JP3936729B2 - Foot-operated parking brake operation device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a foot-operated parking brake operating device, and more particularly to a technique for preventing an operating pedal from suddenly returning and turning when a brake is released.
[0002]
[Prior art]
(a) An operation pedal which is disposed on a bracket fixed to the vehicle body so as to be rotatable about the first axis, and which is depressed from the original position to tighten a brake cable and activate a parking brake; ) A drum that is disposed on the bracket so as to be rotatable about a second axis, is mechanically rotated in conjunction with the rotation of the operation pedal, and has a cylindrical surface centered on the rotation center. And (c) is arranged concentrically with the drum and is brought into close contact with the cylindrical surface, fixed at one end to the bracket and at the other end as a free end, and the operation pedal is depressed from its original position. When the operation pedal is turned back from the depressed position toward the original position, the drum is turned and the drum is further turned. A locking coil that prevents the return rotation of the coil, and (d) when the operation coil is returned and rotated by displacing the free end of the locking coil in the unlocking direction in which the locking coil is loosened. A foot-operated parking brake operating device having release means for allowing the drum to rotate is widely used.
[0003]
The release means is disposed in the bracket so as to be rotatable around a third axis, and is rotated in the release direction according to a brake release operation by a release operation member (release knob or the like) of the driver's seat, The release lever that engages with the free end of the lock coil to displace in the unlocking direction is usually used as a main component. However, such a release means has a problem in that a large hitting sound is generated because the operation pedal is vigorously returned and rotated by loosening the winding of the lock coil by the release lever.
[0004]
In contrast, a damper case is disposed between the operation pedal and its support shaft, and a viscous material is filled between the damper case and the support shaft, while a one-way clutch is provided between the damper case and the operation pedal. (Clutch spring) is provided, and the operation pedal is allowed to rotate relative to the damper case when the operation pedal is depressed, but the damper case and the operation pedal are rotated together when returning. For example, Japanese Patent Application Laid-Open No. 4-39149 discloses a stepping type parking brake operating device in which the return speed is reduced by the viscous resistance of a viscous substance.
[0005]
[Problems to be solved by the invention]
However, such a foot-operated parking brake operating device has a problem that it is necessary to provide a clutch spring and a damper case on the support shaft portion, so that the structure becomes complicated and the assembling work becomes difficult.
[0006]
The present invention has been made against the background of the above circumstances, and an object of the present invention is to prevent a sudden return rotation of the operation pedal when releasing the brake by a simple method.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, according to a first aspect of the present invention, (a) a bracket fixed to a vehicle body is rotatably arranged around a first axis, and is operated by depressing the brake cable from its original position. An operation pedal for tightening and operating the parking brake; and (b) disposed on the bracket so as to be rotatable about the second axis, and mechanically rotated in conjunction with the rotation of the operation pedal. A drum having a cylindrical surface centered on the second axis; and (c) disposed concentrically with the drum and closely contacted with the cylindrical surface, fixed to the bracket at one end and the free end at the other end When the operation pedal is depressed from the original position, the drum becomes loose and allows the drum to rotate, but when the operation pedal is rotated back from the depressed position toward the original position, Tighten Ri freely and become by drum rotation, even a lock coil having a rectangular cross section to prevent the return rotation of the operation pedal, (d) a free end of the lock coil, the unlocking direction to be freely locked coil loose In a foot-operated parking brake operating device having a release means that allows the drum to rotate when the operation pedal is returned and rotated by being displaced, (e) the cylindrical surface of the drum, the lock coil, In the meantime, a lubricating oil having a kinematic viscosity ν at 40 ° C. of 20 mm ² / s or more is applied.
[0009]
The kinematic viscosity ν is defined in JIS-K-2283, and is calculated according to the following formula (1) by measuring the time required for a certain volume of liquid to naturally flow through the capillary of the viscometer.
ν = (100πgD ⁴ ht / 128 VL) − (E / t ² ) (1)
Where g: acceleration of gravity D: diameter of capillary tube h: average effective liquid column height V: volume of liquid flowing at time t L: length of capillary tube E: kinetic energy correction coefficient
The second aspect, in the first shot Ming foot-operated parking brake operating device, at least one surface of the cylindrical surface and the locking coil of the drum, characterized in that the phosphate film is provided.
