阅读说明：本技术 制动装置 (Brake device ) 是由 大野智也 内海崇 于 2020-11-10 设计创作，主要内容包括：本发明提供一种制动装置。抑制输出轴要使旋转杆旋转的转矩的变动。制动装置(50)具备圆筒形状的第1缸(51)。在第1缸的内部配置有沿着该第1缸的轴线方向直线运动的第1活塞(52)。在第1活塞固定有沿着第1缸的轴线方向直线运动的输出轴(53)。在输出轴连结有旋转杆(55),该旋转杆通过输出轴直线运动而将该输出轴的直线运动转换成旋转运动而旋转。旋转杆的辊(58)插入于输出轴的插入孔(53A),与插入孔的内周面之间的接触位置改变。在旋转杆连结有旋转臂(60A)。在旋转臂安装有供制动块(86)固定的安装部(65)。(The invention provides a brake device. The fluctuation of torque of an output shaft to rotate a rotating lever is suppressed. The brake device (50) is provided with a cylindrical 1 st cylinder (51). A1 st piston (52) linearly moving along the axial direction of the 1 st cylinder is disposed in the 1 st cylinder. An output shaft (53) that moves linearly in the axial direction of the 1 st cylinder is fixed to the 1 st piston. A rotating lever (55) is connected to the output shaft, and the rotating lever converts the linear motion of the output shaft into a rotational motion by the linear motion of the output shaft and rotates. A roller (58) for rotating the lever is inserted into an insertion hole (53A) of the output shaft, and the position of contact with the inner peripheral surface of the insertion hole is changed. A rotating arm (60A) is connected to the rotating rod. A mounting part (65) for fixing a brake block (86) is mounted on the rotating arm.)

1. A brake device, wherein,

the braking device is provided with:

an output shaft that moves linearly in the axial direction of the cylinder together with the piston; and

a rotating lever that drives a rotating arm by a force of the output shaft, the rotating arm changing a relative position between the friction member and the member to be braked,

the rotating lever includes a lever contact portion that changes a contact position with the output shaft when the output shaft moves linearly.

2. The braking device according to claim 1,

the contact portion of the output shaft is in line contact or point contact with the contact portion of the lever contact portion,

at least one of the contact portion of the output shaft and the contact portion of the lever contact portion is provided with a curved surface portion having a curved surface shape.

3. The braking device according to claim 1 or 2,

at least one of the output shaft and the lever contact portion includes a rotating body that rotates.

4. The braking device according to any one of claims 1 to 3,

the rotating rod is configured to rotate about a rotation center,

in the axial direction of the cylinder, a direction in which the output shaft protrudes from the cylinder is a protruding direction, and a direction opposite to the protruding direction is a reverse protruding direction, and at this time,

the rotating lever is arranged such that a contact position between the output shaft and the lever contact portion changes within a range from a position on the side of the counter-projecting direction from the rotation center of the rotating lever to a position on the side of the projecting direction from the rotation center of the rotating lever.

5. The braking device according to any one of claims 1 to 4,

the piston is provided with:

a partition plate that partitions an internal space of the cylinder in an axial direction of the cylinder; and

a guide portion extending from an outer edge of the partition plate in an axial direction of the cylinder.

6. The braking device according to any one of claims 1 to 5,

in the axial direction of the cylinder, a direction in which the output shaft protrudes from the cylinder is a protruding direction, and a direction opposite to the protruding direction is a reverse protruding direction, and at this time,

when the output shaft moves linearly in the projecting direction, the rotating lever rotates to one side,

when the output shaft moves linearly in the reverse projecting direction, the rotating lever rotates to the other side.

7. The braking device according to claim 6,

the output shaft is provided with:

a 1 st contact portion that contacts the rotating lever from the cylinder side in an axial direction of the cylinder; and

a 2 nd contact portion that contacts the rotating lever from a side opposite to the cylinder side in an axial direction of the cylinder.

8. The braking device according to any one of claims 1 to 7,

the output shaft is linearly moved in the axial direction of the cylinder by the supply and discharge of the fluid inside the cylinder,

the braking device is provided with:

a drive shaft disposed coaxially with the output shaft on a side of the output shaft opposite to the rotating lever; and

an elastic member that presses the drive shaft toward the output shaft in the axial direction of the cylinder,

when the drive shaft moves the output shaft or the piston toward the rotary rod side in the axial direction of the cylinder by the pressing force of the elastic member, the output shaft can move linearly toward the rotary rod side regardless of the fluid pressure inside the cylinder.

Technical Field

The present disclosure relates to a brake device.

Background

Patent document 1 describes a disc brake type brake device used for a railway vehicle. The brake device includes a cylindrical cylinder. A piston that moves inside the cylinder is housed inside the cylinder. An output shaft is fixed to the piston. The pistons and the output shaft can be tilted with respect to the central axis of the cylinder. One end of a rotary rod rotatably supported is connected to a distal end portion of the output shaft. The brake device further includes a pair of rotating arms that sandwich a disk fixed to the axle. The other end of the rotating rod is connected to one of the pair of rotating arms. A brake pad is attached to the pivot arm.

In the brake device of patent document 1, when the internal pressure of the cylinder increases, the piston moves and the output shaft protrudes. Then, the rotating lever connected to the output shaft rotates, and the rotating arm rotates accordingly. In addition, as the rotating arm rotates, the brake pad moves in a manner of approaching the disc. Then, the brake pad is pressed against the disk by being in contact with the disk, and braking force acts on the disk.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2012/123316

Disclosure of Invention

Problems to be solved by the invention

In the brake device of patent document 1, a force acting in a tangential direction of the rotating lever, out of forces in which the output shaft presses the rotating lever, acts as a force to rotate the rotating lever, that is, a torque. However, in the brake device of patent document 1, the output shaft is inclined as the rotational position of the rotating lever changes as the rotating lever rotates. Therefore, the direction in which the output shaft presses the rotating lever is uncertain, and the torque of the rotating lever varies according to the rotational position of the rotating lever.

The present invention has been made in view of such circumstances, and an object thereof is to suppress fluctuations in torque at which an output shaft rotates a rotating lever.

Means for solving the problems

A braking device according to one aspect of the present disclosure includes: an output shaft that moves linearly in the axial direction of the cylinder together with the piston; and a rotating lever that receives a force of the output shaft to drive a rotating arm that changes a relative position between the friction material and the member to be braked, the rotating lever including a lever contact portion that changes a contact position with the output shaft when the output shaft moves linearly.

