Drum advancing and retreating device and tire testing machine provided with drum advancing and retreating device

Abstract

This invention reduces the impact of device vibration on measurement values ​​even when testing tires larger than those of ordinary passenger car tires. The drum advance / retreat device (400) includes: a drum (4) abutting against the tire; a drum frame (40) rotatably supporting the drum (4); a base frame (100); a pair of ball screws (153); a pair of ball screw nuts (155); and a pair of linear guides (161). The base frame (100) retractably supports the drum frame (40). The base frame (100) has a plurality of longitudinal plates (115) including a pair of first longitudinal plates and a pair of second longitudinal plates, the pair of first longitudinal plates being positioned directly below the pair of ball screws (153), and the pair of second longitudinal plates being positioned directly below the pair of linear guides (161).

Description

Technical Field

[0001] The present invention relates to a drum advancing and retreating device for advancing and retreating a drum relative to a tire for performing specified tests on a tire, and a tire testing machine equipped with the device. Background Technology

[0002] Tire testing machines for measuring tire uniformity, etc., are known in the past. These machines include: a mandrel that rotatably supports the tire about a rotational axis extending vertically; a drum that is rotatably supported about a rotational axis parallel to the mandrel's rotational axis and can abut against the outer circumferential surface of the tire; and a load sensor capable of measuring the load applied to the drum. After the tire, mounted on the mandrel, is inflated and the drum is pressed against the tire's outer circumferential surface, the tire rotates based on the mandrel, and the load sensor mounted on the drum's shaft measures the tire's load fluctuation data. The uniformity (uniformity) of the tire is evaluated based on the measured load fluctuation data.

[0003] In order to measure load fluctuations during tire rotation using a load sensor in a tire testing machine as described above, the device must have sufficient rigidity. Especially when the rigidity of the device is insufficient, vibrations can be transmitted to the load sensor, sometimes affecting the measured values. Therefore, standards for suppressing device vibration have been established in Japanese Industrial Standard JIS D4233-2001, Group Standard JASO C67-2000, and SAE J332REV.NOV2002, to prevent them from affecting the measured values ​​of the load sensor.

[0004] Patent Document 1 discloses a drum retraction device that allows a drum to retract and move forward and backward, enabling it to contact or separate from a tire. The device comprises: a base fixed to a testing location; and a carriage that rotatably supports the drum and is retractable relative to the base. The base has a box-shaped form extending in the front-rear direction. Furthermore, the base includes: a pair of guide rails disposed on the upper portion, each extending in the front-rear direction; and a ball screw extending in the front-rear direction between the pair of guide rails. On the other hand, the carriage includes: a bearing seat disposed on the lower portion, engaging with each of the pair of guide rails; and a ball nut engaging with the ball screw. When the ball screw rotates, its rotational driving force is transmitted to the carriage via the ball nut, causing the carriage to move in the front-rear direction along the pair of guide rails. As a result, the drum, rotatably supported by the carriage, can abut against the outer circumferential surface of the tire.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Publication No. 2018-504586

[0008] The drum advance / retreat device described in Patent Document 1 has the following problem: when testing tires larger than those of ordinary passenger car tires, the device's insufficient rigidity makes its vibrations prone to affecting the load sensor's measurements. Specifically, the international standard ISO 13326 1998 specifies the drum diameter for tires used in ordinary passenger cars and large-diameter tires used in trucks and buses. For tires used in ordinary passenger cars, the drum diameter is specified to be in the range of 830mm to 1000mm (reference value 854mm), while for tires used in trucks and buses, the drum diameter is specified to be in the range of 1520mm to 1710mm (reference value 1600mm). In the latter case, due to the very heavy weight of the drum, the device is prone to vibration due to its low rigidity and low inherent vibration frequency, which can easily affect the load sensor's measurements. The technology described in Patent Document 1 does not disclose a specific technique for maintaining the rigidity of the base under such conditions. Therefore, the following problem exists: when testing tires larger than those of ordinary passenger car tires, the impact of device vibration on the measured values ​​cannot be ignored. Summary of the Invention

[0009] The present invention was made in view of the aforementioned problems, and its object is to provide a drum advance / retreat device and a tire testing machine equipped with the drum advance / retreat device such that even when testing tires larger than ordinary passenger car tires, the influence of device vibration on the measured values ​​can be reduced.

[0010] The drum advance / retreat device provided by this invention is disposed in a tire testing machine, which rotates a tire in a horizontal position about its rotational axis and performs specified tests on the tire. The horizontal position is the position in which the rotational axis of the tire extends vertically. The drum advance / retreat device includes a cylindrical drum, a drum frame, a base frame, a load detector, at least one ball screw, a drive source, at least one ball screw nut, and multiple linear guides. The drum has a drum shaft extending vertically and an outer peripheral surface abutting against the outer peripheral surface of the tire. The drum frame rotatably supports the drum about the drum shaft. The base frame is disposed below the drum frame and has a top plate. The base frame supports the drum frame in such a way that the drum frame can move in the front-rear direction, allowing the outer peripheral surface of the drum to contact or separate from the outer peripheral surface of the tire. The load detector can detect the load borne by the drum from the tire. At least one ball screw is supported on the top plate in such a way that it can rotate about an axis extending in the front-rear direction. A drive source enables the at least one ball screw to rotate about the axis. At least one ball screw nut is fitted to the drum frame and engages with the at least one ball screw in a manner that allows the drum frame to move in the front-back direction as the drive source rotates the at least one ball screw. A plurality of linear guides extend in the front-back direction and are fitted to the top plate of the frame in a manner spaced apart in the left-right direction relative to the at least one ball screw, and movably support the drum frame in the front-back direction. The base frame includes a plurality of longitudinal plates and a plurality of transverse plates. The plurality of longitudinal plates extend in both the vertical and front-back directions and are arranged side-by-side in the left-right direction, each supporting the top plate of the frame. The plurality of longitudinal plates includes at least one first longitudinal plate and a plurality of second longitudinal plates, the at least one first longitudinal plate being arranged to overlap with the at least one ball screw when viewed from the vertical direction, and each of the plurality of second longitudinal plates being arranged to overlap with the plurality of linear guides when viewed from the vertical direction. A plurality of transverse plates connect the plurality of longitudinal plates in the left-right direction. Attached Figure Description

[0011] Figure 1 This is a top view of a tire testing machine according to one embodiment of the present invention.

[0012] Figure 2 This is a side view of a tire testing machine according to one embodiment of the present invention.

[0013] Figure 3 This is a partial perspective view of a tire testing machine according to one embodiment of the present invention.

[0014] Figure 4 This is a perspective view of the drum advance / retreat device of a tire testing machine according to an embodiment of the present invention.

[0015] Figure 5 This is a perspective view of a drum advance / retract device according to an embodiment of the present invention.

[0016] Figure 6 This is an exploded perspective view of a drum advance / retract device according to an embodiment of the present invention.

[0017] Figure 7 This is a perspective view of the base frame of a drum advance / retract device according to an embodiment of the present invention.

[0018] Figure 8 This is a cross-sectional perspective view of the base frame of the drum advance / retract device according to an embodiment of the present invention.

[0019] Figure 9 This is a perspective view of the plurality of longitudinal plates constituting the base frame of the drum advance / retract device according to an embodiment of the present invention.

[0020] Figure 10 This is a perspective view of the drum frame of a drum advance / retreat device according to an embodiment of the present invention.

[0021] Figure 11 This is an exploded perspective view of the drum frame of the drum advance / retreat device according to one embodiment of the present invention.

[0022] Figure 12 This is an exploded perspective view of the drum frame of the drum advance / retreat device according to one embodiment of the present invention. Detailed Implementation

[0023] Hereinafter, an embodiment of the tire testing machine 1 of the present invention will be described in detail with reference to the accompanying drawings. Figure 1 , Figure 2 These are top and side views of the tire testing machine 1 according to this embodiment. Furthermore, Figure 3 This is a partial perspective view of the tire testing machine 1 according to this embodiment. In the following figures, the forward and backward direction of the drum 4 of the drum advance and retreat device 400 constituting part of the tire testing machine 1 is used as the front-back direction, and the up-down and left-right directions are used to represent the directions. However, these directions do not limit the structure or usage of the drum advance and retreat device and the tire testing machine according to the present invention.

