JP2010060062A - Method for manufacturing camshaft with bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a camshaft with bearings, by which an outer circumferential form of a cam piece in the camshaft with a bearing can be improved in precision and besides ground dusts can be prevented from entering the bearings of the camshaft with bearings. <P>SOLUTION: There is provided the method for manufacturing the camshaft W with bearings, into which a plurality of cam pieces CA and a plurality of bearings BR are fitted in an axial direction of an outer surface of a shaft ST. The method includes a step of fitting a plurality of the cam pieces CA and a plurality of the bearings BR into each given position in the axial direction of the shaft ST to assemble the camshaft W with bearings and a step of finishing and grinding a grinding target cam piece by using a processing tool after having masked at least a bearing BR located nearest to a cam piece CA to be ground. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a camshaft with a bearing, in which the outer periphery of the cam piece of a camshaft with a bearing provided with a shaft, a cam piece, and a bearing is finish ground.

Conventionally, a camshaft for operating each valve is rotatably assembled to a cylinder head of an internal combustion engine having an intake valve and an exhaust valve.
A conventional camshaft has a plurality of cam pieces assembled to the shaft. For example, in the prior art described in Patent Document 1, after finishing the shaft and the plurality of cam pieces in a single product, The camshaft is assembled (externally fitted) to assemble the camshaft, and the camshaft is completed without performing finish grinding after assembly.
JP 2000-145411 A

As a method of fitting the cam piece to the shaft, there are shrink fitting, pipe expansion, shaft knurling, and the like. Using these fitting methods, the cam piece is assembled at a desired position in the axial direction of the shaft. In any of the fitting methods, the cam piece inner diameter and the shaft outer diameter have a tightening allowance, and the fitting affects the outer diameter of the cam piece, which may cause cam profile collapse.
For this reason, in order to increase the accuracy of the outer peripheral shape of the cam piece, it is necessary to finish-grind the outer periphery of the cam piece after fitting the cam piece to the shaft and assembling the cam shaft.
In the prior art described in Patent Document 1, after finishing each of the shaft and the plurality of cam pieces in a single product state, the cam piece is fitted (externally fitted) to the shaft, and the cam shaft is assembled. Therefore, it is difficult to finish the outer peripheral shape of the cam piece with higher accuracy. When there is a demand for a more accurate outer peripheral shape, finish grinding must be performed after the camshaft is assembled.

  The present invention has been made in view of such a point, and an object of the present invention is to provide a method of manufacturing a camshaft with a bearing that further improves the accuracy of the outer peripheral shape of the cam piece of the camshaft with a bearing.

As means for solving the above-mentioned problems, a first invention of the present invention is a method for manufacturing a camshaft with a bearing as described in claim 1.
The method for manufacturing a camshaft with bearing according to claim 1 is a method for manufacturing a camshaft with bearing in which one or more cam pieces and one or more bearings are fitted in the axial direction of the outer peripheral surface of the shaft. A step of fitting the plurality of cam pieces and the plurality of bearings to respective predetermined positions in the axial direction of the shaft and assembling them as bearing camshafts, and masking the bearings at least closest to the cam pieces to be ground And masking the cam piece to be ground with a processing tool after masking with the means.

A second invention of the present invention is a method for manufacturing a camshaft with a bearing as recited in claim 2.
The method for manufacturing a camshaft with bearing according to claim 2 is the method for manufacturing the camshaft with bearing according to claim 1, wherein the masking means applies and removes the bearing so as to be sealed. Removable resin, grease filled in the bearing, thin film sheet that can be wound and removed to seal the bearing, or any axial position on the camshaft with bearing Any one or a combination of a plurality of cases that can be accommodated in a sealed state when installed in a sealed state.

A third aspect of the present invention is a method for manufacturing a camshaft with a bearing as set forth in the third aspect.
The method for manufacturing a camshaft with a bearing according to claim 3 is the method for manufacturing a camshaft with a bearing according to claim 1 or 2, wherein the outer periphery of the cam piece is finish-ground when there are a plurality of bearings. Positioning the position of the machining tool with respect to the cam piece to be ground so that the outer periphery of the cam piece to be ground and the machining tool are opposed to each other, rotating the camshaft with bearing around a rotation axis and the masking A cam to be ground by moving the machining tool relative to the camshaft with bearing in a direction perpendicular to the rotation axis while supporting the opposite side of the bearing to the machining tool. And a step of finish grinding by pressing the processing tool on the outer periphery of the piece.

