JP4198532B2 - Machining method of disc brake caliper and machining method of axial groove in cylinder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for machining a disc brake caliper and a method for machining an axial groove in a cylinder.
[0002]
[Prior art]
The disc brake is provided with an action part having a hydraulic cylinder and a piston at one of the opposing positions straddling the disc rotor to press the pad against the disc. In order to make the parking brake mechanism respond to fluctuations in the position of the piston in the cylinder axial direction, an adjuster mechanism is added in the action portion. This adjuster mechanism is generally composed of a clutch nut that comes into contact with the piston and a push rod that is screwed into the clutch nut.
[0003]
The adjuster mechanism rotates the clutch nut and adjusts its position in the cylinder axial direction to cope with fluctuations in the cylinder axial position of the piston. Therefore, the push rod screwed into the clutch nut is prevented from rotating. In order to prevent this rotation, a protrusion is provided on the flange of the push rod, and a cylinder axial groove that engages with this protrusion is formed on the bottom side in the cylinder of the disc brake caliper. Yes (see, for example, Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-153227
[Problems to be solved by the invention]
However, in the thing of the said patent document 1, although a groove | channel is cut in the cylinder of a disc brake caliper, a burr | flash will generate | occur | produce in the groove end part of the rotation direction exit side of a rotary cutting tool at the time of this cutting. Since it is necessary to remove the burr by putting a file to the bottom of the cylinder, the machining of the cylinder is complicated, and there is room for further improvement in terms of improving the manufacturing efficiency of the disc brake. Such a problem occurs not only in the disc brake caliper but also in the case where the axial groove is formed in the cylinder.
[0006]
Therefore, the present invention provides a method for machining a disc brake caliper and a method for machining an axial groove in a cylinder that can improve manufacturing efficiency by efficiently removing burrs generated when the groove is formed in the cylinder axial direction. The purpose is to provide.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, an action portion having a hydraulic cylinder is provided at one of opposing positions straddling the disk rotor, and the parking brake mechanism is prevented from rotating on the bottom side of the hydraulic cylinder. A disk brake caliper machining method for forming a groove in a cylinder axial direction by a rotary cutting tool for forming a predetermined cylinder axial groove inside the hydraulic cylinder by the rotary cutting tool, The rotary cutting tool is retracted from the groove while the burr formed on the end is removed by bringing the rotary cutting tool into contact with the end of the rotary cutting tool on the exit side in the rotational direction. .
[0008]
In this way, after a predetermined cylinder axial groove is formed inside the hydraulic cylinder by the rotary cutting tool, the rotary cutting tool is brought into contact with the end of the rotary cutting tool in the rotational direction of the groove, and the end It becomes a Turkey evacuate grooves while removing the formed burr. Therefore, the burr | flash produced when forming a groove | channel in a cylinder axial direction can be efficiently removed with a rotary cutting tool.
The invention according to claim 2 is a cylinder axial groove for preventing the parking brake mechanism from rotating on the bottom side of the hydraulic cylinder by providing a working portion having a hydraulic cylinder at one of the opposing positions across the disk rotor. The disc brake caliper is formed by a rotary cutting tool, and a groove in a predetermined cylinder axial direction is formed inside the hydraulic cylinder by the rotary cutting tool, and then the rotation of the rotary cutting tool in the groove is performed. While the rotary cutting tool is brought into contact with the end portion on the direction exit side, the rotary cutting tool is retracted obliquely from the groove to form a chamfered portion at the end portion.
In this way, the rotary cutting tool is brought into contact with the end portion of the rotary cutting tool in the rotational direction in the groove, and the rotary cutting tool is retracted obliquely from the groove to form a chamfered portion at the end portion. Therefore, it is possible to prevent the occurrence of air accumulation when filling the brake fluid.
[0009]
The invention according to claim 3 is a method of machining an axial groove in a cylinder in which a groove in the cylinder axial direction is formed inside the cylinder by a rotary cutting tool, and a predetermined cylinder is formed inside the cylinder by the rotary cutting tool. After forming the groove in the axial direction, the rotary cutting tool is brought into contact with the end of the rotary cutting tool in the rotational direction of the rotary cutting tool to remove burrs formed at the end , and the groove is removed from the groove. It is characterized by retracting the rotary cutting tool.