[0024] Tire testing machine 1 includes: a main frame 1S; a spindle 2; a tire conveying mechanism 3; and a drum advance / retreat device 400, which includes a drum 4 and a pair of upper and lower load sensors 4L (load detectors). Figure 4 ); Lifting unit 50 (lifting mechanism); Marking unit 60. The tire testing machine 1 sets the tire to a horizontal position at the specified tire testing position P, i.e., the tire T( Figure 2The tire T is rotated about the tire's rotation center axis, which extends vertically, to perform specified tests on the tire T. In this embodiment, the tire testing machine 1 performs specified tests on tires T used for trucks and buses.

[0025] The main frame 1S is positioned approximately at the center of the tire testing machine 1, and a tire testing position P is formed within it. Furthermore, the main frame 1S rotatably supports the spindle 2. The main frame 1S includes a base frame 100, an intermediate frame 101, and an upper frame 102. Figure 2 and Figure 3 ).

[0026] The mandrel 2, located at the tire test position P, rotates about a reference rotation center axis 2S extending in the vertical direction, supporting the tire T rotatably. The mandrel 2 has a lower mandrel 21 and an upper mandrel 22. Figure 2 and Figure 3 ).

[0027] Tire conveying mechanism 3 ( Figure 2 It is set up so that the tire T, which is in a horizontal position, passes through the tire test position P in a top view and moves along the horizontal transport direction D1. It can move the tire T into the tire test position P and move the tire T out of the tire test position P along the transport direction D1.

[0028] Drum 4 is driven forward and backward by drum advance and retraction device 400 ( Figure 4 The drum 4 is rotatably supported. It is positioned facing the tire test position P (spindle 2) at a specified interval in a direction approximately orthogonal to the transport direction D1 of the tire T being transported by the tire transport mechanism 3. The drum 4 has a drum shaft 4S extending along a direction parallel to the reference rotation center axis 2S of the spindle 2 (vertical direction) and an outer peripheral surface. It is a cylindrical component configured to rotate freely about the drum shaft, and a simulated road surface 4A is formed on the outer peripheral surface of the drum, allowing the tire T to travel. Based on the contact between the simulated road surface 4A and the outer peripheral surface of the tire T, the drum 4 rotates with the tire T.

[0029] In this embodiment, corresponding to the tire T used for trucks and buses, the drum diameter of the drum 4 is set in the range of 1520mm to 1710mm (reference value 1600mm). The drum 4 is a large and heavy rotating body with a drum diameter of at least 1500mm.

[0030] The drum advance / retreat device 400 can bring the drum 4 closer (forward) and further away (backward) relative to the tire T by pushing the drum 4 in a horizontal direction. Other structures of the drum advance / retreat device 400 involved in this embodiment will be described in detail later.

[0031] A pair of load sensors 4L (load detection units) are respectively positioned on the upper and lower extension lines of the rotation center shaft (drum shaft 4S) of the drum 4. Figure 1 (Only the upper side is shown in the image). The load on the drum 4 from the tire T is detected and measured. A load sensor 4L is used to support the drum 4 on the drum advance / retreat device 400. One is provided at the top and one at the bottom of the drum 4, and it measures the load acting on the axis perpendicular to the drum 4. Furthermore, in this embodiment, the load sensor 4L is a biaxial load sensor that controls the aforementioned tire load (controls the advance / retreat position of the drum 4 so that the pressing load of the drum 4 on the tire T is within a specified range), and measures RFV (radial force variation: the magnitude of the fluctuation of the radial force of the tire) and LFV (axial force variation: the magnitude of the fluctuation of the axial force of the tire). That is, the tire testing machine 1 according to this embodiment uses the combination of a ball screw and a motor (described later) to bring the spindle 2 close to the drum 4, and measures the load fluctuation during tire rotation using the load sensor 4L when the tire T contacts the simulated road surface 4A of the drum 4, thereby constituting a tire uniformity evaluation machine for evaluating the uniformity of the tire T.

[0032] The tire conveying mechanism 3 has a conveyor belt structure. The tire conveying mechanism 3 includes an infeed conveyor 7, a conveyor 8, an outfeed conveyor 9, an infeed rack 7S, and an outfeed rack 9S. Figure 1 In the process, tire T is transported from the right side (upstream side) to the left side (downstream side).

[0033] The infeed conveyor 7 transports tire T to the tire testing position P. Tire T transported by infeed conveyor 7 is then transferred to the upstream section of the transfer conveyor 8. The transfer conveyor 8 receives tire T from infeed conveyor 7 and moves tire T to the tire testing position P. The transfer conveyor 8 temporarily stops tire T at the tire testing position P. After performing the specified tests on tire T, the transfer conveyor 8 further transports tire T to the downstream side. Tire T transported by transfer conveyor 8 is then transferred to the outfeed conveyor 9. The outfeed conveyor 9 receives tire T from transfer conveyor 8 and further transports tire T to the downstream side.

[0034] Furthermore, the infeed conveyor 7, the transport conveyor 8, and the outfeed conveyor 9 are driven in a circular motion by a drive unit (not shown) included in the tire transport mechanism 3. Moreover, the transport conveyor 8 is capable of lifting and lowering based on a pneumatic cylinder (not shown) included in the drive unit. The tire T, transported to the tire testing position P, is transferred to the lower spindle 21 as the transport conveyor 8 descends. Figure 3 The symbol indicates the state where the conveyor 8 has moved to the lowest position. If the conveyor 8 moves to the highest position, it is configured at the same height as the infeed conveyor 7 and the outfeed conveyor 9, enabling it to transport the tire T.

[0035] The loading rack 7S can be circumferentially supported by the loading conveyor 7, and the unloading rack 9S can be circumferentially supported by the unloading conveyor 9. Furthermore, the unloading rack 9S supports a marking unit 60 for applying specified markings to the tire T based on the test results at the tire test position P. Figure 2 ).

[0036] Lifting unit 50 ( Figure 3 The upper spindle 22 is supported in a way that allows it to be raised, lowered, and rotated. More specifically, the lifting unit 50 raises and lowers the upper spindle 22 relative to the lower spindle 21 so that the tire T can be positioned between the lower spindle 21 and the upper spindle 22. The lifting unit 50 can move along... Figure 2 , Figure 3 The upper frame 102 has a pair of left and right guide frames 102A. Figure 3 Move it up and down.

[0037] The lower spindle 21 can hold the lower rim 61, which is mounted on the lower side of the tire T in the horizontal position, from below, so that the tire T can rotate about the reference rotation center axis 2S.

[0038] The upper spindle 22 can hold the upper rim 62, which is mounted on the upper side of the tire T in the horizontal position, from above, so that the tire T can rotate about the reference rotation center axis 2S.

[0039] When tire T is positioned at tire test position P, the tire rotation center axis of tire T coincides with the reference rotation center axis 2S of spindle 2. Tire testing machine 1 has various lower rims 61 and upper rims 62 depending on the size (outer diameter, inner diameter, width), shape, etc. of the tire T being tested at tire test position P, and appropriate lower rims 61 and upper rims 62 are positioned at tire test position P according to each tire T.

[0040] Next, the drum advance / retract device 400 involved in this embodiment will be described in further detail. Figure 4 and Figure 5 These are perspective views of the drum advance / retreat device 400 of the tire testing machine 1 according to this embodiment, viewed from the front and rear, respectively. Figure 6 From Figure 4 The diagram shown is an exploded perspective view of the drum advance / retract mechanism 400 in a state where the drum 4 and the drum frame 40 described later have been removed. Figure 7 It means from Figure 6 The diagram shows a perspective view of the base 100 of the drum advance / retract device 400, with the lower spindle 21 and drum advance / retract drive unit 150 removed. Figure 8 yes Figure 7 A three-dimensional cross-sectional view of the cut surface indicated by arrow VIII of the base frame 100 shown. Figure 9 It is a three-dimensional view of the multiple longitudinal plates 115 that make up the base frame 100.

