JP5361120B2 - Roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roller bearing for supporting a camshaft or the like of an engine for an automobile in which rollers can revolve smoothly. <P>SOLUTION: The roller bearing comprises an outer ring formed by continuously connecting circular arc-shaped outer ring members in the circumference and the rollers arranged along the inner diameter surface of the outer ring. A slope surface 22i is formed at either or both of circumferential ends of an inner diameter surface of the outer ring member 22a, and a contour line of the slope surface 22i is directed orthogonally to the revolution direction of the rollers. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a roller bearing that supports a camshaft, a crankshaft, a rocker shaft, and the like for an automobile engine, a camshaft support structure that employs a roller bearing, and an internal combustion engine.

  A conventional bearing that supports a camshaft of an automobile engine is described in, for example, Japanese Patent Application Laid-Open No. 2005-180459 (Patent Document 1). Referring to FIG. 15, a camshaft 101 described in the publication includes a cam lobe 101a, a cylindrical journal portion 101b supported by a roller bearing 102, and an end large diameter portion 101c. .

  Here, the outer diameter of the journal portion 101b is smaller than the maximum outer diameter of the cam lobe 101a and the outer diameter of the large end portion 101c. For this reason, the roller bearing 102 disposed in the journal portion 101 b and rotatably supporting the camshaft 101 cannot be inserted from the axial direction of the camshaft 101.

  Accordingly, the roller bearing 102 is substantially divided into a plurality of rollers 103, a substantially semi-cylindrical holding body 104, 105 divided in the circumferential direction, and a circumferential direction divided between the cylinder head 108 and the cap 109. Semi-cylindrical lace plates 106 and 107 are provided.

  The race plates 106 and 107 have protrusions 106a and 107a that protrude radially outward from both axial end surfaces of the central portion in the circumferential direction. On the other hand, the cylinder head 108 and the cap 109 are provided with recesses 108a and 109a for receiving the projections 106a and 107a of the race plates 106 and 107, respectively. It is described that the movement of the race plates 106 and 107 in the circumferential direction and the axial direction can be prevented by engaging the protrusions 106a and 107a with the recesses 108a and 109a, respectively.

Referring to FIG. 16, one end portion in the circumferential direction of the lace plate 106 is a wedge-shaped protrusion portion 106 b protruding from the center portion, and the other end portion in the circumferential direction is a valley shape recessed in the center portion. The concave portion 106c. And the surface pressing process is given to this circumferential direction both ends, respectively. As a result, it is described that burrs and burrs generated at the end in the circumferential direction by the punching process are compensated, and the shape of the end is also compensated, so that the assembling accuracy is improved.
JP 2005-180459 A

  The above publication does not clearly indicate the direction of surface pressing applied to both ends in the circumferential direction of the lace plate 106 having the above-mentioned configuration, but for the purpose of correcting burrs and burrs and the purpose of correcting the end shape. It is considered that surface pressing is performed in a direction (in the direction of the arrow in FIG. 16) perpendicular to the outer contour of the processed portion.

  However, since the surface pressing portion formed in the above direction is inclined to the left or right with respect to the rolling direction of the rollers 103, the behavior of the rollers 103 passing through the abutting portions of the race plates 106 and 107 is There is a risk of being disturbed by the surface pressing portion.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a roller bearing that supports a camshaft or the like of an automobile engine and that allows the roller to rotate smoothly. It is another object of the present invention to provide a camshaft support structure and an internal combustion engine in which such a roller bearing is adopted as a bearing for supporting the camshaft.

  A roller bearing according to the present invention includes an outer ring formed by connecting a plurality of arc-shaped outer ring members in a circumferential direction, and a plurality of rollers disposed along an inner diameter surface of the outer ring. And the inclined surface is provided in the circumferential direction edge part of the outer ring member at least one side, and the contour line of the inclined surface has faced the direction orthogonal to the revolution direction of a roller.

  By providing an inclined surface along the rolling direction of the roller at the circumferential end of the outer ring member as in the above configuration, the roller passing through the abutting portion of the adjacent outer ring member can smoothly roll. In addition, the effect of this invention can be acquired if an inclined surface is provided only in the circumferential direction edge part of the side where a roller contacts first among two circumferential edge parts of each outer ring member. .