[0010]
Formed in this manner, the end portion in contact with the end of the rotating direction outlet side of the rotary cutting tool for rotary cutting tool in the groove after forming a predetermined cylinder axis direction of the grooves in the cylinder by the rotary cutting tool It becomes a Turkey evacuate grooves while removing the burrs. Therefore, the burr | flash produced when forming a groove | channel in a cylinder axial direction can be efficiently removed with a rotary cutting tool.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
A method for processing a disc brake caliper according to an embodiment of the present invention will be described below with reference to the drawings.
[0012]
As shown in FIG. 1, the disc brake to which this embodiment is applied includes a carrier 11 that is fixed to a non-rotating portion of the vehicle, and a slide that is disposed on both sides of the carrier 11 via a disc rotor 12. A pair of pads 13 that are movably supported, and a caliper (disc brake caliper) 14 that is supported by the carrier 11 so as to be slidable along the axial direction of the disc rotor 12 and that holds the pair of pads 13 from both sides. And is mainly composed.
[0013]
The caliper 14 is provided at one of the opposing positions straddling the disk rotor 12 and has a bottomed cylindrical cylinder (hydraulic cylinder, action part) that opposes the opening 17 on the opposite side to the disk rotor 12 of one pad 13. 18, a disk path portion 19 extending across the outer periphery of the disk rotor 12 from one side in the radial direction of the cylinder 18, and the disk of the other pad 13 from the opposite side to the cylinder 18 of the disk path portion 19. It has a caliper body 21 having a claw portion 20 extending so as to face the rotor 12 on the opposite side.
[0014]
Further, the caliper 14 is formed in a bottomed cylindrical shape, and a piston (action portion) 26 that is slidably fitted into the bore 25 of the cylinder 18 of the caliper body 21 with the bottom 24 side facing the pad 13 side, It has a ring-shaped piston seal 27 that seals the gap between the piston 26 and the inner peripheral surface 28 that forms the bore 25 of the cylinder 18. The piston seal 27 is held by the cylinder 18.
[0015]
The caliper 14 causes the piston 26 to project in the direction of the pad 13 by the brake fluid pressure introduced between the cylinder 18 and the piston 26, so that the piston 26 and the claw portion 20 cause the pair of pads 13 to move from both sides. It is brought into contact with the disk rotor 12 by gripping.
[0016]
As described above, the piston 26 is protruded from the cylinder 18 toward the claw portion 20 by the brake hydraulic pressure introduced into the cylinder 18 from a master cylinder (not shown) during normal braking by depressing the brake pedal. The pair of pads 13 are pressed against the disk rotor 12 to generate a braking force, but the piston 26 is mechanically projected into the cylinder 18 instead of such a brake fluid pressure. A parking brake mechanism 30 is provided that presses the disc rotor 12 to generate a braking force.
[0017]
The parking brake mechanism 30 has a cam mechanism 32.
A cam hole 35 is formed in the bottom 33 of the cylinder 18 so as to be separated from the bottom surface 34 and perpendicular to the axial direction of the cylinder 18, and penetrates from the center position of the bottom surface 34 to the cam hole 35 on the axis. The bottom hole 36 is formed, and the cam mechanism 32 is provided in the cam hole 35 and the bottom hole 36.
[0018]
The cam mechanism 32 has a substantially cylindrical cam body 39 that is rotatably inserted into a cam hole 35 via a bearing 38. The cam main body 39 is formed with a cam recess 40 that is recessed in a substantially V shape from the outer peripheral surface in the radial direction toward the center. The cam recess 40 is offset at the most recessed position with respect to the central axis of the cam body 39.
[0019]
The cam mechanism 32 includes a cam rod 42 having one end inserted into the cam recess 40 and the other end disposed on the bottom hole 36 side. The cam rod 42 has an axis along a direction perpendicular to the axis of the cylinder 18. When the cam body 39 is driven to rotate around, the amount of protrusion from the cam body 39 is changed depending on the shape of the cam recess 40. The cam body 39 is rotated by manual operation of a parking brake lever connected via a wire (not shown), a wire winding operation by an electric motor, or the like.
