JP2011144826A - Brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stabilize the behavior of a piston that is a driving member in a brake device. <P>SOLUTION: An inclined surface portion 50 is formed in a leg portion 32 of the piston which moves forward and backward in Z direction. An output roller unit 60 which contacts with the inclined surface portion 50 is provided on a backward side end portion 43 of a push rod which moves forward and backward in Y direction by the forward and backward movement of the leg portion 32. The output roller unit 60 includes a plurality of rollers 62. The plurality of rollers 62 are arranged in a direction along the inclination of the inclined surface portion 50, and provided on a frame 64 so that the rotating axes thereof are parallel to X direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a brake device that applies a braking force to a braking target such as a wheel.

  As a brake device that applies a braking force to a wheel, for example, there is one described in Patent Document 1 below.

  The brake device described in Patent Document 1 is a piston that moves forward and backward by receiving air pressure as a driving force, a push bar that moves forward and backward by the forward and backward movement of the piston, and a movement that contacts the object to be braked by the forward and backward movement of the push bar. A brake element, two output rollers provided on the push rod, and two reaction force receiving rollers provided on a housing that houses a piston, a push rod, and the like are provided.

  The piston has two leg portions extending in the forward / backward movement direction of the piston, and an inclined surface inclined with respect to the forward / backward movement direction is formed on the leg portion. The outer peripheral surface of the output roller provided in the push rod is in contact with each inclined surface. When the piston moves, the push rod receives a pressing force from the output roller in contact with the inclined surface of the piston and moves the brake. The piston receives a reaction force from the push rod side by applying a pushing force to the push rod via the output roller. In order to prevent the inclined surface of the piston from escaping away from the output roller due to this reaction force, the housing is provided with a reaction force receiving roller in contact with the reaction force transmission surface on the opposite side of each inclined surface of the piston. Yes. That is, the tip end side of the leg portion of the piston is sandwiched between the output roller and the reaction force receiving roller in the advance / retreat direction of the push rod.

US Pat. No. 6,397,986 FIG. 1 and FIG.

  However, in the technique described in Patent Document 1, the inclined surface of the piston that is the driving member and the output roller provided on the push rod that is the driven member are in line contact at one place, and the reaction force transmission surface of the piston Since both the reaction force receiving roller and the reaction force receiving line are in line contact at one point, the tip end side of the leg portion on which the inclined surface and the reaction force transmitting surface are formed easily tilts and twists, and its behavior is difficult to stabilize. . For this reason, an inclined surface or a reaction force transmission surface formed on the distal end side of the leg portion may come into contact with the roller. Further, in the technique described in Patent Document 1, the entire circumference of the roller may not evenly contact the inclined surface or the reaction force transmission surface, and the roller may wear unevenly.

  For this reason, the technique described in Patent Document 1 has a problem that the pressing force of the piston that is the driving member cannot be efficiently transmitted to the pressing rod that is the driven member.

  Therefore, the present invention pays attention to such problems of the prior art, and provides a brake device that can stabilize the behavior of the drive member and efficiently transmit the pressing force of the drive member to the driven member. Objective.

The invention relating to the first brake device for solving the above problems is as follows:
A drive member that moves forward and backward according to the driving force, a driven member that moves forward and backward in a direction different from the direction of the forward and backward movement due to the forward and backward movement of the drive member, and a moving member that moves due to the forward and backward movement of the driven member and contacts the braking target A brake device comprising:
One of the driving member and the driven member is in contact with the other member, and the inclined surface portion that moves the driven member forward and backward in a direction different from the forward and backward movement direction by the forward and backward movement of the driving member. The other member is in contact with a plurality of locations in the inclined direction in which the inclined surface portion is inclined and a plurality of locations in a direction perpendicular to the inclined direction within the plane of the inclined surface portion. It has the contact part which enables two-dimensional contact, It is characterized by the above-mentioned.

  Since the drive member and the driven member are in two-dimensional contact with each other during the forward / backward movement of the drive member, the drive member can be prevented from being tilted or twisted. Therefore, the behavior of the driving member is stabilized, and the pressing force of the driving member can be efficiently transmitted to the driven member.

  Here, the contact portion may include a plurality of small contact portions that are in two-dimensional contact with the inclined surface portion. In this case, the small contact portion of the other member is a relative movement of the inclined surface portion with respect to the small contact portion in a state where the small contact is in contact with the inclined surface portion of the one member. It is preferably a rotating body that rotates. Furthermore, it is more preferable that the rotating body is a roller extending in parallel with the inclined surface portion. As described above, when the contact portion is configured to include a plurality of rotating bodies, the inclined surface portion is in rolling contact, so that the frictional force acting between the contact portion and the inclined surface portion can be reduced. .

  Further, when the contact portion includes the plurality of rotating bodies, the contact portion further includes a frame for restraining the plurality of rotating bodies so as not to change the mutual position of the plurality of rotating bodies. preferable. As described above, by constraining the rotating body with the frame to form a unit, a plurality of rotating bodies can be easily replaced during repair or the like.

  In addition, the outer peripheral lengths of the plurality of rotating bodies included in the contact portion are inclined in the range of the inclined surface portion facing the part in order to contact the part of the contact part. It is preferably shorter than the length. As described above, when the outer peripheral length of the rotating body is short, the rotating body basically performs one or more rotations in the process of the relative movement of the inclined surface portion with respect to the contact portion, so that uneven wear of the rotating body is minimized. be able to.

  Further, the inclined surface portion receives a force in one direction of a movement restriction direction perpendicular to a plane including the direction of the advance / retreat movement of the drive member and the direction of the advance / retreat movement of the driven member. A second regulating surface that receives a force in the other direction, and the contact portion is in two dimensions to contact the first regulating surface in two dimensions, and to the second regulating surface in two dimensions. It is preferable to have the 2nd corresponding part which contacts by.

  In the forward / backward movement process of the drive member, the first restriction surface of the inclined surface portion and the first corresponding surface of the contact portion are in contact with each other, and the second restriction surface of the inclined surface portion and the second corresponding surface of the contact portion are in contact with each other. Therefore, the movement of the inclined surface portion or the contact portion of the drive member in the movement restriction direction is restricted. Therefore, it is possible to prevent the inclined surface portion or the contact portion of the driving member from being inclined or twisted without separately providing a guide or the like that is in sliding contact with the driving member.

  Further, at least one of the contact portion and the inclined surface portion, and the surface in contact with the other is at least one of improved lubricity, improved hardness, and improved wear resistance. It is preferable that a surface treatment is applied.

  As described above, when the contact portion or the inclined surface portion is subjected to a surface treatment for improving lubricity, the frictional force acting between each roller and the contact surface can be reduced. In addition, even when the contact portion or the inclined surface portion is subjected to surface treatment for the purpose of improving hardness and wear resistance, the contact area can be prevented from increasing due to deformation and wear, and the positioning accuracy can be prevented from being lowered. The frictional force acting between each roller and its contact surface can be reduced.

  Also, one end of the advancing side end portion in the advancing direction of the driving member in the advancing / retreating direction and the retreating side end portion of the retreating side in the advancing / retreating direction of the driven member It is preferable that the inclined surface portion is provided in the portion and the contact portion is provided in the other end portion.

