water film on the simulated road surface 20 a And a height detecting device 40.

  The support device 10 includes a shaft 11 on which the tire TA can be attached to the tip, and a base 12 that rotatably supports the shaft 11. Further, the base 12 can move the shaft 11 in the vertical direction. By moving the shaft 11 in the vertical direction, the tire TA attached to the shaft 11 can be arbitrarily attached to the pseudo road surface 20 a on the upper surface of the disk-shaped member 20. Can be pressed with pressing force. The support device 10 can apply an arbitrary braking force to the shaft 11 by a brake (not shown), and can apply an arbitrary rotational force to the shaft 11 by a motor (not shown). Further, the support device 10 can measure the force in each direction applied to the shaft 11.

  The pseudo road surface 20a formed on the upper surface of the disk-shaped member 20 has a surface state equivalent to, for example, a paved road. Further, the lower surface of the disk-shaped member 20 is supported by a driving device 21, and the disk-shaped member 20 can be rotated in a predetermined direction by the driving device 21. That is, when the disk-shaped member 20 rotates, the pseudo road surface 20a moves in a predetermined direction with respect to the tire TA supported by the support device 10.

  The water film forming device 30 includes a water supply device 31 that supplies water onto the simulated road surface 20a, and a gap forming member 32 that can form a gap GA of an arbitrary size between the simulated road surface 20a. The water supply device 31 is made of a tubular member having a plurality of discharge holes 31a formed on the lower side, and water is supplied from a water supply source (not shown). Further, the water supply device 31 is disposed above the pseudo road surface 20 a and is disposed so as to extend in the radial direction of the disk-shaped member 20. Furthermore, the water supply device 31 can arbitrarily adjust the amount of water supplied from each discharge hole 31a to the simulated road surface 20a by a known mechanism such as an electromagnetic valve. The gap forming member 32 is disposed above the pseudo road surface 20 a and is disposed so as to extend in the radial direction of the disk-shaped member 20. Further, the gap forming member 32 can be moved in the vertical direction by a known cylinder 32a. When the gap forming member 32 is moved in the vertical direction by the cylinder 32a, the size of the gap GA between the gap forming member 32 and the pseudo road surface 20a is increased. Change. The cylinder 32a is fixed to a frame (not shown). The gap forming member 32 is disposed downstream of the water supply device 31 in the moving direction of the simulated road surface 20a. That is, by changing the amount of water supplied from the water supply device 31 to the simulated road surface 20a, the water film thickness on the simulated road surface 20a can be adjusted, and the water film thickness can be adjusted depending on the size of the gap GA with the simulated road surface 20a. You can also adjust the height. Further, the characteristic measurement position where the tire TA supported by the support device 10 and the simulated road surface 20a come into contact with each other is arranged on the downstream side in the moving direction of the simulated road surface 20a with respect to the gap forming member 32.

  The water film thickness detecting device 40 is disposed above the simulated road surface 20a and is fixed in a rectangular box-shaped protective member 41 opened to the simulated road surface 20a. The protective member 41 is a rail 42a of the moving mechanism 42. Is supported by. Moreover, the rail 42a is formed so that it may extend in the radial direction of the disk-shaped member 20, and the moving mechanism 42 can move the protection member 41 and the water film thickness detector 40 along the rail 42a. Furthermore, the moving mechanism 42 has an elevating device 42b that moves the rail 42a in the vertical direction. That is, the moving mechanism 42 can move the water film thickness detecting device 40 in a direction intersecting the moving direction of the simulated road surface 20a, and the water film thickness detecting device 40b moves the rail 42a in the vertical direction by the lifting device 42b. The distance between the device 40 and the simulated road surface 20a can be arbitrarily set. Further, the water film thickness detection device 40 is disposed downstream of the gap forming member 32 in the movement direction of the simulated road surface 20a, and is disposed upstream of the characteristic measurement position in the movement direction of the simulated road surface 20a.

  The rail 42a is provided with a position sensor 43 for detecting the position of the water film thickness detecting device 40. The position sensor 43 detects the position of the water film thickness detecting device 40 in a direction intersecting the moving direction of the pseudo road surface 20a. It is like that.

