JP2004278574A - Lock ball device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lock ball device capable of avoiding the occurrence of extreme wearing of a plunger while improving shift feeling. <P>SOLUTION: A lock ball device 200 is provided with a lock ball 1, a plunger 2 which comprises a downward recess 5 whose inside surface is such curved surface as corresponding to a part of a spherical surface and holds the lock ball 1 inside the recess 5, a holder 7 which is constrained in a rolling space 6 defined as a gap between the inside surface of the recess 5 and the outside surface of the lock ball 1 but movably arranged in the rolling space 6, and a plurality of support balls 4 so arranged as to move only in such a range of the rolling space 6 as regulated by the holder 7. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lock ball device for giving a driver a moderation during a shift in a manual transmission or the like.
[0002]
[Prior art]
FIG. 12 shows a partial cross section of a conventional transmission. This transmission includes a conventional lock ball device 100. When the driver operates a shift lever (not shown), the inner lever 101 rotates about the point 105. Then, the lower end of the inner lever 101 slides the shift head 103 fixed to the fork shaft 107 left and right in the drawing, and as a result, the shift fork 104 slides. At the same time, the lock ball device 100 is arranged so as to be pressed downward against the upper end of the inner lever 101, and has a structure in which moderation is provided by attaching and detaching the lock ball 1 to and from the recess 106 of the inner lever 101.
[0003]
FIG. 13 is an enlarged cross-sectional view of the lower end of the conventional lock ball device 100. The lock ball device 100 employs a rolling system instead of a sliding system in order to improve shift feeling. The structure of the lock ball device 100 will be described below.
[0004]
A concave portion 5 whose inner surface corresponds to a part of a spherical surface is provided at the tip of a member called a plunger 2, and the lock ball 1 is rotatably held in the concave portion 5 via a plurality of support balls 4. Have been. The outlet of the recess 5 is smaller than the diameter of the lock ball 1 so that the lock ball 1 does not fall out of the recess 5. The support ball 4 also has a diameter so as not to fall out of the recess 5 and is held inside the recess 5. The entire space defined by the inner surface of the concave portion 5 and the outer surface of the lock ball 1 and in which the support ball 4 can exist is hereinafter referred to as “rolling space” 6.
[0005]
The plunger 2 is urged downward by a spring 3. Even if the lock ball 1 is pressed against the inner lever 101 or the like by this bias, and the lock ball 1 is subjected to an external force in such a direction as to be pushed into the depth of the concave portion 5, the support ball remains in the rolling space 6. Since the number 4 is sufficient, the outer surface of the lock ball 1 does not directly contact the inner surface of the recess 5, and the inner surface of the recess 5 supports the lock ball 1 via the support ball 4. In the lock ball device 100, the lock ball 1 can relatively smoothly rotate by the lubricating action of the rotation and movement of the support ball 4. Such a method is called a rolling method, and it is said that the shift feeling is better than a sliding lock ball in which the lock ball is simply pressed downward by a spring or the like.
[0006]
Techniques related to the above-described rock ball device are disclosed in German Patent Application Publication No. 4204630A1 (Patent Document 1) and German Patent Publication No. 10057377A1 (Patent Document 2). Another example of a mechanism for realizing a moderation at the time of shifting by a ball and a spring is disclosed in Japanese Patent Application Laid-Open No. 6-147315 (Patent Document 3).
[0007]
[Patent Document 1]
DE-A-42 04 630 A1
[Patent Document 2]
DE 100 57 377 A1
[Patent Document 3]
JP-A-6-147315
[Problems to be solved by the invention]
In the lock ball device 100 described above, the support ball 4 can move freely within the recess 5. Therefore, during actual use, the support balls 4 gather at the lower part in the rolling space 6 under the influence of gravity, as shown in FIG. When the positional relationship between the lock ball 1 and the support ball 4 is three-dimensionally shown through the plunger 2, the positional relationship is as shown in FIGS.