According to the above configuration, since the contact position between the lever contact portion of the rotating lever and the output shaft changes according to the rotation position of the rotating lever, the operating direction of the output shaft is always the same direction. In the above configuration, the inclination of the output shaft with respect to the tangential direction of the rotating lever is increased so that the distance from the rotation center of the rotating lever to the contact position of the rotating lever and the output shaft is increased as the force acting from the output shaft in the tangential direction of the rotating lever is decreased. Therefore, the fluctuation of the torque of the output shaft rotating the rotating lever can be suppressed.

In the above configuration, the contact portion of the output shaft and the contact portion of the lever contact portion may be in line contact or point contact, and at least one of the contact portion of the output shaft and the contact portion of the lever contact portion may include a curved surface portion having a curved surface shape. In the above configuration, the resistance at the time of changing the contact position between the output shaft and the lever contact portion of the rotating lever can be reduced as compared with, for example, a configuration in which the lever contact portion of the rotating lever is in surface contact with the output shaft.

In the above configuration, at least one of the output shaft and the lever contact portion may include a rotating body that rotates. According to the above configuration, the rotating body rotates when the contact position between the output shaft and the rotating rod changes. Therefore, resistance at the time of changing the contact position between the output shaft and the rotating lever can be reduced.

In the above brake device, the rotating lever may be configured to rotate about a rotation center, and when a direction in which the output shaft protrudes from the cylinder in an axial direction of the cylinder is a protruding direction and a direction opposite to the protruding direction is an anti-protruding direction, the rotating lever may be arranged such that a contact position between the output shaft and the lever contact portion changes within a range from a position on the anti-protruding direction side of the rotation center of the rotating lever to a position on the protruding direction side of the rotation center of the rotating lever.

According to the above configuration, as long as the contact range between the output shaft and the rotating lever is the same, the rotation range of the rotating lever can be increased compared to a configuration in which the contact position between the output shaft and the rotating lever is changed only at the side of the protruding direction from the rotation center of the rotating lever.

In the above brake device, the piston may include: a partition plate that partitions an internal space of the cylinder in an axial direction of the cylinder; and a guide portion extending from an outer edge of the partition plate in an axial direction of the cylinder.

According to the above configuration, the piston can be suppressed from wobbling in the axial direction of the cylinder during the linear motion. Thereby, the output shaft is made easy to move linearly in the axial direction of the cylinder.

In the above brake device, a direction in which the output shaft protrudes from the cylinder in an axial direction of the cylinder may be a protruding direction, and a direction opposite to the protruding direction may be a reverse protruding direction, and in this case, the rotating lever may rotate to one side when the output shaft moves linearly in the protruding direction, and the rotating lever may rotate to the other side when the output shaft moves linearly in the reverse protruding direction. In the above configuration, the rotation of the rotating lever in both directions can be achieved by the linear motion of the output shaft.

In the above brake device, the output shaft may include: a 1 st contact portion that contacts the rotating lever from the cylinder side in an axial direction of the cylinder; and a 2 nd contact portion that contacts the rotating lever from a side opposite to the cylinder side in an axial direction of the cylinder.

According to the above configuration, when the output shaft protrudes, the 1 st contact portion of the output shaft contacts the rotating lever to rotate the rotating lever. When the output shaft retracts, the 2 nd contact part of the output shaft contacts with the rotating rod, and the rotating rod rotates in the opposite direction to the previous direction. In this way, the rotation of the rotating lever in both directions can be achieved only by contact with the output shaft, and therefore, the structure around the output shaft and the rotating lever can be suppressed from becoming complicated.

In the above brake device, the output shaft may be linearly moved in the axial direction of the cylinder by supply and discharge of the fluid in the cylinder, and the brake device may include: a drive shaft disposed coaxially with the output shaft on a side of the output shaft opposite to the rotating lever; and an elastic member that presses the drive shaft toward the output shaft in the axial direction of the cylinder, wherein when the drive shaft moves the output shaft or the piston toward the rotation rod in the axial direction of the cylinder by the pressing force of the elastic member, the output shaft can move linearly toward the rotation rod regardless of the fluid pressure inside the cylinder.

In the above structure, the output shaft is linearly moved by the drive shaft regardless of the fluid pressure inside the cylinder. Therefore, in the above configuration, even when, for example, fluid is not supplied to the inside of the cylinder and the driving force from the output shaft due to the fluid pressure is not transmitted to the rotating rod, the driving force from the drive shaft is transmitted to the rotating rod via the output shaft, and fluctuation of the torque when the rotating rod is rotated by the driving force of the drive shaft can be suppressed.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the fluctuation of the torque at which the output shaft rotates the rotating lever can be suppressed.

Drawings

Fig. 1 is a schematic diagram showing a schematic configuration of a vehicle.

Fig. 2 is a partial sectional view of the braking device when not braking.

Fig. 3 is a partial sectional view of the braking device at the time of braking.

Fig. 4 is an explanatory diagram showing the output shaft and the rotating lever.

Description of the reference numerals

Theta, an inclination angle; f1, force; f2, force; l1, distance; p1, center of rotation; p2, connecting center; x1, distance; x2, distance; y1, contact point; 10. a vehicle; 20. a vehicle body; 30. an air spring; 41. a bogie; 42. an axle; 43. a wheel; 44. a disc; 46. an air supply source; 47. a control valve; 48. a supply passage; 50. a braking device; 51. 1, a cylinder; 51A, a through hole; 51B, a through hole; 52. 1 st piston; 52A, a partition plate; 52B, a guide part; 53. an output shaft; 53A, insert the hole; 54. a 1 st spring; 55. rotating the rod; 56. a rounded portion; 57. a lever body; 58. a roller; 60. a rotating arm; 65. an installation part; 70. a support; 75. a gap adjusting mechanism; 76. a connecting pin; 81. a 2 nd cylinder; 81A, a through hole; 82. a 2 nd piston; 83. a drive shaft; 84. a 2 nd spring; 86. a brake pad; 90. and a control device.

Detailed Description

Hereinafter, an embodiment of the brake device will be described with reference to fig. 1 to 4. First, a schematic configuration of 1 vehicle out of a plurality of vehicles of a railway vehicle will be described.

