JP4372284B2 - Shock absorber - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shock absorber for absorbing impact force.
[0002]
[Prior art]
Conventionally, there is a starter provided with a shock absorber in order to cut off excessive torque transmission (see Japanese Patent Application Laid-Open No. 63-277859). The shock absorber used in this starter presses the rotating disk against the fixed disk to generate a frictional force between them, and the frictional force restricts the rotation of the rotating disk to transmit the torque. When an impact force of a predetermined torque or more is applied, the impact force is absorbed by the rotating disk sliding (rotating) against the friction force.
In order to form a friction surface, the rotating disk is formed by forming a large number of dimples (recesses) on the surface facing the fixed disk by pressing, and protrusions of about several tens of μ are raised on the outer periphery of the dimple. .
[0003]
[Problems to be solved by the invention]
When a large number of dimples are provided on the surface of the rotating disk, the press die can be easily manufactured by making the shape of the punch corresponding to the dimple a square (square). However, when square dimples are provided, as shown in FIG. 5, when the arrangement direction of the dimples 100 is the same (parallel or orthogonal) to the rolling direction of the material of the rotating disk 200, The heights of the protrusions formed along each side (the amount of rise of the meat) are not uniform, and there are few rises of the meat formed along the two sides 110 parallel to the rolling direction, and two sides perpendicular to the rolling direction The rise of meat formed along 120 increases.
[0004]
For this reason, even if the quadrangular dimple 100 is provided and the projection is formed in a quadrangular shape, the projection hits only at two places against the fixed disk, so that the projection is worn faster than the case of hitting at four places. This causes a problem that durability is lowered.
In addition, if the two places that hit the fixed disk in the initial stage are worn and the remaining two places come into contact with the fixed disk, the friction coefficient changes abruptly, so that torque management is extremely difficult.
The present invention has been made based on the above circumstances, and its object is to provide a shock absorber capable of substantially uniforming the height (amount of rise of meat) of projections formed by providing square dimples on the surface of a rotating disk. Is to provide.
[0005]
[Means for Solving the Problems]
(Means of Claim 1)
Rotating disk used in the dampener, multiple dimples are formed by a press to the fixed disk opposite to the surface, dimples, the shape of the surface of the rotating disk is formed into a square, by the formation of dimples, around the dimple Protrusions are formed on the four sides of the quadrangle dimples, and the four sides of the quadrangle are provided so as to be inclined with respect to the rolling direction of the material of the rotating disk so that the height of the projections on the four sides is substantially uniform. Yes.
In this case, among the sides of the quadrangle forming the dimple, there is no side parallel to the rolling direction of the material, and each side is provided inclined with respect to the rolling direction, so the arrangement direction of the dimples is the rolling direction of the material. Compared with the case where they are provided in the same manner, the difference in the amount of rising of the meat formed along each side of the quadrangle can be reduced. As a result, it can be provided so that the four positions of the protrusions are in contact with the fixed disk.
[0006]
(Means of Claim 2)
The shock absorber according to claim 1,
The dimples are formed in a square shape on the surface of the rotating disk, and the four sides of the square are inclined by 45 degrees with respect to the rolling direction of the material.
In this case, since the inclination of each side with respect to the rolling direction of the raw material is the same, the amount of rising of the meat can be formed substantially the same.
[0007]
(Means of claim 3)
Fixed disk used in the dampener, multiple dimples are formed by pressing the rotating disc opposite to the surface, dimples, the shape of the surface of the fixed disk is formed in a rectangular shape, by the formation of dimples, around the dimple Protrusions are formed on the four sides of the quadrangle dimples, and the four sides of the quadrangle are provided so as to be inclined with respect to the rolling direction of the material of the fixed disk so that the heights of the projections on the four sides are substantially uniform. Yes.
In this case, among the sides of the quadrangle forming the dimple, there is no side parallel to the rolling direction of the material, and each side is provided inclined with respect to the rolling direction, so the arrangement direction of the dimples is the rolling direction of the material. Compared with the case where they are provided in the same manner, the difference in the amount of rising of the meat formed along each side of the quadrangle can be reduced. As a result, it can be provided so that the four positions of the protrusions are in contact with the fixed disk.
