JP2004011699A - Fixed structure of rotating member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing structure of a rotating member capable of dispensing with polishing after fixing of the rotating member, by preventing deformation of a sliding surface from occurring when fixing the rotating member. <P>SOLUTION: In a camshaft 10 formed by fixing a cam pipe 11 to a shaft 12, cylindrical fixing parts 14 and 14 coaxial with a through hole 13A are protrusively disposed on both sides of a cam body 13 having the through hole 13A and a slidable surface 13F, projections 15 are formed on the inner walls of the fixing parts 14. The inner diameter of the fixing parts 14 is smaller than the outer diameter of fixed parts 16 of the shaft 12, and the outer diameter of the fixed parts 16 of the shaft 12 is not larger than the inner diameter of the through hole 13A in the cam body 13. The fixing parts 14 are fixed so that the projections 15 are made to bite into the fixed parts 16, and the shaft 12 is loosely inserted into the through hole 13A. Thus, the cam body 13 does not receive interference from the fixed parts 16 even when the cam pipe 11 is fixed to the shaft 12, so that deformation of the cam body 13 can be restricted. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a rotating member fixing structure for fixing a rotating member having a sliding surface with a mating member on an outer peripheral surface to a shaft.
[0002]
[Prior art]
Conventionally, as a camshaft used in an internal combustion engine of an automobile, a rotating member having an outer peripheral surface such as a cam tube or a journal tube as a sliding surface with a mating member is fixed to a shaft, as disclosed in Japanese Patent Laid-Open Publication No. There was one as described in JP-A-10340.
In this apparatus, a bellows-shaped uneven portion is provided on a shaft, while an inner diameter of a shaft hole through which the shaft is inserted is partially formed in the cam tube to be smaller than an outer diameter of the uneven portion of the shaft, and the cam tube is press-fitted. As a result, the shaft hole of the cam tube is partially cut into the uneven portion of the shaft and fixed.
[0003]
[Problems to be solved by the invention]
However, in the case where the shaft hole of the cam tube is cut into the camshaft as in the above-described fixing structure, the cam tube expands and deforms in the outer radial direction at the biting portion of the shaft hole, and the sliding surface of the cam tube is reduced. Had been transformed. For this reason, after the cam tube was fixed, the sliding surface had to be polished again.
The present invention has been completed on the basis of the above-described circumstances, and prevents deformation of a sliding surface that occurs when a rotating member is fixed, thereby enabling a polishing process to be omitted after the fixing of the rotating member. The purpose is to provide the structure.
[0004]
[Means for Solving the Problems]
As means for achieving the above object, the invention according to claim 1 comprises a shaft, and a rotating member having a shaft as a rotating shaft and a sliding surface formed on an outer peripheral surface thereof with respect to a mating member, A fixing structure for a rotating member, wherein the rotating member is fixed to the shaft by fitting the rotating member to the shaft and engaging one of the shaft and the rotating member with the other at a fitting surface of the rotating member. A main body having an insertion hole through which the sliding surface is formed and through which the shaft can be inserted, and a fixed portion integrally connected to the main body from the main body in the axial direction of the rotating shaft and capable of being tightly fitted and inserted into the shaft. An inner diameter of the fixing portion is smaller than an outer diameter of the shaft, and an outer diameter of the shaft is formed equal to or smaller than an inner diameter of the insertion hole, and the fixing portion is press-fitted into the shaft. Characterized by the place where the whole rotating member is secured to the shaft by being.
[0005]
According to a second aspect of the present invention, in the first aspect, the rotating member is characterized in that the fixing portions are continuously provided on both sides of the rotating shaft of the main body in the axial direction.
[0006]
According to a third aspect of the present invention, in the second aspect, the fixing portion is formed in a tubular shape, and the first fixing portion is disposed on the front side in the insertion direction with respect to the shaft, and is disposed on the rear side in the insertion direction. The shaft is provided with a first fixed portion to which the first fixing portion is fixed and a second fixed portion to which the second fixing portion is fixed. It is characterized in that the inner diameter of the first fixing portion is larger than the outer diameter of the second fixing portion.
[0007]
According to a fourth aspect of the present invention, in the one of the first to third aspects, the fixing portion or the shaft is formed with a ridge that cuts into a mating side along an axial direction of a rotating shaft. However, it has features.
