JP4210607B2 - Disc brake floating structure - Google Patents

Description

  The present invention relates to a structure of a disc brake, and more particularly to a caliper floating structure (or “caliper floating structure”) in a disc brake.

  There are a drum brake type and a disc brake type as a brake type of the vehicle, and the disc brake type is roughly divided into a one-push piston type and an opposed piston type. The opposed piston type is a structure in which both the left and right pads are moved by the opposed pistons to sandwich the disc rotor, so that the brake pad does not drag to the disc rotor when the brake is released, resulting in low running resistance, caliper, and disc rotor both fixed This is superior in terms of improving braking performance, but has many disadvantages in terms of space and weight.

  On the other hand, in the case of the single push piston type, the piston that moves the brake pad has a structure only on one side, so the problem of space and weight can be solved. Especially in the case of caliper floating structure, the piston that moves the brake pad directly Even if it is only on one side, the brake pad on the opposite side can also hold the disc rotor from both sides by moving the floating caliper in the direction of the pad, so there is no problem of braking performance.

However, even the caliper floating type still has a problem in terms of generating running resistance. First, in order to clarify the problem, the structure of the caliper floating type disc brake will be described. The disc brake 10 is generally formed of caliper 12, sleeve 14, pads 16a, 16b as schematically shown in FIG. The carrier 20 is formed. The carrier 20 is fixed to an axle mechanism (not shown) together with the sleeve 14, and the caliper 12 is not fixed to the axle mechanism and is slidable on the sleeve 14 (in this sense, "floating" or Called "floating"). The pads 16a and 16b are opposed to each other with the disk rotor 18 interposed therebetween. Further, the pad 16a applies frictional force to the rotor 18 by the pad 16a sliding in the direction of the disk rotor 18 in contact with the disk rotor 18 during braking according to the movement of a piston (not shown), and brakes when the brake is released. The pad 16a and the rotor 18 are separated from each other by sliding in the opposite direction. Further, when the pad 16a contacts the rotor 18 during braking, a reaction force that opposes the corresponding contact force acts on the pad 16a from the rotor 18 on the contrary. When this reaction force is transmitted to the caliper 12, the caliper 12 slides on the sleeve 14 in the direction opposite to the rotor 18 (left direction in FIG. 7 ). Accordingly, the pad 16b mounted on the caliper 12 so as to face the pad 16a is moved in the rotor direction (left direction in FIG. 7 ) when braking and abuts against the rotor 18 to apply a frictional force. Since the reaction force to 16a is lost, the frictional force due to the contact of the pad 16b is also lost.

As described above, the caliper floating disc brake is of a single-pressing piston type, but the disc rotor can be sandwiched between the pads on both sides during braking, and has high braking performance.
Japanese Patent Laid-Open No. 2001-200875

  However, in a conventional caliper floating disc brake, the brake is released with respect to a structure that secures the caliper floating mechanism, specifically, a sliding structure between the caliper 12 and the sleeve 14 (hereinafter referred to as “floating structure”). In some cases, the pad 16b remains in contact with the rotor 18. With respect to this problem, conventionally, if the brake is released, even if the pad 16b comes into contact with the rotor 18 and is dragged, the rotor 18 is not subjected to a contact load from the pad 16b. Since the pad 16b is naturally pushed back by a swing of 18 or the like, it has not been a big problem. However, in recent years, along with environmental problems, as fuel consumption has improved, energy loss due to drag has become a problem that cannot be ignored.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a disc brake floating structure that does not cause pad dragging when the brake is released.