Preferably, t ₀ the thickness of the thickest portion of the outer ring _member, when the thickness of the inclined surface in the circumferential direction outermost end and t, satisfy _{0.05 ≦ t / t 0 ≦ 0.5} . More preferably, when the inclination angle of the inclined surface is θ, 10 ° ≦ θ ≦ 45 ° is satisfied. In order to obtain a sufficient effect according to the present invention, it is desirable that the thickness and the inclination angle of the inclined surface are within the above ranges.

  A camshaft support structure according to the present invention includes a camshaft, a housing that houses the camshaft, and a roller bearing that rotatably supports the camshaft with respect to the housing. When paying attention to the roller bearing, it includes an outer ring formed by connecting a plurality of arc-shaped outer ring members in the circumferential direction, and a plurality of rollers disposed along the inner diameter surface of the outer ring. And the inclined surface is provided in the circumferential direction edge part of the outer ring member at least one side, and the contour line of the inclined surface has faced the direction orthogonal to the revolution direction of a roller.

  An internal combustion engine according to the present invention includes a housing, a cylinder provided in the housing, a valve for opening and closing an intake passage and an exhaust passage communicating with the cylinder, a camshaft for controlling timing of opening and closing the valve, and a camshaft. And a roller bearing that is rotatably supported. When paying attention to the roller bearing, it includes an outer ring formed by connecting a plurality of arc-shaped outer ring members in the circumferential direction, and a plurality of rollers disposed along the inner diameter surface of the outer ring. And the inclined surface is provided in the circumferential direction edge part of the outer ring member at least one side, and the contour line of the inclined surface has faced the direction orthogonal to the revolution direction of a roller.

  By adopting the roller bearing having the above configuration, a long-life and highly reliable camshaft support structure and an internal combustion engine can be obtained.

  According to this invention, by providing an inclined surface that inclines in the rolling direction of the roller at the circumferential end of the inner diameter surface of the outer ring member, the behavior of the roller passing through the abutting portion of the adjacent outer ring member is increased. Stabilize. As a result, a roller bearing in which the rollers can rotate smoothly can be obtained. In addition, by adopting such a roller bearing, it is possible to obtain a long-life and highly reliable camshaft support structure and internal combustion engine.

  An internal combustion engine 11 according to an embodiment of the present invention will be described with reference to FIGS. 12 is a cross-sectional view showing one of the cylinders of the internal combustion engine 11 according to one embodiment of the present invention, FIG. 13 is a view showing a crankshaft 15 used in the internal combustion engine 11, and FIG. It is a figure which shows the camshaft 19 used.

  First, referring to FIG. 12, an internal combustion engine 11 performs a cylinder block 12 and a cylinder head 13 as a housing, a motion conversion mechanism that converts reciprocating motion into rotational motion, and intake of air-fuel mixture and exhaust of combustion gas. A reciprocating engine including an air supply / exhaust mechanism and a spark plug 20 as an ignition device.

  The motion conversion mechanism is housed in the cylinder block 12 and reciprocates in the cylinder 12a provided in the cylinder block 12, and a transmission (not shown) via a flywheel (not shown) and a clutch (not shown). And a connecting rod 16 having one end connected to the piston 14 and the other end connected to the crankshaft 15 for converting the reciprocating motion of the piston 14 into the rotational motion of the crankshaft 15.

  The air supply / exhaust mechanism is formed in the cylinder head 13 and communicates with the cylinder 12a, the intake passage 13a and the exhaust passage 13b, the intake valve 17 as a valve disposed between the cylinder 12a and the intake passage 13a, the cylinder 12a and the exhaust passage. An exhaust valve 18 as a valve disposed between the passages 13b, and an intake valve 17 and a camshaft 19 for controlling the opening / closing timing of the exhaust valve 18 are provided.

  The intake valve 17 includes a valve stem 17a, a valve head 17b provided at one end of the valve stem 17a, and a valve spring 17c that urges the intake valve 17 in a direction to close the intake passage 13a. A camshaft 19 is connected to the other end portion of the stem 17a. The exhaust valve 18 has the same configuration as the intake valve 17 and will not be described.

  Referring to FIG. 13, a crankshaft 15 used in the internal combustion engine 11 includes a shaft portion 15a, a crank arm 15b, and a crank pin 15c for disposing a connecting rod 16 between adjacent crank arms 15b. . The crankshaft 15 is rotatably supported by a needle roller bearing 21 according to an embodiment of the present invention described later. Further, the same number of crank pins 15c as the number of cylinders of the internal combustion engine 11 are provided.