  The water film thickness detection device 40 irradiates infrared rays toward the simulated road surface 20a and receives infrared rays reflected by the simulated road surface 20a. Further, the water film thickness detecting device 40 detects the water film thickness on the pseudo road surface 20a based on the absorbance of the received infrared light in a predetermined wavelength band W. Here, when infrared rays are irradiated toward the pseudo road surface 20a on which the water film is formed, the water film absorbs the wavelength band near 1.9 μm and 2.9 μm, and the absorbance depends on the water film thickness. Change. FIG. 4 is a graph showing a light absorption state La when the water film is thin (indicated by transmittance on the graph) and a light absorption state Lb when the water film is thick as a reference example. 40 detects the water film thickness based on the absorbance in the predetermined wavelength band W shown in FIG. Specifically, the water film thickness detector 40 has correlation data between the absorbance and the water film thickness as shown in FIG. 5, and the water film thickness detector 40 has the absorbance in the predetermined wavelength band W and the correlation data. The water film thickness is detected based on the above.

  The water film thickness detection device 40 is connected to a control unit 50 comprising a well-known microcomputer, and the control unit 50 is also connected to a water supply device 31, a cylinder 32a, a moving mechanism 42, and a position sensor 43 (see FIG. 6). ).

  In the wet road surface testing machine configured as described above, when measuring the characteristics of the tire TA, first, the tire TA is pressed against the simulated road surface 20a by the support device 10 with a predetermined pressing force, and the drive device 21 is used to rotate the circle. The plate member 20 is rotated, and the simulated road surface 20a is moved in a predetermined direction with respect to the tire TA. Here, the tire TA is supported by the support member 10 so that the traveling direction of the tire TA and the tangential direction of the disk-shaped member 20 coincide. On the other hand, water is supplied onto the simulated road surface 20 a by the water supply device 31 of the water film forming device 30. Thereby, the state where the tire TA is rolling on the pseudo road surface 20a on which the water film is formed is formed.

  Then, the control part 50 controls the water supply apparatus 31 and the cylinder 32a based on the detection result of the water film thickness detection apparatus 40, and adjusts the water film thickness on the simulated road surface 20a. Further, the control unit 50 moves the water film thickness detection device 40 in the direction intersecting the moving direction of the simulated road surface 20a by the moving mechanism 42, and the position detection result of the water film thickness detection device 40 by the position sensor 43. The water film thickness detection result by the water film thickness detector 40 is stored.

  The operation of the control unit 50 when adjusting the water film thickness will be described with reference to the flowchart of FIG. That is, the detection result of the water film thickness detection device 40 is compared with the target thickness (having a predetermined width) of the water film preset in the control unit 50, and if the detection result is thicker than the target thickness ( S1) The amount of water supplied from each discharge hole 31a of the water supply device 31 is reduced by a predetermined amount (S2), and the gap forming member 32 is moved downward by a predetermined distance by the cylinder 32a (S3). On the other hand, the detection result of the water film thickness detection device 40 is compared with the target thickness, and if the detection result is thinner than the target thickness (S4), the amount of water supplied from each discharge hole 31a of the water supply device 31 is a predetermined amount. While increasing (S5), the gap forming member 32 is moved upward by a predetermined distance by the cylinder 32a (S6). Here, the predetermined amount and the predetermined distance are very small, the decrease of the water film thickness by performing Step S2 and Step S3 once is small, and the water film thickness by performing Step S5 and Step S6. The increase in is also small.

  The operation of the control unit 50 when storing the position detection result and the water film thickness detection result while moving the water film thickness detection device 40 will be described with reference to the flowchart of FIG. First, in a state where the water film thickness detection result by the water film thickness detecting device 40 is within the target thickness (S11), the water film thickness detecting device 40 is made to correspond to a predetermined position in the tire width direction by the moving mechanism 42. It arrange | positions at a 1st predetermined position (S12), and memorize | stores the position detection result and water film thickness detection result at that time (S13). Subsequently, the water film thickness detecting device 40 is arranged at a second predetermined position corresponding to another predetermined position in the width direction of the tire by the moving mechanism (S14), and the position detection result and the water film thickness detection result at that time are displayed. Store (S15). On the other hand, the tire TA characteristic measurement result corresponding to the water film thickness detection result in step S13 is separately stored in the control unit 50, and the tire TA characteristic measurement result corresponding to the water film thickness detection result in step S15 is separately controlled. Stored in the unit 50. Here, the position detection result, the water film thickness detection result, and the tire TA characteristic measurement result are stored in the control unit 50 so as to correspond to each other.