[0011]
In this state, the plunger 2 is urged downward by the spring 3, and the lock ball 1 receives a drag upward from the inner lever 101 (see FIG. 12). At this time, the plunger 2 must support this load only by a limited area where the inner surface of the concave portion 5 and the support ball 4 are in contact with each other, but all the support balls 4 contact the inner surface of the concave portion 5 with an equal load. Do not mean. Actually, due to the wedge effect, the load is concentrated on the support ball 4 located on the upper side, and the support ball 4 comes into contact with a particularly high surface pressure. As a result, abrasion generated on the inner surface of the concave portion 5 at a position where the support ball 4 comes into contact increases, which is a problem.
[0012]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a lock ball device that can prevent extreme wear of a plunger while improving shift feeling.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, a lock ball device according to the present invention has a lock ball and a downward concave portion whose inner surface is a curved surface corresponding to a part of a spherical surface, and holds the lock ball inside the concave portion. A plunger, a retainer disposed so as to be movable in the rolling space while being restrained in a rolling space defined as a gap between the inner surface of the concave portion and the outer surface of the lock ball, and the rolling space And a plurality of support balls arranged so as to be movable only within a range defined by the retainer. By adopting this configuration, the support balls can be collected within a range that can support the load in the vertical direction without increasing the number of support balls and maintaining sufficient space even if the spare space is sufficiently large. Surface pressure generated between the inner surface of the recess and the inner surface of the recess can be reduced. As a result, abrasion of the inner surface of the concave portion can be prevented.
[0014]
In the above invention, preferably, the retainer is an annular member having an inner diameter smaller than an outer diameter of the lock ball, and the retainer is configured to be such that when the lock ball is pressed into the retainer, the retainer is fixed to the lock ball. Has a shape such that the height of the lock ball projecting in the radial direction from the outer surface thereof is smaller than the diameter of the support ball. By adopting this configuration, it is possible to avoid that the retainer comes into contact with the inner surface of the concave portion and becomes jammed in the rolling space, and that the retainer rubs against the inner surface of the concave portion to increase the frictional resistance.
[0015]
In the above invention, preferably, the retainer has a C-ring shape having an inner diameter smaller than the outer diameter of the lock ball and a cut portion having a width smaller than the diameter of the support ball, and the retainer holds the lock ball. The retainer has a shape such that a height of the retainer projecting from an outer surface of the lock ball in a radial direction of the lock ball when pressed against the container is smaller than a diameter of the support ball. By adopting this configuration, it is possible to prevent the retainer from contacting the inner surface of the concave portion and clogging the rolling space, and preventing the retainer from rubbing against the inner surface of the concave portion to increase the frictional resistance.
[0016]
In the above invention, preferably, the retainer is an annular member having an inner diameter smaller than the outer diameter of the lock ball, and a part of the plurality of support balls is arranged in a form arranged in a circle in the rolling space. It has a support ball storage part to hold in a state. By adopting this configuration, it is possible to easily adopt a structure in which the retainer does not directly contact the lock ball, thereby preventing the retainer from being caught on the lock ball and preventing the lock ball from being damaged by the retainer. The required number of support balls can be held.
[0017]
In the above invention, preferably, the support ball housing is a through hole provided on the circumference of the annular member. By employing this configuration, the support ball can be stably held while securing the strength of the cage itself.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Prior to the description of the embodiments of the present invention, other technologies examined by the inventor will be described.
[0019]
In order to solve the problem of wear due to the wedge effect in the lock ball device 100 based on the prior art, it is conceivable to first increase the number of the support balls 4 as shown in FIG. In this way, even if the support balls 4 are deflected to the lower side by the gravity in the rolling space 6, there are some support balls 4 on the upper side. Therefore, the number of the support balls 4 that can bear the load in the vertical direction is increased and the load is dispersed, so that the surface pressure between the support balls 4 and the inner surface of the recess 5 can be reduced. However, with such a structure, when the lock ball 1 rotates, it must rotate while contacting with more support balls 4 than in the related art, so that the sliding resistance increases. In addition, the space 8 (hereinafter, referred to as “surplus space”) 8 of the rolling space 6 corresponding to the allowance for the movement of the support ball 4 also becomes smaller, so that the movement of the support ball 4 is more restricted than before. As a result, the sliding resistance increases from this point.