A fourth aspect of the present invention is a method for manufacturing a camshaft with a bearing as set forth in the fourth aspect.
The method for manufacturing a camshaft with a bearing according to claim 4 is the method for manufacturing a camshaft with a bearing according to claim 2, wherein the case includes a bearing accommodated therein and is attached. When a pressing force is applied in a radial direction of the bearing accommodated at a predetermined position on the outer peripheral surface of the case, the case moves relative to the bearing force in the direction of the pressing force. The inner wall of the bearing is in contact with the outer peripheral surface of the bearing, and a force corresponding to the pressing force is applied to the contact portion of the outer peripheral surface of the bearing.
In the case where the case is used as the masking means, when the outer periphery of the cam piece is finish-ground, the position of the processing tool with respect to the cam piece to be ground is set so that the outer periphery of the cam piece to be ground and the processing tool face each other. A step of positioning, rotating the camshaft with bearing about a rotation axis, and supporting the opposite side of the processing tool in the case containing the bearing with respect to the camshaft with bearing And a step of moving the working tool relatively back and forth in a direction perpendicular to the rotational axis and pressing the working tool on the outer periphery of the cam piece to be ground for finish grinding.

  If the method for manufacturing a camshaft with bearing according to claim 1 is used, the cam piece is finish ground after the camshaft with bearing is assembled, so that the outer peripheral shape of the cam piece can be made more accurate, and the bearing Since the cam piece is finish ground after masking by the masking means, it is possible to appropriately prevent the grinding dust from entering the bearing.

  Moreover, according to the manufacturing method of the camshaft with a bearing of Claim 2, the penetration | invasion of the grinding waste to a bearing can be prevented by masking a bearing appropriately.

Further, according to the method for manufacturing a camshaft with a bearing according to claim 3, a bearing that is not masked at a position away from the cam piece to be ground is received when the bearing is actually assembled to the internal combustion engine. Assuming the direction in which the clearance (bearing play) disappears due to the force (see FIG. 3A), the clearance on the side opposite to the processing tool is almost eliminated (see FIG. 3B).
Thereby, the error by the clearance of a bearing at the time of assembling | attaching the camshaft with a bearing to an actual internal combustion engine can be reduced more.

Further, according to the method for manufacturing a camshaft with a bearing according to claim 4, the machining tool can be used only when masking is performed using a case in contrast to claim 3 in which the bearing being masked cannot be supported. The case is supported so that there is almost no clearance on the opposite side (see FIG. 5C).
Thus, if the case is used for masking, even if the bearing is entirely masked, errors due to bearing clearance when the camshaft with bearing is assembled to an actual internal combustion engine can be further reduced.

The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1A is a schematic external view (plan view) of an embodiment of a machine tool 1 for grinding a camshaft with a bearing (workpiece W) by applying the “method for manufacturing a camshaft with a bearing” of the present invention. Is shown. FIG. 1B shows an example of a right side view of the machine tool 1 shown in FIG. In FIG. 1B, illustration of the tailstock device 40 and the like is omitted.
In the description of the present embodiment, the X axis, the Y axis, and the Z axis are orthogonal to each other, the Y axis indicates a vertically upward direction, and the X axis and the Z axis indicate a horizontal direction. Further, the X axis indicates the direction in which the grindstone T cuts into the workpiece W, and the Z axis indicates the main shaft rotation axis direction through the pair of support means (in the example of FIG. 1, the center member 30C and the center member 40C). .