  As described above, when the contact portion or the inclined surface portion is provided at the retreat side end portion of the driven member, an output roller as a contact portion is provided at the intermediate portion of the push rod which is the follower member, and both ends of the push rod are supported. However, the distance between the two support portions can be shortened, and the length of the driven member can be shortened. Furthermore, since no output roller is provided in the intermediate part of the driven member, there is no need to provide output rollers on the left and right sides of the driven member for balancing, and the number of rollers as contact portions and the degree of freedom of arrangement are increased. Can do.

  Further, when the reaction force support portion that receives the reaction force acting on the drive member from the driven member is provided, each of the reaction force support member and the drive member has a contact portion that contacts each other, Of the contact portion of the reaction force support portion and the contact portion of the drive member, the contact portion of one member has a contact surface that extends in the direction of relative movement of the drive member with respect to the reaction force support member. Of the contact portion of the reaction force support portion and the contact portion of the drive member, the contact portion of the other member is within the contact surface of the one member and has a plurality of relative movement directions. It is preferable that the contact portion is a contact portion that enables two-dimensional contact that simultaneously contacts a portion and a plurality of locations in a direction perpendicular to the direction of the relative movement.

  Since the drive member and the reaction force support member are in two-dimensional contact with each other during the forward and backward movement of the drive member, the drive member can be prevented from being tilted or twisted. Therefore, the behavior of the driving member is stabilized, and the pressing force of the driving member can be efficiently transmitted to the driven member.

  Here, among the contact portion of the reaction force support member and the contact portion of the drive member, the contact portion of the other member has a plurality of rollers arranged in the direction of the relative movement. Is preferable. Thus, when one contact part has a some roller, since the contact between both contact parts turns into a rolling contact, the frictional force which acts between both contact parts can be reduced.

  In the present invention, since the drive member and the driven member are in two-dimensional contact during the forward and backward movement of the drive member, the drive member can be prevented from being tilted or twisted. Therefore, according to the present invention, the behavior of the driving member is stabilized, and the pressing force of the driving member can be efficiently transmitted to the driven member.

It is a principal part notched side view of the brake device in 1st embodiment which concerns on this invention. It is the II-II sectional view taken on the line in FIG. It is the III-III sectional view taken on the line in FIG. It is a perspective view of the inclined surface part and its contact part in 1st embodiment which concerns on this invention. It is a side view of the inclined surface part and its contact part in 1st embodiment which concerns on this invention. It is a perspective view of the inclined surface part and its contact part in the modification 1 of 1st embodiment which concerns on this invention. It is a perspective view of the inclined surface part in the modification 2 of 1st embodiment which concerns on this invention, and its contact part. It is sectional drawing of the inclined surface part in the modification 2 of 1st embodiment which concerns on this invention, and its contact part. It is a principal part notch top view of the brake device in the modification 3 of 1st embodiment which concerns on this invention. It is a principal part notched side view of the brake device in the modification 4 of 1st embodiment which concerns on this invention. It is a principal part notch plane of the brake device in the modification 5 of 1st embodiment which concerns on this invention. It is a principal part notched side view of the brake device in 2nd embodiment which concerns on this invention. It is the XIII-XIII sectional view taken on the line in FIG. It is explanatory drawing which shows the modification of the rotary body unit which concerns on this invention.

  Hereinafter, various embodiments of a brake device according to the present invention will be described with reference to the drawings.

"First embodiment"
First, a brake device as a first embodiment according to the present invention will be described with reference to FIGS.

  The brake device of this embodiment is a brake device for a railway vehicle. As shown in FIG. 1, the brake device is in contact with a tread surface S of a wheel to be braked and applies a braking force to the wheel, and a brake shoe 10 that is in a perspective direction with respect to the wheel. And a hanger 15 that movably supports the brake shoe 10.

  The drive unit 20 includes a piston (drive member) 30 that moves forward and backward according to a driving force generated by air pressure, a coil spring 29 that returns the piston 30 that has moved in the traveling direction to the original position shown in FIG. , A push rod (main body of the driven member) 40 that moves forward and backward with respect to the wheels, a pair of output roller units 60 (contact portions of the driven member) and a pair of guide rollers 69 (FIG. 3) provided on the push rod 40. The piston 30 includes a pair of reaction force receiving rollers 65 for receiving a reaction force against the pressing force that pushes the push rod 40, and a housing 21 that houses these.

  Here, in this embodiment, the advance / retreat direction of the push rod 40 is perpendicular to the advance / retreat direction of the piston 30. For the convenience of the following description, the advancing / retreating direction of the push rod 40 is the Y direction, the advancing / retreating direction of the piston 30 is the Z direction, and the direction perpendicular to the Y direction and the Z direction is the X direction. In this embodiment, the advancing / retreating direction of the push rod 40 is perpendicular to the advancing / retreating direction of the piston 30. However, if the advancing / retreating direction of the push rod 40 and the advancing / retreating direction of the piston 30 are different from each other, Good.

  The piston 30 includes a pressure receiving portion 31 that receives air pressure, and a leg portion 32 that extends from the pressure receiving portion 31 toward the advancing direction ((+) Z) of the advancing and retreating directions of the piston 30. The pressure receiving part 31 partitions the inside of the housing 21 and forms the air chamber 22 on the (−) Z side in the housing 21 with the pressure receiving part 31 as a reference. An O-ring, packing, and the like are provided on the outer periphery of the pressure receiving portion 31 in order to ensure the airtightness of the air chamber 22. An air inlet / outlet port 23 for the air chamber 22 is formed in the housing 21.

  One end of a coil spring 29 is attached to the pressure receiving portion 31 of the piston 30 and the (+) Z side surface that is the traveling direction side of the piston 30. The housing 21 is provided with a spring support plate 26 on the (+) Z side with respect to the pressure receiving portion 31 of the piston 30, and the other end of the coil spring 29 is attached to the spring support plate 26. It has been.

  A long side hole 42 penetrating in the X direction and long in the Z direction is formed in the traveling side end portion 41 which is the end portion on the traveling direction ((+) Y) side in the advancing and retreating direction of the push rod 40. In addition, an output roller unit 60 and a guide roller 69 (FIG. 3) are provided at a retreat-side end portion 43 that is an end portion on the retreat direction ((−) Y) side of the push rod 40. Further, a key groove 44 extending in the Y direction is provided on the retreat side ((−) Y side) of the push rod 40 and on the (+) Z side. The housing 21 is formed with a through-hole 27 through which the push rod 40 passes, and the sliding bearing 28 that supports the advance side ((+) Y side) of the push rod 40 in the Y-direction so as to be slidable in the Y-direction. Is provided. Also, a push rod guide key 81 that supports the key groove 44 of the push rod 40 so as to be slidable in the Y direction is provided in the housing 21.

  The leg portion 32 is inclined toward the advancing side ((+) Y side) of the push rod 40, that is, the output roller unit 60 side, with respect to the advancing / retreating direction (Z direction) of the piston 30, and toward the (−) Z side. Accordingly, an inclined surface portion 50 is formed toward the (+) Y side. The inclined surface portion 50 contacts the output roller unit 60. The inclined surface portion 50 includes a front contact inclined surface 51 that comes into contact with the output roller unit 60 in the process of moving the piston 30 in the traveling direction ((+) Z), and a rear contact slope that comes into contact with the output roller unit 60 next. There is a surface 52. The front contact inclined surface 51 and the rear contact inclined surface 52 have different inclination angles. Specifically, the angle with respect to the retreating direction ((−) Z direction) of the piston 30 is earlier than the rear contact inclined surface 52. The inclined surface 51 is larger, in other words, the angle of the push rod 40 with respect to the traveling direction (the (+) Y direction) is smaller in the front contact inclined surface 51 than in the rear contact inclined surface 52.