[0008]
(Means of claim 4)
The shock absorber according to claim 3,
The dimples are formed such that the shape on the surface of the fixed disk is a square, and the four sides of the square are inclined by 45 degrees with respect to the rolling direction of the material.
In this case, since the inclination of each side with respect to the rolling direction of the raw material is the same, the amount of rising of the meat can be formed substantially the same.
[0009]
(Means of claim 5)
The shock absorber described in claims 1 to 4 can be used for a starter for starting the engine.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment in which the shock absorber of the present invention is applied to a starter will be described with reference to the drawings.
(First embodiment)
FIG. 1A is a cross-sectional view of a rotating disk used in a shock absorber, FIG. 1B is a plan view, and FIG. 3 is a half cross-sectional view of a starter.
As shown in FIG. 3, the starter 1 of the present embodiment absorbs an over-torque (impact force) applied to the decelerator and a decelerator that decelerates the rotational speed of a starting motor, which will be described later, and transmits it to the output shaft 2. A shock absorber.
[0011]
The starting motor is a well-known DC electric motor composed of an armature 3, a fixed magnetic pole 4, a yoke 5, a brush 6, and the like. When a key switch (not shown) is turned on and an internal contact (not shown) of the magnet switch 7 is closed. The armature 3 is rotated by being supplied with power to the armature 3 through the brush 6.
The magnet switch 7 opens and closes the internal contact with the movement of a built-in plunger (not shown), and moves the pinion gear 9 back and forth on the output shaft 2 together with the one-way clutch 10 via the lever 8.
[0012]
The pinion gear 9 is slidably fitted to the outer periphery of the output shaft 2 via a bearing 11, and is pushed forward on the output shaft 2 together with the one-way clutch 10 via the lever 8 (left side in FIG. 3). Thus, the rotational force is transmitted to the ring gear 12 by meshing with the ring gear 12 of the engine.
The one-way clutch 10 is fitted to the outer periphery of the output shaft 2 via a helical spline, transmits the rotation of the output shaft 2 to the pinion gear 9, and the rotation speed of the pinion gear 9 is changed to the rotation speed of the output shaft 2 by starting the engine. Exceeds the power transmission between the output shaft 2 and the pinion gear 9.
[0013]
As shown in FIG. 4, the reduction gear includes a sun gear 13 that forms external teeth on the outer periphery of the armature shaft 3 a, a ring-shaped internal gear 14 that forms internal teeth on the outer periphery in the radial direction of the sun gear 13, and the sun gear 13. And the planetary gear 15 which is arranged between the two gears 13 and 14 and is covered with a center case 16 together with a shock absorber described later.
The internal gear 14 has a cylindrical outer peripheral wall 14a that is rotatably fitted to the inner peripheral surface of the outer cylindrical portion 16c of the center case 16, and the rotating disk of the shock absorber is provided at the axial end of the outer peripheral wall 14a. 20, and the rotation of the rotating disk 20 is restricted in a stationary state. In addition, a plurality of notches 14b (see FIG. 4) are formed at equal intervals on the inner periphery of the distal end portion in the axial direction of the outer peripheral wall 14a.
[0014]
The planetary gear 15 is rotatably supported by a pin 17 press-fitted into the rear end portion of the output shaft 2 via a bearing 18.
When the sun gear 13 is rotated by the rotation of the armature 3, the reduction gear is engaged with the sun gear 13 and the internal gear 14, and revolves while rotating around the outer periphery of the sun gear 13. Is transmitted to the output shaft 2 via the pin 17 to rotate the output shaft 2.