[0011]
【The invention's effect】
In such a foot-operated parking brake operating device, a high-viscosity fluid made of lubricating oil having a kinematic viscosity ν at 40 ° C. of 20 mm ² / s or more is applied between the lock coil and the cylindrical surface. The free end of the lock coil is displaced in the unlocking direction by the means, and when the operation pedal is rotated back to the original position while rotating the drum, the viscosity of the lock coil and the drum due to the highly viscous fluid A shearing resistance is generated, a rotational resistance is applied to the drum, and the return speed of the operation pedal is reduced.
[0012]
Here, in the present invention, it is only necessary to apply a high-viscosity fluid between the cylindrical surface of the drum and the lock coil. Therefore, compared with a conventional device in which a clutch spring and a damper case are provided on the support shaft portion of the operation pedal, Is simple and inexpensive, and easy to assemble.
[0013]
Further, since the lock coil is rectangular cross-section, is Ryakumen et brought into contact with the cylindrical surface of the drum, for viscous shear area that face each other across the high viscous fluid is increased, viscous shear resistance is increased along therewith, the operation The pedal return speed is effectively reduced. Since a lubricating oil having a kinematic viscosity ν at 40 ° C. of 20 mm ² / s or more is used as the highly viscous fluid , a large viscous shear resistance can be obtained, and the return speed of the operation pedal is effectively reduced. Since the lubricant has a higher coefficient of friction than grease, the return rotation of the operation pedal is reliably prevented by the friction between the lock coil and the drum during parking brake. The viscous shear resistance F is expressed by the following equation (2) using the viscosity coefficient (viscosity) η, the viscous shear area S, the relative velocity V, and the distance d between the two surfaces, and increases in proportion to the viscous shear area S. At the same time, the viscosity coefficient η increases further in proportion to the kinematic viscosity ν. The viscosity coefficient η is the product of the kinematic viscosity ν and the density ρ.
F = η · S · (V / d) (2)
[0014]
Further, in the second invention in which the phosphate coating is provided on at least one surface of the cylindrical surface of the drum and the lock coil, the holding performance of the highly viscous fluid is improved, and the space between the cylindrical surface of the drum and the lock coil is improved. The highly viscous fluid is well held, and the return speed reduction effect of the operation pedal can be obtained well over a long period of time.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Here, as the lock coil is used as the cross section rectangular (rectangle or square). The highly viscous fluid, 4 0 ° C. kinematic viscosity ν is 20 mm ² / s or more lubricating oils are used in. However, even 30 mm ² / s or more lubricant Ru preferably used. As the lubricating oil, various commonly used oils such as petroleum-based mineral oil are used.
[0016]
As the phosphate film, a zinc-based film is preferably used, but various types such as manganese-based, iron-based, and lead-based films can be employed. Moreover, it is desirable to form on the surface of the lock coil, but it is also possible to form it on the cylindrical surface of the drum. You may make it form in both of them. Such a phosphate film is formed by a chemical reaction, for example, by immersing a lock coil or drum in a predetermined solution.
[0017]
The second axis, which is the axis of the drum or the lock coil, is concentric with the first axis, which is the rotation axis of the operation pedal, and the drum is rotated about the first axis integrally with the operation pedal. Although it is desirable that the second axis is set apart from the first axis and parallel to the first axis, the drum and the operation pedal are mechanically connected by a gear mechanism or a link mechanism. Anyway. If necessary, the first axis and the second axis can intersect with each other or be in a twisted relationship.
[0018]
The release means includes, for example, (a) a release lever that is rotated by a fixed angle around a third axis substantially parallel to the second axis by operating a release operation means provided near the driver's seat; (b) It is integrally attached to the release lever, and is brought into contact with the free end of the lock coil as the release lever rotates, and the free end is displaced in the unlocking direction, and the free end And an adjusting member whose mounting position with respect to the release lever can be adjusted so that the amount of displacement in the unlocking direction can be appropriately set. In this way, even if the position of the free end changes due to a dimensional error or mounting error of the lock coil, the amount of displacement of the free end, in other words, between the lock coil and the drum cylindrical surface when the brake is released. Since the gap dimension (distance d between the two surfaces in equation (2) above) can be adjusted to be constant, variations in viscous shear resistance during the return rotation of the operation pedal are suppressed, resulting in stable product quality To do. Moreover, a desired viscous shear resistance can be obtained by appropriately setting the amount of displacement of the free end (distance d between the two surfaces) according to the kinematic viscosity ν of the highly viscous fluid to be used. The release lever is configured to be mechanically rotated with the operation of the release operation means using, for example, a release cable, but may be rotated using an electric motor or the like.