  In the leg portion 32, a reaction force transmission surface 55 substantially parallel to the advancing / retreating direction (Z direction) of the piston 30 is formed on the retracting side ((−) Y side) of the push rod 40. The reaction force transmission surface 55 comes into contact with the outer peripheral surface of the reaction force receiving roller 65. The reaction force receiving roller 65 is rotatably provided on a reaction force support base (reaction force support member) 82 fixed to the housing 21.

  The reaction force receiving roller 65 and the above-described guide roller 69 are all rolling bearings. Each of the rollers 65.69, which are rolling bearings, is fixed to a rotating shaft whose inner ring extends in the X direction, and cannot move in the X direction.

  A bracket 70 is fixed to the outer surface of the housing 21 on the (+) Y side. Rotating shafts 15 a and 15 b extending in the X direction are provided at both ends of the hanger 15 that supports the brake shoe 10. A rotary shaft 15a at one end (hereinafter referred to as a base end) of the hanger 15 is rotatably provided on the bracket 70, and a rotary shaft 15b at the other end (hereinafter referred to as a swinging end). Is inserted into a long hole 42 formed in the through hole 11 of the brake shoe 10 and the advancing side end 41 of the push rod 40. The bracket 70 and the hanger 15 are connected by a spring (not shown). This spring has a role of urging the brake shoe 10 engaged with the swinging end portion of the hanger 15 in a direction away from the wheel.

  As shown in FIGS. 4 and 5, the output roller unit 60 includes a front contact roller unit 61 a that contacts the front contact inclined surface 51 of the inclined surface portion 50 and a rear contact roller that contacts the rear contact inclined surface 52 of the inclined surface portion 50. And a unit 61b.

  Each roller unit 61a, 61b has a plurality of rollers (small contact portions) 62, 62,... And a frame 64 that holds the plurality of rollers 62, 62,. The rotation shafts 63 of the plurality of rollers 62 are all parallel to the X direction. Further, the plurality of roller rotation shafts 63a of the front contact roller unit 61a are attached to the frame 64 of the front contact roller unit 61a so as to be aligned in parallel with the front contact inclined surface 51 of the inclined surface portion 50 spreading in the X direction. . Further, the plurality of roller rotating shafts 63b of the rear contact roller unit 61b are attached to the frame 64 of the rear contact roller unit 61b so as to be aligned in parallel with the rear contact inclined surface 52 of the inclined surface portion 50 spreading in the X direction. .

  The frame 64 of each roller unit 61a, 61b is detachably fixed to the retreating side end 43 of the push rod 40 using, for example, screws. For this reason, when the plurality of rollers 62 of each of the roller units 61a and 61b are worn and it becomes necessary to replace the plurality of rollers, they can be replaced as a unit.

  As shown in FIGS. 2 and 3, the retreat side end portions 43, 43 of the push rod 40 exist on the (±) X direction side with respect to the central axis Cr of the push rod 40. As described above, the output roller units 60 and 60 are provided at the retreat side end portions 43 and 43, respectively. Further, a guide roller 69 is provided on the (+) X side of the (+) X side output roller unit 60, and a guide roller is also provided on the (−) X side of the (−) X side output roller unit 60. 69 is provided. These guide rollers 69 and 69 are rotatable around a rotation axis extending in the X direction provided at the retreat side end portions 43 and 43 of the push rod 40.

  Guide rails 89 and 89 are fixed to the housing 21 so as to extend in the advancing and retreating direction (Y direction) of the push rod 40 and to which the guide rollers 69 and 69 roll. Further, reaction force receiving rollers 65 and 65 are provided on the (±) X direction side of the reaction force support base 82 fixed to the housing 21 and at positions facing the output roller units 60 and 60. Yes. These two reaction force receiving rollers 65 and 65 are also rotatable around a rotation axis extending in the X direction.

  The leg portions 32 and 32 of the piston 30 are also provided in the same manner as the output roller units 60 and 60 and the reaction force receiving rollers 65 and 65. The two leg portions 32 and 32 are arranged in the X direction, and the inclined surface portions 50 and 50 of the two leg portions 32 and 32 are in contact with the two output roller units 60 and 60 arranged in the X direction. The reaction force transmission surfaces 55 and 55 of the two leg portions 32 and 32 are in contact with two reaction force receiving rollers 65 and 65 arranged in the X direction.

  Of the outer peripheral surface of each roller of the present embodiment and the contact surface with which the outer peripheral surface of each roller contacts, at least one of the surfaces is improved lubricity, improved hardness, and improved wear resistance. Surface treatment for at least one purpose is performed. Specifically, the surface treatment for improving lubricity includes a coating treatment with high Mo-based lubricity, a coating treatment with a Mo-based lubricant, and the like. In addition, examples of the surface treatment for improving the hardness include induction hardening treatment and vacuum hardening treatment. In these induction hardening treatments and vacuum hardening treatments, the object is thermally deformed. Therefore, it is preferable that the object is machined after the hardening treatment so that the dimensions of the object become the target dimensions. In addition, as a surface treatment for improving wear resistance, there is a TiN-based coating treatment.

  As described above, when surface treatment for improving lubricity is performed on the outer peripheral surface of each roller or its contact surface, an increase in frictional force between each roller and its contact surface can be prevented. . In addition, even when the outer peripheral surface of each roller or its contact surface is subjected to surface treatment for the purpose of improving hardness and wear resistance, it prevents an increase in contact area due to deformation or wear, and a decrease in positioning accuracy. As a result, an increase in frictional force between each roller and its contact surface can be prevented.

  One of the outer peripheral surface of each roller and its contact surface was subjected to a surface treatment for the purpose of improving lubricity, improving hardness, and improving wear resistance. In this case, the other surface may be subjected to the same surface treatment, but may be subjected to a surface treatment for other purposes. Also in the embodiments and modifications described below, the same surface treatment as described above is preferably performed on the outer peripheral surface of each roller and the contact surface with which the outer peripheral surface of each roller contacts.

  Next, the operation of the brake device of this embodiment will be described.

  Here, it is assumed that the brake shoe 10 is located closest to the (−) Y side, that is, in the retracted position, as shown in FIG. At this time, the piston 30 is also located at the most retracted position on the (−) Z side, and the volume of the air chamber 22 is minimized. The push rod 40 is also located at the most retracted position on the (−) Y side, and the output roller unit 60 provided on the push rod 40 contacts the tip contact inclined surface 51 of the inclined surface portion 50 of the piston 30. Yes.

  When a braking force is applied to the wheel by the brake shoe 10, air flows into the air chamber 22 of the housing 21 from the air inlet / outlet port 23 of the housing 21. As a result, the pressure receiving portion 31 of the piston 30 receives this air pressure, and the piston 30 moves in the traveling direction ((+) Z side) while the coil spring 29 is contracted as shown in FIG. spread.

  When the piston 30 moves to the (+) Z side, the plurality of rollers 62, 62,... Of the output roller unit 60 that are in contact with the inclined surface portion 50 of the piston 30 are rotated and the inclined surface 50 is moved from the inclined surface 50 to the inclined surface. A pressing force in a direction perpendicular to 50, in other words, a pressing force having a component force in the (+) Y direction is received. Due to the component force in the (+) Y direction, the leg portion 32 of the piston 30 receives a reaction force against the component force in the (+) Y direction from the output roller unit 60 and tries to escape to the (−) Y side. Therefore, in this embodiment, a reaction force transmission surface 55 is formed on the opposite side of the inclined surface 50 of the leg portion 32, and the reaction force receiving roller 65 is brought into contact with the reaction force transmission surface 55, so that the output roller unit 60. The reaction force from the plurality of rollers 62, 62,... Is received to prevent the leg 32 from escaping to the (−) Y side.