[0020]
The parking brake mechanism 30 has a push rod 44 that moves in the axial direction of the cylinder 18 by being pressed by the cam rod 42 of the cam mechanism 32 in the cylinder 18.
[0021]
As shown in FIG. 2, the push rod 44 is divided into a front divided body 45 on the front side in advance, that is, on the piston 26 side, and a rear divided body 46 on the rear side in forward movement, that is, on the cylinder bottom 33 side.
[0022]
The rear divided body 46 of the push rod 44 has a shaft portion 48 and a large-diameter portion 49 having a larger diameter than the shaft portion 48 provided on one end side of the shaft portion 48. A convex spherical portion 50 that is convex along the axial direction is formed at the end opposite to the portion 48. The convex spherical portion 50 has a spherical shape with a center on the central axis of the rear divided body 46. An annular outer end surface portion 51 that is radially outward from the convex spherical portion 50 of the large-diameter portion 49 is along a direction orthogonal to the central axis of the rear divided body 46. A contact recess 52 that is recessed in the axial direction is formed on the opposite side of the large diameter portion 49 of the shaft portion 48 in the axial direction.
[0023]
The rear divided body 46 accommodates the distal end side of the cam rod 42 of the cam mechanism 32 in the contact recess 52 in a state where the shaft portion 48 is fitted in the bottom hole 36. A ring-shaped push rod seal 57 is provided between the shaft portion 48 and the bottom hole 36 of the cylinder 18 to seal these gaps. The push rod seal 57 is held by the shaft portion 48 of the rear divided body 46.
[0024]
The front divided body 45 of the push rod 44 includes a shaft portion 61 having a male screw 60 formed on the outer peripheral surface in the radial direction, and a large diameter portion 62 having a larger diameter than the shaft portion 61 provided on one end side of the shaft portion 61. And has a shape having
[0025]
On the outer diameter side of the large-diameter portion 62, there are a plurality of specific rotation protrusions 63 that protrude outward in the radial direction after protruding to the opposite side with respect to the shaft portion 61. ), The positions in the circumferential direction are different from each other by 180 degrees. Further, on the outer diameter side of the large-diameter portion 62, there are a plurality of specifically, two restricting protrusions 64 shaped to protrude on the opposite side with respect to the shaft portion 61 (only one is shown), and the positions in the circumferential direction are set. These are formed so as to be different from each other by 180 degrees and different from the rotation protrusion 63 by 90 degrees. Here, as shown in FIG. 3, the anti-rotation projections 63 are formed with anti-rotation projections 120 that protrude in a semicircular shape radially outward from the outer peripheral surface. The anti-rotation convex portion 120 has an arc shape having a center on a line orthogonal to the axis of the front divided body 45.
[0026]
As shown in FIG. 2, on the opposite side of the shaft portion 61 of the large-diameter portion 62, a concave spherical surface portion 67 that forms a concave shape along the axial direction is formed inside the rotation projection portion 63 and the regulation projection portion 64. Has been. The concave spherical portion 67 has a spherical shape centered on the central axis of the front divided body 45 and has a larger diameter than the convex spherical portion 50. An annular outer end surface portion 68 that is radially outward from the concave spherical surface portion 67 of the large diameter portion 62 is along a direction orthogonal to the central axis of the front divided body 45.
[0027]
Here, each inner surface of the front divided body 45 of each front protrusion 45 and each regulating protrusion 64 on the axial center side of the front divided body 45 is arranged on the same circle centered on this axial center. The outer diameter of this circle is slightly larger than the outer diameter of the large-diameter portion 49 of the rear divided body 46.
[0028]
Then, the rear divided body 46 makes the convex spherical surface portion 50 abut on the concave spherical surface portion 67 of the front divided body 45 while the large-diameter portion 49 is inserted inside the anti-rotation protruding portion 63 and the restricting protruding portion 64. At this time, in a state where the front divided body 45 and the rear divided body 46 are coaxially arranged, the outer end surface portion 51 outside the convex spherical portion 50 and the outer end surface portion 68 outside the concave spherical portion 67 are disposed. A slight gap is formed. The radius of curvature of the concave spherical portion 67 is slightly larger than the radius of curvature of the convex spherical portion 50.
