JP2006275963A - Apparatus for measuring static friction - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simply and easily measure a measured object at a location at which the measured object is placed or used whether the location is horizontal or not. <P>SOLUTION: A movable frame 20 is pivotally supported by a measurement space 5 in the center of a pair of substrates, and provided with a pressurization means 30 for adjustably forming a fixed vertical load applied to the measured object X, a slip sensing means 45 coaxially aligned with the pressurization means and pivotally supporting an attachment instrument 70, and an angle measuring means 25 for measuring a tilt angle of the movable frame 20 at the moment when the slip sensing means 45 slides to a support shaft 21a for supporting the movable frame. A slip sensor 66 transmits a signal to the angle measuring means 25 at the moment when the fixed vertical load is vertically applied to the measured object X on a road surface by the pressurization means 30 and the measured object X is slipped on the road surface by tilting the movable frame and moving the gravity center of the vertical load. The tilt angle θ of the movable frame 20 is measured and calculated when the movable frame 20 begins to be slipped. A static friction coefficient is displayed on a display screen 9. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a static friction measuring apparatus capable of directly measuring static friction of various footwear in contact with a road surface and various products in contact with a floor surface on a road or floor of a building.

  Conventionally, there are many people who are injured by falling while walking on the road or the floor of a building. In particular, the elderly with weak bodies were dangerous because they could lead to accidents such as the fracture of the femur and the death of the head depending on where they fell. Many causes of these slip-fall accidents are caused by changes in the frictional state between the road surface and the floor of the building and the shoe sole during walking.

  When measuring static friction between a road surface or a building floor and the object to be measured, it is difficult to obtain a sample of the road surface or floor surface. Especially, the road surface condition is dust, oil, etc., dry, wet or puddle. It was difficult to measure the coefficient of static friction under the same conditions as the actual situation in the laboratory because the frictional state changed depending on the state.

On the other hand, as a conventional measuring apparatus and measuring method for measuring the coefficient of static friction of an object to be measured, an inclination measuring method, a resistance measuring method, and the like are generally known. The tilt measurement method is a method of displaying a static friction coefficient with an angle when the object to be measured starts to slide after the object to be measured is horizontally rested on the base and then the base is gradually inclined.
Japanese Patent Laid-Open No. 2001-4528

  In this measurement method, since it is an absolute condition that the base is horizontal, the sample to be measured must be brought to the place where the measurement device is installed, and thus cannot be easily measured. Therefore, there is a drawback that the object to be measured is limited because it is necessary to be able to obtain a sample as the object to be measured.

  There are two types of resistance measurement methods. The first measurement method is to place an object to be measured horizontally on a horizontal base, and place the object under a constant external force (linear sliding force (pulling force). )), The initial frictional force when the object to be measured starts to slide is used as static friction resistance, and the static friction coefficient can be obtained from the static frictional resistance force / body weight.

  In the first resistance force measurement method, it is very difficult to measure the initial resistance force at the moment when the external force is applied to the object to be measured, and the resistance force is increased due to the sampling time of the recording device, the rising characteristics of the external force, and the like. Since differences are likely to occur, it was difficult to perform accurate measurement.

  In the second resistance force measurement method, when the object to be measured is horizontally rested on a horizontally positioned base and {the linear sliding force (pushing force)} is gradually increased, the object to be measured starts to slide (move). The external friction force is the static friction resistance.

This second resistance measurement method is the simplest and most reliable. However, since the base on which the object is placed is horizontal, it is an absolute condition. It couldn't be done anywhere easily.
Japanese Patent Laid-Open No. 10-62273

Since each of the measuring devices described above measures a sample of the object to be measured, the object to be measured for which no sample is available cannot be measured. In addition, the samples had to be brought to the facility where the measurement equipment was installed. For this reason, the measurement is very troublesome and inefficient, and since it is a sample measurement to the last, an error tends to occur between the actual measurement. Furthermore, there are many problems such as that the base surface of the apparatus on which the sample is placed is an absolute condition.
In view of the above problems, the present invention does not use a base of a device on which a sample is placed, and easily covers a place where a measurement object is located or used regardless of whether the place is horizontal. It is an object of the present invention to provide a portable static friction coefficient measuring device capable of measuring a measurement object.