As shown in fig. 1, the vehicle 10 includes two bogies 41 that are disposed apart in the vehicle front-rear direction (the left-right direction in fig. 1). An axle 42 extending in the vehicle width direction (the paper depth direction in fig. 1) is rotatably attached to each bogie 41. The axles 42 are disposed two on each bogie 41 so as to be separated in the vehicle front-rear direction. Wheels 43 having a substantially circular disk shape are fixed to both end portions of the axle 42. A disk 44 having a substantially circular disk shape is fixed to a portion of the axle 42 located between the two wheels 43. Two disks 44 are disposed so as to be separated in the vehicle width direction. Thus, for 1 bogie 41, 4 wheels 43 and 4 disks 44 are provided. Further, the disc 44 is a braked member.

An air spring 30 for absorbing vibration by the elastic force of compressed air is mounted on the bogie 41. A vehicle body 20 defining a vehicle compartment space is mounted on the air spring 30. The vehicle body 20 is a rectangular parallelepiped box shape as a whole, and is elongated in the vehicle front-rear direction.

A brake device 50 for braking rotation of the disc 44 is attached to the bogie 41. The brake device 50 is a caliper brake of a so-called disc brake device that brakes rotation of the disc 44 by clamping the disc 44 with a pair of brake pads 86. A total of 8 brake devices 50 are mounted on the vehicle 10 so as to correspond to a total of 8 discs 44. In fig. 1, only 4 disks 44 and 4 brake devices 50 located on one side in the vehicle width direction are shown.

An air supply source 46 for supplying compressed air is mounted on the vehicle 10. A supply passage 48 extends from the air supply source 46. The supply passage 48 is branched into 8 passages, and the branched passages are connected to 8 brake devices 50, respectively. A control valve 47 that controls the amount of compressed air flowing through the supply passage 48 is attached to the supply passage 48. The control valve 47 is disposed in the supply passage 48 at a position closer to the air supply source 46 than the branch portion. Thus, the control valve 47 is provided with 1 for 8 brake devices 50. The control valve 47 is controlled by a control device 90. Further, an air spring 30 is connected to the air supply source 46 through a passage not shown. The air spring 30 receives a supply of compressed air from an air supply source 46.

Next, a specific configuration of the braking device 50 will be described.

As shown in fig. 2, the brake device 50 includes a 1 st cylinder 51 having a cylindrical outer appearance. The center axis of the 1 st cylinder 51 is along the vehicle width direction. A columnar inner space is defined in the 1 st cylinder 51. A through hole 51A penetrates through a bottom portion of the 1 st cylinder 51 on the axial direction H side (lower side in fig. 2). The through hole 51A is located at the center of the bottom of the 1 st cylinder 51 on the side of the axial direction H. A through hole 51B penetrates through a bottom portion of the 1 st cylinder 51 on the side of the axial direction I (upper side in fig. 2). The through hole 51B is located at the center of the bottom of the 1 st cylinder 51 on the side of the axial direction I. The 1 st cylinder 51 is fixed to a bracket 70 extending in the axial direction of the 1 st cylinder 51. The bracket 70 is supported to be swingable with respect to the bogie 41. Thus, the 1 st cylinder 51 is supported by the bogie 41 via the bracket 70.

A 1 st piston 52 that linearly moves along the axial direction of the 1 st cylinder 51 is disposed inside the 1 st cylinder 51. Partition plate 52A of piston 1 52 has a substantially circular disk shape. The outer diameter of the partition plate 52A is substantially the same as the inner diameter of the 1 st cylinder 51. The partition plate 52A divides the internal space of the 1 st cylinder 51 into two in the axial direction of the 1 st cylinder 51. The guide portion 52B extends from the outer edge of the partition plate 52A toward the axial direction H side. The guide portion 52B extends from the outer edge of the partition plate 52A over the entire circumference, and is formed in an annular shape as a whole. The outer peripheral surface of the guide portion 52B contacts the inner peripheral surface of the 1 st cylinder 51.

The columnar output shaft 53 extends from the center of the partition plate 52A of the 1 st piston 52 toward the axial direction H. The 1 st piston 52 and the output shaft 53 are formed as one body. The output shaft 53 moves linearly along the axial direction of the 1 st cylinder 51 together with the 1 st piston 52. The distal end portion of the output shaft 53 reaches the outside of the 1 st cylinder 51 through the through hole 51A of the 1 st cylinder 51. An insertion hole 53A is formed in the distal end portion of the output shaft 53 in a direction orthogonal to the central axis of the output shaft 53. The axial direction H side is a protruding direction in which the output shaft 53 protrudes from the 1 st cylinder 51. The axial direction I side is an opposite projecting direction which is a direction opposite to the projecting direction.

A 1 st spring 54 is disposed inside the 1 st cylinder 51, and the 1 st spring 54 presses the 1 st piston 52 from the side closer to the axial direction H toward the axial direction I in the 1 st cylinder 51. The 1 st spring 54 is located between the bottom of the 1 st cylinder 51 on the axial direction H side and the partition plate 52A of the 1 st piston 52. Further, a space on the axial direction I side of the 1 st piston 52 in the internal space of the 1 st cylinder 51 communicates with the internal space of the supply passage 48. Therefore, the compressed air from the air supply source 46 can be introduced into the space on the axial direction I side of the 1 st piston 52 in the internal space of the 1 st cylinder 51.

A 2 nd cylinder 81 having a cylindrical outer shape is fixed to a bottom portion of the 1 st cylinder 51 on the axial direction I side. The center axis of the 2 nd cylinder 81 is coaxial with the center axis of the 1 st cylinder 51. A cylindrical inner space is defined inside the 2 nd cylinder 81. A through hole 81A penetrates through a bottom portion of the 2 nd cylinder 81 on the side of the axial direction H. The through hole 81A is located at the center of the bottom of the 2 nd cylinder 81 on the side of the axial direction H, and communicates with the through hole 51B of the 1 st cylinder 51.

A 2 nd piston 82 linearly moving along the axial direction of the 2 nd cylinder 81 is disposed inside the 2 nd cylinder 81. The 2 nd piston 82 has a substantially circular disk shape. The 2 nd piston 82 has an outer diameter substantially the same as the inner diameter of the 2 nd cylinder 81. The 2 nd piston 82 divides the inner space of the 2 nd cylinder 81 into two in the axial direction of the 2 nd cylinder 81.