[0029]
As described above, the convex spherical surface portion 50 of the rear divided body 46 abuts on the concave spherical surface portion 67 of the front divided body 45 at the axial center side of the front divided body 45, specifically, at the axial center position. It can swing with respect to the heart.
[0030]
Here, the inner peripheral surface 28 of the cylinder 18 has a large-diameter inner peripheral surface 73 on the opening 17 side and a small-diameter inner peripheral surface 74 on the bottom 33 side smaller than this, and the small-diameter inner peripheral surface 74. As shown in FIG. 3, a plurality of rotation shaft grooves (grooves) 121 extending in the axial direction of the cylinder 18 are formed in an arc shape on the outer diameter side of the small-diameter inner peripheral surface 74 and extending in the axial direction. It is formed with a position (only one place shown) and a circumferential position different from each other by 180 degrees. Here, as shown in FIG. 2, the rotation shaft groove 121 is located between the large diameter inner peripheral surface 73 and the small diameter inner peripheral surface 74 and extends from the cylinder step 79 to the cylinder 18 along the direction orthogonal to the axis of the cylinder 18. It extends to the vicinity of the bottom surface 34 of the bottom portion 33 of the base plate 33. The rotation shaft groove 121 has a larger diameter than the rotation protrusion 120.
[0031]
When the shaft portion 48 of the rear divided body 46 is fitted into the bottom hole 36 of the cylinder 18 and the front divided body 45 comes into contact with the rear divided body 46 as described above, the front divided portion Each anti-rotation convex portion 120 of the body 45 is engaged with the corresponding anti-rotation shaft groove 121 as shown in FIG. As a result, the front divided body 45 is guided so that the rotation around the axis with respect to the cylinder 18 is restricted when the parking brake mechanism 30 is operated, and the cylinder 18 is slidable in the axial direction. In a state where the rotation around the axis is restricted, the rear divided body 46 can be separated and approached in the axial direction. That is, a rotation shaft groove 121 in the cylinder axial direction for preventing the rotation of the front divided body 45 of the parking brake mechanism 30 is formed on the bottom 33 side of the cylinder 18.
[0032]
Here, as described above, the non-rotating shaft groove 121 has a larger diameter than the non-rotating convex portion 120, and as a result, the non-rotating convex portion 120 contacts the detent shaft groove 121 in an eccentric state. It is like that. By doing so, a sufficient gap 124 is formed between the anti-rotation convex portion 120 and the anti-rotation shaft groove 121, and the air is interposed between the anti-rotation convex portion 120 and the cylinder 18 when filling the brake fluid. To prevent accumulation.
[0033]
The parking brake mechanism 30 includes a substantially cylindrical clutch nut 82 that is screwed into the male screw 60 of the shaft portion 61 of the front divided body 45 of the push rod 44 within the cylinder 18 with a female screw 81 formed on the inner diameter side. is doing.
[0034]
Here, the inner peripheral surface 83 of the piston 26 has a small-diameter inner peripheral surface 84 on the bottom 24 side, and a larger-diameter inner peripheral surface 85 having a larger diameter on the opening side than the small-diameter inner peripheral surface 84. A tapered inner peripheral surface 86 is formed between the small diameter inner peripheral surface 84 and the large diameter inner peripheral surface 84. Further, a groove 87 extending in the axial direction of the piston 26 is formed in the tapered inner peripheral surface 86.
[0035]
The clutch nut 82 has a fitting portion 90 fitted to the small-diameter inner peripheral surface 84 of the piston 26 at the front end side, and a tapered portion 91 that is adjacent to the fitting portion 90 and contacts the tapered inner peripheral surface 86 is formed. Has been.
[0036]
Here, when the amount of protrusion of the cam rod 42 is changed from small to large by rotating the cam body 39 of the cam mechanism 32, the rear divided body 46 and the front divided body 45 of the push rod 44, the clutch nut 82, Linearly moves in the axial direction, and the clutch nut 82 abuts against the taper inner peripheral surface 86 of the piston 26 at the taper portion 91 to slide the piston 26 toward the pad 13 with respect to the cylinder 18.
