JP2002168276A - Brake equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contrive decrease in operating force, dissolution of noises, and compact and lightweight design of the brake equipment. SOLUTION: A brake equipment comprises a lock drum 10 having a braking face 11, a shoe-plate installing member 20 having a shoe-plate installing face 22a, a center gear 50 having an engaging recessed portion 53a, a center holder 40 having a shoe-plate retaining face 40a, and an arm portion 31 rotatably retained on a supporting shaft portion 41 of the shoe-plate retaining face 40a. Further, a contact portion 31a capable of coming into contact with the braking face 11 in the arm portion 31 is provided therein, and an engaging recessed portion 31b capable of engaging with a shaft portion 24 of the shoe-plate installing face 22a at an edge point portion of a peripheral direction is also provided. Furthermore, a shoe-plate 30 having an engaging projecting portion 32a engaged with the engaging recessed portion 53a is provided at an edge point portion of a trunk portion 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake device used for a seat lifter, a window regulator and the like of a seat in a vehicle.

[0002]

2. Description of the Related Art Conventionally, as a brake device employed in a seat lifter or the like, for example, as shown in FIG. 7, a torsion spring 2 is provided in a lock drum 1 and a braking surface formed on the inner periphery of the lock drum 1. A core 3 having a cutout recess 3 a is rotatably disposed inside the torsion spring 2. The core 3 is integrally fixed to a handle shaft 4. In the space of the cutout recess 3 a of the core 3, a claw portion 5 provided integrally with the center gear is disposed so as to be rotatable around the handle shaft 4.

[0003] In response to an input from the center gear, the claw 5 is connected to the hook 2 a of the torsion spring 2.
Alternatively, since the outer diameter of the torsion spring 2 is increased by pressing the torsion spring 2, the pressing force of the torsion spring 2 against the braking surface 1 a of the lock drum 1 is increased, and a braking force is generated. Thereby, the input of the center gear side is not transmitted to the handle shaft 4 side, that is, the rotation of the center gear can be prevented.

On the other hand, the core 3 pushes the hook 2a or 2b of the torsion spring 2 to reduce the outer diameter of the torsion spring 2 with respect to the rotation from the handle shaft 4, so that the pressure contact force is reduced. It becomes weak and the center gear side can be rotated.

[0005] That is, the rotation of the handle shaft 4 is transmitted to the center gear side and can be moved up and down via the center gear, but the brake force acts on the input from the center gear side. It is configured so that the lifting operation cannot be performed.

[0006]

In the above-mentioned brake device, the sliding force between the torsion spring 2 and the lock drum 1 increases the operating force for rotating the handle shaft 4 and generates abnormal noise. There was a problem that it easily occurred. In addition, since the torsion spring 2 employs a multiple winding in order to effectively act on the brake, the lock drum 1 containing the torsion spring 2 is inevitably increased in size and goes against a reduction in size and weight. There was a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a brake device capable of reducing operating force, eliminating abnormal noise, and reducing size and weight.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention according to claim 1 is a lock drum (10) having a braking surface (11) formed by a cylindrical inner peripheral surface.
A shoe plate mounting surface (22a) coaxially disposed inside the braking surface (11), and a handle shaft 21 protruding from the lock drum (10). A shoe plate mounting member (20) rotatably provided around an axis, and a shoe plate mounting member (20) provided at an axial center of the shoe plate mounting member and rotatably provided around the axis thereof; The braking surface (11)
A center gear (50) having an engaging recess (53a) formed at a position corresponding to the above, and a shoe plate holding surface () facing the shoe plate mounting surface (22a) at a predetermined interval in the axial direction. 40a) and the braking surface (1
1) A shoe plate holder (40) rotatably provided around the axis, and the shoe plate holding surface (40).
a) disposed between the shoe plate mounting surface (22a) and the shoe plate holding surface (40a) while being rotatably held by a support shaft portion (41) protruding from the a). An arm (31) extending along a braking surface (11) from a portion corresponding to the support shaft (41), and an axial center side of the braking surface (11) from a portion corresponding to the support shaft (41); Trunk part (32) extending toward
The arm portion (31) has a contact portion (31a) for applying a braking force by coming into contact with the braking surface (11) when swinging around the support shaft portion (41). The trunk portion (32) has an engaging recess (31b) at the front end in the direction, which can be engaged with a shaft (24) projecting from the shoe plate mounting surface (22a). A shoe plate (30) having an engagement projection (32a) engaged with the engagement recess (53a) of the gear (50).