  The push rod 40 to which the output roller unit 60 is attached receives a pressing force from the output roller unit 60 and is guided by the push rod guide key 81 and the guide rail 89 in the direction of travel of the push rod 40 ((+) Y side). Moving. The push rod guide key 81 supports the (+) Z direction force and the (±) X direction force received by the push rod 40 from the piston 30, and the guide rail 89 guides the guide roller from the piston 30 through the push rod 40. The force in the (+) Z direction received by 69 and the moment force around the central axis of the push bar 40 parallel to the Y direction are supported.

  As the push rod 40 moves to the (+) Y side, the rotation shaft 15b of the swing end portion of the hanger 15 in the elongated hole 42 of the advancing side end portion 41 of the push rod 40 is provided on the bracket 70. While contracting a spring (not shown), the spring rotates around the base end of the hanger 15 and moves in a direction approaching the wheel. At this time, the rotating shaft 15b of the swing end of the hanger 15 does not move relative to the Y direction in the elongated hole 42 of the advancing side end 41 of the push rod 40, but moves relative to the Z direction. The movement of the swing end of the hanger 15 causes the brake shoe 10 engaged with the rotating shaft 15b of the swing end of the hanger 15 to move toward the (+) Y side approaching the wheel, and the tread of the wheel. In contact with S, braking force is applied to the wheels.

  The plurality of rollers 62, 62,... Of the output roller unit 60 are moved to the front contact inclined surface 51 before the rear contact inclined surface 52 of the piston 30 in the process of moving the piston 30 in the traveling direction ((+) Z side). Contact. As described above, since the angle of the push rod 40 with respect to the traveling direction of the push rod 40 (the (+) Y direction) is smaller than that of the rear contact tilt surface 52, the front contact inclined surface 51 has a constant movement amount of the piston 30. The push rod 40 can be moved larger than the rear contact inclined surface 52. At this time, the roller 62 of the output roller unit 60 that is in contact with the tip contact inclined surface 51 is the roller 62 of the tip contact roller unit 61a.

  The plurality of rollers 62, 62,... Of the output roller unit 60 subsequently contact the rear contact inclined surface 52 of the piston 30. Since the angle of the rear contact inclined surface 52 with respect to the traveling direction of the push rod 40 (the (+) Y direction) is larger than that of the front contact inclined surface 51, the front contact inclined surface 51 with respect to a certain amount of movement of the piston 30 Although the push rod 40 is not moved greatly, the component force in the (+) Y direction received from the tip contact inclined surface 52 is increased, and the pressing force in the (+) Y direction against the push rod 40 can be increased. At this time, the roller 62 of the output roller unit 60 that contacts the rear contact inclined surface 52 is the roller 62 of the rear contact roller unit 61b.

  Therefore, the push rod 40 moves greatly in the first half of the movement, and the pressing force against the brake shoe 10 increases in the second half of the movement.

  Incidentally, two or more rollers 62 among the plurality of rollers 62, 62,... Of the output roller unit 60 are simultaneously in line contact with the inclined surface portion 50 as shown in FIGS. For this reason, the output roller unit (contact portion) 60 includes the inclined surface portion 50, a plurality of portions in the inclined direction in which the inclined surface portion 50 is inclined, and perpendicular to the inclined direction. It will contact several places in the direction at the same time. That is, the output roller unit (contact portion) 60 is in two-dimensional contact with the inclined surface portion 50. Therefore, in this embodiment, during the movement of the piston in the Z direction, the leg portion 32 of the piston is inclined with respect to the X axis extending in the X direction and the Y axis extending in the Y direction, or the Z axis extending in the Z direction. It is possible to suppress twisting around.

  In the following, similarly to the above, two-dimensional contact means that the roller unit is in contact with a plurality of locations in two different directions within the contact surface in contact with the roller unit.

  Further, as shown in FIG. 5, the outer peripheral length (πd) of each roller 62 is much shorter than the length of the front contact inclined surface 51 in the inclined direction and the length of the rear contact inclined surface 52 in the inclined direction. Therefore, the plurality of rollers 62, 62,... Basically rotate one or more times during the movement of the piston, so that only a part of the outer periphery of the roller 62 comes into contact with the inclined surface portion 50. The uneven wear can be minimized.

  In the present embodiment, more precisely, the outer peripheral length (πd) of each roller 62 is a state in which the output roller unit 60 is in contact with the tip contact inclined surface 51 of the inclined surface portion 50 as shown in FIG. This is much shorter than the moving path length L1 of the output roller unit 60 with respect to the tip contact inclined surface 51. Further, the outer peripheral length (πd) of each roller 62 is the movement of the output roller unit 60 with respect to the rear contact inclined surface 52 in a state where the output roller unit 60 is in contact with the rear contact inclined surface 52 of the inclined surface portion 50. It is much shorter than the path length L2. For this reason, most of the plurality of rollers 62, 62,... Reliably perform one or more revolutions in the course of movement of the piston, so that uneven wear of the roller 62 can be minimized.

  When releasing the braking force applied to the wheels, the air in the air chamber 22 of the housing 21 is caused to flow out from the air inlet / outlet port 23 of the housing 21. Then, the coil spring 29 that has been contracted by the air pressure extends, and the piston 30 moves in the retreat direction ((−) Z side) and returns to the original retracted position, that is, the position shown in FIG. As a result, since the push rod 40 does not receive the force in the Y direction from the piston 30, the contracted spring (not shown) provided in the bracket 70 is extended, and the brake shoe 10, the hanger 15 and the push rod 40 are , Move backward ((−) Y side), and return to the original retracted position, that is, the position shown in FIG.

  As described above, in this embodiment, since the output roller unit 60 is interposed when transmitting the pressing force of the piston 30 to the push rod 40, the friction between the piston 30 and the push rod 40 is not sliding friction. It becomes rolling friction, and the pressing force of the piston 30 can be efficiently transmitted to the push rod 40. Further, in this embodiment, since at least one of the outer peripheral surface of each roller and its contact surface is subjected to surface treatment, the frictional force between the outer peripheral surface of each roller and its contact surface is reduced. Also from this point, the pressing force of the piston 30 can be transmitted to the push rod 40 more efficiently.

  Further, in the present embodiment, as described above, it is possible to prevent the leg portion 32 of the piston 30 from being tilted or twisted in the process of moving the piston 30 in the Z direction, and to contact the inclined surface portion 50. Since uneven wear of the roller 32 as an object can be prevented, the pressing force of the piston 30 can be transmitted to the push rod 40 more efficiently also from this point.

  In this embodiment, since the output roller unit 60 is provided at the retreating side end portion 43 of the push rod 40, the output roller unit 60 is provided at the intermediate portion of the push rod and the push rod 40 is supported rather than supporting both ends of the push rod. The distance between the two support portions, that is, the distance between the sliding bearing 28 and the push rod guide key 81 can be shortened by at least the outer diameter of the output roller. As a result, the length of the push rod 40 can be shortened, and the brake device can be reduced in size and weight.