A cylindrical drive shaft 83 extends from the center of the 2 nd piston 82 toward the axial direction H. The 2 nd piston 82 and the drive shaft 83 are formed integrally. The drive shaft 83 penetrates the through hole 81A of the 2 nd cylinder 81 and the through hole 51B of the 1 st cylinder 51. Further, on the opposite side of the 1 st cylinder 51 from the rotating rod 55 in the axial direction, a drive shaft 83 is disposed coaxially with the output shaft 53. The drive shaft 83 is linearly movable along the axial direction of the 2 nd cylinder 81 together with the 2 nd piston 82.

A 2 nd spring 84 is disposed inside the 2 nd cylinder 81, and the 2 nd spring 84 presses the 2 nd piston 82 from the side closer to the axial direction I toward the axial direction H in the 2 nd cylinder 81. The 2 nd spring 84 is located between the 2 nd piston 82 and the bottom of the 2 nd cylinder 81 on the side of the axial direction I. The pressing force of the 2 nd spring 84 is larger than the pressing force of the 1 st spring 54. The 2 nd spring 84 is an elastic member that presses the drive shaft 83 toward the output shaft 53 in the axial direction of the 1 st cylinder 51. Further, a space on the axial direction H side of the 2 nd piston 82 in the internal space of the 2 nd cylinder 81 communicates with the internal space of the supply passage 48. Therefore, the compressed air from the air supply source 46 can be introduced into the space on the axial direction H side of the 2 nd piston 82 out of the internal space of the 2 nd cylinder 81.

A rotating lever 55 is coupled to the output shaft 53, and when the output shaft 53 is linearly moved, the rotating lever 55 converts the linear movement of the output shaft 53 into a rotational movement and rotates. The circular portion 56 of the rotating lever 55 has a circular shape in plan view, and the central axis of the circle is along the vehicle vertical direction in fig. 1 (the depth direction of the paper in fig. 2). The circular portion 56 is rotatably supported by an end portion of the bracket 70 on the axial direction H side. The center axis of the circular portion 56 becomes the rotation center P1 of the rotating lever 55. A substantially rod-shaped rod main body 57 extends from the outer peripheral surface of the circular portion 56. Further, the rotating lever 55 is provided with a roller 58 that rotates relative to the lever main body 57. The roller 58 is supported by the distal end portion of the lever main body 57. The roller 58 has a substantially cylindrical shape and is rotatable about its central axis. Specifically, the roller 58 is a roller follower having a built-in bearing. The center axis of the roller 58 is orthogonal to the axial direction of the 1 st cylinder 51 and parallel to the center axis of the circular portion 56. The tip end portion of the lever main body 57 and the roller 58 are inserted into the insertion hole 53A of the output shaft 53. The roller 58 has a substantially cylindrical shape, and therefore functions as a curved portion having a curved shape. The roller 58 functions as a rotating body.

When the output shaft 53 moves linearly in the axial direction H with the distal end portion of the lever main body 57 and the roller 58 inserted into the insertion hole 53A of the output shaft 53, the roller 58 comes into contact with a portion of the inner circumferential surface of the insertion hole 53A on the axial direction I side. Therefore, a portion of the inner peripheral surface of the insertion hole 53A closer to the axial direction I functions as a 1 st contact portion, and in the 1 st contact portion, the insertion hole 53A contacts the roller 58, which is a part of the rotating lever 55, from the 1 st cylinder 51 side in the axial direction. Further, the roller 58 is in line contact with a portion of the inner peripheral surface of the insertion hole 53A on the axial direction I side. When the output shaft 53 moves linearly in the axial direction I with the distal end portion of the lever main body 57 and the roller 58 inserted into the insertion hole 53A of the output shaft 53, the roller 58 comes into contact with a portion of the inner circumferential surface of the insertion hole 53A on the axial direction H side. Therefore, a portion of the inner peripheral surface of the insertion hole 53A on the side of the axial direction H functions as a 2 nd contact portion, and in the 2 nd contact portion, the insertion hole 53A contacts the roller 58, which is a portion of the rotating rod 55, from the side opposite to the 1 st cylinder 51 in the axial direction. Further, the roller 58 is in line contact with a portion of the inner peripheral surface of the insertion hole 53A on the side of the axial direction H. In this manner, the output shaft 53 and the rotating lever 55 are in contact so as to be able to perform the linear motion of the output shaft 53 and the rotational motion of the rotating lever 55. That is, the output shaft 53 and the rotating lever 55 are in contact with each other so as to have a degree of freedom of 2, i.e., a straight pair and a rotation pair.

When the 1 st piston 52 is located closest to the axial direction I side, the contact position between the output shaft 53 and the roller 58 of the rotating lever 55 is located closer to the axial direction I side than the rotation center P1 of the rotating lever 55. When the 1 st piston 52 is located closest to the axial direction H side, the contact position between the output shaft 53 and the roller 58 of the rotating lever 55 is located closer to the axial direction H side than the rotation center P1 of the rotating lever 55. That is, the rotating lever 55 is disposed such that the contact position between the output shaft 53 and the roller 58 of the rotating lever 55 changes within the range from the position on the axial direction I side of the rotation center P1 of the rotating lever 55 to the position on the axial direction H side of the rotation center P1 of the rotating lever 55. In the braking device 50, force is transmitted from the output shaft 53 to the rotating rod 55 while changing the contact position between the roller 58 of the rotating rod 55 and the inner peripheral surface of the insertion hole 53A of the output shaft 53. Therefore, the transmission of force from the output shaft 53 to the rotating lever 55 is limited to a range in which the roller 58 of the rotating lever 55 can contact the inner peripheral surface of the insertion hole 53A of the output shaft 53. Further, the roller 58 changes its contact position with the inner peripheral surface of the insertion hole 53A of the output shaft 53 when the output shaft 53 moves linearly, and therefore functions as a lever contact portion of the rotating lever 55.

A rotation arm 60 is coupled to the circular portion 56 of the rotation lever 55, and the rotation arm 60 rotates by receiving a driving force from the output shaft 53, thereby changing the relative position between the brake pad 86 and the disc 44. A coupling center P2, which is the center of the coupling portion between the rotating arm 60 and the rotating lever 55, is eccentric with respect to the rotating center P1 of the rotating lever 55. Specifically, the coupling center P2 is located in the opposite direction to the lever main body 57 with the rotation center P1 therebetween. Further, the rotating arm 60 is linked within the range of the circular portion 56 as such, and therefore, the distance L1 from the rotation center P1 of the rotating lever 55 to the linking center P2 between the rotating arm 60 and the rotating lever 55 is shorter than the shortest distance from the rotation center P1 of the rotating lever 55 to the contact position between the output shaft 53 and the roller 58 of the rotating lever 55. As described above, the circular portion 56 of the rotating lever 55 is rotatably supported by the end of the bracket 70 on the axial direction H side. Therefore, the rotating arm 60 is coupled to the end of the bracket 70 on the axial direction H side via the rotating lever 55.

