JP5466260B2 - Disc brake device - Google Patents

Description

  The present invention relates to a disc brake that performs braking by pressing a brake rotor by pressing a pad through an adjusting screw having an automatic gap adjustment function in which the rotational force of a rotary shaft driven by an electric motor is changed in the axial direction and moves forward. Relates to the device.

  Conventionally, in a disc brake device for a vehicle equipped with a brake, particularly a railway vehicle, there is a caliper disc brake device that performs a brake operation by clamping a disc rotor by an inner pad and an outer pad via a caliper body having a built-in inner pad pressing mechanism. Are known. In such a caliper disc brake device, a highly reliable electromechanical disc brake device having a simple structure in which a brake pad is pressed by an electric motor instead of a piston that is conventionally pressed by hydraulic pressure is frequently used. It has become like this. However, a disc brake that requires a large braking force requires a large pressing force. Therefore, a large output electric motor is required, and the apparatus becomes large. For this reason, a servo mechanism (self-boosting device) that can employ an electric motor with a relatively small output has been proposed (see, for example, Patent Document 1 below).

Japanese Patent Publication No. 2004-525325 (refer to the gazette abstract)

  The conventional electromechanical brake disclosed in Patent Document 1 will be briefly described with reference to FIG. 6. The electric actuator acts on the wedge 118 to face each other to generate two driving mechanisms 134 and 134 ′. Within the range of low operating force, ie tan α≈μ, where μ is the coefficient of friction between the friction member 116 and the brake disc 114 to be braked. Are configured to act against each other to generate a braking force. The wedge 118 is disposed on the back side (left side in the drawing) at an inclination angle α with respect to the brake disk 114 and is supported by complementary wedge surfaces 121 and 121 ′ of the block-shaped counter bearing 122. The wedge 118 and the opposing bearing 122 constitute a part of a self-boosting device that increases the operating force generated by the drive mechanisms 134, 134 '.

  That is, when one of the two drive mechanisms 134 and 134 ′ is actuated by driving the electric actuator, the opposing bearing 122 moves in one of the rotation directions of the brake disk 114. As a result, the wedge 118 presses the friction member 116 against the side surface of the brake disk 114. The wedge 118 that rotates with the brake disk 114 due to the frictional force between the friction member 116 and the brake disk 114 further increases the pressing force to the side surface of the brake disk 114 by either of the complementary wedge surfaces 121 and 121 ′. Demonstrate. When the friction member 116 is worn, each pair of threaded bolts 124 that are non-detachably joined to the opposing bearing 122 is rotated by using an electric motor (not shown) in the adjusting device 142, respectively. The gap between the brake caliper 126 and the brake caliper 126 is adjusted.

With an electromechanical brake having such a configuration, a brake device having a self-boosting function can be realized with only a simple actuator without requiring piping or the like in both cases of forward travel and reverse travel. It was. However, in this conventional example, since the inclination angles of the wedge surfaces 121 and 121 ′ exhibiting the self-boosting function are constant, the generated self-boosting ratio (usually expressed as μ / (tan α−μ)). Was constant. Therefore, since the friction coefficient (μ) of the friction material changes depending on the history of heat, etc., a high boost ratio cannot always be obtained depending on the change of the friction coefficient. As a result of the large reduction in the boost ratio and the need for a large amount of control energy, miniaturization of the electric motor has been hindered.
In addition, such a conventional device requires an electric motor for operating a gap adjusting mechanism that follows the lining wear, and there is a concern that the structure becomes large and complicated. In addition, when the adjustment mechanism is complicated and large as in the conventional apparatus, it is often difficult to install a boot or the like for protecting the components including the self-boosting mechanism. In addition, the operation of the clearance adjustment mechanism and the operation of the self-boosting mechanism are mixed, and there is a possibility that it may be confused at the time of either maintenance or inspection.

  Therefore, the present invention solves the problems of the conventional self-boosting disc brake device, and even with a simple structure, it is easy to protect the components and without providing an electric motor or the like for the gap adjusting mechanism. An object of the present invention is to provide a disc brake device that can perform automatic clearance adjustment and that can easily set an operation condition for selectively switching between an automatic clearance adjustment function and a servo function.