[0041] The drum advance / retreat device 400 is installed in the tire testing machine 1 and constitutes a part of the tire testing machine 1. Furthermore, as... Figure 3 As shown, the drum advance and retraction device 400 supports the conveyor 8 of the tire conveying mechanism 3 and rotatably supports the spindle 2, which includes the lower spindle 21 and the upper spindle 22.

[0042] The drum advance / retreat device 400 includes: a base frame 100; the aforementioned drum 4; a drum frame 40; the aforementioned load sensor 4L; a spindle rotation drive unit 105; and a drum advance / retreat drive unit 150.

[0043] The drum frame 40 supports the rotating drum 4 rotatably around the drum shaft 4S.

[0044] The base frame 100 has a horizontal top plate 112 disposed below the drum 40. The base frame 100 is set on the ground at the test site where the tire testing machine 1 is set up, and supports the drum 40 which can move in the front-rear direction so that the simulated road surface 4A (outer peripheral surface of the drum) of the drum 4 comes into contact with or separates from the outer peripheral surface of the tire T.

[0045] A spindle rotation drive unit 105 is provided at the front end of the base frame 100 and drives the lower spindle 21 of the spindle 2 to rotate about the reference rotation center axis 2S. The spindle rotation drive unit 105 includes a motor, a gearbox, a drive pulley, a drive belt, and a driven pulley, and transmits the rotational power of the motor to the lower spindle 21.

[0046] The drum advance / retreat drive unit 150 causes the drum frame 40 supporting the drum 4 to advance and retract in the front-to-back direction. The drum advance / retreat drive unit 150 includes: a motor M (drive source); a coupling 151; a pair of reducers 152; a pair of ball screws 153; a pair of ball screw supports 154; a pair of ball screw nuts 155; a pair of linear guides (also called guide rails) 161; and four cover supports (also called slides) 162.

[0047] Motor M enables a pair of ball screws 153 to rotate independently about shafts extending in the front-to-back direction. Motor M can rotate in both directions. Motor M is fixed to the rear end of the top plate 112 of the base frame 100 by a bracket. A coupling 151 is provided to transmit the output of motor M to orthogonal reducers 152, to which a pair of reducers 152 are connected. The coupling 151 and the pair of reducers 152 synchronously transmit the rotational driving force of motor M to the pair of ball screws 153. As a result, the pair of ball screws 153 rotate synchronously about their respective shafts in both directions.

[0048] A pair of ball screw supports 154 are respectively arranged at a distance from each other in the left-right direction at the front end of the top plate 112. At this time, a pair of ball screws 153 are arranged facing each other at a distance from each other in the left-right direction. Each ball screw support 154 rotatably supports the front end of the ball screw 153 by means of an internal bearing, and fixes the front end's position in the front-rear direction. In addition, the rear end of the ball screw 153 is connected to and supported by the reducer 152 based on being inserted into the driven shaft of the aforementioned reducer 152. At this time, the driven shaft, which is the output of the reducer 152, fixes the rear end of the ball screw 153 in the rotational direction but does not fix its position in the front-rear direction. As a result, each ball screw 153 is supported on the top plate 112 in a manner that allows it to rotate about an axis extending in the front-rear direction. Furthermore, it is possible to prevent the bearings and reducer 152 from bearing excessive forces from the ball screws 153.

[0049] Figure 6 The pair of ball screw nuts 155 shown are respectively assembled and fixed to the drum frame 40 described later. The pair of ball screw nuts 155 engage with each ball screw 153 in a manner that causes the drum frame 40 to move in the front-back direction as the pair of ball screws 153 driven by the motor M rotate.

[0050] A pair of linear guides 161 are mounted on the top plate 112 in a manner extending in the front-rear direction and spaced apart in the left-right direction relative to a pair of ball screws 153, thereby supporting the drum frame 40 movable in the front-rear direction. In this embodiment, the pair of linear guides 161 are disposed on the left and right outer sides of the pair of ball screws 153. Each linear guide 161 is arranged in a straight line from the front end to the rear end of the top plate 112. Furthermore, four cover supports 162 are respectively fixed to the linear guide mounting portion 414 of the drum frame 40 (described later). Figure 12 It engages with each linear conductor 161 in such a way that it can move back and forth along a pair of linear conductors 161.

[0051] The base frame 100 has a spindle support plate 111, a top plate 112, four longitudinal plates 115, and multiple transverse plates 116.

[0052] The spindle support plate 111 is a horizontal plate that defines the upper part of the front side of the base frame 100. For example... Figure 7 As shown, a circular mandrel receiving hole 111A, extending vertically through the mandrel support plate 111, is formed in the center of the mandrel support plate 111. Furthermore, as... Figure 6As shown, by having the lower spindle 21 of the spindle 2 pass through the spindle receiving hole 111A from above, the spindle support plate 111 (base frame 100) rotatably supports the lower spindle 21 (spindle 2). Furthermore, the upper spindle 22 of the spindle 2 is positioned above the lower spindle 21 via the tire T. During testing, the lower spindle 21, the tire T, and the upper spindle 22 rotate together around the reference rotation center axis 2S. Because the base frame 100 has the spindle support plate 111 to support the spindle 2, when the drum 4 abuts against the tire T and a load is applied, the high rigidity of the base frame 100 can suppress the tilting of the lower spindle 21 relative to the reference rotation center axis 2S.

[0053] The top plate 112 is a horizontal plate that defines the upper part of the rear side of the base frame 100. For example... Figure 6 As shown, the aforementioned spindle support plate 111 is positioned below the top plate 112 of the frame. Furthermore, as... Figure 7 As shown, the top plate 112 has a pair of linear guide assembly portions 112A, a pair of front support portions 112B, and a pair of rear support portions 112C. The pair of linear guide assembly portions 112A are for fixing the aforementioned pair of linear guides 161. Furthermore, the pair of front support portions 112B are for fixing a pair of ball screw support portions 154. Furthermore, the pair of rear support portions 112C are for fixing... Figure 5 , Figure 6 The bracket portion of the reducer 152.

[0054] Secondly, further details are provided in Figure 7 The structure of the base frame 100 shown includes the supporting mandrel support plate 111 and the top plate 112. (As shown...) Figure 8 , Figure 9 As shown, the base frame 100 has a structure with particularly high rigidity in the drum travel direction and vertical direction, based on four longitudinal plates 115 and multiple transverse plates 116.

[0055] Four longitudinal plates 115 extend along the vertical and front-back directions and are arranged side by side in the left-right direction, respectively supporting the spindle support plate 111 and the frame top plate 112.

[0056] Of the four longitudinal plates 115 mentioned above, the two inner longitudinal plates 115 on the left and right sides are defined as the first longitudinal plates. When viewed from above and below, the two first longitudinal plates are aligned with the aforementioned pair of ball screws 153. Figure 6 They are arranged in an overlapping manner. That is, when each ball screw 153 is projected downwards, it overlaps with each of the first longitudinal plates. In other words, each of the first longitudinal plates is arranged parallel to the ball screw 153 below the plumb line. Furthermore, each of the first longitudinal plates, when viewed from the top and bottom directions, overlaps with each other. Figure 6 The ball screw support 154 and the reducer 152 shown are arranged in an overlapping manner. As a result, each of the first longitudinal plates is located at the position where... Figure 7 The vertical line connecting the center of the left and right directions of a front support 112B and the center of the left and right directions of a rear support 112C is shown below the plumb line.

[0057] Similarly, the two outermost longitudinal plates 115 of the four longitudinal plates 115 mentioned above are defined as the second longitudinal plates. When viewed from above, the two second longitudinal plates are aligned with the aforementioned pair of linear guides 161 (…). Figure 6 They are configured in an overlapping manner. That is, when each linear guide 161 is projected downwards, it overlaps with each of the second vertical plates. In other words, each of the second vertical plates is arranged parallel to the linear guide 161 below the plumb line. Furthermore, each of the second vertical plates is located at... Figure 7 Below the plumb bob of the linear guide assembly 112A shown.

[0058] Furthermore, multiple horizontal plates 116 are respectively connected to the aforementioned multiple vertical plates 115 in the left-right direction. For example... Figure 7 As shown, an opening 116B is formed in the front horizontal plate 116A, which is the foremost horizontal plate 116. The spindle rotation drive unit 105 ( Figure 4 The drive belt passes through the opening 116B.