The pivot arm 60 extends substantially on both sides in the vehicle front-rear direction (the left-right direction in fig. 2) with the connection center P2 interposed therebetween. The base end of the rotating arm 60 reaches a position closer to the vehicle front-rear direction J than the 1 st cylinder 51. Further, the distal end of the pivot arm 60 reaches a position closer to the vehicle front-rear direction K than the bracket 70.

The mounting portion 65 is coupled to the distal end portion of the pivot arm 60 via a coupling pin 76. The mounting portion 65 is disposed on the axial direction I side of the first cylinder 51 with respect to the rotating arm 60. The mounting portion 65 can swing about the coupling pin 76. When viewed from the swing axial direction of the mounting portion 65, the mounting portion 65 has a substantially triangular shape with a larger dimension toward the axial direction I side of the 1 st cylinder 51. A brake block 86 is fixed to a surface of the mounting portion 65 on the axial direction I side. The brake block 86 has a substantially flat plate shape similar to the end surface of the disc 44. The brake pad 86 is a brake friction member that is pressed against the disc 44 to generate a braking force that is a frictional force.

A rotation arm 60 is also rotatably connected to an end portion of the holder 70 on the axial direction I side. Further, a mounting portion 65 is also connected to the rotating arm 60 disposed on the side of the axial direction I, and a brake block 86 is also fixed to the mounting portion 65. The rotary arm 60, the mounting portion 65, and the brake block 86 arranged on the side of the axial direction I are similarly configured, except that they are arranged axisymmetrically with respect to the rotary arm 60 arranged on the side of the axial direction H. Therefore, the rotating arm 60, the mounting portion 65, and the brake block 86 disposed on the side of the axial direction I are given the same reference numerals, and detailed description thereof is omitted. However, in the description of distinguishing the two rotation arms 60, the rotation arm 60 located on the side of the axis line direction H is denoted by a reference numeral 60A, and the rotation arm 60 located on the side of the axis line direction I is denoted by a reference numeral 60B.

The base end portions of the two rotating arms 60 are connected to each other by a gap adjusting mechanism 75 for adjusting a gap between the tip end portions of the two rotating arms 60. The base end portion of each rotating arm 60 is connected to a gap adjustment mechanism 75 so as to be rotatable with respect to the gap adjustment mechanism 75. Although not shown in detail, a screw is built in the gap adjustment mechanism 75, and the distance between the base ends of the two rotating arms 60 is changed by rotating the screw. Thereby, the two rotation arms 60 rotate about the coupling portion with the holder 70, and the gap between the distal end portions of the two rotation arms 60 changes.

The brake device 50 configured as described above is fixed to the bogie 41 such that the disc 44 is disposed between the distal ends of the two rotating arms 60. The 1 st cylinder 51 of the brake device 50 is disposed so that the axial direction thereof coincides with the vehicle width direction. Then, the gap adjusting mechanism 75 is operated according to the degree of wear of the brake pad 86 of the brake device 50, and the gap between the distal end portions of the two rotating arms 60 is adjusted.

The operation of the brake device 50 configured as described above will be described. Here, when the vehicle 10 is traveling, the compressed air is introduced into a space on the axial direction H side of the 2 nd piston 82 out of the internal space of the 2 nd cylinder 81. When the compressed air is introduced in this manner, the 2 nd piston 82 and the drive shaft 83 move in the axial direction I against the pressing force of the 2 nd spring 84, and the driving force from the drive shaft 83 due to the pressing force of the 2 nd spring 84 is not transmitted to the output shaft 53. Therefore, in the following description, the operation of the brake device 50 will be described as a case where the driving force from the drive shaft 83 is not transmitted to the output shaft 53.

When the compressed air is introduced into the space on the axial direction I side of the 1 st piston 52 in the internal space of the 1 st cylinder 51, the 1 st piston 52 and the output shaft 53 linearly move in the axial direction H against the pressing force of the 1 st spring 54, as shown in fig. 3. Then, of the inner peripheral surfaces of the insertion holes 53A of the output shaft 53, the inner peripheral surface on the side of the axial direction I is in contact with the roller 58 of the rotating lever 55. Then, the roller 58 of the rotating lever 55 moves in the axial direction H while gradually changing the contact position with the inner circumferential surface on the axial direction I side of the inner circumferential surface of the insertion hole 53A of the output shaft 53. With such movement of the roller 58, the rotating lever 55 rotates in one direction, i.e., clockwise in fig. 3, about the rotation center P1. At this time, the coupling center P2 between the rotating arm 60A and the rotating lever 55 located on the axial direction H side also rotates clockwise around the rotation center P1. Therefore, the rotation arm 60A receives a force toward the axial direction I side at the coupling center P2. As a result, the rotation arm 60A moves toward the axial direction I. Then, the mounting portion 65 and the brake block 86 connected to the rotation arm 60A move closer to the disk 44, and the brake block 86 on the rotation arm 60A side abuts against the end surface of the disk 44.

Further, as described above, when the rotation arm 60A moves in the axial direction I, the gap adjustment mechanism 75 also moves in the axial direction I. Then, the coupling portion between the base end portion of the pivot arm 60B and the gap adjustment mechanism 75 moves toward the axial direction I. Here, the rotation arm 60B is rotatably coupled to the bracket 70 at a substantially central portion in the extending direction thereof. Therefore, the rotation arm 60B rotates counterclockwise around the connection portion between the rotation arm 60B and the bracket 70 as the rotation center. Then, the mounting portion 65 and the brake block 86 connected to the rotation arm 60B move closer to the disk 44, and the brake block 86 on the rotation arm 60B side abuts against the end surface of the disk 44. Then, the disc 44 is braked from rotating by being clamped between the brake shoe 86 on the side of the rotating arm 60A and the brake shoe 86 on the side of the rotating arm 60B in the axial direction of the 1 st cylinder 51.