  The static friction coefficient measuring apparatus according to the present invention is pivotally supported in a measurement space 5 provided between a pair of bases 2A and 2B having flat portions 7 and 7 on the upper surface, respectively, and an operation unit is provided on the upper back side. The swinging arm 30 is provided on the upper part of the movable frame 20 provided with 28, and is provided with a pressurizing means 30 that adjustably applies a constant vertical load to the object to be measured X, and is located on the same axis as the pressurizing means 30. 46 is provided at the lower end of 46 with a slip sensing means 45 that pivotally supports a mounting device 70 for mounting the object to be measured X, and one support shaft 21a that pivotally supports the movable frame 20 is provided with the support shaft 21a. An angle measuring device 25 for outputting the inclination angle of the movable frame 20 is provided, and an arithmetic display device 9 for calculating and displaying an output signal of the angle measuring device and a signal at the moment when the slip sensing means 45 slides is provided on one base 2A. The vertical load is applied by the pressurizing means 30. A load is applied from the right direction to hold the bases 2A and 2B at the measurement location, and the center of gravity of the vertical load is moved by the tilting of the movable frame 20, so that the object X is slipped on the road surface at the moment when the object X slides on the road surface. The swing arm 46 is tilted, the signal from the slip sensor 66 and the signal output from the angle measuring device 25 are transmitted to the calculation display screen 9, and the tilt angle θ of the movable frame 20 where the object to be measured X begins to slide. The coefficient of static friction is displayed by measuring and calculating the value on the calculation display screen 9. The pressurizing means 30 has a mark line 36 in a pressurizing cylinder 31 having a window portion 32 for displaying a pressurizing force on a peripheral surface and a scale portion 33 for displaying the pressurizing pressure on both sides of the window portion. A compression pin 35 having a resilient force, a pressure spring 37 having a resilient force, and a pressure pin 38 having a pin portion 39 are arranged on the same axis, and the pressure screw 41 is disposed above the pressure cylinder. A feature is that a predetermined load can be pressurized by rotation. Further, the slip detecting means 45 pivotally supports a rotating roller 48 at the upper end of the swing arm 46, and a guide shaft 50 for preventing the swing arm 46 from being tilted is inserted into a guide groove 49 provided at a substantially central position. A connecting piece 55 formed by cutting a part of the swing arm is detachably attached, a connecting member 58 composed of a plurality of small pieces is attached to the lower end of the connecting piece, and pivotally supported at the lower part of the connecting member. An attachment device 70 for attaching the object to be measured X is attached to the lower end of the adjustment plate 64 formed of a plurality of plates having different thicknesses at the lower part of the connection shaft 60, and the upper part of the swing arm 46 and the movable frame body. Further, the slip sensor 66 is attached to the swing arm 46, and the slip sensor 66 is provided on the upper side of the swing arm 46 so as to reinforce the movable frame 20 and the sensor 66a made of a light shielding plate. 22 when the swing arm 46 is in a vertical state, the slip sensing unit 66a shields the signal unit 66b, and the movable frame 20 tilts and the measured object X slides. At the same time, it is detected that the swing arm 46 is tilted and the object to be measured X is slid, and at the same time, the sensing unit 66 a is detached from the signal unit 66 b and transmitted to the calculation display screen 9. Further, the angle measuring device 25 is located on the same axis as the one support shaft 21a of the movable frame 20 pivotally supported on the bases 2A and 2B, and rotates together with the tilt of the movable frame. When the swing arm 46 tilts at the moment when the measurement object X slides, the calculation display screen 9 receives an electrical signal from the slip detector 66 and instantaneously determines the tilt angle θ of the movable frame body from the output of the angle measuring device 25. The coefficient of static friction of the object to be measured X converted into a numerical value is digitally displayed on the calculation display screen 9. Further, the movable frame body 20 is attached to one support shaft 21a with a return spring 23 for returning the movable frame body to a vertical position, and the other support shaft 21b buffers the repulsive force of the return spring 23. A damper 27 is attached, and the movable frame 20 after the static friction measurement is provided so that it can be automatically returned to the original vertical position. In the instrument, a plurality of screw holes 72 for adjusting the connection position with the connection shaft 60 are provided at substantially the center of the support plate 71 accommodated in the footwear, and a locking portion 73 for supporting the toe portion of the footwear is provided at the tip. It was attached so that it could be slidably adjusted, and an adjustment part 75 that made it possible to adjust the position of the heel of the footwear was provided at the rear end, and a plurality of stabilizing plates 77 for adjusting the upper height position were attached to the lower surface of the support plate 71. It is characterized by.