According to a second aspect of the present invention, in the first aspect of the invention, the shoe plate (30) is provided with a contact portion (3).
1a) and an arm portion (3) having an engagement recess (31b).
1) are arranged on both sides of the support shaft (41), and each arm (31) is provided on the shoe plate mounting surface (22a).
The shaft portion (24) is located at a position where it can be engaged with the engagement recess (31b) of the shaft.
Is provided.

According to a third aspect of the present invention, in the invention of the second aspect, the shoe plate (30) is provided on each of one side and the other side with respect to a line connecting the two shaft portions (24). And a support shaft portion (41) for rotatably holding each shoe plate (30) is provided on the shoe plate holding surface (40a).

In the invention configured as described above, when an operating torque (operating torque) is input to the handle shaft (21), the entire shoe plate mounting member (20) rotates. Due to the rotation, the shaft portion (24) of the shoe plate mounting surface (22a) is engaged with the engagement concave portion (31b) of the arm portion (31) so as to be pressed. Therefore, the shoe plate (30) also rotates together with the handle shaft (21). However, since the operation torque is transmitted from the shaft portion (24) to the support shaft portion (41) arranged on the same circle, the operation torque does not rotate around the support shaft portion (41). For this reason, the shoe plate (30) rotates together with the shoe plate attachment member (20) without the abutting portion (31a) abutting on the braking surface (11). The rotation of the shoe plate (30) causes the center gear (50) to pass through the engaging protrusion (32a) of the trunk portion (32) and the engaging recess (53a) engaging with the engaging protrusion (32a). ), The center gear (50) is connected to the handle shaft (2).
It rotates together with 1).

Therefore, the center gear (50) can be rotated by operating the handle shaft (21), and based on the rotation of the center gear (50),
For example, through a sheet lifter or window regulator,
Seat and window glass can be moved up and down. In addition, the contact portion (31a) of the shoe plate (30) and the braking surface (11) of the lock drum (10) do not slide, so that the operating force of the handle shaft (21) can be reduced. At the same time, generation of abnormal noise can be prevented.

On the other hand, when a load torque acts from the center gear (50) side, the load torque is applied to the engagement concave portion (53a), the engagement convex portion (32a), and the shoe plate (3).
0) and the support shaft portion (41), the force is transmitted to the shoe plate attachment member (20), and a force for rotating the handle shaft (21) is generated. If the handle shaft (21) is rotated by the load torque, the above-mentioned seat or window glass cannot secure a predetermined height position and immediately falls to the lowest position. Will be lost.

However, when the load torque is applied to the engagement recess (53)
When the shoe plate (30) acts on the shoe plate (30) via the a) and the engaging projection (32a), a torque is generated on the shoe plate (30) to rotate the shoe plate around the support shaft (41). At this time, the engagement concave portion (31) of the arm portion (31) is used.
If the shaft (24) is engaged with b) at a predetermined pressing force,
The shoe plate (30) is supported at two points, the support shaft (41) and the shaft (24).
1) It does not rotate around. However, no operating force is applied to the handle shaft (21), and the shoe plate mounting member (20) is in a rotatable state.
When a force is applied to rotate the shoe plate (30), the engaging recess (31b) causes the shaft portion (24)
You will be out of the box immediately. For this reason, the shoe plate (30) rotates around the support shaft (41), and the contact portion (31a) comes into contact with the braking surface (11).

Then, the friction between the contact portion (31a) and the braking surface (11) causes the shoe plate (3).
0) stops moving in the direction along the braking surface (11), so that the rotation of the center gear (50) stops, and the above-described seat, window glass, and the like can be held at a predetermined height position. .

In addition, the contact portion (31a) is a so-called leading shoe (usually a drum brake) that contacts the braking surface (11) in front of the support shaft portion (41) with respect to the moving direction of the shoe plate (30). ), An extremely large frictional force is generated between the braking surface (11). That is, in the case of the leading shoe, the abutment portion (31a) causes the braking surface (1
Since a rotational force in the direction of pressing against 1) acts, an extremely large frictional force acts between the contact portion (31a) and the braking surface (11).