[0019]
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a right side view of a foot-operated parking brake operating device 10 according to an embodiment of the present invention, and FIG. 2 is a front view, which shows a first bracket 12 fixed to a vehicle body, a support shaft 14 and a plurality of And a second bracket 16 integrally fixed to the first bracket 12 via a connecting pin, and an operation pedal 18 is provided around the axis S of the support shaft 14 between the brackets 12 and 16. It is arrange | positioned so that rotation is possible. The operation pedal 18 is provided with a cable guide 20, and the other end portion of the brake cable 22 whose one end portion is connected to an operating portion of a parking brake (not shown) is wound around the cable guide 20 and locked. By stepping 18 to the left of the axis S from the original position shown in FIG. 1, the brake cable 22 is tightened to activate the parking brake. A nut 24 is screwed to the other end portion of the brake cable 22, and the nut 24 is locked to a locking portion 26 provided on the operation pedal 18. The operation pedal 18 is rotated back to the original position side by cable tension or a return spring (not shown), and is brought into contact with a stopper rubber (not shown) provided between the brackets 12 and 16, thereby causing the original position shown in FIG. Is positioned.
[0020]
As shown in FIG. 3, the operation pedal 18 is integrally provided with a sleeve 28 that is rotatably fitted to the support shaft 14, and concentrically, that is, in an assembled state on the outer peripheral side of the sleeve 28. A cylindrical drum 30 is integrally provided so as to be concentric with the axis S of the support shaft 14. The outer peripheral surface of the drum 30 is a cylindrical surface 32, and a lock coil 34 disposed concentrically on the outer peripheral side of the drum 30 is brought into close contact with the cylindrical surface 32 by its own spring force. As shown in FIG. 1, one end 36 of the lock coil 34 is locked in a lock hole 38 provided in the bracket 12, and the lock coil 34 rotates about the axis S that is the center line of the lock coil 34. On the other hand, the other end of the lock coil 34 is a free end 40, and when the operation pedal 18 is depressed from its original position, it becomes loose and allows the drum 30 to rotate. However, when the operation pedal 18 is rotated back from the depressed position toward the original position, the drum 30 is turned and the rotation of the drum 30 and further the return rotation of the operation pedal 18 are prevented. The axis S of the support shaft 14 corresponds to the first axis that is the rotation center of the operation pedal 18 and the second axis that is the axis of the drum 30.
[0021]
The lock coil 34 has a rectangular cross section, that is, a rectangular cross section as is apparent from FIG. 3, and an arc surface on the inner peripheral side thereof is brought into substantially surface contact with the cylindrical surface 32 of the drum 30. At the same time, a lubricating oil having a kinematic viscosity ν at 40 ° C. of 30 mm ² / s or more is applied between the lock coil 34 and the cylindrical surface 32. Further, the surface of the lock coil 34 is provided with a zinc-based phosphate film by a chemical reaction by immersion in a predetermined solution, so that the lubricating oil can be well maintained over a long period of time. Yes.
[0022]
The operation pedal 18 is provided with an arc-shaped elongated hole 70 centered on the axis S, and the free end 40 of the lock coil 34 projects from the elongated hole 70 to the second bracket 16 side. The long hole 70 has a length that does not interfere with the free end 40 regardless of the depression operation of the operation pedal 18. The second bracket 16 is provided with a support pin 42 in parallel with the support shaft 14. The support pin 42 has an unlocking direction in which the free end 40 of the lock coil 34 is loosened by the lock coil 34. 1 is provided with a release means 44 that allows the drum 30 to rotate when the operation pedal 18 is returned and rotated by displacing the support shaft 14 in the counterclockwise direction (stepping direction of the operation pedal 18). Yes. As shown in an exploded view in FIG. 4, the release means 44 includes a release lever 46, an adjustment member 48, and a return spring (torsion coil spring) 50.