[0059] Further details on the structure of the four longitudinal plates 115: each longitudinal plate 115 has a main body 115A, an upper plate 115B (upper support plate), and a lower plate 115C (lower mounting plate). Figure 9 ).

[0060] The longitudinal plate body 115A includes an upper end portion 115A1 and a lower end portion 115A2, and is a plate-shaped portion extending along the vertical and horizontal directions and the front-back direction. Figure 8 , Figure 9 ).

[0061] The upper plate 115B is connected to the upper end 115A1 of the longitudinal plate body 115A in a manner extending to the left and right respectively, and supports the top plate 112. In this embodiment, the upper plate 115B is only disposed on the rear part of the longitudinal plate body 115A. Figure 9 ).

[0062] The lower plate 115C is connected to the lower end 115A2 of the longitudinal plate body 115A in a manner that extends to the left and right respectively, and is set on the ground of the test site. In addition, other components may also be set between the ground and the lower plate 115C.

[0063] Furthermore, the upper end portion 115A1 of the longitudinal plate body 115A of each of the aforementioned longitudinal plates 115 has a rear upper end portion 115F ( Figure 8 ) and the upper front end 115D ( Figure 9The rear upper end portion 115F is connected to the aforementioned upper plate 115B. Furthermore, the front upper end portion 115D is positioned in front of the rear upper end portion 115F at a position lower than the rear upper end portion 115F, and supports the spindle support plate 111.

[0064] In this embodiment, the four longitudinal plates 115 are formed of known H-beams. That is, as... Figure 9 As shown, four H-beams are arranged adjacent to each other in an I-shape along the vertical direction. A top plate mounting surface 115S is formed on the upper rear side of each of the four H-beams, capable of supporting the top plate 112. Conversely, by cutting off the upper front portion of each of the four H-beams, a support plate mounting surface 115T is formed, capable of supporting the spindle support plate 111. Thus, by using four H-beams with large moments of inertia to form the skeleton of the base frame 100, the number of welding points within the base frame 100 can be reduced, and a cost-effective base frame 100 with high rigidity can be achieved.

[0065] Furthermore, rectangular openings 115E are formed on the two inner longitudinal plates 115 (the first longitudinal plate) of the four longitudinal plates 115. Figure 8 , Figure 9 As a result, the moments of inertia of the two outer longitudinal plates 115 are set to be greater than those of the two inner longitudinal plates 115 (the second longitudinal plate). This allows for a greater maintenance of the rigidity of the outer longitudinal plates 115, enabling a reduction in the thickness of the inner longitudinal plates 115 or the provision of openings or notches, thereby improving the weldability of the base frame 100. In particular, by forming openings 115E in the two inner longitudinal plates 115, access to the interior becomes easier, facilitating the welding of the four longitudinal plates 115 and the multiple transverse plates 116. In this embodiment, no opening 115E is formed on the longitudinal plate 115 below the linear guide 161, but an opening 115E is formed on the longitudinal plate 115 below the ball screw 153. Since the linear guide 161 functions to support the drum frame 40, by not forming an opening 115E on the longitudinal plate 115 directly below it, vibrations caused by deflection due to bending moment are suppressed, as are vibrations in the vertical direction. On the other hand, since the ball screw 153 does not directly support the drum frame 40, vertical vibrations as described above are difficult to occur. Therefore, an opening 115E can be formed on the longitudinal plate 115 directly below it. On the other hand, in other embodiments, when openings 115E are formed on the left and right outer longitudinal plates 115, accessibility from the outside is improved, thereby facilitating welding operations within the base frame 100.

[0066] Furthermore, the drum advance / retreat device 400 has four intermediate frame support portions 113 (support legs). The four intermediate frame support portions 113 are connected to the four corners of the base frame 100 in a manner that surrounds the base frame 100. Each intermediate frame support portion 113 has: a lower end, which is mounted on the ground; an upper end, which supports the lifting unit 50 (lifting mechanism) by supporting the intermediate frame 101 and the upper frame 102; and two connecting portions, which are connected to the base frame 100. The multiple intermediate frame support portions 113 bear the weight of the lifting unit 50, the intermediate frame 101, and the upper frame 102 and are connected to the base frame 100, thereby improving the stability of the base frame 100 and further reducing the impact of device vibration on the measured values.

[0067] Figure 10 This is a perspective view of the drum frame 40 of the drum advance / retract device 400 according to this embodiment. Figure 11 and Figure 12 This is an exploded 3D view of the drum stand 40.

[0068] The drum frame 40 has a lower cover 41 and an upper cover 42. The lower cover 41 is a U-shaped structure when viewed from the front, and the upper cover 42 is connected to the upper end of the lower cover 41. As a result, a drum receiving space 40S is formed between the lower cover 41 and the upper cover 42. The drum receiving space 40S is a space that can accommodate the rotating drum 4 in such a way that the simulated road surface 4A of the rotating drum 4 is exposed in front of the drum frame 40.

[0069] The lower cover 41 has a bottom 411 (bottom wall), a pair of left and right sides 412 (side walls), a pair of left and right ball screw seats 413 (nut holding parts), four linear guide assembly parts 414 (supported parts), and multiple left and right side reinforcing plates 415.

[0070] The bottom 411 is arranged horizontally below the drum 4, providing rotatable support for the drum 4. The bottom 411 has a base plate 411A, multiple bottom horizontal plates 411B, and multiple bottom vertical plates 411C. The base plate 411A is a sheet material that forms the base portion of the bottom 411. A circular drum shaft receiving hole 41S is formed in the center of the base plate 411A. Figure 11 The drum shaft receiving hole 41S receives the lower end of the drum shaft 4S of the rotating drum 4. Multiple bottom horizontal plates 411B and multiple bottom vertical plates 411C are connected in a grid pattern to the lower part of the bottom plate 411A to improve the rigidity of the bottom 411.

[0071] A pair of side panels 412 are erected from the left and right ends of the bottom plate 411. Each side panel 412 has a side base plate 412A, a side upper plate 412B, a plurality of front and rear side cross plates 412C, and a side cover 412D. The side base plate 412A is a sheet material that forms the base portion of the side panel 412 and is connected to the end of the bottom plate 411A. The side upper plate 412B is connected to the upper end of the side base plate 412A and defines the upper end of the side panel 412. The plurality of front and rear side cross plates 412C are fixed to the side base plate 412A and connect the end of the bottom plate 411A and the side upper plate 412B vertically. The side cover 412D closes the side panel from the outside. Figure 12 The space formed by the side base plate 412A, bottom plate 411A, side upper plate 412B, and multiple side cross plates 412C is fixed to each plate. As a result, the side 412 has a box-shaped structure, which maintains the rigidity of the drum frame 40 to a greater extent.

[0072] A pair of ball screw seats 413 are respectively disposed on the inner side of the foremost bottom horizontal plate 411B among the plurality of bottom horizontal plates 411B. Each ball screw seat 413 has a box shape and forms a ball screw insertion hole 413A for receiving the ball screw 153. In addition, the aforementioned ball screw nut 155 ( Figure 6 The ball screw nut 155 is fixed to the ball screw seat 413. That is, the ball screw seat 413 holds the ball screw nut 155 in a manner that allows the drum frame 40 to move relative to the base frame 100 in the front-rear direction. In this embodiment, each ball screw seat 413 is positioned in front of the drum shaft 4S of the drum frame 40. Furthermore, as... Figure 10 As shown, a hole for receiving the ball screw 153 is also formed on the bottom horizontal plate 411B located at the foremost side. Thus, by positioning the ball screw nut 155 at the bottom 411, the vertical distance (relative height) between the ball screw 153 and the drum 4 can be reduced. Consequently, when the drum 4 comes into contact with the tire T, the resulting bending moment can be reduced, and deformation of the drum frame 40 can be suppressed.

[0073] Four linear guide assembly parts 414 are respectively arranged at the front, back, left, and right corners of the bottom 411, and respectively fix the aforementioned cover support part 162. Figure 6 As a result, the drum frame 40 is movably supported in the front-to-back direction on a pair of left and right linear guides 161 via four cover supports 162.