Since the braking torque by the leading shoe can be made larger than the load torque acting on the center gear (50), the seat, the window glass and the like can be securely held at a predetermined height. can do. In addition, even if the external force acting on the sheet or the window glass, that is, the load torque acting on the center gear (50) increases, the frictional force automatically increases as the external force increases. It is impossible.

Further, as compared with the case where a conventional multiple winding torsion spring is used, a sufficiently thin shoe plate (30) can be employed, so that the size and weight can be reduced.

In the invention according to claim 2, the contact portion (3
1a) and an arm portion (3) having an engagement recess (31b).
Since 1) is disposed on both sides of the support shaft (41),
For example, even if load torque is generated clockwise,
Also, even when the load torque is generated in the counterclockwise direction,
Each contact portion 31a can generate a braking torque. Therefore, since it is not necessary to consider the direction of the load torque, the assemblability is good and the size and weight can be reduced.

According to the third aspect of the present invention, since the shoe plates (30) are provided on both sides of the line connecting the two shaft portions (24), compared with the case where one shoe plate (30) is provided. , A double braking torque can be generated.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on embodiments with reference to the drawings. 1 to 5 show a first embodiment, and FIG. 6 shows a second embodiment.

First, a first embodiment will be described with reference to FIGS. The brake device E shown in this embodiment is applied to a seat lifter that moves a vehicle seat up and down, a window regulator that moves a window glass up and down, and the like, and has a braking surface 1 formed by a cylindrical inner peripheral surface.
1 and a handle shaft 21 having a shoe plate mounting surface 22a coaxially arranged inside the braking surface 11 and protruding from the lock drum 10.
And a shoe plate mounting member 20 provided rotatably (rotatably) around the axis of the braking surface 11, and rotatable about the axis of the shoe plate mounting member 20 at the axis thereof. A center gear 50 provided with an engaging recess 53a formed at a position corresponding to the braking surface 11 in the axial direction, and a shoe plate holding surface facing the shoe plate mounting surface 22a at a predetermined interval in the axial direction. Face 4
0a, and a shoe plate holder 40 rotatably provided around the axis of the braking surface 11, and a shoe plate mounting surface rotatably held by a support shaft portion 41 protruding from the shoe plate holding surface 40a. The arm portion 31 is arranged between the shoe plate holding surface 40a and the shoe plate holding surface 40a. The arm portion 31 extends in an arc along the braking surface 11 from a portion corresponding to the support shaft portion 41.
And a trunk portion 32 extending from the portion corresponding to the support shaft portion 4 toward the axis of the braking surface 11.
It has an abutment portion 31a that abuts against the braking surface 11 when it swings around and applies a braking force, and can be engaged with a shaft portion 24 protruding from the shoe plate mounting surface 22a at a circumferential end. It is characterized in that it has an engagement concave portion 31b, and the trunk portion 32 is provided with a shoe plate 30 having an engagement convex portion 32a that engages with the engagement concave portion 53a of the center gear 50 at its tip.

The shoe plate 30 has arms 31 arranged on both sides of the support shaft 41. At the distal end of each arm 31 in the circumferential direction, two arms protruding from the shoe plate mounting surface 22a are provided. An engagement recess 31b that engages with each of the shaft portions 24 is formed. Further, one shoe plate 30 is provided on each of one side and the other side with respect to a line connecting the two shaft portions 24, and each shoe plate 30 is provided from the shoe plate holding surface 40a.
The two support shaft portions 41 that rotatably hold are protruded.

Hereinafter, the above configuration will be described in more detail. That is, the brake device E includes the lock drum 10, the shoe plate attaching member 20, the shoe plate 30,
A shoe plate holder 40 and a center gear 50 are provided as main components.

The lock drum 10 has a cylindrical large-diameter drum portion 10a and a small-diameter drum portion 10b formed coaxially with the large-diameter drum portion 10a on one side of the large-diameter drum portion 10a via a side plate 10c. And a flange portion 10d formed on the outer periphery of the other side of the large-diameter drum portion 10a. The inner surface of the large-diameter drum portion 10a is the above-described braking surface 11, and the inner surface of the small-diameter drum portion 10b is the bearing portion 12 that rotatably supports the handle shaft 21 of the shoe plate mounting member 20. The lock drum 10 is attached to the seat side frame 60 by fixing the flange portion 10d to the seat side frame 60 of a seat lifter, for example.