  Referring to FIG. 14, a camshaft 19 used in the internal combustion engine 11 includes a shaft portion 19a and a plurality of cams 19b. The shaft portion 19a is rotatably supported by a needle roller bearing 21 according to an embodiment of the present invention described later. The camshaft 19 is connected to the crankshaft 15 by a timing belt (not shown), and rotates as the crankshaft 15 rotates.

  Since the cam 19b is connected to the intake valve 17 or the exhaust valve 18, respectively, the same number as the valves 17 and 18 is provided. Further, as shown in FIG. 12, the cam 19b includes a long diameter portion 19c having a relatively large diameter and a short diameter portion 19d having a relatively small diameter, and the plurality of cams 19b are formed as shown in FIG. The position of the long diameter portion 19c is shifted in the circumferential direction. This makes it possible to open and close the valves 17 and 18 connected to the plurality of cams 19b at different timings.

  The internal combustion engine 11 is a DOHC (Double Over Head Camshaft) engine in which the camshaft 19 is disposed on the upper side of the cylinder head 13 and provided on the intake valve 17 side and the exhaust valve 18 side, respectively.

  Next, the operating principle of this internal combustion engine will be described.

  First, in this internal combustion engine 11, when the process of moving the piston 14 between the position where the piston 14 is most elevated (top dead center) and the position where the piston 14 is most lowered (bottom dead center) is defined as one process, This is a four-cycle engine comprising four steps of a compression step, a combustion step, and an exhaust step.

  In the intake process, the piston 14 moves from the top dead center to the bottom dead center with the intake valve 17 open and the exhaust valve 18 closed. As a result, the volume inside the cylinder 12a (referring to the space above the piston 14, hereinafter the same) increases and the internal pressure decreases, so the air-fuel mixture flows from the intake passage 13a into the cylinder 12a. The air-fuel mixture refers to a mixture of air (oxygen) and gasoline in a mist form.

  In the compression process, the piston 14 moves from the bottom dead center to the top dead center with the intake valve 17 and the exhaust valve 18 closed. As a result, the internal volume of the cylinder 12a decreases and the internal pressure increases.

  In the combustion process, the spark plug 20 is ignited with the intake valve 17 and the exhaust valve 18 closed. As a result, the air-fuel mixture in the compressed state expands abruptly by burning, and pushes down the piston 14 from the top dead center to the bottom dead center. By transmitting this force to the crankshaft 15 through the connecting rod 16 as a rotational motion, a driving force is generated.

  In the exhaust process, the piston 14 moves from the bottom dead center to the top dead center with the intake valve 17 closed and the exhaust valve 18 opened. As a result, the volume inside the cylinder 12a is reduced and the combustion gas flows out to the exhaust passage 13b. In this process, after the piston 14 reaches the top dead center, the process returns to the intake process.

  In each of the above steps, “the state in which the intake valve 17 is open” means that the long diameter portion 19c of the cam 19b is in contact with the intake valve 17 and the intake valve 17 is pushed downward against the valve spring 17c. The state where the intake valve 17 is closed is a state in which the short diameter portion 19d of the cam 19b is in contact with the intake valve 17 and the intake valve 17 is pushed upward by the restoring force of the valve spring 17c. Point to. Further, since the same applies to the exhaust valve 18, the description thereof is omitted.

  In each of the above processes, the driving force is generated only in the combustion process, and in the other processes, the piston 14 reciprocates by the driving force generated in the other cylinders. Therefore, from the viewpoint of maintaining smooth rotation of the crankshaft 15, it is desirable to shift the timing of the combustion stroke with a plurality of cylinders.

  With reference to FIGS. 1-10, the needle roller bearing 21 as a roller bearing which concerns on one Embodiment of this invention, and the camshaft support structure using this needle roller bearing 21 are demonstrated. 1, 9, and 10 are diagrams showing states before and after the camshaft support structure according to one embodiment of the present invention is assembled, and FIGS. 2 to 8 are needle rollers according to one embodiment of the present invention. FIG. 3 is a diagram showing each component of a bearing 21.

  First, referring to FIG. 1, a camshaft support structure according to an embodiment of the present invention includes a camshaft 19, a cylinder head 13 and a bearing cap 13 c as a housing for housing the camshaft 19, and the camshaft 19. And a needle roller bearing 21 that rotatably supports the housing.

  The needle roller bearing 21 includes an outer ring 22 formed by connecting a plurality of arc-shaped outer ring members 22 a and 22 b in the circumferential direction, and a needle roller 23 as a plurality of rollers disposed along the inner diameter surface of the outer ring 22. And a cage 24 having a parting line extending in the axial direction of the bearing at one place on the circumference and holding the intervals between the plurality of needle rollers 23.