The present invention includes a slidable caliper on sleeve coupled to the carrier ya over which is fixed to the vehicle body, and a second pad which cooperates with the first pad and the caliper projecting from the caliper, during braking This invention relates to a floating structure of a disc brake having a structure in which a caliper slides on a sleeve by a reaction force generated when the first pad comes into contact with the disc rotor, and the second pad comes into contact with the disc rotor. A rod-like member ( for example, a first member) that extends in the axial direction in the sleeve so as to slide along the axial direction of the sleeve ( for example, the sleeve 104 in the first embodiment ) in cooperation with the first member . the spring guide 110) in the embodiment, in the sleeve such that movement of the sliding direction of the rod-like member during braking is restricted Set by spacers (e.g., spacer 116 in the first embodiment) and a guide member disposed around the rod-like member so as to cooperate with the sliding of the rod-like member (e.g., guide in the first embodiment Member 114 ) and a first spring ( for example, first spring 122 in the first embodiment ) disposed between the spacer and the guide member, and the rod-shaped member slides in the direction of the spacer when the brake is operated. As the guide member approaches the spacer, the first spring is compressed, and when the brake is released, the first spring is extended, so that the guide member is separated from the spacer, and the rod-shaped member is opposite to the spacer. The second spring extends in the axial direction around the rod-shaped member so as to cooperate with the sliding of the rod-shaped member. (For example, the second spring 112 in the first embodiment) is fitted, and the guide member comes into contact with each other when approaching the spacer by a predetermined distance, and the second spring includes the opening bottom surface of the sleeve and the guide member. Further, when the brake is operated, the guide member is pushed toward the spacer while being supported by the second spring as the rod-shaped member slides, and the guide member and the spacer come into contact with each other. After that, when the sliding force of the rod-shaped member exceeds the fitting force of the second spring, the rod-shaped member is released from cooperation with the second spring and the guide member, and slides independently. The member includes a first engaging member (for example, the second snap ring 120 in the first embodiment) protruding in the spacer direction, and when the brake is released. The sliding of definitive the rod-shaped member and the guide member, and the said first engagement member spacer for restricting a range of up to engage.

Further, in the present invention, the guide member has a first outer diameter having a maximum outer diameter of a portion in contact with the second spring, and the outer diameter of the guide member in the axial direction toward the first engaging member. The portion where the first spring arranged between the spacer and the guide member is arranged has a second outer diameter smaller than the first outer diameter, and the spacer is the smallest first. It is preferable to be arranged around a portion having three outer diameters .

In the present invention, the sleeve includes a second engagement member (for example, the first snap ring 118 in the first embodiment) protruding in the spacer direction, and is in the direction opposite to the second spring in the axial direction of the spacer. It is preferable that the movement is restricted.

  According to the present invention, the first spring compressed when the brake is operated is extended when the brake is released, so that the spring guide connected to the caliper is pushed back when the brake is released. Therefore, when the brake is released, the pads can be reliably separated without dragging the disk rotor, and energy loss due to drag can be greatly reduced. Even when the pad wears out and the spring guide needs to slide largely, if a brake operating load exceeding a predetermined value is applied to the spring guide, only the spring guide can slide alone to achieve contact with the rotor. At the same time, if the brake is released, the spring guide can be pushed back to the position moved from the initial position by the amount of wear of the pad, so the caliper can be corrected and placed at an appropriate position corresponding to the wear of the pad. The performance can be greatly improved.

  Referring to FIG. 1, there is shown a schematic sectional view in which the floating structure of the disc brake according to the present invention, particularly the structure of the portion corresponding to the fitting portion (see region A in FIG. 7) of the sleeve and caliper in FIG. It is shown.

First, the floating structure 100 in the vehicle side, especially to the axle mechanism and carry Ya over 102 and the sleeve 104 is fixed. The sleeve 104 forms a hollow shaft portion which opens toward the opposite side of the carrier ya over 102. Further, the caliper 106 is disposed in a nested manner so as to cover the periphery of the sleeve 104, and is fixed to the cap 108 disposed on the end side of the sleeve 104 by press-fitting. Further, the cap 108 is provided with a concave portion at the center thereof, and a spring guide 110 extending in the axial direction of the sleeve 104 is press-fitted into the cap 108. Accordingly, the caliper 106, the cap 108, and the spring guide 110 are integrated and can slide with respect to the sleeve 104.