[0015]
The center case 16 includes an annular front end wall portion 16a orthogonal to the output shaft 2, an inner cylindrical portion 16b extending in a cylindrical shape rearward in the axial direction from the inner peripheral edge of the front end wall portion 16a, and the front end wall portion 16a. The outer cylindrical portion 16c extending axially rearward from the outer peripheral edge, the rear end portion of the outer cylindrical portion 16c being connected to the front end portion of the yoke 5, and a bearing on the inner periphery of the inner cylindrical portion 16b. The output shaft 2 is rotatably supported via 19. A male screw 16d is formed on the outer peripheral surface of the inner cylindrical portion 16b.
[0016]
As shown in FIG. 4, the shock absorber is composed of a rotating disk 20, a fixed disk 21, a disc spring 22, an adjusting screw 23, and the like.
The rotating disk 20 is formed by pressing a metal plate into a ring shape (see FIG. 1), is disposed in close contact with the front end wall portion 16a of the center case 16, and is provided on the outer periphery of the rotating disk 20. The plurality of claw portions 20a are inserted into a notch portion 14b provided at the distal end portion of the outer peripheral wall 14a of the internal gear 14, and are coupled to the internal gear 14 so as not to rotate.
[0017]
A large number of protrusions 24 (see FIG. 2B) are provided on both surfaces of the rotary disk 20 to form friction surfaces. As shown in FIG. 2, the projections 24 are formed so as to rise around the dimples 25 by forming a large number of dimples 25 (dents) on the surface of the rotating disk 20 by pressing.
However, since the dimple 25 is formed using a square pillar punch (not shown), the shape formed on the surface of the rotating disk 20 is square as shown in FIG. The four sides of the square are provided with an inclination of 45 degrees with respect to the rolling direction of the material of the rotating disk 20.
[0018]
The fixed disk 21 is formed in a ring shape by pressing a metal plate in the same manner as the rotating disk 20, and is disposed in close contact with the friction surface of the rotating disk 20. The fixing disk 21 has holes 21a formed at a plurality of locations in the circumferential direction, and the holes 21a are fitted to protrusions 16e projecting from the front end wall portion 16a of the center case 16 so that the center case 16 is fixed. It is held non-rotatable.
The disc spring 22 is a known elastic body, and is used as a means for pressing the fixed disk 21 toward the rotating disk 20.
The adjusting screw 23 can be fitted into a male screw 16d formed on the inner cylindrical portion 16b of the center case 16, and the initial load of the disc spring 22 can be adjusted according to the screwing amount.
[0019]
Next, the operation of the starter 1 will be described.
When a coil (not shown) built in the magnet switch 7 is energized by turning on the key switch, the plunger is attracted to the right in FIG. 10 and the output shaft 2 are pushed forward together.
Further, when the internal contact of the magnet switch 7 is closed by the movement of the plunger, the armature 3 is energized to rotate, and the rotation of the armature 3 is decelerated by the reduction device and transmitted to the output shaft 2.
[0020]
The rotation of the output shaft 2 is transmitted to the pinion gear 9 via the one-way clutch 10. When the pinion gear 9 rotates to a position where it can mesh with the ring gear 12 and meshes with the ring gear 12, the rotation of the pinion gear 9 is transmitted to the ring gear 12. Start the engine.
When the energization of the coil is stopped by turning off the key switch after the engine is started, the plunger that has been sucked up to that time is returned to the initial position, so that the pinion gear 9 is disengaged from the ring gear 12, and the one-way clutch 10 and The output shaft 2 is moved backward together. Further, when the internal contact of the magnet switch 7 is opened, the energization to the armature 3 is stopped and the rotation is stopped.
[0021]
Next, the operation of the shock absorber will be described.
When an impact force of a predetermined torque or more is applied to the rotating disk 20, the shock absorber can absorb the impact force by rotating the rotating disk 20 that has been stationary until then. That is, when the impact force generated when the pinion gear 9 meshes with the ring gear 12 is transmitted to the internal gear 14 of the speed reducer via the output shaft 2, the rotating disk 20 that has been stationary due to the frictional force is moved to the front end wall portion of the center case 16. By sliding in the rotational direction with respect to 16 a and the fixed disk 21, the internal gear 14 whose rotation is restricted by the rotating disk 20 can be rotated. Thereby, it is possible to prevent an impact force of a predetermined torque or more from being applied to the power transmission system from the armature 3 to the pinion gear 9.