Therefore, the technical solution adopted by the present invention is:
In the disc brake device in which the pad is pushed out through an adjusting screw having an automatic gap adjustment function in which the rotational force of the rotating shaft driven by the electric motor is changed in the axial direction and moves forward to press the brake rotor to perform braking. The rotational force of the rotary shaft is configured to rotate the adjustment screw by using a planetary speed reduction mechanism including a gear train having each rotary shaft parallel to the rotary shaft housed in the cylindrical adjustment screw. Disc brake device.
In addition, a servo that generates an axial force through rotation of an eccentric cam caused by rotation of a sun gear of a planetary speed reduction mechanism when the adjusting screw stops when receiving an axial braking reaction force from the pad during braking. A disc brake device configured to operate a mechanism.
The rotation of the sun gear and the eccentric cam is regulated by a set load of a torsion spring for positioning the eccentric cam.
In the disc brake device, a gap urged by a preset spring is provided between the adjusting screw and the servo mechanism.
The servo mechanism includes a rotating eccentric cam, a servo plate moved in the circumferential direction by the eccentric cam, and a stator plate interposed between the adjustment screw end surfaces, and between the stator plate and the servo plate. The servo roller is configured to generate an axial force in the axial direction by escaping from the accommodation groove of the stator plate as the servo plate moves in the circumferential direction. This is a disc brake device.
Further, a slide plate integrated with the inner pad is interposed between the servo plate and the inner pad, and the slide plate abuts on the servo plate in the forward direction and is used for servo operation of the servo plate. The disc brake device is characterized in that it can be made .

  According to the present invention, the pad is pushed out through an adjusting screw having an automatic gap adjustment function in which the rotational force of the rotating shaft driven by the electric motor is changed in the axial direction and moves forward. In a disc brake device that presses the brake rotor to perform braking, a planetary reduction mechanism comprising a gear train having rotational axes parallel to the rotational axis accommodated in the cylindrical adjusting screw is used for the rotational force of the rotational axis. By rotating the adjustment screw, the transmission mechanism that transmits the rotational force of the rotating shaft to the adjustment screw can be configured in the cylindrical adjustment screw using the planetary reduction mechanism. In addition to being able to provide reliable control transmission, the axial direction during braking that acts on the adjusting screw The braking reaction force is not transmitted to the inside of the planetary reduction mechanism composed of a gear train having each rotation shaft parallel to the rotation shaft, but is received by the screw portion to the sleeve or the like on the outer peripheral portion of the adjustment screw. Since the planetary speed reduction mechanism does not need to have high strength, the weight can be reduced.

  Further, the eccentric cam rotates due to the rotation of the sun gear of the planetary reduction mechanism when the adjusting screw is stopped when receiving an axial braking reaction force from the pad during braking. If the servo mechanism that generates axial force is operated, the servo mechanism is activated after the automatic gap adjustment mechanism using the adjusting screw stops, so the automatic gap adjustment mechanism and the servo mechanism can be selectively used. In addition, the automatic gap adjustment mechanism and the servo mechanism can be performed separately at the time of maintenance / inspection, thereby clarifying the work. Furthermore, when the rotation of the sun gear and the eccentric cam, which is a constituent requirement of claim 3, is restricted by the set load of the torsion spring for positioning the eccentric cam, the servo mechanism by the rotation of the eccentric cam, that is, the rotation of the sun gear Can be easily set by the set load of the torsion spring.

Furthermore, when a gap urged by a preset spring is provided between the adjusting screw and the servo mechanism, which is a constituent element of claim 4, it is caused by thermal expansion that occurs when braking is continued. Even if the length of each part in the axial direction increases, the concern that the pad will not be released from the brake rotor when releasing the brake is eliminated. It is also possible to set the stop time. Further, the configuration requirements of claim 5, wherein the servo mechanism includes a stator plate which is interposed between the servo plate to be moved by the eccentric cam and the eccentric cam that rotates in the circumferential direction and the adjusting screw end face, wherein The servo plate is interposed between the stator plate and the servo plate, and is configured to generate an axial force in the axial direction by climbing onto the servo roller as the servo plate moves in the tangential direction. In this case, a reliable and large axial servo force can be easily obtained by the combination of the rotation of the eccentric cam with a simple structure, the tangential movement of the servo plate and the servo roller.

Furthermore, a slide plate integral with the inner pad is interposed between the servo plate and the inner pad, which is a constituent element of claim 6, and the slide plate is in contact with and integrated with the servo plate in the forward direction. In this case, the tangential force generated by braking can be used for servo operation by moving the servo plate further in the tangential direction via the slide plate during forward movement requiring a larger braking force. It is done.