[0020]
In addition, as shown in FIG. 2, it is conceivable to reduce the rolling space 6 while keeping the number of the support balls 4 as compared with the lock ball device 100 based on the prior art. In this case, the surface pressure between the support ball 4 and the inner surface of the concave portion 5 can be reduced without increasing the number of the support balls 4, but the margin 8 is still reduced, and the sliding resistance still remains. Increase is inevitable.
[0021]
The inventor assumed these techniques, studied the problems thereof, and further improved them, and came to the present invention.
[0022]
Hereinafter, embodiments of the present invention will be described.
(Embodiment 1)
(Constitution)
The lock ball device 200 according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 3 is an enlarged cross-sectional view of the lower part of the rock ball device 200. When the positional relationship among the lock ball 1, the support ball 4, and the retainer 7 is three-dimensionally seen through the plunger 2, it becomes as shown in FIGS.
[0023]
As shown in FIG. 3, the lock ball device 200 includes a lock ball 1, a plunger 2, a retainer 7, and a plurality of support balls 4. The plunger 2 has a downward recess 5. The inner surface of the concave portion 5 is a curved surface corresponding to a part of a spherical surface. The plunger 2 holds the lock ball 1 inside the recess 5. The retainer 7 is movable in the rolling space 6 while being restrained in a rolling space 6 defined as a gap between the inner surface of the concave portion 5 and the outer surface of the lock ball 1. The plurality of support balls 4 are each movable only within a range defined by the retainer 7 in the rolling space 6.
[0024]
The retainer 7 is a ring-shaped member, and FIG. 3 shows a ring-shaped member having a circular cross section as an example. As shown in FIG. 5, the retainer 7 has a so-called O-ring shape, and has an inner diameter smaller than the outer diameter of the lock ball 1. Further, as shown in FIG. 6, when the lock ball 1 is pressed so as to fit into the retainer 7, the retainer 7 moves from the outer surface of the lock ball 1 toward the radial direction D of the lock ball 1. It has such a shape that the protruding height a is smaller than the diameter b of the support ball 4. In FIG. 6, for convenience of explanation, only one representative one of the support balls 4 in contact with the outer surface of the lock ball 1 is displayed.
[0025]
(Action / Effect)
In the lock ball device 200 having the above-described configuration, the plurality of support balls 4 can be moved in the rolling space 6 for the time being. However, the support balls 4 cannot move freely over the entire area of the rolling space 6, but can move. Is limited to a part of the rolling space 6 by the annular retainer 7. On the other hand, since the retainer 7 is movable in the rolling space 6, each time the retainer 7 moves, the region in which the support ball 4 can move can also change.
[0026]
Further, since a <b (see FIG. 6), the retainer 7 comes into contact with the inner surface of the concave portion 5 and becomes jammed in the rolling space 6, and the retainer 7 rubs against the inner surface of the concave portion 5 to cause friction. There is no increase in resistance. Only the support ball 4 supports the load between the plunger 2 and the lock ball 1, and the retainer 7 only defines the movable range of the support ball 4.
[0027]
Further, since the inner diameter of the retainer 7 is smaller than the outer diameter of the lock ball 1, the retainer 7 does not fall down beyond the lock ball 1.
[0028]
Since the retainer 7 has an O-ring shape having a circular cross section as shown in FIG. 5, the friction between the retainer 7 and the lock ball 1 can be made relatively smooth, and the degree of hindering the rotation of the lock ball 1 is reduced. can do.