[0074] Multiple side reinforcing plates 415 are fixed side by side at the left and right ends of the bottom 411 to improve the rigidity of the bottom 411 and the pair of left and right sides 412.

[0075] The upper cover 42 is configured to extend horizontally above the drum 4, rotatably supporting the drum 4. The upper cover 42 has an upper cover base plate 420, a pair of front and rear upper cover horizontal plates 421, and multiple left and right upper cover vertical plates 422. Thus, the upper cover 42 also has a lattice-like structure, thereby improving the rigidity of the drum frame 40. A circular drum shaft receiving hole 42S is formed in the center of the upper cover base plate 420. The drum shaft receiving hole 42S receives the upper end of the drum shaft 4S of the drum 4. Furthermore, the aforementioned pair of left and right side portions 412 connect the bottom 411 and the upper cover 42 in the vertical direction.

[0076] Thus, the various parts constituting the lower cover 41 of the drum frame 40 have small box-shaped structures, and their assembly can improve the rigidity of the plate-frame structure of the drum frame 40. This allows for a lighter drum frame 40 and a relatively increased natural vibration frequency. Furthermore, as... Figure 11 As shown, the upper part of the upper cover 42 is open and does not have a box-shaped structure, but based on the multiple upper cover horizontal plates 421 and multiple upper cover vertical plates 422, the rigidity of the upper cover 42 can be maintained to a high degree. As a result, compared with the case where the upper part of the upper cover 42 is closed, the drum frame 40 can be made lighter.

[0077] Furthermore, when the drum 4 is pressed against the tire T, such as Figure 10 As indicated by the dotted-dotted arrow, the drum 4 is intended to vibrate and twist around a horizontal axis. However, in this embodiment, multiple side reinforcing plates 415 are provided around the junction of the left and right sides 412 and the bottom 411. Figure 12 ) and slanted cover 416 ( Figure 10 Furthermore, each side portion 412 has a box-shaped structure. This suppresses the aforementioned torsion of the drum 4 and the drum frame 40 supporting the drum.

[0078] Furthermore, the aforementioned upper and lower pair of load sensors 4L are respectively installed in the drum shaft receiving hole 41S of the lower cover 41 and the drum shaft receiving hole 42S of the upper cover 42. That is, the upper load sensor 4L (upper load sensor) of the upper and lower pair of load sensors 4L is mounted on the upper cover 42 (upper wall) of the drum frame 40 to detect the load applied to the drum shaft 4S. In addition, the lower load sensor 4L (lower load sensor) of the upper and lower pair of load sensors 4L is mounted in the drum shaft receiving hole 41S of the bottom 411 of the lower cover 41 to detect the load applied to the drum shaft 4S. In particular, in this embodiment, a pair of ball screw nuts 155 are arranged on the left and right outer sides of the lower load sensor 4L, and these components are arranged at approximately the same height in the vertical direction. Therefore, the load sensor 4L is less affected by the tilting of the drum frame 40.

[0079] Furthermore, as previously mentioned, the left and right ball screw nuts 155 and the pair of ball screw seats 413 holding them are disposed at the front end of the bottom 411 of the drum 40. Therefore, the distance between the ball screw support portion 154 supporting the ball screw 153 and the ball screw nut 155 is shortened. Figure 6 This improves the rigidity of the system. Furthermore, the load transmission path, which is shortened by transmitting the load in the sequence of tire T, drum 4, drum frame 40, ball screw nut 155, ball screw 153, and ball screw support 154, can suppress the tilting or twisting of the drum frame 40. In addition, the load borne by the drum 4 (drum frame 40) from the tire T is almost entirely avoided by the reducer 152 supporting the rear end of the ball screw 153.

[0080] As described above, in this embodiment, since the base frame 100 supporting the drum 40 in a manner that allows the drum 4 to move forward and backward relative to the tire T has a first longitudinal plate disposed directly below it corresponding to the ball screw 153 and a second longitudinal plate disposed directly below it corresponding to the linear guide 161, even if the load borne by the drum 4 from the tire T is applied from the drum frame 40 to the ball screw 153 and the linear guide 161, each longitudinal plate can stably bear the load in the vertical direction. Therefore, even when the drum 4, which has a large weight according to specified specifications, is supported by the drum frame 40 for testing a tire T that is larger than that of a common passenger car tire T, the rigidity and natural vibration frequency of the base frame 100 can be maintained to a high degree, thereby suppressing the vibration of the drum forward / backward device 400 and reducing the impact of this vibration on the measurement value of the load sensor 4L. In particular, each longitudinal plate can suppress the deformation of the drum frame 40 in the longitudinal and vertical directions, making the drum frame 40 less prone to vibration. Furthermore, in this embodiment, where the center of gravity of the drum frame 40 containing the drum 4 is offset vertically from the drive support point of the ball screw 153 and the guide position of the linear guide 161, the drum frame 40 is prone to swaying in the front-to-back direction when viewed from the side. In this case, the drum frame 40 exerts a large bending moment on the base frame 100, causing the base frame 100 to deform and sway. Even in this case, the base frame 100 in this embodiment has a beam structure with a strong bending moment, thus reducing the impact of vibration on the measurement value of the load sensor 4L.

[0081] Furthermore, based on this structure, the base frame 100 including the first and second longitudinal plates can be miniaturized, reducing its weight and cost. This facilitates transportation and setup at the testing site. In particular, when transporting the drum advance / retract device 400 and the tire testing machine 1 equipped with it, commercially available containers can be used when using a ship, reducing transportation costs and time.

[0082] Furthermore, in this embodiment, based on the plurality of ball screws 153 and the plurality of ball screw nuts 155, the drum frame 40 containing the drum 4 can stably move forward and backward relative to the tire T. Moreover, since the plurality of first longitudinal plates are respectively arranged directly below the plurality of ball screws 153, even if the load borne by the drum 4 from the tire T is applied from the drum frame 40 to the plurality of ball screws 153, each longitudinal plate can stably bear the load in the vertical direction.

[0083] Furthermore, in this embodiment, the height position of the ball screw 153 can be positioned close to the center of gravity of the drum frame 40 containing the drum 4, and the rigidity of the ball screw seat 413 of the drum frame 40 can be sufficiently ensured. Therefore, the vibration of the drum frame 40 can be suppressed, and the base frame 100 can stably withstand the vibration in the vertical direction.

[0084] Furthermore, in the case where the drum frame 40 is moved back and forth by two (or more) ball screws 153 as in this embodiment, the two ball screw seats 413 can be positioned differently in the left-right direction from the drum shaft 4S and the load sensor 4L. In contrast, when the drum frame 40 is moved back and forth by only one ball screw 153, the single ball screw seat 413 is positioned further below the load sensor 4L, resulting in a larger offset relative to the center of gravity of the drum frame 40 containing the drum 4. In this case, compared to the case with two (or more) ball screws 153, maintaining a higher natural vibration frequency of the base frame 100 becomes relatively difficult.

[0085] Furthermore, in this embodiment, since a pair of linear guides 161 stably support the left and right outer portions of the drum 40, the movement of the drum 40 can be guided more stably. Moreover, since both the linear guides 161 and the ball screws 153 are arranged overlapping the longitudinal plate 115, the natural vibration frequency can be relatively increased compared to the case where they are not arranged overlapping the longitudinal plate 115. Furthermore, compared to the case where the pair of linear guides 161 are arranged on the two inner sides of the pair of ball screws 153, they can be relatively arranged near the left and right pairs of side portions 412 (side walls) of the drum 40, thus relatively reducing the decrease in the natural vibration frequency caused by the deformation of the drum 40 when the drum 4 is subjected to a load from the tire T.

[0086] Furthermore, in this embodiment, among the four longitudinal plates 115 comprising two first longitudinal plates and two second longitudinal plates, the moment of inertia of the two outer longitudinal plates is set to be greater than that of the two inner longitudinal plates. With this structure, since the rigidity of the outer longitudinal plates can be maintained to a higher degree, the weight and cost of the base frame 100 can be reduced by thinning the thickness of the inner longitudinal plates, or the weldability of the base frame 100 can be improved by providing openings or notches in the inner longitudinal plates.