[0023]
The release lever 46 is pulled by a pulling operation or the like of a release knob (release operation means) (not shown) provided in the vicinity of the driver's seat with a release cable 54 (see FIG. 1) locked to the locking portion 52 at the tip. The support pin 42, which is the third axis, is rotated counterclockwise about the axis of the axis. The release lever 46 is also provided with an arc-shaped elongated hole 56 centering on the support pin 42, and the adjustment member 48 is released by a fixing screw 58 disposed through the elongated hole 56. The relative angular position of the periphery of the support pin 42 with respect to 46 is fixed to the release lever 46 so as to be changeable. The adjustment member 48 is provided with a contact portion 60 that is brought into contact with the free end 40 of the lock coil 34 by being rotated counterclockwise of the support pin 42 integrally with the release lever 46. In the initial state shown in FIG. 1, the clearance (play) between the contact portion 60 and the free end 40 has a constant dimension, in other words, the free end 40 is unlocked as the release lever 46 rotates by a constant angle. The attachment position of the adjustment member 48 is adjusted according to the position of the free end 40 that changes due to the dimensional error, the assembly error, etc. of the lock coil 34 so that the amount of displacement in the direction becomes substantially constant. The amount of displacement of the free end 40 is appropriately set according to the kinematic viscosity ν of the lubricating oil used so that the desired viscous shear resistance F can be obtained. One end of the return spring 50 is hooked on a locking portion 62 provided on the second bracket 16, and the other end is hooked on a locking member 64 that rotates integrally with the release lever 46. Is urged clockwise around the support pin 42, and the release lever 46 is returned to the initial position shown in FIG. 1 when the operation of the release knob near the driver's seat is released. This initial position is defined, for example, by bringing a release knob near the driver's seat into contact with an instrument panel or the like.
[0024]
In such a foot-operated parking brake operating device 10, when the operation pedal 18 is depressed from the original position, the brake cable 22 is tightened and the parking brake is activated. Since the lock coil 34 brought into close contact with the cylindrical surface 32 of the drum 30 becomes loose at this time, the rotation of the drum 30 and the depression of the operation pedal 18 are allowed. When the depressing operation of the operation pedal 18 is released in the operation state of the parking brake, the operation pedal 18 is subjected to a force that returns and rotates due to the tension of the brake cable 22 or the elastic return force of a return spring (not shown). A rotating force in the return direction is applied to the drum 30 provided in the operation pedal 18, but the lock coil 34 is easily tightened against the rotation in the return direction. The rotation of the drum 30 is prevented by the friction between the operation pedal 18 and the operation pedal 18 cannot return and rotate, and the operation state of the parking brake is maintained.
[0025]
Further, when the release cable 54 is pulled by pulling operation of the release knob or the like in the parking brake operation state, the release lever 46 is rotated counterclockwise against the urging force of the return spring 50. . When the abutting portion 60 of the adjusting member 48 is brought into contact with the free end 40 of the lock coil 34, the lock coil 34 is displaced in the unlocking direction to be loosened, and the lock coil 34 and the cylindrical surface 32 are displaced. The friction between them decreases and the rotation of the drum 30 in the return direction is allowed, and the operation pedal 18 is returned to the original position and rotated by the tension of the brake cable 22 and the elastic return force of a return spring (not shown). Thereby, the operation of the parking brake is released.
[0026]
Here, in this embodiment, since the highly viscous lubricating oil is applied between the lock coil 34 and the cylindrical surface 32 of the drum 30, the free end 40 of the lock coil 34 is displaced in the unlocking direction and locked. When the diameter of the coil 34 is increased, friction is reduced, and the drum 30 starts to rotate clockwise around the shaft center S together with the operation pedal 18, the viscous shear resistance represented by the above equation (2) is caused by the highly viscous lubricant. F is generated, a rotational resistance is applied to the drum 30, and the return speed of the operation pedal 18 is reduced. Thereby, the impact and the hitting sound when the operation pedal 18 contacts the stopper rubber or the like are reduced.
[0027]
In particular, in this embodiment, since the lock coil 34 has a rectangular cross section and is substantially brought into surface contact with the cylindrical surface 32 of the drum 30, the viscous shear area S increases and the viscous shear resistance F increases accordingly. The return speed of 18 is effectively reduced. Further, since a lubricating oil having a kinematic viscosity ν at 40 ° C. of 30 mm ² / s or more is used, the viscosity coefficient η increases in proportion to the kinematic viscosity ν, and a large viscous shear resistance F is obtained in this respect as well. As a result, the return speed of the operation pedal 18 is more effectively reduced. Since the lubricating oil has a higher coefficient of friction than grease, the return rotation of the operation pedal 18 is reliably prevented by the friction between the lock coil 34 and the drum 30 during parking braking.