[0037]
The male screw 60 of the front divided body 45 of the push rod 44 and the female screw 81 of the clutch nut 82 constitute a screwing portion 93. The screwing portion 93 includes the front divided body 45 and the clutch nut. A clearance that can move in the axial direction by a predetermined amount without rotating with respect to each other is provided.
[0038]
Further, as shown in FIG. 1, an air release hole 94 is formed on the bottom 24 side of the piston 26 to open the gap with the clutch nut 82 to the atmosphere.
[0039]
In addition, a ring-shaped clutch nut seal 95 is provided between the fitting portion 90 of the clutch nut 82 and the small-diameter inner peripheral surface 84 of the piston 26 to seal these gaps. The clutch nut seal 95 is held by the fitting portion 90 of the clutch nut 82.
[0040]
The parking brake mechanism 30 includes an adjuster mechanism 97 that adjusts the position of the clutch nut 82 and the front divided body 45 of the push rod 44 in the cylinder 18.
[0041]
The adjuster mechanism 97 is supported between the piston 26 and the clutch nut 82 by a retaining ring 99 that is engaged with an engagement groove 98 formed in the large-diameter inner peripheral surface 85 of the piston 26 so that the clutch nut 82 is disc-mounted. When the piston 26 moves in the axial direction by the brake fluid pressure introduced into the cylinder 18, the adjuster is applied to the push rod 44 which is substantially stopped. While the clutch nut 82 is rotated by the urging force of the mechanism 97, it is caused to follow the piston 26 and move in the axial direction.
[0042]
Further, the adjuster mechanism 97 does not rotate the clutch nut 82 relative to the front divided body 45 when the front divided body 45 of the push rod 44 linearly moves in the axial direction. The clutch nut 82 is linearly moved integrally with the push rod 44 by the threaded portion 93 including the female screw 81.
[0043]
In the cylinder 18, the parking brake mechanism 30 includes a spring cover 101 provided so as to cover a part of the clutch nut 82 and a part of the front divided body 45 and a part of the rear divided body 46 of the push rod 44, and a push rod. And a push rod biasing spring 102 interposed between the large-diameter portion 62 of the front divided body 45 and the piston 26 side of the spring cover 101.
[0044]
The spring cover 101 includes a ring-shaped portion 104 into which the clutch nut 82 is inserted, a cylindrical portion 105 extending from the outer diameter side of the ring-shaped portion 104 to one side in the axial direction, and a ring-shaped portion of the cylindrical portion 105. A plurality of locking pieces 106 cut and raised radially outward from the opposite side with respect to the portion 104, and a plurality of extensions extending further from the opposite side to the one side in the axial direction with respect to the ring-shaped portion 104 of the cylindrical portion 105. And an output piece 107.
[0045]
In the spring cover 101, each extended piece 107 passes through the outside of the outer peripheral surface of the large-diameter portion 62 of the front divided body 45 of the push rod 44, and the tip end portion is bent radially inward. The bent portion 108 after being bent is locked to the shaft portion 48 side of the large diameter portion 49 of the rear divided body 46.
[0046]
In this state, the push rod biasing spring 102 is interposed between the ring-shaped portion 104 of the spring cover 101 and the large diameter portion 62 of the front divided body 45 of the push rod 44, in other words, The spring cover 101 holds the push rod biasing spring 102 between the front divided body 45 of the push rod 44.
[0047]
The parking brake mechanism 30 is a front stage 45 of the push rod 44, a rear part 46 of the push rod 44, a push rod biasing spring 102, and a spring cover 101 before being assembled to the cylinder 18. Is a cartridge 111 of one assembly.
[0048]
That is, for example, the push rod biasing spring 102 is inserted so as to contact the ring-shaped portion 104 of the spring cover 101 in a state before the bent portion 108 is formed, and the front divided body 45 of the push rod 44 is The shaft 61 side is inserted inside the push rod biasing spring 102 and the rotation projection 63 is passed between the extending piece 107 and brought into contact with the push rod biasing spring 102.