The shoe plate mounting member 20 includes a handle shaft 21 provided on one side and a disk 22 provided coaxially with the handle shaft 21 on the other side of the handle shaft 21.
And are formed integrally. The handle shaft 21 is
The base end is rotatably supported by the bearing portion 12 of the lock drum 10, and has a spline key 21 a for attaching the handle 23 at the front end.

The disk 22 has an outer diameter slightly smaller than the inner diameter of the braking surface 11 so that the disk 22 can be rotatably fitted into the braking surface 11 without contacting the braking surface 11. The shoe plate mounting surface 22a is formed in a flat shape on the other side of the disk 22. This shoe plate mounting surface 2
2a, two shaft portions 24 are integrally provided at a position near the outer periphery, that is, at a position near the braking surface 11.
The shaft portion 24 has its axis (center) on a circle centered on the axis of the shoe plate mounting surface 22a and is provided at a position 180 degrees apart in the circumferential direction. It is provided so as to project perpendicularly to the surface 22a.

The shoe plate mounting member 20 includes
A concave bearing hole 25 is formed at the axial center position of the shoe plate mounting surface 22a.

The shoe plate 30 has an arm 31
A through-hole 31c rotatably fitted to the support shaft portion 41 is formed at a central position in the circumferential direction (longitudinal direction) of the support shaft 41. That is, the arm portions 31 are arranged on both sides of the support shaft portion 41. The outer peripheral surface of the arm portion 31 on the side facing the braking surface 11 is formed in an arc shape with a radius smaller than the radius of the braking surface 11. Then, on the outer peripheral surface of the arm portion 31,
A contact portion 31a is formed on both sides of the through hole 31c and at an equal position from the through hole 31c. Each contact part 31a
Is curved in the form of an arc with the same curvature as the braking surface 11 in this embodiment, so that when the shoe plate 30 is tilted around the shaft portion 41 by a predetermined amount, the shoe plate 30 comes into contact with the braking surface 11 to generate a frictional force. It has become. In this example,
Each of the contact portions 31a is curved in the shape of an arc with the same curvature as the braking surface 11, but this does not necessarily have to have the same curvature, and as described above, the shoe plate 30 It suffices that a frictional force is generated by abutting the braking surface 11 when tilted around by a predetermined amount.

The engagement recesses 31b formed at each end of the arm portion 31 are formed in a concave shape with a curvature corresponding to the curvature of the outer peripheral surface of the cylindrical shaft portion 24. Even if the shoe plate 30 is inclined so that the contact portion 31 a contacts the braking surface 11, the shaft portion 24 that moves with the rotation of the shoe plate attachment member 20.
Can be easily engaged.

On the other hand, the engagement projection 32a formed at the tip of the engagement projection 32 is formed in the shape of one tooth of the internal gear.

Further, the shoe plate 30 is provided on the support shaft 4.
1, the shoe plate mounting surface 22
a and the shoe plate holding surface 40a of the shoe plate holder 40, the movement in the axial direction is restricted.

The shoe plate holder 40 is provided together with the center gear 50 so that the through hole 40b at the axial center of the shoe plate holder 40 is rotatably fitted to the outer periphery of the tooth portion 53 having the engaging recess 53a. It is held by the mounting member 20 and is rotatable around the axis of the braking surface 11.

The center gear 50 has a disk-like flange portion 51 at a position closer to the other side in the axial direction, and a pinion 5 is provided on one side of the flange portion 51.
2. The tooth portion 53 having the engagement recess 53a and the shaft portion 54 are formed coaxially in this order. The flange portion 51, the pinion 52, the tooth portion 53, and the shaft portion 54 are configured such that the outer diameter decreases in order toward one side. On the other side of the flange portion 51, a shaft portion 55 is formed coaxially.

In the center gear 50, the shaft portion 54 is fitted into the bearing hole 25 of the shoe plate mounting member 20,
By fitting the shaft portion 55 into the bearing hole 61 of the seat side frame 60, the shaft portion 55 is rotatably supported by the lock drum 10 and the shoe plate mounting member 20. The pinion 52 meshes with a sector gear 62 provided on the seat lifter side, and by rotating this sector gear 62, the entire seat is moved up and down via a seat frame (not shown).