[0028]
Incidentally, according to the experiments by the present inventors, in the foot-operated parking brake 10 of this embodiment, a lubricating oil having a kinematic viscosity ν≈20 mm ² / s is applied between the lock coil 34 and the cylindrical surface 32 of the drum 30. In this case, the impact sound when returning the pedal is reduced by about 1 dB compared to a lubricating oil having a kinematic viscosity ν of 10 mm ² / s or less, and when a lubricating oil having a kinematic viscosity ν≈30 mm ² / s is applied, the kinematic viscosity ν As compared with a lubricating oil having a speed of 10 mm ² / s or less, the hitting sound when the pedal returns is reduced by about 2 dB.
[0029]
On the other hand, since a phosphate film is provided on the surface of the lock coil 34, the retention performance of the highly viscous lubricant is improved, and the lubricant is good between the cylindrical surface 32 of the drum 30 and the lock coil 34. The return speed reduction effect of the operation pedal 18 can be obtained satisfactorily over a long period of time.
[0030]
In this embodiment, the displacement of the free end 40 of the lock coil 34 accompanying the rotation of the release lever 46 when the brake is released, regardless of the position change of the free end 40 due to the dimensional error or mounting error of the lock coil 34. Since the mounting position of the adjustment member 48 with respect to the release lever 46 is adjusted so that the amount is substantially constant, the dimension of the gap between the lock coil 34 and the cylindrical surface 32 of the drum 30 (2 in the above equation (2)). The distance d) between the surfaces becomes substantially constant, and the variation in the viscous shear resistance F during the return rotation of the operation pedal 18 is suppressed, thereby stabilizing the product quality.
[0031]
Further, in this embodiment, it is only necessary to apply a highly viscous lubricating oil between the cylindrical surface 32 of the drum 30 and the lock coil 34, so that a clutch spring or a damper case is provided on the support shaft 14 portion of the operation pedal 18. Compared to the device, the device is simple and inexpensive, and the assembly work is also easy.
[0032]
As mentioned above, although the Example of this invention was described in detail based on drawing, this is an embodiment to the last, and this invention implements in the aspect which added the various change and improvement based on the knowledge of those skilled in the art. Can do.
[Brief description of the drawings]
FIG. 1 is a right side view of a stepping type parking brake operating device according to an embodiment of the present invention.
2 is a front view of the foot-operated parking brake operating device of FIG. 1. FIG.
FIG. 3 is a cross-sectional view showing the vicinity of a drum and a lock coil of the embodiment of FIG. 1;
4 is an exploded perspective view of the release means of the embodiment of FIG.
[Explanation of symbols]
10: Foot-operated parking brake operation device 12, 16: Bracket 18: Operation pedal 30: Drum 32: Cylindrical surface 34: Lock coil 40: Free end 44: Release means S: Axes (first axis, second axis )

Claims (2)

An operation pedal which is disposed on a bracket fixed to the vehicle body so as to be rotatable about a first axis, and which is depressed from an original position to tighten a brake cable to activate a parking brake;
A drum that is disposed on the bracket so as to be rotatable about a second axis, is mechanically rotated in conjunction with the rotation of the operation pedal, and has a cylindrical surface centered on the second axis. When,
It is arranged concentrically with the drum and is brought into close contact with the cylindrical surface, fixed at one end to the bracket and at the other end as a free end, and is loosened when the operation pedal is depressed from its original position. The drum is allowed to rotate, but when the operation pedal is turned back from the depressed position toward the original position, the drum is turned and the operation pedal is returned. A rectangular cross-section locking coil that prevents rotation;
A release means for allowing the drum to rotate when the operation pedal is returned and rotated by displacing a free end of the lock coil in an unlocking direction in which the lock coil is loosened. Type parking brake operating device,
A foot-operated parking brake operating device, wherein a lubricating oil having a kinematic viscosity ν at 40 ° C. of 20 mm ² / s or more is applied between a cylindrical surface of the drum and the lock coil. The foot-operated parking brake operating device according to claim 1, wherein a phosphate film is provided on at least one surface of the cylindrical surface of the drum and the lock coil.

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