  Therefore, the load to be measured is almost the same as the human body weight, and any footwear can be easily mounted and measured on-site, and the movable frame is manually tilted. Since the power supply for operation is unnecessary, it is easy to carry, and an accurate coefficient of static friction can be measured in the field regardless of whether the surface to be measured is inclined or not.

  1 to 9, FIG. 1 is a front view of a static friction measuring device according to the present invention, FIG. 2 is a plan view of the static friction measuring device, and FIG. 3 is a plan view of FIG. 4 is a rear view of the pressurizing cylinder as the pressurizing means, FIG. 5 is a cross-sectional view taken along the line AA of FIG. 4, FIG. 6 is a front view of the slip sensing means, and FIG. 8 is a partially cutaway side view of the first mounting device for mounting the footwear as the object to be measured, FIG. 9 is a plan view of the first mounting device, and FIG. 10 is a state in which the footwear is mounted on the first mounting device. FIG. 11 is a side view of the second fixture.

  A static friction measuring device (hereinafter referred to as a measuring device) 1 is configured so that lower sides of a movable frame 20 disposed in a measurement space 5 provided in the middle of a pair of bases 2A and 2B located on the left and right sides are connected to the bases 2A and 2B. It is pivotally supported. An angle measuring device (potentiometer) 25 for measuring the inclination angle (θ) of the movable frame body 20 is attached to one support shaft 21a provided in the movable frame body, and the upper center of the movable frame body 20 is vertically arranged. A pressurizing means 30 for variably applying a constant load to the object to be measured, a slip detecting means 45 for detecting the moment when the object to be measured slips below the pressureable means 30, and an object to be measured X And mounting fixtures 70 (80) to be mounted on the same axis in the vertical direction.

  As shown in FIG. 2, the bases 2 </ b> A and 2 </ b> B are respectively formed with L-shaped cross sections by providing upright portions 3 </ b> A and 3 </ b> B on the inner side, and the upright portions 3 </ b> A and 3 </ And the connection board 6 is attached and connected to the back side of mutual base | substrate 2A, 2B. The flat portions 7 and 7 that also serve as the footrest portions are formed by providing a line indicating the position of the center of gravity at the center of the upper surface of each of the bases 2A and 2B, and the load applied to the measurement object X on the flat portions 7 and 7 The apparatus is fixed to the measurement site when a weight having the above weight or a person having an equivalent body weight rides.

  Reference numeral 8 is a protective cover display box attached to one base 2A. The calculation display screen 9 digitally displays the coefficient of static friction on the surface of the display box, and the inclination angle of the slip sensor 66 and the movable frame 20 to be described later. A switch 10 is provided for electrically turning on and off the angle measuring device 25 to be measured. Reference numeral 11 denotes a protection box attached to the other base 2B, and accommodates the other support shaft 21b of the movable frame body and a damper 27 attached to the support shaft.

  The movable frame body 20 is formed in a portal shape and attached to the lower portions on both sides, and the support shafts 21a and 21b are pivotally supported on the upright portions 3A and 3B of the bases 2A and 2B so as to be reinforced upward on the back side. A plate 22 is attached to reinforce the movable frame 20.

  One support shaft 21a that pivotally supports the movable frame body 20 is provided with a return spring 23 that automatically returns to the original vertical position after the movable frame body tilts, and the shaft center is the same as the support shaft. A connecting shaft 24 that rotates in the direction is connected, and an angle measuring device 25 that calculates a coefficient of static friction of the object to be measured X by an angle (θ) is attached to one end of the connecting shaft.

The angle measuring device 25 uses a known potentiometer that measures the shaft rotation of the connecting shaft 24 connected to one support shaft 21 a of the movable frame 20 as an angle and digitally displays the friction coefficient on the calculation display screen 9. Then, the slip signal received by the slip sensor 66 described later is received on the calculation display screen 9, and the angle (θ) of the measured object X, which is the output from the angle measuring device 25 at that time, slips is expressed as “tan θ = X The coefficient is digitally displayed on the calculation display screen 9, and is electrically turned on and off by the switch 10, respectively. That is, when the switch 10 is turned on, an output is always output from the angle measuring device 25 and the rotation angle (θ) of the movable frame body is calculated and displayed on the calculation display screen 9.