The tooth portion 53 has an outer peripheral surface formed in a cylindrical surface shape, and is provided at a position which is equally divided into four in the circumferential direction.
3a. Each engagement recess 53a
Are formed so that the above-mentioned engaging projections 32a are fitted precisely, and the shoe plate 30 is
In the angle range swinging around the first engagement projection 32a,
It is formed in such a shape as to be in close contact with.

Next, the operation of the first embodiment of the present invention will be described. First, when the handle shaft 21 is not operated and no force is applied from the seat lifter side, as shown in FIG. 3, one and the other contact portions 31a of each shoe plate 30 are separated from the braking surface 11. It can be in a state.

Next, as shown in FIG. 4, when the handle 23 is turned in one direction to lift the seat, the operating torque (operating torque) at that time is increased by the handle shaft 21, the disk 22, and the shaft portion. 24, engaging recess 31b, shoe plate 3
0, transmitted to the center gear 50 via the engaging projection 32a and the engaging recess 53a, and the rotation of the center gear 50 causes the sheet to move upward. That is, with the rotation of the handle shaft 21, the shaft portion 24 also moves to the handle shaft 21.
It will move so as to turn in the same direction as
The shoe plate 30 also moves so as to pivot in the same direction as the handle shaft 21. Therefore, the center gear 50 having the engaging concave portion 53a meshing with the engaging convex portion 32a of the shoe plate 30 also rotates in the same direction, so that the sheet lifter is driven via the pinion 52 and the sector gear 62, and the sheet is It will move upward.

Further, the operating torque is transmitted from the shaft 24 to the support shaft 41 disposed on the same circumference. For this reason,
Since the shoe plate 30 moves in the circumferential direction without rotating around the support shaft portion 41, the contact portion 31a
Does not contact the braking surface 11.

Therefore, since there is no resistance due to sliding between the contact portion 31a and the braking surface 11, the operating force of the handle 23 can be reduced, and the generation of abnormal noise can be prevented.

When lowering the seat, the handle 2
3 is rotated in the opposite direction to the above, but also in this case, the center gear 50 can be rotated in the opposite direction with the rotation of the handle 23 as described above. The seat can be lowered without causing it to fall. That is, even when the seat is lowered, the operating force can be reduced, and the generation of abnormal noise can be prevented.

On the other hand, when a load torque acts from the center gear 50 side, the load torque is applied to the engagement recess 53.
a, the force is transmitted to the shoe plate 30 via the engaging projections 32a and the like, and a force acts to rotate the shoe plate 30 around the support shaft portion 41. At this time, if the shaft portion 24 is engaged with the engagement concave portion 31b of the arm portion 31 with a predetermined pressing force, the shoe plate 30 is connected to the support shaft portion 41 and the shaft portion 24.
, And does not rotate around the support shaft 41. However, no operating force is applied to the handle shaft 21 and the shoe plate mounting member 20 is in a freely rotatable state.
b cannot be held, the shoe plate 30 rotates around the support shaft 41, and the contact portion 31 a contacts the braking surface 11.

For this reason, the movement of the shoe plate 30 is stopped by the frictional force between the contact portion 31a and the braking surface 11, and the rotation of the center gear 50 is stopped. The held sheet can be held at a predetermined height position.

In addition, the contact portion 31a acts as a so-called leading shoe that contacts the braking surface 11 in front of the support shaft portion 41 in the moving direction of the shoe plate 30, so that the contact portion 31a is extremely close to the braking surface 11. A large frictional force will be generated. That is, in the case of the leading shoe, since a rotational force acts in a direction of pressing the contact portion 31a against the braking surface 11 by the friction force, an extremely large friction force acts between the contact portion 31a and the braking surface 11. Become.

Since the braking torque (braking torque) by the leading shoe can be made larger than the load torque acting on the center gear 50, the seat, the window glass and the like can be securely positioned at a predetermined height. Can be held. Moreover, even if the external force acting on the sheet or the window glass, that is, the load torque acting on the center gear 50 increases, the frictional force automatically increases as the external force increases. impossible.

Further, as compared with the case where a conventional multi-turn torsion spring is used, a sufficiently thin shoe plate 30 can be employed, so that the size and weight can be reduced.

Further, contact portions 31a are provided on both sides of the support shaft portion 41.
Is provided, the brake torque T1 can be generated on the other contact portion 31a side even when the load torque T2 is generated in the opposite direction to the above. Therefore, the assembling can be performed without considering the direction of the load torque.