[0008]
According to a fifth aspect of the present invention, in any one of the fourth aspects, the ridge is formed on the fixing portion continuously provided on both sides of the rotating shaft of the main body in the axial direction. The present invention is characterized in that the ridge formed on the fixed portion on the front side in the insertion direction of the rotating member and the ridge formed on the rear side in the insertion direction are arranged with a phase shift in the circumferential direction.
[0009]
According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the shaft and the rotating member are each provided with a convex portion formed on one of the shafts and the other is fitted to the shaft. It is characterized in that a concave portion that fits in advance with the convex portion formed in the axial direction from the front end of the insertion is positioned in the circumferential direction.
[0010]
According to a seventh aspect of the present invention, in the structure according to any one of the first to sixth aspects, a plurality of the rotating members are arranged in the axial direction with respect to the shaft. The feature is that the fixing portions are in contact with each other.
[0011]
Function and effect of the present invention
<Invention of claim 1>
The rotating member is fixed to the shaft by the fixing portion, but since the insertion hole of the main body allows the shaft to be loosely inserted, even if the fixing portion is deformed, the main body is not deformed and is formed on the main body. The deformation of the sliding surface can be prevented. Therefore, after the attachment to the shaft, the polishing of the sliding surface of the rotating member can be omitted.
[0012]
<Invention of Claim 2>
Since the rotating member is supported on the shaft by the fixing portions formed on both sides of the main body, the rotating member is stabilized.
[0013]
<Invention of Claim 3>
If the first fixed portion and the second fixed portion are formed with the same outer diameter, the second fixed portion is affected by the first fixed portion when the first fixed portion passes through the second fixed portion, and the second fixed portion is affected. When the digging occurs, the second digging is performed, so that the fixing strength is not guaranteed.
On the other hand, if the inner diameter of the first fixing portion is made larger than the outer diameter of the second fixing portion as in the invention according to claim 3, the first fixing portion and the second fixing portion are affected. Therefore, when the rotating member is attached to the shaft, when the first fixing portion provided on the front side in the insertion direction passes through the location where the second fixed portion is provided, the first fixing portion and the second fixing portion are not connected. Since it is possible to pass through the fixed portions without biting, the fixing strength between each fixed portion and the fixed portion is secured. Further, since the first fixed portion and the second fixed portion do not interfere with each other at the time of assembling, the assembling work is facilitated.
[0014]
<Invention of Claim 4>
Since the ridge bites in the axial direction of the rotating shaft, the rotating member can be easily inserted into the shaft during assembly. Further, since the ridge bites in the direction perpendicular to the rotation direction of the rotating member, the fixing force is increased, and the detent effect is high.
[0015]
<Invention of claim 5>
When the fixing portion of the rotating member bites into the shaft, the portion of the protrusion of the fixing portion on the front side in the insertion direction and the protrusion of the fixing portion on the rear side in the insertion direction are different from each other in the shaft. It is possible to make each ridge firmly bite without being affected by the biting trace formed by the ridge of the fixing portion of the boss.
[0016]
<Invention of claim 6>
The positioning in the circumferential direction can be performed by fitting the convex portion and the concave portion.
[0017]
<Invention of Claim 7>
It is possible to easily set the space between the fixing member and the other member adjacent in the axial direction.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
<First embodiment>
A first embodiment of the present invention will be described with reference to FIGS.
The camshaft 10 according to the present embodiment is used for a valve mechanism for an internal combustion engine of an automobile or the like, and has a structure in which a cam tube 11 is fixed to a rod-shaped shaft 12. The outer peripheral surface of the cam body 13 of the cam tube 11 is a sliding surface 13F with a rocker arm (not shown) which is a mating member. When the camshaft 10 is rotated, the sliding surface 13F of the cam tube 11 is locked. The arm is pressed to open and close a valve (not shown). In the present embodiment, the cam tube 11 is formed of a material having a higher hardness than the shaft 12.
[0019]
The cam tube 11 is fixed to the shaft 12 by a pair of fixing portions 14 provided on both sides of the cam body 13 (see FIG. 3).
The cam body 13 has a plate shape with an insertion hole 13A formed therethrough, and has a smooth curved sliding surface 13F on the outer periphery. The insertion hole 13A has a diameter larger than the maximum diameter of the shaft 12 as described later, and allows the shaft 12 to be loosely inserted.