[0029]
Since the range in which the plurality of support balls 4 can be moved by the retainer 7 is limited to a part of the rolling space 6, the rolling space 6 is wide as before and the number of the support balls 4 is the same as before. Even so, it is possible to prevent the support balls 4 from being deviated only downward in the rolling space 6 due to gravity and to collect the support balls 4 within a range that can support the load in the vertical direction. Therefore, the surface pressure generated between the support ball 4 and the inner surface of the recess 5 can be reduced, and as a result, the inner surface of the recess 5 can be prevented from being worn. Moreover, since there is enough room 8 (see FIG. 3), an increase in sliding resistance can be prevented.
[0030]
Here, an example of the O-ring-shaped retainer 7 has been described, but the retainer may have a C-ring shape as shown in FIG. In that case, the width c of the cut portion of the ring needs to be smaller than the diameter of the support ball 4. By doing so, it is possible to prevent the support ball 4 from coming out to the opposite side of the retainer through the disconnected portion.
[0031]
5 (a) and 5 (b) and FIGS. 7 (a) and 7 (b) show examples in which the cross section of the retainer is circular. However, the cross section of the retainer is not limited to a circle, but may have other shapes. Is also good.
[0032]
(Embodiment 2)
(Constitution)
A lock ball device according to a second embodiment of the present invention based on the present invention will be described with reference to FIGS. This lock ball device is basically the same as that described in the first embodiment, but the shape of the retainer is different. This lock ball device includes a retainer 7h shown in FIGS. 8A and 8B instead of the retainer 7 shown in the first embodiment. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. The retainer 7h is an annular member and has an inner diameter smaller than the outer diameter of the lock ball 1. The retainer 7h has a plurality of support ball housings 9 arranged on the circumference in the circumferential direction. Each support ball accommodating portion 9 is a through hole having a mortar-shaped inner surface as shown in FIG. 9, and each support ball 4 comes into contact with the mortar-shaped inner surface during use. FIG. 10 shows the positional relationship between the retainer 7h and other components in the lock ball device. The support ball receiving portion 9 of the holder 7h is for holding a part of the plurality of support balls in a state of being arranged in the rolling space 6 in a ring shape. As shown in FIG. 10, the lowermost row of the support balls 4u is held in the support ball housing 9 of the holder 7h. However, the support ball 4u can be rotated at least while being held in the support ball housing portion 9. The other support balls 4 exist such that the outer edge is confined in a region defined by the annularly arranged support balls 4u.
[0033]
(Action / Effect)
Since the lock ball device according to the present embodiment includes the retainer that holds a part of the support ball by the support ball receiving portion, the support ball that is not retained by the retainer is supported by the retainer directly abutting. Instead, it can be performed by a row of annularly arranged support balls held by a retainer. With this structure, a structure in which the retainer does not directly contact the lock ball can be easily adopted, so that it is possible to prevent the retainer from being caught on the lock ball and the lock ball from being damaged by the retainer.
[0034]
The shape of the retainer may be another shape, and alternatively, a retainer 7i as shown in FIG. 11 may be used. This retainer 7i is similar to the retainer 7h in that through holes are arranged as support ball receiving portions, but has a shape in which a through hole is formed in a thin plate-shaped member.
[0035]
Here, a through hole is shown as an example of the support ball housing, but a cutout having a size such as to receive a support ball may be used in addition to the through hole. In addition, a structure that can be easily processed at the time of manufacturing the cage can be appropriately selected.
[0036]
Further, in each of the above embodiments, the plurality of support balls are described as being distributed only above the retainer. However, the support balls whose movable range is limited by the retainer (the support balls above the retainer). In addition to the ball, one or more other support balls may be provided below the cage.
[0037]
Note that the above-described embodiment disclosed this time is illustrative in all aspects and is not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and includes all modifications within the scope and meaning equivalent to the terms of the claims.
[0038]
【The invention's effect】
According to the present invention, the support balls can be collected within a range capable of supporting the load in the vertical direction without increasing the number of the support balls and maintaining a sufficiently large spare space. The surface pressure generated between the inner surface and the inner surface can be reduced. As a result, abrasion of the inner surface of the concave portion can be prevented.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view of a lock ball device according to a first technique that is a reference of the present invention.