On the other hand, if the compressed air is not introduced into the space on the axial direction I side of the 1 st piston 52 in the internal space of the 1 st cylinder 51 and the pressure in the space is reduced, the 1 st piston 52 and the output shaft 53 move linearly in the axial direction I side due to the pressing force of the 1 st spring 54 as shown in fig. 2. Then, of the inner peripheral surfaces of the insertion holes 53A of the output shaft 53, the inner peripheral surface on the axial direction H side comes into contact with the roller 58 of the rotating lever 55. Then, the roller 58 of the rotating lever 55 moves in the axial direction I while gradually changing the contact position with the inner circumferential surface on the axial direction H side of the inner circumferential surface of the insertion hole 53A of the output shaft 53. With such movement of the roller 58, the rotating lever 55 rotates in the other direction, i.e., counterclockwise in fig. 2, about the rotation center P1. At this time, the coupling center P2 between the rotating arm 60A and the rotating lever 55 also rotates counterclockwise around the rotation center P1. Therefore, the rotation arm 60A receives a force toward the axial direction H side at the coupling center P2. As a result, the rotation arm 60A moves toward the axial direction H. Then, the mounting portion 65 and the brake block 86 connected to the rotation arm 60A move away from the disk 44, and the brake block 86 on the rotation arm 60A side is separated from the end surface of the disk 44.

Further, as described above, when the rotation arm 60A moves toward the axial direction H, the gap adjustment mechanism 75 also moves toward the axial direction H. Then, the coupling portion between the base end portion of the pivot arm 60B and the gap adjustment mechanism 75 moves toward the axial direction H. Then, the rotation arm 60B rotates clockwise around the connection portion between the rotation arm 60B and the bracket 70 as the rotation center. Then, the mounting portion 65 and the brake block 86 connected to the rotation arm 60B move away from the disk 44, and the brake block 86 on the rotation arm 60B side is separated from the end surface of the disk 44.

The force transmission method when the braking device 50 brakes the disc 44 will be discussed in detail. In addition, in the following description, for the sake of simplicity of description, the output shaft 53 is set to be in contact with the roller 58 of the rotating lever 55 at a contact point Y1 on the center axis of the output shaft 53. The force F1 with which the output shaft 53 is to move in the projecting direction is always constant.

As shown in fig. 4, the inclination angle of the rotating lever 55 when the state in which the extending direction of the lever main body 57 of the rotating lever 55 is orthogonal to the axial direction of the output shaft 53 is taken as a reference is "θ". At this time, a tangential force F2 acting on the rotating lever 55 from the output shaft 53 is represented by "F1 cos θ".

On the other hand, the output shaft 53 is movable in the axial direction thereof, but is not able to tilt or move in a direction intersecting the axial direction. Therefore, the distance X1 between the rotation center P1 of the rotating lever 55 and the central axis of the output shaft 53 is always constant. Also, a distance X2 from the rotation center P1 of the rotation lever 55 to the contact point Y1 between the rotation lever 55 and the output shaft 53 is denoted by "X1/cos θ".

Since the force of the output shaft 53 to rotate the rotating lever 55, that is, the torque can be expressed by the product of the tangential force F2 and the distance X2, "F1 × cos θ X1/cos θ — F1 × X1". As described above, the distance X1 between the rotation center P1 of the rotating lever 55 and the central axis of the output shaft 53 is always constant. Therefore, as long as the force F1 by which the output shaft 53 is to move in the protruding direction is constant, the torque of the rotating lever 55 becomes a constant value independent of the inclination angle θ of the rotating lever 55.

When the vehicle 10 is stopped, the compressed air is not introduced into the space on the axial direction I side of the 1 st piston 52 in the internal space of the 1 st cylinder 51. Then, the 1 st piston 52 and the output shaft 53 are moved linearly in the axial direction I by the pressing force of the 1 st spring 54. When the vehicle 10 is stopped, the compressed air is not introduced into the space on the axial direction H side of the 2 nd piston 82 in the internal space of the 2 nd cylinder 81. Then, the 2 nd piston 82 and the drive shaft 83 are moved linearly in the axial direction H by the pressing force of the 2 nd spring 84. When the 1 st piston 52 abuts against the drive shaft 83, the pressing force from the axial direction H side toward the axial direction I side by the 1 st spring 54 and the pressing force from the axial direction I side toward the axial direction H side by the 2 nd spring 84 act on the 1 st piston 52, the output shaft 53, the 2 nd piston 82, and the drive shaft 83. Here, the pressing force of the 2 nd spring 84 is larger than the pressing force of the 1 st spring 54. Therefore, the driving force from the drive shaft 83 from the axial direction I side toward the axial direction H side is transmitted to the 1 st piston 52 and the output shaft 53, and the 1 st piston 52 and the output shaft 53 also move linearly toward the axial direction H side. Further, as described above, the rotating lever 55 rotates in one direction, that is, clockwise in fig. 3, about the rotation center P1 due to the contact between the inner peripheral surface of the insertion hole 53A of the output shaft 53 and the roller 58 of the rotating lever 55. Therefore, when the 1 st piston 52 is moved toward the rotating rod 55 in the axial direction of the 1 st cylinder 51 by the pressing force of the 2 nd spring 84 in the driving shaft 83, the output shaft 53 moves linearly toward the rotating rod 55 regardless of the air pressure inside the 1 st cylinder 51. Further, the fluid supplied and discharged to and from the inside of the 1 st cylinder 51 is air.

The effects of the present embodiment will be described.

(1) In the braking device 50, theoretically, as long as the force F1 of the output shaft 53 to move in the projecting direction is constant, the torque of the rotating rod 55 becomes a constant value independent of the inclination angle θ of the rotating rod 55. In fact, the output shaft 53 is in contact with the roller 58 of the rotating rod 55, and since the outer surface of the roller 58 is a curved surface, it is not necessarily in contact at the contact point Y1 on the central axis of the output shaft 53. In this way, the output shaft 53 contacts the rotating lever 55 while changing the contact position with the rotation of the rotating lever 55, and the torque fluctuation of the rotating lever 55 can be suppressed. Further, as long as the torque fluctuation of the rotating lever 55 can be suppressed, the fluctuation of the force with which the two rotating arms 60 operated by the rotating lever 55 clamp the disk 44 can be suppressed. Therefore, the braking force to the disk 44 can be suppressed from varying with the variation in the torque of the rotating rod 55.