[0022]
(Effects of the first embodiment)
In the shock absorber of this embodiment, the shape of the dimples 25 formed by pressing on the surface of the rotary disk 20 is a square, and the four sides of the square are inclined by 45 degrees with respect to the rolling direction of the material. In this case, among the sides of the square that is the shape of the dimple 25, there is no side parallel to the rolling direction of the material, and each side is provided so as to be evenly inclined with respect to the rolling direction. The amount of swell of the meat formed in this way can be provided substantially uniformly throughout the protrusion 24.
[0023]
As a result, the four positions of the protrusions 24 uniformly hit the fixed disk 21, so that the wear of the protrusions 24 can be reduced as compared with the case where only the two positions described in the prior art are hit. Can increase the sex. Further, since the four locations of the protrusions 24 are uniformly applied to the fixed disk 21 from the beginning, the friction coefficient does not change suddenly during use, and there is an effect that torque management can be facilitated.
[0024]
(Modification)
In the above embodiment, the dimple 25 is formed on the rotating disk 20, but the dimple 25 of the present invention may be formed on the fixed disk 21.
In addition, the dimple 25 shown in FIG. 2A has a corner portion shown as a pin angle, but the corner portion does not necessarily have a pin angle, and may be chamfered with an R (curved surface). .
In the above embodiment, the shock absorber of the present invention is applied to the starter, but it can also be applied to a drive device other than the starter.
Needless to say, the shock absorber of the present invention can also be used as a brake device or a clutch device because of its function.
[Brief description of the drawings]
1A and 1B are a sectional view and a plan view of a rotating disk (first embodiment).
FIG. 2A is a plan view showing an arrangement of dimples, and FIG. 2B is a cross-sectional view of dimples.
FIG. 3 is a half sectional view of a starter.
FIG. 4 is a cross-sectional view showing a configuration of a reduction gear and a shock absorber.
FIG. 5 is a plan view showing the arrangement of dimples (explanation of the prior art).
[Explanation of symbols]
1 Starter 20 Rotating disc 21 Fixed disc 25 Dimple

Claims (5)

A shock absorber that absorbs an impact force by rotating the rotating disk when a rotating disk is pressed against the stationary disk to generate a frictional force between them and an impact force of a predetermined torque or more is applied to the rotating disk. ,
The rotating disk is formed by pressing a large number of dimples on the surface facing the fixed disk,
The dimple has a quadrangular shape on the surface of the rotating disk,
Due to the formation of the dimples, protrusions are formed on the four sides of the quadrangular dimples, which rises around the dimples.
The shock absorber according to claim 4, wherein the four sides of the quadrangle are provided so as to be inclined with respect to the rolling direction of the material of the rotating disk so that the heights of the protrusions on the four sides are substantially uniform . The shock absorber according to claim 1,
The dimple is a shock absorber characterized in that the shape on the surface of the rotating disk is formed in a square shape, and the four sides of the square are inclined by 45 degrees with respect to the rolling direction of the material. A shock absorber that absorbs an impact force by rotating the rotating disk when a rotating disk is pressed against the stationary disk to generate a frictional force between them and an impact force of a predetermined torque or more is applied to the rotating disk. ,
The fixed disk is formed by pressing a large number of dimples on the surface facing the rotating disk,
The dimple is formed in a square shape on the surface of the fixed disk,
Due to the formation of the dimples, protrusions are formed on the four sides of the quadrangular dimples, which rises around the dimples.
The shock absorber according to claim 4, wherein the four sides of the quadrangle are inclined with respect to the rolling direction of the material of the fixed disk so that the heights of the protrusions on the four sides are substantially uniform . The shock absorber according to claim 3,
The dimple is a shock absorber characterized in that the shape on the surface of the fixed disk is formed in a square shape, and four sides of the square are inclined by 45 degrees with respect to the rolling direction of the material. The shock absorber according to any one of claims 1 to 4 is used for a starter for starting an engine.

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