  As a bearing for supporting the camshaft 19, a needle roller bearing 21 is generally employed. The needle roller bearing 21 has an advantage that a high load capacity and high rigidity can be obtained for a small bearing projection area because the needle roller 23 and the raceway surface are in line contact. Therefore, it is preferable in that the thickness dimension in the radial direction of the support portion can be reduced while maintaining the load capacity.

  The outer ring member 22a will be described with reference to FIGS. 2 is a side view of the outer ring member 22a, FIG. 3 is a view of FIG. 2 as viewed from the III direction, FIG. 4 is a view of FIG. 2 as viewed from the IV direction, and FIG. FIG. 6 is a view showing the abutting portions of the outer ring members 22a and 22b. Further, since the outer ring member 22b has the same shape as the outer ring member 22a, description thereof is omitted.

  First, referring to FIG. 2, the outer ring member 22 a has a semicircular shape with a central angle of 180 °, an engagement claw 22 c bent radially outward at one circumferential end, and an axial direction. And a flange portion 22d that protrudes radially inward from both ends. The engaging claw 22c engages with the cylinder head 13 to prevent the outer ring member 22a from rotating with respect to the housing. The flange 22d restricts the movement of the cage 24 in the axial direction and improves the lubricating oil retention of the bearing. The two outer ring members 22a and 22b are connected in the circumferential direction to form an annular outer ring 22. The central portion in the axial direction of the inner diameter surface of the outer ring 22 functions as a raceway surface of the needle rollers 23.

  Also, referring to FIG. 3, two engaging claws 22c are provided at both ends in the axial direction at one end in the circumferential direction of the outer ring member 22a, and between the two engaging claws 22c. Is formed with a substantially V-shaped recess 22e recessed in the circumferential direction. The two engaging claws 22c are arranged on both ends and on a straight line parallel to the rotational axis of the needle roller bearing 21 so as to avoid the central portion in the axial direction as the raceway surface of the outer ring member 22a. That is, the length L between the two engaging claws 22c is set longer than the effective length l of the needle roller 23. In the present specification, the “effective length of the roller” refers to a length obtained by removing the length of the chamfered portions at both ends from the roller length.

  Further, referring to FIG. 4, at the other circumferential end of outer ring member 22a, two flat portions 22f having the same width as the axial width of engagement claw 22c are provided at two axial ends and two flat portions. Between the portions 22f, a substantially V-shaped convex portion 22g having a circular arc tip and protruding in the circumferential direction is provided. The concave portion 22e receives the convex portion 22g of the adjacent outer ring member when the outer ring members 22a and 22b are connected in the circumferential direction. Thus, by making the shape of the abutting portion substantially V-shaped, the needle rollers 23 can rotate smoothly. In addition, the shape of the abutting part of the outer ring members 22a and 22b is not limited to a substantially V shape, and may be any shape that allows the needle rollers 23 to rotate smoothly, for example, a substantially W shape.

  3 and 4, the outer ring member 22a is provided with an oil hole 22h penetrating from the outer diameter side to the inner diameter side. The oil hole 22h is provided at a position facing an oil passage (not shown) provided in the housing, and supplies lubricating oil into the needle roller bearing 21. Note that the size, position, and number of the oil holes 22h depend on the size, position, and number of oil passages provided in the housing.

  Referring to FIG. 5, inclined end faces 22i (shaded portions in FIG. 5) are provided at both ends in the circumferential direction of the inner diameter surface of the outer ring member 22a, and the contour lines of the inclined face 22i are needle-like. It faces in a direction perpendicular to the revolution direction of the roller 23. Thus, by providing the inclined surfaces 22i that are inclined toward the rolling direction of the needle rollers 23 at both circumferential ends of the outer ring members 22a and 22b, the outer ring members 22a and 22b pass through the abutting portions of the adjacent outer ring members 22a and 22b. The needle roller 23 can roll smoothly.

  In this embodiment, the inclined surface 22i on the side where the convex portion 22g is formed (upper side in FIG. 5) is provided in the axially central portion, that is, around the tip of the convex portion 22g. On the other hand, the inclined surfaces 22i on the side where the recesses 22e are formed (the lower side in FIG. 5) are provided on both ends in the axial direction, that is, on both sides of the openings of the recesses 22e.