  Further, the second spring 112 is wound around the spring guide 110 around a part in the longitudinal direction. The inner diameter of the second spring 112 is manufactured to be smaller than the outer diameter of the spring guide 110 in a natural state. Therefore, when the second spring 112 is wound around the spring guide 110, an elastic force acts so as to tighten the spring guide 110, and the both are fixed. Ensure state. A guide member 114 is disposed around the spring guide 110 at a position in contact with the end of the second spring 112. Accordingly, as shown in FIG. 1, the second spring 112 is disposed so as to be sandwiched between the guide member 114 and the opening bottom surface 104 a of the sleeve 104, and movement on the spring guide 110 is restricted.

Further, as shown in the cross section of FIG. 1, the guide member 114 is moved in two steps toward the upward direction (meaning the direction opposite to the second spring 112 (hereinafter, shown with the direction on the paper of FIG. 1)). The diameter is small, and a spacer 116 is disposed around the smallest outer diameter portion. The spacer 116 is restricted from moving upward with respect to the sleeve 104 by a first snap ring 118 fitted to the inner wall of the sleeve 104. The second snap ring 120 is also fitted to the guide member 114, and restricts the upward movement of the spacer 116 with respect to the guide member 114. Further, the first spring 122 is held in the vertical direction in the space between the guide member 114 and the spacer 116, and the first spring 122 expands and contracts as the spacer 116 slides on the guide member 114.

The correlation between the mechanism and the operating state of the brake will be described. Referring to FIG. 2, an enlarged view of the mechanism part of FIG. 1 is shown. In this figure, with the one-dot chain line as a boundary, the right side shows a state when the brake is operated, and the left side shows a state when the brake is released. During braking, caliper 106 slides sleeve 104 on the force upward is applied, moves away from the carry ya over 102. At this time, the spring guide 110 is pushed up in the direction of the arrow X with respect to the sleeve 104, and when the spring guide 110 is further pushed up, the guide member 114 is pushed up together with the second spring 112. When the guide member 114 is pushed up, the first spring 122 sandwiched between the spacer 116 and the guide member 114 is compressed because the upward movement of the spacer 116 is restricted by the first snap ring 118 (right side in FIG. 2). reference).

  Further, when the brake is released, the vertical force on the caliper 106 does not act and the spring guide 110 is also in a free state, so that the compressed first spring 122 recovers to its natural length, that is, with the guide member 114 Elastic force acts so as to expand the space between the spacers 116. At this time, since the upward movement of the spacer 116 is restricted by the first snap ring 118, only the guide member 114 is pushed back downward (see the left side of FIG. 1). Therefore, when the brake is released and no upward force is applied to the caliper 106, the spring guide 110 is slid downward by the first spring 122, and the caliper 106 is also slid downward (pushed back). It becomes.

  When the above is applied to the disc brake 10 shown in FIG. 7 and verified, the caliper 12 slides leftward on the sleeve 14 when the brake is operated, so that the pad 16b contacts the rotor 18 and when the brake is released, the caliper 12 The pad 16b is separated from the rotor 18 by sliding in the right direction. Therefore, drag between the rotor and the pad when the brake is released can be eliminated.

  Next, consider the relationship between the second spring 112 and the first spring 122. Until the guide member 114 and the spacer 116 come into contact with each other, the load acting on the second spring 112 is equal to the load acting on the first spring 122, and the guide member 114 is positioned at a predetermined position with respect to the spring guide 110 and moved vertically. Is retained. However, if the guide member 114 and the spacer 116 come into contact with each other, the brake operating force directly acts on the spacer 116 from the guide member 114 via the caliper 106 and the spring guide 110. In the normal operation range, the guide member 114 and the spacer 116 are set so as not to contact each other, and thus such contact does not occur, but may occur when the pad (corresponding to the pad 16b in FIG. 1) is worn. There is. At this time, if the guide member 114 on the spring guide 110 is always positioned at the same position, even if the pad is worn, the spring guide 110 cannot be slid beyond the contact position, and the pad is properly rotated. Cannot be contacted. Therefore, after the guide member 114 comes into contact with the spacer 116, it is necessary to slide on the spring guide 110. In the present embodiment, the fitting force of the second spring 112 with respect to the spring guide 110 is set smaller than the brake operating force. With this setting, even when the guide member 114 contacts the spacer 116 due to wear of the pad, the second spring 112 moves over the spring guide 110 even when the spring guide 110 needs to slide upward. The relative positional relationship between the guide member 114 and the spring guide 110 can be changed according to the wear amount of the pad.