  Here, as described above, a water film is formed on the simulated road surface 20a, and when the simulated road surface 20a is moved in a predetermined direction with respect to the tire TA, water droplets WD are scattered by rotation of the tire TA, and a gap forming member is formed. When the water passes through the gap GA between the simulated road surface 20a and the pseudo road surface 20a, the water droplet WD is scattered by the gap forming member 32. However, since the water film thickness detecting device 40 is provided in the protective member 41, the protective member 41 Thus, the water film thickness detecting device 40 is protected from the water droplets WD scattered by the rotation of the tire TA and the gap forming member 32 (see FIG. 3).

  Thus, according to the present embodiment, the tire TA is rotatably supported by the support device 10, and the pseudo road surface 20a is in contact with the outer peripheral surface of the tire TA supported by the support device 10 from below, and the water film The forming device 30 forms a water film on the simulated road surface 20a, and the simulated road surface 20a moves in a predetermined direction with respect to the tire TA while the tire TA is in contact with the simulated road surface 20a. A state where the tire TA rolls on the simulated road surface 20a can be formed. In addition, in a state where the tire TA is rolling on the pseudo road surface 20a on which the water film is formed, infrared rays are irradiated toward the pseudo road surface 20a before contacting the tire TA and infrared rays reflected by the pseudo road surface 20a are received. Since the thickness of the water film formed on the pseudo road surface 20a is detected based on the absorbance of the received infrared rays in the predetermined wavelength band W, the water film thickness on the pseudo road surface 20a before contacting the tire TA is not contacted. The relationship between the water film thickness and the characteristics of the tire TA can be accurately measured. Therefore, it is possible to measure in detail the characteristics corresponding to the water film thickness of the tire TA.

  Further, since the water film thickness detecting device 40 detects the water film thickness on the pseudo road surface 20a based on the absorbance in the predetermined wavelength band W, the water film thickness can be continuously measured, and the water of the tire TA can be measured. This is extremely advantageous in measuring the characteristics according to the film thickness in detail.

  Moreover, since the water film thickness detector detects the water film thickness on the pseudo road surface 20a based on the absorbance in the predetermined wavelength band W, it can measure from a thin film of 0.1 μm to a thick film of several mm, for example. This is extremely advantageous in measuring the characteristics according to the water film thickness of the tire TA in detail.

  Further, since the distance between the water film thickness detecting device 40 and the simulated road surface 20a can be arbitrarily set by the moving device 42, the spot diameter of the infrared rays irradiated from the water film thickness detecting device 40 to the simulated road surface 20a is set. It can be arbitrarily set according to the distance.

  Further, since the water film thickness detecting device 40 can be moved by the moving device 42 in a direction intersecting with the moving direction of the simulated road surface 20a, the water film thickness detecting device 40 intersects with the moving direction of the simulated road surface 20a. This is extremely advantageous in measuring the characteristics according to the water film thickness of the tire TA in detail.

  Further, the water film forming device 30 is arranged so that a gap GA of an arbitrary size can be formed between the water supply device 31 for supplying water on the simulated road surface 20a and the simulated road surface 20a, and on the simulated road surface 20a. Since the gap forming member 32 capable of adjusting the water film thickness according to the size of the gap GA is provided, the water film thickness is adjusted by changing the amount of water supplied from the water supply device 31 onto the simulated road surface 20a. In addition, the water film thickness can be adjusted by changing the size of the gap GA, and the water film thickness can be easily adjusted.

  Further, since the protection member 41 protects the water film thickness detection device 40 from the water droplets WD scattered by the rotation of the tire TA, it is extremely advantageous in preventing failure and malfunction of the water film thickness detection device 40.