Further, referring to FIG. 6, the inclined surface 22 i is a tapered surface that is inclined at a predetermined inclination angle θ from the circumferential end to the circumferential center. The plate thickness is the smallest at the circumferential end (t), and the central portion in the circumferential direction, that is, the region between the two inclined surfaces 22i is constant (t ₀ ). Here, in order to obtain a sufficient effect of the present invention, it is desirable that 0.05 ≦ t / t ₀ ≦ 0.5, 10 ° ≦ θ ≦ 45 °. The “inclination angle θ” refers to an angle formed by a straight line orthogonal to the circumferential end surface of the outer ring member 22a and the inclined surface.

When t / t ₀ <0.05 with respect to the plate thickness, the needle rollers 23 are fitted in the recesses formed in the abutting portions of the outer ring members 22a and 22b, thereby inhibiting the smooth rotation of the needle roller bearing 21. . On the other hand, when t / t ₀ > 0.5, the needle rollers 23 passing through the abutting portions of the adjacent outer ring members 22a and 22b collide with the corners formed at the circumferential ends, and the needle rollers 23 is disturbed or the rolling surface is damaged.

If θ <10 ° with respect to the inclination angle, in order to obtain a sufficient effect according to the present invention, t ₀ must be reduced to some extent, and as a result, the circumferential length of the inclined surface 22i becomes longer. This causes a decrease in strength of the outer ring members 22a and 22b. On the other hand, when θ> 45 °, the needle roller 23 passing through the abutting portion of the adjacent outer ring members 22a and 22b collides with a corner portion formed at the end point (circumferential center side) of the inclined surface 22i. The behavior of the needle roller 23 is disturbed or the rolling surface is damaged. Therefore, in order to avoid these adverse effects, it is desirable to set the plate thickness and the inclination angle within the above ranges.

  Next, the retainer 24 will be described with reference to FIGS. 7 and 8. 7 is a side view of the cage 24, and FIG. 8 is a partial sectional view including a divided portion of the cage 24. As shown in FIG. The cage 24 has a substantially C shape having a dividing line extending in the axial direction of the bearing at one place on the circumference, and pockets 24c for accommodating the needle rollers 23 are provided at equal intervals in the circumferential direction. Yes. The cage 24 is formed by injection molding of a resin material.

  The cut end surface 24a on one side in the circumferential direction of the divided portion is provided with a recess 24d, and the cut end surface 24b on the other side is provided with a protrusion 24e corresponding to the recess 24d, and the recess 24d and the protrusion 24e are engaged. By combining, an annular retainer 24 can be obtained. In this embodiment, the width of the tip portion of the convex portion 24e is set larger than that of the root portion, and the width of the opening portion of the concave portion 24d is set smaller than that of the innermost portion. Thereby, the engagement between the concave portion 24d and the convex portion 24e is ensured.

  Next, a procedure for incorporating the needle roller bearing 21 into the camshaft 19 will be described with reference to FIGS. 1, 9, and 10.

  First, the needle rollers 23 are incorporated in the pockets 24 c of the cage 24. Next, using the elasticity of the cage 24, the divided portion is expanded and assembled into the camshaft 19. Further, the concave portion 24d and the convex portion 24e are engaged so that the retainer 24 does not come off.

  Next, the outer ring member 22a on one side, the camshaft 19 around which the cage 24 is wound and fixed, the outer ring member 22b on the other side, and the bearing cap 13c are assembled in this order on the cylinder head 13, and the cylinder head 13 and the bearing are assembled. The cap 13c is fixed with a bolt or the like. At this time, it arrange | positions so that the recessed part 22e of the outer ring member 22a, the convex part 22g of the outer ring member 22b, and the convex part 22g of the outer ring member 22a and the recessed part 22e of the outer ring member 22b may each face | match.

  The engaging claw 22c of the outer ring member 22a is disposed so as to engage with the engaging groove 13d provided on the abutting surface of the cylinder head 13 with the bearing cap 13c, and the engaging claw 22c of the outer ring member 22b is It arrange | positions so that it may engage with the engaging groove 13d provided in the abutting surface with the cylinder head 13 of the bearing cap 13c. As a result, the outer ring members 22a and 22b can be prevented from rotating inside the housing during bearing rotation.

  In the above embodiment, an example in which the needle roller bearing 21 is employed as a bearing for supporting the camshaft 19 has been shown. However, the present invention is also applicable to other roller bearings such as a cylindrical roller bearing and a rod roller bearing. can do.