● [Schematic configuration of machine tool 1 (FIGS. 1A and 1B)]
A machine tool 1 shown in FIGS. 1A and 1B has a plurality of cam pieces CA and a plurality of bearings BR fitted to respective desired positions in the axial direction of the substantially cylindrical shaft ST. The example of the machine tool which finish-grinds the outer periphery of the cam piece of the assembled camshaft W with a bearing (refer FIG. 2 (A) and (B)) is shown.
The machine tool 1 includes a base 2, a spindle table 20, and a grindstone table 10. Note that control means such as a numerical controller that takes in signals from the detection means and outputs drive signals to the motors are omitted.
1A and 1B show an example in which the pair of support means is the center members 30C and 40C. However, the center member 40C can grip the inserted workpiece with the claw portion. A chuck may be used. The schematic shape and structure of the workpiece W will be described later.
The spindle table 20 is Z with respect to the base 2 by a spindle table driving motor 20M (Z-axis driving device) and a feed screw 20B provided on the base 2 and a nut (not shown) provided on the spindle table 20. It can move in the axial direction, and the control means can detect the position of the spindle table 20 in the Z-axis direction with respect to the base 2 based on the detection signal of the detection means 20E such as an encoder. The Z-axis is an axis parallel to a main shaft rotation axis CZ (corresponding to a workpiece rotation axis) passing through a pair of support means (in the example of FIG. 1, the center member 30C and the center member 40C), and the feed screw 20B is Z Parallel to the axis.

On the spindle table 20, a spindle stock 30D and a tailstock 40D are placed.
The spindle stock 30D is provided with a spindle moving motor 30M that can reciprocate the spindle device 30 in the Z-axis direction, and the control means uses a detection signal from a detection means 30E such as an encoder to control the spindle device 30 with respect to the spindle stock 30D. Can be detected in the Z-axis direction. A center member 30 </ b> C that is paired with the center member 40 </ b> C of the tailstock device 40 is provided at the tip of the spindle device 30. Further, the spindle device 30 is provided with a spindle rotating motor that rotates the center member 30C, and the workpiece W supported by a pair of supporting means (in this case, the center members 30C and 40C) is rotated around the spindle rotating axis CZ. Rotate. The spindle rotation motor is provided with detection means (encoder or the like) for detecting the rotation angle or rotation speed of the workpiece W (the spindle device 30 and the tailstock device 40 correspond to the workpiece rotation means). In the example of FIG. 1A, the workpiece W is connected to a main shaft (a member that rotates integrally with the center member 30C) by a connecting member 32.
The tailstock 40D is provided with a tailstock device moving means 42 that can reciprocate the tailstock device 40 in the Z-axis direction. A center member 40 </ b> C that is paired with the center member 30 </ b> C of the spindle device 30 is provided at the tip of the tailstock device 40.
Further, the machine tool 1 is provided with a support device 60 that supports the workpiece W from the opposite side of the grindstone T. In the example shown in FIG. 1A, the support device 60 can move in the Z-axis direction by a control signal from the control means, and a plurality of support devices 60 are provided. There may be. Details of the support device 60 will be described later.
Moreover, although the machine tool 1 is provided with the coolant nozzle etc. which eject a coolant to a process location, description and illustration are abbreviate | omitted about these.

The grindstone table 10 includes a substantially cylindrical grindstone T (corresponding to a processing tool). The grindstone T provided on the bearing 12 is shaped by attaching a CBN chip grindstone to the outer periphery of an iron core, for example, and is grindstone parallel to the Z axis by the grindstone drive motor 11 placed on the grindstone table 10. It rotates around the rotation axis TZ.
Further, the grindstone table 10 is a grindstone table drive motor 10M provided on the base 2 (X-axis drive device, corresponding to the radial side moving means), a feed screw 10B, and a nut provided on the grindstone table 10 (illustrated). Omitted), the grindstone T can be reciprocated in the X-axis direction with respect to the base 2 and the grindstone T is moved back and forth in the direction intersecting the main spindle rotation axis CZ. The X axis is an axis perpendicular to the Z axis, and the feed screw 10B is parallel to the X axis.
The grinding wheel table drive motor 10M is provided with detection means 10E (such as an encoder) for detecting the position of the grinding wheel table 10 in the X-axis direction.
In the example of FIGS. 1A and 1B, the grindstone drive motor 11 is not provided with detection means, but the grindstone drive motor 11 is also provided with speed detection means and the like, and the rotation speed of the grindstone drive motor 11 is increased. It is also possible to perform feedback control.

  The numerical control device (not shown) includes a signal from a detection means (not shown) for detecting the rotation angle (or rotation speed) of the workpiece W and a detection means 10E for detecting the position of the grindstone table 10 in the X-axis direction. , A signal from the detection means 20E for detecting the position of the spindle table 20 in the Z-axis direction, machining data, a machining program, and the like, a spindle rotating motor (not shown), a grindstone table driving motor 10M, a spindle table The drive motor 20M and the grindstone drive motor 11 are controlled.