[0087] Furthermore, the moments of inertia of the two inner longitudinal plates 115 (the second longitudinal plates) are set to be greater than those of the two outer longitudinal plates (the first longitudinal plates). According to this structure, the base frame 100, which is relatively rigid due to a pair of linear guides 161 that are more susceptible to vibration and the two second longitudinal plates positioned below them at their overlapping locations, can primarily withstand the bending moment from the drum frame 40. Therefore, the rigidity of the two first longitudinal plates, which are respectively arranged to overlap with the two ball screws 153 that are less susceptible to vibration, can be relatively reduced.

[0088] Furthermore, in this embodiment, each longitudinal plate 115 has a longitudinal plate body 115A, an upper plate 115B, and a lower plate 115C, thereby improving the stability of each longitudinal plate 115. Therefore, even if the load borne by the drum 4 from the tire T is applied from the drum frame 40 to the ball screw 153 and the linear guide 161, each longitudinal plate can more stably bear the load in the vertical direction.

[0089] Furthermore, in this embodiment, by utilizing general-purpose H-beams with high rigidity, the rigidity of the base frame 100, which includes multiple longitudinal plates 115, can be improved at a lower cost compared to using specialized steel. Moreover, as in this embodiment, by arranging the H-beams in an I-shape, the moment of inertia of the beams constituting the base frame 100 can be increased, deformation caused by bending moments can be suppressed, and vibration of the drum 40 can be stably suppressed. Furthermore, other components can be easily arranged on the upper part of the I-shaped structure, and the lower part can improve its installation on the ground.

[0090] Furthermore, in this embodiment, the spindle 2 can be rotatably supported by the multiple longitudinal plates 115 of the base frame 100 and the spindle support plate 111. Therefore, the base frame 100 can stably withstand the load when the tire T and the drum 4 are pressed against each other. Thus, the vibration of the drum advance / retreat device 400 can be reduced, and the tilting of the spindle 2 can be suppressed.

[0091] Furthermore, in this embodiment, the bottom 411 of the drum frame 40 has two ball screw seats 413, so the drum 4 and the ball screw 513 are arranged close to each other in the vertical direction, which can suppress the tilting and twisting of the drum 4.

[0092] Furthermore, in this embodiment, two ball screw seats 413 are positioned in front of the drum shaft 4S of the drum 4. Additionally, the drum advance / retreat device 400 includes a pair of ball screw supports 154, each mounted on the top plate 112 of the base frame 100, supporting the front end of the ball screw 153 and bearing the load applied from the drum frame 40 to the ball screw 153. This structure reduces the distance between the ball screw supports 154 and the ball screw nut 155 in the front-rear direction, thus shortening the load transmission path, suppressing the tilting or twisting of the drum frame 40, and inhibiting vibration.

[0093] Furthermore, in this embodiment, even when the drum 4 with a diameter of 1500 mm or more is supported by the drum frame 40 according to specified specifications for testing large-size tires T for trucks or buses, the rigidity and inherent vibration frequency of the base frame 100 can be maintained at a high level. Therefore, the vibration of the drum advance / retreat device 400 caused by the rotation of the drum 4 or the load borne by the drum 4 from the tire T can be suppressed, and the influence of such vibration on the measurement value of the load sensor 4L can be reduced.

[0094] Furthermore, in this embodiment, the multiple intermediate frame support portions 113 bear the weight of the lifting unit 50 (intermediate frame 101, upper frame 102) and are connected to the base frame 100. Therefore, the installation stability of the base frame 100 can be improved, and the influence of device vibration on the measured value can be further reduced.

[0095] The drum advance / retreat device 400 and the tire testing machine 1 equipped with the device according to one embodiment of the present invention have been described above. However, the present invention is not limited to these solutions and may be implemented in the following modified embodiments.

[0096] (1) In the above-described embodiments, such as Figure 6 The diagram illustrates a configuration where a pair of ball screws 153 and a pair of linear guides 161 are arranged on the top plate 112 of the base frame 100; however, the invention is not limited to this. Ideally, a single ball screw 153 could be arranged in the center between the pair of linear guides 161. In this case, only one ball screw nut 155 is needed to engage with the ball screw 153 mounted on the drum frame 40. Furthermore, only one of the multiple longitudinal plates 115 needs to be arranged below the plumb line of the ball screw 153 (reducer 152 and ball screw 153).

[0097] In addition, Figure 6Alternatively, a pair of linear guides 161 can be arranged on the inner side in the left-right direction, and a pair of ball screws 153 can be arranged on the left and right outer sides of the pair of linear guides 161. In this case, the pair of ball screws 153 are arranged on the left and right outer sides relative to the pair of linear guides 161, so that the operator can easily perform maintenance on the ball screws 153 and ball screw nuts 155. In addition, since the linear guides 161 and ball screws 153 are arranged overlapping with the longitudinal plates 115, the natural vibration frequency can be relatively increased compared to the case where they are arranged without overlapping with the longitudinal plates 115. Even in this case, it is convenient as long as the four longitudinal plates 115 are respectively arranged under the plumb lines of each linear guide 161 and each ball screw 153. Alternatively, three or more ball screws 153 and three or more linear guides 161 can be arranged on the top plate 112, as long as the longitudinal plates 115 are conveniently arranged under the plumb bobs of each ball screw 153 and each linear guide 161. In other words, multiple ball screws 153 and multiple linear guides 161 can be arranged on the top plate 112. In this case, the longitudinal plate 115 located under the plumb bob of the ball screw 153 constitutes the first longitudinal plate of the present invention, and the longitudinal plate 115 located under the plumb bob of the linear guide 161 constitutes the second longitudinal plate of the present invention.

[0098] (2) Furthermore, in the above embodiment, it was described that the left and right ball screw nuts 155 and the pair of ball screw seats 413 holding them are arranged at the front end of the bottom 411 of the drum 40. However, the present invention is not limited to this, and these components may also be arranged at the front or rear center or rear end of the bottom 411. In addition, when these components are arranged at the rear end of the bottom 411, the ball screw 153 may be supported by the reducer 152, and the ball screw support 154 may be arranged on the immediate front side of the reducer 152.

[0099] The drum advance / retreat device provided by this invention is disposed in a tire testing machine, which rotates a tire in a horizontal position about its rotational axis and performs specified tests on the tire. The horizontal position is the position in which the rotational axis of the tire extends vertically. The drum advance / retreat device includes a cylindrical drum, a drum frame, a base frame, a load detector, at least one ball screw, a drive source, at least one ball screw nut, and multiple linear guides. The drum has a drum shaft extending vertically and an outer peripheral surface abutting against the outer peripheral surface of the tire. The drum frame rotatably supports the drum about the drum shaft. The base frame is disposed below the drum frame and has a top plate. The base frame supports the drum frame in such a way that the drum frame can move in the front-rear direction, allowing the outer peripheral surface of the drum to contact or separate from the outer peripheral surface of the tire. The load detector can detect the load borne by the drum from the tire. At least one ball screw is supported on the top plate in such a way that it can rotate about an axis extending in the front-rear direction. A drive source enables the at least one ball screw to rotate about the axis. At least one ball screw nut is fitted to the drum frame and engages with the at least one ball screw in a manner that allows the drum frame to move in the front-back direction as the drive source rotates the at least one ball screw. A plurality of linear guides extend in the front-back direction and are fitted to the top plate of the frame in a manner spaced apart in the left-right direction relative to the at least one ball screw, and movably support the drum frame in the front-back direction. The base frame includes a plurality of longitudinal plates and a plurality of transverse plates. The plurality of longitudinal plates extend in both the vertical and front-back directions and are arranged side-by-side in the left-right direction, each supporting the top plate of the frame. The plurality of longitudinal plates includes at least one first longitudinal plate and a plurality of second longitudinal plates, the at least one first longitudinal plate being arranged to overlap with the at least one ball screw when viewed from the vertical direction, and each of the plurality of second longitudinal plates being arranged to overlap with the plurality of linear guides when viewed from the vertical direction. A plurality of transverse plates connect the plurality of longitudinal plates in the left-right direction.