  Moreover, although the needle roller bearing 21 in said embodiment showed the example containing the outer ring | wheel 22, the needle roller 23, and the holder | retainer 24, it is not restricted to this, All the rollers which omitted the holder | retainer 24 were shown. It may be a type of roller bearing.

  Moreover, although the inclined surface 22i in said embodiment showed the example which is a taper surface of inclination-angle (theta), it may be arbitrary shapes not restricted to this. For example, it may be a convex curved surface.

  In addition, the inclined surface 22i in the above embodiment may be provided over the entire width of the raceway surface (a region surrounded by a two-dot chain line in FIG. 5). You may provide in a part of. In this case, the effect of the present invention can be obtained if the needle rollers 23 passing through the abutting portions of the adjacent outer ring members 22a and 22b are provided only at the portion where they first contact, that is, the shaded portion in FIG.

  Moreover, although the outer ring | wheel 22 in said embodiment showed the example divided | segmented into the outer ring members 22a and 22b in two places of the circumferential direction, it is possible to divide into arbitrary numbers without restricting to this. For example, the outer ring may be formed by connecting three outer ring members having a central angle of 120 ° in the circumferential direction. Furthermore, an annular outer ring may be formed by combining a plurality of outer ring members having different central angles. Similarly, the cage 24 can be of any form.

  In addition, the cage 24 in the above embodiment is an example of a resin cage having high production efficiency and high elastic deformability. However, the cage is not limited to this and may be a machined cage by cutting. Alternatively, it may be a press cage obtained by pressing a steel plate.

  Further, the needle roller bearing 21 in the above embodiment is not only a bearing that supports the camshaft 19, but also a bearing that supports the shaft portion 15a of the crankshaft 15, the rocker shaft, and the like as shown in FIG. It can be used widely.

  Further, the present invention can be applied to a single-cylinder internal combustion engine, but a shaft portion 15a of a crankshaft 15 employed in a multi-cylinder engine as shown in FIG. 13 or a camshaft 19 as shown in FIG. It is suitable as a bearing for supporting a portion where the needle roller bearing 21 cannot be inserted from the axial direction, such as the shaft portion 19b.

  In the above embodiment, the outer ring member includes the engaging claws 22c that engage with the housing at the circumferential ends, and the flanges 22d that restrict the axial movement of the cage 24 at both axial ends. Although the example which applied this invention to 22a, 22b was shown, the engagement nail | claw 22c and the collar part 22d are not an essential component of this invention, but can be applied to the outer ring member of all forms.

  Next, a method for manufacturing the outer ring member 22a according to one embodiment of the present invention will be described with reference to FIG. FIG. 11 is a diagram showing a part of the manufacturing process of the outer ring member 22a, where the upper stage is a plan view and the lower stage is a cross-sectional view. Moreover, since the manufacturing method of the outer ring member 22b is the same as that of the outer ring member 22a, description thereof is omitted.

  First, carbon steel having a carbon content of 0.15 wt% or more and 1.1 wt% or less is used as a starting material. Specifically, SCM415 or S50C having a carbon content of 0.15 wt% or more and 0.5 wt% or less, or SAE1070 or SK5 having a carbon content of 0.5 wt% or more and 1.1 wt% or less is considered. It is done.

  Carbon steel having a carbon content of less than 0.15 wt% is difficult to form a carburized hardened layer by quenching, and needs to be carbonitrided to obtain the required hardness for the outer ring member 22a. The carbonitriding process increases the equipment cost compared to each quenching process described later, and as a result, the manufacturing cost of the needle roller bearing 21 increases. In addition, in carbon steel having a carbon content of less than 0.15 wt%, a sufficient carburized and hardened layer may not be obtained even by carbonitriding, and surface-origin-type peeling may occur at an early stage on the raceway surface. On the other hand, since carbon steel having a carbon content exceeding 1.1 wt% is remarkably deteriorated in workability, the processing accuracy is lowered, and the production cost is increased due to an increase in the number of processing steps.

  Referring to FIG. 11, as a first step, the outer shape of outer ring member 22a is formed by punching a steel plate (step a). Moreover, the part used as the recessed part 22e and the engaging claw 22c is formed in the one side edge part of a longitudinal direction, and the flat part 22f and the convex part 22g are formed in the other side edge part. Furthermore, the oil hole 22h may be processed simultaneously with the formation of the outer shape.