  Further, in this embodiment, since the output roller unit 60 is provided at the retreating side end portion 43 of the push rod 40, the number and arrangement of various rollers can be more freely set than when the output rollers are provided on both sides of the intermediate portion of the push rod. The degree can be increased. That is, in this embodiment, the output roller units 60 and 60 are provided in the (±) X direction of the push rod 40, and the reaction force receiving rollers 65 and 65 are provided so as to face the output roller units 60 and 60, respectively. However, the roller units 60 and the rollers 65 may not have the quantities and arrangements described above. Therefore, a modified example in which the quantity and arrangement of each roller are changed with respect to the present embodiment will be described in modified example 5 described later.

"Variation 1 of the first embodiment"
Next, Modification 1 of the first embodiment described above will be described with reference to FIG.

  In the first modification, the contact portion 60c that contacts the inclined surface portion 50 includes a front contact surface 61c and a rear contact roller unit 61b. That is, in the first modification, a front contact surface 61c is provided instead of the front contact roller unit 61a in the first embodiment.

  The retraction side end portion 43c of the push rod is provided with the aforementioned front contact surface 61c and a rear contact roller unit 61b. The front contact surface 61c is formed in parallel to the front contact inclined surface 51 of the inclined surface portion 50 at a position where the inclined surface portion 50 of the piston can come into contact with the front contact roller unit 61b in the course of movement of the piston.

  In the first modification, in the course of movement of the piston, the inclined surface portion 50 of the piston first comes into surface contact with the front contact surface 61c of the contact portion 60c, and then the rear contact roller unit of the contact portion 60c. Line contact is made simultaneously with two or more rollers 62. Accordingly, in this embodiment as well, as in the first embodiment, the inclined surface portion 50 and the contact portion 60c come into two-dimensional contact during the movement of the piston, so that the leg portion 32 of the piston is prevented from being tilted or twisted. be able to.

  Therefore, also in the first modification, as in the first embodiment, it is possible to suppress the deterioration of the transmission efficiency of the pressing force from the piston to the push rod due to the inclination or twist of the leg portion 32 of the piston. Here, only a part of the contact portion 60c is formed by the contact surface 61c, but the entire contact portion 60c may be formed by a flat contact surface. However, since the inclined surface portion 50 of the piston and the contact surface of the contact portion 60c are in sliding contact and the frictional force acting between them is large, the force acting between the inclined surface portion 50 and the contact portion increases. The portion that contacts the inclined surface 52 is preferably configured by the roller unit 61b as in the first modification.

“Variation 2 of the first embodiment”
Next, Modification 2 of the first embodiment will be described with reference to FIGS. 7 and 8.

  In the second modification, the shape of the inclined surface portion 50 of the first embodiment and the configuration of the output roller unit 60 are changed. In addition, this modification 2 is the same as that of 1st embodiment fundamentally except the above change.

  As shown in FIG. 8, the inclined surface portion 50d of the second modification has a movement restricting direction perpendicular to the YZ plane including the Y direction and the Z direction, that is, a (+) X direction component in the X direction. It has first restricting surfaces 53d and 53e that receive a force, and second restricting surfaces 54d and 54e that receive a force having a (−) X direction component. The first restricting surfaces 53d and 53e are located on the (−) X side in the inclined surface portion 50d, and are inclined in the moving direction of the push rod 40 ((+) Y direction) toward the (+) X side. ing. Further, the second regulating surfaces 54d and 54e are located on the (+) X side in the inclined surface portion 50d, and incline toward the retreat direction of the push rod (the (−) Y direction) toward the (+) X side. ing. Accordingly, the inclined surface portion 50d has a central portion in the X direction protruding toward the (+) Y side.

  In addition, as shown in FIG. 7, the inclined surface portion 50d includes the contact inclined surface 51d and the rear contact inclined surface 52e described in the first embodiment, and each of them includes the first restricting surface 53d or 53e and the second restricting surface 54d. Or 54e.

  Similarly to the first embodiment, the output roller unit 60d of Modification 2 includes a front contact roller unit 61d and a rear contact roller unit 61e. However, the front contact roller unit 61d of the second modification includes a first corresponding roller unit 63d that contacts the first restricting surface 53d and a second corresponding roller unit 64d that contacts the second restricting surface 54d. The rear contact roller unit 61e of Example 2 also includes a first corresponding roller unit 63e that contacts the first restriction surface 53e and a second corresponding roller unit 64e that contacts the second restriction surface 54e. That is, the output roller unit 60d of the second modification includes the first corresponding roller unit 63d and the second corresponding roller unit 64d of the front contact roller unit 61d, the first corresponding roller unit 63e and the second corresponding roller of the rear contact roller unit 61e. A total of four roller units 63d, 63d, 64d, and 64e of the unit 63e are provided.

  Each of the four roller units 63d, 63d, 64d, 64e includes a plurality of rollers, a plurality of rollers (small contact portions) 62, 62,..., And a frame 64 that holds the plurality of rollers 62, 62,. have.

  As shown in FIG. 8, the rollers 62 of the first corresponding roller units 63d and 63e are arranged at positions where they can come into contact with the first regulating surfaces 53d and 53e, and the rotation shaft 63s thereof is parallel to the first regulating surfaces 53d and 53e. It is provided to be. The rollers 62 of the second corresponding roller units 64d and 64e are provided at positions where they can come into contact with the second restricting surfaces 54d and 54e so that their rotation shafts 64s are parallel to the second restricting surfaces 54d and 54e. Yes. Therefore, the shape in which the roller rotation shaft 63s of the first corresponding roller units 63d and 63e and the roller rotation shaft 64s of the second corresponding roller units 64d and 64e are connected to each other corresponds to the shape of the inclined surface portion 50d, and the center in the X direction. The part protrudes to the (+) Y side.

  Incidentally, the movement of the piston leg 32d to the (−) Y side is restricted by the reaction force receiving roller 65 (FIG. 1) during the movement of the piston in the Z direction. Further, the inclined surface portion 50d of the leg portion 32d is formed with first restricting surfaces 53d and 53e and second restricting surfaces 54d and 54e extending in the direction including the component in the Y direction, and the restricting surfaces 53d, 53e, 54d and 54e are in contact with the rollers 62 of the corresponding roller units 63d, 63e, 64d and 64e of the output roller unit 60d. Therefore, the leg portion 32d is restricted from moving in the X direction perpendicular to the Y direction by the corresponding roller units 63d, 63e, 64d, and 64e of the output roller unit 60d during the movement of the piston in the Z direction. become.

  That is, the movement of the piston leg portion 32d toward the (−) Y side is restricted by the reaction force receiving roller 65 (FIG. 1), and the movement in the X direction is restricted by the output roller unit 60d. Therefore, in this second modification, the leg portion 32d of the piston extends in the X direction more reliably than in the first embodiment without separately providing a leg portion guide or the like on which the leg portion 32d slides. And tilting with respect to the Y axis extending in the Y direction and twisting around the Z axis extending in the Z direction can be prevented. Therefore, in the second modification, the pressing force of the piston can be transmitted to the push rod more efficiently.

"Modification 3 of the first embodiment"
Next, Modification 3 of the first embodiment will be described with reference to FIG.

  Similarly to Modification 2, Modification 3 also changes the shape of the inclined surface portion 50 of the first embodiment and the configuration of the output roller unit 60. The third modification is basically the same as the first embodiment except for the above changes.

  In the third modification, the first modification has a structure in which the first restriction surfaces 53d and 53e and the second restriction surfaces 54d and 54e are formed on the two leg portions 32d and 32d, respectively. A first regulating surface 53f is formed on 32f, and a second regulating surface 54g is formed on the remaining one leg portion 32g.