[0049]
Then, the rear divided body 46 of the push rod 44 is arranged so that the convex spherical portion 50 abuts on the concave spherical portion 67 of the front divided body 45.
[0050]
Next, the distal ends of all the extended piece portions 107 of the spring cover 101 are bent radially inward on the opposite side of the large-diameter portion 49 of the rear divided body 46 with respect to the front divided body 45 to thereby form the bent portions 108. By forming, the removal of the rear divided body 46 from the spring cover 101 is restricted.
[0051]
As described above, the front divided body 45 and the rear divided body 46 of the push rod 44, the push rod biasing spring 102, and the spring cover 101 constitute a cartridge 111 of one assembly.
[0052]
The large-diameter inner peripheral surface 73 of the cylinder 18 is locked to a position closer to the opening 17 side of the cylinder 18 than the contact surface 112 of the push rod 44 with the push rod biasing spring 102. A step 113 is formed. The locking step 113 includes an annular engagement groove 114 formed on the large-diameter inner peripheral surface 73 of the cylinder 18 and a C-shaped retaining ring 115 that engages with the engagement groove 114. Yes.
[0053]
The locking piece 106 of the spring cover 101 is disposed between the cylinder step 79 between the large-diameter inner peripheral surface 73 and the small-diameter inner peripheral surface 74 and the locking step 113, and thereby the spring cover. The axial movement of the cylinder 101 with respect to the cylinder 18 is restricted.
[0054]
In the disc brake having the above-described configuration, when the cam body 39 of the cam mechanism 32 is rotated by operating a parking brake lever (not shown), the cam rod 42 of the cam mechanism 32 increases the protruding amount, and the push rod The rear divided body 46 is moved in the direction of the disk rotor 12. Then, the front divided body 45 abutting against the rear divided body 46 moves in the direction of the disk rotor 12, and the clutch nut 82 moves integrally therewith to move the piston 26 in the direction of the disk rotor 12, thereby Thus, the pair of pads 13 are pressed against the disk rotor 12.
[0055]
On the other hand, when the brake fluid pressure is introduced between the cylinder 18 and the piston 26 by a brake operation with a normal brake pedal, the fluid pressure acts on the piston 26 with respect to the pressure receiving area by the piston seal 27 and the disk rotor 12 However, the hydraulic pressure also acts on the clutch nut 82 against the pressure receiving area of the clutch nut seal 95 to generate a propulsive force in the direction of the disk rotor 12. The piston 44 is pushed by moving in the axial direction without rotating by an amount corresponding to the clearance of screwing in the screwing portion 74 of the rod 44 with the front divided body 45.
[0056]
When the brake fluid pressure is further introduced into the cylinder 18 and exceeds a predetermined fluid pressure, the clutch nut 82 is pressed against the piston 26 by the fluid pressure acting on the clutch nut 82, and the fluid pressure is applied to the piston 26. As a result, a propulsive force in the direction of the disk rotor 12 is generated, and hydraulic pressure also acts on the clutch nut 82 to generate a propulsive force in the direction of the disk rotor 12.
[0057]
As shown in FIG. 3, the rotation shaft groove 121 in the cylinder axial direction formed on the bottom 33 side of the cylinder 18 to prevent the rotation of the front divided body 45 of the parking brake mechanism 30 is formed on the axis of the cylinder 18. It has a substantially semicircular arc-shaped groove 121a having a center on a line orthogonal to each other and a chamfered portion 121b formed over the entire length at the end of the arc-shaped groove 121a. When viewed from the opening 17 side, the arc-shaped groove 121a is formed at the right end in a state where it is disposed on the upper side with respect to the center thereof.