● [Work W Structure and Schematic Shape (Figure 2)]
Next, the structure and schematic shape of the workpiece W used in the present embodiment will be described with reference to FIGS.
The workpiece W described in the present embodiment is a camshaft with a bearing in which a plurality of cam pieces CA and a plurality of bearings BR are fitted and assembled at predetermined positions on a substantially cylindrical shaft ST. The bearing BR is, for example, a radial bearing configured such that the outer ring BO can circulate around the inner ring BI, and has a continuous annular shape. The bearing BR is a so-called split type (divided into two by a plane passing through the rotation shaft). It is not a type that is attached so as to be pinched.
In the present embodiment, in order to make the accuracy of the outer peripheral shape of the cam piece CA of the camshaft with a bearing (work W) higher, the cam piece CA and the bearing BR are assembled to the shaft ST by fitting. A camshaft (hereinafter referred to as a workpiece W) is made, and the outer periphery of the cam piece of the camshaft with bearing after the assembly is finished ground by the machine tool 1.

As shown in FIG. 2B, in the workpiece W, the bearing BR is in a position close to the cam piece CA. When the outer periphery of the cam piece CA is ground using the machine tool 1, coolant (grinding while applying coolant to the grinding part during grinding) and grinding waste may be scattered and coolant and grinding waste may enter the bearing BR. . When grinding waste enters the bearing BR, there is a possibility that the life of the bearing BR will be reduced and indentations may occur.
Therefore, a method for manufacturing a camshaft with a bearing capable of performing finish grinding to finish the outer peripheral shape of the cam piece CA of the workpiece W with high accuracy and preventing coolant and grinding debris from entering the bearing BR will be described below. .

● [Production method of camshaft with bearing (FIGS. 2 to 4)]
FIG. 2A shows a schematic perspective view of the cam piece CA, the bearing BR, and the shaft ST.
In the first step, the insertion holes CAH of the cam pieces CA and the insertion holes BRH of the bearing BR are fitted into predetermined positions in the axial direction of the outer peripheral surface of the shaft ST ( The fitting method is not particularly limited) and a camshaft with a bearing is assembled.
In the next step, at least the bearing BR at the position closest to the cam piece CA to be ground is masked by the masking means MS (after being sealed (see FIG. 2C)), and then the grindstone T of the machine tool 1 is used. Then, the outer peripheral shape of the cam piece CA to be ground is finish ground.
As the masking means, for example, as shown in FIG. 2 (C), from the viewpoint that it does not soak into the bearing BR, is relatively brittle, does not flow down, and can be removed after grinding, the following is possible. Can be mentioned.
Resin that can be applied and removed to seal the bearing BR.
Grease to be filled in the bearing BR (in the case of grease filling, removal after grinding is unnecessary).
A thin film sheet that can be wound and removed to seal the bearing BR.
A case that can be attached to and detached from an arbitrary position in the axial direction of the camshaft with a bearing and that can accommodate the bearing BR in a sealed state when attached (see FIGS. 5A and 5B).
Any one or a combination of these is used to mask the bearing BR.
The machine tool for assembling the cam piece CA and the bearing BR on the shaft ST and the machine tool for masking may be performed using the machine tool 1 or another machine tool.

As a step in finish grinding after masking, first, the workpiece W is set on the machine tool 1 in the first step (in the example of FIG. 1, the workpiece W is supported by a pair of support means 30C and 40C).
In the next step, the grindstone T is moved relative to the cam piece CA to be ground so that the outer periphery of the cam piece CA to be ground and the grindstone T face each other (in the example of FIG. 1, the spindle table drive motor). The spindle table 20 is moved in the Z-axis direction at 20M).
In the next step, the grindstone T is moved back and forth in a direction perpendicular to the spindle rotation axis CZ with respect to the workpiece W while rotating the workpiece W around the spindle rotation axis CZ (corresponding to the rotation axis of the workpiece W) (see FIG. In the example of 1, the grinding wheel table 10 is reciprocated in the X-axis direction by the grinding wheel table drive motor 10 </ b> M), and the grinding wheel T is pressed against the workpiece W to finish grinding.