[0100] According to this technical solution, the base frame supporting the drum assembly, which allows the drum to move forward and backward relative to the tire, has a first longitudinal plate positioned directly below it, corresponding to the ball screw, and a second longitudinal plate positioned directly below it, corresponding to the linear guide. Therefore, even when the load borne by the drum from the tire is applied from the drum assembly to the ball screw and linear guide, each longitudinal plate can stably bear the load in the vertical direction. Thus, even when a drum assembly supports a large-weight drum according to specified specifications for testing tires larger than those of ordinary passenger cars, the rigidity and natural vibration frequency of the base frame can be maintained to a high degree. This suppresses vibrations in the drum movement mechanism caused by drum rotation or the load borne by the drum from the tire, reducing the impact of such vibrations on the load detector's measurements.

[0101] In the above technical solution, the at least one ball screw includes a plurality of ball screws, which are rotatably supported on the top plate of the frame in a manner that is arranged at intervals in the left-right direction. The at least one ball screw nut includes a plurality of ball screw nuts that engage with the plurality of ball screws respectively. The at least one first longitudinal plate among the plurality of longitudinal plates includes a plurality of first longitudinal plates that are arranged in a manner that overlaps with the plurality of ball screws when viewed from the top-bottom direction.

[0102] According to this technical solution, multiple ball screws and multiple ball screw nuts enable the drum frame containing the rotating drum to move stably forward and backward relative to the tire. Furthermore, since multiple first longitudinal plates are respectively arranged directly below the multiple ball screws, even if the load borne by the rotating drum from the tire is applied to the multiple ball screws from the drum frame, each longitudinal plate can stably bear the load in the vertical direction.

[0103] In the above technical solution, the plurality of ball screws includes two ball screws arranged facing each other in the left-right direction, the plurality of linear guides includes two linear guides arranged on the left and right outer sides of the two ball screws, the plurality of first longitudinal plates includes two first longitudinal plates respectively arranged in a manner overlapping the two ball screws when viewed from the top and bottom direction, and the plurality of second longitudinal plates includes two second longitudinal plates respectively arranged in a manner overlapping the two linear guides when viewed from the top and bottom direction.

[0104] According to this technical solution, since a pair of linear guides stably support the left and right outer portions of the drum frame, the movement of the drum frame can be guided more stably. Furthermore, since both the linear guides and the ball screw are configured to overlap with the longitudinal plate, the natural vibration frequency can be relatively increased compared to the case where they are not configured to overlap with the longitudinal plate.

[0105] On the other hand, in the above-mentioned technical solution, the plurality of linear guides includes two linear guides arranged facing each other in the left-right direction, the plurality of ball screws includes two ball screws arranged on the left and right outer sides of the two linear guides, the plurality of first longitudinal plates includes two first longitudinal plates respectively arranged in a manner overlapping the two ball screws when viewed from the top and bottom direction, and the plurality of second longitudinal plates includes two second longitudinal plates respectively arranged in a manner overlapping the two linear guides when viewed from the top and bottom direction.

[0106] According to this technical solution, a pair of ball screws are positioned on the left and right outer sides relative to a pair of linear guides, thus allowing operators to easily maintain the ball screws and ball screw nuts. Furthermore, since both the linear guides and ball screws are configured to overlap with the longitudinal plate, the natural vibration frequency can be relatively increased compared to a configuration where they are not overlapped with the longitudinal plate.

[0107] In the above-mentioned technical solution, it is more ideal that the moment of inertia of the two longitudinal plates located on the left and right outer sides of the four longitudinal plates, including the two first longitudinal plates and the two second longitudinal plates, is set to be greater than the moment of inertia of the two longitudinal plates located on the left and right inner sides.

[0108] According to this technical solution, since the rigidity of the left and right outer longitudinal plates can be maintained to a high degree, the weight of the base frame can be reduced by thinning the thickness of the left and right inner longitudinal plates, or the weldability of the base frame can be improved by setting openings or notches in the left and right inner longitudinal plates.

[0109] In the above technical solution, it is more ideal that the moment of inertia of the two second longitudinal plates is set to be greater than that of the two first longitudinal plates.

[0110] According to this technical solution, the base frame, which is relatively rigid due to the presence of two linear guides that are more susceptible to vibration and two second longitudinal plates positioned below them at their overlapping locations, can primarily withstand the bending moment from the drum frame. Therefore, the rigidity of the two first longitudinal plates, which are respectively arranged to overlap with two ball screws that are less susceptible to vibration, can be relatively reduced.

[0111] In the above-mentioned technical solution, it is more ideal that the plurality of longitudinal plates each include: a longitudinal plate body, including an upper end and a lower end, and extending along the vertical and horizontal directions; an upper support plate, which is connected to the upper end in a manner extending from the upper end of the longitudinal plate body to the left and right directions respectively, and supports the top plate of the frame; and a lower mounting plate, which is connected to the lower end in a manner extending from the lower end of the longitudinal plate body to the left and right directions respectively, and is mounted on the ground.

[0112] According to this technical solution, since the stability of multiple longitudinal plates is improved by having an I-shaped cross-section, even if the load borne by the drum from the tire is applied from the drum frame to the ball screw and linear guide, each longitudinal plate can bear the load more stably in the vertical direction.

[0113] In the above-mentioned technical solutions, the more ideal arrangement is that the multiple longitudinal plates are each formed of H-beams.

[0114] According to this technical solution, by using general-purpose H-beams with high rigidity for each longitudinal plate, the rigidity of a frame containing multiple longitudinal plates can be improved reliably and at low cost compared to using special steel.

[0115] In the above technical solution, it is more ideal that the base frame further includes: a spindle support plate, configured to support the spindle, the spindle rotatably supporting the tire at the tire test position; wherein, the upper end of the main body of the longitudinal plate in the plurality of longitudinal plates respectively has: a rear upper end, connected to the upper support plate; and a front upper end, disposed in front of and below the rear upper end, and supporting the spindle support plate.

[0116] According to this technical solution, the spindle can be rotatably supported by multiple longitudinal plates and spindle support plates based on the base frame. Therefore, the base frame can stably withstand the load when the tire and the drum are pressed against each other. Thus, the vibration of the drum advance and retraction device can be reduced, and the spindle tilting can be suppressed.

[0117] In the above-described technical solution, the drum frame ideally comprises: an upper wall disposed above the drum and rotatably supporting the drum; a bottom wall disposed below the drum and rotatably supporting the drum; and a pair of left and right side walls disposed on the left and right sides of the drum, respectively, connecting the upper wall and the bottom wall to each other; wherein the bottom wall of the drum frame has at least one nut retaining portion, which retains at least one ball screw nut in such a way that the drum frame can move relative to the base frame in the front-back direction.

[0118] According to this technical solution, since the bottom wall of the drum frame has at least one nut retaining part, the drum and the ball screw are arranged close to each other in the vertical direction, which can suppress the tilting and twisting of the drum.

[0119] In the above-mentioned technical solution, it is more ideal to further include: at least one ball screw support portion, which is assembled on the top plate of the base frame, supports the front end of the at least one ball screw, and bears the load applied from the drum frame to the at least one ball screw; wherein, the at least one nut retaining portion is arranged in front relative to the drum shaft.

[0120] According to this technical solution, the distance between the ball screw support and the ball screw nut in the front-rear direction can be reduced. Therefore, the load transmission path from the drum to the ball screw support is shortened, which can further suppress the tilting and twisting of the drum frame.

[0121] In the above-mentioned technical solutions, it is more ideal that the drum is used to test the tires of trucks and buses at the tire test position, and the diameter of the drum is set to be 1500mm or more.

[0122] According to this technical solution, even when a drum with a diameter of 1500mm or more is supported by a drum frame according to specified specifications for testing large-sized tires for trucks or buses, the rigidity of the base frame and the inherent vibration frequency can be maintained at a high level. Therefore, the vibration of the drum advance and retreat device caused by the rotation of the drum or the load borne by the drum from the tire can be suppressed, and the impact of such vibration on the measurement value of the load detector can be reduced.

[0123] Another aspect of the present invention relates to a tire testing machine comprising: a spindle capable of rotating a tire positioned in a horizontal posture at a tire testing position about a rotational center axis of the tire, the horizontal posture being a posture in which the rotational center axis of the tire extends in a vertical direction; a conveying device capable of moving the tire into and out of the tire testing position; and a drum advance / retreat device as described in any of the above-mentioned technical solutions, capable of bringing the drum into contact with or separating it from the outer peripheral surface of the tire disposed at the tire testing position.