  Of the two leg portions 32f and 32g of the piston, the first regulating surface 53f is formed on the (+) X side leg portion 32f, and the second regulating surface 54g is formed on the (−) X side leg portion 32g. ing. Since the first restricting surface 53f receives a force having a component in the (+) X direction, the first restricting surface 53f is inclined in the traveling direction ((+) Y direction) of the push rod 40 toward the (+) X side. Further, since the second regulating surface 54g receives a force having a (−) X direction component, the second regulating surface 54g is inclined in the traveling direction ((+) Y) of the push rod 40 toward the (−) X side.

  In the third modification, in addition to the configuration of the inclined surface portion 50f described above, the (+) X-side retraction-side end portion 43f of the two retraction-side end portions 43f and 43g of the push rod 40 has a first corresponding roller unit. 63f is provided, and the second corresponding roller unit 64g is provided at the (−) X side retreat side end 43g. The roller 62 of the first corresponding roller unit 63f is provided at a position where it can come into contact with the first restricting surface 53f of the inclined surface portion 50f so that its rotational axis is parallel to the first restricting surface 53f. Further, the roller 62 of the second corresponding roller unit 64g is provided at a position where the roller 62 can come into contact with the second regulating surface 54g of the inclined surface portion 50g so that the rotation axis thereof is parallel to the second regulating surface 54g.

  Therefore, in the third modification, the movement of the piston leg portions 32f, 32g in the (−) X direction is restricted by the first corresponding roller unit 63f of the output roller unit 60f, and the (+) of the leg portions 32f, 32g. The movement in the X direction is restricted by the second corresponding roller unit 64g of the output roller unit 60f. For this reason, the movement of the leg portions 32f and 32g of the piston in the X direction is restricted by the output roller unit 60f including the first and second corresponding roller units 63f and 64g in the process of moving the piston in the Z direction. It will be.

  Therefore, in the third modification, as in the second modification, it is possible to prevent the leg portions 32f and 32g of the piston from being inclined or twisted during the movement of the piston.

“Variation 4 of the first embodiment”
Next, Modification 4 of the first embodiment will be described with reference to FIG.

  In the fourth modification, the reaction force receiving roller 65 of the first embodiment is changed to a reaction force receiving roller unit 65h. In addition, this modification 4 is the same as that of 1st embodiment fundamentally except the above change.

  The reaction force receiving roller unit 65 h is fixed to the reaction force support 82. The reaction force receiving roller unit 65h includes a plurality of rollers 62 and a frame for restraining the plurality of rollers 62, similarly to the roller units described above. Each roller 62 is provided at a position where the roller 62 can come into contact with the reaction force transmission surface 55 of the leg portion 32 so that the rotation shaft thereof is parallel to the reaction force transmission surface 55.

  Of the plurality of rollers 62, 62,... Of the reaction force receiving roller unit 65h, two or more rollers 62 are simultaneously in line contact with the reaction force transmission surface 55, respectively. For this reason, the reaction force receiving roller unit 65 h comes into two-dimensional contact with the reaction force transmission surface 55.

  Therefore, in the fourth modification, the inclined surface portion 50 formed on the (+) Y side of the leg portion 32 is in two-dimensional contact with the output roller unit 60 and is formed on the (−) Y side of the leg portion 32. The reaction force transmission surface 55 is in two-dimensional contact with the reaction force receiving roller unit 65h. That is, each of the (+) Y side and the (−) Y side of the leg portion 32 comes into two-dimensional contact with the roller unit. For this reason, in this modification 4, the twist and inclination of the leg part 32 of a piston accompanying the movement of a piston can be suppressed effectively rather than 1st embodiment.

  The outer peripheral length of the roller 62 of the reaction force receiving roller unit 65h is much shorter than the relative movement path length of the reaction force receiving roller unit 65h with respect to the reaction force transmission surface 55 of the leg portion 32. For this reason, since the plurality of rollers 62, 62,... Rotate one or more times during the movement of the piston, uneven wear of the rollers 62 can be minimized.

  In the fourth modification, the forms shown in the first to third modifications may be adopted as in the first embodiment. Further, in the second and third modifications, the movement of the leg portion in the X direction is restricted due to the relationship between the leg portion of the piston and the output roller unit provided on the push rod. The movement of the leg portion 32 in the X direction may be restricted by the relationship between the portion 32 and the reaction force receiving roller unit 65 h provided on the reaction force support base 82. In this case, it is preferable to employ the same technique as that of Modification 2 or Modification 3 as a technique for restricting the movement of the leg 32 in the X direction.

“Variation 5 of the first embodiment”
Next, Modification 5 of the first embodiment will be described with reference to FIG. FIG. 11 shows a state in which the push rod 40i, the output roller 60i, and the like are viewed from the (−) Z side toward the (+) Z side.

  As described above, the fifth modification is a modification in which the number and arrangement of the rollers and the like of the first embodiment are changed. In the fifth modification, one output roller unit 60i is provided on the retraction side end 43i of the push rod 40i on the central axis Cr of the push rod 40i, and the leg portion of the piston is matched to the quantity of the output roller unit 60i. The number 32i is one, and reaction force receiving rollers 65i and 65j are provided on the (±) X side of the leg portion 32i.

  As in the first embodiment, the output roller unit 60i has a front contact roller unit 61i that contacts a front contact inclined surface (not shown) of the inclined surface portion and a rear contact that contacts a rear contact inclined surface (not shown) of the inclined surface portion. And a roller unit 61j.

  Reaction force support portions 82 i and 82 j are formed integrally with the housing 21 at positions facing the reaction force receiving rollers 65 i and 65 j on the (−) Y side of the reaction force receiving rollers 65 i and 65 j. Each reaction force support portion 82i, 82j has a reaction force receiving surface 85i. That contacts the outer peripheral surface of the reaction force receiving rollers 65i, 65j. 85j is formed.

  Reaction force receiving surfaces 85i. 85j is formed with a first restricting surface 86 that receives a force having a (+) X direction component and a second restricting surface 87 that receives a force having a (−) X direction component. The first restricting surface 86 is located on the (−) X side in the reaction force receiving surfaces 85i and 85j, and the push rod 40 moves backward (in the (−) Y direction) toward the (−) X side. Inclined. Further, the second regulating surface 54 is located on the (+) X side in the reaction force receiving surfaces 85i, 85j, and the push rod 40 advances in the direction ((+) Y direction) toward the (−) X side. It is inclined to. Accordingly, the reaction force receiving surfaces 85i and 85j have a central portion in the X direction protruding to the (+) Y side.

  On the outer periphery of each reaction force receiving roller 65i, 65j, a first corresponding surface 66 that contacts the first restriction surface 86 of each reaction force receiving surface 85i, 85j and a second restriction of each reaction force receiving surface 85i, 85j. A second corresponding surface 67 that contacts the surface 87 is formed. As a result, the outer peripheral surface of each of the reaction force receiving rollers 65i, 65j has a central portion in the X direction so that the central portion in the X direction matches the shape of the reaction force receiving surfaces 85i, 85j protruding to the (+) Y side. However, it is dented in the direction which approaches the rotating shaft of each reaction force receiving surface 85i and 85j.

  Therefore, in the fifth modification, the movement in the X direction of the leg portion 32i of the piston is restricted by the reaction force receiving surfaces 85i and 85j.