  Reference numeral 27 denotes a damper attached to the other support shaft 21b that pivotally supports the movable frame 20, and when the movable frame 20 is returned to the vertical position by the return spring 23 attached to the support shaft 21a, the repulsive force of the spring. Is eased, and the movable frame 20 is returned to the vertical direction smoothly.

  Reference numeral 28 denotes an operation portion that also serves as a portable handle attached to the upper back side of the movable frame body 20. The return spring 23 holds the operation portion 28 and attaches the movable frame body 20 to the support shaft 21 a. Against the elastic force, it is tilted slowly in the direction of the arrow in FIG. 3, and tilted by operating with human hands without using driving means such as a motor.

  4, 5, and 6, reference numeral 30 denotes a pressurizing means attached to the upper center of the movable frame body 20, and a vertically long window portion 32 is provided on one side of the pressurizing cylinder 31 having an open lower portion. A scale portion 33 is formed on both sides, and a compression pin 35 having a mark line 36 that can be visually confirmed from the window portion 32 is formed in the pressurizing cylinder 31, and is formed in a spiral shape and repels in the vertical direction. A pressure spring 37 and a pressure pin 38 for receiving the pressure of the spring are provided on the same axis so as to be movable up and down.

  Further, by rotating the screw portion 42 of the pressure screw 41 provided on the upper portion of the pressure cylinder 31 in the clockwise direction or the counterclockwise direction, the mark of the compression pin 35 pressed by the screw portion 42 and the pressure spring 37 is marked. The line 36 can be moved up and down in the window 32 to adjust the pressure. The pressurizing pressure by the pressure screw 41 is set in the range of about 50 to 80 kg which is an average weight of an adult, and the scale unit 33 displays the pressurizing pressure every 0.5 kg. The pressure pin 38 positioned below the pressure cylinder 31 passes through a through hole 20a provided at the center of the upper end of the movable frame body 20, and the tip of the pin portion 39 of the pressure pin is formed in the through hole 20a. It protrudes from the lower surface of the swing arm 46 so as to come into contact with the upper end of a swing arm 46 which will be described later.

  As shown in FIGS. 1, 3, and 6, the slip sensing means 45 includes a prismatic swing arm 46, a connecting piece 55 provided at the lower end of the swing arm, a connecting frame portion 58 connected to the connecting piece, As shown in FIG. 8, a connecting shaft 60 pivotally supported on the connecting frame portion is connected to a connecting shaft 60, and an attachment device 70 for mounting an object to be measured is connected to the lower end of the connecting shaft via an adjusting plate 65 as shown in FIG. A slip sensor 66 is attached to the upper side of the arm 46.

  As shown in FIGS. 1, 3, and 6, the swing arm 46 rotatably supports a rotating roller 48 in which a tip of the pin portion 39 of the pressure pin 38 abuts in a concave groove 47 provided at the center of the upper end. A guide shaft 50 for preventing the swing arm 46 from tilting is inserted into a guide groove 49 provided substantially at the center, and at least one or more connecting pieces 55 each having a part of the swing arm formed into a bowl shape are provided at the lower end. It is attached so that attachment or detachment is possible with this locking screw 57.

  As shown in FIGS. 6 and 7, the connecting member 58 attached to the lower end of the connecting piece 55 is formed so that one horizontal plate 58a and a plurality of side plates 58b can be disassembled, so that the connecting shaft 60 can be easily attached and detached. be able to.

  As shown in FIG. 6, a shaft rod 61 protruding from both sides of the connecting shaft 60 is pivotally supported in a shaft hole 58c of the side plate 58b of the connecting member 58, and the movable frame 20 is centered on the support shafts 21a and 21b. In this manner, the swing arm 46 also tilts about the shaft 61 of the connection shaft 60.

  The adjustment plate 64 mounted below the connecting shaft 60 is covered from the upper end of the swing arm 46 with a plurality of plate pieces of different thicknesses being detachably interposed between the connecting shaft 60 and the mounting device 70. The distance to the road surface including the measurement object X is adjustable.