In the above description, the cam piece CA is finished after the cam piece CA and the bearing BR are fitted (assembled) to the camshaft with bearing in order to make each of the individual outer peripheral shapes of the cam pieces CA more accurate. Grinding was performed. Here, the bearing BR always has a slight clearance (play), and when a camshaft with a bearing is assembled in an actual internal combustion engine, the backlash due to this clearance is different from the error in the outer shape of the cam piece CA. Cause an error.
Thus, as will be described below, when the machine tool 1 finish-grinds the cam piece CA, the bearing BR is supported so as to be pressed from a predetermined direction, thereby reducing an error due to this clearance.

● [Error reduction method due to bearing BR clearance (Figs. 3 and 4)]
FIG. 3A shows an example of a state in which the camshaft W with bearing is assembled to the internal combustion engine, and between the cylinder CD and the cylinder head CH fixed to the cylinder CD with a bolt B or the like. The mode that the bearing BR of the camshaft with a bearing is clamped is shown. In this case, on the cylinder CD side of the internal combustion engine, the tappet TP, which is the end on the opposite side of the exhaust valve or the intake valve, is in a position facing each cam piece CA. The tappet TP is pressed in the direction of the facing cam piece CA by a valve spring or the like. When this pressing force is Fp, the force Fp is transmitted from the cam piece CA to the shaft ST, and the shaft ST is pressed to the cylinder head CH side.
As a result, the clearance of the bearing BR on the side opposite to the tappet TP (cylinder head CH side) (clearance C1a between the inner ring BI and the steel ball BB + clearance C1b between the outer ring BO and the steel ball BB) is almost zero. Thus, the clearance on the tappet TP side (clearance C2a between the inner ring BI and the steel ball BB + clearance C2b between the outer ring BO and the steel ball BB) increases.

Next, FIG. 3B shows a state in which the cam piece CA is ground while the machine tool 1 reproduces a state similar to FIG. 3A in which the bearing-equipped camshaft W is assembled to the internal combustion engine. Show.
The force Ft for pressing the cam piece CA with the grindstone T corresponds to the pressing force Fp from the tappet TP in FIG. The shaft ST is pressed to the side opposite to the grindstone T by the pressing force Ft. Here, in order to make the clearance of the bearing BR on the side opposite to the grindstone T (clearance C1a between the inner ring BI and the steel ball BB + clearance C1b between the outer ring BO and the steel ball BB) substantially zero, The bearing BR is supported from the opposite side by using the bearing support member 62 (the bearing BR is supported so as not to move to the opposite side of the grindstone T).
The bearing support member 62 in FIG. 3B corresponds to the cylinder head CH in FIG. 3A, and the grindstone T in FIG. 3B corresponds to the tappet TP in FIG.

Next, the appearance and configuration of the support device 60 including the bearing support member 62 shown in FIG. 3B will be described with reference to FIG. FIG. 4 shows a state in which the bearing BR not masked is supported. However, when masking is performed using the case CS shown in FIG. 5, the bearing BR is supported via the case CS as will be described later. can do.
The support device 60 includes a support body 61, a bearing support member 62, an auxiliary member 63, and a moving arm 65. The moving arm 65 can reciprocate in the Z-axis direction in FIG. 1A by a control signal from a control means (not shown), and positions the support body 61 at a position facing the bearing BR to be supported.
The bearing support member 62 can reciprocate in the X-axis direction and can be fixed at an appropriate position in the X-axis direction. In this case, the position where the distance D between the outer ring BO and the inner ring BI at the location of the bearing BR in contact with the bearing support member 62 is the smallest (the clearance C1a between the inner ring BI and the steel ball BB on the side opposite to the grinding wheel T + the outer ring BO). And the steel ball BB is fixed at a position where the bearing BR is pressed so that the clearance C1b becomes a substantially zero position.
Further, the auxiliary member 63 can reciprocate in the Y-axis direction, can be fixed at an appropriate position in the Y-axis direction, and can support the bearing BR from below.
The position in the X-axis direction of the bearing support member 62 and the position in the Y-axis direction of the auxiliary member 63 may be configured to be controllable from the control means, or may be manually positioned and fixed by the operator. Good. The auxiliary member 63 may be omitted.