The contact portion 31a and the braking surface 11
The braking torque (braking torque) T1 generated by the frictional force R between the two can be represented by the following equation (the reference numeral in FIG.
reference).

[0049]

T1 = μ × h × d × Q / (2 (a−μ × b)) R = μ × P P = h × Q / a T2 = Q × r where a is the load P The distance between the center point e1 of the contact pressure of the contact portion 31a and the axis of the support shaft portion 41,
The distance in the direction parallel to the load P, and b is the center point e1
And the distance between the axis of the support shaft portion 41 and the direction perpendicular to the load P, d is the diameter of the braking surface 11,
h is an engaging projection 32a receiving a load Q from the engaging recess 53a.
Is the distance between the center point e2 of the surface pressure and the axis of the support shaft portion 41, in the direction parallel to the load Q, and μ is the friction between the braking surface 11 and the contact portion 31a. A coefficient, T2 is a load torque, and Q is a force in a direction centered on the axis C of the center gear 50 (coaxial with the axis C of the shoe plate mounting member 20) and in contact with a circle passing through the center point e2. This is the distance from the axis C to the center point e2.

In the case of the leading shoe, since the frictional force R generates a rotational force in the direction of pressing one of the contact portions 31a against the braking surface 11, an extremely large braking torque T
1 will occur. In the mathematical expression, in the expression for calculating the brake torque T1 in the above (Equation 1), since -μ × b exists in the denominator, it can be said that the brake torque T1 becomes large.

For example, as actual dimensions shown in this embodiment, a = 5.86 mm, b = 5.18 mm, and d =
By substituting 37.6 mm, h = 9.8 mm, and μ = 0.15 into the above (Equation 1), the brake torque T1 is calculated as follows.

[0052]

[Equation 2] T1 = 0.15 × 9.8 × 37.6 × Q / (2 (5.86-0.15 ×
5.18)) = 5.44Q Further, the load torque T2 is calculated as r = 5.1 m in the above (Equation 1).
The following is calculated by substituting m.

[0053]

## EQU3 ## T2 = 5.1Q Accordingly, the following is obtained.

[0054]

T1> T2 That is, no matter how much the load torque T2 increases, the brake torque T1 also increases accordingly, so that the seat can be stably held at a predetermined height position. In addition, by changing the numerical values such as a, b, d, and h described above, it is easy to further increase the brake torque T1.

The above-described brake torque T1 is calculated based on one shoe plate 30, but since there are actually two shoe plates 30, a brake torque T1 twice as large as that described above is obtained. Will happen.

Next, a second embodiment of the present invention will be described with reference to FIG. However, the same reference numerals are given to the same components as the components shown in the first embodiment, and description thereof will be omitted. The difference between the second embodiment and the first embodiment is that
1 and only one shoe plate 30.

That is, the brake torque T1 is generated by the frictional force R between one shoe plate 30 and the braking surface 11.

With this configuration, the brake torque T1 is reduced by half as compared with the first embodiment in which two shoe plates 30 are provided, but the weight is reduced by the reduced number of the shoe plates 30 and the like. And the number of parts can be reduced. Therefore, by applying to a window regulator or the like having a small load torque T2, it is possible to reliably prevent the window glass from lowering, and to obtain a sufficient effect in reducing the weight of the door. In addition,
The structure shown in this embodiment has the same size as that shown in the first embodiment, so that as shown in the above (Equation 4), only one shoe plate 30 is used. Also has a braking force that can reliably prevent the seat from lowering.

Further, not only the component of the load Q in the tangential direction but also the component of the load in the direction orthogonal to the axial direction acts on the tooth portion 53 from the engagement convex portion 32a. In addition, it is preferable to arrange the shoe plate 30 at a position symmetrical with respect to the axis of the tooth portion 53 and to balance the load components in the orthogonal direction in order to make the rotation of the center gear 50 smooth.

Further, the arm portion 31 is arranged on both sides of the support shaft portion 41. This arm portion 31 is provided on one side of the side on which the brake is to be applied (for example, the clock of the support shaft portion 41 in FIG. 5). It may be configured to extend only on the rotation side). In this case, it cannot be applied to a device in which the direction of the load torque is opposite (for example, counterclockwise in FIG. 5), but there is an advantage in reducing the weight and cost.