[0124] According to this technical solution, a tire testing machine can be provided that can reduce the impact of device vibration on the measured values ​​even when testing tires larger than those of ordinary passenger car tires.

[0125] In the above-described technical solution, it is preferable that the mandrel has: an upper mandrel supporting the tire in the horizontal position from above; and a lower mandrel supporting the tire in the horizontal position from below. The tire testing machine further includes: a lifting mechanism that allows the upper mandrel to be raised and lowered relative to the lower mandrel so that the tire can be positioned between the upper and lower mandrels. The drum advance and retreat device further includes: a plurality of support legs arranged to surround the base frame, and each having a lower end on the ground, an upper end supporting the lifting mechanism, and a frame connection portion connected to the base frame.

[0126] According to this technical solution, multiple support legs bear the weight of the lifting mechanism and are connected to the base frame. Therefore, the stability of the base frame can be improved, and the impact of device vibration on the measured values ​​can be further reduced.

[0127] According to the present invention, a drum advance / retreat device and a tire testing machine equipped with the device can be provided such that the influence of device vibration on the measured values ​​can be reduced even when testing tires larger than those of ordinary passenger car tires.

Claims

1. A drum advance / retract device, characterized in that, The tire is positioned in a tire testing machine, which rotates a tire, which is positioned horizontally in a test position, about its rotational axis and performs specified tests on the tire. The horizontal position is defined as the position in which the rotational axis extends vertically. The drum advance / retract device includes: A cylindrical drum has a drum shaft extending in the vertical direction and an outer peripheral surface of the drum that abuts against the outer peripheral surface of the tire; A drum frame that rotatably supports the drum about the drum shaft; A base frame is disposed below the drum frame and has a top plate, and supports the drum frame in such a way that the outer peripheral surface of the drum can move in the front-rear direction to contact or separate from the outer peripheral surface of the tire; A load detector is capable of detecting the load borne by the drum from the tire; At least one ball screw is supported on the top plate of the frame in such a way that it is rotatable about an axis extending in the front-rear direction; A drive source capable of causing the at least one ball screw to rotate about the axis; At least one ball screw nut is fitted to the drum frame and engages with the at least one ball screw in such a way that the drum frame moves in the back-and-forth direction as the drive source rotates the at least one ball screw; and, Multiple linear guides, extending in the front-rear direction and spaced apart in the left-right direction relative to the at least one ball screw, are mounted on the top plate of the frame, and movably support the drum frame in the front-rear direction; wherein, The base frame includes: Multiple longitudinal plates, extending vertically and horizontally respectively, and arranged side-by-side in the left-right direction, respectively support the top plate of the frame, and include at least one first longitudinal plate and multiple second longitudinal plates. The at least one first longitudinal plate is arranged to overlap with the at least one ball screw when viewed from the vertical direction, and each of the multiple second longitudinal plates is arranged to overlap with the multiple linear guides when viewed from the vertical direction; and, Multiple horizontal plates connect the multiple vertical plates in the left-right direction.

2. The drum advance / retract device according to claim 1, characterized in that, The at least one ball screw comprises a plurality of ball screws, which are rotatably supported on the top plate of the frame and are arranged at intervals in the left-right direction. The at least one ball screw nut comprises a plurality of ball screw nuts that respectively engage with the plurality of ball screws. The at least one first longitudinal plate of the plurality of longitudinal plates comprises a plurality of first longitudinal plates respectively configured to overlap with the plurality of ball screws when viewed from the top and bottom direction.

3. The drum advance / retract device according to claim 2, characterized in that, The plurality of ball screws includes two ball screws arranged facing each other in the left-right direction. The plurality of linear guides includes two linear guides disposed on the left and right outer sides of the two ball screws. The plurality of first longitudinal plates includes two first longitudinal plates respectively configured to overlap with the two ball screws when viewed from the top and bottom direction. The plurality of second longitudinal plates comprise two second longitudinal plates respectively configured to overlap with the two linear guides when viewed from the top and bottom.

4. The drum advance / retract device according to claim 2, characterized in that, The plurality of linear conductors includes two linear conductors arranged facing each other in the left-right direction. The plurality of ball screws includes two ball screws disposed on the left and right outer sides of the two linear conductors. The plurality of first longitudinal plates includes two first longitudinal plates respectively configured to overlap with the two ball screws when viewed from the top and bottom direction. The plurality of second longitudinal plates comprise two second longitudinal plates respectively configured to overlap with the two linear guides when viewed from the top and bottom.

5. The drum advance / retract device according to claim 3 or 4, characterized in that, Of the four longitudinal plates including the two first longitudinal plates and the two second longitudinal plates, the moment of inertia of the two longitudinal plates located on the left and right outer sides is set to be greater than that of the two longitudinal plates located on the left and right inner sides.

6. The drum advance / retract device according to claim 3 or 4, characterized in that, The moments of inertia of the two second longitudinal plates are set to be greater than the moments of inertia of the two first longitudinal plates.

7. The drum advance / retract device according to any one of claims 1 to 4, characterized in that, The plurality of longitudinal plates each comprise: The longitudinal plate body includes an upper end and a lower end, and extends along the vertical and horizontal directions as well as the front and back directions; The upper support plate is connected to the upper end in a manner that extends from the upper end of the main body of the longitudinal plate in the left and right directions respectively, and supports the top plate of the frame; as well as, A plate is provided on the lower side, which is connected to the lower end of the main body of the longitudinal plate in a manner that extends to the left and right directions respectively, and is set on the ground.

8. The drum advance / retract device according to claim 6, characterized in that, The plurality of longitudinal plates are each formed of H-beams.

9. The drum advance / retract device according to claim 7, characterized in that, The base frame also includes: A spindle support plate is configured to support a spindle that rotatably supports the tire at the tire testing position; wherein... The upper end of the main body of each of the plurality of longitudinal plates has: The rear upper end is connected to the upper support plate; and, The upper front end is positioned in front of and below the upper rear end and supports the spindle support plate.

10. The drum advance / retract device according to any one of claims 1 to 4, characterized in that, The drum frame has: The upper wall is positioned above the drum and rotatably supports the drum. A bottom wall is disposed below the drum and rotatably supports the drum; A pair of side walls are respectively disposed on the left and right sides of the rotating drum, and connect the upper wall and the bottom wall to each other; wherein, The bottom wall of the drum frame has at least one nut retainer that holds at least one ball screw nut in a manner that allows the drum frame to move relative to the base frame in a front-rear direction.

11. The drum advance / retract device according to claim 10, characterized in that... Also includes: At least one ball screw support is mounted on the top plate of the base frame, supporting the front end of the at least one ball screw and bearing the load applied to the at least one ball screw from the drum frame; wherein, The at least one nut retainer is positioned in front of the drum shaft.

12. The drum advance / retract device according to any one of claims 1 to 4, characterized in that, The drum is used to test tires for trucks and buses at the tire test position, and the diameter of the drum is set to be 1500 mm or more.

13. A tire testing machine, characterized in that... include: A spindle enables a tire, which is positioned horizontally at a tire test position, to rotate about the tire's rotation center axis, wherein the horizontal position is the position in which the tire's rotation center axis extends in the vertical direction. A conveying device capable of moving the tire into and out of the tire testing position; as well as, The drum advance / retreat device of claim 1 is capable of bringing the drum into contact with or separating it from the outer peripheral surface of the tire disposed at the tire test position.

14. The tire testing machine according to claim 13, characterized in that, The mandrel has: The upper spindle supports the tire, which is positioned in the horizontal posture, from above; and, The lower spindle supports the tire, which is positioned in the horizontal orientation, from below. The tire testing machine also includes: A lifting mechanism allows the upper spindle to move relative to the lower spindle, enabling the tire to be positioned between the upper and lower spindles; wherein, The drum advance / retract device also includes: Multiple support legs are configured to surround the base frame, and each has a lower end set on the ground, an upper end supporting the lifting mechanism, and a frame connection portion connected to the base frame.

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