  1 and 3, the slip sensor (photosensor) 66 includes a light emitting portion and a light receiving portion on a sensing portion 66 a attached to the upper side of the swing arm 46 and a reinforcing plate 22 located on the back side of the movable frame body 20. And a signal portion 66b having a portion. When the swing arm 46 is in the vertical state, the sensing unit 66a shields the signal unit 66b. Next, when the movable frame 20 is tilted, when the vertical load moves and the object to be measured X slips and the swing arm 46 tilts, the sensing unit 66a is detached from the signal unit 66b and measured by the angle measuring device 25. The output signal is transmitted to the calculation display screen 9.

  In FIGS. 8 and 9, among the measurement object X, in particular, a first attachment device 70 for removably attaching a footwear is attached to a substantially center of a support plate 71 so that the connection position with the connection shaft 60 can be adjusted. Screw holes 72 are provided. A locking portion 73 for locking the toe of the footwear is attached to the front end of the support plate 71 so as to be slidable. An adjustment portion 75 for locking the heel portion of the footwear is attached to the rear end of the supporting plate 71 with a screw shaft. A plurality of stabilizing plates 77 are attached to the lower surface of the support plate 71 in order to adjust the height of the foot of the footwear.

  FIG. 11 shows a second mounting instrument 80 for mounting and measuring a sample that may slide in contact with the floor or road surface, except for the above-mentioned footwear, in the center of the upper surface of the flat sample mounting plate 81. A plurality of screw holes 82 for adjusting the attachment position with the connection shaft 60 are provided, and a test paper (not shown) as a sample piece is detachably attached to the lower surface abutting portion of the sample attachment plate 81. is there.

  A mounting portion (not shown) for fixing both end portions of the test paper mounted on the lower surface may be provided at both ends in the longitudinal direction of the sample mounting plate 81 as required. Examples of the test paper include rubber plates, cloth pieces, felts, papers, and the like that are likely to come into contact with the building floor.

  Hereinafter, the operation of the embodiment according to the present invention will be described. The measuring device 1 is for measuring a static friction coefficient between an object to be measured, for example, a bottom surface of a footwear X and a road surface, not on a laboratory but on an actual road surface. The road surface need not be horizontal as long as the bottom surface of the measurement object X to be measured is parallel to the abutting road surface portion, and measurement is possible even on an inclined slope.

  The reason is that the pressure pin 38 constituting the pressure means 30, the swing arm 46 as the slip sensing means 45, the connecting shaft 60 and the footwear X are positioned on the same axis in the vertical direction, and the pressure pin 38. Is pressed in the vertical direction with a constant pressure, so that the contact pressure between the object to be measured X and the surface to be measured can be changed not only on the horizontal plane but also on the inclined surface.

  Next, when measuring the footwear, which is the object to be measured X, for example, the sole and road surface or floor surface of a male short boot and the static friction coefficient, the first attachment device 70 is used as shown in FIGS. The connecting piece 55 previously removed from the swing arm 46 is rotated to open the upper surface of the connecting shaft 60, and screw holes 62 and 65 respectively provided in the connecting shaft and the plurality of adjusting plates 64 from the upper surface side of the connecting shaft. The screw 63 is inserted and screwed into the screw hole 72 of the support plate 71 to be connected. The attachment position of the connection shaft 60 to the support plate 71 is attached to a substantially central portion of the footwear, and the center position is prevented from being different depending on the footwear, thereby preventing an error.

  In the plurality of adjusting plates 64, the footwear X is different in the height of the inner bottom of shoes such as men, women or sneakers, and on the other hand, the length of the swing arm 46 is constant, so that the swing arm 46 depends on the type of footwear. The distance from the top edge of the shoe to the bottom of the footwear is corrected to be constant. Therefore, the number or thickness of the adjusting plates 64 to be used can be adjusted according to the type of footwear to be measured, and the distance from the upper end of the swing arm 46 to the bottom surface of the footwear X can be adjusted to be constant.

  After adjusting the locking portion 73 and the adjusting portion 75 provided on the support plate 71 according to the size of the footwear, the stabilizing plate 77 also provided on the lower side of the support plate 71 is inserted into the footwear of the measurement object X, and then The adjustment portion 75 is adjusted and pressed to the inside of the heel to fix the support plate 71 so that it does not shift and move, thereby improving the measurement performance. The attachment direction is such that the shoe tip of the footwear X attached to the first attachment device 70 is positioned in the direction opposite to the tilting direction of the movable frame body 20, and the connecting piece 55 is attached to the lower end of the swing arm 46 with a locking screw 57. It is fixed and connected.