  At this time, the length in the longitudinal direction of the outer ring member 22a is determined based on the diameter of the camshaft 19, and the length in the short direction is determined based on the roller length of the needle roller 23 to be used. However, since the portion that becomes the flange portion 22d is included in the short direction, the length in the short direction in this step is longer than the axial width dimension of the finished product of the outer ring member 22a.

  In this step, all the parts may be punched by a single punching process, or a predetermined shape may be obtained by repeating the punching process a plurality of times. In addition, when using a progressive press, it is good to form the pilot hole 25 for determining the processing position of each processing process, and to provide the connection part 26 between adjacent outer ring members.

  As a 2nd process, the inclined surface 22i is formed in the circumferential direction edge part of the outer ring member 22a by a surface pressing process (b process).

  As a third step, the end portion in the circumferential direction of the outer ring member 22a is bent radially outward by bending to form the engaging claw 22c (step c). The bending angle of the engaging claw 22c is an angle along the engaging groove 13c of the housing. In this embodiment, the engaging claw 22c is bent at an angle of 90 ° with respect to the outer ring member 22a.

  The fourth step includes a step of bending the outer shape of the outer ring member 22a to a predetermined curvature by bending, and a step of forming flange portions 22d protruding radially inward at both axial ends of the outer ring member 22a ( d process-h process). Specifically, bending is performed sequentially from both ends in the longitudinal direction, leaving the central portion including the connecting portion 26 (step d, step e). Next, about the both ends of the longitudinal direction which gave the bending process, a bending process is given to the both ends of a transversal direction, and the collar part 22d is formed (f process). Next, bending is also performed on the central portion in the longitudinal direction so that the outer shape of the outer ring member 22a has a predetermined curvature (step g). Finally, the connecting portion 26 is removed, and the flange portion 22d is formed at the central portion in the longitudinal direction (step h).

  After the press working step is completed, heat treatment is performed to obtain predetermined mechanical properties such as hardness required for the outer ring member 22a. In addition, the surface hardness Hv of the inner diameter surface of the outer ring member 22a that functions as a raceway ring needs to be 635 or more.

  In order for the outer ring member 22a to obtain a hardened layer having a sufficient depth, it is necessary to select an appropriate heat treatment method depending on the carbon content of the starting material. Specifically, in the case of a material having a carbon content of 0.15 wt% or more and 0.5 wt% or less, carburizing and quenching treatment is performed, and for a material having a carbon content of 0.5 wt% or more and 1.1 wt% or less. In some cases, bright quenching or induction quenching is performed.

  The carburizing and quenching process is a heat treatment method utilizing the phenomenon that carbon dissolves in high-temperature steel, and a surface layer (carburized hardened layer) with a large amount of carbon can be obtained while the amount of carbon in the steel is low. . Thereby, the surface is hard, the inside is soft, and the property with high toughness is obtained. Moreover, the equipment cost is low compared with the carbonitriding equipment.

  The bright quenching process refers to a quenching process performed while preventing oxidation of the steel surface by heating in a protective atmosphere or vacuum. In addition, the equipment cost is low compared with carbonitriding equipment and carburizing and quenching equipment.

  Induction hardening is a method of making a hardened hardened layer by rapidly heating and rapidly cooling the steel surface using the principle of induction heating. Compared to other quenching treatment facilities, there is a merit that the equipment cost is significantly lower and that the gas is not used in the heat treatment process, so that it is environmentally friendly. It is also advantageous in that a partial quenching process can be performed.

  Furthermore, it is desirable to perform tempering after the above-mentioned quenching treatment in order to reduce residual stress and internal strain caused by quenching and to improve toughness and stabilize dimensions.

  In this embodiment, the example in which the step of forming the curvature of the outer shape of the outer ring member 22a and the step of forming the flange portion 22d are performed in parallel. However, the present invention is not limited thereto, and the curvature of the outer shape is not limited thereto. You may perform independently the process of forming, and the process of forming the collar part 22d.

  Moreover, said 1st process-4th process is an example of the manufacturing method of the outer ring member which concerns on this invention, Comprising: Each process may be further subdivided and it may also add a required process further. it can. The order of the processing steps can be arbitrarily changed.

  Furthermore, although each said process (a process-h process) may be performed by a single-function press as a separate process, respectively, it is good also as performing by a progressive press or a transfer press. Thereby, each process can be performed continuously. Moreover, productivity can be improved by using the manufacturing apparatus of the outer ring member 22a which has the process part equivalent to all or one part of said each process (a process-h process), and, as a result, needle roller The product price of the bearing 21 can be suppressed.