The fixing portion 14 is formed in a cylindrical shape protruding coaxially with the insertion hole 13A on both sides of the cam body 13. Protrusions 15 extending along the axial direction are provided on the inner peripheral wall of the fixing portion 14 at four positions at 90-degree intervals (see FIG. 1). The inner diameter of the fixing portion 14 on which these ridges 15 are formed is smaller than the outer diameter of the fixed portion 16 of the shaft 12 described later, and the ridge 15 has a substantially semicircular cross section. It can bite into the fixed portion 16 of the shaft 12. Further, in the present embodiment, the ridges 15 are shifted by 45 degrees between the fixing portion 14 on the front side (left side in FIG. 2) and the fixing portion 14 on the rear side (right side in FIG. The formed ridges 15 are arranged so as to be alternated (see FIG. 1).
[0020]
On the other hand, as shown in FIG. 2, the shaft 12 is provided with a pair of fixed portions 16, 16 corresponding to the fixing portions 14, and has a small diameter between the fixed portions 16, 16. A portion 17 is formed.
The fixed portion 16 has a bellows shape in which two convex portions formed over the entire circumference of the shaft 12 are connected in the axial direction.
The small-diameter portion 17 has a length substantially corresponding to the thickness of the cam body 13 and is formed so as to have a diameter slightly smaller than the inner peripheral diameter of the fixing portion 14 including the protrusion 15. ing.
That is, in the present embodiment, the inner diameter of the fixing portion 14 is formed to be smaller than the outer diameter of the fixing portion 16 of the shaft 12, and the outer diameter of the fixing portion 16 is equal to or less than the inner diameter of the insertion hole 13A. It is formed so that it becomes. Further, the outer diameter of the small diameter portion 17 is formed to be smaller than the inner diameter of the insertion hole 13A.
[0021]
Subsequently, assembling of the camshaft 10 according to the present embodiment will be described.
First, the cam tube 11 is fitted into the shaft 12 from the right side in FIG.
When the fixing portion 14 on the front side in the insertion direction (right side in FIG. 2) reaches the fixed portion 16 on the front side in the insertion direction (right side in FIG. 2), the ridge 15 of the front fixing portion 14 is fixed on the front side in the insertion direction. Since it comes into contact with the portion 16, it is pushed in by applying force. Then, the cam tube 11 is inserted into the back while the protrusions 15 of the fixing portion 14 bite into the fixed portion 16.
When the cam tube 11 is further pushed in, the front fixing portion 14 passes through the small-diameter portion 17 to reach the fixed portion 16 on the back side (left side in FIG. 2) in the insertion direction, and the rear fixing portion 14 (right side in FIG. 2). Reaches the portion to be fixed 16 on the near side in the insertion direction, and is further pushed in by applying force. Then, the protrusion 15 of the front fixing portion 14 cuts into the fixed portion 16 on the back side, and the protrusion 15 of the rear fixing portion 14 cuts into the fixed portion 16 on the front side. Thereby, the cam tube 11 is fixed to the shaft 12.
At this time, when the front fixing portion 14 passes through the front fixed portion 16, the corresponding portion is crushed by the ridge 15 of the front fixing portion 14, but the phase of the ridge 15 is different between the front and the rear. It is formed shifted. Accordingly, when the ridge 15 of the rear fixing portion 14 is fitted, the rear ridge 15 newly crushes and bites the portion 16 to be fixed on the front side, so that the fixing portions 14, 14 are fixed. Strength is guaranteed.
Here, an insertion hole 13A is formed in the cam body 13, and the inner diameter of the insertion hole 13A is larger than the outer diameter of the projection of the fixed part 16, so that the fixed part 16 comes into contact with the cam body 13. It is in the loose insertion state where it is not pressed or pressed. This limits the deformation of the cam body 13 during assembly.
At this time, the front fixing portion 14 passes through the small-diameter portion 17 of the shaft 12, but the outer diameter of the small-diameter portion 17 is smaller than the inner diameter of the fixing portion 14. No interference from the fixing portion 14 occurs. Further, since the insertion hole 13A of the cam body 13 has a larger diameter than the maximum diameter of the shaft 12 (the outer diameter of the convex portion of the fixed portion 16), it does not receive any interference from the shaft 12.
[0022]
As described above, according to the present embodiment, when the cam tube 11 is fixed to the shaft 12, the cam tube 13 does not interfere with the cam portion 13 from the fixing portion 14, so that the deformation of the cam body 13 can be limited. This eliminates the need to re-grind the sliding surface of the cam tube 11 after the cam tube 11 is fixed to the shaft 12 as in the related art, so that the production efficiency is excellent.