[0058]
Next, the processing method of the disc brake caliper of this embodiment will be described. As shown in FIGS. 4 and 5A, the rotation shaft groove 121 is formed by a shaft-shaped end mill cutter (rotary cutting tool) 130 having cutting edges formed at the tip and outer periphery. That is, first, the end mill cutter 130 is inserted from the opening 17 side of the cylinder 18 to a predetermined depth in a posture along the cylinder axial direction, and sent to a predetermined position in the radial direction while rotating clockwise as viewed from the processing machine side. Alternatively, the end mill cutter 130 is sent from the opening 17 side of the cylinder 18 along the cylinder axial direction to the predetermined position in the axial direction while rotating clockwise when viewed from the processing machine side. A circular arc groove 121a in a predetermined cylinder axial direction is formed from a predetermined position on the bottom surface 34 side of the bottom 33. Here, what is indicated by reference numeral 131 in FIG. 5 (a) is a burr generated by the rotational cutting of the end mill cutter 130, and this burr 131 is forward in the rotation direction from the rotation direction outlet side of the end mill cutter 130 in the arc-shaped groove 121a. To protrude.
[0059]
Then, after the arc-shaped groove 121a is formed as described above, the end mill cutter 130 is not moved substantially in the axial direction, and the arc-shaped groove 121a is moved from the arc-shaped groove 121a at this time as indicated by Z1 in FIG. The arc-shaped groove 121a is retracted by a predetermined amount in a direction perpendicular to the line connecting both ends of the arc-shaped groove 121a, and then, as indicated by Z2 in FIG. As shown in FIG. 5C, the end mill cutter 130 is removed from the arc-shaped groove 121a while the end mill cutter 130 is in contact with the end on the side, so that the burr 131 is removed. A chamfered portion 121b is formed at an end portion on the exit side in the rotation direction, that is, a right end portion in a state where the arc-shaped groove 121a is disposed on the upper side with respect to the center thereof. As described above, the rotation shaft groove 121 in which the chamfered portion 121b is formed in the arc-shaped groove 121a is formed.
[0060]
Here, the clutch nut 82 screwed into the male screw 60 of the push rod 44 when the parking brake mechanism 30 is operated advances while rotating counterclockwise as viewed from the opening 17 side of the cylinder 18. As a result, the push rod 44 which is going to rotate with the clutch nut 82 is counterclockwise as shown in FIG. 3 when the rotation projection 120 is viewed from the opening 17 side of the cylinder 18. It will contact | abut in the eccentric state to the front side of a direction. In other words, the detent protrusion 120 abuts on the side of the detent shaft groove 121 where the chamfered portion 121b is not formed, in other words, on the side where the rotational force from the push rod 44 of the detent shaft groove 121 is not applied. The chamfered portion 121b is formed only at the groove end portion.
[0061]
According to the present embodiment described above, after the end mill cutter 130 forms the arc-shaped groove 121a in the predetermined cylinder axial direction inside the cylinder 18, the end mill cutter 130 is rotated in the arc-shaped groove 121a in the rotational direction of the end mill cutter 130. When the end mill cutter 130 is retracted from the arc-shaped groove 121a while being in contact with the end portion on the outlet side, the end mill cutter 130 removes the burr 131 formed at the end portion on the outlet side in the rotation direction of the end mill cutter 130 in the arc-shaped groove 121a. Retraction occurs while forming 121b. Therefore, the burr 131 generated when the rotation shaft groove 121 is formed in the cylinder axis direction can be efficiently removed by the end mill cutter 130. Therefore, manufacturing efficiency can be improved.
[0062]
Further, the diameter of the locking shaft groove 121 is larger than that of the locking projection 120, and the locking projection 120 is brought into contact with the locking shaft groove 121 in an eccentric state. A sufficient gap 124 can be formed between the stop shaft groove 121 and the occurrence of air accumulation between the anti-rotation projection 120 and the cylinder 18 when the brake fluid is filled can be prevented.
[0063]
Moreover, since the chamfered portion 121b is formed at the groove end portion of the stop shaft groove 121 on the side where the stop convex portion 120 of the push rod 44 does not contact, the chamfered convex portion 120 is formed by the chamfered portion 121b. The opening of the gap 124 between the rotating shaft groove 121 and the stop shaft groove 121 is widened, so that it is possible to further prevent the occurrence of air accumulation when the brake fluid is filled.
[0064]
The above is not limited to the caliper 14 of the disc brake, but can be applied to various cylinders as a machining method for forming an axial groove in the cylinder.