  As described above in the fifth modification, assuming that the output roller unit 60i is provided at the retreating side end 43i of the push rod 40i, one output roller unit 60i is provided on the central axis Cr of the push rod 40i. The one output roller unit 60i can transmit the pressing force from the piston to the push rod 40i without breaking the balance in the (±) X direction. As described above, the output roller unit 60i can be integrated into one unit. As a result, the piston leg 32i that contacts the outer peripheral surface of the output roller unit 60i can also be integrated into one unit.

  Therefore, in the fifth modification, the number of output roller units and legs can be reduced as compared with the first embodiment, and the brake device can be further reduced in size and weight.

  In the fifth modification, as described above, the movement in the X direction of the leg portion 32i of the piston is restricted by the reaction force receiving surfaces 85i and 85j. Without adding such components, it is possible to reliably prevent the leg portion 32i of the piston from being inclined or twisted during the movement of the piston.

  By the way, in the modified examples 2 and 3, since the output roller units 60d and 60f provided on the push rod 40 that moves forward and backward receives a force having a component in the X direction from the leg portion, the push rod 40 The force of the X direction perpendicular | vertical to the Y direction which is the advance / retreat direction of the push rod 40 will be received. On the other hand, in Modification 5, the reaction force support portions 82i and 82j formed on the housing 21 receive a force having a component in the X direction from the leg portion 32i via the reaction force receiving rollers 65i and 65i. Therefore, the push rod 40i does not receive the force in the X direction perpendicular to the Y direction, which is the forward / backward direction of the push rod 40i, as in the second and third modifications. Therefore, in the fifth modification, the load for moving the push rod 40i is less than in the second and third modifications, and the pressing force of the piston can be transmitted to the push rod 40i more efficiently.

  In the first embodiment and each of the first to fourth modifications described above, the reaction force receiving roller 65 (or the reaction force receiving roller unit 65h) is provided on the reaction force support base 82 fixed to the housing 21. In the fifth modification, the reaction force receiving roller 65i is provided on the leg portion 32i. That is, even if the reaction force receiving roller (or reaction force receiving roller unit) disposed between the leg portion and the reaction force support portion (or reaction force support base) is provided on the leg portion side, the reaction force support is provided. You may provide in the part (or reaction force support stand) side.

  In the fifth modification, the movement of the leg 32i in the X direction is restricted by the relationship between the reaction force support portion 82i and the reaction force receiving roller 65i. The movement of the leg portion 32i in the X direction may be restricted by the relationship between the portion 31i and the output roller unit.

  Furthermore, in the fifth modification, each reaction force receiving surface 85i. As the configuration of 85j and each of the reaction force receiving rollers 65i, the same configurations as the inclined surface portions 50d and 50f and the output roller units 60d and 60f of the second and third modifications may be adopted.

"Second embodiment"
Next, a brake device as a second embodiment according to the present invention will be described with reference to FIGS.

  In the present embodiment, as shown in FIG. 12, an output roller unit (drive member contact portion) 60k and a reaction force receiving roller unit 65k are provided on a leg portion 32k of a piston (drive member main body), and are inclined to a push rod 40k. The surface portion 50k is formed, and other configurations are basically the same as those in the first embodiment.

  An output roller unit 60k is provided on the (+) Y side portion of the leg portion 32k of the piston, and a reaction force receiving roller unit 65k is provided on the (−) Y side portion of the leg portion 32k. A reaction force support portion 82k is integrally formed with the housing 21 on the (−) Y side of the reaction force receiving roller unit 65k and at a position facing the reaction force receiving roller unit 65k. The reaction force support portion 82k is formed with a reaction force receiving surface 85k that is substantially parallel to the advancing / retreating direction (Z direction) of the piston and is in contact with the roller of the reaction force receiving roller unit 65k.

  Similar to the output roller unit 60 of the first embodiment, the inclined surface portion 50k of the push rod 40k is provided at the retracting side end portion 43k of the push rod 40k. Similarly to the first embodiment, the inclined surface portion 50k is also inclined with respect to the advancing / retreating direction (Z direction) of the piston 30, and is directed toward the (+) Y side as it goes toward the (−) Z side. Further, as in the first embodiment, the inclined surface portion 50k includes the tip contact inclined surface 51k that first contacts the output roller unit 60k in the course of movement of the piston in the traveling direction ((+) Z direction), and the next output. There is a rear contact inclined surface 52k that contacts the roller unit 60k. Similarly to the first embodiment, the front contact inclined surface portion 51k has an angle with respect to the retreating direction ((−) Z direction) of the piston larger than the rear contact inclined surface portion 52k.

  A key groove 45k extending in the Y direction is provided on the (+) Z side of the retreat side end portion 43k where the inclined surface portion 50k is formed. The housing 21 is provided with a second push rod guide key 89k that supports the key groove 45k so as to be slidable in the Y direction. As shown in FIG. 13, the key groove 44 provided in the main body of the push rod 40k is slidably supported by the first push rod guide key 81 provided in the housing 21 as in the first embodiment. Has been.

  As shown in FIG. 13, output roller units 60k and 60k are provided on the two leg portions 32k and 32k arranged in the X direction, respectively. The reaction force receiving roller 65k is also provided on each of the two leg portions 32k, although not shown in the drawing. Further, two reaction force support portions 82k are also formed in the housing 21 in accordance with the number of the two reaction force receiving rollers 65k, although not shown in the figure.

  The inclined surface portions 50k, 50k of the push rod 40k and the retreat side end portions 43k, 43k on which the inclined surface portions 50k, 50k are formed are provided in accordance with the number of the two output rollers 60k, 65k. Accordingly, the housing 21 also includes two second push rod guide grooves 89k and 89k that support the retreat side end portions 43k and 43k of the push rod 40.

  As described above, in the present embodiment, the output roller unit 60k provided in the leg portion 32k and the inclined surface portion 50k of the push rod 40k are in two-dimensional contact. Therefore, also in the present embodiment, as in the first embodiment, it is possible to prevent the leg portion 32k of the piston from being inclined or twisted during the movement of the piston.

In the present embodiment, the reaction force receiving roller unit 65k provided in the leg portion 32k and the reaction force support portion 82k formed in the housing 21 are in two-dimensional contact. Therefore, in the present embodiment, as in the fourth modification of the first embodiment, each of the (+) Y side and the (−) Y side of the leg portion 32k comes into contact with the roller unit in two dimensions. As compared with the first embodiment, twisting and tilting of the leg portion 32 of the piston can be effectively suppressed as the piston moves.
Can be prevented.

  In the present embodiment, output roller units 60k and 60k and reaction force receiving rollers 65k and 65k are provided on the two leg portions 32k and 32k, respectively, and the two retreating side end portions 43k and 43k of the push rod 40k are provided. Although the inclined surface portion 50k is provided, like the fifth modification of the first embodiment, the leg portion of the piston and the retreat side end portion of the push rod are respectively made one, and one output roller unit 60k is provided on this leg portion. It is also possible to provide one inclined surface portion at the retreat side end.

  Also in this embodiment, the same configuration as that of the first to fourth modifications of the first embodiment may be adopted.

“Variation of rotating body unit”
Next, a modified example of the rotating body unit will be described with reference to FIG.

  In each of the above-described embodiments and modifications, a roller unit including a plurality of rollers is employed as the rotating body unit. Instead of this roller unit, a ball unit 60m including a plurality of balls 62m is used. May be adopted.