By the way, since the fixing portion 14 receives a pushing force between the ridge 15 and the fixed portion 16, the outer peripheral surface may expand and deform in the outer radial direction. Since it does not function as the valve operating mechanism of the engine, no trouble occurs.
[0023]
<Second embodiment>
Next, a second embodiment of the present invention will be described with reference to FIG.
The camshaft 10 according to the present embodiment differs from the first embodiment in that a positioning projection 18 is formed on the fixing portion 14 of the cam tube 11 as shown in FIG. The same components as those in the above-described embodiment are denoted by the same reference numerals, and redundant description will be omitted.
[0024]
On the inner peripheral wall of the fixing portion 14 at the front in the insertion direction, a positioning convex portion 18 protruding inward is formed over the entire length of the fixing portion 14. As shown in FIG. 4, the positioning projection 18 is provided at one place between a pair of ridges 15, 15 which are circumferentially adjacent to each other between the fixing parts 14, 14.
Further, at a predetermined position of the shaft 12, a positioning concave portion 19 having a groove shape into which the positioning convex portion 18 can be fitted is cut out along the axial direction of the shaft 12 (see FIG. 4). The positioning concave portion 19 is formed along the same straight line from the position corresponding to the fixed portion 16 on the near side in the insertion direction of the cam tube 11 to the small diameter portion 17 and the fixed portion 16 on the far side.
[0025]
According to the present embodiment, when assembling the camshaft 10, the positioning convex portion 18 and the positioning concave portion 19 are fitted and assembled, so that the cam tube 11 can be easily assembled at a desired position. Accuracy can be improved.
[0026]
When a plurality of cam tubes 11 are fixed to the shaft 12, the position of the positioning projection 18 may be changed according to the position of the cam tube 11, or the shaft 12 may be changed according to the position of the cam tube 11. May be formed at a plurality of locations.
[0027]
<Third embodiment>
5 to 8 show a third embodiment of the present invention.
In the camshaft 10 according to the present embodiment, the outer diameter of the fixed portion 16F on the near side (the right side in FIG. 6) in the insertion direction of the shaft 12 is smaller than the fixed portion 16R on the far side (the left side in FIG. 6). The difference from the first embodiment is that the amount of protrusion of the ridge 15 of the fixing portion 14F on the front side (right side in FIG. 6) of the cam tube 11 in the insertion direction is smaller than the amount of protrusion of the fixing portion 14R on the rear side in the insertion direction. The same components as those in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted.
[0028]
With such a configuration, interference between the fixing portion 14F in the front in the insertion direction and the fixed portion 16B on the front side in the insertion direction is prevented at the time of assembling, so that it is not necessary to apply an extra load at the time of fixing, and the production efficiency is excellent. .
[0029]
<Fourth embodiment>
In the camshaft 10 according to the present embodiment, the shape of the fixed portion 16 is different from that of the first embodiment.
The outer peripheral surface of the fixed portion 16 is subjected to mesh-like knurling.
With such a configuration, the processing of the fixed portion 16 is easy, and the friction between the ridge 15 and the fixed portion 16 increases when the cam tube 11 is fixed, so that the fixing force of the cam tube 11 is improved. It becomes possible [0030]
<Fifth embodiment>
In any of the embodiments described above, like the camshaft 10 according to the present embodiment, the fixing portion 14 is set to a predetermined length and is axially adjacent to the cam tube 11 or the journal tube 11A at the time of assembly. It may be used as a so-called spacer that sets a predetermined distance from the rotating member.
According to the present embodiment, the positioning of the shaft 12 in the axial direction can be easily performed by abutting and fitting the tips of the fixing portions 14, 14 of the adjacent cam tubes 11, 11.
When it is desired to set a predetermined gap between the abutting fixing portions 14, 14, the fixing portion 14 of one cam tube 11 and the fixing portion 14 of the other cam tube 11 (or the journal tube 11 </ b> A) are connected to each other. An elastic spacer (not shown) having a predetermined thickness may be fixed to the abutting portion with an elastic material, and then the elastic spacer may be removed.
[0031]
<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and furthermore, besides the following, within the scope not departing from the gist. Can be implemented with various modifications.
(1) In the above-described embodiment, the ridge 15 formed in parallel to the axial direction is cut into the inner peripheral surface of the fixing portion 14. However, for example, the cross-sectional shape of the inner periphery of the fixing portion 14 is made polygonal. The fixed portion 14 may be partially formed to have a smaller diameter than the outer diameter of the fixed portion 16, and the fixing portion 14 thus formed may be cut into the fixed portion 16.