  The case where the object to be measured is attached using the second attachment device 80 shown in FIG. 11 is the same as the case where the first attachment device 70 is attached and detached as shown in FIG.

  As shown in FIGS. 12 and 13, the measuring apparatus 1 is set so that the perpendicular P of the movable frame 20 and the horizontal line O of the base are positioned vertically before the measurement is started. The vertical position is a position where the movable frame body 20 abuts on the space plate 13 mounted between the connecting plate 6 attached to the back side of the bases 2A and 2B and the back side of the movable frame body 20. . The verticality is maintained by always urging in the direction of the space plate 13 by the return elastic force of the return spring 23 attached to one support shaft 21a of the support shaft provided on both lower sides of the movable frame body 20.

  Next, a constant vertical load (weight corresponding to the average body weight of a person) is applied to the footwear X by the pressurizing means 30. The loading is performed by rotating the pressure screw 41 to press the compression pin 35 and compressing the pressure spring 37 to increase the resilience. The load is applied at the position where the scale portion 33 provided on the window portion 32 of the pressurizing cylinder 31 and the mark line 36 provided on the compression pin 35 coincide with each other. For example, when a load of 60 kg is applied to the footwear and the measurement is performed, after placing the measuring device 1 at an arbitrary position on the road surface, a weight of at least 65 kg or more is evenly placed on the fixed portion 7 of the base 2 on the left and right. An operator having a weight equivalent to that of the robot is placed on the flat portions 7 and 7 with his / her feet fixed to the measurement location to prepare for the measurement work.

  If the load is the same as or less than the load applied to the footwear, the holding force of the measuring device 1, that is, the fixing force is weakened during the measurement, and the installation position may be shifted, so that there is a possibility that an accurate static friction coefficient cannot be measured. As the simplest method, a person having a body weight of approximately 65 kg or more can ride on the fixing parts 7 and 7 of the bases 2A and 2B and can stably measure the measuring apparatus 1.

  In order to use this apparatus, the switch 10 is turned on and the movable frame 20 is set to the start position. At the same time, the angle measuring device 25 senses the rotated angle of the movable frame, and the signal output is calculated on the calculation display screen 9. Is set as “tan θ = 0” (FIG. 12). In FIG. 3, the measurement is started by tilting the operation portion 28 provided on the movable frame 20 little by little in the direction of the arrow (forward). The movable frame body 20 is tilted by a human hand by grasping the operation portion 28 of the movable frame body 20 without using a driving means such as a motor. Therefore, the overall structure of the apparatus is simple, the number of parts is small, light weight, convenient to carry, and an inexpensive and economical measuring apparatus can be provided.

  The tilting of the movable frame 20 rotates the movable frame 20 with the shaft centers of the left and right support shafts 21a and 21b as fulcrums, and the connecting shaft 60 provided below the swing arm 46 attached to the movable frame. It tilts at the same angle around the shaft portion 61 of the.

  As the movable frame body 20 tilts, the support shaft 21a that supports the movable frame body rotates in the same direction as the tilt direction. As for the rotation angle of the support shaft 21a, the output from the angle measuring device 25 attached to the connecting shaft 24 connected to the support shaft is displayed on the calculation display screen 9 as “tan θ” in real time.

  When the movable frame body 20 tilts to a certain angle, the footwear X cannot resist the frictional resistance with the road surface and slides in the direction opposite to the tilting direction of the movable frame body 20. When the footwear X slides, the swing arm 46 on which the footwear is loaded on the same axis by the pressurizing means 30 and the slip sensing means 45 is repelled so that the rotating roller 48 is released from the tip pin 39, ie, an arrow. As shown in FIG. 16, it tilts in the same direction as the movable frame 20 (FIGS. 16 and 17).

  At the same time that the swing arm 46 is tilted, the sensing unit 66a attached to the swing arm is detached from the signal unit 66b and sends a slip signal to the calculation display screen 9, and the output of the angle measuring device 25 at that time is instantaneously calculated, The angle at which the footwear slips is converted to “tan θ = X”, and the coefficient is digitally displayed on the calculation display screen 9. Since the swing arm 46 tilted by sliding the footwear is locked by the guide shaft 50 inserted into the guide groove 49, the swing arm 46 is prevented from tilting more than a certain angle.