1 is an overall longitudinal sectional view of a partial cross section of a disc brake device of the present invention. It is AA sectional drawing of FIG. FIG. 3 is an enlarged view of a main part of FIG. It is an exploded perspective view of an eccentric cam and a planetary speed reduction mechanism. 2 is an exploded perspective view of the servo mechanism. FIG. It is explanatory drawing of the servo mechanism in the conventional electromechanical brake.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for implementing a disc brake device of the invention will be described with reference to the drawings. As shown in FIG. 1, the disc brake device of the present invention has an automatic screw adjustment function 3 having an automatic clearance adjustment function in which the rotational force of the rotary shaft 2-1 driven by the electric motor 1-4 is changed in the axial direction and moves forward. In the disc brake device in which the pad 6 is pushed out through -3a and brakes by pressing the brake rotor, the rotating shaft 2 accommodates the rotational force of the rotating shaft 2-1 in a cylindrical adjusting screw 3-3a. The adjusting screw 3-3a is rotated using a planetary reduction mechanism 3-5 including a gear train having rotation axes parallel to -1.

  Examples of the disc brake device of the present invention will be described below. The caliper body 1-1 (see FIG. 2) is fixed to the vehicle body stationary part via an appropriate support 5, and the rotational driving force of the electric motor 1-4 housed and installed in the caliper body 1-1 is shown in FIG. As shown in the figure, it is transmitted to a rotating shaft 2-1 having a parallel rotating shaft through a speed reduction mechanism comprising an appropriate gear train, and the rotational force of the rotating shaft 2-1 is splined or 6 It is transmitted to planetary carrier (B) 3-5c that rotates together by corner fitting. The planetary carrier (B) 3-5c holds the planetary gears 3-5b and 3-5e together with the planetary carrier (A) 3-5a while the planetary gears 3-5b and 3-5e are connected to pads 6 and 7 described later. Together with the eccentric cam (3-6) until a braking operation is started in which a predetermined braking force is generated by contact with a brake rotor (not shown: disposed between the inner pad 6 and the outer pad 7). The periphery of the sun gear 3-5d whose rotation is restricted by the set load of the positioning torsion spring 3-7b is meshed and revolved. Thereby, the planetary gears 3-5b and 3-5e forcibly rotate the ring gear 3-18 that meshes with the outer periphery thereof.

  As shown in FIG. 3 (rotating shaft 2-1 and planetary gears 3-5 d and 3-5 e are not shown) which is an enlarged view of the main part of FIG. -18 is firmly tightened in the axial direction via the spacers 3-17 and 3-19 by the plug 3-20 screwed to the inner periphery of the cylindrical adjustment screw 3-3a to adjust the screw 3-3a. And integrated. A screw portion C is formed on the outer periphery of the adjusting screw 3-3a to be screwed with the inner periphery of the sleeve 3-4. Therefore, the adjusting screw 3-3a rotates together with the ring gear 3-18, and moves forward (leftward in the drawing) in the axial direction with respect to the sleeve 3-4.

  A preset spring 3-between the end surface of the adjusting screw 3-3a and the servo mechanism (3-7 to 3-14), specifically, between the end surface of the adjusting screw 3-3a and the stator plate 3-7a. Even if the axial length of each part increases due to the thermal expansion that occurs when braking is continued, the pad is not released from the brake rotor when the braking is released. It is possible to eliminate the concern and set the stop time of the adjusting screw 3-3a due to the braking reaction force by selecting the biasing force of the preset spring 3-3d. In other words, the biasing force of the preset spring 3-3d affects the screwing frictional force of the screw portion C between the outer periphery of the adjusting screw 3-3a and the inner periphery of the sleeve 3-4, so that the adjusting screw caused by the braking reaction force is applied. The stop time of 3-3a can be set.

  As described above, the eccentric pad 3 is pressed until the inner pad 6 is pressed against the brake rotor to start braking, and until the braking operation is started in which the brake rotor is pinched by the outer pad 7 to generate a predetermined braking force. Since rotation of -6 is restricted by the set load of the torsion spring 3-7b for positioning, the sun gear 3-5d that rotates together with the input end of the eccentric cam 3-6 by spline or hexagonal fitting also rotates. Is regulated. As shown in the exploded view of FIG. 4A, one end of a torsion spring 3-7b is locked to a cam stopper 3-7c on the inner periphery of a non-rotatable stator plate 3-7a and fixed by a screw 3-7d. Is done. The other end of the torsion spring 3-7b is locked to the outer periphery of the eccentric cam 3-6. Thus, the rotation of the eccentric cam 3-6 and the sun gear 3-5d is restricted until a torque of a predetermined value or more is generated in the rotation direction due to the set load of the torsion spring 3-7b.