  Therefore, when the pad is worn, the guide member 114 and the second spring 112 are moved upward from the initial position by the amount of wear of the pad. If a load greater than the fitting force of 112 to the spring guide 110 is applied, the important mechanism can be returned to the initial position without disassembling. That is, when this embodiment is used for a brake with different pad thicknesses, other parts can be made common by simply changing the length of the spring guide 110 according to the wearable amount of the pad. The second spring 112 is preferably a metal helical spring in terms of durability, but may be a rubber part such as an O-ring.

  Further, the disc brake floating structure 100 shown in FIGS. 1 and 2 has not only the drag preventing function described above, but also a function of adjusting the gap amount between the disc rotor and the pad. In FIG. 2, the dimension S corresponds to the gap between the disk rotor and the pad. Therefore, the gap amount between the disk rotor and the pad is adjusted by the dimension of S. The dimension S is affected by component variations if only the minimum load of the second spring 112, the minimum load when the first spring 122 is set, the maximum load during operation, and the maximum sliding resistance of the sleeve 104 are regulated. Therefore, the predetermined value is maintained.

  Referring to FIG. 3, the operation load and the displacement of the first spring 122 (see the solid line portion in the graph) and the second spring 112 (see the broken line portion in the graph) in the mechanism of FIGS. Here, the actual sliding resistance of the sleeve 104 is restricted to f5, the maximum sliding resistance f6, the minimum load f6 of the first spring 122, the maximum load f8, and the minimum load f8 of the first spring 112, and the displacement at the time of brake operation is X6. The displacement when the brake is released is expressed as X5. For example, when the sliding resistance of the sleeve 104 is f5 <f6, the first spring 122 is restricted by the snap ring 120, and the displacement remains X5. On the other hand, since the downward movement of the spacer 116 is restricted by the guide member 114, the displacement of the first spring 122 varies even if the load of the first spring 122 fluctuates if the load of the second spring 112 is larger than the load of the first spring 122 during operation. X6 is maintained as it is. Accordingly, the displacement of the first spring 122 falls within the range of the predetermined value X5 to the predetermined value X6, and S (which is exactly the gap S in FIG. 2), which is the difference between X6 and X5, also maintains the predetermined value. It will be. Therefore, in this embodiment, it is possible to adjust the gap amount between the disk rotor and the pad by adjusting the gap S dimension.

Next , a second embodiment as a reference example is shown in FIG. This embodiment is formed as a modification 200 of the floating structure 100 according to the first embodiment of the present invention shown in FIGS. Accordingly, among the reference numerals assigned to the elements in FIG. 4, those having the same reference numerals as those in FIGS. 1 and 2 mean the elements performing the same function. In the second embodiment shown in FIG. 4, there is no element corresponding to the snap ring 120 of the first embodiment, that is, there is an element that regulates pushing back (sliding in the Y direction) of the spring guide 210 when the brake is released. It will not exist. Therefore, the gap between the pad and the rotor does not vary due to variations in the load acting on the second spring 212, but is affected by variations in the load acting on the first spring 222 and the sliding resistance of the sleeve 204.

FIG. 5 shows a third embodiment as a reference example . This embodiment is also formed as a modified example 300 of the floating structure 100 according to the first embodiment of the present invention shown in FIGS. 1 and 2, and among the reference numerals assigned to the elements in FIG. Similar reference numbers indicate elements that perform similar functions. As shown in FIG. 5, in this embodiment, there is no element corresponding to the guide member 114, the springs 312 and 322 are formed integrally, and the portion corresponding to the first spring 122 of FIGS. A portion corresponding to the second spring 112 functions as the second portion 312. Accordingly, the gap between the pad and the rotor varies due to variations in the fitting force of the second portion 312 to the spring guide 310, the force of pushing back the sleeve 304 when the brake of the first portion 322 is released, and the sliding resistance of the sleeve 304.