[0061]

According to the first aspect of the present invention, the center gear (5) is operated by operating the handle shaft (21).
0) can be rotated. At this time, the contact portion (31a) of the shoe plate (30) and the lock drum (10)
Does not slide with the braking surface (11), the operating force of the handle shaft (21) can be reduced, and
Generation of abnormal noise can be prevented.

Further, as compared with the case where a conventional multiple-turn torsion spring is used, a sufficiently thin shoe plate (30) can be employed, so that the size and weight can be reduced.

According to the second aspect of the present invention, the contact portion (3
1a) and an arm portion (3) having an engagement recess (31b).
Since 1) is disposed on both sides of the support shaft (41),
For example, even if load torque is generated clockwise,
Also, even when the load torque is generated in the counterclockwise direction,
Each contact portion 31a can generate a braking torque. Therefore, since there is no need to consider the direction of the load torque, there is an advantage that the assemblability is good.

According to the third aspect of the present invention, since the shoe plates (30) are provided on both sides of the line connecting the two shaft portions (24), compared with the case where one shoe plate (30) is provided. As a result, double braking torque can be generated.

[Brief description of the drawings]

FIG. 1 is a sectional view of a brake device shown as a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of the brake device.

FIG. 3 is a view showing the brake device, and is a view showing a brake system of FIG.
It is principal part sectional drawing in alignment with the III line.

FIG. 4 is a view showing the operation of the brake device, and FIG.
FIG. 3 is a cross-sectional view of a main part along line III-III of FIG.

FIG. 5 is a view showing an operation principle of the brake device,
FIG. 3 is a cross-sectional view of a main part along a line III-III in FIG. 1.

FIG. 6 is an exploded perspective view of a brake device shown as a second embodiment of the present invention.

FIG. 7 is an explanatory view of a brake device shown as a conventional example.

[Explanation of symbols]

 Reference Signs List 10 lock drum 11 braking surface 20 shoe plate mounting member 21 handle shaft 22a shoe plate mounting surface 24 shaft portion 30 shoe plate 31 arm portion 31a contact portion 31b engaging concave portion 32 trunk portion 32a engaging convex portion 40 shoe plate holder 40a shoe Plate holding surface 41 Support shaft 50 Center gear 53a Engagement recess

Claims (3)

[Claims] 1. A lock drum (10) having a braking surface (11) formed by a cylindrical inner peripheral surface; and a shoe plate mounting surface (22a) coaxially arranged inside the braking surface (11). And a shoe plate mounting member (20) having a handle shaft 21 protruding from the lock drum (10) and rotatably provided around the axis of the braking surface (11). A center which is provided at the axis of the mounting member (20) so as to be rotatable around the axis, and has an engagement recess (53a) formed at a position corresponding to the braking surface (11) in the axial direction. A shoe plate holding surface (4) facing the gear (50) at a predetermined distance in the axial direction from the shoe plate mounting surface (22a);
0a) and a shoe plate holder (40) rotatably provided around the axis of the braking surface (11), and a support shaft (41) protruding from the shoe plate holding surface (40a). The shoe plate mounting surface (22a) and the shoe plate holding surface (4) are movably held.
0a), an arm portion (31) extending along a braking surface (11) from a portion corresponding to the support shaft portion (41), and the support shaft portion (41). ) Has a trunk portion (32) extending toward the axis of the braking surface (11), and the arm portion (31) is provided with a brake when swinging around the support shaft (41). The contact portion (3) which contacts the surface (11) to apply a braking force
1a), and has an engaging recess (31b) at the front end in the circumferential direction that can be engaged with a shaft (24) protruding from the shoe plate mounting surface (22a). A brake device comprising a shoe plate (30) having an engagement projection (32a) engaged with an engagement recess (53a) of the center gear (50) at a tip end thereof. 2. An arm portion (31) having a contact portion (31a) and an engagement concave portion (31b) is disposed on both sides of a support shaft portion (41) on the shoe plate (30). Each arm (3) is attached to the mounting surface (22a).
The shaft portion (2) is located at a position where it can be engaged with the engagement concave portion (31b) of 1).
The brake device according to claim 1, wherein (4) is provided. 3. A shoe plate (30) is provided on each of one side and the other side with respect to a line connecting the two shaft portions (24), and is provided on a shoe plate holding surface (40a). Is a support shaft (4) that rotatably holds each shoe plate (30).
3. The brake device according to claim 2, wherein 1) is provided.