  The ball unit 60m includes a plurality of balls 62m having the same radius and a frame 64m that rotatably holds the balls 62m without changing the relative positions of the plurality of balls 62m.

  The outer circumference of the ball 62m of the ball unit 60m is the same as that of the roller of the first embodiment, and the ball unit 60m is in contact with the inclined surface (or reaction force transmission surface, reaction force receiving surface). It is much shorter than the moving path length of the ball unit 60m with respect to the inclined surface (or reaction force transmission surface, reaction force receiving surface). Therefore, the plurality of balls 62m make one or more revolutions during the movement of the piston, so that uneven wear of the balls 60m can be minimized.

  By the way, in the modification 2 of 1st embodiment, the output roller unit 50d which contacts the inclined surface part 50d from which the inclination of 4 surfaces mutually differs is comprised including four roller units. This is because if the inclination of the surface is different, it is necessary to change the direction of the roller rotation shaft of the roller unit in contact with the surface. On the other hand, in this modified example, the actual rotation axis that is the center of rotation is not required for the ball, and therefore, if the shape of the frame corresponds to the surface shape of the inclined surface portion 40d, it can be configured by one ball unit. it can.

  For this reason, the number of parts can be reduced by adopting the ball unit of the present modification as the rotating body unit that contacts the inclined surface portions 50d whose inclinations of the plurality of surfaces are different from each other.

  10: Brake shoe, 15: Hanger, 20: Drive unit, 21: Housing, 22: Air chamber, 23: Air inlet / outlet, 28: Sliding bearing, 29: Coil spring, 30: Piston (drive member), 31 : Pressure receiving part, 32, 32i, 32d, 32f, 32g, 32i, 32k: leg part, 40, 40i, 40k: push rod (driven member or main body of driven member), 41: advancing side end of push rod, 43, 43c 43d, 43f, 43g, 43i, 43k: Retraction side end of the push rod, 44, 45k: Key groove, 50, 50d, 50f, 50k: Inclined surface portion, 51, 51d, 51k: Tip contact inclined surface, 52, 52e , 52k: rear contact inclined surface, 53, 53d, 53e, 53f, 86: first restriction surface, 54, 54d, 54e, 54g, 87: second restriction surface, 55: reaction force transmission surface, 60, 6 d, 60f, 60i, 60k: output roller unit, 60c: contact portion, 60n: ball unit, 61a, 61d, 61i, 61k: front contact roller unit, 61b, 61e, 61j, 61m: rear contact roller unit, 61c: Contact surface, 62: roller, 62m: ball, 63d, 63e, 63f: first corresponding roller unit, 64d, 64e, 64g: second corresponding roller unit, 65, 65i: reaction force receiving roller, 65h, 65k: counter Force receiving roller unit, 70: bracket, 81, 89: push rod guide key, 82: reaction force support base, 82i, 82k: reaction force support portion

Claims (12)

A drive member that moves forward and backward according to the driving force, a driven member that moves forward and backward in a direction different from the direction of the forward and backward movement due to the forward and backward movement of the drive member, and a moving member that moves due to the forward and backward movement of the driven member and contacts the braking target A brake device comprising:
One of the driving member and the driven member is in contact with the other member, and the inclined surface portion that moves the driven member forward and backward in a direction different from the forward and backward movement direction by the forward and backward movement of the driving member. Have
The other member has two-dimensional contact in contact with a plurality of locations in the inclined direction where the inclined surface portion is inclined and a plurality of locations in a direction perpendicular to the inclined direction within the surface of the inclined surface portion. Has a contact portion that enables,
Brake device characterized by that. The brake device according to claim 1, wherein
The contact portion has a plurality of small contact portions that are in two-dimensional contact with the inclined surface portion.
Brake device characterized by that. The brake device according to claim 2,
The small contact portion of the other member rotates by relative movement of the inclined surface portion with respect to the small contact portion in a state where the small contact is in contact with the inclined surface portion of the one member. The body,
Brake device characterized by that. The brake device according to claim 3,
The rotating body is a roller extending in parallel with the inclined surface portion.
Brake device characterized by that. The brake device according to claim 3 or 4,
The contact portion has a frame that restrains the plurality of rotating bodies so as not to change the mutual position of the plurality of rotating bodies.
Brake device characterized by that. In the brake device according to any one of claims 3 to 5,
The outer peripheral lengths of the plurality of rotating bodies included in the contact portion are longer than the length in the inclined direction within the range of the inclined surface portion facing the part in order to contact the part of the contact part. short,
Brake device characterized by that. In the brake device according to any one of claims 1 to 6,
The inclined surface portion is a first restriction surface that receives a force in one direction of a movement restriction direction perpendicular to a surface including the forward / backward movement direction of the drive member and the forward / backward movement direction of the driven member. And a second regulating surface that receives the force in the other direction,
The contact portion includes a first corresponding portion that contacts the first restriction surface in two dimensions, and a second correspondence portion that contacts the second restriction surface in two dimensions.
Brake device characterized by that. In the brake device according to any one of claims 1 to 7,
At least one of the contact portion and the inclined surface portion, and the surface in contact with the other is intended to be at least one of improved lubricity, improved hardness, and improved wear resistance. Surface treatment is applied,
Brake device characterized by that. In the brake device according to any one of claims 1 to 8,
One end of the advancing side end of the driving member in the advancing and retreating direction and the retreating side end of the retreating side in the advancing and retreating direction of the driven member. The inclined surface portion is provided, and the contact portion is provided at the other end.
Brake device characterized by that. The brake device according to any one of claims 1 to 9,
A reaction force support portion that receives a reaction force acting on the drive member from the driven member;
Each of the reaction force support member and the drive member has a contact portion that contacts each other,
Of the contact portion of the reaction force support portion and the contact portion of the drive member, the contact portion of one member has a contact surface that extends in the direction of relative movement of the drive member with respect to the reaction force support member. And
Of the contact portion of the reaction force support portion and the contact portion of the drive member, the contact portion of the other member is within the contact surface of the one member and is in a plurality of locations in the relative movement direction, And a contact portion that enables two-dimensional contact simultaneously contacting a plurality of locations in a direction perpendicular to the direction of the relative movement.
Brake device characterized by that. A drive member that moves forward and backward according to the driving force, a driven member that moves forward and backward in a direction different from the direction of the forward and backward movement due to the forward and backward movement of the drive member, and a moving member that moves due to the forward and backward movement of the driven member and contacts the braking target A brake device comprising: a braking element that performs a reaction force support portion that receives a reaction force acting on the drive member from the driven member;
One of the driving member and the driven member has an inclined surface portion that contacts the other and makes the driven member move forward and backward in a direction different from the forward and backward movement direction by the forward and backward movement of the driving member. And
Each of the reaction force support member and the drive member has a contact portion that contacts each other,
Of the contact portion of the reaction force support portion and the contact portion of the drive member, the contact portion of one member has a contact surface that extends in the direction of relative movement of the drive member with respect to the reaction force support member. And
Of the contact portion of the reaction force support portion and the contact portion of the drive member, the contact portion of the other member is within the contact surface of the one member and is in a plurality of locations in the relative movement direction, And a contact portion that enables two-dimensional contact simultaneously contacting a plurality of locations in a direction perpendicular to the direction of the relative movement.
Brake device characterized by that. The brake device according to claim 10 or 11,
Of the contact portion of the reaction force support member and the contact portion of the drive member, the contact portion of the other member has a plurality of rollers arranged in the direction of relative movement.
Brake device characterized by that.

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