  The movable frame body 20 stops tilting when the footwear slides, and automatically moves to the vertical position by the elastic force of the return spring 23 attached to the support shaft 21a when the hand is released from the operation portion 28 of the movable base frame 20. Return. At this time, the damper 27 is attached to the other support shaft 21b, thereby preventing the movable frame body 20 from strongly hitting the space plate 13 of the connecting plate by the elastic force of the repulsive spring and preventing the generation of noise.

  As shown in FIG. 16, the swing arm 46 that has come off the axial center of the pressurizing means 30 due to sliding of the footwear X returns to the movable base frame 20 as shown in FIG. 1 along with the return of the movable base frame 20 in the vertical direction. While the guide shaft 50 fixed at both ends moves in the guide groove 49, it moves smoothly in the vertical direction by the auxiliary cylinder 51 attached to the guide shaft and the guide plate 52 provided above the movable frame 20. Then, it can be returned to the original position.

  The side surface of the swing arm 46, the auxiliary cylinder 51, and the guide plate 52 are not in direct contact with each other in order to minimize frictional resistance when the swing arm is tilted, and the vertical direction of the swing arm 46 is shifted due to an unexpected impact or the like. Or the contact portion with the pressure pin 38 is prevented from being detached and tilted.

  When the pin portion 39 of the pressure pin 38 is formed into a spherical shape, a rotating roller 48 is attached to the upper end of the swing arm 46, and the contact portion between the pressure pin 38 and the swing arm 50 is brought into point contact. The separation resistance of the contact portion is reduced, and a more accurate static friction resistance coefficient can be measured.

  Even when the swing arm 46 returns to the original vertical direction, when the rotation roller 48 attached to the head of the swing arm 46 and the pressure pin 38 come into contact with each other, the frictional resistance is reduced and the same axial center position is obtained. Can be reset. The calculation display screen 9 that calculates and displays the static friction coefficient of the footwear X automatically returns to “0” when the movable frame 20 returns to the vertical position.

It is a front view of the static friction measuring device concerning the present invention. It is a top view of the said static friction measuring apparatus. It is a center longitudinal cross-sectional view of FIG. It is a rear view of the pressurization cylinder which is a pressurization means. FIG. 5 is a cross-sectional view taken along the line AA in FIG. 4. It is a front view of a slip detection means. It is an exploded side view of a swing arm. It is the partially broken side view of the 1st fixture which attaches the footwear which is a to-be-measured object. It is a top view of the 1st fixture. It is a side view which shows the state which attached the footwear to the 1st fixture. It is a side view of the 2nd fixture. It is a side view which shows the state before a measurement of a friction measurement means. It is a schematic diagram which shows the relationship between the movable frame body of the said state, a swing arm, a pressurization pin, and an angle measuring device. It is a side view which shows the state which the friction measurement means tilted. It is a schematic diagram which shows the relationship between the movable frame body of the said state, a swing arm, a pressurization pin, and an angle measuring device. It is a side view which shows the moment when the friction measuring means tilted and the object to be measured slides. It is a schematic diagram which shows the relationship between the movable frame body of the said state, a swing arm, a pressurization pin, and an angle measuring device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Measuring apparatus 2 Base 5 Measurement space part 7 Flat part 9 Calculation display screen 20 Movable frame body 21 Support shaft 23 Return spring 24 Connection shaft 25 Angle measuring device 27 Damper 28 Operation part 30 Pressurizing means 31 Pressurizing cylinder 32 Window part 33 Scale part 35 Compression pin 36 Mark line 37 Pressure spring 38 Pressure pin 41 Pressure screw 45 Slip detection means 46 Swing arm 48 Rotating roller 50 Guide shaft 55 Connection piece 58 Connection member 60 Connection shaft 64 Adjustment plate 66 Slide sensor 70 First mounting instrument 71 Support plate 72 Screw hole 73 Locking portion 75 Adjusting portion 77 Stabilizing plate 80 Second mounting instrument X Device under test

Claims (7)