  Furthermore, since the protection member 41 protects the water film thickness detection device 40 from the water droplets WD scattered by the gap forming member 42, it is extremely advantageous in preventing failure and malfunction of the water film thickness detection device 40.

  FIGS. 9 and 10 show a second embodiment of the present invention. FIG. 9 is a sectional view of a wet road surface testing machine, and FIG. 10 is an operation explanatory view taken along the line BB of FIG. In addition, the same code | symbol is attached | subjected and shown to the component equivalent to 1st Embodiment.

  In this wet road surface testing machine, a support device 10 that rotatably supports a tire TA as a test object, and a pseudo road surface 60a that contacts the outer peripheral surface of the tire TA supported by the support device 10 from below is provided on the inner peripheral surface. The formed cylindrical member 60, the water film forming device 30 capable of forming a water film on the simulated road surface 60a on the inner peripheral surface of the cylindrical member 60, and the water capable of detecting the thickness of the water film on the simulated road surface 60a A film thickness detection device 40 and a control unit 50 are provided. In addition, the support apparatus 10, the water film formation apparatus 30, the water film thickness detection apparatus 40, and the control part 50 have the structure equivalent to 1st Embodiment.

  The pseudo road surface 60a formed on the inner peripheral surface of the cylindrical member 60 has a surface state equivalent to, for example, a paved road. The cylindrical member 60 has an end face wall 61 on one end side, and the center of the end face wall 61 is supported by a driving device 62. That is, the cylindrical member 60 can be rotated in a predetermined direction by the driving device 62, and the pseudo road surface 60 a moves in a predetermined direction with respect to the tire TA supported by the support device 10 by rotating the cylindrical member 60. It is like that. Further, the tire TA is supported by the support member 10 so that the traveling direction of the tire TA and the moving direction of the simulated road surface 60a coincide.

  The water supply device 31 of the water film forming apparatus 30 is disposed on the radially inner side of the cylindrical member 60 and is disposed so as to extend in the axial direction of the cylindrical member 60. Further, the gap forming member 32 of the water film forming apparatus 30 is disposed on the radially inner side of the cylindrical member 60 and is disposed so as to extend in the axial direction of the cylindrical member 60. Further, the gap forming member 32 can be moved in the radial direction of the cylindrical member 60 by the cylinder 32a. When the gap forming member 32 is moved in the radial direction by the cylinder 32a, the gap GA between the gap forming member 32 and the pseudo road surface 60a is changed. The size changes. In addition, the characteristic measurement position where the tire TA supported by the support device 10 and the simulated road surface 60a come into contact with each other is disposed downstream of the gap forming member 32 in the moving direction of the simulated road surface 60a.

  The water film thickness detecting device 40 is disposed inside the cylindrical member 60 in the radial direction, and is fixed in a rectangular box-shaped protective member 41 opened on the simulated road surface 60a side, and the protective member 41 is moved by the moving mechanism 42. The rail 42a is supported. The rail 42 a is formed so as to extend in the axial direction of the cylindrical member 60, and the lifting mechanism 42 b can move the rail 42 a in the radial direction of the cylindrical member 60. That is, the moving mechanism 42 can move the water film thickness detecting device 40 in a direction intersecting the moving direction of the simulated road surface 60a, and can arbitrarily set the distance between the water film thickness detecting device 40 and the simulated road surface 60a. is there. The position sensor 43 detects the position of the water film thickness detector 40 in the axial direction of the cylindrical member 60. Further, the water film thickness detection device 40 is disposed downstream of the gap forming member 32 in the movement direction of the simulated road surface 60a, and is disposed upstream of the characteristic measurement position in the movement direction of the simulated road surface 60a.

  As in the first embodiment, the control unit 50 controls the water supply device 31 and the cylinder 32a based on the detection result of the water film thickness detection device 40 to adjust the water film thickness on the simulated road surface 60a. It has become. Similarly to the first embodiment, the control unit 50 moves the water film thickness detecting device 40 in the direction intersecting the moving direction of the simulated road surface 60a by the moving mechanism 42, while the water film thickness by the position sensor 43 is detected. The position detection result of the detection device 40 and the water film thickness detection result by the water film thickness detection device 40 are stored. Further, as in the first embodiment, the control unit 50 stores the characteristic measurement results of the tire TA corresponding to the respective water film thickness detection results, and the position detection result, the water film thickness, and the like. The measurement result and the characteristic measurement result of the tire TA are stored in the control unit 50 so as to correspond to each other.