(2) With the braking device 50, the guide portion 52B extends from the partition plate 52A of the 1 st piston 52 toward the axial direction of the 1 st cylinder 51. Therefore, when the 1 st piston 52 moves linearly in the internal space of the 1 st cylinder 51, the 1 st piston 52 can be suppressed from wobbling in the axial direction of the 1 st cylinder 51. Thus, the output shaft 53 does not shake with the shake of the 1 st piston 52, and the output shaft 53 can be linearly moved along the axial direction of the 1 st cylinder 51.

(3) In the braking device 50, a roller 58 of the rotating lever 55 is inserted into an insertion hole 53A of the output shaft 53. When the output shaft 53 moves in the axial direction of the 1 st cylinder 51, the roller 58 of the rotating rod 55 changes the contact position with the inner peripheral surface of the insertion hole 53A of the output shaft 53 due to the rotation. Therefore, resistance when the output shaft 53 and the rotating lever 55 change the contact position can be reduced.

(4) With the brake device 50, when the output shaft 53 moves in the axial direction of the 1 st cylinder 51, the roller 58 of the rotating rod 55 comes into line contact with the inner periphery of the insertion hole 53A of the output shaft 53. Therefore, in the braking device 50, compared to a structure in which, for example, the rotating rod 55 is in surface contact with the inner peripheral surface of the insertion hole 53A of the output shaft 53, it is possible to reduce resistance when the rotating rod 55 and the inner peripheral surface of the insertion hole 53A of the output shaft 53 change the contact position.

(5) The rotating lever 55 of the brake device 50 is arranged such that the contact position between the portion on the axial direction I side in the inner peripheral surface of the insertion hole 53A of the output shaft 53 and the roller 58 of the rotating lever 55 changes within the range from the position on the axial direction I side with respect to the rotation center P1 of the rotating lever 55 to the position on the axial direction H side with respect to the rotation center P1 of the rotating lever 55. Here, the contact position between the roller 58 of the rotating lever 55 and the inner peripheral surface of the insertion hole 53A of the output shaft 53 varies in the vehicle front-rear direction according to the rotational position of the rotating lever 55. Specifically, as shown in fig. 2, when the roller 58 of the rotating lever 55 is positioned on the axial direction I side of the rotation center P1 of the rotating lever 55, the contact position between the roller 58 of the rotating lever 55 and the inner peripheral surface of the insertion hole 53A of the output shaft 53 moves to the vehicle front-rear direction J side as the rotating lever 55 rotates in one direction, i.e., clockwise in fig. 2. Further, when the roller 58 of the rotating lever 55 is positioned on the axial direction H side of the rotation center P1 of the rotating lever 55, the contact position between the roller 58 of the rotating lever 55 and the inner peripheral surface of the insertion hole 53A of the output shaft 53 moves to the vehicle front-rear direction K side as the rotating lever 55 rotates clockwise. When the rotating lever 55 is rotated clockwise in this way, the contact position between the roller 58 of the rotating lever 55 and the inner peripheral surface of the insertion hole 53A of the output shaft 53 moves in the vehicle front-rear direction J and then moves in the vehicle front-rear direction K. Thus, even if the contact range between the roller 58 of the rotating lever 55 and the inner peripheral surface of the insertion hole 53A of the output shaft 53 is the same, the rotation range of the rotating lever 55 can be increased compared to, for example, a configuration in which the contact position between the roller 58 of the rotating lever 55 and the inner peripheral surface of the insertion hole 53A of the output shaft 53 is changed only at the position on the axial direction H side of the rotation center P1 of the rotating lever 55.

(6) In the brake device 50, when the 1 st piston 52 and the output shaft 53 move in the axial direction H, the inner circumferential surface of the insertion hole 53A of the output shaft 53 on the axial direction I side comes into contact with the roller 58 of the rotating rod 55, and the rotating rod 55 rotates clockwise. When the 1 st piston 52 and the output shaft 53 move in the axial direction I, the inner circumferential surface of the insertion hole 53A of the output shaft 53 on the axial direction H side comes into contact with the roller 58 of the rotating rod 55, and the rotating rod 55 rotates counterclockwise. Thus, the rotation of the rotating lever 55 in both directions can be achieved by the linear motion of the output shaft 53.

(7) A distance L1 from the rotation center P1 of the rotating lever 55 to the coupling center P2 between the rotating arm 60 and the rotating lever 55 is shorter than the shortest distance from the rotation center P1 of the rotating lever 55 to the contact position between the output shaft 53 and the roller 58 of the rotating lever 55. Therefore, the force acting on the rotating arm 60A from the rotating lever 55 in the tangential direction of the rotating arm 60A is larger than the force acting on the rotating lever 55 from the output shaft 53 in the tangential direction of the rotating lever 55. In this way, since the force acting on the rotating lever 55 from the output shaft 53 can be input to the rotating arm 60A after being increased, the force acting on the mounting portion 65 and the brake pad 86 from the distal end portion of the rotating arm 60A in the tangential direction of the rotating arm 60A increases. Thus, the mounting portion 65 and the brake block 86 coupled to the pivot arm 60A are brought into contact with the end surface of the disk 44 with corresponding forces, and a braking force equal to or greater than a predetermined value can be secured against the disk 44.

(8) In the brake device 50, when the compressed air is not introduced from the air supply source 46 into the internal space of the 1 st cylinder 51 and the internal space of the 2 nd cylinder 81, the driving force from the 1 st piston 52 and the output shaft 53 due to the air pressure is not transmitted to the rotating rod 55. Even when the driving force from the 1 st piston 52 and the output shaft 53 is not transmitted to the rotating rod 55 due to the air pressure in this manner, the 2 nd piston 82 and the driving shaft 83 are linearly moved in the axial direction H by the pressing force of the 2 nd spring 84. And, the driving force from the 2 nd piston 82 and the driving shaft 83 caused by the 2 nd spring 84 is transmitted to the rotating rod 55 via the 1 st piston 52 and the output shaft 53, and the rotating rod 55 is rotated by the driving force from the 2 nd piston 82 and the driving shaft 83 caused by the 2 nd spring 84. Therefore, in the braking device 50, the torque fluctuation of the rotating rod 55 at the time of rotating by the driving force from the 2 nd piston 82 and the driving shaft 83 due to the 2 nd spring 84 can be suppressed.

This embodiment can be modified as follows. This embodiment and the following modifications can be combined and implemented within a range not technically contradictory to each other.