The measurement space (5) provided between a pair of bases (2A, 2B) each having a flat portion (7, 7) on the upper surface is pivotally supported by an operation portion (28) on the upper back side. A pressurizing means (30) is provided on the movable frame (20) provided with a pressure means (30) for adjusting a constant vertical load on the object to be measured (X).
A slide formed by pivotally supporting a mounting device (70) for mounting the object to be measured (X) on the lower end of a swing arm (46) positioned on the same axis as the pressurizing means (30). Providing sensing means (45);
An angle measuring device (25) that outputs an inclination angle of the movable frame body 20 is provided on one support shaft (21a) that pivotally supports the movable frame body (20),
An arithmetic display device (9) for calculating and displaying the output signal of the angle measuring device and the signal at the moment when the slip sensing means (45) slides is provided on one base (2A),
A vertical load is applied from the vertical direction by the pressurizing means (30) to hold the base (2A, 2B) at a measurement location, and the center of gravity of the vertical load is moved by tilting the movable frame (20). The swing arm (46) of the slip detection means (45) is tilted at the moment when the measurement object (X) slides on the road surface, and the signal from the slip sensor (66) and the signal output from the angle measurement device (25) are output. Is displayed on the calculation display screen (9), and the static friction coefficient is displayed by measuring and calculating the tilt angle (θ) of the movable frame (20) at which the object to be measured (X) starts to slide on the calculation display screen (9). A static friction measuring machine characterized by   The pressurizing means (30) includes a pressure cylinder (31) having a window portion (32) for displaying a pressurizing force on a peripheral surface and a scale portion (33) for displaying the pressurizing pressure on both sides of the window portion. ), A compression pin (35) having a mark line (36), a pressure spring (37) having a resilient force, and a pressure pin (38) having a pin portion (39) on the same axis. The static friction measuring machine according to claim 1, wherein a predetermined load can be pressurized by rotating a pressure screw (41) from above the pressure cylinder.   The slip sensing means (45) supports a rotating roller (48) at the upper end of the swing arm (46), and a guide shaft for preventing the swing arm (46) from being tilted in a guide groove (49) provided substantially at the center. (50) is inserted, a connecting piece (55) formed by cutting a part of the swing arm is detachably attached to the lower end, and a connecting member (58) comprising a plurality of small pieces is attached to the lower end of the connecting piece. The object to be measured (X) is attached to the lower end of an adjustment plate (64) formed of a plurality of plates having different thicknesses at the lower portion of the connecting shaft (60) pivotally supported at the lower portion of the connecting member. 3. A slip detector (66) is attached between the upper part of the swing arm (46) and the movable frame (20), and the attachment device (70) to be attached is attached. The static friction measuring machine described.   The slip sensor (66) includes a sensing part (66a) made of a light shielding plate on the upper side of the swing arm (46) and a signal part (66b) attached to the reinforcing plate (22) of the movable frame (20). When the swing arm (46) is in a vertical state, the slip detection part (66a) shields the signal part (66b), the movable frame (20) tilts, and the object to be measured (X) slides. At the moment, the swing arm (46) tilts and senses that the object to be measured (X) slides, and at the same time, the sensing unit (66a) leaves the signal unit (66b) and transmits it to the calculation display screen (9). The static friction measuring machine according to any one of claims 1 to 3, wherein   The angle measuring device (25) is located on the same axis as the one support shaft (21a) of the movable frame body (20) pivotally supported by the base (2A, 2B). When the swing arm (46) tilts at the moment when the object to be measured (X) slides by rotating with the tilt of the body, the calculation display screen (9) receives an electrical signal from the slip sensor (66), and an angle measuring device ( 25) The inclination angle (θ) of the movable frame body is instantaneously converted into a numerical value from the output of 25), and the static friction coefficient of the object to be measured (X) is digitally displayed on the calculation display screen (9). The static friction measuring machine according to any one of 1 to 4.   In the movable frame (20), a return spring (23) is attached to one support shaft (21a) to return the movable frame to a vertical position, and the return spring (21b) is attached to the return spring (21b). The damper (27) for buffering the repulsive force of (23) is attached, and the movable frame (20) after the static friction measurement is provided so as to be automatically returnable to the original vertical position. The static friction measuring machine of any one. The mounting device (70) is a mounting device for a footwear to be measured, and is attached to a support plate (71) accommodated in the footwear so that the connection position with the connection shaft (60) can be adjusted. A screw hole (72) is provided, a locking part (73) for supporting the toe part of the shoe is attached to the front end so as to be slidably adjustable, and an adjustment part (75) enabling adjustment of the position of the footwear part of the footwear at the rear end. The static friction measuring machine according to any one of claims 1 to 6, wherein a plurality of stabilizing plates (77) for adjusting an instep height position are attached to the lower surface of the support plate (71).

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