From the above, as a step in the finish grinding after masking, the work W is set on the machine tool 1 in the first step.
In the next step, the grindstone T is moved relative to the cam piece CA to be ground so that the outer periphery of the cam piece CA to be ground and the grindstone T face each other.
In the next step, the workpiece W is rotated around the main shaft rotation axis CZ (corresponding to the rotation axis of the workpiece W), and the workpiece BR is supported on the non-masked bearing BR while supporting the side opposite to the grindstone T. On the other hand, the grindstone T is moved forward and backward in a direction perpendicular to the spindle rotation axis CZ, and the grindstone T is pressed against the workpiece W to finish grinding. This method can be used when there are a plurality of bearings BR and the supporting bearing BR is not masked.

● [Case structure used as masking means (Fig. 5)]
Next, with reference to FIGS. 5A to 5C, the structure of the above-described case (for masking) will be described.
FIG. 5A shows two examples of the schematic appearance of the case CS. In this case, an example of a substantially cylindrical shape and an example of a substantially quadrangular prism shape are shown. Both have a through hole HC for passing the shaft ST of the workpiece W. The case CS has a space in which the bearing BR can be accommodated, and a flexible member P that can be deformed for sealing is provided around the through hole HC.
In addition, as shown in the example of FIG. 5B (an example of a substantially cylindrical shape), when the lock portion R is unlocked, it is divided into two so as to rotate around the hinge TT. The bearing BR is housed inside, and the lock portion R can be locked again.
Further, as shown in an example of a cross-sectional view of FIG. 5C (an example of a substantially cylindrical shape), an arbitrary outer peripheral surface (in parallel with the spindle rotation axis CZ) in the case CS housing the bearing BR ( When the pressing force F is applied in the radial direction of the bearing BR accommodated from the predetermined position on the outer peripheral surface, which is the center position of the side surface when the case CS has a quadrangular prism shape), the flexible member P is deformed. At a position where the case CS moves relatively toward the bearing BR and the pressing force F is applied, the outer peripheral surface of the bearing BR contacts the inner wall of the case CS, and a force corresponding to the pressing force F is applied to the outer periphery of the bearing BR. It is added to the contact point of the surface. Therefore, when the case CS is used, the case CS is supported by the bearing support member 62 shown in FIG. 4 so that the distance D between the outer ring BO and the inner ring BI of the bearing BR is substantially zero. be able to.

From the above, as a step in the finish grinding after masking, the work W is set on the machine tool 1 in the first step.
In the next step, the grindstone T is moved relative to the cam piece CA to be ground so that the outer periphery of the cam piece CA to be ground and the grindstone T face each other.
In the next step, the workpiece W is rotated about the main shaft rotation axis CZ (corresponding to the rotation axis of the workpiece W) and the workpiece CS is supported while supporting the side opposite to the grindstone T in the case CS housing the bearing BR. The grindstone T is moved forward and backward in a direction perpendicular to the spindle rotation axis CZ with respect to W, and the grindstone T is pressed against the workpiece W for finish grinding. In this method, even if all the bearings BR are accommodated in the case CS (all the bearings BR are masked), the cam piece can be finish-ground while supporting any bearing.

As described above, if the manufacturing method of the camshaft with bearing described in the present embodiment is used, the outer peripheral shape of the cam piece CA can be finished with higher accuracy, and the masking means can be used for the bearing BR. It is possible to appropriately prevent the cutting waste and the like from entering.
Further, by supporting the bearing BR from the opposite side of the grindstone T and pressing it in the direction toward the grindstone T, errors due to the clearance of the bearing BR can be further reduced when the camshaft with bearing is assembled to an actual internal combustion engine. Can do.

The manufacturing method of the camshaft with bearing of the present invention is not limited to the method described in the present embodiment, and various modifications, additions and deletions can be made without changing the gist of the present invention.
Further, the structure and overview of the machine tool 1 are not limited to the machine tool 1 shown in FIG.
Further, the structure and overview of the bearing BR are not limited to those described in the present embodiment, and the steel ball BB may be a substantially cylindrical “roller”.
Moreover, although the manufacturing method of the camshaft with a bearing demonstrated in this Embodiment demonstrated the example of the manufacturing method of the camshaft with a bearing which assembled | attached several cam piece CA and several bearing BR to shaft ST, The present invention can be applied to a method of manufacturing a camshaft with a bearing in which one or more cam pieces CA and one or more bearings BR are assembled to the shaft ST.
Further, the case which is one example of the masking means is not limited to the shape of the case CS shown in FIG.