(2) In the above embodiment, the ridge 15 formed on the inner peripheral wall of the fixing portion 14 has a substantially semicircular shape, but may have another shape such as a substantially triangular cross section.
In the above embodiment, the ridges 15 of the front fixing portion 14 and the rear fixing portion 14 in the insertion direction are arranged in the same phase, and the rear ridge 15 projects from the front ridge 15. It may be made to be.
(3) In the above embodiment, the outer peripheral surface of the fixing portion 14 of the cam tube 11 may be used as a journal surface.
(4) In the second embodiment, the positioning projection 18 is formed only on the fixed portion 14 in the front in the insertion direction. However, the positioning projection 18 may be formed on the fixed portion 14 on the rear. At this time, the positioning projections 18 may be formed on both the front and rear fixing portions 14, 14, or the positioning projections 18 may be formed on one of the fixing portions 14.
[Brief description of the drawings]
FIG. 1 is a plan view of a cam tube according to a camshaft according to a first embodiment. FIG. 2 is a partially cutaway side view of a cam shaft before assembly of the cam tube. FIG. 4 is a plan view of a cam tube according to a camshaft according to a second embodiment. FIG. 5 is a plan view of a cam tube according to a camshaft according to a third embodiment. FIG. 6 is a partially broken side view before assembling the cam tube. FIG. 7 is a side sectional view of the camshaft in an assembling process. FIG. 8 is a side sectional view of the camshaft after assembling. FIG. 9 is a side sectional view of the camshaft before assembling according to the fourth embodiment. FIG. 10 is a side sectional view of the camshaft after assembly. FIG. 11 is a side view of the camshaft according to the fifth embodiment.
10 camshaft 11 cam tube (rotating member)
12: shaft 13: cam body (body)
13A ... insertion hole 13F ... sliding surface 14 ... fixed part 15 ... ridge 16 ... fixed part 17 ... small diameter part 18 ... positioning convex part (convex part)
19: Positioning recess (recess)

Claims (7)

A shaft and a rotating member having a sliding surface with respect to a mating member formed on an outer peripheral surface of the rotating shaft, wherein the rotating member is fitted into the shaft, and the shaft, the rotating member, A fixing structure of a rotating member for fixing the rotating member by making one of them bite into the other at the fitting surface of the rotating member,
The rotating member is provided integrally with a main body having the sliding surface formed therein and having an insertion hole through which the shaft can be inserted, and is integrally connected to the main body in the axial direction of the rotation shaft, and is fixedly fitted to the shaft in close contact therewith. Wherein the inner diameter of the fixing portion is smaller than the outer diameter of the shaft, and the outer diameter of the shaft is formed to be smaller than the inner diameter of the insertion hole, and the fixing portion is press-fitted into the shaft. The whole of the rotating member is fixed to the shaft by the above. 2. The rotating member fixing structure according to claim 1, wherein the fixing member is continuously provided on both sides of the rotating member in the axial direction of the rotating shaft. 3. The fixing portion is formed in a tubular shape, and includes a first fixing portion disposed on the front side in the insertion direction with respect to the shaft and a second fixing portion disposed on the rear side in the insertion direction with respect to the shaft.
The shaft includes a first fixed portion to which the first fixing portion is fixed and a second fixed portion to which the second fixing portion is fixed.
The rotating member fixing structure according to claim 2, wherein an inner diameter of the first fixing portion is larger than an outer diameter of the second fixed portion. The fixing structure for a rotating member according to claim 1, wherein a ridge biting into a mating side is formed on the fixing portion or the shaft along an axial direction of a rotation shaft. 5. . The ridge is formed on the fixing portion provided on both sides of the main body in the axial direction of the rotating shaft, and the ridge formed on the fixing portion on the front side in the insertion direction of the rotating member and the rear portion in the insertion direction. The fixing structure for a rotating member according to claim 4, wherein the ridges formed on the side are arranged so as to be shifted in phase in the circumferential direction. The shaft and the rotating member each have a convex portion formed on one side and the other has a concave portion that fits with the convex portion formed in advance in the axial direction from the insertion front end before fitting to the shaft. The fixing structure for a rotating member according to any one of claims 1 to 5, wherein positioning in a circumferential direction is performed. 7. The structure according to claim 1, wherein in the structure in which a plurality of the rotating members are arranged in the axial direction with respect to the shaft, the fixing portions of the adjacent rotating members are in contact with each other. A rotating member fixing structure according to any one of the above.

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