  Here, as described above, a water film is formed on the pseudo road surface 60a, and when the pseudo road surface 60a is moved in a predetermined direction with respect to the tire TA, water droplets WD are scattered by rotation of the tire TA, and a gap forming member is formed. The water droplets WD are scattered by the gap forming member 32 when water passes through the gap GA between the road surface 32 and the pseudo road surface 60a. However, since the water film thickness detecting device 40 is provided in the protective member 41, the protective member 41 Thus, the water film thickness detecting device 40 is protected from the water droplets WD scattered by the rotation of the tire TA and the gap forming member 32.

  Thus, according to the present embodiment, the tire TA is rotatably supported by the support device 10, and the pseudo road surface 60a comes into contact with the outer peripheral surface of the tire TA supported by the support device 10 from below, and the water film The forming device 30 forms a water film on the simulated road surface 60a, and the simulated road surface 60a moves in a predetermined direction with respect to the tire TA while the tire TA is in contact with the simulated road surface 60a. A state in which the tire TA rolls on the simulated road surface 60a can be formed. In addition, in a state where the tire TA is rolling on the simulated road surface 60a on which the water film is formed, infrared rays are irradiated toward the simulated road surface 60a before contacting the tire TA, and infrared rays reflected by the simulated road surface 60a are received. Since the thickness of the water film formed on the pseudo road surface 60a is detected based on the absorbance of the received infrared rays in the predetermined wavelength band W, the water film thickness on the pseudo road surface 60a before contacting the tire TA is not contacted. The relationship between the water film thickness and the characteristics of the tire TA can be accurately measured. Therefore, it is possible to measure in detail the characteristics corresponding to the water film thickness of the tire TA.

  Further, since the water film thickness detecting device 40 can be moved by the moving device 42 in a direction orthogonal to the moving direction of the simulated road surface 60a, the water film thickness detecting device 40 intersects the moving direction of the simulated road surface 60a. This is extremely advantageous in measuring the characteristics according to the water film thickness of the tire TA in detail.

  Further, the water film forming device 30 is arranged so that a gap GA of an arbitrary size can be formed between the water supply device 31 for supplying water on the simulated road surface 60a and the simulated road surface 60a, and on the simulated road surface 60a. Since the gap forming member 32 capable of adjusting the water film thickness according to the size of the gap GA is provided, the water film thickness is adjusted by changing the amount of water supplied from the water supply device 31 onto the simulated road surface 60a. In addition, the water film thickness can be adjusted by changing the size of the gap GA, and the water film thickness can be easily adjusted.

  In the second embodiment, the pseudo road surface 60a is formed on the inner peripheral surface of the cylindrical member 60. However, as shown in FIG. 11, an endless member 70 is provided instead of the cylindrical member 60. Alternatively, the pseudo road surface 70 a may be formed on the outer peripheral surface of the endless member 70, and the endless member 70 may be moved in a predetermined direction by the pair of rollers 71.

  In the first and second embodiments, the water film thickness is adjusted by the amount of water supplied from the water supply device 31 to the simulated road surfaces 20a and 60a and the size of the gap GA between the gap forming member 32 and the simulated road surfaces 20a and 60a. Although what was made to show was shown, it is also possible to adjust a water film thickness only with the said water amount, and it is also possible to adjust a water film thickness only with the magnitude | size of the said clearance gap GA.

  In the first and second embodiments, the characteristics of the tire TA are measured as the test object. However, a disk-shaped member having a rubber sheet attached to the outer peripheral surface or a rubber circle is shown. It is also possible to measure a test object having a rubber outer peripheral surface such as a plate-like member.

  In the first and second embodiments, the water film thickness detection device 40 is configured to measure the water film thickness based on the absorbance in the predetermined wavelength band W. It is also possible to measure the film thickness.