[0065]
【The invention's effect】
As described in detail above, according to the first aspect of the present invention, after the groove in the predetermined cylinder axial direction is formed inside the hydraulic cylinder by the rotary cutting tool, the rotary cutting tool is rotated in this groove. becomes a Turkey evacuate grooves while removing burrs formed on the end portion in contact with the ends of the direction the outlet side. Therefore, the burr | flash produced when forming a groove | channel in a cylinder axial direction can be efficiently removed with a rotary cutting tool. Therefore, manufacturing efficiency can be improved.
According to the second aspect of the invention, the rotary cutting tool is brought into contact with the end portion of the rotary cutting tool in the rotational direction of the groove in the rotational direction, and the rotary cutting tool is retracted obliquely from the groove so that the chamfered portion is provided at the end portion. Since the opening is formed, the opening is widened, and it is possible to prevent the occurrence of air accumulation when the brake fluid is filled.
[0066]
According to the second aspect of the present invention, after a predetermined cylinder axial groove is formed inside the cylinder by the rotary cutting tool, the rotary cutting tool is brought into contact with the end of the rotary cutting tool on the outlet side in the rotational direction. It becomes a Turkey evacuate grooves while removing burrs formed on the end portion Te. Therefore, the burr | flash produced when forming a groove | channel in a cylinder axial direction can be efficiently removed with a rotary cutting tool. Therefore, manufacturing efficiency can be improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a disc brake to which a method for processing a disc brake caliper according to an embodiment of the present invention is applied.
FIG. 2 is a partially enlarged side sectional view of the disc brake.
3 is a cross-sectional view taken along line XX in FIG. 2, showing the main part of the disc brake.
FIG. 4 is an enlarged cross-sectional side view of a main part showing one state of a method for processing a disc brake caliper according to an embodiment of the present invention.
FIG. 5 is an enlarged cross-sectional view of a main part taken along the line YY shown in FIG. 4 showing the processing method of the disc brake caliper of one embodiment of the present invention in time series (a), (b), (c). FIG.
[Explanation of symbols]
12 Disc rotor 14 Caliper (disc brake caliper)
18 cylinders (hydraulic cylinder, working part)
26 Piston (action part)
30 Parking brake mechanism 33 Bottom 121 Rotation shaft groove (groove)
121a Circular groove (groove in the predetermined cylinder axial direction)
121b Chamfer 130 End mill cutter (Rotary cutting tool)

Claims (3)

A disk in which a working part having a hydraulic cylinder is provided at one of the opposing positions across the disk rotor, and a groove in the cylinder axial direction for preventing rotation of the parking brake mechanism is formed on the bottom side of the hydraulic cylinder by a rotary cutting tool Brake caliper processing method,
After a predetermined cylinder axial groove is formed inside the hydraulic cylinder by the rotary cutting tool, the rotary cutting tool is brought into contact with an end of the rotary cutting tool in the rotational direction of the rotary cutting tool. A method for processing a disc brake caliper, wherein the rotary cutting tool is retracted from the groove while removing burrs formed on the portion . A disk in which a working part having a hydraulic cylinder is provided at one of the opposing positions across the disk rotor, and a groove in the cylinder axial direction for preventing rotation of the parking brake mechanism is formed on the bottom side of the hydraulic cylinder by a rotary cutting tool Brake caliper processing method,
  After forming a predetermined cylinder axial groove inside the hydraulic cylinder by the rotary cutting tool, the rotary cutting tool is brought into contact with an end of the rotary cutting tool in the rotational direction outlet side of the groove, A method for machining a disc brake caliper, wherein the rotary cutting tool is retracted obliquely from a groove to form a chamfered portion at the end portion. A method of machining an axial groove in a cylinder, wherein a groove in the cylinder axial direction is formed inside the cylinder by a rotary cutting tool,
After a predetermined cylinder axial groove is formed inside the cylinder by the rotary cutting tool, the rotary cutting tool is brought into contact with the end of the rotary cutting tool in the rotational direction of the rotary cutting tool to the end. A method for machining an axial groove in a cylinder, wherein the rotary cutting tool is retracted from the groove while removing the formed burr .

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