Furthermore, a fourth embodiment as a reference example is shown in FIG. This embodiment is also formed as a modified example 400 of the floating structure 100 according to the first embodiment of the present invention shown in FIGS. 1 and 2, and among the reference numerals assigned to the elements in FIG. Similar reference numbers indicate elements that perform similar functions. However, the present embodiment is characterized in that the guide member 414 is fixed to the end of the spring guide 410 and that a spring corresponding to the second spring 112 does not exist. Accordingly, the spring guide 410 always slides the same, that is, the pad and the rotor are always pushed back to the initial position when the brake is released. As a result, while it is certain to prevent the pad from being dragged, if the pad is worn, the gap between the pad and the rotor inevitably increases.

1 is a schematic cross-sectional view of a first embodiment illustrating a floating structure of the present invention. It is the elements on larger scale of FIG. 1 which shows the main mechanism of a floating structure. It is a graph which shows the relationship between the operating load and displacement of a 1st spring in 1st embodiment of this invention shown to FIG. It is a schematic sectional drawing of 2nd embodiment as a reference example . It is a schematic sectional drawing of 3rd embodiment as a reference example . It is a schematic sectional drawing of 4th embodiment as a reference example . It is a schematic sectional drawing which shows the outline | summary of the whole floating structure of a disc brake.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Floating structure 104 ... Sleeve 106 ... Caliper 110 ... Spring guide 112 ... Second spring 114 ... Guide member 116 ... Spacer 118 ... First snap ring (engaging member)
120 ... Second snap ring (engaging member)
122 ... 1st spring 312 ... 2nd part 322 ... 1st part

Claims (3)

Has a slidable caliper on sleeve coupled to the carrier ya over which is fixed to the vehicle body, and a second pad that cooperates with the first pad and the caliper projecting from the caliper, wherein said at brake actuation A floating structure of a disc brake having a structure in which the caliper slides on the sleeve by a reaction force generated when one pad comes into contact with the disc rotor and the second pad comes into contact with the disc rotor;
A rod-like member disposed extending in the axial direction in the sleeve so as to slide along the axial direction of the sleeve in cooperation with the sliding of the caliper;
A spacer disposed in the sleeve so that movement of the rod-shaped member in the sliding direction during braking is regulated;
A guide member disposed around the rod-shaped member so as to cooperate with sliding of the rod-shaped member ;
A first spring disposed between the spacer and the guide member;
When the brake is activated, the first spring is compressed by the guide member approaching the spacer as the rod-shaped member slides in the spacer direction,
When the brake is released, the first spring is extended so that the guide member is separated from the spacer, and the rod-shaped member is slid in the opposite direction to the spacer .
A second spring is fitted around the rod-shaped member so as to extend in the axial direction of the rod-shaped member so as to cooperate with the sliding of the rod-shaped member, and the guide members come into contact with each other when approaching the spacer by a predetermined distance,
The second spring is disposed between the opening bottom of the sleeve and the guide member;
Further, when the brake is operated, the guide member is pushed in the direction of the spacer while being supported by the second spring as the rod-shaped member slides, and after the guide member and the spacer come into contact with each other, the guide member slides. When the power exceeds the fitting force of the second spring, the rod-like member slides independently with the cooperation of the second spring and the guide member being released,
The guide member includes a first engagement member protruding in the spacer direction, and sliding of the rod-shaped member and the guide member when the brake is released is performed until the first engagement member and the spacer are engaged. The disc brake floating structure is characterized in that it is restricted to the above range . The guide member has a first outer diameter with a maximum outer diameter of a portion in contact with the second spring, and the outer diameter of the guide member decreases stepwise in the axial direction toward the first engagement member. The portion where the first spring disposed between the spacer and the guide member is disposed has a second outer diameter smaller than the first outer diameter, and the spacer is the smallest first. 2. The disc brake floating structure according to claim 1, wherein the floating structure is disposed around a portion having three outer diameters . The said sleeve is provided with the 2nd engaging member which protrudes in the said spacer direction, The movement of the said 2nd spring and the direction opposite to the said 2nd spring is controlled in the axial direction of the said spacer . Disc brake floating structure.

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