  In the first and second embodiments, a moving mechanism 42 that moves the water film thickness detector 40 in a direction that intersects the moving direction of the simulated road surfaces 20a and 60a is provided, and intersects the moving direction of the simulated road surfaces 20a and 60a. However, a plurality of water film thickness detectors 40 are provided at predetermined intervals in a direction crossing the moving direction of the simulated road surfaces 20a and 60a. It is also possible to measure the distribution of the water film thickness in the direction intersecting the moving direction of the simulated road surfaces 20a and 60a.

The front view of the wet road surface testing machine which shows 1st Embodiment of this invention Top view of wet road surface testing machine Explanatory drawing in the AA line cross section of FIG. Graph showing the absorption state of infrared rays received by the water film thickness detector Graph showing the relationship between absorbance and water film thickness Block diagram of wet road surface testing machine Flow chart showing operation of control unit Flow chart showing operation of control unit Sectional drawing of the wet road surface testing machine which shows 2nd Embodiment of this invention FIG. 9 is an explanatory diagram of the operation along the line B-B in FIG. Partial sectional front view of a wet road surface testing machine showing a modification of the second embodiment

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Support apparatus, 11 ... Shaft, 12 ... Base, 20 ... Disk-shaped member, 20a ... Simulated road surface, 21 ... Drive apparatus, 30 ... Water film formation apparatus, 31 ... Water supply apparatus, 31a ... Discharge hole, 32 ... Gap forming member, 32a ... cylinder, 40 ... water film thickness detecting device, 41 ... protective member, 42 ... moving mechanism, 42a ... rail, 42b ... lifting device, 43 ... position sensor, 50 ... control unit, 60 ... cylindrical shape Member 60a ... Simulated road surface 61 ... End face wall 62 ... Drive device 70 ... Endless member 70a ... Simulated road surface 71 ... Roller GA ... Gap W ... Predetermined wavelength band La ... Absorbing state Lb ... Absorbing State, WD ... water droplet, TA ... tire.

Claims (7)

In a wet road surface testing machine for measuring the characteristics of a test object having a rubber outer peripheral surface on a wet road surface,
A support device for rotatably supporting the test object;
A pseudo road surface provided so as to come into contact with the outer peripheral surface of the test object supported by the support device from below, and movable in a predetermined direction with respect to the test object;
A water film forming apparatus for forming a water film on the simulated road surface;
While the test object supported by the support device is in contact with the simulated road surface and the simulated road surface is moving in a predetermined direction with respect to the test object, infrared rays are directed toward the simulated road surface before contacting the test object. And a water film thickness detector for detecting the thickness of the water film formed on the simulated road surface based on the absorbance of the received infrared light at a predetermined wavelength or a predetermined wavelength band. equipped with a,
The water film forming device is disposed so that a gap of an arbitrary size can be formed between the water supply device that supplies water on the simulated road surface and the simulated road surface, and the water film thickness on the simulated road surface is determined by the gap. A wet road surface testing machine comprising a gap forming member that can be adjusted according to the size of the road. The wet road surface testing machine according to claim 1, further comprising distance setting means capable of arbitrarily setting a distance between the water film thickness detecting device and the simulated road surface. 3. The wet road surface testing machine according to claim 1, wherein a plurality of the water film thickness detecting devices are provided at intervals in a direction intersecting with the moving direction of the simulated road surface. The wet road surface testing machine according to claim 1 or 2, further comprising a moving mechanism capable of moving the water film thickness detecting device in a direction crossing a moving direction of the simulated road surface. The wet road surface testing machine according to claim 1, 2, 3, or 4 , further comprising a protective member capable of protecting the water film thickness detection device from water scattered by rotation of the measurement object. The wet road surface testing machine according to claim 5 , wherein the protection member is configured to protect the water film thickness detection device from water scattered by the gap forming member. Adjusting means for adjusting the amount of water supplied by the water supply device and / or the size of the gap between the simulated road surface and the gap forming member based on the detection result of the water film thickness by the water film thickness detection device; The wet road surface testing machine according to claim 1, 2, 3, 4, 5, or 6 .

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