  As described above, when the adjusting screw 3-3a rotates with the ring gear 3-18 and advances in the axial direction with respect to the sleeve 3-4, the adjusting screw 3-3a advances in the axial direction while rotating, The inner pad 6 integrated with the servo holder 3-1 is advanced via the stator plate 3-7 a, and the inner pad 6 is pressed against the brake rotor to start braking, and the brake rotor is pinched by the outer pad 7. When a predetermined braking force is generated, the adjustment screw 3-3a receives the preset load of the preset spring 3-3d when receiving an axial braking reaction force from the pads 6 and 7 during braking. The rotation is prevented by screwing friction in the screw part C with respect to -4. That is, the stop timing of the ring gear 3-18 is set by the preset load of the preset spring 3-3d. As a result, the rotation of the ring gear 3-18 stops, but the planetary carrier (B) 3-5c and the planetary carrier (A) 3-5a continue to rotate, so that the planetary gear 3 that is screwed into the inner periphery of the ring gear 3-18. The sun gear 3-5d is forcibly rotated while 5b and 3-5e (see FIG. 1) rotate.

  The rotation of the sun gear 3-5d is caused by the torsional force set by the set load of the torsion spring 3-7b of the eccentric cam 3-6 integrated with the output end of the sun gear 3-5d by spline or hexagonal fitting. As a result, the eccentric cam 3-6 is rotated. When the eccentric cam 3-6 starts rotating, as shown in the exploded perspective view of FIG. 5, the eccentric portion on the output end side of the eccentric cam 3-6 rotates, so that the servo plate 3-8 moves in the tangential direction. The servo roller 3-14 moved between the servo plate 3-8 and the stator plate 3-7a escapes in the axial direction from the accommodation groove (ramp groove) in the stator plate 3-7a. The plate 3-8 moves in the axial direction to generate an axial force. Self-boosting, that is, servo force acts on the inner pad 6 via the slide plate 3-11.

  Further, an integral slide plate 3-11 is interposed between the servo plate 3-8 and the inner pad 6 so as to engage with the inner pad 6, and the slide plate 3-11 moves forward (see FIG. 3). In the case of being integrated by contacting the servo plate 3-8 (point P in FIG. 3) in the F direction), a tangential force acting on the inner pad 6 generated by braking is required during forward movement requiring a larger braking force. However, since the servo plate 3-8 can be further moved in the tangential direction via the slide plate 3-11 and used for the servo operation of the servo plate 3-8, a larger braking force can be obtained. During reverse travel, the servo holder 3-1, the inner pad 6, and the integral slide plate 3-11 come into contact with each other, and the servo cam 3-6 moves in the opposite direction to the tangential movement of the servo plate 3-8. Although it is reliable and large, the servo action is diminished and slightly smaller.

  In FIG. 1, 1-5 is a positioning pin, 3-15 and 3-16 are washers and retaining rings interposed between the eccentric cam 3-6 and the adjusting screw 3-3a, respectively, and 3-3b is an eccentric cam. A bearing interposed between 3-6 and the adjusting screw 3-3a, 3-3c is a retaining ring of the spring seat 3-3e of the preset spring 3-3d, 3-2 is a sleeve 3-4 and the servo holder 3- 1-9, a boot provided on the outer periphery of the stator plate 3-7a and the slide plate 3-11, and 3-13 between the servo plate 3-8 and the slide plate 3-11. It is a thrust bearing interposed in the.

  In FIG. 2, a sensor housing 4-1 in the axial force sensor unit 4 is pivotally supported by a bearing 4-3 on a rotating shaft 2-1, and the axial force sensor 4-2 is accommodated in the sensor housing 4-1. The sensor housing 4-1 is integrated with the sleeve 3-4 by locking pins 1-2 and 1-3. Reference numerals 3-10 and 3-12 denote set springs for the inner pad 6 to the servo holder 3-1.

  Thus, the planetary speed reduction mechanism 3-5, which is a transmission mechanism, can be protected from water and dust easily and with high reliability, and the braking reaction force in the axial direction during braking acting on the adjusting screw 3-3a. Is not transmitted to the inside of the planetary reduction mechanism 3-5 composed of a gear train having respective rotation shafts parallel to the rotation shaft 2-1, but to the sleeve 3-4 on the outer peripheral portion of the adjustment screw 3-3a. Since the planetary speed reduction mechanism 3-5 does not need to be strengthened by being received by the screw portion C, the weight of the planetary speed reduction mechanism 3-5 can be reduced. In addition, after the automatic gap adjustment mechanism by the adjusting screw 3-3a stops, the servo mechanism 3 Since -7 to 3-14 operate, it is possible to selectively switch between the automatic gap adjustment mechanism and the servo mechanism, and to perform the automatic gap adjustment mechanism and the servo mechanism separately for maintenance and inspection. Made, work is clarified.