FIG. 2 is a partial cross-sectional view of a lock ball device according to a second technique which is a reference of the present invention.
FIG. 3 is a partial cross-sectional view of the lock ball device according to the first embodiment of the present invention.
FIGS. 4A and 4B are diagrams illustrating a positional relationship among a lock ball, a support ball, and a retainer in the lock ball device according to the first embodiment of the present invention, wherein FIG. 4A is a plan view and FIG. It is.
FIGS. 5A and 5B are views of an O-ring-shaped retainer that can be used in the lock ball device according to the first embodiment of the present invention, where FIG. 5A is a plan view and FIG. 5B is a VB-VB line of FIG. FIG.
FIG. 6 is an explanatory diagram of dimensions related to a retainer that can be used in the lock ball device according to the first embodiment of the present invention.
FIGS. 7A and 7B are views of a C-ring-shaped retainer that can be used in the lock ball device according to the first embodiment of the present invention, where FIG. 7A is a plan view and FIG. 7B is a VIIB-VIIB line of FIG. FIG.
FIGS. 8A and 8B are views of a retainer that can be used in the lock ball device according to the second embodiment of the present invention, where FIG. 8A is a plan view and FIG. 8B is a front view.
FIG. 9 is a cross-sectional view taken along line IX-IX in FIG.
FIG. 10 is an explanatory view of a lock ball device according to a second embodiment of the present invention.
FIG. 11 is an explanatory view of a modification of the lock ball device according to the second embodiment based on the present invention.
FIG. 12 is a sectional view of a transmission according to the related art.
FIG. 13 is a partially enlarged cross-sectional view of a lock ball device based on the prior art.
FIG. 14 is a partially enlarged cross-sectional view of a use state of a lock ball device based on a conventional technique.
FIGS. 15A and 15B are diagrams showing a positional relationship among a lock ball, a support ball, and a retainer of a lock ball device based on a conventional technique, wherein FIG. 15A is a plan view and FIG. 15B is a side view.
[Explanation of symbols]
Reference Signs List 1 lock ball, 2 plunger, 3 spring, 4 support ball, 5 recess (of plunger), 6 rolling space, 7 retainer, 8 extra space, 9 support ball housing, 100 lock ball device, 101 inner lever, 103 shift Head, 104 shift fork, 105 (center of rotation of inner lever), 106, recess (of inner lever).

Claims (5)

Rock ball and
A plunger whose inner surface has a downward concave portion that is a curved surface corresponding to a part of a spherical surface, and that holds the lock ball inside the concave portion;
A retainer arranged to be movable in the rolling space while being restrained in a rolling space defined as a gap between the inner surface of the concave portion and the outer surface of the lock ball;
A lock ball device comprising: a plurality of support balls arranged so as to be movable only within a range defined by the retainer in the rolling space. The retainer is an annular member having an inner diameter smaller than the outer diameter of the lock ball, and when the lock ball is pressed so as to fit into the retainer, the retainer moves the lock ball from an outer surface of the lock ball. The lock ball device according to claim 1, wherein a height of the support ball in a radial direction is smaller than a diameter of the support ball. The retainer has a C-ring shape having an inner diameter smaller than the outer diameter of the lock ball, and a cut portion having a width smaller than the diameter of the support ball, and is configured to push the lock ball into the retainer. The lock ball device according to claim 1, wherein the retainer has a shape such that a height of the retainer projecting from an outer surface of the lock ball in a radial direction of the lock ball when applied is smaller than a diameter of the support ball. . The retainer is an annular member having an inner diameter smaller than the outer diameter of the lock ball, and a support ball that holds a part of the plurality of support balls in a state of being arranged in a circular shape in the rolling space. The lock ball device according to claim 1, further comprising a housing. The lock ball device according to claim 4, wherein the support ball receiving portion is a through hole provided on a circumference of the annular member.

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