  In the present specification, “sequential press” refers to a method of continuously processing a material by having a plurality of processing steps in the press and moving the material by a feeder at a press inlet. Shall. In addition, in this specification, “transfer press” means that when a plurality of processing steps are required, the necessary number of stages for performing each step are provided, and processing is performed at each stage while moving the process product by the transfer device. Refers to the method of performing

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  The present invention is advantageously used for a roller bearing, a camshaft support structure, and an internal combustion engine that support a camshaft of an automobile engine.

It is a figure which shows the state before the assembly of the camshaft support structure which concerns on one Embodiment of this invention. It is a figure which shows the outer ring member of the roller bearing which concerns on one Embodiment of this invention. It is the figure seen from the III direction of FIG. It is the figure seen from the IV direction of FIG. It is a figure which shows the internal diameter surface of the outer ring member of FIG. It is an enlarged view of the abutting part when the outer ring member of FIG. 2 is abutted. It is a figure which shows the side view of the holder | retainer of the roller bearing which concerns on one Embodiment of this invention. It is a fragmentary sectional view containing the division | segmentation part of the holder | retainer of FIG. It is sectional drawing which looked at the state after the incorporation of the camshaft support structure of FIG. 1 from the axial direction. It is sectional drawing which looked at the state after the incorporation of the camshaft support structure of FIG. 1 from the radial direction. It is a figure which shows a part of manufacturing process of the outer ring member which concerns on one Embodiment of this invention, Comprising: An upper stage is a top view and a lower stage is sectional drawing. It is sectional drawing which shows one cylinder of the internal combustion engine which concerns on one Embodiment of this invention. It is a figure which shows the crankshaft employ | adopted as the internal combustion engine of FIG. It is a figure which shows the camshaft employ | adopted as the internal combustion engine of FIG. It is a figure which shows the conventional camshaft support structure. It is an enlarged view of the race board of the roller bearing of FIG.

Explanation of symbols

  11 Internal combustion engine, 12 Cylinder block, 12a Cylinder, 13, 108 Cylinder head, 13a Intake passage, 13b Exhaust passage, 13c Bearing cap, 13d Engaging groove, 14 Piston, 15 Crankshaft, 15a Shaft, 15b Crank arm, 15c Crank pin, 16 connecting rod, 17, 18 valve, 17a, 18a valve stem, 17b, 18b valve head, 17c, 18c valve spring, 19, 101 camshaft, 19a shaft part, 19b cam, 19c long diameter part, 19d short diameter part , 101a Cam lobe, 101b Journal part, 101c End large diameter part, 20 Spark plug, 21 Needle roller bearing, 22 Outer ring, 22a, 22b Outer ring member, 22c Engagement claw, 22d collar part, 22e, 24d, 106c, 108a, 109a Concave part, 22f Flat part, 22g, 24e, 106b Convex part, 22h Oil hole, 22i Inclined surface, 23 Needle roller, 24 Cage, 24a, 24b Cutting end face, 24c Pocket, 102 Roller bearing, 103 Roller, 104, 105 holder, 106, 107 lace plate, 106a, 107a protrusion, 108 cylinder head, 109 cap.

Claims (3)

An outer ring formed by connecting a plurality of arc-shaped outer ring members in the circumferential direction, and a plurality of rollers disposed along the inner diameter surface of the outer ring,
One end side of the outer ring member is a V-shaped convex portion at the center, and the other end side is a V-shaped concave portion that receives the V-shaped convex portion,
There are inclined surfaces at the circumferential ends of both ends excluding the V-shaped convex portion on the one end side of the inner surface of the outer ring member and the central portion of the V-shaped concave portion on the other end side. Is provided,
The contour line of the inclined surface faces a direction orthogonal to the revolution direction of the roller,
The axial length of the inclined surface of the convex portion in which the central portion on one end side of the outer ring member is V-shaped is shorter than the effective length of the roller,
Engaging claws for engaging with the housing are provided at both ends of the concave portion on the other end side in the circumferential direction of the outer ring member so as to be bent in the outer diameter direction from the raceway surface.
Roller bearing. When the thickness of the outermost member of the outer ring member is t ₀ and the thickness of the inclined surface at the outermost end in the circumferential direction is t,
0.05 ≦ t / t ₀ ≦ 0.5
The roller bearing according to claim 1, wherein: When the inclination angle of the inclined surface is θ,
10 ° ≦ θ ≦ 45 °
The roller bearing according to claim 1 or 2, wherein:

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