It is a figure explaining the outline appearance figure (top view, side view) in one embodiment of machine tool 1 which finish-grinds cam piece CA of a camshaft (bearing W) with a bearing. It is a figure explaining the state which masked the example of the structure and external appearance shape of a cam shaft with a bearing, and the cam shaft with a bearing. It is a figure which shows the state which assembled | attached the camshaft with a bearing to an actual internal combustion engine, and a figure explaining a mode that the cam piece CA of a camshaft with a bearing is ground using the grindstone T of the machine tool. It is a figure explaining the example of the appearance and composition of support device 60. It is a figure explaining the example of case CS which is one of the masking means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Machine tool 2 Base 10 Grinding wheel table 10M Grinding wheel table drive motor 11 Grinding wheel drive motor 20 Spindle table 20M Spindle table drive motor 30 Spindle device 30C Center member 30D Spindle base 30M Spindle movement motor 40 Tailstock device 40C Center member 40D Tailstock 60 Support device 62 Bearing support member T Grinding wheel (processing tool)
W Workpiece (Camshaft with bearing)
ST Shaft CA Cam piece BR Bearing BO Outer ring BI Inner ring BB Steel ball CZ Spindle rotation axis (work rotation axis)
TZ grinding wheel rotation axis CS case

Claims (4)

A method of manufacturing a camshaft with a bearing in which one or more cam pieces and one or more bearings are fitted in the axial direction of the outer peripheral surface of the shaft,
Fitting the cam piece and the bearing at respective predetermined positions in the axial direction of the shaft and assembling them as a camshaft with bearing;
Masking at least the bearing closest to the cam piece to be ground with a masking means, and then finishing grinding the cam piece to be ground using a processing tool,
A method for manufacturing a camshaft with a bearing. It is a manufacturing method of the camshaft with a bearing according to claim 1,
The masking means is
Resin that can be applied and removed to seal the bearing,
Or grease filled in the bearing,
Or a thin film sheet that can be wound and removed to seal the bearing,
Or a case that can be attached and detached at any position in the axial direction of the camshaft with bearing and that can accommodate the bearing in a sealed state when attached.
Any one of or a combination of a plurality of
A method for manufacturing a camshaft with a bearing. It is a manufacturing method of the camshaft with a bearing according to claim 1 or 2,
When finish grinding the outer periphery of the cam piece in the case of a plurality of the bearings,
Positioning the position of the processing tool relative to the cam piece to be ground so that the outer periphery of the cam piece to be ground and the processing tool face each other;
While rotating the camshaft with bearing about the rotation axis and supporting the opposite side of the machining tool in the bearing that is not masked, the machining tool is relatively moved with respect to the camshaft with bearing. A step of moving forward and backward in a direction perpendicular to the rotation axis and pressing the processing tool on the outer periphery of the cam piece to be ground to finish-grind.
A method for manufacturing a camshaft with a bearing. It is a manufacturing method of the camshaft with a bearing according to claim 2,
The case is accommodated when a pressing force is applied in a radial direction of the bearing accommodated at a predetermined position on the outer peripheral surface of the case in a state where the bearing is accommodated in the case. The inner wall of the case is moved relative to the bearing in the direction of the pressing force so that the inner wall of the case comes into contact with the outer peripheral surface of the bearing, and a force corresponding to the pressing force is applied to the contact portion of the outer peripheral surface of the bearing. Has a structure,
When finishing grinding the outer periphery of the cam piece when the case is used as the masking means,
Positioning the position of the processing tool relative to the cam piece to be ground so that the outer periphery of the cam piece to be ground and the processing tool face each other;
The camshaft with bearing is rotated around a rotation axis, and the processing tool is relatively relative to the camshaft with bearing while supporting the opposite side of the processing tool in the case housing the bearing. A step of moving forward and backward in a direction orthogonal to the rotation axis to press the machining tool on the outer periphery of the cam piece to be ground and finish grinding.
A method for manufacturing a camshaft with a bearing.

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