In the above embodiment, the range in which the contact position between the output shaft 53 and the roller 58 of the rotating lever 55 is changed can be changed. For example, the contact position between the portion of the inner peripheral surface of the insertion hole 53A of the output shaft 53 on the axial direction I side and the roller 58 of the rotating lever 55 may be changed only on the axial direction I side from the rotation center P1 of the rotating lever 55 or only on the axial direction H side from the rotation center P1 of the rotating lever 55.

In the above embodiment, the contact structure between the rotating lever 55 and the output shaft 53 can be changed. For example, the rotating rod 55 may be provided with a polygonal columnar rotating body instead of the roller 58 having a substantially cylindrical shape. In this configuration, if the polygonal columnar rotator of the rotating lever 55 is rotatable, the resistance when the contact position of the output shaft 53 and the rotating lever 55 is changed can be reduced by the rotation of the rotator.

For example, the rotating rod 55 may be provided with a spherical rotating body. In this configuration, too, the spherical rotating body of the rotating lever 55 may be rotated. The spherical rotating body also functions as a curved surface portion that is in point contact with the inner peripheral surface of the insertion hole 53A of the output shaft 53.

For example, the roller 58 of the rotating lever 55 may be omitted, and the lever main body 57 of the rotating lever 55 may be brought into contact with the inner peripheral surface of the insertion hole 53A of the output shaft 53. In this configuration, the lever main body 57 of the rotating lever 55 slides with respect to the inner peripheral surface of the insertion hole 53A of the output shaft 53, so that the rotating lever 55 can be rotated while changing the contact position. In this configuration, the distal end portion of the lever main body 57 of the rotating lever 55 can function as a curved surface portion having a curved surface shape, or the inner peripheral surfaces of the lever main body 57 of the rotating lever 55 and the insertion hole 53A of the output shaft 53 can be coated to reduce the sliding resistance of both.

Alternatively, the roller 58 of the rotating rod 55 may be omitted, and the output shaft 53 may be provided with a roller. Further, the lever main body 57 of the rotating lever 55 may be brought into contact with a roller provided at the tip end portion of the output shaft 53.

In the above embodiment, the output shaft 53 rotates the rotating rod 55 in both directions, but the output shaft 53 may rotate the rotating rod 55 in only one direction. For example, the rotating lever 55 is configured such that the roller 58 of the rotating lever 55 is in surface contact with the tip end of the output shaft 53. Further, a spring for pressing the roller 58 of the rotating lever 55 toward the distal end surface side of the output shaft 53 is attached to a position closer to the axial direction H side than the roller 58 of the rotating lever 55. In this configuration, when the output shaft 53 moves in the axial direction H, the output shaft 53 moves the roller 58 of the rotating lever 55 in the axial direction H against the pressing force of the spring, and the rotating lever 55 rotates clockwise. On the other hand, when the output shaft 53 moves in the axial direction I, the roller 58 of the rotating lever 55 moves in the axial direction I by the pressing force of the spring, and the rotating lever 55 rotates counterclockwise. In this configuration, the insertion hole 53A of the output shaft 53 may be omitted.

In the above embodiment, the distance L1 from the rotation center P1 of the rotation lever 55 to the coupling center P2 between the rotation arm 60 and the rotation lever 55 can be changed. For example, the distance L1 from the rotation center P1 of the rotating lever 55 to the coupling center P2 between the rotating arm 60 and the rotating lever 55 may also be longer than the shortest distance from the rotation center P1 of the rotating lever 55 to the contact position between the output shaft 53 and the roller 58 of the rotating lever 55. In this configuration, when the force acting from the output shaft 53 to the roller 58 of the rotating lever 55 is sufficiently large, a certain braking force or more can be ensured for the disk 44.

In the above embodiment, the configuration of the 1 st piston 52 can be changed. For example, the guide portion 52B need not extend from the entire periphery of the partition plate 52A, but may extend from a part of the outer edge of the partition plate 52A.

For example, the guide portion 52B of the 1 st piston 52 may be omitted. In this configuration, the 1 st piston 52 can be prevented from wobbling inside the 1 st cylinder 51 to some extent by the contact between the outer edge of the partition plate 52A of the 1 st piston 52 and the inner circumferential surface of the 1 st cylinder 51.

In the above embodiment, the connection structure from the rotating lever 55 to the brake block 86 can be changed. For example, another member may be interposed between the rotation arm 60A and the mounting portion 65.

The present disclosure includes the following examples. Reference numerals for some constituent elements of the illustrated embodiments are used in the following examples, not for limiting but for understanding. Some of the items described in the following embodiments may be omitted, and some of the items described in the embodiments may be selected or some of the items described in the embodiments may be extracted and combined.

[ example 1]

In some embodiments, the braking device 50 may be directed to a braking device 50 in which the friction material 86 is brought into contact with the member to be braked 44 to generate a frictional braking force when the piston 52 linearly moves in the axial direction of the cylinder 51,

the braking device 50 includes:

an output shaft 53 that moves linearly together with the piston 52;

and a rotating lever 55 configured to rotate about a rotation center P1 in accordance with the movement of the output shaft 53 to change the relative position between the friction member 86 and the braked member 44,

the braking device 50 may include the connecting element 58, and the connecting element 58 may be a connecting element 58 that connects the output shaft 53 and the rotating lever 55 to be movable relative to each other, and may be non-rigidly connected to one or both of the output shaft 53 and the rotating lever 55.

[ example 2]

In several embodiments, the connecting element 58 may be connected to one or both of the output shaft 53 and the rotating rod 55 with mechanical play relative to one or both of the output shaft 53 and the rotating rod 55.

[ example 3]

In some embodiments, the connection element 58 may be configured such that, when the output shaft 53 moves in the axial direction of the cylinder 51, the connection element 58 moves in a direction intersecting with or orthogonal to the axial direction of the cylinder 51.

[ example 4]

In some embodiments, the connecting element 58 may be configured such that the connecting element 58 is in frictional contact with one or both of the output shaft 53 and the rotating lever 55 in accordance with the movement of the output shaft 53.

[ example 5]

In some embodiments, the connecting element 58 may be or include a roller having a curved outer peripheral surface in contact with one of the output shaft 53 and the rotating rod 55.

[ example 6]

In some embodiments, the curved outer circumferential surface of the roller may have a certain radius of curvature.

[ example 7]

In several embodiments, it is also possible that the rotating lever 55 comprises a lever main body 57 protruding in a radial direction with respect to the rotation center P1,

the connection element 58 may be attached to the tip of the lever main body 57 or the vicinity of the tip of the lever main body 57 so as to be rotatable with respect to the lever main body 57.