Further, the operation start condition of the servo mechanism by the rotation of the eccentric cam 3-6, that is, the rotation of the sun gear 3-5d can be easily set by the set load of the torsion spring 3-7b, and the preset spring 3-3d is interposed. Therefore, even if the axial length of each part due to thermal expansion that occurs when braking is continued increases, the concern that the pad will not be released from the brake rotor when releasing the brake is also eliminated, and the preset spring 3-3d By selecting the urging force, it is possible to set the stop time of the adjusting screw due to the braking reaction force. In addition, the combination of servo cams, inner pads, and slide plates can be obtained easily and reliably by the combination of simple structure eccentric cam rotation, servo plate tangential movement and servo rollers. When moving forward, which requires a larger braking force, the tangential force generated by braking can be used for servo operation by moving the servo plate further in the tangential direction via the slide plate. It was to be obtained.

As described above, the embodiments of the present invention have been described. However, within the scope of the present invention, the shape and type of the electric motor and the form of the speed reduction mechanism on the rotating shaft (in addition to the gear train parallel to the rotating shaft, the umbrella (It is possible to decelerate by tooth meshing and pinion and worm meshing), deceleration rate, shape of adjusting screw, type and automatic clearance adjustment mode, fixing mode between adjusting screw and ring gear (in addition to tightening with plug via spacer, Appropriate tightening methods can be used in relation to assembly and strength resistance), the shape and type of planetary reduction mechanism (if the planetary gear train has a rotation axis parallel to the rotation axis, the long axis pinion gear and the short axis pinion gear mesh with each other Can be used between the ring gear and the sun gear), setting the preset load of the preset spring to the adjustment screw , Selection value of the screw friction coefficient of the screw portion with the sleeve of the adjusting screw, clearance amount between the adjusting screw and the stator plate, set value of the set load of the torsion spring for positioning the eccentric cam, the eccentric cam of the torsion spring and the stator Interposition form on the plate, shape and type of the servo mechanism (in addition to interposing an appropriately shaped servo roller capable of camming between the stator plate and the servo plate, an angle between the stator plate and the servo plate combination of plane and angled concave accept it, etc.), if is integrated in the contact form (forward direction to the servo plate and slide plate of the servo plate is interposed between the inner pad, the appropriate form Can be selected as appropriate. In addition, the specifications described in the examples are merely examples in all respects and should not be interpreted in a limited manner.

  The disc brake device of the present invention is preferably applied to a caliper disc brake of a railway vehicle, but can also be applied to a vehicle such as an automobile, an industrial disc brake, and the like.

1-4 Electric motor 2-1 Rotating shaft 3-3a Adjust screw 3-5 Planetary reduction mechanism 6 Inner pad

Claims (6)

In the disc brake device in which the pad is pushed out through an adjusting screw having an automatic gap adjustment function in which the rotational force of the rotating shaft driven by the electric motor is changed in the axial direction and moves forward to press the brake rotor to perform braking. The rotational force of the rotary shaft is configured to rotate the adjustment screw by using a planetary speed reduction mechanism including a gear train having each rotary shaft parallel to the rotary shaft housed in the cylindrical adjustment screw. Disc brake device. A servo mechanism that generates an axial force through rotation of an eccentric cam caused by rotation of a sun gear of a planetary reduction mechanism when the adjusting screw is stopped when receiving an axial braking reaction force from the pad during braking. The disc brake device according to claim 1, wherein the disc brake device is configured to operate. The disc brake device according to claim 2, wherein the rotation of the sun gear and the eccentric cam is regulated by a set load of a torsion spring for positioning the eccentric cam. 4. The disc brake device according to claim 2, wherein a gap biased by a preset spring is provided between the adjustment screw and the servo mechanism. The servo mechanism includes a rotating eccentric cam, a servo plate that moves in the circumferential direction by the eccentric cam, and a stator plate interposed between the adjustment screw end surfaces, and a space between the stator plate and the servo plate. The servo roller is configured to generate an axial force in the axial direction by escaping from the accommodation groove of the stator plate as the servo plate moves in the circumferential direction. The disc brake device according to claim 4 . A slide plate integral with the inner pad is interposed between the servo plate and the inner pad, and the slide plate abuts on the servo plate in the forward direction so that it can be used for servo operation of the servo plate. disc brake device according to claim 5, characterized in that the.

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